Sample records for renal vascular tone

  1. p66Shc regulates renal vascular tone in hypertension-induced nephropathy. (United States)

    Miller, Bradley; Palygin, Oleg; Rufanova, Victoriya A; Chong, Andrew; Lazar, Jozef; Jacob, Howard J; Mattson, David; Roman, Richard J; Williams, Jan M; Cowley, Allen W; Geurts, Aron M; Staruschenko, Alexander; Imig, John D; Sorokin, Andrey


    Renal preglomerular arterioles regulate vascular tone to ensure a large pressure gradient over short distances, a function that is extremely important for maintaining renal microcirculation. Regulation of renal microvascular tone is impaired in salt-sensitive (SS) hypertension-induced nephropathy, but the molecular mechanisms contributing to this impairment remain elusive. Here, we assessed the contribution of the SH2 adaptor protein p66Shc (encoded by Shc1) in regulating renal vascular tone and the development of renal vascular dysfunction associated with hypertension-induced nephropathy. We generated a panel of mutant rat strains in which specific modifications of Shc1 were introduced into the Dahl SS rats. In SS rats, overexpression of p66Shc was linked to increased renal damage. Conversely, deletion of p66Shc from these rats restored the myogenic responsiveness of renal preglomerular arterioles ex vivo and promoted cellular contraction in primary vascular smooth muscle cells (SMCs) that were isolated from renal vessels. In primary SMCs, p66Shc restricted the activation of transient receptor potential cation channels to attenuate cytosolic Ca2+ influx, implicating a mechanism by which overexpression of p66Shc impairs renal vascular reactivity. These results establish the adaptor protein p66Shc as a regulator of renal vascular tone and a driver of impaired renal vascular function in hypertension-induced nephropathy.

  2. Pretreatment renal vascular tone predicts the effect of specific renin inhibition on natriuresis in essential hypertension

    NARCIS (Netherlands)

    van Paassen, P; Navis, GJ; de Jong, PE; de Zeeuw, D


    Background In essential hypertension an elevated renal vascular resistance (RVR) may be a marker of renin-angiotensin-aldosterone system-mediated impairment of renal sodium excretion. This hypothesis was tested by investigating whether, in subjects with essential hypertension, the natriuretic respon

  3. Regulation of vascular tone by adipocytes

    Directory of Open Access Journals (Sweden)

    Van de Voorde Johan


    Full Text Available Abstract Recent studies have shown that adipose tissue is an active endocrine and paracrine organ secreting several mediators called adipokines. Adipokines include hormones, inflammatory cytokines and other proteins. In obesity, adipose tissue becomes dysfunctional, resulting in an overproduction of proinflammatory adipokines and a lower production of anti-inflammatory adipokines. The pathological accumulation of dysfunctional adipose tissue that characterizes obesity is a major risk factor for many other diseases, including type 2 diabetes, cardiovascular disease and hypertension. Multiple physiological roles have been assigned to adipokines, including the regulation of vascular tone. For example, the unidentified adipocyte-derived relaxing factor (ADRF released from adipose tissue has been shown to relax arteries. Besides ADRF, other adipokines such as adiponectin, omentin and visfatin are vasorelaxants. On the other hand, angiotensin II and resistin are vasoconstrictors released by adipocytes. Reactive oxygen species, leptin, tumour necrosis factor α, interleukin-6 and apelin share both vasorelaxing and constricting properties. Dysregulated synthesis of the vasoactive and proinflammatory adipokines may underlie the compromised vascular reactivity in obesity and obesity-related disorders.

  4. Renal posttransplant's vascular complications

    Directory of Open Access Journals (Sweden)

    Bašić Dragoslav


    Full Text Available INTRODUCTION Despite high graft and recipient survival figures worldwide today, a variety of technical complications can threaten the transplant in the postoperative period. Vascular complications are commonly related to technical problems in establishing vascular continuity or to damage that occurs during donor nephrectomy or preservation [13]. AIM The aim of the presenting study is to evaluate counts and rates of vascular complications after renal transplantation and to compare the outcome by donor type. MATERIAL AND METHODS A total of 463 kidneys (319 from living related donor LD and 144 from cadaveric donor - CD were transplanted during the period between June 1975 and December 1998 at the Urology & Nephrology Institute of Clinical Centre of Serbia in Belgrade. Average recipients' age was 33.7 years (15-54 in LD group and 39.8 (19-62 in CD group. Retrospectively, we analyzed medical records of all recipients. Statistical analysis is estimated using Hi-squared test and Fischer's test of exact probability. RESULTS Major vascular complications including vascular anastomosis thrombosis, internal iliac artery stenosis, internal iliac artery rupture obliterant vasculitis and external iliac vein rupture were analyzed. In 25 recipients (5.4% some of major vascular complications were detected. Among these cases, 22 of them were from CD group vs. three from LD group. Relative rate of these complications was higher in CD group vs. LD group (p<0.0001. Among these complications dominant one was vascular anastomosis thrombosis which occurred in 18 recipients (17 from CD vs. one from LD. Of these recipients 16 from CD lost the graft, while the rest of two (one from each group had lethal outcome. DISCUSSION Thrombosis of renal allograft vascular anastomosis site is the most severe complication following renal transplantation. In the literature, renal allograft thrombosis is reported with different incidence rates, from 0.5-4% [14, 15, 16]. Data from the

  5. Role of renal vascular potassium channels in physiology and pathophysiology

    DEFF Research Database (Denmark)

    Salomonsson, Max; Brasen, Jens Christian; Sorensen, Charlotte Mehlin


    The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm ) in vascular smooth muscle (VSMC......) and endothelial cells (EC). The vascular tone is controlled by Vm via its effect on the opening probability of voltage operated Ca2+ channels (VOCC) in VSMC. When K+ conductance increases Vm becomes more negative and vasodilation follows, while deactivation of K+ channels leads to depolarization...... the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis. This article is protected...

  6. Preserved alpha-adrenergic tone in the leg vascular bed of spinal cord-injured individuals.

    NARCIS (Netherlands)

    Kooijman, H.M.; Rongen, G.A.P.J.M.; Smits, P.; Hopman, M.T.E.


    BACKGROUND: Supraspinal sympathetic control of leg vascular tone is lost in spinal cord-injured individuals, but this does not result in a reduced leg vascular tone: Leg vascular resistance is even increased. The aim of this study was to assess the alpha-adrenergic contribution to the increased vasc

  7. The effect of kisspeptin on the regulation of vascular tone. (United States)

    Mezei, Zsófia; Zamani-Forooshani, Omid; Csabafi, Krisztina; Szikszai, Bence; Papp, Eszter; Ónodi, Ádám; Török, Dóra; Leprán, Ádám; Telegdy, Gyula; Szabó, Gyula


    Kisspeptin has been implicated in cardiovascular control. Eicosanoids play a crucial role in the activation of platelets and the regulation of vascular tone. In the present study, we investigated the effect of kisspeptins on eicosanoid synthesis in platelets and aorta in vitro. Platelets and aorta were isolated from Wistar-Kyoto rats. After preincubation with different doses of kisspeptin, samples were incubated with [1-(14)C]arachidonic acid (0.172 pmol/mL) in tissue culture Medium 199. The amount of labeled eicosanoids was measured with liquid scintillation, after separation with overpressure thin-layer chromatography. Kisspeptin-13 stimulated the thromboxane synthesis. The dose-response curve was bell-shaped and the most effective concentration was 2.5 × 10(-8) mol/L, inducing a 27% increase. Lipoxygenase products of platelets displayed a dose-dependent elevation up to the dose of 5 × 10(-8) mol/L. In the aorta, kisspeptin-13 induced a marked elevation in the production of 6-keto-prostaglandin F1α, the stable metabolite of prostacyclin, and lipoxygenase products. Different effects of kisspeptin on cyclooxygenase and lipoxygenase products indicate that beyond intracellular Ca(2+) mobilization, other signaling pathways might also contribute to its actions. Our data suggest that kisspeptin, through the alteration of eicosanoid synthesis in platelets and aorta, may play a physiologic and (or) pathologic role in the regulation of vascular tone.

  8. Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall (United States)

    Liu, Xiaoping; El-Mahdy, Mohamed A.; Boslett, James; Varadharaj, Saradhadevi; Hemann, Craig; Abdelghany, Tamer M.; Ismail, Raed S.; Little, Sean C.; Zhou, Danlei; Thuy, Le Thi Thanh; Kawada, Norifumi; Zweier, Jay L.


    The identity of the specific nitric oxide dioxygenase (NOD) that serves as the main in vivo regulator of O2-dependent NO degradation in smooth muscle remains elusive. Cytoglobin (Cygb) is a recently discovered globin expressed in fibroblasts and smooth muscle cells with unknown function. Cygb, coupled with a cellular reducing system, efficiently regulates the rate of NO consumption by metabolizing NO in an O2-dependent manner with decreased NO consumption in physiological hypoxia. Here we show that Cygb is a major regulator of NO degradation and cardiovascular tone. Knockout of Cygb greatly prolongs NO decay, increases vascular relaxation, and lowers blood pressure and systemic vascular resistance. We further demonstrate that downregulation of Cygb prevents angiotensin-mediated hypertension. Thus, Cygb has a critical role in the regulation of vascular tone and disease. We suggest that modulation of the expression and NOD activity of Cygb represents a strategy for the treatment of cardiovascular disease.

  9. Diagnosing vascular causes of renal failure. (United States)

    Abuelo, J G


    The incidence of renal failure due to vascular diseases is increasing. Two reasons for this are the epidemic of atherosclerotic vascular disease in the aging population and the widespread use of vasoactive drugs that can adversely affect renal function. These vascular causes of renal failure include vasomotor disorders such as that associated with nonsteroidal antiinflammatory drugs, small-vessel diseases such as cholesterol crystal embolization, and large-vessel diseases such as renal artery stenosis. These causes of azotemia are less familiar to physicians than more classic causes, such as acute tubular necrosis, and are less likely to be recognized in their early stages. This article describes the various vascular diseases that impair renal function and outlines the steps necessary to identify them. Although some of these conditions, such as renal artery stenosis, can gradually impair function, the vascular causes of acute renal failure are emphasized in this article. Because the vasculitides primarily cause renal failure through secondary glomerulonephritis, they are mentioned only briefly. Extensive testing is rarely necessary because the cause is usually suspected through syndrome recognition. The diagnosis can then be confirmed by the results of one or two additional tests or by improved renal function after treatment.

  10. Role of Mitochondria in Cerebral Vascular Function: Energy Production, Cellular Protection, and Regulation of Vascular Tone. (United States)

    Busija, David W; Rutkai, Ibolya; Dutta, Somhrita; Katakam, Prasad V


    Mitochondria not only produce energy in the form of ATP to support the activities of cells comprising the neurovascular unit, but mitochondrial events, such as depolarization and/or ROS release, also initiate signaling events which protect the endothelium and neurons against lethal stresses via pre-/postconditioning as well as promote changes in cerebral vascular tone. Mitochondrial depolarization in vascular smooth muscle (VSM), via pharmacological activation of the ATP-dependent potassium channels on the inner mitochondrial membrane (mitoKATP channels), leads to vasorelaxation through generation of calcium sparks by the sarcoplasmic reticulum and subsequent downstream signaling mechanisms. Increased release of ROS by mitochondria has similar effects. Relaxation of VSM can also be indirectly achieved via actions of nitric oxide (NO) and other vasoactive agents produced by endothelium, perivascular and parenchymal nerves, and astroglia following mitochondrial activation. Additionally, NO production following mitochondrial activation is involved in neuronal preconditioning. Cerebral arteries from female rats have greater mitochondrial mass and respiration and enhanced cerebral arterial dilation to mitochondrial activators. Preexisting chronic conditions such as insulin resistance and/or diabetes impair mitoKATP channel relaxation of cerebral arteries and preconditioning. Surprisingly, mitoKATP channel function after transient ischemia appears to be retained in the endothelium of large cerebral arteries despite generalized cerebral vascular dysfunction. Thus, mitochondrial mechanisms may represent the elusive signaling link between metabolic rate and blood flow as well as mediators of vascular change according to physiological status. Mitochondrial mechanisms are an important, but underutilized target for improving vascular function and decreasing brain injury in stroke patients. © 2016 American Physiological Society. Compr Physiol 6:1529-1548, 2016.

  11. Emergency intervention therapy for renal vascular injury

    Institute of Scientific and Technical Information of China (English)

    LIU Feng-yong; WANG Mao-qiang; FAN Qing-sheng; WANG Zhi-jun; DUAN Feng; SONG Peng


    Objective: To evaluate the efficacy and safety of the interventional techniques in the treatment of renal vascular injury.Methods: A total of 16 patients with renal vascular injuries were treated by superselective arterial embolization.The renal injuries resulted from renal biopsy in 7 patients,endovascular intervention in 2.percutaneous puncture and pyelostomy in 2.local resection of renal tumor in 1 and trauma in 4.With regards to clinical manifestations,there was hemorrhagic shock in 8 patients,severe flank pain in 14,and hematuria in 14.CT and ultrasonography confmued that 15 Patients had perirenal hematoma.The embolization was performed with microcoils in 13 and standard stainless steel coils in 3 patients,associated with polyvinyl alcohol particles (PVA) in 9,and gelfoam particles in 6 cases.Results: Renal angiogram revealed arteriovenous fistula in renal parenchyma in 9 cases,pseudoaneurysm in 3 and extravasation of contrast media in 4.The arterial embolization was successful in all 16 cases in a single session.The angiography at the end of therapy showed that abnormal vessels had disappeared without other major intrarenal arterial branch occlusion.In 13 patients with hemodynamical compromise,blood loss-related symptoms were immediately relieved after blood transfusion.In 14 patients with severe flank pain,the pain was progressively relieved.Hematuda ceased in 14 patients 2-14 days after the embolization procedures.The renal function was impaired after the procedure in 6 cases,in which preoperative renal insufficiency was exacerbated in 3 and developed new renal dysfunction in 3.2 of whom received hemodialysis.The ultrasonography showed that perirenal hematoma was gradually absorbed within 2.6 mortths after the procedure.A11 patients were followed up in 6-78 months (mean,48 months).Six patients died of primary diseases (5 cases of renal failure and multiple organ failure and 1 case of malignant tumor).Ten patients survived without bleeding and further

  12. Total peripheral vascular resistance in pediatric renal transplant patients. (United States)

    Matteucci, Maria Chiara; Giordano, Ugo; Calzolari, Armando; Rizzoni, Gianfranco


    Abnormal cardiovascular reactivity at rest and during physical exercise may be a risk factor for left ventricular hypertrophy (LVH) in pediatric renal transplanted (Tx) patients. Data on total peripheral vascular resistance (TPR) are not available. Eleven renal Tx patients treated with cyclosporine (7 females and 4 males; mean age 14.6 +/- 3.3 years; mean time since transplantation 43 +/- 35 months) were evaluated for 24-hour blood pressure (BP), TPR and echocardiographic left ventricular mass (LVM). TPR values of patients were compared with data of a group of 11 healthy controls matched for sex and age. Twenty-four-hour ambulatory blood pressure monitoring showed that all but one patient had normal daytime BP values and six patients showed a reduced or inverse nocturnal dip. LVH was found in 72% of the patients. In comparison with healthy controls, patients showed significantly elevated TPR at rest and during exercise suggesting an increased vascular tone. The degree of LVH in these patients is severe and appears disproportionate to the BP values. The high incidence of LVH can reflect an augmented cardiovascular reactivity associated with a disturbed circadian pattern. The increase in TPR and the reduction of the nocturnal fall of BP also might contribute to the development of LVH in young renal Tx patients.

  13. A constitutive formulation of arterial mechanics including vascular smooth muscle tone. (United States)

    Zulliger, Martin A; Rachev, Alexander; Stergiopulos, Nikos


    A pseudo-strain energy function (pseudo-SEF) describing the biomechanical properties of large conduit arteries under the influence of vascular smooth muscle (VSM) tone is proposed. In contrast to previous models that include the effects of smooth muscle contraction through generation of an active stress, in this study we consider the vascular muscle as a structural element whose contribution to load bearing is modulated by the contraction. This novel pseudo-SEF models not only arterial mechanics at maximal VSM contraction but also the myogenic contraction of the VSM in response to local increases in stretch. The proposed pseudo-SEF was verified with experimentally obtained pressure-radius curves and zero-stress state configurations from rat carotid arteries displaying distinct differences in VSM tone: arteries from normotensive rats displaying minimal VSM tone and arteries from hypertensive rats exhibiting significant VSM tone. The pressure-radius curves were measured in three different VSM states: fully relaxed, maximally contracted, and normal VSM tone. The model fitted the experimental data very well (r2 > 0.99) in both the normo- and hypertensive groups for all three states of VSM activation. The pseudo-SEF was used to illustrate the localized reduction of circumferential stress in the arterial wall due to normal VSM tone, suggesting that the proposed pseudo-SEF can be of general utility for describing stress distribution not only under passive VSM conditions, as most SEFs proposed so far, but also under physiological and pathological conditions with varying levels of VSM tone.

  14. Vascular tone pathway polymorphisms in relation to primary open-angle glaucoma (United States)

    Kang, J H; Loomis, S J; Yaspan, B L; Bailey, J C; Weinreb, R N; Lee, R K; Lichter, P R; Budenz, D L; Liu, Y; Realini, T; Gaasterland, D; Gaasterland, T; Friedman, D S; McCarty, C A; Moroi, S E; Olson, L; Schuman, J S; Singh, K; Vollrath, D; Wollstein, G; Zack, D J; Brilliant, M; Sit, A J; Christen, W G; Fingert, J; Forman, J P; Buys, E S; Kraft, P; Zhang, K; Allingham, R R; Pericak-Vance, M A; Richards, J E; Hauser, M A; Haines, J L; Wiggs, J L; Pasquale, L R


    Aims Vascular perfusion may be impaired in primary open-angle glaucoma (POAG); thus, we evaluated a panel of markers in vascular tone-regulating genes in relation to POAG. Methods We used Illumina 660W-Quad array genotype data and pooled P-values from 3108 POAG cases and 3430 controls from the combined National Eye Institute Glaucoma Human Genetics Collaboration consortium and Glaucoma Genes and Environment studies. Using information from previous literature and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, we compiled single-nucleotide polymorphisms (SNPs) in 186 vascular tone-regulating genes. We used the ‘Pathway Analysis by Randomization Incorporating Structure' analysis software, which performed 1000 permutations to compare the overall pathway and selected genes with comparable randomly generated pathways and genes in their association with POAG. Results The vascular tone pathway was not associated with POAG overall or POAG subtypes, defined by the type of visual field loss (early paracentral loss (n=224 cases) or only peripheral loss (n=993 cases)) (permuted P≥0.20). In gene-based analyses, eight were associated with POAG overall at permuted P<0.001: PRKAA1, CAV1, ITPR3, EDNRB, GNB2, DNM2, HFE, and MYL9. Notably, six of these eight (the first six listed) code for factors involved in the endothelial nitric oxide synthase activity, and three of these six (CAV1, ITPR3, and EDNRB) were also associated with early paracentral loss at P<0.001, whereas none of the six genes reached P<0.001 for peripheral loss only. Discussion Although the assembled vascular tone SNP set was not associated with POAG, genes that code for local factors involved in setting vascular tone were associated with POAG. PMID:24603425

  15. Increased arterial vascular tone during the night in patients with essential hypertension

    DEFF Research Database (Denmark)

    Scholze, A; Burkert, A; Mardanzai, K;


    The time-dependent incidence of cardiovascular events points to an important role of chronobiology for arterial properties. To evaluate arterial properties in patients with essential hypertension, we assessed arterial vascular tone during sleep at night in patients with essential hypertension...

  16. Role of Adenosine Receptor(s) in the Control of Vascular Tone in the Mouse Pudendal Artery. (United States)

    Labazi, Hicham; Tilley, Stephen L; Ledent, Catherine; Mustafa, S Jamal


    Activation of adenosine receptors (ARs) has been implicated in the modulation of renal and cardiovascular systems, as well as erectile functions. Recent studies suggest that adenosine-mediated regulation of erectile function is mainly mediated through A2BAR activation. However, no studies have been conducted to determine the contribution of AR subtype in the regulation of the vascular tone of the pudendal artery (PA), the major artery supplying and controlling blood flow to the penis. Our aim was to characterize the contribution of AR subtypes and identify signaling mechanisms involved in adenosine-mediated vascular tone regulation in the PA. We used a DMT wire myograph for muscle tension measurements in isolated PAs from wild-type, A2AAR knockout, A2BAR knockout, and A2A/A2BAR double-knockout mice. Real-time reverse transcription-polymerase chain reaction was used to determine the expression of the AR subtypes. Data from our pharmacologic and genetic approaches suggest that AR activation-mediated vasodilation in the PA is mediated by both the A2AAR and A2BAR, whereas neither the A1AR nor A3AR play a role in vascular tone regulation of the PA. In addition, we showed that A2AAR- and A2BAR-mediated vasorelaxation requires activation of nitric oxide and potassium channels; however, only the A2AAR-mediated response requires protein kinase A activation. Our data are complemented by mRNA expression showing the expression of all AR subtypes with the exception of the A3AR. AR signaling in the PA may play an important role in mediating erection and represent a promising therapeutic option for the treatment of erectile dysfunction.

  17. Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells. (United States)

    Warnock, David G; Kusche-Vihrog, Kristina; Tarjus, Antoine; Sheng, Shaohu; Oberleithner, Hans; Kleyman, Thomas R; Jaisser, Frederic


    Sodium transport in the distal nephron is mediated by epithelial sodium channel activity. Proteolytic processing of external domains and inhibition with increased sodium concentrations are important regulatory features of epithelial sodium channel complexes expressed in the distal nephron. By contrast, sodium channels expressed in the vascular system are activated by increased external sodium concentrations, which results in changes in the mechanical properties and function of endothelial cells. Mechanosensitivity and shear stress affect both epithelial and vascular sodium channel activity. Guyton's hypothesis stated that blood pressure control is critically dependent on vascular tone and fluid handling by the kidney. The synergistic effects, and complementary regulation, of the epithelial and vascular systems are consistent with the Guytonian model of volume and blood pressure regulation, and probably reflect sequential evolution of the two systems. The integration of vascular tone, renal perfusion and regulation of renal sodium reabsorption is the central underpinning of the Guytonian model. In this Review, we focus on the expression and regulation of sodium channels, and we outline the emerging evidence that describes the central role of amiloride-sensitive sodium channels in the efferent (vascular) and afferent (epithelial) arms of this homeostatic system.

  18. Deletion of mineralocorticoid receptors in smooth muscle cells blunts renal vascular resistance following acute cyclosporine administration (United States)

    Amador, Cristian A.; Bertocchio, Jean-Philippe; Andre-Gregoire, Gwennan; Placier, Sandrine; Van Huyen, Jean-Paul Duong; El Moghrabi, Soumaya; Berger, Stefan; Warnock, David G.; Chatziantoniou, Christos; Jaffe, Iris Z.; Rieu, Philippe; Jaisser, Frederic


    Calcineurin inhibitors such as cyclosporine A (CsA) are still commonly used after renal transplantation, despite CsA–induced nephrotoxicity (CIN), which is partly related to vasoactive mechanisms. The mineralocorticoid receptor (MR) is now recognized as a key player in the control of vascular tone, and both endothelial cell- and vascular smooth muscle cell (SMC)-MR modulate the vasoactive responses to vasodilators and vasoconstrictors. Here we tested whether vascular MR is involved in renal hemodynamic changes induced by CsA. The relative contribution of vascular MR in acute CsA treatment was evaluated using mouse models with targeted deletion of MR in endothelial cell or SMC. Results indicate that MR expressed in SMC, but not in endothelium, contributes to the increase of plasma urea and creatinine, the appearance of isometric tubular vacuolization, and overexpression of a kidney injury biomarker (neutrophil gelatinase–associated lipocalin) after CsA treatment. Inactivation of MR in SMC blunted CsA–induced phosphorylation of contractile proteins. Finally, the in vivo increase of renal vascular resistance induced by CsA was blunted when MR was deleted from SMC cells, and this was associated with decreased L-type Ca2+ channel activity. Thus, our study provides new insights into the role of vascular MR in renal hemodynamics during acute CIN, and provides rationale for clinical studies of MR antagonism to manage the side effects of calcineurin inhibitors. PMID:26422501

  19. Integrin mobilizes intracellular Ca(2+) in renal vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Chan, W L; Holstein-Rathlou, N H; Yip, K P


    Peptides with the Arg-Gly-Asp (RGD) motif induce vasoconstriction in rat afferent arterioles by increasing the intracellular Ca(2+) concentration ([Ca(2+)](i)) in vascular smooth muscle cells (VSMC). This finding suggests that occupancy of integrins on the plasma membrane of VSMC might affect...... vascular tone. The purpose of this study was to determine whether occupancy of integrins by exogenous RGD peptides initiates intracellular Ca(2+) signaling in cultured renal VSMC. When smooth muscle cells were exposed to 0.1 mM hexapeptide GRGDSP, [Ca(2+)](i) rapidly increased from 91 +/- 4 to 287 +/- 37 n...

  20. Beta2-adrenergic activity modulates vascular tone regulation in lecithin:cholesterol acyltransferase knockout mice. (United States)

    Manzini, S; Pinna, C; Busnelli, M; Cinquanta, P; Rigamonti, E; Ganzetti, G S; Dellera, F; Sala, A; Calabresi, L; Franceschini, G; Parolini, C; Chiesa, G


    Lecithin:cholesterol acyltransferase (LCAT) deficiency is associated with hypoalphalipoproteinemia, generally a predisposing factor for premature coronary heart disease. The evidence of accelerated atherosclerosis in LCAT-deficient subjects is however controversial. In this study, the effect of LCAT deficiency on vascular tone and endothelial function was investigated in LCAT knockout mice, which reproduce the human lipoprotein phenotype. Aortas from wild-type (Lcat(wt)) and LCAT knockout (Lcat(KO)) mice exposed to noradrenaline showed reduced contractility in Lcat(KO) mice (P<0.005), whereas acetylcholine exposure showed a lower NO-dependent relaxation in Lcat(KO) mice (P<0.05). Quantitative PCR and Western blotting analyses suggested an adequate eNOS expression in Lcat(KO) mouse aortas. Real-time PCR analysis indicated increased expression of β2-adrenergic receptors vs wild-type mice. Aorta stimulation with noradrenaline in the presence of propranolol, to abolish the β-mediated relaxation, showed the same contractile response in the two mouse lines. Furthermore, propranolol pretreatment of mouse aortas exposed to L-NAME prevented the difference in responses between Lcat(wt) and Lcat(KO) mice. The results indicate that LCAT deficiency leads to increased β2-adrenergic relaxation and to a consequently decreased NO-mediated vasodilation that can be reversed to guarantee a correct vascular tone. The present study suggests that LCAT deficiency is not associated with an impaired vascular reactivity. Copyright © 2015. Published by Elsevier Inc.

  1. Vascular tone and reactivity to serotonin in the internal and external carotid vascular beds of the dog. (United States)

    Vidrio, H; Hong, E


    The effects of intra-arterial infusions of serotonin on internal and external carotid blood flow were determined in anesthetized dogs by electromagnetic flow measurements. Serotonin decreased flow in the internal carotid and increased it in the external carotid. Both responses were blocked by the serotonin antagonist methysergide. The alpha adrenergic antagonist zolertine, the ganglionic blocking agent chlorisondamine and the vasodilator diazoxide blocked external carotid dilator responses but did not modify constriction in the internal carotid. Blockade of external carotid responses by the three drugs was also demonstrated in experiments in which this bed was perfused at a constant rate. These results indicate that the internal and external carotid vascular beds of the dog react in opposite ways to serotonin, that both responses are mediated through the same type of serotonin receptors and that the dilator responses of the external carotid are dependent on vascular tone.

  2. Estimation of cerebral vascular tone during exercise; evaluation by critical closing pressure in humans

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Brothers, R Matthew; Jeschke, Monica;


    The aim of the present study was to calculate critical closing pressure (CCP) of the cerebral vasculature at rest and during exercise to estimate cerebral vascular tone. Five men and two women were seated upright for 15 min and then performed 15 min of right-legged knee extension exercise at 40, 60...... and 75% of their maximal workload (WL(max)). Middle cerebral artery blood velocity (MCA V) and blood pressure in the radial artery were recorded. The CCP was calculated by linear extrapolation from 1 min recordings of pairs of systolic and diastolic pressure and MCA V waveforms from both the right...

  3. Vascular Variations and Anastomosis Techniques in Renal Transplant Donors

    Directory of Open Access Journals (Sweden)

    ilker Murat Arer


    Conclusion: Preoperative evaluation of renal vasculature of transplant donors is an important issue in means of decreasing peroperative vascular complications and decision for nephrectomy site. [Cukurova Med J 2015; 40(3.000: 542-546

  4. Does aldosterone play a significant role for regulation of vascular tone?

    DEFF Research Database (Denmark)

    Lyngsø, Kristina Sanne; Assersen, Kasper Bostlund; Dalgaard, Emil Geertsen;


    Besides the well-known renal effects of aldosterone, the hormone is now known to have direct vascular effects. Clinical observations underline substantial adverse effects of aldosterone on cardiovascular function. The source of systemic circulating aldosterone is the adrenal gland zona glomerulosa...... cells through stimulus-secretion coupling involving depolarization, opening of L- and T-type calcium channels and aldosterone synthase activation. Local formation and release in peripheral tissues such as perivascular fat is recognized. Where does aldosterone affect the vasculature? Mineralocorticoid...... receptors (MR) are present in endothelial and vascular smooth muscle cells and MR-independent pathways are also involved. The vascular effects of aldosterone are complex, both concentration, temporal and spatial aspects are relevant. The acute response includes vasodilation through endothelial nitric oxide...

  5. Renal vascular dysfunction precedes the development of renal damage in the hypertensive Fawn-Hooded rat

    NARCIS (Netherlands)

    Ochodnicky, Peter; Henning, Robert H.; Buikema, Hendrik J.; de Zeeuw, Dick; Provoost, Abraham P.; van Dokkum, Richard P. E.


    Ochodnicky P, Henning RH, Buikema HJ, de Zeeuw D, Provoost AP, van Dokkum RP. Renal vascular dysfunction precedes the development of renal damage in the hypertensive Fawn-Hooded rat. Am J Physiol Renal Physiol 298: F625-F633, 2010. First published December 9, 2009; doi:10.1152/ajprenal.00289.2009.-I

  6. Melamine Impairs Renal and Vascular Function in Rats. (United States)

    Tian, Xiao Yu; Wong, Wing Tak; Lau, Chi Wai; Wang, Yi-Xiang; Cheang, Wai San; Liu, Jian; Lu, Ye; Huang, Huihui; Xia, Yin; Chen, Zhen Yu; Mok, Chuen-Shing; Lau, Chau-Ming; Huang, Yu


    Melamine incident, linked to nephrotoxicity and kidney stone in infants previously exposed to melamine-contaminated milk products, was unprecedentedly grave in China in 2008 as little was known about the mechanistic process leading to renal dysfunction in affected children. This study investigates whether neonatal ingestion of melamine leads to renal and vascular dysfunction in adulthood; and whether ingestion of melamine in pregnant rats leads to renal dysfunction in their offspring. A combination of approaches employed includes functional studies in rat renal arteries, renal blood flow measurement by functional magnetic resonance imaging, assay for pro-inflammatory and fibrotic biomarkers, immunohistochemistry, and detection of plasma and renal melamine. We provide mechanistic evidence showing for the first time that melamine reduces renal blood flow and impairs renal and vascular function associated with overexpression of inflammatory markers, transforming growth factor-β1, bone morphogenic protein 4 and cyclooxygenase-2 in kidney and renal vasculature. Melamine also induces renal inflammation and fibrosis. More importantly, melamine causes nephropathies in offsprings from pregnant rat exposed to melamine during pregnancy, as well as in neonatal rat exposed to melamine afterbirth, thus supporting the clinical observations of kidney stone and acute renal failure in infants consuming melamine-contaminated milk products.

  7. Effects of catechins on vascular tone in rat thoracic aorta with endothelium. (United States)

    Sanae, Fujiko; Miyaichi, Yukinori; Kizu, Haruhisa; Hayashi, Hisao


    The effects of eight catechin derivatives on vascular tone in rat thoracic aorta were examined. Catechin derivatives (10 microM) potentiated the contractile response to phenylephrine in endothelium-intact arteries. The potentiations produced by EGCg and EGC were almost absent in endothelium-denuded arteries and abolished by N(G)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis. The catechin derivatives also inhibited endothelium-dependent relaxation in response to acetylcholine. The order of catechin derivatives ranked in terms of both increasing vascular reactivity and impairing endothelium-dependent relaxation was similar; (-)-gallocatechin (GC) >or= (-)-epigallocatechin (EGC) >or= (-)-gallocatechin gallate (GCg) >or= (-)-epigallocatechin gallate (EGCg) >or= (-)-catechin (C) >or= (-)-epicatechin (EC) >or= (-)-catechin gallate (Cg) >or= (-)-epicatechin gallate (ECg). In addition, EGC inhibited the endothelium-independent relaxation evoked by both sodium nitroprusside and NOC-7, a spontanous NO releaser, but EGCg inhibited only that by NOC-7. These findings indicate that catechin derivatives produce a potentiation of the contractile response and an inhibition of the vasorelaxant response, probably through inactivation of endothelium-derived nitric oxide (NO), and that the hydroxyl on C-5 of the B ring together with the stereoscopic structure between the C-3 group and the B ring of flavanols was of importance in mediating the above effects and that the substitution of a gallate group of C-3 attenuated the effects, probably due to a decreased response to solube guanylate cyclase in vascular smooth muscle cells.

  8. Sympathy for the devil: the role of thromboxane in the regulation of vascular tone and blood pressure. (United States)

    Sellers, Minga M; Stallone, John N


    Historically, the vasodilatory prostanoids, especially prostacyclin and prostaglandin E(2), are believed to contribute significantly to the regulation of normal vascular tone and blood pressure (BP), primarily by counteracting the prevailing effects of the systemic vasoconstrictor systems, including angiotensin II, the catecholamines, and vasopressin. In contrast, the primary vasoconstrictor prostanoid thromboxane A(2) (TxA(2)) is produced in far smaller quantities in the normal state. While TxA(2) is believed to play a significant role in a variety of cardiovascular diseases, such as myocardial infarction, cerebral vasospasm, hypertension, preeclampsia, and various thrombotic disorders, its role in the regulation of vascular tone and BP in the normal physiological state is, at best, uncertain. Numerous studies have firmly established the dogma that TxA(2), while important in pathophysiological states in males, plays little or no role in the regulation of vascular tone or BP in females, except in the pulmonary vasculature. However, this concept is largely based on the predominant and preferential use of males in animal and human studies. Recent studies from our laboratory and others challenge this dogma and reveal that the TxA(2) pathway in the systemic vascular wall is an estrogen-dependent mechanism that appears to play an important role in the regulation of vascular tone and BP in females, in both normal and pathophysiological states. It is proposed that the potent vasoconstrictor action of TxA(2) is beneficial in the female in the normal state by acting as a local counterregulatory mechanism to increase vascular tone and BP and defend against hypotension that could result from the multiple estrogen-sensitive local vasodilator mechanisms present in the female vascular wall. Validation of this proposal must await further studies at the systemic, tissue, and molecular levels.

  9. An experimental study on vascular changes in renal biopsy injury

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Hoon; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    An experimental study on the vascular alternations of the kidney following biopsy procedure was carried out in 47 kidneys from 28 rabbits to clarify their nature and frequency by renal arteriography and microangiography together with histopathologic investigation. Renal arteriography and microangiography were performed immediately 2 days, 1 week, and 2 weeks after percutaneous biopsy and the findings were correlated with histological nature. The results are summarized as follows: 1. Important biopsy injuries verified by renal arteriography and microangiography were arterial spasm, perfusion defect, arteriovenous fistula, injury to vasa rectae and renal tubules, intrarenal and extrarenal extravasation of contrast media, and arterial obstruction, in order of frequency. 2. Arterial spasm observed in majority of the cases were relieved during the period of 2 weeks. 3. Detectability of perfusion detect was 57% and 72% angiography and microangiography, respectively, and this perfusion defect seemed to be mostly caused by renal infraction due to vascular injury, such as arteriovenous fistula, arterial obstruction and other vascular injuries. 4. Arteriovenous fistula was detected in 28% by angiography and 50% by microangiography. Many of the arteriovenous fistulae appeared to be closed spontaneous within a week. Above findings suggest that renal biopsy procedure results in various degree of vascular injuries with their sequential modification, and that microangiography is assumed the most effective approach in analysis of biopsy injuries such as small arteriovenous fistula, perfusion defect, injury to vasa recta and renal tubules, overcoming the limitation of traditional angiography.

  10. The vascular Ca2+-sensing receptor regulates blood vessel tone and blood pressure. (United States)

    Schepelmann, M; Yarova, P L; Lopez-Fernandez, I; Davies, T S; Brennan, S C; Edwards, P J; Aggarwal, A; Graça, J; Rietdorf, K; Matchkov, V; Fenton, R A; Chang, W; Krssak, M; Stewart, A; Broadley, K J; Ward, D T; Price, S A; Edwards, D H; Kemp, P J; Riccardi, D


    The extracellular calcium-sensing receptor CaSR is expressed in blood vessels where its role is not completely understood. In this study, we tested the hypothesis that the CaSR expressed in vascular smooth muscle cells (VSMC) is directly involved in regulation of blood pressure and blood vessel tone. Mice with targeted CaSR gene ablation from vascular smooth muscle cells (VSMC) were generated by breeding exon 7 LoxP-CaSR mice with animals in which Cre recombinase is driven by a SM22α promoter (SM22α-Cre). Wire myography performed on Cre-negative [wild-type (WT)] and Cre-positive (SM22α)CaSR(Δflox/Δflox) [knockout (KO)] mice showed an endothelium-independent reduction in aorta and mesenteric artery contractility of KO compared with WT mice in response to KCl and to phenylephrine. Increasing extracellular calcium ion (Ca(2+)) concentrations (1-5 mM) evoked contraction in WT but only relaxation in KO aortas. Accordingly, diastolic and mean arterial blood pressures of KO animals were significantly reduced compared with WT, as measured by both tail cuff and radiotelemetry. This hypotension was mostly pronounced during the animals' active phase and was not rescued by either nitric oxide-synthase inhibition with nitro-l-arginine methyl ester or by a high-salt-supplemented diet. KO animals also exhibited cardiac remodeling, bradycardia, and reduced spontaneous activity in isolated hearts and cardiomyocyte-like cells. Our findings demonstrate a role for CaSR in the cardiovascular system and suggest that physiologically relevant changes in extracellular Ca(2+) concentrations could contribute to setting blood vessel tone levels and heart rate by directly acting on the cardiovascular CaSR.

  11. Effects of intracellular alkalinization on resting and agonist-induced vascular tone. (United States)

    Danthuluri, N R; Deth, R C


    To evaluate the influence of intracellular alkalinization on basal and agonist-induced vascular tone, we studied the effect of NH4Cl on rat aorta. NH4Cl induced a gradually developing contraction in a dose-dependent manner. Although the contractile response to 20 mM NH4Cl was associated with a latent period (LP) of 23.4 +/- 2.8 min, intracellular pH (pHi) measurements in cultured rat aortic smooth muscle cells showed that NH4Cl-induced intracellular alkalinization was immediate and transient, returning to basal pHi levels in about 30-35 min. Agents that elevate Ca2+, such as A23187 and high KCl, significantly reduced the LP associated with 20 mM NH4Cl-induced contraction. NH4Cl-induced contractions were sensitive to extracellular Ca2+ removal and to the addition of forskolin (1 microM); however, NH4Cl by itself did not cause Ca2+-influx as shown by 45Ca-uptake studies. Addition of 20 mM NH4Cl to precontracted tissues resulted in a transient relaxation, which was complete in approximately 10 min, followed by a contraction above the original level of tone. NH4Cl pretreatment caused time-dependent alterations in both the rapid and slow phases of phenylephrine and angiotensin II contractions. Rapid-phase of phenylephrine and angiotensin II contractions. Rapid-phase responses were diminished at shorter NH4Cl incubation times (10 min), whereas slow-phase response was augmented after a longer incubation (20 min). Overall, the vasorelaxant and vasoconstrictor effects induced by NH4Cl suggest a complex relationship between intracellular alkalinization and arterial contractility.

  12. Arctigenin improves vascular tone and decreases inflammation in human saphenous vein. (United States)

    Daci, Armond; Neziri, Burim; Krasniqi, Shaip; Cavolli, Raif; Alaj, Rame; Norata, Giuseppe Danilo; Beretta, Giangiacomo


    The goal of this study was to test the effects of bioactive phenylpropanoid dibenzylbutyrolactone lignan arctigenin (ATG) in vascular tone. Human bypass graft vessel, from a saphenous vein (SV), were set up in organ bath system and contracted with potassium chloride (KCl, 40mM). Two concentration-response curves of noradrenaline (NE) (10nM-100μM) separated with an incubation period of 30min without (Control) or with ATG (3-100μM) were established. Inhibitors of nitric oxide, prostaglandins, K(+) related channels or calcium influx were used to delineate the molecular mechanisms beyond ATG effects. To investigate anti-inflammatory actions, SV were treated with 10μM or 100μM ATG and incubated for 18h in the absence or presence of both interleukin-1beta (IL-1β) and lipopolysaccharide (LPS) to mimic the physiological or inflamed tissue conditions. Proatherogenic and inflammatory mediators İnterleukine-1 beta (IL-1β), Monocyte Chemoattractant Proteine-1 (MCP-1), Tumor Necrosis Factor- α (TNF-α), İnterleukine-6 (IL-6), Prostaglandin E2 (PGE2) and İnterleukine-8 (IL-8) in the supernatant were measured. ATG significantly decreased vascular contractile response to NE. Moreover, it reduced contractions induced by KCl and cumulative addition of CaCl2. The mediators were significantly increased in inflammatory conditions compared to normal conditions, an effect which was inhibited by ATG (10 and 100µM). ATG reduces contractions in SV and decreases the production of proinflammatory-proatherogenic mediators, setting the stage for further evaluating the effect of ATG in cardiovascular diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Bilirubin oxidation end products directly alter K+ channels important in the regulation of vascular tone. (United States)

    Hou, Shangwei; Xu, Rong; Clark, Joseph F; Wurster, William L; Heinemann, Stefan H; Hoshi, Toshinori


    The exact etiology of delayed cerebral vasospasm following cerebral hemorrhage is not clear, but a family of compounds termed 'bilirubin oxidation end products (BOXes)' derived from heme has been implicated. As proper regulation of vascular smooth muscle tone involves large-conductance Ca(2+)- and voltage-dependent Slo1 K(+) (BK, maxiK, K(Ca)1.1) channels, we examined whether BOXes altered functional properties of the channel. Electrophysiological measurements of Slo1 channels heterologously expressed in a human cell line and of native mouse BK channels in isolated cerebral myocytes showed that BOXes markedly diminished open probability. Biophysically, BOXes specifically stabilized the conformations of the channel with its ion conduction gate closed. The results of chemical amino-acid modifications and molecular mutagenesis together suggest that two specific lysine residues in the structural element linking the transmembrane ion-permeation domain to the carboxyl cytosolic domain of the Slo1 channel are critical in determining the sensitivity of the channel to BOXes. Inhibition of Slo1 BK channels by BOXes may contribute to the development of delayed cerebral vasospasm following brain hemorrhage.

  14. Multinephron dynamics on the renal vascular network

    DEFF Research Database (Denmark)

    Marsh, Donald J; Wexler, Anthony S; Brazhe, Alexey


    ensemble. Ensembles may synchronize. Smooth muscle cells in the ensemble depolarize periodically, generating electrical signals that propagate along the vascular network. We developed a mathematical model of a nephron-vascular network, with 16 versions of a single nephron model containing representations...... of both mechanisms in the regulatory ensemble, to examine the effects of network structure on nephron synchronization. Symmetry, as a property of a network, facilitates synchronization. Nephrons received blood from a symmetric electrically conductive vascular tree. Symmetry was created by using identical...... nephron models at each of the 16 sites, and symmetry breaking by varying nephron length. The symmetric model achieved synchronization of all elements in the network. As little as 1% variation in nephron length caused extensive desynchronization, although synchronization was maintained in small nephron...

  15. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A


    Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure...... also remained normal. In the high vascular tone state, a large transmural pressure difference must apparently be established before the digital arteries are forced open. The lowered opening pressure constitutes a manifestation of the closure phenomenon of the digital arteries described in patients...

  16. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A


    Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure...... also remained normal. In the high vascular tone state, a large transmural pressure difference must apparently be established before the digital arteries are forced open. The lowered opening pressure constitutes a manifestation of the closure phenomenon of the digital arteries described in patients...

  17. Multiple vascular anomalies involving renal, testicular and suprarenal arteries

    Directory of Open Access Journals (Sweden)

    Suresh Rao


    Full Text Available Knowledge of variations of blood vessels of the abdomen is important during operative, diagnostic and endovascular pro- cedures. During routine dissection of the abdominal cavity, we came across multiple vascular anomalies involving renal, suprarenal and testicular arteries. The left kidney was supplied by two renal arteries originating together from the abdomi- nal aorta, and the right kidney was supplied by two accessory renal arteries, one of which was arising from the right renal artery and the other one from the aorta (about 2 inches below the origin of the renal artery. Accessory renal veins were present on both sides. The right testicular artery was arising from the lower accessory renal artery. The left testicular artery was looping around the inferior tributary of the left renal vein, whereby forming a sharp kink. The left middle suprarenal artery was diving into three small branches; the upper two branches were supplying the left suprarenal gland, whereas the lower branch was supplying the left kidney. Furthermore, detailed literature and the clinical and surgical importance of the case are discussed. [Arch Clin Exp Surg 2015; 4(3.000: 168-171

  18. Vascular reactivity of rabbit isolated renal and femoral resistance arteries in renal wrap hypertension. (United States)

    Khammy, Makhala M; Angus, James A; Wright, Christine E


    In rabbits with cellophane renal wrap hypertension, hindquarter and total vascular resistance changes to pressor and depressor agents are amplified compared to those of normotensive rabbits. The aim of the present study was to evaluate the in vitro pharmacodynamics of hypertensive and normotensive rabbit small artery segments isolated from the renal and hindquarter vascular beds. Using wire myography, the full range (Emax) and sensitivity (EC50) to a range of agonists of segments of renal interlobar (≈ 600 µm i.d.), renal arcuate (≈ 250 µm i.d.) and deep femoral branch (≈ 250 µm i.d.) arteries were assessed under normalised conditions of passive tension. Interlobar arteries from hypertensive rabbits were more sensitive (EC50) than those from normotensive rabbits to noradrenaline (6-fold), methoxamine (3-fold) and angiotensin II (3-fold). Arcuate artery reactivity was largely unaffected by hypertension. Deep femoral arteries from hypertensive rabbits had enhanced sensitivity only to noradrenaline (2-fold) and methoxamine (4-fold). Sensitivity to relaxation by acetylcholine was unaffected by hypertension in all arteries. Deep femoral arteries from hypertensive rabbits were more sensitive to sodium nitroprusside than normotensive counterparts. Adenosine caused little relaxation in renal arteries, but full relaxation in deep femoral arteries, unaltered by hypertension. This study found substantial heterogeneity in the pharmacodynamic profile of vessels isolated from different vascular beds and between arterial segments within the kidney. These profiles were differentially affected by hypertension suggesting that hypertension per se is not a resultant of general vascular dysfunction.

  19. Effects of exogenous oxygen derived free radicals on myocardial capillary permeability, vascular tone, and incidence of ventricular arrhythmias in the canine heart

    DEFF Research Database (Denmark)

    Svendsen, Jesper Hastrup; Bjerrum, P J


    The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo.......The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo....

  20. Vascular access for extracorporeal renal replacement therapy in veterinary patients. (United States)

    Chalhoub, Serge; Langston, Cathy E; Poeppel, Karen


    Vascular access is the first and most basic requirement for successful extracorporeal renal replacement therapy (ERRT). Dual-lumen catheters are the most commonly used method of vascular access for ERRT in veterinary patients. An adequately functioning dialysis catheter allows for smooth and efficient patient management, whereas a poorly functioning catheter frustrates the technician, doctor, and patient. These catheters are fairly quick to place but require meticulous care for optimal function. The most common complications are thrombosis and infection. Monitoring catheter performance should be a routine part of dialysis patient care.

  1. Precise renal artery segmentation for estimation of renal vascular dominant regions (United States)

    Wang, Chenglong; Kagajo, Mitsuru; Nakamura, Yoshihiko; Oda, Masahiro; Yoshino, Yasushi; Yamamoto, Tokunori; Mori, Kensaku


    This paper presents a novel renal artery segmentation method combining graph-cut and template-based tracking methods and its application to estimation of renal vascular dominant region. For the purpose of giving a computer assisted diagnose for kidney surgery planning, it is important to obtain the correct topological structures of renal artery for estimation of renal vascular dominant regions. Renal artery has a low contrast, and its precise extraction is a difficult task. Previous method utilizing vesselness measure based on Hessian analysis, still cannot extract the tiny blood vessels in low-contrast area. Although model-based methods including superellipsoid model or cylindrical intensity model are low-contrast sensitive to the tiny blood vessels, problems including over-segmentation and poor bifurcations detection still remain. In this paper, we propose a novel blood vessel segmentation method combining a new Hessian-based graph-cut and template modeling tracking method. Firstly, graph-cut algorithm is utilized to obtain the rough segmentation result. Then template model tracking method is utilized to improve the accuracy of tiny blood vessel segmentation result. Rough segmentation utilizing graph-cut solves the bifurcations detection problem effectively. Precise segmentation utilizing template model tracking focuses on the segmentation of tiny blood vessels. By combining these two approaches, our proposed method segmented 70% of the renal artery of 1mm in diameter or larger. In addition, we demonstrate such precise segmentation can contribute to divide renal regions into a set of blood vessel dominant regions utilizing Voronoi diagram method.

  2. Cortical and medullary vascularity in renal allograft biopsies



    Aim: To evaluate the relation between cortical and medullary peritubular capillaries (PTCs) and scarring. There are presently no studies about medullary PTCs in renal allograft biopsies. Materials and methods: Nonprotocol allograft biopsies were evaluated and 41 with adequate medullary and cortical tissues were selected. Vascular structures were counted separately at the medulla and cortex on anti-CD34 stained sections. Other histopathological and clinical findings were retrieved from the p...

  3. Understanding the effects of mature adipocytes and endothelial cells on fatty acid metabolism and vascular tone in physiological fatty tissue for vascularized adipose tissue engineering. (United States)

    Huber, Birgit; Volz, Ann-Cathrin; Kluger, Petra J


    Engineering of large vascularized adipose tissue constructs is still a challenge for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Communication between mature adipocytes and endothelial cells is important for homeostasis and the maintenance of adipose tissue mass but, to date, is mainly neglected in tissue engineering strategies. Thus, new co-culture strategies are needed to integrate adipocytes and endothelial cells successfully into a functional construct. This review focuses on the cross-talk of mature adipocytes and endothelial cells and considers their influence on fatty acid metabolism and vascular tone. In addition, the properties and challenges with regard to these two cell types for vascularized tissue engineering are highlighted.

  4. Estudio vascular renal por TC multidetector de 64 canales 64-Multidetector row CT for the Renal Vascular Study

    Directory of Open Access Journals (Sweden)

    Daniela Stoisa


    Full Text Available Objetivo: Mostrar las diversas variantes anatómicas vasculares tanto arteriales como venosas en el estudio angiográfico renal por tomografìa computada multidetector (TCMD de 64 canales, dada su implicancia en un eventual planeamiento quirúrgico. Material y métodos: Evaluamos retrospectivamente 26 estudios realizados con tomógrafo Philips Brilliance de 64 canales. Se obtuvieron secuencias sin contraste y postcontraste e.v. en fases arterial y venosa, administrado con bomba inyectora doble cabezal. Para una fase arterial apropiada se utilizó técnica de bolus track. Las imágenes fueron posteriormente procesadas en Workstation Philips Brilliance 190P en un tiempo promedio de 30 minutos y reconstruidas con técnicas MIP y volumétrica. Resultados: Dentro de las variantes anatómicas arteriales, encontramos: bifurcaciones prehiliares (n=3, arterias accesorias (n=4 y arterias polares (n=9. Dentro de las variantes venosas fueron halladas: venas renales múltiples (n=5, venas circumaórticas (n=2, retroaórticas (n=2 y vena tributaria lumbar prominente (n=1. Conclusión: El estudio vascular renal adquiere importancia en el planeamiento quirúrgico en casos de nefrectomías parciales, laparoscópicas y en el transplante renal. Esto otorga suma utilidad al estudio de TCMD de 64 canales por su eficacia diagnóstica, dada la alta calidad de las reconstrucciones obtenidas, llegando a igualar a la angiografía digital, sin ser un método invasivo.Purpose: To show the wide range of anatomical vascular variants, arterial and venous, that can be seen in the angiographic renal study using 64-multidetector-row computed tomography (64-MDCT, due to its importance in an eventual surgical planning. Material and Methods: We have evaluated retrospectively 26 studies that have been done using a 64 channels Philips Brilliance CT scanner. We have obtained non enhanced and both in arterial and venous enhanced sequences. For the injection of the contrast material we

  5. Bilateral Vascular Variations at the Renal Hilum: A Case Report

    Directory of Open Access Journals (Sweden)

    Naveen Kumar


    Full Text Available Imaging technology with its advancement in the field of urology is the boon for the patients who require minimally invasive approaches for various kidney disorders. These approaches require a precise knowledge of the normal and variant anatomy of vascular structures at the hilum of the kidney in terms of their pattern of arrangement and division. The present paper describes a bilateral anomalous arrangement of the structures at the renal hilum as well as their peculiar branching pattern which is of clinical and surgical relevance. Multiple branching of the renal vessels was observed in both kidneys due to which the hila were congested. The right renal artery immediately after its origin divided into 2 branches. The upper branch represented an aberrant artery whereas the lower branch gave 5 divisions. The left renal artery also divided into 2 branches much before the hilum as anterior and posterior divisions. The anterior branch took an arched course and gave 6 branches. The posterior branch gave 3 terminal branches before entering the renal substance. In addition to anomalous hilar structures, normal architecture of both kidneys was altered and the hilum of the left kidney was found on its anterior surface.

