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Sample records for peritubular capillary endothelial

  1. Mesenchymal stem cell-derived microparticles ameliorate peritubular capillary rarefaction via inhibition of endothelial-mesenchymal transition and decrease tubulointerstitial fibrosis in unilateral ureteral obstruction.

    Science.gov (United States)

    Choi, Hoon Young; Lee, Hyun Gyu; Kim, Beom Seok; Ahn, Sun Hee; Jung, Ara; Lee, Mirae; Lee, Jung Eun; Kim, Hyung Jong; Ha, Sung Kyu; Park, Hyeong Cheon

    2015-03-11

    Microparticles (MPs) derived from kidney-derived mesenchymal stem cells (KMSCs) have recently been reported to ameliorate rarefaction of peritubular capillaries (PTC) in ischemic kidneys via delivery of proangiogenic effectors. This study aimed to investigate whether KMSC-derived MPs show anti-fibrotic effects by ameliorating endothelial-to-mesenchymal transition (EndoMT) in human umbilical vein endothelial cells (HUVEC) in vitro and by preserving PTC in kidneys with unilateral ureteral obstruction (UUO) in vivo. MPs isolated from the supernatants of KMSC were co-cultured with HUVEC to assess their in vitro biologic effects on endothelial cells. Mice were treated with MPs via the tail vein after UUO injury to assess their anti-fibrotic and PTC sparing effects. Renal tubulointerstitial damage and inflammatory cell infiltration were examined with Masson's trichrome, F4/80 and α-smooth muscle actin (α-SMA) staining and PTC rarefaction index was determined by CD31 staining. KMSC-derived MPs significantly ameliorated EndoMT and improved in vitro proliferation of TGF-β1 treated HUVEC. In vivo administration of KMSC-derived MPs significantly inhibited EndoMT of PTC endothelial cells and improved PTC rarefaction in UUO kidneys. Furthermore, administration of KMSC-derived MPs inhibited inflammatory cell infiltration as well as tubulointerstitial fibrosis in UUO mice as demonstrated by decreased F4/80 and α-SMA-positive cells and Masson's trichrome staining, respectively. Our results suggest that KMSC-derived MPs ameliorate PTC rarefaction via inhibition of EndoMT and protect against progression of renal damage by inhibiting tubulointerstitial fibrosis.

  2. Tubulovascular cross-talk by vascular endothelial growth factor a maintains peritubular microvasculature in kidney

    DEFF Research Database (Denmark)

    Dimke, Henrik; Sparks, Matthew A; Thomson, Benjamin R

    2015-01-01

    . Excision of Vegfa from renal tubules resulted in the formation of a smaller kidney, with a striking reduction in the density of peritubular capillaries. Consequently, elimination of tubular Vegfa caused pronounced polycythemia because of increased renal erythropoietin (Epo) production. Reducing hematocrit...... of this communication leads to increased renal Epo production and resulting polycythemia, presumably to counterbalance microvascular losses....

  3. Endothelial marker-expressing stromal cells are critical for kidney formation.

    Science.gov (United States)

    Mukherjee, Elina; Maringer, Katherine; Papke, Emily; Bushnell, Daniel; Schaefer, Caitlin; Kramann, Rafael; Ho, Jacqueline; Humphreys, Benjamin D; Bates, Carlton; Sims-Lucas, Sunder

    2017-09-01

    Kidneys are highly vascularized and contain many distinct vascular beds. However, the origins of renal endothelial cells and roles of the developing endothelia in the formation of the kidney are unclear. We have shown that the Foxd1-positive renal stroma gives rise to endothelial marker-expressing progenitors that are incorporated within a subset of peritubular capillaries; however, the significance of these cells is unclear. The purpose of this study was to determine whether deletion of Flk1 in the Foxd1 stroma was important for renal development. To that end, we conditionally deleted Flk1 (critical for endothelial cell development) in the renal stroma by breeding-floxed Flk1 mice ( Flk1 fl/fl ) with Foxd1cre mice to generate Foxd1cre; Flk1 fl/fl ( Flk1 ST-/- ) mice. We then performed FACsorting, histological, morphometric, and metabolic analyses of Flk1 ST-/- vs. control mice. We confirmed decreased expression of endothelial markers in the renal stroma of Flk1 ST-/- kidneys via flow sorting and immunostaining, and upon interrogation of embryonic and postnatal Flk1 ST-/- mice, we found they had dilated peritubular capillaries. Three-dimensional reconstructions showed reduced ureteric branching and fewer nephrons in developing Flk1 ST-/- kidneys vs. Juvenile Flk1 ST-/- kidneys displayed renal papillary hypoplasia and a paucity of collecting ducts. Twenty-four-hour urine collections revealed that postnatal Flk1 ST-/- mice had urinary-concentrating defects. Thus, while lineage-tracing revealed that the renal cortical stroma gave rise to a small subset of endothelial progenitors, these Flk1-expressing stromal cells are critical for patterning the peritubular capillaries. Also, loss of Flk1 in the renal stroma leads to nonautonomous-patterning defects in ureteric lineages. Copyright © 2017 the American Physiological Society.

  4. Polycythemia, capillary rarefaction, and focal glomerulosclerosis in two adolescents born extremely low birth weight and premature.

    Science.gov (United States)

    Asada, Nariaki; Tsukahara, Takanori; Furuhata, Megumi; Matsuoka, Daisuke; Noda, Shunsuke; Naganuma, Kuniaki; Hashiguchi, Akinori; Awazu, Midori

    2017-07-01

    Low birthweight infants have a reduced number of nephrons and are at high risk of chronic kidney disease. Preterm birth and/or intrauterine growth restriction (IUGR) may also affect peritubular capillary development, as has been shown in other organs. We report two patients with a history of preterm birth and extremely low birthweight who showed polycythemia and renal capillary rarefaction. Patient 1 and 2, born at 25 weeks of gestation with a birthweight of 728 and 466 g, showed mild proteinuria at age 8 and 6 years, respectively. In addition to increasing proteinuria, hemoglobin levels became elevated towards adolescence and their serum erythropoietin (EPO) was high despite polycythemia. Light microscopic examination of renal biopsy specimens showed glomerular hypertrophy, focal segmental glomerulosclerosis, and only mild tubulointerstitial fibrosis. A decrease in the immunohistochemical staining of CD31 and CD34 endothelial cells in renal biopsy specimens was consistent with peritubular capillary rarefaction. Since kidney function was almost normal and fibrosis was not severe, we consider that the capillary rarefaction and polycythemia associated with elevated EPO levels were largely attributable to preterm birth and/or IUGR.

  5. A nanoengineered peptidic delivery system with specificity for human brain capillary endothelial cells

    DEFF Research Database (Denmark)

    Wu, Linping; Moghimi, Seyed Moein

    2016-01-01

    , without manipulating the integrity of the BBB. This may be achieved by simultaneous and appropriate nanoparticle surface decoration with polymers that protect nanoparticles against rapid interception by body's defenses and ligands specific for cerebral capillary endothelial cells. To date, the binding...... avidity of the majority of the so-called ‘brain-specific’ nanoparticles to the brain capillary endothelial cells has been poor, even during in vitro conditions. We have addressed this issue and designed a versatile peptidic nanoplatform with high binding avidity to the human cerebral capillary endothelial...... cells. This was achieved by selecting an appropriate phage-derived peptide with high specificity for human brain capillary endothelial cells, which following careful structural modifications spontaneously formed a nanoparticle-fiber network. The peptidic network was characterized fully and its uptake...

  6. Internalization of targeted quantum dots by brain capillary endothelial cells in vivo.

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    Paris-Robidas, Sarah; Brouard, Danny; Emond, Vincent; Parent, Martin; Calon, Frédéric

    2016-04-01

    Receptors located on brain capillary endothelial cells forming the blood-brain barrier are the target of most brain drug delivery approaches. Yet, direct subcellular evidence of vectorized transport of nanoformulations into the brain is lacking. To resolve this question, quantum dots were conjugated to monoclonal antibodies (Ri7) targeting the murine transferrin receptor. Specific transferrin receptor-mediated endocytosis of Ri7-quantum dots was first confirmed in N2A and bEnd5 cells. After intravenous injection in mice, Ri7-quantum dots exhibited a fourfold higher volume of distribution in brain tissues, compared to controls. Immunofluorescence analysis showed that Ri7-quantum dots were sequestered throughout the cerebral vasculature 30 min, 1 h, and 4 h post injection, with a decline of signal intensity after 24 h. Transmission electron microscopic studies confirmed that Ri7-quantum dots were massively internalized by brain capillary endothelial cells, averaging 37 ± 4 Ri7-quantum dots/cell 1 h after injection. Most quantum dots within brain capillary endothelial cells were observed in small vesicles (58%), with a smaller proportion detected in tubular structures or in multivesicular bodies. Parenchymal penetration of Ri7-quantum dots was extremely low and comparable to control IgG. Our results show that systemically administered Ri7-quantum dots complexes undergo extensive endocytosis by brain capillary endothelial cells and open the door for novel therapeutic approaches based on brain endothelial cell drug delivery. © The Author(s) 2015.

  7. Tumor endothelial marker 5 expression in endothelial cells during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Vallon, Mario, E-mail: m.vallon@arcor.de [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Rohde, Franziska; Janssen, Klaus-Peter [Chirurgische Klinik und Poliklinik, Technische Universitaet Muenchen, Munich (Germany); Essler, Markus [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany)

    2010-02-01

    Tumor endothelial marker (TEM) 5 is an adhesion G-protein-coupled receptor upregulated in endothelial cells during tumor and physiologic angiogenesis. So far, the mechanisms leading to upregulation of TEM5 and its function during angiogenesis have not been identified. Here, we report that TEM5 expression in endothelial cells is induced during capillary-like network formation on Matrigel, during capillary morphogenesis in a three-dimensional collagen I matrix, and upon confluence on a two-dimensional matrix. TEM5 expression was not induced by a variety of soluble angiogenic factors, including VEGF and bFGF, in subconfluent endothelial cells. TEM5 upregulation was blocked by toxin B from Clostridium difficile, an inhibitor of the small GTPases Rho, Rac, and Cdc42. The Rho inhibitor C3 transferase from Clostridium botulinum did not affect TEM5 expression, whereas the Rac inhibitor NSC23766 suppressed TEM5 upregulation. An excess of the soluble TEM5 extracellular domain or an inhibitory monoclonal TEM5 antibody blocked contact inhibition of endothelial cell proliferation resulting in multilayered islands within the endothelial monolayer and increased vessel density during capillary formation. Based on our results we conclude that TEM5 expression during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of proliferation in endothelial cells.

  8. Usefulness of vitamin A binding protein as a marker for capillary endothelial permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ishizaka, Akitoshi; Suzuki, Yukio; Kanazawa, Minoru; Kubo, Atsushi; Kawashiro, Takeo [Keio Univ., Tokyo (Japan). School of Medicine

    1992-06-01

    We performed a preliminary study to assess the usefulness of Vitamin A binding protein (VABP) as a gamma-camera marker for capillary endothelial permeability. We used a guinea pig model of endotoxin (LPS) induced acute lung injury. We calculated the concentration ratio of either {sup 125}I-albumin or {sup 125}I-VABP in lung tissue to that in plasma (tissue plasma ratio; T/P) as a parameter of capillary endothelial permeability. {sup 99m}Tc-diethylene triamine pentaacetic acid (DTPA) was used as marker for pulmonary interstitial volume. We estimated wet to dry lung weight ratio as a parameter of lung water accumulation (W/D). LPS increased the T/P of {sup 125}I-albumin and W/D, suggesting the development of permeability edema. The T/P for {sup 125}I-VABP was also increased, indicating that {sup 125}I-VABP can be used to detect elevated capillary endothelial permeability. In both groups, LPS and saline, the T/P was higher for {sup 125}I-VABP than for {sup 125}I-albumin. These data suggest that the pulmonary capillary endothelium is more permeable to VABP than albumin. (author).

  9. Endothelial cell hypertrophy induced by vascular endothelial growth factor in the retina: new insights into the pathogenesis of capillary nonperfusion

    NARCIS (Netherlands)

    Hofman, P.; van Blijswijk, B. C.; Gaillard, P. J.; Vrensen, G. F.; Schlingemann, R. O.

    2001-01-01

    OBJECTIVE: To investigate the mechanism leading to capillary nonperfusion of the retina in a monkey model of vascular endothelial growth factor A (VEGF)-induced retinopathy in which capillary closure occurs in a late stage after VEGF treatment. METHODS: Two monkeys received 4 intravitreous

  10. Elevated capillary tube hematocrit reflects degradation of endothelial cell glycocalyx by oxidized LDL

    NARCIS (Netherlands)

    Constantinescu, A. A.; Vink, H.; Spaan, J. A.

    2001-01-01

    Proteoglycans and plasma proteins bound to the endothelial cell glycocalyx are essential for vascular function, but at the same time, they lower capillary tube hematocrit by reducing capillary volume available to flowing blood. Because oxidized low-density lipoproteins (oxLDL) reduce the effective

  11. Peritubular dentin lacks piezoelectricity.

    Science.gov (United States)

    Habelitz, S; Rodriguez, B J; Marshall, S J; Marshall, G W; Kalinin, S V; Gruverman, A

    2007-09-01

    Dentin is a mesenchymal tissue, and, as such, is based on a collagenous matrix that is reinforced by apatite mineral. Collagen fibrils show piezoelectricity, a phenomenon that is used by piezoresponse force microscopy (PFM) to obtain high-resolution images. We applied PFM to image human dentin with 10-nm resolution, and to test the hypothesis that zones of piezoactivity, indicating the presence of collagen fibrils, can be distinguished in dentin. Piezoelectricity was observed by PFM in the dentin intertubular matrix, while the peritubular dentin remained without response. High-resolution imaging of chemically treated intertubular dentin attributed the piezoelectric effect to individual collagen fibrils that differed in the signal strength, depending on the fibril orientation. This study supports the hypothesis that peritubular dentin is a non-collagenous tissue and is thus an exception among mineralized tissues that derive from the mesenchyme.

  12. Reviewing the pathogenesis of antibody-mediated rejection and renal graft pathology after kidney transplantation.

    Science.gov (United States)

    Morozumi, Kunio; Takeda, Asami; Otsuka, Yasuhiro; Horike, Keiji; Gotoh, Norihiko; Narumi, Shunji; Watarai, Yoshihiko; Kobayashi, Takaaki

    2016-07-01

    The clinicopathological context of rejection after kidney transplantation was well recognized. Banff conferences greatly contributed to elucidate the pathogenesis and to establish the pathologic criteria of rejection after kidney transplantation. The most important current problem of renal transplantation is de novo donor-specific antibody (DSA) production leading chronic rejection and graft loss. Microvascular inflammation is considered as a reliable pathological marker for antibody-mediated rejection (AMR) in the presence of DSA. Electron microscopic study allowed us to evaluate early changes in peritubular capillaries in T-lymphocyte mediated rejection and transition to antibody-mediated rejection. Severe endothelial injuries with edema and activated lymphocyte invaded into subendothelial space with early multi-layering of peritubular capillary basement membrane suggest T-lymphocyte mediated rejection induce an unbounded chain of antibody-mediated rejection. The risk factors of AMR after ABO-incompatible kidney transplantation are important issues. Anti-ABO blood type antibody titre of IgG excess 32-fold before transplant operation is the only predictable factor for acute AMR. Characteristics of chronic active antibody-mediated rejection (CAAMR) are one of the most important problems. Light microscopic findings and C4d stain of peritubular capillary and glomerular capillary are useful diagnostic criteria of CAAMR. Microvascular inflammation, double contour of glomerular capillary and thickening of peritubular capillary basement are good predictive factors of the presence of de novo DSA. C4d stain of linear glomerular capillary is a more sensitive marker for CAAMR than positive C4d of peritubular capillary. Early and sensitive diagnostic attempts of diagnosing CAAMR are pivotal to prevent chronic graft failure. © 2016 Asian Pacific Society of Nephrology.

  13. Microparticles from kidney-derived mesenchymal stem cells act as carriers of proangiogenic signals and contribute to recovery from acute kidney injury.

    Directory of Open Access Journals (Sweden)

    Hoon Young Choi

    Full Text Available We recently demonstrated the use of in vitro expanded kidney-derived mesenchymal stem cells (KMSC protected peritubular capillary endothelial cells in acute renal ischemia-reperfusion injury. Herein, we isolated and characterized microparticles (MPs from KMSC. We investigated their in vitro biologic effects on human endothelial cells and in vivo renoprotective effects in acute ischemia-reperfusion renal injury. MPs were isolated from the supernatants of KMSC cultured in anoxic conditions in serum-deprived media for 24 hours. KMSC-derived MPs demonstrated the presence of several adhesion molecules normally expressed on KMSC membranes, such as CD29, CD44, CD73, α4, 5, and 6 integrins. Quantitative real time PCR confirmed the presence of 3 splicing variants of VEGF-A (120, 164, 188, bFGF and IGF-1 in isolated MPs. MPs labeled with PKH26 red fluorescence dye were incorporated by cultured human umbilical vein endothelial cells (HUVEC via surface molecules such as CD44, CD29, and α4, 5, and 6 integrins. MP dose dependently improved in vitro HUVEC proliferation and promoted endothelial tube formation on growth factor reduced Matrigel. Moreover, apoptosis of human microvascular endothelial cell was inhibited by MPs. Administration of KMSC-derived MPs into mice with acute renal ischemia was followed by selective engraftment in ischemic kidneys and significant improvement in renal function. This was achieved by improving proliferation, of peritubular capillary endothelial cell and amelioration of peritubular microvascular rarefaction. Our results support the hypothesis that KMSC-derived MPs may act as a source of proangiogenic signals and confer renoprotective effects in ischemic kidneys.

  14. Expression of receptor-type protein tyrosine phosphatase in developing and adult renal vasculature.

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    Keiko Takahashi

    Full Text Available Renal vascular development is a coordinated process that requires ordered endothelial cell proliferation, migration, intercellular adhesion, and morphogenesis. In recent decades, studies have defined the pivotal role of endothelial receptor tyrosine kinases (RPTKs in the development and maintenance of renal vasculature. However, the expression and the role of receptor tyrosine phosphatases (RPTPs in renal endothelium are poorly understood, though coupled and counterbalancing roles of RPTKs and RPTPs are well defined in other systems. In this study, we evaluated the promoter activity and immunolocalization of two endothelial RPTPs, VE-PTP and PTPμ, in developing and adult renal vasculature using the heterozygous LacZ knock-in mice and specific antibodies. In adult kidneys, both VE-PTP and PTPμ were expressed in the endothelium of arterial, glomerular, and medullary vessels, while their expression was highly limited in peritubular capillaries and venous endothelium. VE-PTP and PTPμ promoter activity was also observed in medullary tubular segments in adult kidneys. In embryonic (E12.5, E13.5, E15.5, E17.5 and postnatal (P0, P3, P7 kidneys, these RPTPs were expressed in ingrowing renal arteries, developing glomerular microvasculature (as early as the S-shaped stage, and medullary vessels. Their expression became more evident as the vasculatures matured. Peritubular capillary expression of VE-PTP was also noted in embryonic and postnatal kidneys. Compared to VE-PTP, PTPμ immunoreactivity was relatively limited in embryonic and neonatal renal vasculature and evident immunoreactivity was observed from the P3 stage. These findings indicate 1 VE-PTP and PTPμ are expressed in endothelium of arterial, glomerular, and medullary renal vasculature, 2 their expression increases as renal vascular development proceeds, suggesting that these RPTPs play a role in maturation and maintenance of these vasculatures, and 3 peritubular capillary VE-PTP expression

  15. Gene delivery of therapeutic polypeptides to brain capillary endothelial cells for protein secretion

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    . Results: mRNA expression of proteins with neuroprotective potential in RBEC were enabled. Their expression patters were compared with those of RBE4 and HeLa cells using RT-qPCR analyzes. The evidence for protein synthesis and secretion was obtained by detection of FLAG-tagged to the C-terminal of any......Background: The potential for treatment of chronic disorders affecting the CNS is complicated by the inability of several drugs to cross the blood-brain barrier (BBB). None-viral gene therapy applied to brain capillary endothelial cells (BCECs) denotes a novel approach to overcome the restraints...... in this passage, as turning BCECs into recombinant protein factories by transfection could result in protein secretion into the brain. Aim: The aim of the present study was to investigate the possibility of transfection to primary rat brain capillary endothelial cells (RBEC) for recombinant protein synthesis...

  16. Sulfated glycosaminoglycans in cultured endothelial cells from capillaries and large vessels of human and bovine origin

    International Nuclear Information System (INIS)

    Bar, R.S.; Dake, B.L.; Spanheimer, R.G.

    1985-01-01

    The ( 35 S)glycosaminoglycans (( 35 S)GAG) synthesized by capillary endothelial cells were analyzed and compared to GAG synthesized by endothelial cells cultured from 4 larger vessels. Two separate cultures of endothelial cells were established from bovine fat capillaries and from 4 larger vessels of human origin (umbilical vein) and bovine origin (pulmonary artery, pulmonary vein and aorta). After incubation with 35 SO 4 for 72 h, the ( 35 S)glycosaminoglycans (GAG) composition of the media, pericellular and cellular fractions of each culture were determined by selective degradation with nitrous acid, chondroitinase ABC and chondroitinase AC. All endothelial cells produced large amounts of ( 35 S)GAG with increased proportions of heparinoids (heparan sulfate and heparin) in the cellular and pericellular fractions. Each culture showed a distinct distribution of ( 35 S)GAG in the media, pericellular and cellular fractions with several specific differences found among the 5 cultures. The differences in GAG content were confirmed in a second group of separate cultures from each of the 5 vessels indicating that, although having several features of GAG metabolism in common, each endothelial cell culture demonstrated a characteristic complement of synthesized, secreted and cell surface-sulfated glycosaminoglycans. (author)

  17. Protein secretory patterns of rat Sertoli and peritubular cells are influenced by culture conditions

    International Nuclear Information System (INIS)

    Kierszenbaum, A.L.; Crowell, J.A.; Shabanowitz, R.B.; DePhilip, R.M.; Tres, L.L.

    1986-01-01

    An approach combining two-dimensional gel electrophoresis and autoradiography was used to correlate patterns of secretory proteins in cultures of Sertoli and peritubular cells with those observed in the incubation medium from segments of seminiferous tubules. Sertoli cells in culture and in seminiferous tubules secreted three proteins designated S70 (Mr 72,000-70,000), S45 (Mr 45,000), and S35 (Mr 35,000). Cultured Sertoli and peritubular cells and incubated seminiferous tubules secreted two proteins designated SP1 (Mr 42,000) and SP2 (Mr 50,000). SP1 and S45 have similar Mr but differ from each other in isoelectric point (pI). Cultured peritubular cells secreted a protein designated P40 (Mr 40,000) that was also seen in intact seminiferous tubules but not in seminiferous tubules lacking the peritubular cell wall. However, a large number of high-Mr proteins were observed only in the medium of cultured peritubular cells but not in the incubation medium of intact seminiferous tubules. Culture conditions influence the morphology and patterns of protein secretion of cultured peritubular cells. Peritubular cells that display a flat-stellate shape transition when placed in culture medium free of serum (with or without hormones and growth factors), accumulate various proteins in the medium that are less apparent when these cells are maintained in medium supplemented with serum. Two secretory proteins stimulated by follicle-stimulating hormone (FSH) (designated SCm1 and SCm2) previously found in the medium of cultured Sertoli cells, were also observed in the incubation medium of seminiferous tubular segments stimulated by FSH. Results of this study show that, although cultured Sertoli and peritubular cells synthesize and secrete proteins also observed in segments of incubated seminiferous tubules anther group of proteins lacks seminiferous tubular correlates

  18. A microfluidic renal proximal tubule with active reabsorptive function.

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    Else M Vedula

    Full Text Available In the kidney, the renal proximal tubule (PT reabsorbs solutes into the peritubular capillaries through active transport. Here, we replicate this reabsorptive function in vitro by engineering a microfluidic PT. The microfluidic PT architecture comprises a porous membrane with user-defined submicron surface topography separating two microchannels representing a PT filtrate lumen and a peritubular capillary lumen. Human PT epithelial cells and microvascular endothelial cells in respective microchannels created a PT-like reabsorptive barrier. Co-culturing epithelial and endothelial cells in the microfluidic architecture enhanced viability, metabolic activity, and compactness of the epithelial layer. The resulting tissue expressed tight junctions, kidney-specific morphology, and polarized expression of kidney markers. The microfluidic PT actively performed sodium-coupled glucose transport, which could be modulated by administration of a sodium-transport inhibiting drug. The microfluidic PT reproduces human physiology at the cellular and tissue levels, and measurable tissue function which can quantify kidney pharmaceutical efficacy and toxicity.

  19. Sulfated glycosaminoglycans in cultured endothelial cells from capillaries and large vessels of human and bovine origin

    Energy Technology Data Exchange (ETDEWEB)

    Bar, R.S.; Dake, B.L.; Spanheimer, R.G.

    1985-07-01

    The (/sup 35/S)glycosaminoglycans ((/sup 35/S)GAG) synthesized by capillary endothelial cells were analyzed and compared to GAG synthesized by endothelial cells cultured from 4 larger vessels. Two separate cultures of endothelial cells were established from bovine fat capillaries and from 4 larger vessels of human origin (umbilical vein) and bovine origin (pulmonary artery, pulmonary vein and aorta). After incubation with /sup 35/SO/sub 4/ for 72 h, the (/sup 35/S)glycosaminoglycans (GAG) composition of the media, pericellular and cellular fractions of each culture were determined by selective degradation with nitrous acid, chondroitinase ABC and chondroitinase AC. All endothelial cells produced large amounts of (/sup 35/S)GAG with increased proportions of heparinoids (heparan sulfate and heparin) in the cellular and pericellular fractions. Each culture showed a distinct distribution of (/sup 35/S)GAG in the media, pericellular and cellular fractions with several specific differences found among the 5 cultures. The differences in GAG content were confirmed in a second group of separate cultures from each of the 5 vessels indicating that, although having several features of GAG metabolism in common, each endothelial cell culture demonstrated a characteristic complement of synthesized, secreted and cell surface-sulfated glycosaminoglycans. (author). 16 refs.

  20. Targeting immunoliposomes to transferrin receptors on brain capillary endothelial cells as a mean for cargo transport across the blood-brain barrier

    DEFF Research Database (Denmark)

    Johnsen, Kasper Bendix; Larsen, Annette Burkhart; Bruun, Jonas

    2016-01-01

    Brain capillary endothelial cells (BCECs) express transferrin receptors as opposed to endothelial cells of any organ in the remaining body, suggesting that targeting to the transferrin receptors as a reasonable strategy for delivering drugs to the CNS. However, as the intracellular trafficking...

  1. Tubular and endothelial chimerism in renal allografts using fluorescence and chromogenic in situ hybridization (FISH, CISH) technology.

    Science.gov (United States)

    Varga, Zsuzsanna; Gaspert, Ariana; Behnke, Silvia; von Teichman, Adriana; Fritzsche, Florian; Fehr, Thomas

    2012-04-01

    The role of endothelial and tubular chimerism in renal allograft adaptation and rejection varies in different studies. We addressed the correlation between different clinico-pathological settings and sex-chromosomal endothelial and/or tubular chimerism in renal allografts. We examined the presence or absence of the X and Y chromosomes by fluorescence and chromogenic in situ hybridization (FISH, CISH) methodology on paraffin embedded kidney biopsies in 16 gender mismatched renal transplants (1 to 12 years post-transplantation). Twelve patients were male, four female. Four groups were selected: (i) Vascular calcineurin inhibitor toxicity without rejection; (ii) T-cell mediated vascular rejection; (iii) antibody mediated rejection; and (iv) C4d-positivity in AB0-incompatible transplants with or without rejection. Twelve non-transplant kidney biopsies (8 female, 4 male) were used as controls. Tubular chimerism was detected more frequently (69%) than endothelial chimerism (12%) in renal transplants. One of 12 control patients had tubular and endothelial chimeric cells (8%). The Y chromosome occurred in 8/12 male recipients (67%) in tubular epithelial cells and in 5/12 male recipients (42%) in endothelial cells. Double X chromosomes were detected in 3/4 female recipients in tubular epithelium. Tubular chimerism occurred more often with endothelial chimerism and capillaritis without correlation with other parameters, such as rejection. Combined Y chromosomal tubular and lymphatic endothelial chimerism correlated with T-cell mediated vascular rejection in two out of three patients (66%). Combined Y chromosomal tubular and peritubular capillary chimerism correlated with antibody mediated C4d+ rejection in one out of two patients (50%). Tubular and/or endothelial chimerism occur frequently in gender mismatched renal allografts and, when combined, this is associated with T-cell mediated rejection. © 2012 The Authors. Pathology International © 2012 Japanese Society of

  2. Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla

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    RAÚL VINET

    2009-01-01

    Full Text Available Endothelial cells are directly involved in many functions of the cardiovascular system by regulating blood flow and blood pressure through Ca2+ dependent exocitosis of vasoactive compounds. Using the Ca2+ indicator Fluo-3 and the patch-clamp technique, we show that bovine adrenal medulla capillary endothelial cells (B AMCECs respond to acetylcholine (ACh with a cytosolic Ca2+ increase and depolarization of the membrane potential (20.3±0.9 mV; n=23. The increase in cytosolic Ca2+ induced by 10µM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 µM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 µM or withdrawal of extracellular Ca2+. Taken together, these results give evidence for functional nicotinic receptors (nAChRs in capillary endothelial cells of the adrenal medulla. It suggests that nAChRs in B AMCECs may be involved in the regulation of the adrenal gland's microcirculation by depolarizing the membrane potential, leading to the opening of voltage-activated Ca2+ channels, influx of external Ca2+ and liberation of vasoactive compounds.

  3. Short-term hyperglycemia increases endothelial glycocalyx permeability and acutely decreases lineal density of capillaries with flowing red blood cells

    NARCIS (Netherlands)

    Zuurbier, Coert J.; Demirci, Cihan; Koeman, Anneke; Vink, Hans; Ince, Can

    2005-01-01

    Hyperglycemia is becoming recognized as an important risk factor for microvascular dysfunction. We hypothesized that short-term hyperglycemia, either on the scale of hours or weeks, alters the barrier function and the volume of the endothelial glycocalyx and decreases functional capillary density

  4. Altered expressions of endothelial junction protein of placental capillaries in premature infants with intraventricular hemorrhage

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    Maria Ekawati

    2016-10-01

    Full Text Available Background: Placental hypoxia may lead to oxidative stress, which inflicts damage to capillary protein junction. The aim of this study was to evaluate altered expression of endothelial junction protein of capillaries in hypoxia condition and to observe its correlation with the incidence of  intraventricular hemorrhage in premature infants.Methods: A cross-sectional study was conducted by using placental tissues of premature infants as amodel of capillary integrity (29 hypoxic and 29 non-hypoxic. Hypoxia inducible factor (HIF-1α was measured to define placental tissue response to hypoxia; malondialdehyde (MDA and glutathione (GSH served as markers of oxidative stress. The expressions of junctional proteins, N-cadherin and occludin were analyzed by immunohistochemistry. Intraventricular hemorrhage (IVH was detected by cranial ultrasound at the third day. Unpaired t test, Mann-Whitney, and Chi-square tests were used to analyze the data.Results: The HIF-1α and MDA levels were slightly, but not significantly, higher in hypoxia group {13.64±8.70 pg/mg protein and 10.31 pmol/mg tissue (ranged 1.92–93.61, respectively}  compared to non- hypoxia group {10.65±5.35 pg/mg protein and 9.77 pmol/mg tissue (ranged 2.42–93.31}. GSH levels were not different in both groups (38.14 (ranged 9.44–118.91 and  38.47(ranged 16.49–126.76 ng/mg protein, respectively. mRNA expression of N-cadherin (0.13 and occludin (0.096 were significantly lower in hypoxia comparedto non-hypoxia group (p=0,001, while protein expression of  N-cadherin (3.4; 75.9; 6.9; 13.8% and occludin  (20.7; 3.4; 69.0; 3.4; 6.9%  in hypoxia group was not associated with IVH (p=0.783 and p=0.743.Conclusion: Hypoxia altered expression of endothelial junction protein in placental capillaries, but no association with intraventricular hemorrhage was observed.

  5. Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.

    Science.gov (United States)

    Wagner, Sylvia; Zensi, Anja; Wien, Sascha L; Tschickardt, Sabrina E; Maier, Wladislaw; Vogel, Tikva; Worek, Franz; Pietrzik, Claus U; Kreuter, Jörg; von Briesen, Hagen

    2012-01-01

    The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier.

  6. Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.

    Directory of Open Access Journals (Sweden)

    Sylvia Wagner

    Full Text Available BACKGROUND: The blood-brain barrier (BBB represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. CONCLUSIONS/SIGNIFICANCE: This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier.

  7. Molecular and functional characterization of riboflavin specific transport system in rat brain capillary endothelial cells

    Science.gov (United States)

    Patel, Mitesh; Vadlapatla, Ramya Krishna; Pal, Dhananjay; Mitra, Ashim K.

    2012-01-01

    Riboflavin is an important water soluble vitamin (B2) required for metabolic reactions, normal cellular growth, differentiation and function. Mammalian brain cells cannot synthesize riboflavin and must import from systemic circulation. However, the uptake mechanism, cellular translocation and intracellular trafficking of riboflavin in brain capillary endothelial cells are poorly understood. The primary objective of this study is to investigate the existence of riboflavin-specific transport system and delineate the uptake and intracellular regulation of riboflavin in immortalized rat brain capillary endothelial cells (RBE4). The uptake of [3H]-Riboflavin is sodium, temperature and energy dependent but pH independent. [3H]-Riboflavin uptake is saturable with Km and Vmax values of 19 ± 3 µM and 0.235 ± 0.012 picomoles/min/mg protein, respectively. The uptake process is inhibited by unlabelled structural analogs (lumiflavin, lumichrome) but not by structurally unrelated vitamins. Ca++/calmodulin and protein kinase A (PKA) pathways are found to play an important role in the intracellular regulation of [3H]-Riboflavin. Apical and baso-lateral uptake of [3H]-Riboflavin clearly indicate that riboflavin specific transport system is predominantly localized on the apical side of RBE4 cells. A 628 bp band corresponding to riboflavin transporter is revealed in RT-PCR analysis. These findings, for the first time report the existence of a specialized and high affinity transport system for riboflavin in RBE4 cells. Blood-brain barrier (BBB) is a major obstacle limiting drug transport inside the brain as it regulates drug permeation from systemic circulation. This transporter can be utilized for targeted delivery in enhancing brain permeation of highly potent drugs on systemic administration. PMID:22683359

  8. Renal microvascular disease in an aging population: a reversible process?

    Science.gov (United States)

    Futrakul, Narisa; Futrakul, Prasit

    2008-01-01

    Renal microvascular disease and tubulointerstitial fibrosis are usually demonstrated in aging in humans and animals. It has recently been proposed that renal microvascular disease is the crucial determinant of tubulointerstitial disease or fibrosis. Enhanced circulating endothelial cell loss is a biomarker that reflects glomerular endothelial injury or renal microvascular disease, and fractional excretion of magnesium (FE Mg) is a sensitive biomarker that reflects an early stage of tubulointerstitial fibrosis. In aging in humans, both of these biomarkers are abnormally elevated. In addition, a glomerular endothelial dysfunction determined by altered hemodynamics associated with peritubular capillary flow reduction is substantiated. A correction of such hemodynamic alteration with vasodilators can effectively improve renal perfusion and restore renal function. Thus, anti-aging therapy can reverse the renal microvascular disease and dysfunction associated with the aging process.

  9. Sodium-dependent vitamin C transporter 2 (SVCT2 expression and activity in brain capillary endothelial cells after transient ischemia in mice.

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    Burkhard Gess

    Full Text Available Expression and transport activity of Sodium-dependent Vitamin C Transporter 2 (SVCT2 was shown in various tissues and organs. Vitamin C was shown to be cerebroprotective in several animal models of stroke. Data on expression, localization and transport activity of SVCT2 after cerebral ischemia, however, has been scarce so far. Thus, we studied the expression of SVCT2 after middle cerebral artery occlusion (MCAO in mice by immunohistochemistry. We found an upregulation of SVCT2 after stroke. Co-stainings with Occludin, Von-Willebrand Factor and CD34 demonstrated localization of SVCT2 in brain capillary endothelial cells in the ischemic area after stroke. Time-course analyses of SVCT2 expression by immunohistochemistry and western blots showed upregulation in the subacute phase of 2-5 days. Radioactive uptake assays using (14C-labelled ascorbic acid showed a significant increase of ascorbic acid uptake into the brain after stroke. Taken together, these results provide evidence for the expression and transport activity of SVCT2 in brain capillary endothelial cells after transient ischemia in mice. These results may lead to the development of novel neuroprotective strategies in stroke therapy.

  10. Intracranial capillary hemangioma mimicking a dissociative disorder

    Directory of Open Access Journals (Sweden)

    Alexander Lacasse

    2012-01-01

    Full Text Available Capillary hemangiomas, hamartomatous proliferation of vascular endothelial cells, are rare in the central nervous system (CNS. Intracranial capillary hemangiomas presenting with reversible behavioral abnormalities and focal neurological deficits have rarely been reported. We report a case of CNS capillary hemangioma presenting with transient focal neurological deficits and behavioral abnormalities mimicking Ganser’s syndrome. Patient underwent total excision of the vascular malformation, resulting in complete resolution of his symptoms.

  11. Phosphodiesterase-4 inhibition as a therapeutic approach to treat capillary leakage in systemic inflammation.

    Science.gov (United States)

    Schick, Martin Alexander; Wunder, Christian; Wollborn, Jakob; Roewer, Norbert; Waschke, Jens; Germer, Christoph-Thomas; Schlegel, Nicolas

    2012-06-01

    In sepsis and systemic inflammation, increased microvascular permeability and consecutive breakdown of microcirculatory flow significantly contribute to organ failure and death. Evidence points to a critical role of cAMP levels in endothelial cells to maintain capillary endothelial barrier properties in acute inflammation. However, approaches to verify this observation in systemic models are rare. Therefore we tested here whether systemic application of the phosphodiesterase-4-inhibitors (PD-4-Is) rolipram or roflumilast to increase endothelial cAMP was effective to attenuate capillary leakage and breakdown of microcirculatory flow in severe lipopolysaccharide (LPS)-induced systemic inflammation in rats. Measurements of cAMP in mesenteric microvessels demonstrated significant LPS-induced loss of cAMP levels which was blocked by application of rolipram. Increased endothelial cAMP by application of either PD-4-I rolipram or roflumilast led to stabilization of endothelial barrier properties as revealed by measurements of extravasated FITC-albumin in postcapillary mesenteric venules. Accordingly, microcirculatory flow in mesenteric venules was significantly increased following PD-4-I treatment and blood gas analyses indicated improved metabolism. Furthermore application of PD-4-I after manifestation of LPS-induced systemic inflammation and capillary leakage therapeutically stabilized endothelial barrier properties as revealed by significantly reduced volume resuscitation for haemodynamic stabilization. Accordingly microcirculation was significantly improved following treatment with PD-4-Is. Our results demonstrate that inflammation-derived loss of endothelial cAMP contributes to capillary leakage which was blocked by systemic PD-4-I treatment. Therefore these data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.

  12. Regulation of cyclic AMP by extracellular ATP in cultured brain capillary endothelial cells

    Science.gov (United States)

    Anwar, Zubeya; Albert, Jennifer L; Gubby, Sharon E; Boyle, John P; Roberts, Jonathon A; Webb, Tania E; Boarder, Michael R

    1999-01-01

    In primary unpassaged rat brain capillary endothelial cell cultures (RBECs), using reverse-transcriptase PCR with primers specific for P2Y receptor subtypes, we detected mRNA for P2Y2, P2Y4 and P2Y6, but not P2Y1 receptors.None of the various nucleotides tested reduced forskolin elevated cyclic AMP levels in RBECs. ATP and ATPγS, as well as adenosine, enhanced cyclic AMP accumulation in the presence of forskolin.Comparison of the concentration response curves to ATPγS with those for ATP and adenosine, at different incubation times, indicated that the response to purine nucleotides was not wholly dependent on conversion to adenosine. Adenosine deaminase abolished the response to adenosine but only reduced the response to ATP by about 50%. These results suggest the participation of a receptor responsive to nucleotides.Isobutylmethylxanthine and 8-sulphophenyltheophylline prevented the cyclic AMP response, while neither 8-cyclopentyl-1,3-dipropylxanthine nor SCH58261 were effective antagonists. 2-chloradenosine gave a robust response, but neither 2-chloro-N6-cyclopentyladenosine nor CGS 21680 were agonists.These results show that adenosine and ATP can elevate the cyclic AMP levels of brain endothelial cells by acting on receptors which have a pharmacology apparently distinct from known P2Y and adenosine receptors. PMID:10510459

  13. Up-regulation of Kir2.1 by ER stress facilitates cell death of brain capillary endothelial cells

    International Nuclear Information System (INIS)

    Kito, Hiroaki; Yamazaki, Daiju; Ohya, Susumu; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

    2011-01-01

    Highlights: → We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. → The ER stress facilitated the expression of inward rectifier K + channel (K ir 2.1) and induced sustained membrane hyperpolarization. → The membrane hyperpolarization induced sustained Ca 2+ entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. → The K ir 2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K + channel (K ir 2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K ir channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca 2+ concentration due to Ca 2+ influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K ir 2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  14. Expression and deposition of basement membrane proteins by brain capillary endothelial cells in a primary murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Larsen, Annette Burkhart

    2016-01-01

    The blood-brain barrier (BBB) represents the interface between the blood and the brain parenchyma and consists of endothelial cells which are tightly sealed together by tight junction proteins. The endothelial cells are in addition supported by pericytes, which are embedded in the vascular basement...... of the present study was to create four different in vitro constructs of the murine BBB to characterise if the expression and secretion of basement membrane proteins by the murine brain capillary endothelial cells (mBCECs) was affected by co-culturing with pericytes, mixed glial cells, or both. Primary m......BCECs and pericytes were isolated from brains of adult mice. Mixed glial cells were prepared from cerebral cortices of newborn mice. The mBCECs were grown as mono-culture, or co-cultured with pericytes, mixed glial cells, or both. To study the expression of basement membrane proteins RT-qPCR, mass spectrometry...

  15. Renal and urinary levels of endothelial protein C receptor correlate with acute renal allograft rejection.

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    Lionel Lattenist

    Full Text Available The Endothelial Protein C Receptor (EPCR is expressed on leukocytes, on endothelium of large blood vessels and to a lesser extent on capillaries. Membrane bound EPCR plays an important role in the activation of protein C which has anticoagulant, anti-inflammatory and cytoprotective effects. After cleavage by a protease EPCR is also found as a soluble protein. Acute rejection of kidney allografts can be divided in T-cell-mediated rejection (TCMR and antibody-mediated (ABMR rejection. The latter is characterized by strong activation of coagulation. Currently no reliable non-invasive biomarkers are available to monitor rejection. Renal biopsies were available from 81 renal transplant patients (33 without rejection, 26 TCMR and 22 ABMR, we had access to mRNA material, matched plasma and urine samples for a portion of this cohort. Renal EPCR expression was assessed by RT-PCR and immunostaining. Plasma and urine sEPCR levels were measured by ELISA. ABMR patients showed higher levels of EPCR mRNA than TCMR patients. EPCR expression on glomeruli was significantly elevated in ABMR patients than in TCMR or control patients. In the peritubular capillaries EPCR expression was higher in ABMR patients than in control patients. EPCR expression was higher in tubules and arteries of rejection patients than in control patients. Plasma sEPCR levels did not differ. Urine sEPCR levels were more elevated in the ABMR group than in patients with TCMR or without rejection. ROC analysis demonstrated that urinary sEPCR is appropriate to discriminate between ABMR patients and TCMR or control patients. We conclude that urinary sEPCR could be a novel non-invasive biomarker of antibody mediated rejection in renal transplantation.

  16. Occlusion of retinal capillaries caused by glial cell proliferation in chronic ocular inflammation.

    Science.gov (United States)

    Bianchi, E; Ripandelli, G; Feher, J; Plateroti, A M; Plateroti, R; Kovacs, I; Plateroti, P; Taurone, S; Artico, M

    2015-01-01

    The inner blood-retinal barrier is a gliovascular unit in which glial cells surround capillary endothelial cells and regulate retinal capillaries by paracrine interactions. During chronic ocular inflammation, microvascular complications can give rise to vascular proliferative lesions, which compromise visual acuity. This pathologic remodelling caused by proliferating Müller cells determines occlusion of retinal capillaries. The aim of the present study was to identify qualitative and quantitative alterations in the retinal capillaries in patients with post-traumatic chronic ocular inflammation or post-thrombotic vascular glaucoma. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in retinal inflammation. Our electron microscopy findings demonstrated that during chronic ocular inflammation, thickening of the basement membrane, loss of pericytes and endothelial cells and proliferation of Müller cells occur with irreversible occlusion of retinal capillaries. Angiogenesis takes place as part of a regenerative reaction that results in fibrosis. We believe that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in the treatment of this disease although further studies are required to confirm these findings.

  17. [3H]thymidine labeling of dermal endothelial cells in scleroderma

    International Nuclear Information System (INIS)

    Fleischmajer, R.; Perlish, J.S.

    1977-01-01

    The purpose of this study was to estimate [ 3 H] thymidine labeling of endothelial cells of skin capillaries in localized scleroderma (LS) and systemic scleroderma (SS). Skin specimens from 14 patients with SS, 5 with LS, and 9 matched controls were studied by in vitro autoradiography. Capillaries from patients with SS showed a statistically significant increase in endothelial cell labeling when compared to vessels from controls

  18. In vitro analysis of human periodontal microvascular endothelial cells.

    Science.gov (United States)

    Tsubokawa, Mizuki; Sato, Soh

    2014-08-01

    Endothelial cells (ECs) participate in key aspects of vascular biology, such as maintenance of capillary permeability, initiation of coagulation, and regulation of inflammation. According to previous reports, ECs have revealed highly specific characteristics depending on the organs and tissues. However, some reports have described the characteristics of the capillaries formed by human periodontal ECs. Therefore, the aim of the present study is to examine the functional characteristics of the periodontal microvascular ECs in vitro. Human periodontal ligament-endothelial cells (HPDL-ECs) and human gingiva-endothelial cells (HG-ECs) were isolated by immunoprecipitation with magnetic beads conjugated to a monoclonal anti-CD31 antibody. The isolated HPDL-ECs and HG-ECs were characterized to definitively demonstrate that these cell cultures represented pure ECs. Human umbilical-vein ECs and human dermal microvascular ECs were used for comparison. These cells were compared according to the proliferation potential, the formation of capillary-like tubes, the transendothelial electric resistance (TEER), and the expression of tight junction proteins. HPDL-ECs and HG-ECs with characteristic cobblestone monolayer morphology were obtained, as determined by light microscopy at confluence. Furthermore, the HPDL-ECs and HG-ECs expressed the EC markers platelet endothelial cell adhesion molecule-1 (also known as CD31), von Willebrand factor, and Ulex europaeus agglutinin 1, and the cells stained strongly positive for CD31 and CD309. In addition, the HPDL-ECs and HG-ECs were observed to form capillary-like tubes, and they demonstrated uptake of acetylated low-density lipoprotein. Functional analyses of the HPDL-ECs and HG-ECs showed that, compared to the control cells, tube formation persisted for only a brief period of time, and TEER was substantially reduced at confluence. Furthermore, the cells exhibited delocalization of zonula occludens-1 and occludin at cell-cell contact sites

  19. Structural characterization of proteoglycans produced by testicular peritubular cells and Sertoli cells

    International Nuclear Information System (INIS)

    Skinner, M.K.; Fritz, I.B.

    1985-01-01

    The structural characteristics of proteoglycans produced by seminiferous peritubular cells and by Sertoli cells are defined. Peritubular cells secrete two proteoglycans designated PC I and PC II. PC I is a high molecular mass protein containing chondroitin glycosaminoglycan (GAG) chains (maximum 70 kDa). PC II has a protein core of 45 kDa and also contains chondroitin GAG chains (maximum 70 kDa). Preliminary results imply that PC II may be a degraded or processed form of PC I. Sertoli cells secrete two different proteoglycans, designated SC I and SC II. SC I is a large protein containing both chondroitin (maximum 62 kDa) and heparin (maximum 15 kDa) GAG chains. Results obtained suggest that this novel proteoglycan contains both chondroitin and heparin GAG chains bound to the same core protein. SC II has a 50-kDa protein core and contains chondroitin (maximum 25 kDa) GAG chains. A proteoglycan obtained from extracts of Sertoli cells is described which contains heparin (maximum 48 kDa) GAG chains. In addition, Sertoli cells secrete a sulfoprotein, SC III, which is not a proteoglycan. The stimulation by follicle-stimulating hormone of the incorporation of [ 35 S]SO 2 ) -4 ) into moieties secreted by Sertoli cells is shown to represent an increased production or sulfation of SC III, and not an increased production or sulfation of proteoglycans. Results are discussed in relation to the possible functions of proteoglycans in the seminiferous tubule

  20. Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes

    Science.gov (United States)

    Tseng, Chia-Yi; Chang, Jing-Fen; Wang, Jhih-Syuan; Chang, Yu-Jung; Gordon, Marion K.; Chao, Ming-Wei

    2015-01-01

    Exposure to diesel exhaust particles (DEP) is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione. PMID:26148005

  1. Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes.

    Directory of Open Access Journals (Sweden)

    Chia-Yi Tseng

    Full Text Available Exposure to diesel exhaust particles (DEP is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

  2. Up-regulation of K{sub ir}2.1 by ER stress facilitates cell death of brain capillary endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Kito, Hiroaki [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Yamazaki, Daiju [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Department of Biological Chemistry, Kyoto University, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Ohya, Susumu; Yamamura, Hisao [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

    2011-07-29

    Highlights: {yields} We found that application of endoplasmic reticulum (ER) stress with tunicamycin to brain capillary endothelial cells (BCECs) induced cell death. {yields} The ER stress facilitated the expression of inward rectifier K{sup +} channel (K{sub ir}2.1) and induced sustained membrane hyperpolarization. {yields} The membrane hyperpolarization induced sustained Ca{sup 2+} entry through voltage-independent nonspecific cation channels and consequently facilitated cell death. {yields} The K{sub ir}2.1 up-regulation by ER stress is, at least in part, responsible for cell death of BCECs under pathological conditions. -- Abstract: Brain capillary endothelial cells (BCECs) form blood brain barrier (BBB) to maintain brain homeostasis. Cell turnover of BCECs by the balance of cell proliferation and cell death is critical for maintaining the integrity of BBB. Here we found that stimuli with tunicamycin, endoplasmic reticulum (ER) stress inducer, up-regulated inward rectifier K{sup +} channel (K{sub ir}2.1) and facilitated cell death in t-BBEC117, a cell line derived from bovine BCECs. The activation of K{sub ir} channels contributed to the establishment of deeply negative resting membrane potential in t-BBEC117. The deep resting membrane potential increased the resting intracellular Ca{sup 2+} concentration due to Ca{sup 2+} influx through non-selective cation channels and thereby partly but significantly regulated cell death in t-BBEC117. The present results suggest that the up-regulation of K{sub ir}2.1 is, at least in part, responsible for cell death/cell turnover of BCECs induced by a variety of cellular stresses, particularly ER stress, under pathological conditions.

  3. Capillary regeneration in scleroderma: stem cell therapy reverses phenotype?

    Directory of Open Access Journals (Sweden)

    Jo N Fleming

    2008-01-01

    Full Text Available Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease.We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue, antiangiogenic interferon alpha (overexpressed in the scleroderma dermis and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon alpha and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal.These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease. Since rarefaction has been little studied, these data may have

  4. Identification and functional analysis of endothelial tip cell-enriched genes.

    Science.gov (United States)

    del Toro, Raquel; Prahst, Claudia; Mathivet, Thomas; Siegfried, Geraldine; Kaminker, Joshua S; Larrivee, Bruno; Breant, Christiane; Duarte, Antonio; Takakura, Nobuyuki; Fukamizu, Akiyoshi; Penninger, Josef; Eichmann, Anne

    2010-11-11

    Sprouting of developing blood vessels is mediated by specialized motile endothelial cells localized at the tips of growing capillaries. Following behind the tip cells, endothelial stalk cells form the capillary lumen and proliferate. Expression of the Notch ligand Delta-like-4 (Dll4) in tip cells suppresses tip cell fate in neighboring stalk cells via Notch signaling. In DLL4(+/-) mouse mutants, most retinal endothelial cells display morphologic features of tip cells. We hypothesized that these mouse mutants could be used to isolate tip cells and so to determine their genetic repertoire. Using transcriptome analysis of retinal endothelial cells isolated from DLL4(+/-) and wild-type mice, we identified 3 clusters of tip cell-enriched genes, encoding extracellular matrix degrading enzymes, basement membrane components, and secreted molecules. Secreted molecules endothelial-specific molecule 1, angiopoietin 2, and apelin bind to cognate receptors on endothelial stalk cells. Knockout mice and zebrafish morpholino knockdown of apelin showed delayed angiogenesis and reduced proliferation of stalk cells expressing the apelin receptor APJ. Thus, tip cells may regulate angiogenesis via matrix remodeling, production of basement membrane, and release of secreted molecules, some of which regulate stalk cell behavior.

  5. Apelin is a novel angiogenic factor in retinal endothelial cells

    International Nuclear Information System (INIS)

    Kasai, Atsushi; Shintani, Norihito; Oda, Maki; Kakuda, Michiya; Hashimoto, Hitoshi; Matsuda, Toshio; Hinuma, Shuji; Baba, Akemichi

    2004-01-01

    There has been much focus recently on the possible functions of apelin, an endogenous ligand for the orphan G-protein-coupled receptor APJ, in cardiovascular and central nervous systems. We report a new function of apelin as a novel angiogenic factor in retinal endothelial cells. The retinal endothelial cell line RF/6A highly expressed both apelin and APJ transcripts, while human umbilical venous endothelial cells (HUVECs) only expressed apelin mRNA. In accordance with these observations, apelin at concentrations of 1 pM-1 μM significantly enhanced migration, proliferation, and capillary-like tube formation of RF/6A cells, but not those of HUVECs, whereas VEGF stimulates those parameters of both cell types. In vivo Matrigel plug assay for angiogenesis, the inclusion of 1 nM apelin in the Matrigel resulted in clear capillary-like formations with an increase of hemoglobin content in the plug. This is the first report showing that apelin is an angiogenic factor in retinal endothelial cells

  6. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

    (1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.

  7. Androgen receptor signalling in peritubular myoid cells is essential for normal differentiation and function of adult Leydig cells

    DEFF Research Database (Denmark)

    Welsh, M.; Moffat, L.; Belling, Kirstine Christensen

    2012-01-01

    Testosterone synthesis depends on normal Leydig cell (LC) development, but the mechanisms controlling this development remain unclear. We recently demonstrated that androgen receptor (AR) ablation from a proportion of testicular peritubular myoid cells (PTM-ARKO) did not affect LC number, but res......Testosterone synthesis depends on normal Leydig cell (LC) development, but the mechanisms controlling this development remain unclear. We recently demonstrated that androgen receptor (AR) ablation from a proportion of testicular peritubular myoid cells (PTM-ARKO) did not affect LC number......’ subpopulation that had arrested development and only weakly expressed INSL3, luteinizing hormone receptor, and several steroidogenic enzymes. Furthermore, unlike ‘normal’ LCs in PTM-ARKOs, the ‘abnormal’ LCs did not involute as expected in response to exogenous testosterone. Differential function of these LC...... sub-populations is likely to mean that the ‘normal’ LCs work harder to compensate for the ‘abnormal’ LCs to maintain normal serum testosterone. These findings reveal new paracrine mechanisms underlying adult LC development, which can be further investigated using PTM-ARKOs....

  8. Roles of CD34+ cells and ALK5 signaling in the reconstruction of seminiferous tubule-like structures in 3-D re-aggregate culture of dissociated cells from neonatal mouse testes.

    Science.gov (United States)

    Abe, Shin-Ichi; Abe, Kazuko; Zhang, Jidong; Harada, Tomoaki; Mizumoto, Go; Oshikawa, Hiroki; Akiyama, Haruhiko; Shimamura, Kenji

    2017-01-01

    Tissue reconstruction in vitro can provide, if successful, a refined and simple system to analyze the underlying mechanisms that drive the morphogenesis and maintain the ordered structure. We have recently succeeded in reconstruction of seminiferous cord-like and tubule-like structures using 3-D re-aggregate culture of dissociated testicular cells. In testis formation, endothelial cells that migrated from mesonephroi to embryonic gonads have been shown to be critical for development of testis cords, but how endothelial cells contribute to testis cord formation remains unknown. To decipher the roles of endothelial and peritubular cells in the reconstruction of cord-like and tubule-like structures, we investigated the behavior of CD34+ endothelial and p75+ cells, and peritubular myoid cells (PTMCs) in 3-D re-aggregate cultures of testicular cells. The results showed that these 3 types of cells had the capacity of re-aggregation on their own and with each other, and of segregation into 3 layers in a re-aggregate, which were very similar to interstitial and peritubular tissues in vivo. Observation of behaviors of fluorescent Sertoli cells and other non-fluorescent types of cells using testes from Sox9-EGFP transgenic mice showed dynamic cell movement and segregation in re-aggregate cultures. Cultures of testicular cells deprived of interstitial and peritubular cells resulted in dysmorphic structures, but re-addition of them restored tubule-like structures. Purified CD34+ cells in culture differentiated into p75+ cells and PTMCs. These results indicate that CD34+ cells differentiate into p75+ cells, which then differentiate into PTMCs. TGFβ signaling inhibitors, SB431542 and ALK5i, disturbed the reconstruction of cord-like and tubule-like structures, and the latter compromised re-construction of interstitial-like and peritubular-like structures, as well as the proliferation of CD34+, p75+, PTMCs, and Sertoli cells, and their movement and differentiation. These results

  9. Sertoli cells maintain Leydig cell number and peritubular myoid cell activity in the adult mouse testis.

    Directory of Open Access Journals (Sweden)

    Diane Rebourcet

    Full Text Available The Sertoli cells are critical regulators of testis differentiation and development. In the adult, however, their known function is restricted largely to maintenance of spermatogenesis. To determine whether the Sertoli cells regulate other aspects of adult testis biology we have used a novel transgenic mouse model in which Amh-Cre induces expression of the receptor for Diphtheria toxin (iDTR specifically within Sertoli cells. This causes controlled, cell-specific and acute ablation of the Sertoli cell population in the adult animal following Diphtheria toxin injection. Results show that Sertoli cell ablation leads to rapid loss of all germ cell populations. In addition, adult Leydig cell numbers decline by 75% with the remaining cells concentrated around the rete and in the sub-capsular region. In the absence of Sertoli cells, peritubular myoid cell activity is reduced but the cells retain an ability to exclude immune cells from the seminiferous tubules. These data demonstrate that, in addition to support of spermatogenesis, Sertoli cells are required in the adult testis both for retention of the normal adult Leydig cell population and for support of normal peritubular myoid cell function. This has implications for our understanding of male reproductive disorders and wider androgen-related conditions affecting male health.

  10. Drug-induced trafficking of p-glycoprotein in human brain capillary endothelial cells as demonstrated by exposure to mitomycin C.

    Science.gov (United States)

    Noack, Andreas; Noack, Sandra; Hoffmann, Andrea; Maalouf, Katia; Buettner, Manuela; Couraud, Pierre-Olivier; Romero, Ignacio A; Weksler, Babette; Alms, Dana; Römermann, Kerstin; Naim, Hassan Y; Löscher, Wolfgang

    2014-01-01

    P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. In this study, trafficking of Pgp was investigated in human brain capillary endothelial cells (hCMEC/D3) that were stably transfected with a doxycycline-inducible MDR1-EGFP fusion plasmid. In the presence of doxycycline, these cells exhibited a 15-fold increase in Pgp-EGFP fusion protein expression, which was associated with an increased efflux of the Pgp substrate rhodamine 123 (Rho123). The chemotherapeutic agent mitomycin C (MMC) was used to study drug-induced trafficking of Pgp. Confocal fluorescence microscopy of single hCMEC/D3-MDR1-EGFP cells revealed that Pgp redistribution from intracellular pools to the cell surface occurred within 2 h of MMC exposure. Pgp-EGFP exhibited a punctuate pattern at the cell surface compatible with concentrated regions of the fusion protein in membrane microdomains, i.e., lipid rafts, which was confirmed by Western blot analysis of biotinylated cell surface proteins in Lubrol-resistant membranes. MMC exposure also increased the functionality of Pgp as assessed in three functional assays with Pgp substrates (Rho123, eFluxx-ID Gold, calcein-AM). However, this increase occurred with some delay after the increased Pgp expression and coincided with the release of Pgp from the Lubrol-resistant membrane complexes. Disrupting rafts by depleting the membrane of cholesterol increased the functionality of Pgp. Our data present the first direct evidence of drug-induced Pgp trafficking at the human BBB and indicate that Pgp has to be released from lipid

  11. Drug-Induced Trafficking of P-Glycoprotein in Human Brain Capillary Endothelial Cells as Demonstrated by Exposure to Mitomycin C

    Science.gov (United States)

    Noack, Andreas; Noack, Sandra; Hoffmann, Andrea; Maalouf, Katia; Buettner, Manuela; Couraud, Pierre-Olivier; Romero, Ignacio A.; Weksler, Babette; Alms, Dana; Römermann, Kerstin; Naim, Hassan Y.; Löscher, Wolfgang

    2014-01-01

    P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. In this study, trafficking of Pgp was investigated in human brain capillary endothelial cells (hCMEC/D3) that were stably transfected with a doxycycline-inducible MDR1-EGFP fusion plasmid. In the presence of doxycycline, these cells exhibited a 15-fold increase in Pgp-EGFP fusion protein expression, which was associated with an increased efflux of the Pgp substrate rhodamine 123 (Rho123). The chemotherapeutic agent mitomycin C (MMC) was used to study drug-induced trafficking of Pgp. Confocal fluorescence microscopy of single hCMEC/D3-MDR1-EGFP cells revealed that Pgp redistribution from intracellular pools to the cell surface occurred within 2 h of MMC exposure. Pgp-EGFP exhibited a punctuate pattern at the cell surface compatible with concentrated regions of the fusion protein in membrane microdomains, i.e., lipid rafts, which was confirmed by Western blot analysis of biotinylated cell surface proteins in Lubrol-resistant membranes. MMC exposure also increased the functionality of Pgp as assessed in three functional assays with Pgp substrates (Rho123, eFluxx-ID Gold, calcein-AM). However, this increase occurred with some delay after the increased Pgp expression and coincided with the release of Pgp from the Lubrol-resistant membrane complexes. Disrupting rafts by depleting the membrane of cholesterol increased the functionality of Pgp. Our data present the first direct evidence of drug-induced Pgp trafficking at the human BBB and indicate that Pgp has to be released from lipid

  12. Endothelial glycocalyx dysfunction in disease: albuminuria and increased microvascular permeability.

    Science.gov (United States)

    Salmon, Andrew H J; Satchell, Simon C

    2012-03-01

    Appreciation of the glomerular microcirculation as a specialized microcirculatory bed, rather than as an entirely separate entity, affords important insights into both glomerular and systemic microvascular pathophysiology. In this review we compare regulation of permeability in systemic and glomerular microcirculations, focusing particularly on the role of the endothelial glycocalyx, and consider the implications for disease processes. The luminal surface of vascular endothelium throughout the body is covered with endothelial glycocalyx, comprising surface-anchored proteoglycans, supplemented with adsorbed soluble proteoglycans, glycosaminoglycans and plasma constituents. In both continuous and fenestrated microvessels, this endothelial glycocalyx provides resistance to the transcapillary escape of water and macromolecules, acting as an integral component of the multilayered barrier provided by the walls of these microvessels (ie acting in concert with clefts or fenestrae across endothelial cell layers, basement membranes and pericytes). Dysfunction of any of these capillary wall components, including the endothelial glycocalyx, can disrupt normal microvascular permeability. Because of its ubiquitous nature, damage to the endothelial glycocalyx alters the permeability of multiple capillary beds: in the glomerulus this is clinically apparent as albuminuria. Generalized damage to the endothelial glycocalyx can therefore manifest as both albuminuria and increased systemic microvascular permeability. This triad of altered endothelial glycocalyx, albuminuria and increased systemic microvascular permeability occurs in a number of important diseases, such as diabetes, with accumulating evidence for a similar phenomenon in ischaemia-reperfusion injury and infectious disease. The detection of albuminuria therefore has implications for the function of the microcirculation as a whole. The importance of the endothelial glycocalyx for other aspects of vascular function

  13. Mixed Capillary Venous Retroperitoneal Hemangioma

    Directory of Open Access Journals (Sweden)

    Mohit Godar

    2013-01-01

    Full Text Available We report a case of mixed capillary venous hemangioma of the retroperitoneum in a 61-year-old man. Abdominal ultrasonography showed a mass to be hypoechoic with increased flow in color Doppler imaging. Dynamic contrast-enhanced computed tomography revealed a centripetal filling-in of the mass, located anterior to the left psoas muscle at the level of sacroiliac joint. On the basis of imaging features, preoperative diagnosis of hemangioma was considered and the mass was excised by laparoscopic method. Immunohistochemical studies were strongly positive for CD31 and CD34, and negative for calretinin, EMA, WT1, HMB45, Ki67, synaptophysin, and lymphatic endothelial cell marker D2–40. Histologically, the neoplasm was diagnosed as mixed capillary venous hemangioma.

  14. Small airway epithelial cells exposure to printer-emitted engineered nanoparticles induces cellular effects on human microvascular endothelial cells in an alveolar-capillary co-culture model.

    Science.gov (United States)

    Sisler, Jennifer D; Pirela, Sandra V; Friend, Sherri; Farcas, Mariana; Schwegler-Berry, Diane; Shvedova, Anna; Castranova, Vincent; Demokritou, Philip; Qian, Yong

    2015-01-01

    The printer is one of the most common office equipment. Recently, it was reported that toner formulations for printing equipment constitute nano-enabled products (NEPs) and contain engineered nanomaterials (ENMs) that become airborne during printing. To date, insufficient research has been performed to understand the potential toxicological properties of printer-emitted particles (PEPs) with several studies using bulk toner particles as test particles. These studies demonstrated the ability of toner particles to cause chronic inflammation and fibrosis in animal models. However, the toxicological implications of inhalation exposures to ENMs emitted from laser printing equipment remain largely unknown. The present study investigates the toxicological effects of PEPs using an in vitro alveolar-capillary co-culture model with Human Small Airway Epithelial Cells (SAEC) and Human Microvascular Endothelial Cells (HMVEC). Our data demonstrate that direct exposure of SAEC to low concentrations of PEPs (0.5 and 1.0 µg/mL) caused morphological changes of actin remodeling and gap formations within the endothelial monolayer. Furthermore, increased production of reactive oxygen species (ROS) and angiogenesis were observed in the HMVEC. Analysis of cytokine and chemokine levels demonstrates that interleukin (IL)-6 and MCP-1 may play a major role in the cellular communication observed between SAEC and HMVEC and the resultant responses in HMVEC. These data indicate that PEPs at low, non-cytotoxic exposure levels are bioactive and affect cellular responses in an alveolar-capillary co-culture model, which raises concerns for potential adverse health effects.

  15. Age and diabetes related changes of the retinal capillaries: An ultrastructural and immunohistochemical study.

    Science.gov (United States)

    Bianchi, Enrica; Ripandelli, Guido; Taurone, Samanta; Feher, Janos; Plateroti, Rocco; Kovacs, Illes; Magliulo, Giuseppe; Orlando, Maria Patrizia; Micera, Alessandra; Battaglione, Ezio; Artico, Marco

    2016-03-01

    Normal human aging and diabetes are associated with a gradual decrease of cerebral flow in the brain with changes in vascular architecture. Thickening of the capillary basement membrane and microvascular fibrosis are evident in the central nervous system of elderly and diabetic patients. Current findings assign a primary role to endothelial dysfunction as a cause of basement membrane (BM) thickening, while retinal alterations are considered to be a secondary cause of either ischemia or exudation. The aim of this study was to reveal any initial retinal alterations and variations in the BM of retinal capillaries during diabetes and aging as compared to healthy controls. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in diabetic retina.Transmission electron microscopy (TEM) was performed on 46 enucleated human eyes with particular attention to alterations of the retinal capillary wall and Müller glial cells. Inflammatory cytokines expression in the retina was investigated by immunohistochemistry.Our electron microscopy findings demonstrated that thickening of the BM begins primarily at the level of the glial side of the retina during aging and diabetes. The Müller cells showed numerous cytoplasmic endosomes and highly electron-dense lysosomes which surrounded the retinal capillaries. Our study is the first to present morphological evidence that Müller cells start to deposit excessive BM material in retinal capillaries during aging and diabetes. Our results confirm the induction of pro-inflammatory cytokines TNF-α and IL-1β within the retina as a result of diabetes.These observations strongly suggest that inflammatory cytokines and changes in the metabolism of Müller glial cells rather than changes in of endothelial cells may play a primary role in the alteration of retinal capillaries BM during aging and diabetes. © The Author(s) 2015.

  16. Involvement of insulin-degrading enzyme in insulin- and atrial natriuretic peptide-sensitive internalization of amyloid-β peptide in mouse brain capillary endothelial cells.

    Science.gov (United States)

    Ito, Shingo; Ohtsuki, Sumio; Murata, Sho; Katsukura, Yuki; Suzuki, Hiroya; Funaki, Miho; Tachikawa, Masanori; Terasaki, Tetsuya

    2014-01-01

    Cerebral clearance of amyloid-β peptide (Aβ), which is implicated in Alzheimer's disease, involves elimination across the blood-brain barrier (BBB), and we previously showed that an insulin-sensitive process is involved in the case of Aβ1-40. The purpose of this study was to clarify the molecular mechanism of the insulin-sensitive Aβ1-40 elimination across mouse BBB. An in vivo cerebral microinjection study demonstrated that [125I]hAβ1-40 elimination from mouse brain was inhibited by human natriuretic peptide (hANP), and [125I]hANP elimination was inhibited by hAβ1-40, suggesting that hAβ1-40 and hANP share a common elimination process. Internalization of [125I]hAβ1-40 into cultured mouse brain capillary endothelial cells (TM-BBB4) was significantly inhibited by either insulin, hANP, other natriuretic peptides or insulin-degrading enzyme (IDE) inhibitors, but was not inhibited by phosphoramidon or thiorphan. Although we have reported the involvement of natriuretic peptide receptor C (Npr-C) in hANP internalization, cells stably expressing Npr-C internalized [125I]hANP but not [125I]hAβ1-40, suggesting that there is no direct interaction between Npr-C and hAβ1-40. IDE was detected in plasma membrane of TM-BBB4 cells, and internalization of [125I]hAβ1-40 by TM-BBB4 cells was reduced by IDE-targeted siRNAs. We conclude that elimination of hAβ1-40 from mouse brain across the BBB involves an insulin- and ANP-sensitive process, mediated by IDE expressed in brain capillary endothelial cells.

  17. Exercise induced capillary growth in human skeletal muscle and the dynamics of VEGF

    DEFF Research Database (Denmark)

    Høier, Birgitte; Hellsten, Ylva

    2014-01-01

    , such as shear stress and passive stretch, lead to cellular signalling, enhanced expression of angiogenic factors and initiation of capillary growth. The most central angiogenic factor in skeletal muscle capillary growth is vascular endothelial growth factor (VEGF). During muscle contraction, VEGF increases...... in the muscle interstitium, acts on VEGF receptors on the capillary endothelium and thereby stimulates angiogenic processes. A primary source of muscle interstitial VEGF during exercise is the skeletal muscle fibers which contain large stores of VEGF within vesicles. We propose that, during muscle activity...

  18. Hypoxic stress up-regulates Kir2.1 expression and facilitates cell proliferation in brain capillary endothelial cells

    International Nuclear Information System (INIS)

    Yamamura, Hideto; Suzuki, Yoshiaki; Yamamura, Hisao; Asai, Kiyofumi; Imaizumi, Yuji

    2016-01-01

    The blood-brain barrier (BBB) is mainly composed of brain capillary endothelial cells (BCECs), astrocytes and pericytes. Brain ischemia causes hypoxic encephalopathy and damages BBB. However, it remains still unclear how hypoxia affects BCECs. In the present study, t-BBEC117 cells, an immortalized bovine brain endothelial cell line, were cultured under hypoxic conditions at 4–5% oxygen for 72 h. This hypoxic stress caused hyperpolarization of resting membrane potential. Patch-clamp recordings revealed a marked increase in Ba 2+ -sensitive inward rectifier K + current in t-BBEC117 cells after hypoxic culture. Western blot and real-time PCR analyses showed that Kir2.1 expression was significantly up-regulated at protein level but not at mRNA level after the hypoxic culture. Ca 2+ imaging study revealed that the hypoxic stress enhanced store-operated Ca 2+ (SOC) entry, which was significantly reduced in the presence of 100 μM Ba 2+ . On the other hand, the expression of SOC channels such as Orai1, Orai2, and transient receptor potential channels was not affected by hypoxic stress. MTT assay showed that the hypoxic stress significantly enhanced t-BBEC117 cell proliferation, which was inhibited by approximately 60% in the presence of 100 μM Ba 2+ . We first show here that moderate cellular stress by cultivation under hypoxic conditions hyperpolarizes membrane potential via the up-regulation of functional Kir2.1 expression and presumably enhances Ca 2+ entry, resulting in the facilitation of BCEC proliferation. These findings suggest potential roles of Kir2.1 expression in functional changes of BCECs in BBB following ischemia. -- Highlights: •Hypoxic culture of brain endothelial cells (BEC) caused membrane hyperpolarization. •This hyperpolarization was due to the increased expression of Kir2.1 channels. •Hypoxia enhanced store-operated Ca 2+ (SOC) entry via Kir2.1 up-regulation. •Expression levels of putative SOC channels were not affected by hypoxia.

  19. The Glycoprofile Patterns of Endothelial Cells in Usual Interstitial Pneumonia

    Directory of Open Access Journals (Sweden)

    A Barkhordari

    2014-09-01

    Full Text Available [THIS ARTICLE HAS BEEN RETRACTED FOR DUPLICATE PUBLICATION] Background: The pathological classification of cryptogenic fibrosing alveolitis has been a matter of debate and controversy for histopathologists. Objective: To identify and specify the glycotypes of capillary endothelial cells in usual interstitial pneumonia (UIP compared to those found in normal tissue. Methods: Sections of formalin-fixed, paraffin-embedded blocks from 16 cases of UIP were studied by lectin histochemistry with a panel of 27 biotinylated lectins and an avidin-peroxidase revealing system. Results: High expression of several classes of glycan was seen de novo in capillary endothelial cells from patients with UIP including small complex and bi/tri-antennary bisected complex N-linked sequences bolund by Concanavalin A and erythro-phytohemagglutinin, respectively, GalNAca1 residues bound by Helix pomatia and Maclura pomifera agglutinins, and L-fucosylated derivatives of type II glycan chains recognized by Ulex europaeus agglutinin-I. Glycans bound by agglutinins from Lycopersicon esculentum (β1,4GlcNAc and Wisteria floribunda (GalNAc as well as GlcNAc oligomers bound by Phytolacca americana and succinylated Wheat Germ agglutinin were also seen in the capillary endothelial cells of UIP. In contrast, L-fucosylated derivatives of type I glycan chains were absent in cells from cases of UIP when Anguilla anguilla agglutinin was applied, unlike the situation in normal tissue. Conclusion: These results may indicate existence of two distinct populations of endothelial cell in UIP with markedly different patterns of glycosylation, reflecting a pattern of differentiation and angiogenesis, which is not detectable morphologically.

