Rat Pial Microvascular Changes During Cerebral Blood Flow Decrease and Recovery: Effects of Cyanidin Administration

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Teresa Mastantuono

2018-05-01

Full Text Available The reactive oxygen species (ROS are known to play a major role in many pathophysiological conditions, such as ischemia and reperfusion injury. The present study was aimed to evaluate the in vivo cyanidin (anthocyanin effects on damages induced by rat pial microvascular hypoperfusion-reperfusion injury by cerebral blood flow decrease (CBFD and subsequent cerebral blood flow recovery (CBFR. In particular, the main purpose was to detect changes in ROS production after cyanidin administration. Rat pial microvasculature was investigated using fluorescence microscopy through a cranial window (closed; Strahler's method was utilized to define the geometric features of pial vessels. ROS production was investigated in vivo by 2′-7′-dichlorofluorescein-diacetate assay and neuronal damage was measured on isolated brain sections by 2,3,5-triphenyltetrazolium chloride staining. After 30 min of CBFD, induced by bilateral common carotid artery occlusion, and 60 min of CBFR, rats showed decrease of arteriolar diameter and capillary perfusion; furthermore, increase in microvascular leakage and leukocyte adhesion was observed. Conversely, cyanidin administration induced dose-related arteriolar dilation, reduction in microvascular permeability as well as leukocyte adhesion when compared to animals subjected to restriction of cerebral blood flow; moreover, capillary perfusion was protected. ROS generation increase and marked neuronal damage were detected in animals subjected to CBFD and CBFR. On the other hand, cyanidin was able to reduce ROS generation and neuronal damage. In conclusion, cyanidin treatment showed dose-related protective effects on rat pial microcirculation during CBFD and subsequent CBFR, inducing arteriolar dilation by nitric oxide release and inhibiting ROS formation, consequently preserving the blood brain barrier integrity.

Forecasting Ontario's blood supply and demand.

Science.gov (United States)

Drackley, Adam; Newbold, K Bruce; Paez, Antonio; Heddle, Nancy

2012-02-01

Given an aging population that requires increased medical care, an increasing number of deferrals from the donor pool, and a growing immigrant population that typically has lower donation rates, the purpose of this article is to forecast Ontario's blood supply and demand. We calculate age- and sex-specific donation and demand rates for blood supply based on 2008 data and project demand between 2008 and 2036 based on these rates and using population data from the Ontario Ministry of Finance. Results indicate that blood demand will outpace supply as early as 2012. For instance, while the total number of donations made by older cohorts is expected to increase in the coming years, the number of red blood cell (RBC) transfusions in the 70+ age group is forecasted grow from approximately 53% of all RBC transfusions in 2008 (209,515) in 2008 to 68% (546,996) by 2036. A series of alternate scenarios, including projections based on a 2% increase in supply per year and increased use of apheresis technology, delays supply shortfalls, but does not eliminate them without active management and/or multiple methods to increase supply and decrease demand. Predictions show that demand for blood products will outpace supply in the near future given current age- and sex-specific supply and demand rates. However, we note that the careful management of the blood supply by Canadian Blood Services, along with new medical techniques and the recruitment of new donors to the system, will remove future concerns. © 2012 American Association of Blood Banks.

Inter-arm Blood Pressure Difference and its Relationship with Retinal Microvascular Calibres in Young Individuals: The African-PREDICT Study.

Science.gov (United States)

Strauss, Michél; Smith, Wayne; Schutte, Aletta E

2016-08-01

Bilateral systolic blood pressure (SBP) differences > 10mmHg is a common finding in clinical practice. Such BP differences in older individuals are associated with peripheral vascular disease, linked to microvascular dysfunction. Investigating retinal vessel calibres could provide insight into systemic microvascular function and may predict cardiovascular outcomes. Therefore we investigated the link between inter-arm systolic blood pressure differences (IASBPD) and the retinal microvasculature to determine the usefulness of IASBPD as an early marker of microvascular changes. In this cross-sectional study, we used data from 403 apparently healthy participants (20-30 years) (42% men; 49% black) taking part in the African-PREDICT study. Participants underwent retinal vessel imaging, anthropometric measurements and blood sampling. Brachial BP was measured sequentially in both arms to determine the mean IASBPD. Participants were stratified into two groups with an IASBPD difference in characteristics being a higher right arm SBP in the latter group (p=0.005). We found no association between IASBPD and retinal vessel calibres in any group. Less than 2% of the variance in IASBPD was explained by potential risk factors, with only SBP associating independently with IASBPD (β=115; p=0.039). In a young population an increased IASBPD is not related to retinal vessel diameters suggesting that it does not reflect early microvascular alterations. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Quantitative and qualitative retinal microvascular characteristics and blood pressure.

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Cheung, Carol Y; Tay, Wan T; Mitchell, Paul; Wang, Jie J; Hsu, Wynne; Lee, Mong L; Lau, Qiangfeng P; Zhu, Ai L; Klein, Ronald; Saw, Seang M; Wong, Tien Y

2011-07-01

The present study examined the effects of blood pressure on a spectrum of quantitative and qualitative retinal microvascular signs. Retinal photographs from the Singapore Malay Eye Study, a population-based cross-sectional study of 3280 (78.7% response) persons aged 40-80 years, were analyzed. Quantitative changes in the retinal vasculature (branching angle, vascular tortuosity, fractal dimension, and vascular caliber) were measured using a semi-automated computer-based program. Qualitative signs, including focal arteriolar narrowing (FAN), arteriovenous nicking (AVN), opacification of the arteriolar wall (OAW), and retinopathy (e.g., microaneurysms, retinal hemorrhages), were assessed from photographs by trained technicians. After excluding persons with diabetes and ungradable photographs, 1913 persons provided data for this analysis. In multivariable linear regression models controlling for age, sex, BMI, use of antihypertensive medication, and other factors, retinal arteriolar branching asymmetry ratio, arteriolar tortuosity, venular tortuosity, fractal dimension, arteriolar caliber, venular caliber, FAN, AVN, and retinopathy were independently associated with mean arterial blood pressure. In contrast, arteriolar/venular branching angle, venular branching asymmetry ratio and OAW were not related to blood pressure. Retinal arteriolar caliber (sβ = -0.277) and FAN (sβ = 0.170) had the strongest associations with mean arterial blood pressure, and higher blood pressure levels were associated with increasing number of both quantitative and qualitative retinal vascular signs (P trend qualitative retinal vascular signs, with the number of signs increasing with higher blood pressure levels.

Cholangiocytes and blood supply.

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Gaudio, Eugenio; Franchitto, Antonio; Pannarale, Luigi; Carpino, Guido; Alpini, Gianfranco; Francis, Heather; Glaser, Shannon; Alvaro, Domenico; Onori, Paolo

2006-06-14

The microvascular supply of the biliary tree, the peribiliary plexus (PBP), stems from the hepatic artery branches and flows into the hepatic sinusoids. A detailed three-dimensional study of the PBP has been performed by using the Scanning Electron Microscopy vascular corrosion casts (SEMvcc) technique. Considering that the PBP plays a fundamental role in supporting the secretory and absorptive functions of the biliary epithelium, their organization in either normalcy and pathology is explored. The normal liver shows the PBP arranged around extra- and intrahepatic biliary tree. In the small portal tract PBP was characterized by a single layer of capillaries which progressively continued with the extrahepatic PBP where it showed a more complex vascular network. After common duct ligation (BDL), progressive modifications of bile duct and PBP proliferation are observed. The PBP presents a three-dimensional network arranged around many bile ducts and appears as bundles of vessels, composed by capillaries of homogeneous diameter with a typical round mesh structure. The PBP network is easily distinguishable from the sinusoidal network which appears normal. Considering the enormous extension of the PBP during BDL, the possible role played by the Vascular Endothelial Growth Factor (VEGF) is evaluated. VEGF-A, VEGF-C and their related receptors appeared highly immunopositive in proliferating cholangiocytes of BDL rats. The administration of anti-VEGF-A or anti-VEGF-C antibodies to BDL rats as well as hepatic artery ligation induced a reduced bile duct mass. The administration of rVEGF-A to BDL hepatic artery ligated rats prevented the decrease of cholangiocyte proliferation and VEGF-A expression as compared to BDL control rats. These data suggest the role of arterial blood supply of the biliary tree in conditions of cholangiocyte proliferation, such as it occurs during chronic cholestasis. On the other hand, the role played by VEGF as a tool of cross-talk between

21 CFR 864.9050 - Blood bank supplies.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood bank supplies. 864.9050 Section 864.9050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... and Blood Products § 864.9050 Blood bank supplies. (a) Identification. Blood bank supplies are general...

TRANSFUSION RESTORES BLOOD VISCOSITY AND REINSTATES MICROVASCULAR CONDITIONS FROM HEMORRHAGIC SHOCK INDEPENDENT OF OXYGEN CARRYING CAPACITY

OpenAIRE

Cabrales, Pedro; Intaglietta, Marcos; Tsai, Amy G.

2007-01-01

Systemic and microvascular hemodynamic responses to transfusion of oxygen using functional and non-functional packed fresh red blood cells (RBCs) from hemorrhagic shock were studied in the hamster window chamber model to determine the significance of RBCs on rheological and oxygen transport properties. Moderate hemorrhagic shock was induced by arterial controlled bleeding of 50% of the blood volume, and a hypovolemic state was maintained for one hour. Volume restitution was performed by infus...

Two problems in multiphase biological flows: Blood flow and particulate transport in microvascular network, and pseudopod-driven motility of amoeboid cells

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Bagchi, Prosenjit

2016-11-01

In this talk, two problems in multiphase biological flows will be discussed. The first is the direct numerical simulation of whole blood and drug particulates in microvascular networks. Blood in microcirculation behaves as a dense suspension of heterogeneous cells. The erythrocytes are extremely deformable, while inactivated platelets and leukocytes are nearly rigid. A significant progress has been made in recent years in modeling blood as a dense cellular suspension. However, many of these studies considered the blood flow in simple geometry, e.g., straight tubes of uniform cross-section. In contrast, the architecture of a microvascular network is very complex with bifurcating, merging and winding vessels, posing a further challenge to numerical modeling. We have developed an immersed-boundary-based method that can consider blood cell flow in physiologically realistic and complex microvascular network. In addition to addressing many physiological issues related to network hemodynamics, this tool can be used to optimize the transport properties of drug particulates for effective organ-specific delivery. Our second problem is pseudopod-driven motility as often observed in metastatic cancer cells and other amoeboid cells. We have developed a multiscale hydrodynamic model to simulate such motility. We study the effect of cell stiffness on motility as the former has been considered as a biomarker for metastatic potential. Funded by the National Science Foundation.

[Recent advances on pericytes in microvascular dysfunction and traditional Chinese medicine prevention].

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Liu, Lei; Liu, Jian-Xun; Guo, Hao; Ren, Jian-Xun

2017-08-01

Pericytesis a kind of widespread vascular mural cells embedded within the vascular basement membrane of blood microvessels, constituting the barrier of capillaries and tissue spaces together with endothelial cells. Pericytes communicate with microvascular endothelial cells through cell connections or paracrine signals, playing an important role in important physiological processes such as blood flow, vascular permeability and vascular formation. Pericytes dysfunction may participate in some microvascular dysfunction, and also mediate pathological repair process, therefore pericytes attracted more and more attention. Traditional Chinese medicine suggests that microvascular dysfunction belongs to the collaterals disease; Qi stagnation and blood stasis in collaterals result in function imbalance of internal organs. Traditional Chinese medicine (TCM) has shown effects on pericytes in microvascular dysfunction, for example qi reinforcing blood-circulation activating medicines can reduce the damage of retinal pericytes in diabetic retinopathy. However, there are some limitations of research fields, inaccuracy of research techniques and methods, and lack of mechanism elaboration depth in the study of microvascular lesion pericytes. This paper reviewed the biological characteristics of pericytes and pericytes in microvascular dysfunction, as well as the intervention study of TCM on pericytes. The article aims to provide reference for the research of pericytes in microvascular dysfunction and the TCM study on pericytes. Copyright© by the Chinese Pharmaceutical Association.

Increased muscle blood supply and transendothelial nutrient and insulin transport induced by food intake and exercise: effect of obesity and ageing.

Science.gov (United States)

Wagenmakers, Anton J M; Strauss, Juliette A; Shepherd, Sam O; Keske, Michelle A; Cocks, Matthew

2016-04-15

This review concludes that a sedentary lifestyle, obesity and ageing impair the vasodilator response of the muscle microvasculature to insulin, exercise and VEGF-A and reduce microvascular density. Both impairments contribute to the development of insulin resistance, obesity and chronic age-related diseases. A physically active lifestyle keeps both the vasodilator response and microvascular density high. Intravital microscopy has shown that microvascular units (MVUs) are the smallest functional elements to adjust blood flow in response to physiological signals and metabolic demands on muscle fibres. The luminal diameter of a common terminal arteriole (TA) controls blood flow through up to 20 capillaries belonging to a single MVU. Increases in plasma insulin and exercise/muscle contraction lead to recruitment of additional MVUs. Insulin also increases arteriolar vasomotion. Both mechanisms increase the endothelial surface area and therefore transendothelial transport of glucose, fatty acids (FAs) and insulin by specific transporters, present in high concentrations in the capillary endothelium. Future studies should quantify transporter concentration differences between healthy and at risk populations as they may limit nutrient supply and oxidation in muscle and impair glucose and lipid homeostasis. An important recent discovery is that VEGF-B produced by skeletal muscle controls the expression of FA transporter proteins in the capillary endothelium and thus links endothelial FA uptake to the oxidative capacity of skeletal muscle, potentially preventing lipotoxic FA accumulation, the dominant cause of insulin resistance in muscle fibres. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

How safe is the blood supply?

Science.gov (United States)

1992-06-26

Many poor people in Indian cities sell their blood to commercial blood banks for up to US$2.50. In fact, so many have done so that there once was a Professional Blood Donors Association. It dissolved though after some members died of AIDS. Health workers believe at least 25% of blood donors in Bombay are HIV positive. Yet a recent study of 70 professional blood donors in Bombay shows only 7 who did not test positive for HIV. Still the government of India does not require blood banks to test for HIV, hepatitis, or other blood borne diseases. In fact, the blood supply is monitored in only 5 cities in India. In India as well as in other Asian countries, physicians advise patients to donate their own blood and have it stored until needed for surgery or to ask for safer blood substitutes, e.g., plasma expanders. In fact, in Singapore, the Autologous Blood Bank charges US$21/year to store units of blood for future use. In Japan, most of the 2008 HIV infected people had received blood plasma from mainly the US before Japan required new sterilization regulations on blood imports. The greatest risk from blood donors comes from those who are paid for their blood because they tend to be poor, to practice unsafe sex, and not to be mindful of their health. Most Asian nations such as Japan and Singapore do screen the blood supply. Further, for almost 20 years, Thailand has checked its blood supply for hepatitis B and syphilis. In 1987, it began testing for AIDS. It does not pay for donated blood. In the Philippines, however, even paying blood donors does not meet the needed blood supply and much of the blood comes from commercial blood banks. Yet the Philippine Red Cross has screened for other diseases since 1960 and for AIDS since 1988.

Direct numerical simulation of cellular-scale blood flow in microvascular networks

Science.gov (United States)

Balogh, Peter; Bagchi, Prosenjit

2017-11-01

A direct numerical simulation method is developed to study cellular-scale blood flow in physiologically realistic microvascular networks that are constructed in silico following published in vivo images and data, and are comprised of bifurcating, merging, and winding vessels. The model resolves large deformation of individual red blood cells (RBC) flowing in such complex networks. The vascular walls and deformable interfaces of the RBCs are modeled using the immersed-boundary methods. Time-averaged hemodynamic quantities obtained from the simulations agree quite well with published in vivo data. Our simulations reveal that in several vessels the flow rates and pressure drops could be negatively correlated. The flow resistance and hematocrit are also found to be negatively correlated in some vessels. These observations suggest a deviation from the classical Poiseuille's law in such vessels. The cells are observed to frequently jam at vascular bifurcations resulting in reductions in hematocrit and flow rate in the daughter and mother vessels. We find that RBC jamming results in several orders of magnitude increase in hemodynamic resistance, and thus provides an additional mechanism of increased in vivo blood viscosity as compared to that determined in vitro. Funded by NSF CBET 1604308.

Autologous Latissimus Dorsi Breast Reconstruction Flap Salvage: Microvascular Anastomosis with Serratus Branch

Directory of Open Access Journals (Sweden)

Victoria Kuta, BScH

2017-07-01

Full Text Available Summary:. Autologous breast reconstruction has become a standard option during the recovery of breast cancer survivors. Although pedicle damage is a rare complication of this procedure, extensive torsion or tension can lead to partial or total flap failure. We report a case of partial flap salvage after accidental transection of the pedicled blood supply within the intramuscular course of a latissimus dorsi musculocutaneous flap. This salvage technique involved microvascular anastomosis between the remaining vasculature of the latissimus dorsi pedicle and the serratus branch of the thoracodorsal artery and vein.

The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network.

Science.gov (United States)

Sosa, Jose M; Nielsen, Nathan D; Vignes, Seth M; Chen, Tanya G; Shevkoplyas, Sergey S

2014-01-01

The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0-0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphedema

DEFF Research Database (Denmark)

Jensen, Mads Radmer; Simonsen, Lene; Karlsmark, Tonny

2013-01-01

-enhanced ultrasound; venous occlusion strain-gauge plethysmography; lower-body negative pressure; noninvasive blood pressure measurements; and skin (99m)Tc-pertechnetate clearance technique. Measurements were performed bilaterally and simultaneously in the forearms, enabling use of the nonedematous forearm...... relative microvascular volume, forearm blood flow, skin blood flow, or central or local sympathetic vascular reflexes. Forearm microvascular filtration is increased in patients with BCRL, and more so in the edematous arm. The vascular sympathetic control mechanisms seem to be preserved. We propose...... with unilateral BCRL, the following aspects of upper extremity peripheral circulation were examined: muscle relative microvascular volume; capillary filtration coefficient; central and local sympathetic vascular reflexes; skin blood flow; and forearm blood flow. These were studied via real-time, contrast...

Interactions of the gasotransmitters contribute to microvascular tone (dysregulation in the preterm neonate.

Directory of Open Access Journals (Sweden)

Rebecca M Dyson

Full Text Available Hydrogen sulphide (H2S, nitric oxide (NO, and carbon monoxide (CO are involved in transitional microvascular tone dysregulation in the preterm infant; however there is conflicting evidence on the interaction of these gasotransmitters, and their overall contribution to the microcirculation in newborns is not known. The aim of this study was to measure the levels of all 3 gasotransmitters, characterise their interrelationships and elucidate their combined effects on microvascular blood flow.90 preterm neonates were studied at 24h postnatal age. Microvascular studies were performed by laser Doppler. Arterial COHb levels (a measure of CO were determined through co-oximetry. NO was measured as nitrate and nitrite in urine. H2S was measured as thiosulphate by liquid chromatography. Relationships between levels of the gasotransmitters and microvascular blood flow were assessed through partial correlation controlling for the influence of gestational age. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow and derive a theoretical model of their interactions.No relationship was observed between NO and CO (p = 0.18, r = 0.18. A positive relationship between NO and H2S (p = 0.008, r = 0.28 and an inverse relationship between CO and H2S (p = 0.01, r = -0.33 exists. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow. The model with the best fit is presented.The relationships between NO and H2S, and CO and H2S may be of importance in the preterm newborn, particularly as NO levels in males are associated with higher H2S levels and higher microvascular blood flow and CO in females appears to convey protection against vascular dysregulation. Here we present a theoretical model of these interactions and their overall effects on microvascular flow in the preterm newborn, upon which future mechanistic studies may be based.

Evaluation of MSCTA for parasitic blood supply in hepatic carcinoma

International Nuclear Information System (INIS)

Yang Weihong; Liu Pengcheng; Liang Shanhu; Yuan Zhidong; Yu Hongjian; Deng Qianhua

2008-01-01

Objective: To evaluate the multi-slice spiral computer tomography for hepatocarcinoma parasitic blood supply, and analyze the mechanism of the parasitic angiogenesis. Methods: Forty cases confirmed by DSA and confirmed with the existence of parasitic blood supply through manifestations of MSCTA were retrospectively analized. Comparing the coincidence of different reconstruction modalities of MSCTA and DSA in displaying the parasitic blood supply and then to assess the characteristics of MSCTA of the cases with existing parasitic blood supply. Results: DSA displayed parasitic blood supply in 50 arterial rami and MSCTA displayed only 40 rami, with positive rate of 80%. The best display could be reached by the reconstruction of combining MIP and VRT. This kind of reconstruction revealed not only the parasitic blood supply but also the peripheral sites of the primary focci with average length of diameter of 6.9 cm. Conclusions: MSCTA possesses nearly the same capability with DSA in demonstrating the parasitic blood supply to primary hepatic carcinoma, therefore it could be utilized in evaluation of intervention therapy and surgical, operation and transplantation. The primary hepatic carcinoma with this kind of parasitic blood supply is always located at the bare were of liver and ligmentarn suspensoram together with direct invasion of nearby organs with adhesions may contribute the main factor of parasitic blood supply, furthermore the repetition of TACE inducing the decrease of collateral circulation may also be the another major factor. (authors)

Evaluation of MSCTA for parasitic blood supply in hepatic carcinoma

Energy Technology Data Exchange (ETDEWEB)

Weihong, Yang; Pengcheng, Liu; Shanhu, Liang; Zhidong, Yuan; Hongjian, Yu; Qianhua, Deng [Department of Radiology, Shenzhen Hospital of Beijing College, Guangdong, Shenzhen (China)

2008-09-15

Objective: To evaluate the multi-slice spiral computer tomography for hepatocarcinoma parasitic blood supply, and analyze the mechanism of the parasitic angiogenesis. Methods: Forty cases confirmed by DSA and confirmed with the existence of parasitic blood supply through manifestations of MSCTA were retrospectively analized. Comparing the coincidence of different reconstruction modalities of MSCTA and DSA in displaying the parasitic blood supply and then to assess the characteristics of MSCTA of the cases with existing parasitic blood supply. Results: DSA displayed parasitic blood supply in 50 arterial rami and MSCTA displayed only 40 rami, with positive rate of 80%. The best display could be reached by the reconstruction of combining MIP and VRT. This kind of reconstruction revealed not only the parasitic blood supply but also the peripheral sites of the primary focci with average length of diameter of 6.9 cm. Conclusions: MSCTA possesses nearly the same capability with DSA in demonstrating the parasitic blood supply to primary hepatic carcinoma, therefore it could be utilized in evaluation of intervention therapy and surgical, operation and transplantation. The primary hepatic carcinoma with this kind of parasitic blood supply is always located at the bare were of liver and ligmentarn suspensoram together with direct invasion of nearby organs with adhesions may contribute the main factor of parasitic blood supply, furthermore the repetition of TACE inducing the decrease of collateral circulation may also be the another major factor. (authors)

Canadian inquiry assesses blame for tainted blood supply.

Science.gov (United States)

1997-12-26

A commission of inquiry, headed by Justice Horace Krever of the Ontario Court of Appeal, found that hundreds of hemophiliacs and blood transfusion recipients could have avoided HIV if the government regulators and medical suppliers had taken precautions in the early 1980s to protect Canada's blood supply. The report documents an inventory of errors and misjudgments that resulted in the infection of more than 1,200 people with HIV and roughly 60,000 with hepatitis C. The report noted that one U.S. blood fractionator, Armour Pharmaceutical, violated Canadian law by not informing government regulators in 1985 that its products might be tainted with HIV. Other findings conclude that the Red Cross, the agency with principal responsibility for protecting Canada's blood supply, put forth a halfhearted and ineffective response, and little effort was made to promote the use of safer blood clotting agents for hemophiliacs. Canada only began testing its blood supply for HIV eight months after the U.S. initiated ELISA testing. The commission recommends compensating all past and future recipients of contaminated blood and blood products.

Is endothelial microvascular function equally impaired among patients with chronic Chagas and ischemic cardiomyopathy?

Science.gov (United States)

Borges, Juliana Pereira; Mendes, Fernanda de Souza Nogueira Sardinha; Lopes, Gabriella de Oliveira; Sousa, Andréa Silvestre de; Mediano, Mauro Felippe Felix; Tibiriçá, Eduardo

2018-08-15

Chronic Chagas cardiomyopathy (CCC) and cardiomyopathies due to other etiologies involve differences in pathophysiological pathways that are still unclear. Systemic microvascular abnormalities are associated with the pathogenesis of ischemic heart disease. However, systemic microvascular endothelial function in CCC remains to be elucidated. Thus, we compared the microvascular endothelial function of patients presenting with CCC to those with ischemic cardiomyopathy disease. Microvascular reactivity was assessed in 21 patients with cardiomyopathy secondary to Chagas disease, 21 patients with cardiomyopathy secondary to ischemic disease and 21 healthy controls. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh). Peak increase in forearm blood flow with ACh iontophoresis in relation to baseline was greater in healthy controls than in patients with heart disease (controls: 162.7 ± 58.4% vs. ischemic heart disease: 74.1 ± 48.3% and Chagas: 85.1 ± 68.1%; p < 0.0001). Patients with Chagas and ischemic cardiomyopathy presented similar ACh-induced changes from baseline in skin blood flow (p = 0.55). Endothelial microvascular function was equally impaired among patients with CCC and ischemic cardiomyopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhanced Local Skeletal Muscle Oxidative Capacity and Microvascular Blood Flow Following 7-Day Ischemic Preconditioning in Healthy Humans

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Owen Jeffries

2018-05-01

Full Text Available Ischemic preconditioning (IPC, which involves intermittent periods of ischemia followed by reperfusion, is an effective clinical intervention that reduces the risk of myocardial injury and confers ischemic tolerance to skeletal muscle. Repeated bouts of IPC have been shown to stimulate long-term changes vascular function, however, it is unclear what metabolic adaptations may occur locally in the muscle. Therefore, we investigated 7 days of bilateral lower limb IPC (4 × 5 min above limb occlusion pressure (220 mmHg; n = 10, or sham (20 mmHg; n = 10, on local muscle oxidative capacity and microvascular blood flow. Oxidative capacity was measured using near-infrared spectroscopy (NIRS during repeated short duration arterial occlusions (300 mmHg. Microvascular blood flow was assessed during the recovery from submaximal isometric plantar flexion exercises at 40 and 60% of maximal voluntary contraction (MVC. Following the intervention period, beyond the late phase of protection (72 h, muscle oxidative recovery kinetics were speeded by 13% (rate constant pre 2.89 ± 0.47 min-1 vs. post 3.32 ± 0.69 min-1; P < 0.05 and resting muscle oxygen consumption (mO2 was reduced by 16.4% (pre 0.39 ± 0.16%.s-1 vs. post 0.33 ± 0.14%.s-1; P < 0.05. During exercise, changes in deoxygenated hemoglobin (HHb from rest to steady state were reduced at 40 and 60% MVC (16 and 12%, respectively, P < 0.05 despite similar measures of total hemoglobin (tHb. At the cessation of exercise, the time constant for recovery in oxygenated hemoglobin (O2Hb was accelerated at 40 and 60% MVC (by 33 and 43%, respectively suggesting enhanced reoxygenation in the muscle. No changes were reported for systemic measures of resting heart rate or blood pressure. In conclusion, repeated bouts of IPC over 7 consecutive days increased skeletal muscle oxidative capacity and microvascular muscle blood flow. These findings are consistent with enhanced mitochondrial and vascular function following

Study on the relationship between blood levels of growth hormone, glycosylated hemoglobin and micro-vascular nephropathy in patients with diabetes

International Nuclear Information System (INIS)

Cai Facheng; Yao Yingfei; Zhang Jinchi

2005-01-01

Objective: To evaluate the relationship between blood levels of growth hormone, glycosylated hemoglobin and micro-vascular nephropathy in patients with diabetes. Methods: Blood growth hormone and β 2 -m levels were determined with RIA and GH2 bA 1C , blood glucose were determined with biochemical method in 41 diabetic patients and 32 controls. Results: The blood levels of growth hormone, glycosylated hemoglobin, β 2 -microglobulin and fasting blood glucose in the patients with diabetes well controlled (n=22) were significantly higher than those in controls and levels in patients with diabetes poorly controlled (n=19) were again significantly higher than those in patients with diabetes well controlled (P 2 -microglobulin and fasting blood glucose is very important for early detection of diabetic nephropathy. (authors)

Extrinsic and intrinsic blood supply to the optic chiasm.

Science.gov (United States)

Salaud, Céline; Ploteau, Stéphane; Blery, Pauline; Pilet, Paul; Armstrong, Olivier; Hamel, Antoine

2018-04-01

Although there have been many studies of the arterial cerebral blood supply, only seven have described the optic chiasm (OC) blood supply and their results are contradictory. The aim of this study was to analyze the extrinsic and intrinsic OC blood supply on cadaveric specimens using dissections and microcomputer tomography (Micro-CT). Thirteen human specimens were dissected and the internal or common carotid arteries were injected with red latex, China Ink with gelatin or barium sulfate. Three Micro-CTs were obtained to reveal the intrinsic blood supply to the OC. The superior hypophyseal arteries (SupHypA) (13/13) and posterior communicating artery (PCoA) (12/13) supplied the pial network on the inferior side of the OC. The first segment of the anterior cerebral artery (ACA) (10/10), SupHypA (7/10), the anterior communicating artery (ACoA) (9/10), and PComA (1/10) supplied the pial network of its superior side. The intrinsic OC blood supply was divided into three networks (two lateral and one central). Capillaries entering the OC originated principally from the inferior pial network. The lateral network capillaries had the same orientation as the visual lateral pathways, but the central network was not correlated with the nasal fibers crossing into the OC. There was no anastomosis in the pial or intrinsic networks. Only SupHypA, PCoA, ACoA, and ACA were involved in the OC blood supply. Because there was no extrinsic or intrinsic anastomosis, all arteries should be preserved. Tumor compression of the inferior intrinsic arterial network could contribute to visual defects. Clin. Anat. 31:432-440, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A new method to study changes in microvascular blood volume in muscle and adipose tissue: Real time imaging in humans and rat

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Rattigan, Stephen; Hiscock, Natalie J

2011-01-01

We employed and evaluated a new application of contrast enhanced ultrasound for real time imaging of changes in microvascular blood volume (MVB) in tissues in females, males and rat. Continuous real time imaging was performed using contrast enhanced ultrasound to quantify infused gas filled micro...

Dietary sodium loading impairs microvascular function independent of blood pressure in humans: role of oxidative stress

Science.gov (United States)

Greaney, Jody L; DuPont, Jennifer J; Lennon-Edwards, Shannon L; Sanders, Paul W; Edwards, David G; Farquhar, William B

2012-01-01

Animal studies have reported dietary salt-induced reductions in vascular function independent of increases in blood pressure (BP). The purpose of this study was to determine if short-term dietary sodium loading impairs cutaneous microvascular function in normotensive adults with salt resistance. Following a control run-in diet, 12 normotensive adults (31 ± 2 years) were randomized to a 7 day low-sodium (LS; 20 mmol day−1) and 7 day high-sodium (HS; 350 mmol day−1) diet (controlled feeding study). Salt resistance, defined as a ≤5 mmHg change in 24 h mean BP determined while on the LS and HS diets, was confirmed in all subjects undergoing study (LS: 84 ± 1 mmHg vs. HS: 85 ± 2 mmHg; P > 0.05). On the last day of each diet, subjects were instrumented with two microdialysis fibres for the local delivery of Ringer solution and 20 mm ascorbic acid (AA). Laser Doppler flowmetry was used to measure red blood cell flux during local heating-induced vasodilatation (42°C). After the established plateau, 10 mm l-NAME was perfused to quantify NO-dependent vasodilatation. All data were expressed as a percentage of maximal cutaneous vascular conductance (CVC) at each site (28 mm sodium nitroprusside; 43°C). Sodium excretion increased during the HS diet (P sodium loading impairs cutaneous microvascular function independent of BP in normotensive adults and suggest a role for oxidative stress. PMID:22907057

Temporal distribution of blood donations in three Brazilian blood centers and its repercussion on the blood supply.

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Oliveira, Claudia Di Lorenzo; de Almeida-Neto, Cesar; Liu, Emily Jing; Sabino, Ester Cerdeira; Leão, Silvana Carneiro; Loureiro, Paula; Wright, David; Custer, Brian; Gonçalez, Thelma Therezinha; Capuani, Ligia; Busch, Michael; Proietti, Anna Bárbara de Freitas Carneiro

2013-01-01

Seasonal distribution of blood donation hinders efforts to provide a safe and adequate blood supply leading to chronic and persistent shortages. This study examined whether holidays, geographical area and donation type (community versus replacement) has any impact on the fluctuation of donations. The numbers of blood donations from 2007 through 2010 in three Brazilian Retrovirus Epidemiological Donor Study II (REDS-II) participating centers were analyzed according to the week of donation. The weeks were classified as holiday or non-holiday. To compare donations performed during holiday versus non-holiday weeks, tabulations and descriptive statistics for weekly donations by blood center were examined and time series analysis was conducted. The average weekly number of donations varied according to the blood center and type of week. The average number of donations decreased significantly during Carnival and Christmas and increased during the Brazilian National Donor Week. The fluctuation was more pronounced in Recife and Belo Horizonte when compared to São Paulo and higher among community donors. National bank holidays affect the blood supply by reducing available blood donations. Blood banks should take into account these oscillations in order to plan local campaigns, aiming at maintaining the blood supply at acceptable levels.

Pharmacological enhancement of leg and muscle microvascular blood flow does not augment anabolic responses in skeletal muscle of young men under fed conditions.

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Phillips, Bethan E; Atherton, Philip J; Varadhan, Krishna; Wilkinson, Daniel J; Limb, Marie; Selby, Anna L; Rennie, Michael J; Smith, Kenneth; Williams, John P

2014-01-15

Skeletal muscle anabolism associated with postprandial plasma aminoacidemia and insulinemia is contingent upon amino acids (AA) and insulin crossing the microcirculation-myocyte interface. In this study, we hypothesized that increasing muscle microvascular blood volume (flow) would enhance fed-state anabolic responses in muscle protein turnover. We studied 10 young men (23.2 ± 2.1 yr) under postabsorptive and fed [iv Glamin (∼10 g AA), glucose ∼7.5 mmol/l] conditions. Methacholine was infused into the femoral artery of one leg to determine, via bilateral comparison, the effects of feeding alone vs. feeding plus pharmacological vasodilation. We measured leg blood flow (LBF; femoral artery) by Doppler ultrasound, muscle microvascular blood volume (MBV) by contrast-enhanced ultrasound (CEUS), muscle protein synthesis (MPS) and breakdown (MPB; a-v balance modeling), and net protein balance (NPB) using [1,2-(13)C2]leucine and [(2)H5]phenylalanine tracers via gas chromatography-mass spectrometry (GC-MS). Indexes of anabolic signaling/endothelial activation (e.g., Akt/mTORC1/NOS) were assessed using immunoblotting techniques. Under fed conditions, LBF (+12 ± 5%, P anabolism.

A robust optimization model for blood supply chain in emergency situations

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Meysam Fereiduni

2016-09-01

Full Text Available In this paper, a multi-period model for blood supply chain in emergency situation is presented to optimize decisions related to locate blood facilities and distribute blood products after natural disasters. In disastrous situations, uncertainty is an inseparable part of humanitarian logistics and blood supply chain as well. This paper proposes a robust network to capture the uncertain nature of blood supply chain during and after disasters. This study considers donor points, blood facilities, processing and testing labs, and hospitals as the components of blood supply chain. In addition, this paper makes location and allocation decisions for multiple post disaster periods through real data. The study compares the performances of “p-robust optimization” approach and “robust optimization” approach and the results are discussed.

Microvascular function in pre-eclampsia is influenced by insulin resistance and an imbalance of angiogenic mediators.

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Ghosh, Anshuman; Freestone, Nicholas S; Anim-Nyame, Nicholas; Arrigoni, Francesca I F

2017-04-01

In preeclampsia, maternal microvascular function is disrupted and angiogenesis is dysfunctional. Insulin resistance that occurs in some pregnancies also pathologically affects microvascular function. We wished to examine the relationship of angiogenic mediators and insulin resistance on microvascular health in pregnancy. We performed a nested, case-control study of 16 women who developed preeclampsia with 17 normal pregnant controls. We hypothesized that the impaired microvascular blood flow in preeclamptic women associated with an increased ratio of the antiangiogenic factors; (s-endoglin [sEng] and soluble fms-like tyrosine kinase-1 [sFlt-1]) and proangiogenic molecule (placental growth factor [PlGF]) could be influenced by insulin resistance. Serum samples taken after 28 weeks of gestation were measured for the angiogenic factors, insulin, and glucose alongside the inflammatory marker; tumor necrosis factor-α and endothelial activation, namely; soluble vascular cell adhesion molecule 1, intercellular adhesion molecule-1, and e-selectin. Maternal microvascular blood flow, measured by strain gauge plethysmography, correlated with ratios of pro- and antiangiogenic mediators independently of preeclampsia. Decreased microvascular function measured in preeclampsia strongly correlated with both the antiangiogenic factor (sFlt-1 + sEng): PlGF ratio and high levels of insulin resistance, and combining insulin resistance with antiangiogenic factor ratios further strengthened this relationship. In pregnancy, microvascular blood flow is strongly associated with perturbations in pro- and antiangiogenic mediators. In preeclampsia, the relationship of maternal microvascular dysfunction with antiangiogenic mediators is strengthened when combined with insulin resistance. © 2017 Kingston University. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig.

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Dyson, Rebecca M; Palliser, Hannah K; Lakkundi, Anil; de Waal, Koert; Latter, Joanna L; Clifton, Vicki L; Wright, Ian M R

2014-09-17

Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion-reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29-36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68-71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion-reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Challenges in the management of the blood supply.

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Williamson, Lorna M; Devine, Dana V

2013-05-25

Although blood suppliers are seeing short-term reductions in blood demand as a result of initiatives in patient blood management, modelling suggests that during the next 5-10 years, blood availability in developed countries will need to increase again to meet the demands of ageing populations. Increasing of the blood supply raises many challenges; new approaches to recruitment and retainment of future generations of blood donors will be needed, and care will be necessary to avoid taking too much blood from these donors. Integrated approaches in blood stock management between transfusion services and hospitals will be important to minimise wastage--eg, by use of supply chain solutions from industry. Cross-disciplinary systems for patient blood management need to be developed to lessen the need for transfusion--eg, by early identification and reversal of anaemia with haematinics or by reversal of the underlying cause. Personalised medicine could be applied to match donors to patients, not only with extended blood typing, but also by using genetically determined storage characteristics of blood components. Growing of red cells or platelets in large quantities from stem cells is a possibility in the future, but challenges of cost, scaling up, and reproducibility remain to be solved. Copyright © 2013 Elsevier Ltd. All rights reserved.

The spiral CT manifestations of the blood supply of primary hepatocellular carcinoma: correlation with pathological findings

International Nuclear Information System (INIS)

Huang Juan; Zhou Xiangping; Liu Rongbo; Chen Xian; Xu Chongyong; Yan Zhihan; Xu Jianying

2000-01-01

Objective: To study the correlation between the CT features of tumor blood supplies and the pathological changes in primary hepatocellular carcinoma (PHCC). Methods: Fifty cases with surgically and pathologically proved PHCC underwent spiral CT scanning (plain + dual-phase). One research group blindly evaluated the CT films obtained. According to tumor contrast enhancement and signals showed on CT, the patterns of PHCC was divided into 4 types: arterial blood supplying, portal blood supplying, arterial combining with portal blood supplying, and poorly blood supplying. Microscopically, PHCC was respectively classified into grade I to IV with Edmonson's standard, and into 4 types (trabecular, pseudo-glandular, compact, scirrhous) with WHO histological grading standard. At last, the CT features of tumor blood supplies were correlated with pathologic changes. Results: 36(72%) cases were supplied by hepatic arterial blood, 6(12%) by arterial combining with portal blood supplying, 4(8%) by portal, and 4(8%) were poorly blood supplying. The patterns of tumor blood supplies in PHCC correlated with tumor cells differentiation (P<0.05). PHCC with better tumor cells differentiation was more associated with portal blood supplies. The patterns of tumor blood supplying in PHCC correlated with the histological type of the tumor cell (P < 0.05). All of the scirrhous PHCC were lack of blood supplies, the entire compact and most of the trabecular PHCC were supplied by a arterial blood. Conclusion: The most of PHCC were supplied by hepatic arterial blood and others were supplied by portal blood, arterial combining with portal blood or lack of blood supplies. Evaluation of tumor blood supplies in PHCC is considered to be useful in differential diagnosis and treatment of PHCC

Microvascular Cranial Nerve Palsy

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... Español Eye Health / Eye Health A-Z Microvascular Cranial Nerve Palsy Sections What Is Microvascular Cranial Nerve Palsy? ... Microvascular Cranial Nerve Palsy Treatment What Is Microvascular Cranial Nerve Palsy? Leer en Español: ¿Qué es una parálisis ...

Clinical reference value of retinal microvascular changes in patients with cerebral microbleeds

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Ji-Yuan Guo

2014-12-01

Full Text Available AIM: To study clinical reference value of retinal microvascular changes in patients with cerebral microbleeds(CMBsand discuss its clinical significance. METHODS:From January 2012 to December 2013, 125 hospitalized patients were collected, including 81 cases were male, 44 cases were female, mean age 76.3±11.2 years old. For all patients, functions of liver and kidney, blood-lipoids, blood sugar and blood biochemical examination were tested, and fundus photography and cerebral MR was done. According to the fundus camera eyes, retinal arteriolar equivalent(RAE, retinal venular equivalent(RVE, retinal vein diameter ratio(AVRand arteriovenous crossing sign(AVNwere identified, CMBs were classified with cerebral MRI. All the data were processed by SPSS statistical software. RESULTS: The central retinal arteriolar equivalent(CRAE, central retinal venular equivalent(CRVEand AVR values in the eyes were found no statistical difference(PPCOCLUSION: The results show that retinal microvascular changes, especially small retinal vein arteriovenous cross width, and arteriovenous crossing phenomenon, in which CMBs will happen more likely. After sex, age, hypertension and hyperglycemia in patients with traditional cardiovascular risk factors being ruled out, the retinal microvascular changes are still relatively factors of CMB's occurrence.

The origin of extrarenal arterial blood supply of renal malignancy and its clinical value

International Nuclear Information System (INIS)

Du Duanming; Tong Xiaoqiang; Song Li; Zou Yinghua

2007-01-01

Objective: To study the mechanisms of extrarenal arterial blood supply of renal malignancy for its interventional therapy. Methods: Routine abdominal aortography and selective questionable feeding arteriography were performed in 141 patients with renal malignancy. The characteristics and formation mechanisms of extrarenal arterial blood supply for renal malignancy were analyzed. Results: Of the 141 patients, extrarenal arterial blood supply of renal malignancy were found in 51 patients and there were 87 branchs. The breakthrough of renal capsule with malignancy were found in those 51 patients. No extrarenal arterial blood supply of renal malignancy was found in 90 patients, including 50 patients with and 40 patients without the renal capsule breakthrough with malignancy. The emerge of extrarenal arterial blood supply of renal malignancy were significantly different (χ 2 =31.64, P<0.01) between the patients with and without the breakthrough of renal capsule with malignancy. The origin of extrarenal arterial blood supply were correlated with the location of the tumor. Conclusions: It is important to determine the origin of the extrarenal arterial blood supply in renal malignancy for its interventional therapy. (authors)

Modeling microcirculatory blood flow: current state and future perspectives.

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Gompper, Gerhard; Fedosov, Dmitry A

2016-01-01

Microvascular blood flow determines a number of important physiological processes of an organism in health and disease. Therefore, a detailed understanding of microvascular blood flow would significantly advance biophysical and biomedical research and its applications. Current developments in modeling of microcirculatory blood flow already allow to go beyond available experimental measurements and have a large potential to elucidate blood flow behavior in normal and diseased microvascular networks. There exist detailed models of blood flow on a single cell level as well as simplified models of the flow through microcirculatory networks, which are reviewed and discussed here. The combination of these models provides promising prospects for better understanding of blood flow behavior and transport properties locally as well as globally within large microvascular networks. © 2015 Wiley Periodicals, Inc.

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

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Sarin, Hemant

2010-08-11

Much of our current understanding of microvascular permeability is based on the findings of classic experimental studies of blood capillary permeability to various-sized lipid-insoluble endogenous and non-endogenous macromolecules. According to the classic small pore theory of microvascular permeability, which was formulated on the basis of the findings of studies on the transcapillary flow rates of various-sized systemically or regionally perfused endogenous macromolecules, transcapillary exchange across the capillary wall takes place through a single population of small pores that are approximately 6 nm in diameter; whereas, according to the dual pore theory of microvascular permeability, which was formulated on the basis of the findings of studies on the accumulation of various-sized systemically or regionally perfused non-endogenous macromolecules in the locoregional tissue lymphatic drainages, transcapillary exchange across the capillary wall also takes place through a separate population of large pores, or capillary leaks, that are between 24 and 60 nm in diameter. The classification of blood capillary types on the basis of differences in the physiologic upper limits of pore size to transvascular flow highlights the differences in the transcapillary exchange routes for the transvascular transport of endogenous and non-endogenous macromolecules across the capillary walls of different blood capillary types. The findings and published data of studies on capillary wall ultrastructure and capillary microvascular permeability to lipid-insoluble endogenous and non-endogenous molecules from the 1950s to date were reviewed. In this study, the blood capillary types in different tissues and organs were classified on the basis of the physiologic upper limits of pore size to the transvascular flow of lipid-insoluble molecules. Blood capillaries were classified as non-sinusoidal or sinusoidal on the basis of capillary wall basement membrane layer continuity or lack thereof

Real-time contrast-enhanced ultrasound determination of microvascular blood volume in abdominal subcutaneous adipose tissue in man. Evidence for adipose tissue capillary recruitment

DEFF Research Database (Denmark)

Tobin, L; Simonsen, L; Bülow, J

2010-01-01

The adipose tissue metabolism is dependent on its blood perfusion. During lipid mobilization e.g. during exercise and during lipid deposition e.g. postprandial, adipose tissue blood flow is increased. This increase in blood flow may involve capillary recruitment in the tissue. We investigated...... of ultrasound contrast agent to establish the reproducibility of the technique. In nine subjects, the effect of an oral glucose load on blood flow and microvascular volume was measured in abdominal subcutaneous adipose tissue and forearm skeletal muscle. ¹³³Xe washout and venous occlusion strain......-gauge plethysmography was used to measure the adipose tissue and forearm blood flow, respectively. Ultrasound signal intensity of the first plateau phases was 27 ± dB in the abdominal subcutaneous adipose tissue and 18 ± 2 dB (P

Microvascular Anastomosis Training in Neurosurgery: A Review

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Vadim A. Byvaltsev

2018-01-01

Full Text Available Cerebrovascular diseases are among the most widespread diseases in the world, which largely determine the structure of morbidity and mortality rates. Microvascular anastomosis techniques are important for revascularization surgeries on brachiocephalic and carotid arteries and complex cerebral aneurysms and even during resection of brain tumors that obstruct major cerebral arteries. Training in microvascular surgery became even more difficult with less case exposure and growth of the use of endovascular techniques. In this text we will briefly discuss the history of microvascular surgery, review current literature on simulation models with the emphasis on their merits and shortcomings, and describe the views and opinions on the future of the microvascular training in neurosurgery. In “dry” microsurgical training, various models created from artificial materials that simulate biological tissues are used. The next stage in training more experienced surgeons is to work with nonliving tissue models. Microvascular training using live models is considered to be the most relevant due to presence of the blood flow. Training on laboratory animals has high indicators of face and constructive validity. One of the future directions in the development of microsurgical techniques is the use of robotic systems. Robotic systems may play a role in teaching future generations of microsurgeons. Modern technologies allow access to highly accurate learning environments that are extremely similar to real environment. Additionally, assessment of microsurgical skills should become a fundamental part of the current evaluation of competence within a microneurosurgical training program. Such an assessment tool could be utilized to ensure a constant level of surgical competence within the recertification process. It is important that this evaluation be based on validated models.

Transcranial diffuse optical monitoring of microvascular cerebral hemodynamics after thrombolysis in ischemic stroke

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Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Carrera, David; Martí-Fàbregas, Joan; Durduran, Turgut

2014-01-01

The ultimate goal of therapeutic strategies for ischemic stroke is to reestablish the blood flow to the ischemic region of the brain. However, currently, the local cerebral hemodynamics (microvascular) is almost entirely inaccessible for stroke clinicians at the patient bed-side, and the recanalization of the major cerebral arteries (macrovascular) is the only available measure to evaluate the therapy, which does not always reflect the local conditions. Here we report the case of an ischemic stroke patient whose microvascular cerebral blood flow and oxygenation were monitored by a compact hybrid diffuse optical monitor during thrombolytic therapy. This monitor combined diffuse correlation spectroscopy and near-infrared spectroscopy. The reperfusion assessed by hybrid diffuse optics temporally correlated with the recanalization of the middle cerebral artery (assessed by transcranial-Doppler) and was in agreement with the patient outcome. This study suggests that upon further investigation, diffuse optics might have a potential for bed-side acute stroke monitoring and therapy guidance by providing hemodynamics information at the microvascular level.

Air-drop blood supply in the French Army.

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Javaudin, Olivier; Baillon, A; Varin, N; Martinaud, C; Pouget, T; Civadier, C; Clavier, B; Sailliol, A

2018-02-12

Haemorrhagic shock remains the leading cause of preventable death in overseas and austere settings. Transfusion of blood components is critical in the management of this kind of injury. For French naval and ground military units, this supply often takes too long considering the short shelf-life of red blood cell concentrates (RBCs) and the limited duration of transport in cooling containers (five to six days). Air-drop supply could be an alternative to overcome these difficulties on the condition that air-drop does not cause damage to blood units. After a period of study and technical development of packaging, four air-drops at medium and high altitudes were performed with an aircraft of the French Air Force. After this, one air-drop was carried out at medium altitude with 10 RBCs and 10 French lyophilised plasma (FLYP). A second air-drop was performed with a soldier carrying one FLYP unit at 12 000 feet. For these air-drops real blood products were used, and quality control testing and temperature monitoring were performed. The temperatures inside the containers were within the normal ranges. Visual inspection indicated that transfusion packaging and dumped products did not undergo deterioration. The quality control data on RBCs and FLYP, including haemostasis, suggested no difference before and after air-drop. The operational implementation of the air-drop of blood products seems to be one of the solutions for the supply of blood products in military austere settings or far forward on battlefield, allowing safe and early transfusion. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Progress in the blood supply of Afghanistan.

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Riley, William J; McCullough, Terri Konstenius; Rhamani, Ahmad Masoud; McCullough, Jeffrey

2017-07-01

The blood supply system in Afghanistan was badly damaged by years of conflict. In 2009, the Afghanistan National Blood Safety and Transfusion Service (ANBSTS) was established. For 6 years, we collaborated to assist with policy and infrastructure development; blood bank operations; blood collection, testing, and component production; transfusion practices; and training of technicians, nurses, midwives, and physicians. Policies were established, infrastructure was strengthened, and capable staff was acquired and trained. Standard operating procedures were developed, testing was improved, and quality systems were established. Thirty trainings were held for blood center staff. Four additional formal trainings were held for 39 physicians, 36 nurses and/or midwives, and 38 laboratory technicians. During 5 years of this project, blood collection increased by 40%. The ANBSTS has made impressive progress developing infrastructure, personnel, procedures, quality systems, and training programs and increasing blood collection. Knowledge of transfusion medicine was improved through structured training. © 2017 AABB.

Defibrotide prevents the activation of macrovascular and microvascular endothelia caused by soluble factors released to blood by autologous hematopoietic stem cell transplantation.

Science.gov (United States)

Palomo, Marta; Diaz-Ricart, Maribel; Rovira, Montserrat; Escolar, Ginés; Carreras, Enric

2011-04-01

Endothelial activation and damage occur in association with autologous hematopoietic stem cell transplantation (HSCT). Several of the early complications associated with HSCT seem to have a microvascular location. Through the present study, we have characterized the activation and damage of endothelial cells of both macro (HUVEC) and microvascular (HMEC) origin, occurring early after autologous HSCT, and the potential protective effect of defibrotide (DF). Sera samples from patients were collected before conditioning (Pre), at the time of transplantation (day 0), and at days 7, 14, and 21 after autologous HSCT. Changes in the expression of endothelial cell receptors at the surface, presence and reactivity of extracellular adhesive proteins, and the signaling pathways involved were analyzed. The expression of ICAM-1 at the cell surface increased progressively in both HUVEC and HMEC. However, a more prothrombotic profile was denoted for HMEC, in particular at the time of transplantation (day 0), reflecting the deleterious effect of the conditioning treatment on the endothelium, especially at a microvascular location. Interestingly, this observation correlated with a higher increase in the expression of both tissue factor and von Willebrand factor on the extracellular matrix, together with activation of intracellular p38 MAPK and Akt. Previous exposure and continuous incubation of cells with DF prevented the signs of activation and damage induced by the autologous sera. These observations corroborate that conditioning treatment in autologous HSCT induces a proinflammatory and a prothrombotic phenotype, especially at a microvascular location, and indicate that DF has protective antiinflammatory and antithrombotic effects in this setting. Copyright © 2011 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Functional blood flow patterns of the endolymphatic sac in the rat

DEFF Research Database (Denmark)

Friis, Morten; Qvortrup, Klaus

2008-01-01

Conclusion. Visualization of the endolymphatic sac vascular network under video fluorescence microscopy showed a typical microvascular organization. The microvascular arrangement and the microcirculation may reflect a functional state of the endolymphatic sac. Damage or change of the blood circul...... sac served as return paths for the microcirculation. The blood flow pattern was highly variable between rats.......Conclusion. Visualization of the endolymphatic sac vascular network under video fluorescence microscopy showed a typical microvascular organization. The microvascular arrangement and the microcirculation may reflect a functional state of the endolymphatic sac. Damage or change of the blood...

The association of systemic microvascular changes with lung function and lung density: a cross-sectional study.

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Bianca Harris

Full Text Available Smoking causes endothelial dysfunction and systemic microvascular disease with resultant end-organ damage in the kidneys, eyes and heart. Little is known about microvascular changes in smoking-related lung disease. We tested if microvascular changes in the retina, kidneys and heart were associated with obstructive spirometry and low lung density on computed tomography. The Multi-Ethnic Study of Atherosclerosis recruited participants age 45-84 years without clinical cardiovascular disease. Measures of microvascular function included retinal arteriolar and venular caliber, urine albumin-to-creatinine ratio and, in a subset, myocardial blood flow on magnetic resonance imaging. Spirometry was measured following ATS/ERS guidelines. Low attenuation areas (LAA were measured on lung fields of cardiac computed tomograms. Regression models adjusted for pulmonary and cardiac risk factors, medications and body size. Among 3,397 participants, retinal venular caliber was inversely associated with forced expiratory volume in one second (FEV(1 (P<0.001 and FEV(1/forced vital capacity (FVC ratio (P = 0.04. Albumin-to-creatinine ratio was inversely associated with FEV(1 (P = 0.002 but not FEV(1/FVC. Myocardial blood flow (n = 126 was associated with lower FEV(1 (P = 0.02, lower FEV(1/FVC (P = 0.001 and greater percentage LAA (P = 0.04. Associations were of greater magnitude among smokers. Low lung function was associated with microvascular changes in the retina, kidneys and heart, and low lung density was associated with impaired myocardial microvascular perfusion. These cross-sectional results suggest that microvascular damage with end-organ dysfunction in all circulations may pertain to the lung, that lung dysfunction may contribute to systemic microvascular disease, or that there may be a shared predisposition.

Dysregulation of coronary microvascular reactivity in asymptomatic patients with type 2 diabetes mellitus

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Momose, Mitsuru; Neverve, Jodi; Nekolla, Stephan G.; Schwaiger, Markus; Bengel, Frank M. [Nuklearmedizinische Klinik und Poliklinik der Technischen Universitaet Muenchen, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675 Munich (Germany); Abletshauser, Claudia [Department of Medicine, Novartis Pharma GmbH, Nuernberg (Germany); Schnell, Oliver; Standl, Eberhard [Institut fuer Diabetesforschung, Munich (Germany)

2002-12-01

In diabetic patients, a number of studies have suggested an impairment of vascular reactivity in response to vasodilatory stimuli. The pattern of dysregulation at the coronary microcirculatory level, however, has not been clearly defined. Thus, it was the aim of this study to characterise coronary microvascular function non-invasively in a homogeneous group of asymptomatic type 2 diabetic patients. In 46 patients with type 2 diabetes, myocardial blood flow (MBF) was quantified at baseline, in response to cold pressor test (CPT) and during adenosine-mediated vasodilation using positron emission tomography and nitrogen-13 ammonia. None of the patients had been treated with insulin, and none had symptoms of cardiac disease. Decreased MBF during CPT, indicating microvascular dysregulation, was observed in 16 patients (CPT-), while 30 patients demonstrated increased MBF during CPT (CPT+). Response to CPT was mildly, but significantly correlated with response to adenosine (r=0.44, P=0.0035). There was no difference in HbA1c, serum lipid levels or serum endothelial markers between the groups. Microvascular dysregulation in the CPT- group was associated with elevated baseline MBF (P<0.0001), reduced baseline vascular resistance (P=0.0026) and an abnormal increase in resistance during CPT (P=0.0002). In conclusion, coronary microvascular dysregulation is present in approximately one-third of asymptomatic, non-insulin-treated type 2 diabetic patients. Elevated baseline blood flow and reduced microvascular resistance at rest are characteristics of this dysregulation. These data suggest a state of activation of endothelial-dependent vasodilation at baseline which appears to limit the flow response to stress conditions. (orig.)

Radionuclide assessment of pulmonary microvascular permeability

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Groeneveld, A.B.J. [Medical Intensive Care Unit, Department of Internal Medicine, Free University Hospital, De Boelelaan 1117, 1081 HV Amsterdam (Netherlands)

1997-04-01

The literature has been reviewed to evaluate the technique and clinical value of radionuclide measurements of microvascular permeability and oedema formation in the lungs. Methodology, modelling and interpretation vary widely among studies. Nevertheless, most studies agree on the fact that the measurement of permeability via pulmonary radioactivity measurements of intravenously injected radiolabelled proteins versus that in the blood pool, the so-called pulmonary protein transport rate (PTR), can assist the clinician in discriminating between permeability oedema of the lungs associated with the adult respiratory distress syndrome (ARDS) and oedema caused by an increased filtration pressure, for instance in the course of cardiac disease, i.e. pressure-induced pulmonary oedema. Some of the techniques used to measure PTR are also able to detect subclinical forms of lung microvascular injury not yet complicated by permeability oedema. This may occur after cardiopulmonary bypass and major vascular surgery, for instance. By paralleling the clinical severity and course of the ARDS, the PTR method may also serve as a tool to evaluate new therapies for the syndrome. Taken together, the currently available radionuclide methods, which are applicable at the bedside in the intensive care unit, may provide a gold standard for detecting minor and major forms of acute microvascular lung injury, and for evaluating the severity, course and response to treatment. (orig.). With 2 tabs.

Normal blood supply of the canine patella

International Nuclear Information System (INIS)

Howard, P.E.; Wilson, J.W.; Robbins, T.A.; Ribble, G.A.

1986-01-01

The normal blood supply of the canine patella was evaluated, using microangiography and correlated histology. Arterioles entered the cortex of the patella at multiple sites along the medial, lateral, and dorsal aspects. The body of the patella was vascularized uniformly, with many arterioles that branched and anastomosed extensively throughout the patella. The patella was not dependent on a single nutrient artery for its afferent supply, but had an extensive interior vascular network. These factors should ensure rapid revascularization and healing of patellar fractures, provided appropriate fracture fixation is achieved

Microvascularization on collared peccary placenta

DEFF Research Database (Denmark)

Santos, Tatiana Carlesso; Oliveira, Moacir Franco; Dantzer, Vibeke

2012-01-01

and fetal compartments of the placentae. The immunolocalization of vimentin in the vascular endothelium and in the smooth muscle cells of blood vessels showed indented capillaries along the uterine epithelium and the trophoblast at the sides of complementary maternal and fetal microfolds, or rugae...... into a microvascular network wall in a basket-like fashion. At the base of these baskets venules were formed. On the fetal side, arterioles branched centrally in the fetal rugae into a capillary network in a bulbous form, complementary to the opposite maternal depressions forming the baskets. At the base...

Perfusion MRI derived indices of microvascular shunting and flow control correlate with tumor grade and outcome in patients with cerebral glioma

DEFF Research Database (Denmark)

Tietze, Anna; Mouridsen, Kim; Lassen-Ramshad, Yasmin

2015-01-01

Objectives: Deficient microvascular blood flow control is thought to cause tumor hypoxia and increase resistance to therapy. In glioma patients, we tested whether perfusion-weighted MRI (PWI) based indices of microvascular flow control provide more information on tumor grade and patient outcome...... than does the established PWI angiogenesis marker, cerebral blood volume (CBV). Material and Methods: Seventy-two glioma patients (sixty high-grade, twelve low-grade gliomas) were included. Capillary transit time heterogeneity (CTH) and COV, its ratio to blood mean transit time, provide indices...... of microvascular flow control and the extent to which oxygen can be extracted by tumor tissue. The ability of these parameters and CBV to differentiate tumor grade were assessed by receiver operating characteristic curves and logistic regression. Their ability to predict time to progression and overall survival...

Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study.

Science.gov (United States)

Hueper, Katja; Vogel-Claussen, Jens; Parikh, Megha A; Austin, John H M; Bluemke, David A; Carr, James; Choi, Jiwoong; Goldstein, Thomas A; Gomes, Antoinette S; Hoffman, Eric A; Kawut, Steven M; Lima, Joao; Michos, Erin D; Post, Wendy S; Po, Ming Jack; Prince, Martin R; Liu, Kiang; Rabinowitz, Dan; Skrok, Jan; Smith, Ben M; Watson, Karol; Yin, Youbing; Zambeli-Ljepovic, Alan M; Barr, R Graham

2015-09-01

Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease. To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema. PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below -950 Hounsfield units (-950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output. Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P emphysema-950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers. PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature.

Phase coherence of 0.1 Hz microvascular tone oscillations during the local heating

Science.gov (United States)

Mizeva, I. A.

2017-06-01

The origin of the mechanisms of blood flow oscillations at low frequencies is discussed. It is known that even isolated arteriole demonstrates oscillations with the frequency close to 0.1 Hz, which is caused by the synchronous activity of myocyte cells. On the other hand, oscillations with close frequency are found in the heart rate, which are associated with quite different mechanism. The main purpose of this work is to study phase coherence of the blood flow oscillations in the peripheral vessels under basal and perturbed conditions. Local heating which locally influences the microvascular tone, as one of currently elucidated in sufficient detail physiological test, was chosen. During such provocation blood flow though the small vessels significantly increases because of vasodilation induced by the local synthesis of nitric oxide. In the first part of the paper microvascular response to the local test is quantified in healthy and pathological conditions of diabetes mellitus type 1. It is obtained that regardless of the pathology, subjects with high basal perfusion had lower reserve for vasodilation, which can be caused by the low elasticity of microvascular structure. Further synchronization of pulsations of the heated and undisturbed skin was evaluated on the base of wavelet phase coherency analysis. Being highly synchronised in basal conditions 0.1 Hz pulsations became more independent during heating, especially during NO-mediated vasodilation.

Simulation-optimization model for production planning in the blood supply chain.

Science.gov (United States)

Osorio, Andres F; Brailsford, Sally C; Smith, Honora K; Forero-Matiz, Sonia P; Camacho-Rodríguez, Bernardo A

2017-12-01

Production planning in the blood supply chain is a challenging task. Many complex factors such as uncertain supply and demand, blood group proportions, shelf life constraints and different collection and production methods have to be taken into account, and thus advanced methodologies are required for decision making. This paper presents an integrated simulation-optimization model to support both strategic and operational decisions in production planning. Discrete-event simulation is used to represent the flows through the supply chain, incorporating collection, production, storing and distribution. On the other hand, an integer linear optimization model running over a rolling planning horizon is used to support daily decisions, such as the required number of donors, collection methods and production planning. This approach is evaluated using real data from a blood center in Colombia. The results show that, using the proposed model, key indicators such as shortages, outdated units, donors required and cost are improved.