  6. Vascular function and mild renal impairment in stable coronary artery disease

    NARCIS (Netherlands)

    van der Harst, P; Smilde, TDJ; Buikema, H; Voors, AA; Navis, G; van Veldhuisen, DJ; van Gilst, WH


    Objective - In patients with coronary artery disease, the concomitant presence of renal function impairment is associated with decreased survival. We aimed to assess whether in coronary artery diseased patients renal function impairment is associated with systemic vascular function, functional param

  7. Optical measures of changes in cerebral vascular tone during voluntary breath holding and a Sternberg memory task. (United States)

    Tan, Chin Hong; Low, Kathy A; Schneider-Garces, Nils; Zimmerman, Benjamin; Fletcher, Mark A; Maclin, Edward L; Chiarelli, Antonio M; Gratton, Gabriele; Fabiani, Monica


    The human cerebral vasculature responds to changes in blood pressure and demands for oxygenation via cerebral autoregulation. Changes in cerebrovascular tone (vasoconstriction and vasodilation) also mediate the changes in blood flow measured by the BOLD fMRI signal. This cerebrovascular reactivity is known to vary with age. In two experiments, we demonstrate that cerebral pulse parameters measured using optical imaging can quantify changes in cerebral vascular tone, both globally and locally. In experiment 1, 51 older adults (age range=55-87) performed a voluntary breath-holding task while cerebral pulse amplitude measures were taken. We found significant pulse amplitude variations across breath-holding periods, indicating vasodilation during, and vasoconstriction after breath holding. The breath-holding index (BHI), a measure of cerebrovascular reactivity (CVR) was derived and found to correlate with age. BHI was also correlated with performance in the Modified Mini-Mental Status Examination, even after controlling for age and education. In experiment 2, the same participants performed a Sternberg task, and changes in regional pulse amplitude between high (set-size 6) and low (set-size 2) task loads were compared. Only task-related areas in the fronto-parietal network (FPN) showed significant reduction in pulse amplitude, indicating vasodilation. Non-task-related areas such as the somatosensory and auditory cortices did not show such reductions. Taken together, these experiments suggest that optical pulse parameters can index changes in brain vascular tone both globally and locally, using both physiological and cognitive load manipulations. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Regulation of Vascular and Renal Function by Metabolite Receptors* (United States)

    Peti-Peterdi, János; Kishore, Bellamkonda K.; Pluznick, Jennifer L.


    To maintain metabolic homeostasis, the body must be able to monitor the concentration of a large number of substances, including metabolites, in real time and to use that information to regulate the activities of different metabolic pathways. Such regulation is achieved by the presence of sensors, termed metabolite receptors, in various tissues and cells of the body, which in turn convey the information to appropriate regulatory or positive or negative feedback systems. In this review, we cover the unique roles of metabolite receptors in renal and vascular function. These receptors play a wide variety of important roles in maintaining various aspects of homeostasis—from salt and water balance to metabolism—by sensing metabolites from a wide variety of sources. We discuss the role of metabolite sensors in sensing metabolites generated locally, metabolites generated at distant tissues or organs, or even metabolites generated by resident microbes. Metabolite receptors are also involved in various pathophysiological conditions and are being recognized as potential targets for new drugs. By highlighting three receptor families—(a) citric acid cycle intermediate receptors, (b) purinergic receptors, and (c) short-chain fatty acid receptors—we emphasize the unique and important roles that these receptors play in renal and vascular physiology and pathophysiology. PMID:26667077

  9. Role of vascular potassium channels in the regulation of renal hemodynamics

    DEFF Research Database (Denmark)

    Sørensen, Charlotte Mehlin; Braunstein, Thomas Hartig; von Holstein-Rathlou, Niels-Henrik


    of one or more classes of K+ channels will lead to a change in hemodynamic resistance and therefore of renal blood flow and glomerular filtration pressure. Through these effects, the activity of renal vascular K+ channels influences renal salt and water excretion, fluid homeostasis, and ultimately blood...

  10. Reduced contribution of endothelin to the regulation of systemic and pulmonary vascular tone in severe familial hypercholesterolaemia. (United States)

    Bender, Shawn B; de Beer, Vincent J; Tharp, Darla L; van Deel, Elza D; Bowles, Douglas K; Duncker, Dirk J; Laughlin, M Harold; Merkus, Daphne


    Vascular dysfunction has been associated with familial hypercholesterolaemia (FH), a severe form of hyperlipidaemia. We recently demonstrated that swine with FH exhibit reduced exercise-induced systemic, but not pulmonary, vasodilatation involving reduced nitric oxide (NO) bioavailability. Since NO normally limits endothelin (ET) action, we examined the hypothesis that reduced systemic vasodilatation during exercise in FH swine results from increased ET-mediated vasoconstriction. Systemic and pulmonary vascular responses to exercise were examined in chronically instrumented normal and FH swine in the absence and presence of the ETA/B receptor antagonist tezosentan. Intrinsic reactivity to ET was further assessed in skeletal muscle arterioles. FH swine exhibited ∼9-fold elevation in total plasma cholesterol versus normal swine. Similar to our recent findings, systemic, not pulmonary, vasodilatation during exercise was reduced in FH swine. Blockade of ET receptors caused marked systemic vasodilatation at rest and during exercise in normal swine that was significantly reduced in FH swine. The reduced role of ET in FH swine in vivo was not the result of decreased arteriolar ET responsiveness, as responsiveness was increased in isolated arterioles. Smooth muscle ET receptor protein content was unaltered by FH. However, circulating plasma ET levels were reduced in FH swine. ET receptor antagonism caused pulmonary vasodilatation at rest and during exercise in normal, but not FH, swine. Therefore, contrary to our hypothesis, FH swine exhibit a generalised reduction in the role of ET in regulating vascular tone in vivo probably resulting from reduced ET production. This may represent a unique vascular consequence of severe familial hypercholesterolaemia.

  11. Intragraft vascular occlusive sickle crisis with early renal allograft loss in occult sickle cell trait. (United States)

    Kim, Lisa; Garfinkel, Marc R; Chang, Anthony; Kadambi, Pradeep V; Meehan, Shane M


    Early renal allograft failure due to sickle cell trait is rare. We present clinical and pathologic findings in 2 cases of early renal allograft failure associated with renal vein thrombosis and extensive erythrocyte sickling. Hemoglobin AS was identified in retrospect. In case 1, a 41-year-old female recipient of a deceased donor renal transplant developed abdominal pain and acute allograft failure on day 16, necessitating immediate nephrectomy. In case 2, the transplanted kidney in a 58-year-old female recipient was noted to be mottled blue within minutes of reperfusion. At 24 hours, the patient was oliguric; and the graft was removed. Transplant nephrectomies had diffuse enlargement with diffuse, nonhemorrhagic, cortical, and medullary necrosis. Extensive sickle vascular occlusion was evident in renal vein branches; interlobar, interlobular, and arcuate veins; vasa recta; and peritubular capillaries. The renal arteries had sickle vascular occlusion in case 1. Glomeruli had only focal sickle vascular occlusion. The erythrocytes in sickle vascular occlusion had abundant cytoplasmic filaments by electron microscopy. Acute rejection was not identified in either case. Protein C and S levels, factor V Leiden, and lupus anticoagulant assays were within normal limits. Hemoglobin analysis revealed hemoglobin S of 21.8% and 25.6%, respectively. Renal allograft necrosis with intragraft sickle crisis, characterized by extensive vascular occlusive erythrocyte sickling and prominent renal vein thrombosis, was observed in 2 patients with sickle cell trait. Occult sickle cell trait may be a risk factor for early renal allograft loss.


    Directory of Open Access Journals (Sweden)

    S. N. Orlov


    Full Text Available The article discusses the data on the functioning of Na+,K+,2Cl– cotransport – the carrier providing electroneutral symport of sodium, potassium and chloride, as well as molecular mechanisms of the regulation and physiological significance of this carrier. We analyzed the novel data on involvement of ubiquitous isoform of Na+,K+,2Cl–cotransporter (NKCC1 in regulation of vascular smooth muscle contraction, and role of this carrier in the regulation of cell volume and intracellular chloride concentration.

  13. Renal vascular effects of calcium channel blockers in hypertension. (United States)

    Benstein, J A; Dworkin, L D


    Recent evidence suggests that calcium channel blockers have specific effects on renal hemodynamics in patients with hypertension and may also slow the progression of chronic renal failure. When these agents are studied in vitro, their predominant effect is to reverse afferent arteriolar vasoconstriction induced by catecholamines or angiotensin II. Because efferent resistance may remain high, glomerular filtration rate rises while renal blood flow remains low. The effects in vivo are less consistent. In human hypertension, calcium channel blockers lower renal resistance and may raise both renal blood flow and glomerular filtration rate. In experimental models of chronic renal disease, calcium channel blockers slow the progression of renal damage; however, variable effects on renal hemodynamics have been found. Other factors implicated in the progression of renal damage, including compensatory renal hypertrophy, platelet aggregation, and calcium deposition, may also be favorably influenced by these agents. Recent studies suggest that calcium channel blockers may have similar protective effects in patients with hypertension and chronic renal disease.


    Directory of Open Access Journals (Sweden)

    Charitha GN


    Full Text Available Renal blood supply presents a large degree of variations. In the present case there was existence of bilateral variations in renal blood supply along with right sided bifid ureter. During routine cadaveric dissection in a middle aged male cadaver we found two renal veins draining right kidney and a bifurcating single renal vein on left side. On both sides one polar artery arising from main renal artery going to upper pole of kidney and left side accessory renal artery originating from abdominal aorta and giving origin to left testicular artery were observed. There is bifid ureter on the right side. The knowledge of renal vascular anatomy and its variations are very much essential in case of renal transplantation, renal surgeries, uroradiology, gonadal color Doppler imaging, in abdominal aortic aneurysmal and gonadal surgeries.

  15. Dual-energy computed tomography angiography for evaluating the renal vascular variants

    Institute of Scientific and Technical Information of China (English)

    TAO Xiao-feng; ZHU Jing-qi; WU Ying-wei; TANG Guang-yu; SHI Yu-zhen; ZHANG Lei; LIN Yi


    Background Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery.This study aimed to investigate the renal vascular variants with dual-energy computed tomography (DECT) angiography to provide valuable information for surgery.Methods A total of 378 patients underwent DECT.The number,size,course and relationships of the renal vessels were retrospectively observed from the scans.Anomalies of renal arteries and veins were recorded and classified.Multiplanar reformations (MPR),maximum intensity projections (MIP),and volume renderings (VR) were used for analysis.Results In 378 patients (756 kidneys),renal artery variations were discovered and recorded in 123 kidneys (16.3%,123/756) of 106 patients (28.0%,106/378).Type IB (early branches of the only one main renal artery) and IC (accessory renal artery with only one main renal artery) were found most frequently with an incidence of 11.4% (43/378) and 14.5%(55/378).The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney (12.4% vs.11.1%).The incidence of renal vein variations was detected in 104 patients (27.5%,104/378).The incidence of venous variants in the right kidney was higher than in the left kidney (20.1% vs.7.4%),but left renal vein variations were more complex.Variants of the left renal vein were detected in 28 patients including type 1 (circumaortic left renal vein) in eight cases,type 2 (retroaortic left renal vein) in seven cases,type 3 (abnormal reflux) in six cases,type 4 (late venous confluence of left renal vein) in five cases,and type 5 (rare type) in two cases.The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery (P=0.037).Conclusions The renal vascular variants are rather common and complex.DECT angiography can demonstrate the precise anatomy of the

  16. In vivo vascular wall shear rate and circumferential strain of renal disease patients. (United States)

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F


    This study measures the vascular wall shear rate at the vessel edge using decorrelation based ultrasound speckle tracking. Results for nine healthy and eight renal disease subjects are presented. Additionally, the vascular wall shear rate and circumferential strain during physiologic pressure, pressure equalization and hyperemia are compared for five healthy and three renal disease subjects. The mean and maximum wall shear rates were measured during the cardiac cycle at the top and bottom wall edges. The healthy subjects had significantly higher mean and maximum vascular wall shear rate than the renal disease subjects. The key findings of this research were that the mean vascular wall shear rates and circumferential strain changes between physiologic pressure and hyperemia that was significantly different between healthy and renal disease subjects.

  17. Reduced cyclooxygenase involvement in vascular endothelial function in rat renal transplantation

    NARCIS (Netherlands)

    Smit-Van Oosten, Annemieke; Boonstra, Arnold H.; Navis, Gerjan; Van Goor, Harry; Buikema, Hendrik


    Background: Cardiovascular disease is a major cause of death following renal transplantation. Mechanisms leading to vascular dysfunction outside the transplanted organ involve common risk factors such as hypertension, hypercholesterolemia, proteinuria, but immune-mediated factors may also be involve

  18. Reduced cyclooxygenase involvement in vascular endothelial function in rat renal transplantation

    NARCIS (Netherlands)

    Smit-Van Oosten, Annemieke; Boonstra, Arnold H.; Navis, Gerjan; Van Goor, Harry; Buikema, Hendrik


    Background: Cardiovascular disease is a major cause of death following renal transplantation. Mechanisms leading to vascular dysfunction outside the transplanted organ involve common risk factors such as hypertension, hypercholesterolemia, proteinuria, but immune-mediated factors may also be involve

  19. Beyond neurovascular coupling, role of astrocytes in the regulation of vascular tone. (United States)

    Filosa, J A; Morrison, H W; Iddings, J A; Du, W; Kim, K J


    The brain possesses two intricate mechanisms that fulfill its continuous metabolic needs: cerebral autoregulation, which ensures constant cerebral blood flow over a wide range of arterial pressures and functional hyperemia, which ensures rapid delivery of oxygen and glucose to active neurons. Over the past decade, a number of important studies have identified astrocytes as key intermediaries in neurovascular coupling (NVC), the mechanism by which active neurons signal blood vessels to change their diameter. Activity-dependent increases in astrocytic Ca(2+) activity are thought to contribute to the release of vasoactive substances that facilitate arteriole vasodilation. A number of vasoactive signals have been identified and their role on vessel caliber assessed both in vitro and in vivo. In this review, we discuss mechanisms implicating astrocytes in NVC-mediated vascular responses, limitations encountered as a result of the challenges in maintaining all the constituents of the neurovascular unit intact and deliberate current controversial findings disputing a main role for astrocytes in NVC. Finally, we briefly discuss the potential role of pericytes and microglia in NVC-mediated processes.

  20. Regulation of Vascular and Renal Function by Metabolite Receptors. (United States)

    Peti-Peterdi, János; Kishore, Bellamkonda K; Pluznick, Jennifer L


    To maintain metabolic homeostasis, the body must be able to monitor the concentration of a large number of substances, including metabolites, in real time and to use that information to regulate the activities of different metabolic pathways. Such regulation is achieved by the presence of sensors, termed metabolite receptors, in various tissues and cells of the body, which in turn convey the information to appropriate regulatory or positive or negative feedback systems. In this review, we cover the unique roles of metabolite receptors in renal and vascular function. These receptors play a wide variety of important roles in maintaining various aspects of homeostasis-from salt and water balance to metabolism-by sensing metabolites from a wide variety of sources. We discuss the role of metabolite sensors in sensing metabolites generated locally, metabolites generated at distant tissues or organs, or even metabolites generated by resident microbes. Metabolite receptors are also involved in various pathophysiological conditions and are being recognized as potential targets for new drugs. By highlighting three receptor families-(a) citric acid cycle intermediate receptors, (b) purinergic receptors, and

  1. Demonstration by radionuclide imaging of possible vascular steal from a renal transplant. [I-131, Tc-99

    Energy Technology Data Exchange (ETDEWEB)

    Bloss, R.S.; McConnell, R.W.; McConnell, B.G.; Floyd, M.; Conner, W.T.; Henry, R.G.; Kahan, B.D.


    Radionuclide studies in a renal-transplant patient with congestive heart failure suggested vascular steal from the renal allograft by a contralateral femoral arteriovenous fistula. These reliable, noninvasive diagnostic procedures have potential use in similar settings to evaluate allograft perfusion and function. Correction by removal of the fistula was demonstrated.

  2. Chronic deficit in nitric oxide elicits oxidative stress and augments T-type calcium-channel contribution to vascular tone of rodent arteries and arterioles

    DEFF Research Database (Denmark)

    Howitt, Lauren; Kuo, Ivana Y; Ellis, Anthie;


    AIMS: As cardiovascular disease is characterized by reduced nitric oxide bioavailability, our aim was to determine the impact of this change on the mechanism underlying vascular tone of pressurized arteries in vitro and in vivo. METHODS AND RESULTS: We used pressurized cerebral and mesenteric......, by regulating the bioavailability of reactive oxygen species produced by NADPH oxidase. Our data provide evidence for a novel causal link between nitric oxide deficit, oxidative stress, and T-type calcium channel function....

  3. The effects of angiotensin II receptor antagonist (candesartan on rat renal vascular resistance

    Directory of Open Access Journals (Sweden)

    Supatraviwat, J


    Full Text Available The present study aimed to investigate the action of angiotensin II (AII on renal perfusion pressure and renal vascular resistance using noncompetitive AT1-receptor antagonist (candesartan or CV 11974. Experiments were performed in isolated kidney of adult male Wistar rats. Kreb's Henseleit solution was perfused into the renal artery at the rate of 3.5 ml/min. This flow rate was designed in order to maintain renal perfusion pressure between 80-120 mm Hg. Dose-response relationship between perfusion flow rate and AII concentration were studied. Renal perfusion pressure in response to 1, 10 and 100 nM AII were increased from basal perfusion pressure of 94±8 mm Hg to 127±6, 157±12 and 190±16 mm Hg, respectively. Administration of perfusate containing 11.4 μM candesartan for 30 min had no effect on the basal perfusion pressure. However, this significantly reduced renal perfusion pressure in the presence of AII (1, 10 and 100 nM by 39%, 47% and 61%, (n=7, P<0.05 respectively. At the basal perfusion pressure, calculated renal vascular resistance was 27±2 mm Hg · min · ml-1. However, the vascular resistance were found to be 41±1, 45±2 and 47±2 mm Hg · min · ml-1 when 1, 10 and 100 nM AII were added. Moreover, this dose of candesartan also showed a significant decrease in renal vascular resistance at the corresponding doses of AII by 38%, 48% and 43%, (n=7, P<0.05 respectively. The higher dose of candesartan (22.7 μM completely inhibited the action of 1, 10 and 100 nM AII on renal vasoconstriction. These results may indicate that the action of AII on renal vascular resistance is via AT1-receptor, at least in rat isolated perfusion kidney.

  4. KV 7.4 channels participate in the control of rodent renal vascular resting tone

    DEFF Research Database (Denmark)

    Salomonsson, M.; Brasen, Jens Christian; Braunstein, Thomas Hartig


    ) was measured using an ultrasonic flow probe. The isometric tension of rat interlobar arteries was examined in a wire myograph. Mice afferent arteriolar diameter was assessed utilizing the perfused juxtamedullary nephron technique. Results: Immunofluorescence revealed that KV7.4 channels were expressed in rat...... afferent arterioles. The KV7 blocker XE991 dose-dependently increased the isometric tension of rat interlobar arteries and caused a small (approx. 4.5%) RBF reduction in vivo. Nifedipine abolished these effects. Likewise, XE991 reduced mouse afferent arteriolar diameter by approx. 5%. The KV7.......2–5 stimulator flupirtine dose-dependently relaxed isolated rat interlobar arteries and increased (approx. 5%) RBF in vivo. The RBF responses to NE or Ang II administration were not affected by pre-treatment with XE991 or flupirtine. XE991 pre-treatment caused a minor augmentation of the acetylcholine...

  5. Phosphodiesterase 5 inhibition ameliorates angiotensin II-dependent hypertension and renal vascular dysfunction. (United States)

    Thieme, Manuel; Sivritas, Sema H; Mergia, Evanthia; Potthoff, Sebastian A; Yang, Guang; Hering, Lydia; Grave, Katharina; Hoch, Henning; Rump, Lars C; Stegbauer, Johannes


    Changes in renal hemodynamics have a major impact on blood pressure (BP). Angiotensin (Ang) II has been shown to induce vascular dysfunction by interacting with phosphodiesterase (PDE)1 and PDE5. The predominant PDE isoform responsible for renal vascular dysfunction in hypertension is unknown. Here, we measured the effects of PDE5 (sildenafil) or PDE1 (vinpocetine) inhibition on renal blood flow (RBF), BP, and renal vascular function in normotensive and hypertensive mice. During acute short-term Ang II infusion, sildenafil decreased BP and increased RBF in C57BL/6 (WT) mice. In contrast, vinpocetine showed no effect on RBF and BP. Additionally, renal cGMP levels were significantly increased after acute sildenafil but not after vinpocetine infusion, indicating a predominant role of PDE5 in renal vasculature. Furthermore, chronic Ang II infusion (500 ng·kg(-1)·min(-1)) increased BP and led to impaired NO-dependent vasodilation in kidneys of WT mice. Additional treatment with sildenafil (100 mg·kg(-1)·day(-1)) attenuated Ang II-dependent hypertension and improved NO-mediated vasodilation. During chronic Ang II infusion, urinary nitrite excretion, a marker for renal NO generation, was increased in WT mice, whereas renal cGMP generation was decreased and restored after sildenafil treatment, suggesting a preserved cGMP signaling after PDE5 inhibition. To investigate the dependency of PDE5 effects on NO/cGMP signaling, we next analyzed eNOS-KO mice, a mouse model characterized by low vascular NO/cGMP levels. In eNOS-KO mice, chronic Ang II infusion increased BP but did not impair NO-mediated vasodilation. Moreover, sildenafil did not influence BP or vascular function in eNOS-KO mice. These results highlight PDE5 as a key regulator of renal hemodynamics in hypertension. Copyright © 2017 the American Physiological Society.

  6. Renal trauma: kidney preservation through improved vascular control-a refined approach. (United States)

    McAninch, J W; Carroll, P R


    Indications for renal exploration, nephrectomy, or renal repair for patients with renal trauma continue to be a subject of controversy. The present survey evaluates the results of two series of patients from a single hospital having had renal exploration for injury: Series I (1964-1973) 185 patients previously reported; and Series II (1977-1981), 190 patients. The indications for renal exploration were generally the same in each series. In Series II we used a uniform technique for control of the renal artery and vein before entering Gerota's fascia and exploring the kidney. When renal explorations were required, nephrectomy rates were reduced by this technique to 18% (seven of 39) in Series II, compared to 56% (19 of 34) in Series I. Comparison of the two series indicates that renal salvage can be improved by a consistent approach to evaluation, specific indications for retroperitoneal exploration, and vascular control before opening the retroperitoneum. Results of repair show that renography or partial nephrectomy was performed successfully in 82% of operated cases. All nephrectomies in series II were done because of massive renal destruction or as life-saving procedures for hemorrhage. No patient in Series II having had renal repair needed reoperation or had delayed hemorrhage, urine extravasation, retroperitoneal abscess, or hypertension. Although both time periods had comparable numbers of renal injury and comparable numbers of renal explorations, attention to the above criteria made possible significant improvement in kidney salvage.

  7. Evaluation of the relationship between renal function and renal volume-vascular indices using 3D power Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cansu, Aysegul, E-mail:; Kupeli, Ali; Kul, Sibel; Eyuboglu, Ilker; Oguz, Sukru; Ozturk, Mehmet Halil; Dinc, Hasan


    Purpose: To investigate the relationship between renal function and total renal volume-vascular indices using 3D power Doppler ultrasound (3DPDUS). Materials and methods: One hundred six patients with hypertensive proteinuric nephropathy (HPN) (49 male, 57 female) and 65 healthy controls (32 male, 33 female) were evaluated prospectively using 3DPDUS. Total renal volume (RV), vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using Virtual Organ Computer-aided Analysis (VOCAL). The estimated glomerular filtration rates (GFRs) of the patients with HPN and the control group were calculated. The patients with HPN were divided into two groups on the basis of GFR, normal (≥90) or reduced (<90). Differences between groups were compared using ANOVA. Correlations between GFR, renal volume and vascular indices were analyzed using Pearson's correlation analysis. Significance was set at p < 0.05. Results: The mean total RV, VI, FI and VFI values in the reduced GFR, normal GFR and control groups were RV (ml): 234.7, 280.7 and 294.6; VI: 17.6, 27.6 and 46.8; FI: 79.1, 88.7 and 93.9 and VFI: 7.1, 12.7 and 23.8. There were statistically significant differences between the groups (p < 0.001). Total RVs and vascular indices exhibited significant correlations with estimated GFR (r = 0.53–0.59, p < 0.001) Conclusion: Three-dimensional power Doppler ultrasound is a reliable predictive technique in renal function analysis.

  8. Vascular complications following 1500 consecutive living and cadaveric donor renal transplantations: A single center study

    Directory of Open Access Journals (Sweden)

    Salehipour Mehdi


    Full Text Available The aim of this study was to document vascular complications that occurred fol-lowing cadaveric and living donor kidney transplants in order to assess the overall incidence of these complications at our center as well as to identify possible risk factors. In a retrospective cohort study, 1500 consecutive renal transplant recipients who received a living or cadaveric donor kidney between December 1988 and July 2006 were evaluated. The study was performed at the Nemazee Hospital, Shiraz, Iran. The assessment of the anatomy and number of renal arteries as well as the incidence of vascular complications was made by color doppler ultrasonography, angiography, and/or surgical exploration. Clinically apparent vascular complications were seen in 8.86% of all study patients (n = 133 with the most frequent being hemorrhage (n = 91; 6.1% followed by allo-graft renal artery stenosis (n = 26; 1.7%, renal artery thrombosis (n = 9; 0.6%, and renal vein thrombosis (n = 7; 0.5%. Vascular complications were more frequent in recipients of cadaveric organs than recipients of allografts from living donors (12.5% vs. 7.97%; P= 0.017. The occurrence of vascular complications was significantly more frequent among recipients of renal allografts with multiple arteries when compared with recipients of kidneys with single artery (12.3% vs. 8.2%; P= 0.033. The same was true to venous complications as well (25.4% vs. 8.2%; P< 0.001. Our study shows that vascular complications were more frequent in allografts with multiple renal blood vessels. Also, the complications were much less frequent in recipients of living donor transplants.

  9. Evaluation of a liquid embolization agent (Onyx) for transcatheter embolization for renal vascular lesions

    Energy Technology Data Exchange (ETDEWEB)

    Rennert, Janine; Herold, T.; Schreyer, A.G.; Jung, E.M.; Mueller-Wille, R.; Zorger, N. [Inst. fuer Roentgendiagnostik, Klinikum der Univ. Regensburg (Germany); Banas, B.; Feuerbach, S. [Medizinische Klinik, Nephrologie, Univ. Regensburg (Germany); Lenhart, M. [Klinik fuer Diagnostische und Interventionelle Radiologie, Sozialstiftung Bamberg (Germany)


    Purpose: to evaluate the therapeutic outcome after endovascular treatment of renal vascular lesions using the liquid embolization agent, Onyx. Materials and methods: between 2004 and 2008 nine patients with renal vascular lesions were treated with transcatheter arterial embolization using Onyx. The renal vascular lesions consisted of 4 AV-fistulas, a pseudoaneurysm, bleeding from a single subsegmental artery, diffuse parenchymal bleeding after trauma, septic embolizations and multiple aneurysms in endocarditis. All patients underwent selective angiography of the renal artery. A dimethyl sulfoxide (DMSO)-compatible microcatheter was used and Onyx was injected. The technical and clinical success rate, examination time and procedure-related complications were documented. Results: the overall technical and clinical success rate was 100%. One patient had to be treated twice due to recurrent bleeding after an accidental puncture with a drainage catheter. No loss of viable renal tissue occurred in 4 cases. In 4 patients mild to moderate parenchyma loss was noted. In one patient having diffuse renal bleeding, occlusion of the main renal artery was performed. No procedure-related complications were noted. The mean examination time was 16.17 min when treating with Onyx alone and 60 min when using a combination of Onyx and coils. Within an average follow-up period of 21 months, no recurrent renal bleeding or recurrent AV-fistulas occurred. Conclusion: Onyx is an effective embolization agent for the treatment of renal vascular lesions. It allows controlled and quick application with low complication rates and a short examination time as a standalone agent or in combination with coils. (orig.)

  10. Should blunt segmental vascular renal injuries be considered an American Association for the Surgery of Trauma Grade 4 renal injury? (United States)

    Malaeb, Bahaa; Figler, Brad; Wessells, Hunter; Voelzke, Bryan B


    Renal segmental vascular injury (SVI) following blunt abdominal trauma is not part of the original American Association for the Surgery of Trauma (AAST) renal injury grading system. Recent recommendations support classifying SVI as an AAST Grade 4 (G4) injury. Our primary aim was to compare outcomes following blunt renal SVI and blunt renal collecting system lacerations (CSLs). We hypothesize that renal SVI fare well with conservative management alone and should be relegated a less severe renal AAST grade. We retrospectively identified patients with SVI and G4 CSL admitted to a Level 1 trauma center between 2003 and 2010. Penetrating trauma was excluded. Need for surgical intervention, length of stay, kidney salvage (>25% renal preservation on renography 6-12 weeks after injury), and delayed complication rates were compared between the SVI and CSL injuries. Statistical analysis used χ, Fisher's exact, and t tests. A total of 56 patients with SVI and 88 patients with G4 CSL sustained blunt trauma. Age, Injury Severity Score (ISS), and length of stay were similar for the two groups. Five patients in each group died of concomitant, nonrenal injuries. In the G4 CSL group, 15 patients underwent major interventions, and 32 patients underwent minor interventions. Only one patient in the SVI group underwent a major intervention. The renal salvage rate was 85.7% following SVI versus 62.5% following CSL (p = 0.107). Overall, surgical interventions are significantly lower among the SVI cohort than the G4 CSL cohort. Further analysis using a larger cohort of patients is recommended before revising the current renal grading system. Adding SVI as a G4 injury could potentially increase the heterogeneity of G4 injuries and decrease the ability of the AAST renal injury grading system to predict outcomes, such as nephrectomy rate. Epidemiologic study, level IV.

  11. Nlrp3 prevents early renal interstitial edema and vascular permeability in unilateral ureteral obstruction.

    Directory of Open Access Journals (Sweden)

    Wilco P Pulskens

    Full Text Available Progressive renal disease is characterized by tubulo-interstitial injury with ongoing inflammation and fibrosis. The Nlrp3 inflammasome contributes to these pathophysiological processes through its canonical effects in cytokine maturation. Nlrp3 may additionally exert inflammasome-independent effects following tissue injury. Hence, in this study we investigated potential non-canonical effects of Nlrp3 following progressive renal injury by subjecting WT and Nlrp3-deficient (-/- mice to unilateral ureter obstruction (UUO. Our results revealed a progressive increase of renal Nlrp3 mRNA in WT mice following UUO. The absence of Nlrp3 resulted in enhanced tubular injury and dilatation and an elevated expression of injury biomarker NGAL after UUO. Moreover, interstitial edema was significantly elevated in Nlrp3-/- mice. This could be explained by increased intratubular pressure and an enhanced tubular and vascular permeability. In accordance, renal vascular leakage was elevated in Nlrp3-/- mice that associated with reduced mRNA expression of intercellular junction components. The decreased epithelial barrier function in Nlrp3-/- mice was not associated with increased apoptosis and/or proliferation of renal epithelial cells. Nlrp3 deficiency did not affect renal fibrosis or inflammation. Together, our data reveal a novel non-canonical effect of Nlrp3 in preserving renal integrity and protection against early tubular injury and interstitial edema following progressive renal injury.

  12. Remanent cell traction force in renal vascular smooth muscle cells induced by integrin-mediated mechanotransduction


    Balasubramanian, Lavanya; Lo, Chun-Min; Sham, James S. K.; Yip, Kay-Pong


    It was previously demonstrated in isolated renal vascular smooth muscle cells (VSMCs) that integrin-mediated mechanotransduction triggers intracellular Ca2+ mobilization, which is the hallmark of myogenic response in VSMCs. To test directly whether integrin-mediated mechanotransduction results in the myogenic response-like behavior in renal VSMCs, cell traction force microscopy was used to monitor cell traction force when the cells were pulled with fibronectin-coated or low density lipoprotei...

  13. Renal vascular effects of leukotriene C4 in the isolated perfused kidney of the rat.


    Frölich, J C; Yoshizawa, M.


    1 The vascular effects of leukotriene C4 (LTC4) were investigated in the isolated perfused kidney of the rat. 2 LTC4 (6.4 X 10(-10) to 3.2 X 10(-8) mol kg-1 min-1 given over 5 min) resulted in a prompt, dose-dependent increase in renal vascular resistance in a recirculating system, which lasted for more than 60 min. 3 LTC4 was 10 to 20 fold and 1000 to 2000 fold, respectively, less active on a molar basis than noradrenaline and angiotensin II in eliciting renal vasoconstriction. 4 The vascula...

  14. [Spontaneous recanalization after embolization of the renal artery with an Amplatzer vascular plug 4]. (United States)

    Gómez-Martínez, Pablo; Ciampi Dopazo, Juan José; González Fejás, Ariel; Lanciego, Carlos


    The Amplatzer vascular plug (AVP) is an occluding device used in vascular embolizations. Thanks to its excellent maneuverability and effectiveness, it is being used more and more often. The latest version, the AVP 4, enables access to smaller and more tortuous vessels. To date, the only cases of spontaneous recanalization published occurred with earlier versions of the AVP. We present a case of recanalization after renal artery embolization with an AVP 4. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  15. The role of DPO-1 and XE991-sensitive potassium channels in perivascular adipose tissue-mediated regulation of vascular tone

    Directory of Open Access Journals (Sweden)

    Dmitry Tsvetkov


    Full Text Available The anti-contractile effect of perivascular adipose tissue (PVAT is an important mechanism in the modulation of vascular tone in peripheral arteries. Recent evidence has implicated the XE991-sensitive voltage-gated Kv (KCNQ channels in the regulation of arterial tone by PVAT. However, until now the in vivo pharmacology of the involved vascular Kv channels with regard to XE991 remains undetermined, since XE991 effects may involve Ca2+ activated BKCa channels and/or voltage-dependent Kv1.5 channels sensitive to diphenyl phosphine oxide-1 (DPO-1. In this study, we tested whether Kv1.5 channels are involved in the control of mesenteric arterial tone and its regulation by PVAT. Our study was also aimed at extending our current knowledge on the in situ vascular pharmacology of DPO-1 and XE991 regarding Kv1.5 and BKCa channels, in helping to identify the nature of K+ channels that could contribute to PVAT-mediated relaxation. XE991 at 30 µM reduced the anti-contractile response of PVAT, but had no effects on vasocontraction induced by phenylephrine (PE in the absence of PVAT. Similar effects were observed for XE991 at 0.3 µM, which is known to almost completely inhibit mesenteric artery VSMC Kv currents. 30 µM XE991 did not affect BKCa currents in VSMCs. Kcna5-/- arteries and wild-type arteries incubated with 1 µM DPO-1 showed normal vasocontractions in response to PE in the presence and absence of PVAT. Kv current density and inhibition by 30 µM XE991 were normal in mesenteric artery VSMCs isolated from Kcna5-/- mice. We conclude that Kv channels are involved in the control of arterial vascular tone by PVAT. These channels are present in VSMCs and very potently inhibited by the KCNQ channel blocker XE991. BKCa channels and/or DPO-1 sensitive Kv1.5 channels in VSMCs are not the downstream mediators of the XE991 effects on PVAT-dependent arterial vasorelaxation. Further studies will need to be undertaken to examine the role of other Kv channels in

  16. VASCULAR: Inhibition of myogenic tone in rat cremaster and cerebral arteries by SKA-31, an activator of endothelial KCa2.3 and KCa3.1 channels


    Mishra, Ramesh C.; Wulff, Heike; Hill, Michael A.; Braun, Andrew P.


    Endothelial KCa2.3 and KCa3.1 channels contribute to the regulation of myogenic tone in resistance arteries by Ca2+-mobilizing, vasodilatory hormones. To define further the functional role of these channels in distinct vascular beds, we have examined the vasodilatory actions of the KCa channel activator SKA-31 in myogenically active, rat cremaster and middle cerebral arteries. Vessels pressurized to 70 mmHg constricted by 80–100 microns (i.e. 25–45% of maximal diameter). SKA-31 (10 μM) inhibi...

  17. Penile gangrene in diabetes mellitus with renal failure: A poor prognostic sign of systemic vascular calciphylaxis

    Directory of Open Access Journals (Sweden)

    Mayank Mohan Agarwal


    Full Text Available Penile gangrene associated with chronic renal failure is very uncommon. A 52-year-old man with diabetes mellitus, diffuse atherosclerosis, ischemic cardiomyopathy and end-stage renal disease presented with blackening of distal penis for 10 days. His general condition was poor and gangrene of prepuce and glans was noted. Doppler and magnetic-resonance angiography revealed bilateral internal iliac artery obstruction. He underwent trocar suprapubic cystostomy and was planned for partial penectomy. But he died of severe diabetic complications in the interim period. Penile gangrene is a manifestation of widespread vascular calcifications associated with end-stage renal disease and is a marker of poor prognosis.

  18. Chaos and non-linear phenomena in renal vascular control

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H


    Renal autoregulation of blood flow depends on the functions of the tubuloglomerular feedback (TGF) system and the myogenic response of the afferent arteriole. Studies of the dynamic aspects of these control mechanisms at the level of both the single nephron and the whole kidney have revealed a va...

  19. Renal vascular effects of leukotriene C4 in the isolated perfused kidney of the rat. (United States)

    Frölich, J. C.; Yoshizawa, M.


    1 The vascular effects of leukotriene C4 (LTC4) were investigated in the isolated perfused kidney of the rat. 2 LTC4 (6.4 X 10(-10) to 3.2 X 10(-8) mol kg-1 min-1 given over 5 min) resulted in a prompt, dose-dependent increase in renal vascular resistance in a recirculating system, which lasted for more than 60 min. 3 LTC4 was 10 to 20 fold and 1000 to 2000 fold, respectively, less active on a molar basis than noradrenaline and angiotensin II in eliciting renal vasoconstriction. 4 The vascular response to LTC4 was blocked dose-dependently by FPL 55712, an antagonist of slow reacting substance of anaphylaxis. OKY 1581, a specific thromboxane synthetase inhibitor, and indomethacin, a cyclo-oxygenase inhibitor, did not influence the LTC4 response. 5 LTC4 given in a single-pass perfusion system resulted in a short lasting response with baseline values for renal vascular resistance reached after 4 min. 6 These results show that LTC4 is a short acting renal vasoconstrictor with less potency than noradrenaline and angiotensin II. Its pressor effects seem to be mediated by specific leukotriene receptors and independent of cyclo-oxygenase products. The long-lasting effect in the recirculating arrangement, in contrast to the single pass system, is compatible with formation of active metabolite(s). PMID:3676595

  20. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

    Directory of Open Access Journals (Sweden)

    Xue-ying Chang


    Full Text Available Background. This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d, 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS/p38 mitogen activated protein kinase (p38MAPK pathway was determined to explore the potential mechanism. Results. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA and creatinine levels, malonaldehyde (MDA content, and superoxide dismutase (SOD activity in serum and the increases of calcium and alkaline phosphatase (ALP activity in the aorta (P<0.05 and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

  1. Incidental renal artery stenosis is an independent predictor of mortality in patients with peripheral vascular disease

    NARCIS (Netherlands)

    Mui, KW; Sleeswijk, M; van den Hout, H; van Baal, J; Navis, G; Woittiez, AJ

    In patients with peripheral vascular disease (PVD), mortality is high and renal artery stenosis (RAS) is a frequent incidental finding. RAS carries a high risk for mortality, but whether incidentally discovered RAS is a risk factor for mortality is unknown. The prognostic impact of incidental RAS

  2. Antihypertensive effect of thymectomy in Lyon hypertensive rats. Vascular reactivity, renal histology, and sodium excretion. (United States)

    Bataillard, A; Blanc-Brunat, N; Vivier, G; Medeiros, I; Zhang, B L; Touraine, J L; Sassard, J


    The aim of this study was to search for the possible mechanisms involved in the antihypertensive effect of neonatal thymectomy that we previously observed in Lyon hypertensive (LH) rats. To that end, we studied in LH and normotensive control (LN) rats the consequences of neonatal thymectomy on vascular reactivity, renal structure, and pressure-natriuresis. The increase in pressor responses to angiotensin I and phenylephrine noted in LH rats as compared to LN animals was abolished by neonatal thymectomy. Histological study showed that kidneys from LH rats exhibited arterial wall hypertrophy, segmental hyalinization of the glomeruli, and were infiltrated by mononuclear cells. All these features of kidney injury were reduced in neonatally thymectomized LH rats. Lastly, the responses of isolated perfused kidneys from LH rats to stepwise reductions in renal perfusion pressure differed from those of LN rats by decreased renal perfusion flow and natriuresis. Neonatal thymectomy tended to improve sodium excretion in parallel with a slight decrease in renal vascular resistances. It is concluded that the normalization of vascular responsiveness to vasoconstrictor factors, the alleviation of renal lesions and, to a lesser extent, the moderate improvement of pressure natriuresis may account, at least in part, for the antihypertensive effect of neonatal thymectomy in LH rats.

  3. Renal- and calcium-dependent vascular effects of Polybia paulista wasp venom

    Directory of Open Access Journals (Sweden)

    JFC Vinhote


    Full Text Available In the present study, the effects of Polybia paulista venom (PPV on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 μg/mL had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of α-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.


    Institute of Scientific and Technical Information of China (English)

    Jian-ling Tao; Hang Li; Yu Tang; Yu-bing Wen; Xue-wang Li


    Objective To investigate the clinical and pathological characteristics of lupus nephritis patients complicated with malignant hypertension.Methods We retrospectively studied 19 patients with lupus nephritis complicated with malignant hypertension who underwent renal biopsy between January 2002 and December 2006.Results Of 19 patients, 3 were men and 16 were women, with a mean age of 24. 4±7. 7 years old. All had positive antinuclear antibodies and low serum complement was found in 13 patients. All were anemic and 12 of them were thrombocytopenic. Impaired renal function was found in 17 patients with an average serum creatinine of 184. 5 ± 88.9 μmol/L. Severe intrarenai arteriolar lesion was found in all patients. Six patients had lupus vasculopathy, 11 patients had renal thrombotic microangiopathy lesion, 2 had severe arteriosclerosis. All patients received steroids and immunosuppressive drugs, 15 received angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker ( ARB ) with resultant well-controlled blood pressure. Thrombocytopenia and hemolytic anemia resolved remarkably.The renal function improved or recovered in 14 of 17 patients, and 3 developed end-stage renal disease on maintenance dialysis.Conclusions Severe intrarenal vascular lesion complicated with renal nephritis parallels clinical manifestation of malignant hypertension. Renal pathology is the key of treatment strategy emphasizing on the significance of renal vascular involvement and type. On the basis of immunosuppressive drugs and steroids to control systemic lupus activity, timely initiation of ACEI/ARB could be of benefit to blood pressure control and long term renal survival.

  5. Plexin-D1/Semaphorin 3E pathway may contribute to dysregulation of vascular tone control and defective angiogenesis in systemic sclerosis. (United States)

    Mazzotta, Celestina; Romano, Eloisa; Bruni, Cosimo; Manetti, Mirko; Lepri, Gemma; Bellando-Randone, Silvia; Blagojevic, Jelena; Ibba-Manneschi, Lidia; Matucci-Cerinic, Marco; Guiducci, Serena


    The vascular and nervous systems have several anatomic and molecular mechanism similarities. Emerging evidence suggests that proteins involved in transmitting axonal guidance cues, including members of class III semaphorin (Sema3) family, play a critical role in blood vessel guidance during physiological and pathological vascular development. Sema3E is a natural antiangiogenic molecule that causes filopodial retraction in endothelial cells, inhibiting cell adhesion by disrupting integrin-mediated adhesive structures. The aim of the present study was to investigate whether in systemic sclerosis (SSc) Plexin-D1/Sema3E axis could be involved in the dysregulation of vascular tone control and angiogenesis. Sema3E levels were measured by quantitative colorimetric sandwich ELISA in serum samples from 48 SSc patients, 45 subjects with primary Raynaud's phenomenon (pRP) and 48 age-matched and sex-matched healthy controls. Immunofluorescence staining on skin sections from 14 SSc patients and 12 healthy subjects was performed to evaluate Sema3E and Plexin-D1 expression. Western blotting was used to assess Plexin-D1/Sema3E axis in human SSc and healthy dermal microvascular endothelial cells (SSc-MVECs and H-MVECs, respectively) at basal condition and after stimulation with recombinant human vascular endothelial growth factor (VEGF), SSc and healthy sera. Capillary morphogenesis on Matrigel was performed on H-MVECs treated with healthy, pRP or SSc sera in the presence of Sema3E and Plexin-D1 soluble peptides. Serum Sema3E levels were significantly higher both in pRP subjects and SSc patients than in controls. In SSc, Sema3E levels were significantly increased in patients with early nailfold videocapillaroscopy (NVC) pattern compared to active/late patterns and pRP, and in patients without digital ulcers versus those with ulcers. In SSc skin, Sema3E expression was strongly increased in the microvascular endothelium. Cultured SSc-MVECs showed higher levels of phosphorylated

  6. Amphetamine and environmentally induced hyperthermia differentially alter the expression of genes regulating vascular tone and angiogenesis in the meninges and associated vasculature. (United States)

    Thomas, Monzy; George, Nysia I; Patterson, Tucker A; Bowyer, John F


    An amphetamine (AMPH) regimen that does not produce a prominent blood-brain barrier breakdown was shown to significantly alter the expression of genes regulating vascular tone, immune function, and angiogenesis in vasculature associated with arachnoid and pia membranes of the forebrain. Adult-male Sprague-Dawley rats were given either saline injections during environmentally-induced hyperthermia (EIH) or four doses of AMPH with 2 h between each dose (5, 7.5, 10, and 10 mg/kg d-AMPH, s.c.) that produced hyperthermia. Rats were sacrificed either 3 h or 1 day after dosing, and total RNA and protein was isolated from the meninges, arachnoid and pia membranes, and associated vasculature (MAV) that surround the forebrain. Vip, eNos, Drd1a, and Edn1 (genes regulating vascular tone) were increased by either EIH or AMPH to varying degrees in MAV, indicating that EIH and AMPH produce differential responses to enhance vasodilatation. AMPH, and EIH to a lesser extent, elicited a significant inflammatory response at 3 h as indicated by an increased MAV expression of cytokines Il1b, Il6, Ccl-2, Cxcl1, and Cxcl2. Also, genes related to heat shock/stress and disruption of vascular homeostasis such as Icam1 and Hsp72 were also observed. The increased expression of Ctgf and Timp1 and the decreased expression of Akt1, Anpep, and Mmp2 and Tek (genes involved in stimulating angiogenesis) from AMPH exposure suggest that angiogenesis was arrested or disrupted in MAV to a greater extent by AMPH compared to EIH. Alterations in vascular-related gene expression in the parietal cortex and striatum after AMPH were less in magnitude than in MAV, indicating less of a disruption of vascular homeostasis in these two regions. Changes in the levels of insulin-like growth factor binding proteins Igfbp1, 2, and 5 in MAV, compared to those in striatum and parietal cortex, imply an interaction between these regions to regulate the levels of insulin-like growth factor after AMPH damage. Thus, the

  7. Ansys Fluent versus Sim Vascular for 4-D patient-specific computational hemodynamics in renal arteries (United States)

    Mumbaraddi, Avinash; Yu, Huidan (Whitney); Sawchuk, Alan; Dalsing, Michael


    The objective of this clinical-need driven research is to investigate the effect of renal artery stenosis (RAS) on the blood flow and wall shear stress in renal arteries through 4-D patient-specific computational hemodynamics (PSCH) and search for possible critical RASs that significantly alter the pressure gradient across the stenosis by manually varying the size of RAS from 50% to 95%. The identification of the critical RAS is important to understand the contribution of RAS to the overall renal resistance thus appropriate clinical therapy can be determined in order to reduce the hypertension. Clinical CT angiographic data together with Doppler Ultra sound images of an anonymous patient are used serving as the required inputs of the PSCH. To validate the PSCH, we use both Ansys Fluent and Sim Vascular and compare velocity, pressure, and wall-shear stress under identical conditions. Renal Imaging Technology Development Program (RITDP) Grant.

  8. Reduced contribution of endothelin to the regulation of systemic and pulmonary vascular tone in severe familial hypercholesterolaemia

    NARCIS (Netherlands)

    S.B. Bender (Shawn ); V.J. de Beer (Vincent Jacob); D.L. Tharp (Darla); E.D. van Deel (Elza); D.K. Bowles; D.J.G.M. Duncker (Dirk); H. Laughlin (Harold); D. Merkus (Daphne)


    textabstractVascular dysfunction has been associated with familial hypercholesterolaemia (FH), a severe form of hyperlipidaemia. We recently demonstrated that swine with FH exhibit reduced exercise-induced systemic, but not pulmonary, vasodilatation involving reduced nitric oxide (NO) bioavailabilit

  9. Transduction of interleukin-10 through renal artery attenuates vascular neointimal proliferation and infiltration of immune cells in rat renal allograft. (United States)

    Xie, Jingxin; Li, Xueyi; Meng, Dan; Liang, Qiujuan; Wang, Xinhong; Wang, Li; Wang, Rui; Xiang, Meng; Chen, Sifeng


    Renal transplantation is the treatment of choice for end-stage renal failure. Although acute rejection is not a major issue anymore, chronic rejection, especially vascular rejection, is still a major factor that might lead to allograft dysfunction on the long term. The role of the local immune-regulating cytokine interleukin-10 (IL-10) in chronic renal allograft is unclear. Many clinical observations showed that local IL-10 level was negatively related to kidney allograft function. It is unknown this negative relationship was the result of immunostimulatory property or insufficient immunosuppression property of local IL-10. We performed ex vivo transduction before transplantation through artery of the renal allograft using adeno-associated viral vectors carrying IL-10 gene. Twelve weeks after transplantation, we found intrarenal IL-10 gene transduction significantly inhibited arterial neointimal proliferation, the number of occluded intrarenal artery, interstitial fibrosis, peritubular capillary congestion and glomerular inflammation in renal allografts compared to control allografts receiving PBS or vectors carrying YFP. IL-10 transduction increased serum IL-10 level at 4 weeks but not at 8 and 12 weeks. Renal IL-10 level increased while serum creatinine decreased significantly in IL-10 group at 12 weeks compared to PBS or YFP controls. Immunohistochemical staining showed unchanged total T cells (CD3) and B cells (CD45R/B220), decreased cytotoxic T cells (CD8), macrophages (CD68) and increased CD4+ and FoxP3+ cells in IL-10 group. In summary, intrarenal IL-10 inhibited the allograft rejection while modulated immune response.

  10. POEMS syndrome with vascular lesions and renal carcinoma - possible role of cytokines. (United States)

    Pasqui, A L; Bova, G; Saletti, M; Bruni, F; Di Renzo, M; Auteri, A


    We describe here the case of a 60 years man with POEMS syndrome associated with renal tumor and vascular lesions. The patient had osteosclerotic myeloma IgA-lambda, polyneuropathy, endocrinopathy and skin changes. In addition, he developed renal clear cell carcinoma and gangrena of lower limbs. The humoral study showed thrombocytosis, high levels of IL-1beta and IL-6 and of some coagulative/fibrinolytic and endothelial factors (von Willebrand factor, plasmin-antiplasmine complexes, plasminogen activator). We suggest the hypothesis that these factors are capable of determining some manifestations of POEMS syndrome.

  11. Vasodilatation of afferent arterioles and paradoxical increase of renal vascular resistance by furosemide in mice

    DEFF Research Database (Denmark)

    Oppermann, Mona; Hansen, Pernille B; Castrop, Hayo;


    Loop diuretics like furosemide have been shown to cause renal vasodilatation in dogs and humans, an effect thought to result from both a direct vascular dilator effect and from inhibition of tubuloglomerular feedback. In isolated perfused afferent arterioles preconstricted with angiotensin II or N...... that furosemide, despite its direct vasodilator potential in isolated afferent arterioles, causes a marked increase in flow resistance of the vascular bed of the intact mouse kidney. We suggest that generation of angiotensin II and/or a vasoconstrictor prostaglandin combined with compression of peritubular...

  12. Cardiovascular risk factor treatment targets and renal complications in high risk vascular patients: a cohort study

    Directory of Open Access Journals (Sweden)

    Visseren Frank LJ


    Full Text Available Abstract Background To determine if recommended treatment targets, as specified in clinical practice guidelines for the management of cardiovascular disease, reduces the risk of renal complications in high risk patient populations. Methods This was a cohort study. Participants in Utrecht, The Netherlands either at risk of, or had cardiovascular disease were recruited. Cardiovascular treatment targets were achievement of control in systolic and diastolic blood pressure, total and low-density cholesterol, and treatment of albuminuria. Outcome measures were time to development of end stage renal failure or symptomatic renal atherosclerotic disease requiring intervention. Results The cohort consisted of 7,208 participants; 1,759 diabetics and 4,859 with clinically manifest vascular disease. The median age was 57 years and 67% were male. Overall, 29% of the cohort achieved the treatment target for systolic blood pressure, 39% for diastolic blood pressure, 28% for total cholesterol, 31% for LDL cholesterol and 78% for albuminuria. The incidence rate for end stage renal failure and renal atherosclerotic disease reduced linearly with each additional treatment target achieved (p value less than 0.001. Achievement of any two treatment targets reduced the risk of renal complications, hazard ratio 0.46 (95% CI 0.26-0.82. For patients with clinically manifest vascular disease and diabetes, the hazard ratios were 0.56 (95% CI 0.28 - 1.12 and 0.28 (95%CI 0.10 - 0.79 respectively. Conclusion Clinical guidelines for cardiovascular disease management do reduce risk of renal complications in high risk patients. Benefits are seen with attainment of any two treatment targets.