  20. Regulation of brain capillary endothelial cells by P2Y receptors coupled to Ca2+, phospholipase C and mitogen-activated protein kinase.

    Science.gov (United States)

    Albert, J L; Boyle, J P; Roberts, J A; Challiss, R A; Gubby, S E; Boarder, M R

    1997-11-01

    1. The blood-brain barrier is formed by capillary endothelial cells and is regulated by cell-surface receptors, such as the G protein-coupled P2Y receptors for nucleotides. Here we investigated some of the characteristics of control of brain endothelial cells by these receptors, characterizing the phospholipase C and Ca2+ response and investigating the possible involvement of mitogen-activated protein kinases (MAPK). 2. Using an unpassaged primary culture of rat brain capillary endothelial cells we showed that ATP, UTP and 2-methylthio ATP (2MeSATP) give similar and substantial increases in cytosolic Ca2+, with a rapid rise to peak followed by a slower decline towards basal or to a sustained plateau. Removal of extracellular Ca2+ had little effect on the peak Ca2+-response, but resulted in a more rapid decline to basal. There was no response to alpha,beta-MethylATP (alpha,beta MeATP) in these unpassaged cells, but a response to this P2X agonist was seen after a single passage. 3. ATP (log EC50 -5.1+/-0.2) also caused an increase in the total [3H]-inositol (poly)phosphates ([3H]-InsPx) in the presence of lithium with a rank order of agonist potency of ATP=UTP=UDP>ADP, with 2MeSATP and alpha,beta MeATP giving no detectable response. 4. Stimulating the cells with ATP or UTP gave a rapid rise in the level of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3), with a peak at 10 s followed by a decline to a sustained plateau phase. 2MeSATP gave no detectable increase in the level of Ins(1,4,5)P3. 5. None of the nucleotides tested affected basal cyclic AMP, while ATP and ATPgammaS, but not 2MeSATP, stimulated cyclic AMP levels in the presence of 5 microM forskolin. 6. Both UTP and ATP stimulated tyrosine phosphorylation of p42 and p44 mitogen-activated protein kinase (MAPK), while 2MeSATP gave a smaller increase in this index of MAPK activation. By use of a peptide kinase assay, UTP gave a substantial increase in MAPK activity with a concentration-dependency consistent with

  1. TNAP and EHD1 are over-expressed in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties.

    Directory of Open Access Journals (Sweden)

    Barbara Deracinois

    Full Text Available Although the physiological properties of the blood-brain barrier (BBB are relatively well known, the phenotype of the component brain capillary endothelial cells (BCECs has yet to be described in detail. Likewise, the molecular mechanisms that govern the establishment and maintenance of the BBB are largely unknown. Proteomics can be used to assess quantitative changes in protein levels and identify proteins involved in the molecular pathways responsible for cellular differentiation. Using the well-established in vitro BBB model developed in our laboratory, we performed a differential nano-LC MALDI-TOF/TOF-MS study of Triton X-100-soluble protein species from bovine BCECs displaying either limited BBB functions or BBB functions re-induced by glial cells. Due to the heterogeneity of the crude extract, we increased identification yields by applying a repeatable, reproducible fractionation process based on the proteins' relative hydrophobicity. We present proteomic and biochemical evidence to show that tissue non-specific alkaline phosphatase (TNAP and Eps15 homology domain-containing protein 1(EDH1 are over-expressed by bovine BCECs after the re-induction of BBB properties. We discuss the impact of these findings on current knowledge of endothelial and BBB permeability.

  2. A large-scale electrophoresis- and chromatography-based determination of gene expression profiles in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties

    Directory of Open Access Journals (Sweden)

    Duban-Deweer Sophie

    2010-11-01

    Full Text Available Abstract Background Brain capillary endothelial cells (BCECs form the physiological basis of the blood-brain barrier (BBB. The barrier function is (at least in part due to well-known proteins such as transporters, tight junctions and metabolic barrier proteins (e.g. monoamine oxidase, gamma glutamyltranspeptidase and P-glycoprotein. Our previous 2-dimensional gel proteome analysis had identified a large number of proteins and revealed the major role of dynamic cytoskeletal remodelling in the differentiation of bovine BCECs. The aim of the present study was to elaborate a reference proteome of Triton X-100-soluble species from bovine BCECs cultured in the well-established in vitro BBB model developed in our laboratory. Results A total of 215 protein spots (corresponding to 130 distinct proteins were identified by 2-dimensional gel electrophoresis, whereas over 350 proteins were identified by a shotgun approach. We classified around 430 distinct proteins expressed by bovine BCECs. Our large-scale gene expression analysis enabled the correction of mistakes referenced into protein databases (e.g. bovine vinculin and constitutes valuable evidence for predictions based on genome annotation. Conclusions Elaboration of a reference proteome constitutes the first step in creating a gene expression database dedicated to capillary endothelial cells displaying BBB characteristics. It improves of our knowledge of the BBB and the key proteins in cell structures, cytoskeleton organization, metabolism, detoxification and drug resistance. Moreover, our results emphasize the need for both appropriate experimental design and correct interpretation of proteome datasets.

  3. Silencing p75NTR prevents proNGF-induced endothelial cell death and development of acellular capillaries in rat retina

    Directory of Open Access Journals (Sweden)

    Ahmed Y Shanab

    Full Text Available Accumulation of the nerve growth factor precursor (proNGF and its receptor p75NTR have been associated with several neurodegenerative diseases in both brain and retina. However, whether proNGF contributes to microvascular degeneration remain unexplored. This study seeks to investigate the mechanism by which proNGF/p75NTR induce endothelial cell (EC death and development of acellular capillaries, a surrogate marker of retinal ischemia. Stable overexpression of the cleavage-resistant proNGF and molecular silencing of p75NTR were utilized in human retinal EC and rat retinas in vivo. Stable overexpression of proNGF decreased NGF levels and induced retinal vascular cell death evident by 1.9-fold increase in acellular capillaries and activation of JNK and cleaved-PARP that were mitigated by p75NTRshRNA. In vitro, overexpression of proNGF did not alter TNF-α level, reduced NGF, however induced EC apoptosis evident by activation of JNK and p38 MAPK, cleaved-PARP. Silencing p75NTR using siRNA restored expression of NGF and TrkA activation and prevented EC apoptosis. Treatment of EC with human-mutant proNGF induced apoptosis that coincided with marked protein interaction and nuclear translocation of p75NTR and the neurotrophin receptor interacting factor. These effects were abolished by a selective p75NTR antagonist. Therefore, targeting p75NTR represents a potential therapeutic strategy for diseases associated with aberrant expression of proNGF.

  4. Capillarization and vascular endothelial growth factor expression in hypertrophying anterior latissimus dorsi muscle of the Japanese quail.

    NARCIS (Netherlands)

    Degens, H.; Anderson, R.K.; Alway, S.E.

    2003-01-01

    Hypertrophy may increase the diffusion distances from capillaries to the interior of the muscle fibers. We hypothesized that capillary proliferation occurs during hypertrophy, which is accompanied by an up-regulation of vascular endothelial growth factor (VEGF). Hypertrophy of the left anterior

  5. Vascular endothelial growth factor, capillarization, and function of the rat plantaris muscle at the onset of hypertrophy.

    NARCIS (Netherlands)

    Degens, H.; Moore, J.A.; Alway, S.E.

    2003-01-01

    Capillary proliferation occurs during compensatory hypertrophy. We investigated whether the expression of vascular endothelial growth factor (VEGF) is elevated at the onset of hypertrophy when capillary proliferation is minimal, and whether muscle damage as assessed by muscle force deficits, may

  6. Sertoli cells in culture secrete paracrine factor(s) that inhibit peritubular myoid cell proliferation: identification of heparinoids as likely candidates

    International Nuclear Information System (INIS)

    Tung, P.S.; Fritz, I.B.

    1991-01-01

    Conditioned medium from Sertoli cells, prepared from testes of 20-day-old rats, contains component(s) that inhibit the incorporation of [3H]-thymidine into DNA of peritubular myoid cells (PMC) and inhibit the proliferation of PMC. These components are trypsin-resistant, heat-stable compounds having a molecular weight less than 30,000. The active inhibitory components in Sertoli cell conditioned medium are inactivated by treatment with heparinase, but not by treatment with hyaluronidase or chondroitin sulfate lyases. Addition of heparin or heparan sulfate results in inhibition of DNA synthesis by PMC in a dose-dependent manner, whereas other glycosaminoglycans (GAGs) examined (hyaluronic acid, keratan sulfate, and chondroitin sulfate) have no detectable effects. Heparin and heparan sulfate are unique among GAGs tested in inhibiting the characteristic multilayer growth pattern of PMC following the attainment of confluence in serum-rich medium. On the basis of these and other data presented, it is concluded that heparin and other heparin-like GAGs synthesized by Sertoli cells are implicated in the modulation of growth of PMC in vitro during co-culture. It is postulated that heparin may play a similar role in maintaining the quiescent peritubular myoid cell phenotype in vivo

  7. Antioxidant and Anti-Inflammatory Effects of Blueberry Anthocyanins on High Glucose-Induced Human Retinal Capillary Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Wuyang Huang

    2018-01-01

    Full Text Available Blueberries possess abundant anthocyanins, which benefit eye health. The purpose of this study was to explore the protective functional role of blueberry anthocyanin extract (BAE and its predominant constituents, malvidin (Mv, malvidin-3-glucoside (Mv-3-glc, and malvidin-3-galactoside (Mv-3-gal, on high glucose- (HG- induced injury in human retinal capillary endothelial cells (HRCECs. The results showed that BAE, Mv, Mv-3-glc, and Mv-3-gal enhanced cell viability (P<0.05 versus the HG group at 24 h; decreased the reactive oxygen species (ROS, P<0.01 versus the HG group both at 24 and 48 h; and increased the enzyme activity of catalase (CAT and superoxide dismutase (SOD (P<0.05 versus the HG group both at 24 and 48 h. Mv could greatly inhibit HG-induced Nox4 expression both at 24 and 48 h (P<0.05, while BAE and Mv-3-gal downregulated Nox4 only at 48 h (P<0.05. Mv, Mv-3-glc, and Mv-3-gal also changed nitric oxide (NO levels (P<0.05. BAE and Mv-3-glc also influenced angiogenesis by decreasing the vascular endothelial cell growth factor (VEGF level and inhibiting Akt pathway (P<0.05. Moreover, Mv and Mv-3-glc inhibited HG-induced intercellular adhesion molecule-1 (ICAM-1, P<0.001 and nuclear factor-kappa B (NF-κB (P<0.05. It indicated that blueberry anthocyanins protected HRCECs via antioxidant and anti-inflammatory mechanisms, which could be promising molecules for the development of nutraceuticals to prevent diabetic retinopathy.

  8. Transfection of brain capillary endothelial cells in primary culture with defined blood-brain barrier properties.

    Science.gov (United States)

    Burkhart, Annette; Thomsen, Louiza Bohn; Thomsen, Maj Schneider; Lichota, Jacek; Fazakas, Csilla; Krizbai, István; Moos, Torben

    2015-08-07

    Primary brain capillary endothelial cells (BCECs) are a promising tool to study the blood-brain barrier (BBB) in vitro, as they maintain many important characteristics of the BBB in vivo, especially when co-cultured with pericytes and/or astrocytes. A novel strategy for drug delivery to the brain is to transform BCECs into protein factories by genetic modifications leading to secretion of otherwise BBB impermeable proteins into the central nervous system. However, a huge challenge underlying this strategy is to enable transfection of non-mitotic BCECs, taking a non-viral approach. We therefore aimed to study transfection in primary, non-mitotic BCECs cultured with defined BBB properties without disrupting the cells' integrity. Primary cultures of BCECs, pericytes and astrocytes were generated from rat brains and used in three different in vitro BBB experimental arrangements, which were characterised based on a their expression of tight junction proteins and other BBB specific proteins, high trans-endothelial electrical resistance (TEER), and low passive permeability to radiolabeled mannitol. Recombinant gene expression and protein synthesis were examined in primary BCECs. The BCECs were transfected using a commercially available transfection agent Turbofect™ to express the red fluorescent protein HcRed1-C1. The BCECs were transfected at different time points to monitor transfection in relation to mitotic or non-mitotic cells, as indicated by fluorescence-activated cell sorting analysis after 5-and 6-carboxylfluorescein diacetate succinidyl ester incorporation. The cell cultures exhibited important BBB characteristics judged from their expression of BBB specific proteins, high TEER values, and low passive permeability. Among the three in vitro BBB models, co-culturing with BCECs and astrocytes was well suited for the transfection studies. Transfection was independent of cell division and with equal efficacy between the mitotic and non-mitotic BCECs. Importantly

  9. Hypoxic stress up-regulates Kir2.1 expression and facilitates cell proliferation in brain capillary endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Hideto; Suzuki, Yoshiaki; Yamamura, Hisao [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan); Asai, Kiyofumi [Department of Molecular Neurobiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Imaizumi, Yuji, E-mail: yimaizum@phar.nagoya-cu.ac.jp [Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya (Japan)

    2016-08-05

    The blood-brain barrier (BBB) is mainly composed of brain capillary endothelial cells (BCECs), astrocytes and pericytes. Brain ischemia causes hypoxic encephalopathy and damages BBB. However, it remains still unclear how hypoxia affects BCECs. In the present study, t-BBEC117 cells, an immortalized bovine brain endothelial cell line, were cultured under hypoxic conditions at 4–5% oxygen for 72 h. This hypoxic stress caused hyperpolarization of resting membrane potential. Patch-clamp recordings revealed a marked increase in Ba{sup 2+}-sensitive inward rectifier K{sup +} current in t-BBEC117 cells after hypoxic culture. Western blot and real-time PCR analyses showed that Kir2.1 expression was significantly up-regulated at protein level but not at mRNA level after the hypoxic culture. Ca{sup 2+} imaging study revealed that the hypoxic stress enhanced store-operated Ca{sup 2+} (SOC) entry, which was significantly reduced in the presence of 100 μM Ba{sup 2+}. On the other hand, the expression of SOC channels such as Orai1, Orai2, and transient receptor potential channels was not affected by hypoxic stress. MTT assay showed that the hypoxic stress significantly enhanced t-BBEC117 cell proliferation, which was inhibited by approximately 60% in the presence of 100 μM Ba{sup 2+}. We first show here that moderate cellular stress by cultivation under hypoxic conditions hyperpolarizes membrane potential via the up-regulation of functional Kir2.1 expression and presumably enhances Ca{sup 2+} entry, resulting in the facilitation of BCEC proliferation. These findings suggest potential roles of Kir2.1 expression in functional changes of BCECs in BBB following ischemia. -- Highlights: •Hypoxic culture of brain endothelial cells (BEC) caused membrane hyperpolarization. •This hyperpolarization was due to the increased expression of Kir2.1 channels. •Hypoxia enhanced store-operated Ca{sup 2+} (SOC) entry via Kir2.1 up-regulation. •Expression levels of putative SOC

  10. Characterisation of an in vitro blood-brain barrier model based on primary porcine capillary endothelial cells in monoculture or co-culture with primary rat or porcine astrocytes and pericytes

    DEFF Research Database (Denmark)

    Thomsen, Louiza Bohn; Larsen, Annette Burkhart; Moos, Torben

    to in vivo such as efflux transporters, tight junction proteins, and high transendothelial electric resistance (TEER). Primary BCECs are isolated from a variety of mammals such as rats, mice, cattle and pigs. Often bovine and porcine BCECs are cultured in monoculture or in co-culture with rat astrocytes......In vitro blood-brain barrier (BBB) models based on primary brain capillary endothelial cells (BCECs) in monoculture or in co-culture with primary astrocytes and pericytes are often applied for studying physiology of the BBB. Primary BCECs retain many morphological and biochemical properties similar...... obtained from neonatal rats which have been shown to strengthen the barrier properties of the BCECs. In this study, brain endothelial cells (PBECs), astrocytes and pericytes are isolated from pig brains donated by the local abattoir. The brains are from 6 month old domestic pigs. The availability and high...

  11. Platelet-derived growth factor B retention is essential for development of normal structure and function of conduit vessels and capillaries

    DEFF Research Database (Denmark)

    Nyström, Henrik C.; Lindblom, Per; Wickman, Anna

    2006-01-01

    . This outward eutrophic remodelling of the aorta was accompanied by endothelial dysfunction. RetKO showed decreased capillary density in skeletal muscle and signs of a defective delivery of capillary oxygen to skeletal muscle, as shown by a decreased physical performance. In RetKO mice, echocardiography...

  12. Domains I and IV of annexin A2 affect the formation and integrity of in vitro capillary-like networks.

    Directory of Open Access Journals (Sweden)

    Aase M Raddum

    Full Text Available Annexin A2 (AnxA2 is a widely expressed multifunctional protein found in different cellular compartments. In spite of lacking a hydrophobic signal peptide, AnxA2 is found at the cell surface of endothelial cells, indicative of a role in angiogenesis. Increased extracellular levels of AnxA2 in tumours correlate with neoangiogenesis, metastasis and poor prognosis. We hypothesised that extracellular AnxA2 may contribute to angiogenesis by affecting endothelial cell-cell interactions and motility. To address this question, we studied the effect of heterotetrameric and monomeric forms of AnxA2, as well as its two soluble domains on the formation and maintenance of capillary-like structures by using an in vitro co-culture system consisting of endothelial and smooth muscle cells. In particular, addition of purified domains I and IV of AnxA2 potently inhibited the vascular endothelial growth factor (VEGF-dependent formation of the capillary-like networks in a dose-dependent manner. In addition, these AnxA2 domains disrupted endothelial cell-cell contacts in preformed capillary-like networks, resulting in the internalisation of vascular endothelial (VE-cadherin and the formation of VE-cadherin-containing filopodia-like structures between the endothelial cells, suggesting increased cell motility. Addition of monoclonal AnxA2 antibodies, in particular against Tyr23 phosphorylated AnxA2, also strongly inhibited network formation in the co-culture system. These results suggest that extracellular AnxA2, most likely in its Tyr phosphorylated form, plays a pivotal role in angiogenesis. The exogenously added AnxA2 domains most likely mediate their effects by competing with endogenous AnxA2 for extracellular factors necessary for the initiation and maintenance of angiogenesis, such as those involved in the formation/integrity of cell-cell contacts.

  13. Dynamic Remodeling of Pericytes In Vivo Maintains Capillary Coverage in the Adult Mouse Brain

    Directory of Open Access Journals (Sweden)

    Andrée-Anne Berthiaume

    2018-01-01

    Full Text Available Summary: Direct contact and communication between pericytes and endothelial cells is critical for maintenance of cerebrovascular stability and blood-brain barrier function. Capillary pericytes have thin processes that reach hundreds of micrometers along the capillary bed. The processes of adjacent pericytes come in close proximity but do not overlap, yielding a cellular chain with discrete territories occupied by individual pericytes. Little is known about whether this pericyte chain is structurally dynamic in the adult brain. Using in vivo two-photon imaging in adult mouse cortex, we show that while pericyte somata were immobile, the tips of their processes underwent extensions and/or retractions over days. The selective ablation of single pericytes provoked exuberant extension of processes from neighboring pericytes to contact uncovered regions of the endothelium. Uncovered capillary regions had normal barrier function but were dilated until pericyte contact was regained. Pericyte structural plasticity may be critical for cerebrovascular health and warrants detailed investigation. : Pericyte-endothelial contact is important for many aspects of cerebrovascular health. Berthiaume et al. use longitudinal two-photon imaging to show that the processes of brain capillary pericytes are structurally plastic in vivo. Their processes can grow hundreds of micrometers to ensure contact with exposed endothelium following ablation of a single pericyte. Keywords: capillary, pericyte, endothelium, blood-brain barrier, blood flow, plasticity, two-photon imaging, Alzheimer’s disease, dementia, stroke

  14. Down-regulation of selected Blood-brain Barrier Specific Genes from Capillaries to Bovine In Vitro Models

    DEFF Research Database (Denmark)

    Goldeman, Charlotte; Saaby, Lasse; Brodin, Birger

    Cultures of primary bovine brain endothelial cells (BECs) grown, often together with astrocytes, on permeable supports in two-compartment culture systems are commonly used as an in vitro model of the blood-brain barrier (BBB). While trans-endothelial electrical resistance, restriction...... the in vivo gene expression of brain capillary endothelial cells. Primary bovine endothelial cells and rat astrocytes were cultured in different culture configurations and the mRNA expression of selected genes (vWF, Glut-1, P-gp, claudin-1,-5, occludin, JAM-1, LAT-1, SLC16A1, MRP-1,-4, BCRP, ZO-1, AP, TPA...

  15. A porcine astrocyte/endothelial cell co-culture model of the blood-brain barrier.

    Science.gov (United States)

    Jeliazkova-Mecheva, Valentina V; Bobilya, Dennis J

    2003-10-01

    A method for the isolation of porcine atrocytes as a simple extension of a previously described procedure for isolation of brain capillary endothelial cells from adolescent pigs [Methods Cell Sci. 17 (1995) 2] is described. The obtained astroglial culture purified through two passages and by the method of the selective detachment was validated by a phase contrast microscopy and through an immunofluorescent assay for the glial fibrillary acidic protein (GFAP). Porcine astrocytes were co-cultivated with porcine brain capillary endothelial cells (PBCEC) for the development of an in vitro blood-brain barrier (BBB) model. The model was visualized by an electron microscopy and showed elevated transendothellial electrical resistance and reduced inulin permeability. To our knowledge, this is the first report for the establishment of a porcine astrocyte/endothelial cell co-culture BBB model, which avoids interspecies and age differences between the two cell types, usually encountered in the other reported co-culture BBB models. Considering the availability of the porcine brain tissue and the close physiological and anatomical relation between the human and pig brain, the porcine astrocyte/endothelial cell co-culture system can serve as a reliable and easily reproducible model for different in vitro BBB studies.

  16. Capillary density and capillary-to-fibre ratio in vastus lateralis muscle of untrained and trained men.

    Science.gov (United States)

    Zoladz, J A; Semik, D; Zawadowska, B; Majerczak, J; Karasinski, J; Kolodziejski, L; Duda, K; Kilarski, W M

    2005-01-01

    Muscle fibre profile area (Af), volume density (Vv), capillary-to-fibre ratio (CF) and number of capillaries per fibre square millimetre (CD) were determined from needle biopsies of vastus lateralis of twenty-four male volunteers (mean +/- SD: age 25.4+/-5.8 years, height 178.6+/-5.5 cm, body mass 72.1+/-7.7 kg) of different training background. Seven subjects were untrained students (group A), nine were national and sub-national level endurance athletes (group B) with the background of 7.8+/-2.9 years of specialised training, and eight subjects were sprint-power athletes (group C) with 12.8+/-8.7 years of specialised training. Muscle biopsies of vastus lateralis were analysed histochemically for mATPase. Capillaries were visualized and counted using CD31 antibodies against endothelial cells. There were significant differences in the Vv of type I and type II muscle fibres in both trained groups, B (51.8%; 25.6%) and C (50.5%; 26.4%). However, in untrained group A that was treated as a reference group, the difference between Vv of type I and type II fibres was less prominent, nevertheless statistically significant (42.1%; 35.1%). There was also a significant difference in CF: 1.9 in group A and 2.1 in groups B and C. The number of capillaries per mm2 (CD) was 245 (group A), 308 (group B) and 325 (group C). Significant differences (Pski-jumping, volleyball, soccer and modern dance.

  17. In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

    OpenAIRE

    Helms, Hans C; Abbott, N Joan; Burek, Malgorzata; Cecchelli, Romeo; Couraud, Pierre-Olivier; Deli, Maria A; Förster, Carola; Galla, Hans J; Romero, Ignacio A; Shusta, Eric V; Stebbins, Matthew J; Vandenhaute, Elodie; Weksler, Babette; Brodin, Birger

    2016-01-01

    The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized br...

  18. *NO and oxyradical metabolism in new cell lines of rat brain capillary endothelial cells forming the blood-brain barrier.

    Science.gov (United States)

    Blasig, I E; Giese, H; Schroeter, M L; Sporbert, A; Utepbergenov, D I; Buchwalow, I B; Neubert, K; Schönfelder, G; Freyer, D; Schimke, I; Siems, W E; Paul, M; Haseloff, R F; Blasig, R

    2001-09-01

    To investigate the relevance of *NO and oxyradicals in the blood-brain barrier (BBB), differentiated and well-proliferating brain capillary endothelial cells (BCEC) are required. Therefore, rat BCEC (rBCEC) were transfected with immortalizing genes. The resulting lines exhibited endothelial characteristics (factor VIII, angiotensin-converting enzyme, high prostacyclin/thromboxane release rates) and BBB markers (gamma-glutamyl transpeptidase, alkaline phosphatase). The control line rBCEC2 (mock transfected) revealed fibroblastoid morphology, less factor VIII, reduced gamma-glutamyl transpeptidase, weak radical defence, low prostanoid metabolism, and limited proliferation. Lines transfected with immortalizing genes (especially rBCEC4, polyoma virus large T antigen) conserved primary properties: epitheloid morphology, subcultivation with high proliferation rate under pure culture conditions, and powerful defence against reactive oxygen species (Mn-, Cu/Zn-superoxide dismutase, catalase, glutathione peroxidase, glutathione) effectively controlling radical metabolism. Only 100 microM H2O2 overcame this defence and stimulated the formation of eicosanoids similarly as in primary cells. Some BBB markers were expressed to a lower degree; however, cocultivation with astrocytes intensified these markers (e.g., alkaline phosphatase) and paraendothelial tightness, indicating induction of BBB properties. Inducible NO synthase was induced by a cytokine plus lipopolysaccharide mixture in all lines and primary cells, resulting in *NO release. Comparing the cell lines obtained, rBCEC4 are stable immortalized and reveal the best conservation of properties from primary cells, including enzymes producing or decomposing reactive species. These cells can be subcultivated in large amounts and, hence, they are suitable to study the role of radical metabolism in the BBB and in the cerebral microvasculature. Copyright 2001 Academic Press.

  19. Interaction of human endothelial cells and nickel-titanium materials modified with silicon ions

    Energy Technology Data Exchange (ETDEWEB)

    Lotkov, Aleksandr I., E-mail: lotkov@ispms.tsc.ru; Kashin, Oleg A., E-mail: okashin@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Kudryavtseva, Yuliya A., E-mail: yulia-k1970@mail.ru; Antonova, Larisa V., E-mail: antonova.la@mail.ru; Matveeva, Vera G., E-mail: matveeva-vg@mail.ru; Sergeeva, Evgeniya A., E-mail: sergeewa.ew@yandex.ru [Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, 650002 (Russian Federation); Kudryashov, Andrey N., E-mail: kudryashov@angioline.ru [Angioline Interventional Device Ltd, Novosibirsk, 630090 (Russian Federation)

    2015-10-27

    The paper studies the influence of chemical and phase compositions of NiTi surface layers modified with Si ions by plasma immersion implantation on their interaction with endothelial cells. It is shown that certain technological modes of Si ion implantation enhance the adhesion, proliferation, and viability of endothelial cells. It is found that the Si-modified NiTi surface is capable of stimulating the formation of capillary-like structures in the cell culture.

  20. Severe capillary leak syndrome after inner ear decompression sickness in a recreational scuba diver.

    Science.gov (United States)

    Gempp, Emmanuel; Lacroix, Guillaume; Cournac, Jean-Marie; Louge, Pierre

    2013-07-01

    Post-decompression shock with plasma volume deficit is a very rare event that has been observed under extreme conditions of hypobaric and hyperbaric exposure in aviators and professional divers. We report a case of severe hypovolemic shock due to extravasation of plasma in a recreational scuba diver presenting with inner ear decompression sickness. Impaired endothelial function can lead to capillary leak with hemoconcentration and hypotension in severe cases. This report suggests that decompression-induced circulating bubbles may have triggered the endothelial damage, activating the classic inflammatory pathway of increased vascular permeability. This observation highlights the need for an accurate diagnosis of this potentially life-threatening condition at the initial presentation in the Emergency Department after a diving-related injury. An elevated hematocrit in a diver should raise the suspicion for the potential development of capillary leak syndrome requiring specific treatment using albumin infusion as primary fluid replacement. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Extract of Indian green mussel, Perna viridis (L.) shows inhibition of blood capillary formation in vitro

    Digital Repository Service at National Institute of Oceanography (India)

    Mirshahi, M.; Mirshahi, P.; Negro, S.; Soria, J.; Sreekumar, P.K.; Kotnala, S.; Therwath, A; Chatterji, A

    The extract of the Indian green mussel (Perna viridis L.) was found to inhibit the formation of endothelial cell capillary tube in a concentration dependent manner in vitro. At a concentration of 5 mg/ml of crude extract, there no formation...

  2. Capillary growth, ultrastructure remodeling and exercise training in skeletal muscle of essential hypertensive patients

    DEFF Research Database (Denmark)

    Gliemann, Lasse; Buess, Rahel; Nyberg, Michael Permin

    2015-01-01

    obtained from m. vastus lateralis in essential hypertensive patients (n=10) and normotensive controls (n=11) before and after 8 weeks of aerobic exercise training. Morphometry was performed after transmission electron microscopy and protein levels of several angioregulatory factors were determined. RESULTS......AIM: The aim was to elucidate whether essential hypertension is associated with altered capillary morphology and density and to what extend exercise training can normalize these parameters. METHODS: To investigate angiogenesis and capillary morphology in essential hypertension, muscle biopsies were...... of vascular endothelial growth factor (VEGF), VEGF receptor-2 and thrombospondin-1 were similar in normo- and hypertensive subjects but tissue inhibitor of matrix metalloproteinase was 69% lower in the hypertensive group. After training, angiogenesis was evident by 15% increased capillary-to-fiber ratio...

  3. Reduced sublingual endothelial glycocalyx in type 1 diabetic patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Winther, Signe Abitz; Frimodt-Møller, Marie; Zobel, Emilie Hein

    thickness was assessed by 5 measurements with the GlucoCheck device (GlucoCheck BV, The Netherlands), a non-invasive hand-held microscope generating video recordings of the sublingual capillaries. Endothelial glycocalyx thickness was estimated from the PBR in capillaries with a diameter range of 5-25 μm......- and macroalbuminuric patients (p=0.020) and micro- and macroalbuminuric patients (p=0.042) were significant, but the difference between normo- and microalbuminuric patients was not (p=0.74). After adjustment for age, sex, HbA1c, diabetes duration and systolic blood pressure, differences between normo...

  4. Functional expression of a proton-coupled organic cation (H+/OC antiporter in human brain capillary endothelial cell line hCMEC/D3, a human blood–brain barrier model

    Directory of Open Access Journals (Sweden)

    Shimomura Keita

    2013-01-01

    Full Text Available Abstract Background Knowledge of the molecular basis and transport function of the human blood–brain barrier (BBB is important for not only understanding human cerebral physiology, but also development of new central nervous system (CNS-acting drugs. However, few studies have been done using human brain capillary endothelial cells, because human brain materials are difficult to obtain. The purpose of this study is to clarify the functional expression of a proton-coupled organic cation (H+/OC antiporter in human brain capillary endothelial cell line hCMEC/D3, which has been recently developed as an in vitro human BBB model. Methods Diphenhydramine, [3H]pyrilamine and oxycodone were used as cationic drugs that proved to be H+/OC antiporter substrates. The in vitro uptake experiments by hCMEC/D3 cells were carried out under several conditions. Results Diphenhydramine and [3H]pyrilamine were both transported into hCMEC/D3 cells in a time- and concentration-dependent manner with Km values of 59 μM and 19 μM, respectively. Each inhibited uptake of the other in a competitive manner, suggesting that a common mechanism is involved in their transport. The diphenhydramine uptake was significantly inhibited by amantadine and quinidine, but not tetraethylammonium and 1-methyl-4-phenylpyridinium (substrates for well-known organic cation transporters. The uptake was inhibited by metabolic inhibitors, but was insensitive to extracellular sodium and membrane potential. Further, the uptake was increased by extracellular alkalization and intracellular acidification. These transport properties are completely consistent with those of previously characterized H+/OC antiporter in rat BBB. Conclusions The present results suggest that H+/OC antiporter is functionally expressed in hCMEC/D3 cells.

  5. Neurotrophin p75 receptor (p75NTR) promotes endothelial cell apoptosis and inhibits angiogenesis: implications for diabetes-induced impaired neovascularization in ischemic limb muscles

    NARCIS (Netherlands)

    Caporali, Andrea; Pani, Elisabetta; Horrevoets, Anton J. G.; Kraenkel, Nicolle; Oikawa, Atsuhiko; Sala-Newby, Graciela B.; Meloni, Marco; Cristofaro, Brunella; Graiani, Gallia; Leroyer, Aurelie S.; Boulanger, Chantal M.; Spinetti, Gaia; Yoon, Sung Ok; Madeddu, Paolo; Emanueli, Costanza

    2008-01-01

    Diabetes impairs endothelial function and reparative neovascularization. The p75 receptor of neurotrophins (p75(NTR)), which is scarcely present in healthy endothelial cells (ECs), becomes strongly expressed by capillary ECs after induction of peripheral ischemia in type-1 diabetic mice. Here, we

  6. Application of DCE-MRI in evaluating lower extremity capillary endothelial function in patients with diabetes mellitus complicated by peripheral vascular disease after PTA

    International Nuclear Information System (INIS)

    Tian Hao; Zhao Jinli; Chen Xiaohua; Wu Xianhua; Li Yuehua

    2014-01-01

    Objective: To quantify endothelial function of lower extremity capillary in patients with peripheral vascular disease associated with diabetes mellitus by using DCE-MRI, and to explore the feasibility of DCE-MRI in predicting vascular restenosis in lower extremity after PTA. Methods: During the period form May 2009 to Jan. 2012, a total of 51 patients (study group) with diabetic lower extremity vascular diseases (77 diseased legs in total) were admitted to the hospital and were treated with PTA. Another 20 volunteers were used as control group. K-trans values were measured in soleus muscle using DCE-MRI. Based on the results after 6 months follow-up, the patients were classified into restenosis group and non-restenosis group. The K -trans values and others clinical data were compared between the two groups. Results: Although clinical symptoms and signs were improved in both groups after the treatment, K-trans value of restenosis group showed no obvious changes after PTA, while K-trans value of non-restenosis group was improved significantly. Before PTA, the difference in K -trans value between the two groups was not statistically significant, while K-trans values of the two groups were significantly lower than that of the control group (P<0.05). Conclusion: K-trans value can reflect the endothelial function in diabetes mellitus patients with peripheral vascular disease, and it can also predict the occurrence of restenosis, providing a useful evidence for clinical. therapy. (authors)

  7. Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

    International Nuclear Information System (INIS)

    Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo; Endo, Yuko; Dang, Nam H.; Morimoto, Chikao

    2010-01-01

    Research highlights: → TNF-α or IL-1β induces EC proliferation with reduction of CD26 expression. → CD26 siRNA or DPP-4 inhibition enhances TNF-α or IL-1β-induced EC proliferation. → Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-α or IL-1β. → Capillary formation induced by TNF-α or IL-1β is enahced in the CD26 -/- mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is a key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.

  8. Impaired Hedgehog signalling-induced endothelial dysfunction is sufficient to induce neuropathy: implication in diabetes.

    Science.gov (United States)

    Chapouly, Candice; Yao, Qinyu; Vandierdonck, Soizic; Larrieu-Lahargue, Frederic; Mariani, John N; Gadeau, Alain-Pierre; Renault, Marie-Ange

    2016-02-01

    Microangiopathy, i.e. endothelial dysfunction, has long been suggested to contribute to the development of diabetic neuropathy, although this has never been fully verified. In the present paper, we have identified the role of Hedgehog (Hh) signalling in endoneurial microvessel integrity and evaluated the impact of impaired Hh signalling in endothelial cells (ECs) on nerve function. By using Desert Hedgehog (Dhh)-deficient mice, we have revealed, that in the absence of Dhh, endoneurial capillaries are abnormally dense and permeable. Furthermore, Smoothened (Smo) conditional KO mice clarified that this increased vessel permeability is specifically due to impaired Hh signalling in ECs and is associated with a down-regulation of Claudin5 (Cldn5). Moreover, impairment of Hh signalling in ECs was sufficient to induce hypoalgesia and neuropathic pain. Finally in Lepr(db/db) type 2 diabetic mice, the loss of Dhh expression observed in the nerve was shown to be associated with increased endoneurial capillary permeability and decreased Cldn5 expression. Conversely, systemic administration of the Smo agonist SAG increased Cldn5 expression, decreased endoneurial capillary permeability, and restored thermal algesia to diabetic mice, demonstrating that loss of Dhh expression is crucial in the development of diabetic neuropathy. The present work demonstrates the critical role of Dhh in maintaining blood nerve barrier integrity and demonstrates for the first time that endothelial dysfunction is sufficient to induce neuropathy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  9. Effect of acute hypobaric hypoxia on the endothelial glycocalyx and digital reactive hyperemia in humans

    DEFF Research Database (Denmark)

    Johansson, Pär I; Bergström, Anita; Aachmann-Andersen, Niels Jacob

    2014-01-01

    INTRODUCTION: Hypoxia is associated with increased capillary permeability. This study tested whether acute hypobaric hypoxia involves degradation of the endothelial glycocalyx. METHODS: We exposed 12 subjects to acute hypobaric hypoxia (equivalent to 4500 m for 2-4 h) and measured venous blood...

  10. Lack of inhibitory effects of the anti-fibrotic drug imatinib on endothelial cell functions in vitro and in vivo.

    Science.gov (United States)

    Venalis, Paulius; Maurer, Britta; Akhmetshina, Alfiya; Busch, Nicole; Dees, Clara; Stürzl, Michael; Zwerina, Jochen; Jüngel, Astrid; Gay, Steffen; Schett, Georg; Distler, Oliver; Distler, Jörg H W

    2009-10-01

    Systemic sclerosis (SSc) is a systemic autoimmune disease that is characterized by microangiopathy with progressive loss of capillaries and tissue fibrosis. Imatinib exerts potent anti-fibrotic effects and is currently evaluated in clinical trials. The aim of the present study was to exclude that the anti-fibrotic effects of imatinib are complicated by inhibitory effects on endothelial cell functions, which might augment vascular disease in SSc. Endothelial cells and mice were treated with pharmacologically relevant concentrations of imatinib. The expression of markers of vascular activation was assessed with real-time PCR. Proliferation was analysed with the cell counting experiments and the MTT assay. Apoptosis was quantified with caspase 3 assays, annexin V in vitro and with TUNEL staining in vivo. Migration was studied with scratch and transwell assays. Tube forming was investigated with the matrigel assay. Imatinib did not alter the expression of markers of vascular activation. Imatinib did not increase the percentage of annexin V positive cells or the activity of caspase 3. No reduction in proliferation or metabolic activity of endothelial cells was observed. Imatinib did not affect migration of endothelial cells and did not reduce the formation of capillary tubes. Consistent with the in vitro data, no difference in the number of apoptotic endothelial cells was observed in vivo in mice treated with imatinib. Imatinib does not inhibit activation, viability, proliferation, migration or tube forming of endothelial cells in vitro and in vivo. Thus, treatment with imatinib might not augment further endothelial cell damage in SSc.

  11. Comparative study of four immortalized human brain capillary endothelial cell lines, hCMEC/D3, hBMEC, TY10, and BB19, and optimization of culture conditions, for an in vitro blood–brain barrier model for drug permeability studies

    OpenAIRE

    Eigenmann, Daniela E; Xue, Gongda; Kim, Kwang S; Moses, Ashlee V; Hamburger, Matthias; Oufir, Mouhssin

    2013-01-01

    Background: Reliable human in vitro blood brain barrier (BBB) models suitable for high throughput screening are urgently needed in early drug discovery and development for assessing the ability of promising bioactive compounds to overcome the BBB. To establish an improved human in vitro BBB model we compared four currently available and well characterized immortalized human brain capillary endothelial cell lines hCMEC/D3 hBMEC TY10 and BB19 with respect to barrier tightness and paracellular p...

  12. CURRENT METHODS OF ENDOTHELIAL DYSFUNCTION ASSESSMENT AND THEIR POSSIBLE USE IN THE PRACTICAL MEDICINE

    Directory of Open Access Journals (Sweden)

    A. V. Shabrov

    2016-01-01

    Full Text Available A review contains a description of the most common methods of evaluation and monitoring of "endothelial dysfunction" that are assessed in terms of their information content and applicability in the practice of medicine. The term "endothelial function" is interpreted primarily as a function of the regulation of capillary blood flow, carried out by the expense of the dynamic change of the phase of vasoconstriction and vasodilatation in vessels of resistive type (in accordance with the changing needs of cellular metabolism. Assessment of endothelial dysfunction is understood as a generalized indicator of the extent and nature of violations of the regulation of peripheral circulation. It includes an assessment of imbalances between endotheliumdependent vasoconstrictor and vasodilating factors or mismatch of the local and central regulation of capillary blood flow in response to various functional tests or other effects (eg, cold test, or test with local ischemia. All methods of endothelial dysfunction assessment in the survey are divided into invasive and non-invasive. The main feature of invasive methods lies in the direct effect on the endothelium of the coronary or other vessels by introducing into these vessels vasoactive substances such as acetylcholine. Response to the test (vasoconstriction or vasodilation is evaluated by coronary angiography or by ultrasound. Non-invasive methods of the assessment of endothelial dysfunction or functions of regulation of the peripheral circulation are regarded as the most promising for widespread use. There are two basic methods that underlie functional tests: methods PAT (peripheral arterial tone and PHG (polyhepatography. Assessment of endothelial dysfunction in many modern scientific researches is important. They are regarded as the causative factors of many different diseases. Such assessments can be useful in everyday medical practice. Assessment of endothelial function provides the clinician with

  13. Physical Sequestration of Bacillus anthracis in the Pulmonary Capillaries in Terminal Infection.

    Science.gov (United States)

    Jouvion, Gregory; Corre, Jean-Philippe; Khun, Huot; Moya-Nilges, Marie; Roux, Pascal; Latroche, Claire; Tournier, Jean-Nicolas; Huerre, Michel; Chrétien, Fabrice; Goossens, Pierre L

    2016-07-15

    The lung is the terminal target of Bacillus anthracis before death, whatever the route of infection (cutaneous, inhalational, or digestive). During a cutaneous infection in absence of toxins, we observed encapsulated bacteria colonizing the alveolar capillary network, bacteria and hemorrhages in alveolar and bronchiolar spaces, and hypoxic foci in the lung (endothelial cells) and brain (neurons and neuropil). Circulating encapsulated bacteria were as chains of approximately 13 µm in length. Bacteria of such size were immediately trapped within the lung capillary network, but bacteria of shorter length were not. Controlling lung-targeted pathology would be beneficial for anthrax treatment. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  14. Capillary/myocyte mismatch in the heart in renal failure--a role for erythropoietin?

    Science.gov (United States)

    Amann, K; Buzello, M; Simonaviciene, A; Miltenberger-Miltenyi, G; Koch, A; Nabokov, A; Gross, M L; Gless, B; Mall, G; Ritz, E

    2000-07-01

    Chronic renal failure is characterized by remodeling of the heart with left ventricular hypertrophy (increasing oxygen demand) and capillary deficit leading to capillary/myocyte mismatch (decreasing oxygen supply). Erythropoietin (Epo) has known angiogenic properties causing endothelial cell activation, migration and sprouting, mediated at least in part via the JAK/STAT (Janus kinase/signal transducers and activators of transcription) pathway. In uraemic cardiac hypertrophy the presence of diminished capillary supply implies that capillary growth does not keep pace with development of hypertrophy. To investigate whether this was due to a deficit of the angiogenic hormone Epo we examined whether Epo levels are altered and whether an increase in haematocrit by administration of rhEpo influences capillary supply, i.e. capillary/myocyte mismatch in experimental renal failure. Male Spraque-Dawley rats were either subjected to partial renal ablation or sham operation. Only modest amounts of renal tissue were removed so that the rats were not anemic. Subgroups of rats received either human (rh)Epo alone or in combination with unspecific antihypertensive treatment (dihydralazine plus furosemide) in order to control the Epo induced rise in blood pressure. Capillary supply was measured stereologically as capillary length per volume myocardium using the orientator method. Capillary length density was reduced by approximately 25% after partial renal ablation (3237+/-601 vs 4293+/-501 mm/mm(3) in controls). It was not statistically different in animals with partial renal ablation+rhEpo+antihypertensive treatment (3620+/-828 mm/mm(3)) compared to partial ablation alone. The study shows that lack of Epo does not cause, or contribute to, the deficit of capillary growth in the hypertrophied left ventricle of rats with renal failure. In addition, a rise in haematocrit is not accompanied by beneficial effects on alterations of cardiovascular structure in experimental renal failure.

  15. Renal handling of technetium-99m DMSA: Evidence for glomerular filtration and peritubular uptake

    International Nuclear Information System (INIS)

    de Lange, M.J.; Piers, D.A.; Kosterink, J.G.; van Luijk, W.H.; Meijer, S.; de Zeeuw, D.; van der Hem, G.K.

    1989-01-01

    The finding of an enhanced excretion of [ 99m Tc]dimercaptosuccinic acid (DMSA) in patients with tubular reabsorption disorders prompted us to investigate the role of filtration in the renal handling of [ 99m Tc]DMSA. Our studies in human serum indicated that binding to serum proteins was approximately 90%. Chromatography of human urine and studies in rats showed that the complex was excreted unaltered into the urine. Renal extraction of [ 99m Tc]DMSA in a human volunteer was 5.8%. Continuous infusion of [ 99m Tc]DMSA in 13 individuals with normal renal function gave the following results (mean +/- s.d.): plasma clearance of [ 99m Tc]DMSA 34 +/- 4 ml/min, urinary clearance of [ 99m Tc]DMSA 12 +/- 3 ml/min. The calculated filtered load of [ 99m Tc]DMSA closely resembled the urinary clearance, whereas the plasma clearance was about three times faster. This indicates that peritubular uptake accounts for approximately 65% and filtration for approximately 35% of the renal handling of [ 99m Tc]DMSA

  16. MicroRNA-210 Modulates Endothelial Cell Response to Hypoxia and Inhibits the Receptor Tyrosine Kinase Ligand Ephrin-A3*S⃞

    Science.gov (United States)

    Fasanaro, Pasquale; D'Alessandra, Yuri; Di Stefano, Valeria; Melchionna, Roberta; Romani, Sveva; Pompilio, Giulio; Capogrossi, Maurizio C.; Martelli, Fabio

    2008-01-01

    MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as negative gene expression regulators. In the present study, we investigated miRNAs role in endothelial cell response to hypoxia. We found that the expression of miR-210 progressively increased upon exposure to hypoxia. miR-210 overexpression in normoxic endothelial cells stimulated the formation of capillary-like structures on Matrigel and vascular endothelial growth factor-driven cell migration. Conversely, miR-210 blockade via anti-miRNA transfection inhibited the formation of capillary-like structures stimulated by hypoxia and decreased cell migration in response to vascular endothelial growth factor. miR-210 overexpression did not affect endothelial cell growth in both normoxia and hypoxia. However, anti-miR-210 transfection inhibited cell growth and induced apoptosis, in both normoxia and hypoxia. We determined that one relevant target of miR-210 in hypoxia was Ephrin-A3 since miR-210 was necessary and sufficient to down-modulate its expression. Moreover, luciferase reporter assays showed that Ephrin-A3 was a direct target of miR-210. Ephrin-A3 modulation by miR-210 had significant functional consequences; indeed, the expression of an Ephrin-A3 allele that is not targeted by miR-210 prevented miR-210-mediated stimulation of both tubulogenesis and chemotaxis. We conclude that miR-210 up-regulation is a crucial element of endothelial cell response to hypoxia, affecting cell survival, migration, and differentiation. PMID:18417479

  17. Differentiation state determines neural effects on microvascular endothelial cells

    International Nuclear Information System (INIS)

    Muffley, Lara A.; Pan, Shin-Chen; Smith, Andria N.; Ga, Maricar; Hocking, Anne M.; Gibran, Nicole S.

    2012-01-01

    Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells. -- Highlights: ► Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell proliferation. ► Neural progenitor cells, not dorsal root ganglion neurons, regulate microvascular endothelial cell migration. ► Neural progenitor cells and dorsal root ganglion neurons do not effect microvascular endothelial tube formation. ► Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell production of nitric oxide. ► Neural progenitor cells and dorsal root

  18. In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

    Science.gov (United States)

    Helms, Hans C; Abbott, N Joan; Burek, Malgorzata; Cecchelli, Romeo; Couraud, Pierre-Olivier; Deli, Maria A; Förster, Carola; Galla, Hans J; Romero, Ignacio A; Shusta, Eric V; Stebbins, Matthew J; Vandenhaute, Elodie; Weksler, Babette

    2016-01-01

    The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described. PMID:26868179

  19. Key endothelial cell angiogenic mechanisms are stimulated by the circulating milieu in sickle cell disease and attenuated by hydroxyurea

    Science.gov (United States)

    Lopes, Flavia C. M.; Traina, Fabiola; Almeida, Camila B.; Leonardo, Flavia C.; Franco-Penteado, Carla F.; Garrido, Vanessa T.; Colella, Marina P.; Soares, Raquel; Olalla-Saad, Sara T.; Costa, Fernando F.; Conran, Nicola

    2015-01-01

    As hypoxia-induced inflammatory angiogenesis may contribute to the manifestations of sickle cell disease, we compared the angiogenic molecular profiles of plasma from sickle cell disease individuals and correlated these with in vitro endothelial cell-mediated angiogenesis-stimulating activity and in vivo neovascularization. Bioplex demonstrated that plasma from patients with steady-state sickle cell anemia contained elevated concentrations of pro-angiogenic factors (angiopoietin-1, basic fibroblast growth factor, vascular endothelial growth factor, vascular endothelial growth factor-D and placental growth factor) and displayed potent pro-angiogenic activity, significantly increasing endothelial cell proliferation, migration and capillary-like structure formation. In vivo neovascularization of Matrigel plugs was significantly greater in sickle cell disease mice than in non-sickle cell disease mice, consistent with an up-regulation of angiogenesis in the disease. In plasma from patients with hemoglobin SC disease without proliferative retinopathy, anti-angiogenic endostatin and thrombospondin-2 were significantly elevated. In contrast, plasma from hemoglobin SC individuals with proliferative retinopathy had a pro-angiogenic profile and more significant effects on endothelial cell proliferation and capillary formation than plasma from patients without retinopathy. Hydroxyurea therapy was associated with significant reductions in plasma angiogenic factors and inhibition of endothelial cell-mediated angiogenic mechanisms and neovascularization. Thus, individuals with sickle cell anemia or hemoglobin SC disease with retinopathy present a highly angiogenic circulating milieu, capable of stimulating key endothelial cell-mediated angiogenic mechanisms. Combination anti-angiogenic therapy to prevent the progression of unregulated neovascularization and associated manifestations in sickle cell disease, such as pulmonary hypertension, may be indicated; furthermore, the

  20. Angiogenesis gene expression in murine endothelial cells during post-pneumonectomy lung growth

    Directory of Open Access Journals (Sweden)

    Konerding Moritz A

    2011-07-01

    Full Text Available Abstract Although blood vessel growth occurs readily in the systemic bronchial circulation, angiogenesis in the pulmonary circulation is rare. Compensatory lung growth after pneumonectomy is an experimental model with presumed alveolar capillary angiogenesis. To investigate the genes participating in murine neoalveolarization, we studied the expression of angiogenesis genes in lung endothelial cells. After left pneumonectomy, the remaining right lung was examined on days 3, 6, 14 and 21days after surgery and compared to both no surgery and sham thoracotomy controls. The lungs were enzymatically digested and CD31+ endothelial cells were isolated using flow cytometry cell sorting. The transcriptional profile of the CD31+ endothelial cells was assessed using quantitative real-time polymerase chain reaction (PCR arrays. Focusing on 84 angiogenesis-associated genes, we identified 22 genes with greater than 4-fold regulation and significantly enhanced transcription (p

  1. Transfection of primary brain capillary endothelial cells for protein synthesis and secretion of recombinant erythropoietin: a strategy to enable protein delivery to the brain.

    Science.gov (United States)

    Burkhart, Annette; Andresen, Thomas Lars; Aigner, Achim; Thomsen, Louiza Bohn; Moos, Torben

    2017-07-01

    Treatment of chronic disorders affecting the central nervous system (CNS) is complicated by the inability of drugs to cross the blood-brain barrier (BBB). Non-viral gene therapy applied to brain capillary endothelial cells (BCECs) denotes a novel approach to overcome the restraints in this passage, as turning BCECs into recombinant protein factories by transfection could result in protein secretion further into the brain. The present study aims to investigate the possibility of transfecting primary rat brain endothelial cells (RBECs) for recombinant protein synthesis and secretion of the neuroprotective protein erythropoietin (EPO). We previously showed that 4% of RBECs with BBB properties can be transfected without disrupting the BBB integrity in vitro, but it can be questioned whether this is sufficient to enable protein secretion at therapeutic levels. The present study examined various transfection vectors, with regard to increasing the transfection efficiency without disrupting the BBB integrity. Lipofectamine 3000™ was the most potent vector compared to polyethylenimine (PEI) and Turbofect. When co-cultured with astrocytes, the genetically modified RBECs secreted recombinant EPO into the cell culture medium both luminally and abluminally, and despite lower levels of EPO reaching the abluminal chamber, the amount of recombinant EPO was sufficient to evolve a biological effect on astrocytes cultured at the abluminal side in terms of upregulated gene expression of brain-derived neurotropic factor (BDNF). In conclusion, non-viral gene therapy to RBECs leads to protein secretion and signifies a method for therapeutic proteins to target cells inside the CNS otherwise omitted due to the BBB.

  2. Endothelial cell-based methods for the detection of cyanobacterial anti-inflammatory and wound-healing promoting metabolites.

    Science.gov (United States)

    Wiesner, Christoph; Kopecky, Jiri; Pflueger, Maren; Hundsberger, Harald; Entler, Barbara; Kleber, Christoph; Atzler, Josef; Hrouzek, Pavel; Stys, Dalibor; Lukesova, Alena; Schuett, Wolfgang; Lucas, Rudolf

    2007-12-01

    Acute lung injury is accompanied by an increased endothelial chemokine production and adhesion molecule expression, which may result in an extensive neutrophil infiltration. Moreover, a destruction of the alveolar epithelium and capillary endothelium may result in permeability edema. As such, the search for novel anti-inflammatory substances, able to downregulate these parameters as well as the tissue damage holds therapeutic promise. We therefore describe here the use of human endothelial cell-based in vitro assays for the detection of anti-inflammatory and wound-healing metabolites from cyanobacteria.

  3. Stimulation of proteoglycans by IGF I and II in microvessel and large vessel endothelial cells

    International Nuclear Information System (INIS)

    Bar, R.S.; Dake, B.L.; Stueck, S.

    1987-01-01

    Endothelial cells were cultured from bovine capillaries and pulmonary arteries, and the effect of insulinlike growth factor (IGF) I and II (multiplication-stimulating activity) and insulin on the synthesis of proteoglycans was determined. IGF I and II stimulated 35 SO 4 incorporation into proteoglycans in a dose-dependent manner in both microvessel and pulmonary artery endothelial cells with maximum threefold increases. In pulmonary artery cells, the IGFs caused a general stimulation of all classes of glycosaminoglycan-containing proteoglycans. In microvessel endothelial cells, the IGFs appeared to preferentially increase heparan sulfate-containing proteoglycans. Insulin, at concentrations up to 10 -6 M, had no effect on the synthesis of proteoglycans in either microvessel or pulmonary arterial endothelial cells. Thus, the IGFs stimulate the synthesis of proteoglycans in both microvessel and large vessel endothelial cells, a property that is not mimicked by insulin. Because vascular endothelial cells are bathed by IGFs in vivo, such IGF-mediated functions are likely to be significant in both the normal physiology of vascular endothelium and in disease states such as diabetes mellitus

  4. Roles for Endothelial Cells in Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Nadine A. Dalrymple

    2012-01-01

    Full Text Available Dengue viruses cause two severe diseases that alter vascular fluid barrier functions, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. The endothelium is the primary fluid barrier of the vasculature and ultimately the effects of dengue virus infection that cause capillary leakage impact endothelial cell (EC barrier functions. The ability of dengue virus to infect the endothelium provides a direct means for dengue to alter capillary permeability, permit virus replication, and induce responses that recruit immune cells to the endothelium. Recent studies focused on dengue virus infection of primary ECs have demonstrated that ECs are efficiently infected, rapidly produce viral progeny, and elicit immune enhancing cytokine responses that may contribute to pathogenesis. Furthermore, infected ECs have also been implicated in enhancing viremia and immunopathogenesis within murine dengue disease models. Thus dengue-infected ECs have the potential to directly contribute to immune enhancement, capillary permeability, viremia, and immune targeting of the endothelium. These effects implicate responses of the infected endothelium in dengue pathogenesis and rationalize therapeutic targeting of the endothelium and EC responses as a means of reducing the severity of dengue virus disease.

  5. Comparisons Between Histology and Optical Coherence Tomography Angiography of the Periarterial Capillary-Free Zone.

    Science.gov (United States)

    Balaratnasingam, Chandrakumar; An, Dong; Sakurada, Yoichi; Lee, Cecilia S; Lee, Aaron Y; McAllister, Ian L; Freund, K Bailey; Sarunic, Marinko; Yu, Dao-Yi

    2018-05-01

    To use the capillary-free zone along retinal arteries, a physiologic area of superficial avascularization, as an anatomic paradigm to investigate the reliability of optical coherence tomography angiography (OCTA) for visualizing the deep retinal circulation. Validity analysis and laboratory investigation. Five normal human donor eyes (mean age 69.8 years) were perfusion-labeled with endothelial antibodies and the capillary networks of the perifovea were visualized using confocal scanning laser microscopy. Regions of the capillary-free zone along the retinal artery were imaged using OCTA in 16 normal subjects (age range 24-51 years). Then, 3 × 3-mm scans were acquired using the RTVue XR Avanti (ver. 2016.1.0.26; Optovue, Inc, Fremont, California, USA), PLEX Elite 9000 (ver. 1.5.0.15909; Zeiss Meditec, Inc, Dublin, California, USA), Heidelberg Spectralis OCT2 (Family acquisition module 6.7.21.0; Heidelberg Engineering, Heidelberg, Germany), and DRI-OCT Triton (Ver. 1.1.1; Topcon Corp, Tokyo, Japan). Images of the superficial plexus, deep vascular plexus, and a slab containing all vascular plexuses were generated using manufacturer-recommended default settings. Comparisons between histology and OCTA were performed. Histologic analysis revealed that the capillary-free zone along the retinal artery was confined to the plane of the superficial capillary plexus and did not include the intermediate and deep capillary plexuses. Images derived from OCTA instruments demonstrated a prominent capillary-free zone along the retinal artery in slabs of the superficial plexus, deep plexus, and all capillary plexuses. The number of deep retinal capillaries seen in the capillary-free zone was significantly greater on histology than on OCTA (P zone as an anatomic paradigm, we show that the deep vascular beds of the retina are not completely visualized using OCTA. This may be a limitation of current OCTA techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Physiologic ischaemic training induces endothelial progenitor cell mobilization and myocardial angiogenesis via endothelial nitric oxide synthase related pathway in rabbits.

    Science.gov (United States)

    Xiao, Mingyue; Lu, Xiao; Li, Jianan; Li, Ling; Li, Yongxue

    2014-04-01

    Ischaemia-induced angiogenesis promises to improve neovascularization by delivery of angiogenic factors or endothelial progenitor cells (EPCs) to cardiac ischaemic areas. In order to avoid the risk of excessive myocardial ischaemia, therefore, we hypothesized that physiological ischaemic training (PIT) of normal skeletal muscle might contribute to myocardial angiogenesis via nitric oxide mediated mobilization of EPCs from the bone marrow in the established rabbit model of controllable myocardial ischaemia. The rabbits were grouped by sham-operation, myocardial ischaemia without PIT, PIT and PIT with pretreatment with the endothelial nitric oxide synthase (eNOS) inhibitor L-nitroarginine methyl ester (L-NAME). Controlled myocardial ischaemia was modelled by a water balloon constrictor implanted on the left ventricular branch in a rabbit. The PIT procedure included three cycles of 3 min of cuff inflation followed by 5 min of deflation on hind limbs of the rabbits for 4 weeks. At the endpoints, circulating EPCs (CD34/Flk-1) were measured by fluorescence-activated cell sorter; capillary density, by immunohistochemistry; blood flow, by a microsphere technique; endothelial nitric oxide synthase (eNOS) mRNA and protein, by real-time reverse transcriptase (RT)-PCR and Western blotting. The mRNA levels of eNOS were significantly higher in the PIT and L-NAME groups than in the sham-operation group (P < 0.05). Phospho-eNOS protein expression was higher in the PIT group than in the sham-operation and myocardial ischaemia without PIT groups (P < 0.05), and the effect was inhibited by L-NAME pretreatment (P < 0.05). Compared with sham-operation and myocardial ischaemia without PIT groups, the PIT group had the highest EPC count (P < 0.001), and the increase of capillary density (P < 0.01) and collateral blood flow (P < 0.05) in the ischaemic myocardium was consistent with the finding of EPC count. These effects were also inhibited by pretreatment with

  7. RADIOAUTOGRAPHIC DEMONSTRATION OF 5-HYDROXYTRYPTAMINE-3H UPTAKE BY PULMONARY ENDOTHELIAL CELLS

    Science.gov (United States)

    Strum, Judy M.; Junod, Alain F.

    1972-01-01

    The lung is able to rapidly remove 5-hydroxytryptamme (5-HT) from the circulation by a Na+-dependent transport mechanism. In order to identify the sites of uptake, radioautographic studies were done on rat lungs which had been isolated and perfused with 5-HT-3H and 0 5 mM iproniazid, a monoamine oxidase inhibitor. In control experiments 10-4 M imipramine was added to the perfusate to inhibit the membrane transport of 5-HT At the light microscope level, silver grains were seen concentrated near capillaries and in the endothelium of large vessels From electron microscope radioautographs a semiquantitative grain count was made and 90% of the silver grains were observed over capillary endothelial cells. The grains were found over the nucleus and cytoplasm of the cell and shewed no preferential association with any particular cytoplasmic inclusion bodies, organelles, or vesicles Other cell types were unlabeled except for a few mast cells, certain vascular smooth muscle cells, and one nerve ending. This radioautographic demonstration of the cell type responsible for the rapid removal of 5-HT from the lung circulation clearly establishes the existence of a new metabolic role for pulmonary endothelial cells. PMID:5044755

  8. Effect of flow on endothelial endocytosis of nanocarriers targeted to ICAM-1.

    Science.gov (United States)

    Bhowmick, Tridib; Berk, Erik; Cui, Xiumin; Muzykantov, Vladimir R; Muro, Silvia

    2012-02-10

    Delivery of drugs into the endothelium by nanocarriers targeted to endothelial determinants may improve treatment of vascular maladies. This is the case for intercellular adhesion molecule 1 (ICAM-1), a glycoprotein overexpressed on endothelial cells (ECs) in many pathologies. ICAM-1-targeted nanocarriers bind to and are internalized by ECs via a non-classical pathway, CAM-mediated endocytosis. In this work we studied the effects of endothelial adaptation to physiological flow on the endocytosis of model polymer nanocarriers targeted to ICAM-1 (anti-ICAM/NCs, ~180 nm diameter). Culturing established endothelial-like cells (EAhy926 cells) and primary human umbilical vein ECs (HUVECs) under 4 dyn/cm(2) laminar shear stress for 24 h resulted in flow adaptation: cell elongation and formation of actin stress fibers aligned to the flow direction. Fluorescence microscopy showed that flow-adapted cells internalized anti-ICAM/NCs under flow, although at slower rate versus non flow-adapted cells under static incubation (~35% reduction). Uptake was inhibited by amiloride, whereas marginally affected by filipin and cadaverine, implicating that CAM-endocytosis accounts for anti-ICAM/NC uptake under flow. Internalization under flow was more modestly affected by inhibiting protein kinase C, which regulates actin remodeling during CAM-endocytosis. Actin recruitment to stress fibers that maintain the cell shape under flow may delay uptake of anti-ICAM/NCs under this condition by interfering with actin reorganization needed for CAM-endocytosis. Electron microscopy revealed somewhat slow, yet effective endocytosis of anti-ICAM/NCs by pulmonary endothelium after i.v. injection in mice, similar to that of flow-adapted cell cultures: ~40% (30 min) and 80% (3 h) internalization. Similar to cell culture data, uptake was slightly faster in capillaries with lower shear stress. Further, LPS treatment accelerated internalization of anti-ICAM/NCs in mice. Therefore, regulation of endocytosis

  9. A novel mechanism of bacterial toxin transfer within host blood cell-derived microvesicles.

    Directory of Open Access Journals (Sweden)

    Anne-lie Ståhl

    2015-02-01

    Full Text Available Shiga toxin (Stx is the main virulence factor of enterohemorrhagic Escherichia coli, which are non-invasive strains that can lead to hemolytic uremic syndrome (HUS, associated with renal failure and death. Although bacteremia does not occur, bacterial virulence factors gain access to the circulation and are thereafter presumed to cause target organ damage. Stx was previously shown to circulate bound to blood cells but the mechanism by which it would potentially transfer to target organ cells has not been elucidated. Here we show that blood cell-derived microvesicles, shed during HUS, contain Stx and are found within patient renal cortical cells. The finding was reproduced in mice infected with Stx-producing Escherichia coli exhibiting Stx-containing blood cell-derived microvesicles in the circulation that reached the kidney where they were transferred into glomerular and peritubular capillary endothelial cells and further through their basement membranes followed by podocytes and tubular epithelial cells, respectively. In vitro studies demonstrated that blood cell-derived microvesicles containing Stx undergo endocytosis in glomerular endothelial cells leading to cell death secondary to inhibited protein synthesis. This study demonstrates a novel virulence mechanism whereby bacterial toxin is transferred within host blood cell-derived microvesicles in which it may evade the host immune system.

  10. Capillary density and capillary-to-fibre ratio in vastus lateralis muscle of untrained and trained men

    Directory of Open Access Journals (Sweden)

    W. M. Kilarski

    2011-08-01

    Full Text Available Muscle fibre profile area (Af, volume density (Vv, capillary-to-fibre ratio (CF and number of capillaries per fibre square millimetre (CD were determined from needle biopsies of vastus lateralis of twenty-four male volunteers (mean ± SD: age 25.4±5.8 years, height 178.6±5.5 cm, body mass 72.1±7.7 kg of different training background. Seven subjects were untrained students (group A, nine were national and sub-national level endurance athletes (group B with the background of 7.8±2.9 years of specialised training, and eight subjects were sprint-power athletes (group C with 12.8±8.7 years of specialised training. Muscle biopsies of vastus lateralis were analysed histochemically for mATPase. Capillaries were visualized and counted using CD31 antibodies against endothelial cells. There were significant differences in the Vv of type I and type II muscle fibres in both trained groups, B (51.8%; 25.6% and C (50.5%; 26.4%. However, in untrained group A that was treated as a reference group, the difference between Vv of type I and type II fibres was less prominent, nevertheless statistically significant (42.1%; 35.1%. There was also a significant difference in CF: 1.9 in group A and 2.1 in groups B and C. The number of capillaries per mm2 (CD was 245 (group A, 308 (group B and 325 (group C. Significant differences (P<0.05 in CF and CD, were found only between group A (1.9; 245 and both groups of trained men, B and C (2.1; 308 and 325. However, endurance athletes (group B, such as long-distance runners, cyclists and cross country skiers, did not differ from the athletes representing short term, high power output sports (group C such as ice hockey, karate, ski-jumping, volleyball, soccer and modern dance.

  11. Autocrine EGF receptor activation mediates endothelial cell migration and vascular morphogenesis induced by VEGF under interstitial flow

    International Nuclear Information System (INIS)

    Semino, Carlos E.; Kamm, Roger D.; Lauffenburger, Douglas A.

    2006-01-01

    We show here that autocrine ligand activation of epidermal growth factor (EGF) receptor in combination with interstitial flow is critically involved in the morphogenetic response of endothelial cells to VEGF stimulation. Human umbilical vein endothelial cell (HUVEC) monolayers cultured on a collagen gel and exposed to low interstitial flow in the absence of EGF and VEGF remained viable and mitotic but exhibited little evidence of vascular morphogenesis. Addition of VEGF produced a flow-dependent morphogenetic response within 48 to 72 h, characterized by branched capillary-like structures. The response was substantially abolished by inhibitors related to the autocrine EGF receptor pathway including Galardin, AG1478, PD98059, and an EGF receptor-blocking antibody, indicating that regulation of the morphogenetic process operates via autocrine EGF receptor activation. Moreover, we observed that in our system the EGF receptor was always activated independently of the interstitial flow, and, in addition, the EGF receptor inhibitors used above reduced the phosphorylation state of the receptor, correlating with inhibition of capillary morphogenesis. Finally, 5'bromo-2'-deoxyuridine (BrdU) labeling identified dividing cells at the monolayer but not in the extending capillary-like structures. EGF pathway inhibitors Galardin and AG1478 did not reduce BrdU incorporation in the monolayer, indicating that the EGF-receptor-mediated morphogenetic behavior is mainly due to cell migration rather than proliferation. Based on these results, we propose a two-step model for in vitro capillary morphogenesis in response to VEGF stimulation with interstitial fluid flow: monolayer maintenance by mitotic activity independent of EGF receptors and a migratory response mediated by autocrine EGF receptor activation wherein cells establish capillary-like structures

  12. Inner capillary diameter of hypothalamic paraventricular nucleus of female rat increases during lactation

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    Cortés-Sol Albertina

    2013-01-01

    Full Text Available Abstract Background The role of the endothelial cell (EC in blood flow regulation within the central nervous system has been little studied. Here, we explored EC participation in morphological changes of the anterior hypothalamic paraventricular nucleus (PVN microvasculature of female rats at two reproductive stages with different metabolic demand (virginity and lactation. We measured the inner capillary diameter (ICD of 800 capillaries from either the magnocellular or parvocellular regions. The space occupied by neural (somas, dendrites and axons and glial, but excluding vascular elements of the neurovascular compartment was also measured in 100-μm2 sample fields of both PVN subdivisions. Results The PVN of both groups of animals showed ICDs that ranged from 3 to 10 microns. The virgin group presented mostly capillaries with small ICD, whereas the lactating females exhibited a significant increment in the percentage of capillaries with larger ICD. The space occupied by the neural and glial elements of the neurovascular compartment did not show changes with lactation. Conclusions Our findings suggest that during lactation the microvasculature of the PVN of female rats undergoes dynamic, transitory changes in blood flow as represented by an increment in the ICD through a self-cytoplasmic volume modification reflected by EC changes. A model of this process is proposed.

  13. Research on the promoting role of apelin-13 in proliferation, migration and capillary-like tube formation of RF/6A cells

    Directory of Open Access Journals (Sweden)

    Kun-Peng Xie

    2017-05-01

    Full Text Available AIM: To investigate the effects of apelin-13 on proliferation, migration and capillary-like tube formation of a monkey choroid / retinal endothelial cell line, RF/6A, to clarify whether apelin-13 could promote retinal angiogenesis in vitro.METHODS: RF/6A cells in good conditions were administrated with DMSO(the control group, apelin-13 at 0.1μmol/L(low dose groupor apelin-13 at 1μmol/L(high dose group. Cell proliferation, migration and capillary-like tube formation were detected by using the MTT assay, scratch assay and matrigel assay, respectively, at 24h after plating the cells. RESULTS: Cell proliferation was promoted in both low and high dose apelin-13 groups compared to the control cells(PPPCONCLUSION: Apelin-13 could obviously promote the angiogenesis capacity of RF/6A cells, suggesting that apelin-13 was an important pro-angiogenic factor in retinal endothelial cells.

  14. Loss of CD34 expression in aging human choriocapillaris endothelial cells.

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    Elliott H Sohn

    Full Text Available Structural and gene expression changes in the microvasculature of the human choroid occur during normal aging and age-related macular degeneration (AMD. In this study, we sought to determine the impact of aging and AMD on expression of the endothelial cell glycoprotein CD34. Sections from 58 human donor eyes were categorized as either young (under age 40, age-matched controls (> age 60 without AMD, or AMD affected (>age 60 with early AMD, geographic atrophy, or choroidal neovascularization. Dual labeling of sections with Ulex europaeus agglutinin-I lectin (UEA-I and CD34 antibodies was performed, and the percentage of capillaries labeled with UEA-I but negative for anti-CD34 was determined. In addition, published databases of mouse and human retinal pigment epithelium-choroid were evaluated and CD34 expression compared between young and old eyes. Immunohistochemical studies revealed that while CD34 and UEA-I were colocalized in young eyes, there was variable loss of CD34 immunoreactivity in older donor eyes. While differences between normal aging and AMD were not significant, the percentage of CD34 negative capillaries in old eyes, compared to young eyes, was highly significant (p = 3.8×10(-6. Endothelial cells in neovascular membranes were invariably CD34 positive. Published databases show either a significant decrease in Cd34 (mouse or a trend toward decreased CD34 (human in aging. These findings suggest that UEA-I and endogenous alkaline phosphatase activity are more consistent markers of aging endothelial cells in the choroid, and suggest a possible mechanism for the increased inflammatory milieu in the aging choroid.

  15. Vascular expression of endothelial antigen PAL-E indicates absence of blood-ocular barriers in the normal eye

    NARCIS (Netherlands)

    Schlingemann, R. O.; Hofman, P.; Anderson, L.; Troost, D.; van der Gaag, R.

    1997-01-01

    The endothelium-specific antigen PAL-E is expressed in capillaries and veins throughout the body with the exception of the brain, where the antigen is absent from anatomical sites with a patent blood-brain barrier. In this study we determined vascular endothelial staining for PAL-E in the normal eye

  16. Basement membrane-specific chondroitin sulfate proteoglycan is abnormally associated with the glomerular capillary basement membrane of diabetic rats

    DEFF Research Database (Denmark)

    McCarthy, K J; Abrahamson, D R; Bynum, K R

    1994-01-01

    exception being the normal glomerular capillary basement membrane (GBM), where it is absent. In the present study of mature kidneys we examined the distribution of BM-CSPG in streptozocin-induced diabetes mellitus in rats. We found BM-CSPG atypically associated with the GBM of diabetic animals as early as 1...... month after induction of diabetes mellitus. Immunoelectron microscopy (IEM) of affected capillary loops showed BM-CSPG present in the subendothelial matrix in areas of GBM thickening and absent in areas where the GBM appears to be of normal thickness. Moreover, the association of BM-CSPG with regions...... of the pericapillary GBM affects the morphology of the capillary endothelial cells within these areas, directly displacing the cell body from the GBM proper and causing loss of fenestrae. These new data on BM-CSPG distribution reflect abnormal glomerular extracellular matrix protein biosynthesis/turnover in diabetes...