In-vivo assessment of microvascular functional dynamics by combination of cmOCT and wavelet transform

Science.gov (United States)

Smirni, Salvatore; MacDonald, Michael P.; Robertson, Catherine P.; McNamara, Paul M.; O'Gorman, Sean; Leahy, Martin J.; Khan, Faisel

2018-02-01

The cutaneous microcirculation represents an index of the health status of the cardiovascular system. Conventional methods to evaluate skin microvascular function are based on measuring blood flow by laser Doppler in combination with reactive tests such as post-occlusive reactive hyperaemia (PORH). Moreover, the spectral analysis of blood flow signals by continuous wavelet transform (CWT) reveals nonlinear oscillations reflecting the functionality of microvascular biological factors, e.g. endothelial cells (ECs). Correlation mapping optical coherence tomography (cmOCT) has been previously described as an efficient methodology for the morphological visualisation of cutaneous micro-vessels. Here, we show that cmOCT flow maps can also provide information on the functional components of the microcirculation. A spectral domain optical coherence tomography (SD-OCT) imaging system was used to acquire 90 sequential 3D OCT volumes from the forearm of a volunteer, while challenging the micro-vessels with a PORH test. The volumes were sampled in a temporal window of 25 minutes, and were processed by cmOCT to obtain flow maps at different tissue depths. The images clearly show changes of flow in response to the applied stimulus. Furthermore, a blood flow signal was reconstructed from cmOCT maps intensities to investigate the microvascular nonlinear dynamics by CWT. The analysis revealed oscillations changing in response to PORH, associated with the activity of ECs and the sympathetic innervation. The results demonstrate that cmOCT may be potentially used as diagnostic tool for the assessment of microvascular function, with the advantage of also providing spatial resolution and structural information compared to the traditional laser Doppler techniques.

Catheter-Based Measurements of Absolute Coronary Blood Flow and Microvascular Resistance: Feasibility, Safety, and Reproducibility in Humans.

Science.gov (United States)

Xaplanteris, Panagiotis; Fournier, Stephane; Keulards, Daniëlle C J; Adjedj, Julien; Ciccarelli, Giovanni; Milkas, Anastasios; Pellicano, Mariano; Van't Veer, Marcel; Barbato, Emanuele; Pijls, Nico H J; De Bruyne, Bernard

2018-03-01

The principle of continuous thermodilution can be used to calculate absolute coronary blood flow and microvascular resistance (R). The aim of the study is to explore the safety, feasibility, and reproducibility of coronary blood flow and R measurements as measured by continuous thermodilution in humans. Absolute coronary flow and R can be calculated by thermodilution by infusing saline at room temperature through a dedicated monorail catheter. The temperature of saline as it enters the vessel, the temperature of blood and saline mixed in the distal part of the vessel, and the distal coronary pressure were measured by a pressure/temperature sensor-tipped guidewire. The feasibility and safety of the method were tested in 135 patients who were referred for coronary angiography. No significant adverse events were observed; in 11 (8.1%) patients, bradycardia and concomitant atrioventricular block appeared transiently and were reversed immediately on interruption of the infusion. The reproducibility of measurements was tested in a subgroup of 80 patients (129 arteries). Duplicate measurements had a strong correlation both for coronary blood flow (ρ=0.841, P <0.001; intraclass correlation coefficient=0.89, P <0.001) and R (ρ=0.780, P <0.001; intraclass correlation coefficient=0.89, P <0.001). In Bland-Altman plots, there was no significant bias or asymmetry. Absolute coronary blood flow (in L/min) and R (in mm Hg/L/min or Wood units) can be safely and reproducibly measured with continuous thermodilution. This approach constitutes a new opportunity for the study of the coronary microcirculation. © 2018 American Heart Association, Inc.

Numerical Modeling of Interstitial Fluid Flow Coupled with Blood Flow through a Remodeled Solid Tumor Microvascular Network.

Science.gov (United States)

Soltani, M; Chen, P

2013-01-01

Modeling of interstitial fluid flow involves processes such as fluid diffusion, convective transport in extracellular matrix, and extravasation from blood vessels. To date, majority of microvascular flow modeling has been done at different levels and scales mostly on simple tumor shapes with their capillaries. However, with our proposed numerical model, more complex and realistic tumor shapes and capillary networks can be studied. Both blood flow through a capillary network, which is induced by a solid tumor, and fluid flow in tumor's surrounding tissue are formulated. First, governing equations of angiogenesis are implemented to specify the different domains for the network and interstitium. Then, governing equations for flow modeling are introduced for different domains. The conservation laws for mass and momentum (including continuity equation, Darcy's law for tissue, and simplified Navier-Stokes equation for blood flow through capillaries) are used for simulating interstitial and intravascular flows and Starling's law is used for closing this system of equations and coupling the intravascular and extravascular flows. This is the first study of flow modeling in solid tumors to naturalistically couple intravascular and extravascular flow through a network. This network is generated by sprouting angiogenesis and consisting of one parent vessel connected to the network while taking into account the non-continuous behavior of blood, adaptability of capillary diameter to hemodynamics and metabolic stimuli, non-Newtonian blood flow, and phase separation of blood flow in capillary bifurcation. The incorporation of the outlined components beyond the previous models provides a more realistic prediction of interstitial fluid flow pattern in solid tumors and surrounding tissues. Results predict higher interstitial pressure, almost two times, for realistic model compared to the simplified model.

Numerical Modeling of Interstitial Fluid Flow Coupled with Blood Flow through a Remodeled Solid Tumor Microvascular Network.

Directory of Open Access Journals (Sweden)

M Soltani

Full Text Available Modeling of interstitial fluid flow involves processes such as fluid diffusion, convective transport in extracellular matrix, and extravasation from blood vessels. To date, majority of microvascular flow modeling has been done at different levels and scales mostly on simple tumor shapes with their capillaries. However, with our proposed numerical model, more complex and realistic tumor shapes and capillary networks can be studied. Both blood flow through a capillary network, which is induced by a solid tumor, and fluid flow in tumor's surrounding tissue are formulated. First, governing equations of angiogenesis are implemented to specify the different domains for the network and interstitium. Then, governing equations for flow modeling are introduced for different domains. The conservation laws for mass and momentum (including continuity equation, Darcy's law for tissue, and simplified Navier-Stokes equation for blood flow through capillaries are used for simulating interstitial and intravascular flows and Starling's law is used for closing this system of equations and coupling the intravascular and extravascular flows. This is the first study of flow modeling in solid tumors to naturalistically couple intravascular and extravascular flow through a network. This network is generated by sprouting angiogenesis and consisting of one parent vessel connected to the network while taking into account the non-continuous behavior of blood, adaptability of capillary diameter to hemodynamics and metabolic stimuli, non-Newtonian blood flow, and phase separation of blood flow in capillary bifurcation. The incorporation of the outlined components beyond the previous models provides a more realistic prediction of interstitial fluid flow pattern in solid tumors and surrounding tissues. Results predict higher interstitial pressure, almost two times, for realistic model compared to the simplified model.

Acute cocoa flavanol supplementation improves muscle macro- and microvascular but not anabolic responses to amino acids in older men.

Science.gov (United States)

Phillips, Bethan E; Atherton, Philip J; Varadhan, Krishna; Limb, Marie C; Williams, John P; Smith, Kenneth

2016-05-01

The anabolic effects of nutrition on skeletal muscle may depend on adequate skeletal muscle perfusion, which is impaired in older people. Cocoa flavanols have been shown to improve flow-mediated dilation, an established measure of endothelial function. However, their effect on muscle microvascular blood flow is currently unknown. Therefore, the objective of this study was to explore links between the consumption of cocoa flavanols, muscle microvascular blood flow, and muscle protein synthesis (MPS) in response to nutrition in older men. To achieve this objective, leg blood flow (LBF), muscle microvascular blood volume (MBV), and MPS were measured under postabsorptive and postprandial (intravenous Glamin (Fresenius Kabi, Germany), dextrose to sustain glucose ∼7.5 mmol·L(-1)) conditions in 20 older men. Ten of these men were studied with no cocoa flavanol intervention and a further 10 were studied with the addition of 350 mg of cocoa flavanols at the same time that nutrition began. Leg (femoral artery) blood flow was measured by Doppler ultrasound, muscle MBV by contrast-enhanced ultrasound using Definity (Lantheus Medical Imaging, Mass., USA) perflutren contrast agent and MPS using [1, 2-(13)C2]leucine tracer techniques. Our results show that although older individuals do not show an increase in LBF or MBV in response to feeding, these absent responses are apparent when cocoa flavanols are given acutely with nutrition. However, this restoration in vascular responsiveness is not associated with improved MPS responses to nutrition. We conclude that acute cocoa flavanol supplementation improves muscle macro- and microvascular responses to nutrition, independently of modifying muscle protein anabolism.

Microvascular Remodeling and Wound Healing: A Role for Pericytes

Science.gov (United States)

Dulmovits, Brian M.; Herman, Ira M.

2012-01-01

Physiologic wound healing is highly dependent on the coordinated functions of vascular and non-vascular cells. Resolution of tissue injury involves coagulation, inflammation, formation of granulation tissue, remodeling and scarring. Angiogenesis, the growth of microvessels the size of capillaries, is crucial for these processes, delivering blood-borne cells, nutrients and oxygen to actively remodeling areas. Central to angiogenic induction and regulation is microvascular remodeling, which is dependent upon capillary endothelial cell and pericyte interactions. Despite our growing knowledge of pericyte-endothelial cell crosstalk, it is unclear how the interplay among pericytes, inflammatory cells, glia and connective tissue elements shape microvascular injury response. Here, we consider the relationships that pericytes form with the cellular effectors of healing in normal and diabetic environments, including repair following injury and vascular complications of diabetes, such as diabetic macular edema and proliferative diabetic retinopathy. In addition, pericytes and stem cells possessing “pericyte-like” characteristics are gaining considerable attention in experimental and clinical efforts aimed at promoting healing or eradicating ocular vascular proliferative disorders. As the origin, identification and characterization of microvascular pericyte progenitor populations remains somewhat ambiguous, the molecular markers, structural and functional characteristics of pericytes will be briefly reviewed. PMID:22750474

Intensive blood pressure control affects cerebral blood flow in type 2 diabetes mellitus patients

DEFF Research Database (Denmark)

Kim, Yu-Sok; Davis, Shyrin C A T; Truijen, Jasper

2011-01-01

Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic...... variables and transcranial Doppler-determined cerebral blood flow velocity (CBFV), cerebral CO2 responsiveness, and cognitive function were determined after 3 and 6 months of intensive BP control in 17 type 2 diabetic patients with microvascular complications (T2DM+), in 18 diabetic patients without (T2DM......-) microvascular complications, and in 16 nondiabetic hypertensive patients. Cerebrovascular reserve capacity was lower in T2DM+ versus T2DM- and nondiabetic hypertensive patients (4.6±1.1 versus 6.0±1.6 [P

Invasive assessment of coronary microvascular dysfunction in hypertrophic cardiomyopathy: the index of microvascular resistance

International Nuclear Information System (INIS)

Gutiérrez-Barrios, Alejandro; Camacho-Jurado, Francisco; Díaz-Retamino, Enrique; Gamaza-Chulián, Sergio; Agarrado-Luna, Antonio; Oneto-Otero, Jesús; Del Rio-Lechuga, Ana; Benezet-Mazuecos, Javier

2015-01-01

Summary: We present a review of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and an interesting case of a symptomatic familial HCM patient with inducible ischemia by single photon emission computed tomography. Coronary angiography revealed normal epicardial arteries. Pressure wire measurements of fractional flow reserve (FFR), coronary flow reserve (CFR) and index of microvascular resistance (IMR) demonstrated a significant microcirculatory dysfunction. This is the first such case that documents this abnormality invasively using the IMR. The measurement of IMR, a novel marker of microcirculatory dysfunction, provides novel insights into the pathophysiology of this condition. - Highlights: • Microvascular dysfunction is a common feature in hypertrophic cardiomyopathy (HCM) and represents a strong predictor of unfavorable outcome and cardiovascular mortality. • The index of microvascular resistance (IMR) is a new method for invasively assessing the state of the coronary microcirculation using a single pressure-temperature sensor-tipped coronary wire. • However assessment of IMR in HCM has not been previously reported. We report a case in which microvascular dysfunction is assessed by IMR. This index may be useful in future researches of HCM.

Invasive assessment of coronary microvascular dysfunction in hypertrophic cardiomyopathy: the index of microvascular resistance

Energy Technology Data Exchange (ETDEWEB)

Gutiérrez-Barrios, Alejandro, E-mail: aleklos@hotmail.com [Cardiology Department, Jerez Hospital, Jerez (Spain); Camacho-Jurado, Francisco [Cardiology Department, Punta Europa Hospital, Algeciras (Spain); Díaz-Retamino, Enrique; Gamaza-Chulián, Sergio; Agarrado-Luna, Antonio; Oneto-Otero, Jesús; Del Rio-Lechuga, Ana; Benezet-Mazuecos, Javier [Cardiology Department, Jerez Hospital, Jerez (Spain)

2015-10-15

Summary: We present a review of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and an interesting case of a symptomatic familial HCM patient with inducible ischemia by single photon emission computed tomography. Coronary angiography revealed normal epicardial arteries. Pressure wire measurements of fractional flow reserve (FFR), coronary flow reserve (CFR) and index of microvascular resistance (IMR) demonstrated a significant microcirculatory dysfunction. This is the first such case that documents this abnormality invasively using the IMR. The measurement of IMR, a novel marker of microcirculatory dysfunction, provides novel insights into the pathophysiology of this condition. - Highlights: • Microvascular dysfunction is a common feature in hypertrophic cardiomyopathy (HCM) and represents a strong predictor of unfavorable outcome and cardiovascular mortality. • The index of microvascular resistance (IMR) is a new method for invasively assessing the state of the coronary microcirculation using a single pressure-temperature sensor-tipped coronary wire. • However assessment of IMR in HCM has not been previously reported. We report a case in which microvascular dysfunction is assessed by IMR. This index may be useful in future researches of HCM.

The Ubiquitin-Proteasome System and Microvascular Complications of Diabetes

Directory of Open Access Journals (Sweden)

Saeed Yadranji Aghdam

2013-01-01

Full Text Available The ubiquitin-proteasome system (UPS is the mainstay of protein quality control which regulates cell cycle, differentiation and various signal transduction pathways in eukaryotic cells. The timely and selective degradation of surplus and/or aberrant proteins by the UPS is essential for normal cellular physiology. Any disturbance, delay or exaggeration in the process of selection, sequestration, labeling for degradation and degradation of target proteins by the UPS will compromise cellular and tissue homeostasis. High blood glucose or hyperglycemia caused by diabetes disrupts normal vascular function in several target organs including the retina and kidney resulting in the development of diabetic retinopathy (DR and diabetic nephropathy (DN. We and others have shown that hyperglycemia and oxidative stress modulate UPS activity in the retina and kidney. The majority of studies have focused on the kidney and provided insights into the contribution of dysregulated UPS to microvascular damage in DN. The eye is a unique organ in which a semi-fluid medium, the vitreous humor, separates the neural retina and its anastomosed blood vessels from the semi-solid lens tissue. The complexity of the cellular and molecular components of the eye may require a normal functioning and well tuned UPS for healthy vision. Altered UPS activity may contribute to the development of retinal microvascular complications of diabetes. A better understanding of the molecular nature of the ocular UPS function under normal and diabetic conditions is essential for development of novel strategies targeting its activity. This review will discuss the association of retinal vascular cell UPS activity with microvascular damage in DR with emphasis on alterations of the PA28 subunits of the UPS.

Study on the relationship between blood levels of glycated hemoglobin (HbA1c) and micro-vascular nephropathy in patients with type 2 diabetes

International Nuclear Information System (INIS)

Luo Rong; Li Zhuocheng; Yan Dewen

2004-01-01

Objective: To evaluate the relationship between blood levels of glycated hemoglobin and microvascular nephropathy in patients with type diabetes. Methods: Blood Glycosylated hemoglobin levels were determined with affinity chromatography and 24 hour urinary microalbumin (m-Alb), β 2 microglobin (β 2 -m) quantified with RIA in 76 patients and 30 controls. Results: With glycated hemoglobin within normal range, there were no differences between the amounts of patients' urinary protein contents and those in controls (P>0.05). With higher blood glycated hemoglobin levels, significant differences could be observed (P 2 microglobin. Differences among the 24 hour urinary quantities of mAlb and β 2 -m in the three groups of patients (divided according to the HbA1c levels, namely 9.0%) were also significant (P 2 microglobin is very important for early detection of diabetic nephropathy

Transmural Variation and Anisotropy of Microvascular Flow Conductivity in the Rat Myocardium

KAUST Repository

Smith, Amy F.

2014-05-28

Transmural variations in the relationship between structural and fluid transport properties of myocardial capillary networks are determined via continuum modeling approaches using recent three-dimensional (3D) data on the microvascular structure. Specifically, the permeability tensor, which quantifies the inverse of the blood flow resistivity of the capillary network, is computed by volume-averaging flow solutions in synthetic networks with geometrical and topological properties derived from an anatomically-detailed microvascular data set extracted from the rat myocardium. Results show that the permeability is approximately ten times higher in the principal direction of capillary alignment (the "longitudinal" direction) than perpendicular to this direction, reflecting the strong anisotropy of the microvascular network. Additionally, a 30% increase in capillary diameter from subepicardium to subendocardium is shown to translate to a 130% transmural rise in permeability in the longitudinal capillary direction. This result supports the hypothesis that perfusion is preferentially facilitated during diastole in the subendocardial microvasculature to compensate for the severely-reduced systolic perfusion in the subendocardium.

Depth-dependent flow and pressure characteristics in cortical microvascular networks.

Directory of Open Access Journals (Sweden)

Franca Schmid

2017-02-01

Full Text Available A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations with discrete tracking of red blood cells (RBCs are performed in three realistic microvascular networks from the mouse cerebral cortex. Our analysis is based on trajectories of individual RBCs and focuses on layer-specific flow phenomena until a cortical depth of 1 mm. The individual RBC trajectories reveal that in the capillary bed RBCs preferentially move in plane. Hence, the capillary flow field shows laminar patterns and a layer-specific analysis is valid. We demonstrate that for RBCs entering the capillary bed close to the cortical surface (< 400 μm the largest pressure drop takes place in the capillaries (37%, while for deeper regions arterioles are responsible for 61% of the total pressure drop. Further flow characteristics, such as capillary transit time or RBC velocity, also vary significantly over cortical depth. Comparison of purely topological characteristics with flow-based ones shows that a combined interpretation of topology and flow is indispensable. Our results provide evidence that it is crucial to consider layer-specific differences for all investigations related to the flow and pressure distribution in the cortical vasculature. These findings support the hypothesis that for an efficient oxygen up-regulation at least two regulation mechanisms must be playing hand in hand, namely cerebral blood flow increase and microvascular flow homogenization. However, the contribution of both regulation mechanisms to oxygen up-regulation likely varies over depth.

The effects of anti-obesity intervention with orlistat and sibutramine on microvascular endothelial function.

Science.gov (United States)

Al-Tahami, Belqes Abdullah Mohammad; Ismail, Ab Aziz Al-Safi; Bee, Yvonne Tee Get; Awang, Siti Azima; Salha Wan Abdul Rani, Wan Rimei; Sanip, Zulkefli; Rasool, Aida Hanum Ghulam

2015-01-01

Obesity is associated with impaired microvascular endothelial function. We aimed to determine the effects of orlistat and sibutramine treatment on microvascular endothelial function, anthropometric and lipid profile, blood pressure (BP), and heart rate (HR). 76 subjects were recruited and randomized to receive orlistat 120 mg three times daily or sibutramine 10 mg daily for 9 months. Baseline weight, BMI, BP, HR and lipid profile were taken. Microvascular endothelial function was assessed using laser Doppler fluximetry and iontophoresis process. Maximum change (max), percent change (% change) and peak flux (peak) in perfusion to acetylcholine (ACh) and sodium nitroprusside (SNP) iontophoresis were used to quantify endothelium dependent and independent vasodilatations. 24 subjects in both groups completed the trial. After treatment, weight and BMI were decreased for both groups. AChmax, ACh % change and ACh peak were increased in orlistat-treated group but no difference was observed for sibutramine-treated group. BP and total cholesterol (TC) were reduced for orlistat-treated group. HR was reduced for orlistat-treated group but was increased in sibutramine-treated group. 9 months treatment with orlistat significantly improved microvascular endothelial function. This was associated with reductions in weight, BMI, BP, HR, TC and low density lipoprotein cholesterol. No effect was seen in microvascular endothelial function with sibutramine.

Preventing microvascular complications in type 1 diabetes mellitus

Science.gov (United States)

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c) level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour. PMID:25941647

Uneven Distribution of Regional Blood Supply Prompts the Cystic Change of Pituitary Adenoma.

Science.gov (United States)

Zhang, Jianhe; Gu, Jianjun; Ma, Yiming; Huang, Yinxing; Wang, Jiaxing; Wu, Zhifeng; Zhong, Qun; Wang, Shousen

2017-07-01

Previous studies have suggested that the cystic change of pituitary adenoma might be related to the blood supply and metabolism of the tumor; however, the exact pathologic mechanism underlying the cystic change remains unknown. We aimed to assess the features of regional blood supply of pituitary adenoma and examine its relationship with the cystic change of pituitary adenoma. Patients (N = 79) with pituitary adenoma admitted to our hospital were divided into the parenchyma group (n = 40) or the cystic change group (n = 39). Dynamic contrast-enhanced magnetic resonance imaging of the pituitary adenoma was conducted for the parenchyma group and the steepest slopes (SS max , reflecting regional blood supply) at different areas were calculated. The location of cystic change of the pituitary adenoma was recorded and analyzed for the cystic change group. The parenchyma group showed an upper SS max of 2.52 ± 1.18, a lower SS max of 2.89 ± 1.46, a left SS max of 2.71 ± 1.31, and a right SS max of 2.66 ± 1.29. The difference between the upper and lower SS max was statistically significant (P supply is unevenly distributed in the parenchymal pituitary adenoma, with reduced blood supply in the upper than the lower region. Cystic change mainly occurs in the upper region of pituitary adenoma. Copyright © 2017 Elsevier Inc. All rights reserved.

Cigarette smoking increases white blood cell aggregation in whole blood.

OpenAIRE

Bridges, A B; Hill, A; Belch, J J

1993-01-01

We studied the effect of chronic cigarette smoking on white blood cell aggregation, increased aggregation predisposes to microvascular occlusion and damage. Current smokers had significantly increased white blood cell aggregation when compared with non smokers. The presence of chronically activated white blood cells in current smokers may be relevant in the pathogenesis of ischaemic vascular disease.

The effect of nitroglycerin on microvascular perfusion and oxygenation during gastric tube reconstruction

NARCIS (Netherlands)

Buise, Marc P.; Ince, Can; Tilanus, Hugo W.; Klein, Jan; Gommers, Diederik; van Bommel, Jasper

2005-01-01

Esophagectomy followed by gastric tube reconstruction is the surgical treatment of choice for patients with esophageal cancer. Complications of the cervical anastomosis are associated with impaired microvascular blood flow (MBF) and ischemia in the gastric fundus. The aim of the present study was to

[Biocybernetic approach to the thermometric methods of blood supply measurements of periodontal tissues].

Science.gov (United States)

Pastusiak, J; Zakrzewski, J

1988-11-01

Specific biocybernetic approach to the problem of the blood supply determination of paradontium tissues by means of thermometric methods has been presented in the paper. The compartment models of the measuring procedure have been given. Dilutodynamic methology and classification has been applied. Such an approach enables to select appropriate biophysical parameters describing the state of blood supply of paradontium tissues and optimal design of transducers and measuring methods.

Implications of demographics on future blood supply: a population-based cross-sectional study.

Science.gov (United States)

Greinacher, Andreas; Fendrich, Konstanze; Brzenska, Ralf; Kiefel, Volker; Hoffmann, Wolfgang

2011-04-01

Data on blood recipients are sparse and unconnected to data on blood donors. The objective was to analyze the impact of the demographic change on future blood demand and supply in a German federal state. A population-based cross-sectional study was conducted. For all in-hospital transfused red blood cells (RBCs; n = 95,477), in the German federal state Mecklenburg-Pomerania in 2005, characteristics of the patient and the blood donor (118,406 blood donations) were obtained. Population data were used to predict blood demand and supply until 2020. By 2020 the population increase of those aged 65 years or more (+26.4%) in Mecklenburg-Pomerania will be paralleled by a decrease of the potential donor population (18-68 years; -16.1%). Assuming stable rates per age group until 2020, the demand for in-hospital blood transfusions will increase by approximately 25% (24,000 RBC units) while blood donations will decrease by approximately 27% (32,000 RBC units). The resulting, predicted shortfall is 47% of demand for in-hospital patients (56,000 RBC units). Validation using historical data (1997-2007) showed that the model predicted the RBC demand with a deviation of only 1.2%. Demographic changes are particularly pronounced in former East Germany, but by 2030 most European countries will face a similar situation. The decrease of younger age groups requires an increase of blood donation rates and interdisciplinary approaches to reduce the need for transfusion to maintain sufficient blood supply. Demography is a major determinant of future transfusion demand. All efforts should be made by Western societies to systematically obtain data on blood donors and recipients to develop strategies to meet future blood demand. © 2010 American Association of Blood Banks.

Modified allocation capacitated planning model in blood supply chain management

Science.gov (United States)

Mansur, A.; Vanany, I.; Arvitrida, N. I.

2018-04-01

Blood supply chain management (BSCM) is a complex process management that involves many cooperating stakeholders. BSCM involves four echelon processes, which are blood collection or procurement, production, inventory, and distribution. This research develops an optimization model of blood distribution planning. The efficiency of decentralization and centralization policies in a blood distribution chain are compared, by optimizing the amount of blood delivered from a blood center to a blood bank. This model is developed based on allocation problem of capacitated planning model. At the first stage, the capacity and the cost of transportation are considered to create an initial capacitated planning model. Then, the inventory holding and shortage costs are added to the model. These additional parameters of inventory costs lead the model to be more realistic and accurate.

Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach.

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Panazzolo, Diogo G; Sicuro, Fernando L; Clapauch, Ruth; Maranhão, Priscila A; Bouskela, Eliete; Kraemer-Aguiar, Luiz G

2012-11-13

We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Data from 189 female subjects (34.0 ± 15.5 years, 30.5 ± 7.1 kg/m2), who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA). PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI), waist circumference, systolic and diastolic blood pressure (BP), fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), insulin, C-reactive protein (CRP), and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV) at rest and peak after 1 min of arterial occlusion (RBCV(max)), and the time taken to reach RBCV(max) (TRBCV(max)). A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCV(max) varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCV(max), but in the opposite way. Principal component 3 was associated only with microvascular

Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach

Directory of Open Access Journals (Sweden)

Panazzolo Diogo G

2012-11-01

Full Text Available Abstract Background We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Methods Data from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m2, who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA. PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI, waist circumference, systolic and diastolic blood pressure (BP, fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c, low-density lipoprotein cholesterol (LDL-c, triglycerides (TG, insulin, C-reactive protein (CRP, and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV at rest and peak after 1 min of arterial occlusion (RBCVmax, and the time taken to reach RBCVmax (TRBCVmax. Results A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCVmax varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCVmax, but in the opposite way. Principal component 3 was

Upcyte® Microvascular Endothelial Cells Repopulate Decellularized Scaffold

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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

Patient-specific coronary blood supply territories for quantitative perfusion analysis

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Zakkaroff, Constantine; Biglands, John D.; Greenwood, John P.; Plein, Sven; Boyle, Roger D.; Radjenovic, Aleksandra; Magee, Derek R.

2018-01-01

Abstract Myocardial perfusion imaging, coupled with quantitative perfusion analysis, provides an important diagnostic tool for the identification of ischaemic heart disease caused by coronary stenoses. The accurate mapping between coronary anatomy and under-perfused areas of the myocardium is important for diagnosis and treatment. However, in the absence of the actual coronary anatomy during the reporting of perfusion images, areas of ischaemia are allocated to a coronary territory based on a population-derived 17-segment (American Heart Association) AHA model of coronary blood supply. This work presents a solution for the fusion of 2D Magnetic Resonance (MR) myocardial perfusion images and 3D MR angiography data with the aim to improve the detection of ischaemic heart disease. The key contribution of this work is a novel method for the mediated spatiotemporal registration of perfusion and angiography data and a novel method for the calculation of patient-specific coronary supply territories. The registration method uses 4D cardiac MR cine series spanning the complete cardiac cycle in order to overcome the under-constrained nature of non-rigid slice-to-volume perfusion-to-angiography registration. This is achieved by separating out the deformable registration problem and solving it through phase-to-phase registration of the cine series. The use of patient-specific blood supply territories in quantitative perfusion analysis (instead of the population-based model of coronary blood supply) has the potential of increasing the accuracy of perfusion analysis. Quantitative perfusion analysis diagnostic accuracy evaluation with patient-specific territories against the AHA model demonstrates the value of the mediated spatiotemporal registration in the context of ischaemic heart disease diagnosis. PMID:29392098

Preventing microvascular complications in type 1 diabetes mellitus

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Vijay Viswanathan

2015-01-01

Full Text Available Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c 20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour.

GM-CSF ameliorates microvascular barrier integrity via pericyte-derived Ang-1 in wound healing.

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Yan, Min; Hu, Yange; Yao, Min; Bao, Shisan; Fang, Yong

2017-11-01

Skin wound healing involves complex coordinated interactions of cells, tissues, and mediators. Maintaining microvascular barrier integrity is one of the key events for endothelial homeostasis during wound healing. Vasodilation is observed after vasoconstriction, which causes blood vessels to become porous, facilitates leukocyte infiltration and aids angiogenesis at the wound-area, postinjury. Eventually, vessel integrity has to be reestablished for vascular maturation. Numerous studies have found that granulocyte macrophage colony-stimulating factor (GM-CSF) accelerates wound healing by inducing recruitment of repair cells into the injury area and releases of cytokines. However, whether GM-CSF is involving in the maintaining of microvascular barrier integrity and the underlying mechanism remain still unclear. Aim of this study was to investigate the effects of GM-CSF on modulation of microvascular permeability in wound healing and underlying mechanisms. Wound closure and microvascular leakage was investigated using a full-thickness skin wound mouse model after GM-CSF intervention. The endothelial permeability was measured by Evans blue assay in vivo and in vitro endothelium/pericyte co-culture system using a FITC-Dextran permeability assay. To identify the source of angiopoietin-1 (Ang-1), double staining is used in vivo and ELISA and qPCR are used in vitro. To determine the specific effect of Ang-1 on GM-CSF maintaining microvascular stabilization, Ang-1 siRNA was applied to inhibit Ang-1 production in vivo and in vitro. Wound closure was significantly accelerated and microvascular leakage was ameliorated after GM-CSF treatment in mouse wound sites. GM-CSF decreased endothelial permeability through tightening endothelial junctions and increased Ang-1 protein level that was derived by perictye. Furthermore, applications of siRNAAng-1 inhibited GM-CSF mediated protection of microvascular barrier integrity both in vivo and in vitro. Our data indicate that GM

Microvascular Endothelial Dysfunction in Sedentary, Obese Humans is mediated by NADPH Oxidase; Influence of Exercise Training

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La Favor, Justin D.; Dubis, Gabriel S.; Yan, Huimin; White, Joseph D.; Nelson, Margaret A.M.; Anderson, Ethan J.; Hickner, Robert C.

2016-01-01

Objective The objectives of this study were to determine the impact of in vivo reactive oxygen species (ROS) on microvascular endothelial function in obese human subjects and to determine the efficacy of an aerobic exercise intervention on alleviating obesity-associated dysfunctionality. Approach and Results Young, sedentary men and women were divided into lean (BMI 18–25; n=14), intermediate (BMI 28–32.5; n=13), and obese (BMI 33–40; n=15) groups. A novel microdialysis technique was utilized to detect elevated interstitial hydrogen peroxide (H2O2) and superoxide levels in the vastus lateralis of obese compared to both lean and intermediate subjects. Nutritive blood flow was monitored in the vastus lateralis via the microdialysis-ethanol technique. A decrement in acetylcholine-stimulated blood flow revealed impaired microvascular endothelial function in the obese subjects. Perfusion of apocynin, an NADPH oxidase (Nox) inhibitor, lowered (normalized) H2O2 and superoxide levels and reversed microvascular endothelial dysfunction in obese subjects. Following 8-weeks of exercise, H2O2 levels were decreased in the obese subjects and microvascular endothelial function in these subjects was restored to levels similar to lean subjects. Skeletal muscle protein expression of the Nox subunits p22phox, p47phox, and p67phox were increased in obese relative to lean subjects, where p22phox and p67phox expression was attenuated by exercise training in obese subjects. Conclusions This study implicates Nox as a source of excessive ROS production in skeletal muscle of obese individuals, and links excessive Nox derived ROS to microvascular endothelial dysfunction in obesity. Furthermore, aerobic exercise training proved to be an effective strategy for alleviating these maladies. PMID:27765769

Assessment of glycaemic, lipid and blood pressure control among ...

African Journals Online (AJOL)

Diabetes mellitus (DM) is a metabolic disorder primarily characterized by elevated blood glucose levels and microvascular andmacrovascular complications. Near normal glycaemia will reduce the risk for development of microvascular disease complications, but aggressive management of traditional cardio-vascular risk ...

A stochastic simulator of a blood product donation environment with demand spikes and supply shocks.

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An, Ming-Wen; Reich, Nicholas G; Crawford, Stephen O; Brookmeyer, Ron; Louis, Thomas A; Nelson, Kenrad E

2011-01-01

The availability of an adequate blood supply is a critical public health need. An influenza epidemic or another crisis affecting population mobility could create a critical donor shortage, which could profoundly impact blood availability. We developed a simulation model for the blood supply environment in the United States to assess the likely impact on blood availability of factors such as an epidemic. We developed a simulator of a multi-state model with transitions among states. Weekly numbers of blood units donated and needed were generated by negative binomial stochastic processes. The simulator allows exploration of the blood system under certain conditions of supply and demand rates, and can be used for planning purposes to prepare for sudden changes in the public's health. The simulator incorporates three donor groups (first-time, sporadic, and regular), immigration and emigration, deferral period, and adjustment factors for recruitment. We illustrate possible uses of the simulator by specifying input values for an 8-week flu epidemic, resulting in a moderate supply shock and demand spike (for example, from postponed elective surgeries), and different recruitment strategies. The input values are based in part on data from a regional blood center of the American Red Cross during 1996-2005. Our results from these scenarios suggest that the key to alleviating deficit effects of a system shock may be appropriate timing and duration of recruitment efforts, in turn depending critically on anticipating shocks and rapidly implementing recruitment efforts.

(-)-Epicatechin administration and exercising skeletal muscle vascular control and microvascular oxygenation in healthy rats.

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Copp, Steven W; Inagaki, Tadakatsu; White, Michael J; Hirai, Daniel M; Ferguson, Scott K; Holdsworth, Clark T; Sims, Gabrielle E; Poole, David C; Musch, Timothy I

2013-01-15

Consumption of the dietary flavanol (-)-epicatechin (EPI) is associated with enhanced endothelial function and augmented skeletal muscle capillarity and mitochondrial volume density. The potential for EPI to improve peripheral vascular function and muscle oxygenation during exercise is unknown. We tested the hypothesis that EPI administration in healthy rats would improve treadmill exercise performance secondary to elevated skeletal muscle blood flow and vascular conductance [VC, blood flow/mean arterial pressure (MAP)] and improved skeletal muscle microvascular oxygenation. Rats received water (control, n = 12) or 4 mg/kg EPI (n = 12) via oral gavage daily for 24 days. Exercise endurance capacity and peak O(2) uptake (Vo(2) peak) were measured via treadmill runs to exhaustion. MAP (arterial catheter) and blood flow (radiolabeled microspheres) were measured and VC was calculated during submaximal treadmill exercise (25 m/min, 5% grade). Spinotrapezius muscle microvascular O(2) pressure (Po(2mv)) was measured (phosphorescence quenching) during electrically induced twitch (1 Hz) contractions. In conscious rats, EPI administration resulted in lower (↓~5%) resting (P = 0.03) and exercising (P = 0.04) MAP. There were no differences in exercise endurance capacity, Vo(2) peak, total exercising hindlimb blood flow (control, 154 ± 13; and EPI, 159 ± 8 ml·min(-1)·100 g(-1), P = 0.68), or VC (control, 1.13 ± 0.10; and EPI, 1.24 ± 0.08 ml·min(-1)·100 g(-1)·mmHg(-1), P = 0.21) between groups. Following anesthesia, EPI resulted in lower MAP (↓~16%) but did not impact resting Po(2mv) or any kinetics parameters (P > 0.05 for all) during muscle contractions compared with control. EPI administration (4 mg·kg(-1)·day(-1)) improved modestly cardiovascular function (i.e., ↓MAP) with no impact on exercise performance, total exercising skeletal muscle blood flow and VC, or contracting muscle microvascular oxygenation in healthy rats.

Skeletal muscle microvascular and interstitial PO2 from rest to contractions.

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Hirai, Daniel M; Craig, Jesse C; Colburn, Trenton D; Eshima, Hiroaki; Kano, Yutaka; Sexton, William L; Musch, Timothy I; Poole, David C

2018-03-01

Oxygen pressure gradients across the microvascular walls are essential for oxygen diffusion from blood to tissue cells. At any given flux, the magnitude of these transmural gradients is proportional to the local resistance. The greatest resistance to oxygen transport into skeletal muscle is considered to reside in the short distance between red blood cells and myocytes. Although crucial to oxygen transport, little is known about transmural pressure gradients within skeletal muscle during contractions. We evaluated oxygen pressures within both the skeletal muscle microvascular and interstitial spaces to determine transmural gradients during the rest-contraction transient in anaesthetized rats. The significant transmural gradient observed at rest was sustained during submaximal muscle contractions. Our findings support that the blood-myocyte interface provides substantial resistance to oxygen diffusion at rest and during contractions and suggest that modulations in microvascular haemodynamics and red blood cell distribution constitute primary mechanisms driving increased transmural oxygen flux with contractions. Oxygen pressure (PO2) gradients across the blood-myocyte interface are required for diffusive O 2 transport, thereby supporting oxidative metabolism. The greatest resistance to O 2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O 2 gradients between skeletal muscle microvascular (PO2 mv ) and interstitial (PO2 is ) spaces would be present at rest and maintained or increased during contractions. PO2 mv and PO2 is   were determined via phosphorescence quenching (Oxyphor probes G2 and G4, respectively) in the exposed rat spinotrapezius during the rest-contraction transient (1 Hz, 6 V; n = 8). PO2 mv was higher than PO2 is in all instances from rest (34.9 ± 6.0 versus 15.7 ± 6.4) to contractions (28.4 ± 5

Microvascular versus macrovascular cerebral vasomotor reactivity in patients with severe internal carotid artery stenosis or occlusion.

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Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Martí-Fàbregas, Joan; Durduran, Turgut

2014-02-01

In patients with severe internal carotid artery steno-occlusive lesions (ISOL), impaired cerebrovascular reactivity (CVR) is predictive of future ischemic stroke (IS) or transient ischemic attack (TIA). Therefore, the evaluation of CVR in ISOL patients may be a means to evaluate the risk for IS/TIA and decide on an intervention. Our aim was (1) to explore the feasibility of concurrent near-infrared spectroscopy (NIRS-DOS), diffuse correlation spectroscopy, and transcranial Doppler for CVR assessment in ISOL patients, and (2) to compare macrovascular and microvascular CVR in ISOL patients and explore its potential for IS/TIA risk stratification. Twenty-seven ISOL patients were recruited. The changes in continuous microvascular and macrovascular hemodynamics upon acetazolamide injection were used to determine CVR. Oxyhemoglobin (HbO2, by near-infrared spectroscopy), microvascular cerebral blood flow (CBF, by diffuse correlation spectroscopy) and CBF velocity (by transcranial Doppler) showed significant increases upon acetazolamide injection in all subjects (P < .03). Only macrovascular CVR (P = .024) and none of the microvascular measures were significantly dependent on the presence of ISOL. In addition, while CBF was significantly correlated with HbO2, neither of these microvascular measures correlated with macrovascular CBF velocity. We demonstrated the simultaneous, continuous, and noninvasive evaluation of CVR at both the microvasculature and macrovasculature. We found that macrovascular CVR response depends on the presence of ISOL, whereas the microvascular CVR did not significantly depend on the ISOL presence, possibly due to the role of collaterals other than those of the circle of Willis. The concurrent microvascular and macrovascular CVR measurement in the ISOL patients might improve future IS/TIA risk assessment. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

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

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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.

Adipose tissue-derived microvascular fragments from aged donors exhibit an impaired vascularisation capacity

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MW Laschke

2014-10-01

Full Text Available Adipose tissue-derived microvascular fragments are promising vascularisation units for applications in the field of tissue engineering. Elderly patients are the major future target population of such applications due to an increasing human life expectancy. Therefore, we herein investigated the effect of aging on the fragments’ vascularisation capacity. Microvascular fragments were isolated from epididymal fat pads of adult (8 months and aged (16 months C57BL/6 donor mice. These fragments were seeded onto porous polyurethane scaffolds, which were implanted into dorsal skinfold chambers to study their vascularisation using intravital fluorescence microscopy, histology and immunohistochemistry. Scaffolds seeded with fragments from aged donors exhibited a significantly lower functional microvessel density and intravascular blood flow velocity. This was associated with an impaired vessel maturation, as indicated by vessel wall irregularities, constantly elevated diameters and a lower fraction of CD31/α-smooth muscle actin double positive microvessels in the implants’ border and centre zones. Additional in vitro analyses revealed that microvascular fragments from adult and aged donors do not differ in their stem cell content as well as in their release of angiogenic growth factors, survival and proliferative activity under hypoxic conditions. However, fragments from aged donors exhibit a significantly lower number of matrix metalloproteinase -9-positive perivascular cells. Taken together, these findings demonstrate that aging is a crucial determinant for the vascularisation capacity of isolated microvascular fragments.

Reversible harmless interruption of testicular blood supply in the ram

International Nuclear Information System (INIS)

van Vliet, J.; De Ruiter-Bootsma, A.L.; Oei, Y.H.; Hoekstra, A.; De Rooij, D.G.; Wensing, C.J.

1987-01-01

An effective method of interrupting testicular blood flow temporarily and repeatedly in the ram has been developed. Blockade of flow has been achieved mechanically by an inflatable occluder placed around the testicular artery at the level of the spermatic cord. The effect of the blockade on total testicular blood supply was investigated using Doppler flowmetry and a percutaneous Xenon-133 injection method. With both approaches, the blood flow changes after inflation or deflation of the occluders could be estimated satisfactorily. A substantial decrease of testicular blood flow was achieved in eight of the 10 testes with inflated occluders. However, there were indications that in the remaining two testes blockade of the arterial flow was not complete. After deflation of the occluders, blood flow was restored rapidly and completely in all testes. Macro- and microscopic examinations revealed no long-term damage to the testis after blood flow interruptions lasting 30 or 60 minutes

Efficacy of thermoradiotherapy combined with hyperglycemia in tumors of various sizes and blood supply

International Nuclear Information System (INIS)

Kozin, S.V.; Zajtsev, A.V.

1992-01-01

The mean and individual values of three parameters, tumor size and blood supply level, as well as duration of the tumor growth delay were compared in mice with Erlich's carcinomas of various sizes after irradiation and that followed by artificial hyperthermia and local hyperthermia. Blood supply to the tumors and the antitumor effect of irradiation reduced with the tumor growth. Analysis of individual values of the considered parameters has shown the principle role of tumor blood flow depression in enhancement of the antitumor effect of irradiation by means of postradiation induced hyperglycemia and local hyperthermia, as well as in the relationship between this antitumor effect and the tumor size

Design, manufacture and in-vitro evaluation of a new microvascular anastomotic device.

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Huang, Shao-Fu; Wang, Tien-Hsiang; Wang, Hsuan-Wen; Huang, Shu-Wei; Lin, Chun-Li; Kuo, Hsien-Nan; Yu, Tsung-Chih

2013-01-01

Many microvascular anastomoses have been proposed for use with physical assisted methods, such as cuff, ring-pin, stapler, clip to the anastomose blood vessel. The ring-pin type anastomotic device (e.g., 3M Microvascular Anastomotic System) is the most commonly used worldwide because the anastomotic procedure can be conducted more rapidly and with fewer traumas than using sutures. However, problems including vessel leakage, ring slippage, high cost and high surgical skill demand need to be resolved. The aim of this study is to design and manufacture a new anastomotic device for microvascular anastomosis surgery and validate the device functions with in-vitro testing. The new device includes one pair of pinned rings and a set of semi-automatic flap apparatus designed and made using computer-aided design / computer-aided manufacture program. A pair of pinned rings was used to impale vessel walls and establish fluid communication with rings joined. The semi-automatic flap apparatus was used to assist the surgeon to invert the vessel walls and impale onto each ring pin, then turning the apparatus knob to bring the rings together. The device was revised until it became acceptable for clinical requires. An in-vitro test was performed using a custom-made seepage micro-fluid system to detect the leakage of the anastomotic rings. The variation between input and output flow for microvascular anastomoses was evaluated. The new microvascular anastomotic device was convenient and easy to use. It requires less time than sutures to invert and impale vessel walls onto the pinned rings using the semi-automatic flap apparatus. The in-vitro test data showed that there were no tears from the joined rings seam during the procedures. The new anastomotic devices are effective even with some limitations still remaining. This device can be helpful to simplify the anastomosis procedure and reduce the surgery time.

Bone marrow blood supply in gadolinium-enhanced magnetic resonance imaging

International Nuclear Information System (INIS)

Saifuddin, A.; Bann, K.; Ridgway, J.P.; Butt, W.P.

1994-01-01

A retrospective study was performed to determine whether bone blood supply can be assessed on gadolinium-enhanced magnetic resonance imaging. Lumbar spine magnetic resonance imaging (MRI) examinations of 49 patients attending for post-laminectomy examination were reviewed (30 male, 19 female, mean age 46.4 years, age range 23-84 years). Each study included sagittal T1-weighted spin echo sequences before and after gadolinium administration. Regions of interest were drawn within the L3 vertebral body from a parasagittal slice from each sequence. Signal intensity (SI) values were ascertained and the percentage increase in SI was calculated. For each patient, changes in receiver gain for pre- and post-gadolinium images were corrected by an image scaling factor. In all cases, a measurable increase in SI was found (mean 15.3%, range 4.4-55.7) due to bone vascularity. The results give no indication of the quantity or timing of blood supply but provide a basis for further work. (orig.)

Peripheral Microvascular Responses to Whole-Body Tilting, G(z) Centrifugation, and Lower Body Negative Pressure Stresses in Humans

Science.gov (United States)

Breit, G. A.; Watenpaugh, D. E.; Buckley, T. M.; Ballard, R. E.; Murthy, G.; Hargens, A. R.

1994-01-01

The response of the cutaneous microcirculation to orthostatic stress varies along the length of the body due to the interaction of central controls with regional responses to local blood pressure. We hypothesize that artificial orthostatic stresses such as Gz centrifugation and LBNP differ from whole-body tilting in terms of the distribution of microvascular blood flow. Cutaneous microvascular flows were measured by laser Doppler flowmetry at the neck, thigh, and leg of 15 normal subjects. Volunteers underwent stepwise head-up tilt (HUT) and short- and long-arm centrifugation protocols from supine control (0 Gz) to 0.2, 0.4, 0.6, 0.8, 1.0, 0.8, 0.6, 0.4, 0.2, and 0 Gz at the feet, for 30-s periods with 10-s transitions between levels. The same subjects underwent a corresponding supine LBNP protocol, up to 100 mmHg (in 20 mmHg increments) and back to zero pressure, which produced transmural pressure across blood vessels in the foot approximately equal to the HUT protocol. In general, application of all orthostatic stresses produced significant flow reductions in the lower body (p less than 0.05) and inconsistent changes in the neck. At low levels of each stress (0.4 Gz, 40 mmHg), LBNP generated the greatest relative reduction in flow in the lower body (-66.9+/-5.7%, thigh; -60.6 +/-5.7%, leg, mean +/- SE). HUT caused a less severe flow reduction than LBNP at the thigh and leg (-39.9 +/- 8.1% and -55.9+/-4.8%), while the effects induced by both forms of centrifugation were the least profound. Higher levels of each stress generally resulted in similar responses. These responses exhibit a consistent relationship to hypothesized changes in local microvascular transmural pressure, suggesting that myogenic and veno-arteriolar reflexes play a significant role in determining microvascular perfusion during orthostatic stress.

Treatment of Angina and Microvascular Coronary Dysfunction

Science.gov (United States)

Samim, Arang; Nugent, Lynn; Mehta, Puja K.; Shufelt, Chrisandra; Merz, C. Noel Bairey

2014-01-01

Opinion statement Microvascular coronary dysfunction (MCD) is an increasingly recognized cause of cardiac ischemia and angina, more commonly diagnosed in women. Patients with MCD present with the triad of persistent chest pain, ischemic changes on stress testing, and no obstructive coronary artery disease (CAD) on cardiac catheterization. Data from National Heart, Lung and Blood Institute (NHLBI)-sponsored Women’s Ischemia Syndrome Evaluation (WISE) study has shown that the diagnosis of MCD is not benign, with a 2.5% annual risk of adverse cardiac events including myocardial infarction, stroke, congestive heart failure, or death. The gold standard diagnostic test for MCD is an invasive coronary reactivity test (CRT), which uses acetylcholine, adenosine, and nitroglycerin to test the endothelial dependent and independent, microvascular and macrovascular coronary function. The CRT allows for diagnostic and treatment options as well as further risk stratifying patients for future cardiovascular events. Treatment of angina and MCD should be aimed at ischemia disease management to reduce risk of adverse cardiac events, ameliorating symptoms to improve quality of life, and to decrease the morbidity from unnecessary and repeated cardiac catheterization in patients with open coronary arteries. A comprehensive treatment approach aimed at risk factor managment, including lifestyle counseling regarding smoking cessation, nutrition and physical activity should be initiated. Current pharmacotherapy for MCD can include the treatment of microvascular endothelial dysfunction (statins, angiotensin-converting enzyme inhibitor, low dose aspirin), as well as treatment for angina and myocardial ischemia (beta blockers, calcium channel blockers, nitrates, ranolazine). Additional symptom management techniques can include tri-cyclic medication, enhanced external counterpulsation, autogenic training, and spinal cord stimulation. While our current therapies are effective in the treatment

The involvement of splenic artery in the blood supply of hepatomas: its DSA findings and interventional treatment

International Nuclear Information System (INIS)

Duan Xuhua; Liang Huiming; Feng Gansheng; Zheng Chuangsheng; Ren Jianzhuang

2009-01-01

Objective: To investigate the DSA manifestations of the involvement of splenic artery in supplying blood to hepatomas and to assess the therapeutic value of super-selective interventional embolization. Methods: During the period of March 2005-June 2008, 897 patients with hepatoma underwent angiography and the involvement of splenic artery in the blood supply of hepatoma was confirmed in 7 cases. Splenic arteriography was performed by means of super-selective catheterization with 5 F Yashiro catheter together with 3 F SP catheter. The splenic arteries which supplied blood to hepatomas were embolized with hyper-liquid iodized-oil emulsion mixed with chemotherapy drug, which was followed by the injection of sufficient gelatin sponge or ethanol. The clinical results were analyzed. Results: Splenic arteriography revealed that the splenic artery was the main supplying vessel of the hepatoma in two cases, and was not the main supplying vessel of the hepatoma in five cases. The splenic supplying vessels were completely embolized in all 7 cases. After the procedure, AFP level was decreased over 50%, and in two patients it dropped to normal. CT checkup 4-6 weeks after the surgery revealed that the diameter of tumor decreased to 2.5 - 4.6 cm. Conclusion: The involvement of splenic artery in supplying blood to hepatomas is not common. Super-selective catheterization and sufficient embolization of the splenic supplying vessels are very important for improving the interventional effectiveness. (authors)

Predicting future blood supply and demand in Japan with a Markov model: application to the sex- and age-specific probability of blood donation.

Science.gov (United States)

Akita, Tomoyuki; Tanaka, Junko; Ohisa, Masayuki; Sugiyama, Aya; Nishida, Kazuo; Inoue, Shingo; Shirasaka, Takuma

2016-11-01

Simulation studies were performed to predict the future supply and demand for blood donations, and future shortfalls. Using data from all donations in 2006 to 2009, the Markov model was applied to estimate future blood donations until 2050. Based on data concerning the actual use of blood products, the number of blood products needed was estimated based on future population projections. We estimated that the number of blood donations increased from 5,020,000 in 2008 to 5,260,000 in 2012, but will decrease to 4,770,000 units by 2025. In particular, the number of donors in their 20s and 30s decreased every year. Moreover, the number of donations required to supply blood products would have been increased from 5,390,000 in 2012 to 5,660,000 units in 2025. Thus, the estimated shortfall of blood donations is expected to increase each year from 140,000 in 2012 to 890,000 in 2025 and then more than double to 1,670,000 in 2050. If the current blood donation behaviors continue, a shortfall of blood availability is likely to occur in Japan. Insufficient blood donations are mainly related to a projected reduction in population of 20 to 30 year olds, a significant group of donors. Thus, it is crucial to recruit and retain new donors and to develop recommendations for proper use of blood products to minimize unnecessary use. This study provides useful information that can be used by governments to help ensure the adequacy of the blood supply through promoting donations and conserving blood resources. © 2016 AABB.

Rat muscle microvascular PO2 kinetics during the exercise off-transient.

Science.gov (United States)

McDonough, P; Behnke, B J; Kindig, C A; Poole, D C

2001-05-01

Dependent upon the relative speed of pulmonary oxygen consumption (VO2) and blood flow (Q) kinetics, the exercise off-transient may represent a condition of sub- or supra-optimal perfusion. To date, there are no direct measurements of the dynamics of the VO2/Q relationship within the muscle at the onset of the work/recovery transition. To address this issue, microvascular PO2 (PO2,m) dynamics were studied in the spinotrapezius muscles of 11 female Sprague-Dawley rats (weight approximately 220 g) during and following electrical stimulation (1 Hz) to assess the adequacy of Q. relative to VO2 post exercise. The exercise blood flow response (radioactive microspheres: muscle Q increased approximately 240 %), and post-exercise arterial blood pH (7.40 +/- 0.02) and blood lactate (1.3 +/- 0.4 mM x l(-1)) values were consistent with moderate-intensity exercise. Recovery PO2,m (i.e. off-transient) rose progressively until baseline values were achieved ((Delta)end-recovery exercise PO2,m, 14.0 +/- 1.9 Torr) and at no time fell below exercising PO2,m. The off-transient PO2,m was well fitted by a dual exponential model with both fast (tau = 25.4 +/- 5.1 s) and slow (tau = 71.2 +/- 34.2 s) components. Furthermore, there was a pronounced delay (54.9 +/- 10.7 s) before the onset of the slow component. These data, obtained at the muscle microvascular level, support the notion that muscle VO2 falls with faster kinetics than muscle Q during the off-transient, such that PO2,m increases systematically, though biphasically, during recovery.

Improving the blood supply chain: simulation and optimisation models to support collection, production and location-allocation decisions

OpenAIRE

Osorio Muriel, Andres

2016-01-01

This thesis introduces and studies different problems in the blood supply chain. The problems are focused on aspects less frequently studied in the literature such as the exploitation of the different collection and production alternatives, consideration of multiple products and uncertainty in demand and supply. These important features can be found in different decision levels, including daily collections, annual planning and at the strategic level when the blood supply chain is designed. Fo...

The effect of nitroglycerin on microvascular perfusion and oxygenation during gastric tube reconstruction.

Science.gov (United States)

Buise, Marc P; Ince, Can; Tilanus, Hugo W; Klein, Jan; Gommers, Diederik; van Bommel, Jasper

2005-04-01

Esophagectomy followed by gastric tube reconstruction is the surgical treatment of choice for patients with esophageal cancer. Complications of the cervical anastomosis are associated with impaired microvascular blood flow (MBF) and ischemia in the gastric fundus. The aim of the present study was to differentiate whether the decrease in MBF is a result of arterial insufficiency or of venous congestion. To do this we assessed MBF, microvascular hemoglobin oxygen saturation (muHbSo(2)), and microvascular hemoglobin concentration (muHbcon) simultaneously during different stages of gastric tube reconstruction. In 14 patients, MBF was determined with laser Doppler flowmetry, and muHbSo(2) and muHbcon were determined with reflectance spectro- photometry. After completion of the anastomosis, nitroglycerin was applied at the fundus. Although MBF did not change significantly in the pylorus, MBF decreased progressively during surgery in the fundus from 210 +/- 18 Arbitrary Units at baseline (normal stomach) to 52 +/- 9 Arbitrary Units after completion of reconstruction (mean +/- sem; P tube reconstruction but that muHbSo(2) and muHbcon do not. This decrease might be the result of venous congestion, which can partly be counteracted by application of nitroglycerin.

Significance of determination of bone mineral density and osteocalcin in diabetic patients with diabetic microvascular complications

International Nuclear Information System (INIS)

Kong Xianghui; Mu Junqing; Lu Kuan

2003-01-01

Objective: To study the influence of diabetic microvascular complications on bone mineral density (BMI) and osteocalcin (BGP). Methods: 60 patients with type 2 diabetes mellitus were studied, including 33 with microvascular complications (retinopathy, nephropathy, neuropathy) (group 1) and 27 without complications (group 2). Fasting blood glucose, serum fructosamine (GSP), total alkaline phosphatase (TALP), calcium (Ca 2+ ) levels were measured by biochemical method; osteocalcin (BGP) level was detected by RIA. BMD of the lumbar spine and femur was measured by dual energy X-ray absorptiometry in all patients. Body mass index (BMI) was calculated from the height and body weight. Results: The BMI, GSP, FBG, TALP and Ca 2+ values in the two groups were not much different, but BGP and BMD in group 1 were significantly lower than those in group 2. Conclusion: Bone mineral density (BMD) and BGP values were closely related to the microvascular complications in diabetes, which could decrease bone formation and increase the frequency of osteoporosis

Utilizing Radiofrequency Identification Technology to Improve Safety and Management of Blood Bank Supply Chains.

Science.gov (United States)

Coustasse, Alberto; Meadows, Pamela; Hall, Robert S; Hibner, Travis; Deslich, Stacie

2015-11-01

The importance of efficiency in the supply chain of perishable products, such as the blood products used in transfusion services, cannot be overstated. Many problems can occur, such as the outdating of products, inventory management issues, patient misidentification, and mistransfusion. The purpose of this article was to identify the benefits and barriers associated with radiofrequency identification (RFID) usage in improving the blood bank supply chain. The methodology for this study was a qualitative literature review following a systematic approach. The review was limited to sources published from 2000 to 2014 in the English language. Sixty-five sources were found, and 56 were used in this research study. According to the finding of the present study, there are numerous benefits and barriers to RFID utilization in blood bank supply chains. RFID technology offers several benefits with regard to blood bank product management, including decreased transfusion errors, reduction of product loss, and more efficient inventory management. Barriers to RFID implementation include the cost associated with system implementation and patient privacy issues. Implementation of an RFID system can be a significant investment. However, when observing the positive impact that such systems may have on transfusion safety and inventory management, the cost associated with RFID systems can easily be justified. RFID in blood bank inventory management is vital to ensuring efficient product inventory management and positive patient outcomes.

Microvascular Recruitment in Insulin Resistance

DEFF Research Database (Denmark)

Sjøberg, Kim Anker

the resonating sound from the microbubbles in the systemic circulation were recorded for determination of microvascular recruitment in designated muscle segments. Results showed that microvascular recruitment increased with insulin stimulation by ~30% in rats and ~40% in humans (study I). Furthermore......, it was observed that muscle contractions increased muscle perfusion rapidly by 3-4 fold and by 1-2 fold compared to basal and insulin, respectively, in both rat and human skeletal muscle (study I). The real-time contrast-enhanced ultrasound method was applied to investigate the vaso-active effect of the incretin...... hormone glucagon-like-peptide-1 (GLP-1) in the microcirculation. Glucagon-like-peptide-1 analogs are drugs used for treatments of insulin resistance and type 2 diabetes but the vascular effects of GLP-1 in vivo are elusive. Here it was shown that GLP-1 rapidly increased the microvascular recruitment...

Determination of regional flow by use of intravascular PET tracers: microvascular theory and experimental validation for pig livers

DEFF Research Database (Denmark)

Munk, O L; Bass, L; Feng, H

2003-01-01

Today, the standard approach for the kinetic analysis of dynamic PET studies is compartment models, in which the tracer and its metabolites are confined to a few well-mixed compartments. We examine whether the standard model is suitable for modern PET data or whether theories including more...... physiologic realism can advance the interpretation of dynamic PET data. A more detailed microvascular theory is developed for intravascular tracers in single-capillary and multiple-capillary systems. The microvascular models, which account for concentration gradients in capillaries, are validated and compared...... with the standard model in a pig liver study. METHODS: Eight pigs underwent a 5-min dynamic PET study after (15)O-carbon monoxide inhalation. Throughout each experiment, hepatic arterial blood and portal venous blood were sampled, and flow was measured with transit-time flow meters. The hepatic dual...

Brain microvascular function during cardiopulmonary bypass

International Nuclear Information System (INIS)

Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

1987-01-01

Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass

3D reconstruction of microvascular flow phantoms with hybrid imaging modalities

Science.gov (United States)

Lin, Jingying; Hsiung, Kevin; Ritenour, Russell; Golzarian, Jafar

2011-03-01

Microvascular flow phantoms were built to aid the development of a hemodynamic simulation model for treating hepatocelluar carcinoma. The goal is to predict the blood flow routing for embolotherapy planning. Embolization is to deliver agents (e.g. microspheres) to the vicinity of the tumor to obstruct blood supply and nutrients to the tumor, targeting into 30 - 40 μm arterioles. Due to the size of the catheter, it has to release microspheres at an upper stream location, which may not localize the blocking effect. Accurate anatomical descriptions of microvasculature will help to conduct a reliable simulation and prepare a successful embolization strategy. Modern imaging devices can generate 3D reconstructions with ease. However, with a fixed detector size, larger field of view yields lower resolution. Clinical CT images can't be used to measure micro vessel dimensions, while micro-CT requires more acquisitions to reconstruct larger vessels. A multi-tiered, montage 3D reconstruction method with hybrid-modality imagery is devised to minimize the reconstruction effort. Regular CT is used for larger vessels and micro-CT is used for micro vessels. The montage approach aims to stitch up images with different resolutions and orientations. A resolution-adaptable 3D image registration is developed to assemble the images. We have created vessel phantoms that consist of several tiers of bifurcating polymer tubes in reducing diameters, down to 25 μm. No previous work of physical flow phantom has ventured into this small scale. Overlapping phantom images acquired from clinical CT and micro-CT are used to verify the image registration fidelity.