  13. Increased renal vascular reactivity to ANG II after unilateral nephrectomy in the rat involves 20-HETE. (United States)

    Joly, E; Seqqat, R; Flamion, B; Caron, N; Michel, A; Imig, J D; Kramp, R


    This study examined the role of intrarenal ANG II in the renal vascular reactivity changes occurring in the remaining kidney undergoing adaptation following contralateral nephrectomy. Renal blood flow responses to intrarenal injections of ANG II (0.25 to 5 ng) were measured in anesthetized euvolemic male Wistar rats 1, 4, 12, and 24 wk after uninephrectomy (UNX) or sham procedure (SHAM). At week 4, renal vasoconstriction induced by 2 ng ANG II was greater in UNX (69 +/- 5%) than in SHAM rats (50 +/- 3%; P < 0.01). This response was inhibited, by 50 and 66%, and by 20 and 25%, in SHAM and UNX rats, after combined injections of ANG II and losartan, or PD-123319 (P < 0.05), respectively. Characteristics of ANG II receptor binding in isolated preglomerular resistance vessels were similar in the two groups. After prostanoid inhibition with indomethacin, renal vasoconstriction was enhanced by 42 +/- 8% (P < 0.05), only in SHAM rats, whereas after 20-HETE inhibition with HET0016, it was reduced by 53 +/- 16% (P < 0.05), only in UNX rats. These differences vanished after concomitant prostanoid and 20-HETE inhibition in the two groups. After UNX, renal cortical protein expression of cytochrome P-450 2c23 isoform (CYP2c23) and cyclooxygenase-1 (COX-1) was unaltered, but it was decreased for CYP4a and increased for COX-2. In conclusion, renal vascular reactivity to ANG II was significantly increased in the postuninephrectomy adapted kidney, independently of protein expression, but presumably involving interactions between 20-HETE and COX in the renal microvasculature and changes in the paracrine activity of ANG II and 20-HETE.

  14. Mid-Term Vascular Safety of Renal Denervation Assessed by Follow-up MR Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Axel, E-mail:; Schmieder, Raphael; Lell, Michael; Janka, Rolf [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Veelken, Roland; Schmieder, Roland E. [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany); Uder, Michael [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Ott, Christian [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany)


    Background/AimsRenal denervation (RDN) emerged as a treatment option for reducing blood pressure (BP) in patients with treatment-resistant hypertension (TRH). However, concerns have been raised regarding the incidence of late renal artery stenosis or thromboembolism after RDN. The goal of the current study was, therefore, to conduct a prospective clinical trial on the mid-term vascular integrity of the renal arteries and the perfusion of the renal parenchyma assessed by magnetic resonance imaging (MRI) in the follow-up after catheter-based RDN.MethodsIn our single-centre investigator initiated study, 51 patients with true TRH underwent catheter-based RDN using the Symplicity Flex{sup TM} catheter (Medtronic Inc., Palo Alto, CA). Follow-up MRI was performed at a median of 11 months (interquartile range 6–18 months) after RDN on a 1.5T MR unit. High-resolution MR angiography (MRA) and MRI results were compared to the baseline digital angiography of renal arteries obtained at time of RDN. In case of uncertainties (N = 2) catheter angiography was repeated.ResultsBoth office and 24-h ambulatory BP were significantly reduced 6 and 12 months after RDN. Renal function remained unchanged 6 and 12 months after RDN. In all patients, MRA excluded new or progression of pre-existing low grade renal artery stenosis as well as focal aneurysms at the sites of radiofrequency ablation. In none of the patients new segmental perfusion deficits in either kidney were detected on MRI.ConclusionsNo vascular or parenchymal complications after radiofrequency-based RDN were detected in 51 patients followed up by MRI.


    Institute of Scientific and Technical Information of China (English)


    Introduction In teaching writing, people usually pay attention to grammatical problems from sentence structure to articles. They also pay attention to spelling, capitalisation, punctuation and the choice of words. These are essential-but so is the tone of the writing. In this article, I’d like to present some ideas about tone. Tone

  16. Determination of renal vascular resistance in dogs with diabetes mellitus and hyperadrenocorticism. (United States)

    Novellas, R; de Gopegui, R Ruiz; Espada, Y


    In dogs, diabetes mellitus and hyperadrenocorticism are causes of hypertension associated with increases in vascular peripheral resistance. In human patients, the renal resistive index (ri) and pulsatility index (pi) are related to hypertension and diabetes and are used as indicators of disease severity. In this study the renal vascular resistance was measured in 12 dogs with hyperadrenocorticism, three with diabetes mellitus and four with both conditions, and the possible relationships between the two indices, blood pressure and biochemical parameters were investigated. Hypertension, defined as a systolic blood pressure more than 150 mmHg, was recorded in two of the dogs with hyperadrenocorticism and three of the dogs with hyperadrenocorticism and diabetes. The overall mean values for ri, pi and systolic blood pressure were higher in the diseased group of dogs than in 27 healthy dogs, and both indices were correlated with blood glucose concentration.

  17. Captopril attenuates hypertension and renal injury induced by the vascular endothelial growth factor inhibitor sorafenib (United States)

    Nagasawa, Tasuku; Khan, Abdul Hye; Imig, John D


    SUMMARY Vascular endothelial growth factor inhibitors (VEGFi) are known to cause hypertension and renal injury that severely limits their use as an anticancer therapy. We hypothesized that the angiotensin-converting enzyme inhibitor captopril not only prevents hypertension, but also decreases renal injury caused by the VEGFi sorafenib.Rats were administered sorafenib (20 mg/kg per day) alone or in combination with captopril (40 mg/kg per day) for 4 weeks. Sorafenib administration increased blood pressure, which plateaued by day 10.Concurrent treatment with captopril for 4 weeks resulted in a 30 mmHg decrease in blood pressure compared with sorafenib alone (155 ± 5 vs 182 ± 6 mmHg, respectively; P captopril treatment reduced albuminuria by 50% compared with sorafenib alone (20 ± 8 vs 42 ± 9 mg/day, respectively; P captopril-treated rats administered sorafenib. Renal autoregulatory efficiency was determined by evaluating the afferent arteriolar constrictor response to ATP. Sorafenib administration attenuated the vasoconstriction to ATP, whereas concurrent captopril treatment improved ATP reactivity.In conclusion, captopril attenuated hypertension and renal injury and improved renal autoregulatory capacity in rats administered sorafenib. These findings indicate that captopril treatment, in addition to alleviating the detrimental side-effect of hypertension, decreases the renal injury associated with anticancer VEGFi therapies such as sorafenib. PMID:22443474

  18. Effects of ginsenosides on vascular reactivity in rat cerebral and renal arteries

    Institute of Scientific and Technical Information of China (English)

    WONG Wing-tak; LEUNG Fung-ping; YUNG Lai-hang; TIAN Xiao-yu; WONG Ricky Ngok Shun; HUANG Yu


    Objective To investigate possible mechanisms underlying the antioxidant property (1) and the in vitro vasodilator effects (2) of the two ginsenosides, Rb1 and Rg1, in isolated rat renal and cerebral arteries. Methods Arterial rings were mounted in a multi-channel myograph for recording of isometric tension. To examine the antioxidant activity, some rings were exposed to a free radical-generating reaction (hypoxan-thine and xanthine oxidase) with and without pre-treatment with ginsenosides. The calcium antagonistic effects were tested on rings contracted by membrane depolarization in elevated extracellular potassium ions, a condition that promoted Ca2+ influx in vascular smooth muscle cells. Results Ginsenosides protected endothelial function (endothelial nitric oxide-dependent relaxation) against oxidative stress; (2) ginsenoside Rb1 reduced the high K+ -induced contractions of both renal and cerebral arteries while ginsenoside Rgl relaxed the rat cerebral artery but not the renal artery. Conclusions Ginsenosides are vaso-protective via (1) the antioxidant activity which protects endothelial cell function and (2) the inhibition of Ca2+ influx through voltage-sensitive Ca2+ channels in vascular smooth muscle. The vasodilator effects may suggest the potential preventive or therapeutic values of ginsenosides against stroke and renal hypertension.

  19. Impact of multidisciplinary, early renal education on vascular access placement. (United States)

    Lindberg, Jill S; Husserl, Fred E; Ross, Jamie L; Jackson, Dina; Scarlata, Debra; Nussbaum, Joyce; Cohen, Andrew; Elzein, Hafez


    The Ochsner Clinic Foundation initiated the Healthy Start Clinic to identify, educate, and refer chronic kidney disease patients to nephrologists earlier in the course of their disease. This study investigated the impact of a structured educational session on the type and timing of permanent vascular access placement in patients receiving hemodialysis. Before initiating dialysis, the HSC patient group received a general overview of the kidney and kidney disease, plus one-on-one instruction from a registered nurse, a dietitian, and a social worker. The HSC group was compared with a concurrent, conventionally prepared group of CKD patients who initiated dialysis during the same study period. Of the 147 patients initiating hemodialysis at OCF between April 1997 and December 2000, 61 had received structured HSC education, and 86 had received conventional care. In HSC-educated patients, the incidence of PVAs placed before hemodialysis initiation was twofold greater than in patients who received conventional care (77% HSC; 36% non-HSC, p < 0.001), and more HSC-educated patients initiated hemodialysis using their PVA (49% HSC; 23% non-HSC, p < 0.01). In addition, five times more patients who received HSC education received arteriovenous fistulas (52% HSC; 10% non-HSC, p < 0.001). Finally, significantly fewer HSC-educated patients initiated dialysis on a temporary catheter (51% HSC; 77% non-HSC, p < 0.001). Education programs for CKD patients help increase the number of patients receiving early PVA placement, as well as the proportion of patients receiving AVFs as opposed to grafts or temporary catheters.

  20. Permanent vascular access in patients with end-stage renal disease, Brazil Acceso vascular permanente en pacientes renales crónicos terminales en Brasil Acesso vascular permanente em pacientes renais crônicos terminais no Brasil

    Directory of Open Access Journals (Sweden)

    Gisele Macedo da Silva


    Full Text Available OBJECTIVE: To assess factors associated with the establishment of permanent vascular access for patients with end-stage renal disease. METHODS: Cross-sectional study conducted in a nationally representative sample of Brazilian end-stage renal disease patients in dialysis and transplant centers during 2007. The sample comprised only patients who received hemodialysis as a primary therapy modality and reported the type of vascular access for their primary hemodialysis treatment (N=2,276. Data were from the TRS Project - "Economic and Epidemiologic Evaluation of Modalities of Renal Replacement Therapy in Brazil". Multiple logistic regression analysis was used to assess factors associated with the establishment of permanent vascular access in these patients. RESULTS: About 30% of the patients studied had an arteriovenous vascular access. The following factors were associated with a lower likelihood of having an arteriovenous vascular access as a primary type of access: time of hemodialysis start since the diagnosis of chronic renal failure OBJETIVO: Analizar factores asociados a la provisión de acceso vascular arteriovenoso en Brasil. MÉTODOS: Estudio transversal, nacionalmente representativo, con pacientes con enfermedad renal crónica terminal acompañados en servicios de diálisis o en centros transplantadores en el año de 2007. La muestra incluyó pacientes que tuvieron la hemodiálisis como primera modalidad de tratamiento y que sabían con que tipo de acceso vascular habían iniciado el tratamiento (N=2.276. Los datos son oriundos del Proyecto TRS - "Evaluación económica-epidemiológica de las modalidades de Terapia renal Sustitutiva en Brasil". Fue utilizada la regresión logística múltiple. RESULTADOS: Aproximadamente 30% de los pacientes tenían acceso vascular arteriovenoso. Los factores asociados a la baja probabilidad de tener acceso vascular arteriovenoso como primer tipo de acceso fueron: tiempo de diagnóstico de enfermedad

  1. Two Tones

    DEFF Research Database (Denmark)

    Palludan, Charlotte


    This article examines how kindergarten-children are differentiated and segregated through vocal practices and processes. The analysis is based on empirical data, which originate from a long ethnographic fieldwork in Denmark. The author presents two different language tones: "a teaching tone...... and an exchange tone" and shows a pattern in the ways the two tones are performed. While the teaching tone is heard in the interaction between the staff and the ethnic minority children, the ethnic majority children (the Danes) are addressed in the exchange tone. Pierre Bourdieu's concepts: "linguistic market......", "habitual inclinations" and "feeling for the game" are used as theoretical framework. When the author interprets and explains the language pattern as unequal distribution of recognition and as continuation of reproduction of a socio-cultural hierarchy among the children she relates to this framework...

  2. Two Tones

    DEFF Research Database (Denmark)

    Palludan, Charlotte


    and an exchange tone" and shows a pattern in the ways the two tones are performed. While the teaching tone is heard in the interaction between the staff and the ethnic minority children, the ethnic majority children (the Danes) are addressed in the exchange tone. Pierre Bourdieu's concepts: "linguistic market......", "habitual inclinations" and "feeling for the game" are used as theoretical framework. When the author interprets and explains the language pattern as unequal distribution of recognition and as continuation of reproduction of a socio-cultural hierarchy among the children she relates to this framework...

  3. Vascular Tone Regulation Induced by C-Type Natriuretic Peptide: Differences in Endothelium-Dependent and -Independent Mechanisms Involved in Normotensive and Spontaneously Hypertensive Rats (United States)

    Caniffi, Carolina; Cerniello, Flavia M.; Gobetto, María N.; Sueiro, María L.; Arranz, Cristina


    Given that the role of C-type natriuretic peptide (CNP) in the regulation of vascular tone in hypertensive states is unclear, we hypothesized that impaired response of the nitric oxide system to CNP in spontaneously hypertensive rats (SHR) could affect vascular relaxation induced by the peptide in this model of hypertension, and that other endothelial systems or potassium channels opening could also be involved. We examined the effect of CNP on isolated SHR aortas, and the hindlimb vascular resistance (HVR) in response to CNP administration compared to normotensive rats. Aortas were mounted in an isometric organ bath and contracted with phenylephrine. CNP relaxed arteries in a concentration-dependent manner but was less potent in inducing relaxation in SHR. The action of CNP was diminished by removal of the endothelium, inhibition of nitric oxide synthase by Nω-nitro-L-arginine methyl ester, and inhibition of soluble guanylyl cyclase by 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one in both groups. In contrast, blockade of cyclooxygenase or subtype 2 bradykinin receptor increased CNP potency only in SHR. In both Wistar and SHR, CNP relaxation was blunted by tetraethylammonium and partially inhibited by BaCl2 and iberiotoxin, indicating that it was due to opening of the Kir and BKCa channels. However, SHR seem to be more sensitive to Kir channel blockade and less sensitive to BKCa channel blockade than normotensive rats. In addition, CNP decreases HVR in Wistar and SHR, but the effect of CNP increasing blood flow was more marked in SHR. We conclude that CNP induces aorta relaxation by activation of the nitric oxide system and opening of potassium channels, but the response to the peptide is impaired in conductance vessel of hypertensive rats. PMID:27936197

  4. Rapid estrogen receptor alpha signaling mediated by ERK activation regulates vascular tone in male and ovary-intact female mice. (United States)

    Kim, Seong Chul; Boese, Austin C; Moore, Matthew H; Cleland, Rea M; Chang, Lin; Delafontaine, Patrice; Yin, Ke-Jie; Lee, Jean-Pyo; Hamblin, Milton H


    Estrogen has been shown to affect vascular reactivity. Here, we assessed estrogen receptor-alpha (ERα) dependency of estrogenic effects on vasorelaxation via a rapid nongenomic pathway in both male and ovary-intact female mice. We compared the effect of a primary estrogen, 17 beta-estradiol (E2) or 4,4',4"-(4-propyl-[1H]pyrazole-1,3,5-triyl)tris-phenol (PPT) (selective ERα agonist). We found that E2 and PPT induced greater aortic relaxation in females than males, indicating ERα mediation, which is further validated by employing ERα antagonism. Treatment with 1,3-Bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP dihydrochloride) (ERα antagonist) attenuated PPT-mediated vessel relaxation in both sexes. ERα-mediated vessel relaxation is further validated by the absence of significant PPT-mediated relaxation in aortas isolated from ERα knockout mice. Treatment with a specific extracellular signal-regulated kinase (ERK) inhibitor, PD98059 reduced E2-induced vessel relaxation in both sexes, but to a lesser extent in females. Further, PD98059 prevented PPT-induced vessel relaxation in both sexes. Both E2 and PPT treatment activated ERK as early as 5-10 min, which was attenuated by PD98059 in aortic tissue, cultured primary vascular smooth muscle cells (VSMCs), and endothelial cells (ECs). Aortic rings denuded of endothelium showed no differences in vessel relaxation following E2 or PPT treatment, implicating a role of ECs in the observed sex differences. Here, our results are unique to show estrogen-stimulated rapid ERα signaling mediated by ERK activation in aortic tissue, as well as VSMCs and ECs in vitro, in regulating vascular function by employing side-by-side comparisons in male and ovary-intact female mice in response to E2 or PPT. Copyright © 2017, American Journal of Physiology-Heart and Circulatory Physiology.

  5. Renal and vascular effects of Crotalus durissus cumanensis venom and its crotoxin fraction

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    TP Pereira


    Full Text Available In this study, we evaluated the actions of Crotalus durissus cumanensis venom (CDCmV, and its crotoxin (Crtx fraction, on renal and vascular functions in Wistar rats. In isolated perfused kidneys, CDCmV (10 µg/mL significantly increased the perfusion pressure (PP from 110.7 ± 2.4 to 125.3 ± 2.8 mmHg after 30 minutes. This effect was accompanied by an increased renal vascular resistance (RVR from 5.4 ± 0.1 to 6.2 ± 0.2 mmHg/mL.g-1.min-1. We observed decreases in urinary flow (UF from 0.13 ± 0.01 to 0.05 ± 001 mL.g-1.min-1 and glomerular filtration rate (GFR from 0.66 ± 0.06 to 0.18 ± 0.02 mL.g-1.min-1. Crtx did not change PP or RVR, but diminished GFR (from 0.65 ± 0.05 to 0.26 ± 003 mL.g-1.min-1 and UF (from 0.11 ± 0.008 to 0.09 ± 0.008 mL.g-1.min-1. Both CDCmV and Crtx reduced the percentage of tubular transport of sodium, chloride and potassium. The cytotoxicity of these substances against MDCK cells was tested by the MTT method: only CDCmV caused a decrease in the cell viability with an IC50 of 5.4 µg/mL. In endothelium-intact isolated aortic rings, CDCmV (0.1 to 30 µg/mL increased the sustained phenylephrine-induced contraction to a value of 130.0 ± 6.6% of its corresponding control, but showed a relaxant effect in endothelium-denuded preparations. Similar results were observed in aortic rings contracted with potassium (40 mM. Crtx was ineffective in aortic ring assays. Thus, it is reasonable to suggest that the renal effects induced by the CDCmV may be due to its influence on the endothelium's ability to release factors that can alter the contractile behavior of vascular smooth muscle. In conclusion, CDCmV is toxic to kidney cells. It changes parameters of the renal function including the glomerular filtration rate, renal vascular resistance and tubular transport. The actions induced by CDCmV also involve endothelium-dependent vasoactive properties. Their effects may be only partially attributed to Crtx.

  6. Contour Tones. (United States)

    Yip, Moira


    Argues that contour tones in East Asian languages behave as melodic units consisting of a root node [upper] dominating a branching specification. It is also argued that, with upper as the tonal root node, no more than two rising or falling tones will contrast underlying. (49 references) (JL)

  7. Renal responses to central vascular expansion are suppressed at night in conscious primates (United States)

    Kass, D. A.; Sulzman, F. M.; Fuller, C. A.; Moore-Ede, M. C.


    The renal and hemodynamic responses of squirrel monkeys to central vascular volume expansion induced by lower body positive pressure (LBPP) during the day and night are investigated. Twelve unanesthetized animals trained to sit in a metabolism chair in which they were restrained only at the waist by a partition separating upper and lower body chambers were subjected to 4 h of continuous LBPP during the day and night, and hemodynamic, urinary and drinking data were monitored. LBPP during day and night is found to induce similar increases in central venous pressure, rises in heart rate and elevations in mean arterial blood pressure. However, although daytime LBPP induced a significant increase in urine flow and sodium excretion, a marked nocturnal inhibition of the renal response to LBPP is observed. Analysis of the time course and circadian regulation patterns of the urinary responses suggests that several separate efferent control pathways are involved.

  8. Remanent cell traction force in renal vascular smooth muscle cells induced by integrin-mediated mechanotransduction. (United States)

    Balasubramanian, Lavanya; Lo, Chun-Min; Sham, James S K; Yip, Kay-Pong


    It was previously demonstrated in isolated renal vascular smooth muscle cells (VSMCs) that integrin-mediated mechanotransduction triggers intracellular Ca(2+) mobilization, which is the hallmark of myogenic response in VSMCs. To test directly whether integrin-mediated mechanotransduction results in the myogenic response-like behavior in renal VSMCs, cell traction force microscopy was used to monitor cell traction force when the cells were pulled with fibronectin-coated or low density lipoprotein (LDL)-coated paramagnetic beads. LDL-coated beads were used as a control for nonintegrin-mediated mechanotransduction. Pulling with LDL-coated beads increased the cell traction force by 61 ± 12% (9 cells), which returned to the prepull level after the pulling process was terminated. Pulling with noncoated beads had a minimal increase in the cell traction force (12 ± 9%, 8 cells). Pulling with fibronectin-coated beads increased the cell traction force by 56 ± 20% (7 cells). However, the cell traction force was still elevated by 23 ± 14% after the pulling process was terminated. This behavior is analogous to the changes of vascular resistance in pressure-induced myogenic response, in which vascular resistance remains elevated after myogenic constriction. Fibronectin is a native ligand for α(5)β(1)-integrins in VSMCs. Similar remanent cell traction force was found when cells were pulled with beads coated with β(1)-integrin antibody (Ha2/5). Activation of β(1)-integrin with soluble antibody also triggered variations of cell traction force and Ca(2+) mobilization, which were abolished by the Src inhibitor. In conclusion, mechanical force transduced by α(5)β(1)-integrins triggered a myogenic response-like behavior in isolated renal VSMCs.

  9. Spontaneous Dissection of the Renal Artery in Vascular Ehlers-Danlos Syndrome (United States)

    Pereira, Filipa; Cardoso, Teresa; Sá, Paula


    Ehlers-Danlos syndrome (EDS) is a rare heterogeneous group of connective tissue disorders. The vascular type (vEDS) is an autosomal dominant disorder caused by heterozygous mutations in the COL3A1 gene predisposing to premature arterial, intestinal, or uterine rupture. We report a case of a 38-year-old woman with a recent diagnosis of vEDS admitted in the Emergency Department with a suspicion of a pyelonephritis that evolved to a cardiopulmonary arrest. A fatal retroperitoneal hematoma related with a haemorrhagic dissection of the right renal artery was found after emergency surgery. This case highlights the need to be aware of the particular characteristics of vEDS, such as a severe vascular complication that can lead to a fatal outcome. PMID:26175915

  10. Vascular, hepatic and renal lesions by Dirofilaria immitis invasion in dogs

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    S.A. Pasca


    Full Text Available Morphological investigations were conducted on four bodies of dogs who died due to severe clinical symptoms following a massive invasion of cardiac and pulmonary Dirofilaria. The subjects were monitored clinically and diagnosed serologically positive for the Heartworm disease. The necropsy examination of the cardiovascular system (right ventricle and pulmonary artery revealed the presence of 25 adult parasites in one dog with length ranging between 8 and 33cm. Macroscopically, lesions consistently observed were represented by the right ventricular dilatation and the diffuse wall thickening of the pulmonary artery. Parasitic invasion secondary lesions were present in the lungs, liver and kidneys (cardiac and vascular lesions. The histological examination mainly revealed myocardial injury, vascular (dystrophic, pulmonary (circulatory and inflammatory, hepatic (degenerative and renal (degenerative and inflammatory damage.

  11. Spontaneous Dissection of the Renal Artery in Vascular Ehlers-Danlos Syndrome

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    Filipa Pereira


    Full Text Available Ehlers-Danlos syndrome (EDS is a rare heterogeneous group of connective tissue disorders. The vascular type (vEDS is an autosomal dominant disorder caused by heterozygous mutations in the COL3A1 gene predisposing to premature arterial, intestinal, or uterine rupture. We report a case of a 38-year-old woman with a recent diagnosis of vEDS admitted in the Emergency Department with a suspicion of a pyelonephritis that evolved to a cardiopulmonary arrest. A fatal retroperitoneal hematoma related with a haemorrhagic dissection of the right renal artery was found after emergency surgery. This case highlights the need to be aware of the particular characteristics of vEDS, such as a severe vascular complication that can lead to a fatal outcome.

  12. Inhibition of Extracellular Signal-Regulated Kinases Ameliorates Hypertension-Induced Renal Vascular Remodeling in Rat Models

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    Li Jing


    Full Text Available The aim of this study is to investigate the effect of the extracellular signal-regulated kinases 1/2 (ERK1/2 inhibitor, PD98059, on high blood pressure and related vascular changes. Blood pressure was recorded, thicknesses of renal small artery walls were measured and ERK1/2 immunoreactivity and erk2 mRNA in renal vascular smooth muscle cells (VSMCs and endothelial cells were detected by immunohistochemistry and in situ hybridization in normotensive wistar kyoto (WKY rats, spontaneously hypertensive rats (SHR and PD98059-treated SHR. Compared with normo-tensive WKY rats, SHR developed hypertension at 8 weeks of age, thickened renal small artery wall and asymmetric arrangement of VSMCs at 16 and 24 weeks of age. Phospho-ERK1/2 immunoreactivity and erk2 mRNA expression levels were increased in VSMCs and endothelial cells of the renal small arteries in the SHR. Treating SHR with PD98059 reduced the spontaneous hypertension-induced vascular wall thickening. This effect was associated with suppressions of erk2 mRNA expression and ERK1/2 phosphorylation in VSMCs and endothelial cells of the renal small arteries. It is concluded that inhibition of ERK1/2 ameliorates hypertension induced vascular remodeling in renal small arteries.

  13. Effect of diesel exhaust particles on renal vascular responses in rats with chronic kidney disease. (United States)

    Al Suleimani, Y M; Al Mahruqi, A S; Al Za'abi, M; Shalaby, A; Ashique, M; Nemmar, A; Ali, B H


    Several recent studies have indicated the possible association between exposure to particulate air pollution and the increased rate of morbidity and mortality in patients with kidney diseases. The link of this observation to vascular damage has not been adequately addressed. Therefore, this study aims to investigate possible vascular damage that might be associated with exposure to diesel exhaust particles (DP) in adenine (AD)-induced chronic kidney disease (CKD) in rats, and the possible ameliorative effect of gum acacia (GA). CKD was induced by feeding AD (0.75%, w/w), and DP (0.5 mg/kg) was instilled intratracheally every second day and GA was given concomitantly in the drinking water at a dose of 15% w/v. All treatments were given concomitantly for 28 days. Changes in renal blood flow (RBF) and systolic and diastolic blood pressure were monitored in these animals after anesthesia, together with several other endpoints. Exposure to DP significantly reduced RBF and this was significantly potentiated in AD-treated rats. Phenylephrine-induced decreases in RBF and increases in systolic and diastolic blood pressure were severely potentiated in rats exposed to DP, and these actions were significantly augmented in AD-treated rats. GA did not significantly affect the vascular impairment induced by AD and DP given together. This study provides experimental evidence that exposure to particulate air pollution can exacerbate the vascular damage seen in patients with CKD. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 541-549, 2017.

  14. H2S and NO cooperatively regulate vascular tone by activating a neuroendocrine HNO–TRPA1–CGRP signalling pathway (United States)

    Eberhardt, Mirjam; Dux, Maria; Namer, Barbara; Miljkovic, Jan; Cordasic, Nada; Will, Christine; Kichko, Tatjana I.; de la Roche, Jeanne; Fischer, Michael; Suárez, Sebastián A.; Bikiel, Damian; Dorsch, Karola; Leffler, Andreas; Babes, Alexandru; Lampert, Angelika; Lennerz, Jochen K.; Jacobi, Johannes; Martí, Marcelo A.; Doctorovich, Fabio; Högestätt, Edward D.; Zygmunt, Peter M.; Ivanovic-Burmazovic, Ivana; Messlinger, Karl; Reeh, Peter; Filipovic, Milos R.


    Nitroxyl (HNO) is a redox sibling of nitric oxide (NO) that targets distinct signalling pathways with pharmacological endpoints of high significance in the treatment of heart failure. Beneficial HNO effects depend, in part, on its ability to release calcitonin gene-related peptide (CGRP) through an unidentified mechanism. Here we propose that HNO is generated as a result of the reaction of the two gasotransmitters NO and H2S. We show that H2S and NO production colocalizes with transient receptor potential channel A1 (TRPA1), and that HNO activates the sensory chemoreceptor channel TRPA1 via formation of amino-terminal disulphide bonds, which results in sustained calcium influx. As a consequence, CGRP is released, which induces local and systemic vasodilation. H2S-evoked vasodilatatory effects largely depend on NO production and activation of HNO–TRPA1–CGRP pathway. We propose that this neuroendocrine HNO–TRPA1–CGRP signalling pathway constitutes an essential element for the control of vascular tone throughout the cardiovascular system. PMID:25023795

  15. Effect of exercise on markers of vascular health in renal transplant recipients. (United States)

    Piťha, J; Králová Lesná, I; Stávek, P; Mahrová, A; Racek, J; Sekerková, A; Teplan, V; Štollová, M


    The cornerstone of cardiovascular risk management is lifestyle intervention including exercise which could exert favorable impact also in renal transplant recipients. Nevertheless, reliable assessment of the effect of lifestyle interventions is complicated and the available data in this population are not consistent. The aim of the study was to evaluate the effect of physical activity on selected laboratory markers of vascular health including circulating stem cells, endothelial progenitor cells, microparticles, and plasma asymmetric dimethyl arginine in renal transplant recipients. Nineteen men and 7 women were recruited in 6-month program of standardized and supervised exercise. Control group consisted of 23 men and 13 women of similar age and body mass index not included into the program. One year after the transplantation, the main difference between intervention and control group was found in the change of endothelial progenitor cells (p=0.006). Surprisingly, more favorable change was seen in the control group in which endothelial progenitor cells significantly increased compared to the intervention group. The explanation of this finding might be a chronic activation of reparative mechanisms of vascular system in the population exposed to multiple risk factors which is expressed as relatively increased number of endothelial progenitor cells. Therefore, their decrease induced by exercise might reflect stabilization of these processes.

  16. Interactions among Vascular-Tone Modulators Contribute to High Altitude Pulmonary Edema and Augmented Vasoreactivity in Highlanders (United States)

    Ali, Zahara; Mishra, Aastha; Kumar, Rahul; Alam, Perwez; Pandey, Priyanka; Ram, Rekhbala; Thinlas, Tashi; Mohammad, Ghulam; Pasha, M. A. Qadar


    Background The interactions among various biomarkers remained unexplored under the stressful environment of high-altitude. Present study evaluated interactions among biomarkers to study susceptibility for high altitude pulmonary edema (HAPE) in HAPE-patients (HAPE-p) and adaptation in highland natives (HLs); both in comparison to HAPE-free sojourners (HAPE-f). Methodology/Principal Findings All the subjects were recruited at 3500 m. We measured clinical parameters, biochemical levels in plasma and gene expression using RNA from blood; analyzed various correlations between and among the clinical parameters, especially arterial oxygen saturation (SaO2) and mean arterial pressure (MAP) and biochemical parameters like, asymmetric dimethylarginine (ADMA), serotonin (5-HT), 8-iso-prostaglandin F2α (8-isoPGF2α), endothelin-1 (ET-1), plasma renin activity (PRA), plasma aldosterone concentration (PAC), superoxide dismutase (SOD) and nitric oxide (NO) in HAPE-p, HAPE-f and HLs. ADMA, 5-HT, 8-isoPGF2α, ET-1 levels, and PAC were significantly higher (p0.05) lower in HLs than HAPE-f. The expression of respective genes differed in the three groups. In the correlations, SaO2 inversely correlated with ADMA, 5-HT and 8-isoPGF2α and positively with SOD in HAPE-p (p≤0.009). MAP correlated positively with 5-HT and 8-isoPGF2α in HAPE-p and HLs (p≤0.004). A strong positive correlation was observed between ADMA and 5-HT, 5-HT and 8-isoPGF2α (p≤0.001), whereas inverse correlation of SOD with ET-1 in HAPE-p and HLs (p≤0.004), with 5-HT and 8-isoPGF2α in HAPE-p (p = 0.01) and with 5-HT in HLs (p = 0.05). Conclusions/Significance The interactions among these markers confer enhanced vascular activity in HLs and HAPE in sojourners. PMID:22984459

  17. Interactions among vascular-tone modulators contribute to high altitude pulmonary edema and augmented vasoreactivity in highlanders.

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    Zahara Ali

    Full Text Available BACKGROUND: The interactions among various biomarkers remained unexplored under the stressful environment of high-altitude. Present study evaluated interactions among biomarkers to study susceptibility for high altitude pulmonary edema (HAPE in HAPE-patients (HAPE-p and adaptation in highland natives (HLs; both in comparison to HAPE-free sojourners (HAPE-f. METHODOLOGY/PRINCIPAL FINDINGS: All the subjects were recruited at 3500 m. We measured clinical parameters, biochemical levels in plasma and gene expression using RNA from blood; analyzed various correlations between and among the clinical parameters, especially arterial oxygen saturation (SaO(2 and mean arterial pressure (MAP and biochemical parameters like, asymmetric dimethylarginine (ADMA, serotonin (5-HT, 8-iso-prostaglandin F2α (8-isoPGF2α, endothelin-1 (ET-1, plasma renin activity (PRA, plasma aldosterone concentration (PAC, superoxide dismutase (SOD and nitric oxide (NO in HAPE-p, HAPE-f and HLs. ADMA, 5-HT, 8-isoPGF2α, ET-1 levels, and PAC were significantly higher (p0.05 lower in HLs than HAPE-f. The expression of respective genes differed in the three groups. In the correlations, SaO(2 inversely correlated with ADMA, 5-HT and 8-isoPGF2α and positively with SOD in HAPE-p (p≤0.009. MAP correlated positively with 5-HT and 8-isoPGF2α in HAPE-p and HLs (p ≤ 0.004. A strong positive correlation was observed between ADMA and 5-HT, 5-HT and 8-isoPGF2α (p≤0.001, whereas inverse correlation of SOD with ET-1 in HAPE-p and HLs (p ≤ 0.004, with 5-HT and 8-isoPGF2α in HAPE-p (p = 0.01 and with 5-HT in HLs (p = 0.05. CONCLUSIONS/SIGNIFICANCE: The interactions among these markers confer enhanced vascular activity in HLs and HAPE in sojourners.

  18. Marcadores de daño vascular y renal en orina en niños y adolescentes obesos

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    Lourdes María Pérez Clemente

    Full Text Available Introducción: la microalbuminuria es considerada un marcador de disfunción endotelial, daño vascular, daño renal y enfermedad cardiovascular, considerada un factor de riesgo independiente de morbilidad y mortalidad. De igual manera, la proteinuria ha sido identificada como un factor de riesgo independiente de enfermedad renal crónica, y un predictor de todas las causas de mortalidad. Ambas, son relativamente frecuentes en los sujetos obesos. Objetivo: determinar la frecuencia de marcadores de daño vascular y renal en orina en niños y adolescentes obesos. Métodos: se presenta un estudio observacional, analítico y prospectivo que incluyó a niños y adolescentes obesos atendidos en consulta de referencia "Obesidad y riñón", en el Hospital Pediátrico Docente de Centro Habana. El estudio fue realizado en el periodo comprendido entre enero de 2009 y diciembre de 2012. Se determinaron marcadores de daño vascular y renal en orina (microalbuminuria y proteinuria. El análisis estadístico fue realizado con el programa SPSS versión 13,0. Resultados: solo a un paciente se le identificó proteinuria (0,5 %; sin embargo, al determinar la microalbuminuria, se encontró que más de la mitad (70,8 % tenía este marcador de daño vascular y renal positivo. En el análisis histopatológico de la biopsia renal del paciente con proteinuria se encontró glomerulomegalia con lesión segmentaria de esclerosis y adherencia a la cápsula de Bowman. Conclusiones: los niños y adolescentes obesos tienen una elevada frecuencia de positividad de marcadores de daño vascular y renal, fundamentalmente microalbuminuria.

  19. Massive retroperitoneal hemorrhage from a giant renal angiomyolipoma treated by selective arterial embolization with an Amplatzer Vascular Plug II


    Teichgräber, Ulf KM; de Bucourt, Maximilian


    We report on a 36-year-old Caucasian woman who presented to the emergency department with post-traumatic retroperitoneal bleeding diagnosed by computed tomography. After clinical stabilization of the patient, selective arterial embolization was performed. The angiomyolipoma's feeding artery was successfully treated with an 8-mm Amplatzer Vascular Plug Type II. The upper pole of the left kidney, which was supplied by a separate upper renal artery, was conserved. Consequently, the renal angiomy...

  20. Bone marrow-derived macrophages incorporate into the endothelium and influence vascular and renal function after irradiation

    NARCIS (Netherlands)

    de Cortie, Karin; Russell, Nicola S.; Coppes, Rob P.; Stewart, Fiona A.; Scharpfenecker, Marion

    Purpose: We recently demonstrated that endoglin, an ancillary transforming growth factor beta (TGF-beta) receptor, modulates vascular damage and fibrosis formation and influences renal function after kidney irradiation. We also suggested that this was partially accomplished by endoglin-mediated

  1. Bone marrow-derived macrophages incorporate into the endothelium and influence vascular and renal function after irradiation

    NARCIS (Netherlands)

    de Cortie, Karin; Russell, Nicola S.; Coppes, Rob P.; Stewart, Fiona A.; Scharpfenecker, Marion


    Purpose: We recently demonstrated that endoglin, an ancillary transforming growth factor beta (TGF-beta) receptor, modulates vascular damage and fibrosis formation and influences renal function after kidney irradiation. We also suggested that this was partially accomplished by endoglin-mediated regu

  2. Effects of renal denervation on vascular remodelling in patients with heart failure and preserved ejection fraction: A randomised control trial (United States)

    Hayward, Carl; Keegan, Jennifer; Gatehouse, Peter D; Rajani, Ronak; Khattar, Rajdeep S; Mohiaddin, Raad H; Rosen, Stuart D; Lyon, Alexander R; di Mario, Carlo


    Objective To assess the effect of renal denervation (RDT) on micro- and macro-vascular function in patients with heart failure with preserved ejection fraction (HFpEF). Design A prospective, randomised, open-controlled trial with blinded end-point analysis. Setting A single-centre London teaching hospital. Participants Twenty-five patients with HFpEF who were recruited into the RDT-PEF trial. Main outcome measures Macro-vascular: 24-h ambulatory pulse pressure, aorta distensibilty (from cardiac magnetic resonance imaging (CMR), aorta pulse wave velocity (CMR), augmentation index (peripheral tonometry) and renal artery blood flow indices (renal MR). Micro-vascular: endothelial function (peripheral tonometry) and urine microalbuminuria. Results At baseline, 15 patients were normotensive, 9 were hypertensive and 1 was hypotensive. RDT did not lower any of the blood pressure indices. Though there was evidence of abnormal vascular function at rest, RDT did not affect these at 3 or 12 months follow-up. Conclusions RDT did not improve markers of macro- and micro-vascular function. PMID:28228942

  3. Vascular access versus the effect of statins on inflammation and fibrinolysis in renal dialysis patients. (United States)

    do Sameiro Faria, Maria; Ribeiro, Sandra; Rocha-Pereira, Petronila; Miranda, Vasco; Quintanilha, Alexandre; Reis, Flávio; Costa, Elísio; Belo, Luís; Santos-Silva, Alice


    The aim of this work was to assess the effect of statin therapy on inflammatory and fibrinolytic/endothelial (dys)function markers in end-stage renal disease (ESRD) patients under hemodialysis (HD), according to the type of vascular access. This transversal study includes 191 ESRD patients under regular HD, divided into four groups according to vascular access and statin therapy: 87 patients with arteriovenous fistula (AVF) and no statins (AVF-NS), 61 with AVF and statins (AVF-S), 27 with central venous dialysis catheter (CVC) and no statins (CVC-NS) and 16 with CVC and statins (CVC-S). The basic lipid profile and fibrinolytic/endothelial cell function markers were assessed. Patients with CVC presented significantly higher levels of D-dimers compared with AVF groups. CVC-NS patients also presented the highest IL-6 values, which were significantly higher than those presented by CVC-S patients. AVF-S patients presented significantly higher t-PA and PAI-1 values and lower adiponectin levels compared with AVF-NS. Our results demonstrate that patients with CVC, particularly those not under statin therapy, present a higher production and turnover of fibrin. We also found that statin therapy decreases inflammation in CVC patients but is associated with a reduction of adiponectin and increased endothelial function marker levels in AVF patients.

  4. Associations between Thyroid Hormones, Calcification Inhibitor Levels and Vascular Calcification in End-Stage Renal Disease.

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    Christiaan Lucas Meuwese

    Full Text Available Vascular calcification is a common, serious and elusive complication of end-stage renal disease (ESRD. As a pro-calcifying risk factor, non-thyroidal illness may promote vascular calcification through a systemic lowering of vascular calcification inhibitors such as matrix-gla protein (MGP and Klotho.In 97 ESRD patients eligible for living donor kidney transplantation, blood levels of thyroid hormones (fT3, fT4 and TSH, total uncarboxylated MGP (t-ucMGP, desphospho-uncarboxylated MGP (dp-ucMGP, descarboxyprothrombin (PIVKA-II, and soluble Klotho (sKlotho were measured. The degree of coronary calcification and arterial stiffness were assessed by means of cardiac CT-scans and applanation tonometry, respectively.fT3 levels were inversely associated with coronary artery calcification (CAC scores and measures of arterial stiffness, and positively with dp-ucMGP and sKlotho concentrations. Subfractions of MGP, PIVKA-II and sKlotho did not associate with CAC scores and arterial stiffness. fT4 and TSH levels were both inversely associated with CAC scores, but not with arterial stiffness.The positive associations between fT3 and dp-ucMGP and sKlotho suggest that synthesis of MGP and Klotho is influenced by thyroid hormones, and supports a link between non-thyroidal illness and alterations in calcification inhibitor levels. However, the absence of an association between serum calcification inhibitor levels and coronary calcification/arterial stiffness and the fact that MGP and Klotho undergo post-translational modifications underscore the complexity of this association. Further studies, measuring total levels of MGP and membrane bound Klotho, should examine this proposed pathway in further detail.

  5. Effects of age and caloric restriction in the vascular response of renal arteries to endothelin-1 in rats. (United States)

    Amor, Sara; García-Villalón, Angel Luis; Rubio, Carmen; Carrascosa, Jose Ma; Monge, Luis; Fernández, Nuria; Martín-Carro, Beatriz; Granado, Miriam


    Cardiovascular alterations are the most prevalent cause of impaired physiological function in aged individuals with kidney being one the most affected organs. Aging-induced alterations in renal circulation are associated with a decrease in endothelium-derived relaxing factors such as nitric oxide (NO) and with an increase in contracting factors such as endothelin-1(ET-1). As caloric restriction (CR) exerts beneficial effects preventing some of the aging-induced alterations in cardiovascular system, the aim of this study was to analyze the effects of age and caloric restriction in the vascular response of renal arteries to ET-1 in aged rats. Vascular function was studied in renal arteries from 3-month-old Wistar rats fed ad libitum (3m) and in renal arteries from 8-and 24-month-old Wistar rats fed ad libitum (8m and 24m), or subjected to 20% caloric restriction during their three last months of life (8m-CR and 24m-CR). The contractile response to ET-1 was increased in renal arteries from 8m and 24m compared to 3m rats. ET-1-induced contraction was mediated by ET-A receptors in all experimental groups and also by ET-B receptors in 24m rats. Caloric restriction attenuated the increased contraction to ET-1 in renal arteries from 8m but not from 24m rats possibly through NO release proceeding from ET-B endothelial receptors. In 24m rats, CR did not attenuate the aging-increased response of renal arteries to ET-1, but it prevented the aging-induced increase in iNOS mRNA levels and the aging-induced decrease in eNOS mRNA levels in arterial tissue. In conclusion, aging is associated with an increased response to ET-1 in renal arteries that is prevented by CR in 8m but not in 24m rats.

  6. ATP敏感钾通道调节血管张力的分子机制%KATP channel action in vascular tone regulation: from genetics to diseases

    Institute of Scientific and Technical Information of China (English)

    施巍巍; 杨洋; 石云; 姜淳


    ATP敏感钾通道(ATP-sensitive potassium channel,KATP通道)广泛分布在血管系统,并在血管张力调节中发挥重要作用.KATp通道由4个孔道形成的内向整流钾离子通道(inward rectifier K+ channels,Kir)亚基和4个磺脲受体调节亚基(sulfonylurea receptor,SUR)组成.尽管其它一些亚基在血管中也存在,Kir6.1/SUR2B是主要的血管亚型KATP通道.KATP通道转基因小鼠的研究以及人群中KATP通道基因突变的发现,都强烈支持KATP通道对于心血管系统的动态平衡调控是不可缺少的.大量的血管活性物质通过调节KATP通道活性来改变血管平滑肌细胞的膜电位,从而调节血管张力.多数内源性血管收缩物质,例如血管加压素,激活蛋白激酶C (protein kinase C,PKC),磷酸化KAP通道并抑制其活性;而血管扩张物质,如血管活性肠肽,通过增加cAMP的形成和提高蛋白激酶A(protein kinase A,PKA)的活性来增加KATP通道的活性.PKC作用于Kir6.1亚基C-末端,磷酸化4个保守的丝氨酸,而PKA磷酸化SUR2B亚基第2核苷酸结合域的Ser1387位点.血管KATP通道也受活性氧的调节,其中Kir6.1的Cys176是一个重要的过氧化物调节位点.此外,KATP通道功能可被一些慢性的病理生理条件上调,如感染性休克.核因子-κB依赖的基因转录是脂多糖诱导的血管KATP通道激活的一个机制.本综述将概括性描述血管KATP通道在生理和病理情况下受到的调节,以期阐明血管KATP通道在治疗和预防心血管疾病方面可能是一个有用的靶点.%ATP-sensitive potassium (KATP) channels are widely distributed in vasculatures,and play an important role in the vascular tone regulation.The KATP channels consist of 4 pore-forming inward rectifier K+ channel (Kir) subunits and 4 regulatory sulfonylurea receptors (SUR).The major vascular isoform of KATP channels is composed of Kir6.1/SUR2B,although low levels of other subunits are also present in vascular beds

  7. The Soluble Epoxide Hydrolase Inhibitor AR9281 Decreases Blood Pressure, Ameliorates Renal Injury and Improves Vascular Function in Hypertension

    Directory of Open Access Journals (Sweden)

    Sean Shaw


    Full Text Available Soluble epoxide hydrolase inhibitors (sEHIs are demonstrating promise as potential pharmaceutical agents for the treatment of cardiovascular disease, diabetes, inflammation, and kidney disease. The present study determined the ability of a first-inclass sEHI, AR9281, to decrease blood pressure, improve vascular function, and decrease renal inflammation and injury in angiotensin hypertension. Rats were infused with angiotensin and AR9281 was given orally during the 14-day infusion period. Systolic blood pressure averaged 180 ± 5 mmHg in vehicle treated and AR9281 treatment significantly lowered blood pressure to 142 ± 7 mmHg in angiotensin hypertension. Histological analysis demonstrated decreased injury to the juxtamedullary glomeruli. Renal expression of inflammatory genes was increased in angiotensin hypertension and two weeks of AR9281 treatment decreased this index of renal inflammation. Vascular function in angiotensin hypertension was also improved by AR9281 treatment. Decreased afferent arteriolar and mesenteric resistance endothelial dependent dilator responses were ameliorated by AR9281 treatment of angiotensin hypertensive rats. These data demonstrate that the first-in-class sEHI, AR9281, lowers blood pressure, improves vascular function and reduces renal damage in angiotensin hypertension.

  8. Barnidipine ameliorates the vascular and renal injury in L-NAME-induced hypertensive rats. (United States)

    Alp Yildirim, F Ilkay; Eker Kizilay, Deniz; Ergin, Bülent; Balci Ekmekçi, Özlem; Topal, Gökçe; Kucur, Mine; Demirci Tansel, Cihan; Uydeş Doğan, B Sönmez


    The present study was aimed to investigate the influence of Barnidipine treatment on early stage hypertension by determining the function and morphology of the mesenteric and renal arteries as well as the kidney in N(ω)-Nitro-L-Arginine Methyl Ester (L-NAME)-induced hypertensive rats. Barnidipine (3 mg/kg/day p.o) was applied to rats after 2 weeks of L-NAME (60 mg/kg/day) administration, and continued for the next 3 weeks concomitantly with L-NAME. The systolic blood pressure (SBP) of rats was determined to decrease significantly in Barnidipine treated hypertensive group when compared to that of rats received L-NAME alone. Myograph studies demonstrated that the contractile reactivity to noradrenaline were significantly reduced in both of the resistance arteries while endothelium-dependent relaxations to acethylcholine were significantly diminished particularly in the mesenteric arteries of L-NAME-induced hypertensive rats. The impaired contractile and endothelial responses were completely restored by concomitant treatment of Barnidipine with L-NAME. Histopathological examinations verified structural alterations in the arteries as well as the kidney. Moreover, a decrease in endothelial nitric oxide synthase (eNOS) expression was presented both in the arteries and kidney of hypertensive rats which were increased following Barnidipine treatment. Elevated plasma levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were also reduced in Barnidipine treated hypertensive rats. In conclusion, besides to its efficacy in reducing the elevated SBP, amelioration of vascular function, modulation of arterial and renal eNOS expressions as well as reduction of the plasma levels of oxidative and inflammatory biomarkers are possible supportive mechanisms mediating the favorable implications of Barnidipine in L-NAME-induced hypertension model.

  9. Effects of unfractionated heparin on renal osteodystrophy and vascular calcification in chronic kidney disease rats. (United States)

    Meng, Yan; Zhang, Hao; Li, Yingbin; Li, Qingnan; Zuo, Li


    Unfractionated heparin (UFH) is the most widely used anticoagulant in hemodialysis for chronic kidney disease (CKD) patients. Many studies have verified that UFH can induce bone loss in subjects with normal bone, but few have focused on its effect on renal osteodystrophy. We therefore investigated this issue in adenine-induced CKD rats. As CKD also impairs mineral metabolism systemically, we also studied the impacts of UFH on serum markers of CKD-mineral and bone disorder (CKD-MBD) and vascular calcification. We administered low and high doses of UFH (1U/g and 2U/g body weight, respectively) to CKD rats and compared them with CKD controls. At sacrifice, the serum markers of CKD-MBD did not significantly differ among the two UFH CKD groups and the CKD control group. The mean bone mineral densities (BMDs) of the total femur and a region of interest (ROI) constituted of trabecular and cortical bone were lower in the high-dose UFH (H-UFH) CKD group than in the CKD control group (P<0.05 and P<0.01, respectively). The BMD of the femoral ROI constituted of cortical bone did not differ between the H-UFH CKD group and the CKD control group. Histomorphometrical changes in the CKD rats indicated secondary hyperparathyroidism, and the femoral trabecular bone volume, but not cortical bone volume, significantly decreased with increasing UFH dose. The same decreasing trend was found in osteoblast parameters, and an increasing trend was found in osteoclast parameters; however, most differences were not significant. Moreover, no distinct statistical differences were found in the comparison of vascular calcium or phosphorus content among the CKD control group and the two UFH CKD groups. Therefore, we concluded that UFH could induce bone loss in CKD rats with secondary hyperparathyroidism, mainly by reducing the trabecular volume and had little effect on cortical bone volume. The underlying mechanism might involve inhibition of osteoblast activity and promotion of osteoclast activity

  10. Diabetic nephropathy and endothelial dysfunction: Current and future therapies, and emerging of vascular imaging for preclinical renal-kinetic study. (United States)

    Leung, Wilson Kc; Gao, L; Siu, Parco M; Lai, Christopher Wk


    An explosion in global epidemic of type 2 diabetes mellitus poses major rise in cases with vascular endothelial dysfunction ranging from micro- (retinopathy, nephropathy and neuropathy) to macro-vascular (atherosclerosis and cardiomyopathy) conditions. Functional destruction of endothelium is regarded as an early event that lays the groundwork for the development of renal microangiopathy and subsequent clinical manifestation of nephropathic symptoms. Recent research has shed some light on the molecular mechanisms of type 2 diabetes-associated comorbidity of endothelial dysfunction and nephropathy. Stemming from currently proposed endothelium-centered therapeutic strategies for diabetic nephropathy, this review highlighted some most exploited pathways that involve the intricate coordination of vasodilators, vasoconstrictors and vaso-modulatory molecules in the pathogenesis of diabetic nephropathy. We also emphasized the emerging roles of oxidative and epigenetic modifications of microvasculature as our prospective therapeutics for diabetic renal diseases. Finally, this review in particular addressed the potential use of multispectral optoacoustic tomography in real-time, minimally-invasive vascular imaging of small experimental animals for preclinical renal-kinetic drug trials.