  17. Methyl mercury uptake across bovine brain capillary endothelial cells in vitro: The role of amino acids

    International Nuclear Information System (INIS)

    Aschner, M.; Clarkson, T.W.

    1989-01-01

    Previous studies in the rat in vivo have demonstrated that co-injection of methyl mercury (MeHg) with L-cysteine into the common carotid artery enhances brain Hg levels folowing a single capillary pass through the CNS vasculature. In order to elucidate the relationship between MeHg transport and the neutral amino acid transport carrier system, regulatory aspects of MeHg transport across the bovine blood-brain barrier were investigated in isolated brain microvessel preparations. Following 1 hour co-incubations of 203 Hg-MeHgCl with 0.1 mM L-cysteine at 37 deg. C, 203 Hg uptake by suspended microvessels was significantly increased (P 203 Hg was abolished by co-incubations of microvessels with 0.1 mM L-cysteine-L-methionine, or 0.1 mM L-cysteine plus AT-125 (alpha S, 5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazolacetic acid), an irreversible inhibitor of gamma-glutamyl-transpeptidase. One hr co-incubations of bovine capilaries with 203 Hg-MeHgCl and 0.1 mM D-cysteine at 37 deg. C or 0.1 mM L-cysteine at 0 deg. did not increase rat of 203 Hg uptake compared with controls. These results indicate that L-cysteine enhances the rate of capillary MeHg uptake. The accumulation of 203 Hg in the bovine microvessels appears to be a carrier-mediated process. It is inhibited by L-methionin, a competitive substrate for neutral amino acid transport, and by AT-125. Capillary uptake of 203 Hg is stereospecific to the L-enantiomorph of cystine, suggesting selective uptake of MeHg across the blood-brain barrier. The data emphasize the relationship between the L-enantiomorph neutral amino acid carrier system and MeHg transport across the capillaries. (author)

  18. IL-17A potentiates TNFα-induced secretion from human endothelial cells and alters barrier functions controlling neutrophils rights of passage

    DEFF Research Database (Denmark)

    Bosteen, Markus H; Tritsaris, Katerina; Hansen, Anker J

    2014-01-01

    Interleukin-17A (IL-17A) is an important pro-inflammatory cytokine that regulates leukocyte mobilization and recruitment. To better understand how IL-17A controls leukocyte trafficking across capillaries in the peripheral blood circulation, we used primary human dermal microvascular endothelial...

  19. Gene delivery into primary brain capillary endothelial cells for protein secretion

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Lichota, Jacek

    model was established by co-culturing primary BCECs together with primary astrocytes, both of which were isolated from rats. This was done in order to study the possibility of using gene transfection in an environment closer to the in-vivo BBB situation. The in-vitro BBB barrier model showed trans......-endothelial electrical resistance above 200 ohm*cm2, indicating that the BCECs formed a tight polar monolayer with functional tight junctions. This was confirmed by immunostaining for the thigh junction protein ZO-1. Rat BCECs were transfected with a red fluorescence protein Hc-RED for 24 hours. Positive transfection...

  20. Both cardiomyocyte and endothelial cell Nox4 mediate protection against hemodynamic overload-induced remodelling.

    Science.gov (United States)

    Zhang, Min; Mongue-Din, Heloise; Martin, Daniel; Catibog, Norman; Smyrnias, Ioannis; Zhang, Xiaohong; Yu, Bin; Wang, Minshu; Brandes, Ralf P; Schröder, Katrin; Shah, Ajay M

    2018-03-01

    NADPH oxidase-4 (Nox4) is an important reactive oxygen species (ROS) source that is upregulated in the haemodynamically overloaded heart. Our previous studies using global Nox4 knockout (Nox4KO) mice demonstrated a protective role of Nox4 during chronic abdominal aortic banding, involving a paracrine enhancement of myocardial capillary density. However, other authors who studied cardiac-specific Nox4KO mice reported detrimental effects of Nox4 in response to transverse aortic constriction (TAC). It has been speculated that these divergent results are due to cell-specific actions of Nox4 (i.e. cardiomyocyte Nox4 detrimental but endothelial Nox4 beneficial) and/or differences in the model of pressure overload (i.e. abdominal banding vs. TAC). This study aimed to (i) investigate whether the effects of Nox4 on pressure overload-induced cardiac remodelling vary according to the pressure overload model and (ii) compare the roles of cardiomyocyte vs. endothelial cell Nox4. Global Nox4KO mice subjected to TAC developed worse cardiac remodelling and contractile dysfunction than wild-type littermates, consistent with our previous results with abdominal aortic banding. Next, we generated inducible cardiomyocyte-specific Nox4 KO mice (Cardio-Nox4KO) and endothelial-specific Nox4 KO mice (Endo-Nox4KO) and studied their responses to pressure overload. Both Cardio-Nox4KO and Endo-Nox4KO developed worse pressure overload-induced cardiac remodelling and dysfunction than wild-type littermates, associated with significant decrease in protein levels of HIF1α and VEGF and impairment of myocardial capillarization. Cardiomyocyte as well as endothelial cell Nox4 contributes to protection against chronic hemodynamic overload-induced cardiac remodelling, at least in part through common effects on myocardial capillary density. © The Author 2017 Published by Oxford University Press on behalf of the European Society of Cardiology.

  1. Angiocrine functions of organ-specific endothelial cells

    Science.gov (United States)

    Rafii, Shahin; Butler, Jason M; Ding, Bi-Sen

    2016-01-01

    Preface Endothelial cells lining blood vessel capillaries are not just passive conduits for delivering blood. Tissue-specific endothelium establish specialized vascular niches that deploy specific sets of growth factors, known as angiocrine factors, which actively participate in inducing, specifying, patterning, and guiding organ regeneration and maintaining homeostasis and metabolism. Angiocrine factors upregulated in response to injury orchestrates self-renewal and differentiation of tissue-specific repopulating resident stem and progenitor cells into functional organs. Uncovering the precise mechanisms whereby physiological-levels of angiocrine factors are spatially and temporally produced, and distributed by organotypic endothelium to repopulating cells, will lay the foundation for driving organ repair without scarring. PMID:26791722

  2. Ultrastructural studies on the blood-brain barrier. Mainly as to changes in the permeability of cerebral capillary walls induced by experimental x-ray irradiation and the effect of glucocorticoid on such changes

    Energy Technology Data Exchange (ETDEWEB)

    Ichitsubo, H [Tokyo Medical Coll. (Japan)

    1977-03-01

    In the present study, an ultrastructural examination was made of the role of capillary endothelial cells of the brain which is one of the constituent factors of the blood-brain barrier. In normal cerebral capillaries, both endothelial cells and the basement membrane were demonstrated to be not crossed by a tracer (horseradish peroxidase) even in 60 minutes after its intravenous administration, thus suggesting the blood-brain barrier effect. Author investigated changes in the permeability of cerebral capillary walls induced by experimental brain irradiation and the effect of glucocorticoid on such changes. On forty-eight hours following an appropriate irradiation a marked brain edema was developed; under such circumstances when the tracer was injected intravenously, on 60 minutes thereafter the tracer was demonstrated to be transferred into the neutral tissue, and this was interpreted as indicating that capillary hyperpermeability was induced. These findings were suggested that the mechanism of capillary hyperpermeability might not be based on the passage of a tight junction of the cells of capillary wall but rather on account of activated active transport via an increased number of pinocytotic vesicles. The mechanism of increase of pinocytotic vesicle appeared to be resulting from a breakdown of the controlling system of pinocytotic vesicle production. However, the existence of this controlling system is still speculative. Pre-and post-irradiation administration of glucocorticoid proved to be effective in the prevention of irradiation-induced hyperpermeability of cerebral capillaries, and to be indicating the possible usefulness of the drug for the maintenance or repair of the aforementioned system.

  3. Two-dimensional capillary electrophoresis: capillary isoelectric focusing and capillary zone electrophoresis with laser-induced fluorescence detection

    Science.gov (United States)

    Dickerson, Jane A.; Ramsay, Lauren M.; Dada, Oluwatosin O.; Cermak, Nathan

    2011-01-01

    Capillary isoelectric focusing and capillary zone electrophoresis are coupled with laser-induced fluorescence detection to create an ultrasensitive two-dimensional separation method for proteins. In this method, two capillaries are joined through a buffer filled interface. Separate power supplies control the potential at the injection end of the first capillary and at the interface; the detector is held at ground potential. Proteins are labeled with the fluorogenic reagent Chromeo P503, which preserves the isoelectric point of the labeled protein. The labeled proteins were mixed with ampholytes and injected into the first dimension capillary. A focusing step was performed with the injection end of the capillary at high pH and the interface at low pH. To mobilize components, the interface was filled with a high pH buffer, which was compatible with the second dimension separation. A fraction was transferred to the second dimension capillary for separation. The process of fraction transfer and second dimension separation was repeated two dozen times. The separation produced a spot capacity of 125. PMID:20603830

  4. Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction.

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    Maria Giovanna Scioli

    Full Text Available Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery.We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS reduction, inducible nitric oxide synthase (iNOS and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF, placental growth factor (PlGF and reduction of NADPH-oxidase 4 (Nox4 expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction.PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and

  5. Vildagliptin Stimulates Endothelial Cell Network Formation and Ischemia-induced Revascularization via an Endothelial Nitric-oxide Synthase-dependent Mechanism*

    Science.gov (United States)

    Ishii, Masakazu; Shibata, Rei; Kondo, Kazuhisa; Kambara, Takahiro; Shimizu, Yuuki; Tanigawa, Tohru; Bando, Yasuko K.; Nishimura, Masahiro; Ouchi, Noriyuki; Murohara, Toyoaki

    2014-01-01

    Dipeptidyl peptidase-4 inhibitors are known to lower glucose levels and are also beneficial in the management of cardiovascular disease. Here, we investigated whether a dipeptidyl peptidase-4 inhibitor, vildagliptin, modulates endothelial cell network formation and revascularization processes in vitro and in vivo. Treatment with vildagliptin enhanced blood flow recovery and capillary density in the ischemic limbs of wild-type mice, with accompanying increases in phosphorylation of Akt and endothelial nitric-oxide synthase (eNOS). In contrast to wild-type mice, treatment with vildagliptin did not improve blood flow in ischemic muscles of eNOS-deficient mice. Treatment with vildagliptin increased the levels of glucagon-like peptide-1 (GLP-1) and adiponectin, which have protective effects on the vasculature. Both vildagliptin and GLP-1 increased the differentiation of cultured human umbilical vein endothelial cells (HUVECs) into vascular-like structures, although vildagliptin was less effective than GLP-1. GLP-1 and vildagliptin also stimulated the phosphorylation of Akt and eNOS in HUVECs. Pretreatment with a PI3 kinase or NOS inhibitor blocked the stimulatory effects of both vildagliptin and GLP-1 on HUVEC differentiation. Furthermore, treatment with vildagliptin only partially increased the limb flow of ischemic muscle in adiponectin-deficient mice in vivo. GLP-1, but not vildagliptin, significantly increased adiponectin expression in differentiated 3T3-L1 adipocytes in vitro. These data indicate that vildagliptin promotes endothelial cell function via eNOS signaling, an effect that may be mediated by both GLP-1-dependent and GLP-1-independent mechanisms. The beneficial activity of GLP-1 for revascularization may also be partially mediated by its ability to increase adiponectin production. PMID:25100725

  6. Characterization of an apically derived epithelial membrane glycoprotein from bovine milk, which is expressed in capillary endothelia in diverse tissues.

    Science.gov (United States)

    Greenwalt, D E; Mather, I H

    1985-02-01

    A glycoprotein (PAS IV) of apparent Mr 76,000 was purified from bovine milk-fat-globule membrane and partially characterized. PAS IV contained mannose, galactose, and sialic acid as principal sugars (approximately 5.3% total carbohydrate [wt/wt]) and existed in milk in at least four isoelectric variants. The glycoprotein appeared to be an integral membrane protein by several criteria. PAS IV was recovered in the detergent phase of Triton X-114 extracts of milk-fat-globule membrane at room temperature. When bound to membrane, PAS IV was resistant to digestion by a number of proteinases, although after solubilization with non-ionic detergents, the protein was readily degraded. Amino acid analysis of the purified protein revealed a high percentage of amino acids with nonpolar residues. The location of PAS IV was determined in bovine tissues by using immunofluorescence techniques. In mammary tissue, PAS IV was located on both the apical surfaces of secretory epithelial cells and endothelial cells of capillaries. This glycoprotein was also detected in endothelial cells of heart, liver, spleen, pancreas, salivary gland, and small intestine. In addition to mammary epithelial cells, PAS IV was also located in certain other epithelial cells, most notably the bronchiolar epithelial cells of lung. The potential usefulness of this protein as a specific marker of capillary endothelial cells in certain tissues is discussed.

  7. Early humoral-mediated graft injuries in ABO-incompatible kidney transplantation in human beings.

    Science.gov (United States)

    Sekijima, M; Shimizu, A; Ishii, Y; Kudo, S; Horita, S; Nakajima, I; Fuchinoue, S; Teraoka, S

    2010-04-01

    Acute humoral rejection is the most important risk factor for early graft loss in ABO-incompatible (ABO-i) renal transplantation (RTx) and is present from the early period after RTx. However, the characteristics of early humoral-mediated graft injury are pathologically uncertain. To analyze tissue from 10 protocol graft biopsies performed in 10 patients within 30 days post-RTx to clarify the pathologic features of early humoral-mediated graft injuries in ABO-i RTx. Pathologic findings were examined using light and electron microscopy and immunofluorescence studies for C4d. Protocol biopsies were performed within 30 days after RTx in the absence of an episode of dysfunction (creatinine concentration 1.21-1.81 mg/dL). The immunofluorescence study demonstrated C4d deposition in peritubular and glomerular capillaries. Acute glomerulitis with infiltration of mononuclear cells and neutrophils was observed in 3 patients. Furthermore, glomerulitis was accompanied by endothelial cell injuries, widening of subendothelial spaces with a double-contoured glomerular basement membrane, and mesangiolysis. In ABO-i RTx, early humoral-mediated graft injuries were observed in approximately 30% of patients despite normal graft function. They were characterized by C4d deposition and glomerular capillary injury. These findings suggest that renal glomeruli are the first site of graft injury by anti-A or anti-B blood type antibody with complement activation in ABO-i RTx.

  8. 3D capillary valves for versatile capillary patterning of channel walls

    NARCIS (Netherlands)

    Papadimitriou, Vasileios; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    We demonstrate passive capillary patterning of channel walls with a liquid in situ. Patterning is performed using a novel 3D capillary valve system combining three standard capillary stop valves. A range of different patterns is demonstrated in three channel walls. Capillary patterning was designed

  9. Endothelial trans-differentiation in glioblastoma recurring after radiotherapy.

    Science.gov (United States)

    De Pascalis, Ivana; Morgante, Liliana; Pacioni, Simone; D'Alessandris, Quintino Giorgio; Giannetti, Stefano; Martini, Maurizio; Ricci-Vitiani, Lucia; Malinverno, Matteo; Dejana, Elisabetta; Larocca, Luigi M; Pallini, Roberto

    2018-04-30

    We hypothesized that in glioblastoma recurring after radiotherapy, a condition whereby the brain endothelium undergoes radiation-induced senescence, tumor cells with endothelial phenotype may be relevant for tumor neovascularization. Matched glioblastoma samples obtained at primary surgery and at surgery for tumor recurrence after radiotherapy, all expressing epidermal growth factor receptor variant III (EGFRvIII), were assessed by a technique that combines fluorescent in situ hybridization (FISH) for the EGFR/CEP7 chromosomal probe with immunostaining for endothelial cells (CD31) and activated pericytes (α Smooth Muscle Actin). Five EGFRvIII-expressing paired primary/recurrent glioblastoma samples, in which the tumor cells showed EGFR/CEP7 amplification, were then assessed by CD31 and α Smooth Muscle Actin immunofluorescence. In glomeruloid bodies, the ratio between CD31+ cells with amplified EGFR/CEP7 signal and the total CD31+ cells was 0.23 ± 0.09 (mean ± sem) and 0.63 ± 0.07 in primary tumors and in recurrent ones, respectively (p < 0.002, Student-t test). In capillaries, the ratio of CD31+ cells with amplified EGFR/CEP7 over the total CD31+ cells lining the capillary lumen was 0.21 ± 0.06 (mean ± sem) and 0.42 ± 0.07 at primary surgery and at recurrence, respectively (p < 0.005, Student-t test). Expression of α Smooth Muscle Actin by cells with EGFR/CEP7 amplification was not observed. Then, in glioblastoma recurring after radiotherapy, where the brain endothelium suffers from radiation-induced cell senescence, tumor-derived endothelium plays a role in neo-vascularization.

  10. Exercise training normalizes skeletal muscle vascular endothelial growth factor levels in patients with essential hypertension

    DEFF Research Database (Denmark)

    Hansen, Ane Håkansson; Nielsen, Jens Jung; Saltin, Bengt

    2010-01-01

    METHODS: Vascular endothelial growth factor (VEGF) protein and capillarization were determined in muscle vastus lateralis biopsy samples in individuals with essential hypertension (n = 10) and normotensive controls (n = 10). The hypertensive individuals performed exercise training for 16 weeks....... Muscle samples as well as muscle microdialysis fluid samples were obtained at rest, during and after an acute exercise bout, performed prior to and after the training period, for the determination of muscle VEGF levels, VEGF release, endothelial cell proliferative effect and capillarization. RESULTS......: Prior to training, the hypertensive individuals had 36% lower levels of VEGF protein and 22% lower capillary density in the muscle compared to controls. Training in the hypertensive group reduced (P

  11. Prostacyclin Synthase: Upregulation during Renal Development and in Glomerular Disease as well as Its Constitutive Expression in Cultured Human Mesangial Cells

    Directory of Open Access Journals (Sweden)

    Thomas Klein

    2015-01-01

    Full Text Available Prostacyclin (PGI2 plays a critical role in nephrogenesis and renal physiology. However, our understanding of how prostacyclin release in the kidney is regulated remains poorly defined. We studied expression of prostacyclin synthase (PGIS in developing and adult human kidneys, and also in selected pediatric renal diseases. We also examined PGI2 formation in human mesangial cells in vitro. We observed abundant expression of PGIS in the nephrogenic cortex in humans and in situ hybridization revealed an identical pattern in mice. In the normal adult kidney, PGIS-immunoreactive protein and mRNA appear to localize to mesangial fields and endothelial and smooth muscle cells of arteries and peritubular capillaries. In kidney biopsies taken from pediatric patients, enhanced expression of PGIS-immunoreactive protein was noted mainly in endothelial cells of patients with IgA-nephropathy. Cultured human mesangial cells produce primarily PGI2 and prostaglandin E2, followed by prostaglandin F2α Cytokine stimulation increased PGI2 formation 24-fold. Under these conditions expression of PGIS mRNA and protein remained unaltered whereas mRNA for cyclooxygenase-2 was markedly induced. In contrast to its constitutive expression in vitro, renal expression of prostacyclin-synthase appears to be regulated both during development and in glomerular disease. Further research is needed to identify the factors involved in regulation of PGIS-expression.

  12. The hemostatic agent ethamsylate enhances P-selectin membrane expression in human platelets and cultured endothelial cells.

    Science.gov (United States)

    Alvarez-Guerra, Miriam; Hernandez, Maria Rosa; Escolar, Ginés; Chiavaroli, Carlo; Garay, Ricardo P; Hannaert, Patrick

    2002-09-15

    Ethamsylate possesses antihemorrhagic properties, but whether or not it directly activates blood platelets is unclear. Here we investigated the platelet activation potential of ethamsylate, by measuring membrane P-selectin expression with flow cytometry in human whole blood and also by immunofluorescence imaging of isolated human platelets. Moreover, we measured membrane P-selectin expression in the SV40-transformed aortic rat endothelial cell line (SVAREC) and 14C-ethamsylate membrane binding and/or uptake in platelets and endothelial cells. Whole blood flow cytometry showed a modest, but statistically significant increase by ethamsylate in the percentage of platelets expressing P-selectin (from 2% to 4-5%, p ethamsylate tested (1 microM), with maximal enhancement of P-selectin expression (75-90%) at 10 microM ethamsylate. Similar results were obtained in SVAREC endothelial cells. 14C-ethamsylate specifically bound to platelets and endothelial cell membranes, without significant uptake into the cell interior. In conclusion, ethamsylate enhances membrane P-selectin expression in human platelets and in cultured endothelial cells. Ethamsylate specifically binds to some protein receptor in platelet and endothelial cell membranes, receptor which can signal for membrane P-selectin expression. These results support the view that ethamsylate acts on the first step of hemostasis, by improving platelet adhesiveness and restoring capillary resistance. Copyright 2002 Elsevier Science Ltd.

  13. Neurotrophins promote revascularization by local recruitment of TrkB+ endothelial cells and systemic mobilization of hematopoietic progenitors

    Science.gov (United States)

    Kermani, Pouneh; Rafii, Dahlia; Jin, David K.; Whitlock, Paul; Schaffer, Wendy; Chiang, Anne; Vincent, Loic; Friedrich, Matthias; Shido, Koji; Hackett, Neil R.; Crystal, Ronald G.; Rafii, Shahin; Hempstead, Barbara L.

    2005-01-01

    The neurotrophin brain-derived neurotrophic factor (BDNF) is required for the maintenance of cardiac vessel wall stability during embryonic development through direct angiogenic actions on endothelial cells expressing the tropomysin receptor kinase B (TrkB). However, the role of BDNF and a related neurotrophin ligand, neurotrophin-4 (NT-4), in the regulation of revascularization of the adult tissues is unknown. To study the potential angiogenic capacity of BDNF in mediating the neovascularization of ischemic and non-ischemic adult mouse tissues, we utilized a hindlimb ischemia and a subcutaneous Matrigel model. Recruitment of endothelial cells and promotion of channel formation within the Matrigel plug by BDNF and NT-4 was comparable to that induced by VEGF-A. The introduction of BDNF into non-ischemic ears or ischemic limbs induced neoangiogenesis, with a 2-fold increase in the capillary density. Remarkably, treatment with BDNF progressively increased blood flow in the ischemic limb over 21 days, similar to treatment with VEGF-A. The mechanism by which BDNF enhances capillary formation is mediated in part through local activation of the TrkB receptor and also by recruitment of Sca-1+CD11b+ pro-angiogenic hematopoietic cells. BDNF induces a potent direct chemokinetic action on subsets of marrow-derived Sca-1+ hematopoietic cells co-expressing TrkB. These studies suggest that local regional delivery of BDNF may provide a novel mechanism for inducing neoangiogenesis through both direct actions on local TrkB-expressing endothelial cells in skeletal muscle and recruitment of specific subsets of TrkB+ bone marrow–derived hematopoietic cells to provide peri-endothelial support for the newly formed vessels. PMID:15765148

  14. Arginase 1: an unexpected mediator of pulmonary capillary barrier dysfunction in models of acute lung injury

    Directory of Open Access Journals (Sweden)

    Rudolf eLucas

    2013-08-01

    Full Text Available The integrity of epithelial and endothelial barriers in the lower airspaces of the lungs has to be tightly regulated, in order to prevent leakage and to assure efficient gas exchange between the alveoli and capillaries. Both G- and G+ bacterial toxins, such as LPS and pneumolysin, respectively, can be released in high concentrations within the pulmonary compartments upon antibiotic treatment of patients suffering from acute respiratory distress syndrome (ARDS or severe pneumonia. These toxins are able to impair endothelial barrier function, either directly, or indirectly, by induction of pro-inflammatory mediators and neutrophil sequestration. Toxin-induced endothelial hyperpermeability can involve myosin light chain phosphorylation and/or microtubule rearrangement. Endothelial nitric oxide synthase (eNOS was proposed to be a guardian of basal barrier function, since eNOS knock-out mice display an impaired expression of inter-endothelial junction proteins and as such an increased vascular permeability, as compared to wild type mice. The enzyme arginase, the activity of which can be regulated by the redox status of the cell, exists in two isoforms - arginase 1 (cytosolic and arginase 2 (mitochondrial - both of which can be expressed in lung microvascular endothelial cells. Upon activation, arginase competes with eNOS for the substrate L-arginine, as such impairing eNOS-dependent NO generation and promoting ROS generation by the enzyme. This mini-review will discuss recent findings regarding the interaction between bacterial toxins and arginase during acute lung injury and will as such address the role of arginase in bacterial toxin-induced pulmonary endothelial barrier dysfunction.

  15. Osteogenic stimulatory conditions enhance growth and maturation of endothelial cell microvascular networks in culture with mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Torbjorn O Pedersen

    2012-12-01

    Full Text Available To optimize culture conditions for in vitro prevascularization of tissue-engineered bone constructs, the development of organotypic blood vessels under osteogenic stimulatory conditions (OM was investigated. Coculture of endothelial cells and mesenchymal stem cells was used to assess proangiogenic effects of mesenchymal stem cells on endothelial cells. Four different culture conditions were evaluated for their effect on development of microvascular endothelial cell networks. Mineralization, deposition of extracellular matrix, and perivascular gene expression were studied in OM. After 3 days, endothelial cells established elongated capillary-like networks, and upregulated expression of vascular markers was seen. After 15 days, all parameters evaluated were significantly increased for cultures in OM. Mature networks developed in OM presented lumens enveloped by basement membrane-like collagen IV, with obvious mineralization and upregulated perivascular gene expression from mesenchymal stem cells. Our results suggest osteogenic stimulatory conditions to be appropriate for in vitro development of vascularized bone implants for tissue engineering.

  16. Biocompatibility of Poly-ε-caprolactone-hydroxyapatite composite on mouse bone marrow-derived osteoblasts and endothelial cells

    Directory of Open Access Journals (Sweden)

    Wooley Paul H

    2009-02-01

    Full Text Available Abstract Background Tissue-engineered bone may be developed by seeding the cells capable of both osteogenesis and vascularization on biocompatible composite scaffolds. The current study investigated the performance of mice bone marrow-derived osteogenic cells and endothelial cells as seeded on hydroxyapatite (HA and poly-ε-caprolactone (PCL composite scaffolds. Methods Mononuclear cells were induced to osteoblasts and endothelial cells respectively, which were defined by the expression of osteocalcin, alkaline phosphatase (ALP, and deposits of calcium-containing crystal for osteoblasts, or by the expression of vascular endothelial growth factor receptor-2 (VEGFR-2 and von Willebrand factor (vWF, and the formation of a capillary network in Matrigel™ for endothelial cells. Both types of cell were seeded respectively on PCL-HA scaffolds at HA to PCL weight ratio of 1:1, 1:4, or 0:1 and were evaluated using scanning electron microscopy, ALP activity (of osteoblasts and nitric oxide production (of endothelial cells plus the assessment of cell viability. Results The results indicated that HA led to a positive stimulation of osteoblasts viability and ALP activity, while HA showed less influence on endothelial cells viability. An elevated nitric oxide production of endothelial cells was observed in HA-containing group. Conclusion Supplement of HA into PCL improved biocompatible for bone marrow-derived osteoblasts and endothelial cells. The PCL-HA composite integrating with two types of cells may provide a useful system for tissue-engineered bone grafts with vascularization.

  17. Decellularized matrix from tumorigenic human mesenchymal stem cells promotes neovascularization with galectin-1 dependent endothelial interaction.

    Directory of Open Access Journals (Sweden)

    Jorge S Burns

    Full Text Available BACKGROUND: Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC strain (hMSC-TERT20 immortalized by retroviral vector mediated human telomerase (hTERT gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+ and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. CONCLUSIONS: Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1

  18. Decellularized Matrix from Tumorigenic Human Mesenchymal Stem Cells Promotes Neovascularization with Galectin-1 Dependent Endothelial Interaction

    Science.gov (United States)

    Burns, Jorge S.; Kristiansen, Malthe; Kristensen, Lars P.; Larsen, Kenneth H.; Nielsen, Maria O.; Christiansen, Helle; Nehlin, Jan; Andersen, Jens S.; Kassem, Moustapha

    2011-01-01

    Background Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC) strain (hMSC-TERT20) immortalized by retroviral vector mediated human telomerase (hTERT) gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+) and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. Methodology/Principal Findings Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. Conclusions Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1 expression was

  19. Vildagliptin stimulates endothelial cell network formation and ischemia-induced revascularization via an endothelial nitric-oxide synthase-dependent mechanism.

    Science.gov (United States)

    Ishii, Masakazu; Shibata, Rei; Kondo, Kazuhisa; Kambara, Takahiro; Shimizu, Yuuki; Tanigawa, Tohru; Bando, Yasuko K; Nishimura, Masahiro; Ouchi, Noriyuki; Murohara, Toyoaki

    2014-09-26

    Dipeptidyl peptidase-4 inhibitors are known to lower glucose levels and are also beneficial in the management of cardiovascular disease. Here, we investigated whether a dipeptidyl peptidase-4 inhibitor, vildagliptin, modulates endothelial cell network formation and revascularization processes in vitro and in vivo. Treatment with vildagliptin enhanced blood flow recovery and capillary density in the ischemic limbs of wild-type mice, with accompanying increases in phosphorylation of Akt and endothelial nitric-oxide synthase (eNOS). In contrast to wild-type mice, treatment with vildagliptin did not improve blood flow in ischemic muscles of eNOS-deficient mice. Treatment with vildagliptin increased the levels of glucagon-like peptide-1 (GLP-1) and adiponectin, which have protective effects on the vasculature. Both vildagliptin and GLP-1 increased the differentiation of cultured human umbilical vein endothelial cells (HUVECs) into vascular-like structures, although vildagliptin was less effective than GLP-1. GLP-1 and vildagliptin also stimulated the phosphorylation of Akt and eNOS in HUVECs. Pretreatment with a PI3 kinase or NOS inhibitor blocked the stimulatory effects of both vildagliptin and GLP-1 on HUVEC differentiation. Furthermore, treatment with vildagliptin only partially increased the limb flow of ischemic muscle in adiponectin-deficient mice in vivo. GLP-1, but not vildagliptin, significantly increased adiponectin expression in differentiated 3T3-L1 adipocytes in vitro. These data indicate that vildagliptin promotes endothelial cell function via eNOS signaling, an effect that may be mediated by both GLP-1-dependent and GLP-1-independent mechanisms. The beneficial activity of GLP-1 for revascularization may also be partially mediated by its ability to increase adiponectin production. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Microvascular pericytes in healthy and diseased kidneys

    Science.gov (United States)

    Pan, Szu-Yu; Chang, Yu-Ting; Lin, Shuei-Liong

    2014-01-01

    Pericytes are interstitial mesenchymal cells found in many major organs. In the kidney, microvascular pericytes are defined anatomically as extensively branched, collagen-producing cells in close contact with endothelial cells. Although many molecular markers have been proposed, none of them can identify the pericytes with satisfactory specificity or sensitivity. The roles of microvascular pericytes in kidneys were poorly understood in the past. Recently, by using genetic lineage tracing to label collagen-producing cells or mesenchymal cells, the elusive characteristics of the pericytes have been illuminated. The purpose of this article is to review recent advances in the understanding of microvascular pericytes in the kidneys. In healthy kidney, the pericytes are found to take part in the maintenance of microvascular stability. Detachment of the pericytes from the microvasculature and loss of the close contact with endothelial cells have been observed during renal insult. Renal microvascular pericytes have been shown to be the major source of scar-forming myofibroblasts in fibrogenic kidney disease. Targeting the crosstalk between pericytes and neighboring endothelial cells or tubular epithelial cells may inhibit the pericyte–myofibroblast transition, prevent peritubular capillary rarefaction, and attenuate renal fibrosis. In addition, renal pericytes deserve attention for their potential to produce erythropoietin in healthy kidneys as pericytes stand in the front line, sensing the change of oxygenation and hemoglobin concentration. Further delineation of the mechanisms underlying the reduced erythropoietin production occurring during pericyte–myofibroblast transition may be promising for the development of new treatment strategies for anemia in chronic kidney disease. PMID:24465134

  1. Astrocyte–endothelial interactions and blood–brain barrier permeability*

    Science.gov (United States)

    Abbott, N Joan

    2002-01-01

    The blood–brain barrier (BBB) is formed by brain endothelial cells lining the cerebral microvasculature, and is an important mechanism for protecting the brain from fluctuations in plasma composition, and from circulating agents such as neurotransmitters and xenobiotics capable of disturbing neural function. The barrier also plays an important role in the homeostatic regulation of the brain microenvironment necessary for the stable and co-ordinated activity of neurones. The BBB phenotype develops under the influence of associated brain cells, especially astrocytic glia, and consists of more complex tight junctions than in other capillary endothelia, and a number of specific transport and enzyme systems which regulate molecular traffic across the endothelial cells. Transporters characteristic of the BBB phenotype include both uptake mechanisms (e.g. GLUT-1 glucose carrier, L1 amino acid transporter) and efflux transporters (e.g. P-glycoprotein). In addition to a role in long-term barrier induction and maintenance, astrocytes and other cells can release chemical factors that modulate endothelial permeability over a time-scale of seconds to minutes. Cell culture models, both primary and cell lines, have been used to investigate aspects of barrier induction and modulation. Conditioned medium taken from growing glial cells can reproduce some of the inductive effects, evidence for involvement of diffusible factors. However, for some features of endothelial differentiation and induction, the extracellular matrix plays an important role. Several candidate molecules have been identified, capable of mimicking aspects of glial-mediated barrier induction of brain endothelium; these include TGFβ, GDNF, bFGF, IL-6 and steroids. In addition, factors secreted by brain endothelial cells including leukaemia inhibitory factor (LIF) have been shown to induce astrocytic differentiation. Thus endothelium and astrocytes are involved in two-way induction. Short-term modulation of brain

  2. Slope wavenumber spectrum models of capillary and capillary-gravity waves

    Institute of Scientific and Technical Information of China (English)

    贾永君; 张杰; 王岩峰

    2010-01-01

    Capillary and capillary-gravity waves possess a random character, and the slope wavenumber spectra of them can be used to represent mean distributions of wave energy with respect to spatial scale of variability. But simple and practical models of the slope wavenumber spectra have not been put forward so far. In this article, we address the accurate definition of the slope wavenumber spectra of water surface capillary and capillary-gravity waves. By combining the existing slope wavenumber models and using th...

  3. Upcyte® Microvascular Endothelial Cells Repopulate Decellularized Scaffold

    Science.gov (United States)

    Dally, Iris; Hartmann, Nadja; Münst, Bernhard; Braspenning, Joris; Walles, Heike

    2013-01-01

    A general problem in tissue engineering is the poor and insufficient blood supply to guarantee tissue cell survival as well as physiological tissue function. To address this limitation, we have developed an in vitro vascularization model in which a decellularized porcine small bowl segment, representing a capillary network within a collagen matrix (biological vascularized scaffold [BioVaSc]), is reseeded with microvascular endothelial cells (mvECs). However, since the supply of mvECs is limited, in general, and as these cells rapidly dedifferentiate, we have applied a novel technology, which allows the generation of large batches of quasi-primary cells with the ability to proliferate, whilst maintaining their differentiated functionality. These so called upcyte mvECs grew for an additional 15 population doublings (PDs) compared to primary cells. Upcyte mvECs retained endothelial characteristics, such as von Willebrandt Factor (vWF), CD31 and endothelial nitric oxide synthase (eNOS) expression, as well as positive Ulex europaeus agglutinin I staining. Upcyte mvECs also retained biological functionality such as tube formation, cell migration, and low density lipoprotein (LDL) uptake, which were still evident after PD27. Initial experiments using MTT and Live/Dead staining indicate that upcyte mvECs repopulate the BioVaSc Scaffold. As with conventional cultures, these cells also express key endothelial molecules (vWF, CD31, and eNOS) in a custom-made bioreactor system even after a prolonged period of 14 days. The combination of upcyte mvECs and the BioVaSc represents a novel and promising approach toward vascularizing bioreactor models which can better reflect organs, such as the liver. PMID:22799502

  4. Quantification of local matrix deformations and mechanical properties during capillary morphogenesis in 3D†‡

    Science.gov (United States)

    Kniazeva, Ekaterina; Weidling, John W.; Singh, Rahul; Botvinick, Elliot L.; Digman, Michelle A.; Gratton, Enrico

    2013-01-01

    Reciprocal mechanical interactions between cells and the extracellular matrix (ECM) are thought to play important instructive roles in branching morphogenesis. However, most studies to date have failed to characterize these interactions on a length scale relevant to cells, especially in three-dimensional (3D) matrices. Here we utilized two complementary methods, spatio-temporal image correlation spectroscopy (STICS) and laser optical tweezers-based active microrheology (AMR), to quantify endothelial cell (EC)-mediated deformations of individual ECM elements and the local ECM mechanical properties, respectively, during the process of capillary morphogenesis in a 3D cell culture model. In experiments in which the ECM density was systematically varied, STICS revealed that the rate at which ECs deformed individual ECM fibers on the microscale positively correlated with capillary sprouting on the macroscale. ECs expressing constitutively active V14-RhoA displaced individual matrix fibers at significantly faster rates and displayed enhanced capillary sprouting relative to wild-type cells, while those expressing dominant-negative N19-RhoA behaved in an opposite fashion. In parallel, AMR revealed a local stiffening of the ECM proximal to the tips of sprouting ECs. By quantifying the dynamic physical properties of the cell-ECM interface in both space and time, we identified a correlation linking ECM deformation rates and local ECM stiffening at the microscale with capillary morphogenesis at the macroscale. PMID:22281872

  5. Effects of lead and mercury on histamine uptake by glial and endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Huszti, Z. [Semmelweis Univ. of Medicine, Dept. of Pharmacodynamics, Budapest (Hungary); Balogh, I. [Semmelweis Univ. of Medicine, Forensic Medicine, Budapest (Hungary)

    1995-06-01

    The effects of lead and mercury on [{sup 3}H]-histamine uptake by cultured astroglial and endothelial cells of rat brain were studied. Experimental data showed that both metal ions inhibited the uptake in both cell types of concentrations as low as 1-10 {mu}M. The effects were consistent with non/competitive inhibitions. With either lead or mercury exposure, the inhibition of the uptake was greater in astroglial than in cerebral endothelial cells. Contrary to the above finding, 100 {mu}M of mercuric chloride produced stimulation of histamine uptake and this stimulation was much more pronounced in cultured cerebral endothelial cells than in astroglial cells. Inhibition of [{sup 3}H]-histamine uptake by lead acetate and mercuric chloride was considered to be association with a loss of the transmembrane Na{sup +} and/or K{sup +} gradient while stimulation of the uptake by high concentration of mercury might be related to a direct effect on histamine transporter. It is note-worthy, that cultured astroglial cells, derived from neonatal rat brain, are much more sensitive to the toxic effects of these heavy metal ions than cultured endothelial cells derived from the brain capillaries often same species of animals. (au) 18 refs.

  6. Hypoxia upregulates Bcl-2 expression and suppresses interferon-gamma induced antiangiogenic activity in human tumor derived endothelial cells.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    BACKGROUND: Hypoxia in solid tumors potentially stimulates angiogenesis by promoting vascular endothelial growth factor (VEGF) production and upregulating VEGF receptor expression. However, it is unknown whether hypoxia can modulate the effect of anti-angiogenic treatment on tumor-derived endothelium. METHODS: Human tumor-derived endothelial cells (HTDEC) were freshly isolated from surgically removed human colorectal tumors by collagenase\\/DNase digestion and Percol gradient sedimentation. Cell proliferation was assessed by measuring BrdU incorporation, and capillary tube formation was measured using Matrigel. Cell apoptosis was assessed by flow cytometry and ELISA, and Bcl-2 expression was detected by Western blot analysis. RESULTS: Under aerobic culture conditions (5% CO2 plus 21% O2) HTDEC expressed less Bcl-2 and were more susceptible to IFN-gamma-induced apoptosis with significant reductions in both cell proliferation and capillary tube formation, when compared with normal human macrovascular and microvascular EC. Following exposure of HTDEC to hypoxia (5% CO2 plus 2% O2), IFN-gamma-induced cell apoptosis, and antiangiogenic activity (i.e. an inhibition in cell proliferation and capillary tube formation) in HTDEC were markedly attenuated. This finding correlated with hypoxia-induced upregulation of Bcl-2 expression in HTDEC. CONCLUSIONS: These results indicate that hypoxia can protect HTDEC against IFN-gamma-mediated cell death and antiangiogenic activity, and suggest that improvement of tumor oxygenation may potentiate the efficacy of anti-cancer therapies specifically targeting the inhibition of tumor angiogenesis.

  7. Endothelial surface glycocalyx can regulate flow-induced nitric oxide production in microvessels in vivo.

    Directory of Open Access Journals (Sweden)

    Wanyi Yen

    Full Text Available Due to its unique location, the endothelial surface glycocalyx (ESG at the luminal side of the microvessel wall may serve as a mechano-sensor and transducer of blood flow and thus regulate endothelial functions. To examine this role of the ESG, we used fluorescence microscopy to measure nitric oxide (NO production in post-capillary venules and arterioles of rat mesentery under reduced (low and normal (high flow conditions, with and without enzyme pretreatment to remove heparan sulfate (HS of the ESG and in the presence of an endothelial nitric oxide synthase (eNOS inhibitor, NG-monomethyl-L-arginine (L-NMMA. Rats (SD, 250-300 g were anesthetized. The mesentery was gently taken out from the abdominal cavity and arranged on the surface of a glass coverslip for the measurement. An individual post-capillary venule or arteriole was cannulated and loaded for 45 min with 5 μM 4, 5-Diaminofluorescein diacetate, a membrane permeable fluorescent indictor for NO, then the NO production was measured for ~10 min under a low flow (~300 μm/s and for ~60 min under a high flow (~1000 μm/s. In the 15 min after switching to the high flow, DAF-2-NO fluorescence intensity increased to 1.27-fold of its baseline, DAF-2-NO continuously increased under the high flow, to 1.53-fold of its baseline in 60 min. Inhibition of eNOS by 1 mM L-NMMA attenuated the flow-induced NO production to 1.13-fold in 15 min and 1.30-fold of its baseline in 60 min, respectively. In contrast, no significant increase in NO production was observed after switching to the high flow for 60 min when 1 h pretreatment with 50 mU/mL heparanase III to degrade the ESG was applied. Similar NO production was observed in arterioles under low and high flows and under eNOS inhibition. Our results suggest that ESG participates in endothelial cell mechanosensing and transduction through its heparan sulfate to activate eNOS.

  8. Macrophages commit postnatal endothelium-derived progenitors to angiogenesis and restrict endothelial to mesenchymal transition during muscle regeneration.

    Science.gov (United States)

    Zordan, P; Rigamonti, E; Freudenberg, K; Conti, V; Azzoni, E; Rovere-Querini, P; Brunelli, S

    2014-01-30

    The damage of the skeletal muscle prompts a complex and coordinated response that involves the interactions of many different cell populations and promotes inflammation, vascular remodeling and finally muscle regeneration. Muscle disorders exist in which the irreversible loss of tissue integrity and function is linked to defective neo-angiogenesis with persistence of tissue necrosis and inflammation. Here we show that macrophages (MPs) are necessary for efficient vascular remodeling in the injured muscle. In particular, MPs sustain the differentiation of endothelial-derived progenitors to contribute to neo-capillary formation, by secreting pro-angiogenic growth factors. When phagocyte infiltration is compromised endothelial-derived progenitors undergo a significant endothelial to mesenchymal transition (EndoMT), possibly triggered by the activation of transforming growth factor-β/bone morphogenetic protein signaling, collagen accumulates and the muscle is replaced by fibrotic tissue. Our findings provide new insights in EndoMT in the adult skeletal muscle, and suggest that endothelial cells in the skeletal muscle may represent a new target for therapeutic intervention in fibrotic diseases.

  9. Physiologic upper limits of pore size of different blood capillary types and another perspective on the dual pore theory of microvascular permeability.

    Science.gov (United States)

    Sarin, Hemant

    2010-08-11

    . Non-sinusoidal blood capillaries were further sub-classified as non-fenestrated or fenestrated based on the absence or presence of endothelial cells with fenestrations. The sinusoidal blood capillaries of the liver, myeloid (red) bone marrow, and spleen were sub-classified as reticuloendothelial or non-reticuloendothelial based on the phago-endocytic capacity of the endothelial cells. The physiologic upper limit of pore size for transvascular flow across capillary walls of non-sinusoidal non-fenestrated blood capillaries is less than 1 nm for those with interendothelial cell clefts lined with zona occludens junctions (i.e. brain and spinal cord), and approximately 5 nm for those with clefts lined with macula occludens junctions (i.e. skeletal muscle). The physiologic upper limit of pore size for transvascular flow across the capillary walls of non-sinusoidal fenestrated blood capillaries with diaphragmed fenestrae ranges between 6 and 12 nm (i.e. exocrine and endocrine glands); whereas, the physiologic upper limit of pore size for transvascular flow across the capillary walls of non-sinusoidal fenestrated capillaries with open 'non-diaphragmed' fenestrae is approximately 15 nm (kidney glomerulus). In the case of the sinusoidal reticuloendothelial blood capillaries of myeloid bone marrow, the transvascular transport of non-endogenous macromolecules larger than 5 nm into the bone marrow interstitial space takes place via reticuloendothelial cell-mediated phago-endocytosis and transvascular release, which is the case for systemic bone marrow imaging agents as large as 60 nm in diameter. The physiologic upper limit of pore size in the capillary walls of most non-sinusoidal blood capillaries to the transcapillary passage of lipid-insoluble endogenous and non-endogenous macromolecules ranges between 5 and 12 nm. Therefore, macromolecules larger than the physiologic upper limits of pore size in the non-sinusoidal blood capillary types generally do not accumulate within the

  10. Downregulation of B-myb promotes senescence via the ROS-mediated p53/p21 pathway, in vascular endothelial cells.

    Science.gov (United States)

    Zhou, Zhihui; Yin, Yanlin; Chang, Qun; Sun, Guanqun; Lin, Jiahui; Dai, Yalei

    2017-04-01

    To reveal whether B-myb is involved in preventing senescence of vascular endothelial cells, and if so, to identify possible mechanisms for it. C57/BL6 male mice and primary human aortic endothelial cells (HAECs) were used. Bleomycin was applied to induce stress-related premature senescence. B-myb knockdown was achieved using an siRNA technique and cell senescence was assessed using the senescence-associated β-galactosidase (SA-β-gal) assay. Intracellular reactive oxygen species (ROS) production was analysed using an ROS assay kit and cell proliferation was evaluated using KFluor488 EdU kit. Capillary tube network formation was determined by Matrigel assay. Expressions of mRNA and protein levels were detected by real-time PCR and western blotting. B-myb expression significantly decreased, while p53 and p21 expressions increased in the aortas of aged mice. This expression pattern was also found in replicative senescent HAECs and senescent HAECs induced by bleomycin. B-myb knockdown resulted in upregulation of p22 phox , ROS accumulation and cell senescence of HAECs. Downregulation of B-myb significantly inhibited cell proliferation and capillary tube network formation and activated the p53/p21 signalling pathway. Blocking ROS production or inhibiting p53 activation remarkably attenuated SA-β-gal activity and delayed cell senescence induced by B-myb-silencing. Downregulation of B-myb induced senescence by upregulation of p22 phox and activation of the ROS/p53/p21 pathway, in our vascular endothelial cells, suggesting that B-myb may be a novel candidate for regulating cell senescence to protect against endothelial senescence-related cardiovascular diseases. © 2016 John Wiley & Sons Ltd.

  11. Quantification of local matrix deformations and mechanical properties during capillary morphogenesis in 3D.

    Science.gov (United States)

    Kniazeva, Ekaterina; Weidling, John W; Singh, Rahul; Botvinick, Elliot L; Digman, Michelle A; Gratton, Enrico; Putnam, Andrew J

    2012-04-01

    Reciprocal mechanical interactions between cells and the extracellular matrix (ECM) are thought to play important instructive roles in branching morphogenesis. However, most studies to date have failed to characterize these interactions on a length scale relevant to cells, especially in three-dimensional (3D) matrices. Here we utilized two complementary methods, spatio-temporal image correlation spectroscopy (STICS) and laser optical tweezers-based active microrheology (AMR), to quantify endothelial cell (EC)-mediated deformations of individual ECM elements and the local ECM mechanical properties, respectively, during the process of capillary morphogenesis in a 3D cell culture model. In experiments in which the ECM density was systematically varied, STICS revealed that the rate at which ECs deformed individual ECM fibers on the microscale positively correlated with capillary sprouting on the macroscale. ECs expressing constitutively active V14-RhoA displaced individual matrix fibers at significantly faster rates and displayed enhanced capillary sprouting relative to wild-type cells, while those expressing dominant-negative N19-RhoA behaved in an opposite fashion. In parallel, AMR revealed a local stiffening of the ECM proximal to the tips of sprouting ECs. By quantifying the dynamic physical properties of the cell-ECM interface in both space and time, we identified a correlation linking ECM deformation rates and local ECM stiffening at the microscale with capillary morphogenesis at the macroscale. This journal is © The Royal Society of Chemistry 2012

  12. Angiogenesis in mucous retention cyst: a human in vivo-like model of endothelial cell differentiation in mucous substrate.

    Science.gov (United States)

    Swelam, Wael; Ida-Yonemochi, Hiroko; Saku, Takashi

    2005-01-01

    Mucous retention cysts contain a mucous pool in the lumina, in which pure angiogenic processes are occasionally observed. By using this unique human material, our aim was to understand the in vivo angiogenic process. Fifteen surgical tissue samples of mucous retention cysts of the lip were examined for expression of vascular endothelial markers and extracellular matrix molecules by immunohistochemistry and in situ hybridization (ISH). Endothelial cells forming new vascular channels showed immunopositivities for CD31, CD34, vascular endothelial growth factor (VEGF), and von Willebrand factor (vWF). These newly formed capillaries were surrounded by tenascin-positive matrices and further by a dense infiltration of CD68-positive cells with foamy to epitheloid appearances. Some of these cells were simultaneously positive for CD34, VEGF, and one of its receptors, Flk-1, and they showed definite mRNA as well as protein signals for tenascin. In addition, these cells often tended to be aligned, which suggested tubule formation. The results suggest that monocyte/macrophage lineage cells are a major source for endothelial cells at least in mucous retention cysts and that tenascin produced by those cells plays an important role in differentiation of endothelial cells.

  13. Differential gene expression analysis of tubule forming and non-tubule forming endothelial cells: CDC42GAP as a counter-regulator in tubule formation

    NARCIS (Netherlands)

    Engelse, M.A.; Laurens, N.; Verloop, R.E.; Koolwijk, P.; Hinsbergh, V.W.M. van

    2008-01-01

    The formation of new tubular structures from a quiescent endothelial lining is one of the hallmarks of sprouting angiogenesis. This process can be mimicked in vitro by inducing capillary-like tubular structures in a three-dimensional (3D) fibrin matrix. We aimed to analyze the differential mRNA

  14. Gas-Filled Capillary Model

    International Nuclear Information System (INIS)

    Steinhauer, L. C.; Kimura, W. D.

    2006-01-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration -- Laser Wakefield (STELLA-LW) experiment

  15. Multiple capillary biochemical analyzer

    Science.gov (United States)

    Dovichi, N.J.; Zhang, J.Z.

    1995-08-08

    A multiple capillary analyzer allows detection of light from multiple capillaries with a reduced number of interfaces through which light must pass in detecting light emitted from a sample being analyzed, using a modified sheath flow cuvette. A linear or rectangular array of capillaries is introduced into a rectangular flow chamber. Sheath fluid draws individual sample streams through the cuvette. The capillaries are closely and evenly spaced and held by a transparent retainer in a fixed position in relation to an optical detection system. Collimated sample excitation radiation is applied simultaneously across the ends of the capillaries in the retainer. Light emitted from the excited sample is detected by the optical detection system. The retainer is provided by a transparent chamber having inward slanting end walls. The capillaries are wedged into the chamber. One sideways dimension of the chamber is equal to the diameter of the capillaries and one end to end dimension varies from, at the top of the chamber, slightly greater than the sum of the diameters of the capillaries to, at the bottom of the chamber, slightly smaller than the sum of the diameters of the capillaries. The optical system utilizes optic fibers to deliver light to individual photodetectors, one for each capillary tube. A filter or wavelength division demultiplexer may be used for isolating fluorescence at particular bands. 21 figs.

  16. An In Vitro Study of Differentiation of Hematopoietic Cells to Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Qi Ru Wang

    2011-01-01

    medium (ECCM. BM-EPCs were characterized in terms of phenotype, lineage potential, and their functional properties. Endothelial cell colonies derived from BM-EPC were cultured with ECCM for 3 months. Cultured EPC colony cells expressed endothelial cell markers and formed the capillary-like network in vitro. EPC colony cells expressed differential proliferative capacity; some of the colonies exhibited a high proliferative potential (HPP capacity up to 20 population doublings. More importantly, these HPP-EPCs expressed hematopoietic marker CD45, exhibited endocytic activities, and preserved some of the myeloid cell activity. In addition, the HPP-EPCs secrete various growth factors including VEGF and GM-CSF into the culture medium. The results demonstrate that these EPCs were primarily derived from hematopoietic origin of early precursor cells and maintained high proliferative potential capacity, a feature with a significant potential in the application of cell therapy in ischemic diseases.

  17. Low intensity shear stress increases endothelial ELR+ CXC chemokine production via a focal adhesion kinase-p38{beta} MAPK-NF-{kappa}B pathway.

    Science.gov (United States)

    Shaik, Sadiq S; Soltau, Thomas D; Chaturvedi, Gaurav; Totapally, Balagangadhar; Hagood, James S; Andrews, William W; Athar, Mohammad; Voitenok, Nikolai N; Killingsworth, Cheryl R; Patel, Rakesh P; Fallon, Michael B; Maheshwari, Akhil

    2009-02-27

    CXC chemokines with a glutamate-leucine-arginine (ELR) tripeptide motif (ELR(+) CXC chemokines) play an important role in leukocyte trafficking into the tissues. For reasons that are not well elucidated, circulating leukocytes are recruited into the tissues mainly in small vessels such as capillaries and venules. Because ELR(+) CXC chemokines are important mediators of endothelial-leukocyte interaction, we compared chemokine expression by microvascular and aortic endothelium to investigate whether differences in chemokine expression by various endothelial types could, at least partially, explain the microvascular localization of endothelial-leukocyte interaction. Both in vitro and in vivo models indicate that ELR(+) CXC chemokine expression is higher in microvascular endothelium than in aortic endothelial cells. These differences can be explained on the basis of the preferential activation of endothelial chemokine production by low intensity shear stress. Low shear activated endothelial ELR(+) CXC chemokine production via cell surface heparan sulfates, beta(3)-integrins, focal adhesion kinase, the mitogen-activated protein kinase p38beta, mitogen- and stress-associated protein kinase-1, and the transcription factor.

  18. Capillaries for use in a multiplexed capillary electrophoresis system

    Science.gov (United States)

    Yeung, E.S.; Chang, H.T.; Fung, E.N.

    1997-12-09

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  19. Angiotensin II Evokes Angiogenic Signals within Skeletal Muscle through Co-ordinated Effects on Skeletal Myocytes and Endothelial Cells

    Science.gov (United States)

    Gorman, Jennifer L.; Liu, Sammy T. K.; Slopack, Dara; Shariati, Khashayar; Hasanee, Adam; Olenich, Sara; Olfert, I. Mark; Haas, Tara L.

    2014-01-01

    Skeletal muscle overload induces the expression of angiogenic factors such as vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-2, leading to new capillary growth. We found that the overload-induced increase in angiogenesis, as well as increases in VEGF, MMP-2 and MT1-MMP transcripts were abrogated in muscle VEGF KO mice, highlighting the critical role of myocyte-derived VEGF in controlling this process. The upstream mediators that contribute to overload-induced expression of VEGF have yet to be ascertained. We found that muscle overload increased angiotensinogen expression, a precursor of angiotensin (Ang) II, and that Ang II signaling played an important role in basal VEGF production in C2C12 cells. Furthermore, matrix-bound VEGF released from myoblasts induced the activation of endothelial cells, as evidenced by elevated endothelial cell phospho-p38 levels. We also found that exogenous Ang II elevates VEGF expression, as well as MMP-2 transcript levels in C2C12 myotubes. Interestingly, these responses also were observed in skeletal muscle endothelial cells in response to Ang II treatment, indicating that these cells also can respond directly to the stimulus. The involvement of Ang II in muscle overload-induced angiogenesis was assessed. We found that blockade of AT1R-dependent Ang II signaling using losartan did not attenuate capillary growth. Surprisingly, increased levels of VEGF protein were detected in overloaded muscle from losartan-treated rats. Similarly, we observed elevated VEGF production in cultured endothelial cells treated with losartan alone or in combination with Ang II. These studies conclusively establish the requirement for muscle derived VEGF in overload-induced angiogenesis and highlight a role for Ang II in basal VEGF production in skeletal muscle. However, while Ang II signaling is activated following overload and plays a role in muscle VEGF production, inhibition of this pathway is not sufficient to halt overload

  20. Enhanced glycosylation of factor VIII:C in capillary endothelial cells following β-adrenoreceptor stimulation is not due to increased sugar transport

    International Nuclear Information System (INIS)

    Tavarez-Pagan, J.J.; Oliveira, C.M.; Banerjee, D.K.

    1990-01-01

    Factor VIII:C (Antihemophilia Factor A) in capillary endothelial cells from bovine adrenal medulla found to contain M r 200,000 and M r 46,000 dalton protein species when analyzed by SDS-PAGE under reduced condition. But the secretory FVIII:C under non-reduced condition gave rise to a protein of M r 270,000 dalton indicating that the heavy and light chains are held together by S-S bridge. Upon stimulation of these cells with β-agonist, isoproterenol (10 -7 M), a 2-fold increase in the ratio of [ 3 H]-mannose to [ 35 S]-methionine incorporation in immunoprecipitated FVIII:C was observed. In order to understand the molecular mechanism of this increase, a detail study of sugar transport was carried out. The transport of 2-deoxy-D-[ 3 H]-glucose in these cells was time and temperature dependent. Furthermore, inhibition of 2-deoxy-D-[ 3 H]-glucose uptake by cytochalasin B strongly supported for a carrier mediated process. However, when the transport studies were conducted in the presence of isoproterenol at 10 -5 M or 10 -7 M or 8 Br-cAMP (2 mM) no increase was observed. The kinetic studies indicated that the K m and V max for 2 deoxy-D-[ 3 H]-glucose were 0.24 mM and 0.88 nmol/mg protein/minute, respectively under normal conditions but these values were changed to 0.37 mM and 0.69 nmol/mg protein/minute when stimulated with isoproterenol (10 -7 M)

  1. Contact-mediated and humoral communication between vascular endothelial and smooth muscle cells in vitro

    International Nuclear Information System (INIS)

    Davies, P.F.

    1986-01-01

    Vascular endothelial cells (EC) and smooth muscle cells (SMC) co-exist in close apposition to each other in all blood vessels except capillaries. Investigations of the metabolic interactions that may occur between these cells are essential to an understanding of vascular homeostasis and the pathogenesis of atherosclerosis. The authors have developed two in vitro models of co-temporal vascular cell communication. The first facilitates reversible microcarrier-mediated gap junctional communication between EC and SMC monolayers. When either EC or SMC were prelabelled with 3 H-uridine, intracellular nucleotide rapidly transferred across the region of heterocellular attachment to the complementary cell population. Cytoplasmic continuity between EC and SMC allowed metabolic cooperation via ions and small molecules (<1.5 KD). Thus, vascular reactivity, particularly in the microcirculation where myoendothelial gap junctions have been observed, may involve cytoplasmic second messengers transported from EC to SMC. In the second model, humoral communication was established between separated cultures of EC and SMC which shared the same culture medium. Endothelial-specific stimulation of SMC growth and lipoprotein metabolism via soluble factors was demonstrated. Two mechanisms of stimulation of SMC lipoprotein metabolism were identified; one endothelial derived mitogen-dependent, the other mitogen-independent which was mediated via low molecular weight endothelial cell products

  2. Evidence for thyroxine transport by the lung and heart capillary endothelium

    International Nuclear Information System (INIS)

    Heltianu, C.; Dobrila, L.; Antohe, F.; Simionescu, M.

    1989-01-01

    The uptake and transport of carrier-bound thyroxine by the endothelium were investigated by perfusing through the heart and lung of young rats radiolabeled thyroxine bound to prealbumin ([125I]T4Pa) or serum ([125I]T4S). In addition these complexes were tagged to 5-nm gold particles to obtain quantitative (radioassay) and qualitative (autoradiography) data from the same experiment. The complexes (prewarmed at 37 degrees) were perfused in situ at various concentrations (1 to 50 muCi/ml) for time intervals ranging from 5 to 30 min. After thorough washing of the unbound probe, tissue fragments were either measured for total uptake in a gamma counter or processed for electron microscopy autoradiography. The results showed that both the lung and heart take up [125I]T4 complexes by a process that is saturable at low hormone concentration; uptake is completed by free T4 and Pa. In specimens perfused with double-labeled complexes (iodinated and tagged to gold) autoradiography revealed that silver grains and gold particles colocalize predominantly on endothelial plasmalemmal vesicles. The probe appeared first in vesicles open to the capillary lumen (5 min) and further on in vesicles apparently free within the cytoplasm or open to the abluminal front. At 30 min, only silver grains seem to be present in the pericapillary space, on the alveolar epithelial cells, as well as on the nucleus and mitochondria of heart myocytes. The findings suggest that (1) T4Pa uptake by the endothelial cell (EC) is a specific process (possibly via specific binding sites); (2) T4Pa is taken up and transported across capillary EC by plasmalemmal vesicles; (3) in the pericapillary space T4 seems to dissociate from its carrier

  3. Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration.

    Science.gov (United States)

    Zhou, Jian; Rogers, Jason H; Lee, Scott H; Sun, DongMing; Yao, Hai; Mao, Jeremy J; Kong, Kimi Y

    2017-01-15

    Endothelial progenitor cells/endothelial cells (EPCs/ECs) have great potential to treat pathological conditions such as cardiac infarction, muscle ischemia, and bone fractures, but isolation of EPC/ECs from existing cell sources is challenging due to their low EC frequency. We have isolated endothelial progenitor (EP)-like cells from rat oral mucosa and characterized their yield, immunophenotype, growth, and in vivo angiogenic potential. The frequency of EP-like cells derived from oral mucosa is thousands of folds higher than EPCs derived from donor-match bone marrow samples. EP-like cells from oral mucosa were positive for EC markers CD31, VE-Cadherin, and VEGFR2. Oral mucosa-derived EP-like cells displayed robust uptake of acetylated low-density lipoprotein and formed stable capillary networks in Matrigel. Subcutaneously implanted oral mucosa-derived EP-like cells anastomosed with host blood vessels, implicating their ability to elicit angiogenesis. Similar to endothelial colony-forming cells, EP-like cells from oral mucosa have a significantly higher proliferative rate than human umbilical vein endothelial cells. These findings identify a putative EPC source that is easily accessible in the oral cavity, potentially from discarded tissue specimens, and yet with robust yield and potency for angiogenesis in tissue and organ regeneration.

  4. Endothelial RIG-I activation impairs endothelial function

    International Nuclear Information System (INIS)

    Asdonk, Tobias; Motz, Inga; Werner, Nikos; Coch, Christoph; Barchet, Winfried; Hartmann, Gunther; Nickenig, Georg; Zimmer, Sebastian

    2012-01-01

    Highlights: ► RIG-I activation impairs endothelial function in vivo. ► RIG-I activation alters HCAEC biology in vitro. ► EPC function is affected by RIG-I stimulation in vitro. -- Abstract: Background: Endothelial dysfunction is a crucial part of the chronic inflammatory atherosclerotic process and is mediated by innate and acquired immune mechanisms. Recent studies suggest that pattern recognition receptors (PRR) specialized in immunorecognition of nucleic acids may play an important role in endothelial biology in a proatherogenic manner. Here, we analyzed the impact of endothelial retinoic acid inducible gene I (RIG-I) activation upon vascular endothelial biology. Methods and results: Wild type mice were injected intravenously with 32.5 μg of the RIG-ligand 3pRNA (RNA with triphosphate at the 5′end) or polyA control every other day for 7 days. In 3pRNA-treated mice, endothelium-depended vasodilation was significantly impaired, vascular oxidative stress significantly increased and circulating endothelial microparticle (EMP) numbers significantly elevated compared to controls. To gain further insight in RIG-I dependent endothelial biology, cultured human coronary endothelial cells (HCAEC) and endothelial progenitor cells (EPC) were stimulated in vitro with 3pRNA. Both cells types express RIG-I and react with receptor upregulation upon stimulation. Reactive oxygen species (ROS) formation is enhanced in both cell types, whereas apoptosis and proliferation is not significantly affected in HCAEC. Importantly, HCAEC release significant amounts of proinflammatory cytokines in response to RIG-I stimulation. Conclusion: This study shows that activation of the cytoplasmatic nucleic acid receptor RIG-I leads to endothelial dysfunction. RIG-I induced endothelial damage could therefore be an important pathway in atherogenesis.

  5. Capillary detectors

    International Nuclear Information System (INIS)

    Konijn, J.; Winter, K.; Vilain, P.; Wilquet, G.; Fabre, J.P.; Kozarenko, E.; Kreslo, I.; Goldberg, J.; Hoepfner, K.; Bay, A.; Currat, C.; Koppenburg, P.; Frekers, D.; Wolff, T.; Buontempo, S.; Ereditato, A.; Frenkel, A.; Liberti, B.; Martellotti, G.; Penso, G.; Ekimov, A.; Golovkin, S.; Govorun, V.; Medvedkov, A.; Vasil'chenko, V.

    1998-01-01

    The option for a microvertex detector using glass capillary arrays filled with liquid scintillator is presented. The status of capillary layers development and possible read-out techniques for high rate environment are reported. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  6. Expression of Toll-Like Receptor 4 in Glomerular Endothelial Cells under Diabetic Conditions

    International Nuclear Information System (INIS)

    Takata, Shunsuke; Sawa, Yoshihiko; Uchiyama, Takanobu; Ishikawa, Hiroyuki

    2013-01-01

    Diabetic conditions promote glomerulosclerosis by mesangial cells but the mechanisms are not fully elucidated. The present study evaluated the expression of toll-like receptor 4 in glomerular endothelial cells in the streptozotocin (STZ)-induced type 1 diabetic mouse (ICR-STZ) and the type 2 diabetic KK/TaJcl mouse which were fed a high fat diet feed (KK/Ta-HF). In the ICR-STZ and KK/Ta-HF almost glomeruli were immunostained with anti-TLR4 but there was no glomerulus immunostained by ani-TLR4 in the control ICR and KK/Ta. Laser-scanning confocal microscopy showed that the TLR4-positive region did not coincide with the podoplanin-positive region but coincide with the PECAM-1- and VE-cadherin-positive regions in the glomeruli of the ICR-STZ and KK/Ta-HF. The in situ hybridization showed that almost signals for TLR4 mRNA were present in the glomerulus of the ICR-STZ and KK/Ta-HF to a stronger extent than in the control ICR and KK/Ta. These suggest that glomerular endothelial cells usually express the TLR4 gene and hyperglycemia in the diabetic condition induces the TLR4 protein expression in the glomerular capillary endothelial cells. Cytokine productions through the TLR signaling pathway in glomerular endothelial cells may allow mesangial cells to produce extracellular matrix proteins in the diabetic milieu

  7. Endothelial RIG-I activation impairs endothelial function

    Energy Technology Data Exchange (ETDEWEB)

    Asdonk, Tobias, E-mail: tobias.asdonk@ukb.uni-bonn.de [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Motz, Inga; Werner, Nikos [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Coch, Christoph; Barchet, Winfried; Hartmann, Gunther [Institute for Clinical Chemistry and Clinical Pharmacology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Nickenig, Georg; Zimmer, Sebastian [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer RIG-I activation impairs endothelial function in vivo. Black-Right-Pointing-Pointer RIG-I activation alters HCAEC biology in vitro. Black-Right-Pointing-Pointer EPC function is affected by RIG-I stimulation in vitro. -- Abstract: Background: Endothelial dysfunction is a crucial part of the chronic inflammatory atherosclerotic process and is mediated by innate and acquired immune mechanisms. Recent studies suggest that pattern recognition receptors (PRR) specialized in immunorecognition of nucleic acids may play an important role in endothelial biology in a proatherogenic manner. Here, we analyzed the impact of endothelial retinoic acid inducible gene I (RIG-I) activation upon vascular endothelial biology. Methods and results: Wild type mice were injected intravenously with 32.5 {mu}g of the RIG-ligand 3pRNA (RNA with triphosphate at the 5 Prime end) or polyA control every other day for 7 days. In 3pRNA-treated mice, endothelium-depended vasodilation was significantly impaired, vascular oxidative stress significantly increased and circulating endothelial microparticle (EMP) numbers significantly elevated compared to controls. To gain further insight in RIG-I dependent endothelial biology, cultured human coronary endothelial cells (HCAEC) and endothelial progenitor cells (EPC) were stimulated in vitro with 3pRNA. Both cells types express RIG-I and react with receptor upregulation upon stimulation. Reactive oxygen species (ROS) formation is enhanced in both cell types, whereas apoptosis and proliferation is not significantly affected in HCAEC. Importantly, HCAEC release significant amounts of proinflammatory cytokines in response to RIG-I stimulation. Conclusion: This study shows that activation of the cytoplasmatic nucleic acid receptor RIG-I leads to endothelial dysfunction. RIG-I induced endothelial damage could therefore be an important pathway in atherogenesis.

  8. An improved in vitro blood-brain barrier model: rat brain endothelial cells co-cultured with astrocytes.

    Science.gov (United States)

    Abbott, N Joan; Dolman, Diana E M; Drndarski, Svetlana; Fredriksson, Sarah M

    2012-01-01

    In vitro blood-brain barrier (BBB) models using primary cultured brain endothelial cells are important for establishing cellular and molecular mechanisms of BBB function. Co-culturing with BBB-associated cells especially astrocytes to mimic more closely the in vivo condition leads to upregulation of the BBB phenotype in the brain endothelial cells. Rat brain endothelial cells (RBECs) are a valuable tool allowing ready comparison with in vivo studies in rodents; however, it has been difficult to obtain pure brain endothelial cells, and few models achieve a transendothelial electrical resistance (TEER, measure of tight junction efficacy) of >200 Ω cm(2), i.e. the models are still relatively leaky. Here, we describe methods for preparing high purity RBECs and neonatal rat astrocytes, and a co-culture method that generates a robust, stable BBB model that can achieve TEER >600 Ω cm(2). The method is based on >20 years experience with RBEC culture, together with recent improvements to kill contaminating cells and encourage BBB differentiation.Astrocytes are isolated by mechanical dissection and cell straining and are frozen for later co-culture. RBECs are isolated from 3-month-old rat cortices. The brains are cleaned of meninges and white matter and enzymatically and mechanically dissociated. Thereafter, the tissue homogenate is centrifuged in bovine serum albumin to separate vessel fragments from other cells that stick to the myelin plug. The vessel fragments undergo a second enzyme digestion to separate pericytes from vessels and break down vessels into shorter segments, after which a Percoll gradient is used to separate capillaries from venules, arterioles, and single cells. To kill remaining contaminating cells such as pericytes, the capillary fragments are plated in puromycin-containing medium and RBECs grown to 50-60% confluence. They are then passaged onto filters for co-culture with astrocytes grown in the bottom of the wells. The whole procedure takes ∼2

  9. Fluorescent microangiography is a novel and widely applicable technique for delineating the renal microvasculature.

    Directory of Open Access Journals (Sweden)

    Andrew Advani

    Full Text Available Rarefaction of the renal microvasculature correlates with declining kidney function. However, current technologies commonly used for its evaluation are limited by their reliance on endothelial cell antigen expression and assessment in two dimensions. We set out to establish a widely applicable and unbiased optical sectioning method to enable three dimensional imaging and reconstruction of the renal microvessels based on their luminal filling. The kidneys of subtotally nephrectomized (SNx rats and their sham-operated counterparts were subjected to either routine two-dimensional immunohistochemistry or the novel technique of fluorescent microangiography (FMA. The latter was achieved by perfusion of the kidney with an agarose suspension of fluorescent polystyrene microspheres followed by optical sectioning of 200 µm thick cross-sections using a confocal microscope. The fluorescent microangiography method enabled the three-dimensional reconstruction of virtual microvascular casts and confirmed a reduction in both glomerular and peritubular capillary density in the kidneys of SNx rats, despite an overall increase in glomerular volume. FMA is an uncomplicated technique for evaluating the renal microvasculature that circumvents many of the limitations imposed by conventional analysis of two-dimensional tissue sections.

  10. Improved vascularization of planar membrane diffusion devices following continuous infusion of vascular endothelial growth factor.

    Science.gov (United States)

    Trivedi, N; Steil, G M; Colton, C K; Bonner-Weir, S; Weir, G C

    2000-01-01

    Improving blood vessel formation around an immunobarrier device should improve the survival of the encapsulated tissue. In the present study we investigated the formation of new blood vessels around a planar membrane diffusion device (the Baxter Theracyte System) undergoing a continuous infusion of vascular endothelial growth factor through the membranes and into the surrounding tissue. Each device (20 microl) had both an inner immunoisolation membrane and an outer vascularizing membrane. Human recombinant vascular endothelial growth factor-165 was infused at 100 ng/day (low dose: n = 6) and 500 ng/day (high dose: n = 7) for 10 days into devices implanted s.c. in Sprague-Dawley rats; noninfused devices transplanted for an identical period were used as controls (n = 5). Two days following the termination of VEGF infusion, devices were loaded with 20 microl of Lispro insulin (1 U/kg) and the kinetics of insulin release from the lumen of the device was assessed. Devices were then explanted and the number of blood vessels (capillary and noncapillary) was quantified using morphometry. High-dose vascular endothelial growth factor infusion resulted in two- to threefold more blood vessels around the device than that obtained with the noninfused devices and devices infused with low-dose vascular endothelial growth factor. This increase in the number of blood vessels was accompanied by a modest increase in insulin diffusion from the device in the high-dose vascular endothelial growth factor infusion group. We conclude that vascular endothelial growth factor can be used to improve blood vessel formation adjacent to planar membrane diffusion devices.