The pulmonary artery does not participate in the blood supply of lung cancer: experimental and DSA study

International Nuclear Information System (INIS)

Han Mingjun; Feng Gansheng; Yang Jianyong; Su Hongying; Zhao Zhongchun

2000-01-01

Objective: To investigate whether or not the pulmonary artery participates in the blood supply of lung cancer and its change of morphology and blood flow in lung cancer. Methods: Two different colors of silicone were injected separately into the bronchial and pulmonary arteries of 33 rat models with squamous cell carcinoma of lung. The origin of blood supply of lung cancer and the morphologic change of pulmonary artery were observed under a stereo-microscope. The DSA of bronchial and pulmonary artery were performed simultaneously in 28 patients with lung cancer. Results: The pulmonary branch of rat and patients were reduced,thinned and occluded in the affected lung. The pulmonary artery did not form tumor vessel,and pulmonary blood flow and perfusion were reduced or absent in the affected area. Conclusion: The pulmonary artery did not participate in the blood supply of lung cancer. It is unreasonable to perform transcatheter chemo-embolization for lung cancer via pulmonary artery

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

Directory of Open Access Journals (Sweden)

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

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

Predictive value of PWI for blood supply and T1-spin echo MRI for consistency of pituitary adenoma

Energy Technology Data Exchange (ETDEWEB)

Ma, Zengyi; He, Wenqiang; Zhao, Yao; Zhang, Qilin; Li, Shiqi; Wang, Yongfei [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Yuan, Jie; Wu, Yue; Yao, Zhenwei [Fudan University, Department of Radiology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Chen, Hong [Fudan University, Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Shanghai (China)

2016-01-15

It is a common view that consistency and blood supply of pituitary adenoma (PA) can influence the surgical effect. The aim of this study was to determine whether MRI signal intensity (SI) was correlated to the consistency or blood supply of pituitary macroadenoma. Forty eight pituitary macroadenoma patients were underwent preoperative MRI, including precontrast and contrast-enhanced (CE) T1-spin echo (T1-SE) imaging, CE-sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) imaging, and perfusion-weighted imaging (PWI). The tumor consistency and blood supply were determined by neurosurgeons. The expression of collagen IV and MIB-1 was detected with immunohistology. The correlation of the relative SI (rSI) values (tumor to normal frontal white matter SI) and PWI data to the tumor consistency, blood supply, and the expression level of collagen IV and MIB-1 was statistically studied by Kruskal-Wallis rank test (K-W test). A significant correlation was observed between the tumor consistency and the rSI on precontrast T1-SE imaging (P = 0.004) but not on CE T1-SE and CE SPACE imaging. The expression of collagen IV was also significantly associated with rSI on T1-SE imaging (P = 0.010). The blood supply was correlated with the relative CBV (rCBV) (P = 0.030). In addition, the expression of MIB-1 was correlated with rSI of CE T1-SE imaging (P = 0.007). Our results suggest that T1-SE imaging may be a simple and useful method for predicting consistency of PA. CBV value can provide helpful information for assessing the blood supply of pituitary macroadenoma. (orig.)

Affection of blood supply of focal hepatic mass on apparent diffusion coefficient of the lesions

International Nuclear Information System (INIS)

Chen Zaizhi; Wu Yulin; Xu Zhongfei; Yang Zhenghan; Chen Min; Zhou Cheng; Xie Jingxia

2002-01-01

Objective: To investigate the affection of lesion blood supply on apparent diffusion coefficient (ADC) of focal hepatic mass. Methods: Diffusion-weighted imaging (DWI) with different b values was performed in 87 patients with 159 focal hepatic lesions. ADCs of lesion, liver, spleen, gallbladder were measured in every case. Results: On DWI with small b value and small b value remainder, ADCs were affected by blood perfusion of tissues or lesions. The mean ADC of hypervascular lesions was significantly higher than that of hypovascular lesions on DWI with small b value, and hemoangiomas got the highest mean ADC. The mean ADC of hepatic cysts was not affected by b value. Conclusion: Blood perfusion affects ADC of tissue or focal hepatic lesion, particularly on DWI with small b value, and to some degree, DWI and ADC can reflect the blood supply of focal hepatic lesion

Encouraging effects of a short-term, adapted Nordic diet intervention on skin microvascular function and skin oxygen tension in younger and older adults.

Science.gov (United States)

Rogerson, David; McNeill, Scott; Könönen, Heidi; Klonizakis, Markos

2018-05-01

The microvascular benefits of regional diets appear in the literature; however, little is known about Nordic-type diets. We investigated the effects of a short-term, adapted, Nordic diet on microvascular function in younger and older individuals at rest and during activity. Thirteen young (mean age: 28 y; standard deviation: 5 y) and 15 older (mean age: 68 y; standard deviation: 6 y) participants consumed a modified Nordic diet for 4 wk. Laser Doppler flowmetry and transcutaneous oxygen monitoring were used to assess cutaneous microvascular function and oxygen tension pre- and postintervention; blood pressure, body mass, body fat percentage, ratings of perceived exertion, and peak heart rate during activity were examined concurrently. Axon-mediated vasodilation improved in older participants (1.17 [0.30] to 1.30 [0.30]; P Nordic diet might improve microvascular health. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel effective method for the assessment of microvascular function in male patients with coronary artery disease: a pilot study using laser speckle contrast imaging

Energy Technology Data Exchange (ETDEWEB)

Borges, J.P. [Laboratório de Atividade Física e Promoção è Saúde, Departamento de Desporto Coletivo, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Lopes, G.O. [Laboratório de Atividade Física e Promoção è Saúde, Departamento de Desporto Coletivo, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Verri, V.; Coelho, M.P.; Nascimento, P.M.C.; Kopiler, D.A. [Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Tibirica, E. [Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Laboratório de Investigação Cardiovascular, Departamento Osório de Almeida, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ (Brazil)

2016-09-01

Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function, it has never been used to compare male patients with coronary artery disease with male age-matched healthy controls. Thus, the aim of this study was to determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with established cardiovascular disease (n=61) and healthy age-matched subjects (n=24). Cutaneous blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with the transdermal iontophoretic delivery of acetylcholine and post-occlusive reactive hyperemia. The maximum increase in skin blood flow induced by acetylcholine was significantly reduced in the cardiovascular disease patients compared with the control subjects (74 vs 116%; P<0.01). With regard to post-occlusive reactive hyperemia-induced vasodilation, the patients also presented reduced responses compared to the controls (0.42±0.15 vs 0.50±0.13 APU/mmHg; P=0.04). In conclusion, laser speckle contrast imaging can identify endothelial and microvascular dysfunctions in male individuals with cardiovascular disease. Thus, this technology appears to be an efficient non-invasive technique for evaluating systemic microvascular and endothelial functions, which could be valuable as a peripheral marker of atherothrombotic diseases in men.

A novel effective method for the assessment of microvascular function in male patients with coronary artery disease: a pilot study using laser speckle contrast imaging

International Nuclear Information System (INIS)

Borges, J.P.; Lopes, G.O.; Verri, V.; Coelho, M.P.; Nascimento, P.M.C.; Kopiler, D.A.; Tibirica, E.

2016-01-01

Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function, it has never been used to compare male patients with coronary artery disease with male age-matched healthy controls. Thus, the aim of this study was to determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with established cardiovascular disease (n=61) and healthy age-matched subjects (n=24). Cutaneous blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with the transdermal iontophoretic delivery of acetylcholine and post-occlusive reactive hyperemia. The maximum increase in skin blood flow induced by acetylcholine was significantly reduced in the cardiovascular disease patients compared with the control subjects (74 vs 116%; P<0.01). With regard to post-occlusive reactive hyperemia-induced vasodilation, the patients also presented reduced responses compared to the controls (0.42±0.15 vs 0.50±0.13 APU/mmHg; P=0.04). In conclusion, laser speckle contrast imaging can identify endothelial and microvascular dysfunctions in male individuals with cardiovascular disease. Thus, this technology appears to be an efficient non-invasive technique for evaluating systemic microvascular and endothelial functions, which could be valuable as a peripheral marker of atherothrombotic diseases in men

77 FR 31026 - Use of Computer Simulation of the United States Blood Supply in Support of Planning for Emergency...

Science.gov (United States)

2012-05-24

...] Use of Computer Simulation of the United States Blood Supply in Support of Planning for Emergency... entitled: ``Use of Computer Simulation of the United States Blood Supply in Support of Planning for... and panel discussions with experts from academia, regulated industry, government, and other...

Prediabetes and Type 2 Diabetes Are Associated With Generalized Microvascular Dysfunction: The Maastricht Study.

Science.gov (United States)

Sörensen, Ben M; Houben, Alfons J H M; Berendschot, Tos T J M; Schouten, Jan S A G; Kroon, Abraham A; van der Kallen, Carla J H; Henry, Ronald M A; Koster, Annemarie; Sep, Simone J S; Dagnelie, Pieter C; Schaper, Nicolaas C; Schram, Miranda T; Stehouwer, Coen D A

2016-11-01

Type 2 diabetes (T2DM) is associated with an increased risk of cardiovascular disease. This can be partly explained by large-artery dysfunction, which already occurs in prediabetes ("ticking clock hypothesis"). Whether a similar phenomenon also applies to microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction is already present in prediabetes and is more severe in T2DM. To do so, we investigated the associations of prediabetes, T2DM, and measures of hyperglycemia with microvascular function measured as flicker light-induced retinal arteriolar dilation and heat-induced skin hyperemia. In the Maastricht Study, a T2DM-enriched population-based cohort study (n=2213, 51% men, aged [mean±standard deviation] 59.7±8.2 years), we determined flicker light-induced retinal arteriolar %-dilation (Dynamic Vessel Analyzer), heat-induced skin %-hyperemia (laser-Doppler flowmetry), and glucose metabolism status (oral glucose tolerance test; normal glucose metabolism [n=1269], prediabetes [n=335], or T2DM [n=609]). Differences were assessed with multivariable regression analyses adjusted for age, sex, body mass index, smoking, physical activity, systolic blood pressure, lipid profile, retinopathy, estimated glomerular filtration rate, (micro)albuminuria, the use of lipid-modifying and blood pressure-lowering medication, and prior cardiovascular disease. Retinal arteriolar %-dilation was (mean±standard deviation) 3.4±2.8 in normal glucose metabolism, 3.0±2.7 in prediabetes, and 2.3±2.6 in T2DM. Adjusted analyses showed a lower arteriolar %-dilation in prediabetes (B=-0.20, 95% confidence interval -0.56 to 0.15) with further deterioration in T2DM (B=-0.61 [-0.97 to -0.25]) versus normal glucose metabolism (P for trend=0.001). Skin %-hyperemia was (mean±standard deviation) 1235±810 in normal glucose metabolism, 1109±748 in prediabetes, and 937±683 in T2DM. Adjusted analyses showed a lower %-hyperemia in prediabetes (B=-46

Deleterious Effects of Intra-arterial Administration of Particulate Steroids on Microvascular Perfusion in a Mouse Model.

Science.gov (United States)

Laemmel, Elisabeth; Segal, Nicolas; Mirshahi, Massoud; Azzazene, Dalel; Le Marchand, Sylvie; Wybier, Marc; Vicaut, Eric; Laredo, Jean-Denis

2016-06-01

Purpose To determine the in vivo effects of several particulate steroids on microvascular perfusion by using intravital microscopy in a mice model and to investigate the in vitro interactions between these particulate steroids and red blood cells (RBCs). Materials and Methods The study was conducted in agreement with the guidelines of the National Committee of Ethic Reflection on Animal Experimentation. By using intravital microscopy of mouse cremaster muscle, the in vivo effects of several particulate steroids on microvascular perfusion were assessed. Four to five mice were allocated to each of the following treatment groups: saline solution, dexamethasone sodium phosphate, a nonparticulate steroid, and the particulate steroids cortivazol, methylprednisolone, triamcinolone, and prednisolone. By using in vitro blood microcinematography and electron microscopy, the interactions between these steroids and human RBCs were studied. All results were analyzed by using nonparametric tests. Results With prednisolone, methylprednisolone, or triamcinolone, blood flow was rapidly and completely stopped in all the arterioles and venules (median RBC velocity in first-order arterioles, 5 minutes after administration was zero for these three groups) compared with a limited effect in mice treated with saline, dexamethasone, and cortivazol (20.3, 21.3, and 27.5 mm/sec, respectively; P effect was associated with a large decrease in the functional capillary density (4.21, 0, and 0 capillaries per millimeter for methylprednisolone, triamcinolone, or prednisolone, respectively, vs 21.0, 21.4, and 19.1 capillaries per millimeter in mice treated with saline, dexamethasone, and cortivazol, respectively; P steroids. Conclusion Several particulate steroids have an immediate and massive effect on microvascular perfusion because of formation of RBC aggregates associated with the transformation of RBCs into spiculated RBCs. (©) RSNA, 2016 Online supplemental material is available for this

Correlation Factor Analysis of Retinal Microvascular Changes in Patients With Essential Hypertension

Institute of Scientific and Technical Information of China (English)

Huang Duru; Huang Zhongning

2006-01-01

Objectives To investigate correlation between retinal microvascular signs and essential hypertension classification. Methods The retinal microvascular signs in patients with essential hypertension were assessed with the indirect biomicroscopy lens, the direct and the indirect ophthalmoscopes were used to determine the hypertensive retinopathy grades and retinal arteriosclerosis grades.The rank correlation analysis was used to analysis the correlation these grades with the risk factors concerned with hypertension. Results Of 72 cases with essential hypertension, 28 cases complicated with coronary disease, 20 cases diabetes, 41 cases stroke,17 cases renal malfunction. Varying extent retinal arterioscleroses were found in 71 cases, 1 case with retinal hemorrhage, 2 cases with retina edema, 4 cases with retinal hard exudation, 5 cases with retinal hemorrhage complicated by hard exudation, 2 cases with retinal hemorrhage complicated by hard exudation and cotton wool spot, 1 case with retinal hemorrhage complicated by hard exudation and microaneurysms,1 case with retinal edema and hard exudation, 1 case with retinal microaneurysms, 1 case with branch retinal vein occlusion. The rank correlation analysis showed that either hypertensive retinopathy grades or retinal arteriosclerosis grades were correlated with risk factor lamination of hypertension (r=0.25 or 0.31, P＜0.05), other correlation factors included age and blood high density lipoprotein concerned about hypertensive retinopathy grades or retinal arteriosclerosis grades, but other parameters, namely systolic or diastolic pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, fasting blood glucose,blood urea nitrogen and blood creatinine were not confirmed in this correlation analysis (P ＞ 0.05).Conclusions Either hypertensive retinopathy grade or retinal arteriosclerosis grade is close with the hypertension risk factor lamination, suggesting that the fundus examination of patients with

Effect of Antimicrobial Compounds on Balamuthia mandrillaris Encystment and Human Brain Microvascular Endothelial Cell Cytopathogenicity▿

Science.gov (United States)

Siddiqui, Ruqaiyyah; Matin, Abdul; Warhurst, David; Stins, Monique; Khan, Naveed Ahmed

2007-01-01

Cycloheximide, ketoconazole, or preexposure of organisms to cytochalasin D prevented Balamuthia mandrillaris-associated cytopathogenicity in human brain microvascular endothelial cells, which constitute the blood-brain barrier. In an assay for inhibition of cyst production, these three agents prevented the production of cysts, suggesting that the biosynthesis of proteins and ergosterol and the polymerization of actin are important in cytopathogenicity and encystment. PMID:17875991

Effect of Antimicrobial Compounds on Balamuthia mandrillaris Encystment and Human Brain Microvascular Endothelial Cell Cytopathogenicity▿

OpenAIRE

Siddiqui, Ruqaiyyah; Matin, Abdul; Warhurst, David; Stins, Monique; Khan, Naveed Ahmed

2007-01-01

Cycloheximide, ketoconazole, or preexposure of organisms to cytochalasin D prevented Balamuthia mandrillaris-associated cytopathogenicity in human brain microvascular endothelial cells, which constitute the blood-brain barrier. In an assay for inhibition of cyst production, these three agents prevented the production of cysts, suggesting that the biosynthesis of proteins and ergosterol and the polymerization of actin are important in cytopathogenicity and encystment.

Experimental diode laser-assisted microvascular anastomosis.

Science.gov (United States)

Reali, U M; Gelli, R; Giannotti, V; Gori, F; Pratesi, R; Pini, R

1993-05-01

An experimental study to evaluate a diode-laser approach to microvascular end-to-end anastomoses is reported. Studies were carried out on the femoral arteries and veins of Wistar rats, and effective welding of vessel tissue was obtained at low laser power, by enhancing laser absorption with indocyanine green (Cardio-green) solution. The histologic and surgical effects of this laser technique were examined and compared with those of conventional microvascular sutured anastomoses.

Intensive Blood Pressure Control Affects Cerebral Blood Flow in Type 2 Diabetes Mellitus Patients

NARCIS (Netherlands)

Kim, Yu-Sok; Davis, Shyrin C. A. T.; Truijen, Jasper; Stok, Wim J.; Secher, Niels H.; van Lieshout, Johannes J.

2011-01-01

Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic

Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

Science.gov (United States)

Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

2017-01-01

Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P lower limb heating improves both macro- and microvascular dilator function in an age dependent manner. We demonstrate that lower limb heating acutely improves macro- and microvascular dilator function within the atherosclerotic prone vasculature of the leg in aged adults. These findings provide evidence for a potential therapeutic use of chronic lower limb heating to improve vascular health in primary aging and various disease conditions. Copyright © 2017 the American Physiological Society.

Successful microsurgical lip replantation: Monitoring venous congestion by blood glucose measurements in the replanted lip

OpenAIRE

Kazufumi Tachi; Masanori Mori; Reiko Tsukuura; Rintaro Hirai

2018-01-01

Replantation of an amputated lip using microvascular anastomosis is the best option for restoration of the defect. However, the amputated region often lacks veins with appropriate diameters for microvascular anastomoses and typically necessitates both postoperative exsanguination using medicinal leeches and a blood transfusion. We present a case of the successful replantation of an avulsed lip in which postoperative congestion was evaluated objectively by measuring blood glucose levels in the...

Blood Supply--Susceptible Formation of Melanin Pigment in Hair Bulb Melanocytes of Mice

Directory of Open Access Journals (Sweden)

Shogo Maeda, MD

2015-03-01

Conclusions: Melanin pigment formation in the hair bulb melanocytes appeared to be susceptible to the blood supply, and melanocytosis was promoted in the follicles and in the epidermis of Kitl-Tg C57BL/6 mice.

Long-term effects of bariatric surgery on peripheral endothelial function and coronary microvascular function.

Science.gov (United States)

Tarzia, Pierpaolo; Lanza, Gaetano A; Sestito, Alfonso; Villano, Angelo; Russo, Giulio; Figliozzi, Stefano; Lamendola, Priscilla; De Vita, Antonio; Crea, Filippo

We previously demonstrated that bariatric surgery (BS) leads to a short-term significant improvement of endothelial function and coronary microvascular function. In this study we assessed whether BS maintains its beneficial effect at long-term follow up. We studied 19 morbidly obese patients (age 43±9years, 12 women) without any evidence of cardiovascular disease who underwent BS. Patients were studied before BS, at 3 months and at 4.0±1.5years follow up. Peripheral vascular function was assessed by flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), i.e., brachial artery diameter changes in response to post-ischemic forearm hyperhaemia and to nitroglycerin administration, respectively. Coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to intravenous adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery. Together with improvement of anthropometric and metabolic profile, at long-term follow-up patients showed a significant improvement of FMD (6.43±2.88 vs. 8.21±1.73%, p=0.018), and CBF response to both adenosine (1.73±0.48 vs. 2.58±0.54; pfunction and on coronary microvascular dilator function. Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Blood-brain barrier dysfunction and amyloid precursor protein accumulation in microvascular compartment following ischemia-reperfusion brain injury with 1-year survival.

Science.gov (United States)

Pluta, R

2003-01-01

This study examined the late microvascular consequences of brain ischemia due to cardiac arrest in rats. In reacted vibratome sections scattered foci of extravasated horseradish peroxidase were noted throughout the brain and did not appear to be restricted to any specific area of brain. Ultrastructural investigation of leaky sites frequently presented platelets adhering to the endothelium of venules and capillaries. Endothelial cells demonstrated pathological changes with evidence of perivascular astrocytic swelling. At the same time, we noted C-terminal of amyloid precursor protein/beta-amyloid peptide (CAPP/betaA) deposits in cerebral blood vessels, with a halo of CAPP/betaA immunoreactivity in the surrounding parenchyma suggested diffusion of CAPP/betaA out of the vascular compartment. Changes predominated in the hippocampus, cerebral and entorhinal cortex, corpus callosum, thalamus, basal ganglia and around the lateral ventricles. These data implicate delayed abnormal endothelial function of vessels following ischemia-reperfusion brain injury as a primary event in the pathogenesis of the recurrent cerebral infarction.

[Blood supply and demand at the Fifth District Health Centre in Bamako (Mali)].

Science.gov (United States)

Traore, Mamadou; Dumont, Alexandre; Kaya, Amadou Balobo; Traore, Soumana Oumar; Traore, Oumar Moussokoro; Dolo, Amadou

2011-01-01

An adequate uncontaminated blood supply is an essential element of an effective health care system. A regional blood transfusion policy was defined in 2004 by the Direction of Health in Bamako, Mali. The objective of this study is to analyse the coverage of transfusion needs at the Fifth District health Center in Bamako after the implementation of this policy. This prospective study, conducted from December 2006 through May 2007, included 134 patients for whom transfusion orders were recorded in the laboratory. The coverage rate of transfusion needs was estimated by dividing the number of units transfused by the number of units that health professionals requested. The blood supply was regular (46 units per month, on average) and consistent with demand (59 units per month on average). Overall, 75% of the transfusions were required for obstetric complications. All patients received at least one 450-mL unit of whole blood. The coverage of transfusion needs has reached 65% of the total number of units required (95% CI = 60-70%). The implementation of a functioning system of blood transfusion is complex. In Bamako, a system based on a centralized transfusion center met a high proportion of the needs in a reference hospital where demand was high while ensuring a high level of patient safety. Further studies are needed to guide the implementation of feasible and sustainable strategies for providing sufficient quantities of safe blood in other contexts and to assess the impact of these different strategies on global health, and on maternal health in particular.

Out for blood. The newly overhauled American Red Cross is thirsty for a bigger share of the $2 billion business of supplying blood to hospitals.

Science.gov (United States)

Hensley, S

1998-06-22

The newly overhauled American Red Cross, led by President Elizabeth Dole (left), has launched an ambitious campaign to increase its piece of the more than $2 billion business of supplying blood to hospitals. Its quest for market share has sparked what some call a "blood war" with its main competitors: independent, community-governed blood banks affiliated with America's Blood Centers.

Multimodal reconstruction of microvascular-flow distributions using combined two-photon microscopy and Doppler optical coherence tomography.

Science.gov (United States)

Gagnon, Louis; Sakadžić, Sava; Lesage, Fréderic; Mandeville, Emiri T; Fang, Qianqian; Yaseen, Mohammad A; Boas, David A

2015-01-01

Computing microvascular cerebral blood flow ([Formula: see text]) in real cortical angiograms is challenging. Here, we investigated whether the use of Doppler optical coherence tomography (DOCT) flow measurements in individual vessel segments can help in reconstructing [Formula: see text] across the entire vasculature of a truncated cortical angiogram. A [Formula: see text] computational framework integrating DOCT measurements is presented. Simulations performed on a synthetic angiogram showed that the addition of DOCT measurements, especially close to large inflowing or outflowing vessels, reduces the impact of pressure boundary conditions and estimated vessel resistances resulting in a more accurate reconstruction of [Formula: see text]. Our technique was then applied to reconstruct microvascular flow distributions in the mouse cortex down to [Formula: see text] by combining two-photon laser scanning microscopy angiography with DOCT.

Correlates of time to microvascular complications among diabetes ...

African Journals Online (AJOL)

Socio-demographic and clinical factors have been known to affect the time to microvascular complications and survival probabilities of diabetes mellitus patients. The objective of this study was to identify risk factors and estimate average survival times for the time to the development of microvascular complications of ...

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

Correlation between dynamic contrast-enhanced MRI and quantitative histopathologic microvascular parameters in organ-confined prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Niekerk, Cornelis G. van; Laak, Jeroen A.W.M. van der; Kaa, Christina A.H. de [Radboud University Medical Centre, Department of Pathology, P.O. Box 9101, Nijmegen (Netherlands); Hambrock, Thomas; Huisman, Henk-Jan; Barentsz, Jelle O. [Radboud University Medical Centre, Department of Radiology, Nijmegen (Netherlands); Witjes, J.A. [Radboud University Medical Centre, Department of Urology, Nijmegen (Netherlands)

2014-10-15

To correlate pharmacokinetic parameters of 3-T dynamic contrast-enhanced (DCE-)MRI with histopathologic microvascular and lymphatic parameters in organ-confined prostate cancer. In 18 patients with unilateral peripheral zone (pT2a) tumours who underwent DCE-MRI prior to radical prostatectomy (RP), the following pharmacokinetic parameters were assessed: permeability surface area volume transfer constant (K{sup trans}), extravascular extracellular volume (Ve) and rate constant (K{sub ep}). In the RP sections blood and lymph vessels were visualised immunohistochemically and automatically examined and analysed. Parameters assessed included microvessel density (MVD), area (MVA) and perimeter (MVP) as well as lymph vessel density (LVD), area (LVA) and perimeter (LVP). A negative correlation was found between age and K{sup trans} and K{sub ep} for tumour (r = -0.60, p = 0.009; r = -0.67, p = 0.002) and normal (r = -0.54, p = 0.021; r = -0.46, p = 0.055) tissue. No correlation existed between absolute values of microvascular parameters from histopathology and DCE-MRI. In contrast, the ratio between tumour and normal tissue (correcting for individual microvascularity variations) significantly correlated between K{sub ep} and MVD (r = 0.61, p = 0.007) and MVP (r = 0.54, p = 0.022). The lymphovascular parameters showed only a correlation between LVA and K{sub ep} (r = -0.66, p = 0.003). Significant correlations between DCE-MRI and histopathologic parameters were found when correcting for interpatient variations in microvascularity. (orig.)

Hepatitis B and C seroprevalence in patients with diabetes mellitus and its relationship with microvascular complications

Directory of Open Access Journals (Sweden)

Kadir Gisi

2016-12-01

Full Text Available Introduction: Diabetic patients are susceptible to bacterial, viral and fungal infections because of various deficiencies in the immune system. Aim: To investigate a possible link between hepatitis B/C prevalence and microvascular complications as well as duration of diabetes. Material and methods: In total 1263 diabetic patients (1149 type 2, 114 type 1 were enrolled in the study. The control group consisted of 1482 healthy blood donors who were over 40 years old. All diabetic patients were tested for HBsAg, anti-HBs and anti-HCV beside routine laboratory tests. Diabetic patients were divided into three groups according to their diabetes duration, and all of the patients were scanned for microvascular complications. Demographic data of all patients were recorded. Results : HBsAg seropositivity was 3.7% in diabetic patients and 1.08% in the control group; this difference was statistically significant (p < 0.001. HBsAg positivity rates in type 1 and type 2 diabetics were 0.8% and 4%, respectively (p = 0.09. HCV seropositivity was 2.2% for diabetics and 0.5% for the control group; this difference was statistically significant (p 0.05. Also, no relationship was found between microvascular complications of diabetes and hepatitis B/C seropositivity. Conclusions : Hepatitis B and C seroprevalence was found to be increased in diabetes mellitus; however, there was no relationship between hepatitis seroprevalence and the duration or microvascular complications of diabetes.

Capillaries within compartments: microvascular interpretation of dynamic positron emission tomography data

DEFF Research Database (Denmark)

Munk, O L; Keiding, S; Bass, L

2003-01-01

scanners, little use is made of earlier microvascular research in the compartmental models, which have become the standard model by which the vast majority of dynamic PET data are analysed. However, modern PET scanners provide data with a sufficient temporal resolution and good counting statistics to allow...... single- and multi-capillary systems and include effects of non-exchanging vessels. They are suitable for analysing dynamic PET data from any capillary bed using either intravascular or diffusible tracers, in terms of physiological parameters which include regional blood flow. Udgivelsesdato: 2003-Nov-7......Measurement of exchange of substances between blood and tissue has been a long-lasting challenge to physiologists, and considerable theoretical and experimental accomplishments were achieved before the development of the positron emission tomography (PET). Today, when modeling data from modern PET...

UVB therapy decreases the adhesive interaction between peripheral blood mononuclear cells and dermal microvascular endothelium, and regulates the differential expression of CD54, VCAM-1, and E-selectin in psoriatic plaques

International Nuclear Information System (INIS)

Cai, J.-P.; Harris, K.; Chin, Y.H.

1996-01-01

A dermal lymphocytic infiltrate is a characteristic feature of psoriasis, and may be involved in the pathogenesis of the disease. We have previously shown that specialized dermal microvascular endothelial cells (DMEC) in psoriatic lesions promote the selective adherence of the CD4 CD45Ro helper T-cell subset. In this study, we examined the adhesive interaction between peripheral blood mononuclear cells and psoriatic DMEC in patients treated with ultraviolet B light (UVB), and correlated the results with the expression and function of endothelial adhesion molecules on DMEC. (author)

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

Science.gov (United States)

Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-12-20

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

Graft microvascular disease in solid organ transplantation.

Science.gov (United States)

Jiang, Xinguo; Sung, Yon K; Tian, Wen; Qian, Jin; Semenza, Gregg L; Nicolls, Mark R

2014-08-01

Alloimmune inflammation damages the microvasculature of solid organ transplants during acute rejection. Although immunosuppressive drugs diminish the inflammatory response, they do not directly promote vascular repair. Repetitive microvascular injury with insufficient regeneration results in prolonged tissue hypoxia and fibrotic remodeling. While clinical studies show that a loss of the microvascular circulation precedes and may act as an initiating factor for the development of chronic rejection, preclinical studies demonstrate that improved microvascular perfusion during acute rejection delays and attenuates tissue fibrosis. Therefore, preservation of a functional microvasculature may represent an effective therapeutic strategy for preventing chronic rejection. Here, we review recent advances in our understanding of the role of the microvasculature in the long-term survival of transplanted solid organs. We also highlight microvessel-centered therapeutic strategies for prolonging the survival of solid organ transplants.

Microvascular pressure responses of second-generation rats chronically exposed to 2 g centrifugation

Science.gov (United States)

Richardson, D. R.; Knapp, C. F.

1977-01-01

Preliminary results are presented for a study aimed at a quantitative comparison of microvascular dynamics in second-generation rats reared in a 2-g force field produced by centrifugation with similar data from animals reared in a centrifuge that produced only a 1-g force. It is shown that the pressure distribution in the mesenteric microvasculature of the second generation of rats reared in a 2-g environment, as well as the animals' blood pressure response to epinephrine, are significantly different compared to their 1-g counterparts. In particular, 1-g and 2-g chronic centrifugation enhances the arterial blood pressure, and the 2-g force field attenuates the pressor effects of norepinephrine.

Physiological importance of the coronary arterial blood supply to the rattlesnake heart

DEFF Research Database (Denmark)

Hagensen, Mette; Abe, Augusto S.; Falk, Erling

2008-01-01

Pa and 58.2±2.2 beats min-1, respectively, during activity and the ECG was not affected. This was not different from sham-operated snakes. Thus, while the outer compact layer of the rattlesnake heart clearly has an extensive coronary supply, rattlesnakes sustain a high blood pressure and heart rate during...

The INTERVAL trial to determine whether intervals between blood donations can be safely and acceptably decreased to optimise blood supply: study protocol for a randomised controlled trial.

Science.gov (United States)

Moore, Carmel; Sambrook, Jennifer; Walker, Matthew; Tolkien, Zoe; Kaptoge, Stephen; Allen, David; Mehenny, Susan; Mant, Jonathan; Di Angelantonio, Emanuele; Thompson, Simon G; Ouwehand, Willem; Roberts, David J; Danesh, John

2014-09-17

Ageing populations may demand more blood transfusions, but the blood supply could be limited by difficulties in attracting and retaining a decreasing pool of younger donors. One approach to increase blood supply is to collect blood more frequently from existing donors. If more donations could be safely collected in this manner at marginal cost, then it would be of considerable benefit to blood services. National Health Service (NHS) Blood and Transplant in England currently allows men to donate up to every 12 weeks and women to donate up to every 16 weeks. In contrast, some other European countries allow donations as frequently as every 8 weeks for men and every 10 weeks for women. The primary aim of the INTERVAL trial is to determine whether donation intervals can be safely and acceptably decreased to optimise blood supply whilst maintaining the health of donors. INTERVAL is a randomised trial of whole blood donors enrolled from all 25 static centres of NHS Blood and Transplant. Recruitment of about 50,000 male and female donors started in June 2012 and was completed in June 2014. Men have been randomly assigned to standard 12-week versus 10-week versus 8-week inter-donation intervals, while women have been assigned to standard 16-week versus 14-week versus 12-week inter-donation intervals. Sex-specific comparisons will be made by intention-to-treat analysis of outcomes assessed after two years of intervention. The primary outcome is the number of blood donations made. A key secondary outcome is donor quality of life, assessed using the Short Form Health Survey. Additional secondary endpoints include the number of 'deferrals' due to low haemoglobin (and other factors), iron status, cognitive function, physical activity, and donor attitudes. A comprehensive health economic analysis will be undertaken. The INTERVAL trial should yield novel information about the effect of inter-donation intervals on blood supply, acceptability, and donors' physical and mental well

Microvascular characteristics of the acoustic fats: Novel data suggesting taxonomic differences between deep and shallow-diving odontocetes.

Science.gov (United States)

Gabler, Molly K; Gay, D Mark; Westgate, Andrew J; Koopman, Heather N

2018-04-01

Odontocetes have specialized mandibular fats, the extramandibular (EMFB) and intramandibular fat bodies (IMFB), which function as acoustic organs, receiving and channeling sound to the ear during hearing and echolocation. Recent strandings of beaked whales suggest that these fat bodies are susceptible to nitrogen (N 2 ) gas embolism and empirical evidence has shown that the N 2 solubility of these fat bodies is higher than that of blubber. Since N 2 gas will diffuse from blood into tissue at any blood/tissue interface and potentially form gas bubbles upon decompression, it is imperative to understand the extent of microvascularity in these specialized acoustic fats so that risk of embolism formation when diving can be estimated. Microvascular density was determined in the EMFB, IMFB, and blubber from 11 species representing three odontocete families. In all cases, the acoustic tissues had less (typically 1/3 to 1/2) microvasculature than did blubber, suggesting that capillary density in the acoustic tissues may be more constrained than in the blubber. However, even within these constraints there were clear phylogenetic differences. Ziphiid (Mesoplodon and Ziphius, 0.9 ± 0.4% and 0.7 ± 0.3% for EMFB and IMFB, respectively) and Kogiid families (1.2 ± 0.2% and 1.0 ± 0.01% for EMFB and IMFB, respectively) had significantly lower mean microvascular densities in the acoustic fats compared to the Delphinid species (Tursiops, Grampus, Stenella, and Globicephala, 1.3 ± 0.3% and 1.3 ± 0.3% for EMFB and IMFB, respectively). Overall, deep-diving beaked whales had less microvascularity in both mandibular fats and blubber compared to the shallow-diving Delphinids, which might suggest that there are differences in the N 2 dynamics associated with diving regime, phylogeny, and tissue type. These novel data should be incorporated into diving physiology models to further understand potential functional disruption of the acoustic tissues due to changes

Apolipoprotein B level and diabetic microvascular complications ( is there a correlation?

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Mary N. Rizk

2013-01-01

Conclusion Apo B levels are strongly correlated to diabetic microvascular complications. The higher the degree of nephropathy, the higher the Apo B level. The presence of more than one microvascular complication correlates positively with high levels of Apo B. This suggests the possible use of Apo B as a sensitive biomarker of the presence of early diabetic microvascular complications.

Study on the peripheral white blood cell count in patients with type 2 diabetes complicated with microangiopathy

International Nuclear Information System (INIS)

Cai Wenpin; Zhu Pinghui

2010-01-01

Objective: To study the possible role played by peripheral white blood cells in the development of type 2 diabetes (DM2) and complication of microvascular pathological changes. Methods: White blood cell count and metabolism related parameters (FBG, 2hPBG, 2h Pinsulin, TCH, HDL, LDL, TG, HbA1c, BMI, age) were examined in 33 DM2 patients without complication, 41 DM2 patients with micro-angiopathy and 31 controls. Results: The white blood cell counts in both DM2 patients with no complication and the DM2 with microvascular pathological changes were significantly higher than those in controls (P 0.05). The white blood cell counts were positively correlated with age,body metabolism index (BMI), triglyceride (TG), 2h glucose (PBG) and 2h insulin (the r value 0.248, 0.201, 0.435, 0.225, 0.352 respectively, P<0.05). Conclusion: Peripheral white blood cells possibly played some role in development of DM2 and microvascular pathological changes and might be of some predictive importance. (authors)

Successful microsurgical lip replantation: Monitoring venous congestion by blood glucose measurements in the replanted lip

Directory of Open Access Journals (Sweden)

Kazufumi Tachi

2018-03-01

Full Text Available Replantation of an amputated lip using microvascular anastomosis is the best option for restoration of the defect. However, the amputated region often lacks veins with appropriate diameters for microvascular anastomoses and typically necessitates both postoperative exsanguination using medicinal leeches and a blood transfusion. We present a case of the successful replantation of an avulsed lip in which postoperative congestion was evaluated objectively by measuring blood glucose levels in the replanted region. The patient presented to our hospital with an upper lip avulsion that was caused by a dog bite. The lip was replanted by the microvascular anastomoses of one artery and two veins using interposed vein grafts. The replanted lip showed signs of congestion on postoperative day one; exsanguination using medicinal leeches was attempted, while blood glucose levels were measured every three hours. Critical congestion, which did not occur in this patient, was defined as a blood glucose level lower than 40 mg/dL. Lip replantation was successful without any complications in this patient.

Arterial Blood Supply to the Spinal Cord in Animal Models of Spinal Cord Injury. A Review.

Science.gov (United States)

Mazensky, David; Flesarova, Slavka; Sulla, Igor

2017-12-01

Animal models are used to examine the results of experimental spinal cord injury. Alterations in spinal cord blood supply caused by complex spinal cord injuries contribute significantly to the diversity and severity of the spinal cord damage, particularly ischemic changes. However, the literature has not completely clarified our knowledge of anatomy of the complex three-dimensional arterial system of the spinal cord in experimental animals, which can impede the translation of experimental results to human clinical applications. As the literary sources dealing with the spinal cord arterial blood supply in experimental animals are limited and scattered, the authors performed a review of the anatomy of the arterial blood supply to the spinal cord in several experimental animals, including pigs, dogs, cats, rabbits, guinea pigs, rats, and mice and created a coherent format discussing the interspecies differences. This provides researchers with a valuable tool for the selection of the most suitable animal model for their experiments in the study of spinal cord ischemia and provides clinicians with a basis for the appropriate translation of research work to their clinical applications. Anat Rec, 300:2091-2106, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Photocoagulation of microvascular and hemorrhagic lesions of the vocal fold with the KTP laser.

Science.gov (United States)

Hirano, Shigeru; Yamashita, Masaru; Kitamura, Morimasa; Takagita, Shin-ichi

2006-04-01

Ectasias and varices of the vocal fold are microvascular lesions that are often due to chronic abuse of the voice, and are occasionally encountered in association with other disorders such as polyps, Reinke's edema, and hematoma. The KTP laser can be used for photocoagulation of small vascular lesions, because the laser beam is well absorbed by hemoglobin, and damage to the epithelium is minimal. The present pilot study examined how the KTP laser could be used for microvascular lesions and their associated lesions. Twelve patients who had undergone phonomicrosurgery were enrolled in the present study. The microvascular lesions were treated by photocoagulation with the laser set at a low power of 1.5 W in the continuous mode, while preserving the epithelium, and associated lesions were then treated by microdissection with cold instruments. The postoperative phonatory function was assessed by maximum phonation time, a perceptual test rating (GRBAS scale), and stroboscopy. The procedures were completed successfully in all cases. An exceptional case of a small hemorrhagic polyp allowed treatment with the laser only. The postoperative stroboscopic findings, maximum phonation time, and perceptual test rating all showed significant improvement compared with the preoperative state. No adverse effects, such as scarring or reduction of the mucosal wave, were observed in the current series. KTP laser photocoagulation is a relatively simple and safe procedure for treating microvascular lesions of the vocal fold. It is not recommended for photocoagulation of hemorrhagic polyps or hematomas, because such lesions have little blood flow inside and thus photocoagulation is usually impossible or requires too much laser energy. However, photocoagulation of perimeter or feeding vessels of such disorders may facilitate the following procedure by avoiding unnecessary bleeding, as well as preventing recurrence of hemorrhagic lesions.

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.

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

The Blood Stocks Management Scheme, a partnership venture between the National Blood Service of England and North Wales and participating hospitals for maximizing blood supply chain management.

Science.gov (United States)

Chapman, J F; Cook, R

2002-10-01

The Blood Stocks Management Scheme (BSMS) has been established as a joint venture between the National Blood Service (NBS) in England and North Wales and participating hospitals to monitor the blood supply chain. Stock and wastage data are submitted to a web-based data-management system, facilitating continuous and complete red cell data collection and 'real time' data extraction. The data-management system enables peer review of performance in respect of stock holding levels and red cell wastage. The BSMS has developed an innovative web-based data-management system that enables data collection and benchmarking of practice, which should drive changes in stock management practice, therefore optimizing the use of donated blood.

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

Controversy and discussion on blood supply and interventional therapy of cavernous hemangiomas of the liver

International Nuclear Information System (INIS)

Ouyang Yong; Wang Ying; Ouyang Xuehui; Yu Ming

2004-01-01

Objective: To further explore the blood supply and interventional therapy of adult cavernous hemangiomas of the liver (CHL). Methods: Recently some authors reported that a satisfactory effect resulted from transcatheter portal venous embolization was obtained in few cases of CHL with blood supply of portal vein, and raised an objection to the standpoint that CHL was commonly supplied by hepatic artery completely. In order to get a scientific and reasonable explanation for it, this paper reviewed the vascular embryology and histology of the liver, the pathologic features of CHL as well as the relative literature, and combined with the investigation results of blood dynamic changes of CHL that had been performed in 2000-2002 by us. Results: CHL was caused by the arrested development of hepatic sinusoids at the embryonic stage. Pathologically, CHL was consisted of a lot of enlarged abnormal sinusoids,which were variant in size and closely related with the hemodynamic changes of CHL ( in inverse proportion). The CHL consisted of even and tiny abnormal sinusoids (diameter less than 50 μm) pathologically usually presented a high flow. During the hepatic artery angiography or CTHA, it was rapidly filled by the arterial blood containing contrast media and frequently showed dense opacification or enhancement. Simultaneously this could result in increased pressure of abnormal sinusoids. When the sinusoidal pressure exceeded that of the connecting portal venules, the arterial blood containing contrast media filled in the abnormal sinusoids could lead to retrograde flow in the portal venules. That was arterial-portal venous shunts (APVS). These appearances described as above could also occur in some CHL with intermediate flow, in which many tiny abnormal sinusoids located in the peripheral area were identified pathologically. On the contrary, the CHL consisted of larger abnormal sinusoids (diameter more than 500 μm) pathologically usually presented a low flow. During the

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.

Assessing the residual risk for transfusion-transmitted infections in the Philippine blood supply.

Science.gov (United States)

Lam, Hilton Y; Belizario, Vicente Y; Juban, Noel R; Alejandria, Marissa M; Castillo-Carandang, Nina; Arcellana-Nuqui, Elizabeth; Mirasol, Ma Angelina; Cordero, Cynthia P; Sison, Olivia T; Rivera, Adovich S

2014-09-01

Due to a USAID-funded study on blood banks, a national policy was instituted in 1994 that set standards for Philippine blood services, promoted voluntary donation, and led to a ban on commercial blood banks. In this follow-up study, we assess the safety of the supply by determining the residual risk for transfusion-transmitted infections (syphilis, hepatitis B and C, HIV). We also identified unsafe facility practices and generated policy recommendations. A 1992 study found that transfusion-ready blood was not safe using the LQAS method (P > 0.05). We found that the 2012 residual risk became 0 to 0.9 percent attributable to the national policy. We noted poor to fair adherence to this policy. We identified unsafe practices such as use of rapid tests and lack of random blood retesting. Training and use of regional networks may improve safety. Despite improvement in safety, facilities complain of funding and logistical issues regarding compliance with the policy.

Differential effects of glucagon-like peptide-1 on microvascular recruitment and glucose metabolism in short- and long-term Insulin resistance

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Rattigan, Stephen; Jeppesen, Jacob Fuglsbjerg

2015-01-01

Acute infusion of glucagon-like-peptide-1 (GLP-1) has potent effects on blood flow distribution through the microcirculation in healthy humans and rats. High fat diet induces impairments in insulin-mediated microvascular recruitment (MVR) and muscle glucose uptake, and here we examined whether......-mediated glucose uptake in skeletal muscle by 90% (Prights...

Regulation of Coronary Blood Flow in Health and Ischemic Heart Disease

Science.gov (United States)

Duncker, Dirk J.; Koller, Akos; Merkus, Daphne; Canty, John M.

2018-01-01

The major factors determining myocardial perfusion and oxygen delivery have been elucidated over the past several decades, and this knowledge has been incorporated into the management of patients with ischemic heart disease (IHD). The basic understanding of the fluid mechanical behavior of coronary stenoses has also been translated to the cardiac catheterization laboratory where measurements of coronary pressure distal to a stenosis and coronary flow are routinely obtained. However, the role of perturbations in coronary microvascular structure and function, due to myocardial hypertrophy or coronary microvascular dysfunction, in IHD is becoming increasingly recognized. Future studies should therefore be aimed at further improving our understanding of the integrated coronary microvascular mechanisms that control coronary blood flow, and of the underlying causes and mechanisms of coronary microvascular dysfunction. This knowledge will be essential to further improve the treatment of patients with IHD. PMID:25475073

Elevated plasma plasminogen activator inhibitor type-1 is an independent predictor of coronary microvascular dysfunction in hypertension

International Nuclear Information System (INIS)

Naya, Masanao; Tsukamoto, Takahiro; Inubushi, Masayuki; Morita, Koichi; Katoh, Chietsugu; Furumoto, Tomoo; Fujii, Satoshi; Tsutsui, Hiroyuki; Tamaki, Nagara

2007-01-01

Elevated plasma plasminogen activator inhibitor-1 (PAI-1) is related to cardiovascular events, but its role in subclinical coronary microvascular dysfunction remains unknown. Thus, in the present study it was investigated whether elevated plasma PAI-1 activity is associated with coronary microvascular dysfunction in hypertensive patients. Thirty patients with untreated essential hypertension and 10 age-matched healthy controls were studied prospectively. Myocardial blood flow (MBF) was measured by using 15 O-water positron emission tomography. Clinical variables associated with atherosclerosis (low-density lipoprotein-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, homeostasis model assessment (HOMA-IR), and PAI-1 activity) were assessed to determine their involvement in coronary microvascular dysfunction. Adenosine triphosphate (ATP)-induced hyperemic MBF and coronary flow reserve (CFR) were significantly lower in hypertensive patients than in healthy controls (ATP-induced MBF: 2.77±0.82 vs 3.49±0.71 ml·g -1 ·min -1 ; p<0.02 and CFR: 2.95±1.06 vs 4.25±0.69; p<0.001). By univariate analysis, CFR was positively correlated with HDL-cholesterol (r=0.46, p<0.02), and inversely with HOMA-IR (r=-0.39, p<0.05) and PAI-1 activity (r=-0.61, p<0.001). By multivariate analysis, elevated PAI-1 activity remained a significant independent determinant of diminished CFR. Elevated plasma PAI-1 activity was independently associated with coronary microvascular dysfunction, which suggests that plasma PAI-1 activity is an important clue linking hypofibrinolysis to the development of atherosclerosis. (author)

Mammary blood supply in various diseases as evidenced by color Doppler sonography

International Nuclear Information System (INIS)

Kharchenko, V.P.; Rozhkova, N.I.; Zubovskij, G.A.; Medvedeva, N.A.

1993-01-01

Color dopplerosonography, traditional sonography, and mammography without contrast staining, as well as physical and pathomorphologic methods were used in examinations of the mammary glands of 76 women aged 18 to 65. Characteristic features of the blood supply to the gland were detected, and differential diagnostic criteria defined on the basis of these findings, to simplify differentiation between malignant and benign nodular formations and the diffuse changes in the mamma

Age-related differences in skeletal muscle microvascular response to exercise as detected by contrast-enhanced ultrasound (CEUS).

Science.gov (United States)

Hildebrandt, Wulf; Schwarzbach, Hans; Pardun, Anita; Hannemann, Lena; Bogs, Björn; König, Alexander M; Mahnken, Andreas H; Hildebrandt, Olaf; Koehler, Ulrich; Kinscherf, Ralf

2017-01-01

Aging involves reductions in exercise total limb blood flow and exercise capacity. We hypothesized that this may involve early age-related impairments of skeletal muscle microvascular responsiveness as previously reported for insulin but not for exercise stimuli in humans. Using an isometric exercise model, we studied the effect of age on contrast-enhanced ultrasound (CEUS) parameters, i.e. microvascular blood volume (MBV), flow velocity (MFV) and blood flow (MBF) calculated from replenishment of Sonovue contrast-agent microbubbles after their destruction. CEUS was applied to the vastus lateralis (VLat) and intermedius (VInt) muscle in 15 middle-aged (MA, 43.6±1.5 years) and 11 young (YG, 24.1±0.6 years) healthy males before, during, and after 2 min of isometric knee extension at 15% of peak torque (PT). In addition, total leg blood flow as recorded by femoral artery Doppler-flow. Moreover, fiber-type-specific and overall capillarisation as well as fiber composition were additionally assessed in Vlat biopsies obtained from CEUS site. MA and YG had similar quadriceps muscle MRT-volume or PT and maximal oxygen uptake as well as a normal cardiovascular risk factors and intima-media-thickness. During isometric exercise MA compared to YG reached significantly lower levels in MFV (0.123±0.016 vs. 0.208±0.036 a.u.) and MBF (0.007±0.001 vs. 0.012±0.002 a.u.). In the VInt the (post-occlusive hyperemia) post-exercise peaks in MBV and MBF were significantly lower in MA vs. YG. Capillary density, capillary fiber contacts and femoral artery Doppler were similar between MA and YG. In the absence of significant age-related reductions in capillarisation, total leg blood flow or muscle mass, healthy middle-aged males reveal impaired skeletal muscle microcirculatory responses to isometric exercise. Whether this limits isometric muscle performance remains to be assessed.

Active cooling of microvascular composites for battery packaging

Science.gov (United States)

Pety, Stephen J.; Chia, Patrick X. L.; Carrington, Stephen M.; White, Scott R.

2017-10-01

Batteries in electric vehicles (EVs) require a packaging system that provides both thermal regulation and crash protection. A novel packaging scheme is presented that uses active cooling of microvascular carbon fiber reinforced composites to accomplish this multifunctional objective. Microvascular carbon fiber/epoxy composite panels were fabricated and their cooling performance assessed over a range of thermal loads and experimental conditions. Tests were performed for different values of coolant flow rate, channel spacing, panel thermal conductivity, and applied heat flux. More efficient cooling occurs when the coolant flow rate is increased, channel spacing is reduced, and thermal conductivity of the host composite is increased. Computational fluid dynamics (CFD) simulations were also performed and correlate well with the experimental data. CFD simulations of a typical EV battery pack confirm that microvascular composite panels can adequately cool battery cells generating 500 W m-2 heat flux below 40 °C.

A Green's function method for simulation of time-dependent solute transport and reaction in realistic microvascular geometries.

Science.gov (United States)

Secomb, Timothy W

2016-12-01

A novel theoretical method is presented for simulating the spatially resolved convective and diffusive transport of reacting solutes between microvascular networks and the surrounding tissues. The method allows for efficient computational solution of problems involving convection and non-linear binding of solutes in blood flowing through microvascular networks with realistic 3D geometries, coupled with transvascular exchange and diffusion and reaction in the surrounding tissue space. The method is based on a Green's function approach, in which the solute concentration distribution in the tissue is expressed as a sum of fields generated by time-varying distributions of discrete sources and sinks. As an example of the application of the method, the washout of an inert diffusible tracer substance from a tissue region perfused by a network of microvessels is simulated, showing its dependence on the solute's transvascular permeability and tissue diffusivity. Exponential decay of the washout concentration is predicted, with rate constants that are about 10-30% lower than the rate constants for a tissue cylinder model with the same vessel length, vessel surface area and blood flow rate per tissue volume. © The authors 2015. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Study on blood supply of lung metastasis with trans-pulmonary arterial lipiodol infusion

International Nuclear Information System (INIS)

Zhou Jianqin; Dong Weihua; Dong Weihua; Ouyang Chang; Chang Heng; Xiao Xiangsheng

2008-01-01

Objective: To evaluate the blood supply of pulmonary metastases using small volume of lipiodol through pulmonary arterial infusion. Methods: 10 cases of lung metastasis were enroled including the primary tumors of liver cancer (n=5), renal carcinoma (n=3), chordoma (n=1) and malignant neurofibroma (n=1). Plain CT scan was performed to exclude calcification or ossification within metastasis and then pulmonary arterial DSA was undertaken to evaluate tumor vessels or staining. After pulmonary arteriovenous fistula or other anomalous circulation was excluded by lobar arterial DSA, small volume of lipiodol was infused under fluoroscopy (0.5-1.5 ml for each lobar artery, total volume less than 3.0 ml). CT scan was immediately performed. Blood supply of the pulmonary metastases was assessed according to the accumulation of lipiodol on CT scans. Results: No cases but one experienced cough, expectoration, suffocating or dyspnea. No complication of cerebral or visceral embolism occurred. Totally 27 nodules were studied including 6 nodules with cloudy lipiodol accumulation and 6 nodules with tiny granules of lipiodol accumulation. No enlarged tumor vessel or tumor stain was observed within all 27 nodules on pulmonary arterial DSA. Conclusions: Pulmonary artery supplys only parts of pulmonary metastases, especially those sited at the peripheral region of the lung. Infusion of small volume of lipiodol through pulmonary artery is safe, and the increased density of lung field could return normal after several days. (authors)

Circulating IGF-1 deficiency exacerbates hypertension-induced microvascular rarefaction in the mouse hippocampus and retrosplenial cortex: implications for cerebromicrovascular and brain aging.

Science.gov (United States)

Tarantini, Stefano; Tucsek, Zsuzsanna; Valcarcel-Ares, M Noa; Toth, Peter; Gautam, Tripti; Giles, Cory B; Ballabh, Praveen; Wei, Jeanne Y; Wren, Jonathan D; Ashpole, Nicole M; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

2016-08-01

Strong epidemiological and experimental evidence indicate that both age and hypertension lead to significant functional and structural impairment of the cerebral microcirculation, predisposing to the development of vascular cognitive impairment (VCI) and Alzheimer's disease. Preclinical studies establish a causal link between cognitive decline and microvascular rarefaction in the hippocampus, an area of brain important for learning and memory. Age-related decline in circulating IGF-1 levels results in functional impairment of the cerebral microvessels; however, the mechanistic role of IGF-1 deficiency in impaired hippocampal microvascularization remains elusive. The present study was designed to characterize the additive/synergistic effects of IGF-1 deficiency and hypertension on microvascular density and expression of genes involved in angiogenesis and microvascular regression in the hippocampus. To achieve that goal, we induced hypertension in control and IGF-1 deficient mice (Igf1 f/f  + TBG-Cre-AAV8) by chronic infusion of angiotensin II. We found that circulating IGF-1 deficiency is associated with decreased microvascular density and exacerbates hypertension-induced microvascular rarefaction both in the hippocampus and the neocortex. The anti-angiogenic hippocampal gene expression signature observed in hypertensive IGF-1 deficient mice in the present study provides important clues for subsequent studies to elucidate mechanisms by which hypertension may contribute to the pathogenesis and clinical manifestation of VCI. In conclusion, adult-onset, isolated endocrine IGF-1 deficiency exerts deleterious effects on the cerebral microcirculation, leading to a significant decline in cortical and hippocampal capillarity and exacerbating hypertension-induced cerebromicrovascular rarefaction. The morphological impairment of the cerebral microvasculature induced by IGF-1 deficiency and hypertension reported here, in combination with neurovascular uncoupling, increased

Microvascular dysfunction in the immediate aftermath of chronic total coronary occlusion recanalization.

Science.gov (United States)

Ladwiniec, Andrew; Cunnington, Michael S; Rossington, Jennifer; Thackray, Simon; Alamgir, Farquad; Hoye, Angela

2016-05-01

The aim of this study was to compare microvascular resistance under both baseline and hyperemic conditions immediately after percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) with an unobstructed reference vessel in the same patient Microvascular dysfunction has been reported to be prevalent immediately after CTO PCI. However, previous studies have not made comparison with a reference vessel. Patients with a CTO may have global microvascular and/or endothelial dysfunction, making comparison with established normal values misleading. After successful CTO PCI in 21 consecutive patients, coronary pressure and flow velocity were measured at baseline and hyperemia in distal segments of the CTO/target vessel and an unobstructed reference vessel. Hemodynamics including hyperemic microvascular resistance (HMR), basal microvascular resistance (BMR), and instantaneous minimal microvascular resistance at baseline and hyperemia were calculated and compared between reference and target/CTO vessels. After CTO PCI, BMR was reduced in the target/CTO vessel compared with the reference vessel: 3.58 mm Hg/cm/s vs 4.94 mm Hg/cm/s, difference -1.36 mm Hg/cm/s (-2.33 to -0.39, p = 0.008). We did not detect a difference in HMR: 1.82 mm Hg/cm/s vs 2.01 mm Hg/cm/s, difference -0.20 (-0.78 to 0.39, p = 0.49). Instantaneous minimal microvascular resistance correlated strongly with the length of stented segment at baseline (r = 0.63, p = 0.005) and hyperemia (r = 0.68, p = 0.002). BMR is reduced in a recanalized CTO in the immediate aftermath of PCI compared to an unobstructed reference vessel; however, HMR appears to be preserved. A longer stented segment is associated with increased microvascular resistance. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Microvascular imaging: techniques and opportunities for clinical physiological measurements

International Nuclear Information System (INIS)

Allen, John; Howell, Kevin

2014-01-01

The microvasculature presents a particular challenge in physiological measurement because the vessel structure is spatially inhomogeneous and perfusion can exhibit high variability over time. This review describes, with a clinical focus, the wide variety of methods now available for imaging of the microvasculature and their key applications. Laser Doppler perfusion imaging and laser speckle contrast imaging are established, commercially-available techniques for determining microvascular perfusion, with proven clinical utility for applications such as burn-depth assessment. Nailfold capillaroscopy is also commercially available, with significant published literature that supports its use for detecting microangiopathy secondary to specific connective tissue diseases in patients with Raynaud's phenomenon. Infrared thermography measures skin temperature and not perfusion directly, and it has only gained acceptance for some surgical and peripheral microvascular applications. Other emerging technologies including imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging are also described to show their potential as techniques that could become established tools for clinical microvascular assessment. Growing interest in the microcirculation has helped drive the rapid development in perfusion imaging of the microvessels, bringing exciting opportunities in microvascular research. (topical review)

Do expert assessments converge? An exploratory case study of evaluating and managing a blood supply risk.

Science.gov (United States)

Eyles, John; Heddle, Nancy; Webert, Kathryn; Arnold, Emmy; McCurdy, Bronwen

2011-08-24

Examining professional assessments of a blood product recall/withdrawal and its implications for risk and public health, the paper introduces ideas about perceptions of minimal risk and its management. It also describes the context of publicly funded blood transfusion in Canada and the withdrawal event that is the basis of this study. Interviews with 45 experts from administration, medicine, blood supply, laboratory services and risk assessment took place using a multi-level sampling framework in the aftermath of the recall. These experts either directly dealt with the withdrawal or were involved in the management of the blood supply at the national level. Data from these interviews were coded in NVivo for analysis and interpretation. Analytically, data were interpreted to derive typifications to relate interview responses to risk management heuristics. While all those interviewed agreed on the importance of patient safety, differences in the ways in which the risk was contextualized and explicated were discerned. Risk was seen in terms of patient safety, liability or precaution. These different risk logics are illustrated by selected quotations. Expert assessments did not fully converge and it is possible that these different risk logics and discourses may affect the risk management process more generally, although not necessarily in a negative way. Patient safety is not to be compromised but management of blood risk in publicly funded systems may vary. We suggest ways of managing blood risk using formal and safety case approaches.

Do expert assessments converge? An exploratory case study of evaluating and managing a blood supply risk

Directory of Open Access Journals (Sweden)

Arnold Emmy

2011-08-01

Full Text Available Abstract Background Examining professional assessments of a blood product recall/withdrawal and its implications for risk and public health, the paper introduces ideas about perceptions of minimal risk and its management. It also describes the context of publicly funded blood transfusion in Canada and the withdrawal event that is the basis of this study. Methods Interviews with 45 experts from administration, medicine, blood supply, laboratory services and risk assessment took place using a multi-level sampling framework in the aftermath of the recall. These experts either directly dealt with the withdrawal or were involved in the management of the blood supply at the national level. Data from these interviews were coded in NVivo for analysis and interpretation. Analytically, data were interpreted to derive typifications to relate interview responses to risk management heuristics. Results While all those interviewed agreed on the importance of patient safety, differences in the ways in which the risk was contextualized and explicated were discerned. Risk was seen in terms of patient safety, liability or precaution. These different risk logics are illustrated by selected quotations. Conclusions Expert assessments did not fully converge and it is possible that these different risk logics and discourses may affect the risk management process more generally, although not necessarily in a negative way. Patient safety is not to be compromised but management of blood risk in publicly funded systems may vary. We suggest ways of managing blood risk using formal and safety case approaches.

Multifunctional role of astrocytes as gatekeepers of neuronal energy supply

Directory of Open Access Journals (Sweden)

Jillian L Stobart

2013-04-01

Full Text Available Dynamic adjustments to neuronal energy supply in response to synaptic activity are critical for neuronal function. Glial cells known as astrocytes have processes that ensheath most central synapses and express G-protein-coupled neurotransmitter receptors and transporters that respond to neuronal activity. Astrocytes also release substrates for neuronal oxidative phosphorylation and have processes that terminate on the surface of brain arterioles and can influence vascular smooth muscle tone and local blood flow. Membrane receptor or transporter-mediated effects of glutamate represent a convergence point of astrocyte influence on neuronal bioenergetics. Astrocytic glutamate uptake drives glycolysis and subsequent shuttling of lactate from astrocytes to neurons for oxidative metabolism. Astrocytes also convert synaptically reclaimed glutamate to glutamine, which is returned to neurons for glutamate salvage or oxidation. Finally, astrocytes store brain energy currency in the form of glycogen, which can be mobilized to produce lactate for neuronal oxidative phosphorylation in response to glutamatergic neurotransmission. These mechanisms couple synaptically-driven astrocytic responses to glutamate with release of energy substrates back to neurons to match demand with supply. In addition, astrocytes directly influence the tone of penetrating brain arterioles in response to glutamatergic neurotransmission, coordinating dynamic regulation of local blood flow. We will describe the role of astrocytes in neurometabolic and neurovascular coupling in detail and discuss, in turn, how astrocyte dysfunction may contribute to neuronal bioenergetic deficit and neurodegeneration. Understanding the role of astrocytes as a hub for neurometabolic and neurovascular coupling mechanisms is a critical underpinning for therapeutic development in a broad range of neurodegenerative disorders characterized by chronic generalized brain ischemia and brain microvascular

The blood-brain barrier fatty acid transport protein 1 (FATP1/SLC27A1) supplies docosahexaenoic acid to the brain, and insulin facilitates transport.

Science.gov (United States)

Ochiai, Yusuke; Uchida, Yasuo; Ohtsuki, Sumio; Tachikawa, Masanori; Aizawa, Sanshiro; Terasaki, Tetsuya

2017-05-01

We purposed to clarify the contribution of fatty acid transport protein 1 (FATP1/SLC 27A1) to the supply of docosahexaenoic acid (DHA) to the brain across the blood-brain barrier in this study. Transport experiments showed that the uptake rate of [ 14 C]-DHA in human FATP1-expressing HEK293 cells was significantly greater than that in empty vector-transfected (mock) HEK293 cells. The steady-state intracellular DHA concentration was nearly 2-fold smaller in FATP1-expressing than in mock cells, suggesting that FATP1 works as not only an influx, but also an efflux transporter for DHA. [ 14 C]-DHA uptake by a human cerebral microvascular endothelial cell line (hCMEC/D3) increased in a time-dependent manner, and was inhibited by unlabeled DHA and a known FATP1 substrate, oleic acid. Knock-down of FATP1 in hCMEC/D3 cells with specific siRNA showed that FATP1-mediated uptake accounts for 59.2-73.0% of total [ 14 C]-DHA uptake by the cells. Insulin treatment for 30 min induced translocation of FATP1 protein to the plasma membrane in hCMEC/D3 cells and enhanced [ 14 C]-DHA uptake. Immunohistochemical analysis of mouse brain sections showed that FATP1 protein is preferentially localized at the basal membrane of brain microvessel endothelial cells. We found that two neuroprotective substances, taurine and biotin, in addition to DHA, undergo FATP1-mediated efflux. Overall, our results suggest that FATP1 localized at the basal membrane of brain microvessels contributes to the transport of DHA, taurine and biotin into the brain, and insulin rapidly increases DHA supply to the brain by promoting translocation of FATP1 to the membrane. Read the Editorial Comment for this article on page 324. © 2016 International Society for Neurochemistry.