  11. Human umbilical cord expresses several vasoactive peptides involved in the local regulation of vascular tone: protein and gene expression of Orphanin, Oxytocin, ANP, eNOS and iNOS

    Directory of Open Access Journals (Sweden)

    Aldo Gerbino


    Full Text Available Full-term human umbilical cord contains three blood vessels: two arteries coiled around a vein and surrounded by Wharton’s jelly, a mucous tissue with few mesenchymal stromal cells and abundant extracellular matrix. Umbilical vessels lack innervations, thus endothelial cells must play a role in the control of blood flow. The aim of this study was to investigate in human umbilical cord the expression of five peptides that could be involved in the regulation of vascular tone: Orphanin FQ, Oxytocin, Atrial Natriuretic Peptide (ANP, endothelial Nitric Oxide Synthase (eNOS and inducible Nitric Oxide Synthase (iNOS. The expression of these molecules in full-term human umbilical cord was investigated through immunohistochemistry and RT-PCR. Immunoreactivity for Orphanin FQ was detected in Wharton’s jelly, vessel musculature and endothelium; Oxytocin, ANP and eNOS were expressed by the umbilical epithelium, Wharton’s jelly and endothelium, whereas iNOS only by endothelial cells. RT-PCR analysis showed transcriptional expression of Oxytocin, ANP and eNOS mRNAs. The presence of Orphanin, Oxytocin, ANP, eNOS and iNOS proteins was identified in the human umbilical cord. mRNA expression for Oxytocin, ANP and eNOS suggest that these molecules are synthesized by umbilical cord cells themselves. The expression of these vasoactive molecules could be part of a general mechanism locally regulating vascular tone. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 211–218

  12. Rationale, design and baseline characteristics of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) : A randomized, placebo-controlled trial

    NARCIS (Netherlands)

    Neal, Bruce; Perkovic, Vlado; Matthews, David R.; Mahaffey, Kenneth W.; Fulcher, Greg; Meininger, Gary; Erondu, Ngozi; Desai, Mehul; Shaw, Wayne; Vercruysse, Frank; Yee, Jacqueline; Deng, Hsiaowei; de Zeeuw, Dick

    Aims: The primary aim of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) is to determine whether the favourable effects of inhibition of the sodium glucose co-transporter 2 (SGLT2) on blood glucose, blood pressure and body weight are accompanied by protection against adverse renal

  13. Adrenomedullin Is Associated With Surgical Trauma and Impaired Renal Function in Vascular Surgery Patients. (United States)

    Gillmann, Hans-Jörg; Meinders, Antje; Larmann, Jan; Sahlmann, Bianca; Schrimpf, Claudia; Aper, Thomas; Lichtinghagen, Ralf; Teebken, Omke E; Theilmeier, Gregor


    Patients undergoing vascular surgery are prone to perioperative organ injury because of both higher prevalence of cardiovascular risk factors and the extent of surgery. Early detection of organ failure is essential to facilitate appropriate medical care. Midregional pro-adrenomedullin (MR-proADM) has been investigated in acute medical care settings to guide clinical decision-making regarding patient pathways and to identify patients prone to imminent cardiovascular or inflammatory complications. In this study, we evaluated the impact of perioperative MR-proADM levels as an early marker of perioperative cardiovascular and inflammatory stress reactions and kidney injury. The study was conducted as a monocentric, prospective, noninterventional trial at Hannover Medical School, Germany. A total of 454 consecutive patients who underwent open vascular surgery were followed from the day prior to until 30 days after surgery. The composite primary end point was defined as the occurrence of major adverse cardiac events (MACEs), acute kidney injury (AKI), or systemic inflammatory response syndrome (SIRS). Measurements were correlated with both medical history and postoperative MACE, AKI, or SIRS using univariate and multivariate regression analysis. One hundred thirty-nine (31%) of the patients reached the primary end point within the study interval. Midregional pro-adrenomedullin change was associated with the combined primary end point and with the intensity of surgical trauma. Midregional pro-adrenomedullin change was increased in patients reaching the secondary end points, SIRS (optimal cutoff: 0.2 nmol/L) and AKI (optimal cutoff: 0.7 nmol/L), but not in patients with MACEs. Increased levels of MR-proADM within the perioperative setting (1) were linked to the invasiveness of surgery and (2) identified patients with ongoing loss of renal function. Increased MR-proADM levels may therefore identify a subgroup of patients prone to excessive cardiovascular stress but did not

  14. Niflumic Acid Attenuated Pulmonary Artery Tone and Vascular Structural Remodeling of Pulmonary Arterial Hypertension Induced by High Pulmonary Blood Flow In Vivo. (United States)

    Wang, Kai; Ma, Jianfa; Pang, Yusheng; Lao, Jinquan; Pan, Xuanren; Tang, Qiaoyun; Zhang, Feng; Su, Danyan; Qin, Suyuan; Shrestha, Arnav Prasad


    Calcium-activated chloride channels (CaCCs) play a vital role in regulating pulmonary artery tone during pulmonary arterial hypertension (PAH) induced by high blood flow. The role of CaCCs inhibitor niflumic acid (NFA) in vivo during this process requires further investigation. We established the PAH model by abdominal shunt surgery and treated with NFA in vivo. Fifty rats were randomly divided into normal, sham, shunt, NFA group 1 (0.2 mg/kg), and NFA group 2 (0.4 mg/kg). Pathological changes, right ventricle hypertrophy index, arterial wall area/vessel area, and arterial wall thickness/vessel external diameter were analyzed. Then contraction reactions of pulmonary arteries were measured. Finally, the electrophysiological characteristics of pulmonary arterial smooth muscle cells were investigated using patch-clamp technology. After 11 weeks of shunting, PAH developed, accompanied with increased right ventricle hypertrophy index, arterial wall area/vessel area, and arterial wall thickness/vessel external diameter. In the NFA treatment groups, the pressure and pathological changes were alleviated. The pulmonary artery tone in the shunt group increased, whereas it decreased after NFA treatment. The current density of CaCC was higher in the shunt group, and it was decreased in the NFA treatment groups. In conclusion, NFA attenuated pulmonary artery tone and structural remodeling in PAH induced by high pulmonary blood flow in vivo. CaCCs were involved and the augmented current density was alleviated by NFA treatment.

  15. Vascular calcification is associated with cortical bone loss in chronic renal failure rats with and without ovariectomy: the calcification paradox. (United States)

    De Schutter, Tineke M; Neven, Ellen; Persy, Veerle P; Behets, Geert J; Postnov, Andrei A; De Clerck, Nora M; D'Haese, Patrick C


    Increased bone loss has been associated with the development of vascular calcification in patients with chronic renal failure (CRF). In this study, the effect of impaired bone metabolism on aortic calcifications was investigated in uremic rats with or without ovariectomy. CRF was induced by administration of a 0.75% adenine/2.5% protein diet for 4 weeks. In one group, osteoporosis was induced by ovariectomy (CRF-OVX), while the other group underwent a sham-operation instead (CRF). A third group consisted of ovariectomized rats with normal renal function (OVX). At regular time intervals throughout the study, bone status and aortic calcifications were evaluated by in vivo micro-CT. At sacrifice after 6 weeks of CRF, bone histomorphometry was performed and vascular calcification was assessed by bulk calcium analysis and Von Kossa staining. Renal function was significantly impaired in the CRF-OVX and CRF groups. Trabecular bone loss was seen in all groups. In the CRF-OVX and CRF groups, trabecular bone density was restored after adenine withdrawal, which coincided with cortical bone loss and the development of medial calcifications in the aorta. No significant differences with regard to the degree of aortic calcifications were seen between the two CRF groups. Neither cortical bone loss nor calcifications were seen in the OVX group. Cortical bone loss significantly correlated with the severity of vascular calcification in the CRF-OVX and CRF groups, but no associations with trabecular bone changes were found. Cortical rather than trabecular bone loss is associated with the process of calcification in rats with adenine- induced CRF. Copyright © 2011 S. Karger AG, Basel.

  16. Dynamic Contrast-Enhanced Magnetic Resonance Imaging of Vascular Changes Induced by Sunitinib in Papillary Renal Cell Carcinoma Xenograft Tumors

    Directory of Open Access Journals (Sweden)

    Gilda G. Hillman


    Full Text Available To investigate further the antiangiogenic potential of sunitinib for renal cell carcinoma (RCC treatment, its effects on tumor vasculature were monitored by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI using an orthotopic KCI-18 model of human RCC xenografts in nude mice. Tumor-bearing mice were treated with various doses of sunitinib, and vascular changes were assessed by DCE-MRI and histologic studies. Sunitinib induced dose-dependent vascular changes, which were observed both in kidney tumors and in normal kidneys by DCE-MRI. A dosage of 10 mg/kg per day caused mild changes in Gd uptake and clearance kinetics in kidney tumors. A dosage of 40 mg/kg per day induced increased vascular tumor permeability with Gd retention, probably resulting from the destruction of tumor vasculature, and also caused vascular alterations of normal vessels. However, sunitinib at 20 mg/kg per day caused increased tumor perfusion and decreased vascular permeability associated with thinning and regularization of tumor vessels while mildly affecting normal vessels as confirmed by histologic diagnosis. Alterations in tumor vasculature resulted in a significant inhibition of KCI-18 RCC tumor growth at sunitinib dosages of 20 and 40 mg/kg per day. Sunitinib also exerted a direct cytotoxic effect in KCI-18 cells in vitro. KCI-18 cells and tumors expressed vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor β molecular targets of sunitinib that were modulated by the drug treatment. These data suggest that a sunitinib dosage of 20 mg/kg per day, which inhibits RCC tumor growth and regularizes tumor vessels with milder effects on normal vessels, could be used to improve blood flow for combination with chemotherapy. These studies emphasize the clinical potential of DCE-MRI in selecting the dose and schedule of antiangiogenic compounds.

  17. [Long-term development of Permacath Quinton catheters used as a vascular access route for extra-renal detoxification]. (United States)

    Dupont, D; Morinière, P; Pourchez, T; el Esper, N; Fournier, A


    Between July 1984 and July 1991, we have inserted surgically 147 Permcath Quinton catheters in 126 uremic patients for the following reasons: group I: necessity of hemodialysis without vascular access for acute (group Ia: 44 patients) or chronic renal failure (group Ib: 11 patients); group II: difficulty of creation or loss of vascular access (group II: 45 patients); group III: hemodialysis for patients with short life expectation or contraindications for vascular access on their limbs (group III: 26 patients). The duration of use (+/- SD and range) were respectively for each group: 1.6 +/- 2 (0-10); 3.4 +/- 2.8 (1-11); 7.4 +/- 11 (0-50); 6.7 +/- 8.7 (0.1-34.5) months. Seventeen patients (group IV) coming from groups Ib and II preferred to go on with the use of their catheter for 10.5 +/- 13.5 (0.1-50) months rather than to use their arteriovenous fistula. The complications observed on whole population were: 11 septicemia responsible of 2 deaths, 9 cutaneous local infections, 28 total obstructions of the catheter, 17 partial obstructions with insufficient flow; 10 destructions of the catheter. In conclusion the Permcath Quinton catheter is an adequate long term vascular access for hemodialysis. It is well tolerated since it is preferred to the usual arteriovenous fistula by many patients who have both. The incidence of infection is low. However, obstruction (partial ou total) is frequent (29%), necessitating local fibrinolytic treatment.

  18. 移植肾血栓超声诊断分析%Diagnosis of renal allograft vascular thrombosis by ultrasound

    Institute of Scientific and Technical Information of China (English)

    俞能旺; 张爱民; 孟建中; 郝俊文; 刘毅; 刘贞; 李香铁


    Objective To investigate the specificity of ultrasound in the diagnosis of renal allograft vascular thrombosis. Methods The ultrasound data of 22 patients,from out of 1517 renal transplants from Jan. 1996 to Mar. 2011 in our hospitals, with renal allograft vascular thrombosis diagnosed by ultrasound within 1 year after renal allograft transplantation were retrospectively studied . Results Among the 22 patients,4 patients were diagnosed as renal allograft artery thrombosis by ultrasound , of which 3 were confirmed by surgery and pathology but the other one was misdiagnosed . One patient was diagnosed as inferior renal artery thrombosis and confirmed by surgery thereafter. Four of 8 ultrasound-diagnosed renal vein thrombosis were confirmed ,but 2 of the other 4 patients were proved to be acute rejection by pathology , while the other 2 were proved as misdiagnosis by surgery or other clinical manifestation . As for 9 patients of ultrasound-diagnosed renal vein partial thrombosis , 1 and 3 patients were proved to be misdiagnosis by surgery and clinical manifestation respectively , while the other 5 patients showed no sign of thrombosis on ultrasonography after thrombolytic therapy. Conclusion Ultrasound has a high specificity to diagnose renal allograft artery thrombosis, while a low specificity to diagnose renal allograft vein thrombosis .%目的 探讨超声诊断移植肾血栓的特异度.方法 回顾分析我院1996年1月至2011年3月1517例肾移植术患者中术后1年内超声诊断为移植肾血栓的22例患者超声检查资料,并与磁共振血管造影、CT血管造影、手术探查及术后病理结果比较.结果 22例超声诊断为移植肾血栓的患者中,超声诊断为移植肾主动脉血栓4例,其中3例经手术探查及术后病理证实,另1例手术发现超声检查误诊.超声诊断为移植肾下极血栓1例,经手术探查证实.超声诊断为移植肾主肾静脉血栓8例,其中4例经手术探查和术后病理证实,2例

  19. Vascular smooth muscle G(q) signaling is involved in high blood pressure in both induced renal and genetic vascular smooth muscle-derived models of hypertension. (United States)

    Harris, David M; Cohn, Heather I; Pesant, Stéphanie; Zhou, Rui-Hai; Eckhart, Andrea D


    More than 30% of the US population has high blood pressure (BP), and less than a third of people treated for hypertension have it controlled. In addition, the etiology of most high BP is not known. Having a better understanding of the mechanisms underlying hypertension could potentially increase the effectiveness of treatment. Because G(q) signaling mediates vasoconstriction and vascular function can cause BP abnormalities, we were interested in determining the role of vascular smooth muscle (VSM) G(q) signaling in two divergent models of hypertension: a renovascular model of hypertension through renal artery stenosis and a genetic model of hypertension using mice with VSM-derived high BP. Inhibition of VSM G(q) signaling attenuated BP increases induced by renal artery stenosis to a similar extent as losartan, an ANG II receptor blocker and current antihypertensive therapy. Inhibition of G(q) signaling also attenuated high BP in our genetic VSM-derived hypertensive model. In contrast, BP remained elevated 25% following treatment with losartan, and prazosin, an alpha(1)-adrenergic receptor antagonist, only decreased BP by 35%. Inhibition of G(q) signaling attenuated VSM reactivity to ANG II and resulted in a 2.4-fold rightward shift in EC(50). We also determined that inhibition of G(q) signaling was able to reverse VSM hypertrophy in the genetic VSM-derived hypertensive model. These results suggest that G(q) signaling is an important signaling pathway in two divergent models of hypertension and, perhaps, optimization of antihypertensive therapy could occur with the identification of particular G(q)-coupled receptors involved.

  20. Pre-diabetes augments neuropeptide Y1- and α1-receptor control of basal hindlimb vascular tone in young ZDF rats.

    Directory of Open Access Journals (Sweden)

    Nicole M Novielli

    Full Text Available BACKGROUND: Peripheral vascular disease in pre-diabetes may involve altered sympathetically-mediated vascular control. Thus, we investigated if pre-diabetes modifies baseline sympathetic Y(1-receptor (Y(1R and α(1-receptor (α(1R control of hindlimb blood flow (Q(fem and vascular conductance (VC. METHODS: Q(fem and VC were measured in pre-diabetic ZDF rats (PD and lean controls (CTRL under infusion of BIBP3226 (Y(1R antagonist, prazosin (α(1R antagonist and BIBP3226+prazosin. Neuropeptide Y (NPY concentration and Y(1R and α(1R expression were determined from hindlimb skeletal muscle samples. RESULTS: Baseline Q(fem and VC were similar between groups. Independent infusions of BIBP3226 and prazosin led to increases in Q(fem and VC in CTRL and PD, where responses were greater in PD (p<0.05. The percent change in VC following both drugs was also greater in PD compared to CTRL (p<0.05. As well, Q(fem and VC responses to combined blockade (BIBP3226+prazosin were greater in PD compared to CTRL (p<0.05. Interestingly, an absence of synergistic effects was observed within groups, as the sum of the VC responses to independent drug infusions was similar to responses following combined blockade. Finally, white and red vastus skeletal muscle NPY concentration, Y(1R expression and α(1R expression were greater in PD compared to CTRL. CONCLUSIONS: For the first time, we report heightened baseline Y(1R and α(1R sympathetic control of Q(fem and VC in pre-diabetic ZDF rats. In support, our data suggest that augmented sympathetic ligand and receptor expression in pre-diabetes may contribute to vascular dysregulation.

  1. Renal hemodynamic and neurohumoral responses to urapidil in hypertensive man

    Energy Technology Data Exchange (ETDEWEB)

    de Leeuw, P.W.; van Es, P.N.; de Bruyn, H.A.; Birkenhaeger, W.H.D.


    In order to evaluate the acute effects of urapidil on renal vascular tone and on pressor systems we performed a randomized placebo-controlled crossover study in 8 patients with uncomplicated essential hypertension. Each subject received, on two separate days one week apart, an intravenous injection of either placebo or urapidil (25 mg, to be increased to 50 mg if blood pressure did not fall within 5 minutes). Before and following this injection we measured blood pressure and heart rate (Dinamap), renal plasma flow (/sup 125/I-hippuran), renin, angiotensin II, aldosterone, and catecholamines. The results show that urapidil, when compared to placebo, significantly reduced blood pressure, while increasing heart rate, renal blood flow, noradrenaline and adrenaline. Dopamine levels, on the other hand, were suppressed. While renin and angiotensin II were only mildly stimulated, aldosterone levels increased markedly. It is concluded that urapidil, given intravenously, has an immediate blood pressure lowering effect associated with a fall in renal vascular tone and an increase in renal perfusion. As a consequence both the sympathetic system and the renin-angiotensin system are stimulated, although the latter only to a mild degree. The rise in aldosterone may be related to withdrawal of dopaminergic tone.

  2. Distribution of Vascular Patterns in Different Subtypes of Renal Cell Carcinoma. A Morphometric Study in Two Distinct Types of Blood Vessels. (United States)

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


    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.

  3. Vascular endothelial cell function and cardiovascular risk factors in patients with chronic renal failure

    DEFF Research Database (Denmark)

    Haaber, A B; Eidemak, I; Jensen, T


    Cardiovascular risk factors and markers of endothelial cell function were studied in nondiabetic patients with mild to moderate chronic renal failure. The transcapillary escape rate of albumin and the plasma concentrations of von Willebrand factor, fibrinogen, and plasma lipids were measured in 29...

  4. Bone morphogenetic protein activity and connective tissue growth factor in renal and vascular disease

    NARCIS (Netherlands)

    Leeuwis, J.W.


    Response to renal injury is dependent on growth factors that determine how resident cells act, which cells are attracted to the site of injury, and how these resident cells, together with infiltrating cells and their surrounding matrix act together. These mechanisms are not confined to the kidney an

  5. Effect of Danshen injection on the vascular endothelial function and renal function in patients with pregnancy induced hypertension syndrome

    Institute of Scientific and Technical Information of China (English)

    Jun-Qing Zhang; Wei Gao


    Objective:To explore the effect of Danshen injection on the vascular endothelial function and renal function in patients with pregnancy induced hypertension syndrome (PIH). Methods:A total of 100 patients with PIH who were admitted in our hospital from May, 2015 to May, 2016 were included in the study and randomized into the observation group and the control group. The patients in the control group were given blood pressure reduction, diuresis, spasmolysis, sedation, magnesium sulfate, and comprehensive nursing intervention. On this basis, the patients in the observation group were given additional Danshen injection (20 mL) + 5% glucose (250 mL), ivdrip, 1 time/d. After 10 d treatment, the efficacy was evaluated. The peripheral venous blood before and after treatment in the two groups was collected. The radioimmunoassay was used to detect ET-1. ELISA was used to detect Hcy. The immunoturbidimetry was used to detect vWF. The radioimmunoassay was used to detect BUN, Scr, UA, andβ2-MG. The standard sphygmomanometer was used to monitor the blood pressure and MAP was calculated. The biuret colorimetry was used to determine 24 h Upro. Results:The reduced degree of ET-1, Hcy, and vWF after treatment in the observation group was significantly superior to that in the control group. The reduced degree of BUN, Scr, UA, andβ2-MG after treatment in the observation group was significantly superior to that in the control group. The reduced degree of MPA and 24 h Upro after treatment in the observation group was significantly superior to that in the control group.Conclusions:Routine treatments, comprehensive nursing intervention, and Danshen injection in the treatment of PIH can effectively improve the vascular endothelial function and renal function in order to reduce the blood pressure and alleviate the urine protein.

  6. Renal Denervation Attenuates Multi-Organ Fibrosis and Improves Vascular Remodeling in Rats with Transverse Aortic Constriction Induced Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Kai Wang


    Full Text Available Background/Aims: To investigate the effects of renal denervation (RDN on multi-organ fibrosis and vascular remodeling in cardiomyopathy. Methods: Thirty-six male Sprague-Dawley rats underwent transverse aortic constriction (TAC. Five weeks later, 28 surviving TAC rats were randomly assigned to three groups: (1 RDN, (2 Sham, (3 Carvedilol. Six male Sham TAC rats served as the Control. Ten weeks after TAC, samples were collected. Results: TAC rats showed an increased diastolic interventricular septal thickness at week 5. At 10 weeks, Masson staining showed that left ventricular and renal glomerular fibrosis were significantly reduced in RDN compared with Sham group. In comparison to Sham group, hepatic perivascular fibrosis was attenuated in both RDN and Carvedilol group, so were the media thickness and the media/lumen of aorta. The plasma levels of B-type natriuretic peptide (BNP, Cystatin C (Cys-C, Alanine Transaminase, angiotensin II (Ang II, transforming growth factor beta 1 (TGF-β1, and malondialdehyde increased, and total superoxide dismutase (T-SOD decreased in Sham but not in RDN group, compared with Control group. Both RDN and Carvedilol reduced the Cys-C and TGF-β1 levels, and restored T-SOD concentration, compared with Sham group. While only RDN lowered the plasma levels of BNP and Ang II. No significant effects of RDN on blood pressure (BP and heart rate (HR were oberved. Conclusions: RDN can attenuate multi-organ fibrosis and improve vascular remodeling independent of BP and HR change in TAC-induced cardiomyopathy. These effects of RDN may be associated with the direct inhibition of renin-angiotensin-aldosterone system and oxidative stress.

  7. Effects of tempol on altered metabolism and renal vascular responsiveness in fructose-fed rats. (United States)

    Abdulla, Mohammed H; Sattar, Munavvar A; Johns, Edward J


    This study investigated the effect of tempol (a superoxide dismutase mimetic) on renal vasoconstrictor responses to angiotensin II (Ang II) and adrenergic agonists in fructose-fed Sprague-Dawley rats (a model of metabolic syndrome). Rats were fed 20% fructose in drinking water (F) for 8 weeks. One fructose-fed group received tempol (FT) at 1 mmol·L(-1) in drinking water for 8 weeks or as an infusion (1.5 mg·kg(-1)·min(-1)) intrarenally. At the end of the treatment regimen, the renal responses to noradrenaline, phenylephrine, methoxamine, and Ang II were determined. F rats exhibited hyperinsulinemia, hyperuricemia, hypertriglyceridemia, and hypertension. Tempol reduced blood glucose and insulin levels (all p fructose-fed rats.

  8. The relationship between neutrophil-to-lymphocyte ratio and vascular calcification in end-stage renal disease patients. (United States)

    Turkmen, Kultigin; Ozcicek, Fatih; Ozcicek, Adalet; Akbas, Emin Murat; Erdur, Fatih Mehmet; Tonbul, Halil Zeki


    Chronic inflammation was found to be correlated with coronary (CAC) and thoracic peri-aortic calcification (TAC) in end-stage renal disease (ESRD) patients. Neutrophil-to-lymphocyte ratio (NLR) was introduced as a potential marker to determine inflammation in cardiac and noncardiac disorders. Data regarding NLR and its association with TAC and CAC are lacking. We aimed to determine the relationship between NLR and vascular calcification in ESRD patients. This was a cross-sectional study involving 56 ESRD patients (22 females, 34 males; mean age, 49.9 ± 14.2 years) receiving peritoneal dialysis or hemodialysis for ≥6 months in the Dialysis Unit of Necmettin Erbakan University. TAC and CAC scores were measured by using an electrocardiogram-gated 64-multidetector computed tomography. NLR was calculated as the ratio of the neutrophils and lymphocytes. There was a statistically significant correlation between NLR, TACS and CACS in ESRD patients (r = 0.43, P = 0.001 and r = 0.30, P = 0.02, respectively). The stepwise linear regression analysis revealed that age, as well as NLR were independent predictors of TACS. However, increased age was the only independent predictor of CACS according to linear regression analysis. Simple calculation of NLR can predict vascular calcification in ESRD patients.

  9. Erythropoietin resistance in end-stage renal disease patient with gastric antral vascular ectasia

    Directory of Open Access Journals (Sweden)

    Desiree Ji Re Lee


    Full Text Available AbstractWe observed a case of recombinant human erythropoietin resistance caused by Gastric Antral Vascular Ectasia in a 40-year-old female with ESRD on hemodialysis. Some associated factors such as autoimmune disease, hemolysis, heart and liver disease were discarded on physical examination and complementary tests. The diagnosis is based on the clinical history and endoscopic appearance of watermelon stomach. The histologic findings are fibromuscular proliferation and capillary ectasia with microvascular thrombosis of the lamina propria. However, these histologic findings are not necessary to confirm the diagnosis. Gastric Antral Vascular Ectasia is a serious condition and should be considered in ESRD patients on hemodialysis with anemia and resistance to recombinant human erythropoietin because GAVE is potentially curable with specific endoscopic treatment method or through surgical procedure.

  10. Recovery of renal function after administration of adipose-tissue-derived stromal vascular fraction in rat model of acute kidney injury induced by ischemia/reperfusion injury. (United States)

    Lee, Chunwoo; Jang, Myoung Jin; Kim, Bo Hyun; Park, Jin Young; You, Dalsan; Jeong, In Gab; Hong, Jun Hyuk; Kim, Choung-Soo


    Acute kidney injury (AKI) induced by ischemia/reperfusion (I/R) injury is a major challenge in critical care medicine. The purpose of this study is to determine the therapeutic effects of the adipose-tissue-derived stromal vascular fraction (SVF) and the optimal route for SVF delivery in a rat model of AKI induced by I/R injury. Fifty male Sprague-Dawley rats were randomly divided into five groups (10 animals per group): sham, nephrectomy control, I/R injury control, renal arterial SVF infusion and subcapsular SVF injection. To induce AKI by I/R injury, the left renal artery was clamped with a nontraumatic vascular clamp for 40 min, and the right kidney was removed. Rats receiving renal arterial infusion of SVF had a significantly reduced increase in serum creatinine compared with the I/R injury control group at 4 days after I/R injury. The glomerular filtration rate of the renal arterial SVF infusion group was maintained at a level similar to that of the sham and nephrectomy control groups at 14 days after I/R injury. Masson's trichrome staining showed significantly less fibrosis in the renal arterial SVF infusion group compared with that in the I/R injury control group in the outer stripe (P renal arterial SVF infusion and subcapsular SVF injection groups compared with the I/R injury control group in the outer stripe (P renal function is effectively rescued from AKI induced by I/R injury through the renal arterial administration of SVF in a rat model.

  11. Increased diuresis, renal vascular reactivity, and blood pressure levels in young rats fed high sodium, moderately high fructose, or their association: a comparative evaluation. (United States)

    Da Silva, Rita de Cássia Vilhena A F; de Souza, Priscila; da Silva-Santos, José Eduardo


    Excessive intakes of sodium or fructose have been described as risk factors for hypertension. We hypothesized that even a moderately high fructose diet (6% fructose), either alone or in combination with high sodium (4% NaCl), may impair diuresis and renal and systemic vascular reactivity, contributing to the onset of high blood pressure in rats. Male Wistar rats were fed chow containing 4% NaCl (HS), 6% fructose (MHF), or both 4% NaCl and 6% fructose (HSMHF) for 6 weeks and had their diuresis, plasma creatinine, vascular reactivity of perfused kidneys and systemic arterial pressure evaluated. We found no differences in augmented diuresis among animals given HS, MHF, or HSMHF diets. After 6 weeks both the HS and HSMHF groups had increased weight in their left kidneys, but only the HSMHF group showed augmented plasma creatinine. The effects of phenylephrine on renal vascular perfusion pressure were similarly enhanced in kidneys from the HS, MHF, and HSMHF groups, but not on the systemic arterial pressure. Although when evaluated in anesthetized rats, only the HSMHF group presented augmented blood pressure, evaluation in conscious animals revealed that both the MHF and HSMHF diets, but not the HS alone, were able to induce tachycardia and hypertension. In conclusion, a MHF diet containing 6% fructose was enough to render the renal vascular bed hyperreactive to phenylephrine and to induce both hypertension and tachycardia. The combination of 6% fructose with 4% NaCl led to plasma accumulation of creatinine and accelerated the development of tachycardia.

  12. Effects of chloride channel blockers on rat renal vascular responses to angiotensin II and norepinephrine

    DEFF Research Database (Denmark)

    Steendahl, Joen; Sørensen, Charlotte Mehlin; Salomonsson, Max;


    preglomerular vessels caused a prompt increase in [Ca2+]i. Renal preinfusion of DIDS (0.6 and 1.25 micromol/min) attenuated the ANG II-induced vasoconstriction to approximately 35% of the control response, whereas the effects of NE were unaltered. Niflumic acid (0.14 and 0.28 micromol/min) and 2......-[(2-cyclopentenyl-6,7-dichloro-2,3-dihydro-2-methyl-1-oxo-1H-inden-5-yl)oxy]acetic acid (IAA-94; 0.045 and 0.09 micromol/min) did not affect the vasoconstrictive responses of these compounds. Pretreatment with niflumic acid (50 microM) or IAA-94 (30 microM) for 2 min decreased baseline [Ca2+]i but did not change...

  13. Occurrence of vascular IgA deposits in clinically normal skin of patients with renal disease. (United States)

    Faille-Kuyper, E H; Kater, L; Kuijten, R H; Kooiker, C J; Wagenaar, S S; van der Zouwen, P; Mees, E J


    Skin and kidney biopsies were performed on 262 patients with various nephropathies. In 45 skin biopsy specimens finely granular deposits of predominantly IgA and late-acting complement factors were detected in the walls of superficial capillaries, sometimes concomitantly with IgM, IgG, C4 or a combination of these proteins. Twelve of the 45 patients presented with anaphylactoid purpura and the majority of the other 33 patients had either recurrent macroscopic or microscopic hematuria. The renal lesions in 32 of these 45 patients consisted of focal segmental intracapillary proliferation. In 35 the kidney biopsy specimen showed mesangial deposits of IgA; in one case IgA was deposited along the glomerular basement membrane. In only three of the remaining 217 patients without cutaneous IgA deposits were typical mesangial IgA deposits found. The close correlation between IgA deposits in cutaneous vessels and focal segmental intracapillary proliferation with mesangial IgA deposits suggests that immunofluorescence examination of skin biopsy specimens could prove of diagnostic value. The results provide additional evidence for a close pathogenic relationship between IgA-associated glomerulonephritis and anaphylactoid purpura.

  14. Renal and vascular studies of aqueous extract of Urtica dioica in rats and rabbits

    Directory of Open Access Journals (Sweden)

    K.F. Dizaye


    Full Text Available Urtica dioica has a variety of uses in traditional medicine for genitourinary ailments kidney disorders, allergies, diabetes, anemia, gastrointestinal tract ailments, musculoskeletal aches and alopecia. However, only a few of these uses have scientific bases that support their clinical uses. This study was done to evaluate some of the in vivo and in vitro pharmacological actions of this plant. Eighteen local domestic rabbits (Oryctolagus cuniculus were used for in vitro studies (effect of the plant extract on isolated pulmonary arteries and isolated urinary bladder smooth muscle and in vivo studies (effect of the extract on renal function. Six male albino rats were used for studying the effects of the plant extract on blood pressure and heart rate. Urtica dioica extract produced a significant increase in urine volume and urinary Na+ excretion without significant changes in K+ excretion rates in experimental rabbits. No changes occurred in Glomerular filtration rate and %Na+ reabsorption of filtered load. Neither vasodilatation nor vasoconstriction of isolated pulmonary arteries of the rabbit was seen after applying the aqueous extract of U. dioica. Besides it could not reverse the vasoconstrictor effect of phenylephrine. Urtica dioica has no detectable effects on the isolated bladder; moreover it did not reverse the contraction that was produced by pilocarpine. In experimental rats, the plant extract produced a profound drop in blood pressure associated with decreased heart rate. In conclusion the aqueous extract of U. dioica produced diuretic and natriuretic effects with out significant effect on the K+ excretion rate in rabbits. Moreover it produced a profound drop in blood pressure and heart rate.

  15. Papel del tejido perivascular en la regulación del tono vascular: repercusión en el uso de puentes aorto-coronarios para revascularización miocárdica Role of perivascular tissue in vascular tone regulation: repercussion in the use of aortocoronary bypass for myocardial revascularization

    Directory of Open Access Journals (Sweden)

    Patricio López-Jaramillo

    patients with severe coronary disease. The lifespan of these grafts has shown to be longer with arterial tissue even though its use is limited by its restricted availability. This is why the saphenous vein bypasses, although having a greater risk of presenting occlusion, are the most used in these procedures of myocardial reperfusion. The reasons by which the venous grafts are occluded after its insertion in the arterial site are still not clear; nevertheless, it has been proposed that it could be due to different factors such as: surgical mechanical trauma, increment of arterial pressure and diminished friction stress. In 1996 the «no-touch» preparation technique of venous grafts was described, in which the venous bypasses were implanted in the coronary site along with the surrounding perivascular tissue and demonstrated to improve the lifespan of this type of grafts. Recently it has been proposed that the perivascular fat tissue could play a role in the vascular tone regulation and it has been even described the existence of an adipose cell derived relaxing factor (ADRF, whose nature has not been completely cleared yet. The objective of this article is to review the different factors related to the aortocoronary grafts’ occlusion, the possible physiopathologic channels that form this phenomenon, the new surgical alternatives used for vein grafts preparation and the advances in the description of ADRF and its role in vascular tone regulation.

  16. Propeller tone bursts (United States)

    Succi, G. P.; Munro, D. H.; Ingard, K. U.


    Intense high frequency (25-38 kHz) tone bursts have been observed in acoustic tests of a scale model of a general aviation propeller. The amplitude of the tone burst is approximately equal to the amplitude of the propeller noise signature. The conditions necessary for the production of these tone bursts are described. The experiments indicate that the origin of these bursts is a periodic flow oscillation on the suction surface of the propeller blade tips which may be due to the interaction between an oscillating shock wave and a laminar boundary layer.

  17. Urinary potassium excretion and risk of developing hypertension: the prevention of renal and vascular end-stage disease study. (United States)

    Kieneker, Lyanne M; Gansevoort, Ron T; Mukamal, Kenneth J; de Boer, Rudolf A; Navis, Gerjan; Bakker, Stephan J L; Joosten, Michel M


    Previous prospective cohort studies on the association between potassium intake and risk of hypertension have almost exclusively relied on self-reported dietary data, whereas repeated 24-hour urine excretions, as estimate of dietary uptake, may provide a more objective and quantitative estimate of this association. Risk of hypertension (defined as blood pressure ≥140/90 mm Hg or initiation of blood pressure-lowering drugs) was prospectively studied in 5511 normotensive subjects aged 28 to 75 years not using blood pressure-lowering drugs at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Potassium excretion was measured in two 24-hour urine specimens at baseline (1997-1998) and midway during follow-up (2001-2003). Baseline median potassium excretion was 70 mmol/24 h (interquartile range, 57-85 mmol/24 h), which corresponds to a dietary potassium intake of ≈91 mmol/24 h. During a median follow-up of 7.6 years (interquartile range, 5.0-9.3 years), 1172 subjects developed hypertension. The lowest sex-specific tertile of potassium excretion (men: hypertension after multivariable adjustment (hazard ratio, 1.20; 95% confidence interval, 1.05-1.37), compared with the upper 2 tertiles (Pnonlinearity=0.008). The proportion of hypertension attributable to low potassium excretion was 6.2% (95% confidence interval, 1.7%-10.9%). No association was found between the sodium to potassium excretion ratio and risk of hypertension after multivariable adjustment. Low urinary potassium excretion was associated with an increased risk of developing hypertension. Dietary strategies to increase potassium intake to the recommended level of 90 mmol/d may have the potential to reduce the incidence of hypertension.

  18. Using online tone generators (United States)


    Online tone generators are free, user friendly, and can make for engaging and meaningful study of many topics in the areas of interference, waves, and the physics of music. By using a website such as, and through opening multiple windows simultaneously, students can immediately perform several experiments. In this article, I highlight five lesson ideas that come naturally from these types of websites.

  19. Knockdown of parathyroid hormone related protein in smooth muscle cells alters renal hemodynamics but not blood pressure. (United States)

    Raison, Denis; Coquard, Catherine; Hochane, Mazène; Steger, Jacques; Massfelder, Thierry; Moulin, Bruno; Karaplis, Andrew C; Metzger, Daniel; Chambon, Pierre; Helwig, Jean-Jacques; Barthelmebs, Mariette


    Parathyroid hormone-related protein (PTHrP) belongs to vasoactive factors that regulate blood pressure and renal hemodynamics both by reducing vascular tone and raising renin release. PTHrP is expressed in systemic and renal vasculature. Here, we wanted to assess the contribution of vascular smooth muscle cell endogenous PTHrP to the regulation of cardiovascular and renal functions. We generated a mouse strain (SMA-CreERT2/PTHrPL2/L2 or premutant PTHrPSM-/-), which allows temporally controlled, smooth muscle-targeted PTHrP knockdown in adult mice. Tamoxifen treatment induced efficient recombination of PTHrP-floxed alleles and decreased PTHrP expression in vascular and visceral smooth muscle cells of PTHrPSM-/- mice. Blood pressure remained unchanged in PTHrPSM-/- mice, but plasma renin concentration and creatinine clearance were reduced. Renal hemodynamics were further analyzed during clearance measurements in anesthetized mice. Conditional knockdown of PTHrP decreased renal plasma flow and glomerular filtration rate with concomitant reduction in filtration fraction. Similar measurements were repeated during acute saline volume expansion. Saline volume expansion induced a rise in renal plasma flow and reduced filtration fraction; both were blunted in PTHrPSM-/- mice leading to impaired diuresis. These findings show that endogenous vascular smooth muscle PTHrP controls renal hemodynamics under basal conditions, and it is an essential factor in renal vasodilation elicited by saline volume expansion.

  20. Differential effects of the adenosine A1 receptor agonist adenosine amine congener on renal, femoral and carotid vascular conductance in preterm fetal sheep. (United States)

    Booth, Lindsea C; Tummers, Leonie; Jensen, Ellen C; Barrett, Carolyn J; Malpas, Simon C; Gunn, Alistair J; Bennet, Laura


    1. Adenosine A(1) receptor activation is critical for endogenous neuroprotection from hypoxia-ischaemia, raising the possibility that treatment with A(1) receptor agonists may be an effective physiological protection strategy for vulnerable preterm infants. However, the A(1) receptor can mediate unwanted systemic effects, including vasoconstriction of the afferent glomerular arteriole. There is limited information on whether this occurs at doses that improve cerebral perfusion in the immature brain. 2. Therefore, in the present study, we examined whether infusion of the selective A(1) receptor agonist adenosine amine congener (ADAC) is associated with reduced renal perfusion in chronically instrumented preterm (0.7 gestation) fetal sheep. In the present study, ADAC was given in successive doses of 2.5, 5.0 and 15.0 microg, 45 min apart. 3. Treatment with ADAC was associated with a marked reduction in renal vascular conductance (and blood flow), whereas carotid conductance was increased and there was no significant effect on femoral conductance. In contrast with the stable effects of increasing ADAC dose on vascular conductance, there was a significant dose-related fall in fetal heart rate and blood pressure. 4. In conclusion, these short-term data support the concern that A(1) receptor agonist infusion can selectively impair renal perfusion, even at low doses.

  1. Automated tone transcription

    CERN Document Server

    Bird, S


    In this paper I report on an investigation into the problem of assigning tones to pitch contours. The proposed model is intended to serve as a tool for phonologists working on instrumentally obtained pitch data from tone languages. Motivation and exemplification for the model is provided by data taken from my fieldwork on Bamileke Dschang (Cameroon). Following recent work by Liberman and others, I provide a parametrised F_0 prediction function P which generates F_0 values from a tone sequence, and I explore the asymptotic behaviour of downstep. Next, I observe that transcribing a sequence X of pitch (i.e. F_0) values amounts to finding a tone sequence T such that P(T) {}~= X. This is a combinatorial optimisation problem, for which two non-deterministic search techniques are provided: a genetic algorithm and a simulated annealing algorithm. Finally, two implementations---one for each technique---are described and then compared using both artificial and real data for sequences of up to 20 tones. These programs ...

  2. Effects of angiotensin Ⅱ receptor antagonist olmesartan on renal hemodynamic variables and vascular structural properties in streptozotocin-induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    SONG Hui-fen; CHEN Jian-fei; SUN Ning-ling; LI Hong-wei


    Background Diabetic nephropathy is a major cause of renal failure in diabetes mellitus (DM). It has been known that renin-angiotensin system (RAS) blockers have a renal protective effect. This study aimed to investigate whether treatment with angiotensin Ⅱ receptor blocker, olmesartan, could modify renal hemodynamic variables and vascular structural properties, then attenuate renal injury in streptozotocin (STZ)-induced DM rats.Methods DM was induced in male Wistar rats by intraperitoneal administration of STZ. The rats were then randomized to a DM group and an olmesartan treatment (OLM+DM) group. The normal group (non-DM) were administered only citrate buffer. At the end of the 14th week, blood glucose, kidney weight/body weight and urinary protein-to-creatinine ratio were determined. Further, the flow-pressure and pressure-glomerular filtration rate (GFR) relationships were determined for maximally vasodilated, perfused kidneys. From the relationship, 3 indices of vascular structural properties were estimated: slope of flow-pressure (minimal renal vascular resistance, reflecting overall luminal dimensions of preglomerular and postglomerular vasculature), slope of pressure-GFR (glomerular filtration capacity against pressure)and threshold pressure for beginning filtration at pressure-GFR (preglomerular to postglomerular vascular resistance ratio). Kidneys were then perfusion fixed for histological analysis. The renal histopathology was observed by light microscopy.Results The body weight of DM rats was lower than that of non-DM rats. Blood glucose, kidney weight/body weight,urinary protein-to-creatinine ratio were significantly greater in DM rats than in non-DM rats. The parameters such as kidney weight/body weight, urinary protein-to-creatinine ratio in OLM+DM rats had dramatically decreased compared with those in DM rats. However, the treatment with olmesartan had no effect on blood glucose levels. The slope of flow-pressure relationship was greater in DM rats

  3. Pure-tone Audiometer (United States)

    Kapul, A. A.; Zubova, E. I.; Torgaev, S. N.; Drobchik, V. V.


    The research focuses on a pure-tone audiometer designing. The relevance of the study is proved by high incidence of an auditory analyser in older people and children. At first, the article provides information about subjective and objective audiometry methods. Secondly, we offer block-diagram and basic-circuit arrangement of device. We decided to base on STM32F407VG microcontroller and use digital pot in the function of attenuator. Third, we implemented microcontroller and PC connection. C programming language is used for microcontroller’s program and PC’s interface. Fourthly, we created the pure-tone audiometer prototype. In the future, we will implement the objective method ASSR in addition to pure-tone audiometry.

  4. Serum Vascular Adhesion Protein-1 Predicts End-Stage Renal Disease in Patients with Type 2 Diabetes.

    Directory of Open Access Journals (Sweden)

    Hung-Yuan Li

    Full Text Available Diabetes is the leading cause of end-stage renal disease (ESRD worldwide. Vascular adhesion protein-1 (VAP-1 participates in inflammation and catalyzes the deamination of primary amines into aldehydes, hydrogen peroxide, and ammonia, both of which are involved in the pathogenesis of diabetic complications. We have shown that serum VAP-1 is higher in patients with diabetes and in patients with chronic kidney disease (CKD, and can predict cardiovascular mortality in subjects with diabetes. In this study, we investigated if serum VAP-1 can predict ESRD in diabetic subjects.In this prospective cohort study, a total of 604 type 2 diabetic subjects were enrolled between 1996 to 2003 at National Taiwan University Hospital, Taiwan, and were followed for a median of 12.36 years. The development of ESRD was ascertained by linking our database with the nationally comprehensive Taiwan Society Nephrology registry. Serum VAP-1 concentrations at enrollment were measured by time-resolved immunofluorometric assay.Subjects with serum VAP-1 in the highest tertile had the highest incidence of ESRD (p<0.001. Every 1-SD increase in serum VAP-1 was associated with a hazard ratio of 1.55 (95%CI 1.12-2.14, p<0.01 for the risk of ESRD, adjusted for smoking, history of cardiovascular disease, body mass index, hypertension, HbA1c, duration of diabetes, total cholesterol, use of statins, ankle-brachial index, estimated GFR, and proteinuria. We developed a risk score comprising serum VAP-1, HbA1c, estimated GFR, and proteinuria, which could predict ESRD with good performance (area under the ROC curve = 0.9406, 95%CI 0.8871-0.9941, sensitivity = 77.3%, and specificity = 92.8%. We also developed an algorithm based on the stage of CKD and a risk score including serum VAP-1, which can stratify these subjects into 3 categories with an ESRD risk of 0.101%/year, 0.131%/year, and 2.427%/year, respectively.In conclusion, serum VAP-1 can predict ESRD and is a useful biomarker to

  5. Anatomia vascular das artérias renais natomia e gonadais de Podocnemis unifilis Schweigger, 1812 (Testudines, Pelomedusidae = Vascular anatomy of renal and gonadal arteries of Podocnemis unifilis Schweigger, 1812 (Testudines-Pelomedusidae

    Directory of Open Access Journals (Sweden)

    Líria Queiroz Luz Hirano


    Full Text Available Este trabalho foi desenvolvido com o intuito de enriquecer o conhecimento sobre a morfologia vascular das artérias renais e gonadais de Podocnemis unifilis, facilitando o entendimento da fisiologia clínica e cirúrgica destes animais. Foram utilizados cincoexemplares machos de Podocnemis unifilis (tracajá, coletados segundo a Licença nº 066/2004- Ibama/RAM. A artéria carótida esquerda e a veia femoral direita foram canuladas e, pelas mesmas, foi introduzida solução fisiológica para lavagem do sistema vascular; em seguida,aplicou-se solução de Neoprene Látex “450” corada com pigmento específico (Globo S/A Tintas e Pigmentos. O material foi fixado em solução de Formol tamponado a 10% por um período mínimo de 96h. Uma abertura central e de formato quadrangular foi feita na metade caudal do plastrão e casco, de forma a expor os ramos da artéria aorta que irrigam os rins e as gônadas. Observou-se que as artérias renais se originam da face ventral da artéria aorta dorsal, em número de dois pares para cada rim e, em um único exemplar, elas originaram uma artéria renal direita e duas esquerdas. A artéria gonadal surgiu a partir da artéria renal, e apenas um par penetrou pela face dorsal de cada gônada.This work was developed with the aim of enriching knowledge on the vascular morphology of renal and gonadal arteries of Podocnemisunifilis, thus increasing the understanding of the clinical and surgical physiology of these animals. Five Podocnemis unifilis males were used, collected according to license no. 066/2004-Ibama/RAM.The left carotid artery and right femoral vein were cannulated, and a serum solution was introduced to remove obstructions from the vascular system. A solution of Neoprene Latex “450” dye was injected. The material was fixed in a solution of 10% formaldehyde for a period of 96 hours. Next, a square-shaped central opening was made in the caudal end of the plastron and bridge, exposing the branches

  6. Precise measurement of renal filtration and vascular parameters using a two-compartment model for dynamic contrast-enhanced MRI of the kidney gives realistic normal values

    Energy Technology Data Exchange (ETDEWEB)

    Tofts, Paul S. [Brighton and Sussex Medical School, Falmer, Sussex (United Kingdom); UCL Institute of Neurology, London (United Kingdom); Cutajar, Marica [Brighton and Sussex Medical School, Falmer, Sussex (United Kingdom); UCL Institute of Child Health, London (United Kingdom); Mendichovszky, Iosif A. [University of Manchester, Imaging Science and Biomedical Engineering, Manchester (United Kingdom); Peters, A.M. [Brighton and Sussex Medical School, Falmer, Sussex (United Kingdom); Gordon, Isky [UCL Institute of Child Health, London (United Kingdom)


    To model the uptake phase of T{sub 1}-weighted DCE-MRI data in normal kidneys and to demonstrate that the fitted physiological parameters correlate with published normal values. The model incorporates delay and broadening of the arterial vascular peak as it appears in the capillary bed, two distinct compartments for renal intravascular and extravascular Gd tracer, and uses a small-vessel haematocrit value of 24%. Four physiological parameters can be estimated: regional filtration K{sup trans} (ml min {sup -1} [ml tissue ]{sup -1}), perfusion F (ml min {sup -1} [100 ml tissue ]{sup -1}), blood volume v{sub b} (%) and mean residence time MRT (s). From these are found the filtration fraction (FF; %) and total GFR (ml min {sup -1}). Fifteen healthy volunteers were imaged twice using oblique coronal slices every 2.5 s to determine the reproducibility. Using parenchymal ROIs, group mean values for renal biomarkers all agreed with published values: K{sup trans}: 0.25; F: 219; v{sub b}: 34; MRT: 5.5; FF: 15; GFR: 115. Nominally cortical ROIs consistently underestimated total filtration (by {proportional_to} 50%). Reproducibility was 7-18%. Sensitivity analysis showed that these fitted parameters are most vulnerable to errors in the fixed parameters kidney T{sub 1}, flip angle, haematocrit and relaxivity. These renal biomarkers can potentially measure renal physiology in diagnosis and treatment. circle Dynamic contrast-enhanced magnetic resonance imaging can measure renal function. circle Filtration and perfusion values in healthy volunteers agree with published normal values. circle Precision measured in healthy volunteers is between 7 and 15%. (orig.)

  7. [Vasomotor tone and CBP : monitoring components, pratical and therapeutic approaches]. (United States)

    Isetta, C; Janot, N


    The vasomotor tone is an essential determinant of blood pressure. Vascular resistance is the result of a calculation including vasomotor tone, blood flow and blood viscosity. The vascular tone is modulated by the sympathetic system and the direct actions of drugs (patient's pathology, anaesthesia). The pressure and flow allow the vascular tone apprehension. A decrease in vasomotor tone lowers the mean arterial pressure and may cause an intense vasoplegia with arterial vascular resistance below than 800 dyn/s/cm(5) leading to a lack of tissue oxygenation. Vasomotor paralysis can be caused by the patient medications or an intense inflammatory reaction starting at the extracorporeal circulation onset. Monitoring parameters of extracorporeal circulation such as pressure, flow, arterial and venous oxygen saturation, blood level in the venous reservoir, and extensively blood gases, haemoglobin, CO(2) partial pressure level of the oxygenator vent, bispectral index, and oxygen saturation of cerebral tissue are reviewed. They will know the vasoplegia consequences and bear an indication of adequate tissue oxygenation. It may be obtained by using vasopressors (ephedrine, norepinephrine, terbutalin and vasopressin) methylene blue, increasing blood viscosity (erythrocytes) and blood flow, even by inducing hypothermia.

  8. Phonetics and Phonology of Chicahuaxtla Triqui Tones (United States)

    Matsukawa, Kosuke


    Chicahuaxtla Triqui (Otomanguean, Mexico) is one of the rare tone languages with five contrastive level tones and its underlying tone system is even more complicated than its surface five-level tone system. The complexity of its underlying tone system has developed through the historical tone shifts from Proto-Triqui. The surface tone system of…

  9. Phonetics and Phonology of Chicahuaxtla Triqui Tones (United States)

    Matsukawa, Kosuke


    Chicahuaxtla Triqui (Otomanguean, Mexico) is one of the rare tone languages with five contrastive level tones and its underlying tone system is even more complicated than its surface five-level tone system. The complexity of its underlying tone system has developed through the historical tone shifts from Proto-Triqui. The surface tone system of…

  10. Renal angiomyolipoma

    DEFF Research Database (Denmark)

    Holm-Nielsen, P; Sørensen, Flemming Brandt


    lesion. Three cases of renal angiomyolipoma, 2 of which underwent perfusion-fixation, were studied by electron microscopy to clarify the cellular composition of this lesion. In the smooth muscle cells abundant accumulation of glycogen was found, whereas the lipocytes disclosed normal ultrastructural......-specific vesicular structures. These findings suggest a secondary vascular damage, i.e. the thickened vessels may not be a primary, integral part of renal angiomyolipoma. Evidence of a common precursor cell of renal angiomyolipoma was not disclosed. It is concluded that renal angiomyolipoma is a hamartoma composed...

  11. Contrastive tone in Kalam Kohistani

    Directory of Open Access Journals (Sweden)

    Joan L.G. Baart


    Full Text Available It has been observed that tonal phenomena occur in quite a few Indo-Aryan languages in the northwestern corner of the South-Asian subcontinent. This paper presents a study of the tone system of one of these languages, Kalam Kohistani. After establishing that Kalam Kohistani has five contrastive surface tones—a high tone, a low tone, a rising tone, and two types of falling tone—I propose an analysis of these tones in terms of Autosegmental Phonology. Furthermore, some observations are made on the relation between aspiration and tone, and on the functional load of tone in Kalam Kohistani. Its relatively rich inventory of tones makes Kalam Kohistani, along with two of its close neighbors, stand out as unique among the Indo-Aryan languages.

  12. Change of tone

    CERN Document Server

    Association du personnel


    The President of the Staff Association set the tone by leaving the members of the SCC speechless when he read out a solemn declaration For a start, Management invites us to discuss the Five-Yearly Review without having provided any formal text. Concertation Method of analysis and use of data previously adopted by Council. Salaries. Increase. Employment conditions. Family allowances. Crèche. Career perspectives. Referendum.