  11. Culture and Characterization of Circulating Endothelial Progenitor Cells in Patients with Renal Cell Carcinoma.

    Science.gov (United States)

    Gu, Wenyu; Sun, Wei; Guo, Changcheng; Yan, Yang; Liu, Min; Yao, Xudong; Yang, Bin; Zheng, Junhua

    2015-07-01

    Although emerging evidence demonstrates increased circulating endothelial progenitor cells in patients with solid tumors, to our knowledge it is still unknown whether such cells can be cultured from patients with highly angiogenic renal cell carcinoma. We cultured and characterized circulating endothelial progenitor cells from patients with renal cell carcinoma. The circulating endothelial progenitor cell level (percent of CD45(-)CD34(+) VEGF-R2(+) cells in total peripheral blood mononuclear cells) was quantified in 47 patients with renal cell carcinoma and 40 healthy controls. Peripheral blood mononuclear cells were then isolated from 33 patients with renal cell carcinoma and 30 healthy controls to culture and characterize circulating endothelial progenitor cells. The circulating endothelial progenitor cell level was significantly higher in patients with renal cell carcinoma than in healthy controls (0.276% vs 0.086%, p cells first emerged significantly earlier in patient than in control preparations (6.72 vs 14.67 days, p culture success rate (87.8% vs 40.0% of participants) and the number of colonies (10.06 vs 1.83) were significantly greater for patients than for controls (each p cell level correlated positively with the number of patient colonies (r = 0.762, p Cells cultured from patients and controls showed a similar growth pattern, immunophenotype, ability to uptake Ac-LDL and bind lectin, and form capillary tubes in vitro. However, significantly more VEGF-R2(+) circulating endothelial progenitor cells were found in preparations from patients with renal cell carcinoma than from healthy controls (21.1% vs 13.4%, p cell colonies, a higher cell culture success rate and more colonies were found for patients with renal cell carcinoma than for healthy controls. Results indicate the important significance of VEGF-R2(+) circulating endothelial progenitors in patients with renal cell carcinoma. Copyright © 2015 American Urological Association Education and Research

  12. Interleukin 6-Mediated Endothelial Barrier Disturbances Can Be Attenuated by Blockade of the IL6 Receptor Expressed in Brain Microvascular Endothelial Cells.

    Science.gov (United States)

    Blecharz-Lang, Kinga G; Wagner, Josephin; Fries, Alexa; Nieminen-Kelhä, Melina; Rösner, Jörg; Schneider, Ulf C; Vajkoczy, Peter

    2018-02-10

    Compromised blood-brain barrier (BBB) by dysregulation of cellular junctions is a hallmark of many cerebrovascular disorders due to the pro-inflammatory cytokines action. Interleukin 6 (IL6) is implicated in inflammatory processes and in secondary brain injury after subarachnoid hemorrhage (SAH) but its role in the maintenance of cerebral endothelium still requires a precise elucidation. Although IL6 has been shown to exert pro-inflammatory action on brain microvascular endothelial cells (ECs), the expression of one of the IL6 receptors, the IL6R is controversially discussed. In attempt to reach more clarity in this issue, we present here an evident baseline expression of the IL6R in BBB endothelium in vivo and in an in vitro model of the BBB, the cEND cell line. A significantly increased expression of IL6R and its ligand was observed in BBB capillaries 2 days after experimental SAH in mice. In vitro, we saw IL6 administration resulting in an intracellular and extracellular elevation of IL6 protein, which was accompanied by a reduced expression of tight and adherens junctions, claudin-5, occludin, and vascular-endothelial (VE-) cadherin. By functional assays, we could demonstrate IL6-incubated brain ECs to lose their endothelial integrity that can be attenuated by inhibiting the IL6R. Blockade of the IL6R by a neutralizing antibody has reconstituted the intercellular junction expression to the control level and caused a restoration of the transendothelial electrical resistance of the cEND cell monolayer. Our findings add depth to the current understanding of the involvement of the endothelial IL6R in the loss of EC integrity implicating potential therapy options.

  13. High lung volume increases stress failure in pulmonary capillaries

    Science.gov (United States)

    Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

    1992-01-01

    We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological

  14. Automated Parallel Capillary Electrophoretic System

    Science.gov (United States)

    Li, Qingbo; Kane, Thomas E.; Liu, Changsheng; Sonnenschein, Bernard; Sharer, Michael V.; Kernan, John R.

    2000-02-22

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  15. Capillary growth in human skeletal muscle: physiological factors and the balance between pro-angiogenic and angiostatic factors

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Hoier, Birgitte

    2014-01-01

    . Depending on the mechanical signal provided, capillary growth may occur either by longitudinal splitting (shear stress) or by sprouting (passive stretch). The mechanical signals initiate angiogenic processes by up-regulation or release of angioregulatory proteins that either promote, modulate or inhibit...... by mechanical or by chemical signalling. Mechanical signals originate from shear stress forces on the endothelial cell layer induced by the blood flowing through the vessel, but include also mechanical stretch and compression of the vascular structures and the surrounding tissue, as the muscle contracts...

  16. Transport of monocarboxylic acids at the blood-brain barrier: Studies with monolayers of primary cultured bovine brain capillary endothelial cells

    International Nuclear Information System (INIS)

    Terasaki, T.; Takakuwa, S.; Moritani, S.; Tsuji, A.

    1991-01-01

    The kinetics and mechanism of the transport of monocarboxylic acids (MCAs) were studied by using primary cultured bovine brain capillary endothelial cells. Concentration-dependent uptake of acetic acid was observed, and the kinetic parameters were estimated as follows: the Michaelis constant, Kt, was 3.41 ± 1.87 mM, the maximum uptake rate, Jmax, was 144.7 ± 55.7 nmol/mg of protein/min and the nonsaturable first-order rate constant, Kd, was 6.66 ± 1.98 microliters/mg of protein/min. At medium pH below 7.0, the uptake rate of [3H]acetic acid increased markedly with decreasing medium pH, whereas pH-independent uptake was observed in the presence of 10 mM acetic acid. An energy requirement for [3H]acetic acid uptake was also demonstrated, because metabolic inhibitors (2,4-dinitrophenol and rotenone) reduced significantly the uptake rate (P less than .05). Carbonylcyanide-p-trifluoro-methoxyphenylhydrazone, a protonophore, inhibited significantly the uptake of [3H]acetic acid at medium pH of 5.0 and 6.0, whereas 4,4'-diisothiocyanostilben-2,2'-disulfonic acid did not. Several MCAs inhibited significantly the uptake rate of [3H]acetic acid, whereas di- and tricarboxylic acids did not. The uptake of [3H]acetic acid was competitively inhibited by salicylic acid, with an inhibition constant, Ki, of 3.60 mM, suggesting a common transport system between acetic acid and salicylic acid. Moreover, at the medium pH of 7.4, salicylic acid and valproic acid inhibited significantly the uptake of [3H]acetic acid, demonstrating that the transport of MCA drugs could also be ascribed to the MCA transport system at the physiologic pH

  17. Cutaneous chronic graft-versus-host disease does not have the abnormal endothelial phenotype or vascular rarefaction characteristic of systemic sclerosis.

    Directory of Open Access Journals (Sweden)

    Jo Nadine Fleming

    2009-07-01

    Full Text Available The clinical and histologic appearance of fibrosis in cutaneous lesions in chronic graft-versus -host disease (c-GVHD resembles the appearance of fibrosis in scleroderma (SSc. Recent studies identified distinctive structural changes in the superficial dermal microvasculature and matrix of SSc skin. We compared the dermal microvasculature in human c-GVHD to SSc to determine if c-GVHD is a suitable model for SSc.We analyzed skin biopsies of normal controls (n = 24, patients with SSc (n = 30 and c-GVHD with dermal fibrosis (n = 133. Immunostaining was employed to identify vessels, vascular smooth muscle, dermal matrix, and cell proliferation. C-GVHD and SSc had similar dermal matrix composition and vascular smooth muscle pathology, including intimal hyperplasia. SSc, however, differed significantly from c-GVHD in three ways. First, there were significantly fewer (p = 0.00001 average vessels in SSc biopsies (9.8 when compared with c-GVHD (16.5. Second, in SSc, endothelial markers were decreased significantly (19/19 and 12/14 for VE cadherin and vWF (p = <0.0001 and <0.05, respectively. In contrast, 0/13 c-GVHD biopsies showed loss of staining with canonical endothelial markers. Third, c-GVHD contained areas of microvascular endothelial proliferation not present in the SSc biopsies.The sclerosis associated with c-GVHD appears to resemble wound healing. Focal capillary proliferation occurs in early c-GVHD. In contrast, loss of canonical endothelial markers and dermal capillaries is seen in SSc, but not in c-GVHD. The loss of VE cadherin in SSc, in particular, may be related to microvascular rarefaction because VE cadherin is necessary for angiogenesis. C-GVHD is a suitable model for studying dermal fibrosis but may not be applicable for studying the microvascular alterations characteristic of SSc.

  18. Relationship between biomarkers of inflammation, oxidative stress and endothelial/microcirculatory function in successful aging versus healthy youth: a transversal study.

    Science.gov (United States)

    Bottino, Daniel Alexandre; Lopes, Flávia Gomes; de Oliveira, Francisco José; Mecenas, Anete de Souza; Clapauch, Ruth; Bouskela, Eliete

    2015-04-08

    There is a functional decline of endothelial- dependent vasodilatation in the aging process. The aims of this study were to investigate if various microcirculatory parameters could correlate to anthropometrical variables, oxidative stress and inflammatory biomarkers in successful aging and compare the results to young healthy controls. Healthy elderly women (HE, 74.0 ± 8.7 years, n = 11) and young controls (YC, 23.1 ± 3.6 years, n = 24) were evaluated through nailfold videocapillaroscopy (NVC), venous occlusion plethysmography (VOP) and laboratorial analysis. Functional capillary density (FCD) and diameters, maximum red blood cell velocity (RBCVmax) during the reactive hyperemia response/RBCVbaseline after 1 min arterial occlusion at the finger base, time to reach RBCVmax were determined by NVC, peak increment of forearm blood flow (FBF) during the reactive hyperemia response (%Hyper) and after 0.4 mg sublingual nitroglycerin (%Nitro) by VOP and lipidogram, fibrinogen, fasting and postload glucose, oxidized LDL-cholesterol (oxLDL), sICAM, sVCAM, sE-Selectin, interleukines 1 and 6 and TNF-α by laboratorial analysis. Correlations and linear multiple regression (LMR) between %Hyper, %Nitro, microcirculatory parameters, oxidative stress and inflammatory biomarkers were investigated. sVCAM, sE-Selectin and oxLDL were higher and RBCVmax/RBCVbaseline and %Hyper lower in HE, while %Nitro and FCD remained unchanged. Fibrinogen, LDL-cholesterol, oxLDL correlated negatively to %Hyper while sVCAM correlated negatively to %Hyper and RBCVmax/RBCVbaseline. Healthy aged women presented dilated capillaries with sustained perfusion and endothelial dysfunction with preserved vascular smooth muscle reactivity. Fibrinogen, LDL-cholesterol, oxidized-LDL and sVCAM correlated negatively to endothelial function but not to microcirculatory parameters. Oxidized-LDL and sVCAM could determine %Hyper through LMR. Oxidized-LDL and sVCAM might be used as endothelial

  19. TNF-α inhibits trophoblast integration into endothelial cellular networks.

    Science.gov (United States)

    Xu, B; Nakhla, S; Makris, A; Hennessy, A

    2011-03-01

    Preeclampsia has been linked to shallow trophoblast invasion and failure of uterine spiral artery transformation. Interaction between trophoblast cells and maternal uterine endothelium is critically important for this remodelling. The aim of our study was to investigate the effect of TNF-α on the interactions of trophoblast-derived JEG-3 cells into capillary-like cellular networks. We have employed an in vitro trophoblast-endothelial cell co-culture model to quantify trophoblast integration into endothelial cellular networks and to investigate the effects of TNF-α. Controlled co-cultures were also treated with anti-TNF-α antibody (5 μg/ml) to specifically block the effect of TNF-α. The invasion was evaluated by performing quantitative PCR (Q-PCR) to analyse gene expression of matrix metalloproteinases-2 (MMP-2), MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1, integrins (α(1)β(1) and α(6)β(4)), plasminogen activator inhibitor (PAI)-1, E-cadherin and VE-cadherin. JEG-3 cell integration into endothelial networks was significantly inhibited by exogenous TNF-α. The inhibition was observed in the range of 0.2-5 ng/ml, to a maximum 56% inhibition at the highest concentration. This inhibition was reversed by anti-TNF-α antibody. Q-PCR analysis showed that mRNA expression of integrins α(1)β(1) and MMP-2 was significantly decreased. VE-cadherin mRNA expression was significantly up-regulated (32-80%, p integration into maternal endothelial cellular networks, and this process involves the inhibition of MMP-2 and a failure of integrins switch from α(6)β(4) to α(1)β(1.) These molecular correlations reflect the changes identified in human preeclampsia. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  1. Subcellular localization and mechanism of secretion of vascular endothelial growth factor in human skeletal muscle

    DEFF Research Database (Denmark)

    Høier, Birgitte; Prats Gavalda, Clara; Qvortrup, Klaus

    2013-01-01

    The subcellular distribution and secretion of vascular endothelial growth factor (VEGF) was examined in skeletal muscle of healthy humans. Skeletal muscle biopsies were obtained from m.v. lateralis before and after a 2 h bout of cycling exercise. VEGF localization was conducted on preparations...... regions and between the contractile elements within the muscle fibers; and in pericytes situated on the skeletal muscle capillaries. Quantitation of the subsarcolemmal density of VEGF vesicles, calculated on top of myonuclei, in the muscle fibers revealed a ∼50% increase (P...

  2. Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography

    International Nuclear Information System (INIS)

    Kazarian, Artaches A.; Sanz Rodriguez, Estrella; Deverell, Jeremy A.; McCord, James; Muddiman, David C.; Paull, Brett

    2016-01-01

    Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L"−"1 levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min"−"1, and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L"−"1 for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%. - Highlights: • Novel PS-DVB modified photonic crystal fibres for in-capillary micro-extraction. • New method for micro-extraction of PAHs and HPLC-FL detection at sub-ppb levels. • Demonstration of PS-DVB modified photonic crystal fibres for capillary bioseparations.

  3. Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian, Artaches A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Sanz Rodriguez, Estrella; Deverell, Jeremy A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); McCord, James; Muddiman, David C. [W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Paull, Brett, E-mail: Brett.Paull@utas.edu.au [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); ARC Centre of Excellence for Electromaterials Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia)

    2016-01-28

    Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L{sup −1} levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min{sup −1}, and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L{sup −1} for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%. - Highlights: • Novel PS-DVB modified photonic crystal fibres for in-capillary micro-extraction. • New method for micro-extraction of PAHs and HPLC-FL detection at sub-ppb levels. • Demonstration of PS-DVB modified photonic crystal fibres for capillary bioseparations.

  4. Neutrophil migration through preexisting holes in the basal laminae of alveolar capillaries and epithelium during streptococcal pneumonia.

    Science.gov (United States)

    Walker, D C; Behzad, A R; Chu, F

    1995-11-01

    The purpose of this study was to determine whether or not there are preexisting holes in the endothelial and epithelial basal laminae of alveolar walls and to determine the path taken by neutrophils as they migrate from the capillaries to the airspace of the alveoli during inflammation. Using transmission electron microscopy and serial thin sections of normal rabbit and mouse lung, we have demonstrated the presence of slit-like holes in the capillary basal laminae and round holes in the basal laminae of type 2 pneumocytes. The slits in the capillary basal laminae were observed at the intersection of the thick and thin walls where endothelium, pericytes, and fibroblasts make close contact. The round holes in the type 2 cell basal laminae were observed at sites of close contact with fibroblasts. Neutrophils were observed to migrate through these slits and holes during streptococcal pneumonia in rabbit lungs. We conclude that during inflammation in the lung, migrating neutrophils displace pericytes and fibroblasts from the slits in the capillary basal lamina and then crawl through these slits into the alveolar interstitium. We postulate that neutrophils find their way to type 2 pneumocytes by following interstitial fibroblasts. We believe that neutrophils displace fibroblasts from their close contacts with the type 2 cells and then crawl through the holes in the basal lamina into the basal lateral space of the type 2 cells. From there, neutrophils migrate into the alveolar airspace.

  5. Capillary network formation from dispersed endothelial cells: Influence of cell traction, cell adhesion, and extracellular matrix rigidity

    Science.gov (United States)

    Ramos, João R. D.; Travasso, Rui; Carvalho, João

    2018-01-01

    The formation of a functional vascular network depends on biological, chemical, and physical processes being extremely well coordinated. Among them, the mechanical properties of the extracellular matrix and cell adhesion are fundamental to achieve a functional network of endothelial cells, able to fully cover a required domain. By the use of a Cellular Potts Model and Finite Element Method it is shown that there exists a range of values of endothelial traction forces, cell-cell adhesion, and matrix rigidities where the network can spontaneously be formed, and its properties are characterized. We obtain the analytical relation that the minimum traction force required for cell network formation must obey. This minimum value for the traction force is approximately independent on the considered cell number and cell-cell adhesion. We quantify how these two parameters influence the morphology of the resulting networks (size and number of meshes).

  6. Capillaries modified by noncovalent anionic polymer adsorption for capillary zone electrophoresis, micellar electrokinetic capillary chromatography and capillary electrophoresis mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L; Hansen, S H; Gammelgaard, Bente

    2001-01-01

    A simple coating procedure for generation of a high and pH-independent electroosmotic flow in capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) is described. The bilayer coating was formed by noncovalent adsorption of the ionic polymers Polybrene...... capillaries was (4.9+/-0.1) x 10(-4) cm2V(-1)s(-1) in a pH-range of 2-10 (ionic strength = 30 mM). When alkaline compounds were used as test substances intracapillary and intercapillary migration time variations (n = 6) were less than 1% relative standard deviation (RSD) and 2% RSD, respectively in the entire...... pH range. The coating was fairly stable in the presence of sodium dodecyl sulfate, and this made it possible to perform fast MEKC separations at low pH. When neutral compounds were used as test substances, the intracapillary migration time variations (n = 6) were less than 2% RSD in a pH range of 2...

  7. A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

    Science.gov (United States)

    Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

    2017-02-14

    The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

  8. Nanoparticle-based capillary electroseparation of proteins in polymer capillaries under physiological conditions

    DEFF Research Database (Denmark)

    Nilsson, C.; Harwigsson, I.; Becker, K.

    2010-01-01

    Totally porous lipid-based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas (R), 6.7 cm effective length). In the absence of n...... at protein friendly conditions. The developed capillary-based method facilitates future electrochromatography of proteins on polymer-based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development....

  9. Western Blotting using Capillary Electrophoresis

    OpenAIRE

    Anderson, Gwendolyn J.; Cipolla, Cynthia; Kennedy, Robert T.

    2011-01-01

    A microscale Western blotting system based on separating sodium-dodecyl sulfate protein complexes by capillary gel electrophoresis followed by deposition onto a blotting membrane for immunoassay is described. In the system, the separation capillary is grounded through a sheath capillary to a mobile X-Y translation stage which moves a blotting membrane past the capillary outlet for protein deposition. The blotting membrane is moistened with a methanol and buffer mixture to facilitate protein a...

  10. Sieve plugs in fenestrae of glomerular capillaries--site of the filtration barrier?

    DEFF Research Database (Denmark)

    Rostgaard, Jørgen; Qvortrup, Klaus

    2002-01-01

    The exact location of the filtration barrier of the glomerular capillary wall, which consists of an endothelium, a basement membrane and a visceral epithelium, has not yet been determined. Apparent discrepancies between different investigators in the past could be explained if postmortem...... and a filamentous surface coat about 60 nm thick covered the interfenestral domains of the endothelial cell. Based on these purely morphological data, we dare to suggest that the fenestral plugs are the primary site of the glomerular filtration barrier - albeit highly speculative, nevertheless a logical location...... - and consequently that the glomerular filtration process is a 'tangential-flow' as opposed to a 'dead-end' filtration process. A tangential-flow filtration would minimize 'clogging' and 'concentration polarization' in the 'filter'....

  11. Divalent ion block of inward rectifier current in human capillary endothelial cells and effects on resting membrane potential

    Science.gov (United States)

    Jow, Flora; Numann, Randy

    1998-01-01

    Cultured human capillary endothelial cells (HCEC) contain a large inward rectifier current, IK(IR), that can be abolished by removing external K+ or by adding 50 μm Ba2+.We show that IK(IR) is responsible for maintaining the hyperpolarized potential (−60.6 ± 0.5 mV, n = 83) of HCEC. Blocking IK(IR) with 50 μm Ba2+ shifts the zero current level and depolarizes HCEC by 36.5 ± 1.3 mV (n = 4).Increasing external Ca2+ concentration ([Ca2+]o) from 0.5 to 7 mm reduces the magnitude of IK(IR) by 36.5 ± 2.3 % (n = 5) and depolarizes the cells by 10.33 ± 2.4 mV (n = 3), whereas decreasing [Ca2+]o from 1.8 to 0.5 mm increases the amplitude of IK(IR) by 6.9 ± 1.9 % (n = 4). The relationship between [Ca2+]o and the percentage block of IK(IR) gives a Kd value of 5.4 ± 0.6 mm at −120 mV.IK(IR) is also blocked by other divalent ions, with Ba2+ >> Sr2+ > Mg2+ > Mn2+= Ca2+, and the block of peak current at −120 mV being 85.3 ± 3.2 % (n = 5) for 50 μm Ba2+, 62.9 ± 2.2 % (n = 5) for 5 mm Sr2+, 40.7 ± 2.5 % (n = 9) for 5 mm Mg2+, 33.4 ± 2.1 % (n = 5) for 5 mm Mn2+ and 32.9 ± 2.1 % (n = 5) for 5 mm Ca2+.The voltage dependence of Sr2+ block of peak IK(IR) occurred with a Kd value of 1.0 ± 0.09 mm for −140 mV, 1.9 ± 0.16 mm for −130 mV, 3.1 ± 0.28 mm for −120 mV, 4.6 ± 0.34 mm for −110 mV and 6.4 ± 0.5 mm for −100 mV (n = 5), with a calculated electrical distance (δ) of 0.44 from the outside. PMID:9729622

  12. Thrombospondin-1 plays a profibrotic and pro-inflammatory role during ureteric obstruction.

    Science.gov (United States)

    Bige, Naïke; Shweke, Nasim; Benhassine, Safa; Jouanneau, Chantal; Vandermeersch, Sophie; Dussaule, Jean-Claude; Chatziantoniou, Christos; Ronco, Pierre; Boffa, Jean-Jacques

    2012-06-01

    Thrombospondin-1 (TSP-1) is an endogenous activator of transforming growth factor-β (TGF-β), and an anti-angiogenic factor, which may prevent kidney repair. Here we investigated whether TSP-1 is involved in the development of chronic kidney disease using rats with unilateral ureteral obstruction, a well-known model to study renal fibrosis. Obstruction of 10 days duration induced inflammation, tubular cell atrophy, dilation, apoptosis, and proliferation, leading to interstitial fibrosis. TSP-1 expression was increased in parallel to that of collagen III and TGF-β. Relief of the obstruction at day 10 produced a gradual improvement in renal structure and function, the reappearance of peritubular capillaries, and restoration of renal VEGF content over a 7- to 15-day post-relief period. TSP-1 expression decreased in parallel with that of TGF-β1 and collagen III. Mice in which the TSP-1 gene was knocked out displayed less inflammation and had better preservation of renal tissue and the peritubular capillary network compared to wild-type mice. Additional studies showed that the inflammatory effect of TSP-1 was mediated, at least in part, by monocyte chemoattractant protein-1 and activation of the Th17 pathway. Thus, TSP-1 is an important profibrotic and inflammatory mediator of renal disease. Blockade of its action may be a treatment against the development of chronic kidney disease.

  13. Capillary gas-solid chromatography

    International Nuclear Information System (INIS)

    Berezkin, V.G.

    1996-01-01

    Modern state of gas adsorption chromatography in open capillary columns has been analyzed. The history of the method development and its role in gas chromatography, ways to construct open adsorptional capillary columns, foundations of the theory of retention and washing of chromatographic regions in gas adsorption capillary columns have been considered. The fields is extensively and for analyzing volatile compounds of different isotopic composition, inorganic and organic gases, volatile organic polar compounds, aqueous solutions of organic compounds. Separation of nuclear-spin isomers and isotopes of hydrogen is the first illustrative example of practical application of the adsorption capillary chromatography. It is shown that duration of protium and deuterium nuclear isomers may be reduced if the column temperature is brought to 47 K

  14. Growth of metal-organic framework HKUST-1 in capillary using liquid-phase epitaxy for open-tubular capillary electrochromatography and capillary liquid chromatography.

    Science.gov (United States)

    Bao, Tao; Zhang, Juan; Zhang, Wenpeng; Chen, Zilin

    2015-02-13

    Much attention is being paid to applying metal-organic frameworks (MOFs) as stationary phases in chromatography because of their fascinating properties, such as large surface-to-volume ratios, high levels of porosity, and selective adsorption. HKUST-1 is one of the best-studied face-centered-cubic MOF containing nano-sized channels and side pockets for film growth. However, growth of HKUST-1 framework inside capillary column as stationary phase for capillary electrochromatography is a challenge work. In this work, we carry out the growth of HKUST-1 on the inner wall of capillary by using liquid-phase epitaxy process at room temperature. The fabricated HKUST-1@capillary can be successfully used for the separation of substituted benzene including methylbenzene, ethylbenzene, styrene, chlorobenzene, bromobenzene, o-dichlorobenzene, benzene series, phenolic acids, and benzoic acids derivates. High column efficiency of 1.5×10(5) N/m for methylbenzene was achieved. The formation of HKUST-1 grown in the capillary was confirmed and characterized by scanning electron microscopy images, Fourier transform infrared spectra and X-ray diffraction. The column showed long lifetime and excellent stability. The relative standard deviations for intra-day and inter-day repeatability of the HKUST-1@capillary were lower than 7%. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Boosting the signal: Endothelial inward rectifier K+ channels.

    Science.gov (United States)

    Jackson, William F

    2017-04-01

    Endothelial cells express a diverse array of ion channels including members of the strong inward rectifier family composed of K IR 2 subunits. These two-membrane spanning domain channels are modulated by their lipid environment, and exist in macromolecular signaling complexes with receptors, protein kinases and other ion channels. Inward rectifier K + channel (K IR ) currents display a region of negative slope conductance at membrane potentials positive to the K + equilibrium potential that allows outward current through the channels to be activated by membrane hyperpolarization, permitting K IR to amplify hyperpolarization induced by other K + channels and ion transporters. Increases in extracellular K + concentration activate K IR allowing them to sense extracellular K + concentration and transduce this change into membrane hyperpolarization. These properties position K IR to participate in the mechanism of action of hyperpolarizing vasodilators and contribute to cell-cell conduction of hyperpolarization along the wall of microvessels. The expression of K IR in capillaries in electrically active tissues may allow K IR to sense extracellular K + , contributing to functional hyperemia. Understanding the regulation of expression and function of microvascular endothelial K IR will improve our understanding of the control of blood flow in the microcirculation in health and disease and may provide new targets for the development of therapeutics in the future. © 2016 John Wiley & Sons Ltd.

  16. Quantitative study of the microvasculature and its endothelial cells in the porcine iris.

    Science.gov (United States)

    Yang, Hongfang; Yu, Paula K; Cringle, Stephen J; Sun, Xinghuai; Yu, Dao-Yi

    2015-03-01

    The roles of the iris microvasculature have been increasingly recognised in the pathogenesis of glaucoma and cataract; however limited information exists regarding the iris microvasculature and its endothelium. This study quantitatively assessed the iris microvascular network and its endothelium using intra-luminal micro-perfusion, fixation, and staining of the porcine iris. The temporal long posterior ciliary artery of 11 isolated porcine eyes was cannulated, perfusion-fixed and labelled using silver nitrate. The iris microvasculature was studied for its distribution, orders and endothelial morphometrics. The density of three layers of microvasculature was measured. Endothelial cell length and width were measured for each vessel order. The iris has an unusual vascular distribution which consisted of abundant large vessels in the middle of the iris stroma, branching over a relatively short distance to the microvasculature located in the superficial and deep stroma as well as the pupil edge. The average vascular density of the middle, superficial, and deep layers were 38.9 ± 1.93%, 10.9 ± 1.61% and 8.0 ± 0.79% respectively. Multiple orders of iris vessels (capillary, 6 orders of arteries, and 4 orders of veins) with relatively large capillary and input arteries (319.5 ± 25.6 μm) were found. Significant heterogeneity of vascular diameter and shape of the endothelia was revealed in different orders of the iris vasculature. Detailed information of topography and endothelium of the iris microvasculature combined with unique structural features of the iris may help us to further understand the physiological and pathogenic roles of the iris in relevant ocular diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Endothelial cell permeability during hantavirus infection involves factor XII-dependent increased activation of the kallikrein-kinin system.

    Directory of Open Access Journals (Sweden)

    Shannon L Taylor

    Full Text Available Hemorrhagic fever with renal syndrome (HFRS and hantavirus pulmonary syndrome (HPS are diseases caused by hantavirus infections and are characterized by vascular leakage due to alterations of the endothelial barrier. Hantavirus-infected endothelial cells (EC display no overt cytopathology; consequently, pathogenesis models have focused either on the influx of immune cells and release of cytokines or on increased degradation of the adherens junction protein, vascular endothelial (VE-cadherin, due to hantavirus-mediated hypersensitization of EC to vascular endothelial growth factor (VEGF. To examine endothelial leakage in a relevant in vitro system, we co-cultured endothelial and vascular smooth muscle cells (vSMC to generate capillary blood vessel-like structures. In contrast to results obtained in monolayers of cultured EC, we found that despite viral replication in both cell types as well as the presence of VEGF, infected in vitro vessels neither lost integrity nor displayed evidence of VE-cadherin degradation. Here, we present evidence for a novel mechanism of hantavirus-induced vascular leakage involving activation of the plasma kallikrein-kinin system (KKS. We show that incubation of factor XII (FXII, prekallikrein (PK, and high molecular weight kininogen (HK plasma proteins with hantavirus-infected EC results in increased cleavage of HK, higher enzymatic activities of FXIIa/kallikrein (KAL and increased liberation of bradykinin (BK. Measuring cell permeability in real-time using electric cell-substrate impedance sensing (ECIS, we identified dramatic increases in endothelial cell permeability after KKS activation and liberation of BK. Furthermore, the alterations in permeability could be prevented using inhibitors that directly block BK binding, the activity of FXIIa, or the activity of KAL. Lastly, FXII binding and autoactivation is increased on the surface of hantavirus-infected EC. These data are the first to demonstrate KKS activation

  18. The increased number of osteoblasts and capillaries in orthodontic tooth movement post-administration of Robusta coffee extract

    Directory of Open Access Journals (Sweden)

    H. Herniyati

    2017-06-01

    Full Text Available Background: The application of orthodontic forces subjects blood capillaries to considerable pressure, resulting in hypoxia on the pressure side. Vascular endothelial growth factor (VEGF, expressed in osteoblasts represents an important mitogen that induces angiogenesis. Osteoblasts and blood capillaries play an important role in bone formation. Robusta coffee contains chlorogenic acid and caffeic acid both of which produce antioxidant effects capable of reducing oxidative stress in osteoblasts. Purpose: The aim of this study was to analyze the effects of Robusta coffee extract on the number of osteoblasts and blood capillaries in orthodontic tooth movement. Methods: This research constituted a laboratory-based experimental study involving the use of sixteen male rodents divided into two groups, namely; control group (C consisting of eight mice given orthodontic mechanical force (OMF and a treatment group (T containing eight mice administered OMF and dried Robusta coffee extract at a dose of 20mg/ 100 g BW. The OMF was performed by installing a ligature wire on the maxillary right first molar and both maxillary incisors. In the following stage, the maxillary right first molar was moved to the mesial using Tension Gauze with a Nickel Titanium Orthodontic closed coil spring. Observation was subsequently undertaken on the 15th day by extracting the maxillary right first and second molar with their periodontal tissues. Thereafter, histological examination was performed using hematoxylin-eosin (HE staining technique to measure the number of osteoblasts and blood capillaries on the mesial and distal periodontal ligaments of the maxillary right first molar. Results: The administration of Robusta coffee extract increases the number of blood capillaries and osteoblasts on both the pressure and tension sides were found to be significantly higher in the T group compared to the C group (p<0,05. Conclusion: Robusta coffee extract increase the number of

  19. Biomedical applications of capillary electrophoresis

    International Nuclear Information System (INIS)

    Kartsova, L A; Bessonova, E A

    2015-01-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references

  20. The regulatory mechanism of Hsp90α secretion from endothelial cells and its role in angiogenesis during wound healing

    International Nuclear Information System (INIS)

    Song, Xiaomin; Luo, Yongzhang

    2010-01-01

    Research highlights: → Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90α secretion from endothelial cells. → Secreted Hsp90α localizes on the leading edge of activated endothelial cells. → Secreted Hsp90α promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90α (Hsp90α) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90α can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation and migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90α from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90α in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90α but not Hsp90β is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90α localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90α neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90α localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90α can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90α as a stimulator for wound repair.

  1. The regulatory mechanism of Hsp90{alpha} secretion from endothelial cells and its role in angiogenesis during wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiaomin [National Engineering Laboratory for Anti-tumor Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Luo, Yongzhang, E-mail: yluo@tsinghua.edu.cn [National Engineering Laboratory for Anti-tumor Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084 (China); Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084 (China)

    2010-07-16

    Research highlights: {yields} Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90{alpha} secretion from endothelial cells. {yields} Secreted Hsp90{alpha} localizes on the leading edge of activated endothelial cells. {yields} Secreted Hsp90{alpha} promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90{alpha} (Hsp90{alpha}) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90{alpha} can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation and migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90{alpha} from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90{alpha} in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90{alpha} but not Hsp90{beta} is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90{alpha} localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90{alpha} neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90{alpha} localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90{alpha} can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90{alpha} as a stimulator for wound repair.

  2. Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier.

    Science.gov (United States)

    Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette; Stensballe, Allan; Moos, Torben

    2017-03-01

    The brain vascular basement membrane is important for both blood-brain barrier (BBB) development, stability, and barrier integrity and the contribution hereto from brain capillary endothelial cells (BCECs), pericytes, and astrocytes of the BBB is probably significant. The aim of this study was to analyse four different in vitro models of the murine BBB for expression and possible secretion of major basement membrane proteins from murine BCECs (mBCECs). mBCECs, pericytes and glial cells (mainly astrocytes and microglia) were prepared from brains of C57BL/6 mice. The mBCECs were grown as monoculture, in co-culture with pericytes or mixed glial cells, or as a triple-culture with both pericytes and mixed glial cells. The integrity of the BBB models was validated by measures of transendothelial electrical resistance (TEER) and passive permeability to mannitol. The expression of basement membrane proteins was analysed using RT-qPCR, mass spectrometry and immunocytochemistry. Co-culturing mBCECs with pericytes, mixed glial cells, or both significantly increased the TEER compared to the monoculture, and a low passive permeability was correlated with high TEER. The mBCECs expressed all major basement membrane proteins such as laminin-411, laminin-511, collagen [α1(IV)] 2 α2(IV), agrin, perlecan, and nidogen 1 and 2 in vitro. Increased expression of the laminin α5 subunit correlated with the addition of BBB-inducing factors (hydrocortisone, Ro 20-1724, and pCPT-cAMP), whereas increased expression of collagen IV α1 primarily correlated with increased levels of cAMP. In conclusion, BCECs cultured in vitro coherently form a BBB and express basement membrane proteins as a feature of maturation. Cover Image for this issue: doi: 10.1111/jnc.13789. © 2016 International Society for Neurochemistry.

  3. Alpha-, gamma- and delta-tocopherols reduce inflammatory angiogenesis in human microvascular endothelial cells.

    Science.gov (United States)

    Wells, Shannon R; Jennings, Merilyn H; Rome, Courtney; Hadjivassiliou, Vicky; Papas, Konstantinos A; Alexander, Jonathon S

    2010-07-01

    Vitamin E, a micronutrient (comprising alpha-, beta-, gamma- and delta-tocopherols, alpha-, beta-, gamma- and delta-tocotrienols), has documented antioxidant and non-antioxidant effects, some of which inhibit inflammation and angiogenesis. We compared the abilities of alpha-, gamma- and delta-tocopherols to regulate human blood cytotoxicity (BEC) and lymphatic endothelial cytotoxicity (LEC), proliferation, invasiveness, permeability, capillary formation and suppression of TNF-alpha-induced VCAM-1 as in vitro models of inflammatory angiogenesis. alpha-, gamma- and delta-tocopherols were not toxic to either cell type up to 40 microM. In BEC, confluent cell density was decreased by all concentrations of delta- and gamma-tocopherol (10-40 microM) but not by alpha-tocopherol. LEC showed no change in cell density in response to tocopherols. delta-Tocopherol (40 microM), but not other isomers, decreased BEC invasiveness. In LEC, all doses of gamma-tocopherol, as well as the highest dose of alpha-tocopherol (40 microM), decreased cell invasiveness. delta-Tocopherol had no effect on LEC invasiveness at any molarity. delta-Tocopherol dose dependently increased cell permeability at 48 h in BEC and LEC; alpha- and gamma-tocopherols showed slight effects. Capillary tube formation was decreased by high dose (40 microM) concentrations of alpha-, gamma- and delta-tocopherol, but showed no effects with smaller doses (10-20 microM) in BEC. gamma-Tocopherol (10-20 microM) and alpha-tocopherol (10 microM), but not delta-tocopherol, increased LEC capillary tube formation. Lastly, in BEC, alpha-, gamma- and delta-tocopherol each dose-dependently reduced TNF-alpha-induced expression of VCAM-1. In LEC, there was no significant change to TNF-alpha-induced VCAM-1 expression with any concentration of alpha-, gamma- or delta-tocopherol. These data demonstrate that physiological levels (0-40 microM) of alpha-, gamma- and delta-tocopherols are nontoxic and dietary tocopherols, especially delta

  4. Capillary concentrators for synchrotron radiation beamlines

    International Nuclear Information System (INIS)

    Heald, S.M.; Brewe, D.L.; Kim, K.H.; Brown, F.C.; Barg, B.; Stern, E.A.

    1996-01-01

    Capillary concentrators condense x-rays by multiple reflections down a gradually tapering capillary. They can provide sub-micron beam spots, and are promising candidates for use in the next generation x-ray microprobe beamlines. The weak energy dependence of their properties make them especially useful for energy scanning applications such as micro-XAFS. This paper examines the potential performance of capillary optics for an x-ray microprobe, as well as some practical issues such as fabrication and alignment. Best performance at third generation sources requires long capillaries, and the authors have been using fiber optics techniques to fabricate capillaries up to one meter in length. The performance of shorter (less than about 0.5 m) capillaries has often been found to agree well with theoretical calculations, indicating the inner surface is a high quality x-ray reflector. These capillaries have been tested at the NSLS for imaging and micro-XAFS down to 2.6 microm resolution with excellent results. On an unfocused bend magnet line flux density approaching 10 6 ph/sec/microm 2 has been achieved. While nearly optimum profiles have been achieved for longer capillaries, the results have been disappointing, and alignment problems are suspected. The dramatic improvement in performance possible at third generation synchrotrons such as the APS is discussed along with improvements possible by using the capillaries in conjunction with coupling optics

  5. Capillary pumped loop body heat exchanger

    Science.gov (United States)

    Swanson, Theodore D. (Inventor); Wren, deceased, Paul (Inventor)

    1998-01-01

    A capillary pumped loop for transferring heat from one body part to another body part, the capillary pumped loop comprising a capillary evaporator for vaporizing a liquid refrigerant by absorbing heat from a warm body part, a condenser for turning a vaporized refrigerant into a liquid by transferring heat from the vaporized liquid to a cool body part, a first tube section connecting an output port of the capillary evaporator to an input of the condenser, and a second tube section connecting an output of the condenser to an input port of the capillary evaporator. A wick may be provided within the condenser. A pump may be provided between the second tube section and the input port of the capillary evaporator. Additionally, an esternal heat source or heat sink may be utilized.

  6. Brugia malayi microfilariae adhere to human vascular endothelial cells in a C3-dependent manner.

    Directory of Open Access Journals (Sweden)

    Jan-Hendrik Schroeder

    2017-05-01

    Full Text Available Brugia malayi causes the human tropical disease, lymphatic filariasis. Microfilariae (Mf of this nematode live in the bloodstream and are ingested by a feeding mosquito vector. Interestingly, in a remarkable co-evolutionary adaptation, Mf appearance in the peripheral blood follows a circadian periodicity and reaches a peak when the mosquito is most likely to feed. For the remaining hours, the majority of Mf sequester in the lung capillaries. This circadian phenomenon has been widely reported and is likely to maximise parasite fitness and optimise transmission potential. However, the mechanism of Mf sequestration in the lungs remains largely unresolved. In this study, we demonstrate that B. malayi Mf can, directly adhere to vascular endothelial cells under static conditions and under flow conditions, they can bind at high (but not low flow rates. High flow rates are more likely to be experienced diurnally. Furthermore, a non-periodic nematode adheres less efficiently to endothelial cells. Strikingly C3, the central component of complement, plays a crucial role in the adherence interaction. These novel results show that microfilariae have the ability to bind to endothelial cells, which may explain their sequestration in the lungs, and this binding is increased in the presence of inflammatory mediators.

  7. Ectopic norrin induces growth of ocular capillaries and restores normal retinal angiogenesis in Norrie disease mutant mice.

    Science.gov (United States)

    Ohlmann, Andreas; Scholz, Michael; Goldwich, Andreas; Chauhan, Bharesh K; Hudl, Kristiane; Ohlmann, Anne V; Zrenner, Eberhart; Berger, Wolfgang; Cvekl, Ales; Seeliger, Mathias W; Tamm, Ernst R

    2005-02-16

    Norrie disease is an X-linked retinal dysplasia that presents with congenital blindness, sensorineural deafness, and mental retardation. Norrin, the protein product of the Norrie disease gene (NDP), is a secreted protein of unknown biochemical function. Norrie disease (Ndp(y/-)) mutant mice that are deficient in norrin develop blindness, show a distinct failure in retinal angiogenesis, and completely lack the deep capillary layers of the retina. We show here that the transgenic expression of ectopic norrin under control of a lens-specific promoter restores the formation of a normal retinal vascular network in Ndp(y/-) mutant mice. The improvement in structure correlates with restoration of neuronal function in the retina. In addition, lenses of transgenic mice with ectopic expression of norrin show significantly more capillaries in the hyaloid vasculature that surrounds the lens during development. In vitro, lenses of transgenic mice in coculture with microvascular endothelial cells induce proliferation of the cells. Transgenic mice with ectopic expression of norrin show more bromodeoxyuridine-labeled retinal progenitor cells at embryonic day 14.5 and thicker retinas at postnatal life than wild-type littermates, indicating a putative direct neurotrophic effect of norrin. These data provide direct evidence that norrin induces growth of ocular capillaries and that pharmacologic modulation of norrin might be used for treatment of the vascular abnormalities associated with Norrie disease or other vascular disorders of the retina.

  8. Revisiting nanoparticle technology for blood-brain barrier transport: Unfolding at the endothelial gate improves the fate of transferrin receptor-targeted liposomes.

    Science.gov (United States)

    Johnsen, Kasper Bendix; Moos, Torben

    2016-01-28

    An unmet need exists for therapeutic compounds to traverse the brain capillary endothelial cells that denote the blood-brain barrier (BBB) to deliver effective treatment to the diseased brain. The use of nanoparticle technology for targeted delivery to the brain implies that targeted liposomes encapsulating a drug of interest will undergo receptor-mediated uptake and transport through the BBB with a subsequent unfolding of the liposomal content inside the brain, hence revealing drug release to adjacent drug-demanding neurons. As transferrin receptors (TfRs) are present on brain capillary endothelial, but not on endothelial cells elsewhere in the body, the use of TfR-targeted liposomes - colloidal particulates with a phospholipid bilayer membrane - remains the most relevant strategy to obtain efficient drug delivery to the brain. However, many studies have failed to provide sufficient quantitative data to proof passage of the BBB and significant appearance of drugs inside the brain parenchyma. Here, we critically evaluate the current evidence on the use of TfR-targeted liposomes for brain drug delivery based on a thorough investigation of all available studies within this research field. We focus on issues with respect to experimental design and data analysis that may provide an explanation to conflicting reports, and we discuss possible explanations for the current lack of sufficient transcytosis across the BBB for implementation in the design of TfR-targeted liposomes. We finally provide a list of suggestions for strategies to obtain substantial uptake and transport of drug carriers at the BBB with a concomitant transport of therapeutics into the brain. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis

    Science.gov (United States)

    Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

    2014-01-01

    Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (PM. R., Samiei, S., Soheili, Z.-S., Frimmel, S., Zhang, Z., Ablonczy, Z., Ahmadieh, H., Hafezi-Moghadam, A. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis. PMID:24903276

  10. Expression of Vascular Endothelial Growth Factor Receptors in Benign Vascular Lesions of the Orbit: A Case Series.

    Science.gov (United States)

    Atchison, Elizabeth A; Garrity, James A; Castillo, Francisco; Engman, Steven J; Couch, Steven M; Salomão, Diva R

    2016-01-01

    Vascular lesions of the orbit, although not malignant, can cause morbidity because of their location near critical structures in the orbit. For the same reason, they can be challenging to remove surgically. Anti-vascular endothelial growth factor (VEGF) drugs are increasingly being used to treat diseases with prominent angiogenesis. Our study aimed to determine to what extent VEGF receptors and their subtypes are expressed on selected vascular lesions of the orbit. Retrospective case series of all orbital vascular lesions removed by one of the authors (JAG) at the Mayo Clinic. A total of 52 patients who underwent removal of vascular orbital lesions. The pathology specimens from the patients were retrieved, their pathologic diagnosis was confirmed, demographic and clinical information were gathered, and sections from vascular tumors were stained with vascular endothelial growth factor receptor (VEGFR), vascular endothelial growth factor receptor type 1 (VEGFR1), vascular endothelial growth factor receptor type 2 (VEGFR2), and vascular endothelial growth factor receptor type 3 (VEGFR3). The existence and pattern of staining with VEGF and its subtypes on these lesions. There were 28 specimens of venous malformations, 4 capillary hemangiomas, 7 lymphatic malformations, and 6 lymphaticovenous malformations. All samples stained with VEGF, 55% stained with VEGFR1, 98% stained with VEGFR2, and 96% stained with VEGFR3. Most (94%) of the VEGFR2 staining was diffuse. Most orbital vascular lesions express VEGF receptors, which may suggest a future target for nonsurgical treatment. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  11. Capillary optics for radiation focusing

    International Nuclear Information System (INIS)

    Peurrung, A.J.; Reeder, P.L.; Bliss, M.; Craig, R.A.; Lepel, E.A.; Stromswold, D.C.; Stoffels, J.; Sunberg, D.S.; Tenny, H.

    1996-11-01

    Capillary lens technology may ultimately bring benefits to neutron and x-ray-based science like conventional lenses with visible light. Although the technology is not yet 10 years old, these lenses have already had a significant impact in engineering, science, and medicine. Capillary lenses are advantageous when it is desirable to increase the radiation flux at a location without regard to its angular divergence. PNNL has worked to improve the technology in several ways. A single, optimally tapered capillary was manufactured, which allows intensity gains of a factor of 270 for an initially parallel, incident x-ray beam. Feasibility of constructing neutron lenses using 58 Ni (particularly effective at reflecting neutrons) has been explored. Three applications for capillary optics have been identified and studied: neutron telescope, Gandolphi x-ray diffractometry, and neutron radiotherapy. A brief guide is given for determining which potential applications are likely to be helped by capillary optics

  12. Local CD34-positive capillaries decrease in mouse models of kidney disease associating with the severity of glomerular and tubulointerstitial lesions.

    Science.gov (United States)

    Masum, Md Abdul; Ichii, Osamu; Elewa, Yaser Hosny Ali; Nakamura, Teppei; Kon, Yasuhiro

    2017-09-04

    The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases. Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05). Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34 + glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34 + tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34 + glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively. From the analysis of mouse models, we identified inverse pathological correlations between the number of

  13. Capillary waves of compressible fluids

    International Nuclear Information System (INIS)

    Falk, Kerstin; Mecke, Klaus

    2011-01-01

    The interplay of thermal noise and molecular forces is responsible for surprising features of liquids on sub-micrometer lengths-in particular at interfaces. Not only does the surface tension depend on the size of an applied distortion and nanoscopic thin liquid films dewet faster than would be expected from hydrodynamics, but also the dispersion relation of capillary waves differ at the nanoscale from the familiar macroscopic behavior. Starting with the stochastic Navier-Stokes equation we study the coupling of capillary waves to acoustic surface waves which is possible in compressible fluids. We find propagating 'acoustic-capillary waves' at nanometer wavelengths where in incompressible fluids capillary waves are overdamped.

  14. Fluid Delivery System For Capillary Electrophoretic Applications.

    Science.gov (United States)

    Li, Qingbo; Liu, Changsheng; Kane, Thomas E.; Kernan, John R.; Sonnenschein, Bernard; Sharer, Michael V.

    2002-04-23

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  15. Monoliths in capillary electrochromatography and capillary liquid chromatography in conjunction with mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Moravcová, Dana; Rantamäki, A. H.; Duša, Filip; Wiedmer, S. K.

    2016-01-01

    Roč. 37, 7-8 (2016), s. 880-912 ISSN 0173-0835 Institutional support: RVO:68081715 Keywords : capillary electrochromatography * capillary liquid chromatography * mass spec- trometry * monolithic columns Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.744, year: 2016

  16. Hyperosmotic stimulus induces reversible angiogenesis within the hypothalamic magnocellular nuclei of the adult rat: a potential role for neuronal vascular endothelial growth factor

    Directory of Open Access Journals (Sweden)

    Vincent Anne

    2005-03-01

    Full Text Available Abstract Background In mammals, the CNS vasculature is established during the postnatal period via active angiogenesis, providing different brain regions with capillary networks of various densities that locally supply adapted metabolic support to neurons. Thereafter this vasculature remains essentially quiescent excepted for specific pathologies. In the adult rat hypothalamus, a particularly dense network of capillary vessels is associated with the supraoptic (SON and paraventricular (PVN nuclei containing the magnocellular neurons secreting vasopressin and oxytocin, two neurohormones involved in the control of the body fluid homoeostasis. In the seventies, it was reported that proliferation of astrocytes and endothelial cells occurs within these hypothalamic nuclei when strong metabolic activation of the vasopressinergic and oxytocinergic neurons was induced by prolonged hyperosmotic stimulation. The aim of the present study was to determine whether such proliferative response to osmotic stimulus is related to local angiogenesis and to elucidate the cellular and molecular mechanisms involved. Results Our results provide evidence that cell proliferation occurring within the SON of osmotically stimulated adult rats corresponds to local angiogenesis. We show that 1 a large majority of the SON proliferative cells is associated with capillary vessels, 2 this proliferative response correlates with a progressive increase in density of the capillary network within the nucleus, and 3 SON capillary vessels exhibit an increased expression of nestin and vimentin, two markers of newly formed vessels. Contrasting with most adult CNS neurons, hypothalamic magnocellular neurons were found to express vascular endothelial growth factor (VEGF, a potent angiogenic factor whose production was increased by osmotic stimulus. When VEGF was inhibited by dexamethasone treatment or by the local application of a blocking antibody, the angiogenic response was strongly

  17. Femtosecond laser cutting of endothelial grafts: comparison of endothelial and epithelial applanation.

    Science.gov (United States)

    Bernard, Aurélien; He, Zhiguo; Gauthier, Anne Sophie; Trone, Marie Caroline; Baubeau, Emmanuel; Forest, Fabien; Dumollard, Jean Marc; Peocʼh, Michel; Thuret, Gilles; Gain, Philippe

    2015-02-01

    Stromal surface quality of endothelial lamellae cut for endothelial keratoplasty with a femtosecond laser (FSL) with epithelial applanation remains disappointing. Applanation of the endothelial side of the cornea, mounted inverted on an artificial chamber, has therefore been proposed to improve cut quality. We compared lamellar quality after FSL cutting using epithelial versus endothelial applanation. Lamellae were cut with an FSL from organ-cultured corneas. After randomization, 7 were cut with epithelial applanation and 7 with endothelial applanation. Lamellae of 50-, 75-, and 100-μm thickness were targeted. Thickness was measured by optical coherence tomography before and immediately after cutting. Viable endothelial cell density was quantified immediately after cutting using triple labeling with Hoechst/ethidium/calcein-AM coupled with image analysis with ImageJ. The stromal surface was evaluated by 9 masked observers using semiquantitative scoring of scanning electronic microscopy images. Histology of 2 samples was also analyzed before lamellar detachment. Precision (difference in target/actual thickness) and thickness regularity [coefficient of variation (CV) of 10 measurements] were significantly better with endothelial applanation (precision: 18 μm; range, 10-30; CV: 11%; range, 8-12) than with epithelial applanation (precision: 84 μm; range, 54-107; P = 0.002; CV: 24%; range, 13-47; P = 0.001). Endothelial applanation provided thinner lamellae. However, viable endothelial cell density was significantly lower after endothelial applanation (1183 cells/mm2; range, 787-1725 versus 1688 cells/mm2; range, 1288-2025; P = 0.018). FSL cutting of endothelial lamellae using endothelial applanation provides thinner more regular grafts with more predictable thickness than with conventional epithelial applanation but strongly reduces the pool of viable endothelial cells.

  18. A Chip-Capillary Hybrid Device for Automated Transfer of Sample Pre-Separated by Capillary Isoelectric Focusing to Parallel Capillary Gel Electrophoresis for Two-Dimensional Protein Separation

    Science.gov (United States)

    Lu, Joann J.; Wang, Shili; Li, Guanbin; Wang, Wei; Pu, Qiaosheng; Liu, Shaorong

    2012-01-01

    In this report, we introduce a chip-capillary hybrid device to integrate capillary isoelectric focusing (CIEF) with parallel capillary sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS-PAGE) or capillary gel electrophoresis (CGE) toward automating two-dimensional (2D) protein separations. The hybrid device consists of three chips that are butted together. The middle chip can be moved between two positions to re-route the fluidic paths, which enables the performance of CIEF and injection of proteins partially resolved by CIEF to CGE capillaries for parallel CGE separations in a continuous and automated fashion. Capillaries are attached to the other two chips to facilitate CIEF and CGE separations and to extend the effective lengths of CGE columns. Specifically, we illustrate the working principle of the hybrid device, develop protocols for producing and preparing the hybrid device, and demonstrate the feasibility of using this hybrid device for automated injection of CIEF-separated sample to parallel CGE for 2D protein separations. Potentials and problems associated with the hybrid device are also discussed. PMID:22830584

  19. On hydraulics of capillary tubes

    Directory of Open Access Journals (Sweden)

    N.G. Aloyan

    2016-03-01

    Full Text Available The article considers the laws of motion of water in the capillary tubes, taken as a model for flowing well, on the analogical net count device. For capillary tube the lower limit value of flow rate is empirically determined above which the total hydraulic resistance of the capillary is practically constant. The specificity of the phenomenon is that the regime of motion, by a Reynolds number, for a given flow rate still remains laminar. This circumstance can perplex the specialists, so the author invites them to the scientific debate on the subject of study. Obviously, to identify the resulting puzzle it is necessary to conduct a series of experiments using capillaries of different lengths and diameters and with different values of overpressure. The article states that in tubes with very small diameter the preliminary magnitude of capillary rise of water in the presence of flow plays no role and can be neglected.

  20. Western blotting using capillary electrophoresis.

    Science.gov (United States)

    Anderson, Gwendolyn J; M Cipolla, Cynthia; Kennedy, Robert T

    2011-02-15

    A microscale Western blotting system based on separating sodium-dodecyl sulfate protein complexes by capillary gel electrophoresis followed by deposition onto a blotting membrane for immunoassay is described. In the system, the separation capillary is grounded through a sheath capillary to a mobile X-Y translation stage which moves a blotting membrane past the capillary outlet for protein deposition. The blotting membrane is moistened with a methanol and buffer mixture to facilitate protein adsorption. Although discrete protein zones could be detected, bands were broadened by ∼1.7-fold by transfer to membrane. A complete Western blot for lysozyme was completed in about one hour with 50 pg mass detection limit from low microgram per milliliter samples. These results demonstrate substantial reduction in time requirements and improvement in mass sensitivity compared to conventional Western blots. Western blotting using capillary electrophoresis shows promise to analyze low volume samples with reduced reagents and time, while retaining the information content of a typical Western blot.

  1. Nasal Lobular Capillary Hemangioma

    Directory of Open Access Journals (Sweden)

    Prashant Patil

    2013-01-01

    Full Text Available Nasal lobular capillary hemangioma is a rare benign tumor of the paranasal sinuses. This lesion is believed to grow rapidly in size over time. The exact etiopathogenesis is still a dilemma. We discuss a case of nasal lobular capillary hemangioma presenting with a history of epistaxis. Contrast enhanced computed tomography of paranasal sinuses revealed an intensely enhancing soft-tissue mass in the left nasal cavity and left middle and inferior meati with no obvious bony remodeling or destruction. We present imaging and pathologic features of nasal lobular capillary hemangioma and differentiate it from other entities like nasal angiofibroma.

  2. Evaluation of microvascular endothelial function and capillary density in patients with infective endocarditis using laser speckle contrast imaging and video-capillaroscopy.

    Science.gov (United States)

    Barcelos, Amanda; Tibirica, Eduardo; Lamas, Cristiane

    2018-07-01

    To evaluate the systemic microcirculation of patients with infective endocarditis (IE). This is a comparative study of patients with definite IE by the modified Duke criteria admitted to our center for treatment. A reference group of sex- and age-matched healthy volunteers was included. Microvascular flow was evaluated in the forearm using a laser speckle contrast imaging system, for noninvasive measurement of cutaneous microvascular perfusion, in combination with skin iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to test microvascular reactivity. Microvascular density was evaluated using skin video-capillaroscopy. We studied 22 patients with IE; 15 were male and seven female. The mean age and standard deviation (SD) were 45.5 ± 17.3 years. Basal skin microvascular conductance was significantly increased in patients with IE, compared with healthy individuals (0.36 ± 0.13 versus 0.21 ± 0.08 APU/mmHg; P < 0.0001). The increase in microvascular conductance induced by ACh in patients was 0.21 ± 0.17 and in the reference group, it was 0.37 ± 0.14 APU/mmHg (P = 0.0012). The increase in microvascular conductance induced by SNP in patients was 0.18 ± 0.14 and it was 0.29 ± 0.15 APU/mmHg (P = 0.0140) in the reference group. The basal mean skin capillary density of patients (135 ± 24 capillaries/mm 2 ) was significantly higher, compared with controls (97 ± 21 capillaries/mm 2 ; P < 0.0001). The main findings in the microcirculation of patients with IE were greater basal vasodilation and a reduction of the endothelium-dependent and -independent microvascular reactivity, as well as greater functional skin capillary density compared to healthy individuals. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  4. Progression of Diabetic Capillary Occlusion: A Model.

    Directory of Open Access Journals (Sweden)

    Xiao Fu

    2016-06-01

    Full Text Available An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.

  5. Improvement of insulin sensitivity in response to exercise training in type 2 diabetes mellitus is associated with vascular endothelial growth factor A expression.

    Science.gov (United States)

    Wagner, Henrik; Fischer, Helene; Degerblad, Marie; Alvarsson, Michael; Gustafsson, Thomas

    2016-09-01

    Insulin sensitivity changes in response to exercise training demonstrate a large variation. Vascular endothelial growth factor A could promote increased insulin sensitivity through angiogenesis. We investigated associations between changes in expression of key genes and insulin sensitivity, aerobic capacity and glycaemic control following exercise training in diabetes mellitus type 2. Subjects with diabetes mellitus type 2 underwent 12 weeks of structured exercise. Euglycaemic clamp, exercise test and HbA1c were performed. Muscle biopsies were obtained for mRNA expression. A total of 16 subjects completed the study. Change in vascular endothelial growth factor A expression was positively associated with an increase in insulin sensitivity (p = 0.004) and with a decrease in HbA1c (p = 0.034). Vascular endothelial growth factor A receptor-1 expression showed similar associations. The variation in physical adaptation to exercise training in diabetes mellitus type 2 was associated with changes in expression of vascular endothelial growth factor A in muscle. This difference in induced gene expression could contribute to the variation in exercise training effects on insulin sensitivity. Measures of capillary blood flow need to be assessed in future studies. © The Author(s) 2016.

  6. Maslinic acid inhibits proliferation of renal cell carcinoma cell lines and suppresses angiogenesis of endothelial cells

    Directory of Open Access Journals (Sweden)

    Parth Thakor

    2017-03-01

    Full Text Available Despite the introduction of many novel therapeutics in clinical practice, metastatic renal cell carcinoma (RCC remains a treatment-re-sistant cancer. As red and processed meat are considered risk factors for RCC, and a vegetable-rich diet is thought to reduce this risk, research into plant-based therapeutics may provide valuable complementary or alternative therapeutics for the management of RCC. Herein, we present the antiproliferative and antiangiogenic effects of maslinic acid, which occurs naturally in edible plants, particularly in olive fruits, and also in a variety of medicinal plants. Human RCC cell lines (ACHN, Caki-1, and SN12K1, endothelial cells (human umbilical vein endothelial cell line [HUVEC], and primary cultures of kidney proximal tubular epithelial cells (PTEC were treated with maslinic acid. Maslinic acid was relatively less toxic to PTEC when compared with RCC under similar experimental conditions. In RCC cell lines, maslinic acid induced a significant reduction in proliferation, proliferating cell nuclear antigen, and colony formation. In HUVEC, maslinic acid induced a significant reduction in capillary tube formation in vitro and vascular endothelial growth factor. This study provides a rationale for incorporating a maslinic acid–rich diet either to reduce the risk of developing kidney cancer or as an adjunct to existing antiangiogenic therapy to improve efficacy.

  7. Effects of angiotensin II and ionomycin on fluid and bicarbonate absorption in the rat proximal tubule

    International Nuclear Information System (INIS)

    Chatsudthipong, V.; Chan, Y.L.

    1986-01-01

    Microperfusion of proximal convoluted tubule(PCT) and peritubular capillaries was performed to examine the effects of angiotensin II(Ang II) and ionomycin on fluid and bicarbonate absorption. Bicarbonate was determined by microcalorimetry and C-14 inulin was used as a volume marker. The rates of bicarbonate absorption (JHCO 3 ) was 143 peq/min x mm and fluid absorption(Jv) was 2.70 nl/min x mm, when PCT and capillary perfusate contained normal Ringer solution. Addition of Ang II (10 -6 M) to the capillary perfusate caused reductions of JHCO 3 and Jv by 35%. A similar effect was observed when ionomycin was added to the capillary perfusate. Ang II antagonist, (Sar 1 , Ile 8 )-Angiotensin II(10 -6 M), completely blocked the inhibitory effect of Ang II on Jv and JHCO 3 . Removal of calcium from both luminal and capillary perfusate did not change the effect of Ang II on Jv and JHCO 3 . Our results indicate that Ang II inhibits the sodium-hydrogen exchanger in the proximal tubule via interacting with angiotensin receptor. The mechanism of Ang II action may involve mobilization of intracellular calcium

  8. Capillary waves in slow motion

    International Nuclear Information System (INIS)

    Seydel, Tilo; Tolan, Metin; Press, Werner; Madsen, Anders; Gruebel, Gerhard

    2001-01-01

    Capillary wave dynamics on glycerol surfaces has been investigated by means of x-ray photon correlation spectroscopy performed at grazing angles. The measurements show that thermally activated capillary wave motion is slowed down exponentially when the sample is cooled below 273 K. This finding directly reflects the freezing of the surface waves. The wave-number dependence of the measured time constants is in quantitative agreement with theoretical predictions for overdamped capillary waves

  9. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis.

    Science.gov (United States)

    Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

    2014-09-01

    Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (P<0.01), compared to normal controls. More than 80% of the VEGFR-2 in the diabetic retina was in the capillaries, compared to 47% in normal controls (P<0.01). Angiography in rabbit retinas revealed microvascular capillaries to be the location for VEGF-A-induced leakage, as expressed by significantly higher rate of fluorophore spreading with VEGF-A injection when compared to vehicle control (26±2 vs. 3±1 μm/s, P<0.05). Immunohistochemistry showed VEGFR-2 expression in capillaries of diabetic animals but not in normal controls. Macular vessels from diabetic patients (n=7) showed significantly more VEGFR-2 compared to nondiabetic controls (n=5) or peripheral retinal regions of the same retinas (P<0.01 in both cases). Here we introduce a new approach for early diagnosis of DR and VEGFR-2 as a molecular marker. VEGFR-2 could become a key diagnostic target, one that might help to prevent retinal vascular leakage and proliferation in diabetic patients. © FASEB.

  10. Endothelial Activation and Blood-Brain Barrier Disruption in Neurotoxicity after Adoptive Immunotherapy with CD19 CAR-T Cells.

    Science.gov (United States)

    Gust, Juliane; Hay, Kevin A; Hanafi, Laïla-Aïcha; Li, Daniel; Myerson, David; Gonzalez-Cuyar, Luis F; Yeung, Cecilia; Liles, W Conrad; Wurfel, Mark; Lopez, Jose A; Chen, Junmei; Chung, Dominic; Harju-Baker, Susanna; Özpolat, Tahsin; Fink, Kathleen R; Riddell, Stanley R; Maloney, David G; Turtle, Cameron J

    2017-12-01

    Lymphodepletion chemotherapy followed by infusion of CD19-targeted chimeric antigen receptor-modified T (CAR-T) cells can be complicated by neurologic adverse events (AE) in patients with refractory B-cell malignancies. In 133 adults treated with CD19 CAR-T cells, we found that acute lymphoblastic leukemia, high CD19 + cells in bone marrow, high CAR-T cell dose, cytokine release syndrome, and preexisting neurologic comorbidities were associated with increased risk of neurologic AEs. Patients with severe neurotoxicity demonstrated evidence of endothelial activation, including disseminated intravascular coagulation, capillary leak, and increased blood-brain barrier (BBB) permeability. The permeable BBB failed to protect the cerebrospinal fluid from high concentrations of systemic cytokines, including IFNγ, which induced brain vascular pericyte stress and their secretion of endothelium-activating cytokines. Endothelial activation and multifocal vascular disruption were found in the brain of a patient with fatal neurotoxicity. Biomarkers of endothelial activation were higher before treatment in patients who subsequently developed grade ≥4 neurotoxicity. Significance: We provide a detailed clinical, radiologic, and pathologic characterization of neurotoxicity after CD19 CAR-T cells, and identify risk factors for neurotoxicity. We show endothelial dysfunction and increased BBB permeability in neurotoxicity and find that patients with evidence of endothelial activation before lymphodepletion may be at increased risk of neurotoxicity. Cancer Discov; 7(12); 1404-19. ©2017 AACR. See related commentary by Mackall and Miklos, p. 1371 This article is highlighted in the In This Issue feature, p. 1355 . ©2017 American Association for Cancer Research.

  11. Comprehensive protein profiling by multiplexed capillary zone electrophoresis using cross-linked polyacrylamide coated capillaries.

    Science.gov (United States)

    Liu, Shaorong; Gao, Lin; Pu, Qiaosheng; Lu, Joann J; Wang, Xingjia

    2006-02-01

    We have recently developed a new process to create cross-linked polyacrylamide (CPA) coatings on capillary walls to suppress protein-wall interactions. Here, we demonstrate CPA-coated capillaries for high-efficiency (>2 x 10(6) plates per meter) protein separations by capillary zone electrophoresis (CZE). Because CPA virtually eliminates electroosmotic flow, positive and negative proteins cannot be analyzed in a single run. A "one-sample-two-separation" approach is developed to achieve a comprehensive protein analysis. High throughput is achieved through a multiplexed CZE system.

  12. Ion guiding and losses in insulator capillaries

    International Nuclear Information System (INIS)

    Juhasz, Z.; Sulik, B.; Vikor, Gy.; Biri, S.; Fekete, E.; Ivan, I.; Gall, F.; Toekesi, K.; Matefi-Tempfli, S.; Matefi-Tempfli, M.

    2007-01-01

    Complete text of publication follows. Not long ago it was discovered that insulating capillaries can guide slow ions, so that the ions avoid close contact with the capillary walls and preserve their initial charge state. This phenomenon did not only give a new puzzle for theoreticians but opened the way for new possible applications where ions are manipulated (deflected, focused and directed to different patterns on the irradiated media) with small capillary devices. The most important question for such applications is how large fraction of the ions can be guided to the desired direction. It is already known that the ion guiding is due to the charging up of the inner capillary walls by earlier ion impact events. In tilted capillaries one side of the capillary walls charges up. This deflects the later arriving ions, so that some of them pass through the capillaries nearly parallel with respect to their axes. The angle where the transmission drops to 1/e of the direct transmission at 0 deg is the guiding angle, which characterize the guiding ability. At 0 deg the ideal 100 percent transmission for the ions, which enter the capillaries, is reduced due to the mirror charge attraction and geometrical imperfections. These losses appear in the transmission for tilted capillaries with similar magnitude, since after the deflection region, which usually restricted to the close surroundings of the capillary openings, the guided ions pass through the rest of the capillaries as in non-tilted samples. In our experimental studies with Al 2 O 3 capillaries we found that around 90 percent of the incoming ions are lost. To understand these significant losses, the effects of the mirror charge attraction and geometrical imperfections have been calculated classically. The mirror charge potential was taken from.The model of the capillaries used in the calculations can be seen in Figure 1. The calculations have shown that the effects of mirror charge attraction and the angular

  13. DNA typing by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, N.

    1997-10-08

    Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.

  14. Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

    Science.gov (United States)

    Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

    2013-12-01

    Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

  15. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Gordaliza, Estefanía, E-mail: emorenog@ucm.es [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain); Stigter, Edwin C.A. [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Molecular Cancer Research, Universitair Medisch Centrum Utrecht, Wilhelmina Kinder Ziekenhuis, Lundlaan 6, 3584, EA Utrecht (Netherlands); Lindenburg, Petrus W.; Hankemeier, Thomas [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands)

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10{sup −9} m{sup 2} V{sup −1} s{sup −1}) when compared with unmodified fused silica (5.9 ± 0.1 10{sup −8} m{sup 2} V{sup −1} s{sup −1}). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1–1.8% coefficient-of-variation (CV) within a day) and 2–3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. - Highlights: • New coating using recrystallized surface-layer proteins on

  16. Capillary Condensation in Confined Media

    OpenAIRE

    Charlaix, Elisabeth; Ciccotti, Matteo

    2009-01-01

    28 pages - To appear in 2010 in the Handbook of Nanophysics - Vol 1 - Edited by Klaus Sattler - CRC Press; We review here the physics of capillary condensation of liquids in confined media, with a special regard to the application in nanotechnologies. The thermodynamics of capillary condensation and thin film adsorption are first exposed along with all the relevant notions. The focus is then shifted to the modelling of capillary forces, to their measurements techniques (including SFA, AFM and...

  17. Capillary-Condenser-Pumped Heat-Transfer Loop

    Science.gov (United States)

    Silverstein, Calvin C.

    1989-01-01

    Heat being transferred supplies operating power. Capillary-condenser-pumped heat-transfer loop similar to heat pipe and to capillary-evaporator-pumped heat-transfer loop in that heat-transfer fluid pumped by evaporation and condensation of fluid at heat source and sink, respectively. Capillary condenser pump combined with capillary evaporator pump to form heat exchanger circulating heat-transfer fluids in both loops. Transport of heat more nearly isothermal. Thermal stress in loop reduced, and less external surface area needed in condenser section for rejection of heat to heat sink.

  18. Curcumin induces therapeutic angiogenesis in a diabetic mouse hindlimb ischemia model via modulating the function of endothelial progenitor cells.

    Science.gov (United States)

    You, Jinzhi; Sun, Jiacheng; Ma, Teng; Yang, Ziying; Wang, Xu; Zhang, Zhiwei; Li, Jingjing; Wang, Longgang; Ii, Masaaki; Yang, Junjie; Shen, Zhenya

    2017-08-03

    Neovascularization is impaired in diabetes mellitus, which leads to the development of peripheral arterial disease and is mainly attributed to the dysfunction of endothelial progenitor cells (EPCs). Previous studies proved the promotional effect of curcumin on neovascularization in wound healing of diabetes. Thus, we hypothesize that curcumin could promote neovascularization at sites of hindlimb ischemia in diabetes and might take effect via modulating the function of EPCs. Streptozotocin-induced type 1 diabetic mice and nondiabetic mice both received unilateral hindlimb ischemic surgery. Curcumin was then administrated to the mice by lavage for 14 days consecutively. Laser Doppler perfusion imaging was conducted to demonstrate the blood flow reperfusion. Capillary density was measured in the ischemic gastrocnemius muscle. In addition, angiogenesis, migration, proliferation abilities, and senescence were determined in EPCs isolated from diabetic and nondiabetic mice. Quantitative PCR was then used to determine the mRNA expression of vascular endothelial growth factor (VEGF) and angiopoetin-1 (Ang-1) in EPCs. Curcumin application to type 1 diabetic mice significantly improved blood reperfusion and increased the capillary density in ischemic hindlimbs. The in-vitro study also revealed that the angiogenesis, migration, and proliferation abilities of EPCs and the number of senescent EPCs were reversed by curcumin application. Quantitative PCR confirmed the overexpression of VEGF-A and Ang-1 in EPCs after curcumin treatment. Curcumin could enhance neovascularization via promoting the function of EPCs in a diabetic mouse hindlimb ischemia model.

  19. The Pharmaceutical Device Prisma® Skin Promotes in Vitro Angiogenesis through Endothelial to Mesenchymal Transition during Skin Wound Healing.

    Science.gov (United States)

    Belvedere, Raffaella; Bizzarro, Valentina; Parente, Luca; Petrella, Francesco; Petrella, Antonello

    2017-07-25

    Glycosaminoglycans are polysaccharides of the extracellular matrix supporting skin wound closure. Mesoglycan is a mixture of glycosaminoglycans such as chondroitin-, dermatan-, heparan-sulfate and heparin and is the main component of Prisma ® Skin, a pharmaceutical device developed by Mediolanum Farmaceutici S.p.a. Here, we show the in vitro effects of this device in the new vessels formation by endothelial cells, since angiogenesis represents a key moment in wound healing. We found a strong increase of migration and invasion rates of these cells treated with mesoglycan and Prisma ® Skin which mediate the activation of the pathway triggered by CD44 receptor. Furthermore, endothelial cells form longer capillary-like structures with a great number of branches, in the presence of the same treatments. Thus, the device, thanks to the mesoglycan, leads the cells to the Endothelial-to-Mesenchymal Transition, suggesting the switch to a fibroblast-like phenotype, as shown by immunofluorescence assays. Finally, we found that mesoglycan and Prisma ® Skin inhibit inflammatory reactions such as nitric oxide secretion and NF-κB nuclear translocation in endothelial cells and Tumor Necrosis Factor-α production by macrophages. In conclusion, based on our data, we suggest that Prisma ® Skin may be able to accelerate angiogenesis in skin wound healing, and regulate inflammation avoiding chronic, thus pathological, responses.