[Evaluation and Optimization of Microvascular Arterial Anastomoses by Transit Time Flow Measurement].

Science.gov (United States)

Herberhold, S; Röttker, J; Bartmann, D; Solbach, A; Keiner, S; Welz, A; Bootz, F; Laffers, W

2016-03-01

INDRODUCTION: The regular application of transit time flow measurement in microvascular anastomoses during heart surgery has lead to improvements of the outcome of coronary artery bypass grafts. Our study was meant to discover whether this measurement method was also applicable for evaluation and optimization of microvascular arterial anastomoses of radial forearm flaps. In this prospective examination a combining ultrasound imaging and transit time flow measurement device (VeriQ, MediStim) was used during surgery to assess anastomotic quality of 15 radial forearm flaps. Pulsatility index (PI) and mean blood flow were measured immediately after opening the arterial anastomosis as well as 15 min afterwards. Furthermore, application time and description of handling were recorded seperately for every assessment. Mean blood flow immediately after opening the anastomosis and 15 min later were 3.9 and 3.4 ml/min resepectively showing no statistically significant difference (p=0.96). There was no significance in the increase of pulsatility index from 22.1 to 27.2 (p=0.09) during the same time range, either. Due to measurement results showing atypical pulse curves in 2 cases decision for surgical revision of the anastomoses was made. All forearm flaps showed good vascularisation during follow-up. Time for device set up, probe placement and measurements was about 20 min. Handling was described to be uncomplicated without exception. There were no noteworthy problems. Transit time flow measurement contributes to the improvement of anastomotic quality and therefore to the overall outcome of radial forearm flaps. The examined measurement method provides objective results and is useful for documentation purposes. © Georg Thieme Verlag KG Stuttgart · New York.

Pilot study on microvascular anastomosis: performance and future educational prospects.

Science.gov (United States)

Berretti, G; Colletti, G; Parrinello, G; Iavarone, A; Vannucchi, P; Deganello, A

2017-11-30

The introduction of microvascular free flaps has revolutionised modern reconstructive surgery. Unfortunately, access to training opportunities at standardised training courses is limited and expensive. We designed a pilot study on microvascular anastomoses with the aim of verifying if a short course, easily reproducible, could transmit microvascular skills to participants; if the chosen pre-test was predictive of final performance; and if age could influence the outcome. A total of 30 participants (10 students, 10 residents and 10 surgeons) without any previous microvascular experience were instructed and tested during a single 3 to 5 hour course. The two microanastomoses evaluated were the first ever performed by each participant. More than the half of the cohort was able to produce both patent microanastomoses in less than 2 hours; two-thirds of the attempted microanastomoses were patent. The pretest predicted decent scores from poor performances with a sensitivity of 61.5%, specificity of 100%, positive predictive value of 100% and negative predictive value of 40%. Students and residents obtained significantly higher scores than surgeons. Since our course model is short, cost-effective and highly reproducible, it could be introduced and implemented anywhere as an educational prospect for preselecting young residents showing talent and natural predisposition and having ambitions towards microvascular reconstructive surgery. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

Predicting bifurcation angle effect on blood flow in the microvasculature.

Science.gov (United States)

Yang, Jiho; Pak, Y Eugene; Lee, Tae-Rin

2016-11-01

Since blood viscosity is a basic parameter for understanding hemodynamics in human physiology, great amount of research has been done in order to accurately predict this highly non-Newtonian flow property. However, previous works lacked in consideration of hemodynamic changes induced by heterogeneous vessel networks. In this paper, the effect of bifurcation on hemodynamics in a microvasculature is quantitatively predicted. The flow resistance in a single bifurcation microvessel was calculated by combining a new simple mathematical model with 3-dimensional flow simulation for varying bifurcation angles under physiological flow conditions. Interestingly, the results indicate that flow resistance induced by vessel bifurcation holds a constant value of approximately 0.44 over the whole single bifurcation model below diameter of 60μm regardless of geometric parameters including bifurcation angle. Flow solutions computed from this new model showed substantial decrement in flow velocity relative to other mathematical models, which do not include vessel bifurcation effects, while pressure remained the same. Furthermore, when applying the bifurcation angle effect to the entire microvascular network, the simulation results gave better agreements with recent in vivo experimental measurements. This finding suggests a new paradigm in microvascular blood flow properties, that vessel bifurcation itself, regardless of its angle, holds considerable influence on blood viscosity, and this phenomenon will help to develop new predictive tools in microvascular research. Copyright © 2016 Elsevier Inc. All rights reserved.

Distribution of the blood flow supplied by the vertebral artery in humans as assessed by emission CT

International Nuclear Information System (INIS)

Taki, W.; Handa, H.; Higa, T.; Tanada, S.; Fukuyama, H.; Fujita, T.; Yonekawa, Y.; Kameyama, M.; Torizuka, K.

1984-01-01

Though unilateral blood distribution of the vertebral artery has not been studied in humans, it is significant when considering the ischemic events especially embolic occlusion in vertebrobasilar system. To clarify the blood distribution, Krypton-81m was continuously infused into the vertebral arteries of 10 patients. Radioactivity was recorded by a rotating gamma camera. The perfusion images, reconstructed by computer in the transaxial plane, were classified according to whether the distribution was equal, or predominantly unilateral. Overlapping of blood supply from each vertebral artery was studied. In addition, the perfusion from one of the vertebral arteries revealed four distribution patterns with respect to laterality. A) ipsilateral; B) contralateral; C) bilateral; D) mosaic. Images obtained following perfusion of the vertebral artery show less uniformity compared to that of the internal carotid artery, suggesting a complicated vascular supply of the vertebral basilar territory. This complex distribution can be classified by the use of continuous infusion of Krypton-81m

Insulin-resistant glucose metabolism in patients with microvascular angina--syndrome X

DEFF Research Database (Denmark)

Vestergaard, H; Skøtt, P; Steffensen, R

1995-01-01

Studies in patients with microvascular angina (MA) or the cardiologic syndrome X have shown a hyperinsulinemic response to an oral glucose challenge, suggesting insulin resistance and a role for increased serum insulin in coronary microvascular dysfunction. The aim of the present study was to exa......Studies in patients with microvascular angina (MA) or the cardiologic syndrome X have shown a hyperinsulinemic response to an oral glucose challenge, suggesting insulin resistance and a role for increased serum insulin in coronary microvascular dysfunction. The aim of the present study...... was to examine whether patients with MA are insulin-resistant. Nine patients with MA and seven control subjects were studied. All were sedentary and glucose-tolerant. Coronary arteriography was normal in all participants, and exercise-induced coronary ischemia was demonstrated in all MA patients. A euglycemic...... metabolism (8.4 +/- 0.9 v 12.5 +/- 1.3 mg.kg FFM-1.min-1, P

Profile of Microvascular Disease in Type 2 Diabetes in a Tertiary ...

African Journals Online (AJOL)

Background: Diabetes mellitus (DM) is a metabolic disorder complicated by microvascular and macrovascular diseases. The clinical profile of these complications has not been adequately studied in many tertiary health care centers in India. Aim: The authors studied the clinical profile of microvascular diabetes ...

System design of blood supply chain management based on Supplier Customer Relationship Management (SCRM approach

Directory of Open Access Journals (Sweden)

Allamsyah Zuhdi

2018-01-01

Full Text Available Blood supply chain management is very complex system. By considering blood’s demand that characterized as stochastic, therefore information and communication among stakeholders are considered as important cycle in supply chain. This research is objected to design interactive communication model based on information technology with android as platform to create effective customer-supplier relationship to support Customer Relationship Management or better known as CRM. The methods that suggested in designing its information system are Quality Function Deployment (QFD approach, Kano Model and Morphological Chart. From mentioned methods, attributes of design and specification priorities of purposed android system technology design are established. Attributes of design will be adjusted with customers’ requirements derived from customer voice that will further be integrated with technical responds in QFD. Technical responds will provide priorities on each design’s attribute of android information system and will be forwarded to the specifications determination by using morphological chart. Later, work flow of design system will be generated by using Data Flow Diagram (DFD. The result of the research will demonstrate the design of information system technology based on android that already adjusted with the requirement of donors as means of communication between suppliers and customers in blood supply chain.

Potential Pathways for CNS Drug Delivery Across the Blood-Cerebrospinal Fluid Barrier

OpenAIRE

Strazielle, Nathalie; Ghersi-Egea, Jean-Fran?ois

2016-01-01

The blood-brain interfaces restrict the cerebral bioavailability of pharmacological compounds. Various drug delivery strategies have been developed to improve drug penetration into the brain. Most strategies target the microvascular endothelium forming the blood-brain barrier proper. Targeting the blood-cerebrospinal fluid (CSF) barrier formed by the epithelium of the choroid plexuses in addition to the blood-brain barrier may offer added-value for the treatment of central nervous system dise...

Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules

OpenAIRE

Zhang, Wujie; Choi, Jung K.; He, Xiaoming

2017-01-01

Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. ...

A computational approach to modeling cellular-scale blood flow in complex geometry

Science.gov (United States)

Balogh, Peter; Bagchi, Prosenjit

2017-04-01

We present a computational methodology for modeling cellular-scale blood flow in arbitrary and highly complex geometry. Our approach is based on immersed-boundary methods, which allow modeling flows in arbitrary geometry while resolving the large deformation and dynamics of every blood cell with high fidelity. The present methodology seamlessly integrates different modeling components dealing with stationary rigid boundaries of complex shape, moving rigid bodies, and highly deformable interfaces governed by nonlinear elasticity. Thus it enables us to simulate 'whole' blood suspensions flowing through physiologically realistic microvascular networks that are characterized by multiple bifurcating and merging vessels, as well as geometrically complex lab-on-chip devices. The focus of the present work is on the development of a versatile numerical technique that is able to consider deformable cells and rigid bodies flowing in three-dimensional arbitrarily complex geometries over a diverse range of scenarios. After describing the methodology, a series of validation studies are presented against analytical theory, experimental data, and previous numerical results. Then, the capability of the methodology is demonstrated by simulating flows of deformable blood cells and heterogeneous cell suspensions in both physiologically realistic microvascular networks and geometrically intricate microfluidic devices. It is shown that the methodology can predict several complex microhemodynamic phenomena observed in vascular networks and microfluidic devices. The present methodology is robust and versatile, and has the potential to scale up to very large microvascular networks at organ levels.

Integration of Self-Assembled Microvascular Networks with Microfabricated PEG-Based Hydrogels.

Science.gov (United States)

Cuchiara, Michael P; Gould, Daniel J; McHale, Melissa K; Dickinson, Mary E; West, Jennifer L

2012-11-07

Despite tremendous efforts, tissue engineered constructs are restricted to thin, simple tissues sustained only by diffusion. The most significant barrier in tissue engineering is insufficient vascularization to deliver nutrients and metabolites during development in vitro and to facilitate rapid vascular integration in vivo. Tissue engineered constructs can be greatly improved by developing perfusable microvascular networks in vitro in order to provide transport that mimics native vascular organization and function. Here a microfluidic hydrogel is integrated with a self-assembling pro-vasculogenic co-culture in a strategy to perfuse microvascular networks in vitro. This approach allows for control over microvascular network self-assembly and employs an anastomotic interface for integration of self-assembled micro-vascular networks with fabricated microchannels. As a result, transport within the system shifts from simple diffusion to vessel supported convective transport and extra-vessel diffusion, thus improving overall mass transport properties. This work impacts the development of perfusable prevascularized tissues in vitro and ultimately tissue engineering applications in vivo.

Changes in microvascular permeability of the middle ear mucosa following the occulsion of the eustachian tube of rabbits

International Nuclear Information System (INIS)

Kikuchi, Yasutaka

1988-01-01

Serial changes in submucosal microvascular permeability of the middle ear and the response to histamine after occlusion of the eustachian tube were functionally investigated using radioisotope in rabbits with experimentally induced otitis media with effusion. Tritium water was administered through intravenous injection and transference of tritium water into the middle ear cavity was measured by radioactivity of the middle ear perfusate. Morphological changes were concurrently examined for comparison. Vascular permeability, as measured one, 7, and 14 days after occlusion of the eustachian tube, increased with time. A histological study showed an edematous hypertrophy of the submucosal tissue of the middle ear, suggesting a noticeable increase in microvascular permeability. The response of the middle ear mucosa to histamine, which was added to the fluid for perfusion, gradually decreased after occlusion of the eustachian tube, although the effect of histamine tended to persist for a long time, irrespective of the amount of administration. The results indicated that the mucosal membrane of the middle ear has a noticeable permeability at least up to 14 days after occlusion, and that histamine may be responsible for the increase of submucosal microvascular permeability not only in the normal middle ear cavity but also in otitis media with effusion which results in the persistance of the disease. The presence of factors permeable to the blood, other than histamine, caused microvascular peameability to increase, probably resulting in chronic or irreversible inflammation. This may be explained by markedly proliferative or parenchymatous connective tissues observed 7 and l0 weeks after occlusion. It should be noted that surgical treatment be performed as early as possible in the case of otitis media with effusion. (Namekawa, K) 80 refs

Studies on blood supply of liver metastasis with DSA, CT and portal vein perfusion CT during superior mesenteric arterial portography

International Nuclear Information System (INIS)

Li Zhigang; Shi Gaofeng; Huang Jingxiang; Li Shunzong; Liang Guoqing; Wang Hongguang; Han Pengyin; Wang Qi; Gu Tieshu

2008-01-01

Objective: To probe the blood supply of liver metastasis by celiac artery, proper hepatic artery DSA, portal vein perfusion CT during superior mesenteric arterial portography (PCTAP). Methods: One hundred patients with liver metastases were examined prospectively by plain CT scan, multiphase enhanced CT scan, celiac arteriography and proper hepatic arteriography. Of them, 56 patients were examined by PCTAP. All primary lesions were confirmed by operation and (or) pathology examination. In order to investigate the blood supply of metastasis lesions, the software of Photoshop was used to obtain the time-attenuation curves (TDC) of tumor center, tumor edge, portal vein and normal liver parenchyma adjacent to the tumor to calculate liver perfusion for DSA image analysis, while a deconvolution model from CT perfusion software was designed for the dual blood supply. Results: DSA findings: TDC of proper hepatic arteriography showed: the mean peak concentration (K value) in tumor centers was (67 ± 12)%, and it was (76 ± 15)% for peritumor tissue, (51 ± 10)% in normal liver parenchyma. TDC of celiac arteriogaphy showed that the contrast concentration of tumor centers and tumor edge increased fast in early stage, then maintained a slight upward plateau, in the meanwhile, the contrast concentration of normal liver parenchyma kept increasing slowly. PCTAP findings: tumors exhibited no enhancement during 30 s continued scans. Conclusion: The blood supply of liver metastasis mainly comes from hepatic artery, but barely from portal vein. (authors)

In vitro model of cerebral ischemia by using brain microvascular endothelial cells derived from human induced pluripotent stem cells.

Science.gov (United States)

Kokubu, Yasuhiro; Yamaguchi, Tomoko; Kawabata, Kenji

2017-04-29

Brain-derived microvascular endothelial cells (BMECs), which play a central role in blood brain barrier (BBB), can be used for the evaluation of drug transport into the brain. Although human BMEC cell lines have already been reported, they lack original properties such as barrier integrity. Pluripotent stem cells (PSCs) can be used for various applications such as regenerative therapy, drug screening, and pathological study. In the recent study, an induction method of BMECs from PSCs has been established, making it possible to more precisely study the in vitro human BBB function. Here, using induced pluripotent stem (iPS) cell-derived BMECs, we examined the effects of oxygen-glucose deprivation (OGD) and OGD/reoxygenation (OGD/R) on BBB permeability. OGD disrupted the barrier function, and the dysfunction was rapidly restored by re-supply of the oxygen and glucose. Interestingly, TNF-α, which is known to be secreted from astrocytes and microglia in the cerebral ischemia, prevented the restoration of OGD-induced barrier dysfunction in an apoptosis-independent manner. Thus, we could establish the in vitro BBB disease model that mimics the cerebral ischemia by using iPS cell-derived BMECs. Copyright © 2017 Elsevier Inc. All rights reserved.

Large arteriolar component of oxygen delivery implies a safe margin of oxygen supply to cerebral tissue.

Science.gov (United States)

Sakadžić, Sava; Mandeville, Emiri T; Gagnon, Louis; Musacchia, Joseph J; Yaseen, Mohammad A; Yucel, Meryem A; Lefebvre, Joel; Lesage, Frédéric; Dale, Anders M; Eikermann-Haerter, Katharina; Ayata, Cenk; Srinivasan, Vivek J; Lo, Eng H; Devor, Anna; Boas, David A

2014-12-08

What is the organization of cerebral microvascular oxygenation and morphology that allows adequate tissue oxygenation at different activity levels? We address this question in the mouse cerebral cortex using microscopic imaging of intravascular O2 partial pressure and blood flow combined with numerical modelling. Here we show that parenchymal arterioles are responsible for 50% of the extracted O2 at baseline activity, and the majority of the remaining O2 exchange takes place within the first few capillary branches. Most capillaries release little O2 at baseline acting as an O2 reserve that is recruited during increased neuronal activity or decreased blood flow. Our results challenge the common perception that capillaries are the major site of O2 delivery to cerebral tissue. The understanding of oxygenation distribution along arterio-capillary paths may have profound implications for the interpretation of blood-oxygen-level dependent (BOLD) contrast in functional magnetic resonance imaging and for evaluating microvascular O2 delivery capacity to support cerebral tissue in disease.

Microvascularization in trigeminal ganglion of the common tree shrew (Tupaia glis).

Science.gov (United States)

Kongstaponkit, S; Pradidarcheep, W; Toutip, S; Chunhabundit, P; Somana, R

1997-01-01

Since there is only a limited number of studies of the blood supply to the trigeminal ganglion (TG) in mammalian species, the TG from 16 common tree shrews (Tupaia glis) were investigated by light microscope, transmission electron microscope (TEM) and the corrosion cast technique in conjunction with scanning electron microscope (SEM). It was found that the TG contained clusters of neurons in the peripheral region whereas the bundles of nerve fibers were located more centrally. Each ganglionic neuron had a concentric nucleus and was ensheathed by satellite cells. It was noted that blood vessels of a continuous type were predominantly found in the area where the neurons were densely located and were much less frequently observed in the area occupied by nerve fibers. With TEM, the TG was shown to be mainly associated with large neurons containing big nuclei and prominent nucleoli. The blood supply of the TG is derived from the most rostral branch of the pontine artery, from the stapedial artery or sometimes from the supraorbital artery, and from the accessory meningeal artery which is a branch of the maxillary artery passing through the foramen ovale. These arteries give off branches and become capillary networks in the ganglion before draining blood to the peripheral region. The veins at the medial border drained into the cavernous sinus directly or through the inferior hypophyseal vein, while those at the lateral side of the ganglion carried the blood into the pterygoid plexus via an accessory meningeal vein. The veins along the trigeminal nerve root joined the posterior part of the cavernous sinus. These studies establish a unique anatomical distribution of the TG blood supply in the tree shrew and the utility of the cast/SEM technique in discerning detailed features of the blood supply in the nervous system.

Therapeutic Effects of PPARα on Neuronal Death and Microvascular Impairment

Directory of Open Access Journals (Sweden)

Elizabeth P. Moran

2015-01-01

Full Text Available Peroxisome-proliferator activated receptor-alpha (PPARα is a broadly expressed nuclear hormone receptor and is a transcription factor for diverse target genes possessing a PPAR response element (PPRE in the promoter region. The PPRE is highly conserved, and PPARs thus regulate transcription of an extensive array of target genes involved in energy metabolism, vascular function, oxidative stress, inflammation, and many other biological processes. PPARα has potent protective effects against neuronal cell death and microvascular impairment, which have been attributed in part to its antioxidant and anti-inflammatory properties. Here we discuss PPARα’s effects in neurodegenerative and microvascular diseases and also recent clinical findings that identified therapeutic effects of a PPARα agonist in diabetic microvascular complications.

Studies of pathological dynamics after microvascular injury using nonlinear optical methods

Science.gov (United States)

Rosidi, Nathanael L.

Microvascular lesions are a common feature in the aging brain and clinical evidence has correlated microvascular pathology with the development of neurodegenerative diseases such as Alzheimer's disease and dementia. Traditional animal models that replicate hemorrhagic and ischemic lesions in the brain typically affect large regions in the cortex and do not reproduce the small-scale lesions linked to neurodegeneration that likely stem from injuries to single microvessels. Due in part to this lack of small-scale injury animal models, there remains an incomplete understanding of the cellular and pathophysiological dynamics following small-scale vascular lesions, making progress on therapeutic strategies difficult. We used tightly focused femtosecond laser pulses to injure single penetrating arterioles (PA) (i.e., arterioles that plunge into the brain) in the cortex of live anesthetized rodents and used two-photon excited fluorescence (2PEF) imaging to quantify blood flow changes and to determine the time course of pathological consequences in the brain after injury. We find that after ischemic occlusion of a PA, nearby pial and penetrating arterioles do not actively compensate for the reduction of blood flow observed near the occluded blood vessel. We find that capillaries connected downstream to the clotted vessel dilate but other capillaries in the vicinity do not, suggesting that any compensatory signal that results in a physiological response travels vascularly. We ruptured individual PAs to induce microhemorrhages that resulted in extravasation of blood into the parenchyma. We find that tissue compression due to the hematoma does not collapse capillaries and cause acute ischemia. 2PEF imaging of mice expressing yellow fluorescent protein (YFP) in a subset of cortical neurons revealed no dendrite degeneration out to seven days after microhemorrhage. However, we did observe an inflammatory response by microglia/macrophages as quickly as 1.5-hrs after

Uric acid is associated with inflammation, coronary microvascular dysfunction, and adverse outcomes in postmenopausal women

Science.gov (United States)

Prasad, Megha; Matteson, Eric L.; Herrmann, Joerg; Gulati, Rajiv; Rihal, Charanjit S.; Lerman, Lilach O.; Lerman, Amir

2016-01-01

Uric acid is a risk factor for coronary artery disease (CAD) in postmenopausal women but the association with inflammation and coronary microvascular endothelial dysfunction (CED) is not well-defined. The aim of this study was to determine the relationship of serum uric acid (SUA), inflammatory markers and CED. In this prospective cohort study, serum uric acid, hsCRP levels, and neutrophil count were measured in 229 postmenopausal women who underwent diagnostic catheterization, were found to have no obstructive CAD and underwent coronary microvascular function testing, to measure coronary blood flow (CBF) response to intracoronary acetylcholine. The average age was 58 years (IQR 52, 66) years. Hypertension was present in 48%, type 2 diabetes mellitus in 5.6%, and hyperlipidemia in 61.8%. CED was diagnosed in 59% of postmenopausal women. Mean uric acid level was 4.7 ± 1.3 mg/dL. Postmenopausal women with CED had significantly higher SUA compared to patients without CED (4.9 ± 1.3 vs. 4.4 ± 1.3 mg/dL; p=0.02). There was a significant correlation between SUA and % change in CBF to acetylcholine (p=0.009), and this correlation persisted in multivariable analysis. SUA levels were significantly associated with increased neutrophil count (p=0.02) and hsCRP levels (p=0.006) among patients with CED, but not those without CED. Serum uric acid is associated with coronary microvascular endothelial dysfunction in postmenopausal women and may be related to inflammation. These findings link serum uric acid levels to early coronary atherosclerosis in postmenopausal women. PMID:27993955

Non-invasive detection and quantification of brain microvascular deficits by near-infrared spectroscopy in a rat model of Vascular Cognitive Impairment

Science.gov (United States)

Hallacoglu, Bertan; Sassaroli, Angelo M.; Rosenberg, Irwin H.; Troen, Aron; Fantini, Sergio

2011-02-01

Structural abnormalities in brain microvasculature are commonly associated with Alzheimer's Disease and other dementias. However, the extent to which structural microvascular abnormalities cause functional impairments in brain circulation and thereby to cognitive impairment is unclear. Non-invasive, near-infrared spectroscopy (NIRS) methods can be used to determine the absolute hemoglobin concentration and saturation in brain tissue, from which additional parameters such as cerebral blood volume (a theoretical correlate of brain microvascular density) can be derived. Validating such NIRS parameters in animal models, and understanding their relationship to cognitive function is an important step in the ultimate application of these methods to humans. To this end we applied a non-invasive multidistance NIRS method to determine the absolute concentration and saturation of cerebral hemoglobin in rat, by separately measuring absorption and reduced scattering coefficients without relying on pre- or post-correction factors. We applied this method to study brain circulation in folate deficient rats, which express brain microvascular pathology1 and which we have shown to develop cognitive impairment.2 We found absolute brain hemoglobin concentration ([HbT]) and oxygen saturation (StO2) to be significantly lower in folate deficient rats (n=6) with respect to control rats (n=5) (for [HbT]: 73+/-10 μM vs. 95+/-14 μM for StO2: 55%+/-7% vs. 66% +/-4%), implicating microvascular pathology and diminished oxygen delivery as a mechanism of cognitive impairment. More generally, our study highlights how noninvasive, absolute NIRS measurements can provide unique insight into the pathophysiology of Vascular Cognitive Impairment. Applying this method to this and other rat models of cognitive impairment will help to validate physiologically meaningful NIRS parameters for the ultimate goal of studying cerebral microvascular disease and cognitive decline in humans.

Microvascular anastomosis in rodent model evaluated by Fourier domain Doppler optical coherence tomography

Science.gov (United States)

Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.

2014-03-01

Vascular and microvascular anastomosis are critical components of reconstructive microsurgery, vascular surgery and transplant surgery. Imaging modality that provides immediate, real-time in-depth view and 3D structure and flow information of the surgical site can be a great valuable tool for the surgeon to evaluate surgical outcome following both conventional and innovative anastomosis techniques, thus potentially increase the surgical success rate. Microvascular anastomosis for vessels with outer diameter smaller than 1.0 mm is extremely challenging and effective evaluation of the outcome is very difficult if not impossible using computed tomography (CT) angiograms, magnetic resonance (MR) angiograms and ultrasound Doppler. Optical coherence tomography (OCT) is a non-invasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. Phaseresolved Doppler OCT that explores the phase information of OCT signals has been shown to be capable of characterizing dynamic blood flow clinically. In this work, we explore the capability of Fourier domain Doppler OCT as an evaluation tool to detect commonly encountered post-operative complications that will cause surgical failure and to confirm positive result with surgeon's observation. Both suture and cuff based techniques were evaluated on the femoral artery and vein in the rodent model.

Expansion of microvascular networks in vivo by phthalimide neovascular factor 1 (PNF1).

Science.gov (United States)

Wieghaus, Kristen A; Nickerson, Meghan M; Petrie Aronin, Caren E; Sefcik, Lauren S; Price, Richard J; Paige, Mikell A; Brown, Milton L; Botchwey, Edward A

2008-12-01

Phthalimide neovascular factor (PNF1, formerly SC-3-149) is a potent stimulator of proangiogenic signaling pathways in endothelial cells. In this study, we evaluated the in vivo effects of sustained PNF1 release to promote ingrowth and expansion of microvascular networks surrounding biomaterial implants. The dorsal skinfold window chamber was used to evaluate the structural remodeling response of the local microvasculature. PNF1 was released from poly(lactic-co-glycolic acid) (PLAGA) films, and a transport model was utilized to predict PNF1 penetration into the surrounding tissue. PNF1 significantly expanded microvascular networks within a 2mm radius from implants after 3 and 7 days by increasing microvessel length density and lumenal diameter of local arterioles and venules. Staining of histological sections with CD11b showed enhanced recruitment of circulating white blood cells, including monocytes, which are critical for the process of vessel enlargement through arteriogenesis. As PNF1 has been shown to modulate MT1-MMP, a facilitator of CCL2 dependent leukocyte transmigration, aspects of window chamber experiments were repeated in CCR2(-/-) (CCL2 receptor) mouse chimeras to more fully explore the critical nature of monocyte recruitment on the therapeutic benefits of PNF1 function in vivo.

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats

NARCIS (Netherlands)

L. Zafrani (Lara); B. Ergin (Bulent); Kapucu, A. (Aysegul); C. Ince (Can)

2016-01-01

textabstractBackground: The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Methods: Twenty-seven Wistar

Gap filling of 3-D microvascular networks by tensor voting.

Science.gov (United States)

Risser, L; Plouraboue, F; Descombes, X

2008-05-01

We present a new algorithm which merges discontinuities in 3-D images of tubular structures presenting undesirable gaps. The application of the proposed method is mainly associated to large 3-D images of microvascular networks. In order to recover the real network topology, we need to fill the gaps between the closest discontinuous vessels. The algorithm presented in this paper aims at achieving this goal. This algorithm is based on the skeletonization of the segmented network followed by a tensor voting method. It permits to merge the most common kinds of discontinuities found in microvascular networks. It is robust, easy to use, and relatively fast. The microvascular network images were obtained using synchrotron tomography imaging at the European Synchrotron Radiation Facility. These images exhibit samples of intracortical networks. Representative results are illustrated.

Age-related differences in skeletal muscle microvascular response to exercise as detected by contrast-enhanced ultrasound (CEUS.

Directory of Open Access Journals (Sweden)

Wulf Hildebrandt

Full Text Available Aging involves reductions in exercise total limb blood flow and exercise capacity. We hypothesized that this may involve early age-related impairments of skeletal muscle microvascular responsiveness as previously reported for insulin but not for exercise stimuli in humans.Using an isometric exercise model, we studied the effect of age on contrast-enhanced ultrasound (CEUS parameters, i.e. microvascular blood volume (MBV, flow velocity (MFV and blood flow (MBF calculated from replenishment of Sonovue contrast-agent microbubbles after their destruction. CEUS was applied to the vastus lateralis (VLat and intermedius (VInt muscle in 15 middle-aged (MA, 43.6±1.5 years and 11 young (YG, 24.1±0.6 years healthy males before, during, and after 2 min of isometric knee extension at 15% of peak torque (PT. In addition, total leg blood flow as recorded by femoral artery Doppler-flow. Moreover, fiber-type-specific and overall capillarisation as well as fiber composition were additionally assessed in Vlat biopsies obtained from CEUS site. MA and YG had similar quadriceps muscle MRT-volume or PT and maximal oxygen uptake as well as a normal cardiovascular risk factors and intima-media-thickness.During isometric exercise MA compared to YG reached significantly lower levels in MFV (0.123±0.016 vs. 0.208±0.036 a.u. and MBF (0.007±0.001 vs. 0.012±0.002 a.u.. In the VInt the (post-occlusive hyperemia post-exercise peaks in MBV and MBF were significantly lower in MA vs. YG. Capillary density, capillary fiber contacts and femoral artery Doppler were similar between MA and YG.In the absence of significant age-related reductions in capillarisation, total leg blood flow or muscle mass, healthy middle-aged males reveal impaired skeletal muscle microcirculatory responses to isometric exercise. Whether this limits isometric muscle performance remains to be assessed.

Bang-bang Model for Regulation of Local Blood Flow

Science.gov (United States)

Golub, Aleksander S.; Pittman, Roland N.

2013-01-01

The classical model of metabolic regulation of blood flow in muscle tissue implies the maintenance of basal tone in arterioles of resting muscle and their dilation in response to exercise and/or tissue hypoxia via the evoked production of vasodilator metabolites by myocytes. A century-long effort to identify specific metabolites responsible for explaining active and reactive hyperemia has not been successful. Furthermore, the metabolic theory is not compatible with new knowledge on the role of physiological radicals (e.g., nitric oxide, NO, and superoxide anion, O2−) in the regulation of microvascular tone. We propose a model of regulation in which muscle contraction and active hyperemia are considered the physiologically normal state. We employ the “bang-bang” or “on/off” regulatory model which makes use of a threshold and hysteresis; a float valve to control the water level in a tank is a common example of this type of regulation. Active bang-bang regulation comes into effect when the supply of oxygen and glucose exceeds the demand, leading to activation of membrane NADPH oxidase, release of O2− into the interstitial space and subsequent neutralization of the interstitial NO. Switching arterioles on/off when local blood flow crosses the threshold is realized by a local cell circuit with the properties of a bang-bang controller, determined by its threshold, hysteresis and dead-band. This model provides a clear and unambiguous interpretation of the mechanism to balance tissue demand with a sufficient supply of nutrients and oxygen. PMID:23441827

Microvascular endothelial function and cognitive performance: The ELSA-Brasil cohort study.

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Brant, Luisa; Bos, Daniel; Araujo, Larissa Fortunato; Ikram, M Arfan; Ribeiro, Antonio Lp; Barreto, Sandhi M

2018-06-01

Impaired microvascular endothelial function may be implicated in the etiology of cognitive decline. Yet, current data on this association are inconsistent. Our objective is to investigate the relation of microvascular endothelial function to cognitive performance in the ELSA-Brasil cohort study. A total of 1521 participants from ELSA-Brasil free of dementia underwent peripheral arterial tonometry (PAT) to quantify microvascular endothelial function (PAT-ratio and mean baseline pulse amplitude (BPA)) and cognitive tests that covered the domains of memory, verbal fluency, and executive function at baseline. Cognitive tests in participants aged 55 years old and above were repeated during the second examination (mean follow-up: 3.5 (0.3) years). Linear regression and generalized linear models were used to evaluate the association between endothelial function, global cognitive performance, and performance on specific cognitive domains. In unadjusted cross-sectional analyses, we found that BPA and PAT-ratio were associated with worse global cognitive performance (mean difference for BPA: -0.07, 95% CI: -0.11; -0.03, p<0.01; mean difference for PAT-ratio: 0.11, 95% CI: 0.01; 0.20, p=0.02), worse performance on learning, recall, and word recognition tests (BPA: -0.87, 95% CI: -1.21; -0.52, p<0.01; PAT-ratio: 1.58, 95% CI: 0.80; 2.36, p<0.01), and only BPA was associated with worse performance in verbal fluency tests (-0.70, 95% CI: -1.19; -0.21, p<0.01). Adjustments for age, sex, and level of education rendered the associations statistically non-significant. Longitudinally, there was no association between microvascular endothelial and cognitive functions. The associations between microvascular endothelial function and cognition are explained by age, sex, and educational level. Measures of microvascular endothelial function may be of limited value with regard to preclinical cognitive deficits.

Perioperative antibiotics in the setting of microvascular free tissue transfer: current practices

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Reiffel, Alyssa J.; Kamdar, Mehul R.; Kadouch, Daniel J. M.; Rohde, Christine H.; Spector, Jason A.

2010-01-01

Microvascular free tissue transfer is a ubiquitous and routine method of restoring anatomic defects. There is a paucity of data regarding the role of perioperative antibiotics in free tissue transfer. We designed a survey to explore usage patterns among microvascular surgeons and thereby define a

Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules.

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Zhang, Wujie; Choi, Jung K; He, Xiaoming

2017-02-01

Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. This approach provides an alternative and promising method for constructing vascularized tissues.

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats

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Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-01-01

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into

The impact of obesity on the relationship between epicardial adipose tissue, left ventricular mass and coronary microvascular function

International Nuclear Information System (INIS)

Bakkum, M.J.; Danad, I.; Romijn, M.A.J.; Stuijfzand, W.J.A.; Leonora, R.M.; Rossum, A.C. van; Knaapen, P.; Tulevski, I.I.; Somsen, G.A.; Lammertsma, A.A.; Kuijk, C. van; Raijmakers, P.G.

2015-01-01

Epicardial adipose tissue (EAT) has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction. However, its injurious effect may also impact the underlying myocardium. This study aimed to determine the impact of obesity on the quantitative relationship between left ventricular mass (LVM), EAT and coronary microvascular function. A total of 208 (94 men, 45 %) patients evaluated for CAD but free of coronary obstructions underwent quantitative [ 15 O]H 2 O hybrid positron emission tomography (PET)/CT imaging. Coronary microvascular resistance (CMVR) was calculated as the ratio of mean arterial pressure to hyperaemic myocardial blood flow. Obese patients [body mass index (BMI) > 25, n = 133, 64 % of total] had more EAT (125.3 ± 47.6 vs 93.5 ± 42.1 cc, p < 0.001), a higher LVM (130.1 ± 30.4 vs 114.2 ± 29.3 g, p < 0.001) and an increased CMVR (26.6 ± 9.1 vs 22.3 ± 8.6 mmHg x ml -1 x min -1 x g -1 , p < 0.01) as compared to nonobese patients. Male gender (β = 40.7, p < 0.001), BMI (β = 1.61, p < 0.001), smoking (β = 6.29, p = 0.03) and EAT volume (β = 0.10, p < 0.01) were identified as independent predictors of LVM. When grouped according to BMI status, EAT was only independently associated with LVM in nonobese patients. LVM, hypercholesterolaemia and coronary artery calcium score were independent predictors of CMVR. EAT volume is associated with LVM independently of BMI and might therefore be a better predictor of cardiovascular risk than BMI. However, EAT volume was not related to coronary microvascular function after adjustments for LVM and traditional risk factors. (orig.)

The impact of obesity on the relationship between epicardial adipose tissue, left ventricular mass and coronary microvascular function

Energy Technology Data Exchange (ETDEWEB)

Bakkum, M.J.; Danad, I.; Romijn, M.A.J.; Stuijfzand, W.J.A.; Leonora, R.M.; Rossum, A.C. van; Knaapen, P. [VU University Medical Center, Department of Cardiology, Amsterdam (Netherlands); Tulevski, I.I.; Somsen, G.A. [Cardiology Centers of the Netherlands, Amsterdam (Netherlands); Lammertsma, A.A.; Kuijk, C. van; Raijmakers, P.G. [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands)

2015-09-15

Epicardial adipose tissue (EAT) has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction. However, its injurious effect may also impact the underlying myocardium. This study aimed to determine the impact of obesity on the quantitative relationship between left ventricular mass (LVM), EAT and coronary microvascular function. A total of 208 (94 men, 45 %) patients evaluated for CAD but free of coronary obstructions underwent quantitative [{sup 15}O]H{sub 2}O hybrid positron emission tomography (PET)/CT imaging. Coronary microvascular resistance (CMVR) was calculated as the ratio of mean arterial pressure to hyperaemic myocardial blood flow. Obese patients [body mass index (BMI) > 25, n = 133, 64 % of total] had more EAT (125.3 ± 47.6 vs 93.5 ± 42.1 cc, p < 0.001), a higher LVM (130.1 ± 30.4 vs 114.2 ± 29.3 g, p < 0.001) and an increased CMVR (26.6 ± 9.1 vs 22.3 ± 8.6 mmHg x ml{sup -1} x min{sup -1} x g{sup -1}, p < 0.01) as compared to nonobese patients. Male gender (β = 40.7, p < 0.001), BMI (β = 1.61, p < 0.001), smoking (β = 6.29, p = 0.03) and EAT volume (β = 0.10, p < 0.01) were identified as independent predictors of LVM. When grouped according to BMI status, EAT was only independently associated with LVM in nonobese patients. LVM, hypercholesterolaemia and coronary artery calcium score were independent predictors of CMVR. EAT volume is associated with LVM independently of BMI and might therefore be a better predictor of cardiovascular risk than BMI. However, EAT volume was not related to coronary microvascular function after adjustments for LVM and traditional risk factors. (orig.)

A population-based longitudinal study on the implications of demographics on future blood supply.

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Greinacher, Andreas; Weitmann, Kerstin; Lebsa, Anne; Alpen, Ulf; Gloger, Doris; Stangenberg, Wolfgang; Kiefel, Volker; Hoffmann, Wolfgang

2016-12-01

Changes in demographics with increases in older age groups and decreases in younger age groups imply an increased demand for blood transfusions paralleled by a decrease in the population eligible for blood donation. However, more restrictive transfusion triggers and the patient blood management initiative also reduce the demand for red blood cells (RBCs). Eastern Germany is a model region for the impact of demographic changes, which manifest in this region approximately 10 years earlier than in other regions due to the 50% birth rate decline after 1989. We report the 2010 longitudinal 5-year follow-up of the study assessing all whole blood donations and RBC transfusions in Mecklenburg-West Pomerania. We compared the projections that were made 5 years ago with: 1) the current age structure of the blood donor and transfusion recipient populations and 2) its impact on blood demand and blood donation numbers in specific age groups. Transfusion rates were lower and blood donation rates were higher than predicted in 2005. Although transfusion rates/1000 decreased in nearly all age groups, the overall annual transfusion rate increased to 66.4 RBC units/1000 (in 2005, 62.2/1000) due to the absolute increase in the elderly population. Despite a 7.4% decline in the population 18 to 65 years of age, whole blood donations increased by 11.7% between 2005 and 2010, but thereafter decreased by 21% (first-time donors by 39.4%), reflecting the effect of the post-1990 birth rate decline on the donor population. Changes in demography and medical practice impact the delicate balance between available blood supply and potential future transfusion needs. In times of pronounced demographic changes, regular monitoring of the blood demand and age structure of blood recipients and donors is required to allow strategic planning to prevent blood shortages or overproduction. © 2016 AABB.

Direct microvascular monitoring of a free autologous jejunal flap using microendoscopy: a case report

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Hopper Colin

2006-09-01

Full Text Available Abstract Background Early identification of flap failure is an indispensable prerequisite for flap salvage. Although many technical developments of free flap monitoring have now reached clinical application, very few are considered to be reliable and non-invasive for early recognition of flap failure. Case presentation We used microendoscopic technique for microvascular monitoring of free autologous jejunal flap by the direct visualisation of the flow of erythrocytes through the capillary vasculature on both the mucosal and serosal surfaces. Blood flow was seen to be pulsatile, with individual erythrocytes visible in the capillaries. The best view was obtained when the scope was focussed directly on the capillary rather than the graft surface. The view of the unstained mucosal surface was bland apart from the fine capillary loops which were seen to fill with each pulsatile event. The microendoscopic examination of the serosal surface revealed much larger calibre vessels with obvious blood flow. Conclusion The microendoscopic monitoring technique is simple and safe with direct visualisation of blood flow. The technique may also be useful for the monitoring of other free bowel transplants.

Microvascular oxygen pressure in the pig intestine during haemorrhagic shock and resuscitation

NARCIS (Netherlands)

Sinaasappel, M.; van Iterson, M.; Ince, C.

1999-01-01

1. The aim of this study was to investigate the relation between microvascular and venous oxygen pressures during haemorrhagic shock and resuscitation in the pig intestine. To this end microvascular PO2 (microPO2) was measured by quenching of Pd-porphyrin phosphorescence by oxygen and validated for

The Development of a Canine Anorectal Autotransplantation Model Based on Blood Supply: A Preliminary Case Report

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Nakamura, Tatsuo; Sato, Tomoyuki; Naito, Munekazu; Fujii, Satoshi; Mihara, Makoto; Koshima, Isao

2012-01-01

Colostomy is conventionally the only treatment for anal dysfunction. Recently, a few trials of anorectal transplantation in animals have been published; however, further development of this technique is required. Moreover, it is crucial to perform this research in dogs, which resemble humans in anorectal anatomy and biology. We designed a canine anorectal transplantation model, wherein anorectal autotransplantation was performed by anastomoses of the rectum, inferior mesenteric artery (IMA) and vein, and pudendal nerves. Resting pressure in the anal canal and anal canal pressure fluctuation were measured before and after surgery. Graft pathology was examined three days after surgery. The anal blood supply was compared with that in three beagles using indocyanine green (ICG) fluorescence angiography. The anorectal graft had sufficient arterial blood supply from the IMA; however, the graft’s distal end was congested and necrotized. Functional examination demonstrated reduced resting pressure and the appearance of an irregular anal canal pressure wave after surgery. ICG angiography showed that the pudendal arteries provided more blood flow than the IMA to the anal segment. This is the first canine model of preliminary anorectal autotransplantation, and it demonstrates the possibility of establishing a transplantation model in dogs using appropriate vascular anastomoses, thus contributing to the progress of anorectal transplantation. PMID:22970198

Transfer of Learning from Practicing Microvascular Anastomosis on Silastic Tubes to Rat Abdominal Aorta.

Science.gov (United States)

Mokhtari, Pooneh; Tayebi Meybodi, Ali; Lawton, Michael T; Payman, Andre; Benet, Arnau

2017-12-01

Learning to perform microvascular anastomosis is difficult. Laboratory practice models using artificial vessels are frequently used for this purpose. However, the efficacy of such practice models has not been objectively assessed for the performance of microvascular anastomosis during live surgical settings. This study was conducted to assess the transfer of learning from practicing microvascular anastomosis on tubes to anastomosing rat abdominal aorta. Ten surgeons without any experience in microvascular anastomosis were randomly assigned to an experimental or a control group. Both groups received didactic and visual training on end-to-end microvascular anastomosis. The experimental group received 24 sessions of hands-on training on microanastomosis using Silastic tubes. Next, both groups underwent recall tests on weeks 1, 2, and 8 after training. The recall test consisted of completing an end-to-end anastomosis on the rat's abdominal aorta. Anastomosis score, the time to complete the anastomosis, and the average time to place 1 stitch on the vessel perimeter were compared between the 2 groups. Compared with the control group, the experimental group did significantly better in terms of anastomosis score, total time, and per-stitch time. The measured variables showed stability and did not change significantly between the 3 recall tests. The skill of microvascular anastomosis is transferred from practicing on Silastic tubes to rat's abdominal aorta. Considering the relative advantages of Silastic tubes to live rodent surgeries, such as lower cost and absence of ethical issues, our results support the widespread use of Silastic tubes in training programs for microvascular anastomosis. Copyright © 2017 Elsevier Inc. All rights reserved.

COAGULATION PROFILE IN DIABETES MELLITUS AND ITS ASSOCIATION WITH MICROVASCULAR COMPLICATIONS

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Uma Shankar Mishra

2017-12-01

Full Text Available BACKGROUND This study intends to assess the changes in the simple routine coagulation parameters in diabetes mellitus and to investigate whether any relationship exists among changes in these coagulation parameters and development of microvascular complication in diabetes mellitus. MATERIALS AND METHODS Period of study was from 2010-2012. It was done in M.K.C.G. Medical College with the approval from Berhampur University. It is a case control study. 50 diabetic patients and 50 age and sex matched non-diabetic patients were randomly selected. Simple coagulation parameters like Activated Partial Thromboplastin Time (aPTT, Prothrombin Time (PT, serum fibrinogen, platelet count and Plasminogen Activator Inhibitor-1 (PAI-1 were measured. Statistical study was done using unpaired t-test and analysis and calculations were done using GraphPad software. RESULTS Serum fibrinogen was found to be increased in diabetic patients when compared to non-diabetic patients (mean 278 ± 26.9 v/s 232.52 ± 16.5, P value - 0.009, significant. PAI-1 levels was found to be higher among the diabetics when compared to nondiabetics (47.64 ± 8.82 v/s 31.06 ± 7.12, the two-tailed P value is <0.0001, considered extremely significant. Platelet count through within normal limits. It was found to be decreased in diabetic patient when compared to non-diabetic (2.25 ± 0.18 v/s 2.33 ± 0.03, P value - 0.022. Prothrombin Time (PT (13.15 ± 0.52 v/s 13.04 ± 0.49, P value - 0.28 and PTT (33.04 ± 1.31 v/s 32.99 ± 1.29, P value 0.85, found to be statistically insignificant. Among 50 diabetic patients, 24 had neuropathy, 20 had nephropathy, 10 had retinopathy and 21 had none of these complications. On comparing diabetic patients with microvascular complications and without microvascular complications, significant age difference was observed (59.55 ± 5.06 v/s 51.00 ± 3.31, P=0.003. This probably was a reflection of increase in microvascular complications with increasing duration

COMPARISON OF REAL-TIME MICROVASCULAR ABNORMALITIES IN PEDIATRIC AND ADULT SICKLE CELL ANEMIA PATIENTS

Science.gov (United States)

Cheung, Anthony T.W.; Miller, Joshua W.; Craig, Sarah M.; To, Patricia L.; Lin, Xin; Samarron, Sandra L.; Chen, Peter C.Y.; Zwerdling, Theodore; Wun, Ted; Li, Chin-Shang; Green, Ralph

2010-01-01

The conjunctival microcirculation in 14 pediatric and 8 adult sickle cell anemia (SCA) patients was studied using computer-assisted intravital microscopy. The bulbar conjunctiva in SCA patients in both age groups exhibited a blanched/avascular appearance characterized by decreased vascularity. SCA patients from both age groups had many of the same abnormal morphometric {vessel diameter, vessel distribution, morphometry (shape), tortuosity, arteriole:venule (A:V) ratio, and hemosiderin deposits} and dynamic {vessel sludging/sludged flow, boxcar blood (trickled) flow and abnormal flow velocity} abnormalities. A severity index (SI) was computed to quantify the degree of vasculopathy for comparison between groups. The severity of vasculopathy differed significantly between the pediatric and adult patients (SI: 4.2 ± 1.8 vs 6.6 ± 2.4; p=0.028), indicative of a lesser degree of overall severity in the pediatric patients. Specific abnormalities that were less prominent in the pediatric patients included abnormal vessel morphometry and tortuosity. Sludged flow, abnormal vessel distribution, abnormal A:V ratio, and boxcar flow, appeared in high prevalence in both age groups. The results indicate that SCA microvascular abnormalities develop in childhood and the severity of vasculopathy likely progresses with age. Intervention and effective treatment/management modalities should target pediatric patients to ameliorate, slow down or prevent progressive microvascular deterioration. PMID:20872552

Defense at the border : the blood-brain barrier versus bacterial foreigners

NARCIS (Netherlands)

van Sorge, Nina M.; Doran, Kelly S.

Bacterial meningitis is among the top ten causes of infectious disease-related deaths worldwide, with up to half of the survivors left with permanent neurological sequelae. The blood-brain barrier (BBB), composed mainly of specialized brain microvascular endothelial cells, maintains biochemical

Investigating tissue respiration and skin microhaemocirculation under adaptive changes and the synchronization of blood flow and oxygen saturation rhythms

International Nuclear Information System (INIS)

Dunaev, A V; Palmer, S G; Stewart, N A; Sokolovski, S G; Rafailov, E U; Sidorov, V V; Krupatkin, A I; Rafailov, I E

2014-01-01

Multi-functional laser non-invasive diagnostic systems allow the study of a number of microcirculatory parameters, including index of blood microcirculation (I m ) (by laser Doppler flowmetry, LDF) and oxygen saturation (S t O 2 ) of skin tissue (by tissue reflectance oximetry, TRO). This research aimed to use such a system to investigate the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted on eight healthy volunteers of 21–49 years. These volunteers were observed between one and six months, totalling 422 basic tests (3 min each). Measurements were performed on the palmar surface of the right middle finger and the lower forearm's medial surface. Rhythmic oscillations of LDF and TRO were studied using wavelet analysis. Combined tissue oxygen consumption data for all volunteers during ‘adaptive changes’ increased relative to normal conditions with and without arteriovenous anastomoses. Data analysis revealed resonance and synchronized rhythms in microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and possibly psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes may lead to increased oxygen consumption as a result of increased microvascular blood flow velocity. (paper)

Microvascular transplantation and replantation of the dog submandibular gland.

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Su, Wan Fu; Jen, Yee Min; Chen, Shyi Gen; Nieh, Shin; Wang, Chih-Hung

2006-05-01

Transplantation and replantation of the submandibular gland with microvascular techniques were demonstrated in a previous study, with good gland survival. The application of radiation on the neck bed was attempted to address an actual clinical scenario in this study. Five canine submandibular glands were transplanted using microvascular techniques to the ipsilateral femoral system. Radiotherapy at a dosage level of 3,600 cGy using 600 cGy q.d was delivered to the nasopharyngeal and neck regions 2 weeks after transplantation. The transferred glands were then reintroduced into the original but radiated neck bed. The glands were harvested for histological examination 8 weeks later. Four of five canine submandibular glands can withstand microvascular transplantation and then replantation into a radiated neck bed for at least 8 weeks. However, the salivary function was depleted. The canine submandibular gland can survive the transplantation and replantation for at least 8 weeks in spite of precipitating radiation insult on the neck bed for 3 weeks. Neurorraphy is, however, essential to maintaining the glandular function.

Serum ADEPONECTIN Level In Children And Adolescents With Type I Diabetes Mellitus And Its Association With Microvascular Complications

International Nuclear Information System (INIS)

MOAWAD, A.T.

2010-01-01

Adiponectin, an adipo cytokine, is secreted from the adipose tissue and plays an important role in obesity, type II diabetes and cardiovascular disease. This study aimed to determine the concentration of serum adiponectin in type I diabetic children and to establish its association with microvascular complications. For this reason, weight (kg), height (m), body mass index (BMI) (kg/m2), random blood sugar, HbAIc, kidney functions, urinary microalbuminuria, lipid profiles and serum adiponectin were assessed in 25 children (11 males, 14 females) with type I diabetes and twenty healthy control children. Careful history, clinical examination, acetomorphine and pirbuterol assessment were done for all patients and controls. The diabetic patients were stratified depending on the pubertal stage into pre-pubertal group and pubertal group, and according to gender into male group and female group. The results obtained displayed significant elevated values for random blood glucose (P<0.001), HbAIc (P<0.001), total cholesterol (P<0.05), low density lipoprotein (LDL) (P<0.05), BUN (P<0.001), creatinine (P<0.05), urinary microalbuminuria (P<0.001) and serum adiponectin (P<0.001) in diabetic children and control. In patients suffering from microvascular diabetic complications as retinopathy, nephropathy and neuropathy, serum adiponectin level showed high significant increase in patients with diabetic nephropathy and neuropathy than without. On the other hand, patients with retinopathy had no significant increase in serum adiponectin as compared with patients without retinopathy but this result may be due to small sample size. Positive significant correlation was detected between serum adiponectin and HbAIc, total cholesterol and urinary microalbuminuria in the same patients. Negative significant correlation was observed between serum adiponectin level and body mass index (BMI). It could be concluded that serum adiponectin which increased in diabetic children than healthy control

The role of coronary microvascular dysfunction in the genesis of cardiovascular diseases

International Nuclear Information System (INIS)

Parodi, O.; Sambuceti, G.

1996-01-01

Using PET, myocardial perfusion abnormalities secondary to microvascular disorders have beeen investigated in arterial hypertension (AH), dilated and hypertrophic cardiomyopathy (CM), as well as in ischemic heart disease (CAD). In AH, regional perfusion at rest is within the normal range, while the coronary reserve and flow response to increase in metabolic demand are blunted. Both dilated and hypertrophic CM demonstrate abnormal vasodilaing capability, wich as bee schown to be presented in the subclinical form of dilated DM; the reduction of coronary reserve is not related to the presence and extent of the hemodynamic impairment in dilated CM, and involved also nonhypertropied myocardium in asymmetric hypertropic CM. These finding indicate a primary involvement of coronary microcirculation in non advanced forms of dilated and hypertrophic CM. Finally, in patients with CAD, myocardia teritories supplied by angiographically normal coronary arteries schow abnormal coronary reserve and flow during pacing, tachycardia, indicating that, even in absence of epicardial coronary artery obstruction, microcirculation is impaired in subject with coronary atherosclerosis. this abnormally can smooth perfusion differences, between control andd jeopardized regions. Although the agreement with the angiographic documantation of coronary artery disease has been frequently considered to characterize the diagnostic reliability of these techiques, the evaluation of myocardial perfusion provides an independent tool for the functional assessment of patient with heart disease. The possibility of obtain measurement of regional myocardial blood flow, provided by positron emission thermography, helps to identify the mechanisms affecting flow regulation in the myocardium. This tool thus provides a new rationale for the application of perfusion imaging, to obtain a more precise characterization of these patients, beyond the agreement with the morphological angiographic picture

Quercetin protects human brain microvascular endothelial cells from fibrillar β-amyloid1–40-induced toxicity

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Yongjie Li

2015-01-01

Full Text Available Amyloid beta-peptides (Aβ are known to undergo active transport across the blood-brain barrier, and cerebral amyloid angiopathy has been shown to be a prominent feature in the majority of Alzheimer׳s disease. Quercetin is a natural flavonoid molecule and has been demonstrated to have potent neuroprotective effects, but its protective effect on endothelial cells under Aβ-damaged condition is unclear. In the present study, the protective effects of quercetin on brain microvascular endothelial cells injured by fibrillar Aβ1–40 (fAβ1–40 were observed. The results show that fAβ1–40-induced cytotoxicity in human brain microvascular endothelial cells (hBMECs can be relieved by quercetin treatment. Quercetin increases cell viability, reduces the release of lactate dehydrogenase, and relieves nuclear condensation. Quercetin also alleviates intracellular reactive oxygen species generation and increases superoxide dismutase activity. Moreover, it strengthens the barrier integrity through the preservation of the transendothelial electrical resistance value, the relief of aggravated permeability, and the increase of characteristic enzyme levels after being exposed to fAβ1–40. In conclusion, quercetin protects hBMECs from fAβ1–40-induced toxicity.

Microvascular responses to (hyper-)gravitational stress by short-arm human centrifuge: arteriolar vasoconstriction and venous pooling.

Science.gov (United States)

Habazettl, H; Stahn, Alexander; Nitsche, Andrea; Nordine, Michael; Pries, A R; Gunga, H-C; Opatz, O

2016-01-01

We hypothesized that lower body microvessels are particularly challenged during exposure to gravity and hypergravity leading to failure of resistance vessels to withstand excessive transmural pressure during hypergravitation and gravitation-dependent microvascular blood pooling. Using a short-arm human centrifuge (SAHC), 12 subjects were exposed to +1Gz, +2Gz and +1Gz, all at foot level, for 4 min each. Laser Doppler imaging and near-infrared spectroscopy were used to measure skin perfusion and tissue haemoglobin concentrations, respectively. Pretibial skin perfusion decreased by 19% during +1Gz and remained at this level during +2Gz. In the dilated area, skin perfusion increased by 24 and 35% during +1Gz and +2Gz, respectively. In the upper arm, oxygenated haemoglobin (Hb) decreased, while deoxy Hb increased with little change in total Hb. In the calf muscle, O2Hb and deoxy Hb increased, resulting in total Hb increase by 7.5 ± 1.4 and 26.6 ± 2.6 µmol/L at +1Gz and +2Gz, respectively. The dynamics of Hb increase suggests a fast and a slow component. Despite transmural pressures well beyond the upper myogenic control limit, intact lower body resistance vessels withstand these pressures up to +2Gz, suggesting that myogenic control may contribute only little to increased vascular resistance. The fast component of increasing total Hb indicates microvascular blood pooling contributing to soft tissue capacitance. Future research will have to address possible alterations of these acute adaptations to gravity after deconditioning by exposure to micro-g.

Coherence and Coupling Functions Reveal Microvascular Impairment in Treated Hypertension

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Valentina Ticcinelli

2017-10-01

Full Text Available The complex interactions that give rise to heart rate variability (HRV involve coupled physiological oscillators operating over a wide range of different frequencies and length-scales. Based on the premise that interactions are key to the functioning of complex systems, the time-dependent deterministic coupling parameters underlying cardiac, respiratory and vascular regulation have been investigated at both the central and microvascular levels. Hypertension was considered as an example of a globally altered state of the complex dynamics of the cardiovascular system. Its effects were established through analysis of simultaneous recordings of the electrocardiogram (ECG, respiratory effort, and microvascular blood flow [by laser Doppler flowmetry (LDF]. The signals were analyzed by methods developed to capture time-dependent dynamics, including the wavelet transform, wavelet-based phase coherence, non-linear mode decomposition, and dynamical Bayesian inference, all of which can encompass the inherent frequency and coupling variability of living systems. Phases of oscillatory modes corresponding to the cardiac (around 1.0 Hz, respiratory (around 0.25 Hz, and vascular myogenic activities (around 0.1 Hz were extracted and combined into two coupled networks describing the central and peripheral systems, respectively. The corresponding spectral powers and coupling functions were computed. The same measurements and analyses were performed for three groups of subjects: healthy young (Y group, 24.4 ± 3.4 y, healthy aged (A group, 71.1 ± 6.6 y, and aged treated hypertensive patients (ATH group, 70.3 ± 6.7 y. It was established that the degree of coherence between low-frequency oscillations near 0.1 Hz in blood flow and in HRV time series differs markedly between the groups, declining with age and nearly disappearing in treated hypertension. Comparing the two healthy groups it was found that the couplings to the cardiac rhythm from both respiration and

Partitioning of red blood cell aggregates in bifurcating microscale flows

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Kaliviotis, E.; Sherwood, J. M.; Balabani, S.

2017-03-01

Microvascular flows are often considered to be free of red blood cell aggregates, however, recent studies have demonstrated that aggregates are present throughout the microvasculature, affecting cell distribution and blood perfusion. This work reports on the spatial distribution of red blood cell aggregates in a T-shaped bifurcation on the scale of a large microvessel. Non-aggregating and aggregating human red blood cell suspensions were studied for a range of flow splits in the daughter branches of the bifurcation. Aggregate sizes were determined using image processing. The mean aggregate size was marginally increased in the daughter branches for a range of flow rates, mainly due to the lower shear conditions and the close cell and aggregate proximity therein. A counterintuitive decrease in the mean aggregate size was apparent in the lower flow rate branches. This was attributed to the existence of regions depleted by aggregates of certain sizes in the parent branch, and to the change in the exact flow split location in the T-junction with flow ratio. The findings of the present investigation may have significant implications for microvascular flows and may help explain why the effects of physiological RBC aggregation are not deleterious in terms of in vivo vascular resistance.

Free and microvascular bone grafting in the irradiated dog mandible

International Nuclear Information System (INIS)

Altobelli, D.E.; Lorente, C.A.; Handren, J.H. Jr.; Young, J.; Donoff, R.B.; May, J.W. Jr.

1987-01-01

Microvascular and free rib grafts were placed in 4.5 cm defects in an edentate mandibular body defect 18 to 28 days after completion of 50 Gy of irradiation from a 60 Co source. The animals were sacrificed from two to forty weeks postoperatively and evaluated clinically, radiographically, and histologically. There was a marked difference in the alveolar mucosal viability with the two grafts. Mucosal dehiscence was not observed over any of the microvascular grafts, but was present in seven-eighths of the free grafts. Union of the microvascular bone graft to the host bone occurred within six weeks. In contrast, after six weeks the free graft was sequestered in all the animals. An unexpected finding with both types of graft was the marked subperiosteal bone formation. This bone appeared to be derived from the host bed, stabilizing and bridging the defects bilaterally. The results suggest that radiated periosteum may play an important role in osteogenesis

Microvascular Anastomosis: Proposition of a Learning Curve.

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Mokhtari, Pooneh; Tayebi Meybodi, Ali; Benet, Arnau; Lawton, Michael T

2018-04-14

Learning to perform a microvascular anastomosis is one of the most difficult tasks in cerebrovascular surgery. Previous studies offer little regarding the optimal protocols to maximize learning efficiency. This failure stems mainly from lack of knowledge about the learning curve of this task. To delineate this learning curve and provide information about its various features including acquisition, improvement, consistency, stability, and recall. Five neurosurgeons with an average surgical experience history of 5 yr and without any experience in bypass surgery performed microscopic anastomosis on progressively smaller-caliber silastic tubes (Biomet, Palm Beach Gardens, Florida) during 24 consecutive sessions. After a 1-, 2-, and 8-wk retention interval, they performed recall test on 0.7-mm silastic tubes. The anastomoses were rated based on anastomosis patency and presence of any leaks. Improvement rate was faster during initial sessions compared to the final practice sessions. Performance decline was observed in the first session of working on a smaller-caliber tube. However, this rapidly improved during the following sessions of practice. Temporary plateaus were seen in certain segments of the curve. The retention interval between the acquisition and recall phase did not cause a regression to the prepractice performance level. Learning the fine motor task of microvascular anastomosis adapts to the basic rules of learning such as the "power law of practice." Our results also support the improvement of performance during consecutive sessions of practice. The objective evidence provided may help in developing optimized learning protocols for microvascular anastomosis.

Cyclic adenosine monophosphate levels and the function of skin microvascular endothelial cells.