  13. Acesso vascular para hemodiálise com cateter temporário de duplo lúmen em cães com insuficiência renal aguda Hemodialysis vascular access with temporary double-lumen catheter in dogs with acute renal failure

    Directory of Open Access Journals (Sweden)

    Alessandra Melchert


    Full Text Available A hemodiálise é uma modalidade terapêutica que pode sustentar a vida do paciente com insuficiência renal aguda (IRA, enquanto este recupera a função renal. Para sua realização, é necessário estabelecer circulação extracorpórea, para que seja realizada a filtração do sangue, impondo a necessidade de um acesso vascular viável e eficiente. O objetivo deste estudo foi avaliar a eficiência e as complicações do acesso vascular para hemodiálise (HD, com cateter temporário de duplo lúmen inserido na veia jugular externa. Foram estudados 10 cães com IRA induzida por gentamicina, submetidos a sessões diárias de HD, com duração de uma hora, até a recuperação da função renal ou óbito. Foram realizadas 104 sessões de HD nos animais estudados, observando-se necessidade de troca do cateter em sete sessões (6,7%, devido à obstrução do lúmen do cateter em seis sessões (5,8% ou por saída acidental do mesmo em uma sessão (1,0%. Não se observou migração do cateter, infecção, hemorragia ou hematoma no local de entrada do cateter na pele, obtendo-se fluxo sanguíneo patente em 90,4% das sessões. Concluiu-se que o acesso vascular na veia jugular externa com cateter temporário de duplo-lúmen mostrou-se viável, com ocorrência de poucas complicações, sendo, portanto, indicado como forma de acesso para a circulação extracorpórea para HD em cães com IRA.Hemodialysis is a therapeutic procedure that can sustain the patient's life in acute renal failure (ARF, during the renal function recover. To perform hemodialysis (HD, an extracorporeal circulation is established to blood filtration, imposing the need of a viable and efficient vascular access. The aim of this study was to evaluate the effectiveness and complications of the HD vascular access with temporary double-lumen catheter inserted into the external jugular vein. Ten mongrel dogs with ARF, induced by gentamicin administration, were submitted to daily

  14. Closure of multiple types of K+ channels is necessar to induce changes in renal vascular resistance in vivo in rats

    DEFF Research Database (Denmark)

    Sørensen, Charlotte Mehlin; Giese, Isaiah; Braunstein, Thomas Hartig


    flow (RBF) in vivo in anesthetized Sprague-Dawley rats. Test agents were infused directly into the renal artery to avoid systemic effects. Inhibition of BK(Ca) and K(ir) channels (with TEA and Ba(2+), respectively) caused small and transient reductions in RBF (to 93¿±¿2% and 95¿±¿1% of baseline...... the vasoconstriction induced by bolus injections of norepinephrine or angiotensin II (by 33¿±¿5% and 60¿±¿5%, respectively). Our results indicate that closure of numerous types of K(+) channels could participate in the mediation of agonist-induced renal vasoconstriction. Our results also suggest that renal...

  15. Trauma renal Renal trauma

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior


    Full Text Available Apresentamos uma revisão sobre trauma renal, com ênfase na avaliação radiológica, particularmente com o uso da tomografia computadorizada, que tem se tornado o exame de eleição, ao invés da urografia excretora e arteriografia. O sucesso no tratamento conservador dos pacientes com trauma renal depende de um acurado estadiamento da extensão da lesão, classificado de acordo com a Organ Injury Scaling do Colégio Americano de Cirurgiões. O tratamento conservador não-operatório é seguro e consiste de observação contínua, repouso no leito, hidratação endovenosa adequada e antibioti- coterapia profilática, evitando-se uma exploração cirúrgica desnecessária e possível perda renal. As indicações para exploração cirúrgica imediata são abdome agudo, rápida queda do hematócrito ou lesões associadas determinadas na avaliação radiológica. Quando indicada, a exploração renal após controle vascular prévio é segura, permitindo cuidadosa inspeção do rim e sua reconstrução com sucesso, reduzindo a probabilidade de nefrectomia.We present a revision of the renal trauma with emphasis in the radiographic evaluation, particularly CT scan that it has largely replaced the excretory urogram and arteriogram in the diagnostic worh-up and management of the patient with renal trauma. The successful management of renal injuries depends upon the accurate assessment of their extent in agreement with Organ Injury Scaling classification. The conservative therapy managed by careful continuous observation, bed rest, appropriate fluid ressuscitation and prophylactic antibiotic coverage after radiographic staging for severely injured kidneys can yield favorable results and save patients from unnecessary exploration and possible renal loss. The indications for immediate exploratory laparotomy were acute abdomen, rapidly dropping hematocrit or associated injuries as determinated from radiologic evaluation. When indicated, renal exploration

  16. Endothelin-like action of Pausinystalia yohimbe aqueous extract on vascular and renal regional hemodynamics in Sprague Dawley rats. (United States)

    Ajayi, A A; Newaz, M; Hercule, H; Saleh, M; Bode, C O; Oyekan, A O


    The bark of the African tree Pausinystalia yohimbe has been used as a food additive with aphrodisiac and penile erection enhancing properties. The effect of an aqueous extract of P. yohimbe (CCD-X) on renal circulation was assessed in order to test the hypothesis that it possesses additional effects on nitric oxide production and/or endothelin-1 (ET-1)-like actions. In vivo studies with CCD-X in Sprague Dawley rats demonstrated a dose-dependent (1-1000 ng/kg) increase in mean blood pressure (p < 0.001) and an increase in medullary blood flow (MBF) (p < 0.001). Both the pressor action and renal medullary vasodilation were blocked by endothelinA (ETA) receptor antagonist BMS182874 and endothelinB (ETB) receptor antagonist BQ788 in combination. L-Nomega-nitro-l-arginine methyl ester (L-NAME; 10 mg/kg) also inhibited the increase in MBF induced by CCD-X. In vitro studies in isolated perfused kidney and in pressurized renal microvessels confirmed the dose-dependent vasoconstrictor action of this extract. ETA receptor antagonist BQ610 and ETB receptor antagonist BQ788 separately and significantly attenuated the renal vasoconstrictor actions of the extract (p < 0.001 ANOVA). These preliminary observations indicate that, in addition to the alpha-adrenergic antagonist actions that characterize yohimbine, CCD-X possesses endothelin-like actions and affects nitric oxide (NO) production in renal circulation. These findings suggest a strong possibility of post-receptor cross-talk between alpha2-adrenoceptors and endothelin, as well as a direct effect of alpha2-adrenoceptors on renal NO production.

  17. Oxidative stress and modification of renal vascular permeability are associated with acute kidney injury during P. berghei ANKA infection. (United States)

    Elias, Rosa Maria; Correa-Costa, Matheus; Barreto, Claudiene Rodrigues; Silva, Reinaldo Correia; Hayashida, Caroline Y; Castoldi, Angela; Gonçalves, Giselle Martins; Braga, Tarcio Teodoro; Barboza, Renato; Rios, Francisco José; Keller, Alexandre Castro; Cenedeze, Marcos Antonio; Hyane, Meire Ioshie; D'Império-Lima, Maria Regina; Figueiredo-Neto, Antônio Martins; Reis, Marlene Antônia; Marinho, Cláudio Romero Farias; Pacheco-Silva, Alvaro; Câmara, Niels Olsen Saraiva


    Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.

  18. Oxidative Stress and Modification of Renal Vascular Permeability Are Associated with Acute Kidney Injury during P. berghei ANKA Infection (United States)

    Elias, Rosa Maria; Correa-Costa, Matheus; Barreto, Claudiene Rodrigues; Silva, Reinaldo Correia; Hayashida, Caroline Y.; Castoldi, Ângela; Gonçalves, Giselle Martins; Braga, Tarcio Teodoro; Barboza, Renato; Rios, Francisco José; Keller, Alexandre Castro; Cenedeze, Marcos Antonio; Hyane, Meire Ioshie; D'Império-Lima, Maria Regina; Figueiredo-Neto, Antônio Martins; Reis, Marlene Antônia; Marinho, Cláudio Romero Farias; Pacheco-Silva, Alvaro; Câmara, Niels Olsen Saraiva


    Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA. PMID:22952850

  19. Tone features in whispered Chinese

    Institute of Scientific and Technical Information of China (English)

    LI Xueli; XU Boling


    Study on the whispered tone is important to speech recognition and conversion in whispered Chinese. In this paper, the characteristics of whispered speech are introduced and the tone features in whispered Chinese are discussed. There is no fundamental frequency in the whispered speech, so other features, such as the amplitude envelope, duration, glottal area, lip area, forrnant, and vocal tract length, are extracted and their contributions to the automatic tone recognition are compared. From the experiments with six simple Chinese whispered vowels in four tones, it is proved that loudness-weighted 32 Mel-frequency bands log-amplitude envelopes and duration can be used as the main tone features in the whispered Chinese tone recognition. The average tone recognition rate approaches that of the human perception level.

  20. Mechanisms of oxidative stress and vascular dysfunction (United States)

    Nedeljkovic, Z; Gokce, N; Loscalzo, J


    The endothelium regulates vascular homoeostasis through local elaboration of mediators that modulate vascular tone, platelet adhesion, inflammation, fibrinolysis, and vascular growth. Impaired vascular function contributes to the pathogenesis of atherosclerosis and acute coronary syndromes. There is growing pathophysiological evidence that increased generation of reactive oxygen species and oxidative stress participates in proatherogenic mechanisms of vascular dysfunction and atherothrombosis. In this review, the role of oxidative stress in mechanisms of vascular dysfunction is discussed, and potential antioxidant strategies are reviewed. PMID:12743334

  1. Iodination of vasopressin analogues with agonistic and antagonistic properties: effects on biological properties and affinity for vascular and renal vasopressin receptors. (United States)

    Jard, S; Lombard, C; Seyer, R; Aumelas, A; Manning, M; Sawyer, W H


    Twelve L- and D-tyrosine-containing vasopressin analogues were prepared in their mono- and diiodinated forms. These include six arginine vasopressin (AVP) vascular (V1) type antagonists/antidiuretic (V2) agonists, four V1/V2 antagonists, and two V1/V2 agonists, one of which is AVP itself. Ten peptides were iodinated on the tyrosyl residue in position 2; two were iodinated on a tyrosyl amide residue replacing the glycyl amide residue at position 9. All peptides were tested both for their biological activities in vivo (rat vasopressor and antidiuretic tests) and for their ability to bind to vasopressin receptors of the V1 (vascular) and V2 (renal) types from rat liver and rat kidney membranes, respectively. It is shown that monoiodination of the tyrosyl residue in the vasopressin analogues that were tested either preserves or reduces to a highly variable extent the in vivo and in vitro biological activities of these analogues. In most cases diiodonitation resulted in a marked decrease in biological activity. The effects of iodination on the affinity of vasopressin analogues for hepatic V1 receptors and renal V2 receptors were more related to the affinity of the noniodinated peptide for these receptors than to the biological properties (antagonist versus agonist) of the tested analogues, the nature (L versus D) of the iodinated tyrosyl residue, or the position (2 versus 9) at which this residue was introduced. The loss of affinity due to iodination was usually more pronounced for peptides exhibiting high affinity for vasopressin receptors. However, we show that among the monoiodinated peptides some (especially monoiodinated [2-D-Tyrosine]-AVP) retained enough affinity for vasopressin binding sites to suggest that their radioiodinated conterparts would be promising labeled ligands for use in studies in vasopressin receptors.

  2. Programación temprana de alteraciones en el sistema del óxido nítrico renal y vascular inducidas por la deficiencia de cinc

    Directory of Open Access Journals (Sweden)

    María A. Costa


    Full Text Available Resumen:IntroducciónNumerosos estudios mostraron que la deficiencia nutricional durante la vida fetal y posnatal predisponen al desarrollo de patologías en la vida adulta, como la hipertensión arterial y las enfermedades renales. La distribución ubicua del cinc y sus propiedades químicas determinan su esencialidad en los sistemas biológicos.ObjetivosEvaluar si las alteraciones renales y cardiovasculares en la vida adulta inducidas por la restricción moderada de cinc durante la vida fetal, la lactancia y/o el crecimiento se asocian con cambios en el sistema del óxido nítrico.Material y métodosRatas Wistar hembra recibieron durante la preñez hasta el destete de las crías una dieta control o una baja en cinc. Luego del destete, las crías macho se asignaron al azar a dos grupos que recibieron una dieta control o una baja en cinc durante 60 días.ResultadosLos resultados mostraron que el aporte insuficiente de cinc durante el crecimiento previo y/o posterior al destete indujo un aumento de la presión arterial y una disminución del volumen de filtrado glomerular en la vida adulta, asociados con una disminución del sistema del óxido nítrico renal y vascular. Además, el bajo aporte de este mineral durante la vida fetal indujo un peso menor al nacer, que se correlacionó en forma negativa con la presión arterial en la vida adulta.ConclusionesEste trabajo brinda evidencias importantes que sugieren que el aporte inadecuado de cinc durante el crecimiento prenatal y posnatal constituye un factor de riesgo cardiovascular y renal, dado que induce alteraciones en la regulación de la presión arterial y en la función renal en el individuo adulto.REV ARGENT CARDIOL 2008;76:459-464.

  3. Transactivation of epidermal growth factor receptor in vascular and renal systems in rats with experimental hyperleptinemia: role in leptin-induced hypertension. (United States)

    Jamroz-Wiśniewska, Anna; Wójcicka, Grazyna; Łowicka, Ewelina; Ksiazek, Marta; Bełtowski, Jerzy


    We examined the role of epidermal growth factor (EGF) receptor in the pathogenesis of leptin-induced hypertension in the rat. Leptin, administered in increasing doses (0.1-0.5 mg/kg/day) for 10 days, increased phosphorylation levels of non-receptor tyrosine kinase, c-Src, EGF receptor and extracellular signal-regulated kinases (ERK) in aorta and kidney, which was accompanied by the increase in plasma concentration and urinary excretion of isoprostanes and H2O2. Blood pressure and renal Na+,K+-ATPase activity were higher, whereas urinary sodium excretion was lower in animals receiving leptin. The effects of leptin on renal Na+,K+-ATPase, natriuresis and blood pressure were abolished by NADPH oxidase inhibitor, apocynin, Src kinase inhibitor, PP2, EGF receptor inhibitor, AG1478, protein farnesyltransferase inhibitor, manumycin A, and ERK inhibitor, PD98059. In contrast, inhibitors of insulin-like growth factor-1 and platelet-derived growth factor receptors, AG1024 and AG1295, respectively, only slightly reduced ERK phosphorylation and had no effect on blood pressure in rats receiving leptin. These data indicate that: (1) experimental hyperleptinemia is associated with oxidative stress and c-Src-dependent transactivation of the EGF receptor, which stimulates ERK in vascular wall and the kidney, (2) overactivity of EGF receptor-ERK pathway contributes to leptin-induced hypertension by stimulating renal Na+,K+-ATPase and reducing sodium excretion, (3) inhibitors of c-Src, EGF receptor and ERK may be considered as a novel therapy for hypertension associated with hyperleptinemia, e.g. in patients with obesity and metabolic syndrome.

  4. Recombinant vascular endothelial growth factor 121 infusion lowers blood pressure and improves renal function in rats with placentalischemia-induced hypertension. (United States)

    Gilbert, Jeffrey S; Verzwyvelt, Joseph; Colson, Drew; Arany, Marietta; Karumanchi, S Ananth; Granger, Joey P


    Antagonism of vascular endothelial growth factor (VEGF) signaling by soluble fms-like tyrosine kinase 1 occurs during preeclampsia and is proposed to play an important role in the pathogenesis of preeclampsia. We reported recently that hypertension associated with chronic reductions in uteroplacental perfusion pressure (RUPP) is associated with increased soluble fms-like tyrosine kinase 1 and decreased free VEGF. Whether restoration of circulating VEGF can restore renal function and chronically decrease arterial pressure associated with placental ischemia remains unknown. We hypothesized that chronic infusion of VEGF(121) would attenuate hypertension, increase glomerular filtration rate, and reverse the endothelial dysfunction associated with chronic RUPP. VEGF(121) (at either 90 or 180 microg/kg per day) was administered for 5 days via osmotic minipump placed IP. Mean arterial pressure, renal function, and tissues were obtained on day 19 of pregnancy from RUPP+VEGF, RUPP, and normal pregnant dams. Mean arterial pressure was increased in the RUPP (131+/-3 mm Hg) compared with the normal pregnant (102+/-1 mm Hg) rats, and infusion of VEGF(121) resolved the hypertension (105+/-5 mm Hg). Glomerular filtration rate was decreased in the RUPP dams (1.5+/-0.3 mL/min) and restored to normal pregnant levels (3.1+/-0.5 mL/min) by VEGF(121) treatment (3.1+/-0.4 mL/min). Effective renal plasma flow, decreased by RUPP, was also increased by VEGF(121) infusion. Relaxation to acetylcholine was enhanced by the VEGF treatment (Phigh blood pressure associated with placental ischemia. The present results suggest that VEGF(121) may be a candidate molecule for management of preeclampsia and its related complications.

  5. Initial evidence demonstrating the association between the vascular status in surgically resected renal parenchymal pathology and sexual function. (United States)

    Sejima, T; Iwamoto, H; Masago, T; Morizane, S; Yao, A; Umekita, Y; Honda, M; Takenaka, A


    Our goal is to evaluate the association between histopathology of glomerulosclerosis (GS) and atherosclerosis (AS) in the nephrectomized normal parenchyma together with patients' background, and erectile dysfunction (ED) of patients treated with radical nephrectomy (RN) for renal cell carcinoma (RCC). ED was assessed with the International Index of Erectile Function in 65 patients who were less than age 70 years at the time of questionnaire. Glomeruli status was assessed by the extent of global GS. AS was graded based on lumen occlusion and frequency of involvement. Patients' backgrounds included any comorbidities, post-RN renal insufficiency, tumor pathology, demographics and social status. The presence of diabetes mellitus and lack of a spouse were independent predictors for severe ED, whereas G0/1 AS was an independent predictor for mild/no ED. The extent of global GS was significantly lower in patients with mild/no ED than in other patients. Our study represents the first report identifying healthy arterial status in the renal parenchyma as a significant indicator of favorable erectile function and that the evaluation of AS severity is not a superior indicator of severe ED in the presence of comorbidities or social status among patients treated with RN.

  6. Strategies for Analyzing Tone Languages (United States)

    Coupe, Alexander R.


    This paper outlines a method of auditory and acoustic analysis for determining the tonemes of a language starting from scratch, drawing on the author's experience of recording and analyzing tone languages of north-east India. The methodology is applied to a preliminary analysis of tone in the Thang dialect of Khiamniungan, a virtually undocumented…

  7. Expression of BMP-2 in Vascular Endothelial Cells of Recipient May Predict Delayed Graft Function After Renal Transplantation

    Directory of Open Access Journals (Sweden)

    Nikolina Basic-Jukic


    Full Text Available Background/Aims: Delayed graft function (DGF is associated with adverse outcomes after renal transplantation. Bone morphogenetic protein-2 (BMP-2 is involved in both endothelial function and immunological events. We compared expression of BMP-2 in epigastric artery of renal transplant recipients with immediate graft function (IGF and DGF. Methods: 79 patients were included in this prospective study. Patients were divided in IGF group (64 patients and DGF group (15 patients. BMP-2 expression in intima media (BMP2m and endothelium (BMP2e of epigastric artery was assessed by immunohistochemistry. Results: Lower intensity of BMP2e staining was recorded in DGF compared to IGF. In DGF patients, 93% had no expression of BMP2e and 7% had 1st grade expression, compared to 45% and 41% in IGF group, respectively (P=0.001 (Pst grade expression. Patients who had BMP2e staining positive had lower odds for DGF (OR 0.059 [0.007, 0.477] and this remained significant even after adjustment for donor and recipient variables, cold ischemia time, and immunological matching (OR 0.038 [0.003, 0.492]. Conclusions: Our results demonstrate that BMP-2 expression in endothelial cells of epigastric arteries may predict development of DGF.

  8. Preserved regulation of renal perfusion pressure by small and intermediate conductance K-Ca channels in hypertensive mice with or without renal failure

    DEFF Research Database (Denmark)

    Waeckel, L.; Bertin, F.; Clavreul, N.;


    The purpose of this study was to assess, in the murine kidney, the mechanisms underlying the endothelium-dependent control of vascular tone and whether or not, in a severe model of hypertension and renal failure, K-Ca channels contribute to its regulation. Wild-type (BL) and double...... hypertensive without kidney disease while ARSL developed severe hypertension and renal failure. In the four groups, methacholine induced biphasic endothelium-dependent responses, a transient decrease in RPP followed by a cyclooxygenase-dependent increase in RPP. In the presence or not of indomethacin......-transgenic female mice expressing human angiotensinogen and renin (AR) genes received either control or a high-salt diet associated to a nitric oxide (NO) synthase inhibitor treatment (BLSL and ARSL). Changes in renal perfusion pressure (RPP) were measured in isolated perfused kidneys. BLSL and AR were moderately...

  9. Alteracoes vasculares em rins de doadores falecidos retardam a recuperacao da funcao do enxerto apos o transplante renal

    Directory of Open Access Journals (Sweden)

    Igor Denizarde Bacelar Marques


    Full Text Available Objetivo: Analisar as características do doador de múltiplos órgãos, incidência e duração da função retardada do enxerto (FRE, e seu impacto na função renal no primeiro ano após o transplante. Métodos: Foi realizado um estudo retrospectivo, unicêntrico, observacional, analisando os transplantes renais com doador falecido realizados em 2010 no nosso serviço. Resultados: A taxa de FRE foi de 68%, com mediana de duração de 12 dias (variação, 1-61 dias. Quarenta e quatro (38% pacientes apresentaram FRE com 12 ou mais dias de duração (FRE prolongada. A idade média dos doadores foi de 43 ± 13 anos e 37% deles eram hipertensos. Em 59% dos doadores, a causa da morte foi acidente cerebrovascular, e o tempo de isquemia fria (TIF médio foi de 23 ± 5 horas. Os receptores tinham idade média de 51 ± 15 anos, tempo em diálise de 43 meses (variação, 1-269 e 25% eram sensibilizados (PRA > 0%. No modelo de regressão logística multivariada, a presença de vasculopatia na biópsia de captação foi o único fator de risco independente para o desenvolvimento de FRE prolongada [OR 3,6 IC 95% (1,2-10,2, p = 0,02]. Os pacientes com FRE prolongada apresentaram pior função renal 1 ano após o transplante em comparação com os pacientes sem FRE (SCr 1,7 vs. 1,3 mg/dL, respectivamente, p = 0,03. Conclusão: A presença de vasculopatia na biópsia de captação foi identificada como fator de risco independente para o desenvolvimento de FRE prolongada. A FRE prolongada foi associada com pior função renal no 1º ano após o transplante.

  10. Protein Kinase C Inhibitors as Modulators of Vascular Function and Their Application in Vascular Disease

    Directory of Open Access Journals (Sweden)

    Raouf A. Khalil


    Full Text Available Blood pressure (BP is regulated by multiple neuronal, hormonal, renal and vascular control mechanisms. Changes in signaling mechanisms in the endothelium, vascular smooth muscle (VSM and extracellular matrix cause alterations in vascular tone and blood vessel remodeling and may lead to persistent increases in vascular resistance and hypertension (HTN. In VSM, activation of surface receptors by vasoconstrictor stimuli causes an increase in intracellular free Ca2+ concentration ([Ca2+]i, which forms a complex with calmodulin, activates myosin light chain (MLC kinase and leads to MLC phosphorylation, actin-myosin interaction and VSM contraction. Vasoconstrictor agonists could also increase the production of diacylglycerol which activates protein kinase C (PKC. PKC is a family of Ca2+-dependent and Ca2+-independent isozymes that have different distributions in various blood vessels, and undergo translocation from the cytosol to the plasma membrane, cytoskeleton or the nucleus during cell activation. In VSM, PKC translocation to the cell surface may trigger a cascade of biochemical events leading to activation of mitogen-activated protein kinase (MAPK and MAPK kinase (MEK, a pathway that ultimately increases the myofilament force sensitivity to [Ca2+]i, and enhances actin-myosin interaction and VSM contraction. PKC translocation to the nucleus may induce transactivation of various genes and promote VSM growth and proliferation. PKC could also affect endothelium-derived relaxing and contracting factors as well as matrix metalloproteinases (MMPs in the extracellular matrix further affecting vascular reactivity and remodeling. In addition to vasoactive factors, reactive oxygen species, inflammatory cytokines and other metabolic factors could affect PKC activity. Increased PKC expression and activity have been observed in vascular disease and in certain forms of experimental and human HTN. Targeting of vascular PKC using PKC inhibitors may function in

  11. Rimonabant-mediated changes in intestinal lipid metabolism and improved renal vascular dysfunction in the JCR:LA-cp rat model of prediabetic metabolic syndrome. (United States)

    Russell, James C; Kelly, Sandra E; Diane, Abdoulaye; Wang, Ye; Mangat, Rabban; Novak, Susan; Vine, Donna F; Proctor, Spencer D


    Rimonabant (SR141716) is a specific antagonist of the cannabinoid-1 receptor. Activation of the receptor initiates multiple effects on central nervous system function, metabolism, and body weight. The hypothesis that rimonabant has protective effects against vascular disease associated with the metabolic syndrome was tested using JCR:LA-cp rats. JCR:LA-cp rats are obese if they are cp/cp, insulin resistant, and exhibit associated micro- and macrovascular disease with end-stage myocardial and renal disease. Treatment of obese rats with rimonabant (10, 12-24 wk of age) caused transient reduction in food intake for 2 wk, without reduction in body weight. However, by 4 wk, there was a modest, sustained reduction in weight gain. Glycemic control improved marginally compared with controls, but at the expense of increased insulin concentration. In contrast, rimonabant normalized fasting plasma triglyceride and reduced plasma plasminogen activator inhibitor-1 and acute phase protein haptoglobin in cp/cp rats. Furthermore, these changes were accompanied by reduced postprandial intestinal lymphatic secretion of apolipoprotein B48, cholesterol, and haptoglobin. While macrovascular dysfunction and ischemic myocardial lesion frequency were unaffected by rimonabant treatment, both microalbuminuria and glomerular sclerosis were substantially reduced. In summary, rimonabant has a modest effect on body weight in freely eating obese rats and markedly reduces plasma triglyceride levels and microvascular disease, in part due to changes in intestinal metabolism, including lymphatic secretion of apolipoprotein B48 and haptoglobin. We conclude that rimonabant improves renal disease and intestinal lipid oversecretion associated with an animal model of the metabolic syndrome that appears to be independent of hyperinsulinemia or macrovascular dysfunction.

  12. Risk factors and model for predicting toxicity-related treatment discontinuation in patients with metastatic renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy: Results from the International Metastatic Renal Cell Carcinoma Database Consortium. (United States)

    Kaymakcalan, Marina D; Xie, Wanling; Albiges, Laurence; North, Scott A; Kollmannsberger, Christian K; Smoragiewicz, Martin; Kroeger, Nils; Wells, J Connor; Rha, Sun-Young; Lee, Jae Lyun; McKay, Rana R; Fay, André P; De Velasco, Guillermo; Heng, Daniel Y C; Choueiri, Toni K


    Vascular endothelial growth factor (VEGF)-targeted therapies are standard treatment for metastatic renal cell carcinoma (mRCC); however, toxicities can lead to drug discontinuation, which can affect patient outcomes. This study was aimed at identifying risk factors for toxicity and constructing the first model to predict toxicity-related treatment discontinuation (TrTD) in mRCC patients treated with VEGF-targeted therapies. The baseline characteristics, treatment outcomes, and toxicity data were collected for 936 mRCC patients receiving first-line VEGF-targeted therapy from the International Metastatic Renal Cell Carcinoma Database Consortium. A competing risk regression model was used to identify risk factors for TrTD, and it accounted for other causes as competing risks. Overall, 198 (23.8%) experienced TrTD. Sunitinib was the most common VEGF-targeted therapy (77%), and it was followed by sorafenib (18.4%). The median time on therapy was 7.1 months for all patients and 4.4 months for patients with TrTD. The most common toxicities leading to TrTD included fatigue, diarrhea, and mucositis. In a multivariate analysis, significant predictors for TrTD were a baseline age ≥60 years, a glomerular filtration rate (GFR) factors to predict the risk of TrTD. In the largest series to date, age, GFR, number of metastatic sites, and baseline sodium level were found to be independent risk factors for TrTD in mRCC patients receiving VEGF-targeted therapy. Based on the number of risk factors present, a model for predicting TrTD was built to be used as a tool for toxicity monitoring in clinical practice. © 2015 American Cancer Society.

  13. Plasma 1,25-Dihydroxyvitamin D and the Risk of Developing Hypertension: The Prevention of Renal and Vascular End-Stage Disease Study. (United States)

    van Ballegooijen, Adriana J; Gansevoort, Ron T; Lambers-Heerspink, Hiddo J; de Zeeuw, Dick; Visser, Marjolein; Brouwer, Ingeborg A; Kema, Ido P; de Borst, Martin H; Bakker, Stephan J L; Joosten, Michel M


    Previous observational studies on the vascular effects of vitamin D have predominantly relied on measurement of its inactive precursor, 25-hydroxyvitamin D, whereas the active metabolite 1,25-dihydroxyvitamin D may be of more physiological relevance. We prospectively studied the associations of 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D with hypertension risk (blood pressure ≥140/90 mm Hg or initiation of blood pressure-lowering drugs) in 5066 participants aged 28 to 75 years, free of hypertension at baseline from the Prevention of Renal and Vascular End-Stage Disease Study, a well-defined cohort with serial follow-up. We measured plasma 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D using liquid chromatography-tandem mass spectrometry. Mean±SD plasma concentration of 1,25-dihydroxyvitamin D was 145±47.0 pmol/L and 25-hydroxyvitamin D was 58.6±23.8 nmol/L. During a median follow-up of 6.4 years, 1036 participants (20.5%) developed hypertension. As expected, low 25-hydroxyvitamin D was associated with a higher hypertension risk; each 1-SD decrement in 25-hydroxyvitamin D was associated with a 8% higher hypertension risk (hazard ratio, 1.08; 95% confidence interval, 1.01-1.16) after adjustment for potential confounders. However, the association of 1,25-dihydroxyvitamin D was in the opposite direction; each 1-SD decrement of 1,25-dihydroxyvitamin D was associated with a 10% lower hypertension risk (hazard ratio, 0.90; 95% confidence interval, 0.84-0.96), independent of potential confounders. In contrast to the inverse association between 25-hydroxyvitamin D and hypertension risk, 1,25-dihydroxyvitamin D was positively associated with risk of hypertension. Thus, higher circulating concentrations of 1,25-dihydroxyvitamin D are associated with a higher risk of hypertension.

  14. The effects of epinine on arterial blood pressure and regional vascular resistances in anesthetized rats. (United States)

    Martínez-Mir, I; Palop, V; Morales-Olivas, F J; Estañ, L; Rubio, E


    1. We carried out experiments in anesthetized rats to study the hemodynamic effects of intravenous injections of epinine. 2. Epinine (1-320 micrograms/kg) produced a biphasic effect on mean arterial blood pressure (n = 30). At doses lower than 40 micrograms/kg, arterial blood pressure decreased (by as much as 21.5 +/- 3.4%), though at higher doses it increased dose dependently (by as much as 73.2 +/- 14.5%). Epinine also produced bradicardia in a dose-dependent manner (by as much as 26.4 +/- 4.9%). Sulpiride (100 micrograms/kg) suppressed the hypotensive effect of epinine but did not change the hypertensive effect. In the presence of prazosin (1,000 micrograms/kg), arterial blood pressure remained significantly decreased at all doses of epinine. Neither sulpiride nor prazosin changed the bradycardic effect of epinine. 3. Prazosin produced a significant decrease in renal vascular resistance. Epinine (5 micrograms/kg) after prazosin reverted the effects of prazosin in renal vascular resistance, without any significant modification in the renal blood flows. However, 20 micrograms/kg epinine increased the renal vascular resistances and, moreover, produced a significant decrease in the blood flows of both kidneys. Neither prazosin nor epinine produced modifications in the intestinal vascular bed. 4. Although epinine possesses significant dopamine and alpha-adrenergic activities that are involved in the biphasic effect of the agent on mean arterial blood pressure in anesthetized rats, in the presence of prazosin, it is not possible to manifest dopaminergic activity involved in the increase in renal or mesenteric blood flow; this may be due to the low tone of the vascular wall induced by the alpha-adrenergic antagonist, though an alpha 2-activity cannot be discarded.

  15. Reactive oxygen species and vascular biology: implications in human hypertension. (United States)

    Touyz, Rhian M; Briones, Ana M


    Increased vascular production of reactive oxygen species (ROS; termed oxidative stress) has been implicated in various chronic diseases, including hypertension. Oxidative stress is both a cause and a consequence of hypertension. Although oxidative injury may not be the sole etiology, it amplifies blood pressure elevation in the presence of other pro-hypertensive factors. Oxidative stress is a multisystem phenomenon in hypertension and involves the heart, kidneys, nervous system, vessels and possibly the immune system. Compelling experimental and clinical evidence indicates the importance of the vasculature in the pathophysiology of hypertension and as such much emphasis has been placed on the (patho)biology of ROS in the vascular system. A major source for cardiovascular, renal and neural ROS is a family of non-phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox), including the prototypic Nox2 homolog-based NADPH oxidase, as well as other Noxes, such as Nox1 and Nox4. Nox-derived ROS is important in regulating endothelial function and vascular tone. Oxidative stress is implicated in endothelial dysfunction, inflammation, hypertrophy, apoptosis, migration, fibrosis, angiogenesis and rarefaction, important processes involved in vascular remodeling in hypertension. Despite a plethora of data implicating oxidative stress as a causative factor in experimental hypertension, findings in human hypertension are less conclusive. This review highlights the importance of ROS in vascular biology and focuses on the potential role of oxidative stress in human hypertension.

  16. Effect of Lowering Asymmetric Dimethylarginine (ADMA on Vascular Pathology in Atherosclerotic ApoE-Deficient Mice with Reduced Renal Mass

    Directory of Open Access Journals (Sweden)

    Johannes Jacobi


    Full Text Available The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS inhibitor asymmetric dimethylarginine (ADMA and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1, on atherosclerosis in subtotally nephrectomized (SNX ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n = 39 and C57Bl/6J wild-type littermates (WT, n = 27 with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction ApoE-competent DDAH1 transgenic and wild-type littermates (n = 11 served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD in this mouse model.

  17. Paraneoplastic hormones: parathyroid hormone-related protein (PTHrP) and erythropoietin (EPO) are related to vascular endothelial growth factor (VEGF) expression in clear cell renal cell carcinoma. (United States)

    Feng, Chen-chen; Ding, Guan-xiong; Song, Ning-hong; Li, Xuan; Wu, Zhong; Jiang, Hao-wen; Ding, Qiang


    To investigate the correlation between parathyroid hormone-related protein (PTHrP), erythropoietin (EPO), and vascular endothelial growth factor (VEGF) expression in clear cell renal cell carcinoma (ccRCC). Immunohistochemical studies on PTHrP, EPO and VEGF were performed in 249 patients with ccRCC. Serum calcium level and haematocrit were analyzed. The expression of the factors and clinicopathological parameters were studied statistically for possible correlations. The incidence for hypercalcaemia and polycythaemia were 15.3% and 2.0% respectively. Expression of PTHrP, EPO, and VEGF were respectively related to advanced stage (P PTHrP was not related to tumour grade. Expressions of EPO and VEGF were correlated to tumour grade significantly. All factors were expressed higher in hypercalcaemic patients. PTHrP, EPO, and VEGF were positively correlated with each other in non-hypercalcaemic patients yet not in hypercalcaemic ones. PTHrP and EPO are related to VEGF expression and to the progression of ccRCC. This finding offers us new insight on the behaviour of ccRCC and offers possible targets in RCC treatment.

  18. Tone compatibility between HDR displays (United States)

    Bist, Cambodge; Cozot, Rémi; Madec, Gérard; Ducloux, Xavier


    High Dynamic Range (HDR) is the latest trend in television technology and we expect an in ux of HDR capable consumer TVs in the market. Initial HDR consumer displays will operate on a peak brightness of about 500-1000 nits while in the coming years display peak brightness is expected to go beyond 1000 nits. However, professionally graded HDR content can range from 1000 to 4000 nits. As with Standard Dynamic Range (SDR) content, we can expect HDR content to be available in variety of lighting styles such as low key, medium key and high key video. This raises concerns over tone-compatibility between HDR displays especially when adapting to various lighting styles. It is expected that dynamic range adaptation between HDR displays uses similar techniques as found with tone mapping and tone expansion operators. In this paper, we survey simple tone mapping methods of 4000 nits color-graded HDR content for 1000 nits HDR displays. We also investigate tone expansion strategies when HDR content graded in 1000 nits is displayed on 4000 nits HDR monitors. We conclude that the best tone reproduction technique between HDR displays strongly depends on the lighting style of the content.

  19. Vascular access for incident hemodialysis patients in Catalonia: analysis of data from the Catalan Renal Registry (2000-2011). (United States)

    Roca-Tey, Ramon; Arcos, Emma; Comas, Jordi; Cao, Higini; Tort, Jaume


    Arteriovenous fístula is the best vascular access (VA) for hemodialysis. We analyzed the VA used at first session and the factors associated with the likelihood to start hemodialysis by fistula in 2000-2011. Data of VA type were obtained in 9,956 incident hemodialysis patients from the Catalan Registry. Overall, 47.9% of patients initiated hemodialysis with a fistula, 1.2% with a graft, 15.9% with a tunneled catheter and 35% with an untunneled catheter. The percentage of incident patients with fistula and catheter has remained stable at around 50% over the years. The likelihood to start hemodialysis with fistula was significantly lower in females [adjusted odds ratio: 0.69, 95% confidence interval (CI): 0.61-0.75], patients aged 18-44 years (0.78, 95% CI: 0.64-0.94), patients with comorbidity (0.67, 95% CI: 0.60-0.75) and tended to be lower in patients aged over 74 years (0.89, 95% CI: 0.78-1.01). The probability to use fistula was significantly higher in patients with polycystic kidney disease (2.08, 95% CI: 1.63-2.67), predialysis nephrology care longer than 2 years (4.14, 95% CI: 3.63-4.73) and steady chronic kidney disease (CKD) progression (10.97, 95% CI: 8.41-14.32). During 1 year of follow-up, 67.2% and 59.6% of patients using untunneled and tunneled catheter changed to fistula, respectively. Starting hemodialysis by fistula was related with nonmodifiable patient characteristics and modifiable CKD practice processes, such as predialysis care duration. Half of the incident patients were exposed annually in Catalonia to potential catheter complications. This scenario can be improved by optimizing the processes of CKD care.

  20. Influence of acute renal failure on coronary vasoregulation in dogs. (United States)

    Kingma, John G; Vincent, Chantal; Rouleau, Jacques R; Kingma, Iris


    Impaired renal function is associated with an increased risk for cardiovascular events and death, but the pathophysiology is poorly defined. The hypothesis that coronary blood flow regulation and distribution of ventricular blood flow could be compromised during acute renal failure (ARF) was tested. In two separate groups (n = 14 each) of dogs with ARF, (1) coronary autoregulation (pressure-flow relations), vascular reserve (reactive hyperemia), and myocardial blood flow distribution (microspheres) and (2) coronary vessel responses to intracoronary infusion of select endothelium-dependent and -independent vasodilators were evaluated. In addition, coronary pressure-flow relations and vascular reserve after inhibition of nitric oxide and prostaglandin release were evaluated. Under resting conditions, myocardial oxygen consumption increased in dogs with ARF compared with no renal failure (NRF; 11.8 +/- 9.2 versus 5.0 +/- 1.5 ml O(2)/min per 100 g; P = 0.01), and the autoregulatory break point of the coronary pressure-flow relation was shifted to higher diastolic coronary pressures (60 +/- 17 versus 52 +/- 8 mmHg in NRF; P = 0.003); the latter was shifted further rightward after inhibition of both nitric oxide and prostaglandin release. The endocardial/epicardial blood flow ratio was comparable for both groups, suggesting preserved ventricular distribution of blood flow. In dogs with ARF, coronary vascular conductance also was reduced (P = 0.001 versus NRF), but coronary zero-flow pressure was unchanged. Vessel reactivity to each endothelium-dependent/independent compound also was blunted significantly. In conclusion, under resting conditions, coronary vascular tone, reserve, and vessel reactivity are markedly diminished with ARF, suggesting impaired vascular function. Consequently, during ARF, small increases in myocardial oxygen demand would induce subendocardial ischemia as a result of a limited capacity to increase oxygen supply and thereby contribute to higher

  1. Regulation of Vascular Tone, Angiogenesis and Cellular Bioenergetics by the 3-Mercaptopyruvate Sulfurtransferase/H2S Pathway: Functional Impairment by Hyperglycemia and Restoration by DL-α-Lipoic Acid. (United States)

    Coletta, Ciro; Módis, Katalin; Szczesny, Bartosz; Brunyánszki, Attila; Oláh, Gábor; Rios, Ester C S; Yanagi, Kazunori; Ahmad, Akbar; Papapetropoulos, Andreas; Szabo, Csaba


    Hydrogen sulfide (H2S), as a reducing agent and an antioxidant molecule, exerts protective effects against hyperglycemic stress in the vascular endothelium. The mitochondrial enzyme 3-mercaptopyruvate sulfurtransferase (3-MST) is an important biological source of H2S. We have recently demonstrated that 3-MST activity is inhibited by oxidative stress in vitro and speculated that this may have an adverse effect on cellular homeostasis. In the current study, given the importance of H2S as a vasorelaxant, angiogenesis stimulator and cellular bioenergetic mediator, we first determined whether the 3-MST/H2S system plays a physiological regulatory role in endothelial cells. Next, we tested whether a dysfunction of this pathway develops during the development of hyperglycemia and μmol/L to diabetes-associated vascular complications. Intraperitoneal (IP) 3-MP (1 mg/kg) raised plasma H2S levels in rats. 3-MP (10 1 mmol/L) promoted angiogenesis in vitro in bEnd3 microvascular endothelial cells and in vivo in a Matrigel assay in mice (0.3-1 mg/kg). In vitro studies with bEnd3 cell homogenates demonstrated that the 3-MP-induced increases in H2S production depended on enzymatic activity, although at higher concentrations (1-3 mmol/L) there was also evidence for an additional nonenzymatic H2S production by 3-MP. In vivo, 3-MP facilitated wound healing in rats, induced the relaxation of dermal microvessels and increased mitochondrial bioenergetic function. In vitro hyperglycemia or in vivo streptozotocin diabetes impaired angiogenesis, attenuated mitochondrial function and delayed wound healing; all of these responses were associated with an impairment of the proangiogenic and bioenergetic effects of 3-MP. The antioxidants DL-α-lipoic acid (LA) in vivo, or dihydrolipoic acid (DHLA) in vitro restored the ability of 3-MP to stimulate angiogenesis, cellular bioenergetics and wound healing in hyperglycemia and diabetes. We conclude that diabetes leads to an impairment of the 3-MST

  2. Multimodality intra-Arterial imaging assessment of the vascular trauma induced by balloon-based and nonballoon-based renal denervation systems

    NARCIS (Netherlands)

    A. Karanasos (Antonios); N.M. van Mieghem (Nicolas); M.W. Bergmann (Martin W.); E.M.J. Hartman (Eline); J.M.R. Ligthart (Jürgen); E. van der Heide (Elco); C.-H. Heeger (Christian-H.); M. Ouhlous (Mohamed); F. Zijlstra (Felix); E.S. Regar (Eveline); J. Daemen (Joost)


    textabstractBackground-Renal denervation is a new treatment considered for several possible indications. As new systems are introduced, the incidence of acute renal artery wall injury with relation to the denervation method is unknown. We investigated the acute repercussion of renal denervation on

  3. Synergistic effects of conjugated linoleic acid and chromium picolinate improve vascular function and renal pathophysiology in the insulin-resistant JCR:LA-cp rat. (United States)

    Proctor, S D; Kelly, S E; Stanhope, K L; Havel, P J; Russell, J C


    Conjugated linoleic acid (CLA) is a natural constituent of dairy products, specific isomers of which have recently been found to have insulin sensitizing and possible antiobesity actions. Chromium is a micronutrient which, as the picolinate (CrP), has been shown to increase insulin sensitivity in animal models, including the JCR:LA-cp rat. We tested the hypothesis that these agents may have beneficial synergistic effects on the micro- and macrovasculopathy associated with hyperinsulinaemia and early type 2 diabetes. Insulin-resistant cp/cp rats of the JCR:LA-cp strain were treated with mixed isomers of CLA (1.5% w/w in the chow) and/or CrP at 80 microg/kg/day (expressed as Cr) from 4 weeks of age to 12 weeks of age. Plasma insulin, lipid and adiponectin levels, aortic vascular function, renal function and glomerular sclerosis were assessed. CLA administration reduced food intake, body weight and fasting insulin in JCR:LA-cp rats. Plasma adiponectin levels were significantly elevated in rats treated with both CLA and CrP. Aortic hypercontractility was reduced and the relaxant response to the nitric oxide-releasing agent acetylcholine (Ach) was increased in CrP-treated rats. Striking reductions were also observed in the level of urinary albumin and the severity of glomerular sclerosis in rats treated specifically with CLA. CLA and CrP have beneficial effects ameliorating several of the pathophysiologic features of an insulin-resistant rat model. These supplements may be useful adjuncts in the management of patients with the metabolic syndrome and warrant further study.

  4. Vascular endothelial growth factor (VEGF)-targeted therapy for the treatment of adult metastatic Xp11.2 translocation renal cell carcinoma (United States)

    Choueiri, Toni K.; Lim, Zita Dubauskas; Hirsch, Michelle S.; Tamboli, Pheroze; Jonasch, Eric; McDermott, David F.; Cin, Paola Dal; Corn, Paul; Vaishampayan, Ulka; Heng, Daniel Y.C.; Tannir, Nizar M.


    Introduction Adult “translocation” renal cell carcinoma (RCC), bearing TFE3 gene fusions at Xp11.2, is a recently recognized unique entity for which prognosis and therapy remain poorly understood. We investigated the effect of vascular-endothelial growth factor (VEGF)-targeted therapy in this distinct subtype of RCC. Patients and Methods We conducted a retrospective review to describe the clinical characteristics and outcome of adult patients with metastatic Xp11.2 RCC, who had strong TFE-3 nuclear immunostaining, and received anti-VEGF therapy. Tumor response to anti-VEGF therapy was evaluated by RECIST. Kaplan-Meier methods were used to estimate progression-free survival (PFS) and overall survival (OS) distributions. Results Fifteen patients were identified of which 10, 3, and 2 received sunitinib, sorafenib and monoclonal anti-VEGF antibodies, respectively. The median follow-up was 19.1 months, the median age of the patients was 41 years, and the female:male ratio was 4:1. Initial histologic description included clear cell (n=8), papillary (n=1) or mixed clear cell/papillary RCC (n=6). Five patients had prior systemic therapy. Five patients had FISH analysis and all demonstrated a translocation involving chromosome Xp11.2. When treated with VEGF-targeted therapy, 3 patients had a partial response, 7 patients had stable disease and 5 patients had progressive disease. The median PFS and OS of the entire cohort were 7.1 months and 14.3 months respectively. Conclusion Adult-onset translocation-associated metastatic RCC is an aggressive disease that affects a younger population of patients with a female predominance. VEGF-targeted agents demonstrated some efficacy in this small retrospective series. PMID:20665500

  5. Impact of Pregnancy on Underlying Renal Disease


    Baylis, Chris


    Normal pregnancy involves marked renal vasodilation and large increases in glomerular filtration rate (GFR). Studies in rats reveal that the gestational renal vasodilation is achieved by parallel reductions in tone in afferent and efferent arterioles so GFR rises without a change in glomerular blood pressure. There is some evidence from animal studies that increased renal generation of nitric oxide (NO) may be involved. Although chronic renal vasodilation has been implicated in causing progre...

  6. Tone and inflection: An introduction


    Palancar, Enrique L.; Léonard, Jean-Léo


    Accepted in Enrique L. Palancar & Jean-Léo Léonard (eds.), Tone and Inflection: New facts under new perspectives. Submitted to DeGruyter, Oct. 2014; Tone is about melody and meaning, inflection is about grammar and this book is about a bit of both. The different papers in this book study possible and sometimes very complex ways in which the melodies of a given language engage in the expression of grammatical meaning. In this light, the volume aims to broaden our understanding of the role of t...

  7. Small artery tone under control of the endothelium : on the importance of EDHF and myogenic tone in organ (dys)function

    NARCIS (Netherlands)

    Gschwend, Simone Katharina


    Small artery tone is a major determinant of organ tissue blood flow and of total peripheral resistance. Pathophysiological alterations in small artery function towards a more constrictive state (“small artery dysfunction”) restricts the organ’s blood supply, and increases peripheral vascular

  8. Small artery tone under control of the endothelium : on the importance of EDHF and myogenic tone in organ (dys)function

    NARCIS (Netherlands)

    Gschwend, Simone Katharina


    Small artery tone is a major determinant of organ tissue blood flow and of total peripheral resistance. Pathophysiological alterations in small artery function towards a more constrictive state (“small artery dysfunction”) restricts the organ’s blood supply, and increases peripheral vascular resista

  9. Vascular function in health, hypertension, and diabetes

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Gliemann, Lasse; Hellsten, Ylva


    to the formation of vasodilators such as nitric oxide (NO) and prostacyclin. In essential hypertension and type II diabetes, the endothelial function and regulation of vascular tone is impaired with consequent increases in peripheral vascular resistance and inadequate regulation of oxygen supply to the skeletal...

  10. Impaired renal vascular response to a D-1-like receptor agonist but not to an ACE inhibitor in conscious spontaneously hypertensive rats

    NARCIS (Netherlands)

    de Vries, P.A.M.; Navis, Ger Jan; De Jong, P.E.; de Zeeuw, Dick


    The natriuretic response to a dopamine 1-like receptor agonist is blunted in spontaneously hypertensive rats (SHRs). Whether the renal vasodilator response to D-1-like receptor stimulation in SHRs is defective also is unclear. To determine whether the renal hemodynamic response to a D-1-like recepto

  11. Successful management of neonatal renal venous thrombosis. (United States)

    Piscitelli, Antonio; Galiano, Rossella; Piccolo, Vincenzo; Concolino, Daniela; Strisciuglio, Pietro


    Renal vein thrombosis is the most common vascular condition involving the newborn kidney and it can result in severe renal damage. We report a newborn with renal vein thrombosis treated with continuous infusion of unfractionated heparin who had normal total renal function after 3 years of follow up, despite reduction of the functional contribution of the affected kidney.

  12. [Complex vascular access]. (United States)

    Mangiarotti, G; Cesano, G; Thea, A; Hamido, D; Pacitti, A; Segoloni, G P


    Availability of a proper vascular access is a basic condition for a proper extracorporeal replacement in end-stage chronic renal failure. However, biological factors, management and other problems, may variously condition their middle-long term survival. Therefore, personal experience of over 25 years has been critically reviewed in order to obtain useful information. In particular "hard" situations necessitating complex procedures have been examined but, if possible, preserving the peripherical vascular features.

  13. Reduced KCNQ4-encoded voltage-dependent potassium channel activity underlies impaired ß-adrenoceptor-mediated relaxation of renal arteries in hypertension

    DEFF Research Database (Denmark)

    Chadha, Preet S; Zunke, Friederike; Zhu, Hai-Lei;


    KCNQ4-encoded voltage-dependent potassium (Kv7.4) channels are important regulators of vascular tone that are severely compromised in models of hypertension. However, there is no information as to the role of these channels in responses to endogenous vasodilators. We used a molecular knockdown...... strategy, as well as pharmacological tools, to examine the hypothesis that Kv7.4 channels contribute to ß-adrenoceptor-mediated vasodilation in the renal vasculature and underlie the vascular deficit in spontaneously hypertensive rats. Quantitative PCR and immunohistochemistry confirmed gene and protein...... spontaneously hypertensive rats, which was associated with ˜60% decrease in Kv7.4 abundance. This study provides the first evidence that Kv7 channels contribute to ß-adrenoceptor-mediated vasodilation in the renal vasculature and that abrogation of Kv7.4 channels is strongly implicated in the impaired ß...

  14. Designing Tone Reservation PAR Reduction

    Directory of Open Access Journals (Sweden)

    Johansson Albin


    Full Text Available Tone reservation peak-to-average (PAR ratio reduction is an established area when it comes to bringing down signal peaks in multicarrier (DMT or OFDM systems. When designing such a system, some questions often arise about PAR reduction. Is it worth the effort? How much can it give? How much does it give depending on the parameter choices? With this paper, we attempt to answer these questions without resolving to extensive simulations for every system and every parameter choice. From a specification of the allowed spectrum, for instance prescribed by a standard, including a PSD-mask and a number of tones, we analytically predict achievable PAR levels, and thus implicitly suggest parameter choices. We use the ADSL2 and ADSL2+ systems as design examples.

  15. Perception of Mandarin Chinese Tone 2/Tone 3 and the Role of Creaky Voice (United States)

    Cao, Rui


    Research has shown that lexical tones, a suprasegmental feature, are processed by native speakers as linguistic elements just like other segmental information. Among the four tones of Mandarin Chinese, in particular, Tone 2 and Tone 3 are very similar in their pitch contour shapes and thus can be difficult to distinguish in native and nonnative…

  16. Root Tone: A Holistic Approach to Tone Pedagogy of Western Classical Flute (United States)

    BastaniNezhad, Arya


    This article examines how key components of holistic tone production can help flutists form a resonant tone. This is framed in an exploration of tone pedagogy and includes a model of tone evaluation and education. This research is also applicable to other instrumentalists, especially wind players. In this case study information was collected by…

  17. The Role of Tone Height, Melodic Contour, and Tone Chroma in Melody Recognition. (United States)

    Massaro, Dominic W.; And Others


    Relationships among tone height, melodic contour, tone chroma, and recognition of recently learned melodies were investigated. Results replicated previous studies using familiar folk songs, providing evidence that melodic contour, tone chroma, and tone height contribute to recognition of both highly familiar and recently learned melodies.…

  18. Effects of acid-base imbalance on vascular reactivity

    Directory of Open Access Journals (Sweden)

    A.C. Celotto


    Full Text Available Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo and those occurring within the intracellular space (pHi, although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent, prostacyclin (PGI2/cAMP-dependent and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.