  20. The Pharmaceutical Device Prisma® Skin Promotes in Vitro Angiogenesis through Endothelial to Mesenchymal Transition during Skin Wound Healing

    Directory of Open Access Journals (Sweden)

    Raffaella Belvedere

    2017-07-01

    Full Text Available Glycosaminoglycans are polysaccharides of the extracellular matrix supporting skin wound closure. Mesoglycan is a mixture of glycosaminoglycans such as chondroitin-, dermatan-, heparan-sulfate and heparin and is the main component of Prisma® Skin, a pharmaceutical device developed by Mediolanum Farmaceutici S.p.a. Here, we show the in vitro effects of this device in the new vessels formation by endothelial cells, since angiogenesis represents a key moment in wound healing. We found a strong increase of migration and invasion rates of these cells treated with mesoglycan and Prisma® Skin which mediate the activation of the pathway triggered by CD44 receptor. Furthermore, endothelial cells form longer capillary-like structures with a great number of branches, in the presence of the same treatments. Thus, the device, thanks to the mesoglycan, leads the cells to the Endothelial-to-Mesenchymal Transition, suggesting the switch to a fibroblast-like phenotype, as shown by immunofluorescence assays. Finally, we found that mesoglycan and Prisma® Skin inhibit inflammatory reactions such as nitric oxide secretion and NF-κB nuclear translocation in endothelial cells and Tumor Necrosis Factor-α production by macrophages. In conclusion, based on our data, we suggest that Prisma® Skin may be able to accelerate angiogenesis in skin wound healing, and regulate inflammation avoiding chronic, thus pathological, responses.

  1. Capillary leak syndrome: etiologies, pathophysiology, and management.

    Science.gov (United States)

    Siddall, Eric; Khatri, Minesh; Radhakrishnan, Jai

    2017-07-01

    In various human diseases, an increase in capillary permeability to proteins leads to the loss of protein-rich fluid from the intravascular to the interstitial space. Although sepsis is the disease most commonly associated with this phenomenon, many other diseases can lead to a "sepsis-like" syndrome with manifestations of diffuse pitting edema, exudative serous cavity effusions, noncardiogenic pulmonary edema, hypotension, and, in some cases, hypovolemic shock with multiple-organ failure. The term capillary leak syndrome has been used to describe this constellation of disease manifestations associated with an increased capillary permeability to proteins. Diseases other than sepsis that can result in capillary leak syndrome include the idiopathic systemic capillary leak syndrome or Clarkson's disease, engraftment syndrome, differentiation syndrome, the ovarian hyperstimulation syndrome, hemophagocytic lymphohistiocytosis, viral hemorrhagic fevers, autoimmune diseases, snakebite envenomation, and ricin poisoning. Drugs including some interleukins, some monoclonal antibodies, and gemcitabine can also cause capillary leak syndrome. Acute kidney injury is commonly seen in all of these diseases. In addition to hypotension, cytokines are likely to be important in the pathophysiology of acute kidney injury in capillary leak syndrome. Fluid management is a critical part of the treatment of capillary leak syndrome; hypovolemia and hypotension can cause organ injury, whereas capillary leakage of administered fluid can worsen organ edema leading to progressive organ injury. The purpose of this article is to discuss the diseases other than sepsis that produce capillary leak and review their collective pathophysiology and treatment. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  2. Electro-capillary effects in capillary filling dynamics of electrorheological fluids.

    Science.gov (United States)

    Dhar, Jayabrata; Ghosh, Uddipta; Chakraborty, Suman

    2015-09-21

    The flow of electrorheological fluids is characterized by an apparent increase in viscosity manifested by the yield stress property of the fluid, which is a function of the applied electric field and the concentration of the suspended solute phase within the dielectric medium. This property of electrorheological fluids generally hinders flow through a capillary if the imposed shear stress is lower than the induced yield stress. This results in a plug-like zone in the flow profile, thus giving the fluid Bingham plastic properties. In the present work, we study such influences of the yield stress on the capillary filling dynamics of an electrorheological fluid by employing a rheologically consistent reduced order formalism. One important feature of the theoretical formalism is its ability to address the intricate interplay between the surface tension and viscous forces, both of which depend sensitively on the electric field. Our analysis reveals that the progress of the capillary front is hindered at an intermediate temporal regime, which is attributable to the increase of the span of the plug-zone across the channel width with time. With a preliminary understanding on the cessation of the capillary front advancement due to the yield stress property of the electrorheological fluids, we further strive to achieve a basic comparison with an experimental study made earlier. Reasonable agreements with the reported data support our theoretical framework. Comprehensive scaling analysis brings further insight to our reported observations over various temporal regimes.

  3. Validation of capillary blood analysis and capillary testing mode on the epoc Point of Care system

    Directory of Open Access Journals (Sweden)

    Jing Cao

    2017-12-01

    Full Text Available Background: Laboratory test in transport is a critical component of patient care, and capillary blood is a preferred sample type particularly in children. This study evaluated the performance of capillary blood testing on the epoc Point of Care Blood Analysis System (Alere Inc. Methods: Ten fresh venous blood samples was tested on the epoc system under the capillary mode. Correlation with GEM 4000 (Instrumentation Laboratory was examined for Na+, K+, Cl-, Ca2+, glucose, lactate, hematocrit, hemoglobin, pO2, pCO2, and pH, and correlation with serum tested on Vitros 5600 (Ortho Clinical Diagnostics was examined for creatinine. Eight paired capillary and venous blood was tested on epoc and ABL800 (Radiometer for the correlation of Na+, K+, Cl-, Ca2+, glucose, lactate, hematocrit, hemoglobin, pCO2, and pH. Capillary blood from 23 apparently healthy volunteers was tested on the epoc system to assess the concordance to reference ranges used locally. Results: Deming regression correlation coefficients for all the comparisons were above 0.65 except for ionized Ca2+. Accordance of greater than 85% to the local reference ranges were found in all assays with the exception of pO2 and Cl-. Conclusion: Data from this study indicates that capillary blood tests on the epoc system provide comparable results to reference method for these assays, Na+, K+, glucose, lactate, hematocrit, hemoglobin, pCO2, and pH. Further validation in critically ill patients is needed to implement the epoc system in patient transport. Impact of the study: This study demonstrated that capillary blood tests on the epoc Point of Care Blood Analysis System give comparable results to other chemistry analyzers for major blood gas and critical tests. The results are informative to institutions where pre-hospital and inter-hospital laboratory testing on capillary blood is a critical component of patient point of care testing. Keywords: Epoc, Capillary, Transport, Blood gas, Point of care

  4. [The role of endothelial cells and endothelial precursor cells in angiogenesis].

    Science.gov (United States)

    Poreba, Małgorzata; Usnarska-Zubkiewicz, Lidia; Kuliczkowski, Kazimierz

    2006-01-01

    Endothelium plays a key role in maintenance of vascular homeostasis in human organism. According to new data endothelial cells and hematopoietic cells have a common precursor in prenatal life--a hemangioblast, which explains the fact of sharing the same determinants on the surface of both type of cells. Circulating endothelial precursors were identified in adults and this suggests that hemangioblasts may be present not only during embriogenesis. In some clinical situations the increased numbers of endothelial cells and endothelial precursors were noted, and especially in patients with neoplastic diseases, which is probably the result of increased angiogenesis. Endothelial precursors are thought to be the promice for therapeutic purposes in future--to increase local angiogenesis.

  5. A novel podoplanin-GFPCre mouse strain for gene deletion in lymphatic endothelial cells.

    Science.gov (United States)

    Gil, Hyea Jin; Ma, Wanshu; Oliver, Guillermo

    2018-04-01

    The lymphatic vascular system is a one-direction network of thin-walled capillaries and larger vessels covered by a continuous layer of endothelial cells responsible for maintaining fluid homeostasis. Some of the main functions of the lymphatic vasculature are to drain fluid from the extracellular spaces and return it back to the blood circulation, lipid absorption from the intestinal tract, and transport of immune cells to lymphoid organs. A number of genes controlling the development of the mammalian lymphatic vasculature have been identified in the last few years, and their functional roles started to be characterized using gene inactivation approaches in mice. Unfortunately, only few mouse Cre strains relatively specific for lymphatic endothelial cells (LECs) are currently available. In this article, we report the generation of a novel Podoplanin (Pdpn) GFPCre transgenic mouse strain using its 5' regulatory region. Pdpn encodes a transmembrane mucin-type O-glycoprotein that is expressed on the surface of embryonic and postnatal LECs, in addition to few other cell types. Our detailed characterization of this novel strain indicates that it will be a valuable additional genetic tool for the analysis of gene function in LECs. © 2018 Wiley Periodicals, Inc.

  6. Microfluidic PMMA interfaces for rectangular glass capillaries

    International Nuclear Information System (INIS)

    Evander, Mikael; Tenje, Maria

    2014-01-01

    We present the design and fabrication of a polymeric capillary fluidic interface fabricated by micro-milling. The design enables the use of glass capillaries with any kind of cross-section in complex microfluidic setups. We demonstrate two different designs of the interface; a double-inlet interface for hydrodynamic focusing and a capillary interface with integrated pneumatic valves. Both capillary interfaces are presented together with examples of practical applications. This communication shows the design optimization and presents details of the fabrication process. The capillary interface opens up for the use of complex microfluidic systems in single-use glass capillaries. They also enable simple fabrication of glass/polymer hybrid devices that can be beneficial in many research fields where a pure polymer chip negatively affects the device's performance, e.g. acoustofluidics. (technical note)

  7. Simultaneous isolation of vascular endothelial cells and mesenchymal stem cells from the human umbilical cord.

    Science.gov (United States)

    Kadam, Sachin S; Tiwari, Shubha; Bhonde, Ramesh R

    2009-01-01

    The umbilical cord represents the link between mother and fetus during pregnancy. This cord is usually discarded as a biological waste after the child's birth; however, its importance as a "store house" of stem cells has been explored recently. We developed a method of simultaneous isolation of endothelial cells (ECs) from the vein and mesenchymal stem cells from umbilical cord Wharton's jelly of the same cord. The isolation protocol has been simplified, modified, and improvised with respect to choice of enzyme and enzyme mixture, digestion time, cell yield, cell growth, and culture medium. Isolated human umbilical vascular ECs (hUVECs) were positive for von-Willibrand factor, a classical endothelial marker, and could form capillary-like structures when seeded on Matrigel, thus proving their functionality. The isolated human umbilical cord mesenchymal stem cells (hUCMSCs) were found positive for CD44, CD90, CD 73, and CD117 and were found negative for CD33, CD34, CD45, and CD105 surface markers; they were also positive for cytoskeleton markers of smooth muscle actin and vimentin. The hUCMSCs showed multilineage differentiation potential and differentiated into adipogenic, chondrogenic, osteogenic, and neuronal lineages under influence of lineage specific differentiation medium. Thus, isolating endothelial cells as well as mesenchymal cells from the same umbilical cord could lead to complete utilization of the available tissue for the tissue engineering and cell therapy.

  8. A complete soil hydraulic model accounting for capillary and adsorptive water retention, capillary and film conductivity, and hysteresis

    NARCIS (Netherlands)

    Sakai, Masaru; Van Genuchten, Martinus Th|info:eu-repo/dai/nl/31481518X; Alazba, A. A.; Setiawan, Budi Indra; Minasny, Budiman

    2015-01-01

    A soil hydraulic model that considers capillary hysteretic and adsorptive water retention as well as capillary and film conductivity covering the complete soil moisture range is presented. The model was obtained by incorporating the capillary hysteresis model of Parker and Lenhard into the hydraulic

  9. Validation of capillary blood analysis and capillary testing mode on the epoc Point of Care system.

    Science.gov (United States)

    Cao, Jing; Edwards, Rachel; Chairez, Janette; Devaraj, Sridevi

    2017-12-01

    Laboratory test in transport is a critical component of patient care, and capillary blood is a preferred sample type particularly in children. This study evaluated the performance of capillary blood testing on the epoc Point of Care Blood Analysis System (Alere Inc). Ten fresh venous blood samples was tested on the epoc system under the capillary mode. Correlation with GEM 4000 (Instrumentation Laboratory) was examined for Na+, K+, Cl-, Ca2+, glucose, lactate, hematocrit, hemoglobin, pO2, pCO2, and pH, and correlation with serum tested on Vitros 5600 (Ortho Clinical Diagnostics) was examined for creatinine. Eight paired capillary and venous blood was tested on epoc and ABL800 (Radiometer) for the correlation of Na+, K+, Cl-, Ca2+, glucose, lactate, hematocrit, hemoglobin, pCO2, and pH. Capillary blood from 23 apparently healthy volunteers was tested on the epoc system to assess the concordance to reference ranges used locally. Deming regression correlation coefficients for all the comparisons were above 0.65 except for ionized Ca2+. Accordance of greater than 85% to the local reference ranges were found in all assays with the exception of pO2 and Cl-. Data from this study indicates that capillary blood tests on the epoc system provide comparable results to reference method for these assays, Na+, K+, glucose, lactate, hematocrit, hemoglobin, pCO2, and pH. Further validation in critically ill patients is needed to implement the epoc system in patient transport. This study demonstrated that capillary blood tests on the epoc Point of Care Blood Analysis System give comparable results to other chemistry analyzers for major blood gas and critical tests. The results are informative to institutions where pre-hospital and inter-hospital laboratory testing on capillary blood is a critical component of patient point of care testing.

  10. Quantification of nucleotides by ICPMS: coupling of ICPMS with capillary electrophoresis or capillary HPLC

    International Nuclear Information System (INIS)

    Inagaki, K.; Fujii, S.; Takatsu, A.; Yarita, T.; Zhu, Y.; Chiba, K.

    2009-01-01

    Full text: Quantification of nucleotides in small volumes of biological samples has eagerly been demanded. A method using ICPMS coupled with capillary electrophoresis or capillary liquid chromatography is reported. A new interface system, which consists of a double tube nebulizer inserted with a fused silica capillary tube and a cylinder mini-chamber with a sheath gas inlet, was designed. Moreover, the surface conditions of the sampling and skimmer cones, and the introduction of H 2 gas into the plasma were found to significantly improve the signal/background ratio for phosphorus determination at m/z 31. (author)

  11. X-ray focusing using capillary arrays

    International Nuclear Information System (INIS)

    Nugent, K.A.; Chapman, H.N.

    1990-01-01

    A new form of X-ray focusing device based on glass capillary arrays is presented. Theoretical and experimental results for array of circular capillaries and theoretical and computational results for square hole capillaries are given. It is envisaged that devices such as these will find wide applications in X-ray optics as achromatic condensers and collimators. 3 refs., 4 figs

  12. Targeting of the pulmonary capillary vascular niche promotes lung alveolar repair and ameliorates fibrosis.

    Science.gov (United States)

    Cao, Zhongwei; Lis, Raphael; Ginsberg, Michael; Chavez, Deebly; Shido, Koji; Rabbany, Sina Y; Fong, Guo-Hua; Sakmar, Thomas P; Rafii, Shahin; Ding, Bi-Sen

    2016-02-01

    Although the lung can undergo self-repair after injury, fibrosis in chronically injured or diseased lungs can occur at the expense of regeneration. Here we study how a hematopoietic-vascular niche regulates alveolar repair and lung fibrosis. Using intratracheal injection of bleomycin or hydrochloric acid in mice, we show that repetitive lung injury activates pulmonary capillary endothelial cells (PCECs) and perivascular macrophages, impeding alveolar repair and promoting fibrosis. Whereas the chemokine receptor CXCR7, expressed on PCECs, acts to prevent epithelial damage and ameliorate fibrosis after a single round of treatment with bleomycin or hydrochloric acid, repeated injury leads to suppression of CXCR7 expression and recruitment of vascular endothelial growth factor receptor 1 (VEGFR1)-expressing perivascular macrophages. This recruitment stimulates Wnt/β-catenin-dependent persistent upregulation of the Notch ligand Jagged1 (encoded by Jag1) in PCECs, which in turn stimulates exuberant Notch signaling in perivascular fibroblasts and enhances fibrosis. Administration of a CXCR7 agonist or PCEC-targeted Jag1 shRNA after lung injury promotes alveolar repair and reduces fibrosis. Thus, targeting of a maladapted hematopoietic-vascular niche, in which macrophages, PCECs and perivascular fibroblasts interact, may help to develop therapy to spur lung regeneration and alleviate fibrosis.

  13. Targeting of the pulmonary capillary vascular niche promotes lung alveolar repair and ameliorates fibrosis

    Science.gov (United States)

    Cao, Zhongwei; Lis, Raphael; Ginsberg, Michael; Chavez, Deebly; Shido, Koji; Rabbany, Sina Y.; Fong, Guo-Hua; Sakmar, Thomas P.; Rafii, Shahin; Ding, Bi-Sen

    2016-01-01

    Although the lung can undergo self-repair after injury, fibrosis in chronically injured or diseased lungs can occur at the expense of regeneration. Here we study how a hematopoietic-vascular niche regulates alveolar repair and lung fibrosis. Using intratracheal injection of bleomycin or hydrochloric acid in mice, we show that repetitive lung injury activates pulmonary capillary endothelial cells (PCECs) and perivascular macrophages, impeding alveolar repair and promoting fibrosis. Whereas the chemokine receptor CXCR7, expressed on PCECs, acts to prevent epithelial damage and ameliorate fibrosis after a single round of treatment with bleomycin or hydrochloric acid, repeated injury leads to suppression of CXCR7 expression and recruitment of vascular endothelial growth factor receptor 1 (VEGFR1)-expressing perivascular macrophages. This recruitment stimulates Wnt/β-catenin–dependent persistent upregulation of the Notch ligand Jagged1 (encoded by Jag1) in PCECs, which in turn stimulates exuberant Notch signaling in perivascular fibroblasts and enhances fibrosis. Administration of a CXCR7 agonist or PCEC-targeted Jag1 shRNA after lung injury promotes alveolar repair and reduces fibrosis. Thus, targeting of a maladaptbed hematopoietic-vascular niche, in which macrophages, PCECs and perivascular fibroblasts interact, may help to develop therapy to spur lung regeneration and alleviate fibrosis. PMID:26779814

  14. Capillary condenser/evaporator

    Science.gov (United States)

    Valenzuela, Javier A. (Inventor)

    2010-01-01

    A heat transfer device is disclosed for transferring heat to or from a fluid that is undergoing a phase change. The heat transfer device includes a liquid-vapor manifold in fluid communication with a capillary structure thermally connected to a heat transfer interface, all of which are disposed in a housing to contain the vapor. The liquid-vapor manifold transports liquid in a first direction and conducts vapor in a second, opposite direction. The manifold provides a distributed supply of fluid (vapor or liquid) over the surface of the capillary structure. In one embodiment, the manifold has a fractal structure including one or more layers, each layer having one or more conduits for transporting liquid and one or more openings for conducting vapor. Adjacent layers have an increasing number of openings with decreasing area, and an increasing number of conduits with decreasing cross-sectional area, moving in a direction toward the capillary structure.

  15. Micro-injector for capillary electrophoresis.

    Science.gov (United States)

    Sáiz, Jorge; Koenka, Israel Joel; García-Ruiz, Carmen; Müller, Beat; Chwalek, Thomas; Hauser, Peter C

    2015-08-01

    A novel micro-injector for capillary electrophoresis for the handling of samples with volumes down to as little as 300 nL was designed and built in our laboratory for analyses in which the available volume is a limitation. The sample is placed into a small cavity located directly in front of the separation capillary, and the injection is then carried out automatically by controlled pressurization of the chamber with compressed air. The system also allows automated flushing of the injection chamber as well as of the capillary. In a trial with a capillary electrophoresis system with contactless conductivity detector, employing a capillary of 25 μm diameter, the results showed good stability of migration times and peak areas. To illustrate the technique, the fast separation of five inorganic cations (Na(+) , K(+) , NH4 (+) , Ca(2+) , and Mg(2+) ) was set up. This could be achieved in less than 3 min, with good limits of detection (10 μM) and linear ranges (between about 10 and 1000 μM). The system was demonstrated for the determination of the inorganic cations in porewater samples of a lake sediment core. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Design of Capillary Flows with Spatially Graded Porous Films

    Science.gov (United States)

    Joung, Young Soo; Figliuzzi, Bruno Michel; Buie, Cullen

    2013-11-01

    We have developed a new capillary tube model, consisting of multi-layered capillary tubes oriented in the direction of flow, to predict capillary speeds on spatially graded porous films. Capillary flows through thin porous media have been widely utilized for small size liquid transport systems. However, for most media it is challenging to realize arbitrary shapes and spatially functionalized micro-structures with variable flow properties. Therefore, conventional media can only be used for capillary flows obeying Washburn's equation and the modifications thereof. Given this background, we recently developed a method called breakdown anodization (BDA) to produce highly wetting porous films. The resulting surfaces show nearly zero contact angles and fast water spreading speed. Furthermore, capillary pressure and spreading diffusivity can be expressed as functions of capillary height when customized electric fields are used in BDA. From the capillary tube model, we derived a general capillary flow equation of motion in terms of capillary pressure and spreading diffusivity. The theoretical model shows good agreement with experimental capillary flows. The study will provide novel design methodologies for paper-based microfluidic devices.

  17. Effect of silica nanoparticles with variable size and surface functionalization on human endothelial cell viability and angiogenic activity

    Science.gov (United States)

    Guarnieri, Daniela; Malvindi, Maria Ada; Belli, Valentina; Pompa, Pier Paolo; Netti, Paolo

    2014-02-01

    Silica nanoparticles could be promising delivery vehicles for drug targeting or gene therapy. However, few studies have been undertaken to determine the biological behavior effects of silica nanoparticles on primary endothelial cells. Here we investigated uptake, cytotoxicity and angiogenic properties of silica nanoparticle with positive and negative surface charge and sizes ranging from 25 to 115 nm in primary human umbilical vein endothelial cells. Dynamic light scattering measurements and nanoparticle tracking analysis were used to estimate the dispersion status of nanoparticles in cell culture media, which was a key aspect to understand the results of the in vitro cellular uptake experiments. Nanoparticles were taken up by primary endothelial cells in a size-dependent manner according to their degree of agglomeration occurring after transfer in cell culture media. Functionalization of the particle surface with positively charged groups enhanced the in vitro cellular uptake, compared to negatively charged nanoparticles. However, this effect was contrasted by the tendency of particles to form agglomerates, leading to lower internalization efficiency. Silica nanoparticle uptake did not affect cell viability and cell membrane integrity. More interestingly, positively and negatively charged 25 nm nanoparticles did not influence capillary-like tube formation and angiogenic sprouting, compared to controls. Considering the increasing interest in nanomaterials for several biomedical applications, a careful study of nanoparticle-endothelial cells interactions is of high relevance to assess possible risks associated to silica nanoparticle exposure and their possible applications in nanomedicine as safe and effective nanocarriers for vascular transport of therapeutic agents.

  18. Proper Use of Capillary Number in Chemical Flooding

    Directory of Open Access Journals (Sweden)

    Hu Guo

    2017-01-01

    Full Text Available Capillary number theory is very important for chemical flooding enhanced oil recovery. The difference between microscopic capillary number and the microscopic one is easy to confuse. After decades of development, great progress has been made in capillary number theory and it has important but sometimes incorrect application in EOR. The capillary number theory was based on capillary tube bundles and Darcy’s law hypothesis, and this should always be kept in mind when used in chemical flooding EOR. The flow in low permeability porous media often shows obvious non-Darcy effects, which is beyond Darcy’s law. Experiments data from ASP flooding and SP flooding showed that remaining oil saturation was not always decreasing as capillary number kept on increasing. Relative permeability was proved function of capillary number; its rate dependence was affected by capillary end effects. The mobility control should be given priority rather than lowering IFT. The displacement efficiency was not increased as displacement velocity increased as expected in heavy oil chemical flooding. Largest capillary number does not always make highest recovery in chemical flooding in heterogeneous reservoir. Misuse of CDC in EOR included the ignorance of mobility ratio, Darcy linear flow hypothesis, difference between microscopic capillary number and the microscopic one, and heterogeneity caused flow regime alteration. Displacement of continuous oil or remobilization of discontinuous oil was quite different.

  19. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  20. Separation of oligopeptides, nucleobases, nucleosides and nucleotides using capillary electrophoresis/electrochromatography with sol-gel modified inner capillary wall.

    Science.gov (United States)

    Svobodová, Jana; Kofroňová, Olga; Benada, Oldřich; Král, Vladimír; Mikšík, Ivan

    2017-09-29

    The aim of this article is to study the modification of an inner capillary wall with sol-gel coating (pure silica sol-gel or silica sol-gel containing porphyrin-brucine conjugate) and determine its influence on the separation process using capillary electrophoresis/electrochromatography method. After modification of the inner capillary surface the separation of analytes was performed using two different phosphate buffers (pH 2.5 and 9.0) and finally the changes in electrophoretic mobilities of various samples were calculated. To confirm that the modification of the inner capillary surface was successful, the parts of the inner surfaces of capillaries were observed using scanning electron microscopy. The analytes used as testing samples were oligopeptides, nucleosides, nucleobases and finally nucleotides. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Anti-glomerular basement membrane (anti-GBM) disease accompanied by vasculitis that was not positive for antineutrophil cytoplasmic antibodies to myeloperoxidase and proteinase 3: a report of two cases and the incidence of anti-GBM disease at one institution.

    Science.gov (United States)

    Nakabayashi, Kimimasa; Fujioka, Yasunori; Arimura, Yoshihiro; Fukuoka, Toshihito; Marumo, Tomohumi; Umino, Michiru; Kamiya, Yasushi; Okai, Takahiro; Tsurumaki, Shigeru; Nagasawa, Toshihiko; Yamada, Akira

    2011-08-01

    Anti-glomerular basement membrane (anti-GBM) disease is thought to be distinct from vasculitis. In contrast, there have been several papers suggesting the presence of angiitis in cases that were positive for anti-GBM antibody (Ab), as well as for either myeloperoxidase (MPO)- or proteinase 3 (PR3)-anti-neutrophil cytoplasmic antibody (ANCA) (Group I). We experienced four patients who had anti-GBM Abs, but not MPO- and PR3-ANCA (Group II), and two of these patients were found to have vasculitis. Therefore, we performed an in-depth study on these two patients. The patients with anti-GBM disease were isolated from 578 cases whose renal tissues were examined, and they were categorized into two groups. We have already published the data about Group I. We then proceeded to study two vasculitic patients in Group II clinically, pathologically, and serologically. The anti-GBM Ab and ANCA levels were detected by enzyme-linked immunosorbent assays. Renal specimens were studied by routine staining as well as immunohistochemical investigations of CD31 and type IV collagen. The total number of patients with anti-GBM disease was 7 (7/578 = 1.2%), with 3 patients belonging to Group I and 4 patients belonging to Group II. Two patients in Group II were diagnosed to have vasculitis, but the remaining 2 patients did not. One vasculitic patient was complicated by pulmonary hemorrhage, while the other vasculitic patient displayed peripheral neuropathy as well as a small cavity lesion in the lung. The latter patient was found to be positive for perinuclear (p)-ANCA, but not for any other ANCA subsets. The renal pathology in the two vasculitic patients showed crescentic glomerulonephritis (CSGN) and immunoglobulin (Ig) G linear deposits along the glomerular capillary loops. The former patient showed fibrinoid angiitis in an afferent arteriole as well as peritubular capillaritis. The latter patient demonstrated peritubular capillaritis. These peritubular capillaritides were diagnosed by

  2. Reliability of widefield capillary microscopy to measure nailfold capillary density in systemic sclerosis.

    Science.gov (United States)

    Hudson, M; Masetto, A; Steele, R; Arthurs, E; Baron, M

    2010-01-01

    To determine intra- and inter-observer reliability of widefield microscopy to measure nailfold capillary density in patients with systemic sclerosis (SSc). Five SSc patients were examined with a STEMV-8 Zeiss biomicroscope with 50x magnification. The nailfold of the second, third, fourth and fifth fingers of both hands of each patient were photographed twice by each of two observers, once in the morning and again in the afternoon (total of 32 pictures). Two raters reviewed the photographs to produce capillary density readings. Intra- and inter-rater reliability of the readings were computed using intra-class correlations (ICC). Additional analyses were undertaken to determine the impact of other sources of variability in the data, namely patient, finger, technician and time. Intra-and inter-rater reliability were substantial (ICC 0.72-0.84) when raters were reading the same photographs or photographs taken at the same time of day. Agreement was only fair between morning and afternoon density readings (ICC 0.30-0.37). Patients, individual fingers and technician accounted for a large part of the variability in the data (combined variance component of 7.69 out of the total 12.23). The coefficient of variation of widefield microscopy was 24%. Although intra- and inter-rater reliability of nailfold capillary density measurements using widefield microscopy are good, proper standardisation of the conditions under which capillaroscopy is done and better imaging of nailfold capillary abnormalities should be considered if nailfold capillary density is to be used as an outcome measure in multi-centre clinical trials in SSc.

  3. Poly(ethylmethacrylate-co-diethylaminoethyl acrylate) coating improves endothelial re-population, bio-mechanical and anti-thrombogenic properties of decellularized carotid arteries for blood vessel replacement.

    Science.gov (United States)

    López-Ruiz, Elena; Venkateswaran, Seshasailam; Perán, Macarena; Jiménez, Gema; Pernagallo, Salvatore; Díaz-Mochón, Juan J; Tura-Ceide, Olga; Arrebola, Francisco; Melchor, Juan; Soto, Juan; Rus, Guillermo; Real, Pedro J; Diaz-Ricart, María; Conde-González, Antonio; Bradley, Mark; Marchal, Juan A

    2017-03-24

    Decellularized vascular scaffolds are promising materials for vessel replacements. However, despite the natural origin of decellularized vessels, issues such as biomechanical incompatibility, immunogenicity risks and the hazards of thrombus formation, still need to be addressed. In this study, we coated decellularized vessels obtained from porcine carotid arteries with poly (ethylmethacrylate-co-diethylaminoethylacrylate) (8g7) with the purpose of improving endothelial coverage and minimizing platelet attachment while enhancing the mechanical properties of the decellularized vascular scaffolds. The polymer facilitated binding of endothelial cells (ECs) with high affinity and also induced endothelial cell capillary tube formation. In addition, platelets showed reduced adhesion on the polymer under flow conditions. Moreover, the coating of the decellularized arteries improved biomechanical properties by increasing its tensile strength and load. In addition, after 5 days in culture, ECs seeded on the luminal surface of 8g7-coated decellularized arteries showed good regeneration of the endothelium. Overall, this study shows that polymer coating of decellularized vessels provides a new strategy to improve re-endothelialization of vascular grafts, maintaining or enhancing mechanical properties while reducing the risk of thrombogenesis. These results could have potential applications in improving tissue-engineered vascular grafts for cardiovascular therapies with small caliber vessels.

  4. Applications of capillary optics for focused ion beams

    International Nuclear Information System (INIS)

    Umezawa, Kenji

    2014-01-01

    This article introduces applications of focused ion beams (∼1 μm) with glass capillaries systems. A first report on the interaction between ion beams and glass capillaries was published in 1996. The guiding capabilities of glass capillaries were discovered due to ion reflection from inner wall of glass surfaces. Meanwhile, the similar optics have been already realized in focusing X-rays using glass capillaries. The basic technology of X-rays optics using glass capillaries had been developed in the 1980's and 1900's. Also, low energy atom scattering spectroscopy for insulator material analysis will be mentioned. (author)

  5. Cultured bovine brain capillary endothelial cells (BBCEC) - a blood-brain barrier model for studying the binding and internalization of insulin and insulin-like growth factor 1

    International Nuclear Information System (INIS)

    Keller, B.T.; Borchardt, R.T.

    1987-01-01

    Cultured bovine brain capillary endothelial cells (BBCEC) have previously been reported by their laboratory as a working model for studying nutrient and drug transport and metabolism at the blood-brain barrier. In the present study, they have utilized this culture system to investigate the binding and internalization of [ 125 I]-labelled insulin (INS) and insulin-like growth factor 1(IGF-1) by BBCEC. After 2 hrs at 23 0 C, the specific binding of INS and IGF-1 was 1.6% and 13.6%, respectively. At 37 0 C, the maximum specific binding was 0.9% for INS and 5.8% for IGF-1. Using an acid-wash technique to assess peptide internalization, it was observed that, at 37 0 C, approximately 60% of the bound INS rapidly became resistant to acid treatment, a value which was constant over 2 hr. With IGF-1, a similar proportion of the bound material, 62%, became resistant by 30 min, but subsequently decreased to 45% by 2 hr. Scatchard analysis of competitive binding studies indicated the presence of two binding sites for each protein, having K/sub d/'s of 0.82 nM and 19.2 nM for INS and 0.39 nM and 3.66 nM for IGF-1. Little change in the amount of INS binding was observed over a four-day interval as the cultures became a confluent monolayer. The present report of binding and internalization of these proteins suggests that the BBCEC may utilize a receptor-mediated process to internalize and/or transport (transcytosis) INS and IGF-1 from the circulation

  6. Capillary density: An important parameter in nailfold capillaroscopy.

    Science.gov (United States)

    Emrani, Zahra; Karbalaie, Abdolamir; Fatemi, Alimohammad; Etehadtavakol, Mahnaz; Erlandsson, Björn-Erik

    2017-01-01

    Nailfold capillaroscopy is one of the various noninvasive bioengineering methods used to investigate skin microcirculation. It is an effective examination for assessing microvascular changes in the peripheral circulation; hence it has a significant role for the diagnosis of Systemic sclerosis with the classic changes of giant capillaries as well as the decline in capillary density with capillary dropout. The decline in capillary density is one of microangiopathic features existing in connective tissue disease. It is detectable with nailfold capillaroscopy. This parameter is assessed by applying quantitative measurement. In this article, we reviewed a common method for calculating the capillary density and the relation between the number of capillaries as well as the existence of digital ulcers, pulmonary arterial hypertension, autoantibodies, scleroderma patterns and different scoring system. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Endothelial-regenerating cells: an expanding universe.

    Science.gov (United States)

    Steinmetz, Martin; Nickenig, Georg; Werner, Nikos

    2010-03-01

    Atherosclerosis is the most common cause for cardiovascular diseases and is based on endothelial dysfunction. A growing body of evidence suggests the contribution of bone marrow-derived endothelial progenitor cells, monocytic cells, and mature endothelial cells to vessel formation and endothelial rejuvenation. To this day, various subsets of these endothelial-regenerating cells have been identified according to cellular origin, phenotype, and properties in vivo and in vitro. However, the definition and biology, especially of endothelial progenitor cells, is complex and under heavy debate. In this review, we focus on current definitions of endothelial progenitor cells, highlight the clinical relevance of endothelial-regenerating cells, and provide new insights into cell-cell interactions involved in endothelial cell rejuvenation.

  8. Capillary Interactions between a Probe Tip and a Nanoparticle

    International Nuclear Information System (INIS)

    Li-Ning, Sun; Le-Feng, Wang; Wei-Bin, Rong

    2008-01-01

    To understand capillary interactions between probe tips and nanoparticles under ambient conditions, a theoretical model of capillary forces between them is developed based on the geometric relations. It is found that the contribution of surface tension force to the total capillary force attains to similar order of magnitude as the capillary pressure force in many cases. It is also shown that the tip shape and the radial distance of the meniscus have great influence on the capillary force. The capillary force decreases with the increasing separation distances, and the variance of the contact angles may change the magnitudes of capillary forces several times at large radial distances. The applicability of the symmetric meniscus approximation is discussed. (condensed matter: structure, mechanical and thermal properties)

  9. An in vitro model of the glomerular capillary wall using electrospun collagen nanofibres in a bioartificial composite basement membrane.

    Directory of Open Access Journals (Sweden)

    Sadie C Slater

    Full Text Available The filtering unit of the kidney, the glomerulus, contains capillaries whose walls function as a biological sieve, the glomerular filtration barrier. This comprises layers of two specialised cells, glomerular endothelial cells (GEnC and podocytes, separated by a basement membrane. Glomerular filtration barrier function, and dysfunction in disease, remains incompletely understood, partly due to difficulties in studying the relevant cell types in vitro. We have addressed this by generation of unique conditionally immortalised human GEnC and podocytes. However, because the glomerular filtration barrier functions as a whole, it is necessary to develop three dimensional co-culture models to maximise the benefit of the availability of these cells. Here we have developed the first two tri-layer models of the glomerular capillary wall. The first is based on tissue culture inserts and provides evidence of cell-cell interaction via soluble mediators. In the second model the synthetic support of the tissue culture insert is replaced with a novel composite bioartificial membrane. This consists of a nanofibre membrane containing collagen I, electrospun directly onto a micro-photoelectroformed fine nickel supporting mesh. GEnC and podocytes grew in monolayers on either side of the insert support or the novel membrane to form a tri-layer model recapitulating the human glomerular capillary in vitro. These models will advance the study of both the physiology of normal glomerular filtration and of its disruption in glomerular disease.

  10. Microgravity Investigation of Capillary Driven Imbibition

    Science.gov (United States)

    Dushin, V. R.; Nikitin, V. F.; Smirnov, N. N.; Skryleva, E. I.; Tyurenkova, V. V.

    2018-05-01

    The goal of the present paper is to investigate the capillary driven filtration in porous media under microgravity conditions. New mathematical model that allows taking into account the blurring of the front due to the instability of the displacement that is developing at the front is proposed. The constants in the mathematical model were selected on the basis of the experimental data on imbibition into unsaturated porous media under microgravity conditions. The flow under the action of a combination of capillary forces and a constant pressure drop or a constant flux is considered. The effect of capillary forces and the type of wettability of the medium on the displacement process is studied. A criterion in which case the capillary effects are insignificant and can be neglected is established.

  11. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  12. Comparative study of four immortalized human brain capillary endothelial cell lines, hCMEC/D3, hBMEC, TY10, and BB19, and optimization of culture conditions, for an in vitro blood-brain barrier model for drug permeability studies.

    Science.gov (United States)

    Eigenmann, Daniela E; Xue, Gongda; Kim, Kwang S; Moses, Ashlee V; Hamburger, Matthias; Oufir, Mouhssin

    2013-11-22

    Reliable human in vitro blood-brain barrier (BBB) models suitable for high-throughput screening are urgently needed in early drug discovery and development for assessing the ability of promising bioactive compounds to overcome the BBB. To establish an improved human in vitro BBB model, we compared four currently available and well characterized immortalized human brain capillary endothelial cell lines, hCMEC/D3, hBMEC, TY10, and BB19, with respect to barrier tightness and paracellular permeability. Co-culture systems using immortalized human astrocytes (SVG-A cell line) and immortalized human pericytes (HBPCT cell line) were designed with the aim of positively influencing barrier tightness. Tight junction (TJ) formation was assessed by transendothelial electrical resistance (TEER) measurements using a conventional epithelial voltohmmeter (EVOM) and an automated CellZscope system which records TEER and cell layer capacitance (CCL) in real-time.Paracellular permeability was assessed using two fluorescent marker compounds with low BBB penetration (sodium fluorescein (Na-F) and lucifer yellow (LY)). Conditions were optimized for each endothelial cell line by screening a series of 24-well tissue culture inserts from different providers. For hBMEC cells, further optimization was carried out by varying coating material, coating procedure, cell seeding density, and growth media composition. Biochemical characterization of cell type-specific transmembrane adherens junction protein VE-cadherin and of TJ proteins ZO-1 and claudin-5 were carried out for each endothelial cell line. In addition, immunostaining for ZO-1 in hBMEC cell line was performed. The four cell lines all expressed the endothelial cell type-specific adherens junction protein VE-cadherin. The TJ protein ZO-1 was expressed in hCMEC/D3 and in hBMEC cells. ZO-1 expression could be confirmed in hBMEC cells by immunocytochemical staining. Claudin-5 expression was detected in hCMEC/D3, TY10, and at a very low level

  13. Scutellarin promotes in vitro angiogenesis in human umbilical vein endothelial cells

    International Nuclear Information System (INIS)

    Gao, Zhong-Xiu-Zi; Huang, Da-Yong; Li, Hai-Xia; Zhang, Li-Na; Lv, Yan-Hong; Cui, Hai-Dong; Zheng, Jin-Hua

    2010-01-01

    Research highlights: → It has been shown that scutellarin exhibits a variety of pharmacological actions, including anti-oxidative, anti-inflammatory, vasodilator as well as cardiovascular and cerebrovascular ischemia protective effects, indicating beneficial vascular effects of scutellarin. Therefore, it is speculated that scutellarin may be able to stimulate angiogenesis, which could be beneficial in the treatment of ischemic disease, wound healing and tissue regeneration. → The purpose of the present study was to elucidate the direct angiogenic actions of scutellarin on human umbilical vein endothelial cells (HUVECs) in vitro. → Our results showed that scutellarin to directly induce in vitro angiogenesis, which is closely correlated with upregulated MMP-2 expression, suggesting a potential for increasing angiogenesis. -- Abstract: Angiogenesis is critical to a wide range of physiological and pathological processes. Scutellarin, a major flavonoid of a Chinese herbal medicine Erigeron breviscapus (Vant.) Hand. Mazz. has been shown to offer beneficial effects on cardiovascular and cerebrovascular functions. However, scutellarin's effects on angiogenesis and underlying mechanisms are not fully elucidated. Here, we studied angiogenic effects of scutellarin on human umbilical vein endothelial cells (HUVECs) in vitro. Scutellarin was found by MTT assay to induce proliferation of HUVECs. In scutellarin-treated HUVECs, a dramatic increase in migration was measured by wound healing assay; Transwell chamber assay found significantly more invading cells in scutellarin-treated groups. Scutellarin also promoted capillary-like tube formation in HUVECs on Matrigel, and significantly upregulated platelet endothelial cell adhesion molecule-1 at both mRNA and protein levels. Scutellarin's angiogenic mechanism was investigated in vitro by measuring expression of angiogenic factors associated with cell migration and invasion. Scutellarin strongly induced MMP-2 activation and m

  14. Olive oil compounds inhibit vascular endothelial growth factor receptor-2 phosphorylation

    International Nuclear Information System (INIS)

    Lamy, Sylvie; Ouanouki, Amira; Béliveau, Richard; Desrosiers, Richard R.

    2014-01-01

    Vascular endothelial growth factor (VEGF) triggers crucial signaling processes that regulate tumor angiogenesis and, therefore, represents an attractive target for the development of novel anticancer therapeutics. Several epidemiological studies have confirmed that abundant consumption of foods from plant origin is associated with reduced risk of developing cancers. In the Mediterranean basin, the consumption of extra virgin olive oil is an important constituent of the diet. Compared to other vegetable oils, the presence of several phenolic antioxidants in olive oil is believed to prevent the occurrence of a variety of pathological processes, such as cancer. While the strong antioxidant potential of these molecules is well characterized, their antiangiogenic activities remain unknown. The aim of this study is to investigate whether tyrosol (Tyr), hydroxytyrosol (HT), taxifolin (Tax), oleuropein (OL) and oleic acid (OA), five compounds contained in extra virgin olive oil, can affect in vitro angiogenesis. We found that HT, Tax and OA were the most potent angiogenesis inhibitors through their inhibitory effect on specific autophosphorylation sites of VEGFR-2 (Tyr951, Tyr1059, Tyr1175 and Tyr1214) leading to the inhibition of endothelial cell (EC) signaling. Inhibition of VEGFR-2 by these olive oil compounds significantly reduced VEGF-induced EC proliferation and migration as well as their morphogenic differentiation into capillary-like tubular structures in Matrigel. Our study demonstrates that HT, Tax and OA are novel and potent inhibitors of the VEGFR-2 signaling pathway. These findings emphasize the chemopreventive properties of olive oil and highlight the importance of nutrition in cancer prevention. - Highlights: • We investigated five compounds contained in extra virgin olive oil on angiogenesis. • Hydroxytyrosol, taxifolin and oleic acid are the best angiogenesis inhibitors. • Olive oil compounds affect endothelial cell functions essential for

  15. Scutellarin promotes in vitro angiogenesis in human umbilical vein endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhong-Xiu-Zi [Department of Anatomy, Basic Medical Science College, Harbin Medical University, Harbin (China); Huang, Da-Yong [Department of Oncology, The Second Clinical Hospital, Harbin Medical University, Harbin (China); Li, Hai-Xia; Zhang, Li-Na; Lv, Yan-Hong; Cui, Hai-Dong [Department of Anatomy, Basic Medical Science College, Harbin Medical University, Harbin (China); Zheng, Jin-Hua, E-mail: jhzhenghrbmu@yahoo.cn [Department of Anatomy, Basic Medical Science College, Harbin Medical University, Harbin (China)

    2010-09-10

    Research highlights: {yields} It has been shown that scutellarin exhibits a variety of pharmacological actions, including anti-oxidative, anti-inflammatory, vasodilator as well as cardiovascular and cerebrovascular ischemia protective effects, indicating beneficial vascular effects of scutellarin. Therefore, it is speculated that scutellarin may be able to stimulate angiogenesis, which could be beneficial in the treatment of ischemic disease, wound healing and tissue regeneration. {yields} The purpose of the present study was to elucidate the direct angiogenic actions of scutellarin on human umbilical vein endothelial cells (HUVECs) in vitro. {yields} Our results showed that scutellarin to directly induce in vitro angiogenesis, which is closely correlated with upregulated MMP-2 expression, suggesting a potential for increasing angiogenesis. -- Abstract: Angiogenesis is critical to a wide range of physiological and pathological processes. Scutellarin, a major flavonoid of a Chinese herbal medicine Erigeron breviscapus (Vant.) Hand. Mazz. has been shown to offer beneficial effects on cardiovascular and cerebrovascular functions. However, scutellarin's effects on angiogenesis and underlying mechanisms are not fully elucidated. Here, we studied angiogenic effects of scutellarin on human umbilical vein endothelial cells (HUVECs) in vitro. Scutellarin was found by MTT assay to induce proliferation of HUVECs. In scutellarin-treated HUVECs, a dramatic increase in migration was measured by wound healing assay; Transwell chamber assay found significantly more invading cells in scutellarin-treated groups. Scutellarin also promoted capillary-like tube formation in HUVECs on Matrigel, and significantly upregulated platelet endothelial cell adhesion molecule-1 at both mRNA and protein levels. Scutellarin's angiogenic mechanism was investigated in vitro by measuring expression of angiogenic factors associated with cell migration and invasion. Scutellarin strongly

  16. Olive oil compounds inhibit vascular endothelial growth factor receptor-2 phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Lamy, Sylvie, E-mail: lamy.sylvie@uqam.ca; Ouanouki, Amira; Béliveau, Richard; Desrosiers, Richard R.

    2014-03-10

    Vascular endothelial growth factor (VEGF) triggers crucial signaling processes that regulate tumor angiogenesis and, therefore, represents an attractive target for the development of novel anticancer therapeutics. Several epidemiological studies have confirmed that abundant consumption of foods from plant origin is associated with reduced risk of developing cancers. In the Mediterranean basin, the consumption of extra virgin olive oil is an important constituent of the diet. Compared to other vegetable oils, the presence of several phenolic antioxidants in olive oil is believed to prevent the occurrence of a variety of pathological processes, such as cancer. While the strong antioxidant potential of these molecules is well characterized, their antiangiogenic activities remain unknown. The aim of this study is to investigate whether tyrosol (Tyr), hydroxytyrosol (HT), taxifolin (Tax), oleuropein (OL) and oleic acid (OA), five compounds contained in extra virgin olive oil, can affect in vitro angiogenesis. We found that HT, Tax and OA were the most potent angiogenesis inhibitors through their inhibitory effect on specific autophosphorylation sites of VEGFR-2 (Tyr951, Tyr1059, Tyr1175 and Tyr1214) leading to the inhibition of endothelial cell (EC) signaling. Inhibition of VEGFR-2 by these olive oil compounds significantly reduced VEGF-induced EC proliferation and migration as well as their morphogenic differentiation into capillary-like tubular structures in Matrigel. Our study demonstrates that HT, Tax and OA are novel and potent inhibitors of the VEGFR-2 signaling pathway. These findings emphasize the chemopreventive properties of olive oil and highlight the importance of nutrition in cancer prevention. - Highlights: • We investigated five compounds contained in extra virgin olive oil on angiogenesis. • Hydroxytyrosol, taxifolin and oleic acid are the best angiogenesis inhibitors. • Olive oil compounds affect endothelial cell functions essential for

  17. Genetic variability of Artemisia capillaris (Wormwood capillary) by ...

    African Journals Online (AJOL)

    The genetic variability among individuals of Artemisia capillaris from state of Terengganu, Malaysia was examined by using the random amplified polymorphic DNA (RAPD) technique. The samples were collected from differences regional in Terengganu State. The genomic DNA was extracted from the samples leaves.

  18. Endothelial chimerism and vascular sequestration protect pancreatic islet grafts from antibody-mediated rejection

    Science.gov (United States)

    Chen, Chien-Chia; Pouliquen, Eric; Broisat, Alexis; Andreata, Francesco; Racapé, Maud; Bruneval, Patrick; Kessler, Laurence; Ahmadi, Mitra; Bacot, Sandrine; Saison-Delaplace, Carole; Marcaud, Marina; Van Huyen, Jean-Paul Duong; Loupy, Alexandre; Villard, Jean; Demuylder-Mischler, Sandrine; Morelon, Emmanuel; Tsai, Meng-Kun; Kolopp-Sarda, Marie-Nathalie; Koenig, Alice; Mathias, Virginie; Ghezzi, Catherine; Dubois, Valerie; Defrance, Thierry

    2017-01-01

    Humoral rejection is the most common cause of solid organ transplant failure. Here, we evaluated a cohort of 49 patients who were successfully grafted with allogenic islets and determined that the appearance of donor-specific anti-HLA antibodies (DSAs) did not accelerate the rate of islet graft attrition, suggesting resistance to humoral rejection. Murine DSAs bound to allogeneic targets expressed by islet cells and induced their destruction in vitro; however, passive transfer of the same DSAs did not affect islet graft survival in murine models. Live imaging revealed that DSAs were sequestrated in the circulation of the recipients and failed to reach the endocrine cells of grafted islets. We used murine heart transplantation models to confirm that endothelial cells were the only accessible targets for DSAs, which induced the development of typical microvascular lesions in allogeneic transplants. In contrast, the vasculature of DSA-exposed allogeneic islet grafts was devoid of lesions because sprouting of recipient capillaries reestablished blood flow in grafted islets. Thus, we conclude that endothelial chimerism combined with vascular sequestration of DSAs protects islet grafts from humoral rejection. The reduced immunoglobulin concentrations in the interstitial tissue, confirmed in patients, may have important implications for biotherapies such as vaccines and monoclonal antibodies. PMID:29202467

  19. Geometry-induced phase transition in fluids: capillary prewetting.

    Science.gov (United States)

    Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

    2013-02-01

    We report a new first-order phase transition preceding capillary condensation and corresponding to the discontinuous formation of a curved liquid meniscus. Using a mean-field microscopic approach based on the density functional theory we compute the complete phase diagram of a prototypical two-dimensional system exhibiting capillary condensation, namely that of a fluid with long-ranged dispersion intermolecular forces which is spatially confined by a substrate forming a semi-infinite rectangular pore exerting long-ranged dispersion forces on the fluid. In the T-μ plane the phase line of the new transition is tangential to the capillary condensation line at the capillary wetting temperature T(cw). The surface phase behavior of the system maps to planar wetting with the phase line of the new transition, termed capillary prewetting, mapping to the planar prewetting line. If capillary condensation is approached isothermally with T>T(cw), the meniscus forms at the capping wall and unbinds continuously, making capillary condensation a second-order phenomenon. We compute the corresponding critical exponent for the divergence of adsorption.

  20. Impaired skin capillary recruitment in essential hypertension is caused by both functional and structural capillary rarefaction

    NARCIS (Netherlands)

    Serne, EH; Gans, ROB; ter Maaten, JC; Tangelder, GJ; Donker, AJM; Stehouwer, CDA

    Capillary rarefaction occurs in many tissues in patients with essential hypertension and may contribute to an increased vascular resistance and impaired muscle metabolism. Rarefaction may be caused by a structural (anatomic) absence of capillaries, functional nonperfusion, or both. The aim of this

  1. On Capillary Rise and Nucleation

    Science.gov (United States)

    Prasad, R.

    2008-01-01

    A comparison of capillary rise and nucleation is presented. It is shown that both phenomena result from a balance between two competing energy factors: a volume energy and a surface energy. Such a comparison may help to introduce nucleation with a topic familiar to the students, capillary rise. (Contains 1 table and 3 figures.)

  2. Manufacture of endothelial colony-forming progenitor cells from steady-state peripheral blood leukapheresis using pooled human platelet lysate.

    Science.gov (United States)

    Siegel, Georg; Fleck, Erika; Elser, Stefanie; Hermanutz-Klein, Ursula; Waidmann, Marc; Northoff, Hinnak; Seifried, Erhard; Schäfer, Richard

    2018-05-01

    Endothelial colony-forming progenitor cells (ECFCs) are promising candidates for cell therapies. However, ECFC translation to the clinic requires optimized isolation and manufacture technologies according to good manufacturing practice (GMP). ECFCs were manufactured from steady-state peripheral blood (PB) leukapheresis (11 donors), using GMP-compliant technologies including pooled human platelet (PLT) lysate, and compared to human umbilical cord endothelial cells, human aortic endothelial cells, and human cerebral microvascular endothelial cells. Specific variables assessed were growth kinetics, phenotype, trophic factors production, stimulation of tube formation, and Dil-AcLDL uptake. ECFCs could be isolated from PB leukapheresis units with mean processed volume of 5411 mL and mean white blood cell (WBC) concentration factor of 8.74. The mean frequency was 1.44 × 10 -8 ECFCs per WBC, corresponding to a mean of 177.8 ECFCs per apheresis unit. Expandable for up to 12 cumulative population doublings, calculated projection showed that approximately 730 × 10 3 ECFCs could be manufactured from 1 apheresis unit. ECFCs produced epidermal growth factor, hepatocyte growth factor, vascular endothelial growth factor (VEGF)-A, PLT-derived growth factor-B, interleukin-8, and monocyte chemoattractant protein-1, featured high potential for capillary-like tubes formation, and showed no telomerase activity. They were characterized by CD29, CD31, CD44, CD105, CD117, CD133, CD144, CD146, and VEGF-R2 expression, with the most common subpopulation CD34+CD117-CD133-. Compared to controls, ECFCs featured greater Dil-AcLDL uptake and higher expression of CD29, CD31, CD34, CD44, CD144, and VEGF-R2. Here we show that isolation of ECFCs with proangiogenic profile from steady-state PB leukapheresis is feasible, marking a first step toward ECFC product manufacture according to GMP. © 2018 AABB.

  3. Fast separation of enantiomers by capillary electrophoresis using a combination of two capillaries with different internal diameters.

    Science.gov (United States)

    Šebestová, Andrea; Petr, Jan

    2017-12-01

    The combination of capillaries with different internal diameters was used to accelerate the separation of enantiomers in capillary electrophoresis. Separation of R,S-1,1'-binaphthalene-2,2'-diyl hydrogen phosphate using isopropyl derivative of cyclofructan 6 was studied as a model system. The best separation conditions included 500 mM sodium borate pH 9.5 with 60 mM concentration of the chiral selector. Separation lasted approx. 1.5 min using the combination of 50 and 100 μm id capillaries of 9.7 cm and 22.9 cm, respectively. It allowed approx. 12-fold acceleration in comparison to the traditional long-end separation mainly due to the higher electroosmotic flow generated in the connected capillaries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Simulation of capillary bridges between nanoscale particles.

    Science.gov (United States)

    Dörmann, Michael; Schmid, Hans-Joachim

    2014-02-04

    Capillary forces are very important as they exceed in general other adhesion forces. But at the same time the exact calculation of these forces is very complex, so often assumptions and approximations are used. Previous research was done with regard to micrometer sized particles, but the behavior of nanoscale particles is different. Hence, the results for micrometer sized particles cannot be directly transferred when considering nanoscale particles. Therefore, a simulation method was developed to calculate numerically the shape of a rotationally symmetrical capillary bridge between two spherical particles or a particle and a plate. The capillary bridge in the gap between the particles is formed due to capillary condensation and is in thermodynamic equilibrium with the gas phase. Hence the Kelvin equation and the Young-Laplace equation can be used to calculate the profile of the capillary bridge, depending on the relative humidity of the surrounding air. The bridge profile consists of several elements that are determined consecutively and interpolated linearly. After the shape is determined, the volume and force, divided into capillary pressure force and surface tension force, can be calculated. The validation of this numerical model will be shown by comparison with several different analytical calculations for micrometer-sized particles. Furthermore, it is demonstrated that two often used approximations, (1) the toroidal approximation and (2) the use of an effective radius, cannot be used for nanoscale particles without remarkable mistake. It will be discussed how the capillary force and its components depend on different parameters, like particle size, relative humidity, contact angle, and distance, respectively. The rupture of a capillary bridge due to particle separation will also be presented.

  5. Analysis of glycated hemoglobin A1c by capillary electrophoresis and capillary isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Koval, Dušan; Kašička, Václav; Cottet, H.

    2011-01-01

    Roč. 413, č. 1 (2011), s. 8-15 ISSN 0003-2697 R&D Projects: GA ČR GP203/09/P485; GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : capillary zone electrophoresis * capillary isoelectric focusing * glycated hemoglobin HbA1c Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.996, year: 2011

  6. Capillary detectors for high resolution tracking

    International Nuclear Information System (INIS)

    Annis, P.; Bay, A.; Bonekaemper, D.; Buontempo, S.; Ereditato, A.; Fabre, J.P.; Fiorillo, G.; Frekers, D.; Frenkel, A.; Galeazzi, F.; Garufi, F.; Goldberg, J.; Golovkin, S.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Liberti, B.; Martellotti, G.; Medvedkov, A.; Mommaert, C.; Panman, J.; Penso, G.; Petukhov, Yu.; Rondeshagen, D.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Vischers, J.L.; Wilquet, G.; Winter, K.; Wolff, T.; Wong, H.

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 x 10 5 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on electron bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented. (orig.)

  7. Open tubular capillary column for the separation of cytochrome C tryptic digest in capillary electrochromatography.

    Science.gov (United States)

    Ali, Faiz; Cheong, Won Jo

    2015-10-01

    A silica capillary of 50 μm internal diameter and 500 mm length (416 mm effective length) was chemically modified with 4-(trifluoromethoxy) phenyl isocyanate in the presence of dibutyl tin dichloride as catalyst. Sodium diethyl dithiocarbamate was reacted with the terminal halogen of the bound ligand to incorporate the initiator moiety, and in situ polymerization was performed using a monomer mixture of styrene, N-phenylacrylamide, and methacrylic acid. The resultant open tubular capillary column immobilized with the copolymer layer was used for the separation of tryptic digest of cytochrome C in capillary electrochromatography. The sample was well eluted and separated into many components. The elution patterns of tryptic digest of cytochrome C were studied with respect to pH and water content in the mobile phase. This preliminary study demonstrates that open tubular capillary electrochromatography columns with a modified copolymer layer composed of proper nonpolar and polar units fabricated by reversible addition-fragmentation transfer polymerization can be useful as separation media for proteomic analysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Human endothelial precursor cells express tumor endothelial marker 1/endosialin/CD248.

    Science.gov (United States)

    Bagley, Rebecca G; Rouleau, Cecile; St Martin, Thia; Boutin, Paula; Weber, William; Ruzek, Melanie; Honma, Nakayuki; Nacht, Mariana; Shankara, Srinivas; Kataoka, Shiro; Ishida, Isao; Roberts, Bruce L; Teicher, Beverly A

    2008-08-01

    Angiogenesis occurs during normal physiologic processes as well as under pathologic conditions such as tumor growth. Serial analysis of gene expression profiling revealed genes [tumor endothelial markers (TEM)] that are overexpressed in tumor endothelial cells compared with normal adult endothelial cells. Because blood vessel development of malignant tumors under certain conditions may include endothelial precursor cells (EPC) recruited from bone marrow, we investigated TEM expression in EPC. The expression of TEM1 or endosialin (CD248) and other TEM has been discovered in a population of vascular endothelial growth factor receptor 2+/CD31+/CD45-/VE-cadherin+ EPC derived from human CD133+/CD34+ cells. EPC share some properties with fully differentiated endothelial cells from normal tissue, yet reverse transcription-PCR and flow cytometry reveal that EPC express higher levels of endosialin at the molecular and protein levels. The elevated expression of endosialin in EPC versus mature endothelial cells suggests that endosialin is involved in the earlier stages of tumor angiogenesis. Anti-endosialin antibodies inhibited EPC migration and tube formation in vitro. In vivo, immunohistochemistry indicated that human EPC continued to express endosialin protein in a Matrigel plug angiogenesis assay established in nude mice. Anti-endosialin antibodies delivered systemically at 25 mg/kg were also able to inhibit circulating murine EPC in nude mice bearing s.c. SKNAS tumors. EPC and bone marrow-derived cells have been shown previously to incorporate into malignant blood vessels in some instances, yet they remain controversial in the field. The data presented here on endothelial genes that are up-regulated in tumor vasculature and in EPC support the hypothesis that the angiogenesis process in cancer can involve EPC.

  9. Immunohistochemical properties of the expression of endothelial nitric oxide synthase in placenta in its dysfunction in women with iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    I. A. Ancheva

    2014-08-01

    Full Text Available Aim. The pertinence of the study is related to a large prevalence of dysfunction of the placenta in pregnant women suffering from anemia. To evaluate the immunohistochemical expression characteristics of endothelial NO-synthase (eNOS in the placenta during its dysfunction in women against the background of anemia 30 samples of placental tissue were studied with the use of immunohistochemical and micrometer methods. Materials and results. It was found that the expression of eNOS in patients with iron defi ciency anemia in the cytoplasm of syncytium of villi and fetal capillary endothelium as well as decidual vessels decreases, with the most pronounced changes in the expression of eNOS observed in the presence of the combination of placental dysfunction and iron defi ciency anemia in the form of paradoxical increase in expression. Conclusion. This indicates the necessity for correction of endothelial function in women with anemia during pregnancy.

  10. Albendazole inhibits endothelial cell migration, tube formation, vasopermeability, VEGF receptor-2 expression and suppresses retinal neovascularization in ROP model of angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Pourgholami, Mohammad H., E-mail: mh.pourgholami@unsw.edu.au [University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney (Australia); Khachigian, Levon M.; Fahmy, Roger G. [Centre for Vascular Research, The University of New South Wales, Department of Haematology, The Prince of Wales Hospital, Sydney (Australia); Badar, Samina; Wang, Lisa; Chu, Stephanie Wai Ling; Morris, David Lawson [University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney (Australia)

    2010-07-09

    The angiogenic process begins with the cell proliferation and migration into the primary vascular network, and leads to vascularization of previously avascular tissues and organs as well to growth and remodeling of the initially homogeneous capillary plexus to form a new microcirculation. Additionally, an increase in microvascular permeability is a crucial step in angiogenesis. Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis. We have previously reported that albendazole suppresses VEGF levels and inhibits malignant ascites formation, suggesting a possible effect on angiogenesis. This study was therefore designed to investigate the antiangiogenic effect of albendazole in non-cancerous models of angiogenesis. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with albendazole led to inhibition of tube formation, migration, permeability and down-regulation of the VEGF type 2 receptor (VEGFR-2). In vivo albendazole profoundly inhibited hyperoxia-induced retinal angiogenesis in mice. These results provide new insights into the antiangiogenic effects of albendazole.

  11. Albendazole inhibits endothelial cell migration, tube formation, vasopermeability, VEGF receptor-2 expression and suppresses retinal neovascularization in ROP model of angiogenesis

    International Nuclear Information System (INIS)

    Pourgholami, Mohammad H.; Khachigian, Levon M.; Fahmy, Roger G.; Badar, Samina; Wang, Lisa; Chu, Stephanie Wai Ling; Morris, David Lawson

    2010-01-01

    The angiogenic process begins with the cell proliferation and migration into the primary vascular network, and leads to vascularization of previously avascular tissues and organs as well to growth and remodeling of the initially homogeneous capillary plexus to form a new microcirculation. Additionally, an increase in microvascular permeability is a crucial step in angiogenesis. Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis. We have previously reported that albendazole suppresses VEGF levels and inhibits malignant ascites formation, suggesting a possible effect on angiogenesis. This study was therefore designed to investigate the antiangiogenic effect of albendazole in non-cancerous models of angiogenesis. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with albendazole led to inhibition of tube formation, migration, permeability and down-regulation of the VEGF type 2 receptor (VEGFR-2). In vivo albendazole profoundly inhibited hyperoxia-induced retinal angiogenesis in mice. These results provide new insights into the antiangiogenic effects of albendazole.

  12. Assembly for connecting the column ends of two capillary columns

    International Nuclear Information System (INIS)

    Kolb, B.; Auer, M.; Pospisil, P.

    1984-01-01

    In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A ''straight-forward operation'' having capillary columns connected in series and a ''flush-back operation'' are possible. The dead volume between the capillary columns can be kept small

  13. Biomimetic Unidirectional Capillary Action

    Science.gov (United States)

    Rupert, Eric; Moran, Patrick; Dahl, Jason

    2017-11-01

    In arid environments animals require specialized adaptations to collect adequate water. The Texas horned lizard (P. cornutum) has superhydrophylic skin which draws water out of moist soil or directly from water sources. The water then makes its way into the lizard's unidirectional capillary system, made of overlapping scales, which serves to channel water to its mouth. Testing different channel geometries, repeated ``D'' shaped chambers as in Commans et al. (2015) and truncated isosceles triangle chambers, as found in P. cornutum, we show the ability to have passive, unidirectional, fluid transport. Tests were carried out with the capillaries in a horizontal configuration. While both capillary geometries produced the desired traits, the triangular chambers showed superior unidirectionality, with no observed back flow, while ``D'' chambers showed back flow under testing conditions. The chambers provided similar flow rates. These types of channel systems will find use in microfluidics, notably in medical, printing, and lab-on-chip applications.

  14. Rapid capillary coating by epoxy-poly-(dimethylacrylamide): Performance in capillary zone electrophoresis of protein and polystyrene carboxylate

    Czech Academy of Sciences Publication Activity Database

    Chiari, M.; Cretich, M.; Šťastná, Miroslava; Radko, S. P.; Chrambach, A.

    2001-01-01

    Roč. 22, č. 4 (2001), s. 656-659 ISSN 0173-0835 Institutional research plan: CEZ:AV0Z4031919 Keywords : capillary coating * capillary zone electrophoresis * proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.282, year: 2001

  15. The penetration of aerosols through fine capillaries

    International Nuclear Information System (INIS)

    Mitchell, J.P.; Edwards, R.T.; Ball, M.H.E.

    1989-10-01

    A novel experimental technique has been developed to study the penetration of aerosol particles ranging from about 1 to 15 μm aerodynamic diameter through capillaries varying from 20 to 80 μm bore and from 10 to 50 mm in length. When the driving pressure was 100 kPa, the penetration of the airborne particles was considerably smaller than expected from a simple comparison of particle diameter with the bore of the capillary. Particle size distributions determined after penetration through the capillaries were in almost all cases similar to the particle size distribution of the aerosol at the capillary entrance. This lack of size-selectivity can be explained in terms of the capillary behaving as a conventional suction-based sampler from a near still (calm) air environment. The resulting particle penetration data are important in assessing the potential for the leakage of aerosols through seals in containers used to transport radioactive materials. (author)

  16. Capillary condensation between disks in two dimensions

    OpenAIRE

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial capillary fluctuations play a dominant role. A simple approximative analytical expression of the interfacial free energy is developed and is validated numerically. The capillary condensation is characteri...

  17. Measurement of Capillary Radius and Contact Angle within Porous Media.

    Science.gov (United States)

    Ravi, Saitej; Dharmarajan, Ramanathan; Moghaddam, Saeed

    2015-12-01

    The pore radius (i.e., capillary radius) and contact angle determine the capillary pressure generated in a porous medium. The most common method to determine these two parameters is through measurement of the capillary pressure generated by a reference liquid (i.e., a liquid with near-zero contact angle) and a test liquid. The rate of rise technique, commonly used to determine the capillary pressure, results in significant uncertainties. In this study, we utilize a recently developed technique for independently measuring the capillary pressure and permeability to determine the equivalent minimum capillary radii and contact angle of water within micropillar wick structures. In this method, the experimentally measured dryout threshold of a wick structure at different wicking lengths is fit to Darcy's law to extract the maximum capillary pressure generated by the test liquid. The equivalent minimum capillary radii of different wick geometries are determined by measuring the maximum capillary pressures generated using n-hexane as the working fluid. It is found that the equivalent minimum capillary radius is dependent on the diameter of pillars and the spacing between pillars. The equivalent capillary radii of micropillar wicks determined using the new method are found to be up to 7 times greater than the current geometry-based first-order estimates. The contact angle subtended by water at the walls of the micropillars is determined by measuring the capillary pressure generated by water within the arrays and the measured capillary radii for the different geometries. This mean contact angle of water is determined to be 54.7°.

  18. Genetics Home Reference: megalencephaly-capillary malformation syndrome

    Science.gov (United States)

    ... Additional NIH Resources (1 link) National Institute of Neurological Disorders and Stroke: Megalencephaly Educational Resources (5 links) Boston Children's Hospital: Capillary Malformation Cincinnati Children's Hospital: Capillary Malformations ...

  19. The endothelial αENaC contributes to vascular endothelial function in vivo

    DEFF Research Database (Denmark)

    Tarjus, Antoine; Maase, Martina; Jeggle, Pia

    2017-01-01

    The Epithelial Sodium Channel (ENaC) is a key player in renal sodium homeostasis. The expression of α β γ ENaC subunits has also been described in the endothelium and vascular smooth muscle, suggesting a role in vascular function. We recently demonstrated that endothelial ENaC is involved in aldo......-mediated dilation. Our data suggest that endothelial αENaC contributes to vascular endothelial function in vivo....

  20. Cell adhesion during bullet motion in capillaries.

    Science.gov (United States)

    Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger D; Ishikawa, Takuji

    2016-08-01

    A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. Copyright © 2016 the American Physiological Society.

  1. Catalase and superoxide dismutase conjugated with platelet-endothelial cell adhesion molecule antibody distinctly alleviate abnormal endothelial permeability caused by exogenous reactive oxygen species and vascular endothelial growth factor.

    Science.gov (United States)

    Han, Jingyan; Shuvaev, Vladimir V; Muzykantov, Vladimir R

    2011-07-01

    Reactive oxygen species (ROS) superoxide anion (O(2)()) and hydrogen peroxide (H(2)O(2)) produced by activated leukocytes and endothelial cells in sites of inflammation or ischemia cause endothelial barrier dysfunction that may lead to tissue edema. Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet-endothelial cell adhesion molecule-1 (PECAM-1) specifically bind to endothelium, quench the corresponding ROS, and alleviate vascular oxidative stress and inflammation. In the present work, we studied the effects of anti-PECAM/catalase and anti-PECAM/SOD conjugates on the abnormal permeability manifested by transendothelial electrical resistance decline, increased fluorescein isothiocyanate-dextran influx, and redistribution of vascular endothelial-cadherin in human umbilical vein endothelial cell (HUVEC) monolayers. Anti-PECAM/catalase protected HUVEC monolayers against H(2)O(2)-induced endothelial barrier dysfunction. Polyethylene glycol-conjugated catalase exerted orders of magnitude lower endothelial uptake and no protective effect, similarly to IgG/catalase. Anti-PECAM/catalase, but not anti-PECAM/SOD, alleviated endothelial hyperpermeability caused by exposure to hypoxanthine/xanthine oxidase, implicating primarily H(2)O(2) in the disruption of the endothelial barrier in this model. Thrombin-induced endothelial permeability was not affected by treatment with anti-PECAM/AOEs or the NADPH oxidase inhibitor apocynin or overexpression of AOEs, indicating that the endogenous ROS play no key role in thrombin-mediated endothelial barrier dysfunction. In contrast, anti-PECAM/SOD, but not anti-PECAM/catalase, inhibited a vascular endothelial growth factor (VEGF)-induced increase in endothelial permeability, identifying a key role of endogenous O(2)() in the VEGF-mediated regulation of endothelial barrier function. Therefore, AOEs targeted to endothelial cells provide versatile molecular tools for testing the roles of

  2. Endothelial microparticle-mediated transfer of MicroRNA-126 promotes vascular endothelial cell repair via SPRED1 and is abrogated in glucose-damaged endothelial microparticles.

    Science.gov (United States)

    Jansen, Felix; Yang, Xiaoyan; Hoelscher, Marion; Cattelan, Arianna; Schmitz, Theresa; Proebsting, Sebastian; Wenzel, Daniela; Vosen, Sarah; Franklin, Bernardo S; Fleischmann, Bernd K; Nickenig, Georg; Werner, Nikos

    2013-10-29

    Repair of the endothelium after vascular injury is crucial for preserving endothelial integrity and preventing the development of vascular disease. The underlying mechanisms of endothelial cell repair are largely unknown. We sought to investigate whether endothelial microparticles (EMPs), released from apoptotic endothelial cells (ECs), influence EC repair. Systemic treatment of mice with EMPs after electric denudation of the endothelium accelerated reendothelialization in vivo. In vitro experiments revealed that EMP uptake in ECs promotes EC migration and proliferation, both critical steps in endothelial repair. To dissect the underlying mechanisms, Taqman microRNA array was performed, and microRNA (miR)-126 was identified as the predominantly expressed miR in EMPs. The following experiments demonstrated that miR-126 was transported into recipient human coronary artery endothelial cells by EMPs and functionally regulated the target protein sprouty-related, EVH1 domain-containing protein 1 (SPRED1). Knockdown of miR-126 in EMPs abrogated EMP-mediated effects on human coronary artery endothelial cell migration and proliferation in vitro and reendothelialization in vivo. Interestingly, after simulating diabetic conditions, EMPs derived from glucose-treated ECs contained significantly lower amounts of miR-126 and showed reduced endothelial repair capacity in vitro and in vivo. Finally, expression analysis of miR-126 in circulating microparticles from 176 patients with stable coronary artery disease with and without diabetes mellitus revealed a significantly reduced miR-126 expression in circulating microparticles from diabetic patients. Endothelial microparticles promote vascular endothelial repair by delivering functional miR-126 into recipient cells. In pathological hyperglycemic conditions, EMP-mediated miR-126-induced EC repair is altered.

  3. Pathways for insulin access to the brain: the role of the microvascular endothelial cell.

    Science.gov (United States)

    Meijer, Rick I; Gray, Sarah M; Aylor, Kevin W; Barrett, Eugene J

    2016-11-01

    Insulin affects multiple important central nervous system (CNS) functions including memory and appetite, yet the pathway(s) by which insulin reaches brain interstitial fluid (bISF) has not been clarified. Recent studies demonstrate that to reach bISF, subarachnoid cerebrospinal fluid (CSF) courses through the Virchow-Robin space (VRS) which sheaths penetrating pial vessels down to the capillary level. Whether insulin predominantly enters the VRS and bISF by local transport through the blood-brain barrier, or by being secreted into the CSF by the choroid plexus, is unknown. We injected 125 I-TyrA14-insulin or regular insulin intravenously and compared the rates of insulin reaching subarachnoid CSF with its plasma clearance by brain tissue samples (an index of microvascular endothelial cell binding/uptake/transport). The latter process was more than 40-fold more rapid. We then showed that selective insulin receptor blockade or 4 wk of high-fat feeding each inhibited microvascular brain 125 I-TyrA14-insulin clearance. We further confirmed that 125 I-TyrA14-insulin was internalized by brain microvascular endothelial cells, indicating that the in vivo tissue association reflected cellular transport, not simply microvascular tracer binding. Copyright © 2016 the American Physiological Society.