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Tuder, R M; Karasek, M A; Bensch, K G

1990-02-01

The maintenance of the normal epithelioid morphology of human dermal microvascular endothelial cells (MEC) grown in vitro depends strongly on the presence of factors that increase intracellular levels of cyclic AMP. Complete removal of dibutyryl cAMP and isobutylmethylxanthine (IMX) from the growth medium results in a progressive transition from an epithelioid to a spindle-shaped cell line. This transition cannot be reversed by the readdition of dibutyryl cAMP and IMX to the growth medium or by addition of agonists that increase cAMP levels. Spindle-shaped MEC lose the ability to express Factor VIII rAG and DR antigens and to bind peripheral blood mononuclear leukocyte (PBML). Ultrastructural analyses of transitional cells and spindle-shaped cells show decreased numbers of Weibel-Palade bodies in transitional cells and their complete absence in spindle-shaped cells. Interferon-gamma alters several functional properties of both epithelioid and spindle-shaped cells. In the absence of dibutyryl cAMP it accelerates the transition from epithelial to spindle-shaped cells, whereas in the presence of cyclic AMP interferon-gamma increases the binding of PBMLs to both epithelioid and spindle-shaped MEC and the endocytic activity of the endothelial cells. These results suggest that cyclic AMP is an important second messenger in the maintenance of several key functions of microvascular endothelial cells. Factors that influence the levels of this messenger in vivo can be expected to influence the angiogenic and immunologic functions of the microvasculature.

Estimating the arterial input function from dynamic contrast-enhanced MRI data with compensation for flow enhancement (II): Applications in spine diagnostics and assessment of crohn's disease

NARCIS (Netherlands)

van Schie, Jeroen J. N.; Lavini, Cristina; van Vliet, Lucas J.; Kramer, Gem; Pieters-van den Bos, Indra; Marcus, J. T.; Stoker, Jaap; Vos, Frans M.

2017-01-01

Pharmacokinetic (PK) models can describe microvascular density and integrity. An essential component of PK models is the arterial input function (AIF) representing the time-dependent concentration of contrast agent (CA) in the blood plasma supplied to a tissue. To evaluate a novel method for

Effects of Red Blood Cell Aggregation on the Apparent Viscosity of Blood Flow in Tubes.

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Hitt, Darren L.; Lowe, Mary L.

1996-11-01

In arterioles and venules (20-200μ diameter), the low shear rates enable red blood cells to form aggregate structures of varying sizes and morphology. The size and distribution of the aggregates affect the flow impedance within a microvascular network; this effect may be characterized by an "apparent viscosity". In this study, we measure the apparent viscosity of blood flow in 50μ glass tubes as a function of shear rate and red blood cell volume fraction (hematocrit); for a fixed tube geometry and an imposed flow rate, the viscosity is determined by measuring the pressure drop across the tube. To correlate the apparent viscosity with the size and spatial distribution of the aggregates in the flow, video images of the flow are recorded and analyzed using power spectral techniques. Pig blood and sheep blood are used as the models for aggregating and non-aggregating blood, respectively. Supported by NSF PFF Award CTS-9253633

Arterial blood supply to midbrain, thalamus and internal capsule on CT, 3

International Nuclear Information System (INIS)

Takeshita, Gen; Ottomo, Michinori; Sasaki, Taisuke; Fukuda, Eiko.

1984-01-01

The selective injection of dye into the anterior choroidal artery (blue), the medial posterior choroidal artery (green), and the lateral posterior choroidal artery (red), using seven post-mortem brains, was performed. After fixation, sections parallel with the orbito-meatal line were obtained. The distribution of the anterior choroidal artery was visualized in the uncal region of the temporal lobe and the cerebral peduncle below the slice of the third ventricle. On the slice of the third ventricle, the lateral part of the geniculate region, the globus pallidus, and the posterior limb of the internal capsule were supplied by the anterior choroidal artery. The blood supply of the posterior limb of the internal capsule was also demonstrated on the slice of the anterior horn and on the body of the lateral ventricle. The distribution of the medial posterior choroidal artery was visualized in the tegmentum of the midbrain below the slice of the third ventricle, and on the slice of the anterior horn, the pineal body and the posterior part of the thalamus were also supplied. The distribution of the lateral posterior choroidal artery was visualized in the lateral part of the midbrain, around the red nucleus, below the slice of the third ventricle, and on the slice of the third ventricle, the upper part of the cerebral peduncle, the posterior part of the hypothalamus, and the medial part of the geniculate region were also supplied. Also, distribution to the medial and posterior parts of the thalamus was noted on the slice of the anterior horn. It was quite useful to identify the distribution of each choroidal artery on CT sections for the CT diagnosis of cerebrovascular disorders. (author)

Effect of thrombus composition and viscosity on sonoreperfusion efficacy in a model of microvascular obstruction

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Black, John J.; Yu, Francois T. H.; Schnatz, Rick G.; Flordeliza, Xucai Chen; Villanueva, S.; Pacella, John J.

2016-01-01

Distal embolization of microthrombi during stenting for myocardial infarction (MI) causes microvascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasonic (US) therapy, resolves MVO from venous microthrombi in vitro in saline. However, blood is more viscous than saline and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial microthrombi are more resistant to SRP therapy compared with venous microthrombi and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MB suspended in plasma with adjusted viscosity (1.1 or 4.0 cP) were passed through tubing bearing a mesh with 40 μm pores to simulate a microvascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous microthrombi to increase upstream pressure to 40±5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector (PCD). MVO caused by arterial microthrombi at either blood or plasma viscosity resulted in less effective SRP therapy, compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. PCD showed a decrease in inertial cavitation when viscosity was increased while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy, increased viscosity decreases SRP efficacy, and both inertial and stable cavitation are implicated in observed SRP efficacy. PMID:27207018

Serum Levels of Progranulin Are Closely Associated with Microvascular Complication in Type 2 Diabetes

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Lin Xu

2015-01-01

Full Text Available Objective. Progranulin (PGRN was recently introduced as a novel marker of chronic inflammatory response in obesity and type 2 diabetes capable of directly affecting the insulin signaling pathway. This study aimed to investigate the correlation between PGRN and type 2 diabetics with microvascular complications. Methods. PGRN serum levels and glucose metabolism related substance were measured in 84 type 2 diabetic patients with or without microangiopathies and 12 health persons. Further analyses of serum PGRN in different stages of diabetic microangiopathies were conducted. Results. Serum levels of PGRN were markedly higher in type 2 diabetic patients with microangiopathies. PGRN serum levels increased with the progress of diabetic microangiopathies with significantly highest values detectable in clinical diabetic nephropathy (CDN and proliferative diabetic retinopathy (PDR groups. Serum PGRN concentrations in all individuals positively and markedly correlated with systolic blood pressure (SBP, diastolic blood pressure (DBP, body mass index (BMI, triglyceride (TG, urinary albumin excretion rate (UAER, blood urea nitrogen (BUN, creatinine (CRE, white blood cell (WBC, disease duration, IL-6, and TNF-α, while correlating negatively and significantly with eGFR. Multiple linear regression analysis showed that only UAER and CRE were independently associated with serum PGRN. Conclusion. PGRN might be considered as a marker for diabetic microangiopathy and its severity.

Generation of erythroid cells from polyploid giant cancer cells: re-thinking about tumor blood supply.

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Yang, Zhigang; Yao, Hong; Fei, Fei; Li, Yuwei; Qu, Jie; Li, Chunyuan; Zhang, Shiwu

2018-04-01

During development and tumor progression, cells need a sufficient blood supply to maintain development and rapid growth. It is reported that there are three patterns of blood supply for tumor growth: endothelium-dependent vessels, mosaic vessels, and vasculogenic mimicry (VM). VM was first reported in highly aggressive uveal melanomas, with tumor cells mimicking the presence and function of endothelial cells forming the walls of VM vessels. The walls of mosaic vessels are randomly lined with both endothelial cells and tumor cells. We previously proposed a three-stage process, beginning with VM, progressing to mosaic vessels, and eventually leading to endothelium-dependent vessels. However, many phenomena unique to VM channel formation remain to be elucidated, such as the origin of erythrocytes before VM vessels connect with endothelium-dependent vessels. In adults, erythroid cells are generally believed to be generated from hematopoietic stem cells in the bone marrow. In contrast, embryonic tissue obtains oxygen through formation of blood islands, which are largely composed of embryonic hemoglobin with a higher affinity with oxygen, in the absence of mature erythrocytes. Recent data from our laboratory suggest that embryonic blood-forming mechanisms also exist in cancer tissue, particularly when these tissues are under environmental stress such as hypoxia. We review the evidence from induced pluripotent stem cells in vitro and in vivo to support this previously underappreciated cell functionality in normal and cancer cells, including the ability to generate erythroid cells. We will also summarize the current understanding of tumor angiogenesis, VM, and our recent work on polyploid giant cancer cells, with emphasis on their ability to generate erythroid cells and their association with tumor growth under hypoxia. An alternative embryonic pathway to obtain oxygen in cancer cells exists, particularly when they are under hypoxic conditions.

Replacing the Transfusion of 1–2 Units of Blood with Plasma Expanders that Increase Oxygen Delivery Capacity: Evidence from Experimental Studies

Directory of Open Access Journals (Sweden)

Amy G. Tsai

2014-10-01

Full Text Available At least a third of the blood supply in the world is used to transfuse 1–2 units of packed red blood cells for each intervention and most clinical trials of blood substitutes have been carried out at this level of oxygen carrying capacity (OCC restoration. However, the increase of oxygenation achieved is marginal or none at all for molecular hemoglobin (Hb products, due to their lingering vasoactivity. This has provided the impetus for the development of “oxygen therapeutics” using Hb-based molecules that have high oxygen affinity and target delivery of oxygen to anoxic areas. However it is still unclear how these oxygen carriers counteract or mitigate the functional effects of anemia due to obstruction, vasoconstriction and under-perfusion. Indeed, they are administered as a low dosage/low volume therapeutic Hb (subsequently further diluted in the circulatory pool and hence induce extremely small OCC changes. Hyperviscous plasma expanders provide an alternative to oxygen therapeutics by increasing the oxygen delivery capacity (ODC; in anemia they induce supra-perfusion and increase tissue perfusion (flow by as much as 50%. Polyethylene glycol conjugate albumin (PEG-Alb accomplishes this by enhancing the shear thinning behavior of diluted blood, which increases microvascular endothelial shear stress, causes vasodilation and lowering peripheral vascular resistance thus facilitating cardiac function. Induction of supra-perfusion takes advantage of the fact that ODC is the product of OCC and blood flow and hence can be maintained by increasing either or both. Animal studies suggest that this approach may save a considerable fraction of the blood supply. It has an additional benefit of enhancing tissue clearance of toxic metabolites.

Depletion of blood supply and cost due to indeterminate donations at the Guillermo Almenara Irigoyen National Hospital

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Jeel Moya-Salazar

2017-06-01

Full Text Available Objective: To evaluate the depletion of blood supply and the cost due to indeterminate donations at Hospital Nacional Guillermo Almenara Irigoyen during 2014. Materials and methods: A retrospective cross-sectional study and a cost-utility analysis were conducted in donations showing results in the gray zone (sample value/cutoff value between >0.85 and <1 after a serological screening of seven infectious markers (HIV, HBsAg, HBcAb, HCV, HTLV-1/2, syphilis and Chagas disease and the simultaneous determination of the HIV Ag/Ab combo by means of a fourth generation ELISA. Data was encoded and tabulated using the e-Delphyn® system. The cost-utility analysis was performed considering the current exchange rate. Results: Out of 9,560 donations, 20.7% (1977 donations showed results in the gray zone which caused a loss of 863.9 liters of blood and USD 92,640. The highest and lowest rate of seroprevalence were observed in HBcAb with 10.18% (973 indeterminate test results and anti-HIV with 0.39% (47 indeterminate test results, respectively (p<0.05. No significant differences were found between the anti-HIV y HIV Ag/Ab combo screening methods (p=0.776. Conclusions: It was demonstrated that more than 800 liters of discarded blood generated a more than USD 90,000 cost due to indeterminate donations causing economic damages to the hospital budget and a depletion of blood supply available for patients at Hospital Nacional Guillermo Almenara Irigoyen.

Zingiber officinale attenuates retinal microvascular changes in diabetic rats via anti-inflammatory and antiangiogenic mechanisms

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Dongare, Shirish; Mathur, Rajani; Saxena, Rohit; Mathur, Sandeep; Agarwal, Renu; Nag, Tapas C.; Srivastava, Sushma; Kumar, Pankaj

2016-01-01

Purpose Diabetic retinopathy is a common microvascular complication of long-standing diabetes. Several complex interconnecting biochemical pathways are activated in response to hyperglycemia. These pathways culminate into proinflammatory and angiogenic effects that bring about structural and functional damage to the retinal vasculature. Since Zingiber officinale (ginger) is known for its anti-inflammatory and antiangiogenic properties, we investigated the effects of its extract standardized to 5% 6-gingerol, the major active constituent of ginger, in attenuating retinal microvascular changes in rats with streptozotocin-induced diabetes. Methods Diabetic rats were treated orally with the vehicle or the ginger extract (75 mg/kg/day) over a period of 24 weeks along with regular monitoring of bodyweight and blood glucose and weekly fundus photography. At the end of the 24-week treatment, the retinas were isolated for histopathological examination under a light microscope, transmission electron microscopy, and determination of the retinal tumor necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and vascular endothelial growth factor (VEGF) levels. Results Oral administration of the ginger extract resulted in significant reduction of hyperglycemia, the diameter of the retinal vessels, and vascular basement membrane thickness. Improvement in the architecture of the retinal vasculature was associated with significantly reduced expression of NF-κB and reduced activity of TNF-α and VEGF in the retinal tissue in the ginger extract–treated group compared to the vehicle-treated group. Conclusions The current study showed that ginger extract containing 5% of 6-gingerol attenuates the retinal microvascular changes in rats with streptozotocin-induced diabetes through anti-inflammatory and antiangiogenic actions. Although precise molecular targets remain to be determined, 6-gingerol seems to be a potential candidate for further investigation. PMID:27293376

A study of red blood cell deformability in diabetic retinopathy using optical tweezers

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Smart, Thomas J.; Richards, Christopher J.; Bhatnagar, Rhythm; Pavesio, Carlos; Agrawal, Rupesh; Jones, Philip H.

2015-08-01

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus (DM) in which high blood sugar levels cause swelling, leaking and occlusions in the blood vessels of the retina, often resulting in a loss of sight. The microvascular system requires red blood cells (RBCs) to undergo significant cellular deformation in order to pass through vessels whose diameters are significantly smaller than their own. There is evidence to suggest that DM impairs the deformability of RBCs, and this loss of deformability has been associated with diabetic kidney disease (or nephropathy) - another microvascular complication of DM. However, it remains unclear whether reduced deformability of RBCs correlates with the presence of DR. Here we present an investigation into the deformability of RBCs in patients with diabetic retinopathy using optical tweezers. To extract a value for the deformability of RBCs we use a dual-trap optical tweezers set-up to stretch individual RBCs. RBCs are trapped directly (i.e. without micro-bead handles), so rotate to assume a `side-on' orientation. Video microscopy is used to record the deformation events, and shape analysis software is used to determine parameters such as initial and maximum RBC length, allowing us to calculate the deformability for each RBC. A small decrease in deformability of diabetes cells subject to this stretching protocol is observed when compared to control cells. We also report on initial results on three dimensional imaging of individual RBCs using defocussing microscopy.

[Microvascular decompression for hemifacial spasm. Ten years of experience].

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Revuelta-Gutiérrez, Rogelio; Vales-Hidalgo, Lourdes Olivia; Arvizu-Saldaña, Emiliano; Hinojosa-González, Ramón; Reyes-Moreno, Ignacio

2003-01-01

Hemifacial spasm characterized by involuntary paroxistic contractions of the face is more frequent on left side and in females. Evolution is progressive and in a few cases may disappear. Management includes medical treatment, botulinum toxin, and microvascular decompression of the nerve. We present the results of 116 microvascular decompressions performed in 88 patients over 10 years. All patients had previous medical treatment. All patients were operated on with microsurgical technique by asterional craniotomy. Vascular compression was present in all cases with one exception. Follow-up was from 1 month to 133 months. Were achieved excellent results in 70.45% of cases after first operation, good results in 9.09%, and poor results in 20.45% of patients. Long-term results were excellent in 81.82%, good in 6.82%, and poor in 11.36% of patients. Hypoacusia and transitory facial palsy were the main complications. Hemifacial spasm is a painless but disabling entity. Medical treatment is effective in a limited fashion. Injection of botulinum toxin has good response but benefit is transitory. Microvascular decompression is treatment of choice because it is minimally invasive, not destructive, requires minimum technical support, and yields best long-term results.

Microvascular disease during pregnancy in type 1 diabetes is associated with ambulatory arterial stiffness

DEFF Research Database (Denmark)

Tjessem, Ingvild; Al-Far, Hanine M; Fuglsang, Jens

2017-01-01

Objectives: The objective of this study was to evaluate the association between the ambulatory arterial stiffness index (AASI) and markers of microvascular disease during pregnancy in women with type 1 diabetes. Study design: A total of 151 women with type 1 diabetes mellitus were recruited...... during pregnancy in women with type 1 diabetes. Together with the flattened circadian rhythm this indicates a pregnancy-related functional change in the vascular bed....... for repeat 24-h BP recordings thrice during pregnancy and once three months post partum. Fifty women without diabetes served as controls. The AASI and pulse pressure (PP) were computed from blood pressure recordings. Repeated measures analysis of variance was used for comparison between groups during...

Microvascular lesions of the true vocal fold.

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Postma, G N; Courey, M S; Ossoff, R H

1998-06-01

Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.

Implementation of digital optical capillaroscopy for quantifying and estimating the microvascular abnormalities in type 2 diabetes mellitus

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Gurfinkel, Yu. I.; Suchkova, O. V.; Sasonko, M. L.; Priezzhev, A. V.

2016-04-01

This study is aimed to define the extent of digital capillaroscopy possibilities for the quantification and estimation of microvascular abnormalities in type 2 diabetes mellitus (T2DM). A total of 196 adult persons were enrolled in the study including the group of compensated T2DM (n = 52), decompensated diabetics (n = 68), and healthy volunteers (n = 76) with normal blood glucose and without signs of cardiovascular pathology. All participants of the study were examined with the digital optical capillaroscope ("AET", Russia). This instrument is equipped with an image-processing program allowing for quantifying the diameters of the arterial and venous segments of the capillaries and their ratio (coefficient of remodeling), perivascular zone size, capillary blood velocity, and the degree of arterial loops narrowing and the density of the capillary network. Also we estimated the relative amount of coil-shaped capillaries. The study revealed significant difference in the capillary density and the remodeling coefficient in comparison of T2DM patients with non-diabetic individuals. Significant changes are found in the decompensated T2DM group compared to the compensated group of diabetic patients. Furthermore, the number of coil-shaped capillaries differed greatly in T2DM patients as compared to the healthy subjects. The study did not reveal any statistically significant differences in the capillary density between the patients with compensated and decompensated T2DM. The digital optical capillaroscope equipped with the advanced image-processing algorithm opens up new possibilities for obtaining clinically important information on microvascular abnormalities in patients suffering from diabetes mellitus.

Tezosentan reduces the microvascular filtration coefficient in isolated lungs from rats subjected to cecum ligation and puncture.

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Kuklin, Vladimir; Sovershaev, Mikhail; Andreasen, Thomas; Skogen, Vegard; Ytrehus, Kirsti; Bjertnaes, Lars

2005-01-01

We recently demonstrated that the non-selective endothelin-1 (ET-1) receptor blocker tezosentan antagonizes ovine acute lung injury (ALI) following infusion of endotoxin or ET-1 by reducing the enhanced lung microvascular pressure, although we could not exclude the possibility of a simultaneous decline in microvascular permeability. In the present study, our aim was to find out if tezosentan reverses the rise in microvascular filtration coefficient (Kfc) in rat lungs that have been isolated and perfused 12 h after cecum ligation and puncture (CLP) or infusion of ET-1. Wistar rats (n = 42) were subjected to CLP. Postoperatively, rats were randomized to a CLP group (n = 7) and a CLP + tezosentan group (n = 7); the latter received tezosentan 30 mg/kg. A sham-operated group (n = 5) underwent laparotomy without CLP. Twelve hours postoperatively, the lungs were isolated and perfused with blood from similarly treated rats that also were used to assess plasma concentration of ET-1 and protein kinase Calpha (PKCalpha) in lung tissue. Additionally, isolated blood perfused lungs from healthy rats were randomized to a control group (n = 8), an ET-1 group (n = 7) subjected to pulmonary arterial injection of ET-1 10 nM, and an ET-1 + tezosentan group (n = 7) that received tezosentan 30 mg/kg. All lung preparations received papaverine 0.1 microg/kg added to the perfusate for vasoplegia. Pulmonary hemodynamic variables, Kfc and lung compliance (CL) were assessed. After CLP, the plasma concentration of ET-1 increased. Papaverine abolished the vasoconstrictor response to ET-1 and the pulmonary vascular pressures remained close to baseline throughout the experiments. Both CLP and injection of ET-1 caused significant changes in Kfc and CL that were prevented in tezosentan-treated rats. Compared to sham-operated animals, CLP increased the content of PKCalpha by 50% and 70% in the cytosolic and the membrane fractions of lung tissue homogenates, respectively. Tezosentan prevented the

Wide-area mapping of resting state hemodynamic correlations at microvascular resolution with multi-contrast optical imaging (Conference Presentation)

Science.gov (United States)

Senarathna, Janaka; Hadjiabadi, Darian; Gil, Stacy; Thakor, Nitish V.; Pathak, Arvind P.

2017-02-01

Different brain regions exhibit complex information processing even at rest. Therefore, assessing temporal correlations between regions permits task-free visualization of their `resting state connectivity'. Although functional MRI (fMRI) is widely used for mapping resting state connectivity in the human brain, it is not well suited for `microvascular scale' imaging in rodents because of its limited spatial resolution. Moreover, co-registered cerebral blood flow (CBF) and total hemoglobin (HbT) data are often unavailable in conventional fMRI experiments. Therefore, we built a customized system that combines laser speckle contrast imaging (LSCI), intrinsic optical signal (IOS) imaging and fluorescence imaging (FI) to generate multi-contrast functional connectivity maps at a spatial resolution of 10 μm. This system comprised of three illumination sources: a 632 nm HeNe laser (for LSCI), a 570 nm ± 5 nm filtered white light source (for IOS), and a 473 nm blue laser (for FI), as well as a sensitive CCD camera operating at 10 frames per second for image acquisition. The acquired data enabled visualization of changes in resting state neurophysiology at microvascular spatial scales. Moreover, concurrent mapping of CBF and HbT-based temporal correlations enabled in vivo mapping of how resting brain regions were linked in terms of their hemodynamics. Additionally, we complemented this approach by exploiting the transit times of a fluorescent tracer (Dextran-FITC) to distinguish arterial from venous perfusion. Overall, we demonstrated the feasibility of wide area mapping of resting state connectivity at microvascular resolution and created a new toolbox for interrogating neurovascular function.

Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

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Yu, Cai-Guo; Zhang, Ning; Yuan, Sha-Sha; Ma, Yan; Yang, Long-Yan; Feng, Ying-Mei; Zhao, Dong

2016-01-01

Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs) in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF) treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on "VEGF uncoupling with nitric oxide" and "competitive angiopoietin 1/angiopoietin 2" mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics.

The feasibility and reliability of capillary blood pressure measurements in the fingernail fold

NARCIS (Netherlands)

de Graaff, Jurgen C.; Ubbink, Dirk Th; Lagarde, Sjoerd M.; Jacobs, Michael J. H. M.

2002-01-01

Capillary blood pressure is an essential parameter in the study of the (patho-)physiology of microvascular perfusion. Currently, capillary pressure measurements in humans are performed using a servo-nulling micropressure system containing an oil-water interface, which suffers some drawbacks. In

No difference in acute effects of supplemental v. dietary calcium on blood pressure and microvascular function in obese women challenged with a high-fat meal: a cross-over randomised study.

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Ferreira, Thaís da Silva; Leal, Priscila Mansur; Antunes, Vanessa Parada; Sanjuliani, Antonio Felipe; Klein, Márcia Regina Simas Torres

2016-11-01

Recent studies suggest that supplemental Ca (SC) increases the risk of cardiovascular events, whereas dietary Ca (DC) decreases the risk of cardiovascular events. Although frequently consumed with meals, it remains unclear whether Ca can mitigate or aggravate the deleterious effects of a high-fat meal on cardiovascular risk factors. This study aimed to evaluate the effects of SC or DC on blood pressure (BP) and microvascular function (MVF) in the postprandial period in obese women challenged with a high-fat meal. In this cross-over controlled trial, sixteen obese women aged 20-50 years were randomly assigned to receive three test meals (2908 kJ (695 kcal); 48 % fat): high DC (HDCM; 547 mg DC), high SC (HSCM; 500 mg SC-calcium carbonate) and low Ca (LCM; 42 mg DC). BP was continuously evaluated from 15 min before to 120 min after meals by digital photoplethysmography. Before and 120 min after meals, participants underwent evaluation of serum Ca and microvascular flow after postocclusive reactive hyperaemia (PORH) by laser speckle contrast imaging. Ionised serum Ca rose significantly only after HSCM. Systolic BP increased after the three meals, whereas diastolic BP increased after LCM and HDCM. Hyperaemia peak, hyperaemia amplitude and AUC evaluated after PORH decreased with LCM. After HDCM, there was a reduction in hyperaemia peak and hyperaemia amplitude, whereas HSCM decreased only hyperaemia peak. However, comparative analyses of the effects of three test meals on serum Ca, BP and MVF revealed no significant meal×time interaction. This study suggests that in obese women SC and DC do not interfere with the effects of a high-fat meal on BP and MVF.

Omega-3 Polyunsaturated Fatty Acids Enriched Hen Eggs Consumption Enhances Microvascular Reactivity in Young Healthy Individuals.

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Stupin, Ana; Rasic, Lidija; Matic, Anita; Stupin, Marko; Kralik, Zlata; Kralik, Gordana; Grcevic, Manuela; Drenjancevic, Ines

2018-04-10

Whilst the beneficial effect of omega-3 polyunsaturated fatty acids (PUFAs) supplementation on cardiovascular (CV) system is well supported in CV patients, the effect of consumption of omega-3 PUFAs enriched functional food in healthy individuals is still not fully elucidated. This study aimed to determine the effect of consumption of omega-3 PUFAs enriched hen eggs on microvascular reactivity (primary outcome), blood pressure (BP) and serum lipid profile in young healthy individuals. Control group (N=16) ate three ordinary hen eggs (277 mg omega-3 PUFAs/day), and OMEGA-3 group (N=20) ate three omega-3 PUFAs enriched eggs containing 259 mg of omega-3 PUFAs/egg daily (ALA 167 mg/egg, EPA 7 mg/egg, DHA 84 mg/egg) for 3 weeks (777 mg omega-3 PUFAs/day). Post-occlusive reactive hyperemia (PORH) in skin microcirculation assessed by laser Doppler flowmetry, serum lipid profile, fasting blood glucose, high-sensitivity C-reactive protein (hsCRP) and arterial BP were measured in all subjects before and after the protocol. PORH was significantly enhanced, and triglycerides, hsCRP and BP were significantly decreased in OMEGA-3 group compared to baseline measurement, while there was no significant difference in Control group after the protocol compared to baseline. This is the first study to demonstrate that consumption of a mixture of omega-3 PUFAs (ALA+EPA+DHA), provided via enriched hen eggs, elicits changes in microvascular reactivity, BP and triglycerides level in healthy subjects that are associated with CV benefits, thus suggesting that daily consumption of omega-3 PUFAs enriched eggs in healthy individuals may potentially contribute to CV risk factors attenuation and disease prevention.

[Construction of 2-dimensional tumor microvascular architecture phenotype in non-small cell lung cancer].

Science.gov (United States)

Liu, Jin-kang; Wang, Xiao-yi; Xiong, Zeng; Zhou, Hui; Zhou, Jian-hua; Fu, Chun-yan; Li, Bo

2008-08-01

To construct a technological platform of 2-dimensional tumor microvascular architecture phenotype (2D-TAMP) expression. Thirty samples of non-small cell lung cancer (NSCLC) were collected after surgery. The corresponding sections of tumor tissue specimens to the slice of CT perfusion imaging were selected. Immunohistochemical staining,Gomori methenamine silver stain, and electron microscope observation were performed to build a technological platform of 2D-TMAP expression by detecting the morphology and the integrity of basement membrane of microvasculature, microvascular density, various microvascular subtype, the degree of the maturity and lumenization of microvasculature, and the characteristics of immunogenetics of microvasculature. The technological platform of 2D-TMAP expression was constructed successfully. There was heterogeneity in 2D-TMAP expression of non-small cell lung cancer. The microvascular of NSCLC had certain characteristics. 2D-TMAP is a key technology that can be used to observe the overall state of micro-environment in tumor growth.

Acute Cutaneous Microvascular Flow Responses to Whole-Body Tilting in Humans

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Breit, Gregory A.; Watenpaugh, Donald E.; Ballard, Richard E.; Hargens, Alan R.

1993-01-01

The transition from upright to head-down tilt (HDT) posture in humans increases blood pressure superior to the heart and decreases pressure inferior to the heart. Consequently, above heart level, myogenic arteriolar tone probably increases with HDT, in opposition to the withdrawal of baroreceptor-mediated sympathetic tone. We hypothesized that due to antagonism between central and local controls, the response of the facial cutaneous microcirculation to acute postural change will be weaker than that in the leg, where these two mechanisms reinforce each other. Cutaneous microvascular flow was measured by laser Doppler flowmetry simultaneously at the shin and the neck of 7 male and 3 female subjects. Subjects underwent a stepwise tilt protocol from standing control to 54 deg head-up tilt (HUT), 30 deg, 12 deg, O deg, -6 deg (HDT), -12 deg, -6 deg, O deg, 12 deg, 30 deg, 54 deg, and standing, for 30-sec periods with 10-sec transitions between postures. Flows at the shin and the neck increased significantly (P less than 0.05) from standing baseline to 12 deg HUT (252 +/- 55 and 126 +/- 9% (bar X +/- SE) of baseline, respectively). From 12 deg to -12 deg tilt, flows continued to increase at the shin (509 +/- 71% of baseline) but decreased at the neck to baseline levels (100 +/- 15% of baseline). Cutaneous microvascular flow recovered at both sites during the return to standing posture with significant hysteresis. Flow increases from standing to near-supine posture are attributed at both sites to baroreceptor-mediated vasodilation. The great dissimilarity in flow response magnitudes at the two measurement sites may be indicative of central/local regulatory antagonism above heart level and reinforcement below heart level.

Microvascular and Macrovascular Abnormalities and Cognitive and Physical Function in Older Adults: Cardiovascular Health Study.

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Kim, Dae Hyun; Grodstein, Francine; Newman, Anne B; Chaves, Paulo H M; Odden, Michelle C; Klein, Ronald; Sarnak, Mark J; Lipsitz, Lewis A

2015-09-01

To evaluate and compare the associations between microvascular and macrovascular abnormalities and cognitive and physical function Cross-sectional analysis of the Cardiovascular Health Study (1998-1999). Community. Individuals with available data on three or more of five microvascular abnormalities (brain, retina, kidney) and three or more of six macrovascular abnormalities (brain, carotid artery, heart, peripheral artery) (N = 2,452; mean age 79.5). Standardized composite scores derived from three cognitive tests (Modified Mini-Mental State Examination, Digit-Symbol Substitution Test, Trail-Making Test (TMT)) and three physical tests (gait speed, grip strength, 5-time sit to stand) Participants with high microvascular and macrovascular burden had worse cognitive (mean score difference = -0.30, 95% confidence interval (CI) = -0.37 to -0.24) and physical (mean score difference = -0.32, 95% CI = -0.38 to -0.26) function than those with low microvascular and macrovascular burden. Individuals with high microvascular burden alone had similarly lower scores than those with high macrovascular burden alone (cognitive function: -0.16, 95% CI = -0.24 to -0.08 vs -0.13, 95% CI = -0.20 to -0.06; physical function: -0.15, 95% CI = -0.22 to -0.08 vs -0.12, 95% CI = -0.18 to -0.06). Psychomotor speed and working memory, assessed using the TMT, were only impaired in the presence of high microvascular burden. Of the 11 vascular abnormalities considered, white matter hyperintensity, cystatin C-based glomerular filtration rate, large brain infarct, and ankle-arm index were independently associated with cognitive and physical function. Microvascular and macrovascular abnormalities assessed using noninvasive tests of the brain, kidney, and peripheral artery were independently associated with poor cognitive and physical function in older adults. Future research should evaluate the usefulness of these tests in prognostication. © 2015, Copyright the Authors Journal compilation © 2015

Cell proliferation along vascular islands during microvascular network growth

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Kelly-Goss Molly R

2012-06-01

Full Text Available Abstract Background Observations in our laboratory provide evidence of vascular islands, defined as disconnected endothelial cell segments, in the adult microcirculation. The objective of this study was to determine if vascular islands are involved in angiogenesis during microvascular network growth. Results Mesenteric tissues, which allow visualization of entire microvascular networks at a single cell level, were harvested from unstimulated adult male Wistar rats and Wistar rats 3 and 10 days post angiogenesis stimulation by mast cell degranulation with compound 48/80. Tissues were immunolabeled for PECAM and BRDU. Identification of vessel lumens via injection of FITC-dextran confirmed that endothelial cell segments were disconnected from nearby patent networks. Stimulated networks displayed increases in vascular area, length density, and capillary sprouting. On day 3, the percentage of islands with at least one BRDU-positive cell increased compared to the unstimulated level and was equal to the percentage of capillary sprouts with at least one BRDU-positive cell. At day 10, the number of vascular islands per vascular area dramatically decreased compared to unstimulated and day 3 levels. Conclusions These results show that vascular islands have the ability to proliferate and suggest that they are able to incorporate into the microcirculation during the initial stages of microvascular network growth.

Assessment of macrovascular endothelial function using pulse wave analysis and its association with microvascular reactivity in healthy subjects.

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Ibrahim, N N I N; Rasool, A H G

2017-08-01

Pulse wave analysis (PWA) and laser Doppler fluximetry (LDF) are non-invasive methods of assessing macrovascular endothelial function and microvascular reactivity respectively. The aim of this study was to assess the correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF. 297 healthy and non-smoking subjects (159 females, mean age (±SD) 23.56 ± 4.54 years) underwent microvascular reactivity assessment using LDF followed by macrovascular endothelial function assessments using PWA. Pearson's correlation showed no correlation between macrovascular endothelial function and microvascular reactivity (r = -0.10, P = 0.12). There was no significant correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF in healthy subjects. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Retinal Vascular Fractals and Microvascular and Macrovascular Complications in Type 1 Diabetes

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Grauslund, Jakob; Green, Anders; Kawasaki, Ryo

2010-01-01

diabetes. DESIGN: Cross-sectional study. PARTICIPANTS: This was a cross-sectional study of 208 long-term surviving type 1 diabetes patients from a population-based Danish cohort identified in 1973. METHODS: Retinal photographs were obtained at a clinical examination in 2007 or 2008. D(f) was measured......, respectively. Median D(f) was 1.4610 (range, 1.3774-1.5188). After adjustments for age, gender, duration of diabetes, systolic blood pressure, and smoking, persons with lower D(f) were more likely to have proliferative retinopathy (odds ratio [OR], 1.45 per standard deviation [SD] decrease in D(f); 95......PURPOSE: Fractal analysis is a method to quantify the geometric pattern and complexity of the retinal vessels. This study examined the association of retinal fractal dimension (D(f)) and microvascular and macrovascular complications in a population-based cohort of Danish patients with type 1...

Transit time homogenization in ischemic stroke - A novel biomarker of penumbral microvascular failure?

DEFF Research Database (Denmark)

Engedal, Thorbjørn S; Hjort, Niels; Hougaard, Kristina D

2017-01-01

Cerebral ischemia causes widespread capillary no-flow in animal studies. The extent of microvascular impairment in human stroke, however, is unclear. We examined how acute intra-voxel transit time characteristics and subsequent recanalization affect tissue outcome on follow-up MRI in a historic...... cohort of 126 acute ischemic stroke patients. Based on perfusion-weighted MRI data, we characterized voxel-wise transit times in terms of their mean transit time (MTT), standard deviation (capillary transit time heterogeneity - CTH), and the CTH:MTT ratio (relative transit time heterogeneity), which...... tissue, prolonged mean transit time (>5 seconds) and very low cerebral blood flow (≤6 mL/100 mL/min) was associated with high risk of infarction, largely independent of recanalization status. In the remaining mismatch region, low relative transit time heterogeneity predicted subsequent infarction...

Impaired coronary microvascular function in diabetics

International Nuclear Information System (INIS)

Tsujimoto, Go

2000-01-01

Global and regional myocardial uptake was determined with technetium-99m tetrofosmin and a 4 hour exercise (370 MBq iv) and rest (740 MBq iv) protocol, in 24 patients with non-insulin dependent diabetes mellitus and in 22 control subjects. The purpose of this study was to evaluate impaired coronary microvascular function in diabetics by measurement of % uptake increase in myocardial counts. The parameter of % uptake increase (ΔMTU) was calculated as the ratio of exercise counts to rest myocardial counts with correction of myocardial uptake for dose administered and physical decay between the exercise study and the rest study. Global ΔMTU was significantly lower in the diabetics than in control subjects (14.4±5.4% vs. 21.7±8.5%, p<0.01). Regional ΔMTU in each of 4 left ventricular regions (anterior, septal, inferior, posterolateral) was significantly lower in the diabetic group than in the control group (p<0.01) respectively, but there were no significant differences between ΔMTU in the 4 left ventricular regions in the same group. ΔMTU was useful as a non-invasive means of evaluating impaired coronary microvascular function in diabetics. (author)

Long noncoding RNA-MEG3 is involved in diabetes mellitus-related microvascular dysfunction

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Qiu, Gui-Zhen [Department of Health, Linyi People' s Hospital, Shandong University, Shandong (China); Tian, Wei [Department of Nursing, Linyi Oncosurgical Hospital, Shandong (China); Fu, Hai-Tao [Department of Ophthalmology, Linyi People' s Hospital, Shandong University, Shandong (China); Li, Chao-Peng, E-mail: lcpcn@163.com [Eye Institute of Xuzhou, Jiangsu (China); Liu, Ban, E-mail: liuban@126.com [Department of Cardiology, Shanghai Tenth People' s Hospital, Tongji University School of Medicine, Shanghai (China)

2016-02-26

Microvascular dysfunction is an important characteristic of diabetic retinopathy. Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. In this study, we investigated the role of lncRNA-MEG3 in diabetes-related microvascular dysfunction. We show that MEG3 expression level is significantly down-regulated in the retinas of STZ-induced diabetic mice, and endothelial cells upon high glucose and oxidative stress. MEG3 knockdown aggravates retinal vessel dysfunction in vivo, as shown by serious capillary degeneration, and increased microvascular leakage and inflammation. MEG3 knockdown also regulates retinal endothelial cell proliferation, migration, and tube formation in vitro. The role of MEG3 in endothelial cell function is mainly mediated by the activation of PI3k/Akt signaling. MEG3 up-regulation may serve as a therapeutic strategy for treating diabetes-related microvascular complications. - Highlights: • LncRNA-MEG3 level is down-regulated upon diabetic stress. • MEG3 knockdown aggravates retinal vascular dysfunction in vivo. • MEG3 regulates retinal endothelial cell function in vitro. • MEG3 regulates endothelial cell function through PI3k/Akt signaling.

Long noncoding RNA-MEG3 is involved in diabetes mellitus-related microvascular dysfunction

International Nuclear Information System (INIS)

Qiu, Gui-Zhen; Tian, Wei; Fu, Hai-Tao; Li, Chao-Peng; Liu, Ban

2016-01-01

Microvascular dysfunction is an important characteristic of diabetic retinopathy. Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. In this study, we investigated the role of lncRNA-MEG3 in diabetes-related microvascular dysfunction. We show that MEG3 expression level is significantly down-regulated in the retinas of STZ-induced diabetic mice, and endothelial cells upon high glucose and oxidative stress. MEG3 knockdown aggravates retinal vessel dysfunction in vivo, as shown by serious capillary degeneration, and increased microvascular leakage and inflammation. MEG3 knockdown also regulates retinal endothelial cell proliferation, migration, and tube formation in vitro. The role of MEG3 in endothelial cell function is mainly mediated by the activation of PI3k/Akt signaling. MEG3 up-regulation may serve as a therapeutic strategy for treating diabetes-related microvascular complications. - Highlights: • LncRNA-MEG3 level is down-regulated upon diabetic stress. • MEG3 knockdown aggravates retinal vascular dysfunction in vivo. • MEG3 regulates retinal endothelial cell function in vitro. • MEG3 regulates endothelial cell function through PI3k/Akt signaling.

Dual energy spectral CT imaging for the evaluation of small hepatocellular carcinoma microvascular invasion.

Science.gov (United States)

Yang, Chuang-Bo; Zhang, Shuang; Jia, Yong-Jun; Yu, Yong; Duan, Hai-Feng; Zhang, Xi-Rong; Ma, Guang-Ming; Ren, Chenglong; Yu, Nan

2017-10-01

To study the clinical value of dual-energy spectral CT in the quantitative assessment of microvascular invasion of small hepatocellular carcinoma. This study was approved by our ethics committee. 50 patients with small hepatocellular carcinoma who underwent contrast enhanced spectral CT in arterial phase (AP) and portal venous phase (VP) were enrolled. Tumour CT value and iodine concentration (IC) were measured from spectral CT images. The slope of spectral curve, normalized iodine concentration (NIC, to abdominal aorta) and ratio of IC difference between AP and VP (RIC AP-VP : [RIC AP-VP =(IC AP -IC VP )/IC AP ]) were calculated. Tumours were identified as either with or without microvascular invasion based on pathological results. Measurements were statistically compared using independent samples t test. The receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of tumours microvascular invasion assessment. The 70keV images were used to simulate the results of conventional CT scans for comparison. 56 small hepatocellular carcinomas were detected with 37 lesions (Group A) with microvascular invasion and 19 (Group B) without. There were significant differences in IC, NIC and slope in AP and RIC AP-VP between Group A (2.48±0.70mg/ml, 0.23±0.05, 3.39±1.01 and 0.28±0.16) and Group B (1.65±0.47mg/ml, 0.15±0.05, 2.22±0.64 and 0.03±0.24) (all phepatocellular carcinoma with and without microvascular invasion. Quantitative iodine concentration measurement in spectral CT may be used to provide a new method to improve the evaluation for small hepatocellular carcinoma microvascular invasion. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhaled nitric oxide pretreatment but not posttreatment attenuates ischemia-reperfusion-induced pulmonary microvascular leak.

Science.gov (United States)

Chetham, P M; Sefton, W D; Bridges, J P; Stevens, T; McMurtry, I F

1997-04-01

Ischemia-reperfusion (I/R) pulmonary edema probably reflects a leukocyte-dependent, oxidant-mediated mechanism. Nitric oxide (NO) attenuates leukocyte-endothelial cell interactions and I/R-induced microvascular leak. Cyclic adenosine monophosphate (cAMP) agonists reverse and prevent I/R-induced microvascular leak, but reversal by inhaled NO (INO) has not been tested. In addition, the role of soluble guanylyl cyclase (sGC) activation in the NO protection effect is unknown. Rat lungs perfused with salt solution were grouped as either I/R, I/R with INO (10 or 50 ppm) on reperfusion, or time control. Capillary filtration coefficients (Kfc) were estimated 25 min before ischemia (baseline) and after 30 and 75 min of reperfusion. Perfusate cell counts and lung homogenate myeloperoxidase activity were determined in selected groups. Additional groups were treated with either INO (50 ppm) or isoproterenol (ISO-10 microM) after 30 min of reperfusion. Guanylyl cyclase was inhibited with 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ-15 microM), and Kfc was estimated at baseline and after 30 min of reperfusion. (1) Inhaled NO attenuated I/R-induced increases in Kfc. (2) Cell counts were similar at baseline. After 75 min of reperfusion, lung neutrophil retention (myeloperoxidase activity) and decreased perfusate neutrophil counts were similar in all groups. (3) In contrast to ISO, INO did not reverse microvascular leak. (4) 8-bromoguanosine 3',5'-cyclic monophosphate (8-br-cGMP) prevented I/R-induced microvascular leak in ODQ-treated lungs, but INO was no longer effective. Inhaled NO attenuates I/R-induced pulmonary microvascular leak, which requires sGC activation and may involve a mechanism independent of inhibition of leukocyte-endothelial cell interactions. In addition, INO is ineffective in reversing I/R-induced microvascular leak.

Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

International Nuclear Information System (INIS)

Server, Andres; Nakstad, Per H.; Orheim, Tone E.D.; Graff, Bjoern A.; Josefsen, Roger; Kumar, Theresa

2011-01-01

Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

Energy Technology Data Exchange (ETDEWEB)

Server, Andres; Nakstad, Per H. [Oslo University Hospital-Ullevaal, Section of Neuroradiology, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Oslo (Norway); Orheim, Tone E.D. [Oslo University Hospital, Interventional Centre, Oslo (Norway); Graff, Bjoern A. [Oslo University Hospital-Ullevaal, Department of Radiology and Nuclear Medicine, Oslo (Norway); Josefsen, Roger [Oslo University Hospital-Ullevaal, Department of Neurosurgery, Oslo (Norway); Kumar, Theresa [Oslo University Hospital-Ullevaal, Department of Pathology, Oslo (Norway)

2011-05-15

Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

Implications Enzymatic Degradation of the Endothelial Glycocalyx on the Microvascular Hemodynamics and the Arteriolar Red Cell Free Layer of the Rat Cremaster Muscle

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Ozlem Yalcin

2018-03-01

Full Text Available The endothelial glycocalyx is a complex network of glycoproteins, proteoglycans, and glycosaminoglycans; it lines the vascular endothelial cells facing the lumen of blood vessels forming the endothelial glycocalyx layer (EGL. This study aims to investigate the microvascular hemodynamics implications of the EGL by quantifying changes in blood flow hydrodynamics post-enzymatic degradation of the glycocalyx layer. High-speed intravital microscopy videos of small arteries (around 35 μm of the rat cremaster muscle were recorded at various time points after enzymatic degradation of the EGL. The thickness of the cell free layer (CFL, blood flow velocity profiles, and volumetric flow rates were quantified. Hydrodynamic effects of the presence of the EGL were observed in the differences between the thickness of CFL in microvessels with an intact EGL and glass tubes of similar diameters. Maximal changes in the thickness of CFL were observed 40 min post-enzymatic degradation of the EGL. Analysis of the frequency distribution of the thickness of CFL allows for estimation of the thickness of the endothelial surface layer (ESL, the plasma layer, and the glycocalyx. Peak flow, maximum velocity, and mean velocity were found to statistically increase by 24, 27, and 25%, respectively, after enzymatic degradation of the glycocalyx. The change in peak-to-peak maximum velocity and mean velocity were found to statistically increase by 39 and 32%, respectively, after 40 min post-enzymatic degradation of the EGL. The bluntness of blood flow velocity profiles was found to be reduced post-degradation of the EGL, as the exclusion volume occupied by the EGL increased the effective volume impermeable to RBCs in microvessels. This study presents the effects of the EGL on microvascular hemodynamics. Enzymatic degradation of the EGL resulted in a decrease in the thickness of CFL, an increase in blood velocity, blood flow, and decrease of the bluntness of the blood flow

Implications Enzymatic Degradation of the Endothelial Glycocalyx on the Microvascular Hemodynamics and the Arteriolar Red Cell Free Layer of the Rat Cremaster Muscle.

Science.gov (United States)

Yalcin, Ozlem; Jani, Vivek P; Johnson, Paul C; Cabrales, Pedro

2018-01-01

The endothelial glycocalyx is a complex network of glycoproteins, proteoglycans, and glycosaminoglycans; it lines the vascular endothelial cells facing the lumen of blood vessels forming the endothelial glycocalyx layer (EGL). This study aims to investigate the microvascular hemodynamics implications of the EGL by quantifying changes in blood flow hydrodynamics post-enzymatic degradation of the glycocalyx layer. High-speed intravital microscopy videos of small arteries (around 35 μm) of the rat cremaster muscle were recorded at various time points after enzymatic degradation of the EGL. The thickness of the cell free layer (CFL), blood flow velocity profiles, and volumetric flow rates were quantified. Hydrodynamic effects of the presence of the EGL were observed in the differences between the thickness of CFL in microvessels with an intact EGL and glass tubes of similar diameters. Maximal changes in the thickness of CFL were observed 40 min post-enzymatic degradation of the EGL. Analysis of the frequency distribution of the thickness of CFL allows for estimation of the thickness of the endothelial surface layer (ESL), the plasma layer, and the glycocalyx. Peak flow, maximum velocity, and mean velocity were found to statistically increase by 24, 27, and 25%, respectively, after enzymatic degradation of the glycocalyx. The change in peak-to-peak maximum velocity and mean velocity were found to statistically increase by 39 and 32%, respectively, after 40 min post-enzymatic degradation of the EGL. The bluntness of blood flow velocity profiles was found to be reduced post-degradation of the EGL, as the exclusion volume occupied by the EGL increased the effective volume impermeable to RBCs in microvessels. This study presents the effects of the EGL on microvascular hemodynamics. Enzymatic degradation of the EGL resulted in a decrease in the thickness of CFL, an increase in blood velocity, blood flow, and decrease of the bluntness of the blood flow velocity profile in

Failure of controlling massive hemoptysis in bronchiectasis through BAE due to aberration blood supply from inferior phrenic arteries

International Nuclear Information System (INIS)

Liu Fengyong; Duan Feng; Wang Maoqiang; Song Peng; Wang Zhijun; Wang Zhongpu

2008-01-01

Objective: To describe the manifestations of the inferior phrenic arterial (IPA) blood supply in hemoptysis of bronchiectasis and to evaluate the safety and efficacy of transcatheter arterial embolization (TAE)of the IPA. Methods: During the past 5 years, 62 patients with hemoptysis due to bronchiectasis underwent BAE including 10 with additional blood supply from IPA. Mean patient age was 42.5 years (range, 26-58 years). Supplemental TAE using gelatin sponge particles and microcoils was undertaken in IPA supplying cases. The imaging findings of the IPA angiography, the predictive factors, the technique and clinical significance including safety of IPA embolization, were evaluated. Results: Selective arteriogram demonstrated enlargement of IPA, with numerous branches and neovasculature in all 10 cases, including contrast material extravasation in 4, and non-specific staining in 6 cases. In addition, there were IPA-to- pulmonary shunting in 8 cases, adjacent to the pleurae involving diaphragmatic and mediastinal pleura in 6 and only mediastinal pleura in 4. Technical success of IPA embolization was achieved in all 10 cases. Embolization of other nonbronchial systemic arteries (the internal thoracic artery in 4 and intercostal artery in 2)were performed at the same session. All bleedings ceased immediately after supplemental IPA embolization. Follow- up ranged from 8 months to 3 years, including mild recurrent hemoptysis in 2 patients at 2, 3 months respectively, but responsible to conservative management and no recurrent bleeding in 8 patients. Conclusion: Bronchiectatic hemoptysis may be further supplied by IPA, resulting in clinical failure of BAE and supplemental TAE of IPA is a safe and effective adjunct to BAE in the management. (authors)

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

Brain microvascular pericytes are immunoactive in culture: cytokine, chemokine, nitric oxide, and LRP-1 expression in response to lipopolysaccharide

Directory of Open Access Journals (Sweden)

Erickson Michelle A

2011-10-01

Full Text Available Abstract Background Brain microvascular pericytes are important constituents of the neurovascular unit. These cells are physically the closest cells to the microvascular endothelial cells in brain capillaries. They significantly contribute to the induction and maintenance of the barrier functions of the blood-brain barrier. However, very little is known about their immune activities or their roles in neuroinflammation. Here, we focused on the immunological profile of brain pericytes in culture in the quiescent and immune-challenged state by studying their production of immune mediators such as nitric oxide (NO, cytokines, and chemokines. We also examined the effects of immune challenge on pericyte expression of low density lipoprotein receptor-related protein-1 (LRP-1, a protein involved in the processing of amyloid precursor protein and the brain-to-blood efflux of amyloid-β peptide. Methods Supernatants were collected from primary cultures of mouse brain pericytes. Release of nitric oxide (NO was measured by the Griess reaction and the level of S-nitrosylation of pericyte proteins measured with a modified "biotin-switch" method. Specific mitogen-activated protein kinase (MAPK pathway inhibitors were used to determine involvement of these pathways on NO production. Cytokines and chemokines were analyzed by multianalyte technology. The expression of both subunits of LRP-1 was analyzed by western blot. Results Lipopolysaccharide (LPS induced release of NO by pericytes in a dose-dependent manner that was mediated through MAPK pathways. Nitrative stress resulted in S-nitrosylation of cellular proteins. Eighteen of twenty-three cytokines measured were released constitutively by pericytes or with stimulation by LPS, including interleukin (IL-12, IL-13, IL-9, IL-10, granulocyte-colony stimulating factor, granulocyte macrophage-colony stimulating factor, eotaxin, chemokine (C-C motif ligand (CCL-3, and CCL-4. Pericyte expressions of both subunits of

Sleep quality and duration are related to microvascular function: the Amsterdam Growth and Health Longitudinal Study

NARCIS (Netherlands)

Bonsen, T.; Wijnstok, N.J.; Hoekstra, T.; Eringa, E.C.; Serne, E.H.; Smulders, Y.M.; Twisk, J.W.R.

2015-01-01

Sleep and sleep disorders are related to cardiovascular disease, and microvascular function is an early cardiovascular disease marker. Therefore, the relationship of sleep (measured in sleep quality and duration) with microvascular function was examined in healthy adults. Sleep quality was assessed

Effects of Laparascopic Hernia Repair by PIRS (Percutan Internal Ring Suturing) Technique on Testicular Artery Blood Supply.

Science.gov (United States)

Oral, Akgun; Karaca, Leyla; Ahiskalioglu, Ali; Yildiz, Abdullah; Yigiter, Murat; Celikkaya, Mehmet Emin; Chyndolotov, Temirlan; Salman, Ahmet Bedii

2018-02-02

Percutaneous internal ring suturing technique (PIRS) is a minimally invasive technique in pediatric inguinal hernia repair. In the present study, a negative effect on testicular blood flow using PIRS technique has been investigated. Forty male patients were included in the study prospectively. Two groups were formed as conventional open surgery (Group I) and PIRS technique (Group II). The resistive index (RI) value of the testicular artery was measured prospectively by using SMI (superb micro-vascular imaging) software with the color doppler ultrasound technique preoperatively and postoperatively at the first month. Inguinal hernia was present on the left in 35% (n = 14) of the patients and on the right in 65% (n = 26) of the patients. There was no statistically significant difference (p = 0.727) between Group I and II with regard to preoperative RI value (0.66 ± 0.07 vs. 0.66 ± 0.45, respectively). Similarly, there was no statistically significant difference (p = 0.220) between Group I and II with regard to the RI values measured at the postoperative first month (0.58 ± 0.04 vs. 0.60 ± 0.04, respectively). Although the postoperative RI values decreased compared to the preoperative values in both groups, this difference was not statistically significant. (p = 0.447 in Group I, and p = 0.175 in Group II for intragroup comparison). Besides PIRS technique has the advantages provided by all other laparoscopic techniques defined for inguinal hernia repair, there is no significant difference between this technique and conventional open surgery with regard to testicular blood flow. It is an innovative candidate technique instead of the open surgery method besides its additional advantages.

Uptake of Single-Walled Carbon Nanotubes Conjugated with DNA by Microvascular Endothelial Cells

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Joseph Harvey

2012-01-01

Full Text Available Single-walled carbon nanotubes (SWCNTs have been proposed to have great therapeutic potential. SWCNTs conjugated with drugs or genes travel in the systemic circulation to reach target cells or tissues following extravasation from microvessels although the interaction between SWCNT conjugates and the microvascular endothelial cells (ECs remains unknown. We hypothesized that SWCNT-DNA conjugates would be taken up by microvascular ECs and that this process would be facilitated by SWCNTs compared to facilitation by DNA alone. ECs were treated with various concentrations of SWCNT-DNA-FITC conjugates, and the uptake and intracellular distribution of these conjugates were determined by a confocal microscope imaging system followed by quantitative analysis of fluorescence intensity. The uptake of SWCNT-DNA-FITC conjugates (2 μg/mL by microvascular ECs was significantly greater than that of DNA-FITC (2 μg/mL, observed at 6 hrs after treatment. For the intracellular distribution, SWCNT-DNA-FITC conjugates were detected in the nucleus of ECs, while DNA-FITC was restricted to the cytoplasm. The fluorescence intensity and distribution of SWCNTs were concentration and time independent. The findings demonstrate that SWCNTs facilitate DNA delivery into microvascular ECs, thus suggesting that SWCNTs serving as drug and gene vehicles have therapeutic potential.

Blood wastage management in a regional blood transfusion centre.

Science.gov (United States)

Javadzadeh Shahshahani, H; Taghvai, N

2017-10-01

The aim of this study was to determine the rate of blood component wastage before and after interventions at Yazd Blood Transfusion Center. The growing need for blood components along with blood safety issues and rising costs constantly pressurise blood centres to improve their efficiency. Reducing the quantity of discarded blood at all stages of the supply chain can decrease the total costs. Data on discarded blood components were extracted from the database of Yazd Blood Transfusion Center. Multiple interventions, including implementation of wastage management standard operating procedures and reduction of red blood cells (RBCs) inventory level, were implemented. Discard rates of blood components in the 3 years after intervention (2013-2015) were compared with the discard rates in the 3 years before interventions. The total wastage rate of blood components decreased by almost 60%. Discard rates of RBCs, platelets and plasma decreased from 9·7%, 18·5% and 5·4% to 2·9%, 10·5% and 2·3%, (P supply saving. © 2017 British Blood Transfusion Society.

BLOOD SUBSTITUTES: EVOLUTION FROM NON-CARRYING TO OXYGEN AND GAS CARRYING FLUIDS

Science.gov (United States)

Cabrales, Pedro; Intaglietta, Marcos

2013-01-01

The development of oxygen (O2) carrying blood substitutes has evolved from the goal of replicating blood O2 transports properties to that of preserving microvascular and organ function, reducing the inherent or potential toxicity of the material used to carry O2, and treating pathologies initiated by anemia and hypoxia. Furthermore, the emphasis has shifted from blood replacement fluid to “O2 therapeutics” that restore tissue oxygenation to specific tissues regions. This review covers the different alternatives, potential and limitations of hemoglobin based O2 carriers (HBOCs) and perfluorocarbon based O2 carriers (PFCOCs), with emphasis on the physiological conditions disturbed in the situation that they will be used. It describes how concepts learned from plasma expanders without O2 carrying capacity can be applied to maintain O2 delivery and summarizes the microvascular responses due to HBOCs and PFCOCs. This review also presents alternative applications of HBOCs and PFCOCs namely: 1) How HBOC O2 affinity can be engineered to target O2 delivery to hypoxic tissues; and 2) How the high gas solubility of PFCOCs provides new opportunities for carrying, dissolving and delivering gases with biological activity. It is concluded that current blood substitutes development has amplified their applications horizon by devising therapeutic functions for oxygen carriers requiring limited O2 delivery capacity restoration. Conversely, full, blood-like O2 carrying capacity re-establishment awaits control of O2 carrier toxicity. PMID:23820271

Role of aldose reductase C-106T polymorphism among diabetic Egyptian patients with different microvascular complications

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Nermine Hossam Zakaria

2014-04-01

Full Text Available The aldose reductase pathway proves that elevated blood glucose promotes cellular dysfunction. The polyol pathway converts excess intracellular glucose into alcohols via activity of the aldose reductase. This enzyme catalyzes the conversion of glucose to sorbitol which triggers variety of intracellular changes in the tissues. Among diabetes, activity is drastically increased in association with three main consequences inside the cells. The aim of this study was to detect the association of the C-106 T polymorphism of the aldose reductase gene and its frequency among a sample of 150 Egyptian adults with type 2 diabetic patients having diabetic microvascular. The detection of the aldose reductase C-106 T polymorphism gene was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP. The genotype distribution of the C-106 T polymorphism showed that CC genotype was statistically significantly higher among patients with retinopathy compared to nephropathy. Patients with nephropathy had significant association with the TT genotype when compared with diabetic retinopathy patients. Follow up study after the genotype detection among recently diagnosed diabetic patients in order to give a prophylactic aldose reductase inhibitors; studying the microvascular complications and its relation to the genotype polymorphisms. The study may include multiple gene polymorphisms to make the relation between the gene and the occurrence of these complications more evident.

Classification of hypervascular liver lesions based on hepatic artery and portal vein blood supply coefficients calculated from triphasic CT scans.

Science.gov (United States)

Boas, F Edward; Kamaya, Aya; Do, Bao; Desser, Terry S; Beaulieu, Christopher F; Vasanawala, Shreyas S; Hwang, Gloria L; Sze, Daniel Y

2015-04-01

Perfusion CT of the liver typically involves scanning the liver at least 20 times, resulting in a large radiation dose. We developed and validated a simplified model of tumor blood supply that can be applied to standard triphasic scans and evaluated whether this can be used to distinguish benign and malignant liver lesions. Triphasic CTs of 46 malignant and 32 benign liver lesions were analyzed. For each phase, regions of interest were drawn in the arterially enhancing portion of each lesion, as well as the background liver, aorta, and portal vein. Hepatic artery and portal vein blood supply coefficients for each lesion were then calculated by expressing the enhancement curve of the lesion as a linear combination of the enhancement curves of the aorta and portal vein. Hepatocellular carcinoma (HCC) and hypervascular metastases, on average, both had increased hepatic artery coefficients compared to the background liver. Compared to HCC, benign lesions, on average, had either a greater hepatic artery coefficient (hemangioma) or a greater portal vein coefficient (focal nodular hyperplasia or transient hepatic attenuation difference). Hypervascularity with washout is a key diagnostic criterion for HCC, but it had a sensitivity of 72 % and specificity of 81 % for diagnosing malignancy in our diverse set of liver lesions. The sensitivity for malignancy was increased to 89 % by including enhancing lesions that were hypodense on all phases. The specificity for malignancy was increased to 97 % (p = 0.039) by also examining hepatic artery and portal vein blood supply coefficients, while maintaining a sensitivity of 76 %.

Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

International Nuclear Information System (INIS)

Thai, Cao Tan; Karam, Ibrahim Michel; Nguyen-Thi, Phi Linh; Lefèvre, Frédéric; Hubert, Jacques; Felblinger, Jacques; Eschwège, Pascal

2015-01-01

Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures

Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

Energy Technology Data Exchange (ETDEWEB)

Thai, Cao Tan, E-mail: bstanhatinh@gmail.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Karam, Ibrahim Michel [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); Department of Anatomy, Faculty of Medicine Nancy, 9 Avenue de la Foret de haye BP, 54505 Vandoeuvre Lès Nancy Cedex (France); Nguyen-Thi, Phi Linh [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); INSERM, CIC-EC CIE6, 92 Avenue du Maréchal de Lattre de Tassigny, 54000 Nancy (France); Lefèvre, Frédéric [Department of Radiology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); Hubert, Jacques [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Felblinger, Jacques [IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Eschwège, Pascal [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France)

2015-05-15

Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures.

Brazil nuts intake improves lipid profile, oxidative stress and microvascular function in obese adolescents: a randomized controlled trial

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Koury Josely C

2011-05-01

Full Text Available Abstract Background Obesity is a chronic disease associated to an inflammatory process resulting in oxidative stress that leads to morpho-functional microvascular damage that could be improved by some dietary interventions. In this study, the intake of Brazil nuts (Bertholletia excelsa, composed of bioactive substances like selenium, α- e γ- tocopherol, folate and polyunsaturated fatty acids, have been investigated on antioxidant capacity, lipid and metabolic profiles and nutritive skin microcirculation in obese adolescents. Methods Obese female adolescents (n = 17, 15.4 ± 2.0 years and BMI of 35.6 ± 3.3 kg/m2, were randomized 1:1 in two groups with the diet supplemented either with Brazil nuts [BNG, n = 08, 15-25 g/day (equivalent to 3 to 5 units/day] or placebo [PG (lactose, n = 09, one capsule/day] and followed for 16 weeks. Anthropometry, metabolic-lipid profiles, oxidative stress and morphological (capillary diameters and functional [functional capillary density, red blood cell velocity (RBCV at baseline and peak (RBCVmax and time (TRBCVmax to reach it during post-occlusive reactive hyperemia, after 1 min arterial occlusion] microvascular variables were assessed by nailfold videocapillaroscopy at baseline (T0 and after intervention (T1. Results T0 characteristics were similar between groups. At T1, BNG (intra-group variation had increased selenium levels (p = 0.02, RBCV (p = 0.03 and RBCVmax (p = 0.03 and reduced total (TC (p = 0.02 and LDL-cholesterol (p = 0.02. Compared to PG, Brazil nuts intake reduced TC (p = 0.003, triglycerides (p = 0.05 and LDL-ox (p = 0.02 and increased RBCV (p = 0.03. Conclusion Brazil nuts intake improved the lipid profile and microvascular function in obese adolescents, possibly due to its high level of unsaturated fatty acids and bioactive substances. Trial Registration Clinical Trials.gov NCT00937599

Impact of an endothelial progenitor cell capturing stent on coronary microvascular function: comparison with drug-eluting stents.