  19. Vascular Cures (United States)

    ... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...

  20. Anti-inflamatórios não esteroides: Efeitos cardiovasculares, cérebro-vasculares e renais Antiinflamatorios no esteroides: efectos cardiovasculares, cerebrovasculares y renales Nonsteroidal anti-inflammatory drugs: cardiovascular, cerebrovascular and renal effects

    Directory of Open Access Journals (Sweden)

    Michel Batlouni


    Full Text Available Os anti-inflamatórios não esteroides (AINEs encontram-se entre os medicamentos mais prescritos em todo o mundo. Essa classe heterogênea de fármacos inclui a aspirina e vários outros agentes inibidores da ciclo-oxigenase (COX, seletivos ou não. Os AINEs não seletivos são os mais antigos, e designados como tradicionais ou convencionais. Os AINEs seletivos para a COX-2 são designados COXIBEs. Nos últimos anos, tem sido questionada a segurança do uso dos AINEs na prática clínica, particularmente dos inibidores seletivos da COX-2. As evidências sobre o aumento do risco cardiovascular com o uso de AINEs são ainda incompletos, pela ausência de ensaios randomizados e controlados com poder para avaliar desfechos cardiovasculares relevantes. Entretanto, os resultados de estudos clínicos prospectivos e de meta-análises indicam que os inibidores seletivos da COX-2 exercem importantes efeitos cardiovasculares adversos, que incluem aumento do risco de infarto do miocárdio, acidente vascular cerebral, insuficiência cardíaca, insuficiência renal e hipertensão arterial. O risco desses efeitos adversos é maior em pacientes com história prévia de doença cardiovascular ou com alto risco para desenvolvê-la. Nesses pacientes, o uso de inibidores da COX-2 deve ser limitado àqueles para os quais não há alternativa apropriada e, mesmo assim, somente em doses baixas e pelo menor tempo necessário. Embora os efeitos adversos mais frequentes tenham sido relacionados à inibição seletiva da COX-2, a ausência de seletividade para essa isoenzima não elimina completamente o risco de eventos cardiovasculares, de modo que todos os fármacos do largo espectro dos AINEs somente devem ser prescritos após consideração do balanço risco/benefício.Los antiinflamatorios no esteroides (AINEs se encuentran entre los medicamentos más prescriptos en todo el mundo. Esta clase heterogénea de fármacos incluye la aspirina y varios otros agentes

  1. Angiotensin II blockade causes acute renal failure in eNOS-deficient mice

    Directory of Open Access Journals (Sweden)

    Jürgen Schnermann


    Full Text Available Compared with wild-type mice, adult endothelial nitric oxide synthase (eNOS knockout mice (eight months of age have increased blood pressure (BP (126±9 mmHg vs. 100±4 mmHg, and an increased renal vascular resistance (155±16 vs. 65±4 mmHg.min/ml. Renal vascular resistance responses to i.v. administration of noradrenaline were markedly enhanced in eNOS knockout mice. Glomerular filtration rate (GFR of anaesthetised eNOS -/- mice was 324±57 µl/min gKW, significantly lower than the GFR of 761±126 µl/min.gKW in wild-type mice. AT1-receptor blockade with i.v. candesartan (1—1.5 mg/kg reduced arterial blood pressure and renal vascular resistance, and increased renal blood flow (RBF to about the same extent in wild-type and eNOS -/- mice. Candesartan did not alter GFR in wild-type mice (761±126 vs. 720±95 µl/min.gKW, but caused a marked decrease in GFR in eNOS -/- mice (324.5±75.2 vs. 77±18 µl/min.gKW. A similar reduction in GFR of eNOS deficient mice was also caused by angiotensin-converting enzyme (ACE inhibition. Afferent arteriolar granularity, a measure of renal renin expression, was found to be reduced in eNOS -/- compared with wild-type mice. In chronically eNOS-deficient mice, angiotensin II (Ang II is critical for maintaining glomerular filtration pressure and GFR, presumably through its effect on efferent arteriolar tone.

  2. Ultrasound -- Vascular (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate ... the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces pictures ...

  3. Ultrasound -- Vascular (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate the ... are the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces ...

  4. Renal tubule cell repair following acute renal injury. (United States)

    Humes, H D; Lake, E W; Liu, S


    Experimental data suggests the recovery of renal function after ischemic or nephrotoxic acute renal failure is due to a replicative repair process dependent upon predominantly paracrine release of growth factors. These growth factors promote renal proximal tubule cell proliferation and a differentiation phase dependent on the interaction between tubule cells and basement membrane. These insights identify the molecular basis of renal repair and ischemic and nephrotoxic acute renal failure, and may lead to potential therapeutic modalities that accelerate renal repair and lessen the morbidity and mortality associated with these renal disease processes. In this regard, there is a prominent vasoconstrictor response of the renal vasculature during the postischemic period of developing acute renal failure. The intravenous administration of pharmacologic doses of atrial natriuretic factor (ANF) in the postischemic period have proven efficacious by altering renal vascular resistance, so that renal blood flow and glomerular filtration rate improve. ANF also appears to protect renal tubular epithelial integrity and holds significant promise as a therapeutic agent in acute renal failure. Of equal or greater promise are the therapeutic interventions targeting the proliferative reparative zone during the postischemic period. The exogenous administration of epidermal growth factor or insulin-like growth factor-1 in the postischemic period have effectively decreased the degree of renal insufficiency as measured by the peak serum creatinine and has hastened renal recovery as measured by the duration of time required to return the baseline serum creatinine values. A similarly efficacious role for hepatocyte growth factor has also been recently demonstrated.

  5. Manejo de accesos vasculares permanentes para hemodiálisis en los pacientes con enfermedad renal crónica del Hospital Hormero Castanier Crespo


    Ortega Cárdenas, Raquel Fernanda


    La enfermedad renal crónica afecta en promedio a una de cada diez personas en todo el mundo y se asocia con la diabetes mellitus y la hipertensión arterial siendo estas dos sus precursoras, tal como lo describe la Organización Mundial de la Salud (2014). Se estima que la prevalencia de enfermedades como la falla renal aumenta proporcionalmente con la esperanza de vida, permitiendo evidenciar el deterioro de órganos vitales como el riñón y las complicaciones derivadas de ello, como los altos c...

  6. Anatomia vascular das artérias renais e gonadais de Podocnemis unifilis Schweigger, 1812 (Testudines, Pelomedusidae - DOI: 10.4025/actascibiolsci.v31i2.680 Vascular anatomy of renal and gonadal arteries of Podocnemis unifilis Schweigger, 1812 (Testudines-Pelomedusidae - DOI: 10.4025/actascibiolsci.v31i2.680

    Directory of Open Access Journals (Sweden)

    Árthur Paulino Sanzo Kaminishi


    Full Text Available Este trabalho foi desenvolvido com o intuito de enriquecer o conhecimento sobre a morfologia vascular das artérias renais e gonadais de Podocnemis unifilis, facilitando o entendimento da fisiologia clínica e cirúrgica destes animais. Foram utilizados cinco exemplares machos de Podocnemis unifilis (tracajá, coletados segundo a Licença nº 066/2004-Ibama/RAM. A artéria carótida esquerda e a veia femoral direita foram canuladas e, pelas mesmas, foi introduzida solução fisiológica para lavagem do sistema vascular; em seguida, aplicou-se solução de Neoprene Látex “450” corada com pigmento específico (Globo S/A Tintas e Pigmentos. O material foi fixado em solução de Formol tamponado a 10% por um período mínimo de 96h. Uma abertura central e de formato quadrangular foi feita na metade caudal do plastrão e casco, de forma a expor os ramos da artéria aorta que irrigam os rins e as gônadas. Observou-se que as artérias renais se originam da face ventral da artéria aorta dorsal, em número de dois pares para cada rim e, em um único exemplar, elas originaram uma artéria renal direita e duas esquerdas. A artéria gonadal surgiu a partir da artéria renal, e apenas um par penetrou pela face dorsal de cada gônada.This work was developed with the aim of enriching knowledge on the vascular morphology of renal and gonadal arteries of Podocnemis unifilis, thus increasing the understanding of the clinical and surgical physiology of these animals. Five Podocnemis unifilis males were used, collected according to license no. 066/2004-Ibama/RAM. The left carotid artery and right femoral vein were cannulated, and a serum solution was introduced to remove obstructions from the vascular system. A solution of Neoprene Latex “450” dye was injected. The material was fixed in a solution of 10% formaldehyde for a period of 96 hours. Next, a square-shaped central opening was made in the caudal end of the plastron and bridge, exposing the

  7. Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves. (United States)

    Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H


    Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation.

  8. High-Dose Estradiol-Replacement Therapy Enhances the Renal Vascular Response to Angiotensin II via an AT2-Receptor Dependent Mechanism

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    Tahereh Safari


    Full Text Available Physiological levels of estrogen appear to enhance angiotensin type 2 receptor- (AT2R- mediated vasodilatation. However, the effects of supraphysiological levels of estrogen, analogous to those achieved with high-dose estrogen replacement therapy in postmenopausal women, remain unknown. Therefore, we pretreated ovariectomized rats with a relatively high dose of estrogen (0.5 mg/kg/week for two weeks. Subsequently, renal hemodynamic responses to intravenous angiotensin II (Ang II, 30–300 ng/kg/min were tested under anesthesia, while renal perfusion pressure was held constant. The role of AT2R was examined by pretreating groups of rats with PD123319 or its vehicle. Renal blood flow (RBF decreased in a dose-related manner in response to Ang II. Responses to Ang II were enhanced by pretreatment with estradiol. For example, at 300 ng kg−1 min−1, Ang II reduced RBF by 45.7±1.9% in estradiol-treated rats but only by 27.3±5.1% in vehicle-treated rats. Pretreatment with PD123319 blunted the response of RBF to Ang II in estradiol-treated rats, so that reductions in RBF were similar to those in rats not treated with estradiol. We conclude that supraphysiological levels of estrogen promote AT2R-mediated renal vasoconstriction. This mechanism could potentially contribute to the increased risk of cardiovascular disease associated with hormone replacement therapy using high-dose estrogen.

  9. The influence of the ACE (I/D) polymorphism on systemic and renal vascular responses to angiotensins in normotensive, normoalbuminuric Type 1 diabetes mellitus

    NARCIS (Netherlands)

    Luik, PT; Hoogenberg, K; Kerstens, MN; Beusekamp, BJ; de Jong, PE; Dullaart, RPF; Navis, GJ

    Aim/hypothesis. The renin-angiotensin-aldosterone system is important in diabetic nephropathy, with the angiotensin-converting-enzyme DD-genotype being a renal risk factor. The D-allele is associated with higher ACE concentrations, but functional consequences in diabetes mellitus are not known. To

  10. Rationale, design, and baseline characteristics of a trial of prevention of cardiovascular and renal disease with Fosinopril and Pravastatin in nonhypertensive, nonhypercholesterolemic subjects with microalbuminuria (the Prevention of REnal and Vascular ENdstage Disease Intervention Trial [PREVEND IT])

    NARCIS (Netherlands)

    Diercks, GFH; Janssen, WMT; van Boven, AJ; Bak, AAA; de Jong, PE; Crijns, HJGM; van Gilst, WH


    This study describes the rationale, design, and baseline characteristics of a trial to determine whether treatment with fosinopril 20 mg/day and/or pravastatin 40 mg/day will prevent cardiovascular and renal disease in nonhypertensive (RR 10 mg/L once in an early morning spot urine and 15 to 300 mg/

  11. Splenic and renal shunt vein post-transplantation:treatment with vascular plug assisted retrograde transvenous obliteration%肝移植术后残留脾肾分流的逆行介入封堵治疗

    Institute of Scientific and Technical Information of China (English)

    王浩; 陈光; 高海军; 伊正甲; 温连芳; 王鹏辉; 杨颐馨; 张莉


    目的:探讨经静脉逆向封堵治疗肝移植术后残留脾肾分流的技术安全性和临床有效性。方法回顾性分析3例肝移植术后残留脾肾分流患者的资料,所有患者均行经皮肝门静脉穿刺造影、测压,经股静脉逆向于脾肾分流道远端植入房间隔封堵器,对患者临床资料、影像随访资料、介入治疗的并发症和预后等情况进行总结。结果介入治疗的技术成功率为100%,无介入相关并发症发生。术后复查CT发现脾肾分流静脉完全闭塞,且术后1周及1个月复查超声显示门静脉血流量较术前明显增加。其中1例患者因胆道并发症接受二次肝移植,在平均4个月的随访中,该2例患者的肝功能、门静脉血流均较术前明显改善。结论经静脉逆向封堵治疗肝移植术后残留脾肾分流是一种安全、有效且微创的治疗方法。%Objective To evaluate the therapeutic results of vascular plug-assisted retrograde transvenous obliteration(RTO) for treatment of splenic and renal shunt vein following liver transplantation.Methods3 patients who had undergone vascular plug-assisted RTO were etrospectively evaluated from August2015 to February 2016. Percutaneous transhepatic angiography of the portal vein was performed in all patients,and then retrograde transvenous placement of a vascular plug in the shunt vein. The clinical data, imaging follow-up data, complications of interventional treatment and prognosis was summarized.Results In all patients,the percutaneous transhepatic angioplasty and placement of the vascular plug successfully, with no procedure-related complications. Follow-up CT after vascular plug-assisted RTO showed complete thrombosis of shunts in all patients,follow-up ultrasonic doppler within1 week and1 month the portal vein blood flow increase obviously.1 patient received second liver transplantation because of the biliary tract complications. Improvement in Child-Pugh score was

  12. Ultrasound-guided percutaneous renal biopsy-induced accessory renal artery bleeding in an amyloidosis patient

    Directory of Open Access Journals (Sweden)

    Zhang Qing


    Full Text Available Abstract Ultrasound-guided percutaneous renal biopsy is an important technique for diagnosis of glomerular diseases, and the biopsy-induced life-threatening bleeding rarely happens. Primary systemic amyloidosis is a rare disease which may lead to organ dysfunction including arterial stiffness. The accessory renal artery is a kind of renal vascular variation which goes into the renal parenchyma directly or via the renal hilum. Here we reported a rare case of percutaneous renal biopsy-induced accessory renal artery life-threatening bleeding in a renal amyloidosis patient, and our experience of successful rescue in this patient. Virtual Slides

  13. Renal involvement in antiphospholipid syndrome. (United States)

    Pons-Estel, Guillermo J; Cervera, Ricard


    Renal involvement can be a serious problem for patients with antiphospholipid syndrome (APS). However, this complication has been poorly recognized and studied. It can be present in patients who have either primary or systemic lupus erythematosus-associated APS. Clinical and laboratory features of renal involvement in APS include hypertension, hematuria, acute renal failure, and progressive chronic renal insufficiency with mild levels of proteinuria that can progress to nephrotic-range proteinuria. The main lesions are renal artery stenosis, venous renal thrombosis, and glomerular lesions (APS nephropathy) that may be acute (thrombotic microangiopathy) and/or chronic (arteriosclerosis, arterial fibrous intimal hyperplasia, tubular thyroidization, arteriolar occlusions, and focal cortical atrophy). APS can also cause end-stage renal disease and allograft vascular thrombosis. This article reviews the range of renal abnormalities associated with APS, and their diagnosis and treatment options.

  14. Plasma 1,25-Dihydroxyvitamin D and the Risk of Developing Hypertension : The Prevention of Renal and Vascular End-Stage Disease Study

    NARCIS (Netherlands)

    van Ballegooijen, Adriana J.; Gansevoort, Ron T.; Lambers-Heerspink, Hiddo J.; de Zeeuw, Dick; Visser, Marjolein; Brouwer, Ingeborg A.; Kema, Ido P.; de Borst, Martin H.; Bakker, Stephan J. L.; Joosten, Michel M.


    Previous observational studies on the vascular effects of vitamin D have predominantly relied on measurement of its inactive precursor, 25-hydroxyvitamin D, whereas the active metabolite 1,25-dihydroxyvitamin D may be of more physiological relevance. We prospectively studied the associations of 1,25

  15. The Phonology and Phonetics of Tone Perception (United States)

    Ramadoss, Deepti


    This dissertation studies the perception of tones in Thai, and aims to contribute to a formal characterization of speech perception more generally. Earlier work had argued that perception of tones involves retrieval of some abstract "autosegmental" representation provided by the phonology, while another line of work had argued for the…

  16. The Phonology and Phonetics of Tone Perception (United States)

    Ramadoss, Deepti


    This dissertation studies the perception of tones in Thai, and aims to contribute to a formal characterization of speech perception more generally. Earlier work had argued that perception of tones involves retrieval of some abstract "autosegmental" representation provided by the phonology, while another line of work had argued for the…

  17. Recovering Asynchronous Watermark Tones from Speech (United States)


    Audio steganography for covert data transmission by impercep- tible tone insertion,” Proceedings Communications Sys- tems and Applications, IEEE, vol. 4, pp. 1647–1653, 2004. 1408 a comfortable margin. Index Terms— Speech Watermarking, Hidden Tones, Speech Steganography , Speech Data Hiding 1. BACKGROUND Imperceptibly

  18. Lexical tone and stuttering in Cantonese. (United States)

    Law, Thomas; Packman, Ann; Onslow, Mark; To, Carol K-S; Tong, Michael C-F; Lee, Kathy Y-S


    Cantonese is a tone language, in which the variation of the fundamental frequency contour of a syllable can change meaning. There are six different lexical tones in Cantonese. While research with Western languages has shown an association between stuttering and syllabic stress, nothing is known about whether stuttering in Cantonese speakers is associated with one or more of the six lexical tones. Such an association has been reported in conversational speech in Mandarin, which is also a tone language, but which varies markedly from Cantonese. Twenty-four native Cantonese-speaking adults who stutter participated in this study, ranging in age from 18-33 years. There were 18 men and 6 women. Participants read aloud 13 Cantonese syllables, each of which was produced with six contrastive lexical tones. All 78 syllables were embedded in the same carrier sentence, to reduce the influence of suprasegmental or linguistic stress, and were presented in random order. No significant differences were found for stuttering moments across the six lexical tones. It is suggested that this is because lexical tones, at least in Cantonese, do not place the task demands on the speech motor system that typify varying syllabic stress in Western languages: variations not only in fundamental frequency, but also in duration and intensity. The findings of this study suggest that treatments for adults who stutter in Western languages, such as speech restructuring, can be used with Cantonese speakers without undue attention to lexical tone.

  19. Influence of Exposure to Chronic Persistent Low-Dose Ionizing Radiation on the Tumor Biology of Clear-Cell Renal-Cell Carcinoma. An Immunohistochemical and Morphometric Study of Angiogenesis and Vascular Related Factors. (United States)

    Ruiz-Saurí, Amparo; Valencia-Villa, Gerardo; Romanenko, Alina; Pérez, Jesús; García, Raúl; García, Heydi; Benavent, José; Sancho-Tello, María; Carda, Carmen; Llombart-Bosch, Antonio


    Increased angiogenesis is related to boosted growth and malignancy in carcinomas. "Chronic Persistent Low-Dose Ionizing Radiation" (CPLDIR) exposure increases incidence and aggressive behavior of clear-cell renal-cell carcinoma (CCRCC). The aim was to study the biology of angiogenesis, including microvessel density (MVD), in human clear-cell renal-cell carcinomas (CCRCC) originating from a radio-contaminated geographical area (Ukraine) and to compare with similar tumors diagnosed in non-contaminated regions of Europe (Spain, Valencia) and Latin America (Colombia, Barranquilla). MVD was comparatively examined in 124 patients diagnosed with CCRCC from three geographical areas by means of digital micro-imaging and computerized analysis. Additionally, 50 adult normal kidneys were used for controls (autopsy kidneys from Valencia and Barranquilla). Furthermore, an immunohistochemical study of several vascular related growth factors was undertaken using a similar methodology. MVD as well as VEFG are the most discriminating factors associated with an aggressive behavior of CCRCC. Their expression increased in proportion to the level of exposure to chronic low-dose ionizing radiation in Ukrainian patients in the 25 years since the Chernobyl accident substantiated by comparison with the two control groups of renal carcinomas present in non-irradiated areas (Spain and Colombia). No major biological differences relating to angiogenesis appear to exist between the CCRCC diagnosed in two distant geographical areas of the world. HIF-1α expression was similar in all groups, with no statistical significance. Present findings demonstrate the existence of a significant relationship between MVD and VEGF in CCRCC: an increased expression of VEGF is associated with a high level of angiogenesis.

  20. Vascular Cures (United States)

    ... is Possible EVERY DOLLAR SAVES LIVES. Donate Now Vascular Cures innovates patient-centered research, catalyzes breakthrough collaborations and empowers people in their vascular health journey. what is vascular disease PATIENTS see ...

  1. Vascular ring (United States)

    ... subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... Vascular ring is rare. It accounts for less than 1% of all congenital heart problems. The condition ...

  2. Perception and production of tone in aphasia. (United States)

    Gandour, J; Petty, S H; Dardarananda, R


    An acoustical and perceptual study of lexical tone was conducted to evaluate the extent and nature of tonal disruption in aphasia. The language under investigation was Thai, a tone language which has five lexical tones--mid, low, falling, high, and rising. Subjects included six left brain-damaged aphasics (two Broca's, one transcortical motor, one global, one conduction, one Wernicke), one right brain-damaged nonaphasic, one cerebellar dysarthric, and five normals. High-quality tape recordings of each subject's productions of a minimal set of five, monosyllabic Thai words were presented to 10 adult Thai listeners for identification. Results from the phonemic identification tests indicated that tone production is relatively spared in aphasic patients with unilateral left hemisphere lesions. The performance of the global aphasic, however, was considerably below normal. Patterns of tonal confusions further revealed that the performance of all aphasics, except the global, differed from that of normal speakers primarily in degree rather than in kind. Tonal contrasts were signaled at a high level of proficiency by the right brain-damaged and dysarthric patients. Acoustical analysis revealed that F0 contours associated with the five tones for all aphasics, except the global, were similar in overall shape as well as position in the tone space to those of normals. F0 contours for the right brain-damaged patient and the dysarthric also generally agreed with those of normals in terms of shape and position. F0 ranges of both aphasic and nonaphasic brain-damaged speakers were generally larger than those of normals for all five tones. The relationship between tone and vowel duration was generally similar to that of normals for all brain-damaged speakers. A comparison of aphasics' performance on tone perception (J. Gandour & R. Dardarananda, 1983, Brain and Language, 18, 94-114) and tone production indicated that, for the normal and right brain-damaged subjects, performance on

  3. Dopamine D1-like receptor stimulation inhibits hypertrophy induced by platelet-derived growth factor in cultured rat renal vascular smooth muscle cells. (United States)

    Yasunari, K; Kohno, M; Kano, H; Yokokawa, K; Minami, M; Yoshikawa, J


    Vascular smooth muscle cell (VSMC) hypertrophy is believed to play some roles in atherosclerosis. To elucidate the role of vascular D1-like receptors in VSMC hypertrophy, the effects of dopamine and specific D1-like receptor agonists SKF 38393 and YM 435 on platelet-derived growth factor (PDGF) BB-mediated VSMC hypertrophy was studied. We observed that cells stimulated by PDGF-BB 5 ng/mL showed increased VSMC hypertrophy. These effects were prevented by coincubation with dopamine, SKF 38393, and YM 435 1-10 mumol/L, and this prevention was reversed by Sch 23390 1 to 10 mumol/L, a specific D1-like receptor antagonist. These actions are mimicked by forskolin 1 to 10 mumol/L, a direct activator of adenylate cyclase and 8-bromo-cAMP 0.1 to 1 mmol/L, and are blocked by a specific protein kinase A (PKA) inhibitor N-[2-(P-bromcoinnamylamino)ethyl]-5-isoquinoline-sulfonamide (H89) but not blocked by its negative control. PDGF-BB (5 ng/mL)-mediated mitogen-activated protein kinase (MAPK) activity was significantly suppressed by coincubation with D1-like receptor agonists, which were reversed by PKA inhibitor H 89. These results suggest that vascular D1-like receptor agonists inhibit hypertrophy of VSMC, possibly through PKA activation and suppression of activated MAPK activity.

  4. Antioxidants Condition Pleiotropic Vascular Responses to Exogenous H2O2: Role of Modulation of Vascular TP Receptors and the Heme Oxygenase System (United States)

    Zhang, Fan; Monu, Sumit R.; Sodhi, Komal; Bellner, Lars; Lamon, Brian D.; Zhang, Yilun; Abraham, Nader G.; Nasjletti, Alberto


    Abstract Aims: Hydrogen peroxide (H2O2), a nonradical oxidant, is employed to ascertain the role of redox mechanisms in regulation of vascular tone. Where both dilation and constriction have been reported, we examined the hypothesis that the ability of H2O2 to effect vasoconstriction or dilation is conditioned by redox mechanisms and may be modulated by antioxidants. Results: Exogenous H2O2 (0.1–10.0 μM), dose-dependently reduced the internal diameter of rat renal interlobular and 3rd-order mesenteric arteries (pantioxidants, including tempol, pegylated superoxide dismutase (PEG-SOD), butylated hydroxytoluene (BHT), and biliverdin (BV). However, as opposed to tempol or PEG-SOD, BHT & BV, antioxidants targeting radicals downstream of H2O2, also uncovered vasodilation. Innovations: Redox-dependent vasoconstriction to H2O2 was blocked by inhibitors of cyclooxygenase (COX) (indomethacin-10 μM), thromboxane (TP) synthase (CGS13080-10 μM), and TP receptor antagonist (SQ29548-1 μM). However, H2O2 did not increase vascular thromboxane B2 release; instead, it sensitized the vasculature to a TP agonist, U46619, an effect reversed by PEG-SOD. Antioxidant-conditioned dilatory response to H2O2 was accompanied by enhanced vascular heme oxygenase (HO)-dependent carbon monoxide generation and was abolished by HO inhibitors or by HO-1 & 2 antisense oligodeoxynucleotides treatment of SD rats. Conclusion: These results demonstrate that H2O2 has antioxidant-modifiable pleiotropic vascular effects, where constriction and dilation are brought about in the same vascular segment. H2O2-induced oxidative stress increases vascular TP sensitivity and predisposes these arterial segments to constrictor prostanoids. Conversely, vasodilation is reliant upon HO-derived products whose synthesis is stimulated only in the presence of antioxidants targeting radicals downstream of H2O2. Antioxid. Redox Signal. 18, 471–480. PMID:22867102

  5. Regulation of Vascular Function on Posttranscriptional Level

    Directory of Open Access Journals (Sweden)

    Andreas Eisenreich


    Full Text Available Posttranscriptional control of gene expression is crucial for regulating plurality of proteins and functional plasticity of the proteome under (pathophysiologic conditions. Alternative splicing as well as micro (miRNA-mediated mechanisms play an important role for the regulation of protein expression on posttranscriptional level. Both alternative splicing and miRNAs were shown to influence cardiovascular functions, such as endothelial thrombogenicity and the vascular tone, by regulating the expression of several vascular proteins and their isoforms, such as Tissue Factor (TF or the endothelial nitric oxide synthase (eNOS. This review will summarize and discuss the latest findings on the (pathophysiologic role of alternative splicing processes as well as of miRNAs on modulation of vascular functions, such as coagulation, thrombosis, and regulation of the vascular tone.

  6. Valoración pronóstica de las complicaciones vasculares en el trasplante renal mediante el uso de ecopotenciadores


    Hermosín Peña, Antonio


    El estudio en el trasplante renal abarco una serie de diferentes técnias o exploraciones, desde un análisis morfoestructural del injerto mediante ecografía, hasta la valoración funcional con el uso de métodos diagnósticos no radiológicos. El paciente trasplantado era sometido a una cadena de técnicas diagnosticas, realizadas en las primeras 24 horas posttrasplante. Las técnicas radiológicas empleadas fueron la ecografía Modo B, Doppler Color-Espectral y la Ecografía con contraste ecográ...

  7. Catheter dysfunction and dialysis performance according to vascular access among 736 critically ill adults requiring renal replacement therapy: a randomized controlled study. (United States)

    Parienti, Jean-Jacques; Mégarbane, Bruno; Fischer, Marc-Olivier; Lautrette, Alexandre; Gazui, Nicole; Marin, Nathalie; Hanouz, Jean-Luc; Ramakers, Michel; Daubin, Cédric; Mira, Jean-Paul; Charbonneau, Pierre; du Cheyron, Damien


    To compare dialysis catheter function according to catheter site. Multicenter, open, randomized controlled trial. Nine university-affiliated hospitals and three general hospitals in France. Seven hundred thirty-six patients in intensive care units who required a first venous catheterization to perform either intermittent hemodialysis (470 patients with 1275 sessions) or continuous renal replacement therapy (266 patients with 1003 days). Patients randomly received either femoral (n = 370) or jugular (n = 366) catheterization. For the jugular site, right-side position (n = 252) was recommended. Time to catheter ablation for dysfunction, urea reduction ratio (intermittent hemodialysis), and downtime (continuous renal replacement therapy) were assessed for all participants and evaluated by randomly assigned catheterization site (femoral or jugular). Baseline demography and dialysis prescriptions were similar between the site arms. In modified intent-to-treat, catheter dysfunction occurred in 36 of 348 (10.3%) and 38 of 342 (11.1%) patients in the femoral and jugular groups, respectively. The risk of catheter dysfunction did not significantly differ between randomized groups (hazard ratio, 1.06; 95% confidence interval, 0.67-1.68; p = .80). Compared to the femoral site, the observed risk of dysfunction decreased in the right jugular position (15 of 226; 6.6%; adjusted hazard ratio, 0.58; 95% confidence interval, 0.31-1.07; p = .09) and significantly increased in the left jugular position (23 of 118; 19.5%; adjusted hazard ratio, 1.89; 95% confidence interval, 1.12-3.21; p hemodialysis mean urea reduction ratio per session was 50.8% (standard deviation, 16.1) for femoral vs. 52.8% (standard deviation, 15.8) for jugular (p = .30) sites, and the median continuous renal replacement therapy downtime per patient-day was 1.17 hrs (interquartile range, 0.75-1.50) for both sites (p = .98). In terms of catheter dysfunction and dialysis performance among critically ill adults

  8. The pulsatility index and the resistive index in renal arteries. Associations with long-term progression in chronic renal failure

    DEFF Research Database (Denmark)

    Petersen, L J; Petersen, J R; Talleruphuus, U


    The pulsatility index (PI) and the resistive index (RI) are used as pulsed-wave Doppler measurements of downstream renal artery resistance. PI and RI have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma flow in chronic renal failure. The aim...

  9. Impaired renal allograft function is associated with increased arterial stiffness in renal transplant recipients

    DEFF Research Database (Denmark)

    Kneifel, M; Scholze, A; Burkert, A;


    It is important whether impairment of renal allograft function may deteriorate arterial stiffness in renal transplant recipients. In a cross-sectional study, arterial vascular characteristics were non-invasively determined in 48 patients with renal allograft using applanation tonometry and digital...... of large arteries S1 and small arteries S2 in renal transplant recipients (each p renal allograft (p ...-Wallis test between groups). It is concluded that impairment of renal allograft function is associated with an increased arterial stiffness in renal transplant recipients....

  10. 二维联合实时三维超声造影在检测移植肾血管并发症中的应用%The application value of two-dimensional contrast-enhanced ultrasound combined with real time three-dimensional con-trast-enhanced ultrasound in detecting transplant renal vascular complications

    Institute of Scientific and Technical Information of China (English)

    张艳; 马苏亚; 谢晓红; 马骥; 胡杏珍; 张斌


    Objective To discuss the application value of 2D-CEUS and RT3D-CEUS in the evaluation of transplant renal vas-cular complications.Methods A retrospective analysis was performed with 2D-CEUS and RT3D-CEUS datas in 19 patients suf-fered from vascular complications of renal transplantation.The diagnosis standard based on computer temography angiography (CTA) and digital subtraction angiography (DSA) was set to evaluate the diagnostic value of 2D-CEUS and RT3D-CEUS in transplant renal vascular complications.Results Among 19 cases of transplant renal vascular complications performed by 2D-CEUS and RT3D-CEUS, 16 were transplant renal artery stenosis, 2 were vein stenosis and 1 case was acute renal artary occlusion combined with focal infarction 1 year after stent implantation.All results were consistent with CTA or DSA.Conclusion The combination of 2D-CEUS and 3D-CEUS was an efficiency way in the diagnosis of transplant renal vascular complications.%目的:探讨二维联合实时三维超声造影在移植肾血管并发症中的应用价值。方法回顾性分析19例移植肾血管异常的患者的二维及实时三维超声造影图像资料,以CT血管造影( CTA)、数字减影血管造影( DSA)为诊断标准,分析二维及实时三维超声造影在移植肾血管并发症中的诊断价值。结果接受超声造影的19例患者中,移植肾动脉狭窄16例,移植肾静脉狭窄2例,移植肾动脉支架术后一年急性闭塞合并肾内局灶性梗死1例,所有病例结果与CTA或DSA检查结果吻合。结论二维联合实时三维超声造影是诊断移植肾血管并发症的有效手段。

  11. ADVANCE: Study to Evaluate Cinacalcet Plus Low Dose Vitamin D on Vascular Calcification in Subjects With Chronic Kidney Disease Receiving Hemodialysis (United States)


    Chronic Kidney Disease; End Stage Renal Disease; Coronary Artery Calcification; Vascular Calcification; Calcification; Cardiovascular Disease; Chronic Renal Failure; Hyperparathyroidism; Kidney Disease; Nephrology; Secondary Hyperparathyroidism

  12. Musical imagery: generation of tones and chords. (United States)

    Hubbard, T L; Stoeckig, K


    Four experiments are reported that examine subjects' ability to form and use images of tones and chords. In Experiments 1 and 3, subjects heard a cue tone or chord and formed an image of a tone or chord one whole step in pitch above the cue. This image was then compared to a probe tone or chord that was either the same as the image in pitch, different from the image in pitch and harmonically closely related, or different and harmonically distantly related. Image formation times and response times were measured. In Experiment 3 a random-tone mask was used to control for possible contribution of the cue in echoic memory. In both experiments tone images were formed faster than chord images, a result consistent with the idea of structural complexity as a determinant of image formation time. Response times and accuracy rates were found to parallel results found in music perception studies, results consistent with the idea of shared mechanisms in the processing of musical images and percepts. Experiments 2 and 4 were control experiments examining the possible influence of demand characteristics and subjects' knowledge. In experiment 2 subjects predicted the results of "an average person" using imagery, and in Experiment 4 subjects completed the task without receiving imagery instructions. The findings ruled out the possibility that demand characteristics and subjects' knowledge were solely responsible for the results of Experiments 1 and 3 and support the argument for the role of imagery.

  13. A novel microporous polyurethane vascular graft: in vivo evaluation of the UTA prosthesis implanted as infra-renal aortic substitute in dogs. (United States)

    Marois, Y; Akoum, A; King, M; Guidoin, R; von Maltzahn, W; Kowligi, R; Eberhart, R C; Teijeira, F J; Verreault, J


    A novel microporous polyurethane blood conduit developed at the University of Texas at Arlington was implanted as an infra-renal substitute in dogs. The prosthesis was fabricated by precipitating a solution of the polymer with dry nitrogen onto a rotating mandrel. The grafts were sterilized either by gamma radiation (series I) or ethylene oxide (series II); they were implanted for the following prescheduled periods: 4, 24, 48 hours, and 1 week (short-term) and 2, 4 weeks, 3 and 6 months (medium-term). The thrombohematological characteristics of each animal were evaluated prior to implantation and confirmed that the index of blood coagulability was normal. In the short-term group, five out of eight grafts were patent and three were partially occluded; four grafts in the medium-term group were patent; one was partially occluded; and three were thrombosed at retrieval. One week after implantation, the prostheses were surrounded by an external capsule, which was present mainly at the two anastomoses. The external capsule covered the entire graft at 3 months. No kinking of the grafts was observed and the presence of a mild yellow stain related to bilirubin uptake was detected at 2 weeks, 1, 3, and 6 months. Histological studies have revealed the formation of a thin internal capsule at both anastomoses, 2 weeks postimplantation, which was not anchored to the graft wall. In the medium-term group, the thrombosed grafts failed to develop an internal capsule, whereas the patent graft exhibited a thick internal capsule made of neocollagenous tissue over the entire graft. This new microporous polyurethane prosthesis did not perform satisfactorily as an infra-renal substitute in dogs and its in vivo stability requires further assessment. Thus, the concept of a polyurethane with closed pores does not achieve what was anticipated.

  14. Preattentive cortical-evoked responses to pure tones, harmonic tones, and speech: influence of music training. (United States)

    Nikjeh, Dee A; Lister, Jennifer J; Frisch, Stefan A


    Cortical auditory evoked potentials, including mismatch negativity (MMN) and P3a to pure tones, harmonic complexes, and speech syllables, were examined across groups of trained musicians and nonmusicians. Because of the extensive formal and informal auditory training received by musicians throughout their lifespan, it was predicted that these electrophysiological indicators of preattentive pitch discrimination and involuntary attention change would distinguish musicians from nonmusicians and provide insight regarding the influence of auditory training and experience on central auditory function. A total of 102 (67 trained musicians, 35 nonmusicians) right-handed young women with normal hearing participated in three auditory stimulus conditions: pure tones (25 musicians/15 nonmusicians), harmonic tones (42 musicians/20 nonmusicians), and speech syllables (26 musicians/15 nonmusicians). Pure tone and harmonic tone stimuli were presented in multideviant oddball paradigms designed to elicit MMN and P3a. Each paradigm included one standard and two infrequently occurring deviants. For the pure tone condition, the standard pure tone was 1000 Hz, and the two deviant tones differed in frequency from the standard by either 1.5% (1015 Hz) or 6% (1060 Hz). The harmonic tone complexes were digitally created and contained a fundamental frequency (F0) and three harmonics. The amplitude of each harmonic was divided by its harmonic number to create a natural amplitude contour in the frequency spectrum. The standard tone was G4 (F0 = 392 Hz), and the two deviant tones differed in fundamental frequency from the standard by 1.5% (F0 = 386 Hz) or 6% (F0 = 370 Hz). The fundamental frequencies of the harmonic tones occur within the average female vocal range. The third condition to elicit MMN and P3a was designed for the presentation of speech syllables (/ba/ and /da/) and was structured as a traditional oddball paradigm (one standard/one infrequent deviant). Each speech stimulus was

  15. Ageing and vascular ageing (United States)

    Jani, B; Rajkumar, C


    There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the vascular wall, which leads to the loss of arterial elasticity and reduced arterial compliance. Arterial compliance can be measured by different parameters like pulse wave velocity, augmentation index, and systemic arterial compliance. There is evidence that arterial compliance is reduced in disease states such as hypertension, diabetes, and end stage renal failure. Changes in arterial compliance can be present before the clinical manifestation of cardiovascular disease. Pharmacological and non‐pharmacological measures have been shown to improve arterial compliance. Arterial compliance may constitute an early cardiovascular risk marker and may be useful in assessing the effects of drugs on the cardiovascular system. Pharmacogenetics and genetics of arterial compliance in the future will improve our knowledge and understanding about vascular ageing. PMID:16754702

  16. Juvenile growth reduces the influence of epithelial sodium channels on myogenic tone in skeletal muscle arterioles. (United States)

    Kang, Lori S; Masilamani, Shyama; Boegehold, Matthew A


    Previous studies have documented that rapid juvenile growth is accompanied by functional changes in the arteriolar endothelium, but much less is known about functional changes in arteriolar smooth muscle over this period. In this study, we investigate the possible contribution of epithelial sodium channels (ENaC) to the myogenic behaviour of arterioles at two stages of juvenile growth. The effects of the ENaC inhibitor benzamil on different levels of myogenic tone were studied in isolated gracilis muscle arterioles from rats aged 21-28 days ("weanlings") and 42-49 days ("juveniles"). ENaC subunit expression in the arteriolar wall was also determined, and the interaction between ENaC and nitric oxide (NO) in regulating vascular tone was explored by combined use of benzamil and N(G) -monomethyl-l-arginine (l-NMMA). At physiological pressures, both steady-state myogenic tone and the dynamic adjustments in this tone triggered by acute pressure changes were less in juvenile arterioles than in weanling arterioles. α, β and γ ENaC protein was present in arterioles at both ages, but benzamil only had an effect on myogenic tone in weanling arterioles. In these vessels, benzamil increased, rather than decreased, myogenic tone, and this effect was prevented by l-NMMA or endothelial removal. These findings suggest that although ENaC is present in gracilis muscle arterioles of both weanling and juvenile rats, it is not obligatory for the genesis of myogenic activity in these vessels at either age. However, ENaC activity can significantly modulate the level of myogenic tone through stimulation of endothelial NO release at an early stage of growth. © 2016 John Wiley & Sons Australia, Ltd.

  17. Post-transplant urological and vascular complications

    Directory of Open Access Journals (Sweden)

    Safa Javid


    Full Text Available To determine the prevalence of urological and vascular complications in renal trans-plant recipients (RTx at Tabriz Renal Transplant Center, we studied 55 recipients of renal allo-grafts (25 male and 29 female patients with a mean age of 38.3 ± 13.4 years from October 2005 to November 2006. The surgical complications in our study included hematomas: 20.4%, renal artery stenosis: 20.4%, calculi: 7.4%, hydronephrosis or ureteral stricture: 5.6%, urinary leakage: 5.6%, lymphoceles: 1.9%, and renal vein thrombosis: 1.9%. We conclude that the most common urologic complications in our center were ureteric strictures and urine leaks, and the most common vascular complication was renal artery stenosis.

  18. Effect of elevated interstitial pressure on the renal cortical hemodynamics. (United States)

    Källskog, O; Wolgast, M


    The influence of renal interstitial pressure on the resistance pattern within the superficial cortical vasculature has been investigated from determinations of 1) the glomerular blood flow eith a modified microsphere technique and 2) the intravascular hydrostatic pressures. Interstitial pressure was monitored via a 50 mum PVC-catheter placed into the subcapsular interstitial space. Two conditions were analyzed viz. a) elevation of uretheral pressure to 20 mm Hg and b) venous stasis to 10-15 mm Hg. Both conditions produced an increase in the interstitial pressure from 1-2 mm Hg to about 5 mm Hg as well as an increased hilar lymph flow and protein flow of about the same size. The vascular reactions were different, however. Uretheral stasis (but not the stasis of a single nephron) produced a decreased resistance in the afferent arteriolae with a concomitant increae in the pressures in the glomerular capillaries, and the peritobular capillary network. In contrast, venous stasis produced only small changes in the parameters studied but for the obvious rise in the peritubular capillary pressure. The results suggest that factors other than the interstitial pressure are governing the afferent vascular tone; the tubular wall tension might be one of these factors.

  19. Computational Support for Early Elicitation and Classification of Tone (United States)

    Bird, Steven; Lee, Haejoong


    Investigating a tone language involves careful transcription of tone on words and phrases. This is challenging when the phonological categories--the tones or melodies--have not been identified. Effects such as coarticulation, sandhi, and phrase-level prosody appear as obstacles to early elicitation and classification of tone. This article presents…

  20. Impact of pregnancy on underlying renal disease. (United States)

    Baylis, Chris


    Normal pregnancy involves marked renal vasodilation and large increases in glomerular filtration rate (GFR). Studies in rats reveal that the gestational renal vasodilation is achieved by parallel reductions in tone in afferent and efferent arterioles so GFR rises without a change in glomerular blood pressure. There is some evidence from animal studies that increased renal generation of nitric oxide (NO) may be involved. Although chronic renal vasodilation has been implicated in causing progression of renal disease in nonpregnant states by glomerular hypertension, there are no long-term deleterious effects of pregnancies on the kidney when maternal renal function is normal because glomerular blood pressure remains normal. When maternal renal function is compromised before conception, there are no long-term adverse effects on renal function in most types of renal disease, providing that the GFR is well maintained before conception. When serum creatinine exceeds approximately 1.4 mg/dL, pregnancy may accelerate the renal disease increases and when serum creatinine >2 mg/dL, the chances are greater than 1 in 3 that pregnancy will hasten the progression of the renal disease. The available animal studies suggest that glomerular hypertension does not occur despite diverse injuries. Thus, the mechanisms of the adverse interaction between pregnancy and underlying renal disease remain unknown.

  1. Studying Emergent Tone-Systems in Nepal: Pitch, Phonation and Word-Tone in Tamang (United States)

    Mazaudon, Martine


    This paper focuses on the particular kinds of difficulties which arise in the study of an emergent tone-system, exemplified by Tamang in Nepal, where pitch, phonation and other laryngeal features combine in the definition of a tone. As a consequence, conducting a well-ordered analysis in stages first of phonetic transcription, then variation in…

  2. Perception of tones by infants learning a non-tone language

    NARCIS (Netherlands)

    Kager, René; Liu, Liquan


    This article examines the perception of tones by non-tone-language-learning (non-tonelearning) infants between 5 and 18 months in a study that reveals infants’ initial sensitivity to tonal contrasts, deterioration yet plasticity of tonal sensitivity at the end of the first year, and a perceptual reb

  3. Renal arteriography (United States)

    ... Read More Acute arterial occlusion - kidney Acute kidney failure Aneurysm Atheroembolic renal disease Blood clots Renal cell carcinoma Renal venogram X-ray Review Date 1/5/2016 Updated by: Jason Levy, ...

  4. Managing Vascular Tumors-Open Approaches. (United States)

    Schmalbach, Cecelia E; Gourin, Christine


    The most common vascular tumors encountered by the otolaryngologist are rare chromaffin cell tumors termed paragangliomas. Within the head and neck region, they commonly arise from the carotid body, vagus nerve (glomus vagale), and jugular vein (glomus jugulare). Other vascular head and neck tumors include sinonasal malignancies, because of proximity to or involvement of the pterygoid plexus as well as the rich vascularity of the sinonasal mucosa; juvenile nasopharyngeal angiofibroma, a vascular tumor of male adolescents; unusual vascular tumors such as hemangiopericytoma; and metastatic renal cell cancer, which has a proclivity for an unusually rich blood supply.

  5. Enhanced visual perception through tone mapping (United States)

    Harrison, Andre; Mullins, Linda L.; Raglin, Adrienne; Etienne-Cummings, Ralph


    Tone mapping operators compress high dynamic range images to improve the picture quality on a digital display when the dynamic range of the display is lower than that of the image. However, tone mapping operators have been largely designed and evaluated based on the aesthetic quality of the resulting displayed image or how perceptually similar the compressed image appears relative to the original scene. They also often require per image tuning of parameters depending on the content of the image. In military operations, however, the amount of information that can be perceived is more important than the aesthetic quality of the image and any parameter adjustment needs to be as automated as possible regardless of the content of the image. We have conducted two studies to evaluate the perceivable detail of a set of tone mapping algorithms, and we apply our findings to develop and test an automated tone mapping algorithm that demonstrates a consistent improvement in the amount of perceived detail. An automated, and thereby predictable, tone mapping method enables a consistent presentation of perceivable features, can reduce the bandwidth required to transmit the imagery, and can improve the accessibility of the data by reducing the needed expertise of the analyst(s) viewing the imagery.

  6. Direct Numerical Simulation of Automobile Cavity Tones (United States)

    Kurbatskii, Konstantin; Tam, Christopher K. W.


    The Navier Stokes equation is solved computationally by the Dispersion-Relation-Preserving (DRP) scheme for the flow and acoustic fields associated with a laminar boundary layer flow over an automobile door cavity. In this work, the flow Reynolds number is restricted to R(sub delta*) < 3400; the range of Reynolds number for which laminar flow may be maintained. This investigation focuses on two aspects of the problem, namely, the effect of boundary layer thickness on the cavity tone frequency and intensity and the effect of the size of the computation domain on the accuracy of the numerical simulation. It is found that the tone frequency decreases with an increase in boundary layer thickness. When the boundary layer is thicker than a certain critical value, depending on the flow speed, no tone is emitted by the cavity. Computationally, solutions of aeroacoustics problems are known to be sensitive to the size of the computation domain. Numerical experiments indicate that the use of a small domain could result in normal mode type acoustic oscillations in the entire computation domain leading to an increase in tone frequency and intensity. When the computation domain is expanded so that the boundaries are at least one wavelength away from the noise source, the computed tone frequency and intensity are found to be computation domain size independent.

  7. Vascular Diseases (United States)

    The vascular system is the body's network of blood vessels. It includes the arteries, veins and capillaries that carry ... to and from the heart. Problems of the vascular system are common and can be serious. Arteries ...

  8. Renal blood flow and metabolism after cold ischaemia

    DEFF Research Database (Denmark)

    Henriksen, J H; Petersen, H K


    Peroperative measurements of renal blood flow (RBF), renal O2-uptake, and renal venous lactate/pyruvate (L/P) ratio were performed before and after a period of 30-71 min of hypothermic (10-15 degrees C) renal ischaemia in nine patients, undergoing surgery for renal calculi. Before ischaemia, RBF.......01) immediately after re-established perfusion and 36% (P less than 0.02) 30 min later. In one additional patient, who had a short warm ischaemia (8 min), the flow pattern was the same. As arterial pressure remained constant, the reduced RBF signifies an increased renal vascular resistance. Renal O2-uptake...... and renal venous L/P ratio were almost constant, indicating no significant anaerobic processes being involved in the flow response. None of the patients showed any signs of reactive hyperaemia. It is concluded that hypothermic renal ischaemia may be followed by an increased renal vascular resistance even...

  9. Contribuição ao estudo dos elementos vasculares, arteriais e venosos do hilo renal em suínos Sus scrofa domestica - Linnaeus - 1758 da raça LargeWhite

    Directory of Open Access Journals (Sweden)

    Orlando Marques da Costa


    Full Text Available Estudou-se, em 30 pares de rins de suínos da raça Large White, 15 machos e 15 fêmeas, com aproximadamente quatro meses de idade, procedentes do Matadouro e Frigorífico "Eder", em Itapecerica da Serra, Estado de São Paulo, a distribuição arterial e venosa do hilo deste órgão, mediante disseccão dos elementos vasculares do pedículo renal, após a fixação do material em solução aquosa de formol a 10,0%. Nestes animais, a artéria renal direita fornece de seis (10,0% a vinte (3,3% ramos, com maior frequência de dez (20,0% e a esquerda de quatro (3,3% a dezoito (3,3%, com maior incidência de dez(16,7% e demonstrou uma maior concentração no quadrante craniodorsal, seguido dos quadrantes cranioventral, caudoventral e caudodorsal. No que tange ao número de raízes venosas, a veia renal direita apresenta uma variação de uma (10,0% a cinco (33,8% raízes, com maior frequência de cinco (33,8%,a esquerda de duas (13,3% e sete (3,3%, com maior concentração de três e quatro (53,4%, situadas com maior incidência no quadrante cranioventral, seguido dos quadrantes caudoventral, craniodorsal ecaudodorsal. Quanto à situação global, os ramos das artérias renais direita e esquerda se apresentam em maior número de vezes preponderantemente periféricos(43,3%, enquanto as raízes venosas se mostram exclusivamente periféricas (16,7%. Há igualdade no número de ramos das artérias renais e raízes das veias renais, direitas e esquerdas, apenas 1 vez (3,3%, com distribuião desigual nos quadrantes. Não existem diferenças estatisticamente significantes quanto ao sexo. Estudou-se, em 30 pares de rins de suínos da raça Large White, 15 machos e 15 fêmeas, com aproximadamente quatro meses de idade, procedentes do Matadouro e Frigorífico "Eder", em Itapecerica da Serra, Estado de São Paulo, a distribuição arterial e venosa do hilo deste órgão, mediante dissecção do selementos vasculares do pedículo renal, após a fixação do

  10. Vascular Vertigo


    Mazyar Hashemilar; Masoud Nikanfar; Dariush Savadi Oskoui


    Vertigo is a common complaint in neurology and medicine. The most common causes of vertigo are benign paroxysmal positional vertigo, vestibular neuritis, Meniere’s disease, and vascular disorders. Vertigo of vascular origin is usually limited to migraine, transient ischemic attacks, and ischemic or hemorrhagic stroke. Vascular causes lead to various central or peripheral vestibular syndromes with vertigo. This review provides an overview of epidemiology and clinical syndromes of vascular vert...

  11. Prostanoid Receptors in the Human Vascular Wall

    Directory of Open Access Journals (Sweden)

    Xavier Norel


    Full Text Available The mechanisms involved in vascular homeostasis and disease are mostly dependent on the interactions between blood, vascular smooth muscle, and endothelial cells. There is an accumulation of evidence for the involvement of prostanoids, the arachidonic acid metabolites derived from the cyclooxygenase enzymatic pathway, in physiological and/or pathophysiological conditions. In humans, the prostanoids activate different receptors. The classical prostanoid receptors (DP, EP1–4, FP, IP, and TP are localized at the cell plasma or nuclear membrane. In addition, CRTH2 and the nuclear PPAR receptors are two other targets for prostanoids, namely, prostacyclin (PGI2 or the natural derivatives of prostaglandin D2. While there is little information on the role of CRTH2, there are many reports on PPAR activation and the consecutive expression of genes involved in the human vascular system. The role of the classical prostanoid receptors stimulated by PGI2 and thromboxane in the control of the vascular tone has been largely documented, whereas the other receptor subtypes have been overlooked. There is now increasing evidence that suggests a role of PGE2 and the EP receptor subtypes in the control of the human vascular tone and remodeling of the vascular wall. These receptors are also present on leukocytes and platelets, and they are implicated in most of the inflammatory processes within the vascular wall. Consequently, the EP receptor subtypes or isoforms would provide a novel and specific cardiovascular therapeutic approach in the near future.