  4. A novel in situ strategy for the preparation of a β-cyclodextrin/polydopamine-coated capillary column for capillary electrochromatography enantioseparations.

    Science.gov (United States)

    Guo, Heying; Niu, Xiaoying; Pan, Congjie; Yi, Tao; Chen, Hongli; Chen, Xingguo

    2017-06-01

    Inspired by the chiral recognition ability of β-cyclodextrin and the natural adhesive properties of polydopamine under alkaline conditions, in this study, a rapid and in situ modification strategy was developed to fabricate β-cyclodextrin/polydopamine composite material coated-capillary columns for open tubular capillary electrochromatography. The results of scanning electron microscopy, FTIR spectroscopy, streaming potential, and electro-osmotic flow studies indicated that β-cyclodextrin/polydopamine was successfully fixed on the inner wall of the capillary column. This coating can be achieved within 1 h affording a greatly reduced capillary preparation time. The performance of the β-cyclodextrin/polydopamine-coated capillary was validated by the analysis of seven pairs of chiral analytes, namely epinephrine, norepinephrine, isoprenaline, terbutaline, verapamil, tryptophane, carvedilol. Good enantioseparation efficiencies were achieved for all. For three consecutive runs, the relative standard deviations for the migration times of the analytes for intraday, interday, and column-to-column repeatability were in the range of 0.41-1.74, 1.03-4.18, and 1.66-8.24%, respectively. Moreover, the separation efficiency of the β-cyclodextrin/polydopamine-coated capillary column did not decrease obviously over 90 runs. The strategy should also be feasible to introduce and immobilize other chiral selectors on the inner walls surface of capillary columns. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Intramedullary capillary haemangioma.

    LENUS (Irish Health Repository)

    Kelleher, T

    2012-02-03

    Intramedullary capillary haemangioma is extremely rare and only four cases have been previously reported. We describe a further case, outlining the clinical, radiological, surgical and pathological features.

  6. Colloid mobilization and transport during capillary fringe fluctuations.

    Science.gov (United States)

    Aramrak, Surachet; Flury, Markus; Harsh, James B; Zollars, Richard L

    2014-07-01

    Capillary fringe fluctuations due to changing water tables lead to displacement of air-water interfaces in soils and sediments. These moving air-water interfaces can mobilize colloids. We visualized colloids interacting with moving air-water interfaces during capillary fringe fluctuations by confocal microscopy. We simulated capillary fringe fluctuations in a glass-bead-filled column. We studied four specific conditions: (1) colloids suspended in the aqueous phase, (2) colloids attached to the glass beads in an initially wet porous medium, (3) colloids attached to the glass beads in an initially dry porous medium, and (4) colloids suspended in the aqueous phase with the presence of a static air bubble. Confocal images confirmed that the capillary fringe fluctuations affect colloid transport behavior. Hydrophilic negatively charged colloids initially suspended in the aqueous phase were deposited at the solid-water interface after a drainage passage, but then were removed by subsequent capillary fringe fluctuations. The colloids that were initially attached to the wet or dry glass bead surface were detached by moving air-water interfaces in the capillary fringe. Hydrophilic negatively charged colloids did not attach to static air-bubbles, but hydrophobic negatively charged and hydrophilic positively charged colloids did. Our results demonstrate that capillary fringe fluctuations are an effective means for colloid mobilization.

  7. Capillary contact angle in a completely wet groove.

    Science.gov (United States)

    Parry, A O; Malijevský, A; Rascón, C

    2014-10-03

    We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θ(cap)(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θ(cap) > 0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θ(cap)(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

  8. Endothelial MMP14 is required for endothelial-dependent growth support of human airway basal cells

    Science.gov (United States)

    Ding, Bi-Sen; Gomi, Kazunori; Rafii, Shahin; Crystal, Ronald G.; Walters, Matthew S.

    2015-01-01

    ABSTRACT Human airway basal cells are the stem (or progenitor) population of the airway epithelium, and play a central role in anchoring the epithelium to the basement membrane. The anatomic position of basal cells allows for potential paracrine signaling between them and the underlying non-epithelial stromal cells. In support of this, we have previously demonstrated that endothelial cells support growth of basal cells during co-culture through vascular endothelial growth factor A (VEGFA)-mediated signaling. Building on these findings, we found, by RNA sequencing analysis, that basal cells expressed multiple fibroblast growth factor (FGF) ligands (FGF2, FGF5, FGF11 and FGF13) and that only FGF2 and FGF5 were capable of functioning in a paracrine manner to activate classical FGF receptor (FGFR) signaling. Antibody-mediated blocking of FGFR1 during basal-cell–endothelial-cell co-culture significantly reduced the endothelial-cell-dependent basal cell growth. Stimulation of endothelial cells with basal-cell-derived growth factors induced endothelial cell expression of matrix metallopeptidase 14 (MMP14), and short hairpin RNA (shRNA)-mediated knockdown of endothelial cell MMP14 significantly reduced the endothelial-cell-dependent growth of basal cells. Overall, these data characterize a new growth-factor-mediated reciprocal ‘crosstalk’ between human airway basal cells and endothelial cells that regulates proliferation of basal cells. PMID:26116571

  9. The endo-lysosomal system of brain endothelial cells is influenced by astrocytes in vitro

    DEFF Research Database (Denmark)

    Toth, Andrea E; Siupka, Piotr; P Augustine, Thomas J

    2018-01-01

    Receptor- and adsorptive-mediated transport through brain endothelial cells (BEC) of the blood-brain barrier (BBB) involves a complex array of subcellular vesicular structures, the endo-lysosomal system. It consists of several types of vesicles, such as early, recycling, and late endosomes......, retromer-positive structures, and lysosomes. Since this system is important for receptor-mediated transcytosis of drugs across brain capillaries, our aim was to characterise the endo-lysosomal system in BEC with emphasis on their interactions with astrocytes. We used primary porcine BEC in monoculture....... Altogether, our data pin-point unique features of BEC trafficking network, essentially mapping the endo-lysosomal system of in vitro BBB models. Consequently, our findings constitute a valuable basis for planning the optimal route across the BBB when advancing drug delivery to the brain....

  10. Cell biology of mesangial cells: the third cell that maintains the glomerular capillary.

    Science.gov (United States)

    Kurihara, Hidetake; Sakai, Tatsuo

    2017-03-01

    The renal glomerulus consists of glomerular endothelial cells, podocytes, and mesangial cells, which cooperate with each other for glomerular filtration. We have produced monoclonal antibodies against glomerular cells in order to identify different types of glomerular cells. Among these antibodies, the E30 clone specifically recognizes the Thy1.1 molecule expressed on mesangial cells. An injection of this antibody into rats resulted in mesangial cell-specific injury within 15 min, and induced mesangial proliferative glomerulonephritis in a reproducible manner. We examined the role of mesangial cells in glomerular function using several experimental tools, including an E30-induced nephritis model, mesangial cell culture, and the deletion of specific genes. Herein, we describe the characterization of E30-induced nephritis, formation of the glomerular capillary network, mesangial matrix turnover, and intercellular signaling between glomerular cells. New molecules that are involved in a wide variety of mesangial cell functions are also introduced.

  11. Soft x-ray lasing in a capillary discharge

    International Nuclear Information System (INIS)

    Lee, Tong-Nyong; Shin, Hyun-Joon; Kim, Dong-Eon

    1995-01-01

    Soft x-ray lasing in the C VI Balmer α transition is observed in a capillary discharge. The capillary is made of polyethylene with a bore diameter of 1.2 mm. Plasma radiation from the discharge is analyzed using a toroidal mirror and a two-meter grazing-incidence spectrograph-monochromator. The electron temperatures are measured at both the axial and the peripheral region close to the capillary wall, using space-resolved spectra. A comparison of the branching ratio in the hot (axial) and the cool (peripheral) plasma regions indicates that there is a large population inversion between n=3 and 2 states of C 5+ ions in the cool (Te∼13 eV) region of the capillary plasma. Relative line intensities of the C VI Hα and a number of non-lasing lines are compared in this cool region as a function of capillary length. The C VI Hα line intensity increases exponentially whereas those of non-lasing transitions increase linearly with an increase of the capillary length. The gain coefficient thus measured indicates 2.8 cm -1 . The lasing line intensity does not seem to increase exponentially beyond a capillary length of 16 mm and the gain-length product, gL, obtained here is 3.9, which is a typical value one would expect for a recombination soft x-ray laser. The photoelectric signals of the lasing line indicate that the lasing takes place about 40 ns after the current peak in the first half cycle of the capillary discharge, with a lasing pulse width of 60 ns in FWHM

  12. Viscosity measurement in the capillary tube viscometer under unsteady flow

    International Nuclear Information System (INIS)

    Park, Heung Jun; Yoo, Sang Sin; Suh, Sang Ho

    2000-01-01

    The objective of the present study is to develop a new device that the viscous characteristics of fluids are determined by applying the unsteady flow concept to the traditional capillary tube viscometer. The capillary tube viscometer consists of a small cylindrical reservoir, capillary tube, a load cell system that measures the mass flow rate, interfaces, and computer. Due to the small size of the reservoir the height of liquid in the reservoir decreases as soon as the liquid in the reservoir drains out through the capillary and the mass flow rate in the capillary decreases as the hydrostatic pressure in the reservoir decreases resulting in a decrease of the shear rate in the capillary tube. The instantaneous shear rate and driving force in the capillary tube are determined by measuring the mass flow rate through the capillary, and the fluid viscosity is determined from the measured flow rate and the driving force

  13. Endothelial microparticles: Pathogenic or passive players in endothelial dysfunction in autoimmune rheumatic diseases?

    Science.gov (United States)

    McCarthy, E M; Wilkinson, F L; Parker, B; Alexander, M Y

    2016-11-01

    Autoimmune rheumatic diseases are characterised by systemic inflammation and complex immunopathology, with an increased risk of cardiovascular disease, initiated by endothelial dysfunction in a chronic inflammatory environment. Endothelial microparticles (EMPs) are released into the circulation from activated endothelial cells and may therefore, reflect disease severity, vascular and endothelial dysfunction, that could influence disease pathogenesis via autocrine/paracrine signalling. The exact function of EMPs in rheumatic disease remains unknown, and this has initiated research to elucidate EMP composition and function, which may be determined by the mode of endothelial activation and the micro environment. To date, EMPs are thought to play a role in angiogenesis, thrombosis and inflammation by transferring specific proteins and microRNAs (miRs) to target cells. Here, we review the mechanisms underlying the generation and composition of EMPs and the clinical and experimental studies describing the involvement of EMPs in rheumatic diseases, since we have previously shown endothelial dysfunction and an elevated risk of cardiovascular disease are characteristics in systemic lupus erythematosus. We will also discuss the potential of EMPs as future biomarkers of cardiovascular risk in these diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Early capillary flux homogenization in response to neural activation.

    Science.gov (United States)

    Lee, Jonghwan; Wu, Weicheng; Boas, David A

    2016-02-01

    This Brief Communication reports early homogenization of capillary network flow during somatosensory activation in the rat cerebral cortex. We used optical coherence tomography and statistical intensity variation analysis for tracing changes in the red blood cell flux over hundreds of capillaries nearly at the same time with 1-s resolution. We observed that while the mean capillary flux exhibited a typical increase during activation, the standard deviation of the capillary flux exhibited an early decrease that happened before the mean flux increase. This network-level data is consistent with the theoretical hypothesis that capillary flow homogenizes during activation to improve oxygen delivery. © The Author(s) 2015.

  15. Can positrons be guided by insulating capillaries?

    International Nuclear Information System (INIS)

    DuBois, R.D.; Toekesi, K.

    2011-01-01

    Complete text of publication follows. Investigations of guiding of few hundred eV antiparticles by macroscopic insulating capillaries have been described. Using subfemtoamp positron and electron beams, we demonstrated that a portion of the entering beams were transmitted and emerged in the direction of the capillary. We also demonstrated that the transmitted intensities decreased as the capillary tilt angle was increased (see Fig. 1). Both of these are indications of guiding. However, a comparison with transmitted photon data implies that the positron transmission may result from geometric factors associated with our diffuse beams and tapered capillary used in these studies. For electrons, the comparison indicates differences which could imply that even very low intensity beams can be guided. Measurements of the transmitted intensity as a function of charge entering the capillary were inconclusive as no major increases in the transmitted intensity were observed. 2D static simulations imply that our beam intensities, although extremely small with respect to previous guiding experiments, were capable of supplying sufficient charge for guiding to occur. Although not definitive, our study implies that sub-femtoamp beam intensities are sufficient to form charge patches and produce guiding. This may have been observed for electrons with the question remaining open for positrons. That guiding was not clearly seen may have been due to the capillary geometry used or it may indicate that although sufficient charge is being supplied, the surface and bulk resistivities of glass permit this charge to dissipate faster than it is formed. This aspect was not taken into consideration in our simulations but a crude estimate of the discharge rate implies that beam intensities on the order of pA, rather than fA as used here, may be required for guiding to occur in the capillaries used here. Additional studies are required to definitively answer the question as to whether antiparticles

  16. Paramecium swimming in capillary tube

    Science.gov (United States)

    Jana, Saikat; Um, Soong Ho; Jung, Sunghwan

    2012-04-01

    Swimming organisms in their natural habitat need to navigate through a wide range of geometries and chemical environments. Interaction with boundaries in such situations is ubiquitous and can significantly modify the swimming characteristics of the organism when compared to ideal laboratory conditions. We study the different patterns of ciliary locomotion in glass capillaries of varying diameter and characterize the effect of the solid boundaries on the velocities of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight lines as the diameter of the capillary tubes decreases. We predict the swimming velocity in capillaries by modeling the system as a confined cylinder propagating longitudinal metachronal waves that create a finite pressure gradient. Comparing with experiments, we find that such pressure gradient considerations are necessary for modeling finite sized ciliary organisms in restrictive geometries.

  17. Curcumin modulates endothelial permeability and monocyte transendothelial migration by affecting endothelial cell dynamics.

    Science.gov (United States)

    Monfoulet, Laurent-Emmanuel; Mercier, Sylvie; Bayle, Dominique; Tamaian, Radu; Barber-Chamoux, Nicolas; Morand, Christine; Milenkovic, Dragan

    2017-11-01

    Curcumin is a phenolic compound that exhibits beneficial properties for cardiometabolic health. We previously showed that curcumin reduced the infiltration of immune cells into the vascular wall and prevented atherosclerosis development in mice. This study aimed to investigate the effect of curcumin on monocyte adhesion and transendothelial migration (TEM) and to decipher the underlying mechanisms of these actions. Human umbilical vein endothelial cells (HUVECs) were exposed to curcumin (0.5-1μM) for 3h prior to their activation by Tumor Necrosis Factor alpha (TNF-α). Endothelial permeability, monocyte adhesion and transendothelial migration assays were conducted under static condition and shear stress that mimics blood flow. We further investigated the impact of curcumin on signaling pathways and on the expression of genes using macroarrays. Pre-exposure of endothelial cells to curcumin reduced monocyte adhesion and their transendothelial migration in both static and shear stress conditions. Curcumin also prevented changes in both endothelial permeability and the area of HUVECs when induced by TNF-α. We showed that curcumin modulated the expression of 15 genes involved in the control of cytoskeleton and endothelial junction dynamic. Finally, we showed that curcumin inhibited NF-κB signaling likely through an antagonist interplay with several kinases as suggested by molecular docking analysis. Our findings demonstrate the ability of curcumin to reduce monocyte TEM through a multimodal regulation of the endothelial cell dynamics with a potential benefit on the vascular endothelial function barrier. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Glial cell ceruloplasmin and hepcidin differentially regulate iron efflux from brain microvascular endothelial cells.

    Science.gov (United States)

    McCarthy, Ryan C; Kosman, Daniel J

    2014-01-01

    We have used an in vitro model system to probe the iron transport pathway across the brain microvascular endothelial cells (BMVEC) of the blood-brain barrier (BBB). This model consists of human BMVEC (hBMVEC) and C6 glioma cells (as an astrocytic cell line) grown in a transwell, a cell culture system commonly used to quantify metabolite flux across a cell-derived barrier. We found that iron efflux from hBMVEC through the ferrous iron permease ferroportin (Fpn) was stimulated by secretion of the soluble form of the multi-copper ferroxidase, ceruloplasmin (sCp) from the co-cultured C6 cells. Reciprocally, expression of sCp mRNA in the C6 cells was increased by neighboring hBMVEC. In addition, data indicate that C6 cell-secreted hepcidin stimulates internalization of hBMVEC Fpn but only when the end-feet projections characteristic of this glia-derived cell line are proximal to the endothelial cells. This hepcidin-dependent loss of Fpn correlated with knock-down of iron efflux from the hBMVEC; this result was consistent with the mechanism by which hepcidin regulates iron efflux in mammalian cells. In summary, the data support a model of iron trafficking across the BBB in which the capillary endothelium induce the underlying astrocytes to produce the ferroxidase activity needed to support Fpn-mediated iron efflux. Reciprocally, astrocyte proximity modulates the effective concentration of hepcidin at the endothelial cell membrane and thus the surface expression of hBMVEC Fpn. These results are independent of the source of hBMVEC iron (transferrin or non-transferrin bound) indicating that the model developed here is broadly applicable to brain iron homeostasis.

  19. Vascular endothelial growth factor A protein level and gene expression in intracranial meningiomas with brain edema

    DEFF Research Database (Denmark)

    Nassehi, Damoun; Dyrbye, Henrik; Andresen, Morten

    2011-01-01

    Meningiomas are the second most common primary intracranial tumors in adults. Although meningiomas are mostly benign, more than 50% of patients with meningioma develop peritumoral brain edema (PTBE), which may be fatal because of increased intracranial pressure. Vascular endothelial growth factor....... Forty-three patients had primary, solitary, supratentorial meningiomas with PTBE. In these, correlations in PTBE, edema index, VEGF-A protein, VEGF gene expression, capillary length, and tumor water content were investigated. DNA-branched hybridization was used for measuring VEGF gene expression...... in tissue homogenates prepared from frozen tissue samples. The method for VEGF-A analysis resembled an ELISA assay, but was based on chemiluminescence. The edema index was positively correlated to VEGF-A protein (p = 0.014) and VEGF gene expression (p

  20. Low Immunogenic Endothelial Cells Maintain Morphological and Functional Properties Required for Vascular Tissue Engineering.

    Science.gov (United States)

    Lau, Skadi; Eicke, Dorothee; Carvalho Oliveira, Marco; Wiegmann, Bettina; Schrimpf, Claudia; Haverich, Axel; Blasczyk, Rainer; Wilhelmi, Mathias; Figueiredo, Constança; Böer, Ulrike

    2018-03-01

    The limited availability of native vessels suitable for the application as hemodialysis shunts or bypass material demands new strategies in cardiovascular surgery. Tissue-engineered vascular grafts containing autologous cells are considered ideal vessel replacements due to the low risk of rejection. However, endothelial cells (EC), which are central components of natural blood vessels, are difficult to obtain from elderly patients of poor health. Umbilical cord blood represents a promising alternative source for EC, but their allogeneic origin corresponds with the risk of rejection after allotransplantation. To reduce this risk, the human leukocyte antigen class I (HLA I) complex was stably silenced by lentiviral vector-mediated RNA interference (RNAi) in EC from peripheral blood and umbilical cord blood and vein. EC from all three sources were transduced by 93.1% ± 4.8% and effectively, HLA I-silenced by up to 67% compared to nontransduced (NT) cells or transduced with a nonspecific short hairpin RNA, respectively. Silenced EC remained capable to express characteristic endothelial surface markers such as CD31 and vascular endothelial cadherin important for constructing a tight barrier, as well as von Willebrand factor and endothelial nitric oxide synthase important for blood coagulation and vessel tone regulation. Moreover, HLA I-silenced EC were still able to align under unidirectional flow, to take up acetylated low-density lipoprotein, and to form capillary-like tube structures in three-dimensional fibrin gels similar to NT cells. In particular, addition of adipose tissue-derived mesenchymal stem cells significantly improved tube formation capability of HLA I-silenced EC toward long and widely branched vascular networks necessary for prevascularizing vascular grafts. Thus, silencing HLA I by RNAi represents a promising technique to reduce the immunogenic potential of EC from three different sources without interfering with EC-specific morphological and

  1. Capillary condensation between disks in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial...... capillary fluctuations play a dominant role. A simple approximative analytical expression of the interfacial free energy is developed and is validated numerically. The capillary condensation is characterized by the analysis of the coverage of the condensed phase, its stability, and asymptotic behaviors...

  2. Capillary interactions in nano-particle suspensions

    International Nuclear Information System (INIS)

    Bossev, D.P.; Warren, G.

    2009-01-01

    We have investigated the structures formed by colloidal particles suspended in solvents at volume fractions below 10% and interacting through capillary bridges. Such systems resemble colloidal gas of sticky nano-spheres that form pearl-necklace like chains that, in turn, induce strong viscoelasticity due to the formation of 3-D fractal network. The capillary force dominates the electrostatic and Van der Waals forces in solutions and can bridge multiple particles depending of the volume of the capillary bridge. We have investigated the morphology of the structures formed at different fractions of the bridging fluid. Small-angle neutron scattering (SANS) is used to study nanoparticles with an average diameter of 10 nm in polar and non-polar organic solvents at ambient temperatures. SANS intensity as a function of the scattering vector is analyzed as a product of a form factor, that depends on the particle shape, and a structure factor, that characterizes the interparticle inter reactions. The interaction of particles in polar solvents is considered to be through electrostatic repulsion and the data is successfully fitted by Hayter-Penfold mean spherical approximation (HPMSA). Computer simulations of a pearl necklace-like chain of spheres is conducted to explain the structure factor when capillary bridges are present. Alternatively, we have analyzed the slope of the intensity at low scattering vector in a double logarithmic plot to determine the dimension of the fractal structures formed by the particles at different volume fraction of the bridging fluid. We have also studied the properties of the capillary bridge between a pair of particles. The significance of this study is to explore the possibility of using capillary force as a tool to engineer new colloidal structures and materials in solutions and to optimize their viscoelastic properties. (author)

  3. Generalized polymer effective charge measurement by capillary isotachophoresis.

    Science.gov (United States)

    Chamieh, Joseph; Koval, Dušan; Besson, Adeline; Kašička, Václav; Cottet, Hervé

    2014-11-28

    In this work, we have generalized the use of capillary isotachophoresis as a universal method for determination of effective charge of anionic and cationic (co)polymers on ordinary capillary electrophoresis instruments. This method is applicable to a broad range of strong or weak polyelectrolytes with good repeatability. Experimental parameters (components and concentrations of leading and terminating electrolytes, capillary diameters, constant electric current intensity) were optimized for implementation in 100 μm i.d. capillaries for both polyanions and polycations. Determined values of polymer effective charge were in a very good agreement with those obtained by capillary electrophoresis with indirect UV detection. Uncertainty of the effective charge measurement using isotachophoresis was addressed and estimated to be ∼5-10% for solutes with mobilities in the 20-50 × 10(-9)m(2)V(-1)s(-1) range. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Isotherms of Capillary Condensation Influenced by Formation of Adsorption Films.

    Science.gov (United States)

    Churaev; Starke; Adolphs

    2000-01-15

    Isotherms of capillary condensation are often used to determine the vapor sorption capacity of porous adsorbents as well as the pore size distribution by radii. In this paper, for calculating the volume of capillary condensate and of adsorption films in a porous body, an approach based on the theory of surface forces is used. Adsorption isotherms and disjoining pressure isotherms of wetting films are presented here in an exponential form discussed earlier. The calculations were made for straight cylindrical capillaries of different radii and slit pores of different width. The mechanisms of capillary condensation differ in cylindrical and slit pores. In cylindrical pores capillary condensation occurs due to capillary instability of curved wetting films on a capillary surface, when film thickness grows. In the case of slit pores, coalescence of wetting films formed on opposite slit surfaces proceeds under the action of attractive dispersion forces. Partial volumes of liquid in the state of both capillary condensate and adsorbed films are calculated dependent on the relative vapor pressure in a surrounding media. Copyright 2000 Academic Press.

  5. Geometry Effects of Capillary on the Evaporation from the Meniscus

    International Nuclear Information System (INIS)

    Choi, Choong Hyo; Jin, Song Wan; Yoo, Jung Yul

    2007-01-01

    The effect of capillary cross-section geometry on evaporation is investigated in terms of the meniscus shape, evaporation rate and evaporation-induced flow for circular, square and rectangular cross-sectional capillaries. The shapes of water and ethanol menisci are not much different from each other in square and rectangular capillaries even though the surface tension of water is much larger than that of ethanol. On the other hand, the shapes of water and ethanol menisci are very different from each other in circular capillary. The averaged evaporation fluxes in circular and rectangular capillaries are measured by tracking the meniscus position. At a given position, the averaged evaporation flux in rectangular capillaries in much larger than that in circular capillary with comparable hydraulic diameter. The flow near the evaporating meniscus is also measured using micro-PIV, so that the rotating vortex motion is observed near the evaporating ethanol and methanol menisci except for the case of methanol meniscus in rectangular capillary. This difference is considered to be due to the existence of corner menisci at the four corners

  6. Animal study on transplantation of human umbilical vein endothelial cells for corneal endothelial decompensation

    Directory of Open Access Journals (Sweden)

    Li Cui

    2014-06-01

    Full Text Available AIM: To explore the feasibility of culturing human umbilical vein endothelial cells(HUVECon acellular corneal stroma and performing the posterior lamellar endothelial keratoplasty(PLEKtreating corneal endothelial decompensation.METHODS: Thirty New-Zealand rabbits were divided into three groups randomly, 10 rabbits for experimental group, 10 for stroma group and 10 for control group. Corneal endothelial cells were removed to establish animal model of corneal endothelial failure. PLEK was performed on the rabbits of experimental group and stroma group, and nothing was transplantated onto the rabbits of control group with the deep layer excised only. Postoperative observation was taken for 3mo. The degree of corneal edema and central corneal thickness were recorded for statistical analysis.RESULTS: Corneas in experimental group were relieved in edema obviously compared with that in stroma group and the control group, and showed increased transparency 7d after the operation. The average density of endothelial cells was 2 026.4±129.3cells/mm2, and average central corneal thickness was 505.2±25.4μm in experimental group, while 1 535.6±114.5μm in stroma group and 1 493.5±70.2μm in control group 3mo after operation.CONCLUSION:We achieved preliminary success in our study that culturing HUVEC on acellular corneal stroma and performing PLEK for corneal endothelial decompensation. HUVEC transplanted could survive in vivo, and have normal biological function of keeping cornea transparent. This study provides a new idea and a new way clinically for the treatment of corneal endothelial diseases.

  7. Subretinal Hemorrhage after Photodynamic Therapy for Juxtapapillary Retinal Capillary Hemangioma

    Directory of Open Access Journals (Sweden)

    Takayuki Baba

    2011-04-01

    Full Text Available A 75-year-old Japanese woman presented with a juxtapapillary retinal capillary hemangioma (RCH in her left eye. Twelve months after the initial examination, the size of the hemangioma had increased and the exudation from the RCH involved the macula. Her best-corrected visual acuity (BCVA had decreased from 0.8 to 0.3. A total of five intravitreal injections of bevacizumab (IVB; 1.25 mg was given but the RCH did not respond. A photodynamic therapy (PDT was done using multiple laser spots to avoid damaging the optic nerve head. After the first PDT, the subfoveal fluid was reduced but not completely gone. One week after the second PDT, a massive subretinal hemorrhage developed. The subretinal hemorrhage was successfully displaced by injecting intraocular sulfur hexafluoride (SF6 gas. At the 3-year follow-up examination, no subretinal hemorrhage or fluid was observed at the macula and the BCVA remained at 0.05. Our case was resistant to the combination of anti-vascular endothelial growth factor (VEGF and PDT and had a rare massive subretinal hemorrhage. A further collection of RCH cases treated with anti-VEGF and PDT that would justify this treatment is necessary.

  8. Microinjection study on potassium transport of rat kidney

    International Nuclear Information System (INIS)

    Miyamoto, Makoto

    1978-01-01

    Wister rate were divided into the following four groups. (A) control group (B) high-potassium diet group (C) low-potassium diet group (D) nephron population reduction (N.P.R.) group. Microinjection of the artificial solutions containing both 86 Rb and 3 H-inulin were performed into the proximal and distal convoluted tubules as well as cortical peritubular capillaries in rats undergoing mannitol diuresis. Excretory patterns of these substances were analyzed in successive urine samples. 3 H-inulin is entirely recovered in the urine of the experimental kidney following the injection into the proximal and distal tubules. 86 Rb is an adequate tracer for potassium and is absorbed into the potassium pool from either proximal tubular injections or peritubular capillaries. 86 Rb excreted with a time course similar to that of 3 H-inulin is termed as 'direct recovery' and that excreted more slowly, 'delayed recovery'. The 86 Rb recoveries which were obtained after proximal injections were independent of the injection site and averaged 9%. Secretion of 86 Rb into the urine was stimulate during enhanced K secretion and decreased during reduced K secretion along the distal nephron. Distal tubular injections gave 100% direct recovery in control, high-K diet, and N.P.R. rats. It was apparent that the 86 Rb recovery was significantly reduced, although not delayed, in animals deprived of dietary potassium for several weeks. At the collecting duct, the extensive net potassium reabsorption is observed in potassium depleted rats, whereas K absorption might be reduced or even secretion is seemingly taking place in potassium loading rats. In conclution, distal convolution and collecting duct play the major role in the regulation of urinary potassium excretion. (auth.)

  9. Endothelial dysfunction after non-cardiac surgery

    DEFF Research Database (Denmark)

    Søndergaard, E S; Fonnes, S; Gögenur, I

    2015-01-01

    was to systematically review the literature to evaluate the association between non-cardiac surgery and non-invasive markers of endothelial function. METHODS: A systematic search was conducted in MEDLINE, EMBASE and Cochrane Library Database according to the PRISMA guidelines. Endothelial dysfunction was described only...... transplantation and vascular surgery respectively) had an improvement in endothelial dysfunction 1 month after surgery. CONCLUSION: Endothelial function changes in relation to surgery. Assessment of endothelial function by non-invasive measures has the potential to guide clinicians in the prevention or treatment...

  10. Integrated refractive index optical ring resonator detector for capillary electrophoresis.

    Science.gov (United States)

    Zhu, Hongying; White, Ian M; Suter, Jonathan D; Zourob, Mohammed; Fan, Xudong

    2007-02-01

    We developed a novel miniaturized and multiplexed, on-capillary, refractive index (RI) detector using liquid core optical ring resonators (LCORRs) for future development of capillary electrophoresis (CE) devices. The LCORR employs a glass capillary with a diameter of approximately 100 mum and a wall thickness of a few micrometers. The circular cross section of the capillary forms a ring resonator along which the light circulates in the form of the whispering gallery modes (WGMs). The WGM has an evanescent field extending into the capillary core and responds to the RI change due to the analyte conducted in the capillary, thus permitting label-free measurement. The resonating nature of the WGM enables repetitive light-analyte interaction, significantly enhancing the LCORR sensitivity. This LCORR architecture achieves dual use of the capillary as a sensor head and a CE fluidic channel, allowing for integrated, multiplexed, and noninvasive on-capillary detection at any location along the capillary. In this work, we used electro-osmotic flow and glycerol as a model system to demonstrate the fluid transport capability of the LCORRs. In addition, we performed flow speed measurement on the LCORR to demonstrate its flow analysis capability. Finally, using the LCORR's label-free sensing mechanism, we accurately deduced the analyte concentration in real time at a given point on the capillary. A sensitivity of 20 nm/RIU (refractive index units) was observed, leading to an RI detection limit of 10-6 RIU. The LCORR marries photonic technology with microfluidics and enables rapid on-capillary sample analysis and flow profile monitoring. The investigation in this regard will open a door to novel high-throughput CE devices and lab-on-a-chip sensors in the future.

  11. High-intensity interval exercise attenuates but does not eliminate endothelial dysfunction after a fast food meal.

    Science.gov (United States)

    Tucker, Wesley J; Sawyer, Brandon J; Jarrett, Catherine L; Bhammar, Dharini M; Ryder, Justin R; Angadi, Siddhartha S; Gaesser, Glenn A

    2018-02-01

    We investigated whether two different bouts of high-intensity interval exercise (HIIE) could attenuate postprandial endothelial dysfunction. Thirteen young (27 ± 1 yr), nonexercise-trained men underwent three randomized conditions: 1) four 4-min intervals at 85-95% of maximum heart rate separated by 3 min of active recovery (HIIE 4 × 4), 2) 16 1-min intervals at 85-95% of maximum heart rate separated by 1 min of active recovery (HIIE 16 × 1), and 3) sedentary control. HIIE was performed in the afternoon, ~18 h before the morning fast food meal (1,250 kcal, 63g of fat). Brachial artery flow-mediated dilation (FMD) was performed before HIIE ( baseline 1), during fasting before meal ingestion ( baseline 2), and 30 min, 2 h, and 4 h postprandial. Capillary glucose and triglycerides were assessed at fasting, 30 min, 1 h, 2 h, and 4 h (triglycerides only). Both HIIE protocols increased fasting FMD compared with control (HIIE 4 × 4: 6.1 ± 0.4%, HIIE 16 × 1: 6.3 ± 0.5%, and control: 5.1 ± 0.4%, P fast food meal can attenuate but not entirely eliminate postprandial decreases in FMD. This effect is not dependent on reductions in postprandial lipemia or glycemia. NEW & NOTEWORTHY Two similar high-intensity interval exercise (HIIE) protocols performed ∼18 h before ingestion of a high-energy fast food meal attenuated but did not entirely eliminate postprandial endothelial dysfunction in young men largely by improving fasting endothelial function. Both HIIE protocols produced essentially identical results, suggesting high reproducibility of HIIE effects.

  12. Iron uptake and transport at the blood-brain barrier

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved...... in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity....... The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We...

  13. Mitochondria and Endothelial Function

    Science.gov (United States)

    Kluge, Matthew A.; Fetterman, Jessica L.; Vita, Joseph A.

    2013-01-01

    In contrast to their role in other cell types with higher energy demands, mitochondria in endothelial cells primarily function in signaling cellular responses to environmental cues. This article provides an overview of key aspects of mitochondrial biology in endothelial cells, including subcellular location, biogenesis, dynamics, autophagy, ROS production and signaling, calcium homeostasis, regulated cell death, and heme biosynthesis. In each section, we introduce key concepts and then review studies showing the importance of that mechanism to endothelial control of vasomotor tone, angiogenesis, and inflammatory activation. We particularly highlight the small number of clinical and translational studies that have investigated each mechanism in human subjects. Finally, we review interventions that target different aspects of mitochondrial function and their effects on endothelial function. The ultimate goal of such research is the identification of new approaches for therapy. The reviewed studies make it clear that mitochondria are important in endothelial physiology and pathophysiology. A great deal of work will be needed, however, before mitochondria-directed therapies are available for the prevention and treatment of cardiovascular disease. PMID:23580773

  14. Urokinase receptor expression on human microvascular endothelial cells is increased by hypoxia: Implications for capillary-like tube formation in a fibrin matrix

    NARCIS (Netherlands)

    Kroon, M.E.; Koolwijk, P.; Vecht, B. van der; Hinsbergh, V.W.M. van

    2000-01-01

    Hypoxia stimulates angiogenesis, the formation of new blood vessels. This study evaluates the direct effect of hypoxia (1% oxygen) on the angiogenic response of human microvascular endothelial cells (hMVECs) seeded on top of a 3-dimensional fibrin matrix, hMVECs stimulated with fibroblast growth

  15. Modulation of ephrinB2 leads to increased angiogenesis in ischemic myocardium and endothelial cell proliferation

    International Nuclear Information System (INIS)

    Mansson-Broberg, Agneta; Siddiqui, Anwar J.; Genander, Maria; Grinnemo, Karl-Henrik; Hao Xiaojin; Andersson, Agneta B.; Waerdell, Eva; Sylven, Christer; Corbascio, Matthias

    2008-01-01

    Eph/ephrin signaling is pivotal in prenatal angiogenesis while its potential role in postnatal angiogenesis largely remains to be explored. Therefore its putative angiogenic and therapeutic effects were explored in endothelium and in myocardial ischemia. In culture of human aortic endothelial cells the fusion protein ephrinB2-Fc induced cell proliferation (p < 0.0005) and in the murine aortic ring model ephrinB2-Fc induced increased sprouting (p < 0.05). Myocardial infarction was induced by ligation of the left anterior descending artery in mouse. During the following 2 weeks mRNA of the receptor/ligand pair EphB4/ephrinB2 was expressed dichotomously (p < 0.05) and other Eph/ephrin pairs were expressed to a lesser degree. Twenty-four hours after intraperitoneal administration of ephrinB2-Fc it was detected in abundance throughout the myocardium along capillaries, showing signs of increased mitosis. After 4 weeks the capillary density was increased 28% in the periinfarcted area (p < 0.05) to a level not different from healthy regions of the heart where no change was observed. These results implicate that EphB4/ephrinB2 is an important signaling pathway in ischemic heart disease and its modulation may induce therapeutic angiogenesis

  16. Aging-induced dysregulation of dicer1-dependent microRNA expression impairs angiogenic capacity of rat cerebromicrovascular endothelial cells.

    Science.gov (United States)

    Ungvari, Zoltan; Tucsek, Zsuzsanna; Sosnowska, Danuta; Toth, Peter; Gautam, Tripti; Podlutsky, Andrej; Csiszar, Agnes; Losonczy, Gyorgy; Valcarcel-Ares, M Noa; Sonntag, William E; Csiszar, Anna

    2013-08-01

    Age-related impairment of angiogenesis is likely to play a central role in cerebromicrovascular rarefaction and development of vascular cognitive impairment, but the underlying mechanisms remain elusive. To test the hypothesis that dysregulation of Dicer1 (ribonuclease III, a key enzyme of the microRNA [miRNA] machinery) impairs endothelial angiogenic capacity in aging, primary cerebromicrovascular endothelial cells (CMVECs) were isolated from young (3 months old) and aged (24 months old) Fischer 344 × Brown Norway rats. We found an age-related downregulation of Dicer1 expression both in CMVECs and in small cerebral vessels isolated from aged rats. In aged CMVECs, Dicer1 expression was increased by treatment with polyethylene glycol-catalase. Compared with young cells, aged CMVECs exhibited altered miRNA expression profile, which was associated with impaired proliferation, adhesion to vitronectin, collagen and fibronectin, cellular migration (measured by a wound-healing assay using electric cell-substrate impedance sensing technology), and impaired ability to form capillary-like structures. Overexpression of Dicer1 in aged CMVECs partially restored miRNA expression profile and significantly improved angiogenic processes. In young CMVECs, downregulation of Dicer1 (siRNA) resulted in altered miRNA expression profile associated with impaired proliferation, adhesion, migration, and tube formation, mimicking the aging phenotype. Collectively, we found that Dicer1 is essential for normal endothelial angiogenic processes, suggesting that age-related dysregulation of Dicer1-dependent miRNA expression may be a potential mechanism underlying impaired angiogenesis and cerebromicrovascular rarefaction in aging.

  17. Clinical significance of nailfold capillaroscopy in systemic lupus erythematosus: correlation with endothelial cell activation markers and disease activity.

    Science.gov (United States)

    Kuryliszyn-Moskal, A; Ciolkiewicz, M; Klimiuk, P A; Sierakowski, S

    2009-01-01

    To evaluate whether nailfold capillaroscopy (NC) changes are associated with the main serum endothelial cell activation markers and the disease activity of systemic lupus erythematosus (SLE). Serum levels of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), soluble E-selectin (sE-selectin), and soluble thrombomodulin (sTM) were determined by an enzyme-linked immunosorbent assay (ELISA) in 80 SLE patients and 33 healthy controls. Nailfold capillary abnormalities were seen in 74 out of 80 (92.5%) SLE patients. A normal capillaroscopic pattern or mild changes were found in 33 (41.25%) and moderate/severe abnormalities in 47 (58.75%) of all SLE patients. In SLE patients a capillaroscopic score >1 was more frequently associated with the presence of internal organ involvement (p 1 and controls. SLE patients with severe/moderate capillaroscopic abnormalities showed significantly higher VEGF serum levels than patients with mild changes (p < 0.001). Moreover, there was a significant positive correlation between the severity of capillaroscopic changes and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) (p < 0.005) as well as between capillaroscopic score and VEGF serum levels (p < 0.001). Our findings confirm the usefulness of NC as a non-invasive technique for the evaluation of microvascular involvement in SLE patients. A relationship between changes in NC, endothelial cell activation markers and clinical features of SLE suggest an important role for microvascular abnormalities in clinical manifestation of the disease.

  18. Vascular Endothelial Growth Factor and Angiopoietin-1 Stimulate Postnatal Hematopoiesis by Recruitment of Vasculogenic and Hematopoietic Stem Cells

    Science.gov (United States)

    Hattori, Koichi; Dias, Sergio; Heissig, Beate; Hackett, Neil R.; Lyden, David; Tateno, Masatoshi; Hicklin, Daniel J.; Zhu, Zhenping; Witte, Larry; Crystal, Ronald G.; Moore, Malcolm A.S.; Rafii, Shahin

    2001-01-01

    Tyrosine kinase receptors for angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) are expressed not only by endothelial cells but also by subsets of hematopoietic stem cells (HSCs). To further define their role in the regulation of postnatal hematopoiesis and vasculogenesis, VEGF and Ang-1 plasma levels were elevated by injecting recombinant protein or adenoviral vectors expressing soluble VEGF165, matrix-bound VEGF189, or Ang-1 into mice. VEGF165, but not VEGF189, induced a rapid mobilization of HSCs and VEGF receptor (VEGFR)2+ circulating endothelial precursor cells (CEPs). In contrast, Ang-1 induced delayed mobilization of CEPs and HSCs. Combined sustained elevation of Ang-1 and VEGF165 was associated with an induction of hematopoiesis and increased marrow cellularity followed by proliferation of capillaries and expansion of sinusoidal space. Concomitant to this vascular remodeling, there was a transient depletion of hematopoietic activity in the marrow, which was compensated by an increase in mobilization and recruitment of HSCs and CEPs to the spleen resulting in splenomegaly. Neutralizing monoclonal antibody to VEGFR2 completely inhibited VEGF165, but not Ang-1–induced mobilization and splenomegaly. These data suggest that temporal and regional activation of VEGF/VEGFR2 and Ang-1/Tie-2 signaling pathways are critical for mobilization and recruitment of HSCs and CEPs and may play a role in the physiology of postnatal angiogenesis and hematopoiesis. PMID:11342585

  19. Capillary array electrophoresis using laser-excited confocal fluorescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.C.; Quesada, M.A.; Mathies, R.A. [Univ. of California, Berkeley, CA (United States)

    1992-04-15

    Capillary electrophoresis (CE) has found widespread application in analytical and biomedical research, and the scope and sophistication of CE is still rapidly advancing. Gel-filled capillaries have been employed for the rapid separation and analysis of synthetic polynucleotides, DNA sequencing fragments, and DNA restriction fragments. Open-tube capillary electrophoresis has attained subattomole detection levels in amino acid separations 14 and proven its utility for the separation of proteins, viruses, and bacteria. Separation of the optical isomers of dansyl amino acids has also been successfully demonstrated. Micellar electrokinetic capillary chromatography, isoelectric focusing, and on-column derivatization can all be performed on CE columns, demonstrating the utility of capillary electrophoresis as an analytical and micropreparative tool. 29 refs., 6 figs., 1 tab.

  20. Capillary Rise: Validity of the Dynamic Contact Angle Models.

    Science.gov (United States)

    Wu, Pingkeng; Nikolov, Alex D; Wasan, Darsh T

    2017-08-15

    The classical Lucas-Washburn-Rideal (LWR) equation, using the equilibrium contact angle, predicts a faster capillary rise process than experiments in many cases. The major contributor to the faster prediction is believed to be the velocity dependent dynamic contact angle. In this work, we investigated the dynamic contact angle models for their ability to correct the dynamic contact angle effect in the capillary rise process. We conducted capillary rise experiments of various wetting liquids in borosilicate glass capillaries and compared the model predictions with our experimental data. The results show that the LWR equations modified by the molecular kinetic theory and hydrodynamic model provide good predictions on the capillary rise of all the testing liquids with fitting parameters, while the one modified by Joos' empirical equation works for specific liquids, such as silicone oils. The LWR equation modified by molecular self-layering model predicts well the capillary rise of carbon tetrachloride, octamethylcyclotetrasiloxane, and n-alkanes with the molecular diameter or measured solvation force data. The molecular self-layering model modified LWR equation also has good predictions on the capillary rise of silicone oils covering a wide range of bulk viscosities with the same key parameter W(0), which results from the molecular self-layering. The advantage of the molecular self-layering model over the other models reveals the importance of the layered molecularly thin wetting film ahead of the main meniscus in the energy dissipation associated with dynamic contact angle. The analysis of the capillary rise of silicone oils with a wide range of bulk viscosities provides new insights into the capillary dynamics of polymer melts.

  1. Vacuum scanning capillary photoemission microscopy.

    Science.gov (United States)

    Aseyev, S A; Cherkun, A P; Mironov, B N; Petrunin, V V; Chekalin, S V

    2017-08-01

    We demonstrate the use of a conical capillary in a scanning probe microscopy for surface analysis. The probe can measure photoemission from a substrate by transmitting photoelectrons along the capillary as a function of probe position. The technique is demonstrated on a model substrate consisting of a gold reflecting layer on a compact disc which has been illuminated by an unfocused laser beam with a wavelength 400nm, from a femtosecond laser with a beam size of 4mm. A quartz capillary with a 2-µm aperture has been used in the experiments. The period of gold microstructure, shown to be 1.6µ, was measured by the conical probe operating in shear force mode. In shear force regime, the dielectric capillary has been used as a "classical" SPM tip, which provided images reflecting the surface topology. In a photoelectron regime photoelectrons passed through hollow tip and entered a detector. The spatial distribution of the recorded photoelectrons consisted of periodic mountain-valley strips, resembling the surface profile of the sample. Submicron spatial resolution has been achieved. This approach paves the way to study pulsed photodesorption of large organic molecular ions with high spatial and element resolution using the combination of a hollow-tip scanner with time-of-flight technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Anesthetic propofol overdose causes endothelial cytotoxicity in vitro and endothelial barrier dysfunction in vivo

    International Nuclear Information System (INIS)

    Lin, Ming-Chung; Chen, Chia-Ling; Yang, Tsan-Tzu; Choi, Pui-Ching; Hsing, Chung-Hsi; Lin, Chiou-Feng

    2012-01-01

    An overdose and a prolonged treatment of propofol may cause cellular cytotoxicity in multiple organs and tissues such as brain, heart, kidney, skeletal muscle, and immune cells; however, the underlying mechanism remains undocumented, particularly in vascular endothelial cells. Our previous studies showed that the activation of glycogen synthase kinase (GSK)-3 is pro-apoptotic in phagocytes during overdose of propofol treatment. Regarding the intravascular administration of propofol, we therefore hypothesized that propofol overdose also induces endothelial cytotoxicity via GSK-3. Propofol overdose (100 μg/ml) inhibited growth in human arterial and microvascular endothelial cells. After treatment, most of the endothelial cells experienced caspase-independent necrosis-like cell death. The activation of cathepsin D following lysosomal membrane permeabilization (LMP) determined necrosis-like cell death. Furthermore, propofol overdose also induced caspase-dependent apoptosis, at least in part. Caspase-3 was activated and acted downstream of mitochondrial transmembrane potential (MTP) loss; however, lysosomal cathepsins were not required for endothelial cell apoptosis. Notably, activation of GSK-3 was essential for propofol overdose-induced mitochondrial damage and apoptosis, but not necrosis-like cell death. Intraperitoneal administration of a propofol overdose in BALB/c mice caused an increase in peritoneal vascular permeability. These results demonstrate the cytotoxic effects of propofol overdose, including cathepsin D-regulated necrosis-like cell death and GSK-3-regulated mitochondrial apoptosis, on endothelial cells in vitro and the endothelial barrier dysfunction by propofol in vivo. Highlights: ► Propofol overdose causes apoptosis and necrosis in endothelial cells. ► Propofol overdose triggers lysosomal dysfunction independent of autophagy. ► Glycogen synthase kinase-3 facilitates propofol overdose-induced apoptosis. ► Propofol overdose causes an increase

  3. Anesthetic propofol overdose causes endothelial cytotoxicity in vitro and endothelial barrier dysfunction in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ming-Chung [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Department of Anesthesiology, Chi Mei Medical Center, Liouying, Tainan, Taiwan (China); Chen, Chia-Ling [Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Yang, Tsan-Tzu; Choi, Pui-Ching [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Hsing, Chung-Hsi [Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan (China); Department of Anesthesiology, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Lin, Chiou-Feng, E-mail: cflin@mail.ncku.edu.tw [Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China)

    2012-12-01

    An overdose and a prolonged treatment of propofol may cause cellular cytotoxicity in multiple organs and tissues such as brain, heart, kidney, skeletal muscle, and immune cells; however, the underlying mechanism remains undocumented, particularly in vascular endothelial cells. Our previous studies showed that the activation of glycogen synthase kinase (GSK)-3 is pro-apoptotic in phagocytes during overdose of propofol treatment. Regarding the intravascular administration of propofol, we therefore hypothesized that propofol overdose also induces endothelial cytotoxicity via GSK-3. Propofol overdose (100 μg/ml) inhibited growth in human arterial and microvascular endothelial cells. After treatment, most of the endothelial cells experienced caspase-independent necrosis-like cell death. The activation of cathepsin D following lysosomal membrane permeabilization (LMP) determined necrosis-like cell death. Furthermore, propofol overdose also induced caspase-dependent apoptosis, at least in part. Caspase-3 was activated and acted downstream of mitochondrial transmembrane potential (MTP) loss; however, lysosomal cathepsins were not required for endothelial cell apoptosis. Notably, activation of GSK-3 was essential for propofol overdose-induced mitochondrial damage and apoptosis, but not necrosis-like cell death. Intraperitoneal administration of a propofol overdose in BALB/c mice caused an increase in peritoneal vascular permeability. These results demonstrate the cytotoxic effects of propofol overdose, including cathepsin D-regulated necrosis-like cell death and GSK-3-regulated mitochondrial apoptosis, on endothelial cells in vitro and the endothelial barrier dysfunction by propofol in vivo. Highlights: ► Propofol overdose causes apoptosis and necrosis in endothelial cells. ► Propofol overdose triggers lysosomal dysfunction independent of autophagy. ► Glycogen synthase kinase-3 facilitates propofol overdose-induced apoptosis. ► Propofol overdose causes an increase

  4. Equilibrium capillary forces with atomic force microscopy

    NARCIS (Netherlands)

    Sprakel, J.H.B.; Besseling, N.A.M.; Leermakers, F.A.M.; Cohen Stuart, M.A.

    2007-01-01

    We present measurements of equilibrium forces resulting from capillary condensation. The results give access to the ultralow interfacial tensions between the capillary bridge and the coexisting bulk phase. We demonstrate this with solutions of associative polymers and an aqueous mixture of gelatin

  5. Multianalyte detection using a capillary-based flow immunosensor.

    Science.gov (United States)

    Narang, U; Gauger, P R; Kusterbeck, A W; Ligler, F S

    1998-01-01

    A highly sensitive, dual-analyte detection system using capillary-based immunosensors has been designed for explosive detection. This model system consists of two capillaries, one coated with antibodies specific for 2,4,6-trinitrotoluene (TNT) and the other specific for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) combined into a single device. The fused silica capillaries are prepared by coating anti-TNT and anti-RDX antibodies onto the silanized inner walls using a hetero-bifunctional crosslinker. After immobilization, the antibodies are saturated with a suitable fluorophorelabeled antigen. A "T" connector is used to continuously flow the buffer solution through the individual capillaries. To perform the assay, an aliquot of TNT or RDX or a mixture of the two analytes is injected into the continuous flow stream. In each capillary, the target analyte displaces the fluorophore-labeled antigen from the binding pocket of the antibody. The labeled antigen displaced from either capillary is detected downstream using two portable spectrofluorometers. The limits of detection for TNT and RDX in the multi-analyte formate are 44 fmol (100 microliters of 0.1 ng/ml TNT solution) and 224 fmol (100 microliters of 0.5 ng/ml RDX solution), respectively. The entire assay for both analytes can be performed in less than 3 min.

  6. A fully automated 384 capillary array for DNA sequencer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qingbo; Kane, T

    2003-03-20

    Phase I SpectruMedix has successfully developed an automatic 96-capillary array DNA prototype based on the multiplexed capillary electrophoresis system originated from Ames Laboratory-USDOE, Iowa State University. With computer control of all steps involved in a 96-capillary array running cycle, the prototype instrument (the SCE9600) is now capable of sequencing 450 base pairs (bp) per capillary, or 48,000 bp per instrument run within 2 hrs. Phase II of this grant involved the advancement of the core 96 capillary technologies, as well as designing a high density 384 capillary prototype. True commercialization of the 96 capillary instrument involved finalization of the gel matrix, streamlining the instrument hardware, creating a more reliable capillary cartridge, and further advancement of the data processing software. Together these silos of technology create a truly commercializable product (the SCE9610) capable of meeting the operation needs of the sequencing centers.

  7. Weight-controlled capillary viscometer

    Science.gov (United States)

    Digilov, Rafael M.; Reiner, M.

    2005-11-01

    The draining of a water column through a vertical discharge capillary tube is examined with the aid of a force sensor. The change of the mass of the liquid in the column with time is found to be not purely exponential as implied by Poiseuille's law. Using observed residuals associated with a kinetic energy correction, an approximate formula for the mass as a function of time is derived and excellent agreement with experimental data is attained. These results are verified by a viscosity test of distilled water at room temperature. A simple and inexpensive weight-controlled capillary viscometer is proposed that is especially suitable for undergraduate physics and chemistry laboratories.

  8. STUDIES ON ENDOTHELIAL REACTIONS

    Science.gov (United States)

    Foot, Nathan Chandler

    1923-01-01

    of this experiment strengthen the foregoing conclusions materially. It was found that there were many polymorphonuclear amphophils in the pulmonary capillaries of the splenectomized animals and that there were numerous focal necroses in the livers. The controls showed much fewer polymorphonuclear cells in the lungs and no focal necroses in the livers, while the spleens were actively congested and inflamed. Otherwise the experiment was not of sufficient importance to warrant a separate report. The question as to why the endothelium of the pulmonary capillaries shows no stimulation similar to that observed in the carbon experiment, but rather less activity than that of the controls, must be answered hypothetically for the present. With the carbon, comparatively huge amounts of foreign matter were injected repeatedly; here but one injection of a much smaller amount of suspended tubercle bacilli was administered. The resulting stimulus to the pulmonary endothelium would, therefore, differ materially in the two instances. In one there would be succeeding waves of stimulation following each injection of irritating foreign substance. In the other an entirely different sort of stimulus would result; the bacteria would be withdrawn from the circulation within an hour or two, judging by past experience, and would then multiply, to be cast off into the circulation in driblets, as the lesions containing them broke down. At least it can be said that there is a good theoretical reason for the difference in the endothelial reaction in the lungs of the two groups of animals. PMID:19868788

  9. Functionally induced changes in water transport in the proximal tubule segment of rat kidneys

    DEFF Research Database (Denmark)

    Faarup, Poul; von Holstein-Rathlou, Niels-Henrik; Nørgaard, Tove

    2011-01-01

    To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the pr......To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure...... segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries....

  10. Renal uptake of dimercaptosuccinic acid and glomerular filtration rate in chronic nephropathy at angiotensin converting enzyme inhibition

    International Nuclear Information System (INIS)

    Kamper, A.L.; Thomsen, H.S.; Nielsen, S.L.; Strandgaard, S.; Herlev Hospital

    1990-01-01

    Glomerular filtration rate (GFR) and renal uptake of dimercaptosuccinic acid (DMSA) were measured in 31 patients with progressive chronic nephropathy before and immediately after the start of treatment with angiotensin converting enzyme (ACE) inhibitor in order to control adverse effects on kidney function. Scintigrams of the kidneys showed an unaltered distribution of DMSA during treatment. GFR estimated by 51 Cr-EDTA plasma clearance fell by 14% (P 99m Tc-DMSA increased by 10% (P<0.01). It is concluded that DMSA in chronic renal failure is mainly taken up by the tubular cells from the peritubular capillaries since the uptake was unaffected by the acute decrease in GFR. (orig.)

  11. Capillary electrophoresis: principles and applications in illicit drug analysis.

    Science.gov (United States)

    Tagliaro, F; Turrina, S; Smith, F P

    1996-02-09

    Capillary electrophoresis, which appeared in the early 1980s, is now rapidly expanding into many scientific disciplines, including analytical chemistry, biotechnology and biomedical and pharmaceutical sciences. In capillary electrophoresis,electrokinetic separations are carried out in tiny capillaries at high voltages (10-30 kV), thus obtaining high efficiencies (N > 10(5)) and excellent mass sensitivities (down to 10(-18)-10(-20) moles). The main features of capillary electrophoresis are: versatility of application (from inorganic ions to large DNA fragments), use of different separation modes with different selectivity, extremely low demands on sample volume, negligible running costs, possibility of interfacing with different detection systems, ruggedness and simplicity of instrumentation. Capillary electrophoresis applications in forensic sciences have appeared only recently, but are now rapidly growing, particularly in forensic toxicology. The present paper briefly describes the basic principles of capillary electrophoresis, from both the instrumental and analytical points of view. Furthermore, the main applications in the analysis of illicit/controlled drugs in both illicit preparations and biological samples are presented and discussed (43 references). It is concluded that the particular separation mechanism and the high complementarity of this technique to chromatography makes capillary electrophoresis a new powerful tool of investigation in the hands of forensic toxicologists.

  12. Apoptosis of Endothelial Cells by 13-HPODE Contributes to Impairment of Endothelial Barrier Integrity

    Directory of Open Access Journals (Sweden)

    Valerie E. Ryman

    2016-01-01

    Full Text Available Inflammation is an essential host response during bacterial infections such as bovine mastitis. Endothelial cells are critical for an appropriate inflammatory response and loss of vascular barrier integrity is implicated in the pathogenesis of Streptococcus uberis-induced mastitis. Previous studies suggested that accumulation of linoleic acid (LA oxygenation products derived from 15-lipoxygenase-1 (15-LOX-1 metabolism could regulate vascular functions. The initial LA derivative from the 15-LOX-1 pathway, 13-hydroperoxyoctadecadienoic acid (HPODE, can induce endothelial death, whereas the reduced hydroxyl product, 13-hydroxyoctadecadienoic acid (HODE, is abundantly produced during vascular activation. However, the relative contribution of specific LA-derived metabolites on impairment of mammary endothelial integrity is unknown. Our hypothesis was that S. uberis-induced LA-derived 15-LOX-1 oxygenation products impair mammary endothelial barrier integrity by apoptosis. Exposure of bovine mammary endothelial cells (BMEC to S. uberis did not increase 15-LOX-1 LA metabolism. However, S. uberis challenge of bovine monocytes demonstrated that monocytes may be a significant source of both 13-HPODE and 13-HODE during mastitis. Exposure of BMEC to 13-HPODE, but not 13-HODE, significantly reduced endothelial barrier integrity and increased apoptosis. Changing oxidant status by coexposure to an antioxidant during 13-HPODE treatment prevented adverse effects of 13-HPODE, including amelioration of apoptosis. A better understanding of how the oxidant status of the vascular microenvironment impacts endothelial barrier properties could lead to more efficacious treatments for S. uberis mastitis.

  13. A biphasic endothelial stress-survival mechanism regulates the cellular response to vascular endothelial growth factor A

    International Nuclear Information System (INIS)

    Latham, Antony M.; Odell, Adam F.; Mughal, Nadeem A.; Issitt, Theo; Ulyatt, Clare; Walker, John H.; Homer-Vanniasinkam, Shervanthi; Ponnambalam, Sreenivasan

    2012-01-01

    Vascular endothelial growth factor A (VEGF-A) is an essential cytokine that regulates endothelial function and angiogenesis. VEGF-A binding to endothelial receptor tyrosine kinases such as VEGFR1 and VEGFR2 triggers cellular responses including survival, proliferation and new blood vessel sprouting. Increased levels of a soluble VEGFR1 splice variant (sFlt-1) correlate with endothelial dysfunction in pathologies such as pre-eclampsia; however the cellular mechanism(s) underlying the regulation and function of sFlt-1 are unclear. Here, we demonstrate the existence of a biphasic stress response in endothelial cells, using serum deprivation as a model of endothelial dysfunction. The early phase is characterized by a high VEGFR2:sFlt-1 ratio, which is reversed in the late phase. A functional consequence is a short-term increase in VEGF-A-stimulated intracellular signaling. In the late phase, sFlt-1 is secreted and deposited at the extracellular matrix. We hypothesized that under stress, increased endothelial sFlt-1 levels reduce VEGF-A bioavailability: VEGF-A treatment induces sFlt-1 expression at the cell surface and VEGF-A silencing inhibits sFlt-1 anchorage to the extracellular matrix. Treatment with recombinant sFlt-1 inhibits VEGF-A-stimulated in vitro angiogenesis and sFlt-1 silencing enhances this process. In this response, increased VEGFR2 levels are regulated by the phosphatidylinositol-3-kinase and PKB/Akt signaling pathways and increased sFlt-1 levels by the ERK1/2 signaling pathway. We conclude that during serum withdrawal, cellular sensing of environmental stress modulates sFlt-1 and VEGFR2 levels, regulating VEGF-A bioavailability and ensuring cell survival takes precedence over cell proliferation and migration. These findings may underpin an important mechanism contributing to endothelial dysfunction in pathological states. -- Highlights: ► Endothelial cells mount a stress response under conditions of low serum. ► Endothelial VEGFR levels are

  14. Increased endothelial cell-leukocyte interaction in murine schistosomiasis: possible priming of endothelial cells by the disease.

    Directory of Open Access Journals (Sweden)

    Suellen D S Oliveira

    Full Text Available BACKGROUND AND AIMS: Schistosomiasis is an intravascular parasitic disease associated with inflammation. Endothelial cells control leukocyte transmigration and vascular permeability being modulated by pro-inflammatory mediators. Recent data have shown that endothelial cells primed in vivo in the course of a disease keep the information in culture. Herein, we evaluated the impact of schistosomiasis on endothelial cell-regulated events in vivo and in vitro. METHODOLOGY AND PRINCIPAL FINDINGS: The experimental groups consisted of Schistosoma mansoni-infected and age-matched control mice. In vivo infection caused a marked influx of leukocytes and an increased protein leakage in the peritoneal cavity, characterizing an inflamed vascular and cellular profile. In vitro leukocyte-mesenteric endothelial cell adhesion was higher in cultured cells from infected mice as compared to controls, either in the basal condition or after treatment with the pro-inflammatory cytokine tumor necrosis factor (TNF. Nitric oxide (NO donation reduced leukocyte adhesion to endothelial cells from control and infected groups; however, in the later group the effect was more pronounced, probably due to a reduced NO production. Inhibition of control endothelial NO synthase (eNOS increased leukocyte adhesion to a level similar to the one observed in the infected group. Besides, the adhesion of control leukocytes to endothelial cells from infected animals is similar to the result of infected animals, confirming that schistosomiasis alters endothelial cells function. Furthermore, NO production as well as the expression of eNOS were reduced in cultured endothelial cells from infected animals. On the other hand, the expression of its repressor protein, namely caveolin-1, was similar in both control and infected groups. CONCLUSION/SIGNIFICANCE: Schistosomiasis increases vascular permeability and endothelial cell-leukocyte interaction in vivo and in vitro. These effects are partially

  15. CS5931, a Novel Polypeptide in Ciona savignyi, Represses Angiogenesis via Inhibiting Vascular Endothelial Growth Factor (VEGF and Matrix Metalloproteinases (MMPs

    Directory of Open Access Journals (Sweden)

    Ge Liu

    2014-03-01

    Full Text Available CS5931 is a novel polypeptide from Ciona savignyi with anticancer activities. Previous study in our laboratory has shown that CS5931 can induce cell death via mitochondrial apoptotic pathway. In the present study, we found that the polypeptide could inhibit angiogenesis both in vitro and in vivo. CS5931 inhibited the proliferation, migration and formation of capillary-like structures of HUVECs (Human Umbilical Vein Endothelial Cell in a dose-dependent manner. Additionally, CS5931 repressed spontaneous angiogenesis of the zebrafish vessels. Further studies showed that CS5931 also blocked vascular endothelial growth factor (VEGF production but without any effect on its mRNA expression. Moreover, CS5931 reduced the expression of matrix metalloproteinases (MMP-2 and MMP-9 both on protein and mRNA levels in HUVEC cells. We demonstrated that CS5931 possessed strong anti-angiogenic activity both in vitro and in vivo, possible via VEGF and MMPs. This study indicates that CS5931 has the potential to be developed as a novel therapeutic agent as an inhibitor of angiogenesis for the treatment of cancer.

  16. THE CAPILLARY PATTERN IN HUMAN MASSETER MUSCLE DURING AGEING

    Directory of Open Access Journals (Sweden)

    Erika Cvetko

    2013-10-01

    Full Text Available The effect of ageing on the capillary network in skeletal muscles has produced conflicting results in both, human and animals studies. Some of the inconsistencies are due to non-comparable and biased methods that were applied on thin transversal sections, especially in muscles with complicated morphological structures, such as in human masseter muscle. We present a new immunohistochemical method for staining capillaries and muscle fibres in 100 µm thick sections as well as novel approach to 3D visualization of capillaries and muscle fibres. Applying confocal microscopy and virtual 3D stereological grids, or tracing capillaries in virtual reality, length of capillaries within a muscle volume or length of capillaries adjacent to muscle fibre per fibre length, fibre surface or fibre volume were evaluated in masseter muscle of young and old subjects by an unbiased approach. Our findings show that anatomic capillarity is well maintained in masseter muscle in old subjects; however, vascular remodelling occurs with age, which could be a response to changed muscle function and age-related muscle fibre type transformations.

  17. An integrated multiple capillary array electrophoresis system for high-throughput DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.

    1998-03-27

    A capillary array electrophoresis system was chosen to perform DNA sequencing because of several advantages such as rapid heat dissipation, multiplexing capabilities, gel matrix filling simplicity, and the mature nature of the associated manufacturing technologies. There are two major concerns for the multiple capillary systems. One concern is inter-capillary cross-talk, and the other concern is excitation and detection efficiency. Cross-talk is eliminated through proper optical coupling, good focusing and immersing capillary array into index matching fluid. A side-entry excitation scheme with orthogonal detection was established for large capillary array. Two 100 capillary array formats were used for DNA sequencing. One format is cylindrical capillary with 150 {micro}m o.d., 75 {micro}m i.d and the other format is square capillary with 300 {micro}m out edge and 75 {micro}m inner edge. This project is focused on the development of excitation and detection of DNA as well as performing DNA sequencing. The DNA injection schemes are discussed for the cases of single and bundled capillaries. An individual sampling device was designed. The base-calling was performed for a capillary from the capillary array with the accuracy of 98%.

  18. Minimized Capillary End Effect During CO2 Displacement in 2-D Micromodel by Manipulating Capillary Pressure at the Outlet Boundary in Lattice Boltzmann Method

    Science.gov (United States)

    Kang, Dong Hun; Yun, Tae Sup

    2018-02-01

    We propose a new outflow boundary condition to minimize the capillary end effect for a pore-scale CO2 displacement simulation. The Rothman-Keller lattice Boltzmann method with multi-relaxation time is implemented to manipulate a nonflat wall and inflow-outflow boundaries with physically acceptable fluid properties in 2-D microfluidic chip domain. Introducing a mean capillary pressure acting at CO2-water interface to the nonwetting fluid at the outlet effectively prevents CO2 injection pressure from suddenly dropping upon CO2 breakthrough such that the continuous CO2 invasion and the increase of CO2 saturation are allowed. This phenomenon becomes most pronounced at capillary number of logCa = -5.5, while capillary fingering and massive displacement of CO2 prevail at low and high capillary numbers, respectively. Simulations with different domain length in homogeneous and heterogeneous domains reveal that capillary pressure and CO2 saturation near the inlet are reproducible compared with those with a proposed boundary condition. The residual CO2 saturation uniquely follows the increasing tendency with increasing capillary number, corroborated by experimental evidences. The determination of the mean capillary pressure and its sensitivity are also discussed. The proposed boundary condition is commonly applicable to other pore-scale simulations to accurately capture the spatial distribution of nonwetting fluid and corresponding displacement ratio.

  19. Condensation and Evaporation Transitions in Deep Capillary Grooves

    OpenAIRE

    Malijevský, A. (Alexandr); Parry, A.O.

    2014-01-01

    We study the order of capillary condensation and evaporation transitions of a simple fluid adsorbed in a deep capillary groove using a fundamental measure density functional theory (DFT). The walls of the capillary interact with the fluid particles via long-ranged, dispersion, forces while the fluid-fluid interaction is modelled as a truncated Lennard-Jones-like potential. We find that below the wetting temperature $T_w$ condensation is first-order and evaporation is continuous with the metas...

  20. Hierarchical capillary adhesion of microcantilevers or hairs

    International Nuclear Information System (INIS)

    Liu Jianlin; Feng Xiqiao; Xia Re; Zhao Hongping

    2007-01-01

    As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams

  1. Application of CHESS single-bounce capillaries at synchrotron beamlines

    Science.gov (United States)

    Huang, R.; Szebenyi, T.; Pfeifer, M.; Woll, A.; Smilgies, D.-M.; Finkelstein, K.; Dale, D.; Wang, Y.; Vila-Comamala, J.; Gillilan, R.; Cook, M.; Bilderback, D. H.

    2014-03-01

    Single-bounce capillaries are achromatic X-ray focusing optics that can provide efficient and high demagnification focusing with large numerical apertures. Capillary fabrication at CHESS can be customized according to specific application requirements. Exemplary applications are reviewed in this paper, as well as recent progress on condensers for high-resolution transmission X-ray microscopy and small focal size capillaries.

  2. A Study of Coherent Radiation Generated in an Ablative Capillary Discharge

    Directory of Open Access Journals (Sweden)

    Jakub Hübner

    2013-01-01

    Full Text Available Feasible soft-X-ray amplification in the CVI and NVII Balmer transition is investigated in a capillary discharge. The best conditions and parameters for the experimental set-up are found for an ablative capillary. The most optimistic results have shown that the gain would be greater than one, which is the condition for successful ASE (Amplified spontaneous emission in capillary discharges. The capillary discharge evolution is modeled using the NPINCH program, employing a one-dimensional physical model based on MHD equations. The information about the capillary discharge evolution is processed in the FLY, FLYPAPER, FLYSPEC programs, enabling the population to be modeled on specific levels during capillary discharge.

  3. Rho-Kinase Inhibition Ameliorates Dasatinib-Induced Endothelial Dysfunction and Pulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Csilla Fazakas

    2018-05-01

    Full Text Available The multi-kinase inhibitor dasatinib is used for treatment of imatinib-resistant chronic myeloid leukemia, but is prone to induce microvascular dysfunction. In lung this can manifest as capillary leakage with pleural effusion, pulmonary edema or even pulmonary arterial hypertension. To understand how dasatinib causes endothelial dysfunction we examined the effects of clinically relevant concentrations of dasatinib on both human pulmonary arterial macro- and microvascular endothelial cells (ECs. The effects of dasatinib was compared to imatinib and nilotinib, two other clinically used BCR/Abl kinase inhibitors that do not inhibit Src. Real three-dimensional morphology and high resolution stiffness mapping revealed softening of both macro- and microvascular ECs upon dasatinib treatment, which was not observed in response to imatinib. In a dose-dependent manner, dasatinib decreased transendothelial electrical resistance/impedance and caused a permeability increase as well as disruption of tight adherens junctions in both cell types. In isolated perfused and ventilated rat lungs, dasatinib increased mean pulmonary arterial pressure, which was accompanied by a gain in lung weight. The Rho-kinase inhibitor Y27632 partly reversed the dasatinib-induced changes in vitro and ex vivo, presumably by acting downstream of Src. Co-administration of the Rho-kinase inhibitor Y27632 completely blunted the increased pulmonary pressure in response to dasatinib. In conclusion, a dasatinib-induced permeability increase in human pulmonary arterial macro- and microvascular ECs might explain many of the adverse effects of dasatinib in patients. Rho-kinase inhibition might be suitable to ameliorate these effects.

  4. Channeling of neutral particles in micro- and nano-capillaries

    International Nuclear Information System (INIS)

    Dabagov, S.B.

    2003-01-01

    After briefly reviewing the main directions in X-ray optics and analyzing the development of capillary optics, a general theory of radiation propagation through capillary structures is described in both geometrical optics and wave optics approximations. Analysis of radiation field structure inside a capillary waveguide shows that wave propagation in channels can be of a purely modal nature, with transmitted energy mostly concentrated in the immediate neighbourhood of capillary inner walls. A qualitative change in radiation scattering with decreasing channel diameter 0 namely, the transition from surface channeling in microcapillaries to bulk channeling in nanocapillaries - is discussed [ru

  5. Vascular endothelial growth factor A protein level and gene expression in intracranial meningiomas with brain edema

    DEFF Research Database (Denmark)

    Nassehi, Damoun; Dyrbye, Henrik; Andresen, Morten

    2011-01-01

    (VEGF) is an endothelial cell-specific mitogen and angiogen. VEGF-A protein, which is identical to vascular permeability factor, is a regulator of angiogenesis. In this study, 101 patients with meningiomas, and possible co-factors to PTBE, such as meningioma subtypes and tumor location, were examined....... Forty-three patients had primary, solitary, supratentorial meningiomas with PTBE. In these, correlations in PTBE, edema index, VEGF-A protein, VEGF gene expression, capillary length, and tumor water content were investigated. DNA-branched hybridization was used for measuring VEGF gene expression...... in tissue homogenates prepared from frozen tissue samples. The method for VEGF-A analysis resembled an ELISA assay, but was based on chemiluminescence. The edema index was positively correlated to VEGF-A protein (p = 0.014) and VEGF gene expression (p

  6. X-ray Talbot interferometry with capillary plates

    International Nuclear Information System (INIS)

    Momose, Atsushi; Kawamoto, Shinya

    2006-01-01

    An X-ray Talbot interferometer consisting of two capillary plates, which were used as X-ray amplitude gratings, was evaluated for X-ray phase imaging. A theoretical aspect of capillary X-ray Talbot interferometry is presented with a preliminary operation result using synchrotron radiation. A two-dimensional X-ray Talbot effect, or self-imaging effect, which was the basis of Talbot interferometry, was observed with the capillary plate, and moire images formed by the X-ray Talbot interferometer exhibited contrasts corresponding to the differential phase shift caused by phase objects placed in front of the interferometer. Finally, the possibility of quantitative phase measurement with a fringe scanning technique is discussed. (author)

  7. Capillary Optics as an x-ray Condensing Lens An Alignment

    CERN Document Server

    Cappuccio, G

    2000-01-01

    The procedure of capillary lens alignment is described in detail. The theoretical basis of capillary optics is given in the framework of a comparative analysis of monocapillary and polycapillary optics. The results of x-ray $9 distribution scanning behind the capillary lens for various angle planes, together with the tting results, are presented. A qualitative explanation is given for the discrepancy between the expected and observed divergences of x-ray $9 beams transmitted by the capillary lens.