Science.gov (United States)

Choi, Woong Gil; Kim, Soo Hyun; Yoon, Hyung Seok; Lee, Eun Joo; Kim, Dong Woon

2015-01-01

Although drug-eluting stents (DESs) effectively reduce restenosis following percutaneous coronary intervention (PCI), they also delay re-endothelialization and impair microvascular function, resulting in adverse clinical outcomes. Endothelial progenitor cell (EPC) capturing stents, by providing a functional endothelial layer on the stent, have beneficial effects on microvascular function. However, data on coronary microvascular function in patients with EPC stents versus DESs are lacking. Seventy-four patients who previously underwent PCI were enrolled in this study. Microvascular function was evaluated 6 months after PCI based on the index of microvascular resistance (IMR) and the coronary flow reserve (CFR). IMR was calculated as the ratio of the mean distal coronary pressure at maximal hyperemia to the inverse of the hyperemic mean transit time (hTmn). The CFR was calculated by dividing the hTmn by the baseline mean transit time. Twenty-one patients (age, 67.2 ± 9.6 years; male:female, 15:6) with an EPC stent and 53 patients (age, 61.5 ± 14.7 years; male:female, 40:13) with second-generation DESs were included in the study. There were no significant differences in the baseline clinical and angiographic characteristics of the two groups. Angiography performed 6 months postoperatively did not show significant differences in their CFR values. However, patients with the EPC stent had a significantly lower IMR than patients with second-generation DESs (median, 25.5 [interquartile range, 12.85 to 28.18] vs. 29.0 [interquartile range, 15.42 to 39.23]; p = 0.043). Microvascular dysfunction was significantly improved after 6 months in patients with EPC stents compared to those with DESs. The complete re-endothelialization achieved with the EPC stent may provide clinical benefits over DESs, especially in patients with microvascular dysfunction.

Conflicting interactions of apolipoprotein A and high density lipoprotein cholesterol with microvascular complications of type 2 diabetes.

Science.gov (United States)

Aryan, Zahra; Afarideh, Mohsen; Ghajar, Alireza; Esteghamati, Sadaf; Esteghamati, Alireza; Nakhjavani, Manouchehr

2017-11-01

This study is amid at investigating the associations, and interactions of serum lipid biomarkers with microvascular complications of type 2 diabetes (T2D). A nested case-control study was conducted within an ongoing prospective study on patients with T2D. Microvascular complications of T2D including diabetic neuropathy, diabetic retinopathy and diabetic nephropathy were investigated. A total of 444 cases with at least one of the microvascular complications of T2D and 439 age- and gender-matched controls free of any of the chronic microvascular complications of T2D were included. The associations and interactions of a panel of serum lipid biomarkers with the microvascular complications of T2D were investigated. Serum triglyceride had the strongest association with microvascular complications of T2D (crude model: β=0.632, P value=0.045). Each standard deviation increment in serum TG was associated with 3.7 times increased frequency of microvascular complications. Despite high density lipoprotein cholesterol (HDL-C), serum apolipoprotein A1 (Apo A1) was positively associated with the presence of diabetic neuropathy. Each standard deviation increment in serum ApoA1 was associated with increased frequency of diabetic neuropathy (OR, 1.2, 95% CI, (1.1-1.3), P value=0.006). The frequency of diabetic neuropathy was higher in 2nd and 3rd quartiles of serum Lp(a) compared to diabetic patients in the first quartile (OR, 5.52, 95% (1.17-25.8), P value=0.047). ApoA1 but not HDL-C is straightly associated with diabetic neuropathy. Even Slight rise in serum Lp(a) is associated with increased frequency of diabetic retinopathLipid variables could serve as specific predictors of vascular complications in diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Thrombus Composition and Viscosity on Sonoreperfusion Efficacy in a Model of Micro-Vascular Obstruction.

Science.gov (United States)

Black, John J; Yu, Francois T H; Schnatz, Rick G; Chen, Xucai; Villanueva, Flordeliza S; Pacella, John J

2016-09-01

Distal embolization of micro-thrombi during stenting for myocardial infarction causes micro-vascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasound (US) therapy, resolves MVO from venous micro-thrombi in vitro in saline. However, blood is more viscous than saline, and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial micro-thrombi are more resistant to SRP therapy compared with venous micro-thrombi, and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MBs suspended in plasma with adjusted viscosity (1.1 cP or 4.0 cP) were passed through tubing bearing a mesh with 40-μm pores to simulate a micro-vascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous micro-thrombi to increase upstream pressure to 40 mmHg ± 5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector. MVO caused by arterial micro-thrombi at either blood or plasma viscosity resulted in less effective SRP therapy compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. The passive cavitation detector showed a decrease in inertial cavitation when viscosity was increased, while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy; increased viscosity decreases SRP efficacy; and both inertial and stable cavitation are implicated in observed SRP efficacy. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Blood banks meet the paradox of Gabriel's Horn: what are the options to maintain supply as demand decreases?

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Beckman, N; Yazer, M; Land, K; Chesneau, S; Caulfield, J

2016-06-01

Blood services worldwide have observed a decline in the demand for red blood cells (RBC). Despite this general decline, the demand profile has changed significantly with the demand for O D negative RBCs being maintained; whereas B D positive and AB D positive RBC demand has been reduced. In 2015, the blood type O D negative was seen in 6·3% of the combined first time donors among the five American Blood Centres involved in this study and 7·4% of first time Australian donors in 2014/2015, whereas O D negative distributions accounted for 10·5% of all red cell units issued by the American centres and 13·9% by the Australian centres. Inventory can therefore be of sufficient overall quantity but may not be adequate for the demand for units with specific blood types. Recruitment of new donors may need to become more targeted and/or financial or inventory control measures could also be required to ensure inventory matches demand. Blood Services will need to consider the available options in order to ensure that sufficiency of supply is secure and the donor panel is optimised to meet the new demand paradigm. © 2016 British Blood Transfusion Society.

Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity

Science.gov (United States)

Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W.; Barrett, Eugene J.; Cao, Wenhong

2015-01-01

Endothelial dysfunction and vascular insulin resistance usually coexist and chronic inflammation engenders both. In the present study, we investigate the temporal relationship between vascular insulin resistance and metabolic insulin resistance. We assessed insulin responses in all arterial segments, including aorta, distal saphenous artery and the microvasculature, as well as the metabolic insulin responses in muscle in rats fed on a high-fat diet (HFD) for various durations ranging from 3 days to 4 weeks with or without sodium salicylate treatment. Compared with controls, HFD feeding significantly blunted insulin-mediated Akt (protein kinase B) and eNOS [endothelial nitric oxide (NO) synthase] phosphorylation in aorta in 1 week, blunted vasodilatory response in small resistance vessel in 4 weeks and microvascular recruitment in as early as 3 days. Insulin-stimulated whole body glucose disposal did not begin to progressively decrease until after 1 week. Salicylate treatment fully inhibited vascular inflammation, prevented microvascular insulin resistance and significantly improved muscle metabolic responses to insulin. We conclude that microvascular insulin resistance is an early event in diet-induced obesity and insulin resistance and inflammation plays an essential role in this process. Our data suggest microvascular insulin resistance contributes to the development of metabolic insulin resistance in muscle and muscle microvasculature is a potential therapeutic target in the prevention and treatment of diabetes and its related complications. PMID:26265791

Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques

NARCIS (Netherlands)

Calcagno, Claudia; Lobatto, Mark E.; Dyvorne, Hadrien; Robson, Philip M.; Millon, Antoine; Senders, Max L.; Lairez, Olivier; Ramachandran, Sarayu; Coolen, Bram F.; Black, Alexandra; Mulder, Willem J. M.; Fayad, Zahi A.

2015-01-01

Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI

Microvascular anastomosis simulation using a chicken thigh model: Interval versus massed training.

Science.gov (United States)

Schoeff, Stephen; Hernandez, Brian; Robinson, Derek J; Jameson, Mark J; Shonka, David C

2017-11-01

To compare the effectiveness of massed versus interval training when teaching otolaryngology residents microvascular suturing on a validated microsurgical model. Otolaryngology residents were placed into interval (n = 7) or massed (n = 7) training groups. The interval group performed three separate 30-minute practice sessions separated by at least 1 week, and the massed group performed a single 90-minute practice session. Both groups viewed a video demonstration and recorded a pretest prior to the first training session. A post-test was administered following the last practice session. At an academic medical center, 14 otolaryngology residents were assigned using stratified randomization to interval or massed training. Blinded evaluators graded performance using a validated microvascular Objective Structured Assessment of Technical Skill tool. The tool is comprised of two major components: task-specific score (TSS) and global rating scale (GRS). Participants also received pre- and poststudy surveys to compare subjective confidence in multiple aspects of microvascular skill acquisition. Overall, all residents showed increased TSS and GRS on post- versus pretest. After completion of training, the interval group had a statistically significant increase in both TSS and GRS, whereas the massed group's increase was not significant. Residents in both groups reported significantly increased levels of confidence after completion of the study. Self-directed learning using a chicken thigh artery model may benefit microsurgical skills, competence, and confidence for resident surgeons. Interval training results in significant improvement in early development of microvascular anastomosis skills, whereas massed training does not. NA. Laryngoscope, 127:2490-2494, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

VEGF expression and microvascular density in relation to high-risk ...

African Journals Online (AJOL)

Bassma M. El Sabaa

2012-01-13

Jan 13, 2012 ... Eleven cases were low grade and 19 were high-grade cases. VEGF expression .... increasing microvascular permeability,26 degradation of extra- ...... soluble receptors in pre-invasive, invasive and recurrent cervical cancer.

Microvascular resistance of the culprit coronary artery in acute ST-elevation myocardial infarction

Science.gov (United States)

Carrick, David; Haig, Caroline; Carberry, Jaclyn; McCartney, Peter; Welsh, Paul; Ahmed, Nadeem; McEntegart, Margaret; Petrie, Mark C.; Eteiba, Hany; Lindsay, Mitchell; Hood, Stuart; Watkins, Stuart; Rauhalammi, Samuli M.O.; Mordi, Ify; Ford, Ian; Radjenovic, Aleksandra; Sattar, Naveed; Oldroyd, Keith G.

2016-01-01

BACKGROUND. Failed myocardial reperfusion is common and prognostically important after acute ST-elevation myocardial infarction (STEMI). The purpose of this study was to investigate coronary flow reserve (CFR), a measure of vasodilator capacity, and the index of microvascular resistance (IMR; mmHg × s) in the culprit artery of STEMI survivors. METHODS. IMR (n = 288) and CFR (n = 283; mean age [SD], 60 [12] years) were measured acutely using guide wire–based thermodilution. Cardiac MRI disclosed left ventricular pathology, function, and volumes at 2 days (n = 281) and 6 months after STEMI (n = 264). All-cause death or first heart failure hospitalization was independently adjudicated (median follow-up 845 days). RESULTS. Myocardial hemorrhage and microvascular obstruction occurred in 89 (42%) and 114 (54%) patients with evaluable T2*-MRI maps. IMR and CFR were associated with microvascular pathology (none vs. microvascular obstruction only vs. microvascular obstruction and myocardial hemorrhage) (median [interquartile range], IMR: 17 [12.0–33.0] vs. 17 [13.0–39.0] vs. 37 [21.0–63.0], P < 0.001; CFR: 1.7 [1.4–2.5] vs. 1.5 [1.1–1.8] vs. 1.4 [1.0–1.8], P < 0.001), whereas thrombolysis in myocardial infarction blush grade was not. IMR was a multivariable associate of changes in left ventricular end-diastolic volume (regression coefficient [95% CI] 0.13 [0.01, 0.24]; P = 0.036), whereas CFR was not (P = 0.160). IMR (5 units) was a multivariable associate of all-cause death or heart failure hospitalization (n = 30 events; hazard ratio [95% CI], 1.09 [1.04, 1.14]; P < 0.001), whereas CFR (P = 0.124) and thrombolysis in myocardial infarction blush grade (P = 0.613) were not. IMR had similar prognostic value for these outcomes as <50% ST-segment resolution on the ECG. CONCLUSIONS. IMR is more closely associated with microvascular pathology, left ventricular remodeling, and health outcomes than the angiogram or CFR. TRIAL REGISTRATION. NCT02072850. FUNDING. A

Obesity is associated with lower coronary microvascular density.

Directory of Open Access Journals (Sweden)

Duncan J Campbell

Full Text Available BACKGROUND: Obesity is associated with diastolic dysfunction, lower maximal myocardial blood flow, impaired myocardial metabolism and increased risk of heart failure. We examined the association between obesity, left ventricular filling pressure and myocardial structure. METHODS: We performed histological analysis of non-ischemic myocardium from 57 patients (46 men and 11 women undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation or loop diuretic therapy. RESULTS: Non-obese (body mass index, BMI, ≤ 30 kg/m(2, n=33 and obese patients (BMI >30 kg/m(2, n=24 did not differ with respect to myocardial total, interstitial or perivascular fibrosis, arteriolar dimensions, or cardiomyocyte width. Obese patients had lower capillary length density (1145 ± 239, mean ± SD, vs. 1371 ± 333 mm/mm(3, P=0.007 and higher diffusion radius (16.9 ± 1.5 vs. 15.6 ± 2.0 μm, P=0.012, in comparison with non-obese patients. However, the diffusion radius/cardiomyocyte width ratio of obese patients (0.73 ± 0.11 μm/μm was not significantly different from that of non-obese patients (0.71 ± 0.11 μm/μm, suggesting that differences in cardiomyocyte width explained in part the differences in capillary length density and diffusion radius between non-obese and obese patients. Increased BMI was associated with increased pulmonary capillary wedge pressure (PCWP, P<0.0001, and lower capillary length density was associated with both increased BMI (P=0.043 and increased PCWP (P=0.016. CONCLUSIONS: Obesity and its accompanying increase in left ventricular filling pressure were associated with lower coronary microvascular density, which may contribute to the lower maximal myocardial blood flow, impaired myocardial metabolism, diastolic dysfunction and higher risk of heart failure in obese individuals.

Muscle Oxygen Supply Impairment during Exercise in Poorly Controlled Type 1 Diabetes

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TAGOUGUI, SEMAH; LECLAIR, ERWAN; FONTAINE, PIERRE; MATRAN, RÉGIS; MARAIS, GAELLE; AUCOUTURIER, JULIEN; DESCATOIRE, AURÉLIEN; VAMBERGUE, ANNE; OUSSAIDENE, KAHINA; BAQUET, GEORGES; HEYMAN, ELSA

2015-01-01

ABSTRACT Purpose Aerobic fitness, as reflected by maximal oxygen (O2) uptake (V˙O2max), is impaired in poorly controlled patients with type 1 diabetes. The mechanisms underlying this impairment remain to be explored. This study sought to investigate whether type 1 diabetes and high levels of glycated hemoglobin (HbA1c) influence O2 supply including O2 delivery and release to active muscles during maximal exercise. Methods Two groups of patients with uncomplicated type 1 diabetes (T1D-A, n = 11, with adequate glycemic control, HbA1c 8%) were compared with healthy controls (CON-A, n = 11; CON-I, n = 12, respectively) matched for physical activity and body composition. Subjects performed exhaustive incremental exercise to determine V˙O2max. Throughout the exercise, near-infrared spectroscopy allowed investigation of changes in oxyhemoglobin, deoxyhemoglobin, and total hemoglobin in the vastus lateralis. Venous and arterialized capillary blood was sampled during exercise to assess arterial O2 transport and factors able to shift the oxyhemoglobin dissociation curve. Results Arterial O2 content was comparable between groups. However, changes in total hemoglobin (i.e., muscle blood volume) was significantly lower in T1D-I compared with that in CON-I. T1D-I also had impaired changes in deoxyhemoglobin levels and increase during high-intensity exercise despite normal erythrocyte 2,3-diphosphoglycerate levels. Finally, V˙O2max was lower in T1D-I compared with that in CON-I. No differences were observed between T1D-A and CON-A. Conclusions Poorly controlled patients displayed lower V˙O2max and blunted muscle deoxyhemoglobin increase. The latter supports the hypotheses of increase in O2 affinity induced by hemoglobin glycation and/or of a disturbed balance between nutritive and nonnutritive muscle blood flow. Furthermore, reduced exercise muscle blood volume in poorly controlled patients may warn clinicians of microvascular dysfunction occurring even before overt

Globular adiponectin ameliorates metabolic insulin resistance via AMPK-mediated restoration of microvascular insulin responses

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Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W; Barrett, Eugene J; Cao, Wenhong; Liu, Zhenqi

2015-01-01

Abstract Hypoadiponectinaemia is closely associated with endothelial dysfunction and insulin resistance, and microvasculature plays a critical role in the regulation of insulin action in muscle. Here we tested whether adiponectin replenishment could improve metabolic insulin sensitivity in male rats fed a high-fat diet (HFD) via the modulation of microvascular insulin responses. Male Sprague–Dawley rats were fed either a HFD or low-fat diet (LFD) for 4 weeks. Small resistance artery myograph changes in tension, muscle microvascular recruitment and metabolic response to insulin were determined. Compared with rats fed a LFD, HFD feeding abolished the vasodilatory actions of globular adiponectin (gAd) and insulin on pre-constricted distal saphenous arteries. Pretreatment with gAd improved insulin responses in arterioles isolated from HFD rats, which was blocked by AMP-activated protein kinase (AMPK) inhibition. Similarly, HFD abolished microvascular responses to either gAd or insulin and decreased insulin-stimulated glucose disposal by ∼60%. However, supplementing gAd fully rescued insulin’s microvascular action and significantly improved the metabolic responses to insulin in HFD male rats and these actions were abolished by inhibition of either AMPK or nitric oxide production. We conclude that HFD induces vascular adiponectin and insulin resistance but gAd administration can restore vascular insulin responses and improve insulin’s metabolic action via an AMPK- and nitric oxide-dependent mechanism in male rats. Key points Adiponectin is an adipokine with anti-inflammatory and anti-diabetic properties. Hypoadiponectinaemia is closely associated with endothelial dysfunction and insulin resistance in obesity and diabetes. Insulin resistance is present in muscle microvasculature and this may contribute to decreased insulin delivery to, and action in, muscle. In this study we examined whether adiponectin ameliorates metabolic insulin resistance by affecting muscle

Microvascular inflammation in atherosclerosis

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Laura Vitiello

2014-06-01

Full Text Available Atherogenesis is the pathogenetic process leading to formation of the atheroma lesion. It is associated to a chronic inflammatory state initially stimulated by an aberrant accumulation of lipid molecules beyond the endothelial barrier. This event triggers a cascade of deleterious events mainly through immune cell stimulation with the consequent liberation of potent pro-inflammatory and tissue damaging mediators. The atherogenetic process implies marked modifications of endothelial cell functions and a radical change in the endothelial–leukocyte interaction pattern. Moreover, accumulating evidence shows an important link between microvascular and inflammatory responses and major cardiovascular risk factors. This review illustrates the current knowledge on the effects of obesity, hypercholesterolemia and diabetes on microcirculation; their pathophysiological implications will be discussed.

Analysis of microvascular perfusion with multi-dimensional complete ensemble empirical mode decomposition with adaptive noise algorithm: Processing of laser speckle contrast images recorded in healthy subjects, at rest and during acetylcholine stimulation.

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Humeau-Heurtier, Anne; Marche, Pauline; Dubois, Severine; Mahe, Guillaume

2015-01-01

Laser speckle contrast imaging (LSCI) is a full-field imaging modality to monitor microvascular blood flow. It is able to give images with high temporal and spatial resolutions. However, when the skin is studied, the interpretation of the bidimensional data may be difficult. This is why an averaging of the perfusion values in regions of interest is often performed and the result is followed in time, reducing the data to monodimensional time series. In order to avoid such a procedure (that leads to a loss of the spatial resolution), we propose to extract patterns from LSCI data and to compare these patterns for two physiological states in healthy subjects: at rest and at the peak of acetylcholine-induced perfusion peak. For this purpose, the recent multi-dimensional complete ensemble empirical mode decomposition with adaptive noise (MCEEMDAN) algorithm is applied to LSCI data. The results show that the intrinsic mode functions and residue given by MCEEMDAN show different patterns for the two physiological states. The images, as bidimensional data, can therefore be processed to reveal microvascular perfusion patterns, hidden in the images themselves. This work is therefore a feasibility study before analyzing data in patients with microvascular dysfunctions.

Short-term poor glycemic control and retinal microvascular changes in pediatric Type 1 Diabetes patients in Singapore: a pilot study.

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Li, Ling-Jun; Lamoureux, Ecosse; Wong, Tien Yin; Lek, Ngee

2017-06-15

Poor glycemic control in Type 1 Diabetes (T1D) patients is strongly associated with an increased risk of diabetes-related microvascular complications later in life, but it is unclear whether short period of poor glycemic control in children with T1D can cause evident microvascular morphological changes long before any pathological manifestation. Our study aimed to investigate the longitudinal association between poor glycemic control and subsequent changes in retinal microvasculature, in a pilot study of 55 pediatric T1D patients from Singapore after a one-year follow-up. This is a hospital-based, exposure-matched and retrospective longitudinal study. A total of 55 T1D patients were included from Singapore KK Women's and Children Hospital, 28 of whom had poor glycemic control (average glycated hemoglobin [HbA1c] ≥8% during the year) while the other 27 age- and gender-matched subjects had good glycemic control (HbA1c Singapore I Vessel Assessment [SIVA], version 4.0, Singapore Eye Research Institute, Singapore) and a spectrum of retinal vascular parameters (e.g. caliber, tortuosity, branching angle and fractal dimension) were measured quantitatively from 0.5 to 2.0 disc diameters. There was no significant difference in ethnicity, duration of T1D, blood pressure, body mass index (BMI) and low-density cholesterol lipoprotein (LDL) between the two groups. Retinal imaging was obtained at the end of 1 year of glycemic control assessment. In multiple linear regression adjusting for ethnicity, BMI, LDL and duration of T1D, patients with poor glycemic control tended to have marginally wider retinal arteriolar caliber (6.0 μm, 95% CI: -0.9, 12.8) and had significantly larger retinal arteriolar branching angle (10.1 degrees, 95% CI: 1.4, 18.9) compared with their age- and gender- matched counterparts with good glycemic control. Our findings showed that abnormal retinal microvascular morphology was evident in pediatric patients with T1D after one-year's poor glycemic

The influence of blood supply pattern of hepatic metastases on the short-term effect of TACE

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Li Guowen; Liang Zhaoyu; Yu Xiaoping; Gu Shanzhi; Zhang Tiegang; He Qing; Xiong Zhengping; Huang Manping

2010-01-01

Objective: To discuss the influence of blood supply pattern of hepatic metastases on the short-term effect of transcatheter arterial chemoembolization (TACE). Methods: A total of 58 cases of liver metastases who had been treated with TACE were selected, the clinical data and short-term effects were retrospectively analyzed. Results: Based on the DSA findings, 58 cases of liver metastases were divided into the hypervascular pattern (n=14), the isovascular pattern (n=12) and the hypovascular pattern group (n=32). After TACE the clinical effective rate (CR + PR) of hypervascular, isovascular and hypo vascular pattern group was 92.9% (13 /14), 83.3% (10/12) and 9.4% (3/32) respectively, with a significant difference existing between hyper vascular and hypo vascular group as well as between iso vascular and hypo vascular group (P 0.05). The survival rate at half and one year after Tace treatment for all cases was 67.2% and 42.3%, respectively. The survival rate at half and one year for hyper vascular, iso vascular and hypo vascular group was 100% and 78.6%, 100% and 58.3%, 40.6% and 7.6%, respectively. A significant difference in the survival rate existed between hypervascular and hypovascular group as well as between isovascular and hypovascular group (P 0.05). Conclusion: TACE shows much better effectiveness for the hypervascular hepatic metastases, and it is very useful for making an appropriate therapeutic plan to distinguish the blood supply pattern of hepatic metastases. (authors)

[Macrovascular and microvascular complications in type 2 diabetes patients].

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Rosolová, H; Petrlová, B; Simon, J; Sifalda, P; Sípová, I; Sefrna, F

2008-03-01

The prevalence of chronic vascular complications is higher in patients with type 2 diabetes mellitus (DM2). The objective of our cross-sectional study was to assess the incidence and types of macrovascular (MVC) and microvascular (mvc) complications and to analyse their relation to the different risk factors and biomarkers in order to improve their prevention. 415 patients (219 men and 196 women) with an average age of 66 +/- 9 years enrolled in the study. A total of 95% of patients with DM2 had a history of hypertension, 27% had MVC (of which 55% had ischaemic heart disease), and 54% had mvc (ofwhich 95% had diabetic nephropathy). The patients with vascular complications were significantly older and had a longer history of DM2; they did not differ for their systolic blood pressure, but had a higher pulse pressure and took more antihypertensives. They did not differ for their lipid levels or the respective therapy. Diabetic patients with MVC and mvc had higher insulin resistance, higher plasmatic levels of total homocysteine and a higher incidence ofalbuminuria or proteinuria. The factors which significantly and independently associated with MVC were male gender, age over 60 years, higher hs-C-reactive protein (hs-CRP) exceeding 1 mg/l, glycaemia over 5.6 mmol/l, lower diastolic blood pressure and lower HDL-cholesterol; mvc associated with higher age over 60 years, a history of DM2 exceeding 8 years, and hs-CRP above 1 mg/l. Our results show that patients with DM2 have a high incidence ofvascular complications significantly associated with age, DM2 history and higher hs-CRP, irrespective of the other monitored parametres.

Developing Quality Control Procedures to Sustain a Supply of High Quality Blood for Mass Rearing Tsetse Flies

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De Beer, C J; Venter, G J; Potgieter, F T [ARC-Onderstepoort Veterinary Institute, Old Soutpans Road, Private Bag X05, 0110 Onderstepoort (South Africa)

2012-07-15

Mass rearing tsetse flies Glossina spp. is dependent on the sustained availability of a high quality blood diet. In any mass rearing facility, the logistics for obtaining sterile, high quality fresh blood is challenging. An added complication is the influence of potential chemical, physical and microbiological elements present in the blood of donors, as well as contamination during collection, handling and storage. Research at the Agricultural Research Council - Onderstepoort Veterinary institute (ARC-OVI) is directed towards the development of quality control procedures for the supply of the in vitro diet used to maintain productive colonies of Glossina brevipalpis Newstead and Glossina austeni Newstead. Factors that may influence the blood diet, e.g. defibrination, feeding times, collection of blood in anticoagulants, treatment of blood with taste stimuli, repeated freezing and thawing of blood, effect of bovine growth hormones, and also a preference for bovine or porcine blood were tested. A 25 day bioassay was used to determine the effects of these factors on tsetse survival and reproduction. Defibrination of the blood for 10 to 15 minutes gave the best results for both species. It was found that G. brevipalpis should be fed three times per week for 5 minutes each time, and G. austeni three times per week for 10 minutes. Heparin, acid citrate dextrose (ACD), citric acid, citrate phosphate dextrose adenine (CPDA) and a combination of sodium citrate and citric acid were effective anticoagulants in the blood diets of G. brevipalpis and G. austeni. Blood treated with inosine triphosphate (ITP) gave the highest quality factor (QFC) values for both G. austeni and G. brevipalpis. Repeated freezing and thawing of blood definitely affects pupal production negatively; G. brevipalpis especially produced significantly smaller pupae. A premixed diet of equal amounts of bovine and porcine blood was found to be best suited for G. brevipalpis, and for G. austeni a mixture of

Tumor necrosis factor-alpha increases myocardial microvascular transport in vivo

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Hansen, P R; Svendsen, Jesper Hastrup; Høyer, S

1994-01-01

Tumor necrosis factor-alpha (TNF-alpha) is a primary mediator in the pathogenesis of tissue injury, and high circulating levels of TNF-alpha are found in a variety of pathological conditions. In open-chest anesthetized dogs, the effects of intracoronary recombinant human TNF-alpha (rTNF-alpha; 100...... in cardiac output and was associated with the appearance of areas with myocardial necrosis in the regional left ventricular wall. The myocardial plasma flow rate and maximum plasma flow rate in response to a 30-s coronary occlusion were not influenced by rTNF-alpha, although a decrease in the myocardial...... ng/kg for 60 min) on myocardial microvascular transport of a small hydrophilic indicator was examined by the single-injection, residue-detection method. Intracoronary infusion of rTNF-alpha increased myocardial microvascular transport after 120 min. This increase was preceded by a sustained decline...

CORRELATION OF VOLUME BLOOD CIRCULATION IN THE HEPATIC ARTERY AND THE STATE OF MICROCIRCULATORY BLOODSTREAM OF THE TRANSPLANTED LIVER AFTER ITS REVASCULIZATION

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D. A. Granov

2014-01-01

Full Text Available Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30 comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30 had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC in the hepatic artery (HA was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01.Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.

Modeling of pulsatile flow-dependent nitric oxide regulation in a realistic microvascular network.

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Wang, Ruofan; Pan, Qing; Kuebler, Wolfgang M; Li, John K-J; Pries, Axel R; Ning, Gangmin

2017-09-01

Hemodynamic pulsatility has been reported to regulate microcirculatory function. To quantitatively assess the impact of flow pulsatility on the microvasculature, a mathematical model was first developed to simulate the regulation of NO production by pulsatile flow in the microcirculation. Shear stress and pressure pulsatility were selected as regulators of endothelial NO production and NO-dependent vessel dilation as feedback to control microvascular hemodynamics. The model was then applied to a real microvascular network of the rat mesentery consisting of 546 microvessels. As compared to steady flow conditions, pulsatile flow increased the average NO concentration in arterioles from 256.8±93.1nM to 274.8±101.1nM (Pflow as compared to steady flow conditions. Network perfusion and flow heterogeneity were improved under pulsatile flow conditions, and vasodilation within the network was more sensitive to heart rate changes than pulse pressure amplitude. The proposed model simulates the role of flow pulsatility in the regulation of a complex microvascular network in terms of NO concentration and hemodynamics under varied physiological conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct emergence of the dorsospinal artery from the aorta and spinal cord blood supply. Case reports and literature review

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Siclari, Francesca; Fasel, Jean H.D.; Gailloud, Philippe

2006-01-01

Direct emergence of a dorsospinal artery from the aorta is a rare anatomic variant, of which a total of seven cases have been reported. This report offers an additional angiographic observation and reviews the literature. Two observations of common intercostal trunks documented during spinal angiography are described. In the first observation, the common intercostal trunk provided complete blood supply to two adjacent vertebral levels (T11 and T12). In other words, the trunk included an intercostal branch and a dorsospinal branch for each level. In the second observation, the common intercostal trunk provided an intercostal branch for each level (T9 and T10), but only one dorsospinal branch (T10). An isolated dorsospinal artery (DA) originated separately from the aorta at the T9 level, and provided a significant contribution to the anterior spinal axis. The two reported cases illustrate the concept of ''complete'' versus ''incomplete'' common intercostal trunks. In instances where an incomplete trunk is documented, a separate DA originating directly from the aorta must be looked for. A review of the literature indicates a tendency for isolated DAs to participate in the blood supply to the spinal cord. (orig.)

Barotrauma and microvascular injury in lungs of nonadult rabbits: effect of ventilation pattern.

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Peevy, K J; Hernandez, L A; Moise, A A; Parker, J C

1990-06-01

To study the pulmonary microvascular injury produced by ventilation barotrauma, the isolated perfused lungs of 4 to 6-wk-old New Zealand white rabbits were ventilated by one of the following methods: peak inspiratory pressure (PIP) 23 cm H2O, gas flow rate 1.1 L/min (group 1); PIP 27 cm H2O, gas flow rate 6.9 L/min (group 2); PIP 50 cm H2O, gas flow rate 1.9 L/min (group 3); or PIP 53 cm H2O, gas flow rate 8.3 L/min (group 4). Microvascular permeability was assessed using the capillary filtration coefficient (Kfc) before and 5, 30, and 60 min after a 15-min period of ventilation. Baseline Kfc was not significantly different between groups. A significant increase over the baseline Kfc was noted at 60 min in group 2 and in all postventilation Kfc values in groups 3 and 4 (p less than .05). Group 1 Kfc values did not change significantly after ventilation. At all post-ventilation times, values for Kfc were significantly greater in groups 3 and 4 than in group 1 (p less than .05). Group 4 Kfc values were significantly greater than those in group 2 at 5 and 30 min postventilation. These data indicate that high PIP, and to a lesser extent, high gas flow rates cause microvascular injury in the compliant nonadult lung and suggest that the combination of high PIP and high gas flow rates are the most threatening to microvascular integrity.

Distribution of Vascular Patterns in Different Subtypes of Renal Cell Carcinoma. A Morphometric Study in Two Distinct Types of Blood Vessels.

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Ruiz-Saurí, Amparo; García-Bustos, V; Granero, E; Cuesta, S; Sales, M A; Marcos, V; Llombart-Bosch, A

2017-07-01

To analyze the presence of mature and immature vessels as a prognostic factor in patients with renal cell carcinoma and propose a classification of renal cancer tumor blood vessels according to morphometric parameters. Tissue samples were obtained from 121 renal cell carcinoma patients who underwent radical nephrectomy. Staining with CD31 and CD34 was used to differentiate between immature (CD31+) and mature (CD34+) blood vessels. We quantified the microvascular density, microvascular area and different morphometric parameters: maximum diameter, minimum diameter, major axis, minor axis, perimeter, radius ratio and roundness. We found that the microvascular density was higher in CD31+ than CD34+ vessels, but CD34+ vessels were larger than CD31+ vessels, as well as being strongly correlated with the ISUP tumor grade. We also identified four vascular patterns: pseudoacinar, fascicular, reticular and diffuse. Pseudoacinar and fascicular patterns were more frequent in clear cell renal cell carcinoma (37.62 and 35.64% respectively), followed by reticular pattern (21.78%), while in chromophobe tumors the reticular pattern predominated (90%). The isolated pattern was present in all papillary tumors (100%). In healthy renal tissue, the pseudoacinar and isolated patterns were differentially found in the renal cortex and medulla respectively. We defined four distinct vascular patterns significantly related with the ISUP tumor grade in renal cell carcinomas. Further studies in larger series are needed in order to validate these results. Analysis of both mature and immature vessels (CD34+ and CD31+) provides additional information when evaluating microvascular density.

The artery blood supply variant of the upper limb

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MASLARSKI, IVAN

2015-01-01

Variations of arterial patterns in the upper limb have represented the most common subject of vascular anatomy. Different types of artery branching pattern of the upper limb are very important for orthopedists in angiographic and microvascular surgical practice. The brachial artery (BA) is the most important vessel in the normal vascular anatomy of the upper limb. The classical pattern of the palmar hand region distribution shows the superficial palmar arch. Normally this arch is formed by the superficial branch of the ulnar artery and completed on the lateral side by one of these arteries: the superficial palmar branch of the radial artery, the princeps pollicis artery, the superficial palmar branch of the radial artery or the median artery. After the routine dissection of the right upper limb of an adult male cadaver, we found a very rare variant of the superficial arch artery – a division in a higher level brachial artery. We found this division at 10.4 cm from the beginning of the brachial artery. This superficial brachial artery became a radial artery and was not involved in the formation of the palm arch. In the forearm region, the artery variant was present with the median artery and the ulnar artery, which form the superficial palm arch. PMID:26733754

Hepatocellular carcinomas supplied by inferior phrenic arteries.

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Tanabe, N; Iwasaki, T; Chida, N; Suzuki, S; Akahane, T; Kobayashi, N; Ishii, M; Toyota, T

1998-07-01

To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). A total of 126 consecutive cases of HCC were studied by contract-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 1, 1, and 4. HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography.

Hepatocellular carcinomas supplied by inferior phrenic arteries

International Nuclear Information System (INIS)

Tanabe, N.; Iwasaki, T.; Akahane, T.; Kobayashi, N.; Ishii, M.; Toyota, T.; Chida, N.; Suzuki, S.

1998-01-01

Purpose: To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). Material and Methods: A total of 126 consecutive cases of HCC were studied by contrast-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. Results: In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 7, 1, and 4. Conclusion: HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography. (orig.)

Hepatocellular carcinomas supplied by inferior phrenic arteries

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Tanabe, N.; Iwasaki, T.; Akahane, T.; Kobayashi, N.; Ishii, M.; Toyota, T. [Tohoku Univ. School of Medicine (Japan). Third Dept. of Internal Medicine; Chida, N.; Suzuki, S. [National Sendai Hospital (Japan). Dept. of Gastroenterology

1998-07-01

Purpose: To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). Material and Methods: A total of 126 consecutive cases of HCC were studied by contrast-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. Results: In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 7, 1, and 4. Conclusion: HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography. (orig.)

Longitudinal study of microvascular involvement by nailfold capillaroscopy in children with Henoch-Schönlein purpura.

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Zampetti, Anna; Rigante, Donato; Bersani, Giulia; Rendeli, Claudia; Feliciani, Claudio; Stabile, Achille

2009-09-01

The aim of this study is to describe by video-nailfold capillaroscopy the microvascular involvement and capillary changes in children with Henoch-Schönlein purpura (HSp) and to establish a possible correlation with clinical outcome. Thirty-one patients underwent capillaroscopic evaluation through a videomicroscope during the acute phase and after 6 months. Twenty sex/age-matched controls were also examined. All capillaroscopic variables were statistically examined in combination with laboratoristic/clinical data. Architectural and morphological changes recorded during the acute phase were statistically significant in comparison to the controls (p capillaroscopy changes, laboratoristic/clinical data, and outcome. Video-nailfold capillaroscopy can be a simple tool to evaluate microvascular abnormalities in the acute phase of HSp, and the persistence of oedema could suggest an incomplete disease resolution at a microvascular level.

Improved myocardial perfusion after transmyocardial laser revascularization in a patient with microvascular coronary artery disease

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Peyman Mesbah Oskui

2014-03-01

Full Text Available We report the case of a 59-year-old woman who presented with symptoms of angina that was refractory to medical management. Although her cardiac catheterization revealed microvascular coronary artery disease, her symptoms were refractory to optimal medical management that included ranolazine. After undergoing transmyocardial revascularization, her myocardial ischemia completely resolved and her symptoms dramatically improved. This case suggests that combination of ranolazine and transmyocardial revascularization can be applied to patients with microvascular coronary artery disease.

Topical combinations aimed at treating microvascular dysfunction reduce allodynia in rat models of CRPS-I and neuropathic pain.

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Ragavendran, J Vaigunda; Laferrière, André; Xiao, Wen Hua; Bennett, Gary J; Padi, Satyanarayana S V; Zhang, Ji; Coderre, Terence J

2013-01-01

Growing evidence indicates that various chronic pain syndromes exhibit tissue abnormalities caused by microvasculature dysfunction in the blood vessels of skin, muscle, or nerve. We tested whether topical combinations aimed at improving microvascular function would relieve allodynia in animal models of complex regional pain syndrome type I (CRPS-I) and neuropathic pain. We hypothesized that topical administration of either α(2)-adrenergic (α(2)A) receptor agonists or nitric oxide (NO) donors combined with either phosphodiesterase (PDE) or phosphatidic acid (PA) inhibitors would effectively reduce allodynia in these animal models of chronic pain. Single topical agents produced significant dose-dependent antiallodynic effects in rats with chronic postischemia pain, and the antiallodynic dose-response curves of PDE and PA inhibitors were shifted 2.5- to 10-fold leftward when combined with nonanalgesic doses of α(2)A receptor agonists or NO donors. Topical combinations also produced significant antiallodynic effects in rats with sciatic nerve injury, painful diabetic neuropathy, and chemotherapy-induced painful neuropathy. These effects were shown to be produced by a local action, lasted up to 6 hours after acute treatment, and did not produce tolerance over 15 days of chronic daily dosing. The present results support the hypothesis that allodynia in animal models of CRPS-I and neuropathic pain is effectively relieved by topical combinations of α(2)A or NO donors with PDE or PA inhibitors. This suggests that topical treatments aimed at improving microvascular function may reduce allodynia in patients with CRPS-I and neuropathic pain. This article presents the synergistic antiallodynic effects of combinations of α(2)A or NO donors with PDE or PA inhibitors in animal models of CRPS-I and neuropathic pain. The data suggest that effective clinical treatment of chronic neuropathic pain may be achieved by therapies that alleviate microvascular dysfunction in affected

Acceptance of Umbilical Cord Blood as an Alternative to Adult Blood ...

African Journals Online (AJOL)

Background: Inadequate supply of safe blood has been a source of worry to health facilities in Nigeria. One way of addressing this is problem is to consider the use of Umbilical Cord Blood (UCB) as an alternative to adult blood for the purpose of blood transfusion. This will only be possible if we accept this alternative.

Data set characterizing the systemic alterations of microvascular reactivity and capillary density, in patients presenting with infective endocarditis.

Science.gov (United States)

Tibirica, Eduardo; Barcelos, Amanda; Lamas, Cristiane

2018-06-01

This article represents data associated with a prior publication from our research group, under the title: Evaluation of microvascular endothelial function and capillary density in patients with infective endocarditis using laser speckle contrast imaging and video-capillaroscopy [1]. Patients with definite infective endocarditis, under stable clinical conditions, were prospectively included. The clinical and laboratory features are presented for each of them in raw form. Microvascular reactivity was evaluated using a laser speckle contrast imaging (LSCI) system with a laser wavelength of 785 nm. LSCI was used in combination with the iontophoresis of acetylcholine (ACh) or sodium nitroprusside (SNP) for the noninvasive, continuous measurement of cutaneous microvascular perfusion changes in arbitrary perfusion units (APU). The images were analyzed using the manufacturer's software. One skin site on the ventral surface of the forearm was chosen for the experiment. Microvascular reactivity was also evaluated using post-occlusive reactive hyperemia, whereby arterial occlusion was achieved with supra-systolic pressure (50 mmHg above the systolic arterial pressure) using a sphygmomanometer for three minutes. Following the release of pressure, maximum flux was measured. Data on cutaneous microvascular density were obtained using intravital video-capillaroscopy. The data obtained may be helpful by showing the usefulness of laser-based noninvasive techniques in systemic infectious diseases other than sepsis, in different clinical settings and countries.

Quantifying the microvascular origin of BOLD-fMRI from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe.

Science.gov (United States)

Gagnon, Louis; Sakadžić, Sava; Lesage, Frédéric; Musacchia, Joseph J; Lefebvre, Joël; Fang, Qianqian; Yücel, Meryem A; Evans, Karleyton C; Mandeville, Emiri T; Cohen-Adad, Jülien; Polimeni, Jonathan R; Yaseen, Mohammad A; Lo, Eng H; Greve, Douglas N; Buxton, Richard B; Dale, Anders M; Devor, Anna; Boas, David A

2015-02-25

The blood oxygenation level-dependent (BOLD) contrast is widely used in functional magnetic resonance imaging (fMRI) studies aimed at investigating neuronal activity. However, the BOLD signal reflects changes in blood volume and oxygenation rather than neuronal activity per se. Therefore, understanding the transformation of microscopic vascular behavior into macroscopic BOLD signals is at the foundation of physiologically informed noninvasive neuroimaging. Here, we use oxygen-sensitive two-photon microscopy to measure the BOLD-relevant microvascular physiology occurring within a typical rodent fMRI voxel and predict the BOLD signal from first principles using those measurements. The predictive power of the approach is illustrated by quantifying variations in the BOLD signal induced by the morphological folding of the human cortex. This framework is then used to quantify the contribution of individual vascular compartments and other factors to the BOLD signal for different magnet strengths and pulse sequences. Copyright © 2015 the authors 0270-6474/15/353663-13$15.00/0.

ANAEMIA AS A RISK FACTOR FOR MICROVASCULAR COMPLICATIONS IN TYPE 2 DM- A CROSS-SECTIONAL STUDY

Directory of Open Access Journals (Sweden)

Kamanuru Ethirajulu Govindarajulu

2016-11-01

Full Text Available BACKGROUND It is well known that diabetes adversely affects the kidneys finally leading to anaemia by various mechanisms. Several studies had postulated that anaemia developing before renal complications has an independent association with microvascular complication in type 2 diabetic patients. The aim of the study is to estimate the prevalence of anaemia in persons with type 2 diabetes mellitus and its role as a risk factor for the presence and the severity of microvascular complication in a populationbased study. MATERIALS AND METHODS This is a cross-sectional study conducted in patients coming to OPD of the Department of General Medicine in Government Vellore Medical College for a duration of 3 months from June 01, 2016, to August 31, 2016. Type 2 DM patients between the age group 20-60 years attending our diabetic clinic of both sex were included in our study. RESULTS From a total of 100 patients, 41% had anaemia including 34% with normochromic normocytic, 65.85% with hyperchromic microcytic anaemia and none of the patient had macrocytic anaemia. Patients who are anaemic had more frequent microvascular complications. There was no significant difference between males and females. The average duration of diabetes has a positive correlation with anaemia. All the microvascular complications like neuropathy, nephropathy and retinopathy had significant association with the presence of anaemia in type 2 patients. Nephropathy had a significant higher frequency compared to others as a complication in type 2 DM. CONCLUSION Our study shows that there is increased prevalence of anaemia in type 2 DM patients and the prevalence of microvascular complications is significantly higher among the diabetic patients with anaemia.

Ovarian blood supply in women of reproductive age and echo-graphic evaluation of influence of subtotal hysterectomy on it

Directory of Open Access Journals (Sweden)

Т. V. Lescheva

2017-12-01

Full Text Available Purpose of the study. To study the peculiarities of ovarian blood supply after subtotal hysterectomy in the reproductive age. Materials and methods of research. In accordance with the purpose and objectives of the work 150 women of reproductive age were included, there were 4 groups. 125 patients suffered from uterine leiomyoma, 100 of whom had a hysterectomy (HE – a supravaginal uterus amputation (SUA, which corresponds to a subtotal HE (SHE. Results. When examining a group of healthy women of the control group, we determined the average volume of the ovaries – 5.2 ± 0.2 cm2, which did not differ from the average size for healthy women of reproductive age. When studying the structure of the ovaries and their size, several large ovarian dimensions (6.0 ± 0.4 cm2 and the presence of cystic changes in some of them have attracted attention in patients with leiomyoma of the uterus. In addition to the study of the anatomical characteristics of the ovaries, we investigated the blood flow in the ovarian arteries, and the study of blood flow was carried out according to the phases of the menstrual cycle in the women of the control group, as well as in patients with uterine leiomyoma – one year before and after the operation. Conclusions. Ultrasound showed a gradual decrease in volume as the duration of the postoperative period increased. Duplex scanning with the determination of indices characterizing the blood flow revealed a slight deterioration in the blood supply of the ovaries within 1 year after removal of the uterus compared with patients with uterine leiomyoma and healthy women of similar age. IER was the most sensitive index, which was the first to react to the change in the tone of the vascular bed. In more than half of operated patients we did not find any cyclic changes in the blood flow in the ovarian artery, which was characteristic of healthy patients of reproductive age. Change in blood flow is early and more sensitive sign of

Preventing microvascular complications in type 1 diabetes mellitus

OpenAIRE

Viswanathan, Vijay

2015-01-01

Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progressi...

PET measurements of myocardial blood flow post myocardial infarction: Relationship to invasive and cardiac magnetic resonance studies and potential clinical applications.

Science.gov (United States)

Gewirtz, Henry

2017-12-01

This review focuses on clinical studies concerning assessment of coronary microvascular and conduit vessel function primarily in the context of acute and sub acute myocardial infarction (MI). The ability of quantitative PET measurements of myocardial blood flow (MBF) to delineate underlying pathophysiology and assist in clinical decision making in this setting is discussed. Likewise, considered are physiological metrics fractional flow reserve, coronary flow reserve, index of microvascular resistance (FFR, CFR, IMR) obtained from invasive studies performed in the cardiac catheterization laboratory, typically at the time of PCI for MI. The role both of invasive studies and cardiac magnetic resonance (CMR) imaging in assessing microvascular function, a key determinant of prognosis, is reviewed. The interface between quantitative PET MBF measurements and underlying pathophysiology, as demonstrated both by invasive and CMR methodology, is discussed in the context of optimal interpretation of the quantitative PET MBF exam and its potential clinical applications.

The brain microvascular endothelium supports T cell proliferation and has potential for alloantigen presentation.

Directory of Open Access Journals (Sweden)

Julie Wheway

Full Text Available Endothelial cells (EC form the inner lining of blood vessels and are positioned between circulating lymphocytes and tissues. Hypotheses have formed that EC may act as antigen presenting cells based on the intimate interactions with T cells, which are seen in diseases like multiple sclerosis, cerebral malaria (CM and viral neuropathologies. Here, we investigated how human brain microvascular EC (HBEC interact with and support the proliferation of T cells. We found HBEC to express MHC II, CD40 and ICOSL, key molecules for antigen presentation and co-stimulation and to take up fluorescently labeled antigens via macropinocytosis. In co-cultures, we showed that HBEC support and promote the proliferation of CD4(+ and CD8(+ T cells, which both are key in CM pathogenesis, particularly following T cell receptor activation and co-stimulation. Our findings provide novel evidence that HBEC can trigger T cell activation, thereby providing a novel mechanism for neuroimmunological complications of infectious diseases.

Thrombin stimulates albumin transcytosis in lung microvascular endothelial cells via activation of acid sphingomyelinase.

Science.gov (United States)

Kuebler, Wolfgang M; Wittenberg, Claudia; Lee, Warren L; Reppien, Eike; Goldenberg, Neil M; Lindner, Karsten; Gao, Yizhuo; Winoto-Morbach, Supandi; Drab, Marek; Mühlfeld, Christian; Dombrowsky, Heike; Ochs, Matthias; Schütze, Stefan; Uhlig, Stefan

2016-04-15

Transcellular albumin transport occurs via caveolae that are abundant in lung microvascular endothelial cells. Stimulation of albumin transcytosis by proinflammatory mediators may contribute to alveolar protein leak in lung injury, yet the regulation of albumin transport and its underlying molecular mechanisms are so far incompletely understood. Here we tested the hypothesis that thrombin may stimulate transcellular albumin transport across lung microvascular endothelial cells in an acid-sphingomyelinase dependent manner. Thrombin increased the transport of fluorescently labeled albumin across confluent human lung microvascular endothelial cell (HMVEC-L) monolayers to an extent that markedly exceeds the rate of passive diffusion. Thrombin activated acid sphingomyelinase (ASM) and increased ceramide production in HMVEC-L, but not in bovine pulmonary artery cells, which showed little albumin transport in response to thrombin. Thrombin increased total caveolin-1 (cav-1) content in both whole cell lysates and lipid rafts from HMVEC-L, and this effect was blocked by inhibition of ASM or de novo protein biosynthesis. Thrombin-induced uptake of albumin into lung microvascular endothelial cells was confirmed in isolated-perfused lungs by real-time fluorescence imaging and electron microscopy of gold-labeled albumin. Inhibition of ASM attenuated thrombin-induced albumin transport both in confluent HMVEC-L and in intact lungs, whereas HMVEC-L treatment with exogenous ASM increased albumin transport and enriched lipid rafts in cav-1. Our findings indicate that thrombin stimulates transcellular albumin transport in an acid sphingomyelinase-dependent manner by inducing de novo synthesis of cav-1 and its recruitment to membrane lipid rafts. Copyright © 2016 the American Physiological Society.

Donated blood--gift or commodity? Some economic and ethical considerations on voluntary vs commercial donation of blood.

Science.gov (United States)

von Schubert, H

1994-07-01

The author applies the theory of public goods on donated blood. Donated blood may be taken as a 'public good' like water and air, police and fire brigades. This theory trends to imply a preference for voluntary donation and bloodbanking by public and nonprofit organisations as well as for low cost supply. An additional commercial supply of blood nevertheless is welcome. Quality as well as quantity of blood depend first of all on the willingness to donate and the honesty of the donors about their health. An altruistic motivation alone, which is not triggered by some material incentive, does not in all systems guarantee a sufficient quantity of safe blood. Both the altruistic as well as the reimbursement-oriented donor's willingness and honesty have to be guarded by sound practice in bloodbanking and adequate public control within a legal framework which reflects the vital role of blood supply. A legal implementation of product liability will certainly be an important instrument in this field.

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.

Management of the blood supply for a Jk(a-b-) patient with an anti-Jk3 in preparation for an urgent heart transplant: An illustrative example of a successful international cooperation.

Science.gov (United States)

Thonier, V; Cohen-Bacrie, S; Loussert, I; Thornton, N; Djoudi, R; Woimant, G; Boulat, C; Pirenne, F; Peyrard, T

2018-05-22

The Kidd blood group system currently comprises two polymorphic and antithetical antigens, Jk a and Jk b , and one high-prevalence antigen, Jk3. Jk null individuals do not express any of the Kidd antigens, and are at risk of developing an anti-Jk3 which is known to be dangerous and responsible for acute or delayed hemolytic transfusion reaction. We report a case of an immunized Jk null patient, who was scheduled to undergo a heart transplant. In order to organize his blood provision management, two conference calls were held between the clinical team and the different staff involved in this challenging blood supply. In light of the blood needs, the available resources, and the constraints, a mix of fresh and frozen units were used. As the supply from France was not sufficient, Finland and New Zealand provided the majority of the fresh units. We report here how this international supply chain was organized, including the difficulties that we encountered. Anticipation, communication and flexibility were essential in making this heart transplant possible without needing to transfuse incompatible units. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Catabolism of exogenously supplied thymidine to thymine and dihydrothymine by platelets in human peripheral blood

International Nuclear Information System (INIS)

Pero, R.W.; Johnson, D.; Olsson, A.

1984-01-01

The interference of platelets with the estimation of unscheduled DNA synthesis in human peripheral mononuclear leukocytes following genotoxic exposure was studied. A 96% reduction in the unscheduled DNA synthesis value was achieved by incubating [ 3 H]thymidine with platelet-rich plasma for 5 hr at 37 degrees. Using radioactive thymine-containing compounds, together with quantitative analyses based on thin-layer and ion-exchange chromatographies, we have shown that thymidine was converted to thymine which, in turn, was converted to dihydrothymine in platelet-rich plasma. The enzymes responsible were separated from platelet lysates by gel filtration and were identified as thymidine phosphorylase and dihydrothymine dehydrogenase. The phosphorylase reversibly catalyzed the formation of thymine from thymidine and converted bromodeoxyuridine to bromouracil. The dehydrogenase reversibly catalyzed the interconversion of thymine and dihydrothymine in a reaction dependent on NADP(H), and it was inhibited by diazouracil and by thymine. Nearly all the thymidine-catabolizing activity found in whole blood samples supplied exogenously with thymidine was accounted for by the platelets. Since most genetic toxicological tests that use blood samples do not involve removing platelets from the blood cell cultures, then it is concluded that precautions should be taken in the future to determine the influence of platelets on these test systems. This is particularly true for methods dependent on thymidine pulses such as unscheduled DNA synthesis, or those dependent on bromodeoxyuridine, such as sister chromatid exchanges, since this nucleoside is also a substrate for thymidine phosphorylase

GLP-1 increases microvascular recruitment but not glucose uptake in human and rat skeletal muscle

DEFF Research Database (Denmark)

Sjøberg, Kim Anker; Holst, Jens Juul; Rattigan, Stephen

2014-01-01

The insulinotropic gut hormone, glucagon-like-peptide-1 (GLP-1) has been proposed to have effects on vascular function and glucose disposal. However, whether GLP-1 is able to increase microvascular recruitment (MVR) in humans has not been investigated. GLP-1 was infused in the femoral artery...... in overnight fasted healthy young men. Microvascular recruitment was measured with real time contrast-enhanced ultrasound and leg glucose uptake by the leg balance technique with and without inhibition of the insulinotropic response of GLP-1 by co-infusion of octreotide. As a positive control, MVR and leg...

Can a decentralized blood system ensure self-sufficiency and blood safety? The Lebanese experience.

Science.gov (United States)

Haddad, Antoine; Bou Assi, Tarek; Garraud, Olivier

2017-08-01

Lebanon has adopted a liberal economic system that also applies to healthcare procurement. There is no national Lebanese blood transfusion service and the blood supply is divided between a large number of licensed (45 per cent) and unlicensed (55 per cent) blood banks, many of them issuing a very limited number of blood components. All blood banks are hospital based and operate the entire transfusion chain, from collection to the release of blood units. Blood donation is voluntary and non-remunerated in 20-25 per cent of donations; it relies principally on replacement donations. Recently, Lebanon has faced political instability and war, and now welcomes an enormous number of refugees from neighboring countries at war. This has had an important impact on heath care and on the transfusion supply. We discuss the impact of the blood donation organization on the transfusion safety and ethics, to set the foundation for a more developed and safer transfusion programs.

Relationship between blood flow, bone structure, and 239Pu deposition in the mouse skeleton

International Nuclear Information System (INIS)

Humphreys, E.R.; Green, D.; Howells, G.R.; Thorne, M.C.

1982-01-01

The rate at which blood is supplied to several bones in female CBA mice was calculated from 18 F measurements in bone and blood. Blood flow measurements were compared with plutonium uptake in whole bone and on endosteal and periosteal bone surfaces. The results showed that: the rate at which blood is supplied to bone determines the rate of deposition of plutonium; there is a threshold rate of blood supply below which plutonium is not deposited; and the rate of blood supply determines the density of plutonium deposition on endosteal but not on periosteal bone surfaces. These results are discussed in the light of the current bone blood supply hypotheses. (orig.)

Impaired Muscle Oxygenation and Elevated Exercise Blood Pressure in Hypertensive Patients: Links With Vascular Stiffness.

Science.gov (United States)

Dipla, Konstantina; Triantafyllou, Areti; Koletsos, Nikolaos; Papadopoulos, Stavros; Sachpekidis, Vasileios; Vrabas, Ioannis S; Gkaliagkousi, Eugenia; Zafeiridis, Andreas; Douma, Stella

2017-08-01

This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher ( P age and body mass index (BMI) adjusted). When exercising at the same submaximal intensity, hypertensives required a significantly greater ( P hypertension exhibit prominent reductions in in vivo indices of skeletal muscle oxidative capacity, suggestive of mitochondrial dysfunction, and blunted muscle microvascular reactivity. These dysfunctions were associated with higher aortic systolic BP and arterial stiffness. Dysregulations in muscle oxygen delivery/utilization and microvascular stiffness, in hypertensive patients, partially contribute to their exaggerated BP during exercise. © 2017 American Heart Association, Inc.

Hemifacial spasm : Intraoperative electromyographic monitoring as a guide for microvascular decompression

NARCIS (Netherlands)

Mooij, JJA; Mustafa, MK; van Weerden, TW

2001-01-01

OBJECTIVE: Microvascular decompression is the logical and well-accepted treatment of choice for hemifacial spasm (HFS). In experienced hands, good to excellent results can be obtained. However, sometimes the exact site of the vascular compression is unclear. The aim of this study was to analyze

MICROVASCULAR CHANGES IN AGED RAT FOREBRAIN - EFFECTS OF CHRONIC NIMODIPINE TREATMENT

NARCIS (Netherlands)

de Jong, Giena; Weerd, H. de; Schuurman, T.; Traber, J.; Luiten, P.G.M.

1990-01-01

In the present study the effects of long-term treatment with the 1,4-dihydropyridine calcium antagonist nimodipine on ultrastructural alterations of the microvascular morphology were examined in the frontoparietal cortex, entorhinal cortex and CA1 of the hippocampus in the aged rat. Qualitative

Imaging blood-brain barrier dysfunction as a biomarker for epileptogenesis.

Science.gov (United States)

Bar-Klein, Guy; Lublinsky, Svetlana; Kamintsky, Lyn; Noyman, Iris; Veksler, Ronel; Dalipaj, Hotjensa; Senatorov, Vladimir V; Swissa, Evyatar; Rosenbach, Dror; Elazary, Netta; Milikovsky, Dan Z; Milk, Nadav; Kassirer, Michael; Rosman, Yossi; Serlin, Yonatan; Eisenkraft, Arik; Chassidim, Yoash; Parmet, Yisrael; Kaufer, Daniela; Friedman, Alon

2017-06-01

A biomarker that will enable the identification of patients at high-risk for developing post-injury epilepsy is critically required. Microvascular pathology and related blood-brain barrier dysfunction and neuroinflammation were shown to be associated with epileptogenesis after injury. Here we used prospective, longitudinal magnetic resonance imaging to quantitatively follow blood-brain barrier pathology in rats following status epilepticus, late electrocorticography to identify epileptic animals and post-mortem immunohistochemistry to confirm blood-brain barrier dysfunction and neuroinflammation. Finally, to test the pharmacodynamic relevance of the proposed biomarker, two anti-epileptogenic interventions were used; isoflurane anaesthesia and losartan. Our results show that early blood-brain barrier pathology in the piriform network is a sensitive and specific predictor (area under the curve of 0.96, P brain barrier pathology as a clinically relevant predictive, diagnostic and pharmaco!dynamics biomarker for acquired epilepsy. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Whole blood pathogen reduction technology and blood safety in sub-Saharan Africa: A systematic review with regional discussion

OpenAIRE

Nkohkwo, Asa?ah; Agbor, Gabriel; Asongalem, Emmanuel; Tagny, Claude; Asonganyi, Tazoacha

2016-01-01

Background: Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region. Objective: This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region. Method: The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinic...

[Blood transfusion and supply chain management safety].

Science.gov (United States)

Quaranta, Jean-François; Caldani, Cyril; Cabaud, Jean-Jacques; Chavarin, Patricia; Rochette-Eribon, Sandrine

2015-02-01

The level of safety attained in blood transfusion now makes this a discipline better managed care activities. This was achieved both by scientific advances and policy decisions regulating and supervising the activity, as well as by the quality system, which we recall that affects the entire organizational structure, responsibilities, procedures, processes and resources in place to achieve quality management. So, an effective quality system provides a framework within which activities are established, performed in a quality-focused way and continuously monitored to improve outcomes. This system quality has to irrigate all the actors of the transfusion, just as much the establishments of blood transfusion than the health establishments. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Proteolytic receptor cleavage in the pathogenesis of blood rheology and co-morbidities in metabolic syndrome. Early forms of autodigestion.

Science.gov (United States)

Mazor, Rafi; Schmid-Schönbein, Geert W

2015-01-01

Abnormal blood rheological properties seldom occur in isolation and instead are accompanied by other complications, often designated as co-morbidities. In the metabolic syndrome with complications like hypertension, diabetes and lack of normal microvascular blood flow, the underlying molecular mechanisms that simultaneously lead to elevated blood pressure and diabetes as well as abnormal microvascular rheology and other cell dysfunctions have remained largely unknown. In this review, we propose a new hypothesis for the origin of abnormal cell functions as well as multiple co-morbidities. Utilizing experimental models for the metabolic disease with diverse co-morbidities we summarize evidence for the presence of an uncontrolled extracellular proteolytic activity that causes ectodomain receptor cleavage and loss of their associated cell function. We summarize evidence for unchecked degrading proteinase activity, e.g. due to matrix metalloproteases, in patients with hypertension, Type II diabetes and obesity, in addition to evidence for receptor cleavage in the form of receptor fragments and decreased extracellular membrane expression levels. The evidence suggest that a shift in blood rheological properties and other co-morbidities may in fact be derived from a common mechanism that is due to uncontrolled proteolytic activity, i.e. an early form of autodigestion. Identification of the particular proteases involved and the mechanisms of their activation may open the door to treatment that simultaneously targets multiple co-morbidities in the metabolic syndrome.