  12. Cantonese-Speaking Children Do Not Acquire Tone Perception before Tone Production-A Perceptual and Acoustic Study of Three-Year-Olds' Monosyllabic Tones. (United States)

    Wong, Puisan; Fu, Wing M; Cheung, Eunice Y L


    Models of phonological development assume that speech perception precedes speech production and that children acquire suprasegmental features earlier than segmental features. Studies of Chinese-speaking children challenge these assumptions. For example, Chinese-speaking children can produce tones before two-and-a-half years but are not able to discriminate the same tones until after 6 years of age. This study compared the perception and production of monosyllabic Cantonese tones directly in 3 -year-old children. Twenty children and their mothers identified Cantonese tones in a picture identification test and produced monosyllabic tones in a picture labeling task. To control for lexical biases on tone ratings, the mother- and child-productions were low-pass filtered to eliminate lexical information and were presented to five judges for tone classification. Detailed acoustic analysis was performed. Contrary to the view that children master lexical tones earlier than segmental phonemes, results showed that 3-year-old children could not perceive or produce any Cantonese tone with adult-like proficiency and incorrect tone productions were acoustically different from criterion. In contrast to previous findings that Cantonese-speaking children mastered tone production before tone perception, we observed more accuracy during speech perception than production. Findings from Cantonese-speaking children challenge some of the established tenets in theories of phonological development that have been tested mostly with native English speakers.

  13. Acute renal dysfunction in liver diseases

    Institute of Scientific and Technical Information of China (English)


    Renal dysfunction is common in liver diseases, either as part of multiorgan involvement in acute illness or secondary to advanced liver disease. The presence of renal impairment in both groups is a poor prognostic indicator. Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction. Obstructive or post renal dysfunction only rarely complicates liver disease. Hepatorenal syndrome (MRS) is a unique form of renal failure associated with advanced liver disease or cirrhosis, and is characterized by functional renal impairment without significant changes in renal histology. Irrespective of the type of renal failure, renal hypoperfusion is the central pathogenetic mechanism, due either to reduced perfusion pressure or increased renal vascular resistance. Volume expansion, avoidance of precipitating factors and treatment of underlying liver disease constitute the mainstay of therapy to prevent and reverse renal impairment. Splanchnic vasoconstrictor agents, such as terlipressin, along with volume expansion, and early placement of transjugular intrahepatic portosystemic shunt (TIPS) may be effective in improving renal function in HRS. Continuous renal replacement therapy (CRRT) and molecular absorbent recirculating system (MARS) in selected patients may be life saving while awaiting liver transplantation.

  14. Characterisation of K+ Channels in Human Fetoplacental Vascular Smooth Muscle Cells


    Brereton, Melissa F.; Mark Wareing; Rebecca L Jones; Greenwood, Susan L.


    Adequate blood flow through placental chorionic plate resistance arteries (CPAs) is necessary for oxygen and nutrient transfer to the fetus and a successful pregnancy. In non-placental vascular smooth muscle cells (SMCs), K(+) channels regulate contraction, vascular tone and blood flow. Previous studies showed that K(+) channel modulators alter CPA tone, but did not distinguish between effects on K(+) channels in endothelial cells and SMCs. In this study, we developed a preparation of freshly...

  15. Sodium pump α2 subunits control myogenic tone and blood pressure in mice (United States)

    Zhang, Jin; Lee, Moo Yeol; Cavalli, Maurizio; Chen, Ling; Berra-Romani, Roberto; Balke, C William; Bianchi, Giuseppe; Ferrari, Patrizia; Hamlyn, John M; Iwamoto, Takahiro; Lingrel, Jerry B; Matteson, Donald R; Wier, W Gil; Blaustein, Mordecai P


    A key question in hypertension is: How is long-term blood pressure controlled? A clue is that chronic salt retention elevates an endogenous ouabain-like compound (EOLC) and induces salt-dependent hypertension mediated by Na+/Ca2+ exchange (NCX). The precise mechanism, however, is unresolved. Here we study blood pressure and isolated small arteries of mice with reduced expression of Na+ pump α1 (α1+/−) or α2 (α2+/−) catalytic subunits. Both low-dose ouabain (1–100 nm; inhibits only α2) and high-dose ouabain (≥1 μm; inhibits α1) elevate myocyte Ca2+ and constrict arteries from α1+/−, as well as α2+/− and wild-type mice. Nevertheless, only mice with reduced α2 Na+ pump activity (α2+/−), and not α1 (α1+/−), have elevated blood pressure. Also, isolated, pressurized arteries from α2+/−, but not α1+/−, have increased myogenic tone. Ouabain antagonists (PST 2238 and canrenone) and NCX blockers (SEA0400 and KB-R7943) normalize myogenic tone in ouabain-treated arteries. Only the NCX blockers normalize the elevated myogenic tone in α2+/− arteries because this tone is ouabain independent. All four agents are known to lower blood pressure in salt-dependent and ouabain-induced hypertension. Thus, chronically reduced α2 activity (α2+/− or chronic ouabain) apparently regulates myogenic tone and long-term blood pressure whereas reduced α1 activity (α1+/−) plays no persistent role: the in vivo changes in blood pressure reflect the in vitro changes in myogenic tone. Accordingly, in salt-dependent hypertension, EOLC probably increases vascular resistance and blood pressure by reducing α2 Na+ pump activity and promoting Ca2+ entry via NCX in myocytes. PMID:16166162

  16. Raised tone reveals ATP as a sympathetic neurotransmitter in the porcine mesenteric arterial bed. (United States)

    Shatarat, Amjad; Dunn, William R; Ralevic, Vera


    The relative importance of ATP as a functional sympathetic neurotransmitter in blood vessels has been shown to be increased when the level of preexisting vascular tone or pressure is increased, in studies carried out in rat mesenteric arteries. The aim of the present study was to determine whether tone influences the involvement of ATP as a sympathetic cotransmitter with noradrenaline in another species. We used the porcine perfused mesenteric arterial bed and porcine mesenteric large, medium and small arteries mounted for isometric tension recording, because purinergic cotransmission can vary depending on the size of the blood vessel. In the perfused mesenteric bed at basal tone, sympathetic neurogenic vasocontractile responses were abolished by prazosin, an α1-adrenoceptor antagonist, but there was no significant effect of α,β-methylene ATP, a P2X receptor-desensitizing agent. Submaximal precontraction of the mesenteric arterial bed with U46619, a thromboxane A2 mimetic, augmented the sympathetic neurogenic vasocontractile responses; under these conditions, both α,β-methylene ATP and prazosin attenuated the neurogenic responses. In the mesenteric large, medium and small arteries, prazosin attenuated the sympathetic neurogenic contractile responses under conditions of both basal and U46619-raised tone. α,β-Methylene ATP was effective in all of these arteries only under conditions of U46619-induced tone, causing a similar inhibition in all arteries, but had no significant effect on sympathetic neurogenic contractions at basal tone. These data show that ATP is a cotransmitter with noradrenaline in porcine mesenteric arteries; the purinergic component was revealed under conditions of partial precontraction, which is more relevant to physiological conditions.

  17. Sonographic Findings in Fetal Renal Vein Thrombosis. (United States)

    Gerber, Rebecca E; Bromley, Bryann; Benson, Carol B; Frates, Mary C


    We present the sonographic findings of fetal renal vein thrombosis in a series of 6 patients. The mean gestational age at diagnosis was 31.2 weeks. Four cases were unilateral, and 2 were bilateral. The most common findings were renal enlargement and intrarenal vascular calcifications, followed by increased renal parenchymal echogenicity. Inferior vena cava thrombosis was found in 4 patients and common iliac vein thrombosis in 2. Fetal renal vein thrombosis is an uncommon diagnosis with characteristic sonographic findings. The presence of these findings should prompt Doppler interrogation of the renal vein and inferior vena cava to confirm the diagnosis.

  18. Cochlear Mechanics: Analysis for a Pure Tone, (United States)


    Frommer , 1979; Zwislocki, 1980; Lighthill, 1981; Khanna, 1983). The problem is made more difficult by the current state of the experimental evidence...pathology of high-tone deafness," Bull. Johns Hopkins Hosp. 54, 315-379 Frommer , G.H. (1979). "Fluid motion in the mammalian organ of Corti: a

  19. Local adaptive tone mapping for video enhancement (United States)

    Lachine, Vladimir; Dai, Min (.


    As new technologies like High Dynamic Range cameras, AMOLED and high resolution displays emerge on consumer electronics market, it becomes very important to deliver the best picture quality for mobile devices. Tone Mapping (TM) is a popular technique to enhance visual quality. However, the traditional implementation of Tone Mapping procedure is limited by pixel's value to value mapping, and the performance is restricted in terms of local sharpness and colorfulness. To overcome the drawbacks of traditional TM, we propose a spatial-frequency based framework in this paper. In the proposed solution, intensity component of an input video/image signal is split on low pass filtered (LPF) and high pass filtered (HPF) bands. Tone Mapping (TM) function is applied to LPF band to improve the global contrast/brightness, and HPF band is added back afterwards to keep the local contrast. The HPF band may be adjusted by a coring function to avoid noise boosting and signal overshooting. Colorfulness of an original image may be preserved or enhanced by chroma components correction by means of saturation function. Localized content adaptation is further improved by dividing an image to a set of non-overlapped regions and modifying each region individually. The suggested framework allows users to implement a wide range of tone mapping applications with perceptional local sharpness and colorfulness preserved or enhanced. Corresponding hardware circuit may be integrated in camera, video or display pipeline with minimal hardware budget

  20. Collaborative Documentation and Revitalization of Cherokee Tone (United States)

    Herrick, Dylan; Berardo, Marcellino; Feeling, Durbin; Hirata-Edds, Tracy; Peter, Lizette


    Cherokee, the sole member of the southern branch of Iroquoian languages, is a severely endangered language. Unlike other members of the Iroquoian family, Cherokee has lexical tone. Community members are concerned about the potential loss of their language, and both speakers and teachers comment on the difficulty that language learners have with…

  1. Problems in the Acquisition of Grammatical Tone. (United States)

    Demuth, Katherine

    An autosegmental account of the child's acquisition of grammatical tone in Sesotho, a southern Bantu language, is presented. The following theoretical questions are addressed: (1) When and how does the child figure out that Sesotho is a tonal rather than intonational, stress, or accentual language?; (2) How does the child acquire tonal rules?; and…

  2. The value of visualizing tone of voice. (United States)

    Pullin, Graham; Cook, Andrew


    Whilst most of us have an innate feeling for tone of voice, it is an elusive quality that even phoneticians struggle to describe with sufficient subtlety. For people who cannot speak themselves this can have particularly profound repercussions. Augmentative communication often involves text-to-speech, a technology that only supports a basic choice of prosody based on punctuation. Given how inherently difficult it is to talk about more nuanced tone of voice, there is a risk that its absence from current devices goes unremarked and unchallenged. Looking ahead optimistically to more expressive communication aids, their design will need to involve more subtle interactions with tone of voice-interactions that the people using them can understand and engage with. Interaction design can play a role in making tone of voice visible, tangible, and accessible. Two projects that have already catalysed interdisciplinary debate in this area, Six Speaking Chairs and Speech Hedge, are introduced together with responses. A broader role for design is advocated, as a means to opening up speech technology research to a wider range of disciplinary perspectives, and also to the contributions and influence of people who use it in their everyday lives.

  3. The internist and the renal resistive index: truths and doubts. (United States)

    Boddi, Maria; Natucci, Fabrizia; Ciani, Elisa


    The renal resistive index (RRI) is measured by Doppler sonography in an intrarenal artery, and is the difference between the peak systolic and end-diastolic blood velocities divided by the peak systolic velocity. The RRI is used for the study of vascular and renal parenchymal renal abnormalities, but growing evidence indicates that it is also a dynamic marker of systemic vascular properties. Renal vascular resistance is only one of several renal (vascular compliance, interstitial and venous pressure), and extrarenal (heart rate, aortic stiffness, pulse pressure) determinants that combine to determine the RRI values, and not the most important one. RRI cannot always be considered a specific marker of renal disease. To summarize from the literature: (1) hydronephrosis, abdominal hypertension, renal vein thrombosis and acute kidney injury are all associated with an acute increase in interstitial and venous pressure that determine RRI values. In all these conditions, RRI is a reliable marker of the severity of renal damage. (2) The hemodynamic impact of renal artery stenosis can be assayed by the RRI decrease in the homolateral kidney by virtue of decreasing pulse pressure. However, renal diseases that often coexist, increase renal vascular stiffness and hide the hemodynamic effect of renal stenosis. (3) In transplant kidney and in chronic renal disease, high RRI values (>0.80) can independently predict renal and clinical outcomes, but systemic (pulse pressure) rather than renal hemodynamic determinants sustain the predictive role of RRI. (4) Higher RRI detects target renal organ damage in hypertension and diabetes when renal function is still preserved, as a marker of systemic atherosclerotic burden. Is this the fact? We attempt to answer.

  4. Increased pressure-induced tone in rat parenchymal arterioles vs. middle cerebral arteries: role of ion channels and calcium sensitivity. (United States)

    Cipolla, Marilyn J; Sweet, Julie; Chan, Siu-Lung; Tavares, Matthew J; Gokina, Natalia; Brayden, Joseph E


    Brain parenchymal arterioles (PAs) are high-resistance vessels that branch off pial arteries and perfuse the brain parenchyma. PAs are the target of cerebral small vessel disease and have been shown to have greater pressure-induced tone at lower pressures than pial arteries. We investigated mechanisms by which brain PAs have increased myogenic tone compared with middle cerebral arteries (MCAs), focusing on differences in vascular smooth muscle (VSM) calcium and ion channel function. The amount of myogenic tone and VSM calcium was measured using Fura 2 in isolated and pressurized PAs and MCAs. Increases in intraluminal pressure caused larger increases in tone and cytosolic calcium in PAs compared with MCAs. At 50 mmHg, myogenic tone was 37 ± 5% for PAs vs. 6.5 ± 4% for MCAs (P channel (VDCC) inhibitor nifedipine than MCAs (EC50 for PAs was 3.5 ± 0.4 vs. 82.1 ± 2.1 nmol/l for MCAs;P channel inhibitor iberiotoxin, whereas MCAs constricted ∼15%. Thus increased myogenic tone in PAs appears related to differences in ion channel activity that promotes VSM membrane depolarization but not to a direct sensitization of the contractile apparatus to calcium.

  5. [Sympathetic nerve activity in chronic renal failure - what are the therapeutic options?]. (United States)

    Hausberg, M; Tokmak, F


    Patients with chronic renal failure are characterized by a tonic elevation of sympathetic tone. This factor largely contributes to their increased cardiovascular risk. The increased sympathetic drive is caused by activiation of renal afferent fibers in the diseased kidneys. Therapeutic options for hypertensive patients with chronic renal failure with respect to their sympathetic overactivity are inhibitors of the renin-angiotensin-system and central sympatholytic drugs. The role of catheter-based renal denervation in these patients is currently under investigation.

  6. A crosslinguistic PET study of tone perception. (United States)

    Gandour, J; Wong, D; Hsieh, L; Weinzapfel, B; Van Lancker, D; Hutchins, G D


    In studies of pitch processing, a fundamental question is whether shared neural mechanisms at higher cortical levels are engaged for pitch perception of linguistic and nonlinguistic auditory stimuli. Positron emission tomography (PET) was used in a crosslinguistic study to compare pitch processing in native speakers of two tone languages (that is, languages in which variations in pitch patterns are used to distinguish lexical meaning), Chinese and Thai, with those of English, a nontone language. Five subjects from each language group were scanned under three active tasks (tone, pitch, and consonant) that required focused-attention, speeded-response, auditory discrimination judgments, and one passive baseline as silence. Subjects were instructed to judge pitch patterns of Thai lexical tones in the tone condition; pitch patterns of nonspeech stimuli in the pitch condition; syllable-initial consonants in the consonant condition. Analysis was carried out by paired-image subtraction. When comparing the tone to the pitch task, only the Thai group showed significant activation in the left frontal operculum. Activation of the left frontal operculum in the Thai group suggests that phonological processing of suprasegmental as well as segmental units occurs in the vicinity of Broca's area. Baseline subtractions showed significant activation in the anterior insular region for the English and Chinese groups, but not Thai, providing further support for the existence of possibly two parallel, separate pathways projecting from the temporo-parietal to the frontal language area. More generally, these differential patterns of brain activation across language groups and tasks support the view that pitch patterns are processed at higher cortical levels in a top-down manner according to their linguistic function in a particular language.

  7. Biophysical characteristics of gap junctions in vascular wall cells: implications for vascular biology and disease

    Directory of Open Access Journals (Sweden)

    P.R. Brink


    Full Text Available The role gap junction channels play in the normal and abnormal functioning of the vascular wall is the subject of much research. The biophysical properties of gap junctions are an essential component in understanding how gap junctions function to allow coordinated relaxation and contraction of vascular smooth muscle. This study reviews the properties thus far elucidated and relates those properties to tissue function. We ask how biophysical and structural properties such as gating, permselectivity, subconductive states and channel type (heteromeric vs homotypic vs heterotypic might affect vascular smooth muscle tone.

  8. Renal parameter estimates in unrestrained dogs (United States)

    Rader, R. D.; Stevens, C. M.


    A mathematical formulation has been developed to describe the hemodynamic parameters of a conceptualized kidney model. The model was developed by considering regional pressure drops and regional storage capacities within the renal vasculature. Estimation of renal artery compliance, pre- and postglomerular resistance, and glomerular filtration pressure is feasible by considering mean levels and time derivatives of abdominal aortic pressure and renal artery flow. Changes in the smooth muscle tone of the renal vessels induced by exogenous angiotensin amide, acetylcholine, and by the anaesthetic agent halothane were estimated by use of the model. By employing totally implanted telemetry, the technique was applied on unrestrained dogs to measure renal resistive and compliant parameters while the dogs were being subjected to obedience training, to avoidance reaction, and to unrestrained caging.

  9. Development of the renal arterioles. (United States)

    Sequeira Lopez, Maria Luisa S; Gomez, R Ariel


    The kidney is a highly vascularized organ that normally receives a fifth of the cardiac output. The unique spatial arrangement of the kidney vasculature with each nephron is crucial for the regulation of renal blood flow, GFR, urine concentration, and other specialized kidney functions. Thus, the proper and timely assembly of kidney vessels with their respective nephrons is a crucial morphogenetic event leading to the formation of a functioning kidney necessary for independent extrauterine life. Mechanisms that govern the development of the kidney vasculature are poorly understood. In this review, we discuss the anatomical development, embryological origin, lineage relationships, and key regulators of the kidney arterioles and postglomerular circulation. Because renal disease is associated with deterioration of the kidney microvasculature and/or the reenactment of embryonic pathways, understanding the morphogenetic events and processes that maintain the renal vasculature may open new avenues for the preservation of renal structure and function and prevent the progression of renal disease.

  10. A Pedagogical Study of Tone Neutralization in Cibemba Phonetics ...

    African Journals Online (AJOL)

    Nekky Umera

    the argument of the present writer is that the phenomenon of tone is essentially a .... and phonology. What that means is that in Cibemba names of two countries, .... human language to distinguish prosodic features such as tone and vowel.

  11. Realisations of a single high tone in Northern Sotho | Zerbian ...

    African Journals Online (AJOL)

    Southern African Linguistics and Applied Language Studies ... The results are interpreted as both phonological and phonetic influences on high tone ... this study provides a ground for cross-dialectal comparison of Southern Bantu tone.

  12. Influences on tone in Sepedi, a Southern Bantu language

    CSIR Research Space (South Africa)

    Zerbian, S


    Full Text Available Tone in Bantu languages is rarely studied experimentally. This paper reports a production study which reveals the intricate interaction of tonal context and morphological structure in surface tone realization in Sepedi, a South African Bantu...

  13. The pulsatility index and the resistive index in renal arteries. Associations with long-term progression in chronic renal failure

    DEFF Research Database (Denmark)

    Petersen, L J; Petersen, J R; Talleruphuus, U


    The pulsatility index (PI) and the resistive index (RI) are used as pulsed-wave Doppler measurements of downstream renal artery resistance. PI and RI have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma flow in chronic renal failure. The aim...... of the present study was to evaluate the potential relationship between these indices and the rate of decline in renal function, as reflected by changes in different parameters of renal function in patients with chronic renal failure....

  14. Active haemorrhage of a renal allograft detected on portable ultrasound


    Ricketts, James; Pang, Chun Lap; Dissanayake, Prageeth; Hutchinson, Rachel; Gutteridge, Catherine


    Function of a renal allograft relies on the integrity of its vascular anatomy. Renal biochemistry, ultrasound and percutaneous biopsy are used in combination to determine allograft function. Biopsy is not without risk, and in this case study we demonstrate a rare but a potentially life-threatening complication of renal allograft biopsy.

  15. What Is Vascular Disease? (United States)

    ... Donors Corporate Sponsors Donor Privacy Policy What Is Vascular Disease? What Is Vascular Disease? Vascular disease is any abnormal condition of ... steps to prevent vascular disease here. Understanding the Vascular System Your vascular system – the highways of the ...

  16. Impaired vascular responses to relaxin in diet-induced overweight female rats.

    NARCIS (Netherlands)

    Drongelen, J. van; Koppen, A. van; Pertijs, J.C.L.M.; Gooi, J.H.; Parry, L.J.; Sweep, F.C.; Lotgering, F.K.; Smits, P.; Spaanderman, M.E.A.


    Relaxin mediates renal and mesenteric vascular adaptations to pregnancy by increasing endothelium-dependent vasodilation and compliance and decreasing myogenic reactivity. Diet-induced overweight and obesity are associated with impaired endothelial dysfunction and vascular remodeling leading to a re

  17. Renal Osteodystrophy

    Directory of Open Access Journals (Sweden)

    Aynur Metin Terzibaşoğlu


    Full Text Available Chronic renal insufficiency is a functional definition which is characterized by irreversible and progressive decreasing in renal functions. This impairment is in collaboration with glomeruler filtration rate and serum creatinine levels. Besides this, different grades of bone metabolism disorders develop in chronic renal insufficiency. Pathologic changes in bone tissue due to loss of renal paranchyme is interrelated with calcium, phosphorus vitamine-D and parathyroid hormone. Clinically we can see high turnover bone disease, low turnover bone disease, osteomalacia, osteosclerosis and osteoporosis in renal osteodystropy. In this article we aimed to review pathology of bone metabolism disorders due to chronic renal insufficiency, clinic aspects and treatment approaches briefly.

  18. English and Thai Speakers' Perception of Mandarin Tones (United States)

    Li, Ying


    Language learners' language experience is predicted to display a significant effect on their accurate perception of foreign language sounds (Flege, 1995). At the superasegmental level, there is still a debate regarding whether tone language speakers are better able to perceive foreign lexical tones than non-tone language speakers (i.e Lee et al.,…

  19. [Vascular dementia

    NARCIS (Netherlands)

    Leeuw, H.F. de; Gijn, J. van


    Vascular dementia is one of the most frequently occurring dementia syndromes. Its prevalence is about 5% among subjects above 85 years of age. Elevated blood pressure and atherosclerosis are the most important risk factors. According to international criteria, vascular dementia usually occurs within

  20. Vildagliptin restores renal myogenic function and attenuates renal sclerosis independently of effects on blood glucose or proteinuria in Zucker Diabetic Fatty rat

    NARCIS (Netherlands)

    Vavrinec, Peter; Henning, Robert H.; Landheer, Sjoerd W.; Wang, Yumei; Deelman, Leo E.; van Dokkum, Richard P. E.; Buikema, Hendrik


    Type 2 diabetes mellitus (T2DM) is associated with risk for chronic kidney disease (CKD), which is associated with a decrease in renal myogenic tone - part of renal autoregulatory mechanisms. Novel class of drugs used for the treatment of T2DM, dipeptidyl peptidase-4 (DPP-4) inhibitors, have protect

  1. CT in vascular pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, C.; Neri, E.; Caramella, D. [Diagnostic and Interventional Radiology Department of Oncology, University of Pisa, Via Roma 67, I-56100 Pisa (Italy)


    Since the introduction of helical scanners, CT angiography (CTA) has achieved an essential role in many vascular applications that were previously managed with conventional angiography. The performance of CTA is based on the accurate selection of collimation width, pitch, reconstruction spacing and scan delay, which must be modulated on the basis of the clinical issue. However, the major improvement of CT has been provided by the recent implementation of many post-processing techniques, such as multiplanar reformatting, shaded surface display, maximum intensity projections, 3D perspectives of surface and volume rendering, which simulate virtual intravascular endoscopy. The integration of the potentialities of the scanner and of the image processing techniques permitted improvement of: (a) the evaluation of aneurysms, dissection and vascular anomalies involving the thoracic aorta; (b) carotid artery stenosis; (c) aneurysms of abdominal aorta; (d) renal artery stenosis; (e) follow-up of renal artery stenting; and (f) acute or chronic pulmonary embolism. Our experience has shown that the assessment of arterial pathologies with CTA requires the integration of 3D post-processing techniques in most applications. (orig.) With 4 figs., 34 refs.

  2. Auditory streaming of tones of uncertain frequency, level, and duration. (United States)

    Chang, An-Chieh; Lutfi, Robert A; Lee, Jungmee


    Stimulus uncertainty is known to critically affect auditory masking, but its influence on auditory streaming has been largely ignored. Standard ABA-ABA tone sequences were made increasingly uncertain by increasing the sigma of normal distributions from which the frequency, level, or duration of tones were randomly drawn. Consistent with predictions based on a model of masking by Lutfi, Gilbertson, Chang, and Stamas [J. Acoust. Soc. Am. 134, 2160-2170 (2013)], the frequency difference for which A and B tones formed separate streams increased as a linear function of sigma in tone frequency but was much less affected by sigma in tone level or duration.

  3. Hydrogen sulfide and vascular relaxation

    Institute of Scientific and Technical Information of China (English)

    SUN Yan; TANG Chao-shu; DU Jun-bao; JIN Hong-fang


    Objective To review the vasorelaxant effects of hydrogen sulfide (H2S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved.Data sources The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and ""vascular relaxation".Study selection Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected.Results H2S plays an important role in the regulation of cardiovascular tone.The vasomodulatory effects of H2S depend on factors including concentration,species and tissue type.The H2S donor,sodium hydrosulfide (NarS),causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner.This effect was more pronounced than that observed in pulmonary arterial rings.The expression of KATP channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings.H2S is involved in the pathogenesis of a variety of cardiovascular diseases.Downregulation of the endogenous H2S pathway is an important factor in the pathogenesis of cardiovascular diseases.The vasorelaxant effects of H2S have been shown to be mediated by activation of KATP channels in vascular smooth muscle cells and via the induction of acidification due to activation of the CI/HCO3 exchanger.It is speculated that the mechanisms underlying the vasoconstrictive function of H2S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation.Conclusion H2S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.

  4. Vascular rings. (United States)

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K


    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Congenital amusia (or tone-deafness interferes with pitch processing in tone languages

    Directory of Open Access Journals (Sweden)

    Barbara eTillmann


    Full Text Available Congenital amusia is a neurogenetic disorder that affects music processing and that is ascribed to a deficit in pitch processing. We investigated whether this deficit extended to pitch processing in speech, notably the pitch changes used to contrast lexical tones in tonal languages. Congenital amusics and matched controls, all non-tonal language speakers, were tested for lexical tone discrimination in Mandarin Chinese (Experiment 1 and in Thai (Experiment 2. Tones were presented in pairs and participants were required to make same/different judgments. Experiment 2 additionally included musical analogs of Thai tones for comparison. Performance of congenital amusics was inferior to that of controls for all materials, suggesting a domain-general pitch-processing deficit. The pitch deficit of amusia is thus not limited to music, but may compromise the ability to process and learn tonal languages. Combined with acoustic analyses of the tone material, the present findings provide new insights into the nature of the pitch-processing deficit exhibited by amusics.

  6. Developmental androgen excess programs sympathetic tone and adipose tissue dysfunction and predisposes to a cardiometabolic syndrome in female mice. (United States)

    Nohara, Kazunari; Waraich, Rizwana S; Liu, Suhuan; Ferron, Mathieu; Waget, Aurélie; Meyers, Matthew S; Karsenty, Gérard; Burcelin, Rémy; Mauvais-Jarvis, Franck


    Among women, the polycystic ovarian syndrome (PCOS) is considered a form of metabolic syndrome with reproductive abnormalities. Women with PCOS show increased sympathetic tone, visceral adiposity with enlarged adipocytes, hypoadiponectinemia, insulin resistance, glucose intolerance, increased inactive osteocalcin, and hypertension. Excess fetal exposure to androgens has been hypothesized to play a role in the pathogenesis of PCOS. Previously, we showed that neonatal exposure to the androgen testosterone (NT) programs leptin resistance in adult female mice. Here, we studied the impact of NT on lean and adipose tissues, sympathetic tone in cardiometabolic tissues, and the development of metabolic dysfunction in mice. Neonatally androgenized adult female mice (NTF) displayed masculinization of lean tissues with increased cardiac and skeletal muscle as well as kidney masses. NTF mice showed increased and dysfunctional white adipose tissue with increased sympathetic tone in both visceral and subcutaneous fat as well as increased number of enlarged and insulin-resistant adipocytes that displayed altered expression of developmental genes and hypoadiponectinemia. NTF exhibited dysfunctional brown adipose tissue with increased mass and decreased energy expenditure. They also displayed decreased undercarboxylated and active osteocalcin and were predisposed to obesity during chronic androgen excess. NTF showed increased renal sympathetic tone associated with increased blood pressure, and they developed glucose intolerance and insulin resistance. Thus, developmental exposure to testosterone in female mice programs features of cardiometabolic dysfunction, as can be observed in women with PCOS, including increased sympathetic tone, visceral adiposity, insulin resistance, prediabetes, and hypertension.

  7. Role of BKCa channels in diabetic vascular complications

    Institute of Scientific and Technical Information of China (English)

    Qian Lingling; Liu Xiaoyu; Wang Ruxing


    Objective This review focuses on the role of the large conductance calcium-activated potassium (BKCa) channels in diabetic vascular complications.Data sources Relevant articles published in English or Chinese from 1981 to present were selected from PubMed.The search terms were "BKCa channels" and "diabetes".Important references from selected articles were also retrieved.Study selection Articles regarding the role of BKCa channels in diabetic vascular complications and relevant mechanisms were selected.Results The BKCa channels are abundantly expressed in vascular smooth cells and play an important role in regulation of vascular tone.Multiple studies indicated that the expression and function of BKCa channels are altered by different mechanisms in diabetic vascular diseases such as coronary arterial disease,cerebral arterial disease,and diabetic retinopathy.Conclusion BKCa channels may play an important role in diabetic vascular complications and may be an effective therapeutic target for relieving and reducing the burden of diabetic vascular complications.

  8. Aging effect on Mandarin Chinese vowel and tone identification. (United States)

    Yang, Xiaohu; Wang, Yuxia; Xu, Lilong; Zhang, Hui; Xu, Can; Liu, Chang


    Mandarin Chinese speech sounds (vowels × tones) were presented to younger and older Chinese-native speakers with normal hearing. For the identification of vowel-plus-tone, vowel-only, and tone-only, younger listeners significantly outperformed older listeners. The tone 3 identification scores correlated significantly with the age of older listeners. Moreover, for older listeners, the identification rate of vowel-plus-tone was significantly lower than that of vowel-only and tone-only, whereas for younger listeners, there was no difference among the three identification scores. Therefore, aging negatively affected Mandarin vowel and tone perception, especially when listeners needed to process both phonemic and tonal information.

  9. Renal perfusion scintiscan (United States)

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...


    African Journals Online (AJOL)

    Thromboses can result from venous stasis, vascular injury or hypercoagulability, and those involving the deep veins proximal to the knee are linked to an increased risk of PE.2 .... tool for DVT in hospitalised patients, where higher scores.

  11. Vascular Dementia (United States)

    ... that includes enjoyable activities well within the comfort zone of the person with vascular dementia. New situations, ... your cholesterol in check. A healthy, low-fat diet and cholesterol-lowering medications if you need them ...

  12. vascular hemiplegia


    Voto Bernales, Jorge; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú


    The vascular hemiplegia is the functional disorder of a lateral half of the body produced by alterations of cerebral vessels. Should review the concepts of this common condition, with the dual aim of expanding its nosographic value and considering the hemiplegic patient as worthy of the highest professional care La hemiplejia vascular, es el trastorno funcional de una mitad lateral del cuerpo producido por alteraciones de los vasos cerebrales. Conviene revisar los conceptos sobre esta frec...

  13. vascular hemiplegia


    Voto Bernales, Jorge; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú


    The vascular hemiplegia is the functional disorder of a lateral half of the body produced by alterations of cerebral vessels. Should review the concepts of this common condition, with the dual aim of expanding its nosographic value and considering the hemiplegic patient as worthy of the highest professional care La hemiplejia vascular, es el trastorno funcional de una mitad lateral del cuerpo producido por alteraciones de los vasos cerebrales. Conviene revisar los conceptos sobre esta frec...

  14. Acetylcholine's effect on vascular resistance and compliance in the pulmonary circulation. (United States)

    Barman, S A; Senteno, E; Smith, S; Taylor, A E


    Acetylcholine's effect on the distribution of vascular resistance and compliance in the canine pulmonary circulation was determined under control and elevated vascular tone by the arterial, venous, and double occlusion techniques in isolated blood-perfused dog lungs at both constant flow and constant pressure. Large and small blood vessel resistances and compliances were studied in lungs given concentrations of acetylcholine ranging from 2.0 ng/ml to 200 micrograms/ml. The results of this study indicate that acetylcholine dilates large arteries at low concentrations (less than or equal to 20 ng/ml) and constricts small and large veins at concentrations of at least 2 micrograms/ml. Characterization of acetylcholine's effects at constant pulmonary blood flow indicates that 1) large artery vasodilation may be endothelial-derived relaxing factor-mediated because the dilation is blocked with methylene blue; 2) a vasodilator of the arachidonic acid cascade (blocked by ibuprofen), probably prostacyclin, lessens acetylcholine's pressor effects; 3) when vascular tone was increased, acetylcholine's hemodynamic effects were attenuated; and 4) acetylcholine decreased middle compartment and large vessle compliance under control but not elevated vascular tone. Under constant pressure at control vascular tone acetylcholine increases resistance in all segments except the large artery, and at elevated vascular tone the pressor effects were enhanced, and large artery resistance was increased.

  15. Blunt Renal Trauma in a Pre-Existing Renal Lesion

    Directory of Open Access Journals (Sweden)

    G.V. Soundra Pandyan


    Full Text Available A 70-year-old male presented with direct trauma to his loin with gross hematuria, as an isolated case of blunt renal trauma (BRT due to a traffic accident. A pre-existing renal lesion (PERL was strongly suspected by his past history of gross macroscopic hematuria and monotrauma to the kidney without other associated injuries. Spiral CT scan with contrast and a retrograde pyelogram (RGP confirmed an occult complex renal cyst. The gold standard of CT diagnosis in this situation is stressed. Computed tomography is particularly useful in evaluating traumatic injuries to kidneys with pre-existing abnormalities. The decision on the initial course of conservative management, ureteral retrograde stenting to drain extravasation, and its final outcome are discussed. Radical nephroureterectomy was carried out by a transperitoneal approach with an early vascular control of the renal pedicle. A brief review of recent literature has been undertaken.

  16. Electrotonic vascular signal conduction and nephron synchronization

    DEFF Research Database (Denmark)

    Marsh, D.J.; Toma, I.; Sosnovtseva, Olga


    Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF) and the ......Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF...

  17. Renal histology in polycystic kidney disease with incipient and advanced renal failure. (United States)

    Zeier, M; Fehrenbach, P; Geberth, S; Möhring, K; Waldherr, R; Ritz, E


    Renal specimens were obtained at surgery or postmortem from patients with autosomal dominant polycystic kidney disease (ADPKD). Patients had either serum creatinine (SCr) below 350 mumol/liter (N = 12) or terminal renal failure (N = 50). Specimens were examined by two independent observers using a carefully validated score system. Mean glomerular diameters were similar in ADPKD patients with early renal failure (176 +/- 38 microns) and in victims of traffic accidents (177 +/- 23 microns), while they were significantly greater in diabetics with comparable renal function (205 +/- 16 microns). Glomerular diameters in ADPKD patients with terminal renal failure (191 +/- 45 microns) and with early renal failure were not significantly different. On average, 29% of glomeruli (17 to 62) were globally sclerosed in early renal failure, and 49% (19 to 93) in terminal renal failure. The proportion of glomeruli with segmental sclerosis was less than 4% in both groups. Marked vascular sclerosis, interstitial fibrosis, and tubular atrophy were present in early renal failure, and even more so in terminal renal failure. Interstitial infiltrates were scarce and consisted mainly of CD4 positive lymphocytes and CD68 positive macrophages. Immunestaining with monoclonal renin antibodies showed an increased juxtaglomerular index and expression of renin by arterioles adjacent to cysts, as well as by cyst wall epithelia. The data show more severe vascular and interstitial, but not glomerular, changes in ADPKD with advanced as compared to early renal failure.

  18. Multidetector CT angiography of renal vasculature: normal anatomy and variants

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    Tuerkvatan, Aysel; Oezdemir, Mustafa; Cumhur, Turhan; Oelcer, Tuelay [Tuerkiye Yueksek ihtisas Hospital, Department of Radiology, Sihhiye, Ankara (Turkey)


    Knowledge of the variations in renal vascular anatomy is important before laparoscopic donor or partial nephrectomy and vascular reconstruction for renal artery stenosis or abdominal aortic aneurysm. Recently, multidetector computed tomographic (MDCT) angiography has become a principal imaging investigation for assessment of the renal vasculature and has challenged the role of conventional angiography. It is an excellent imaging technique because it is a fast and non-invasive tool that provides highly accurate and detailed evaluation of normal renal vascular anatomy and variants. The number, size and course of the renal arteries and veins are easily identified by MDCT angiography. The purpose of this pictorial essay is to illustrate MDCT angiographic appearance of normal anatomy and common variants of the renal vasculature. (orig.)

  19. Myogenic tone is impaired at low arterial pressure in mice deficient in the low-voltage-activated Cav3.1 T-type Ca2+ channel

    DEFF Research Database (Denmark)

    Björling, K.; Morita, H.; Olsen, M. F.


    Using mice deficient in the CaV 3.1 T-type Ca(2+) channel, the aim of the present study was to elucidate the molecular identity of non-L-type channels involved in vascular tone regulation in mesenteric arteries and arterioles....

  20. Affective evaluation of simultaneous tone combinations in congenital amusia. (United States)

    Marin, Manuela M; Thompson, William Forde; Gingras, Bruno; Stewart, Lauren


    Congenital amusia is a neurodevelopmental disorder characterized by impaired pitch processing. Although pitch simultaneities are among the fundamental building blocks of Western tonal music, affective responses to simultaneities such as isolated dyads varying in consonance/dissonance or chords varying in major/minor quality have rarely been studied in amusic individuals. Thirteen amusics and thirteen matched controls enculturated to Western tonal music provided pleasantness ratings of sine-tone dyads and complex-tone dyads in piano timbre as well as perceived happiness/sadness ratings of sine-tone triads and complex-tone triads in piano timbre. Acoustical analyses of roughness and harmonicity were conducted to determine whether similar acoustic information contributed to these evaluations in amusics and controls. Amusic individuals' pleasantness ratings indicated sensitivity to consonance and dissonance for complex-tone (piano timbre) dyads and, to a lesser degree, sine-tone dyads, whereas controls showed sensitivity when listening to both tone types. Furthermore, amusic individuals showed some sensitivity to the happiness-major association in the complex-tone condition, but not in the sine-tone condition. Controls rated major chords as happier than minor chords in both tone types. Linear regression analyses revealed that affective ratings of dyads and triads by amusic individuals were predicted by roughness but not harmonicity, whereas affective ratings by controls were predicted by both roughness and harmonicity. We discuss affective sensitivity in congenital amusia in view of theories of affective responses to isolated chords in Western listeners.

  1. A fundamental residue pitch perception bias for tone language speakers (United States)

    Petitti, Elizabeth

    A complex tone composed of only higher-order harmonics typically elicits a pitch percept equivalent to the tone's missing fundamental frequency (f0). When judging the direction of residue pitch change between two such tones, however, listeners may have completely opposite perceptual experiences depending on whether they are biased to perceive changes based on the overall spectrum or the missing f0 (harmonic spacing). Individual differences in residue pitch change judgments are reliable and have been associated with musical experience and functional neuroanatomy. Tone languages put greater pitch processing demands on their speakers than non-tone languages, and we investigated whether these lifelong differences in linguistic pitch processing affect listeners' bias for residue pitch. We asked native tone language speakers and native English speakers to perform a pitch judgment task for two tones with missing fundamental frequencies. Given tone pairs with ambiguous pitch changes, listeners were asked to judge the direction of pitch change, where the direction of their response indicated whether they attended to the overall spectrum (exhibiting a spectral bias) or the missing f0 (exhibiting a fundamental bias). We found that tone language speakers are significantly more likely to perceive pitch changes based on the missing f0 than English speakers. These results suggest that tone-language speakers' privileged experience with linguistic pitch fundamentally tunes their basic auditory processing.

  2. Taurine and the renal system (United States)


    Taurine participates in a number of different physiologic and biologic processes in the kidney, often reflected by urinary excretion patterns. The kidney is key to aspects of taurine body pool size and homeostasis. This review will examine the renal-taurine interactions relative to ion reabsorption; renal blood flow and renal vascular endothelial function; antioxidant properties, especially in the glomerulus; and the role of taurine in ischemia and reperfusion injury. In addition, taurine plays a role in the renal cell cycle and apoptosis, and functions as an osmolyte during the stress response. The role of the kidney in adaptation to variations in dietary taurine intake and the regulation of taurine body pool size are described. Finally, the protective function of taurine against several kidney diseases is reviewed. PMID:20804616

  3. Renal infarction complicating fibromuscular dysplasia. (United States)

    Gavalas, M; Meisner, R; Labropoulos, N; Gasparis, A; Tassiopoulos, A


    Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory vascular disease that most commonly affects the renal and extracranial carotid arteries. We present 3 cases of renal infarction complicating renal artery FMD in 42-, 43-, and 46-year-old females and provide a comprehensive review of the literature on this topic. In our patients, oral anticoagulation therapy was used to treat all cases of infarction, and percutaneous angioplasty was used nonemergently in one case to treat refractory hypertension. All patients remained stable at 1-year follow-up. This is consistent with outcomes in previously published reports where conservative medical management was comparable to surgical and interventional therapies. Demographic differences may also exist in patients with renal infarction and FMD. A higher prevalence of males and a younger age at presentation have been found in these patients when compared to the general population with FMD.

  4. First Language Attrition: An Investigation of Taiwanese Tones and Tone Sandhi (United States)

    Chang, Yufen


    First language (L1) attrition research focuses on syntactic and morphological deterioration in environments where L1 "attriters" rarely have contact with their L1, such as immigrants. There is no study that investigates L1 attrition in tones and in contexts where L1 can still be often heard. This study examines this attrition type in…

  5. Perception of touch quality in piano tones. (United States)

    Goebl, Werner; Bresin, Roberto; Fujinaga, Ichiro


    Both timbre and dynamics of isolated piano tones are determined exclusively by the speed with which the hammer hits the strings. This physical view has been challenged by pianists who emphasize the importance of the way the keyboard is touched. This article presents empirical evidence from two perception experiments showing that touch-dependent sound components make sounds with identical hammer velocities but produced with different touch forms clearly distinguishable. The first experiment focused on finger-key sounds: musicians could identify pressed and struck touches. When the finger-key sounds were removed from the sounds, the effect vanished, suggesting that these sounds were the primary identification cue. The second experiment looked at key-keyframe sounds that occur when the key reaches key-bottom. Key-bottom impact was identified from key motion measured by a computer-controlled piano. Musicians were able to discriminate between piano tones that contain a key-bottom sound from those that do not. However, this effect might be attributable to sounds associated with the mechanical components of the piano action. In addition to the demonstrated acoustical effects of different touch forms, visual and tactile modalities may play important roles during piano performance that influence the production and perception of musical expression on the piano.

  6. [Nonischemic dilated cardiomyopathy. Parameters of autonomic tone]. (United States)

    Demming, Thomas; Sandrock, Sarah; Bonnemeier, Hendrik


    Nonischemic dilated cardiomyopathies (DCM) are the most common reason for heart failure in developed countries after ischemic disease. They often lead to device therapy. Left ventricular ejection fraction as a single parameter to identify patients at risk for sudden cardiac death revealed inconclusive data in patients with DCM. Autonomic tone, measured by classical and innovative parameters of heart rate variability (HRV), heart rate turbulence or baroreceptor reflex, was demonstrated to give valuable prognostic information especially in patients with ischemic disease and after acute myocardial infarction. In patients with DCM, classical parameters of HRV showed inhomogeneous data in a heterogeneous patient collective caused by unsystematic measurement of single parameters in various patient collectives. Innovative parameters of HRV are promising in patients with DCM and showed prognostic relevance although patient numbers are limited and prospective data are missing. Further studies are needed in this field. Despite the in part convincing evidence for the relevance of autonomic tone as a prognostic marker in patients with DCM, their evaluation is still not part of clinical routine. Additional parameters to estimate the risk of sudden cardiac death are urgently needed.

  7. Rupture of Renal Transplant

    Directory of Open Access Journals (Sweden)

    Shona Baker


    Full Text Available Background. Rupture of renal allograft is a rare and serious complication of transplantation that is usually attributed to acute rejection, acute tubular necrosis, or renal vein thrombosis. Case Presentation. LD, a 26-year-old male with established renal failure, underwent deceased donor transplantation using kidney from a 50-year-old donor with acute kidney injury (Cr 430 mmol/L. LD had a stormy posttransplant recovery and required exploration immediately for significant bleeding. On day three after transplant, he developed pain/graft swelling and another significant haemorrhage with cardiovascular compromise which did not respond to aggressive resuscitation. At reexploration, the renal allograft was found to have a longitudinal rupture and was removed. Histology showed features of type IIa Banff 97 acute vascular rejection, moderate arteriosclerosis, and acute tubular necrosis. Conclusion. Possible ways of avoiding allograft rupture include use of well-matched, good quality kidneys; reducing or managing risk factors that would predispose to delayed graft function; ensuring a technically satisfactory transplant procedure with short cold and warm ischemia times; and avoiding large donor-recipient age gradients.

  8. 17beta-estradiol modulates baroreflex sensitivity and autonomic tone of female rats. (United States)

    Saleh, T M; Connell, B J


    The following experiments examine the role of estrogen as a central modulator of autonomic tone and baroreflex sensitivity in the female rat. Female Sprague-Dawley rats were ovariectomized and then supplemented daily for 7 days with a fixed dose of estrogen (5 microg/kg; sc) to produce a stable level of estrogen similar to that present at proestrous (17 pg/ml). The rats were then anaesthetized with sodium thiobutabarbital (100 mg/kg) and instrumented to record blood pressure, heart rate and both vagal and renal efferent nerve activities. The sensitivity of the cardiac baroreflex was tested using intravenous injection of multiple doses of either phenylephrine hydrochloride or sodium nitroprusside. Estrogen-supplemented female rats exhibited a significantly enhanced BRS as compared to male rats from a previous study (0.78 vs. 0.5). Furthermore, bolus injection of estrogen (1x10(-2) mg/kg; iv) in estrogen-supplemented female rats produced a significant increase in vagal nerve activity and a significant decrease in renal nerve activity which together resulted in a further enhancement of the BRS (0.78 vs. 2.4). Injection of the selective estrogen receptor antagonist, ICI 182,780, into nucleus ambiguus and the intrathecal space of the spinal cord blocked the respective changes in parasympathetic and sympathetic nerve activities indicating that intravenously administered estrogen modulates baseline autonomic tone via the activation of central estrogen receptors.

  9. FFT-DMAC:a tone based DMAC protocol

    Institute of Scientific and Technical Information of China (English)

    Li Ying; Li Minglu; Shu Wei; Wu Minyou


    This paper presents the flip-flop tone (FFT) DMAC protocol, a tone based MAC protocol using directional antennas to solve the deafness problem, hidden terminal and exposed terminal problems simultaneously. It uses two pairs of flip-flop tones. The first pair of tone is to send omni-directionally to reach every neighboring node to announce the start and the end of communication, and therefore to alleviate the deafness problem. The second pair of tone is to send directionally towards the sender. It is used to solve the hidden terminal problem as well as the exposed terminal problem. Evaluation shows that FFT-DMAC can achieve better performance compared to the 802.11 and ToneDMAC protocol.

  10. Effect of musical experience on learning lexical tone categories. (United States)

    Zhao, T Christina; Kuhl, Patricia K


    Previous studies suggest that musicians show an advantage in processing and encoding foreign-language lexical tones. The current experiments examined whether musical experience influences the perceptual learning of lexical tone categories. Experiment I examined whether musicians with no prior experience of tonal languages differed from nonmusicians in the perception of a lexical tone continuum. Experiment II examined whether short-term perceptual training on lexical tones altered the perception of the lexical tone continuum differentially in English-speaking musicians and nonmusicians. Results suggested that (a) musicians exhibited higher sensitivity overall to tonal changes, but perceived the lexical tone continuum in a manner similar to nonmusicians (continuously), in contrast to native Mandarin speakers (categorically); and (b) short-term perceptual training altered perception; however, there were no significant differences between the effects of training on musicians and nonmusicians.

  11. Adaptation of active tone in the mouse descending thoracic aorta under acute changes in loading. (United States)

    Murtada, S-I; Lewin, S; Arner, A; Humphrey, J D


    Arteries can adapt to sustained changes in blood pressure and flow, and it is thought that these adaptive processes often begin with an altered smooth muscle cell activity that precedes any detectable changes in the passive wall components. Yet, due to the intrinsic coupling between the active and passive properties of the arterial wall, it has been difficult to delineate the adaptive contributions of active smooth muscle. To address this need, we used a novel experimental-computational approach to quantify adaptive functions of active smooth muscle in arterial rings excised from the proximal descending thoracic aorta of mice and subjected to short-term sustained circumferential stretches while stimulated with various agonists. A new mathematical model of the adaptive processes was derived and fit to data to describe and predict the effects of active tone adaptation. It was found that active tone was maintained when the artery was adapted close to the optimal stretch for maximal active force production, but it was reduced when adapted below the optimal stretch; there was no significant change in passive behavior in either case. Such active adaptations occurred only upon smooth muscle stimulation with phenylephrine, however, not stimulation with KCl or angiotensin II. Numerical simulations using the proposed model suggested further that active tone adaptation in vascular smooth muscle could play a stabilizing role for wall stress in large elastic arteries.

  12. Rate of angiotensin II generation within the human pulmonary vascular bed

    DEFF Research Database (Denmark)

    Giese, Jacob; Kappelgaard, A M; Tønnesen, K H


    Plasma angiotensin II concentration gradients across the pulmonary vascular bed were measured during diagnostic renal venous/right heart catheterization in twenty-seven hypertensive patients with renal or renovascular disease. There was a linear correlation between the plasma angiotensin II...... vascular bed varied from 0.7 to 1.71/min, i.e. within a fairly narrow range....



    Narwaria, Manish; Perreira Da Silva, Matthieu; Le Callet, Patrick; Pépion, Romuald


    International audience; Tone mapping or range reduction is often used in High Dynamic Range (HDR) visual signal compression to take advantage of the existing image/video coding architectures. Thus, it is important to study the impact of tone mapping on the visual quality of decompressed HDR visual signals. To our knowledge, most of the existing studies focus only on the quality loss in the resultant low dynamic range (LDR) signal (obtained via tone mapping) and typically employ LDR displays f...

  14. Neuromagnetic responses to frequency modulation of a continuous tone. (United States)

    Hari, R; Mäkelä, J P


    Neuromagnetic responses to frequency modulation of a continuous tone were studied in nine subjects. The latencies of the transient responses increased and the amplitudes decreased with decreasing speed of modulation. The equivalent dipoles for modulation of a 1,000 Hz tone were slightly but statistically significantly anterior to the dipoles activated by modulation of a 500 Hz tone. The generation mechanisms of N100m are discussed.



    Gall, Andrew J.; Poremba, Amy; Blumberg, Mark S.


    In week-old rats, lesions of the dorsolateral pontine tegmentum (DLPT) and nucleus pontis oralis (PnO) have opposing effects on nuchal muscle tone. Specifically, pups with DLPT lesions exhibit prolonged bouts of nuchal muscle atonia (indicative of sleep) and pups with PnO lesions exhibit prolonged bouts of high nuchal muscle tone (indicative of wakefulness). Here we test the hypothesis that nuchal muscle tone is modulated, at least in part, by cholinergically mediated interactions between the...

  16. Coexistence of pheochromocytoma with uncommon vascular lesions

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Kota


    Full Text Available Background: Pheochromocytoma/paragangliomas have been described to be associated with rare vascular abnormalities like renal artery stenosis. Coexistence of physiologically significant renal artery lesions is a compounding factor that alters management and prognosis of pheochromocytoma patients. Apart from individual case reports, data on such association in Indian population is not available. The aim of this study is to find the nature and prevalence of associated vascular abnormalities. Materials and Methods: From 1990 to 2010, a total of 50 patients were diagnosed with pheochromocytoma/paragangliomas. Hospital charts of these patients were reviewed retrospectively to identify those with unusual vascular abnormalities. Available literature was also reviewed. Results: Of the 50 patients with pheochromocytoma, 7 (14% had coexisting vascular lesions including renal artery stenosis in 4, aortoarteritis in 1, aortic aneurysm in 1 and inferior vena cava thrombosis in 1. Pheochromocytoma was adrenal in 42 and extra adrenal in 8. Laparoscopic adrenalectomy was done in the patients. One patient with renal artery stenosis due to intimal fibrosis was subjected to percutaneous balloon angioplasty; the other three improved after adrenalectomy and lysis of fibrous adhesive bands. The patient with aortoarteritos was treated with oral steroids. Inferior vena cava thrombosis was reversed with anticoagulants. The patient with abdominal aortic aneurysm was advised for annual follow-up on account of its size of 4.5 cm and asymptomatic presentation. Conclusion: There are multiple mechanisms that can lead to renal artery stenosis and other vascular abnormalities in a case of pheochromocytoma. A high index of suspicion is necessary to enable both entities to be diagnosed preoperatively and allow proper planning of surgical therapy. Incomplete diagnosis may lead to persistent hypertension postoperatively in a case of associated renal artery stenosis.