  8. Reduced Ang2 expression in aging endothelial cells

    International Nuclear Information System (INIS)

    Hohensinner, P.J.; Ebenbauer, B.; Kaun, C.; Maurer, G.; Huber, K.; Wojta, J.

    2016-01-01

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. -- Highlights: •Endothelial cells display signs of aging before reaching proliferative senescence. •Aging endothelial cells express more angiopoietin 1 and less angiopoietin 2 than young endothelial cells. •Migratory capacity is reduced in aging endothelial cells.

  9. Reduced Ang2 expression in aging endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Hohensinner, P.J., E-mail: philipp.hohensinner@meduniwien.ac.at [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ebenbauer, B. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); Kaun, C.; Maurer, G. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Huber, K. [Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); 3rd Medical Department, Wilhelminenhospital, Vienna (Austria); Sigmund Freud University, Medical Faculty, Vienna (Austria); Wojta, J. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); Core Facilities, Medical University of Vienna, Vienna (Austria)

    2016-06-03

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. -- Highlights: •Endothelial cells display signs of aging before reaching proliferative senescence. •Aging endothelial cells express more angiopoietin 1 and less angiopoietin 2 than young endothelial cells. •Migratory capacity is reduced in aging endothelial cells.

  10. Paper Capillary Enables Effective Sampling for Microfluidic Paper Analytical Devices.

    Science.gov (United States)

    Shangguan, Jin-Wen; Liu, Yu; Wang, Sha; Hou, Yun-Xuan; Xu, Bi-Yi; Xu, Jing-Juan; Chen, Hong-Yuan

    2018-06-06

    Paper capillary is introduced to enable effective sampling on microfluidic paper analytical devices. By coupling mac-roscale capillary force of paper capillary and microscale capillary forces of native paper, fluid transport can be flexibly tailored with proper design. Subsequently, a hybrid-fluid-mode paper capillary device was proposed, which enables fast and reliable sampling in an arrayed form, with less surface adsorption and bias for different components. The resulting device thus well supports high throughput, quantitative, and repeatable assays all by hands operation. With all these merits, multiplex analysis of ions, proteins, and microbe have all been realized on this platform, which has paved the way to level-up analysis on μPADs.

  11. In situ preparation of multilayer coated capillary column with HKUST-1 for separation of neutral small organic molecules by open tubular capillary electrochromatography.

    Science.gov (United States)

    Xu, Yin-Yin; Lv, Wen-Juan; Ren, Cui-Ling; Niu, Xiao-Ying; Chen, Hong-Li; Chen, Xing-Guo

    2018-01-12

    The popularity of novel nanoparticles coated capillary column has aroused widespread attention of researchers. Metal organic frameworks (MOFs) with special structure and chemical properties have received great interest in separation sciences. This work presents the investigation of HKUST-1 (Hong Kong University of Science and Technology-1, called Cu 3 (BTC) 2 or MOF-199) nanoparticles as a new type of coating material for capillary electrochromatography. For the first time, three layers coating (3-LC), five layers coating (5-LC), ten layers coating (10-LC), fifteen layers coating (15-LC), twenty layers coating(20-LC) and twenty-five layers coating (25-LC) capillary columns coated with HKUST-1 nanoparticles were synthesized by covalent bond with in situ, layer-by-layer self-assembly approach. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD) and plasma atomic emission spectrometry (ICP-AES) indicated that HKUST-1 was successfully grafted on the inner wall of the capillary. The separating performances of 3-LC, 5-LC, 10-LC, 15-LC, 20-LC and 25-LC open tubular (OT) capillary columns were studied with some neutral small organic molecules. The results indicated that the neutral small organic molecules were separated successfully with 10-LC, 15-LC and 20-LC OT capillary columns because of the size selectivity of lattice aperture and hydrophobicity of organic ligands. In addition, 10-LC and 15-LC OT capillary columns showed better performance for the separation of certain phenolic compounds. Furthermore, 10-LC, 15-LC and 20-LC OT capillary columns exhibited good intra-day repeatability with the relative standard deviations (RSDs; %) of migration time and peak areas lying in the range of 0.3-1.2% and 0.5-4.2%, respectively. For inter-day reproducibility, the RSDs of the three OT capillary columns were found to be lying in the range of 0.3-5.5% and 0.3-4.5% for migration time and peak area, respectively. The RSDs of retention times for column

  12. Signaling hierarchy regulating human endothelial cell development.

    Science.gov (United States)

    Kelly, Melissa A; Hirschi, Karen K

    2009-05-01

    Our present knowledge of the regulation of mammalian endothelial cell differentiation has been largely derived from studies of mouse embryonic development. However, unique mechanisms and hierarchy of signals that govern human endothelial cell development are unknown and, thus, explored in these studies. Using human embryonic stem cells as a model system, we were able to reproducibly and robustly generate differentiated endothelial cells via coculture on OP9 marrow stromal cells. We found that, in contrast to studies in the mouse, bFGF and VEGF had no specific effects on the initiation of human vasculogenesis. However, exogenous Ihh promoted endothelial cell differentiation, as evidenced by increased production of cells with cobblestone morphology that coexpress multiple endothelial-specific genes and proteins, form lumens, and exhibit DiI-AcLDL uptake. Inhibition of BMP signaling using Noggin or BMP4, specifically, using neutralizing antibodies suppressed endothelial cell formation; whereas, addition of rhBMP4 to cells treated with the hedgehog inhibitor cyclopamine rescued endothelial cell development. Our studies revealed that Ihh promoted human endothelial cell differentiation from pluripotent hES cells via BMP signaling, providing novel insights applicable to modulating human endothelial cell formation and vascular regeneration for human clinical therapies.

  13. Practical capillary electrophoresis

    CERN Document Server

    Weinberger, Robert

    2000-01-01

    In the 1980s, capillary electrophoresis (CE) joined high-performance liquid chromatography (HPLC) as the most powerful separation technique available to analytical chemists and biochemists. Published research using CE grew from 48 papers in the year of commercial introduction (1988) to 1200 in 1997. While only a dozen major pharmaceutical and biotech companies have reduced CE to routine practice, the applications market is showing real or potential growth in key areas, particularly in the DNA marketplace for genomic mapping and forensic identification. For drug development involving small molecules (including chiral separations), one CE instrument can replace 10 liquid chromatographs in terms of speed of analysis. CE also uses aqueous rather than organic solvents and is thus environmentally friendlier than HPLC. The second edition of Practical Capillary Electrophoresis has been extensively reorganized and rewritten to reflect modern usage in the field, with an emphasis on commercially available apparatus and ...

  14. Laws of physics help explain capillary non-perfusion in diabetic retinopathy.

    Science.gov (United States)

    Stefánsson, E; Chan, Y K; Bek, T; Hardarson, S H; Wong, D; Wilson, D I

    2018-02-01

    The purpose is to use laws of physics to elucidate the mechanisms behind capillary non-perfusion in diabetic retinopathy. In diabetic retinopathy, loss of pericytes weakens capillary walls and the vessel dilates. A dilated capillary has reduced resistance to flow, therefore increased flow in that vessel and decreased in adjoining capillaries. A preferential shunt vessel is thus formed from the dilated capillary and the adjacent capillaries become non-perfused. We apply the laws of Laplace and Hagen-Poiseuille to better understand the phenomena that lead to capillary non-perfusion. These laws of physics can give a foundation for physical or mathematical models to further elucidate this field of study. The law of Laplace predicts that a weaker vessel wall will dilate, assuming constant transmural pressure. The Hagen-Poiseuille equation for flow and the Ostwald-de Waele relationship for viscosity predict that a dilated vessel will receive a higher portion of the fluid flow than the adjoining capillaries. Viscosity will decrease in the dilated vessel, furthering the imbalance and resulting in a patch of non-perfused capillaries next to the dilated 'preferential' shunt vessel. Physical principles support or inspire novel hypotheses to explain poorly understood phenomena in ophthalmology. This thesis of pericyte death and capillary remodelling, which was first proposed by Cogan and Kuwabara, already agrees with histological and angiographical observations in diabetic retinopathy. We have shown that it is also supported by classical laws of physics.

  15. Experimental and numerical studies of choked flow through adiabatic and diabatic capillary tubes

    International Nuclear Information System (INIS)

    Deodhar, Subodh D.; Kothadia, Hardik B.; Iyer, K.N.; Prabhu, S.V.

    2015-01-01

    Capillary tubes are extensively used in several cooling applications like refrigeration, electronic cooling etc. Local pressure variation in adiabatic straight capillary tube (mini channel) is studied experimentally and numerically with R134a as the working fluid. Experiments are performed on two straight capillary tubes. It is found that the diameter is the most sensitive design parameter of the capillary tube. Experiments are performed on five helically coiled capillary tubes to quantify the effect of pitch and curvature of helically coiled capillary tube on the pressure drop. Non dimensionalized factor to account coiling of capillary tube is derived to calculate mass flow rate in helically coiled capillary tubes. Flow visualization in adiabatic capillary tube confirms the bubbly nature of two phase flow. Numerical and experimental investigations in diabatic capillary tube suggest that the use of positive displacement pump and choking at the exit of the channel ensures flow stability. - Highlights: • Model is developed to design capillary tube in adiabatic and diabatic condition. • Effect of coil curvature on pressure drop is studied experimentally. • Correlation is developed to predict mass flow rate in helical capillary tubes. • Flow visualization is carried out to check the type of two phase flow. • Effect of choked flow on diabatic capillary tubes is studied experimentally.

  16. Ion guiding in macro-size insulating capillaries: straight, tapered, and curved shapes

    Science.gov (United States)

    Kojima, Takao M.

    2018-02-01

    When keV energy ions are injected into a tilted insulating capillary, a certain fraction of the injected ions are transported through the tilt angle of the capillary. This ion guiding phenomenon is considered to be caused by a self-organizing charge distribution, where the inner wall of the capillary becomes charged by initial incoming ions. The charge distribution, which is formed, can guide following ions toward the exit of the capillary. Since the initial discovery of this effect, studies of ion guiding by insulating capillaries have been extended to various materials, and different sizes and shapes of capillaries. In recent years, some investigations of the guiding effect of macro-size curved capillaries have also been reported. In this review, relevant studies in a history of ion guiding in curved capillaries are discussed and future directions in this field are considered.

  17. Evolution of endothelial keratoplasty.

    Science.gov (United States)

    Price, Francis W; Price, Marianne O

    2013-11-01

    Endothelial keratoplasty has evolved into a popular alternative to penetrating keratoplasty (PK) for the treatment of endothelial dysfunction. Although the earliest iterations were challenging and were not widely adopted, the iteration known as Descemet stripping endothelial keratoplasty (DSEK) has gained widespread acceptance. DSEK combines a simplified technique for stripping dysfunctional endothelium from the host cornea and microkeratome dissection of the donor tissue, a step now commonly completed in advance by eye bank technicians. Studies show that a newer endothelial keratoplasty iteration, known as Descemet membrane endothelial keratoplasty (DMEK), provides an even faster and better visual recovery than DSEK does. In addition, DMEK significantly reduces the risk of immunologic graft rejection episodes compared with that in DSEK or in PK. Although the DMEK donor tissue, consisting of the bare endothelium and Descemet membrane without any stroma, is more challenging to prepare and position in the recipient eye, recent improvements in instrumentation and surgical techniques are increasing the ease and the reliability of the procedure. DSEK successfully mitigates 2 of the main liabilities of PK: ocular surface complications and structural problems (including induced astigmatism and perpetually weak wounds), whereas DMEK further mitigates the 2 principal remaining liabilities of PK: immunologic graft reactions and secondary glaucoma from prolonged topical corticosteroid use.

  18. Trifluoperazine: corneal endothelial phototoxicity

    International Nuclear Information System (INIS)

    Hull, D.S.; Csukas, S.; Green, K.

    1983-01-01

    Trifluoperazine is used for the treatment of psychiatric disorders. Perfusion of corneal endothelial cells with trifluoperazine-HC1 concurrent with exposure to long wavelength ultraviolet light resulted in a corneal swelling rate greater than that found in perfused corneas not exposed to ultraviolet light. Exposure of endothelial cells to 25 W incandescent light during perfusion with trifluoperazine-HC1 did not result in a higher corneal swelling rate compared to those perfused in the dark. The increased corneal swelling rate could be produced by pre-exposure of the trifluoperazine-HC1 perfusing solution to ultraviolet light suggesting the production of toxic photoproducts during exposure of trifluoperazine-HC1 to ultraviolet light. Perfusion of corneal endothelial cells with non-ultraviolet illuminated trifluoperazine-HC1 had no effect on endothelial cell membranes or ultrastructure. This is in contrast to cells perfused with trifluoperazine-HC1 that had been exposed to ultraviolet light in which there was an alteration of mitochondria and a loss of cytoplasmic homogeneity. The data imply that the trifluoperazine-HC1 photoproduct had an adverse effect on cellular transport mechanisms. The study also further demonstrates the value of the corneal endothelial cell model for identifying the physiological and anatomical changes occuring in photo-induced toxic reactions. (author)

  19. Cortical capillary dysfunction in patients suspected of Alzheimer’s disease

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Gyldensted, Louise; Nagenthiraja, Kartheeban

    Vascular risk factors are suspected to play a role in the etiology of Alzheimer’s disease. Recently, a model that relates capillary dysfunction to the development of AD was proposed[1]. The model predicts that capillary dysfunction in form of increased capillary transit time heterogeneity (CTH...

  20. Expression of Shiga toxin 2e glycosphingolipid receptors of primary porcine brain endothelial cells and toxin-mediated breakdown of the blood-brain barrier.

    Science.gov (United States)

    Meisen, Iris; Rosenbrück, Regina; Galla, Hans-Joachim; Hüwel, Sabine; Kouzel, Ivan U; Mormann, Michael; Karch, Helge; Müthing, Johannes

    2013-06-01

    Shiga toxin (Stx) 2e, released by certain Stx-producing Escherichia coli, is presently the best characterized virulence factor responsible for pig edema disease, which is characterized by hemorrhagic lesions, neurological disorders and often fatal outcomes. Although Stx2e-mediated brain vascular injury is the key event in development of neurologic signs, the glycosphingolipid (GSL) receptors of Stx2e and toxin-mediated impairment of pig brain endothelial cells have not been investigated so far. Here, we report on the detailed structural characterization of Stx2e receptors globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), which make up the major neutral GSLs in primary porcine brain capillary endothelial cells (PBCECs). Various Gb3Cer and Gb4Cer lipoforms harboring sphingenine (d18:1) or sphinganine (d18:0) and mostly a long-chain fatty acid (C20-C24) were detected. A notable batch-to-batch heterogeneity of primary endothelial cells was observed regarding the extent of ceramide hydroxylation of Gb3Cer or Gb4Cer species. Gb3Cer, Gb4Cer and sphingomyelin preferentially distribute to detergent-resistant membrane fractions and can be considered lipid raft markers in PBCECs. Moreover, we employed an in vitro model of the blood-brain barrier (BBB), which exhibited strong cytotoxic effects of Stx2e on the endothelial monolayer and a rapid collapse of the BBB. These data strongly suggest the involvement of Stx2e in cerebral vascular damage with resultant neurological disturbance characteristic of edema disease.

  1. Obstructive sleep apnoea syndrome, endothelial function and markers of endothelialization. Changes after CPAP.

    Science.gov (United States)

    Muñoz-Hernandez, Rocio; Vallejo-Vaz, Antonio J; Sanchez Armengol, Angeles; Moreno-Luna, Rafael; Caballero-Eraso, Candela; Macher, Hada C; Villar, Jose; Merino, Ana M; Castell, Javier; Capote, Francisco; Stiefel, Pablo

    2015-01-01

    This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy. Observational study, before and after CPAP therapy. We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process. After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, pDNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/μL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together. CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage.

  2. First report of microcephaly-capillary malformations syndrome in ...

    African Journals Online (AJOL)

    Background: Microcephaly-capillary malformation (MIC-CAP) syndrome is a newly described autosomal recessive syndrome characterized by microcephaly, multiple cutaneous capillary malformations, intractable epilepsy and profound developmental delay. We present the first description of MIC-CAP syndrome in Russia.

  3. Radiation Effects on the Cytoskeleton of Endothelial Cells and Endothelial Monolayer Permeability

    International Nuclear Information System (INIS)

    Gabrys, Dorota; Greco, Olga; Patel, Gaurang; Prise, Kevin M.; Tozer, Gillian M.; Kanthou, Chryso

    2007-01-01

    Purpose: To investigate the effects of radiation on the endothelial cytoskeleton and endothelial monolayer permeability and to evaluate associated signaling pathways, which could reveal potential mechanisms of known vascular effects of radiation. Methods and Materials: Cultured endothelial cells were X-ray irradiated, and actin filaments, microtubules, intermediate filaments, and vascular endothelial (VE)-cadherin junctions were examined by immunofluorescence. Permeability was determined by the passage of fluorescent dextran through cell monolayers. Signal transduction pathways were analyzed using RhoA, Rho kinase, and stress-activated protein kinase-p38 (SAPK2/p38) inhibitors by guanosine triphosphate-RhoA activation assay and transfection with RhoAT19N. The levels of junction protein expression and phosphorylation of myosin light chain and SAPK2/p38 were assessed by Western blotting. The radiation effects on cell death were verified by clonogenic assays. Results: Radiation induced rapid and persistent actin stress fiber formation and redistribution of VE-cadherin junctions in microvascular, but not umbilical vein endothelial cells, and microtubules and intermediate filaments remained unaffected. Radiation also caused a rapid and persistent increase in microvascular permeability. RhoA-guanosine triphosphatase and Rho kinase were activated by radiation and caused phosphorylation of downstream myosin light chain and the observed cytoskeletal and permeability changes. SAPK2/p38 was activated by radiation but did not influence either the cytoskeleton or permeability. Conclusion: This study is the first to show rapid activation of the RhoA/Rho kinase by radiation in endothelial cells and has demonstrated a link between this pathway and cytoskeletal remodeling and permeability. The results also suggest that the RhoA pathway might be a useful target for modulating the permeability and other effects of radiation for therapeutic gain

  4. Imbibition of ``Open Capillary'': Fundamentals and Applications

    Science.gov (United States)

    Tani, Marie; Kawano, Ryuji; Kamiya, Koki; Okumura, Ko

    2015-11-01

    Control or transportation of small amount of liquid is one of the most important issues in various contexts including medical sciences or pharmaceutical industries to fuel delivery. We studied imbibition of ``open capillary'' both experimentally and theoretically, and found simple scaling laws for both statics and dynamics of the imbibition, similarly as that of imbibition of capillary tubes. Furthermore, we revealed the existence of ``precursor film,'' which developed ahead of the imbibing front, and the dynamics of it is described well by another scaling law for capillary rise in a corner. Then, to show capabilities of open capillaries, we demonstrated two experiments by fabricating micro mixing devices to achieve (1) simultaneous multi-color change of the Bromothymol blue (BTB) solution and (2) expression of the green florescent protein (GFP). This research was partly supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan). M. T. is supported by the Japan Society for the Promotion of Science Research Fellowships for Young Scientists.

  5. Van de Graaff generator for capillary electrophoresis.

    Science.gov (United States)

    Lee, Seung Jae; Castro, Eric R; Guijt, Rosanne M; Tarn, Mark D; Manz, Andreas

    2017-09-29

    A new approach for high voltage capillary electrophoresis (CE) is proposed, which replaces the standard high voltage power supply with a Van de Graaff generator, a low current power source. Because the Van de Graaff generator is a current-limited source (10μA), potentials exceeding 100kV can be generated for CE when the electrical resistance of the capillary is maximized. This was achieved by decreasing the capillary diameter and reducing the buffer ionic strength. Using 2mM borate buffer and a 5μm i.d. capillary, fluorescently labeled amino acids were separated with efficiencies up to 3.5 million plates; a 5.7 fold improvement in separation efficiency compared to a normal power supply (NPS) typically used in CE. This separation efficiency was realized using a simple set-up without significant Joule heating, making the Van de Graaff generator a promising alternative for applying the high potentials required for enhancing resolution in the separation and analysis of highly complex samples, for example mixtures of glycans. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Nitric oxide level and von Willebrand factor (vWF) secretion are not ...

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... potassium channels; RBECs, rat brain capillary endothelial cells. and transport of ... addition, adenine nucleotides modulate the release of endothelial-derive ..... A cellular model of endothelial cell ischemia. J Surg Res. 44(5): ...

  7. Influence of the inner diameters of capillary on the Z-Pinch plasma of the capillary discharge soft X-ray laser

    International Nuclear Information System (INIS)

    Jiang, Shan; Zhao, Yong-peng; Cui, Huai-yu; Li, Lian-bo; Ding, Yu-jie; Zhang, Wen-hong; Li, Wei

    2015-01-01

    In this paper, the effects of inner diameters on the Z-pinch plasma of capillary discharge soft X-ray laser were investigated with the 3.2 mm and 4.0 mm inner diameter alumina capillaries. The intensities of the laser emitted from the 3.2 mm and 4.0 mm inner diameter alumina capillaries were measured under different initial pressures. To understand the underlying physics of the experimental measurements, the Z-pinch plasma simulations had been conducted with a one-dimensional cylindrical symmetry Lagrangian magneto-hydrodynamics (MHD) code. The parametric studies of Z-pinch plasma, such as the electron temperature, the electron density and the Ne-like Ar ion density, were performed with the MHD code. With the experimental and the simulated results, the discussions had been conducted on the Z-pinch plasma of Ne-like Ar 46.9 nm laser with the 3.2 mm and 4.0 mm inner diameter alumina capillaries. The analysis had been made on the difference of the gain coefficients under the optimum pressures with both capillaries. Then, the effects of inner diameters on the optimum pressure and the pressure domain were analyzed. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Recent advances of capillary electrophoresis in pharmaceutical analysis.

    Science.gov (United States)

    Suntornsuk, Leena

    2010-09-01

    This review covers recent advances of capillary electrophoresis (CE) in pharmaceutical analysis. The principle, instrumentation, and conventional modes of CE are briefly discussed. Advances in the different CE techniques (non-aqueous CE, microemulsion electrokinetic chromatography, capillary isotachophoresis, capillary electrochromatography, and immunoaffinity CE), detection techniques (mass spectrometry, light-emitting diode, fluorescence, chemiluminescence, and contactless conductivity), on-line sample pretreatment (flow injection) and chiral separation are described. Applications of CE to assay of active pharmaceutical ingredients (APIs), drug impurity testing, chiral drug separation, and determination of APIs in biological fluids published from 2008 to 2009 are tabulated.

  9. Transmission of fast highly charged ions through straight and tapered glass capillaries

    International Nuclear Information System (INIS)

    Ayyad, Asma M; Keerthisinghe, D; Kayani, A; Tanis, J A; Dassanayake, B S; Ikeda, T

    2013-01-01

    The transmission of 1 and 3 MeV protons through a borosilicate straight glass capillary and a tapered glass capillary was investigated. The straight capillary had a diameter of ∼0.18 mm and a length of ∼14.4 mm, while the tapered capillary had an inlet diameter of ∼0.71 mm, an outlet diameter of ∼0.10 mm and a length of ∼28 mm. The results show that the 1 and 3 MeV protons traverse through both samples without energy loss, while the tapered capillary showed better transmission than the straight capillary. (paper)

  10. Alcohol consumption negates estrogen-mediated myocardial repair in ovariectomized mice by inhibiting endothelial progenitor cell mobilization and function.

    Science.gov (United States)

    Mackie, Alexander R; Krishnamurthy, Prasanna; Verma, Suresh K; Thorne, Tina; Ramirez, Veronica; Qin, Gangjian; Abramova, Tatiana; Hamada, Hiromichi; Losordo, Douglas W; Kishore, Raj

    2013-06-21

    We have shown previously that estrogen (estradiol, E2) supplementation enhances voluntary alcohol consumption in ovariectomized female rodents and that increased alcohol consumption impairs ischemic hind limb vascular repair. However, the effect of E2-induced alcohol consumption on post-infarct myocardial repair and on the phenotypic/functional properties of endothelial progenitor cells (EPCs) is not known. Additionally, the molecular signaling of alcohol-estrogen interactions remains to be elucidated. This study examined the effect of E2-induced increases in ethanol consumption on post-infarct myocardial function/repair. Ovariectomized female mice, implanted with 17β-E2 or placebo pellets were given access to alcohol for 6 weeks and subjected to acute myocardial infarction. Left ventricular functions were consistently depressed in mice consuming ethanol compared with those receiving only E2. Alcohol-consuming mice also displayed significantly increased infarct size and reduced capillary density. Ethanol consumption also reduced E2-induced mobilization and homing of EPCs to injured myocardium compared with the E2-alone group. In vitro, exposure of EPCs to ethanol suppressed E2-induced proliferation, survival, and migration and markedly altered E2-induced estrogen receptor-dependent cell survival signaling and gene expression. Furthermore, ethanol-mediated suppression of EPC biology was endothelial nitric oxide synthase-dependent because endothelial nitric oxide synthase-null mice displayed an exaggerated response to post-acute myocardial infarction left ventricular functions. These data suggest that E2 modulation of alcohol consumption, and the ensuing EPC dysfunction, may negatively compete with the beneficial effects of estrogen on post-infarct myocardial repair.

  11. Design and evaluation of capillary coupled with optical fiber light-emitting diode induced fluorescence detection for capillary electrophoresis.

    Science.gov (United States)

    Ji, Hongyun; Li, Meng; Guo, Lihong; Yuan, Hongyan; Wang, Chunling; Xiao, Dan

    2013-09-01

    A new detector, capillary coupled with optical fiber LED-induced fluorescence detector (CCOF-LED-IFD, using CCOF for short), is introduced for CE. The strategy of the present work was that the optical fiber and separation capillary were, in the parallel direction, fastened in a fixation capillary with larger inner diameter. By employing larger inner diameter, the fixation capillary allowed the large diameter of the optical fiber to be inserted into it. By transmitting an enhanced excitation light through the optical fiber, the detection sensitivity was improved. The advantages of the CCOF-CE system were validated by the detection of riboflavin, and the results were compared to those obtained by the in-capillary common optical fiber LED-induced fluorescence detector (IC-COF-LED-IFD, using COF for short). The LODs of CCOF-CE and COF-CE were 0.29 nM and 11.0 nM (S/N = 3), respectively. The intraday (n = 6) repeatability and interday (n = 6) reproducibility of migration time and corresponding peak area for both types of CE were all less than 1.10 and 3.30%, respectively. The accuracy of the proposed method was judged by employing standard addition method, and recoveries obtained were in the range of 98.0-102.4%. The results indicated that the sensitivity of the proposed system was largely improved, and that its reproducibility and accuracy were satisfactory. The proposed system was successfully applied to separate and determine riboflavin in real sample. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Vulvar Lobular Capillary Hemangioma (Pyogenic Granuloma

    Directory of Open Access Journals (Sweden)

    Kian-Mei Chong

    2005-03-01

    Conclusion: Pyogenic granuloma is considered a reactive hyperproliferative vascular response to trauma or other stimuli. The name “pyogenic granuloma” is a misnomer since the condition is not associated with pus and does not represent a granuloma histologically. There are a few cases of lobular capillary hemangioma of the glans penis but it is rare on the female genitalia. We present this case to help physicians become aware that lobular capillary hemangiomas may occur at this site.

  13. Autologous bone-marrow mesenchymal stem cell implantation and endothelial function in a rabbit ischemic limb model.

    Directory of Open Access Journals (Sweden)

    Shinsuke Mikami

    Full Text Available BACKGROUND: The purpose of this study was to determine whether autologous mesenchymal stem cells (MSCs implantation improves endothelial dysfunction in a rabbit ischemic limb model. METHODS: We evaluated the effect of MSC implantation on limb blood flow (LBF responses to acetylcholine (ACh, an endothelium-dependent vasodilator, and sodium nitroprusside (SNP, an endothelium-independent vasodilator, in rabbits with limb ischemia in which cultured MSCs were implanted (n = 20 or saline was injected as a control group (n = 20. LBF was measured using an electromagnetic flowmeter. A total of 10(6 MSCs were implanted into each ischemic limb. RESULTS: Histological sections of ischemic muscle showed that capillary index (capillary/muscle fiber was greater in the MSC implantation group than in the control group. Laser Doppler blood perfusion index was significantly increased in the MSC implantation group compared with that in the control group. LBF response to ACh was greater in the MSC group than in the control group. After administration of N(G-nitro-L-arginine, a nitric oxide synthase inhibitor, LBF response to ACh was similar in the MSC implantation group and control group. Vasodilatory effects of SNP in the two groups were similar. CONCLUSIONS: These findings suggest that MSC implantation induces angiogenesis and augments endothelium-dependent vasodilation in a rabbit ischemic model through an increase in nitric oxide production.

  14. Obstructive sleep apnoea syndrome, endothelial function and markers of endothelialization. Changes after CPAP.

    Directory of Open Access Journals (Sweden)

    Rocio Muñoz-Hernandez

    Full Text Available This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA syndrome at baseline and after three months with CPAP therapy.Observational study, before and after CPAP therapy.We studied 30 patients with apnoea/hypopnoea index (AHI >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA and microparticles (MPs were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF was determined as a marker of endothelial restoration process.After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005 cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/μL, p<0.05, respectively and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05. These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005 but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together.CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage.

  15. Physalis minima Leaves Extract Induces Re-Endothelialization in Deoxycorticosterone Acetate-Salt-Induced Endothelial Dysfunction in Rats

    Directory of Open Access Journals (Sweden)

    Dian Nugrahenny

    2018-02-01

    Full Text Available The administration of deoxy-corticosterone acetate (DOCA-salt can induce oxidative stress leading to decrease the bioavailability of nitric oxide (NO, increase senescence of circulating endothelial progenitor cells (EPCs, thus contributing to endothelial dysfunction. This study was aimed to investigate the effects of Physalis minima L. leaves extract on serum NO levels, circulating EPCs number, and histopathology of tail artery endothelial cells in DOCA-salt-induced endothelial dysfunction in rats. Twenty-five male Wistar rats were randomly divided into five groups: rats without any treatment (normal, rats treated with DOCA (10 mg/kgBW s.c. twice weekly and given 0.9% NaCl to drink ad libitum for 6 weeks, and DOCA-salt-induced rats orally supplemented with P. minima leaves extract at doses of 500, 1500, or 2500 mg/kgBW for 4 weeks. Serum NO levels were measured by colorimetry. The number of circulating EPCs (CD34+/CD133+ cells was determined by flow cytometry. The tail artery sections were histologically processed with hematoxylin-eosin staining. DOCA-salt-induced rats showed significantly (p<0.05 decrease in serum NO levels and circulating EPCs number compared to the normal. There was also more detached tail artery endothelial cells in DOCA-salt-induced rats. P. minima leaves extract at a dose of 500 mg/kgBW significantly (p<0.05 increased serum NO level and circulating EPCs number, and also induced an optimal re-endothelialization in DOCA-salt-induced rats. P. minima leave extract dose-dependently increases NO bioavailability contributing to enhanced EPCs mobilization, thereby promoting re-endothelialization in DOCA-salt-induced endothelial dysfunction in rats.

  16. Intermittent whole-body vibration attenuates a reduction in the number of the capillaries in unloaded rat skeletal muscle.

    Science.gov (United States)

    Kaneguchi, Akinori; Ozawa, Junya; Kawamata, Seiichi; Kurose, Tomoyuki; Yamaoka, Kaoru

    2014-09-26

    Whole-body vibration has been suggested for the prevention of muscle mass loss and muscle wasting as an attractive measure for disuse atrophy. This study examined the effects of daily intermittent whole-body vibration and weight bearing during hindlimb suspension on capillary number and muscle atrophy in rat skeletal muscles. Sixty male Wistar rats were randomly divided into four groups: control (CONT), hindlimb suspension (HS), HS + weight bearing (WB), and HS + whole-body vibration (VIB) (n = 15 each). Hindlimb suspension was applied for 2 weeks in HS, HS + WB, and HS + VIB groups. During suspension, rats in HS + VIB group were placed daily on a vibrating whole-body vibration platform for 20 min. In HS + WB group, suspension was interrupted for 20 min/day, allowing weight bearing. Untreated rats were used as controls. Soleus muscle wet weights and muscle fiber cross-sectional areas (CSA) significantly decreased in HS, HS + WB, and HS + VIB groups compared with CONT group. Both muscle weights and CSA were significantly greater in HS + WB and HS + VIB groups compared with HS group. Capillary numbers (represented by capillary-to-muscle fiber ratio) were significantly smaller in all hindlimb suspension-treated groups compared with CONT group. However, a reduction in capillary number by unloading hindlimbs was partially prevented by whole-body vibration. These findings were supported by examining mRNA for angiogenic-related factors. Expression levels of a pro-angiogenic factor, vascular endothelial growth factor-A mRNA, were significantly lower in all hindlimb suspension-treated groups compared with CONT group. There were no differences among hindlimb suspension-treated groups. Expression levels of an anti-angiogenic factor, CD36 (receptor for thrombospondin-1) mRNA, were significantly higher in all hindlimb suspension-treated groups compared with CONT group. Among the hindlimb suspension-treated groups, expression of CD

  17. Influence of Levamisole and Other Angiogenesis Inhibitors on Angiogenesis and Endothelial Cell Morphology in Vitro

    Energy Technology Data Exchange (ETDEWEB)

    Friis, Tina; Engel, Anne-Marie; Bendiksen, Christine D.; Larsen, Line S.; Houen, Gunnar, E-mail: gh@ssi.dk [Department of Clinical Biochemistry, Immunology and Genetics, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen (Denmark)

    2013-06-24

    Angiogenesis, the formation of new blood vessels from existing vessels is required for many physiological processes and for growth of solid tumors. Initiated by hypoxia, angiogenesis involves binding of angiogenic factors to endothelial cell (EC) receptors and activation of cellular signaling, differentiation, migration, proliferation, interconnection and canalization of ECs, remodeling of the extracellular matrix and stabilization of newly formed vessels. Experimentally, these processes can be studied by several in vitro and in vivo assays focusing on different steps in the process. In vitro, ECs form networks of capillary-like tubes when propagated for three days in coculture with fibroblasts. The tube formation is dependent on vascular endothelial growth factor (VEGF) and omission of VEGF from the culture medium results in the formation of clusters of undifferentiated ECs. Addition of angiogenesis inhibitors to the coculture system disrupts endothelial network formation and influences EC morphology in two distinct ways. Treatment with antibodies to VEGF, soluble VEGF receptor, the VEGF receptor tyrosine kinase inhibitor SU5614, protein tyrosine phosphatase inhibitor (PTPI) IV or levamisole results in the formation of EC clusters of variable size. This cluster morphology is a result of inhibited EC differentiation and levamisole can be inferred to influence and block VEGF signaling. Treatment with platelet factor 4, thrombospondin, rapamycin, suramin, TNP-470, salubrinal, PTPI I, PTPI II, clodronate, NSC87877 or non-steriodal anti-inflammatory drugs (NSAIDs) results in the formation of short cords of ECs, which suggests that these inhibitors have an influence on later steps in the angiogenic process, such as EC proliferation and migration. A humanized antibody to VEGF is one of a few angiogenesis inhibitors used clinically for treatment of cancer. Levamisole is approved for clinical treatment of cancer and is interesting with respect to anti-angiogenic activity

  18. Hysteretic capillary condensation of 4He on Nuclepore substrates

    International Nuclear Information System (INIS)

    Godshalk, K.M.; Smith, D.T.; Hallock, R.B.

    1987-01-01

    Measurements of the approach to capillary condensation and the hysteresis encountered in capillary condensation are reported for helium adsorbed on the polycarbonate substrate Nuclepore. (Author) (5 refs., 3 figs.)

  19. Density functional study of condensation in capped capillaries.

    Science.gov (United States)

    Yatsyshin, P; Savva, N; Kalliadasis, S

    2015-07-15

    We study liquid adsorption in narrow rectangular capped capillaries formed by capping two parallel planar walls (a slit pore) with a third wall orthogonal to the two planar walls. The most important transition in confined fluids is arguably condensation, where the pore becomes filled with the liquid phase which is metastable in the bulk. Depending on the temperature T, the condensation in capped capillaries can be first-order (at T≤Tcw) or continuous (at T>Tcw), where Tcw is the capillary wetting temperature. At T>Tcw, the capping wall can adsorb mesoscopic amounts of metastable under-condensed liquid. The onset of condensation is then manifested by the continuous unbinding of the interface between the liquid adsorbed on the capping wall and the gas filling the rest of the capillary volume. In wide capped capillaries there may be a remnant of wedge filling transition, which is manifested by the adsorption of liquid drops in the corners. Our classical statistical mechanical treatment predicts a possibility of three-phase coexistence between gas, corner drops and liquid slabs adsorbed on the capping wall. In sufficiently wide capillaries we find that thick prewetting films of finite length may be nucleated at the capping wall below the boundary of the prewetting transition. Prewetting then proceeds in a continuous manner manifested by the unbinding interface between the thick and thin films adsorbed on the side walls. Our analysis is based on a detailed numerical investigation of the density functional theory for the fluid equilibria for a number of illustrative case studies.

  20. Driver-witness electron beam acceleration in dielectric mm-scale capillaries

    Science.gov (United States)

    Lekomtsev, K.; Aryshev, A.; Tishchenko, A. A.; Shevelev, M.; Lyapin, A.; Boogert, S.; Karataev, P.; Terunuma, N.; Urakawa, J.

    2018-05-01

    We investigated a corrugated mm-scale capillary as a compact accelerating structure in the driver-witness acceleration scheme, and suggested a methodology to measure the acceleration of the witness bunch. The accelerating fields produced by the driver bunch and the energy spread of the witness bunch in a corrugated capillary and in a capillary with a constant inner radius were measured and simulated for both on-axis and off-axis beam propagation. Our simulations predicted a change in the accelerating field structure for the corrugated capillary. Also, an approximately twofold increase of the witness bunch energy gain on the first accelerating cycle was expected for both capillaries for the off-axis beam propagation. These results were confirmed in the experiment, and the maximum measured acceleration of 170 keV /m at 20 pC driver beam charge was achieved for off-axis beam propagation. The driver bunch showed an increase in energy spread of up to 11%, depending on the capillary geometry and beam propagation, with a suppression of the longitudinal energy spread in the witness bunch of up to 15%.

  1. Principles of Micellar Electrokinetic Capillary Chromatography Applied in Pharmaceutical Analysis

    Directory of Open Access Journals (Sweden)

    Árpád Gyéresi

    2013-02-01

    Full Text Available Since its introduction capillary electrophoresis has shown great potential in areas where electrophoretic techniques have rarely been used before, including here the analysis of pharmaceutical substances. The large majority of pharmaceutical substances are neutral from electrophoretic point of view, consequently separations by the classic capillary zone electrophoresis; where separation is based on the differences between the own electrophoretic mobilities of the analytes; are hard to achieve. Micellar electrokinetic capillary chromatography, a hybrid method that combines chromatographic and electrophoretic separation principles, extends the applicability of capillary electrophoretic methods to neutral analytes. In micellar electrokinetic capillary chromatography, surfactants are added to the buffer solution in concentration above their critical micellar concentrations, consequently micelles are formed; micelles that undergo electrophoretic migration like any other charged particle. The separation is based on the differential partitioning of an analyte between the two-phase system: the mobile aqueous phase and micellar pseudostationary phase. The present paper aims to summarize the basic aspects regarding separation principles and practical applications of micellar electrokinetic capillary chromatography, with particular attention to those relevant in pharmaceutical analysis.

  2. Effect of shear stress on iPSC-derived human brain microvascular endothelial cells (dhBMECs).

    Science.gov (United States)

    DeStefano, Jackson G; Xu, Zinnia S; Williams, Ashley J; Yimam, Nahom; Searson, Peter C

    2017-08-04

    The endothelial cells that form the lumen of capillaries and microvessels are an important component of the blood-brain barrier. Cell phenotype is regulated by transducing a range of biomechanical and biochemical signals in the local microenvironment. Here we report on the role of shear stress in modulating the morphology, motility, proliferation, apoptosis, and protein and gene expression, of confluent monolayers of human brain microvascular endothelial cells derived from induced pluripotent stem cells. To assess the response of derived human brain microvascular endothelial cells (dhBMECs) to shear stress, confluent monolayers were formed in a microfluidic device. Monolayers were subjected to a shear stress of 4 or 12 dyne cm -2 for 40 h. Static conditions were used as the control. Live cell imaging was used to assess cell morphology, cell speed, persistence, and the rates of proliferation and apoptosis as a function of time. In addition, immunofluorescence imaging and protein and gene expression analysis of key markers of the blood-brain barrier were performed. Human brain microvascular endothelial cells exhibit a unique phenotype in response to shear stress compared to static conditions: (1) they do not elongate and align, (2) the rates of proliferation and apoptosis decrease significantly, (3) the mean displacement of individual cells within the monolayer over time is significantly decreased, (4) there is no cytoskeletal reorganization or formation of stress fibers within the cell, and (5) there is no change in expression levels of key blood-brain barrier markers. The characteristic response of dhBMECs to shear stress is significantly different from human and animal-derived endothelial cells from other tissues, suggesting that this unique phenotype that may be important in maintenance of the blood-brain barrier. The implications of this work are that: (1) in confluent monolayers of dhBMECs, tight junctions are formed under static conditions, (2) the formation

  3. Sustained apnea induces endothelial activation.

    Science.gov (United States)

    Eichhorn, Lars; Dolscheid-Pommerich, Ramona; Erdfelder, Felix; Ayub, Muhammad Ajmal; Schmitz, Theresa; Werner, Nikos; Jansen, Felix

    2017-09-01

    Apnea diving has gained worldwide popularity, even though the pathophysiological consequences of this challenging sport on the human body are poorly investigated and understood. This study aims to assess the influence of sustained apnea in healthy volunteers on circulating microparticles (MPs) and microRNAs (miRs), which are established biomarkers reflecting vascular function. Short intermittent hypoxia due to voluntary breath-holding affects circulating levels of endothelial cell-derived MPs (EMPs) and endothelial cell-derived miRs. Under dry laboratory conditions, 10 trained apneic divers performed maximal breath-hold. Venous blood samples were taken, once before and at 4 defined points in time after apnea. Samples were analyzed for circulating EMPs and endothelial miRs. Average apnea time was 329 seconds (±103), and SpO 2 at the end of apnea was 79% (±12). Apnea was associated with a time-dependent increase of circulating endothelial cell-derived EMPs and endothelial miRs. Levels of circulating EMPs in the bloodstream reached a peak 4 hours after the apnea period and returned to baseline levels after 24 hours. Circulating miR-126 levels were elevated at all time points after a single voluntary maximal apnea, whereas miR-26 levels were elevated significantly only after 30 minutes and 4 hours. Also miR-21 and miR-92 levels increased, but did not reach the level of significance. Even a single maximal breath-hold induces acute endothelial activation and should be performed with great caution by subjects with preexisting vascular diseases. Voluntary apnea might be used as a model to simulate changes in endothelial function caused by hypoxia in humans. © 2017 Wiley Periodicals, Inc.

  4. Neutrophil-endothelial cell interactions on endothelial monolayers grown on micropore filters.

    Science.gov (United States)

    Taylor, R F; Price, T H; Schwartz, S M; Dale, D C

    1981-01-01

    We have developed a technique for growing endothelial monolayers on micropore filters. These monolayers demonstrate confluence by phase and electron microscopy and provide a functional barrier to passage of radiolabeled albumin. Neutrophils readily penetrate the monolayer in response to chemotaxin, whereas there is little movement in the absence of chemotaxin. This system offers unique advantages over available chemotaxis assays and may have wider applications in the study of endothelial function. Images PMID:7007441

  5. Recent applications of nanomaterials in capillary electrophoresis.

    Science.gov (United States)

    González-Curbelo, Miguel Ángel; Varela-Martínez, Diana Angélica; Socas-Rodríguez, Bárbara; Hernández-Borges, Javier

    2017-10-01

    Nanomaterials have found an important place in Analytical Chemistry and, in particular, in Separation Science. Among them, metal-organic frameworks, magnetic and non-magnetic nanoparticles, carbon nanotubes and graphene, as well as their combinations, are the most important nanomaterials that have been used up to now. Concerning capillary electromigration techniques, these nanomaterials have also been used as both pseudostationary phases in electrokinetic chromatography (EKC) and as stationary phases in microchip capillary electrophoresis (CE) and capillary electrochromatography (CEC), as a result of their interesting and particular properties. This review article pretends to provide a general and critical revision of the most recent applications of nanomaterials in this field (period 2010-2017). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Targeted Functionalization of Nanoparticle Thin Films via Capillary Condensation

    KAUST Repository

    Gemici, Zekeriyya; Schwachulla, Patrick I.; Williamson, Erik H.; Rubner, Michael F.; Cohen, Robert E.

    2009-01-01

    Capillary condensation, an often undesired natural phenomenon in nanoporous materials, was used advantageously as a universal functionalization strategy in nanoparticle thin films assembled layer-by-layer. Judicious choice of nanoparticle (and therefore pore) size allowed targeted capillary condensation of chemical vapors of both hydrophilic and hydrophobic molecules across film thickness. Heterostructured thin films with modulated refractive index profiles produced in this manner exhibited broadband antireflection properties with an average reflectance over the visible region of the spectrum of only 0.4%. Capillary condensation was also used to modify surface chemistry and surface energy. Photosensitive capillary-condensates were UV-cross-linked in situ. Undesired adventitious condensation of humidity could be avoided by condensation of hydrophobic materials such as poly(dimethyl siloxane). © 2009 American Chemical Society.

  7. Targeted Functionalization of Nanoparticle Thin Films via Capillary Condensation

    KAUST Repository

    Gemici, Zekeriyya

    2009-03-11

    Capillary condensation, an often undesired natural phenomenon in nanoporous materials, was used advantageously as a universal functionalization strategy in nanoparticle thin films assembled layer-by-layer. Judicious choice of nanoparticle (and therefore pore) size allowed targeted capillary condensation of chemical vapors of both hydrophilic and hydrophobic molecules across film thickness. Heterostructured thin films with modulated refractive index profiles produced in this manner exhibited broadband antireflection properties with an average reflectance over the visible region of the spectrum of only 0.4%. Capillary condensation was also used to modify surface chemistry and surface energy. Photosensitive capillary-condensates were UV-cross-linked in situ. Undesired adventitious condensation of humidity could be avoided by condensation of hydrophobic materials such as poly(dimethyl siloxane). © 2009 American Chemical Society.

  8. Targeted functionalization of nanoparticle thin films via capillary condensation.

    Science.gov (United States)

    Gemici, Zekeriyya; Schwachulla, Patrick I; Williamson, Erik H; Rubner, Michael F; Cohen, Robert E

    2009-03-01

    Capillary condensation, an often undesired natural phenomenon in nanoporous materials, was used advantageously as a universal functionalization strategy in nanoparticle thin films assembled layer-by-layer. Judicious choice of nanoparticle (and therefore pore) size allowed targeted capillary condensation of chemical vapors of both hydrophilic and hydrophobic molecules across film thickness. Heterostructured thin films with modulated refractive index profiles produced in this manner exhibited broadband antireflection properties with an average reflectance over the visible region of the spectrum of only 0.4%. Capillary condensation was also used to modify surface chemistry and surface energy. Photosensitive capillary-condensates were UV-cross-linked in situ. Undesired adventitious condensation of humidity could be avoided by condensation of hydrophobic materials such as poly(dimethyl siloxane).

  9. GPIHBP1 autoantibodies in a patient with unexplained chylomicronemia

    NARCIS (Netherlands)

    Hu, Xuchen; Dallinga-Thie, Geesje M.; Hovingh, G. Kees; Chang, Sandy Y.; Sandoval, Norma P.; Dang, Tiffany Ly P.; Fukamachi, Isamu; Miyashita, Kazuya; Nakajima, Katsuyuki; Murakami, Masami; Fong, Loren G.; Ploug, Michael; Young, Stephen G.; Beigneux, Anne P.

    2017-01-01

    GPIHBP1, a glycolipid-anchored protein of capillary endothelial cells, binds lipoprotein lipase (LPL) in the interstitial spaces and transports it to the capillary lumen. GPIHBP1 deficiency prevents LPL from reaching the capillary lumen, resulting in low intravascular LPL levels, impaired

  10. A macrothermodynamic approach to the limit of reversible capillary condensation.

    Science.gov (United States)

    Trens, Philippe; Tanchoux, Nathalie; Galarneau, Anne; Brunel, Daniel; Fubini, Bice; Garrone, Edoardo; Fajula, François; Di Renzo, Francesco

    2005-08-30

    The threshold of reversible capillary condensation is a well-defined thermodynamic property, as evidenced by corresponding states treatment of literature and experimental data on the lowest closure point of the hysteresis loop in capillary condensation-evaporation cycles for several adsorbates. The nonhysteretical filling of small mesopores presents the properties of a first-order phase transition, confirming that the limit of condensation reversibility does not coincide with the pore critical point. The enthalpy of reversible capillary condensation can be calculated by a Clausius-Clapeyron approach and is consistently larger than the condensation heat in unconfined conditions. Calorimetric data on the capillary condensation of tert-butyl alcohol in MCM-41 silica confirm a 20% increase of condensation heat in small mesopores. This enthalpic advantage makes easier the overcoming of the adhesion forces by the capillary forces and justifies the disappearing of the hysteresis loop.

  11. A submicron synchrotron X-ray beam generated by capillary optics

    International Nuclear Information System (INIS)

    Engstroem, P.; Larsson, S.; Rindby, A.; Buttkewitz, A.; Garbe, S.; Gaul, G.; Knoechel, A.; Lechtenberg, F.; Deutsches Elektronen-Synchrotron

    1991-01-01

    A novel capillary optics technique for focusing synchrotron X-ray beams has been applied in an experiment performed at the DORIS storage ring at HASYLAB. This new technqiue, which utilizes the total reflection properties of X-rays inside small capillaries, has recently been applied to generate microbeams of X-rays, with a beam size down to about 10 μm using conventional X-ray tubes. The result from our recent experiment shows that capillary optics can also be used to generate a submicron beam of X-rays from a synchrotron light source. A description of the capillary unit, and the alignment procedure is given. The influence of the thermal load on the device caused by the intense flux of synchrotron radiation will be discussed. Future perspectives of the capillary techniques as applied to synchrotron radiation will be discussed. (orig.)

  12. Numerical simulations of capillary barrier field tests

    International Nuclear Information System (INIS)

    Morris, C.E.; Stormont, J.C.

    1997-01-01

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior

  13. Organic grape juice intake improves functional capillary density and postocclusive reactive hyperemia in triathletes

    Directory of Open Access Journals (Sweden)

    Mariana Correa Gonçalves

    2011-01-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effect of organic grape juice intake on biochemical variables and microcirculatory parameters in triathlon athletes. INTRODUCTION: The physiological stress that is imposed by a strenuous sport, such as a triathlon, together with an insufficient amount of antioxidants in the diet may cause oxidative imbalance and endothelial dysfunction. METHODS: Ten adult male triathletes participated in this study. A venous blood sample was drawn before (baseline and after 20 days of organic grape juice intake (300 ml/day. Serum insulin, plasma glucose and uric acid levels, the total content of polyphenols, and the erythrocyte superoxide dismutase activity were determined. The functional microcirculatory parameters (the functional capillary density, red blood cell velocity at baseline and peak levels, and time required to reach the peak red blood cell velocity during postocclusive reactive hyperemia after a one-min arterial occlusion were evaluated using nailfold videocapillaroscopy. RESULTS: Compared with baseline levels, the peak levels of serum insulin ( p = 0.02, plasma uric acid ( p = 0.04, the functional capillary density ( p = 0.003, and the red blood cell velocity (p < 0.001 increased, whereas the plasma glucose level (p,0.001, erythrocyte superoxide dismutase activity ( p = 0.04, and time required to reach red blood cell velocity during postocclusive reactive hyperemia ( p = 0.04 decreased after organic grape juice intake. CONCLUSION: Our data showed that organic grape juice intake improved glucose homeostasis, antioxidant capacity, and microvascular function, which may be due to its high concentration of polyphenols. These results indicate that organic grape juice has a positive effect in endurance athletes.

  14. Permeability of peritoneal and glomerular capillaries: what are the differences according to pore theory?

    Science.gov (United States)

    Rippe, Bengt; Davies, Simon

    2011-01-01

    Pore and fiber-matrix theory can both be used to model the peritoneal and glomerular filtration barriers in an attempt to shed light on their differing structure-function relationships. The glomerular filtration barrier (GFB) is structurally more specialized, morphologically complex, and also highly dynamic; but paradoxically, because of its uniformity, it conforms more closely to the predictions of pore theory than does the peritoneum, and it in fact resembles a more simple synthetic membrane. Compared with the peritoneal capillary wall, the GFB has no transcellular "third" pores (aquaporins), and it is far less leaky and more size-selective to proteins, mainly as a result of having far fewer "large" pores. It does have charge-selective properties, although these are considered much less important in excluding albumin than was once thought, and it is also able to select polymers according to their shape and flexibility. Even this property might reflect the relative uniformity of the GFB, which has a high diffusion area and short diffusion distances, compared with the peritoneal barrier, which behaves more like a gel filtration column. Furthermore, the length of the diffusion path across the peritoneal membrane is much greater for small solutes, given the relatively high ultrafiltration coefficient for that membrane compared with the GFB--a situation that reflects both the tortuosity of the interendothelial clefts and the distribution of peritoneal capillaries within the interstitium. These comparisons reveal the peritoneal barrier as a relatively complex structure to model; and yet this model may be more representative of the general microcirculation, and thus shed light on systemic endothelial function in renal failure.

  15. Exploring Ultimate Water Capillary Evaporation in Nanoscale Conduits.

    Science.gov (United States)

    Li, Yinxiao; Alibakhshi, Mohammad Amin; Zhao, Yihong; Duan, Chuanhua

    2017-08-09

    Capillary evaporation in nanoscale conduits is an efficient heat/mass transfer strategy that has been widely utilized by both nature and mankind. Despite its broad impact, the ultimate transport limits of capillary evaporation in nanoscale conduits, governed by the evaporation/condensation kinetics at the liquid-vapor interface, have remained poorly understood. Here we report experimental study of the kinetic limits of water capillary evaporation in two dimensional nanochannels using a novel hybrid channel design. Our results show that the kinetic-limited evaporation fluxes break down the limits predicated by the classical Hertz-Knudsen equation by an order of magnitude, reaching values up to 37.5 mm/s with corresponding heat fluxes up to 8500 W/cm 2 . The measured evaporation flux increases with decreasing channel height and relative humidity but decreases as the channel temperature decreases. Our findings have implications for further understanding evaporation at the nanoscale and developing capillary evaporation-based technologies for both energy- and bio-related applications.

  16. Sickle erythrocytes inhibit human endothelial cell DNA synthesis

    International Nuclear Information System (INIS)

    Weinstein, R.; Zhou, M.A.; Bartlett-Pandite, A.; Wenc, K.

    1990-01-01

    Patients with sickle cell anemia experience severe vascular occlusive phenomena including acute pain crisis and cerebral infarction. Obstruction occurs at both the microvascular and the arterial level, and the clinical presentation of vascular events is heterogeneous, suggesting a complex etiology. Interaction between sickle erythrocytes and the endothelium may contribute to vascular occlusion due to alteration of endothelial function. To investigate this hypothesis, human vascular endothelial cells were overlaid with sickle or normal erythrocytes and stimulated to synthesize DNA. The erythrocytes were sedimented onto replicate monolayers by centrifugation for 10 minutes at 17 g to insure contact with the endothelial cells. Incorporation of 3H-thymidine into endothelial cell DNA was markedly inhibited during contact with sickle erythrocytes. This inhibitory effect was enhanced more than twofold when autologous sickle plasma was present during endothelial cell labeling. Normal erythrocytes, with or without autologous plasma, had a modest effect on endothelial cell DNA synthesis. When sickle erythrocytes in autologous sickle plasma were applied to endothelial monolayers for 1 minute, 10 minutes, or 1 hour and then removed, subsequent DNA synthesis by the endothelial cells was inhibited by 30% to 40%. Although adherence of sickle erythrocytes to the endothelial monolayers was observed under these experimental conditions, the effect of sickle erythrocytes on endothelial DNA synthesis occurred in the absence of significant adherence. Hence, human endothelial cell DNA synthesis is partially inhibited by contact with sickle erythrocytes. The inhibitory effect of sickle erythrocytes occurs during a brief (1 minute) contact with the endothelial monolayers, and persists for at least 6 hours of 3H-thymidine labeling

  17. Bauhinia bauhinioides cruzipain inhibitor reduces endothelial proliferation and induces an increase of the intracellular Ca2+ concentration.

    Science.gov (United States)

    Bilgin, Mehmet; Neuhof, Christiane; Doerr, Oliver; Benscheid, Utz; Andrade, Sheila S; Most, Astrid; Abdallah, Yaser; Parahuleva, Mariana; Guenduez, Dursun; Oliva, Maria L; Erdogan, Ali

    2010-12-01

    Proteinase inhibitors, isolated from different types of Bauhinia, have an effect on apoptosis, angiogenesis and inflammation. The Bauhinia bauhinioides cruzipain inhibitor (BbCI) is a Kunitz-type inhibitor and inactivates the cysteine proteinases cruzipain and cruzain from Trypanosoma cruzi. Cruzipain and tissue kallikrein have similar biochemical properties, e.g. the proteolytic cleavage of the kininogen precursor of lys-bradykinin. Tissue kallikrein stimulation in endothelial cells causes migration and capillary tube formation. The aim of this study was to examine whether the antiproliferative effect of BbCI is dependent on changes of the intracellular calcium concentration and membrane hyperpolarization. Endothelial cells were isolated from human umbilical cord veins (HUVEC). For proliferation experiments, HUVEC were incubated with BbCI (10-100 μmol/L) for 48 h. The proliferation was detected by cell counting with a Neubauer chamber. The effect of BbCI (10-100 μM) on the membrane potential was measured with the fluorescence dye DiBAC4(3) and the effect on [Ca+2]i with the fluorescence probe Fluo-3 AM. The change of the fluorescence intensity was determined with a GENios plate reader (Tecan). The experiments showed that BbCI (10-100 μmol/L) reduces the endothelial cell proliferation significantly in a concentration-dependent manner with a maximum effect at 100 μmol/L (35.1±1.8% as compared to control (p≤0.05; n=45)). As compared to the control, the addition of BbCI (100 μmol/L) caused a significant increase of systolic Ca2+ of 28.4±5.0% after 30 min incubation. HUVEC treatment with BbCI (100 μmol/L) showed a weak but significant decrease of the membrane potential of 9.5±0.9% as compared to control (p≤0.05; n=80). BbCI influenced significantly the endothelial proliferation, the intracellular Ca2+ concentration and the membrane potential.

  18. Modeling aerobic biodegradation in the capillary fringe.

    Science.gov (United States)

    Luo, Jian; Kurt, Zohre; Hou, Deyi; Spain, Jim C

    2015-02-03

    Vapor intrusion from volatile subsurface contaminants can be mitigated by aerobic biodegradation. Laboratory column studies with contaminant sources of chlorobenzene and a mixture of chlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene showed that contaminants were rapidly degraded in thin reactive zones with high biomass and low substrate concentrations in the vicinity of the capillary fringe. Such behavior was well characterized by a model that includes oxygen-, substrate-, and biomass-dependent biodegradation kinetics along with diffusive transport processes. An analytical solution was derived to provide theoretical support for the simplification of reaction kinetics and the approximation of reactive zone location and mass flux relationships at steady state. Results demonstrate the potential of aerobic natural attenuation in the capillary fringe for preventing contaminant migration in the unsaturated zone. The solution indicates that increasing contaminant mass flux into the column creates a thinner reactive zone and pushes it toward the oxygen boundary, resulting in a shorter distance to the oxygen source and a larger oxygen mass flux that balances the contaminant mass flux. As a consequence, the aerobic biodegradation can reduce high contaminant concentrations to low levels within the capillary fringe and unsaturated zone. The results are consistent with the observations of thin reactive layers at the interface in unsaturated zones. The model considers biomass while including biodegradation in the capillary fringe and unsaturated zone and clearly demonstrates that microbial communities capable of using the contaminants as electron donors may lead to instantaneous degradation kinetics in the capillary fringe and unsaturated zone.

  19. Endothelial dysfunction in metabolic and vascular disorders.

    Science.gov (United States)

    Polovina, Marija M; Potpara, Tatjana S

    2014-03-01

    Vascular endothelium has important regulatory functions in the cardiovascular system and a pivotal role in the maintenance of vascular health and metabolic homeostasis. It has long been recognized that endothelial dysfunction participates in the pathogenesis of atherosclerosis from early, preclinical lesions to advanced, thrombotic complications. In addition, endothelial dysfunction has been recently implicated in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Considering that states of insulin resistance (eg, metabolic syndrome, impaired fasting glucose, impaired glucose tolerance, and T2DM) represent the most prevalent metabolic disorders and risk factors for atherosclerosis, it is of considerable scientific and clinical interest that both metabolic and vascular disorders have endothelial dysfunction as a common background. Importantly, endothelial dysfunction has been associated with adverse outcomes in patients with established cardiovascular disease, and a growing body of evidence indicates that endothelial dysfunction also imparts adverse prognosis in states of insulin resistance. In this review, we discuss the association of insulin resistance and T2DM with endothelial dysfunction and vascular disease, with a focus on the underlying mechanisms and prognostic implications of the endothelial dysfunction in metabolic and vascular disorders. We also address current therapeutic strategies for the improvement of endothelial dysfunction.

  20. Targeted endothelial nanomedicine for common acute pathological conditions.

    Science.gov (United States)

    Shuvaev, Vladimir V; Brenner, Jacob S; Muzykantov, Vladimir R

    2015-12-10

    Endothelium, a thin monolayer of specialized cells lining the lumen of blood vessels is the key regulatory interface between blood and tissues. Endothelial abnormalities are implicated in many diseases, including common acute conditions with high morbidity and mortality lacking therapy, in part because drugs and drug carriers have no natural endothelial affinity. Precise endothelial drug delivery may improve management of these conditions. Using ligands of molecules exposed to the bloodstream on the endothelial surface enables design of diverse targeted endothelial nanomedicine agents. Target molecules and binding epitopes must be accessible to drug carriers, carriers must be free of harmful effects, and targeting should provide desirable sub-cellular addressing of the drug cargo. The roster of current candidate target molecules for endothelial nanomedicine includes peptidases and other enzymes, cell adhesion molecules and integrins, localized in different domains of the endothelial plasmalemma and differentially distributed throughout the vasculature. Endowing carriers with an affinity to specific endothelial epitopes enables an unprecedented level of precision of control of drug delivery: binding to selected endothelial cell phenotypes, cellular addressing and duration of therapeutic effects. Features of nanocarrier design such as choice of epitope and ligand control delivery and effect of targeted endothelial nanomedicine agents. Pathological factors modulate endothelial targeting and uptake of nanocarriers. Selection of optimal binding sites and design features of nanocarriers are key controllable factors that can be iteratively engineered based on their performance from in vitro to pre-clinical in vivo experimental models. Targeted endothelial nanomedicine agents provide antioxidant, anti-inflammatory and other therapeutic effects unattainable by non-targeted counterparts in animal models of common acute severe human disease conditions. The results of animal

  1. 21 CFR 864.6150 - Capillary blood collection tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Capillary blood collection tube. 864.6150 Section 864.6150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6150 Capillary...

  2. Capillary sieving electrophoresis and micellar electrokinetic capillary chromatography produce highly correlated separation of tryptic digests

    Science.gov (United States)

    Dickerson, Jane A.; Dovichi, Norman J.

    2011-01-01

    We perform two-dimensional capillary electrophoresis on fluorescently labeled proteins and peptides. Capillary sieving electrophoresis was performed in the first dimension and micellar electrokinetic capillary chromatography was performed in the second. A cellular homogenate was labeled with the fluorogenic reagent FQ and separated using the system. This homogenate generated a pair of ridges; the first had essentially constant migration time in the CSE dimension, while the second had essentially constant migration time in the MEKC dimension. In addition a few spots were scattered through the electropherogram. The same homogenate was digested using trypsin, and then labeled and subjected to the two dimensional separation. In this case, the two ridges observed from the original two-dimensional separation disappeared, and were replaced by a set of spots that fell along the diagonal. Those spots were identified using a local-maximum algorithm and each was fit using a two-dimensional Gaussian surface by an unsupervised nonlinear least squares regression algorithm. The migration times of the tryptic digest components were highly correlated (r = 0.862). When the slowest migrating components were eliminated from the analysis, the correlation coefficient improved to r = 0.956. PMID:20564272

  3. Endothelial cell capture of heparin-binding growth factors under flow.

    Directory of Open Access Journals (Sweden)

    Bing Zhao

    2010-10-01

    Full Text Available Circulation is an important delivery method for both natural and synthetic molecules, but microenvironment interactions, regulated by endothelial cells and critical to the molecule's fate, are difficult to interpret using traditional approaches. In this work, we analyzed and predicted growth factor capture under flow using computer modeling and a three-dimensional experimental approach that includes pertinent circulation characteristics such as pulsatile flow, competing binding interactions, and limited bioavailability. An understanding of the controlling features of this process was desired. The experimental module consisted of a bioreactor with synthetic endothelial-lined hollow fibers under flow. The physical design of the system was incorporated into the model parameters. The heparin-binding growth factor fibroblast growth factor-2 (FGF-2 was used for both the experiments and simulations. Our computational model was composed of three parts: (1 media flow equations, (2 mass transport equations and (3 cell surface reaction equations. The model is based on the flow and reactions within a single hollow fiber and was scaled linearly by the total number of fibers for comparison with experimental results. Our model predicted, and experiments confirmed, that removal of heparan sulfate (HS from the system would result in a dramatic loss of binding by heparin-binding proteins, but not by proteins that do not bind heparin. The model further predicted a significant loss of bound protein at flow rates only slightly higher than average capillary flow rates, corroborated experimentally, suggesting that the probability of capture in a single pass at high flow rates is extremely low. Several other key parameters were investigated with the coupling between receptors and proteoglycans shown to have a critical impact on successful capture. The combined system offers opportunities to examine circulation capture in a straightforward quantitative manner that

  4. Exercise training improves in vivo endothelial repair capacity of early endothelial progenitor cells in subjects with metabolic syndrome.

    Science.gov (United States)

    Sonnenschein, Kristina; Horváth, Tibor; Mueller, Maja; Markowski, Andrea; Siegmund, Tina; Jacob, Christian; Drexler, Helmut; Landmesser, Ulf

    2011-06-01

    Endothelial dysfunction and injury are considered to contribute considerably to the development and progression of atherosclerosis. It has been suggested that intense exercise training can increase the number and angiogenic properties of early endothelial progenitor cells (EPCs). However, whether exercise training stimulates the capacity of early EPCs to promote repair of endothelial damage and potential underlying mechanisms remain to be determined. The present study was designed to evaluate the effects of moderate exercise training on in vivo endothelial repair capacity of early EPCs, and their nitric oxide and superoxide production as characterized by electron spin resonance spectroscopy analysis in subjects with metabolic syndrome. Twenty-four subjects with metabolic syndrome were randomized to an 8 weeks exercise training or a control group. Superoxide production and nitric oxide (NO) availability of early EPCs were characterized by using electron spin resonance (ESR) spectroscopy analysis. In vivo endothelial repair capacity of EPCs was examined by transplantation into nude mice with defined carotid endothelial injury. Endothelium-dependent, flow-mediated vasodilation was analysed using high-resolution ultrasound. Importantly, exercise training resulted in a substantially improved in vivo endothelial repair capacity of early EPCs (24.0 vs 12.7%; p exercise training, but not in the control group. Moreover, exercise training reduced superoxide production of EPCs, which was not observed in the control group. The present study suggests for the first time that moderate exercise training increases nitric oxide production of early endothelial progenitor cells and reduces their superoxide production. Importantly, this is associated with a marked beneficial effect on the in vivo endothelial repair capacity of early EPCs in subjects with metabolic syndrome.

  5. Platelet lysate gel and endothelial progenitors stimulate microvascular network formation in vitro: tissue engineering implications.

    Science.gov (United States)

    Fortunato, Tiago M; Beltrami, Cristina; Emanueli, Costanza; De Bank, Paul A; Pula, Giordano

    2016-05-04

    Revascularisation is a key step for tissue regeneration and complete organ engineering. We describe the generation of human platelet lysate gel (hPLG), an extracellular matrix preparation from human platelets able to support the proliferation of endothelial colony forming cells (ECFCs) in 2D cultures and the formation of a complete microvascular network in vitro in 3D cultures. Existing extracellular matrix preparations require addition of high concentrations of recombinant growth factors and allow only limited formation of capillary-like structures. Additional advantages of our approach over existing extracellular matrices are the absence of any animal product in the composition hPLG and the possibility of obtaining hPLG from patients to generate homologous scaffolds for re-implantation. This discovery has the potential to accelerate the development of regenerative medicine applications based on implantation of microvascular networks expanded ex vivo or the generation of fully vascularised organs.

  6. Modeling the ischemic blood-brain barrier; the effects of oxygen-glucose deprivation (OGD) on endothelial cells in culture

    DEFF Research Database (Denmark)

    Tornabene, Erica; Helms, Hans Christian Cederberg; Berndt, Philipp

    Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming...... pathways across the barrier in ischemic and postischemic brain endothelium is important for developing new medical therapies capable to exploit the barrier changes occurring during/after ischemia to permeate in the brain and treat this devastating disease. Materials and Methods - Primary cultures...... the wall of brain capillaries. The restrictive nature of the BBB is due to the tight junctions (TJs), which seal the intercellular clefts, limiting the paracellular diffusion, efflux transporters, which extrude xenobiotics, and metabolizing enzymes, which may break down or convert molecules during...

  7. Major involvement of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) in uptake of biotin and pantothenic acid by human brain capillary endothelial cells.

    Science.gov (United States)

    Uchida, Yasuo; Ito, Katsuaki; Ohtsuki, Sumio; Kubo, Yoshiyuki; Suzuki, Takashi; Terasaki, Tetsuya

    2015-07-01

    The purpose of this study was to clarify the expression of Na(+) -dependent multivitamin transporter (SLC5A6/SMVT) and its contribution to the supply of biotin and pantothenic acid to the human brain via the blood-brain barrier. DNA microarray and immunohistochemical analyses confirmed that SLC5A6 is expressed in microvessels of human brain. The absolute expression levels of SLC5A6 protein in isolated human and monkey brain microvessels were 1.19 and 0.597 fmol/μg protein, respectively, as determined by a quantitative targeted absolute proteomics technique. Using an antibody-free method established by Kubo et al. (2015), we found that SLC5A6 was preferentially localized at the luminal membrane of brain capillary endothelium. Knock-down analysis using SLC5A6 siRNA showed that SLC5A6 accounts for 88.7% and 98.6% of total [(3) H]biotin and [(3) H]pantothenic acid uptakes, respectively, by human cerebral microvascular endothelial cell line hCMEC/D3. SLC5A6-mediated transport in hCMEC/D3 was markedly inhibited not only by biotin and pantothenic acid, but also by prostaglandin E2, lipoic acid, docosahexaenoic acid, indomethacin, ketoprofen, diclofenac, ibuprofen, phenylbutazone, and flurbiprofen. This study is the first to confirm expression of SLC5A6 in human brain microvessels and to provide evidence that SLC5A6 is a major contributor to luminal uptake of biotin and pantothenic acid at the human blood-brain barrier. In humans, it was unclear (not concluded) about what transport system at the blood-brain barrier (BBB) is responsible for the brain uptakes of two vitamins, biotin and pantothenic acid, which are necessary for brain proper function. This study clarified for the first time that the solute carrier 5A6/Na(+) -dependent multivitamin transporter SLC5A6/SMVT is responsible for the supplies of biotin and pantothenic acid into brain across the BBB in humans. DHA, docosahexaenoic acid; NSAID, non-steroidal anti-inflammatory drug; PGE2, prostaglandin E2. © 2015

  8. Functional Differences Between Placental Micro- and Macrovascular Endothelial Colony-Forming Cells

    Science.gov (United States)

    Solomon, Ioana; O’Reilly, Megan; Ionescu, Lavinia; Alphonse, Rajesh S.; Rajabali, Saima; Zhong, Shumei; Vadivel, Arul; Shelley, W. Chris; Yoder, Mervin C.

    2016-01-01

    Alterations in the development of the placental vasculature can lead to pregnancy complications, such as preeclampsia. Currently, the cause of preeclampsia is unknown, and there are no specific prevention or treatment strategies. Further insight into the placental vasculature may aid in identifying causal factors. Endothelial colony-forming cells (ECFCs) are a subset of endothelial progenitor cells capable of self-renewal and de novo vessel formation in vitro. We hypothesized that ECFCs exist in the micro- and macrovasculature of the normal, term human placenta. Human placentas were collected from term pregnancies delivered by cesarean section (n = 16). Placental micro- and macrovasculature was collected from the maternal and fetal side of the placenta, respectively, and ECFCs were isolated and characterized. ECFCs were CD31+, CD105+, CD144+, CD146+, CD14−, and CD45−, took up 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl-indocarbocyanine perchlorate-labeled acetylated low-density lipoprotein, and bound Ulex europaeus agglutinin 1. In vitro, macrovascular ECFCs had a greater potential to generate high-proliferative colonies and formed more complex capillary-like networks on Matrigel compared with microvascular ECFCs. In contrast, in vivo assessment demonstrated that microvascular ECFCs had a greater potential to form vessels. Macrovascular ECFCs were of fetal origin, whereas microvascular ECFCs were of maternal origin. ECFCs exist in the micro- and macrovasculature of the normal, term human placenta. Although macrovascular ECFCs demonstrated greater vessel and colony-forming potency in vitro, this did not translate in vivo, where microvascular ECFCs exhibited a greater vessel-forming ability. These important findings contribute to the current understanding of normal placental vascular development and may aid in identifying factors involved in preeclampsia and other pregnancy complications. Significance This research confirms that resident endothelial colony

  9. Endothelial cell repopulation after stenting determines in-stent neointima formation: effects of bare-metal vs. drug-eluting stents and genetic endothelial cell modification.