Impact of hemoglobin nitrite to nitric oxide reductase on blood transfusion for resuscitation from hemorrhagic shock

Directory of Open Access Journals (Sweden)

Chad Brouse

2015-01-01

Full Text Available Background: Transfusion of blood remains the gold standard for fluid resuscitation from hemorrhagic shock. Hemoglobin (Hb within the red blood cell transports oxygen and modulates nitric oxide (NO through NO scavenging and nitrite reductase. Aims: This study was designed to examine the effects of incorporating a novel NO modulator, RRx-001, on systemic and microvascular hemodynamic response after blood transfusion for resuscitation from hemorrhagic shock in a hamster window chamber model. In addition, to RRx-001 the role of low dose of nitrite (1 × 10−9 moles per animal supplementation after resuscitation was studied. Materials and Methods: Severe hemorrhage was induced by arterial controlled bleeding of 50% of the blood volume (BV and the hypovolemic state was maintained for 1 h. The animals received volume resuscitation by an infusion of 25% of BV using fresh blood alone or with added nitrite, or fresh blood treated with RRx-001 (140 mg/kg or RRx-001 (140 mg/kg with added nitrite. Systemic and microvascular hemodynamics were followed at baseline and at different time points during the entire study. Tissue apoptosis and necrosis were measured 8 h after resuscitation to correlate hemodynamic changes with tissue viability. Results: Compared to resuscitation with blood alone, blood treated with RRx-001 decreased vascular resistance, increased blood flow and functional capillary density immediately after resuscitation and preserved tissue viability. Furthermore, in RRx-001 treated animals, both mean arterial pressure (MAP and met Hb were maintained within normal levels after resuscitation (MAP >90 mmHg and metHb <2%. The addition of nitrite to RRx-001 did not significantly improve the effects of RRx-001, as it increased methemoglobinemia and lower MAP. Conclusion: RRx-001 alone enhanced perfusion and reduced tissue damage as compared to blood; it may serve as an adjunct therapy to the current gold standard treatment for resuscitation from

Improving healthcare value through clinical community and supply chain collaboration.

Science.gov (United States)

Ishii, Lisa; Demski, Renee; Ken Lee, K H; Mustafa, Zishan; Frank, Steve; Wolisnky, Jean Paul; Cohen, David; Khanna, Jay; Ammerman, Joshua; Khanuja, Harpal S; Unger, Anthony S; Gould, Lois; Wachter, Patricia Ann; Stearns, Lauren; Werthman, Ronald; Pronovost, Peter

2017-03-01

We hypothesized that integrating supply chain with clinical communities would allow for clinician-led supply cost reduction and improved value in an academic health system. Three clinical communities (spine, joint, blood management) and one clinical community-like physician led team of surgeon stakeholders partnered with the supply chain team on specific supply cost initiatives. The teams reviewed their specific utilization and cost data, and the physicians led consensus-building conversations over a series of team meetings to agree to standard supply utilization. The spine and joint clinical communities each agreed upon a vendor capping model that led to cost savings of $3 million dollars and $1.5 million dollars respectively. The blood management decreased blood product utilization and achieved $1.2 million dollars savings. $5.6 million dollars in savings was achieved by a clinical community-like group of surgeon stakeholders through standardization of sutures and endomechanicals. Physician led clinical teams empowered to lead change achieved substantial supply chain cost savings in an academic health system. The model of combining clinical communities with supply chain offers hope for an effective, practical, and scalable approach to improving value and engaging physicians in other academic health systems. This clinician led model could benefit both private and academic health systems engaging in value optimization efforts. N/A. Copyright © 2016 Elsevier Inc. All rights reserved.

Increased Angiotensin II Sensitivity Contributes to Microvascular Dysfunction in Women Who Have Had Preeclampsia.

Science.gov (United States)

Stanhewicz, Anna E; Jandu, Sandeep; Santhanam, Lakshmi; Alexander, Lacy M

2017-08-01

Women who have had preeclampsia have increased cardiovascular disease risk; however, the mechanism(s) responsible for this association remain unclear. Microvascular damage sustained during a preeclamptic pregnancy may persist postpartum. The putative mechanisms mediating this dysfunction include a reduction in NO-dependent dilation and an increased sensitivity to angiotensin II. In this study, we evaluated endothelium-dependent dilation, angiotensin II sensitivity, and the therapeutic effect of angiotensin II receptor blockade (losartan) on endothelium-dependent dilation in vivo in the microvasculature of women with a history of preeclampsia (n=12) and control women who had a healthy pregnancy (n=12). We hypothesized that preeclampsia would have (1) reduced endothelium-dependent dilation, (2) reduced NO-mediated dilation, and (3) increased sensitivity to angiotensin II. We further hypothesized that localized losartan would increase endothelium-dependent vasodilation in preeclampsia. We assessed microvascular endothelium-dependent vasodilator function by measurement of cutaneous vascular conductance responses to graded infusion of acetylcholine (acetylcholine; 10 -7 -102 mmol/L) and a standardized local heating protocol in control sites and sites treated with 15 mmol/L L-NAME ( N G -nitro-l-arginine methyl ester; NO-synthase inhibitor) or 43 µmol/L losartan. Further, we assessed microvascular vasoconstrictor sensitivity to angiotensin II (10 -20 -10 -4 mol/L). Preeclampsia had significantly reduced endothelium-dependent dilation (-0.3±0.5 versus -1.0±0.4 log EC50 ; P Preeclampsia also had augmented vasoconstrictor sensitivity to angiotensin II (-10.2±1.3 versus -8.3±0.5; P =0.006). Angiotensin II type I receptor inhibition augmented endothelium-dependent vasodilation and NO-dependent dilation in preeclampsia but had no effect in healthy pregnancy. These data suggest that women who have had preeclampsia have persistent microvascular dysfunction postpartum

Better microvascular function on long-term treatment with lisinopril than with nifedipine in renal transplant recipients.

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Asberg, A; Midtvedt, K; Vassbotn, T; Hartmann, A

2001-07-01

The prevalence of hypertension in renal transplant recipients is high but the pathophysiology is poorly defined. Impaired endothelial function may be a factor of major importance. The present study addresses the effects of long-term treatment with either lisinopril or slow-release nifedipine on microvascular function and plasma endothelin in renal transplant recipients on cyclosporin A (CsA). Seventy-five hypertensive renal transplant recipients were double-blind randomized to receive slow-release nifedipine (NIF, n=40) or lisinopril (LIS, n=35). Ten normotensive, age-matched recipients served as controls. All patients received CsA-based immunosuppressive therapy including prednisolone and azathioprine. Microvascular function was assessed in the forearm skin vasculature, using laser Doppler flowmetry in combination with post-occlusive reactive hyperaemia and endothelial-dependent function during local acetylcholine (ACh) stimulation. The analysis of microvascular function (AUC(rh)) showed that nifedipine-treated patients had significantly lower responses compared with lisinopril-treated patients (20+/-17 and 43+/-20 AU x min respectively, P=0.0016). Endothelial function was borderline significantly lower in the NIF group compared with the LIS group (640+/-345 and 817+/-404 AU x min respectively, P=0.056). The responses in the LIS group were comparable with those in non-hypertensive controls (AUC(rh) was 37+/-16 and AUC(ACh) was 994+/-566 AU x min). Plasma endothelin-1 concentrations were significantly higher in the NIF group compared with the LIS group (0.44+/-0.19 vs. 0.34+/-0.10 fmol/ml respectively, P=0.048), and were 0.29+/-0.09 fmol/ml in the control patients. AUC(ACh) was associated with plasma endothelin-1 (P=0.0053), while AUC(rh) was not (P=0.080). The study indicates that long-term treatment with lisinopril, when compared with nifedipine, yields a more beneficial effect on microvascular function in hypertensive renal transplant recipients on CsA. The

ZO-1 expression is suppressed by GM-CSF via miR-96/ERG in brain microvascular endothelial cells.

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Zhang, Hu; Zhang, Shuhong; Zhang, Jilin; Liu, Dongxin; Wei, Jiayi; Fang, Wengang; Zhao, Weidong; Chen, Yuhua; Shang, Deshu

2018-05-01

The level of granulocyte-macrophage colony-stimulating factor (GM-CSF) increases in some disorders such as vascular dementia, Alzheimer's disease, and multiple sclerosis. We previously reported that in Alzheimer's disease patients, a high level of GM-CSF in the brain parenchyma downregulated expression of ZO-1, a blood-brain barrier tight junction protein, and facilitated the infiltration of peripheral monocytes across the blood-brain barrier. However, the molecular mechanism underlying regulation of ZO-1 expression by GM-CSF is unclear. Herein, we found that the erythroblast transformation-specific (ETS) transcription factor ERG cooperated with the proto-oncogene protein c-MYC in regulation of ZO-1 transcription in brain microvascular endothelial cells (BMECs). The ERG expression was suppressed by miR-96 which was increased by GM-CSF through the phosphoinositide-3 kinase (PI3K)/Akt pathway. Inhibition of miR-96 prevented ZO-1 down-regulation induced by GM-CSF both in vitro and in vivo. Our results revealed the mechanism of ZO-1 expression reduced by GM-CSF, and provided a potential target, miR-96, which could block ZO-1 down-regulation caused by GM-CSF in BMECs.

Cost-effective practices in the blood service sector.

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Katsaliaki, Korina

2008-05-01

The objective of this study is to recommend alternative policies, which are tested on a computer simulation model, towards a more cost-effective management of the blood supply chain in the UK. With the use of primary and secondary data from the National Blood Service (NBS) and the supplied hospitals, statistical analysis is conducted and a detailed discrete event simulation model of a vertical part of the UK supply chain of blood products is developed to test and identify good ordering, inventory and distribution practices. Fewer outdates, group substitutions, shortages and deliveries could be achieved by blood banks: holding stock of rare blood groups of red blood cells (RBC), having a second routine delivery per weekday, exercising a more insensitive ordering point for RBC, reducing the total crossmatch release period to less than 1.5 days, increasing the transfusion-to-crossmatch ratio to 70%, adhering to an age-based issuing of orders, holding RBC stock of a weighted average of approximately 4 days. The blood supply simulation model can offer useful pieces of advice to the stakeholders of the examined system which leads to cost reductions and increased safety. Moreover, it provides a great range of experimental capabilities in a risk-free environment.

Magnetic alginate microfibers as scaffolding elements for the fabrication of microvascular-like structures.

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Sun, Tao; Shi, Qing; Huang, Qiang; Wang, Huaping; Xiong, Xiaolu; Hu, Chengzhi; Fukuda, Toshio

2018-01-15

Traditional cell-encapsulating scaffolds may elicit adverse host responses and inhomogeneity in cellular distribution. Thus, fabrication techniques for cellular self-assembly with micro-scaffold incorporation have been used recently to generate toroidal cellular modules for the bottom-up construction of vascular-like structures. The micro-scaffolds show advantage in promoting tissue formation. However, owing to the lack of annular cell micro-scaffolds, it remains a challenge to engineer micro-scale toroidal cellular modules (micro-TCMs) to fabricate microvascular-like structures. Here, magnetic alginate microfibers (MAMs) are used as scaffolding elements, where a winding strategy enables them to be formed into micro-rings as annular cell micro-scaffolds. These micro-rings were investigated for NIH/3T3 fibroblast growth as a function of surface chemistry and MAM size. Afterwards, micro-TCMs were successfully fabricated with the formation of NIH/3T3 fibroblasts and extracellular matrix layers on the three-dimensional micro-ring surfaces. Simple non-contact magnetic assembly was used to stack the micro-TCMs along a micro-pillar, after which cell fusion rapidly connected the assembled micro-TCMs into a microvascular-like structure. Endothelial cells or drugs encapsulated in the MAMs could be included in the microvascular-like structures as in vitro cellular models for vascular tissue engineering, or as miniaturization platforms for pharmaceutical drug testing in the future. Magnetic alginate microfibers functioned as scaffolding elements for guiding cell growth in micro-scale toroidal cellular modules (micro-TCMs) and provided a magnetic functionality to the micro-TCMs for non-contact 3D assembly in external magnetic fields. By using the liquid/air interface, the non-contact spatial manipulation of the micro-TCMs in the liquid environment was performed with a cost-effective motorized electromagnetic needle. A new biofabrication paradigm of construct of microvascular

Induction of complement proteins in a mouse model for cerebral microvascular Aβ deposition

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DeFilippis Kelly

2007-09-01

Full Text Available Abstract The deposition of amyloid β-protein (Aβ in cerebral vasculature, known as cerebral amyloid angiopathy (CAA, is a common pathological feature of Alzheimer's disease and related disorders. In familial forms of CAA single mutations in the Aβ peptide have been linked to the increase of vascular Aβ deposits accompanied by a strong localized activation of glial cells and elevated expression of neuroinflammatory mediators including complement proteins. We have developed human amyloid-β precursor protein transgenic mice harboring two CAA Aβ mutations (Dutch E693Q and Iowa D694N that mimic the prevalent cerebral microvascular Aβ deposition observed in those patients, and the Swedish mutations (K670N/M671L to increase Aβ production. In these Tg-SwDI mice, we have reported predominant fibrillar Aβ along microvessels in the thalamic region and diffuse plaques in cortical region. Concurrently, activated microglia and reactive astrocytes have been detected primarily in association with fibrillar cerebral microvascular Aβ in this model. Here we show that three native complement components in classical and alternative complement pathways, C1q, C3, and C4, are elevated in Tg-SwDI mice in regions rich in fibrillar microvascular Aβ. Immunohistochemical staining of all three proteins was increased in thalamus, hippocampus, and subiculum, but not frontal cortex. Western blot analysis showed significant increases of all three proteins in the thalamic region (with hippocampus as well as the cortical region, except C3 that was below detection level in cortex. Also, in the thalamic region (with hippocampus, C1q and C3 mRNAs were significantly up-regulated. These complement proteins appeared to be expressed largely by activated microglial cells associated with the fibrillar microvascular Aβ deposits. Our findings demonstrate that Tg-SwDI mice exhibit elevated complement protein expression in response to fibrillar vascular Aβ deposition that is

The pleiotropic effects of simvastatin on retinal microvascular endothelium has important implications for ischaemic retinopathies.

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Reinhold J Medina

Full Text Available BACKGROUND: Current guidelines encourage the use of statins to reduce the risk of cardiovascular disease in diabetic patients; however the impact of these drugs on diabetic retinopathy is not well defined. Moreover, pleiotropic effects of statins on the highly specialised retinal microvascular endothelium remain largely unknown. The objective of this study was to investigate the effects of clinically relevant concentrations of simvastatin on retinal endothelium in vitro and in vivo. METHODS AND FINDINGS: Retinal microvascular endothelial cells (RMECs were treated with 0.01-10 microM simvastatin and a biphasic dose-related response was observed. Low concentrations enhanced microvascular repair with 0.1 microM simvastatin significantly increasing proliferation (p<0.05, and 0.01 microM simvastatin significantly promoting migration (p<0.05, sprouting (p<0.001, and tubulogenesis (p<0.001. High concentration of simvastatin (10 microM had the opposite effect, significantly inhibiting proliferation (p<0.01, migration (p<0.01, sprouting (p<0.001, and tubulogenesis (p<0.05. Furthermore, simvastatin concentrations higher than 1 microM induced cell death. The mouse model of oxygen-induced retinopathy was used to investigate the possible effects of simvastatin treatment on ischaemic retinopathy. Low dose simvastatin (0.2 mg/Kg promoted retinal microvascular repair in response to ischaemia by promoting intra-retinal re-vascularisation (p<0.01. By contrast, high dose simvastatin(20 mg/Kg significantly prevented re-vascularisation (p<0.01 and concomitantly increased pathological neovascularisation (p<0.01. We also demonstrated that the pro-vascular repair mechanism of simvastatin involves VEGF stimulation, Akt phosphorylation, and nitric oxide production; and the anti-vascular repair mechanism is driven by marked intracellular cholesterol depletion and related disorganisation of key intracellular structures. CONCLUSIONS: A beneficial effect of low

Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

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Barleon Bernhard

2010-07-01

Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

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McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

2009-01-01

OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These

Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

DEFF Research Database (Denmark)

Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk

2016-01-01

OBJECTIVE AND DESIGN: Patients with type 2 diabetes mellitus (T2D) have an increased fracture risk despite a normal or elevated bone mineral density (BMD). The aim of this cross-sectional in vivo study was to assess parameters of peripheral bone microarchitecture, estimated bone strength and bone...... remodeling in T2D patients with and without diabetic microvascular disease (MVD+ and MVD- respectively) and to compare them with healthy controls. METHODS: Fifty-one T2D patients (MVD+ group: n=25) were recruited from Funen Diabetic Database and matched for age, sex and height with 51 healthy subjects. High...... deficits are not a characteristic of all T2D patients but of a subgroup characterized by the presence of microvascular complications. Whether this influences fracture rates in these patients needs further investigation....

Improving diagnosis and treatment of women with angina pectoris and microvascular disease

DEFF Research Database (Denmark)

Prescott, Eva; Abildstrøm, Steen Zabell; Aziz, Ahmed

2014-01-01

BACKGROUND: The iPOWER study aims at determining whether routine assessment of coronary microvascular dysfunction (CMD) in women with angina and no obstructive coronary artery disease is feasible and identifies women at risk. METHODS: All women with angina referred to invasive angiographic assess...

Presence of diabetic microvascular complications does not incrementally increase risk of ischemic stroke in diabetic patients with atrial fibrillation

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Chou, Annie Y.; Liu, Chia-Jen; Chao, Tze-Fan; Wang, Kang-Ling; Tuan, Ta-Chuan; Chen, Tzeng-Ji; Chen, Shih-Ann

2016-01-01

Abstract Conventional stroke risk prediction tools used in atrial fibrillation (AF) incorporate the presence of diabetes mellitus (DM) as a risk factor. However, it is unknown whether this risk is homogenous or dependent on the presence of diabetic microvascular complications, such as diabetic retinopathy, nephropathy, and neuropathy. The present study examined the risk of ischemic stroke in diabetic patients with and without microvascular complications. The present study used the National Health Insurance Research Database in Taiwan with detailed healthcare data on all-comers to the Taiwanese medical system from January 1, 1996 to December 31, 2011. AF and DM were identified when listed as discharge diagnoses or confirmed more than twice in the outpatient department. Patients on antithrombotic agents were excluded. The clinical endpoint was ischemic stroke. Among the 50,180 AF patients with DM, the majority had no microvascular complications (72.7%), while 2.6% had diabetic retinopathy, 8.4% had diabetic nephropathy, and 16.1% had diabetic neuropathy. Ischemic stroke occurred in 6003 patients, with a 4.74% annual risk of ischemic stroke. When compared with DM patients without microvascular complications, those with diabetic retinopathy, nephropathy, or neuropathy had higher incidences of ischemic stroke (4.65 vs 5.07, 4.77, or 5.20 per 100 person-years, respectively). However, after adjusting for confounding factors, the differences were no longer significant. In a large nationwide AF cohort with DM, risk of ischemic stroke was similar between patients with and without microvascular complications, suggesting that risk stratification of these patients does not require inclusion of diabetic retinopathy, nephropathy, and neuropathy. PMID:27399075

Is there a need to phase out replacement blood donors by voluntary blood donors in hospital based blood transfusion services?

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Praneeta Jaswant Singh

2017-01-01

Conclusion: Data highlight that RD contributed major source of blood supply in hospital-based blood transfusion services and the prevalence of TTI was higher among them in comparison to first-time voluntary donors. Thus, efforts should be made to increase the number of VBD.

The quest for an Indian blood law as of blood transfusion services regulatory framework

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Pal Ranabir

2011-01-01

Full Text Available Background: Blood transfusion services are a vital part of the national health delivery system. The responsibility for ensuring a continuous supply of blood rests with health administrators, who need to galvanize entire communities towards regular and non-remunerated blood donation. Objective: The present study aimed to examine the prevailing global regulations and practices related to blood transfusion and press the case for a dedicated blood law in India. Materials and Methods: We attempted a comprehensive, annotated assembly of published studies on blood transfusion services in India. Data Abstraction and Synthesis: Laws related to blood transfusion services exist in India as a part of the Drugs and Cosmetics Law. In the developed world, most blood donors are unpaid volunteers who give blood for a community supply. In order to augment safe blood transfusion services in India, we have to develop operational legal guidelines on recruitment and retention of voluntary blood donors to direct related organizations for this imperative activity. Conclusion: Several factors, such as political will and a professional and ethical approach can help in formulating a common vision, building trust, by providing optimum information towards a social movement for the rational blood transfusion services. We have to come together for a dedicated blood law in order to improve the quality of blood transfusion services in India.

[Microvascular injury effects and possibility of early anastomosis in the maxillofacial region following high velocity missile wound: an experimental study in dogs].

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Yan, Y

1990-02-01

In order to provide the basis of microvascular anastomosis for reconstruction of maxillofacial defects from firearm injury by using vascularized free tissue transplantation, we studied the mechanism and pathology of microvascular injuries and the possibility of their early anastomosis. The dogs' face were wounded by 0.7 g or 1.03 g steel spheres whose muzzle velocity were 1300 m/s or 1500 m/s. The injury effects of microvascular angiograms were recorded through high speed X-ray camera at the impacting moment the specimens of small vessel were collected for light and electron microscopy at different times after wound. Some dogs were used for performing microvascular anastomosis in the wound region at different times after wound. We found that there were temporary cavity effects in maxillofacial firearm wounds, in and around which small vessel blunt injuries were found, which spread 3 cm from the wound edge. Microvascular anastomosis 3 days after the wound could get higher shortterm patency rate. These results support the conclusion that if we use microsurgical methods to repair defects in maxillofacial firearm wound region, the pedicles of the flap should be laid beyond 3 cm from the wound edge, and the reconstructive operation should be done 3 days after the wound.

Bottlenecks of blood processing in Uganda

NARCIS (Netherlands)

Kajja, I.; Kyeyune, D.; Bimenya, G. S.; Sibinga, C. T. S.

2010-01-01

Aim: To identify where and why delays occur in Uganda blood banks. Background: The timely provision and supply of safe and efficacious blood components to hospitals depends on sound systems in the processing blood banks. Poorly managed systems lead to apparent blood shortages in hospitals and

Anatomy and histophysiology of the periosteum: quantification of the periosteal blood supply to the adjacent bone with 85Sr and gamma spectrometry.

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Chanavaz, M

1995-01-01

The periosteum or periosteal membrane is a continuous composite fibroelastic covering membrane of the bone to which it is intimately linked. Although the bone cortex is the main beneficiary of the principal anatomical and physiological functions of the periosteal membrane, the behavior of the entire bone remains closely influenced by periosteal activity. These principal functions are related to the cortical blood supply, osteogenesis, and muscle and ligament attachments. Through its elastic and contractile nature, it participates in the maintenance of bone shape, and plays an important role in metabolic ionic exchange and physiologic distribution of electro-chemical potential differences across its membranous structure. It has also been suggested that the periosteum may have its own specific proprioceptive property. This paper presents a study of the anatomy and histophysiology of the periosteum, and discusses in detail its main functions of cortical blood supply and osteogenesis. It also presents the third intermediary report on a current study of the quantification of cortical vascularization of femoral bone via the periosteum, using an isotonic salt solution containing 85 Strontium. The afferent-efferent (arterio-venous) flows of this solution in the thigh vascular system of guinea pigs were measured by gamma spectrometry after a series of selective macro- and micro-injections of radioactive salt into the femoral arterial system was carried out. Each vascular territory was meticulously selected and the injections were made according to size, starting with the larger vessels, with or without ligatures of neighboring vessels, going progressively to smaller and smaller vessels with diameters not exceeding 100 microns. The principal technical difficulty at this stage of experimentation was related to the identifying and acquiring of appropriate microcatheters. The study also includes a series of measurements after blockage of the transmuscular blood flow and the

Mandibular reconstruction with composite microvascular tissue transfer

International Nuclear Information System (INIS)

Coleman, J.J. III; Wooden, W.A.

1990-01-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons [lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)]. Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure

Mandibular reconstruction with composite microvascular tissue transfer

Energy Technology Data Exchange (ETDEWEB)

Coleman, J.J. III; Wooden, W.A. (Emory Univ. School of Medicine, Atlanta, GA (USA))

1990-10-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons (lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)). Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure.

Quantitative evaluation of capillaroscopic microvascular changes in patients with established coronary heart disease.

Science.gov (United States)

Sanchez-Garcia, M Esther; Ramirez-Lara, Irene; Gomez-Delgado, Francisco; Yubero-Serrano, Elena M; Leon-Acuña, Ana; Marin, Carmen; Alcala-Diaz, Juan F; Camargo, Antonio; Lopez-Moreno, Javier; Perez-Martinez, Pablo; Tinahones, Francisco José; Ordovas, Jose M; Caballero, Javier; Blanco-Molina, Angeles; Lopez-Miranda, Jose; Delgado-Lista, Javier

2018-02-23

Microcirculation disturbances have been associated to most of the cardiovascular risk factors as well as to multiple inflammatory diseases. However, whether these abnormalities are specifically augmented in patients with coronary heart disease is still unknown. We aimed to evaluate if there is a relationship between the presence of coronary heart disease and the existence of functional and structural capillary abnormalities evaluated in the cutaneous microcirculation by videocapillaroscopy. Two matched samples of 30 participants with and without coronary heart disease but with similar clinical and anthropometric characteristics were evaluated by videocapillaroscopy at the dorsal skin of the third finger of the non-dominant hand. We calculated basal capillary density as well as capillary density after a period of arterial and venous occlusion in order to evaluate functionality and maximum capillary density. We also measured capillary recruitment. Microvascular capillary density at rest was significantly lower in patients suffering from coronary heart disease than in controls. This fact was also found after dynamic tests (arterial and venous occlusion), suggesting functional impairments. Capillary recruitment of the samples was not different in our sample. In our study, patients with coronary heart disease exhibit functional and structural microvascular disturbances. Although this is a very preliminary study, these findings open the door for further studying the microvascular functionality in coronary patients and how it relates to the response to treatment and/or the prognosis of the disease. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Vitamin D levels and microvascular complications in type 2 diabetes

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Sarita Bajaj

2014-01-01

Full Text Available Background: Vitamin D has important actions on glucose metabolism. These include improved insulin exocytosis, direct stimulation of insulin receptor, improved uptake of glucose by peripheral tissues, improving insulin resistance. It has got various pleiotropic effects like suppression of cell mediated immunity, regulation of cell proliferation, stimulation of neurotropic factors such as nerve growth factor, Glial cell line-derived neurotrophic factor, neurotropin, suppression of RAAS, reduction of albuminuria, immunomodulatory effects, and anti-inflammatory effects. Thus, vitamin D is implicated in many ways in the pathogenesis of retinopathy, neuropathy and nephropathy. Objectives: To study the correlation of vitamin D levels with microvascular complications in type 2 diabetes. Materials and Methods: Cross-sectional case-control study of 18 patients (18-70 years, who met the American Diabetes Association 2011 criteria for type 2 diabetes, was conducted. Age and sex matched healthy controls were taken. Subjects were evaluated for the presence of microvascular complications by clinical evaluation, urine examination, fundus examination, nerve conduction studies, and various biochemical tests. 25-OH cholecalciferol levels were done for each. Cut off level for vitamin D deficiency was 20 ng/ml. Results: Mean vitamin D was lower in type 2 diabetics than healthy subjects (19.046 vs. 27.186 ng/ml. Prevalence of vitamin D deficiency and insufficiency was found to significantly higher in diabetics when compared to healthy subjects (P = 0.0001. Vitamin D deficiency was found to be significantly associated with neuropathy (χ2 = 5.39, df = 1, P = 0.020, retinopathy, (χ2 = 6.6, df = 1, P = 0.010 and nephropathy (χ2 = 10. 52, df = 1, P = 0.001. Lower levels of vitamin D were found to be associated with increasing prevalence of combinations of microvascular complications namely neuropathy with retinopathy (P = 0.036, neuropathy with nephropathy (P = 0

Ghrelin stimulates angiogenesis in human microvascular endothelial cells: Implications beyond GH release

International Nuclear Information System (INIS)

Li Aihua; Cheng Guangli; Zhu Genghui; Tarnawski, Andrzej S.

2007-01-01

Ghrelin, a peptide hormone isolated from the stomach, releases growth hormone and stimulates appetite. Ghrelin is also expressed in pancreas, kidneys, cardiovascular system and in endothelial cells. The precise role of ghrelin in endothelial cell functions remains unknown. We examined the expression of ghrelin and its receptor (GHSR1) mRNAs and proteins in human microvascular endothelial cells (HMVEC) and determined whether ghrelin affects in these cells proliferation, migration and in vitro angiogenesis; and whether MAPK/ERK2 signaling is important for the latter action. We found that ghrelin and GHSR1 are constitutively expressed in HMVEC. Treatment of HMVEC with exogenous ghrelin significantly increased in these cells proliferation, migration, in vitro angiogenesis and ERK2 phosphorylation. MEK/ERK2 inhibitor, PD 98059 abolished ghrelin-induced in vitro angiogenesis. This is First demonstration that ghrelin and its receptor are expressed in human microvascular endothelial cells and that ghrelin stimulates HMVEC proliferation, migration, and angiogenesis through activation of ERK2 signaling

The March of Extrahepatic Collaterals: Analysis of Blood Supply to Hepatocellular Carcinoma Located in the Bare Area of the Liver After Chemoembolization

International Nuclear Information System (INIS)

Miyayama, Shiro; Yamashiro, Masashi; Okuda, Miho; Yoshie, Yuichi; Nakashima, Yoshiko; Ikeno, Hiroshi; Orito, Nobuaki; Matsui, Osamu

2010-01-01

The purpose of this study was to evaluate changes in vascular supply to hepatocellular carcinoma (HCC) located in the bare area of the liver in patients who were mainly treated with chemoembolization. Twenty-six patients with HCC showing a mean diameter of 3.1 ± 1.4 cm (mean ± standard deviation) were mainly treated with chemoembolization. All patients underwent 2.7 ± 2.3 chemoembolization sessions over 40.1 ± 25.2 months. Tumor feeding branches demonstrated in each chemoembolization session were retrospectively evaluated. Initially, 18 tumors (59.2%) were supplied by the hepatic artery (H) and 8 (30.8%) by both the hepatic and the extrahepatic arteries (H + C). Fourteen tumors (53.8%) recurred at the posterior aspect of the tumor and were supplied by H (n = 4), H + C (n = 5), and extrahepatic collaterals (C) (n = 5). Several tumors recurred despite repeated chemoembolization, and these were supplied by H (n = 1), H + C (n = 7), and C (n = 2) at the second recurrence, by H (n = 1), H + C (n = 2), and C (n = 3) at the third, by H + C (n = 2) and C (n = 2) at the fourth, by H + C (n = 2) and C (n = 2) at the fifth, and by H (n = 1) and C (n = 1) at the sixth. One tumor was supplied by H at the seventh and by H + C at the eighth recurrence. As the number of local recurrences increased, the feeding vessel shifted from H to C. Especially, the right inferior phrenic artery (IPA) and renal capsular artery (RCA) supplied the tumor early, while the small right RCAs, adrenal arteries, and intercostal and lumbar artery supplied late recurrences in turns. In conclusion, HCCs located in the bare area are frequently supplied by extrahepatic vessels initially, while recurrence after chemoembolization is mainly due to extrahepatic blood supply. The right IPA and RCA are common feeding vessels demonstrated early, while other extrahepatic collateral supply from the retroperitoneal circulation occurs in turns during the later course.

Assessment of speed distribution of red blood cells in the microvascular network in healthy volunteers and type 1 diabetes using laser Doppler spectra decomposition

International Nuclear Information System (INIS)

Wojtkiewicz, S; Maniewski, R; Liebert, A; Wojcik-Sosnowska, E; Jasik, M; Karnafel, W

2014-01-01

We applied a recently reported method of decomposition of laser Doppler power density spectra for in vivo monitoring of speed distributions of red blood cells (RBCs) in the microvascular network. The spectrum decomposition technique allows us to derive the distribution of RBC speed (in absolute units (mm s −1 )) versus RBC concentration (in arbitrary units). We carried out postocclusive reactive hyperaemia (PORH) test in 15 healthy volunteers and 21 diabetic patients in which the duration of type 1 diabetes was longer than 10 years. Measurements were carried out simultaneously with the use of a typical laser Doppler commercial instrument and speed resolved laser Doppler instrument utilizing the new technique based on decomposition of the laser Doppler spectra. We show that for the classical laser Doppler instrument, none of the PORH parameters revealed a statistical significance of difference between the groups analyzed. In contrast, the RBC speed distributions obtained from laser Doppler spectra during rest in the control group and type 1 diabetes are statistically significant. This result suggests that speed distribution measurements in the rest state (without any kind of stimulation test) allows for the assessment of microcirculation disorders. Measurements carried out in healthy subjects show that the first moment of speed distributions (mean speed of the distributions) is 2.32 ± 0.54 mm s −1  and 2.57 ± 0.41 mm s −1  for optodes located on the toe and finger of the hand, respectively. Respective values in type 1 diabetes were higher: 3.00 ± 0.36 mm s −1  and 3.10 ± 0.48 mm s −1 . (paper)

Traumatic Arteriovenous Fistula of the Scalp in the Left Temporoparietal Region with Intra- and Extracranial Blood Supply

Directory of Open Access Journals (Sweden)

Feng Zheng

2016-01-01

Full Text Available Traumatic AVF of the scalp is a rare abnormal vascular disease. It is defined as a communication between the high flow arterial system and the low flow venous network, which directly connects the arterial feeding vessels of the scalp and the draining veins without an intervening capillary bed. The superficial temporal artery (STA was involved in 90% of the cases, and 71% of the patients only had one dominant feeding STA. Here, we report the case of a rare large traumatic arteriovenous fistula (AVF of the scalp that is fed by intra- and extracranial blood supply. The clinical and radiological features are presented, and the possible pathogenesis and surgical technique are discussed.

Blood hero: An application for encouraging the blood donation by applying gamification.

Science.gov (United States)

Domingos, Daniela C L; Lima, Luis F S G; Messias, Thiago F; Feijo, Jose V L; Diniz, Anthony A R; Soares, Heliana B

2016-08-01

There is a strong need for actions to supply the blood demand in the World. Based on this fact, it was designed an application, named `Blood Hero', by applying the `gamification' concept, which allows users to be rewarded by social acts related to the blood donation. It takes advantage of the application of mobile devices, implementing a specific social network, to attract and retain blood donators. This application makes possible an interaction between users and blood centers, and is being tested aiming at evaluating its acceptance and impact in bloodstocks.

[The periosteum: the "umbilical cord" of bone. Quantification of the blood supply of cortical bone of periosteal origin].

Science.gov (United States)

Chanavaz, M

1995-01-01

The Periosteum or periosteal membrane is a continuous composite fibroelastic covering membrane of the bone to which it is intimately linked. It consists of multipotent mesodermal cells (11, 15). Although the bone cortex is the main beneficiary of the principal anatomical and physiological functions of the periosteal membrane, the behaviour of the entire bone remains closely influenced by the periosteal activity. These principal functions are related to the cortical blood supply, osteogenesis, muscle and ligament attachments. Through its elastic and contractile nature, it participates in the maintenance of bone shape, and plays an important role in metabolic ionic exchange and physiological distribution of electro-chemical potential difference across its membranous structure. It has also been suggested that the periosteum may have its own specific proprioceptive property. This presentation will study the histo-anatomy and physiology of the periosteum and will discuss in detail its main functions of cortical blood supply and osteogenesis (fig. 1 and 2). It will also present the third intermediary report on a current study of the quantification of cortical vascularisation of femoral bone via the periosteum, using an isotonic salt solution of 85Strontium. The afferent-efferent (arterio-venous) flows of this solution in the thigh vascular system of guinea pigs were measured by gamma spectrometry after a series of selective macro and micro injections of radioactive salt into the femoral arterial system were carried out. Each vascular territory was meticulously selected and the injections were made according to size, starting with the larger vessels, with or without ligatures of neighbouring vessels, going progressively to smaller and smaller vessels not exceeding 100m in diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

Science.gov (United States)

Kise, Yuya; Kuniyoshi, Yukio; Inafuku, Hitoshi; Nagano, Takaaki; Hirayasu, Tsuneo; Yamashiro, Satoshi

2015-01-01

During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P flow with and without distal perfusion (r = 0.803, P network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring

Inhaled insulin for controlling blood glucose in patients with diabetes

Directory of Open Access Journals (Sweden)

Bernard L Silverman

2008-01-01

Full Text Available Bernard L Silverman1, Christopher J Barnes2, Barbara N Campaigne3, Douglas B Muchmore31Alkermes, Inc, Cambridge, MA, USA; 2i3 Statprobe, Ann Arbor, MI; 3Eli Lilly and Company, Indianapolis, IN, USAAbstract: Diabetes mellitus is a significant worldwide health problem, with the incidence of type 2 diabetes increasing at alarming rates. Insulin resistance and dysregulated blood glucose control are established risk factors for microvascular complications and cardiovascular disease. Despite the recognition of diabetes as a major health issue and the availability of a growing number of medications designed to counteract its detrimental effects, real and perceived barriers remain that prevent patients from achieving optimal blood glucose control. The development and utilization of inhaled insulin as a novel insulin delivery system may positively influence patient treatment adherence and optimal glycemic control, potentially leading to a reduction in cardiovascular complications in patients with diabetes.Keywords: diabetes, inhaled insulin, cardiovascular disease, blood glucose

Material & equipment, procurement & maintenance: Impact on blood safety.

Science.gov (United States)

Emmanuel, Jean C

2010-01-01

Blood Transfusion Safety is dependent on effectively organised and managed blood services, which have adequate financial resources, skilled manpower, appropriate infrastructure and quality management systems in place. 80% of the world's population has access to 20% of the supply blood products, of which little is consistently safe. HIV highlighted the importance of blood safety. The lack of effective blood services in low human development index (LHDI), developing countries, has lead to international funding and capacity building for more than three decades. The initial strategies focused on providing HIV testing reagents to prevention transmission, however this only addresses one part of blood safety. Blood safety is not only dependent on preventing HIV transmission. In many populations there are other infectious agents, which have a higher prevalence. Ensuring the correct blood is provided to the patient depends on: well managed services with effective leadership and adequate budgets; capacity building and retention of skilled experienced staff; availability of laboratory equipment, correctly maintained; blood cold chain systems; procedures for tendering, purchasing and ensuring an unbroken supply of reagents and consumables; and quality management systems. Barriers for simplified effective tendering, procurement and contracting require urgent attention and coordination of all funding organisations to ensure an unbroken supply of reagents. Copyright 2009. Published by Elsevier Ltd.

The effect of intramedullary bone endoscopy on the endosteal blood supply in long bones. An experimental study in sheep.

Science.gov (United States)

Herget, Georg W; Haberstroh, Jörg; Südkamp, Norbert; Riede, Ursus; Oberst, Michael

2011-02-01

This study investigated whether the Intramedullary Bone Endoscopy (IBE) procedure within the cavity of an intact long bone will interfere with the local endosteal blood supply. In a sheep model, 10 animals underwent the IBE procedure with complete perioperative anaesthesiology monitoring. After the femora were harvested, histological analysis was performed to examine destruction of the endosteum and consecutive reduction in perfusion. Only one animal showed evidence of detachment of the endosteum with destruction of several microns of the endosteum, although this did not interfere with the cortical perfusion. None of the vessels were occluded by fat or other causes of occlusion, e.g. blood coagulation. Our findings indicate that with the IBE procedure under visual control there is a potential risk to damage the endosteum. However, the interference was limited to a small part of the endosteum and did not lead to a reduction in the cortical perfusion. Clinical use could be in localized intramedullary lesions such as osteomyelitis or benign bone tumours.

RFID in the blood supply chain--increasing productivity, quality and patient safety.

Science.gov (United States)

Briggs, Lynne; Davis, Rodeina; Gutierrez, Alfonso; Kopetsky, Matthew; Young, Kassandra; Veeramani, Raj

2009-01-01

As part of an overall design of a new, standardized RFID-enabled blood transfusion medicine supply chain, an assessment was conducted for two hospitals: the University of Iowa Hospital and Clinics (UIHC) and Mississippi Baptist Health System (MBHS). The main objectives of the study were to assess RFID technological and economic feasibility, along with possible impacts to productivity, quality and patient safety. A step-by-step process analysis focused on the factors contributing to process "pain points" (errors, inefficiency, product losses). A process re-engineering exercise produced blueprints of RFID-enabled processes to alleviate or eliminate those pain-points. In addition, an innovative model quantifying the potential reduction in adverse patient effects as a result of RFID implementation was created, allowing improvement initiatives to focus on process areas with the greatest potential impact to patient safety. The study concluded that it is feasible to implement RFID-enabled processes, with tangible improvements to productivity and safety expected. Based on a comprehensive cost/benefit model, it is estimated for a large hospital (UIHC) to recover investment from implementation within two to three years, while smaller hospitals may need longer to realize ROI. More importantly, the study estimated that RFID technology could reduce morbidity and mortality effects substantially among patients receiving transfusions.

Palmitate-induced inflammatory pathways in human adipose microvascular endothelial cells promote monocyte adhesion and impair insulin transcytosis.

Science.gov (United States)

Pillon, Nicolas J; Azizi, Paymon M; Li, Yujin E; Liu, Jun; Wang, Changsen; Chan, Kenny L; Hopperton, Kathryn E; Bazinet, Richard P; Heit, Bryan; Bilan, Philip J; Lee, Warren L; Klip, Amira

2015-07-01

Obesity is associated with inflammation and immune cell recruitment to adipose tissue, muscle and intima of atherosclerotic blood vessels. Obesity and hyperlipidemia are also associated with tissue insulin resistance and can compromise insulin delivery to muscle. The muscle/fat microvascular endothelium mediates insulin delivery and facilitates monocyte transmigration, yet its contribution to the consequences of hyperlipidemia is poorly understood. Using primary endothelial cells from human adipose tissue microvasculature (HAMEC), we investigated the effects of physiological levels of fatty acids on endothelial inflammation and function. Expression of cytokines and adhesion molecules was measured by RT-qPCR. Signaling pathways were evaluated by pharmacological manipulation and immunoblotting. Surface expression of adhesion molecules was determined by immunohistochemistry. THP1 monocyte interaction with HAMEC was measured by cell adhesion and migration across transwells. Insulin transcytosis was measured by total internal reflection fluorescence microscopy. Palmitate, but not palmitoleate, elevated the expression of IL-6, IL-8, TLR2 (Toll-like receptor 2), and intercellular adhesion molecule 1 (ICAM-1). HAMEC had markedly low fatty acid uptake and oxidation, and CD36 inhibition did not reverse the palmitate-induced expression of adhesion molecules, suggesting that inflammation did not arise from palmitate uptake/metabolism. Instead, inhibition of TLR4 to NF-κB signaling blunted palmitate-induced ICAM-1 expression. Importantly, palmitate-induced surface expression of ICAM-1 promoted monocyte binding and transmigration. Conversely, palmitate reduced insulin transcytosis, an effect reversed by TLR4 inhibition. In summary, palmitate activates inflammatory pathways in primary microvascular endothelial cells, impairing insulin transport and increasing monocyte transmigration. This behavior may contribute in vivo to reduced tissue insulin action and enhanced tissue

Systemic oxidative-nitrosative-inflammatory stress during acute exercise in hypoxia; implications for microvascular oxygenation and aerobic capacity.

Science.gov (United States)

Woodside, John D S; Gutowski, Mariusz; Fall, Lewis; James, Philip E; McEneny, Jane; Young, Ian S; Ogoh, Shigehiko; Bailey, Damian M

2014-12-01

Exercise performance in hypoxia may be limited by a critical reduction in cerebral and skeletal tissue oxygenation, although the underlying mechanisms remain unclear. We examined whether increased systemic free radical accumulation during hypoxia would be associated with elevated microvascular deoxygenation and reduced maximal aerobic capacity (V̇O2 max ). Eleven healthy men were randomly assigned single-blind to an incremental semi-recumbent cycling test to determine V̇O2 max in both normoxia (21% O2) and hypoxia (12% O2) separated by a week. Continuous-wave near-infrared spectroscopy was employed to monitor concentration changes in oxy- and deoxyhaemoglobin in the left vastus lateralis muscle and frontal cerebral cortex. Antecubital venous blood samples were obtained at rest and at V̇O2 max to determine oxidative (ascorbate radical by electron paramagnetic resonance spectroscopy), nitrosative (nitric oxide metabolites by ozone-based chemiluminescence and 3-nitrotyrosine by enzyme-linked immunosorbent assay) and inflammatory stress biomarkers (soluble intercellular/vascular cell adhesion 1 molecules by enzyme-linked immunosorbent assay). Hypoxia was associated with increased cerebral and muscle tissue deoxygenation and lower V̇O2 max (P exercise-induced increase in oxidative-nitrosative-inflammatory stress, hypoxia per se did not have an additive effect (P > 0.05 versus normoxia). Consequently, we failed to observe correlations between any metabolic, haemodynamic and cardiorespiratory parameters (P > 0.05). Collectively, these findings suggest that altered free radical metabolism cannot explain the elevated microvascular deoxygenation and corresponding lower V̇O2 max in hypoxia. Further research is required to determine whether free radicals when present in excess do indeed contribute to the premature termination of exercise in hypoxia. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

PROGRESS IN BLOOD TRANSFUSION SERVICES IN KENYA ...

African Journals Online (AJOL)

2009-12-02

Dec 2, 2009 ... Background: Provision of safe and adequate supplies of blood is dependent on a well organised blood ... effective legislative policies governing operations of blood transfusion .... policy and push for semi autonomy. (iv) Put up ...

Seroprevalence of Trypanosoma cruzi in blood donors at the National Blood Transfusion Services--Guyana.

Science.gov (United States)

Bwititi, P T; Browne, J

2012-09-01

Blood transfusion is an important transmission route of Trypanosoma cruzi (T cruzi), a major parasitic infection in Central and South America. The limited treatment options are most effective in acute Chagas' infection. At present, there is no current data on the prevalence of T cruzi in the blood donor population of Guyana. This information is necessary to protect the supply of the blood donation programme. This study sought to determine the prevalence of T cruzi in the blood supply at the National Blood Transfusion Services of Guyana with the hope of providing knowledge to the on-going surveillance for Chagas' disease worldwide and therefore address the risk of its spread by blood transfusion. Two commercialized ELISAs utilizing crude or recombinant T cruzi antigens were used to study 2000 blood samples voluntarily donated for the purpose of altruistic or family replacement donation retrospectively. The results showed that approximately 1 in 286 donations tested positive for antibodies to T cruzi. These results indicate that T cruzi continues to be a risk in Guyana and there is a need to continue screening donated blood. Trypanosoma cruzi is a life-long infection and infected persons may be asymptomatic chronic carriers of the disease. Education, housing improvement, and controlled use of insecticides should be introduced to contain Chagas' disease.

Recycled incomplete identification procedures for blood screening

NARCIS (Netherlands)

Bar-Lev, S.K.; Boxma, O.J.; Kleiner, I.; Perry, D.; Stadje, W.

2017-01-01

The operation of blood banks aims at the cost-efficient supply of uncontaminated human blood. Each unit of donated blood goes through multiple testing for the presence of various pathogens which are able to cause transfusion-transmitted diseases. The blood screening process is comprised of two

Whole blood pathogen reduction technology and blood safety in sub-Saharan Africa: A systematic review with regional discussion.

Science.gov (United States)

Nkohkwo, Asa'ah; Agbor, Gabriel; Asongalem, Emmanuel; Tagny, Claude; Asonganyi, Tazoacha

2016-01-01

Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region. This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region. The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinicians, scientists and professional bodies in the region, including the World Health Organization's Regional Office for Africa, to examine the suitability of PRT for improving the safety of whole blood transfusion, a prevalent transfusion format in the region. Existing literature suggests that combining PRT with current blood safety measures (such as serology) would improve the safety and adequacy of the blood supply for transfusions in sub-Saharan Africa. This was echoed by the findings of the stakeholder meetings. Following a detailed appraisal of two leading PRT systems, the Mirasol ® PRT System and the Cerus S-303 System, we suggest that companies conduct comprehensive toxicological evaluation of the agents used for PRT and publish this in the scientific literature. We also recommend that the safety and efficacy of these technologies should be established in a randomised clinical trial conducted in sub-Saharan Africa.

HIV and the Blood Supply: An Analysis of Crisis Decisionmaking

National Research Council Canada - National Science Library

Leveton, Lauren B; Sox, Harold C. Jr; Stoto, Michael A

.... Because little reliable information existed at the time AIDS first began showing up in hemophiliacs and in others who had received transfusions, experts disagreed about whether blood and blood...

GLP-1-based therapies have no microvascular effects in type 2 diabetes mellitus

NARCIS (Netherlands)

Smits, Mark M.; Tonneijck, Lennart; Muskiet, Marcel H.A.; Hoekstra, Trynke; Kramer, Mark H.H.; Diamant, Michaela; Serné, Erik H.; Van Raalte, Daniël H.

2016-01-01

Objective - To assess the effects of glucagon-like peptide (GLP)-1-based therapies (ie, GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) on microvascular function in patients with type 2 diabetes mellitus. Approach and Results - We studied 57 patients with type 2 diabetes mellitus

Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model

NARCIS (Netherlands)

van Bommel, J.; Siegemund, M.; Henny, C. P.; van den Heuvel, D. A.; Trouwborst, A.; Ince, C.

2000-01-01

The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2).

Hepatic microvascular dysfunction and increased advanced glycation end products are components of non-alcoholic fatty liver disease.

Science.gov (United States)

Pereira, Evelyn Nunes Goulart da Silva; Silvares, Raquel Rangel; Flores, Edgar Eduardo Ilaquita; Rodrigues, Karine Lino; Ramos, Isalira Peroba; da Silva, Igor José; Machado, Marcelo Pelajo; Miranda, Rosiane Aparecida; Pazos-Moura, Carmen Cabanelas; Gonçalves-de-Albuquerque, Cassiano F; Faria-Neto, Hugo Caire de Castro; Tibiriça, Eduardo; Daliry, Anissa

2017-01-01

This study aimed to investigate the pathophysiology of hepatic microcirculatory dysfunction in non-alcoholic fatty liver disease (NAFLD). In Wistar rats, NAFLD model was induced by 20 weeks of high-fat diet (HFD) feeding. Rolling and adhesion of leukocytes and tissue perfusion in hepatic microcirculation were examined using in vivo microscopic and laser speckle contrast imaging (LSCI), respectively. Oxidative stress and inflamatory parameters were analysed by TBARs, catalase enzyme activity, RT-PCR and ELISA. The participation of advanced glycation end-products (AGE) and its receptor RAGE was evaluated by the measurement of gene and protein expression of RAGE by RT-PCR and Western-blot, respectively and by liver and serum quantification of fluorescent AGEs. Wistar rats fed high-fat diet (HFD) showed increase in epididymal and abdominal fat content, systolic arterial blood pressure, fasting blood glucose levels, hepatic triglycerides and cholesterol, and impairment of glucose and insulin metabolisms. Liver histology confirmed the presence of steatosis and ultrasound analysis revealed increased liver size and parenchymal echogenicity in HFD-fed rats. HFD causes significant increases in leukocyte rolling and adhesion on hepatic microcirculation and decrease in liver microvascular blood flow. Liver tissue presented increase in oxidative stress and inflammtion. At 20 weeks, there was a significantly increase in AGE content in the liver and serum of HFD-fed rats and an increase in RAGE gene expression in the liver. The increase in liver AGE levels and microcirculatory disturbances could play a role in the pathogenesis of liver injury and are key components of NAFLD.

HIV and the Blood Supply: An Analysis of Crisis Decisionmaking

National Research Council Canada - National Science Library

Leveton, Lauren B; Sox, Harold C. Jr; Stoto, Michael A

.... This volume provides a balanced inquiry into the blood safety controversy, which involves private sexual practices, personal tragedy for the victims of HIV/AIDS, and public confidence in America's blood services system...

A microvascular compartment model validated using 11C-methylglucose liver PET in pigs

Science.gov (United States)

Munk, Ole L.; Keiding, Susanne; Baker, Charles; Bass, Ludvik

2018-01-01

The standard compartment model (CM) is widely used to analyse dynamic PET data. The CM is fitted to time-activity curves to estimate rate constants that describe the transport of a tracer between well-mixed compartments. The aim of this study was to develop and validate a more realistic microvascular compartment model (MCM) that includes capillary tracer concentration gradients, backflux from cells into the perfused capillaries and multiple re-uptakes during the passage through a capillary. The MCM incorporates only parameters with clear physiological meaning, it is easy to implement, and it does not require numerical solution. We compared the MCM and CM for the analysis of 3 min dynamic PET data of pig livers (N  =  5) following injection of 11C-methylglucose. During PET scans, the tracer concentrations in blood were measured in the abdominal aorta, portal vein and liver vein by manual sampling. We found that the MCM outperformed the CM and that dynamic PET data include information which cannot be extracted using standard CM. The MCM fitted dynamic PET data better than the CM (Akaike values were 46  ±  4 for best MCM fits, and 82  ±  8 for best CM fits; mean  ±  standard deviation) and extracted physiologically reasonable parameter estimates such as blood perfusion that were in agreement with independent measurements. The difference between model-independent perfusion estimates and the best MCM perfusion estimates was  -0.01  ±  0.05 ml/ml/min, whereas the difference was 0.30  ±  0.13 ml/ml/min using the CM. In addition, the MCM predicted the time course of concentrations in the liver vein, a prediction fundamentally unobtainable using the CM as it does not return tracer backflux from cells to capillary blood. The results demonstrate the benefit of using models that include more physiology and that models including concentration gradients should be preferred when analysing the blood-cell exchange of

Microvascular volume in symptomatic Achilles tendons is associated with VISA-A score.

Science.gov (United States)

Praet, S F E; Ong, J H; Purdam, C; Welvaert, M; Lovell, G; Dixon, L; Gaida, J E; Anglim, J; Manzanero, S; Vlahovich, N; Hughes, D; Waddington, G

2018-05-15

The role of neovascularisation in tendinopathy is still poorly understood, potentially due to technical limitations of conventional power Doppler ultrasound. This study aimed to investigate the association between contrast-enhanced ultrasound (CEUS) microvascular volume (MV), Victorian Institute of Sports Assessment-Achilles (VISA-A) scores and intrinsic Achilles tendon tenderness, as well as two different Power Doppler modes. Cross-sectional study. 20 individuals with uni- or bilateral Achilles tendinopathy completed a VISA-A questionnaire, and underwent microvascular volume measurements of the Achilles tendon mid-portion using both conventional, ultrasensitive (SMI™) power Doppler ultrasound and CEUS. Intrinsic tendon tenderness was assessed with sensation detection threshold to extracorporeal shock waves (ESW). Linear Mixed Model analysis was used to determine the association between microvascular volume (MV), VISA-A, and ESW-detection threshold for both symptomatic and asymptomatic Achilles tendons. There was a significant association between VISA-A and MV (B=-5.3, 95%CI=[-8.5; -2.0], P=0.0004), and between MV and symptom duration (B=-1.7, 95%CI=[-3.2; -5.0], P=0.023). No significant associations were found between power Doppler ultrasound and CEUS-based MV or between CEUS-based MV and ESW-detection threshold. In comparison with conventional power Doppler ultrasound, SMI™ showed on average similar detection capacity for neovessels in the mid-portion of the Achilles tendon, whilst being superior for detecting neovessels within Kager's fat pad (t=3.46, 95%CI=[0.27; 1.03], P<0.005). Our results indicate that CEUS-based MV of the Achilles tendon is moderately associated with Achilles tendon symptoms. In accordance, CEUS-detected MV could be a novel target for treatment as it seems to be more sensitive than PDU and is correlated with symptoms. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Determination of bone blood supply with /sup 99m/Tc red blood cells and /sup 113m/In transferrin in fractures of femoral neck: concise communication

Energy Technology Data Exchange (ETDEWEB)

Kempi, V.; Sandegard, J.

1982-05-01

The uptake of in vivo labeled /sup 99m/Tc RBCs and /sup 113/In transferrin was studied in femoral bone of 21 patients who had recent operations for fracture of the femoral neck. Femoral bone biopsies and blood samples were obtained during the operation. The activity values for bone biopsies, erythrocytes, and serum were determined, and the uptake ratios between bone and erythrocyte cpm/g and between bone and serum were calculated. Biopsy samples were taken from the femoral head in 21 cases and from the trochanteric region in 14. The activity ratios for the two tracers correlated well: r . 0.94 for femoral head biopsies (P less than 0.001) and r . 0.98 for samples from the trochanteric region (P less than 0.001). Thus, the procedures are interchangeable and either may be valuable in assessing bone blood supply. An additional patient, studied only with /sup 99m/Tc RBCs, had a subsequent operation for nonunion of a fracture. Samples of both cancellous and cortical bone were obtained from the removed head. The activity ratios for the two types of bone tissue differed significantly (P . 0.02).

Determination of bone blood supply with /sup 99m/Tc red blood cells and /sup 113m/In transferrin in fractures of femoral neck: concise communication

International Nuclear Information System (INIS)

Kempi, V.; Sandegard, J.

1982-01-01

The uptake of in vivo labeled /sup 99m/Tc RBCs and 113 In transferrin was studied in femoral bone of 21 patients who had recent operations for fracture of the femoral neck. Femoral bone biopsies and blood samples were obtained during the operation. The activity values for bone biopsies, erythrocytes, and serum were determined, and the uptake ratios between bone and erythrocyte cpm/g and between bone and serum were calculated. Biopsy samples were taken from the femoral head in 21 cases and from the trochanteric region in 14. The activity ratios for the two tracers correlated well: r . 0.94 for femoral head biopsies (P less than 0.001) and r . 0.98 for samples from the trochanteric region (P less than 0.001). Thus, the procedures are interchangeable and either may be valuable in assessing bone blood supply. An additional patient, studied only with /sup 99m/Tc RBCs, had a subsequent operation for nonunion of a fracture. Samples of both cancellous and cortical bone were obtained from the removed head. The activity ratios for the two types of bone tissue differed significantly

Early impairment of coronary microvascular perfusion capacity in rats on a high fat diet

NARCIS (Netherlands)

van Haare, Judith; Kooi, M. Eline; Vink, Hans; Post, Mark J.; van Teeffelen, Jurgen W. G. E.; Slenter, Jos; Munts, Chantal; Cobelens, Hanneke; Strijkers, Gustav J.; Koehn, Dennis; van Bilsen, Marc

2015-01-01

It remains to be established if, and to what extent, the coronary microcirculation becomes compromised during the development of obesity and insulin resistance. Recent studies suggest that changes in endothelial glycocalyx properties contribute to microvascular dysfunction under (pre-)diabetic

Alternative wavelengths for sutureless laser microvascular anastomosis: a preliminary study on acute samples.

Science.gov (United States)

Bass, L S; Oz, M C; Libutti, S K; Treat, M R

1992-06-01

Attempts to improve the speed and patency of microvascular anastomosis with laser-assisted techniques have provided a modest reduction in operative time and comparable success rates. Using sutureless microvascular anastomoses, 30 end-to-end anastomoses were created in the rat carotid artery using the gallium-aluminum-arsenide diode laser (808 nm). Indocyanine green and fibrinogen were applied to enhance tissue absorption of the laser energy and strengthen the bond created. These were compared with previously reported welds using the THC:YAG laser (2150 nm). Mean welding times were 140 and 288 s, and mean bursting pressures immediately after welding were 515 and 400 mmHg for the diode and THC:YAG laser groups, respectively. Histologically, both lateral and vertical spread of thermal damage was limited. Since both lasers create welds of adequate initial strength without stay sutures and are faster and easier to use than existing systems, evaluation of long-term patency would be worthwhile.

DETECTION OF MICROVASCULAR COMPLICATIONS OF TYPE 2 DIABETES BY EZSCAN AND ITS COMPARISON WITH STANDARD SCREENING METHODS

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Sarita Bajaj

2016-08-01

Full Text Available BACKGROUND EZSCAN is a new, noninvasive technique to detect sudomotor dysfunction and thus neuropathy in diabetes patients at an early stage. It further predicts chances of development of other microvascular complications. In this study, we evaluated EZSCAN for detection of microvascular complications in Type 2 diabetes patients and compared accuracy of EZSCAN with standard screening methods. MATERIALS AND METHODS 104 known diabetes patients, 56 males and 48 females, were studied. All cases underwent the EZSCAN test, Nerve Conduction Study (NCS test, Vibration perception threshold test (VPT, Monofilament test, Fundus examination and Urine micral test. The results of EZSCAN were compared with standard screening methods. The data has been analysed and assessed by applying appropriate statistical tests within different groups. RESULTS Mean age of the subjects was 53.5 ± 11.4 years. For detection of diabetic neuropathy, sensitivity and specificity of EZSCAN was found to be 77.0 % and 95.3%, respectively. Odd’s ratio (OR was 68.82 with p < 0.0001. AUC in ROC curve was 0.930. Sensitivity and specificity of EZSCAN for detection of nephropathy were 67.1% and 94.1%, respectively. OR = 32.69 with p < 0.0001. AUC was 0.926. Sensitivity of EZSCAN for detection of retinopathy was 90% while specificity is 70.3%. OR = 21.27; p< 0.0001. AUC came out to be 0.920. CONCLUSION Results of EZSCAN test compared significantly to the standard screening methods for the detection of microvascular complications of diabetes and can be used as a simple, noninvasive and quick method to detect microvascular complications of diabetes.

[Evaluation of three-dimensional tumor microvascular architecture phenotype heterogeneity in non-small cell carcinoma and its significance].

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Zhou, Hui; Liu, Jinkang; Chen, Shengxi; Xiong, Zeng; Zhou, Jianhua; Tong, Shiyu; Chen, Hao; Zhou, Moling

2012-06-01

To explore the degree, mechanism and clinical significance of three-dimensional tumor microvascular architecture phenotype heterogeneity (3D-TMAPH) in non-small cell carcinoma (NSCLC). Twenty-one samples of solitary pulmonary nodules were collected integrally. To establish two-dimensional tumor microvascular architecture phenotype (2D-TMAP) and three-dimensional tumor microvascular architecture phenotype (3D-TMAP), five layers of each nodule were selected and embedded in paraffin. Test indices included the expressions of vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), EphB4, ephfinB2 and microvascular density marked by anti-CD34 (CD34-MVD). The degrees of 3D-TMAPH were evaluated by the coefficient of variation and extend of heterogeneity. Spearman rank correlation analysis was used to investigate the relationships between 2D-TMAP, 3D-TMAP and clinicopathological features. 3D-TMAPH showed that 2D-TMAP heterogeneity was expressed in the tissues of NSCLC. The heterogeneities in the malignant nodules were significantly higher than those in the active inflammatory nodules and tubercular nodules. In addition, different degrees of heterogeneity of CD34-MVD and PCNA were found in NSCLC tissues. The coefficients of variation of CD34- MVD and PCNA were positively related to the degree of differentiation (all P0.05). The level of heterogeneity of various expression indexes (ephrinB2, EphB4, VEGF) in NSCLC tissues were inconsistent, but there were no significant differences in heterogeneity in NSCLC tissues with different histological types (P>0.05). 3D-TMAPH exists widely in the microenvironment during the genesis and development of NSCLC and has a significant impact on its biological complexity.

Meeting blood requirements following terrorist attacks: the Israeli experience.

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Shinar, Eilat; Yahalom, Vered; Silverman, Barbara G

2006-11-01

Blood services worldwide must be prepared to meet surges in demand for blood components needed by casualties of domestic disasters and acts of terrorism. Israel's National Blood Services, operated by Magen David Adom, has extensive experience in managing blood collections and supply in emergencies. This review summarizes the structure and function of Magen David Adom's national blood program, and relates its experience to other practices that have been reported in the medical literature. Between 2000 and 2005, 7497 victims (85% civilians) were involved in 1645 terrorist attacks in Israel. On-site triage resulted in 967 (13%) deaths at the scene, 615 (8%) with severe injuries, 897 (12%) with moderate injuries and 5018 (67%) with mild injuries. Requests for blood averaged 1.3 blood units and 0.9 components per casualty, or 6.7 units and 4.5 components per severe and moderately injured patient. Public appeals for blood donations were managed centrally to match supply with demand and prevent wastage. This experience illustrates the advantages of a comprehensive program for managing blood operations in emergency situations. A coordinated national program can stabilize in-hospital inventories during routine activities, ensure instant access to precisely defined inventories, facilitate sufficient supply in times of disasters, and minimize outdating and wastage.

Concise review: stem cell-based approaches to red blood cell production for transfusion.

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Shah, Siddharth; Huang, Xiaosong; Cheng, Linzhao

2014-03-01

Blood transfusion is a common procedure in modern medicine, and it is practiced throughout the world; however, many countries report a less than sufficient blood supply. Even in developed countries where the supply is currently adequate, projected demographics predict an insufficient supply as early as 2050. The blood supply is also strained during occasional widespread disasters and crises. Transfusion of blood components such as red blood cells (RBCs), platelets, or neutrophils is increasingly used from the same blood unit for multiple purposes and to reduce alloimmune responses. Even for RBCs and platelets lacking nuclei and many antigenic cell-surface molecules, alloimmunity could occur, especially in patients with chronic transfusion requirements. Once alloimmunization occurs, such patients require RBCs from donors with a different blood group antigen combination, making it a challenge to find donors after every successive episode of alloimmunization. Alternative blood substitutes such as synthetic oxygen carriers have so far proven unsuccessful. In this review, we focus on current research and technologies that permit RBC production ex vivo from hematopoietic stem cells, pluripotent stem cells, and immortalized erythroid precursors.

Uterine microvascular sensitivity to nanomaterial inhalation: An in vivo assessment

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Stapleton, P.A.; McBride, C.R.; Yi, J.; Nurkiewicz, T.R., E-mail: tnurkiewicz@hsc.wvu.edu

2015-11-01

With the tremendous number and diverse applications of engineered nanomaterials incorporated in daily human activity, exposure can no longer be solely confined to occupational exposures of healthy male models. Cardiovascular and endothelial cell dysfunction have been established using in vitro and in situ preparations, but the translation to intact in vivo models is limited. Intravital microscopy has been used extensively to understand microvascular physiology while maintaining in vivo neurogenic, humoral, and myogenic control. However, a tissue specific model to assess the influences of nanomaterial exposure on female reproductive health has not been fully elucidated. Female Sprague Dawley (SD) rats were exposed to nano-TiO{sub 2} aerosols (171 ± 6 nm, 10.1 ± 0.39 mg/m{sup 3}, 5 h) 24-hours prior to experimentation, leading to a calculated deposition of 42.0 ± 1.65 μg. After verifying estrus status, vital signs were monitored and the right horn of the uterus was exteriorized, gently secured over an optical pedestal, and enclosed in a warmed tissue bath using intravital microscopy techniques. After equilibration, significantly higher leukocyte-endothelium interactions were recorded in the exposed group. Arteriolar responsiveness was assessed using ionophoretically applied agents: muscarinic agonist acetylcholine (0.025 M; ACh; 20, 40, 100, and 200 nA), and nitric oxide donor sodium nitroprusside (0.05 M; SNP; 20, 40, and 100 nA), or adrenergic agonist phenylephrine (0.05 M; PE; 20, 40, and 100 nA) using glass micropipettes. Passive diameter was established by tissue superfusion with 10{sup −4} M adenosine. Similar to male counterparts, female SD rats present systemic microvascular dysfunction; however the ramifications associated with female health and reproduction have yet to be elucidated. - Highlights: • Female reproductive health associated with nanomaterial exposure is understudied. • We examined uterine microvascular alterations 24-hours after nano

Neocortical Transplants in the Mammalian Brain Lack a Blood-Brain Barrier to Macromolecules

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Rosenstein, Jeffrey M.

1987-02-01

In order to determine whether the blood-brain barrier was present in transplants of central nervous tissue, fetal neocortex, which already possesses blood-brain and blood-cerebrospinal fluid barriers to protein, was grafted into the undamaged fourth ventricle or directly into the neocortex of recipient rats. Horseradish peroxidase or a conjugated human immunoglobulin G-peroxidase molecule was systemically administered into the host. These proteins were detected within the cortical transplants within 2 minutes regardless of the age of the donor or postoperative time. At later times these compounds, which normally do not cross the blood-brain barrier, inundated the grafts and adjacent host brain and also entered the cerebrospinal fluid. Endogenous serum albumin detected immunocytochemically in untreated hosts had a comparable although less extensive distribution. Thus, transplants of fetal central nervous tissue have permanent barrier dysfunction, probably due to microvascular changes, and are not integrated physiologically within the host. Blood-borne compounds, either systemically administered or naturally occurring, which should never contact normal brain tissue, have direct access to these transplants and might affect neuronal function.

Arterial blood supply to the thalamus and midbrain on CT sections, 2

International Nuclear Information System (INIS)

Takeshita, Gen; Ottomo, Michinori; Satoh, Nobuko; Yokoyama, Yoshiaki.

1984-01-01

The selective injection of a dyestuff into thalamoperforating arteries from the posterior part of the circle of Willis, using five postmortem brains, was performed. After fixation, sections parallel to the orbito-meatal line were obtained. In cases which showed a standard development of the posterior communicating arteries, the usual patterns were as follows: the area supplied by perforators of the posterior communicating artery (anterior thalamoperforating artery) was visualized in the hypothalamus and the antero-lateral part of the thalamus; the area supplied by perforators of the proximal segment of the posterior cerebral artery (interpeduncular thalamoperforating artery) was visualized in the midbrain and the medial part of thalamus; the area supplied by perforators of the ambient segment of the posterior cerebral artery (thalamogeniculate artery) was visualized in the medial part of the geniculate body and the posterior part of the thalamus. According to the development of the posterior communicating artery, the area supplied by each perforator was quite variable. Three CT sections were obtained containing three different patterns of the posterior communicating artery: 1) well-developed; 2) moderately developed; and 3) poorly developed. The identification of the area supplied by thalamoperforating arteries on CT sections was quite useful in the CT diagnosis of cerebrovascular disorders which involved the thalamus and the midbrain. (author)

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

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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.

Effects of anesthesia on the cerebral capillary blood flow in young and old mice

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Moeini, Mohammad; Tabatabaei, Maryam S.; Bélanger, Samuel; Avti, Pramod; Castonguay, Alexandre; Pouliot, Philippe; Lesage, Frédéric

2015-03-01

Despite recent findings on the possible role of age-related cerebral microvasculature changes in cognition decline, previous studies of capillary blood flow in aging (using animal models) are scarce and limited to anesthetized conditions. Since anesthesia can have different effects in young and old animals, it may introduce a confounding effect in aging studies. The present study aimed to eliminate the potential confound introduced by anesthesia by measuring capillary blood flow parameters in both awake conditions and under isoflurane anesthesia. We used 2-photon laser scanning fluorescence microscopy to measure capillary diameter, red blood cell velocity and flux, hematocrit and capillary volumetric flow in individual capillaries in the barrel cortex of 6- and 24-month old C57Bl/6 mice. It was observed that microvascular properties are significantly affected by anesthesia leading to different trends in capillary blood flow parameters with aging when measured under awake or anesthetized conditions. The findings in this study suggest taking extra care in interpreting aging studies from anesthetized animals.

Coronary Microvascular Function and Cardiovascular Risk Factors in Women With Angina Pectoris and No Obstructive Coronary Artery Disease

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Mygind, Naja Dam; Michelsen, Marie Mide; Peña, Adam

2016-01-01

BACKGROUND: The majority of women with angina-like chest pain have no obstructive coronary artery disease when evaluated with coronary angiography. Coronary microvascular dysfunction is a possible explanation and associated with a poor prognosis. This study evaluated the prevalence of coronary...... microvascular dysfunction and the association with symptoms, cardiovascular risk factors, psychosocial factors, and results from diagnostic stress testing. METHODS AND RESULTS: After screening 3568 women, 963 women with angina-like chest pain and a diagnostic coronary angiogram without significant coronary.......01), hypertension (P=0.02), current smoking (Ppain characteristics or results from diagnostic stress testing...

Low Red Blood Cell Vitamin C Concentrations Induce Red Blood Cell Fragility: A Link to Diabetes Via Glucose, Glucose Transporters, and Dehydroascorbic Acid

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Hongbin Tu

2015-11-01

Full Text Available Strategies to prevent diabetic microvascular angiopathy focus on the vascular endothelium. Because red blood cells (RBCs are less deformable in diabetes, we explored an original concept linking decreased RBC deformability to RBC ascorbate and hyperglycemia. We characterized ascorbate concentrations from human and mouse RBCs and plasma, and showed an inverse relationship between RBC ascorbate concentrations and deformability, measured by osmotic fragility. RBCs from ascorbate deficient mice were osmotically sensitive, appeared as spherocytes, and had decreased β-spectrin. These aberrancies reversed with ascorbate repletion in vivo. Under physiologic conditions, only ascorbate's oxidation product dehydroascorbic acid (DHA, a substrate for facilitated glucose transporters, was transported into mouse and human RBCs, with immediate intracellular reduction to ascorbate. In vitro, glucose inhibited entry of physiologic concentrations of dehydroascorbic acid into mouse and human RBCs. In vivo, plasma glucose concentrations in normal and diabetic mice and humans were inversely related to respective RBC ascorbate concentrations, as was osmotic fragility. Human RBC β-spectrin declined as diabetes worsened. Taken together, hyperglycemia in diabetes produced lower RBC ascorbate with increased RBC rigidity, a candidate to drive microvascular angiopathy. Because glucose transporter expression, DHA transport, and its inhibition by glucose differed for mouse versus human RBCs, human experimentation is indicated.

Analysis of inventory strategies for blood components in a regional blood center using process simulation.

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Baesler, Felipe; Nemeth, Matías; Martínez, Cristina; Bastías, Alfonso

2014-02-01

The storage of blood components is an important concern in the blood supply chain. Because these are perishable products, the definition of good inventory policies is crucial to reduce shortages and spills. To analyze and propose inventory policies in a regional blood center, a discrete event simulation model was created using simulation software (Arena 12.0, Rockwell Software). The model replicates the activities that are performed along the supply chain including donation arrivals, testing, production, inventory management, and dispatching. Twelve different scenarios were analyzed, with each one representing different inventory policies composed of a combination of an optimal inventory, a reorder point, and a level of extra donations. The best scenario demonstrates that it is possible to decrease unsatisfied demand and wastage of red blood cell units by 2.5 and 3%, respectively, when compared to current practices. This study shows that simulation is an alternative that can be used to model inventory components in blood centers. A responsible selection of inventory variables can improve the capability of the system to respond to the final patient requirements. © 2013 American Association of Blood Banks.

Effects of exercise training on calf muscle oxygen extraction and blood flow in patients with peripheral artery disease.

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Baker, Wesley B; Li, Zhe; Schenkel, Steven S; Chandra, Malavika; Busch, David R; Englund, Erin K; Schmitz, Kathryn H; Yodh, Arjun G; Floyd, Thomas F; Mohler, Emile R

2017-12-01

We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain near-infrared spectroscopy (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow and oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD patients ( n = 64) were randomly assigned to exercise and control groups. Patients in the exercise group received 3 mo of supervised exercise training. Calf muscle blood flow and oxygen extraction were optically monitored before, during, and after performance of a graded treadmill protocol at baseline and at 3 mo in both groups. Additionally, measurements of the ankle-brachial index (ABI) and peak walking time (PWT) to maximal claudication were made during each patient visit. Supervised exercise training was found to increase the maximal calf muscle blood flow and oxygen extraction levels during treadmill exercise by 29% (13%, 50%) and 8% (1%, 12%), respectively [ P group population were significantly higher than corresponding changes in the control group ( P training also increased PWT by 49% (18%, 101%) ( P = 0.01). However, within statistical error, the ABI, resting calf muscle blood flow and oxygen extraction, and the recovery half-time for hemoglobin\\myoglobin desaturation following cessation of maximal exercise were not altered by exercise training. The concurrent monitoring of both blood flow and oxygen extraction with the hybrid DCS/FD-NIRS instrument revealed enhanced muscle oxidative metabolism during physical activity from exercise training, which could be an underlying mechanism for the observed improvement in PWT. NEW & NOTEWORTHY We report on noninvasive optical measurements of skeletal muscle blood flow and oxygen extraction dynamics before/during/after treadmill exercise in peripheral artery disease patients who experience claudication. The measurements tracked the effects of a 3-mo supervised

A model of physical factors in the structural adaptation of microvascular networks in normotension and hypertension

DEFF Research Database (Denmark)

Jacobsen, Jens Christian Brings; Gustafsson, Finn; Holstein-Rathlou, N.-H.

2003-01-01

Adequate function of the microcirculation is vital to any tissue. To maintain an optimal function, microvascular networks must be able to adapt structurally to changes in the physical environment. Here we present a mathematical network model based on vessel wall mechanics. We assume based...... diameter, until equilibrium is restored. The model explains several of the key features observed experimentally in the microcirculation in normotension and hypertension. Most importantly, it suggests a scenario where overall network structure and network hemodynamics depend on adaptation to local...... hemodynamic stimuli in the individual vessel. Simulated results show emanating microvascular networks with properties similar to those observed in vivo. The model points to an altered endothelial function as a key factor in the development of vascular changes characteristic of hypertension....

Intercellular adhesion molecule-1 blockade attenuates inflammatory response and improves microvascular perfusion in rat pancreas grafts.

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Preissler, Gerhard; Eichhorn, Martin; Waldner, Helmut; Winter, Hauke; Kleespies, Axel; Massberg, Steffen

2012-10-01

After pancreas transplantation (PTx), early capillary malperfusion and leukocyte recruitment indicate the manifestation of severe ischemia/reperfusion injury (IRI). Oscillatory blood-flow redistribution (intermittent capillary perfusion, IP), leading to an overall decrease in erythrocyte flux, precedes complete microvascular perfusion failure with persistent blood flow cessation. We addressed the role of intercellular adhesion molecule-1 (ICAM-1) for leukocyte-endothelial interactions (LEIs) after PTx and evaluated the contribution of IP and malperfusion. Pancreas transplantation was performed in rats after 18-hour preservation, receiving either isotype-matched IgG or monoclonal anti-ICAM-1 antibodies (10 mg/kg intravenously) once before reperfusion. Leukocyte-endothelial interaction, IP, erythrocyte flux, and functional capillary density, respectively, were examined in vivo during 2-hour reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. In grafts of IgG-treated animals, IP was encountered already at an early stage after reperfusion and steadily increased over 2 hours, whereas erythrocyte flux declined continuously. In contrast, inhibition of ICAM-1 significantly improved erythrocyte flux and delayed IP appearance by 2 hours. Further, anti-ICAM-1 significantly reduced LEI and leukocyte tissue infiltration when compared to IgG; edema development was less pronounced in response to anti-ICAM-1 monoclonal antibody. Intercellular adhesion molecule-1 blockade significantly attenuates IRI via immediate reduction of LEI and concomitant improvement of capillary perfusion patterns, emphasizing its central role during IRI in PTx.

75 FR 61143 - Meeting of the Advisory Committee on Blood Safety and Availability

Science.gov (United States)

2010-10-04

... and availability of the blood supply and blood products, (2) broad public health, ethical and legal... availability of various economic factors affecting product cost and supply. In keeping with its established...

Microvascularity, blood flow and tissue structure at the subchondral plate using an X-ray fluorescence technique

International Nuclear Information System (INIS)

Muthuvelu, P.; Ellis, R.E.; Green, E.M.; Attenburrow, D.; Arkill, K.; Colridge, D.B.; Winlove, C.P.; Bradley, D.A.

2007-01-01

The measurement of blood flow and blood in bone and cartilaginous tissues is crucial to understanding of the development of various diseases, but it presents a formidable technical challenge. We have therefore developed a method based on the detection of metallized microspheres using X-ray fluorescence. This approach provides unrivalled sensitivity and spatial resolution and also allows us simultaneously to measure other markers of the metabolic status of the tissue. (author)

Revaluing donor and recipient bodies in the globalised blood economy: transitions in public policy on blood safety in the United Kingdom.

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Busby, Helen; Kent, Julie; Farrell, Anne-Maree

2014-01-01

The clinical use of blood has a long history, but its apparent stability belies the complexity of contemporary practices in this field. In this article, we explore how the production, supply and deployment of blood products are socially mediated, drawing on theoretical perspectives from recent work on 'tissue economies'. We highlight the ways in which safety threats in the form of infections that might be transmitted through blood and plasma impact on this tissue economy and how these have led to a revaluation of donor bodies and restructuring of blood economies. Specifically, we consider these themes in relation to the management of recent threats to blood safety in the United Kingdom. We show that the tension between securing the supply of blood and its products and ensuring its safety may give rise to ethical concerns and reshape relations between donor and recipient bodies.

Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts

International Nuclear Information System (INIS)

Berggren, A.; Weiland, A.J.; Ostrup, L.T.

1982-01-01

Researchers studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts were evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding

Microvascular Outcomes of Pediatric-Onset Type 1 Diabetes Mellitus: A Single-Center Observational Case Reviews in Sana’a, Yemen

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Abdallah Ahmed Gunaid

2018-01-01

Full Text Available Microvascular complications of pediatric-onset type 1 diabetes are common in low-income countries. In this study, we aimed at reviewing microvascular outcomes in 6 cases with type 1 diabetes over 14 to 31 years of follow-up. Severe proliferative diabetic retinopathy (PDR and/or diabetic macular edema (maculopathy (DME and overt diabetic nephropathy (macroalbuminuria were seen among 4 of 6 patients, whereas severe diabetic peripheral neuropathy with Charcot neuroarthropathy was seen in 1 patient only, who had the longest duration of follow-up. The weighted mean (SD (95% confidence interval hemoglobin A 1c was 8.9 (1.6 (8.4-9.4% [74 (17 (68-80 mmol/mol] for PDR/DME and 8.6 (1.7 (8.0-9.0% [71 (19 (65-77 mmol/mol] for macroalbuminuria. Thyroid autoimmunity was positive in 3 patients with overt hypothyroidism in 2 of them. Worse microvascular outcomes among these cases might be attributed to poor glycemic control, lack of knowledge, and limited financial resources.

Comparative Aspects of the Regulation of Cutaneous and Cerebral Microcirculation During Acute Blood Loss

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I. A. Ryzhkov

2017-01-01

Full Text Available Objective. Using laser Doppler flowmetry (LDF and wavelet-analysis of microvascular blood flow oscillations to determine the features of regulation of cutaneous and cerebral microhemocirculation at early stages of acute fixed volume blood loss.Materials and methods.Experiments were carried out on 31 male outbred rats weighing 300 g to 400 g. The animals were anesthetized by intraperitoneal injection of pentobarbital (45 mg/kg. The tail artery was catheterized for invasive measurement of mean blood pressure (BP and blood withdrawal. The LDF method (ЛАКК-02 device, LAZMA, Russia was used to record microvascular blood flow simultaneously in the right ear and the pial vessels of the left parietal region. An acute fixed-volume hemorrhage model was used. The target blood loss volume was 30% of the total blood volume (TBV. Within 10 minutes after the end of hemorrhage (posthemorrhagic period, the blood pressure and the LDF-gram were recorded. The following LDF-gram parameters were analyzed: the mean value of IP; the maximum amplitude of blood flow oscillations (Amax and the corresponding frequency (Fmax in the frequency band 0.01—0.4 Hz. Statistical processing of the data was performed using Statistica 7.0.Results. At baseline, the values of IP, Аmax and Fmax in the brain were higher than in the skin. At posthemorrhagic period, BP decreased, on average, from 105 to 41 mm Hg. Against this background, IP in the skin decreased by 65%, while in the brain it reduced only by 17%, as compared with the baseline values (P0,0001. In the same time these organs were characterized by a unidirectional dynamics of patterns of fluxmotion. In both investigated organs, Amax increased sharply, and Fmax decreased. In posthemorrhagic period, fluxmotion not only «slowed down», but was also synchronized in a relatively narrow frequency band: for the skin Fmax was about 0.04 Hz (at the border of the endothelial and neurogenic band, for the brain about 0.09 Hz

Problems and Approaches for Blood Transfusion in the Developing Countries.

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Roberts, David J; Field, Stephen; Delaney, Meghan; Bates, Imelda

2016-04-01

A safe supply of blood and the knowledge, skill, and resources for the appropriate use of blood are essential for medical services. Many problems are faced in the development of transfusion services in low- or medium-income countries (LMICs). Unfortunately, in many countries, providing safe blood is made more difficult by a lack of blood donors and the high frequency of transfusion-transmissible infections. The problems are compounded by the frequent need for urgent life-saving transfusions. This article examines the problems in supply, safety, and use of blood and how they are being addressed in LMICs, predominantly focusing on sub-Saharan Africa. Copyright © 2016 Elsevier Inc. All rights reserved.

Microvascular decompression for the patient with painful tic convulsif after Bell palsy.

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Jiao, Wei; Zhong, Jun; Sun, Hui; Zhu, Jin; Zhou, Qiu-Meng; Yang, Xiao-Sheng; Li, Shi-Ting

2013-05-01

Painful tic convulsif is referred to as the concurrent trigeminal neuralgia and hemifacial spasm. However, painful tic convulsif after ipsilateral Bell palsy has never been reported before. We report a case of a 77-year-old woman with coexistent trigeminal neuralgia and hemifacial spasm who had experienced Bell palsy half a year ago. The patient underwent microvascular decompression. Intraoperatively, the vertebrobasilar artery was found to deviate to the symptomatic side and a severe adhesion was observed in the cerebellopontine angle. Meanwhile, an ectatic anterior inferior cerebellar artery and 2 branches of the superior cerebellar artery were identified to compress the caudal root entry zone (REZ) of the VII nerve and the rostroventral cisternal portion of the V nerve, respectively. Postoperatively, the symptoms of spasm ceased immediately and the pain disappeared within 3 months. In this article, the pathogenesis of the patient's illness was discussed and it was assumed that the adhesions developed from inflammatory reactions after Bell palsy and the anatomic features of the patient were the factors that generated the disorder. Microvascular decompression surgery is the suggested treatment of the disease, and the dissection should be started from the caudal cranial nerves while performing the operation.

Microvascular disease in children and adolescents with type 1 diabetes and obesity.

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Marcovecchio, M Loredana; Chiarelli, Francesco

2011-03-01

The incidence of type 1 diabetes (T1D) is increasing worldwide and is associated with a significant burden, mainly related to the development of vascular complications. Over the last decades, concomitant with the epidemic of childhood obesity, there has been an increasing number of cases of type 2 diabetes (T2D) among children and adolescents. Microvascular complications of diabetes, which include nephropathy, retinopathy and neuropathy, are characterized by damage to the microvasculature of the kidney, retina and neurons. Although clinically evident microvascular complications are rarely seen among children and adolescents with diabetes, there is clear evidence that their pathogenesis and early signs develop during childhood and accelerate during puberty. Diabetic vascular complications are often asymptomatic during their early stages, and once symptoms develop, there is little to be done to cure them. Therefore, screening needs to be started early during adolescence and, in the case of T2D, already at diagnosis. Identification of risk factors and subclinical signs of complications is essential for the early implementation of preventive and therapeutic strategies, which could change the course of vascular complications and improve the prognosis of children, adolescents and young adults with diabetes.

Association of Retinopathy and Retinal Microvascular Abnormalities With Stroke and Cerebrovascular Disease.

Science.gov (United States)

Hughes, Alun D; Falaschetti, Emanuela; Witt, Nicholas; Wijetunge, Sumangali; Thom, Simon A McG; Tillin, Therese; Aldington, Steve J; Chaturvedi, Nish

2016-11-01

Abnormalities of the retinal circulation may be associated with cerebrovascular disease. We investigated associations between retinal microvascular abnormalities and (1) strokes and subclinical cerebral infarcts and (2) cerebral white matter lesions in a UK-based triethnic population-based cohort. A total of 1185 participants (age, 68.8±6.1 years; 77% men) underwent retinal imaging and cerebral magnetic resonance imaging. Cerebral infarcts and white matter hyperintensities were identified on magnetic resonance imaging, retinopathy was graded, and retinal vessels were measured. Higher retinopathy grade (odds ratio [OR], 1.40 [95% confidence interval (95% CI), 1.16-1.70]), narrower arteriolar diameter (OR, 0.98 [95% CI, 0.97-0.99]), fewer symmetrical arteriolar bifurcations (OR, 0.84 [95% CI, 0.75-0.95]), higher arteriolar optimality deviation (OR, 1.16 [95% CI, 1.00-1.34]), and more tortuous venules (OR, 1.20 [95% CI, 1.09-1.32]) were associated with strokes/infarcts and white matter hyperintensities. Associations with quantitative retinal microvascular measures were independent of retinopathy. Abnormalities of the retinal microvasculature are independently associated with stroke, cerebral infarcts, and white matter lesions. © 2016 American Heart Association, Inc.

Fluid resuscitation following a burn injury: implications of a mathematical model of microvascular exchange.

Science.gov (United States)

Bert, J; Gyenge, C; Bowen, B; Reed, R; Lund, T

1997-03-01

A validated mathematical model of microvascular exchange in thermally injured humans has been used to predict the consequences of different forms of resuscitation and potential modes of action of pharmaceuticals on the distribution and transport of fluid and macromolecules in the body. Specially, for 10 and/or 50 per cent burn surface area injuries, predictions are presented for no resuscitation, resuscitation with the Parkland formula (a high fluid and low protein formulation) and resuscitation with the Evans formula (a low fluid and high protein formulation). As expected, Parkland formula resuscitation leads to interstitial accumulation of excess fluid, while use of the Evans formula leads to interstitial accumulation of excessive amounts of proteins. The hypothetical effects of pharmaceuticals on the transport barrier properties of the microvascular barrier and on the highly negative tissue pressure generated postburn in the injured tissue were also investigated. Simulations predict a relatively greater amelioration of the acute postburn edema through modulation of the postburn tissue pressure effects.

Time-based analysis of the apheresis platelet supply chain in England.

Science.gov (United States)

Wilding, R; Cotton, S; Dobbin, J; Chapman, J; Yates, N

2011-10-01

During 2009/2010 loss of platelets within NHS Blood and Transplant (NHSBT) due to time expiry was 9.3%. Hospitals remain reluctant to hold stocks of platelets due to the poor shelf life at issue. The purpose of this study was to identify areas for time compression in the apheresis platelet supply chain to extend the shelf life available for hospitals and reduce wastage in NHSBT. This was done within the context of NHSBT reconfiguring their supply chain and moving towards a consolidated and centralised approach. Time based process mapping was applied to identify value and non-value adding time in two manufacturing models. A large amount of the non-value adding time in the apheresis platelet supply chain is due to transportation and waiting for the next process in the manufacturing process to take place. Time based process mapping provides an effective 'lens' for supply chain professionals to identify opportunities for improvement in the platelet supply chain. © 2011 The Author(s). Vox Sanguinis © 2011 International Society of Blood Transfusion.

An Analysis of and Recommendations for the Peruvian Blood Collection and Transfusion System.

Science.gov (United States)

George, Paul E; Vidal, Julio; Garcia, Patricia J

2016-05-01

Peru experienced a crisis in its blood collection and supply system in the mid-2000s, as contaminated blood led to several transfusion-transmitted infections (TTI), occurring in the backdrop of extremely low voluntary donation rates and a national blood supply shortage. Thus, the Peruvian Ministry of Health (MINSA) implemented a national investigation on the safety and quality of the Peruvian blood collection/transfusion network. Every Peruvian blood bank was evaluated by MINSA from 2007-2008. These evaluations consisted of an update of the national registry of blood banks and visits to each blood bank from MINSA oversight teams. Information was collected on the condition of the blood bank personnel, equipment, supplies, and practices. Further, previously-collected blood at each blood bank was randomly selected and screened for TTI-causing pathogens. Uncovered in this investigation was a fragmented, under-equipped, and poorly-staffed blood collection and transfusion network, consisting of 241 independent blood banks and resulting in suboptimal allocation of resources. Further, blood with evidence of TTI-causing pathogens (including Hepatitis B, Hepatitis C, and syphilis) and set for transfusion was discovered at three separate blood banks as part of the random screening process. Using the successful reorganizations of national blood supply systems in other Latin American countries as examples, Peru would be well-served to form large, high-volume, regional blood collection and transfusion centers, responsible for blood collection and screening for the entire country. The small, separate blood banks would then be transformed into a network of blood transfusion centers, not responsible for blood collection. This reorganization would allow Peru to better utilize its resources, standardize the blood collection and transfusion process, and increase voluntary donation, resulting in a safer, more abundant national blood product.

Moderate glucose supply reduces hemolysis during systemic inflammation

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Jägers J

2018-03-01

Full Text Available Johannes Jägers,1 Stephan Brauckmann,2 Michael Kirsch,1 Katharina Effenberger-Neidnicht1,3 1Institute of Physiological Chemistry, University Hospital Essen, Essen, Germany; 2Clinic for Anesthesiology and Intensive Care, University Hospital Essen, Essen, Germany; 3Institute of Physiological Chemistry, University Hospital Essen, Essen, Germany Background: Systemic inflammation alters energy metabolism. A sufficient glucose level, however, is most important for erythrocytes, since erythrocytes rely on glucose as sole source of energy. Damage to erythrocytes leads to hemolysis. Both disorders of glucose metabolism and hemolysis are associated with an increased risk of death. The objective of the study was to investigate the impact of intravenous glucose on hemolysis during systemic inflammation.Materials and methods: Systemic inflammation was accomplished in male Wistar rats by continuous lipopolysaccharide (LPS infusion (1 mg LPS/kg and h, 300 min. Sham control group rats received Ringer’s solution. Glucose was supplied moderately (70 mg glucose/kg and h or excessively (210 mg glucose/kg and h during systemic inflammation. Vital parameters (eg, systemic blood pressure as well as blood and plasma parameters (eg, concentrations of glucose, lactate and cell-free hemoglobin, and activity of lactate dehydrogenase were measured hourly. Clot formation was analyzed by thromboelastometry.Results: Continuous infusion of LPS led to a so-called post-aggression syndrome with disturbed electrolyte homeostasis (hypocalcemia, hyperkalemia, and hypernatremia, changes in hemodynamics (tachycardia and hypertension, and a catabolic metabolism (early hyperglycemia, late hypoglycemia, and lactate formation. It induced severe tissue injury (significant increases in plasma concentrations of transaminases and lactate dehydrogenase, alterations in blood coagulation (disturbed clot formation, and massive hemolysis. Both moderate and excessive glucose supply reduced LPS

Comparison between invasive and noninvasive techniques of evaluation of microvascular structural alterations.

Science.gov (United States)

De Ciuceis, Carolina; Agabiti Rosei, Claudia; Caletti, Stefano; Trapletti, Valentina; Coschignano, Maria A; Tiberio, Guido A M; Duse, Sarah; Docchio, Franco; Pasinetti, Simone; Zambonardi, Federica; Semeraro, Francesco; Porteri, Enzo; Solaini, Leonardo; Sansoni, Giovanna; Pileri, Paola; Rossini, Claudia; Mittempergher, Francesco; Portolani, Nazario; Ministrini, Silvia; Agabiti-Rosei, Enrico; Rizzoni, Damiano

2018-05-01

The evaluation of the morphological characteristics of small resistance arteries in humans is challenging. The gold standard method is generally considered to be the measurement by wire or pressure micromyography of the media-to-lumen ratio of subcutaneous small vessels obtained by local biopsies. However, noninvasive techniques for the evaluation of retinal arterioles were recently proposed; in particular, two approaches, scanning laser Doppler flowmetry (SLDF) and adaptive optics, seem to provide useful information; both of them provide an estimation of the wall-to-lumen ratio (WLR) of retinal arterioles. Moreover, a noninvasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. No direct comparison of these three noninvasive techniques in the same population was previously performed; in particular, adaptive optics was never validated against micromyography. In the current study, we enrolled 41 controls and patients: 12 normotensive lean controls, 12 essential hypertensive lean patients, nine normotensive obese patients and eight hypertensive obese patients undergoing elective surgery. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance artery structure was assessed by wire micromyography and the media-to-lumen ratio was calculated. WLR of retinal arterioles was obtained by SLDF and adaptive optics. Functional (basal) and structural (total) microvascular density was evaluated by capillaroscopy before and after venous congestion. Our data suggest that adaptive optics has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, as WLR measured with adaptive optics is more closely correlated with the M/L of subcutaneous small arteries (r = 0.84, P < 0.001 vs. r = 0.52, P < 0.05, slopes of the relations: P < 0.01 adaptive optics vs. SLDF). In addition, the reproducibility of the evaluation of the WLR with adaptive optics is

Associations between diabetes self-management and microvascular complications in patients with type 2 diabetes

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Fatemeh Mehravar

2016-01-01

Full Text Available OBJECTIVES: Diabetes is a major public health problem that is approaching epidemic proportions globally. Diabetes self-management can reduce complications and mortality in type 2 diabetic patients. The purpose of this study was to examine associations between diabetes self-management and microvascular complications in patients with type 2 diabetes. METHODS: In this cross-sectional study, 562 Iranian patients older than 30 years of age with type 2 diabetes who received treatment at the Diabetes Research Center of the Endocrinology and Metabolism Research Institute of the Tehran University of Medical Sciences were identified. The participants were enrolled and completed questionnaires between January and April 2014. Patients’ diabetes self-management was assessed as an independent variable by using the Diabetes Self-Management Questionnaire translated into Persian. The outcomes were the microvascular complications of diabetes (retinopathy, nephropathy, and neuropathy, identified from the clinical records of each patient. A multiple logistic regression model was used to estimate odds ratios (ORs and 95% confidence intervals (CIs between diabetes self-management and the microvascular complications of type 2 diabetes, adjusting for potential confounders. RESULTS: After adjusting for potential confounders, a significant association was found between the diabetes self-management sum scale and neuropathy (adjusted OR, 0.64; 95% CI, 0.45 to 0.92, p=0.01. Additionally, weak evidence was found of an association between the sum scale score of diabetes self-management and nephropathy (adjusted OR, 0.71; 95% CI, 0.47 to 1.05, p=0.09. CONCLUSIONS: Among patients with type 2 diabetes, a lower diabetes self-management score was associated with higher rates of nephropathy and neuropathy.

The number of microvascular complications is associated with an increased risk for severity of periodontitis in type 2 diabetes patients: Results of a multicenter hospital-based cross-sectional study.

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Nitta, Hiroshi; Katagiri, Sayaka; Nagasawa, Toshiyuki; Izumi, Yuichi; Ishikawa, Isao; Izumiyama, Hajime; Uchimura, Isao; Kanazawa, Masao; Chiba, Hiroshige; Matsuo, Akira; Utsunomiya, Kazunori; Tanabe, Haruyasu; Takei, Izumi; Asanami, Soichiro; Kajio, Hiroshi; Ono, Toaki; Hayashi, Yoichi; Ueki, Kiichi; Tsuji, Masatomi; Kurachi, Yoichi; Yamanouchi, Toshikazu; Ichinokawa, Yoshimi; Inokuchi, Toshiki; Fukui, Akiko; Miyazaki, Shigeru; Miyauchi, Takashi; Kawahara, Reiko; Ogiuchi, Hideki; Yoshioka, Narihito; Negishi, Jun; Mori, Masatomo; Mogi, Kenji; Saito, Yasushi; Tanzawa, Hideki; Nishikawa, Tetsuo; Takada, Norihiko; Nanjo, Kishio; Morita, Nobuo; Nakamura, Naoto; Kanamura, Narisato; Makino, Hirofumi; Nishimura, Fusanori; Kobayashi, Kunihisa; Higuchi, Yoshinori; Sakata, Toshiie; Yanagisawa, Shigetaka; Tei, Chuwa; Ando, Yuichi; Hanada, Nobuhiro; Inoue, Shuji

2017-09-01

To explore the relationships between periodontitis and microvascular complications as well as glycemic control in type 2 diabetes patients. This multicenter, hospital-based, cross-sectional study included 620 patients with type 2 diabetes. We compared the prevalence and severity of periodontitis between patients with ≥1 microvascular complication and those without microvascular complications. We also compared the prevalence and severity of periodontitis among patients with different degrees of glycemic control. After adjusting for confounding factors, multiple logistic regression analysis showed that the severity of periodontitis was significantly associated with the number of microvascular complications (odds ratio 1.3, 95% confidence interval 1.1-1.6), glycated hemoglobin ≥8.0% (64 mmol/mol; odds ratio 1.6; 95% confidence interval 1.1-2.3), and older age (≥50 years; odds ratio 1.7; 95% confidence interval 1.1-2.6). However, the prevalence of periodontitis was not significantly associated with the number of microvascular complications, but was associated with male sex, high glycated hemoglobin (≥8.0% [64 mmol/mol]), older age (≥40 years), longer duration of diabetes (≥15 years) and fewer teeth (≤25). Furthermore, propensity score matching for age, sex, diabetes duration and glycated hemoglobin showed that the incidence of severe periodontitis was significantly higher among patients with microvascular complications than among those without microvascular complications (P periodontitis in patients with type 2 diabetes, whereas poor glycemic control is a risk factor for increased prevalence and severity of periodontitis. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Dose-response studies of Ropivacaine in blood flow of upper extremity after supraclavicular block: a double-blind randomized controlled study.

Science.gov (United States)

Li, Ting; Ye, Qiguang; Wu, Daozhu; Li, Jun; Yu, Jingui

2017-12-02

The sympathetic block of upper limb leading to increased blood flow has important clinical implication in microvascular surgery. However, little is known regarding the relationship between concentration of local anesthetic and blood flow of upper limb. The aim of this dose-response study was to determine the ED 50 and ED 95 of ropivacaine in blood flow after supraclavicular block (SB). Patients undergoing upper limb surgery and supraclavicular block were randomly assigned to receive 30ml ropivacaine in concentrations of 0.125%(A Group), 0.2%(B Group), 0.25%(C Group), 0.375%(D Group), 0.5%(E Group), or 0.75%(F Group) (n=13 per group). All patients received supraclavicular block (SB). Time average maximum velocity (TAMAX), cross-sectional area (CSA) of brachial artery and skin temperatures (T s ) were measured repeatedly at the same marked points, they were taken at baseline (before block, t 0 ) and at 30min after SB (t 1 ). Blood flow(BF) = TAMAX× CSA×60 sec.. Relative blood flow (ΔBF) = BF t1 / BF t0 . Success of SB was assessed simultaneously. Supplementary anesthesia and other adverse events (AE) were recorded. Significant increase in TAMAX, CSA, BF and T s were seen in all concentration groups at t 1 comparing with t 0 (Pblock were 0.18/0.33% (0.15-0.21/0.27-0.51), R 2 =0.904. The dose-response curve between SB ropivacaine and the changes of BF was determined. The ED 50 /ED 95 of ropivacaine of ΔBF are 0.35/1.94% (0.25-0.45/0.83-4.52). TAMAX, CSA and BF consistently increased with ropivacaine concentration. The maximal sympathetic block needs higher concentration than that complete sensation block needs which may benefit for microvascular surgery. Clinicaltrials.gov NCT02139982 . Retrospectively registered (Date of registration: May, 2014).

[Successful microvascular decompression of the medulla oblongata for a case with respiratory failure: case report].

Science.gov (United States)

Koguchi, Motofumi; Nakahara, Yukiko; Kawashima, Masatou; Takase, Yukinori; Matsushima, Toshio

2011-11-01

We report a case of the medulla oblongata syndrome successfully treated by microvascular decompression surgery. The patient was a 75-year-old woman and had been suffering from gradual progressive dyspnea since July, 2009. Two month later, intubation and medial ventilator treatments were began because of severe respiratory problems. The central respiratory problems were considered in extensive testing by the physician. The head MR imaging showed that the left vertebral artery had markedly compressed the medulla oblongata. We thought that her respiratory problems were associated with this vertebral artery compression of the medulla oblongata. We performed the microvascular decompression surgery by left trans-condylar fossa approach. Her hypoventilation graduately improved after the surgery and she needed neither ventilator nor oxygen in several months. She is able to perform daily activities by herself. We report the case, and discuss the cause of respiratory problems especially by compression of the medulla oblongata.

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.

Scintiangiographic demonstration of parasitization of systemic blood supply by inflammatory lung disease

Energy Technology Data Exchange (ETDEWEB)

Schlesinger, A.E.; Lee, V.W.; Shapiro, J.H.

1985-03-01

An unusual case in which a computed tomogram demonstrated abnormal, enlarged vessels in the right lower lobe of the lung and suggested an arteriovenous malformation is presented. A scintiangiogram showed abnormal systemic supply to this area in the aortic phase. Contrast angiography demonstrated hypertrophy of the right inferior phrenic artery with abnormal systemic supply to the pleura and parenchyma of the right lower lobe, presumably on the basis of old infection.

Modeling Group B Streptococcus and Blood-Brain Barrier Interaction by Using Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells

OpenAIRE

Kim, Brandon J.; Bee, Olivia B.; McDonagh, Maura A.; Stebbins, Matthew J.; Palecek, Sean P.; Doran, Kelly S.; Shusta, Eric V.

2017-01-01

ABSTRACT Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Streptococcus agalactiae (group B Streptococcus [GBS]), possess the ability to interact with a...

Seroprevalence, cost per donation and reduction in blood supply due to positive and indeterminate results for infectious markers in a blood bank in Lima, Peru

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Jeel Moya-Salazar

Full Text Available ABSTRACT Introduction: Safety in Transfusion Medicine is subject to regulations and government legislation within a total quality framework. The aim of this study was to evaluate the impact of seroprevalence and indeterminate results on lost units and cost per donation. Methods: A prospective cross-sectional study was performed in the Blood Bank and Transfusion Therapy Department of the Hospital Central de la Policia Nacional del Perú in Lima, Peru. All completed donations (replacement/voluntary without complications were included in this study. Every donation met the institutional requirements and quality criteria of Programa Nacional de Hemoterapia y Bancos de Sangre (PRONAHEBAS. Data analysis was achieved using the Statistical Package for the Social Sciences. Results: A total of 7723 donations were evaluated during 2014 and 2015 with 493 being seropositive (overall prevalence 5.25% and 502 having indeterminate results (overall prevalence 5.35%. Thus total loss was 995 units, 437.8 L of blood and 49,750 US dollars. The most common seropositive infectious markers were the core antibody of hepatitis B virus (2.82% and syphilis (1.02%, and the most common indeterminate results were Chagas disease (1.27% and the core antibody of hepatitis B virus (1.26%. There was no significant change in the prevalence of seropositivity (p-value = 0.243 or indeterminate results (p-value = 0.227 over the two-year period of the study. A statistical correlation was found between the cost per lost donation and the most prevalent markers (rho = 0.848; p-value = <0.001. Conclusion: Seroprevalence was lower than the regional mean, but the prevalence of indeterminate results was elevated causing a great impact on blood supply and economic losses to this institution.

Seroprevalence, cost per donation and reduction in blood supply due to positive and indeterminate results for infectious markers in a blood bank in Lima, Peru.

Science.gov (United States)

Moya-Salazar, Jeel; Ubidia-Incio, Roberto; Incio-Grande, Maritza; Blejer, Jorgelina L; Gonzalez, Carlos A

Safety in Transfusion Medicine is subject to regulations and government legislation within a total quality framework. The aim of this study was to evaluate the impact of seroprevalence and indeterminate results on lost units and cost per donation. A prospective cross-sectional study was performed in the Blood Bank and Transfusion Therapy Department of the Hospital Central de la Policia Nacional del Perú in Lima, Peru. All completed donations (replacement/voluntary) without complications were included in this study. Every donation met the institutional requirements and quality criteria of Programa Nacional de Hemoterapia y Bancos de Sangre (PRONAHEBAS). Data analysis was achieved using the Statistical Package for the Social Sciences. A total of 7723 donations were evaluated during 2014 and 2015 with 493 being seropositive (overall prevalence 5.25%) and 502 having indeterminate results (overall prevalence 5.35%). Thus total loss was 995units, 437.8L of blood and 49,750 US dollars. The most common seropositive infectious markers were the core antibody of hepatitis B virus (2.82%) and syphilis (1.02%), and the most common indeterminate results were Chagas disease (1.27%) and the core antibody of hepatitis B virus (1.26%). There was no significant change in the prevalence of seropositivity (p-value=0.243) or indeterminate results (p-value=0.227) over the two-year period of the study. A statistical correlation was found between the cost per lost donation and the most prevalent markers (rho=0.848; p-value=<0.001). Seroprevalence was lower than the regional mean, but the prevalence of indeterminate results was elevated causing a great impact on blood supply and economic losses to this institution. Copyright © 2017 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Superselective angiographic findings and the blood supply in the cases of avascular necrosis of the femoral head: a preliminary study

International Nuclear Information System (INIS)

Zhou Weisheng; Wang Fangjun; Ling Yisheng; Zhao Tianqing

2003-01-01

Objective: To study the superselective angiographic findings and blood supply in the case of avascular necrosis of the femoral head (ANFH). Methods: One hundred and sixty five patients (214 hips) with ANFH proved by clinic and radiology underwent superselective angiography and DSA findings were retrospectively studied. Results: Abnormal angiographic findings of the medial circumflex artery and its branches, with or without other abnormal vascularities, could be obtained in 162 hips out of 211 (98.6%). Angiographic findings of ANFH were the followings: abnormal superior and inferior capsular branch of the medial circumflex artery, especially the former one; abnormalities in the ascending branch of lateral circumflex artery; opacification of the femoral head and neck in the parenchymal phase of DSA; revasculization of the small arterial branches or a hypervascular area surrounding the necrotic lesions; anastomosis between the medial circumflex artery and the inferior and superior gluteal arteries; and the venous stasis. Conclusion: Morphological changes of blood vessels in ANFH are demonstrated by superselective angiography, in which the medial circumflex artery and its branches are mostly involved, or in some cases, accompanied by venous stasis

distribution of abo, rhesus blood groups and haemoglobin ...

African Journals Online (AJOL)

Daniel Owu

fetal blood leaks through the placenta and mixes with the mother's blood, the mother ... competence of the blood to supply oxygen to the tissue (Weatherall, ... on a tile and mixed with three drops of water to lyse the red cells. With the aid of an ...

Donor blood procurement and the risk of transfusion transmissible ...

African Journals Online (AJOL)

Background: Blood and blood products are scarce commodities. The demand often outweighs the supply. This study is directed at investigating the blood procurement sources and the risk of viral transfusion transmissible infection. Materials and Methods: The records of the blood transfusion unit of a tertiary health facility in ...

Simulation of motor unit recruitment and microvascular unit perfusion: spatial considerations.

Science.gov (United States)

Fuglevand, A J; Segal, S S

1997-10-01

Muscle fiber activity is the principal stimulus for increasing capillary perfusion during exercise. The control elements of perfusion, i.e., microvascular units (MVUs), supply clusters of muscle fibers, whereas the control elements of contraction, i.e., motor units, are composed of fibers widely scattered throughout muscle. The purpose of this study was to examine how the discordant spatial domains of MVUs and motor units could influence the proportion of open capillaries (designated as perfusion) throughout a muscle cross section. A computer model simulated the locations of perfused MVUs in response to the activation of up to 100 motor units in a muscle with 40,000 fibers and a cross-sectional area of 100 mm2. The simulation increased contraction intensity by progressive recruitment of motor units. For each step of motor unit recruitment, the percentage of active fibers and the number of perfused MVUs were determined for several conditions: 1) motor unit fibers widely dispersed and motor unit territories randomly located (which approximates healthy human muscle), 2) regionalized motor unit territories, 3) reversed recruitment order of motor units, 4) densely clustered motor unit fibers, and 5) increased size but decreased number of motor units. The simulations indicated that the widespread dispersion of motor unit fibers facilitates complete capillary (MVU) perfusion of muscle at low levels of activity. The efficacy by which muscle fiber activity induced perfusion was reduced 7- to 14-fold under conditions that decreased the dispersion of active fibers, increased the size of motor units, or reversed the sequence of motor unit recruitment. Such conditions are similar to those that arise in neuromuscular disorders, with aging, or during electrical stimulation of muscle, respectively.

Stationary Treatment Compared with Individualized Chinese Medicine for Type 2 Diabetes Patients with Microvascular Complications: Study Protocol for a Randomized Controlled Trial.

Science.gov (United States)

Huo, Jian; Liu, Li-Sha; Jian, Wen-Yuan; Zeng, Jie-Ping; Duan, Jun-Guo; Lu, Xue-Jing; Yin, Shuo

2018-06-18

Microvascular complications in type 2 diabetes (T2DM), including diabatic retinopathy (DR), diabetic kidney disease (DKD), diabetic peripheral neuropathy (DPN) are the leading causes of visual loss, end-stage renal disease or amputation, while the current therapies are still unsatisfactory. Chinese medicine (CM) has been widely used for treating diabetic mellitus. However, most of the previous studies focused on the single complication. The role of CM treatment in T2DM patients with 2 or multiple microvascular complications is not clear. To appraise the curative effect of CM in T2DM patients with 2 or multiple microvascular complications, and to compare the effects of stationary treatment and individualized treatment in T2DM patients with microvascular complications. This trial will be an 8-center, randomized, controlled study with 8 parallel groups. A total of 432 patients will be randomized to 8 groups: DR study group (32 cases) and a corresponding control group (32 cases), DR+DKD study group (64 cases) and a corresponding control group (64 cases), DR+DPN study group (64 cases) and a corresponding control group (64 cases), DR+DKD+DPN study group (56 cases) and a corresponding control group (56 cases). The control group will receive stationary treatment, and the study group will receive individualized treatment based on CM syndrome differentiation in addition to stationary treatment. The study duration will be 50 weeks, comprising a 2-week run-in period, 24 weeks of intervention, and 24 weeks of follow-up. The outcomes will assess efficacy of treatment, improvement in CM symptoms, safety assessments, adherence to the treatment, and adverse events. This study will provide evidence of evidence-based medicine for CM treatment in two or multiple microvascular complications caused by T2DM. (Registration No. ChiCTR-IPR-15007072).

West Nile virus-induced cell adhesion molecules on human brain microvascular endothelial cells regulate leukocyte adhesion and modulate permeability of the in vitro blood-brain barrier model.

Directory of Open Access Journals (Sweden)

Kelsey Roe

Full Text Available Characterizing the mechanisms by which West Nile virus (WNV causes blood-brain barrier (BBB disruption, leukocyte infiltration into the brain and neuroinflammation is important to understand the pathogenesis of WNV encephalitis. Here, we examined the role of endothelial cell adhesion molecules (CAMs in mediating the adhesion and transendothelial migration of leukocytes across human brain microvascular endothelial cells (HBMVE. Infection with WNV (NY99 strain significantly induced ICAM-1, VCAM-1, and E-selectin in human endothelial cells and infected mice brain, although the levels of their ligands on leukocytes (VLA-4, LFA-1and MAC-1 did not alter. The permeability of the in vitro BBB model increased dramatically following the transmigration of monocytes and lymphocytes across the models infected with WNV, which was reversed in the presence of a cocktail of blocking antibodies against ICAM-1, VCAM-1, and E-selectin. Further, WNV infection of HBMVE significantly increased leukocyte adhesion to the HBMVE monolayer and transmigration across the infected BBB model. The blockade of these CAMs reduced the adhesion and transmigration of leukocytes across the infected BBB model. Further, comparison of infection with highly neuroinvasive NY99 and non-lethal (Eg101 strain of WNV demonstrated similar level of virus replication and fold-increase of CAMs in HBMVE cells suggesting that the non-neuropathogenic response of Eg101 is not because of its inability to infect HBMVE cells. Collectively, these results suggest that increased expression of specific CAMs is a pathological event associated with WNV infection and may contribute to leukocyte infiltration and BBB disruption in vivo. Our data further implicate that strategies to block CAMs to reduce BBB disruption may limit neuroinflammation and virus-CNS entry via 'Trojan horse' route, and improve WNV disease outcome.

Homocysteine, S-adenosylmethionine and S-adenosylhomocysteine are associated with retinal microvascular abnormalities : the Hoorn Study

NARCIS (Netherlands)

van Hecke, Manon V.; Dekker, Jacqueline M.; Nijpels, Giel; Teeerlink, Tom; Jakobs, Cornelis; Stolk, Ronald P.; Heine, Rob J.; Bouter, Lex M.; Polak, Bettine C. P.; Stehouwer, Coen D. A.

The aim of the present study was to investigate the relationship between homocysteine and homocysteine metabolism components and retinal microvascular disorders in subjects with and without Type 2 diabetes. In this population-based study of 256 participants, aged 60-85 years, we determined total

Comparative study between microvascular tone regulation and rheological properties of blood in patients with type 2 diabetes mellitus.

Science.gov (United States)

Antonova, N; Tsiberkin, K; Podtaev, S; Paskova, V; Velcheva, I; Chaushev, N

2016-01-01

The aim of the study is to investigate the changes of the skin blood flow responses to cold stress in patients with diabetes mellitus type 2 through wavelet analysis of the peripheral skin temperature oscillations and to estimate their relationship with the blood viscosity values. The amplitudes of the skin temperature pulsations (ASTP) were monitored by "Microtest" device ("FM-Diagnostics", Russia); the whole blood viscosity and the shear stresses were measured by Contraves LS30 viscometer (Switzerland) at a steady flow in 9 healthy subjects and in 30 patients with type 2 diabetes mellitus. Power law and Herschel-Bulkley (HB) equations were applied to describe the blood rheology. Both models include consistency (k) and flow index (m), and the HB also gives the yield stress (τ0). The Spearman rank correlations between these parameters and the ASTP in the frequency ranges, corresponding to the myogenic, neurogenic and endothelial mechanisms of the microcirculation tone regulation were calculated. The ASTP values decreased when the blood viscosity increased. The correlation analysis revealed good ASTP-m (r > 0.5) and ASTP-k (r diabetes.

Contrast ultrasound targeted treatment of gliomas in mice via drug-bearing nanoparticle delivery and microvascular ablation.

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Burke, Caitlin W; Price, Richard J

2010-12-15

We are developing minimally-invasive contrast agent microbubble based therapeutic approaches in which the permeabilization and/or ablation of the microvasculature are controlled by varying ultrasound pulsing parameters. Specifically, we are testing whether such approaches may be used to treat malignant brain tumors through drug delivery and microvascular ablation. Preliminary studies have been performed to determine whether targeted drug-bearing nanoparticle delivery can be facilitated by the ultrasound mediated destruction of "composite" delivery agents comprised of 100nm poly(lactide-co-glycolide) (PLAGA) nanoparticles that are adhered to albumin shelled microbubbles. We denote these agents as microbubble-nanoparticle composite agents (MNCAs). When targeted to subcutaneous C6 gliomas with ultrasound, we observed an immediate 4.6-fold increase in nanoparticle delivery in MNCA treated tumors over tumors treated with microbubbles co-administered with nanoparticles and a 8.5 fold increase over non-treated tumors. Furthermore, in many cancer applications, we believe it may be desirable to perform targeted drug delivery in conjunction with ablation of the tumor microcirculation, which will lead to tumor hypoxia and apoptosis. To this end, we have tested the efficacy of non-theramal cavitation-induced microvascular ablation, showing that this approach elicits tumor perfusion reduction, apoptosis, significant growth inhibition, and necrosis. Taken together, these results indicate that our ultrasound-targeted approach has the potential to increase therapeutic efficiency by creating tumor necrosis through microvascular ablation and/or simultaneously enhancing the drug payload in gliomas.

Intravenous Infusion of Magnesium Chloride Improves Epicenter Blood Flow during the Acute Stage of Contusive Spinal Cord Injury in Rats

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Muradov, Johongir M.

2013-01-01

Abstract Vasospasm, hemorrhage, and loss of microvessels at the site of contusive or compressive spinal cord injury lead to infarction and initiate secondary degeneration. Here, we used intravenous injection of endothelial-binding lectin followed by histology to show that the number of perfused microvessels at the injury site is decreased by 80–90% as early as 20 min following a moderate T9 contusion in adult female rats. Hemorrhage within the spinal cord also was maximal at 20 min, consistent with its vasoconstrictive actions in the central nervous system (CNS). Microvascular blood flow recovered to up to 50% of normal volume in the injury penumbra by 6 h, but not at the epicenter. A comparison with an endothelial cell marker suggested that many microvessels fail to be reperfused up to 48 h post-injury. The ischemia was probably caused by vasospasm of vessels penetrating the parenchyma, because repeated Doppler measurements over the spinal cord showed a doubling of total blood flow over the first 12 h. Moreover, intravenous infusion of magnesium chloride, used clinically to treat CNS vasospasm, greatly improved the number of perfused microvessels at 24 and 48 h. The magnesium treatment seemed safe as it did not increase hemorrhage, despite the improved parenchymal blood flow. However, the treatment did not reduce acute microvessel, motor neuron or oligodendrocyte loss, and when infused for 7 days did not affect functional recovery or spared epicenter white matter over a 4 week period. These data suggest that microvascular blood flow can be restored with a clinically relevant treatment following spinal cord injury. PMID:23302047

A novel approach to optimal blood platelets logistics

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Smit Sibinga, C.; Dijk, van N.M.; Haijema, R.; Wal, van der J.

2006-01-01

The production and inventory management of blood platelets at blood establishments and hospital blood banks is a service problem of general human interest. Shortages or inadequate supplies may pur lives at risk and thus have to be managed and kept to a minimum. However, platelets have a limited

Binding of human endothelium to Ulex europaeus I-coated Dynabeads: application to the isolation of microvascular endothelium.

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Jackson, C J; Garbett, P K; Nissen, B; Schrieber, L

1990-06-01

A major problem encountered when isolating human microvascular endothelium is the presence of contaminating cells such as fibroblasts that rapidly over-grow the endothelial cells. We describe here a simple, rapid technique for purifying endothelial cells derived from the microvasculature of neonatal foreskin and osteoarthritic and rheumatoid arthritic synovium. This technique is based on the selective binding of the lectin Ulex europaeus I (UEA I) to the endothelial cell surface via fucose residues. Initially UEA I was covalently bound to tosyl-activated super-paramagnetic polystyrene beads (Dynabeads) by incubation for 24 h at room temperature. Cells were isolated by extracting microvascular segments from enzyme-treated (trypsin and Pronase) cubes of tissue. The mixed population of cells obtained were purified by incubating them at 4 degrees C for 10 min with the UEA I-coated Dynabeads. Endothelium bound to the beads whilst contaminating cells were removed by five washes with HBSS using a magnetic particle concentrator. The endothelial cells thus obtained grew to confluence as a cobblestone-like monolayer and expressed von Willebrand factor antigen. The cells were released from the Dynabeads by the competitive binding of fucose (10 min at 4 degrees C). This new method is simple and reproducible and allows pure human microvascular endothelial cells to be cultured within 2 h of obtaining a specimen.

Potential of Dietary Non-Provitamin A Carotenoids in the Prevention and Treatment of Diabetic Microvascular Complications12

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Murillo, Ana Gabriela

2016-01-01

Diabetes is a chronic metabolic disease that affects a substantial part of the population around the world. Whether type I or type II, this disease has serious macro- and microvascular complications that constitute the primary cause of death in diabetic patients. Microvascular complications include diabetic retinopathy, nephropathy, and neuropathy. Although these complications are clinically and etiologically diverse, they share a common factor: glucose-induced damage. In the progression of diabetic complications, oxidative stress, inflammation, and the formation of glycation end products play an important role. Previous studies have shown that a healthy diet is vital in preventing these complications; in particular, the intake of antioxidants has been studied for their potential effect in ameliorating hyperglycemic injuries. Carotenoids are lipid-soluble pigments synthesized by plants, bacteria, and some kinds of algae that are responsible for the yellow, red, and orange colors in food. These compounds are part of the antioxidant machinery in plants and have also shown their efficacy in quenching free radicals, scavenging reactive oxygen species, modulating gene expression, and reducing inflammation in vitro and in vivo, showing that they can potentially be used as part of a preventive strategy for metabolic disorders, including diabetes and its related complications. This review highlights the potential protective effects of 4 non-provitamin A carotenoids—lutein, zeaxanthin, lycopene, and astaxanthin—in the development and progression of diabetic microvascular complications. PMID:26773012

Zika Virus Infects, Activates, and Crosses Brain Microvascular Endothelial Cells, without Barrier Disruption

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Papa, Michelle P.; Meuren, Lana M.; Coelho, Sharton V. A.; Lucas, Carolina G. de Oliveira; Mustafá, Yasmin M.; Lemos Matassoli, Flavio; Silveira, Paola P.; Frost, Paula S.; Pezzuto, Paula; Ribeiro, Milene R.; Tanuri, Amilcar; Nogueira, Mauricio L.; Campanati, Loraine; Bozza, Marcelo T.; Paula Neto, Heitor A.; Pimentel-Coelho, Pedro M.; Figueiredo, Claudia P.; de Aguiar, Renato S.; de Arruda, Luciana B.

2017-01-01

Zika virus (ZIKV) has been associated to central nervous system (CNS) harm, and virus was detected in the brain and cerebrospinal fluids of microcephaly and meningoencephalitis cases. However, the mechanism by which the virus reaches the CNS is unclear. Here, we addressed the effects of ZIKV replication in human brain microvascular endothelial cells (HBMECs), as an in vitro model of blood brain barrier (BBB), and evaluated virus extravasation and BBB integrity in an in vivo mouse experimental model. HBMECs were productively infected by African and Brazilian ZIKV strains (ZIKVMR766 and ZIKVPE243), which induce increased production of type I and type III IFN, inflammatory cytokines and chemokines. Infection with ZIKVMR766 promoted earlier cellular death, in comparison to ZIKVPE243, but infection with either strain did not result in enhanced endothelial permeability. Despite the maintenance of endothelial integrity, infectious virus particles crossed the monolayer by endocytosis/exocytosis-dependent replication pathway or by transcytosis. Remarkably, both viruses' strains infected IFNAR deficient mice, with high viral load being detected in the brains, without BBB disruption, which was only detected at later time points after infection. These data suggest that ZIKV infects and activates endothelial cells, and might reach the CNS through basolateral release, transcytosis or transinfection processes. These findings further improve the current knowledge regarding ZIKV dissemination pathways. PMID:29312238

Keyhole craniotomy through retrosigmoid approach followed by microvascular decompression for primary trigeminal neuralgia:a report of 23 cases

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Gang-ge CHENG

2011-03-01

Full Text Available Objective To explore the surgical technique,effects,and complications of keyhole craniotomy through retrosigmoid approach followed by microvascular decompression for primary trigeminal neuralgia.Methods The craniotomy with a keyhole incision above postauricular hairline followed by microvascular decompression was performed in 23 patients with primary trigeminal neuralgia.Dissection of intracranial part of trigeminal nerve under microscope was done to search for the offending vessels,which were thereby freed and between which and the root entry zone(REZ of trigeminal nerve the Teflon grafts were placed.Effects and complications were observed in follow-up,ranging from 1 month to 2 years.Results Out of 23 patients who were all found compression in REZ of trigeminal nerves by the offending vessels in operation,disappearance of symptoms post-surgery was found in 22 cases,face numbness on the surgical side in 3 cases and no effects in 1 case.Recurrence of pain was not observed in patients who had initially benefited from the surgery at the follow-up.Conclusion The keyhole craniotomy through retrosigmoid approach followed by microvascular decompression is safe and effective for primary trigeminal neuralgia,in which accurate technique during operation plays a vital role in the decrease of complications and the outcome post-surgery.

Comparison of Generated Parallel Capillary Arrays to Three-Dimensional Reconstructed Capillary Networks in Modeling Oxygen Transport in Discrete Microvascular Volumes

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Fraser, Graham M.; Goldman, Daniel; Ellis, Christopher G.

2013-01-01

Objective We compare Reconstructed Microvascular Networks (RMN) to Parallel Capillary Arrays (PCA) under several simulated physiological conditions to determine how the use of different vascular geometry affects oxygen transport solutions. Methods Three discrete networks were reconstructed from intravital video microscopy of rat skeletal muscle (84×168×342 μm, 70×157×268 μm and 65×240×571 μm) and hemodynamic measurements were made in individual capillaries. PCAs were created based on statistical measurements from RMNs. Blood flow and O2 transport models were applied and the resulting solutions for RMN and PCA models were compared under 4 conditions (rest, exercise, ischemia and hypoxia). Results Predicted tissue PO2 was consistently lower in all RMN simulations compared to the paired PCA. PO2 for 3D reconstructions at rest were 28.2±4.8, 28.1±3.5, and 33.0±4.5 mmHg for networks I, II, and III compared to the PCA mean values of 31.2±4.5, 30.6±3.4, and 33.8±4.6 mmHg. Simulated exercise yielded mean tissue PO2 in the RMN of 10.1±5.4, 12.6±5.7, and 19.7±5.7 mmHg compared to 15.3±7.3, 18.8±5.3, and 21.7±6.0 in PCA. Conclusions These findings suggest that volume matched PCA yield different results compared to reconstructed microvascular geometries when applied to O2 transport modeling; the predominant characteristic of this difference being an over estimate of mean tissue PO2. Despite this limitation, PCA models remain important for theoretical studies as they produce PO2 distributions with similar shape and parameter dependence as RMN. PMID:23841679