    Science.gov (United States)

    Douglas, Gillian; Van Kampen, Erik; Hale, Ashley B; McNeill, Eileen; Patel, Jyoti; Crabtree, Mark J; Ali, Ziad; Hoerr, Robert A; Alp, Nicholas J; Channon, Keith M

    2013-11-01

    Understanding endothelial cell repopulation post-stenting and how this modulates in-stent restenosis is critical to improving arterial healing post-stenting. We used a novel murine stent model to investigate endothelial cell repopulation post-stenting, comparing the response of drug-eluting stents with a primary genetic modification to improve endothelial cell function. Endothelial cell repopulation was assessed en face in stented arteries in ApoE(-/-) mice with endothelial-specific LacZ expression. Stent deployment resulted in near-complete denudation of endothelium, but was followed by endothelial cell repopulation, by cells originating from both bone marrow-derived endothelial progenitor cells and from the adjacent vasculature. Paclitaxel-eluting stents reduced neointima formation (0.423 ± 0.065 vs. 0.240 ± 0.040 mm(2), P = 0.038), but decreased endothelial cell repopulation (238 ± 17 vs. 154 ± 22 nuclei/mm(2), P = 0.018), despite complete strut coverage. To test the effects of selectively improving endothelial cell function, we used transgenic mice with endothelial-specific overexpression of GTP-cyclohydrolase 1 (GCH-Tg) as a model of enhanced endothelial cell function and increased NO production. GCH-Tg ApoE(-/-) mice had less neointima formation compared with ApoE(-/-) littermates (0.52 ± 0.08 vs. 0.26 ± 0.09 mm(2), P = 0.039). In contrast to paclitaxel-eluting stents, reduced neointima formation in GCH-Tg mice was accompanied by increased endothelial cell coverage (156 ± 17 vs. 209 ± 23 nuclei/mm(2), P = 0.043). Drug-eluting stents reduce not only neointima formation but also endothelial cell repopulation, independent of strut coverage. In contrast, selective targeting of endothelial cell function is sufficient to improve endothelial cell repopulation and reduce neointima formation. Targeting endothelial cell function is a rational therapeutic strategy to improve vascular healing and decrease neointima formation after stenting.

  10. Reducing the Edge Chipping for Capillary End Face Grinding and Polishing

    Directory of Open Access Journals (Sweden)

    Hošek J.

    2013-05-01

    Full Text Available This paper presents results of glass capillary end face grinding and polishing by approach that reduces the edge chipping. Brittle materials have natural tendency for edge chipping what leads to beveling the sharp edges. Not beveled sharp edges on glass capillary are important for special applications like surface tension measurement of small liquid samples. We use common grinding and polishing process for capillary end face machining modified with gradual decreasing of grinding load based on the relation of the critical chipping load. Achieved surface roughness is measured using atomic force microscopy (AFM. Capillary inner edge quality is checked both with optical microscopes and electron microscope too. We achieved a non-chipped capillary inner edge with radius down to 100 nm.

  11. Endothelial cell senescence with aging in healthy humans: prevention by habitual exercise and relation to vascular endothelial function.

    Science.gov (United States)

    Rossman, Matthew J; Kaplon, Rachelle E; Hill, Sierra D; McNamara, Molly N; Santos-Parker, Jessica R; Pierce, Gary L; Seals, Douglas R; Donato, Anthony J

    2017-11-01

    Cellular senescence is emerging as a key mechanism of age-related vascular endothelial dysfunction, but evidence in healthy humans is lacking. Moreover, the influence of lifestyle factors such as habitual exercise on endothelial cell (EC) senescence is unknown. We tested the hypothesis that EC senescence increases with sedentary, but not physically active, aging and is associated with vascular endothelial dysfunction. Protein expression (quantitative immunofluorescence) of p53, a transcription factor related to increased cellular senescence, and the cyclin-dependent kinase inhibitors p21 and p16 were 116%, 119%, and 128% greater (all P age-related differences were not present (all P > 0.05) in venous ECs from older exercising adults (57 ± 1 yr, n = 13). Furthermore, venous EC protein levels of p53 ( r  = -0.49, P = 0.003), p21 ( r  = -0.38, P = 0.03), and p16 ( r  = -0.58, P = 0.002) were inversely associated with vascular endothelial function (brachial artery flow-mediated dilation). Similarly, protein expression of p53 and p21 was 26% and 23% higher (both P healthy older sedentary (63 ± 1 yr, n = 18) versus young sedentary (25 ± 1 yr, n = 9) adults; age-related changes in arterial EC p53 and p21 expression were not observed ( P > 0.05) in older habitually exercising adults (59 ± 1 yr, n = 14). These data indicate that EC senescence is associated with sedentary aging and is linked to endothelial dysfunction. Moreover, these data suggest that prevention of EC senescence may be one mechanism by which aerobic exercise protects against endothelial dysfunction with age. NEW & NOTEWORTHY Our study provides novel evidence in humans of increased endothelial cell senescence with sedentary aging, which is associated with impaired vascular endothelial function. Furthermore, our data suggest an absence of age-related increases in endothelial cell senescence in older exercising adults, which is linked with preserved vascular endothelial function

  12. The solid-state fermentation of Artemisia capillaris leaves with Ganoderma lucidum enhances the anti-inflammatory effects in a model of atopic dermatitis.

    Science.gov (United States)

    Son, Hyeong-U; Lee, Seul; Heo, Jin-Chul; Lee, Sang-Han

    2017-05-01

    Artemisia capillaris, which belongs to the Asteraceae family and the genus Artemisia, has been reported to exert inhibitory effects on diabetes, cancer and inflammation. In this study, in order to enhance the bioactivity potential of the leaves of Artemisia by Ganoderma lucidum mycelium, we prepared aqueous samples of Artemisia capillaris (Ac) leaves, Ganoderma lucidum (Gl) and aqueous fractions produced by the solid fermentation of Ganoderma lucidum on Artemisia capillaris leaves (afAc/Gl). Thereafter, we evaluated whether these samples have potential to attenuate inflammation-related symptoms in an amimal model of 2,4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis. We found that afAc/Gl exhibited enhanced anti-inflamamatory activity following the solid fermentation process when compared with Ac or Gl on ear thickness, ear epidermal thickness and eosinophil infiltration in the skin tissues. The expression of nitric oxide (NO) synthases (NOSs) was measured by immunohistochemical staining. The results revealed that afAc/Gl decreased endothelial NOS and inducible NOS expression compared with the DNFB group, while neuronal NOS expression was not altered. By comparing NO production, we found that as opposed to Ac, afAc/Gl has potential to inhibit atopic dermatitis-related symptoms during the inflammatory event. As regards matrix metalloproteinase (MMP) expression patterns, afAc/Gl exerted potent inhibitory activity on the mRNA expression of MMP-2, -7, -9, -12, -14 and -19. Taken together, these results suggest that the solid state fermentation of Ac by Gl is an effective strategy to obtaining useful ingredients which are converted into valuable compounds during an atopic inflammatory insult.

  13. On the performance of capillary barriers as landfill cover

    Science.gov (United States)

    Kämpf, M.; Montenegro, H.

    Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  14. On the performance of capillary barriers as landfill cover

    Directory of Open Access Journals (Sweden)

    M. Kämpf

    1997-01-01

    Full Text Available Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m. In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

  15. COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

    Science.gov (United States)

    Polverino, Francesca; Celli, Bartolome R.

    2018-01-01

    Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the “vascular COPD phenotype” including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested

  16. Capillary electrophoresis and nanomaterials - Part I: Capillary electrophoresis of nanomaterials.

    Science.gov (United States)

    Adam, Vojtech; Vaculovicova, Marketa

    2017-10-01

    Nanomaterials are in analytical science used for a broad range of purposes, covering the area of sample pretreatment as well as separation, detection, and identification of target molecules. This part of the review covers capillary electrophoresis (CE) of nanomaterials and focuses on the application of CE as a method for characterization used during nanomaterial synthesis and modification as well as the monitoring of their properties and interactions with other molecules. The heterogeneity of the nanomaterial family is extremely large. Depending on different definitions of the term Nanomaterial/Nanoparticle, the group may cover metal and polymeric nanoparticles, carbon nanomaterials, liposomes and even dendrimers. Moreover, these nanomaterials are usually subjected to some kind of surface modification or functionalization, which broadens the diversity even more. Not only for purposes of verification of nanomaterial synthesis and batch-to-batch quality check, but also for determination the polydispersity and for functionality characterization on the nanoparticle surface, has CE offered very beneficial capabilities. Finally, the monitoring of interactions between nanomaterials and other (bio)molecules is easily performed by some kind of capillary electromigration technique. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan, E-mail: yangjing_928@126.com

    2017-06-15

    Highlights: • A micro X-ray fluorescence setup based on an ellipsoidal capillary was presented. • The optimal parameters of ellipsoidal capillary were designed. • The 2D mapping image of biological sample was obtained. - Abstract: A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

  18. GPIHBP1 and Plasma Triglyceride Metabolism

    DEFF Research Database (Denmark)

    Fong, Loren G; Young, Stephen G; Beigneux, Anne P

    2016-01-01

    GPIHBP1, a GPI-anchored protein in capillary endothelial cells, is crucial for the lipolytic processing of triglyceride-rich lipoproteins (TRLs). GPIHBP1 shuttles lipoprotein lipase (LPL) to its site of action in the capillary lumen and is essential for the margination of TRLs along capillaries -...

  19. Pulmonary capillary haemangiomatosis: a rare cause of pulmonary hypertension.

    Science.gov (United States)

    Babu, K Anand; Supraja, K; Singh, Raj B

    2014-01-01

    Pulmonary capillary haemangiomatosis (PCH) is a rare disorder of unknown aetiology, characterised by proliferating capillaries that invade the pulmonary interstitium, alveolar septae and the pulmonary vasculature. It is often mis-diagnosed as primary pulmonary hypertension and pulmonary veno-occlusive disease. Pulmonary capillary haemangiomatosis is a locally aggressive benign vascular neoplasm of the lung. We report the case of a 19-year-old female who was referred to us in the early post-partum period with severe pulmonary artery hypertension, which was diagnosed as PCH by open lung biopsy.

  20. Capillary electrophoresis in a fused-silica capillary with surface roughness gradient

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Šlais, Karel; Karásek, Pavel; Růžička, F.; Šalplachta, Jiří; Šesták, Jozef; Kahle, Vladislav; Roth, Michal

    2016-01-01

    Roč. 39, č. 19 (2016), s. 3827-3834 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supercritical water * surface roughness gradient Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.557, year: 2016

  1. Capillary electrophoresis in a fused-silica capillary with surface roughness gradient

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Šlais, Karel; Karásek, Pavel; Růžička, F.; Šalplachta, Jiří; Šesták, Jozef; Kahle, Vladislav; Roth, Michal

    2016-01-01

    Roč. 39, č. 19 (2016), s. 3827-3834 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supercritical water * surface roughness gradient Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.557, year: 2016

  2. Managment of superficial infantile capillary hemangiomas with topical timolol maleate solution.

    Science.gov (United States)

    Rizvi, Syed Ali Raza; Yusuf, Faraz; Sharma, Rajeev; Rizvi, Syed Wajahat Ali

    2015-01-01

    Capillary hemangioma is the most common benign tumor of eyelids and orbit in children. Recently, a topical beta blocker has been reported as an effective treatment for superficial capillary hemangiomas. We present a case report of two children having large capillary hemangiomas who responded well to topical treatment by 0.5% timolol maleate solution. After 12 months of treatment, the lesion has significantly reduced in size, thickness, and color in both cases. Thus, we conclude that long-term use of topical 0.5% timolol maleate solution is safe and effective in treating superficial capillary hemangiomas.

  3. Endogenous Vascular Endothelial Growth Factor-A (VEGF-A) Maintains Endothelial Cell Homeostasis by Regulating VEGF Receptor-2 Transcription*

    Science.gov (United States)

    E, Guangqi; Cao, Ying; Bhattacharya, Santanu; Dutta, Shamit; Wang, Enfeng; Mukhopadhyay, Debabrata

    2012-01-01

    Vascular endothelial growth factor A (VEGF-A) is one of the most important factors controlling angiogenesis. Although the functions of exogenous VEGF-A have been widely studied, the roles of endogenous VEGF-A remain unclear. Here we focused on the mechanistic functions of endogenous VEGF-A in endothelial cells. We found that it is complexed with VEGF receptor 2 (VEGFR-2) and maintains a basal expression level for VEGFR-2 and its downstream signaling activation. Endogenous VEGF-A also controls expression of key endothelial specific genes including VEGFR-2, Tie-2, and vascular endothelial cadherin. Of importance, endogenous VEGF-A differs from exogenous VEGF-A by regulating VEGFR-2 transcription through mediation of FoxC2 binding to the FOX:ETS motif, and the complex formed by endogenous VEGF-A with VEGFR-2 is localized within the EEA1 (early endosome antigen 1) endosomal compartment. Taken together, our results emphasize the importance of endogenous VEGF-A in endothelial cells by regulating key vascular proteins and maintaining the endothelial homeostasis. PMID:22167188

  4. Exercise Training Could Improve Age-Related Changes in Cerebral Blood Flow and Capillary Vascularity through the Upregulation of VEGF and eNOS

    Directory of Open Access Journals (Sweden)

    Sheepsumon Viboolvorakul

    2014-01-01

    Full Text Available This study aimed to investigate the effect of exercise training on age-induced microvascular alterations in the brain. Additionally, the association with the protein levels of vascular endothelial growth factor (VEGF and endothelial nitric oxide synthase (eNOS was also assessed. Male Wistar rats were divided into four groups: sedentary-young (SE-Young, n=5, sedentary aged (SE-Aged, n=8, immersed-aged (IM-Aged, n=5, and exercise trained-aged (ET-Aged, 60 minutes/day and 5 days/week for 8 weeks, n=8 rats. The MAPs of all aged groups, SE-Aged, IM-Aged, and ET-Aged, were significantly higher than that of the SE-Young group. The regional cerebral blood flow (rCBF in the SE-Aged and IM-Aged was significantly decreased as compared to SE-Young groups. However, rCBF of ET-Aged group was significantly higher than that in the IM-Aged group (P<0.05. Moreover, the percentage of capillary vascularity (%CV and the levels of VEGF and eNOS in the ET-Aged group were significantly increased compared to the IM-Aged group (P<0.05. These results imply that exercise training could improve age-induced microvascular changes and hypoperfusion closely associated with the upregulation of VEGF and eNOS.

  5. Impairment of microcirculation in juvenile idiopathic arthritis - studies by nailfold videocapillaroscopy and correlation with serum levels of sICAM and VEGF.

    Directory of Open Access Journals (Sweden)

    Slawomir Chlabicz

    2009-01-01

    Full Text Available Impairment of vascular endothelium plays a key role in the pathogenesis of inflammatory diseases including juvenile idiopathic arthritis (JIA and atherosclerosis. We hypothesized that structural abnormalities of the smallest blood vessels (capillaries might exist and reflect endothelial dysfunction in children with JIA. Microcirculation was studied, by means of nailfold videocapillaroscopy with computer-associated image analysis, in 43 patients with JIA and compared with 20 healthy children. Moreover, capillaroscopic findings were correlated with the activity of the disease and the levels of serum biomarkers of endothelial injury, namely soluble intercellular adhesion molecule (sICAM and vascular endothelial growth factor (VEGF. We found that in JIA patients capillaries were significantly wider and longer than in healthy controls. Moreover, irregular capillaries and dilated subpapillary venous plexus were found significantly more frequently in JIA in comparison with the control group. Serum levels of sICAM and VEGF were significantly higher in JIA patients with capillary abnormalities than in JIA patients with normal capillaroscopy. Our study indicates that there are structural changes in the microcirculation of patients with JIA and that these changes might reflect endothelial injury. Whether capillaroscopy might have a role in early identification of JIA patients being at higher risk of atherosclerosis requires further studies.

  6. First attempts to combine capillary tubes with photocathodes

    CERN Document Server

    Peskov, Vladimir; Sokolova, T; Radionov, I

    1999-01-01

    We describe our efforts to combine glass capillary plates, operating as a gas amplification structure at approx 1 atm, with photocathodes sensitive to visible light. Such capillary tubes are a by-product of the manufacture of Microchannel Plates and are commercially available. Preliminary tests indicate that gas gains >10 sup 3 could be achieved without photon feedback. With two capillary plates in tandem (double-step multiplication) overall gains up to 10 sup 5 were possible at counting rate <100 Hz/mm sup 2. This approach may open new possibilities for detection of visible photons by gaseous detectors. Potential advantages are: high gains, large sensitive area, high granularity, and insensitivity to magnetic fields.

  7. Factors affecting the separation performance of proteins in capillary electrophoresis.

    Science.gov (United States)

    Zhu, Yueping; Li, Zhenqing; Wang, Ping; Shen, Lisong; Zhang, Dawei; Yamaguchi, Yoshinori

    2018-04-15

    Capillary electrophoresis (CE) is an effective tool for protein separation and analysis. Compared with capillary gel electrophoresis (CGE), non-gel sieving capillary electrophoresis (NGSCE) processes the superiority on operation, repeatability and automaticity. Herein, we investigated the effect of polymer molecular weight and concentration, electric field strength, and the effective length of the capillary on the separation performance of proteins, and find that (1) polymer with high molecular weight and concentration favors the separation of proteins, although concentrated polymer hinders its injection into the channel of the capillary due to its high viscosity. (2) The resolution between the adjacent proteins decreases with the increase of electric field strength. (3) When the effective length of the capillary is long, the separation performance improves at the cost of separation time. (4) 1.4% (w/v) hydroxyethyl cellulose (HEC), 100 V/cm voltage and 12 cm effective length offers the best separation for the proteins with molecular weight from 14,400 Da to 97,400 Da. Finally, we employed the optimal electrophoretic conditions to resolve Lysozyme, Ovalbumin, BSA and their mixtures, and found that they were baseline resolved within 15 min. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Capillary condensation of short-chain molecules.

    Science.gov (United States)

    Bryk, Paweł; Pizio, Orest; Sokolowski, Stefan

    2005-05-15

    A density-functional study of capillary condensation of fluids of short-chain molecules confined to slitlike pores is presented. The molecules are modeled as freely jointed tangent spherical segments with a hard core and with short-range attractive interaction between all the segments. We investigate how the critical parameters of capillary condensation of the fluid change when the pore width decreases and eventually becomes smaller than the nominal linear dimension of the single-chain molecule. We find that the dependence of critical parameters for a fluid of dimers and of tetramers on pore width is similar to that of the monomer fluid. On the other hand, for a fluid of chains consisting of a larger number of segments we observe an inversion effect. Namely, the critical temperature of capillary condensation decreases with increasing pore width for a certain interval of values of the pore width. This anomalous behavior is also influenced by the interaction between molecules and pore walls. We attribute this behavior to the effect of conformational changes of molecules upon confinement.

  9. Separation of oligopeptides, nucleobases, nucleosides and nucleotides using capillary electrophoresis/electrochromatography with sol–gel modified inner capillary wall

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Jana; Kofroňová, Olga; Benada, Oldřich; Král, V.; Mikšík, Ivan

    2017-01-01

    Roč. 1517, Sep 29 (2017), s. 185-194 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA15-01948S; GA MŠk(CZ) LO1509 Institutional support: RVO:67985823 ; RVO:61388971 Keywords : capillary electrochromatography (CEC) * open-tubular capillary electrochromatography (OT-CEC) * nucleo-compounds * oligopeptides * sol–gel methods * Porphyrin * scanning electron microscopy (SEM) Subject RIV: CB - Analytical Chemistry, Separation; CE - Biochemistry (MBU-M) OBOR OECD: Analytical chemistry; Biochemistry and molecular biology (MBU-M) Impact factor: 3.981, year: 2016

  10. Modeling capillary bridge dynamics and crack healing between surfaces of nanoscale roughness

    Science.gov (United States)

    Soylemez, Emrecan; de Boer, Maarten P.

    2017-12-01

    Capillary bridge formation between adjacent surfaces in humid environments is a ubiquitous phenomenon. It strongly influences tribological performance with respect to adhesion, friction and wear. Only a few studies, however, assess effects due to capillary dynamics. Here we focus on how capillary bridge evolution influences crack healing rates. Experimental results indicated a logarithmic decrease in average crack healing velocity as the energy release rate increases. Our objective is to model that trend. We assume that capillary dynamics involve two mechanisms: capillary bridge growth and subsequently nucleation followed by growth. We show that by incorporating interface roughness details and the presence of an adsorbed water layer, the behavior of capillary force dynamics can be understood quantitatively. We identify three important regimes that control the healing process, namely bridge growth, combined bridge growth and nucleation, and finally bridge nucleation. To fully capture the results, however, the theoretical model for nucleation time required an empirical modification. Our model enables significant insight into capillary bridge dynamics, with a goal of attaining a predictive capability for this important microelectromechanical systems (MEMS) reliability failure mechanism.

  11. Circulating endothelial cells as marker of endothelial damage in male hypogonadism.

    Science.gov (United States)

    Milardi, Domenico; Grande, Giuseppe; Giampietro, Antonella; Vendittelli, Francesca; Palumbo, Sara; Tartaglione, Linda; Marana, Riccardo; Pontecorvi, Alfredo; de Marinis, Laura; Zuppi, Cecilia; Capoluongo, Ettore

    2012-01-01

    Testosterone deficiency has become a frequently diagnosed condition in today's society affected by epidemic obesity, and is associated with cardiovascular risk. Recent studies have established the importance of altered vascular endothelium function in cardiovascular disease. The damage to the endothelium might also cause endothelial cell detachment, resulting in increased numbers of circulating endothelial cells (CEC) within the bloodstream. To evaluate whether hypogonadism could modify CEC count in peripheral bloodstream, we investigated peripheral blood CEC count using the CellSearch System, a semiautomatic method to accurately and reliably enumerate CECs, which are sorted based on a CD146(+), CD105(+), DAPI(+), CD45(-) phenotype, in a population of 20 patients with hypogonadism. The control group comprised 10 age- and sex-matched healthy participants. CEC count per milliliter was significantly increased in patients with hypogonadism vs the control group. In the group with hypogonadism, an inverse exponential correlation was present between testosterone levels and CEC count per milliliter. A direct linear correlation was present between waist circumference and CECs and between body mass index and CECs. The regression analysis showed that testosterone was the significant independent determinant of CECs. Our results underline that male hypogonadism is associated with endothelial dysfunction. The correlation between CEC and waist circumference underlines that visceral obesity may be synergically implicated in this regulation. Future studies are required to unveil the mechanisms involved in the pathogenesis of testosterone-induced endothelial disfunction, which may provide novel therapeutic targets to be incorporated in the management of hypogonadism.

  12. Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng\\/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5\\'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

  13. Endothelial progenitor cells in chronic obstructive pulmonary disease and emphysema

    Science.gov (United States)

    Tracy, Russell P.; Parikh, Megha A.; Hoffman, Eric A.; Shimbo, Daichi; Austin, John H. M.; Smith, Benjamin M.; Hueper, Katja; Vogel-Claussen, Jens; Lima, Joao; Gomes, Antoinette; Watson, Karol; Kawut, Steven; Barr, R. Graham

    2017-01-01

    Endothelial injury is implicated in the pathogenesis of COPD and emphysema; however the role of endothelial progenitor cells (EPCs), a marker of endothelial cell repair, and circulating endothelial cells (CECs), a marker of endothelial cell injury, in COPD and its subphenotypes is unresolved. We hypothesized that endothelial progenitor cell populations would be decreased in COPD and emphysema and that circulating endothelial cells would be increased. Associations with other subphenotypes were examined. The Multi-Ethnic Study of Atherosclerosis COPD Study recruited smokers with COPD and controls age 50–79 years without clinical cardiovascular disease. Endothelial progenitor cell populations (CD34+KDR+ and CD34+KDR+CD133+ cells) and circulating endothelial cells (CD45dimCD31+CD146+CD133-) were measured by flow cytometry. COPD was defined by standard spirometric criteria. Emphysema was assessed qualitatively and quantitatively on CT. Full pulmonary function testing and expiratory CTs were measured in a subset. Among 257 participants, both endothelial progenitor cell populations, and particularly CD34+KDR+ endothelial progenitor cells, were reduced in COPD. The CD34+KDR+CD133+ endothelial progenitor cells were associated inversely with emphysema extent. Both endothelial progenitor cell populations were associated inversely with extent of panlobular emphysema and positively with diffusing capacity. Circulating endothelial cells were not significantly altered in COPD but were inversely associated with pulmonary microvascular blood flow on MRI. There was no consistent association of endothelial progenitor cells or circulating endothelial cells with measures of gas trapping. These data provide evidence that endothelial repair is impaired in COPD and suggest that this pathological process is specific to emphysema. PMID:28291826

  14. Viscoelastic capillary flow: the case of whole blood

    Directory of Open Access Journals (Sweden)

    David Rabaud

    2016-07-01

    Full Text Available The dynamics of spontaneous capillary flow of Newtonian fluids is well-known and can be predicted by the Lucas-Washburn-Rideal (LWR law. However a wide variety of viscoelastic fluids such as alginate, xanthan and blood, does not exhibit the same Newtonian behavior.In this work we consider the Herschel-Bulkley (HB rheological model and Navier-Stokes equation to derive a generic expression that predicts the capillary flow of non-Newtonian fluids. The Herschel-Bulkley rheological model encompasses a wide variety of fluids, including the Power-law fluids (also called Ostwald fluids, the Bingham fluids and the Newtonian fluids. It will be shown that the proposed equation reduces to the Lucas-Washburn-Rideal law for Newtonian fluids and to the Weissenberg-Rabinowitsch-Mooney (WRM law for power-law fluids. Although HB model cannot reduce to Casson’s law, which is often used to model whole blood rheology, HB model can fit the whole blood rheology with the same accuracy.Our generalized expression for the capillary flow of non-Newtonian fluid was used to accurately fit capillary flow of whole blood. The capillary filling of a cylindrical microchannel by whole blood was monitored. The blood first exhibited a Newtonian behavior, then after 7 cm low shear stress and rouleaux formation made LWR fails to fit the data: the blood could not be considered as Newtonian anymore. This non-Newtonian behavior was successfully fit by the proposed equation.

  15. Activation of Endothelial Nitric Oxide (eNOS Occurs through Different Membrane Domains in Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Jason Tran

    Full Text Available Endothelial cells respond to a large range of stimuli including circulating lipoproteins, growth factors and changes in haemodynamic mechanical forces to regulate the activity of endothelial nitric oxide synthase (eNOS and maintain blood pressure. While many signalling pathways have been mapped, the identities of membrane domains through which these signals are transmitted are less well characterized. Here, we manipulated bovine aortic endothelial cells (BAEC with cholesterol and the oxysterol 7-ketocholesterol (7KC. Using a range of microscopy techniques including confocal, 2-photon, super-resolution and electron microscopy, we found that sterol enrichment had differential effects on eNOS and caveolin-1 (Cav1 colocalisation, membrane order of the plasma membrane, caveolae numbers and Cav1 clustering. We found a correlation between cholesterol-induced condensation of the plasma membrane and enhanced high density lipoprotein (HDL-induced eNOS activity and phosphorylation suggesting that cholesterol domains, but not individual caveolae, mediate HDL stimulation of eNOS. Vascular endothelial growth factor (VEGF-induced and shear stress-induced eNOS activity was relatively independent of membrane order and may be predominantly controlled by the number of caveolae on the cell surface. Taken together, our data suggest that signals that activate and phosphorylate eNOS are transmitted through distinct membrane domains in endothelial cells.

  16. Development and characterization of a spheroidal coculture model of endothelial cells and fibroblasts for improving angiogenesis in tissue engineering

    DEFF Research Database (Denmark)

    Wenger, Andreas; Kowalewski, Nadja; Stahl, Andreas

    2005-01-01

    Neovascularization is a critical step in tissue engineering applications since implantation of voluminous grafts without sufficient vascularity results in hypoxic cell death of central tissues. We have developed a three-dimensional spheroidal coculture system consisting of human umbilical vein...... endothelial cells (HUVECs) and human primary fibroblasts (hFBs) to improve angiogenesis in tissue engineering applications. Morphological analysis of cryosections from HUVEC/hFB cospheroids revealed a characteristic temporal and spatial organization with HUVECs located in the center of the cospheroid...... to the formation of heterogenic cell contacts between HUVECs and hFBs within the cospheroid. The model system introduced in this study is suitable for the development of a preformed lumenized capillary-like network ex vivo and may therefore be useful for improving angiogenesis in in vivo tissue engineering...

  17. Intramuscular capillary-type hemangioma: radiologic-pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Sabri; Alomari, Ahmad I.; Chaudry, Gulraiz [Boston Children' s Hospital and Harvard Medical School, Vascular Anomalies Center, Boston, MA (United States); Boston Children' s Hospital and Harvard Medical School, Division of Vascular and Interventional Radiology, Boston, MA (United States); Kozakewich, Harry P. [Boston Children' s Hospital and Harvard Medical School, Vascular Anomalies Center, Boston, MA (United States); Boston Children' s Hospital and Harvard Medical School, Department of Pathology, Boston, MA (United States); Fishman, Steven J. [Boston Children' s Hospital and Harvard Medical School, Vascular Anomalies Center, Boston, MA (United States); Boston Children' s Hospital and Harvard Medical School, Department of Surgery, Boston, MA (United States); Mulliken, John B. [Boston Children' s Hospital and Harvard Medical School, Vascular Anomalies Center, Boston, MA (United States); Boston Children' s Hospital and Harvard Medical School, Department of Plastic and Oral Surgery, Boston, MA (United States)

    2014-05-15

    Infantile hemangiomas demonstrate a pattern of proliferative growth in infancy followed by a slow phase of involution. In contrast a rare type of vascular tumor, intramuscular capillary-type hemangioma, usually presents beyond the period of infancy with nonspecific symptoms and no evidence of involution. The purpose of this study was to characterize the clinical, imaging, histopathological characteristics and management of intramuscular capillary-type hemangioma. We performed a retrospective review of a 20-year period to identify children diagnosed with intramuscular capillary-type hemangioma. Patient demographics, imaging and histopathological findings were recorded. We included 18 children (10 boys, 8 girls) with histologically proven intramuscular capillary-type hemangioma - and adequate imaging. The mean age at presentation was 8.1 years (range 1 day to 19 years). Twelve lesions involved muscles of the extremities, 4 were located in the trunk and 2 were in the head and neck. MRI had been performed in all children and demonstrated a soft-tissue mass with flow voids, consistent with fast flow. The lesion was well-circumscribed in 16 children and intralesional fat was seen in 14. Doppler US demonstrated a heterogeneous lesion, predominantly isoechoic to surrounding muscle, with enlarged arterial feeders. Enlarged feeding arteries, inhomogeneous blush and lack of arteriovenous shunting were noted on angiography (n = 5). The most common histopathological findings were lobules of capillaries with plump endothelium and at least some adipose tissue. The lesions were excised in six children. Two children were lost to follow-up. In the remaining 10, follow-up MRI studies ranging from 3 months to 10 years showed that the lesion enlarged in proportion to the child (n = 7), demonstrated slow growth (n = 2) or remained stable (n = 1). There was no change in imaging characteristics on follow-up. Intramuscular capillary-type hemangioma is a rare benign vascular tumor of

  18. Evaluation of Tillandsia capillaris Ruiz amd Pav. f. capillaris as biomonitor of atmospheric pollution in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Pignata, M.L. [Univ. Nacional de Cordoba, Cordoba (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales]|[Instituto Multidisciplinario de Biologia Vegetal (IMBIV-UNC), Cordoba (Argentina); Wannaz, E.D.; Martinez, M.S.; Caminotti, G. [Univ. Nacional de Cordoba, Cordoba (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales

    2002-07-01

    The behaviour of Tillandsia capillaris Ruiz and Pav. f. capillaris, when exposed to atmospheric pollutants, was assessed by measuring chemical parameters indicating foliar damage and the contents of some heavy metals. Samples were transplanted to three sites in the City of Cordoba and were collected back after 15, 30, 60 and 90 days of exposure. At the same time, samples coming from the collection site were analyzed for each of said exposure times. Chlorophylls, hydroperoxy conjugated dienes, water contents, malondialdehyde, sulfur, Cu, Pb, Ni, Co, Mn, Zn and Fe were measured in the samples. A Foliar Damage Index was calculated from some of these parameters. (orig.)

  19. Intracerebral Capillary Hemangioma: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Youn, In Young; Kim, Jae Kyun; Byun, Jun Soo [Dept. of Radiology, Chung Ang University Medical Center, Chung Ang University College of Medicine, Seoul (Korea, Republic of); Park, Eon Sub [Dept. of Radiology, Chung Ang University Medical Center, Chung Ang University College of Medicine, Seoul (Korea, Republic of)

    2012-01-15

    Intracerebral capillary hemangiomas are very rare benign vascular tumors that mostly occur during infancy. We described a 69-year-old man with generalized tonic-clonic seizures who was diagnosed with an intracranial mass. Multidetector computed tomography, magnetic resonance imaging and digital subtraction angiography studies were performed for evaluation of brain, and there was a well-enhancing mass found in the right temporal lobe without a definite feeding vessel. The patient underwent surgery and the pathologic examination demonstrated marked proliferation of small vessels with a lobular pattern in the brain parenchyma, which was confirmed to be capillary hemangioma.

  20. Heterodimerization with vascular endothelial growth factor receptor-2 (VEGFR-2) is necessary for VEGFR-3 activity

    International Nuclear Information System (INIS)

    Alam, Antoine; Herault, Jean-Pascal; Barron, Pauline; Favier, Benoit; Fons, Pierre; Delesque-Touchard, Nathalie; Senegas, Isabelle; Laboudie, Patricia; Bonnin, Jacques; Cassan, Cecile; Savi, Pierre; Ruggeri, Bruce; Carmeliet, Peter; Bono, Francoise; Herbert, Jean-Marc

    2004-01-01

    VEGFR-3 is essential for vascular development and maintenance of lymphatic vessel's integrity. Little is known about its cooperative effect with other receptors of the same family. Contrary to VEGFR-2, stimulation of VEGFR-3 by VEGF-C and -D failed to enhance its phosphorylation either in HEK293T or in PAE cells. These ligands were unable to induce angiogenesis of PAEC expressing VEGFR-3 alone. In the presence of VEGFR-2, VEGF-C and -D induced heterodimerization of VEGFR-3 with VEGFR-2. This heterodimerization was associated with enhanced VEGFR-3 phosphorylation and subsequent cellular responses as evidenced by the formation of capillary-like structures in PAE cells and proliferation of primary human endothelial cells expressing both receptors. Taken together, these results show for the first time that VEGFR-3 needs to be associated to VEGFR-2 to induce ligand-dependent cellular responses

  1. Uptake of low density lipoproteins by the hamster lung. Interactions with capillary endothelium

    International Nuclear Information System (INIS)

    Nistor, A.; Simionescu, M.

    1986-01-01

    The mechanism by which the circulating low density lipoproteins (LDL) contribute to the lung surfactant cholesterol was investigated by perfusing the hamster lung in situ with LDL either radiolabeled or coupled to gold, or both. Part of [ 125 I]-LDL and [ 3 H]-cholesterol LDL were taken up by a specific process which was time- and concentration-dependent and reached saturation within 20 to 30 min of perfusion. Competition experiments and removal of receptor-bound LDL by heparin suggested that about 50% of LDL uptake is receptor-independent. Experiments using double labeled LDL showed a preferential uptake of 3 H-cholesterol versus 125 I by the lung both in situ and in vivo. LDL-gold particles (LDL-Au), recirculated through the isolated lung, bound to the endothelial luminal plasma membrane and to features potentially involved in receptor-mediated endocytosis (coated pits, coated vesicles, lysosomelike structures) and in transcytosis (plasmalemmal vesicles). The results suggest that LDL uptake by the lung takes place by both receptor-mediated and receptor-independent mechanisms. Cholesterol may be in part transferred to the lung without the apoprotein moiety; the alveolar capillary endothelium appears to be the first monitor of this complex process

  2. Potential of capillary electrophoresis for the profiling of propolis

    NARCIS (Netherlands)

    Hilhorst, M.J; Somsen, G.W; de Jong, G.J.

    1998-01-01

    The usefulness of capillary electrophoresis (CE) with diode array detection for the profiling of Propolis, a hive product, is investigated. Water extracts of Propolis were analyzed with both capillary zone electrophoresis (CZE) at pH 7.0 and 9.3, and micellar electrokinetic chromatography (MEKC)

  3. Microvascular remodelling in preeclampsia: quantifying capillary rarefaction accurately and independently predicts preeclampsia.

    Science.gov (United States)

    Antonios, Tarek F T; Nama, Vivek; Wang, Duolao; Manyonda, Isaac T

    2013-09-01

    Preeclampsia is a major cause of maternal and neonatal mortality and morbidity. The incidence of preeclampsia seems to be rising because of increased prevalence of predisposing disorders, such as essential hypertension, diabetes, and obesity, and there is increasing evidence to suggest widespread microcirculatory abnormalities before the onset of preeclampsia. We hypothesized that quantifying capillary rarefaction could be helpful in the clinical prediction of preeclampsia. We measured skin capillary density according to a well-validated protocol at 5 consecutive predetermined visits in 322 consecutive white women, of whom 16 subjects developed preeclampsia. We found that structural capillary rarefaction at 20-24 weeks of gestation yielded a sensitivity of 0.87 with a specificity of 0.50 at the cutoff of 2 capillaries/field with the area under the curve of the receiver operating characteristic value of 0.70, whereas capillary rarefaction at 27-32 weeks of gestation yielded a sensitivity of 0.75 and a higher specificity of 0.77 at the cutoff of 8 capillaries/field with area under the curve of the receiver operating characteristic value of 0.82. Combining capillary rarefaction with uterine artery Doppler pulsatility index increased the sensitivity and specificity of the prediction. Multivariable analysis shows that the odds of preeclampsia are increased in women with previous history of preeclampsia or chronic hypertension and in those with increased uterine artery Doppler pulsatility index, but the most powerful and independent predictor of preeclampsia was capillary rarefaction at 27-32 weeks. Quantifying structural rarefaction of skin capillaries in pregnancy is a potentially useful clinical marker for the prediction of preeclampsia.

  4. The free-jet expansion from a capillary source

    International Nuclear Information System (INIS)

    Miller, D.R.; Fineman, M.A.; Murphy, H.

    1985-01-01

    This paper presents a comparison of the free-jet expansions originating from an orifice and a capillary by measuring the terminal gas properties. Time-of-flight and intensity data are reported for pure gases (He, Ar, CO 2 ) and mixtures of CO 2 /He, together with condensed dimer intensities for Ar and Co 2 . Pitot tube data are reported for N 2 . The results suggest that the free-jet expansions are nearly the same, provided the capillary is modeled as a non-isentropic Fanno flow process. The Fanno flow is slightly non-adiabatic, which complicates the analysis. Only the condensation kinetics appear strongly sensitive to the differences in the initial conditions for the supersonic expansion; any kinetic process relaxing near the capillary orifice exit would be affected

  5. Delayed post-traumatic capillary haemangioma of the spine.

    Science.gov (United States)

    Shilton, Hamish; Goldschlager, Tony; Kelman, Anthony; Xenos, Chris

    2011-11-01

    Capillary haemangiomas are well-circumscribed aggregates of closely packed, thin-walled capillaries separated by connective tissue stroma. In subcutaneous tissue they are termed pyogenic granuloma and commonly follow trauma. They rarely occur in the spine. We present a 43-year-old woman with a 6-week history of thoracic myelopathy and back pain on a background of T7 and T8 vertebral compression fractures from a motor vehicle accident 10 years previously. MRI demonstrated a posteriorly based extradural homogeneously enhancing mass at this level. The lesion was resected and diagnosed histopathologically as a capillary haemangioma. The patient's symptoms resolved and she made an uneventful recovery. The literature is reviewed and the possible pathogenesis is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. The Effect of Ion Motion on Laser-Driven Plasma Wake in Capillary

    International Nuclear Information System (INIS)

    Zhou Suyun; Li Yanfang; Chen Hui

    2016-01-01

    The effect of ion motion in capillary-guided laser-driven plasma wake is investigated through rebuilding a two-dimensional analytical model. It is shown that laser pulse with the same power can excite more intense wakefield in the capillary of a smaller radius. When laser intensity exceeds a critical value, the effect of ion motion reducing the wakefield rises, which becomes significant with a decrease of capillary radius. This phenomenon can be attributed to plasma ions in smaller capillary obtaining more energy from the plasma wake. The dependence of the difference value between maximal scalar potential of wake for two cases of ion rest and ion motion on the radius of the capillary is discussed. (paper)

  7. New type of capillary for use as ion beam collimator and air-vacuum interface

    Energy Technology Data Exchange (ETDEWEB)

    Stoytschew, V., E-mail: valostoytschew@hotmail.com [Ruđer Bošković Institute, Bijenicka Cesta 54, 10000 Zagreb (Croatia); Schulte-Borchers, M. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, CH-8093 Zurich (Switzerland); Božičević Mihalića, Iva [Ruđer Bošković Institute, Bijenicka Cesta 54, 10000 Zagreb (Croatia); Perez, R.D. [FaMAF, Universidad Nacional de Córdoba, (5000) Ciudad Universitaria, Córdoba (Argentina)

    2016-08-01

    Glass capillaries offer a unique way to combine small diameter ion beam collimation with an air-vacuum interface for ambient pressure ion beam applications. Usually they have an opening diameter of a few microns, limiting the air inflow sufficiently to maintain stable conditions on the vacuum side. As the glass capillaries generally are quite thin and fragile, handling of the capillary in the experiment becomes difficult. They also introduce an X-ray background produced by the capillary wall material, which has to be shielded or subtracted from the data for Particle Induced X-ray Emission (PIXE) applications. To overcome both drawbacks, a new type of conical glass capillary has been developed. It has a higher wall thickness eliminating the low energy X-ray background produced by common capillaries and leading to a more robust lens. The results obtained in first tests show, that this new capillary is suitable for ion beam collimation and encourage further work on the capillary production process to provide thick wall capillaries with an outlet diameter in the single digit micro- or even nanometre range.

  8. Capillary-induced crack healing between surfaces of nanoscale roughness.

    Science.gov (United States)

    Soylemez, Emrecan; de Boer, Maarten P

    2014-10-07

    Capillary forces are important in nature (granular materials, insect locomotion) and in technology (disk drives, adhesion). Although well studied in equilibrium state, the dynamics of capillary formation merit further investigation. Here, we show that microcantilever crack healing experiments are a viable experimental technique for investigating the influence of capillary nucleation on crack healing between rough surfaces. The average crack healing velocity, v̅, between clean hydrophilic polycrystalline silicon surfaces of nanoscale roughness is measured. A plot of v̅ versus energy release rate, G, reveals log-linear behavior, while the slope |d[log(v̅)]/dG| decreases with increasing relative humidity. A simplified interface model that accounts for the nucleation time of water bridges by an activated process is developed to gain insight into the crack healing trends. This methodology enables us to gain insight into capillary bridge dynamics, with a goal of attaining a predictive capability for this important microelectromechanical systems (MEMS) reliability failure mechanism.

  9. In Vivo Microscopy Reveals Extensive Embedding of Capillaries within the Sarcolemma of Skeletal Muscle Fibers

    Science.gov (United States)

    Glancy, Brian; Hsu, Li-Yueh; Dao, Lam; Bakalar, Matthew; French, Stephanie; Chess, David J.; Taylor, Joni L.; Picard, Martin; Aponte, Angel; Daniels, Mathew P.; Esfahani, Shervin; Cushman, Samuel; Balaban, Robert S.

    2013-01-01

    Objective To provide insight into mitochondrial function in vivo, we evaluated the 3D spatial relationship between capillaries, mitochondria, and muscle fibers in live mice. Methods 3D volumes of in vivo murine Tibialis anterior muscles were imaged by multi-photon microscopy (MPM). Muscle fiber type, mitochondrial distribution, number of capillaries, and capillary-to-fiber contact were assessed. The role of myoglobin-facilitated diffusion was examined in myoglobin knockout mice. Distribution of GLUT4 was also evaluated in the context of the capillary and mitochondrial network. Results MPM revealed that 43.6 ± 3.3% of oxidative fiber capillaries had ≥ 50% of their circumference embedded in a groove in the sarcolemma, in vivo. Embedded capillaries were tightly associated with dense mitochondrial populations lateral to capillary grooves and nearly absent below the groove. Mitochondrial distribution, number of embedded capillaries, and capillary-to-fiber contact were proportional to fiber oxidative capacity and unaffected by myoglobin knockout. GLUT4 did not preferentially localize to embedded capillaries. Conclusions Embedding capillaries in the sarcolemma may provide a regulatory mechanism to optimize delivery of oxygen to heterogeneous groups of muscle fibers. We hypothesize that mitochondria locate to paravascular regions due to myofibril voids created by embedded capillaries, not to enhance the delivery of oxygen to the mitochondria. PMID:25279425

  10. Influence of the capillary on the ignition of the transient spark discharge

    International Nuclear Information System (INIS)

    Gerling, T; Hoder, T; Brandenburg, R; Bussiahn, R; Weltmann, K-D

    2013-01-01

    A self-pulsing negative dc discharge in argon generated in a needle-to-plane geometry at open atmosphere is investigated. Additionally, the needle electrode can be surrounded by a quartz capillary. It is shown that the relative position of the capillary end to the needle tip strongly influences the discharge inception and its spatio-temporal dynamics. Without the capillary for the selected working parameters a streamer corona is ignited, but when the capillary surrounds the needle, the transient spark (TS) discharge is ignited after a pre-streamer (PS) occurs. The time between PS and TS discharge depends on the relative capillary end position. The existence of the PS is confirmed by electro-optical characterization. Furthermore, spectrally and spatio-temporally resolved cross-correlation spectroscopy is applied to show the most active region of pre-phase emission activity as indicators for high local electric field strength. The results indicate that with a capillary in place, the necessary energy input of the pre-phase into the system is mainly reduced by additional electrical fields at the capillary edge. Even such a small change as a shift of dielectric surface close to the plasma largely changes the energy balance in the system. (paper)

  11. Evaluation and management of Periocular Capillary Hemangioma: A review

    International Nuclear Information System (INIS)

    Al-Motowa, Saeed A.; Chaudhry, Imtiaz A.

    2006-01-01

    To review the salient features of periocular capillary hemangioma, provide the ophthalmologist with clinical, diagnostic and histological features characteristic of the tumor and discuss various methods of management. Methods were literature review of periocular capillary hemangioma, diagnostic evaluation with emphasis on treatment through the presentation of illustrative clinical cases. Capillary hemangioma is the most common benign vascular tumor found on the head and neck area including eyelids and orbit. The lesion typically manifests within the first few weeks of life, grows rapidly in the first year during the proliferative phase, then invariably and slowly regresses over the next 4 to 5 years during the involutional phase. The lesion may resolve without leaving any significant cosmetic sequelae in vast majority of patients, however, the functional defects in the form of amblyopia, squint, facial disfigurement and rarely optic atrophy may persist long after complete resolution of the tumor. The diagnosis of the capillary hemangioma requires a combination of clinical and imaging studies such as ultrasonography, computerized tomography, magnetic resonance imaging and angiography in selected cases. With the advent of less invasive diagnostic techniques, the need for biopsy in capillary hemangioma has decreased. Nevertheless, it should be differentiated from other periocular tumors such as rhabdomyosarcoma, lymphangioma, chloroma, neuroblastoma, orbital cyst, and orbital cellulites. Treatment is indicated to prevent amblyopia or cosmetic disfigurement. If indicated, intra-lesional corticosteroids may be used to enhance resolution of the tumor. Other forms of treatment tried with variable success include systematic and topical corticosteroids, radiation, surgical excision and intravenous embolization of the tumor. Indecent years, laser ablation of the tumor has been found effective in some cases. Interferon-u has been utilized effectively in cases of capillary

  12. Descemet Stripping Automated Endothelial Keratoplasty for Endothelial Dysfunction in Xeroderma Pigmentosum: A Clinicopathological Correlation and Review of Literature.

    Science.gov (United States)

    Vira, Divya; Fernandes, Merle; Mittal, Ruchi

    2016-07-01

    Xeroderma pigmentosum (XP) mainly affects the ocular surface; however, endothelial damage may also occur. We would like to report changes in the endothelial-Descemet layer and review the literature on similar findings in patients with XP, including the role of Descemet stripping automated endothelial keratoplasty (DSAEK) in the management of a 21-year-old man who presented with nonresolving corneal edema in the right eye after excision biopsy for conjunctival intraepithelial neoplasia. His best-corrected visual acuity (BCVA) was 20/200 in the right eye and 20/20 in the left eye. On general examination, there was patchy hyperpigmentation of the exposed areas of skin suggestive of XP. On examination of the right eye, there was stromal edema involving the exposed half of cornea. The left eye appeared normal. Pachymetry readings were 860 and 600 μm in the right and left eye, respectively. Descemet stripping automated endothelial keratoplasty was performed for endothelial dysfunction and the stripped endothelium, and Descemet membrane (DM) was sent for histopathologic evaluation. Postoperatively, the donor lenticule was well apposed and the overlying stromal edema resolved. The patient achieved a BCVA of 20/30 in the right eye without progression of corneal scarring at 1-year follow-up. In the meanwhile, however, the left eye developed corneal edema. Histopathology revealed gross attenuation of endothelial cells with uniform thickness of the DM. Corneal endothelial dysfunction in XP is amenable to treatment with DSAEK.

  13. Transcapillary permeability and subendothelial distribution of endothelial and amniotic fluid insulin-like growth factor binding proteins in the rat heart

    International Nuclear Information System (INIS)

    Bar, R.S.; Clemmons, D.R.; Boes, M.; Busby, W.H.; Booth, B.A.; Dake, B.L.; Sandra, A.

    1990-01-01

    Insulin-like growth factor (IGF) binding proteins (IGFBP) were purified from conditioned media of cultured bovine endothelial cells (ECBP) and from human amniotic fluid (IGFBP-1), and then labeled by radioiodination. 125I-ECBP and 125I-IGFBP-1 were perfused through isolated beating rat hearts for 1 and 5 min, and the hearts fixed and analyzed for 125I-BP content and distribution. One to 4% of the perfused 125I-ECBP and 125I-IGFBP-1 crossed the capillary boundary. The ECBPs predominantly localized as intact 125I-BP in connective tissue elements of the heart with less 125I-BP in cardiac muscle. The ratio of 125I-ECBP in connective tissue: muscle (normalized to percent vol of these compartments) was greater than or equal to 10:1. In contrast, the IGFBP-1 had a greater affinity for cardiac muscle with ratios of 125I-IGFBP-1 in connective tissue:muscle of approximately 1:2. When 125I-IGF-I, in the absence of any BPs, was perfused through the hearts approximately 3-5% left the microcirculation and was found in subendothelial tissues. 125I-IGF-I localized primarily to cardiac muscle with a distribution of connective tissue:cardiac muscle of about 1:3. The findings in the isolated perfused heart were confirmed in intact animals. After 125I-IGFBP-1 was injected into anesthetized rats and allowed to circulate for 5 min, substantial radioactivity was associated with the heart. As in the isolated heart, the IGFBP-1 preferentially localized to cardiac muscle with a connective tissue:cardiac muscle ratio of 1:3. We conclude that IGFBPs produced by endothelial cells and the IGFBP-1 contained in amniotic fluid can cross the capillary boundaries of the rat heart, and that the ECBPs preferentially localize in connective tissue elements of the myocardium, whereas IGFBP-1 predominantly localizes in cardiac muscle

  14. Strategies to reverse endothelial progenitor cell dysfunction in diabetes.

    Science.gov (United States)

    Petrelli, Alessandra; Di Fenza, Raffaele; Carvello, Michele; Gatti, Francesca; Secchi, Antonio; Fiorina, Paolo

    2012-01-01

    Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

  15. Strategies to Reverse Endothelial Progenitor Cell Dysfunction in Diabetes

    Directory of Open Access Journals (Sweden)

    Alessandra Petrelli

    2012-01-01

    Full Text Available Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial, their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs. Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

  16. Self-Assembly of Microscale Parts through Magnetic and Capillary Interactions

    Directory of Open Access Journals (Sweden)

    Madan Dubey

    2011-03-01

    Full Text Available Self-assembly is a promising technique to overcome fundamental limitations with integrating, packaging, and general handling of individual electronic-related components with characteristic lengths significantly smaller than 1 mm. Here we describe the use of magnetic and capillary forces to self-assemble 280 µm sized silicon building blocks into interconnected structures which approach a three-dimensional crystalline configuration. Integrated permanent magnet microstructures provided magnetic forces, while a low-melting-point solder alloy provided capillary forces. A finite element model of forces between the magnetic features demonstrated the utility of magnetic forces at this size scale. Despite a slight departure from designed dimensions in the actual fabricated parts, the combination of magnetic and capillary forces improved the assembly yield to 8%, over approximately 0.1% achieved previously with capillary forces alone.

  17. Reduced Ang2 expression in aging endothelial cells.

    Science.gov (United States)

    Hohensinner, P J; Ebenbauer, B; Kaun, C; Maurer, G; Huber, K; Wojta, J

    2016-06-03

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Endothelial Protein C–Targeting Liposomes Show Enhanced Uptake and Improved Therapeutic Efficacy in Human Retinal Endothelial Cells

    DEFF Research Database (Denmark)

    Arta, Anthoula; Eriksen, Anne Z.; Melander, Fredrik

    2018-01-01

    PURPOSE. To determine whether human retinal endothelial cells (HRECs) express the endothelial cell protein C receptor (EPCR) and to realize its potential as a targeting moiety by developing novel single and dual corticosteroid–loaded functionalized liposomes that exhibit both enhanced uptake by H...... of cell tube formations in contrast to nontargeting liposomes. CONCLUSIONS. We show that HRECs express EPCR and this receptor could be a promising nanomedicine target in ocular diseases where the endothelial barrier of the retina is compromised....

  19. Oxidative stress induced pulmonary endothelial cell proliferation is ...

    African Journals Online (AJOL)

    Cellular hyper-proliferation, endothelial dysfunction and oxidative stress are hallmarks of the pathobiology of pulmonary hypertension. Indeed, pulmonary endothelial cells proliferation is susceptible to redox state modulation. Some studies suggest that superoxide stimulates endothelial cell proliferation while others have ...

  20. Simulation and application of micro X-ray fluorescence based on an ellipsoidal capillary

    Science.gov (United States)

    Yang, Jing; Li, Yude; Wang, Xingyi; Zhang, Xiaoyun; Lin, Xiaoyan

    2017-06-01

    A micro X-ray fluorescence setup was presented, based on an ellipsoidal capillary and a traditional laboratorial X-ray source. Using Ray-tracing principle, we have simulated the transmission path of X-ray beam in the ellipsoidal capillary and designed the optimal parameters of the ellipsoidal capillary for the micro X-ray fluorescence setup. We demonstrate that ellipsoidal capillary is well suited as condenser for the micro X-ray fluorescence based on traditional laboratorial X-ray source. Furthermore, we obtain the 2D mapping image of the leaf blade sample by using the ellipsoidal capillary we designed.

  1. Quantitative analysis by microchip capillary electrophoresis – current limitations and problem-solving strategies

    NARCIS (Netherlands)

    Revermann, T.; Götz, S.; Künnemeyer, Jens; Karst, U.

    2008-01-01

    Obstacles and possible solutions for the application of microchip capillary electrophoresis in quantitative analysis are described and critically discussed. Differences between the phenomena occurring during conventional capillary electrophoresis and microchip-based capillary electrophoresis are

  2. Endothelial glycocalyx on brain endothelial cells is lost in experimental cerebral malaria

    DEFF Research Database (Denmark)

    Hempel, Casper; Hyttel, Poul; Kurtzhals, Jørgen Al

    2014-01-01

    We hypothesized that the glycocalyx, which is important for endothelial integrity, is lost in severe malaria. C57BL/6 mice were infected with Plasmodium berghei ANKA, resulting in cerebral malaria, or P. chabaudi AS, resulting in uncomplicated malaria. We visualized the glycocalyx with transmission...... electron microscopy and measured circulating glycosaminoglycans by dot blot and ELISA. The glycocalyx was degraded in brain vasculature in cerebral and to a lesser degree uncomplicated malaria. It was affected on both intact and apoptotic endothelial cells. Circulating glycosaminoglycan levels suggested...

  3. Targeted drug delivery to the brain using magnetic nanoparticles.

    Science.gov (United States)

    Thomsen, Louiza Bohn; Thomsen, Maj Schneider; Moos, Torben

    2015-01-01

    Brain capillary endothelial cells denote the blood-brain barrier (BBB), and conjugation of nanoparticles with antibodies that target molecules expressed by these endothelial cells may facilitate their uptake and transport into the brain. Magnetic nanoparticles can be encapsulated in liposomes and carry large molecules with therapeutic potential, for example, siRNA, cDNA and polypeptides. An additional approach to enhance the transport of magnetic nanoparticles across the BBB is the application of extracranially applied magnetic force. Stepwise targeting of magnetic nanoparticles to brain capillary endothelial cells followed by transport through the BBB using magnetic force may prove a novel mechanism for targeted therapy of macromolecules to the brain.

  4. The endothelial border to health

    DEFF Research Database (Denmark)

    Hansen, Nina Wærling; Hansen, Anker Jon; Sams, Anette

    2017-01-01

    player for maintenance of health and for development of a number of diseases. Endothelial dysfunction is known to be an important component of type 2 diabetes, but is also assumed to be involved in many other diseases, for example, rheumatoid arthritis, inflammatory bowel disease, asthma...... extracellular proteins form epitopes for potential specific antibody formation upon interactions with reducing sugars. This paper reviews the endothelial metabolism, biology, inflammatory processes, physical barrier functions, and summarizes evidence that although stochastic in nature, endothelial responses...... to hyperglycemia are major contributors to disease pathophysiology. We present molecular and mechanistic evidence that both biological and physical barriers, protein function, specific immunity, and inflammatory processes are compromised by hyperglycemic events and thus, hyperglycemic events alone should...

  5. Qualitative and quantitative assessment of nailfold capillaries by capillaroscopy in healthy volunteers.

    Science.gov (United States)

    Hoerth, Christian; Kundi, Michael; Katzenschlager, Reinhold; Hirschl, Mirko

    2012-01-01

    Nailfold capillaroscopy (NVC) is a diagnostic tool particularly useful in the differential diagnosis of rheumatic and connective tissue diseases. Although successfully applied since many years, little is known about prevalence and distribution of NVC changes in healthy individuals. NVC was performed in 120 individuals (57 men and 63 women; age 18 to 70 years) randomly selected according to predefined age and sex strata. Diseases associated with NVC changes were excluded. The nailfolds of eight fingers were assessed according to standardized procedures. A scoring system was developed based on the distribution of the number of morphologically deviating capillaries, microhaemorrhages, and capillary density. Only 18 individuals (15 %) had no deviation in morphology, haemorrhages, or capillary density on any finger. Overall 67 % had morphological changes, 48 % had microhaemorrhages, and 40 % of volunteers below 40 years of age and 18 % above age 40 had less than 8 capillaries/mm. Among morphological changes tortous (43 %), ramified (47 %), and bushy capillaries (27 %) were the most frequently altered capillary types. A semiquantitative scoring system was developed in such a way that a score above 1 indicates an extreme position (above the 90th percentile) in the distribution of scores among healthy individuals. Altered capillaries occur frequently among healthy individuals and should be interpreted as normal unless a suspicious increase in their frequency is determined by reference to the scoring system. Megacapillaries and diffuse loss of capillaries were not found and seem to be of specific diagnostic value.

  6. Assessing the permeability of engineered capillary networks in a 3D culture.

    Directory of Open Access Journals (Sweden)

    Stephanie J Grainger

    Full Text Available Many pathologies are characterized by poor blood vessel growth and reduced nutrient delivery to the surrounding tissue, introducing a need for tissue engineered blood vessels. Our lab has developed a 3D co-culture method to grow interconnected networks of pericyte-invested capillaries, which can anastamose with host vasculature following implantation to restore blood flow to ischemic tissues. However, if the engineered vessels contain endothelial cells (ECs that are misaligned or contain wide junctional gaps, they may function improperly and behave more like the pathologic vessels that nourish tumors. The purpose of this study was to test the resistance to permeability of these networks in vitro, grown with different stromal cell types, as a metric of vessel functionality. A fluorescent dextran tracer was used to visualize transport across the endothelium and the pixel intensity was quantified using a customized MATLAB algorithm. In fibroblast-EC co-cultures, the dextran tracer easily penetrated through the vessel wall and permeability was high through the first 5 days of culture, indicative of vessel immaturity. Beyond day 5, dextran accumulated at the periphery of the vessel, with very little transported across the endothelium. Quantitatively, permeability dropped from initial levels of 61% to 39% after 7 days, and to 7% after 2 weeks. When ECs were co-cultured with bone marrow-derived mesenchymal stem cells (MSCs or adipose-derived stem cells (AdSCs, much tighter control of permeability was achieved. Relative to the EC-fibroblast co-cultures, permeabilities were reduced 41% for the EC-MSC co-cultures and 50% for the EC-AdSC co-cultures after 3 days of culture. By day 14, these permeabilities decreased by 68% and 77% over the EC-fibroblast cultures. Co-cultures containing stem cells exhibit elevated VE-cadherin levels and more prominent EC-EC junctional complexes when compared to cultures containing fibroblasts. These data suggest the stromal

  7. Capillary waves with surface viscosity

    Science.gov (United States)

    Shen, Li; Denner, Fabian; Morgan, Neal; van Wachem, Berend; Dini, Daniele

    2017-11-01

    Experiments over the last 50 years have suggested a correlation between the surface (shear) viscosity and the stability of a foam or emulsion. With recent techniques allowing more accurate measurements of the elusive surface viscosity, we examine this link theoretically using small-amplitude capillary waves in the presence of the Marangoni effect and surface viscosity modelled via the Boussinesq-Scriven model. The surface viscosity effect is found to contribute a damping effect on the amplitude of the capillary wave with subtle differences to the effect of the convective-diffusive Marangoni transport. The general wave dispersion is augmented to take into account the Marangoni and surface viscosity effects, and a first-order correction to the critical damping wavelength is derived. The authors acknowledge the financial support of the Shell University Technology Centre for fuels and lubricants.

  8. Delivery of small interfering RNA for inhibition of endothelial cell apoptosis by hypoxia and serum deprivation

    International Nuclear Information System (INIS)

    Cho, Seung-Woo; Hartle, Lauren; Son, Sun Mi; Yang, Fan; Goldberg, Michael; Xu, Qiaobing; Langer, Robert; Anderson, Daniel G.

    2008-01-01

    RNA interference (RNAi) for anti-angiogenic or pro-apoptotic factors in endothelial cells (ECs) has great potential for the treatment of ischemic diseases by promoting angiogenesis or inhibiting apoptosis. Here, we report the utility of small interfering RNA (siRNA) in inhibiting EC apoptosis induced by tumor necrosis factor-α (TNF-α). siRNA was designed and synthesized targeting tumor necrosis factor-α receptor-1 (TNFR-1) and Src homology 2 domain-containing protein tyrosine phosphatase-1 (SHP-1). Human umbilical vein endothelial cells (HUVECs) were cultured under in vitro hypoxic and serum-deprived conditions to simulate in vivo ischemic conditions. Two days after liposomal delivery of siRNA targeting TNFR-1 and SHP-1, significant silencing of each target (TNFR-1; 76.5% and SHP-1; 97.2%) was detected. Under serum-deprived hypoxic (1% oxygen) conditions, TNF-α expression in HUVECs increased relative to normoxic (20% oxygen) and serum-containing conditions. Despite enhanced TNF-α expression, suppression of TNFR-1 or SHP-1 by siRNA delivery not only enhanced expression of angiogenic factors (KDR/Flk-1 and eNOS) and anti-apoptotic factor (Bcl-xL) but also reduced expression of a pro-apoptotic factor (Bax). Transfection of TNFR-1 or SHP-1 siRNA significantly decreased the HUVEC apoptosis while significantly enhancing HUVEC proliferation and capillary formation. The present study demonstrates that TNFR-1 and SHP-1 may be useful targets for the treatment of myocardial or hindlimb ischemia

  9. Radioprotection of mouse CNS endothelial cells in vivo

    International Nuclear Information System (INIS)

    Lyubimova, N.; Coultas, P.; Martin, R.

    1996-01-01

    Full text: Radioprotection using the minor groove binding DNA ligand Hoechst 33342 has been demonstrated in vitro, and more recently in vivo, in mouse lung. Intravenous administration was used for the lung studies, and both endothelial and alveolar epithelial cells-showed good up-take. Radiation damage to the endothelial cell population has also been postulated as important in late developing radionecrosis of spinal cord and brain. Endothelial cell density in brain can be readily determined by a fluorescent-histochemical technique. Treatment with a monoamine oxidase inhibitor and subsequent injection with L-DOPA results in an accumulation of dopamine (DA) in CNS endothelial cells. DA is converted to a fluorophore by exposure to paraformaldehyde, and cell numbers assayed by fluorescence microscopy. Earlier studies used this technique to monitor post-irradiation changes in endothelial cell density in rodent brain and showed the loss, within 24 hours, of a sensitive subpopulation comprising about 15% of the endothelial cells. Ten minutes after intravenous injection of Hoechst 33342 (80mg/kg) the ligand is confined by its limited penetration to the endothelial cells in mouse brain. When we irradiated at this time, there was protection against early endothelial cell loss. Ablation of the sensitive subpopulation in unprotected mice takes place over a dose range of 1 to 3 Gy γ-rays, but doses between 12 to 20 Gy are required in the presence of ligand. This protection equates to a very high dose modification factor of about 7 and possibly reflects a suppression of apoptosis in the sensitive endothelial subpopulation. The extent to which there is enhanced survival in the endothelial population as a whole and how the observed protection affects late CNS necrosis development has yet to be determined. However present results clearly show potential for the use of DNA-binding radioprotectors with limited penetration for investigations into the relative significance of

  10. Use of Plastic Capillaries for Macromolecular Crystallization

    Science.gov (United States)

    Potter, Rachel R.; Hong, Young-Soo; Ciszak, Ewa M.

    2003-01-01

    Methods of crystallization of biomolecules in plastic capillaries (Nalgene 870 PFA tubing) are presented. These crystallization methods used batch, free-interface liquid- liquid diffusion alone, or a combination with vapor diffusion. Results demonstrated growth of crystals of test proteins such as thaumatin and glucose isomerase, as well as protein studied in our laboratory such dihydrolipoamide dehydrogenase. Once the solutions were loaded in capillaries, they were stored in the tubes in frozen state at cryogenic temperatures until the desired time of activation of crystallization experiments.

  11. Endothelial remodelling and intracellular calcium machinery.

    Science.gov (United States)

    Moccia, F; Tanzi, F; Munaron, L

    2014-05-01

    Rather being an inert barrier between vessel lumen and surrounding tissues, vascular endothelium plays a key role in the maintenance of cardiovascular homeostasis. The de-endothelialization of blood vessels is regarded as the early event that results in the onset of severe vascular disorders, including atherosclerosis, acute myocardial infarction, brain stroke, and aortic aneurysm. Restoration of the endothelial lining may be accomplished by the activation of neighbouring endothelial cells (ECs) freed by contact inhibition and by circulating endothelial progenitor cells (EPCs). Intracellular Ca(2+) signalling is essential to promote wound healing: however, the molecular underpinnings of the Ca(2+) response to injury are yet to be fully elucidated. Similarly, the components of the Ca(2+) toolkit that drive EPC incorporation into denuded vessels are far from being fully elucidated. The present review will survey the current knowledge on the role of Ca(2+) signalling in endothelial repair and in EPC activation. We propose that endothelial regeneration might be boosted by intraluminal release of specific Ca(2+) channel agonists or by gene transfer strategies aiming to enhance the expression of the most suitable Ca(2+) channels at the wound site. In this view, connexin (Cx) channels/hemichannels and store-operated Ca(2+) entry (SOCE) stand amid the most proper routes to therapeutically induce the regrowth of denuded vessels. Cx stimulation might trigger the proliferative and migratory behaviour of ECs facing the lesion site, whereas activation of SOCE is likely to favour EPC homing to the wounded vessel.

  12. Dietary phosphorus acutely impairs endothelial function.

    Science.gov (United States)

    Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji

    2009-07-01

    Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.

  13. Endothelial network formed with human dermal microvascular endothelial cells in autologous multicellular skin substitutes.

    Science.gov (United States)

    Ponec, Maria; El Ghalbzouri, Abdoelwaheb; Dijkman, Remco; Kempenaar, Johanna; van der Pluijm, Gabri; Koolwijk, Pieter

    2004-01-01

    A human skin equivalent from a single skin biopsy harboring keratinocytes and melanocytes in the epidermal compartment, and fibroblasts and microvascular dermal endothelial cells in the dermal compartment was developed. The results of the study revealed that the nature of the extracellular matrix of the dermal compartments plays an important role in establishment of endothelial network in vitro. With rat-tail type I collagen matrices only lateral but not vertical expansion of endothelial networks was observed. In contrast, the presence of extracellular matrix of entirely human origin facilitated proper spatial organization of the endothelial network. Namely, when human dermal fibroblasts and microvascular endothelial cells were seeded on the bottom of an inert filter and subsequently epidermal cells were seeded on top of it, fibroblasts produced extracellular matrix throughout which numerous branched tubes were spreading three-dimensionally. Fibroblasts also facilitated the formation of basement membrane at the epidermal/matrix interface. Under all culture conditions, fully differentiated epidermis was formed with numerous melanocytes present in the basal epidermal cell layer. The results of the competitive RT-PCR revealed that both keratinocytes and fibroblasts expressed VEGF-A, -B, -C, aFGF and bFGF mRNA, whereas fibroblasts also expressed VEGF-D mRNA. At protein level, keratinocytes produced 10 times higher amounts of VEGF-A than fibroblasts did. The generation of multicellular skin equivalent from a single human skin biopsy will stimulate further developments for its application in the treatment of full-thickness skin defects. The potential development of biodegradable, biocompatible material suitable for these purposes is a great challenge for future research.

  14. An immobilized graphene oxide stationary phase for open-tubular capillary electrochromatography.

    Science.gov (United States)

    Wang, Chun; de Rooy, Sergio; Lu, Cheng-Fei; Fernand, Vivian; Moore, Leonard; Berton, Paula; Warner, Isiah M

    2013-04-01

    The research literature currently abounds with studies of graphene-related materials as a result of the extraordinary properties of such materials. On the basis of these citations, it is clear that the range of applications for such materials is substantial. In this manuscript, we report the immobilization of graphene oxide (GO) onto a fused-silica capillary to form a potential stationary phase for use in open-tubular CEC. We successfully incorporated GO through an in situ condensation reaction with (3-aminopropyl)triethoxysilane after silanization with (3-aminopropyl)triethoxysilane on the inner surface of the capillary. This GO-incorporated capillary was then characterized by use of SEM, infrared spectroscopy, and measurements of EOF. The electrochromatographic features of this stationary phase have also been investigated. Evaluation of acquired data indicates high electrochromatographic resolution and good capillary efficiency. Highly reproducible results between runs, days, and capillaries were also obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

    Science.gov (United States)

    Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

    2001-04-01

    The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

  16. Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient.

    Science.gov (United States)

    Andrade, R S; Wangensteen, O D; Jo, J K; Tsai, M Y; Bolman, R M

    2000-07-27

    We previously demonstrated that surfactant dilution and inhibition occur immediately after pulmonary artery flushing with hypothermic modified Euro-Collins solution. Consequently, we speculated that increased capillary permeability contributed to these surfactant changes. To test this hypothesis, we evaluated the effects of hypothermic pulmonary artery flushing on the pulmonary capillary filtration coefficient (Kfc), and additionally performed a biochemical analysis of surfactant. We used a murine isolated, perfused lung model to measure the pulmonary capillary filtration coefficient and hemodynamic parameters, to determine the wet to dry weight ratio, and to evaluate surfactant by biochemical analysis of lung lavage fluid. We defined three study groups. In group I (controls), we harvested lungs without hypothermic pulmonary artery flushing, and measured Kfc immediately. In group II (in situ flush), we harvested lungs after hypothermic pulmonary artery flushing with modified Euro-Collins solution, and then measured Kfc. Experiments in groups I and II were designed to evaluate persistent changes in Kfc after pulmonary artery flushing. In group III (ex vivo flush), we flushed lungs ex vivo to evaluate transient changes in Kfc during hypothermic pulmonary artery flushing. Groups I and II did not differ significantly in capillary filtration coefficient and hemodynamics. Group II showed significant alterations on biochemical surfactant analysis and a significant increase in wet-to-dry weight ratio, when compared with group I. In group III, we observed a significant transient increase in capillary filtration coefficient during pulmonary artery flushing. Hypothermic pulmonary artery flushing transiently increases the capillary filtration coefficient, leads to an increase in the wet to dry weight ratio, and induces biochemical surfactant changes. These findings could be explained by the effects of hypothermic modified Euro-Collins solution on pulmonary capillary

  17. Resveratrol: A Multifunctional Compound Improving Endothelial Function

    OpenAIRE

    Li, Huige; F?rstermann, Ulrich

    2009-01-01

    The red wine polyphenol resveratrol boosts endothelium-dependent and -independent vasorelaxations. The improvement of endothelial function by resveratrol is largely attributable to nitric oxide (NO) derived from endothelial NO synthase (eNOS). By stimulating eNOS expression, eNOS phosphorylation and eNOS deacetylation, resveratrol enhances endothelial NO production. By upregulating antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and suppressing the expression a...

  18. Thermodynamics of Capillary Rise: Why Is the Meniscus Curved?

    Science.gov (United States)

    Henriksson, Ulf; Eriksson, Jan Christer

    2004-01-01

    The thermodynamics of capillary rise is explained as the gravitational elevation of the whole column of liquid caused by the positive connection between the liquid, and the solid wall of the capillary tube. The curvature of the meniscus is ascribed to the maintenance of a physiochemical balance throughout the gravitational column of liquid.

  19. Endothelial dysfunction – A predictor of atherosclerosis | Chhabra ...

    African Journals Online (AJOL)

    Endothelial dysfunction is a systemic disorder and a critical element in the pathogenesis of atherosclerotic diseases and its complications. Growing evidences suggest that the individual burden of currently known cardiovascular risk factors is not the only determinant of endothelial function; rather endothelial integrity ...

  20. CAPILLARY BARRIERS IN UNSATURATED FRACTURED ROCKS OF YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    Wu, Y.S.; Zhang, W.; Pan, L.; Hinds, J.; Bodvarsson, G.

    2000-01-01

    This work presents modeling studies investigating the effects of capillary barriers on fluid-flow and tracer-transport processes in the unsaturated zone of Yucca Mountain, Nevada, a potential site for storing high-level radioactive waste. These studies are designed to identify factors controlling the formation of capillary barriers and to estimate their effects on the extent of possible large-scale lateral flow in unsaturated fracture rocks. The modeling approach is based on a continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. Flow processes in fractured porous rock are described using a dual-continuum concept. In addition, approximate analytical solutions are developed and used for assessing capillary-barrier effects in fractured rocks. This study indicates that under the current hydrogeologic conceptualization of Yucca Mountain, strong capillary-barrier effects exist for significantly diverting moisture flow