  17. Renal Toxicities of Targeted Therapies. (United States)

    Abbas, Anum; Mirza, Mohsin M; Ganti, Apar Kishor; Tendulkar, Ketki


    With the incorporation of targeted therapies in routine cancer therapy, it is imperative that the array of toxicities associated with these agents be well-recognized and managed, especially since these toxicities are distinct from those seen with conventional cytotoxic agents. This review will focus on these renal toxicities from commonly used targeted agents. This review discusses the mechanisms of these side effects and management strategies. Anti-vascular endothelial growth factor (VEGF) agents including the monoclonal antibody bevacizumab, aflibercept (VEGF trap), and anti-VEGF receptor (VEGFR) tyrosine kinase inhibitors (TKIs) all cause hypertension, whereas some of them result in proteinuria. Monoclonal antibodies against the human epidermal growth factor receptor (HER) family of receptors, such as cetuximab and panitumumab, cause electrolyte imbalances including hypomagnesemia and hypokalemia due to the direct nephrotoxic effect of the drug on renal tubules. Cetuximab may also result in renal tubular acidosis. The TKIs, imatinib and dasatinib, can result in acute or chronic renal failure. Rituximab, an anti-CD20 monoclonal antibody, can cause acute renal failure following initiation of therapy because of the onset of acute tumor lysis syndrome. Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, can result in proteinuria. Discerning the renal adverse effects resulting from these agents is essential for safe treatment strategies, particularly in those with pre-existing renal disease.


    Directory of Open Access Journals (Sweden)

    A. V. Govorov


    Full Text Available Renal cryoablation is an alternative minimally-invasive method of treatment for localized renal cell carcinoma. The main advantages of this methodology include visualization of the tumor and the forming of "ice ball" in real time, fewer complications compared with other methods of treatment of renal cell carcinoma, as well as the possibility of conducting cryotherapy in patients with concomitant pathology. Compared with other ablative technologies cryoablation has a low rate of repeat sessions and good intermediate oncological results. The studies of long-term oncological and functional results of renal cryoablation are presently under way.

  19. Musicians' working memory for tones, words, and pseudowords. (United States)

    Benassi-Werke, Mariana E; Queiroz, Marcelo; Araújo, Rúben S; Bueno, Orlando F A; Oliveira, Maria Gabriela M


    Studies investigating factors that influence tone recognition generally use recognition tests, whereas the majority of the studies on verbal material use self-generated responses in the form of serial recall tests. In the present study we intended to investigate whether tonal and verbal materials share the same cognitive mechanisms, by presenting an experimental instrument that evaluates short-term and working memories for tones, using self-generated sung responses that may be compared to verbal tests. This paradigm was designed according to the same structure of the forward and backward digit span tests, but using digits, pseudowords, and tones as stimuli. The profile of amateur singers and professional singers in these tests was compared in forward and backward digit, pseudoword, tone, and contour spans. In addition, an absolute pitch experimental group was included, in order to observe the possible use of verbal labels in tone memorization tasks. In general, we observed that musical schooling has a slight positive influence on the recall of tones, as opposed to verbal material, which is not influenced by musical schooling. Furthermore, the ability to reproduce melodic contours (up and down patterns) is generally higher than the ability to reproduce exact tone sequences. However, backward spans were lower than forward spans for all stimuli (digits, pseudowords, tones, contour). Curiously, backward spans were disproportionately lower for tones than for verbal material-that is, the requirement to recall sequences in backward rather than forward order seems to differentially affect tonal stimuli. This difference does not vary according to musical expertise.

  20. Auditory pre-attentive processing of Chinese tones

    Institute of Scientific and Technical Information of China (English)

    YANG Li-jun; CAO Ke-li; WEI Chao-gang; LIU Yong-zhi


    Background Chinese tones are considered important in Chinese discrimination.However,the relevant reports on auditory central mechanisms concerning Chinese tones are limited.In this study,mismatch negativity (MMN),one of the event related potentials (ERP),was used to investigate pre-attentive processing of Chinese tones,and the differences between the function of oddball MMN and that of control MMN are discussed.Methods Ten subjects (six men and four women) with normal hearing participated in the study.A sequence was presented to these subjects through a loudspeaker,the sequence included four blocks,a control block and three oddball blocks.The control block was made up of five components (one pure tone and four Chinese tones) with equiprobability.The oddball blocks were made up of two components,one was a standard stimulus (tone 1) and the other was a deviant stimulus (tone 2 or tone 3 or tone 4).Electroencephalogram (EEG) data were recorded when the sequence was presented and MMNs were obtained from the analysis of the EEG data.Results Two kinds of MMNs were obtained,oddball MMN and control MMN.Oddball MMN was obtained by subtracting the ERP elicited by standard stimulation (tone 1) from that elicited by deviant stimulation (tone 2 or tone 3 or tone 4) in the oddball block; control MMN was obtained by subtracting the ERP elicited by the tone in control block,which was the same tone as the deviant stimulation in the oddball block,from the ERP elicited by deviant stimulation (tone 2 or tone 3 or tone 4)in the oddball block.There were two negative waves in oddball MMN,one appeared around 150 ms (oddball MMN 1),the other around 300 ms (oddball MMN 2).Only one negative wave appeared around 300 ms in control MMN,which was corresponding to the oddball MMN 2.We performed the statistical analyses in each paradigm for latencies and amplitudes for oddball MMN 2 in discriminating the three Chinese tones and reported no significant differences.But the latencies and amplitudes

  1. Scleroderma Renal Crisis: A Pathology Perspective

    Directory of Open Access Journals (Sweden)

    Ibrahim Batal


    Full Text Available Scleroderma renal crisis (SRC is an infrequent but serious complication of systemic sclerosis (SSc. It is associated with increased vascular permeability, activation of coagulation cascade, and renin secretion, which may lead to the acute renal failure typically associated with accelerated hypertension. The histologic picture of SRC is that of a thrombotic microangiopathy process with prominent small vessel involvement manifesting as myxoid intimal changes, thrombi, onion skin lesions, and/or fibrointimal sclerosis. Renal biopsies play an important role in confirming the clinical diagnosis, excluding overlapping/superimposed diseases that might lead to acute renal failure in SSc patients, helping to predict the clinical outcome and optimizing patient management. Kidney transplantation may be the only treatment option available for a subset of SRC patients who develop end-stage renal failure despite aggressive angiotensin-converting enzyme inhibitor therapy. However, the posttransplant outcome for SSc patients is currently suboptimal compared to the general renal transplant population.

  2. Measurement of intraindividual airway tone heterogeneity and its importance in asthma


    Brown, Robert H.; Togias, Alkis


    While airways have some degree of baseline tone, the level and variability of this tone is not known. It is also unclear whether there is a difference in airway tone or in the variability of airway tone between asthmatic and healthy individuals. This study examined airway tone and intraindividual airway tone heterogeneity (variance of airway tone) in vivo in 19 individuals with asthma compared with 9 healthy adults. All participants underwent spirometry, body plethysmography, and high-resolut...

  3. Reduced KCNQ4-encoded voltage-dependent potassium channel activity underlies impaired β-adrenoceptor-mediated relaxation of renal arteries in hypertension. (United States)

    Chadha, Preet S; Zunke, Friederike; Zhu, Hai-Lei; Davis, Alison J; Jepps, Thomas A; Olesen, Søren P; Cole, William C; Moffatt, James D; Greenwood, Iain A


    KCNQ4-encoded voltage-dependent potassium (Kv7.4) channels are important regulators of vascular tone that are severely compromised in models of hypertension. However, there is no information as to the role of these channels in responses to endogenous vasodilators. We used a molecular knockdown strategy, as well as pharmacological tools, to examine the hypothesis that Kv7.4 channels contribute to β-adrenoceptor-mediated vasodilation in the renal vasculature and underlie the vascular deficit in spontaneously hypertensive rats. Quantitative PCR and immunohistochemistry confirmed gene and protein expression of KCNQ1, KCNQ3, KCNQ4, KCNQ5, and Kv7.1, Kv7.4, and Kv7.5 in rat renal artery. Isoproterenol produced concentration-dependent relaxation of precontracted renal arteries and increased Kv7 channel currents in isolated smooth muscle cells. Application of the Kv7 blocker linopirdine attenuated isoproterenol-induced relaxation and current. Isoproterenol-induced relaxations were also reduced in arteries incubated with small interference RNAs targeted to KCNQ4 that produced a ≈60% decrease in Kv7.4 protein level. Relaxation to isoproterenol and the Kv7 activator S-1 were abolished in arteries from spontaneously hypertensive rats, which was associated with ≈60% decrease in Kv7.4 abundance. This study provides the first evidence that Kv7 channels contribute to β-adrenoceptor-mediated vasodilation in the renal vasculature and that abrogation of Kv7.4 channels is strongly implicated in the impaired β-adrenoceptor pathway in spontaneously hypertensive rats. These findings may provide a novel pathogenic link between arterial dysfunction and hypertension.

  4. Vascular emergencies. (United States)

    Semashko, D C


    This article reviews the initial assessment and emergent management of several common as well as uncommon vascular emergencies. Aortic dissection, aneurysms, and arterial occlusive disease are familiar but challenging clinical entities. Less frequently encountered conditions are also discussed including an aortic enteric fistula, mesenteric venous thrombosis, phlegmasia alba dolens, and subclavian vein thrombosis.

  5. Vascular Disease Foundation (United States)

    ... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...

  6. What Is Vascular Disease? (United States)

    ... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...

  7. Unravelling the complexities of vascular smooth muscle ion channels

    DEFF Research Database (Denmark)

    Jepps, Thomas A


    Which ion channel is the most important for regulating vascular tone? Which one is responsible for controlling the resting membrane potential or repolarization? Which channels are recruited by different intracellular signalling pathways or change in certain vascular diseases? Many different ion...... to off-target effects. As cardiovascular diseases are expected to increase worldwide to epidemic proportions, ion channel research and the hunt for the next major therapeutic target to treat different vascular diseases has never been more important. However, I believe that the question we should now...

  8. Tune in to the Tone: Lexical Tone Identification is Associated with Vocabulary and Word Recognition Abilities in Young Chinese Children. (United States)

    Tong, Xiuli; Tong, Xiuhong; McBride-Chang, Catherine


    Lexical tone is one of the most prominent features in the phonological representation of words in Chinese. However, little, if any, research to date has directly evaluated how young Chinese children's lexical tone identification skills contribute to vocabulary acquisition and character recognition. The present study distinguished lexical tones from segmental phonological awareness and morphological awareness in order to estimate the unique contribution of lexical tone in early vocabulary acquisition and character recognition. A sample of 199 Cantonese children aged 5-6 years was assessed on measures of lexical tone identification, segmental phonological awareness, morphological awareness, nonverbal ability, vocabulary knowledge, and Chinese character recognition. It was found that lexical tone awareness and morphological awareness were both associated with vocabulary knowledge and character recognition. However, there was a significant relationship between lexical tone awareness and both vocabulary knowledge and character recognition, even after controlling for the effects of age, nonverbal ability, segmental phonological awareness and morphological awareness. These findings suggest that lexical tone is a key factor accounting for individual variance in young children's lexical acquisition in Chinese, and that lexical tone should be considered in understanding how children learn new Chinese vocabulary words, in either oral or written forms.

  9. Disorders of pitch production in tone deafness. (United States)

    Bella, Simone Dalla; Berkowska, Magdalena; Sowiński, Jakub


    Singing is as natural as speaking for the majority of people. Yet some individuals (i.e., 10-15%) are poor singers, typically performing or imitating pitches and melodies inaccurately. This condition, commonly referred to as "tone deafness," has been observed both in the presence and absence of deficient pitch perception. In this article we review the existing literature concerning normal singing, poor-pitch singing, and, briefly, the sources of this condition. Considering that pitch plays a prominent role in the structure of both music and speech we also focus on the possibility that speech production (or imitation) is similarly impaired in poor-pitch singers. Preliminary evidence from our laboratory suggests that pitch imitation may be selectively inaccurate in the music domain without being affected in speech. This finding points to separability of mechanisms subserving pitch production in music and language.

  10. Classical conditioned responses to absent tones

    Directory of Open Access Journals (Sweden)

    Häusler Udo


    Full Text Available Abstract Background Recent evidence for a tight coupling of sensorimotor processes in trained musicians led to the question of whether this coupling extends to preattentively mediated reflexes; particularly, whether a classically conditioned response in one of the domains (auditory is generalized to another (tactile/motor on the basis of a prior association in a second-order Pavlovian paradigm. An eyeblink conditioning procedure was performed in 17 pianists, serving as a model for overlearned audiomotor integration, and 14 non-musicians. Results: During the training session, subjects were conditioned to respond to auditory stimuli (piano tones. During a subsequent testing session, when subjects performed keystrokes on a silent piano, pianists showed significantly higher blink rates than non-musicians. Conclusion These findings suggest a tight coupling of the auditory and motor domains in musicians, pointing towards training-dependent mechanisms of strong cross-modal sensorimotor associations even on sub-cognitive processing levels.

  11. 不同血管活性药物治疗肾移植术后感染性休克的临床观察%Clinical observation of different vascular drugs in septic shock after renal transplantation

    Institute of Scientific and Technical Information of China (English)

    张磊; 孙雯; 解泽林; 田野


    Objective To evaluate the effect of dopamine (DA) and norepinephrine ( NE ) on early changes of hemodynamics and renal perfusion in patients with septic shock after kidney transplantation. Methods twenty-three patients, who conformed to the inclusive criteria, were enrolled and randomly assigned to accept DA and NE continuous infusion. Heart rate (HR), variations of mean arterial pressure (MAP), systemic vascular resistance index (SVRJ), cardiac index (CI), lactate (LAC), mixed venous oxygen saturation (ScVO2), urine volume per hour (UV), creatinine clearance (Ccr), serum creatinine (Scr) were determined before treatment (T0) and 6,12,24,48 h after DA or NE infusion. Results MAP, SVRI, CI and ScVO2 increased significantly (P < 0.05) after treatment with DA and NE compared with the baseline (T0), and no statistic differences were found between the two groups at the same time point. HR increased in DA group ,but comparing to TO, there was no statistical significance. However, it decreased significantly in NE group from T12 comparing to T0 (P < 0.0S), and HR in NE group was obviously lower than that in DA group at each corresponding time point (P < 0.05). LAC decreased in both groups, and has statistical significant since the time point of 24 h compared to T0 (P < 0.05). Scr level was similar in both groups, however, UV and Ccr increased significantly in both groups after treatment (P < 0.05), UV was significantly higher in NE group than that in DA group from the time point of 12 h. Conclusions Compared to DA, NE has a better effect on enhancing organ perfusion and tissue oxygenation, as well as improving renal function. NE should be considered as a preferable vasopressor in the management of septic shock after kidney transplantation.%目的 探讨多巴胺(dopamine,DA)与去甲肾上腺素(norepinephrine,NE)对肾移植术后感染性休克患者血流动力学及肾脏灌注的影响.方法 符合入选标准的肾移植术后感染性休克患者23例,随机分组

  12. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.


    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all acknowle

  13. Renal fallure

    Institute of Scientific and Technical Information of China (English)


    920705 Endothelin and acute renal failure:study on their relationship and possiblemechanisms. LIN Shanyan(林善锬), et al.Renal Res Lab, Huashan Hosp, Shanghai MedUniv, Shanghai, 200040. Natl Med J China 1992;72(4): 201-205. In order to investigate the role of endothelin

  14. Renal cancer.

    NARCIS (Netherlands)

    Corgna, E.; Betti, M.; Gatta, G.; Roila, F.; Mulder, P.H.M. de


    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  15. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.


    In Europe, renal cancer (that is neoplasia of the kidney, renal pelvis or ureter (ICD-9 189 and ICD-10 C64-C66)) ranks as the seventh most common malignancy in men amongst whom there are 29,600 new cases each year (3.5% of all cancers). Tobacco, obesity and a diet poor in vegetables are all

  16. Endothelial Dysfunction in Renal Failure: Current Update. (United States)

    Radenkovic, Miroslav; Stojanovic, Marko; Prostran, Milica


    Endothelial dysfunction is principally characterized by impaired endothelium- dependent transduction mechanisms related to vascular relaxation, as an outcome of decreased release of endothelium-derived relaxing factors, mainly nitric oxide, as well as augmented oxidative stress, increased inflammation and predominance of vascular action produced by endothelium-derived contracting factors. Current data strongly suggest that pathological development of different types of kidney impairment with further progression to renal failure includes notable vascular changes associated with endothelial dysfunction. In accordance, this scientific field represents an advancing area of investigation, involving different biomarkers of endothelial dysfunction linked to renal impairment, as well as clinical findings with new information that can provide a more comprehensive understanding of the role of endothelial dysfunction in kidney disease. With regards to quoted facts, the aim of this article was to review the latest data related to endothelial dysfunction and renal failure by selection of relevant articles released from 2010 to 2015.

  17. Beneficial effects of renal denervation on pulmonary vascular remodeling in experimental pulmonary artery hypertension%肾去交感神经对肺动脉高压模型犬肺血管重构的影响

    Institute of Scientific and Technical Information of China (English)

    张淑娟; 赵庆彦; 蒋学俊; 杨波; 代子玄; 王晓占; 王徐乐; 郭宗文; 于胜波


    目的 探讨肾去交感神经(RSD)对肺动脉高压(PAH)模型犬肺血管重构的影响.方法 24只比格犬按随机数字表法随机均分为对照组、PAH组、PAH+ RSD组各8只.检测各组犬实验前血清神经激素水平、心脏超声和血流动力学参数后,对照组右心房注入二甲基甲酰胺(0.1 ml/kg),PAH组右心房注入脱氢野百合碱(2 ml/kg),PAH+ RSD组先行肾去交感神经术,后右心房注入脱氢野百合碱(2 ml/kg).喂养8周,检测各组犬实验后的血清神经激素水平、心脏超声和血流动力学参数后,开胸取肺组织检测肺血管形态学.结果 实验后PAH组、PAH+ RSD组右心室收缩压(RVSP)和肺动脉收缩压(PASP)均显著高于对照组[(42.8±8.7)、(30.8±6.8)比(23.2±5.7) mmHg(1mmHg =0.133 kPa)和(45.1±11.2)、(32.6±7.9)比(24.7 ±7.1)mmHg],且PAH组RVSP和PASP显著高于PAH+ RSD组[均P<0.01].实验后PAH组血清血管紧张素Ⅱ(AngⅡ)和内皮素1水平均显著高于实验前[(228 ±41)比(113±34) pg/ml和(135 ±15)比(77±7)pg/ml,均P<0.01],且肺组织中AngⅡ和内皮素1水平[(65±10)和(96±10)pg/ml]均显著高于对照组[(38±7)和(54±6)pg/ml]和PAH+ RSD组[(46±8)和(67±9)pg/ml](均P<0.01).与对照组相比,PAH组肺泡2型细胞破坏严重,组织纤维化明显,而PAH+ RSD组肺泡2型细胞破坏及组织纤维化较PAH组轻.结论 RSD可降低PAH模型犬肺动脉高压并抑制肺血管重构,此作用可能与其降低神经激素水平有关.%Objective To explore the effects of renal sympathetic denervation (RSD) on pulmonary vascular remodeling in a model of pulmonary arterial hypertension (PAH).Methods According to the random number table,24 beagles were randomized into control,PAH and PAH + RSD groups (n =8 each).The levels of neurohormone,echocardiogram and dynamics parameters were measured.Then 0.1 ml/kg dimethylformamide (control group) or 2 mg/kg dehydromonocrotaline (PAH and PAH + RSD groups) were injected.The PAH + RSD group

  18. Empirical measurements on a Sesotho tone labeling algorithm

    CSIR Research Space (South Africa)

    Raborife, M


    Full Text Available This paper discusses the empirical assessments employed on two versions of a Sesotho tone labeling algorithm. This algorithm uses linguistically-defined Sesotho tonal rules to predict the tone labels on the syllables of Sesotho words. The two...

  19. Analysis on the relations between piano touch and tone


    Nie, Lai-Mei


    In piano playing, different ways of touch lead to different tones. The effects of changing forces on keys are presented by changing interaction between hammer and string. The thesis focuses on several important variables in hammer-string system and draws conclusions to the question about piano touch and tone.

  20. Pilot tones in WDM networks with wavelength converters

    DEFF Research Database (Denmark)

    Kloch, Allan; Mikkelsen, Benny; Stubkjær, Kristian


    Here we investigate the transmission of a pilot tone through an interferometric wavelength converter (IWC) in conjunction with a 2.5 Gbit/s experiment. The pilot tone is added by sinusoidal modulation of the bias current to the signal laser. After the IWC (Michelson interferometer) the converted...

  1. Dissimilation in the Second Language Acquisition of Mandarin Chinese Tones (United States)

    Zhang, Hang


    This article extends Optimality Theoretic studies to the research on second language tone phonology. Specifically, this work analyses the acquisition of identical tone sequences in Mandarin Chinese by adult speakers of three non-tonal languages: English, Japanese and Korean. This study finds that the learners prefer not to use identical lexical…

  2. Dissimilation in the Second Language Acquisition of Mandarin Chinese Tones (United States)

    Zhang, Hang


    This article extends Optimality Theoretic studies to the research on second language tone phonology. Specifically, this work analyses the acquisition of identical tone sequences in Mandarin Chinese by adult speakers of three non-tonal languages: English, Japanese and Korean. This study finds that the learners prefer not to use identical lexical…

  3. Tone sandhi, prosodic phrasing, and focus marking in Wenzhou Chinese

    NARCIS (Netherlands)

    Scholz, Franziska


    In most languages, focus (i.e. highlighting information) is marked by modifying the melody of the sentence. But how is focus marked in a Chinese dialect with eight different citation tones and a complex tonal phonology? This thesis investigates the connection between tonal realization and tone chang

  4. One-tone suppression in the frog auditory nerve

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B


    Sixty-seven fibers of a sample of 401 in the auditory nerve of grassfrogs (Rana temporaria) showed one-tone suppression, i.e., their spontaneous activity was suppressed by tones. All fibers were afferents from the amphibian papilla with best frequencies between 100 and 400 Hz. Best suppression...

  5. Renal Heme Oxygenase-1 Induction with Hemin Augments Renal Hemodynamics, Renal Autoregulation, and Excretory Function

    Directory of Open Access Journals (Sweden)

    Fady T. Botros


    Full Text Available Heme oxygenases (HO-1; HO-2 catalyze conversion of heme to free iron, carbon monoxide, and biliverdin/bilirubin. To determine the effects of renal HO-1 induction on blood pressure and renal function, normal control rats (n=7 and hemin-treated rats (n=6 were studied. Renal clearance studies were performed on anesthetized rats to assess renal function; renal blood flow (RBF was measured using a transonic flow probe placed around the left renal artery. Hemin treatment significantly induced renal HO-1. Mean arterial pressure and heart rate were not different (115±5 mmHg versus 112±4 mmHg and 331±16 versus 346±10 bpm. However, RBF was significantly higher (9.1±0.8 versus 7.0±0.5 mL/min/g, P<0.05, and renal vascular resistance was significantly lower (13.0±0.9 versus 16.6±1.4 [mmHg/(mL/min/g], P<0.05. Likewise, glomerular filtration rate was significantly elevated (1.4±0.2 versus 1.0±0.1 mL/min/g, P<0.05, and urine flow and sodium excretion were also higher (18.9±3.9 versus 8.2±1.0 μL/min/g, P<0.05 and 1.9±0.6 versus 0.2±0.1 μmol/min/g, P<0.05, resp.. The plateau of the autoregulation relationship was elevated, and renal vascular responses to acute angiotensin II infusion were attenuated in hemin-treated rats reflecting the vasodilatory effect of HO-1 induction. We conclude that renal HO-1 induction augments renal function which may contribute to the antihypertensive effects of HO-1 induction observed in hypertension models.

  6. Factors Influencing Sensitivity to Lexical Tone in an Artificial Language: Implications for Second Language Learning (United States)

    Caldwell-Harris, Catherine L.; Lancaster, Alia; Ladd, D. Robert; Dediu, Dan; Christiansen, Morten H.


    This study examined whether musical training, ethnicity, and experience with a natural tone language influenced sensitivity to tone while listening to an artificial tone language. The language was designed with three tones, modeled after level-tone African languages. Participants listened to a 15-min random concatenation of six 3-syllable words.…

  7. Renal infarction due to lupus vasculopathy. (United States)

    Varalaxmi, B; Sandeep, P; Sridhar, A V S S N; Raveendra, P; Kishore, C Krishna; Ram, R; Kumar, V Siva


    In the ISN/RPS 2003 classification of lupus nephritis (LN) renal vascular lesions are not mentioned. We present a patient with postpartum lupus vasculopathy. The renal biopsy in our patient showed concentric intimal thickening with narrowed lumen. No inflammatory changes were found. It also revealed immunoglobulin and complement deposition on the wall of the arteriole. These changes indicate lupus vasculopathy. The glomeruli revealed diffuse proliferative glomerulonephritis, with wire loops and cellular crescent in one glomerulus. The patient showed improvement with immunosuppression.

  8. Brainstem cholinergic modulation of muscle tone in infant rats. (United States)

    Gall, Andrew J; Poremba, Amy; Blumberg, Mark S


    In week-old rats, lesions of the dorsolateral pontine tegmentum (DLPT) and nucleus pontis oralis (PnO) have opposing effects on nuchal muscle tone. Specifically, pups with DLPT lesions exhibit prolonged bouts of nuchal muscle atonia (indicative of sleep) and pups with PnO lesions exhibit prolonged bouts of high nuchal muscle tone (indicative of wakefulness). Here we test the hypothesis that nuchal muscle tone is modulated, at least in part, by cholinergically mediated interactions between these two regions. First, in unanesthetized pups, we found that chemical infusion of the cholinergic agonist carbachol (22 mm, 0.1 microL) within the DLPT produced high muscle tone. Next, chemical lesions of the PnO were used to produce a chronic state of high nuchal muscle tone, at which time the cholinergic antagonist scopolamine (10 mm, 0.1 microL) was infused into the DLPT. Scopolamine effectively decreased nuchal muscle tone, thus suggesting that lesions of the PnO increase muscle tone via cholinergic activation of the DLPT. Using 2-deoxyglucose autoradiography, metabolic activation throughout the DLPT was observed after PnO lesions. Finally, consistent with the hypothesis that PnO inactivation produces high muscle tone, infusion of the sodium channel blocker lidocaine (2%) into the PnO of unanesthetized pups produced rapid increases in muscle tone. We conclude that, even early in infancy, the DLPT is critically involved in the regulation of muscle tone and behavioral state, and that its activity is modulated by a cholinergic mechanism that is directly or indirectly controlled by the PnO.

  9. Effects of Early Bilingual Experience with a Tone and a Non-Tone Language on Speech-Music Integration

    NARCIS (Netherlands)

    Asaridou, S.S.; Hagoort, P.; McQueen, J.M.


    We investigated music and language processing in a group of early bilinguals who spoke a tone language and a non-tone language (Cantonese and Dutch). We assessed online speech-music processing interactions, that is, interactions that occur when speech and music are processed simultaneously in songs,

  10. Renal transplantation in a child with thrombosed inferior vena cava

    Directory of Open Access Journals (Sweden)

    Surjeet Kumar


    Full Text Available The external iliac vein is commonly used in renal transplantation for vascular anastomosis of the allograft renal vein. However, there are rare instances when the transplant surgeon may encounter thrombosis of the ilio-caval vein during surgery, making renal transplantation a challenge. Often, these patients are considered unsuitable for renal transplantation. We report a case of thrombosis of the inferior vena cava in an asymptomatic pediatric patient in whom the splenic vein was used, at transplantation, for venous drainage. This case highlights that pre-operative Doppler screening should be performed in all potential renal transplant recipients.

  11. Renal teratogens. (United States)

    Morgan, Thomas M; Jones, Deborah P; Cooper, William O


    In utero exposure to certain drugs early in pregnancy may adversely affect nephrogenesis. Exposure to drugs later in pregnancy may affect the renin-angiotensin system, which could have an impact on fetal or neonatal renal function. Reduction in nephron number and renal function could have adverse consequences for the child several years later. Data are limited on the information needed to guide decisions for patients and providers regarding the use of certain drugs in pregnancy. The study of drug nephroteratogenicity has not been systematized, a large, standardized, global approach is needed to evaluate the renal risks of in utero drug exposures.

  12. Regulation of rat intrapulmonary arterial tone by arachidonic acid and prostaglandin E2 during hypoxia.

    Directory of Open Access Journals (Sweden)

    Gaoliang Yan

    Full Text Available AIMS: Arachidonic acid (AA and its metabolites, prostaglandins (PG are known to be involved in regulation of vascular homeostasis including vascular tone and vessel wall tension, but their potential role in Hypoxic pulmonary vasoconstriction (HPV remains unclear. In this study, we examined the effects of AA and PGE2 on the hypoxic response in isolated rat intrapulmonary arteries (IPAs. METHODS AND RESULTS: We carried out the investigation on IPAs by vessel tension measurement. Isotetrandrine (20 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. Both indomethacin (100 µM and NS398 attenuated KPSS-induced vessel contraction and phase I, phase IIb and phase IIc of HPV, implying that COX-2 plays a primary role in the hypoxic response of rat IPAs. PGE2 alone caused a significant vasoconstriction in isolated rat IPAs. This constriction is mediated by EP4. Blockage of EP4 by L-161982 (1 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. However, AH6809 (3 µM, an antagonist of EP1, EP2, EP3 and DP1 receptors, exerted no effect on KPSS or hypoxia induced vessel contraction. Increase of cellular cAMP by forskolin could significantly reduce KPSS-induced vessel contraction and abolish phase I, phase II b and phase II c of HPV. CONCLUSION: Our results demonstrated a vasoconstrictive effect of PGE2 on rat IPAs and this effect is via activation of EP4. Furthermore, our results suggest that intracellular cAMP plays dual roles in regulation of vascular tone, depending on the spatial distribution of cAMP and its coupling with EP receptor and Ca(2+ channels.

  13. Attention deficits revealed by passive auditory change detection for pure tones and lexical tones in ADHD children

    Directory of Open Access Journals (Sweden)

    Ming-Tao eYang


    Full Text Available Inattention has been a major problem in children with attention deficit/hyperactivity disorder (ADHD, accounting for their behavioral and cognitive dysfunctions. However, there are at least three processing steps underlying attentional control for auditory change detection, namely pre-attentive change detection, involuntary attention orienting, and attention reorienting for further evaluation. This study aimed to examine whether children with ADHD would show deficits in any of these subcomponents by using mismatch negativity (MMN, P3a, and late discriminative negativity (LDN as event-related potential (ERP markers, under the passive auditory oddball paradigm. Two types of stimuli - pure tones and Mandarin lexical tones - were used to examine if the deficits were general across linguistic and non-linguistic domains. Participants included 15 native Mandarin-speaking children with ADHD and 16 age-matched controls (across groups, age ranged between 6 and 15 years. Two passive auditory oddball paradigms (lexical tones and pure tones were applied. Pure tone paradigm included standard stimuli (1000 Hz, 80% and two deviant stimuli (1015 Hz and 1090 Hz, 10% each. The Mandarin lexical tone paradigm’s standard stimuli was /yi3/ (80% and two deviant stimuli were /yi1/ and /yi2/ (10% each. The results showed no MMN difference, but did show attenuated P3a and enhanced LDN to the large deviants for both pure and lexical tone changes in the ADHD group. Correlation analysis showed that children with higher ADHD tendency, as indexed by parents’ and teachers’ rating on ADHD symptoms, showed less positive P3a amplitudes when responding to large lexical tone deviants. Thus, children with ADHD showed impaired auditory change detection for both pure tones and lexical tones in both involuntary attention switching, and attention reorienting for further evaluation. These ERP markers may therefore be used for evaluation of anti-ADHD drugs that aim to alleviate these

  14. The effect of nifedipine on renal function in normotensive cyclosporin-A-treated renal allograft recipients. (United States)

    McNally, P G; Walls, J; Feehally, J


    Intrarenal vasoconstriction is a characteristic feature of CsA nephrotoxicity. The influence of nifedipine, a dihydropyridine calcium channel blocker and potent renal vasodilator, on renal haemodynamics was investigated in 11 cyclosporin A (CsA)- and 9 azathioprine (Aza)-treated normotensive long-term renal allograft recipients. Baseline Cr51-EDTA clearance and effective renal plasma flow (ERPF) were similar in both groups. Nifedipine 20 mg twice daily for 28 days significantly increased Cr51-EDTA clearance (+14.8%) in the CsA group; however, ERPF, renal vascular resistance (RVR), and filtration fraction did not change. Nifedipine did not influence renal haemodynamics in the azathioprine group. The increase in Cr51-EDTA clearance in the CsA group did not correlate with baseline renal function, CsA dose or whole blood levels, donor age, duration of graft, or renal functional reserve capacity. This study suggests that nifedipine confers a beneficial effect on renal haemodynamics in long-term CsA-treated renal allograft recipients and appears to improve renal function by a non-haemodynamic mechanism.

  15. Sarcoidose renal

    Directory of Open Access Journals (Sweden)



    Full Text Available Em uma mulher de 62 anos, branca, em avaliação pré-operatória de facectomia, foram detectadas alterações urinárias, tendo sido firmados os diagnósticos de calculose renal esquerda e exclusão renal homolateral. No pré-operatório da nefrectomia foram evidenciados processo pulmonar intersticial bilateral e adenopatia torácica, cuja investigação foi adiada para após a cirurgia. No rim retirado foram detectados granulomas epitelióides não necrotizantes, o mesmo ocorrendo posteriormente em biópsia transbrônquica. A paciente foi tratada com metilprednisolona, com discreta melhora pulmonar, o que não ocorreu com a função renal. O diagnóstico final foi de sarcoidose com envolvimento pulmonar, ganglionar torácico e renal.

  16. Renal failure

    Institute of Scientific and Technical Information of China (English)


    930150 Epidermal growth factor and its recep-tor in the renal tissue of patients with acute re-nal failure and normal persons.LIU Zhihong(刘志红),et al.Jinling Hosp,Nanjing,210002.Natl Med J China 1992;72(10):593-595.Epidermal growth factor(EGF)and its receptor(EGF-R)were identified by immunohis-tochemical method(4 layer PAP)in the renaltissue specimens obtained from 11 normal kid-neys and 17 cases of acute renal failure(ARF).The quantitative EGF and EGF-R in the tissuewere expressed as positive tubules per mm~2.The amount of EGF and EGF-R in renal tissue

  17. Renal failure

    Institute of Scientific and Technical Information of China (English)


    2005234 Association between serum fetuin-A and clinical outcome in end-stage renal disease patients. WANG Kai(王开), Dept Renal Dis, Renji Hosp Shanghai, 2nd Med Univ, Shanghai 200001. Chin J Nephrol, 2005;21(2):72-75. Objective: To investigate the change of serum fetuin-A level before and after dialysis, and the association of serum fetuin-A level with clinical parameters

  18. Renal failure

    Institute of Scientific and Technical Information of China (English)


    950351 Serum erythropoietin levels in chronic renalinsufficiency.ZHAI Depei(翟德佩),et al.DeptNephrol.General Hosp,Tianjin Med Univ,Tianjin,300000.Tianjin Med J 1995;23(1):19-21.Patients with chronic renal insufficiency(CRI) areoften associated with anemia.The deficiency of EPOproduction in the kidney is thought to be a key factorin the pathogenesis of renal anemia.Serum erythropoi-

  19. Renal failure

    Institute of Scientific and Technical Information of China (English)


    2008463 Protective effect of recombination rat augmenter of liver regeneration on kidney in acute renal failure rats. TANG Xiaopeng(唐晓鹏), et al. Dept Nephrol, 2nd Affili Hosp Chongqing Med Univ, Chongqing 400010.Chin J Nephrol 2008;24(6):417-421. Objective To investigate the protective effects of recombination rat augmenter of liver regeneration (rrALR) on tubular cell injury and renal dysfunction

  20. Renal Hemangiopericytoma

    Directory of Open Access Journals (Sweden)

    İbrahim Halil Bozkurt


    Full Text Available Hemangiopericytoma is an uncommon perivascular tumor originating from pericytes in the pelvis, head and tneck, and the meninges; extremely rarely in the urinary system. We report a case of incidentally detected renal mass in which radiologic evaluation was suggestive of renal cell carcinoma. First, we performed partial nephrectomy, and then, radical nephrectomy because of positive surgical margins and the pathological examination of the surgical specimen that revealed a hemangiopericytoma. No additional treatment was administered.

  1. Impaired learning of event frequencies in tone deafness. (United States)

    Loui, Psyche; Schlaug, Gottfried


    Musical knowledge is ubiquitous, effortless, and implicitly acquired all over the world via exposure to musical materials in one's culture. In contrast, one group of individuals who show insensitivity to music, specifically the inability to discriminate pitches and melodies, is the tone-deaf. In this study, we asked whether difficulties in pitch and melody discrimination among the tone-deaf could be related to learning difficulties, and, if so, what processes of learning might be affected in the tone-deaf. We investigated the learning of frequency information in a new musical system in tone-deaf individuals and matched controls. Results showed significantly impaired learning abilities in frequency matching in the tone-deaf. This impairment was positively correlated with the severity of tone deafness as assessed by the Montreal Battery for Evaluation of Amusia. Taken together, the results suggest that tone deafness is characterized by an impaired ability to acquire frequency information from pitched materials in the sound environment. © 2012 New York Academy of Sciences.

  2. Differential effects of superoxide and hydrogen peroxide on myogenic signaling, membrane potential, and contractions of mouse renal afferent arterioles. (United States)

    Li, Lingli; Lai, En Yin; Wellstein, Anton; Welch, William J; Wilcox, Christopher S


    Myogenic contraction is the principal component of renal autoregulation that protects the kidney from hypertensive barotrauma. Contractions are initiated by a rise in perfusion pressure that signals a reduction in membrane potential (Em) of vascular smooth muscle cells to activate voltage-operated Ca(2+) channels. Since ROS have variable effects on myogenic tone, we investigated the hypothesis that superoxide (O2 (·-)) and H2O2 differentially impact myogenic contractions. The myogenic contractions of mouse isolated and perfused single afferent arterioles were assessed from changes in luminal diameter with increasing perfusion pressure (40-80 mmHg). O2 (·-), H2O2, and Em were assessed by fluorescence microscopy during incubation with paraquat to increase O2 (·-) or with H2O2 Paraquat enhanced O2 (·-) generation and myogenic contractions (-42 ± 4% vs. -19 ± 4%, P contractions (-10 ± 1% vs. -19 ± 2%, P contractions with paraquat without preventing the reduction in Em Myogenic contractions were independent of the endothelium and largely independent of nitric oxide. We conclude that O2 (·-) and H2O2 activate different signaling pathways in vascular smooth muscle cells linked to discreet membrane channels with opposite effects on Em and voltage-operated Ca(2+) channels and therefore have opposite effects on myogenic contractions.

  3. The Neural Substrates Underlying the Implementation of Phonological Rule in Lexical Tone Production: An fMRI Study of the Tone 3 Sandhi Phenomenon in Mandarin Chinese. (United States)

    Chang, Claire H C; Kuo, Wen-Jui


    This study examined the neural substrates underlying the implementation of phonological rule in lexical tone by the Tone 3 sandhi phenomenon in Mandarin Chinese. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (33 →23) during speech production. Tone 3 sandhi enables the examination of tone processing in the phonological level with the least involvement of segments. Using the fMRI technique, we measured brain activations corresponding to the monosyllable and disyllable sequences of the four Chinese lexical tones, while manipulating the requirement on overt oral response. The application of Tone 3 sandhi to disyllable sequence of Tone 3 was confirmed by our behavioral results. Larger brain responses to overtly produced disyllable Tone 3 (33 > 11, 22, and 44) were found in right posterior IFG by both whole-brain and ROI analyses. We suggest that the right IFG was responsible for the processing of Tone 3 sandhi. Intense temporo-frontal interaction is needed in speech production for self-monitoring. The involvement of the right IFG in tone production might result from its interaction with the right auditory cortex, which is known to specialize in pitch. Future studies using tools with better temporal resolutions are needed to illuminate the dynamic interaction between the right inferior frontal regions and the left-lateralized language network in tone languages.

  4. Frequency ratios and the perception of tone patterns. (United States)

    Schellenberg, E G; Trehub, S E


    We quantified the relative simplicity of frequency ratios and reanalyzed data from several studies on the perception of simultaneous and sequential tones. Simplicity of frequency ratios accounted for judgments of consonance and dissonance and for judgments of similarity across a wide range of tasks and listeners. It also accounted for the relative ease of discriminating tone patterns by musically experienced and inexperienced listeners. These findings confirm the generality of previous suggestions of perceptual processing advantages for pairs of tones related by simple frequency ratios.

  5. A linear programming approach for optimal contrast-tone mapping. (United States)

    Wu, Xiaolin


    This paper proposes a novel algorithmic approach of image enhancement via optimal contrast-tone mapping. In a fundamental departure from the current practice of histogram equalization for contrast enhancement, the proposed approach maximizes expected contrast gain subject to an upper limit on tone distortion and optionally to other constraints that suppress artifacts. The underlying contrast-tone optimization problem can be solved efficiently by linear programming. This new constrained optimization approach for image enhancement is general, and the user can add and fine tune the constraints to achieve desired visual effects. Experimental results demonstrate clearly superior performance of the new approach over histogram equalization and its variants.

  6. Coarctation of the aorta and renal artery stenosis in tuberous sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, P.M.; Robinson, M.B.; Stapleton, F.B.; Roy, S. III; Koh, G.; Tonkin, I.L.D.


    Among neurocutaneous disorders, coarctation of the abdominal aorta and renal artery stenosis have traditionally been associated with neurofibromatosis. We report a 5-year-old girl who was discovered to have bilateral renal artery stenosis, coarctation of the abdominal aorta, renal cysts and typical skin lesions of tuberous clerosis during the evaluation of asymptomatic hypertension. Renal vascular hypertension has not been reported previously in tuberous sclerosis. We conclude that the tuberous sclerosis complex should be expanded to include vascular malformations and the hypertension should not be assumed to be secondary to renal hamartomata or cysts in patients with tuberous sclerosis.

  7. Regulation of renal function and blood pressure control by P2 purinoceptors in the kidney. (United States)

    Van Beusecum, Justin; Inscho, Edward W


    Kidneys are important regulators of extracellular fluid volume (ECFV) homeostasis. ECFV is a key regulatory component of long-term blood pressure control influenced by controlling tubular sodium transport. In recent decades, renal P2 purinoceptors (P2 receptors) have come to the forefront as a mechanism for regulating ECFV. P2 receptors are broadly distributed in renal tubular and vascular elements where they confer segmental control of renal vascular resistance, autoregulation, and tubular reabsorption. Activation or impairment of renal P2 purinoceptors is implicated in the regulating blood pressure or causing renal pathologies including hypertension. In this brief review, we discuss the role of renal vascular and tubular P2 purinoceptors in the regulation of renal hemodynamics, maintenance of ECFV, regulation of sodium reabsorption and the control of blood pressure.

  8. Renal dysfunctions in glomerulonephropathy with rapidly declined renal failure. (United States)

    Futrakul, N; Pochanugool, C; Sitprija, V; Singkhwa, V; Futrakul, P; Yenrudi, S; Sensirivatana, R; Watana, D; Poshyachinda, M


    Eight patients aged between 5 and 26 years developed rapid deterioration of renal function and became oliguric/anuric with duration ranging from 1 to 21 days. The initial functional assessment revealed severe degree of glomerular, tubular, and vascular dysfunctions. The magnitude of renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunctions were inversely proportional to the renal plasma flow and peritubular capillary blood flow (PTCB), respectively. Similar findings have been observed in a variety of severe glomerulonephropathies. In this aspect, it is likely that the reduction of peritubular capillary blood flow and tubulointerstitial disease are interrelated. Further evidence to support the primary role of reduction of PTCB in inducing tubulointerstitial disease is provided by the following: (a) Reduction of PTCB is documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (b) Ischemic insult can induce tubulointerstitial disease in experimental setting of renal artery occlusion in animal, (c) Improved tubular function can be achieved following the increase in PTCB with the enhanced renal perfusion therapy.

  9. Vascular smooth muscle cells express the alpha(1A) subunit of a P-/Q-type voltage-dependent Ca(2+)Channel, and It is functionally important in renal afferent arterioles

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Jensen, Boye L.; Andreasen, D


    in rat aorta, brain, aortic smooth muscle cells (A7r5), VSMCs, and mesangial cells. Immunolabeling with an anti-alpha(1A) antibody was positive in acid-macerated, microdissected preglomerular vessels and in A7r5 cells. Patch-clamp experiments on aortic A7r5 cells showed 22+/-4% (n=6) inhibition of inward...... Ca(2+) current by omega-Agatoxin IVA (10(-8) mol/L), which in this concentration is a specific inhibitor of P-type VDCCs. Measurements of intracellular Ca(2+) in afferent arterioles with fluorescence-imaging microscopy showed 32+/-9% (n=10) inhibition of the K(+)-induced rise in Ca(2...... preglomerular resistance vessels and aorta, as well as mesangial cells, and that P-type VDCCs contribute to Ca(2+) influx in aortic and renal VSMCs and are involved in depolarization-mediated contraction in renal afferent arterioles....

  10. T-type voltage-gated calcium channels regulate the tone of mouse efferent arterioles

    DEFF Research Database (Denmark)

    Poulsen, Christian B; Al-Mashhadi, Rozh H; Cribbs, Leanne L;


    Voltage-gated calcium channels are important for the regulation of renal blood flow and the glomerular filtration rate. Excitation-contraction coupling in afferent arterioles is known to require activation of these channels and we studied their role in the regulation of cortical efferent arteriolar...... tone. We used microdissected perfused mouse efferent arterioles and found a transient vasoconstriction in response to depolarization with potassium; an effect abolished by removal of extracellular calcium. The T-type voltage-gated calcium channel antagonists mibefradil and nickel blocked this potassium....... Low concentrations of nickel, an agent that blocks Ca(v)3.2, had a similar effect. Thus, T-type voltage-gated calcium channels are functionally important for depolarization-induced vasoconstriction and subsequent dilatation in mouse cortical efferent arterioles.Kidney International advance online...

  11. Voice low tone to high tone ratio--a new index for nasal airway assessment. (United States)

    Lee, Guoshe; Yang, Cheryl C H; Kuo, Terry B J


    There are several methodology based on voice analysis to evaluate nasal airway. Here we introduce a new quantitative index based on voice spectrum analysis to evaluate nasal obstruction. Ten subjects of nasal blockage were instructed to produced the sustained consonant-vowel syllable /m partial partial differential/ at comfortable levels of speech for at least 5 seconds. After nasal decongestant treatment, the second voice sample was collected. Sound spectrum was obtained by the algorithm of fast Fourier transform and the fundamental frequency (F0) was calculated by the method of autocorrelation. Voice low tone to high tone ratio (VLHR) was defined as the division of low frequency power (LFP) into high frequency power (HFP) of the sound power spectrum and was finally expressed in decibels. The cut-off frequency was the product of F0 and square root of (4 x 5). The VLHR after nasal decongestant treatment increased significantly as compared with that before treatment (P < 0.01). VLHR is a new index derived from sound spectral analysis and that may detect the changes in frequency characteristics of voice during treatment for nasal obstruction. The index is quantitative, non-invasive, and potentially useful for basic researches and clinical applications.

  12. Global Database of Events, Language, and Tone (GDELT Project) (United States)

    World Wide Human Geography Data Working Group — The Global Database of Events, Language, and Tone (GDELT Project) monitors the world's broadcast, print, and web news from nearly every corner of every country in...

  13. Tone realisation in a Yoruba speech recognition corpus

    CSIR Research Space (South Africa)

    Van Niekerk, D


    Full Text Available The authors investigate the acoustic realisation of tone in short continuous utterances in Yoruba. Fundamental frequency contours are extracted for automatically aligned syllables from a speech corpus of 33 speakers collected for speech recognition...

  14. Two-tone masking in normal hearing listeners. (United States)

    Rabinowitz, W M; Bilger, R C; Trahiotis, C; Nuetzel, J


    Psychophysical measurements of two-tone masking [E. Zwicker, Acustica 4, 415-420 (1954)] were made at 0.25, 0.5, 1, 2, and 4 kHz utilizing a masker level of 62 dB SPL/tone. Fifty-eight "untrained" subjects were tested using a single run of a 4IFC adaptive procedure for each condition. Individual data were highly variable. Average data were systematic; they were analyzed using a two-line-regression procedure and the obtained critical-bandwidth estimates approximated normative values. Analysis of the literature revealed that a substantial increase of estimated critical bandwidth versus masker level occurs in two-tone masking. A portion of this increase appears artificial and stems from the relative effectiveness of the higher frequency masker tone at high masker levels. An alternative masker-frequency spacing is suggested to reduce level effects. Implications for an underlying critical-band mechanism are discussed.

  15. 'tone at the top': fighting military corruption in latin america

    African Journals Online (AJOL)


    to assess and measure military governance and integrity. It appears that ... corrupt military environment more effectively by finding the right tone. Method ..... In order to bring about a change in an ethically soiled corporate military culture, the ...

  16. Syllabification, Tone Marking, and Minimality in Eleme Ngulube ...

    African Journals Online (AJOL)

    Mrs Afam

    EL's prosodic system. Specifically, I argue ... (1987) can correctly predict EL's tone system, since only that framework allows tautosyllabic ..... between the Grammar and Physics of Speech. 283-333. ... Niger Delta languages 1: Classification.

  17. Vasoplegia in sepsis depends on the vascular system, vasopressor, and time-point: a comparative evaluation in vessels from rats subjected to the cecal ligation puncture model

    National Research Council Canada - National Science Library

    Da Silva, Rita de C.V. de A.F; Da Silva-Santos, José Eduardo; Corrêa, Thiago; Bernardelli, Angélica K


    We evaluated the effects of phenylephrine, norepinephrine, angiotensin II, and vasopressin in mesenteric, renal, carotid, and tail arteries, and in perfused mesenteric vascular bed from rats subjected...

  18. Tone-3 Accent Realization in Short Chinese Sentences

    Institute of Scientific and Technical Information of China (English)

    CAO Wen; ZHANG Jinsong


    To investigate how a low tone (tone-3,T3) syllable in Chinese can be perceived to be focal ac-canted or not,a total of 156 sentences containing tone-3 words were synthesized and used as stimuli in a perceptual study.The sentences differed in the falling value between the two high pitches,and in the dura-tion and phonation types of the T3 syllables.Thirty-nine subjects were asked to judge where the focus or accent was for each sentence.The results show that at least three degrees of pitch drop are involved in the focus recognition: a big sized drop of about 10 semitones; a middle sized drop of about 6 semitones; a small sized drop of about 2 semitones.The results suggest that the three sizes of pitch drop have different indica-tions in Chinese intonation,depending on both the tone and the tone combination.In perception,there are various ways to realize tone-3 focus in the Tx-T3-Ty sentences series,but in production or for text-to-speech synthesis,the rule simply is making a middle sized pitch drop with a long and creaky T3 syllable.Similarly,to focus on the low tone syllable in the T3-Tx-Ty sentences,a creaky T3 syllable is essential.However,a long T3 syllable is a strong determinant for a low tone focus in the Tx-Ty-T3 sentences.

  19. Pilot tone modulation used for channel identification in OTDM networks

    DEFF Research Database (Denmark)

    Clausen, Anders; Bennike, Jon; Oxenløwe, Leif Katsuo


    The principle of applying a pilot tone to an OTDM signal, in order to identify a specific channel, is presented. The impact on BER system performance is characterised as function of modulation index.......The principle of applying a pilot tone to an OTDM signal, in order to identify a specific channel, is presented. The impact on BER system performance is characterised as function of modulation index....

  20. Increased dynamic regulation of postural tone through Alexander Technique training


    Cacciatore, TW; Gurfinkel, VS; Horak, FB; Cordo, PJ; Ames, KE


    Gurfinkel and colleagues (2006) recently found that healthy adults dynamically modulate postural muscle tone in the body axis during anti-gravity postural maintenance and that this modulation is inversely correlated with axial stiffness. Our objective in the present study was to investigate whether dynamic modulation of axial postural tone can change through training. We examined whether teachers of the Alexander Technique (AT), who undergo “long-term” (3-year) training, have greater modulati...

  1. Method to Measure Tone of Axial and Proximal Muscle



    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs1, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the ...

  2. Visual emotional context modulates brain potentials elicited by unattended tones


    Sugimoto, Sayaka; Nittono, Hiroshi; Hori, Tadao


    To examine whether brain electrical responses to environmental stimuli were influenced by emotional contexts, event-related potentials (ERPs) elicited by nonstartle probe tones were recorded from 13 student volunteers while they were viewing emotionally positive, neutral, and negative slides of the International Affective Picture System. The auditory stimuli consisted of high-deviant (2000 Hz, p=.08), low-deviant (1050 Hz, p=.08), and standard (1000 Hz, p=.84) tones with a mean onset-to-onset...

  3. Effect of harmonic rank on the streaming of complex tones

    DEFF Research Database (Denmark)

    Madsen, Sara Miay Kim; Dau, Torsten; Moore, Brian C.J.


    The effect of the rank of the harmonics on sequential stream segregation of complex tones was investigated for normal-hearing participants with no musical training. It was hypothesized that stream segregation would be greater for tones with high pitch salience, as assessed by fundamental frequency....... There was a significant trend for less stream segregation with increasing harmonic rank. The amount of stream segregation was inversely correlated with the f0 difference limens, consistent with the hypothesis....

  4. Gastrointestinal complications in renal transplantation

    Directory of Open Access Journals (Sweden)

    Kamal Jeet Singh


    Full Text Available Objective: Gastrointestinal complications are responsible for substantial morbidity and mortality among renal allograft recipients. We retrospectively analyzed incidence of these complications and their impact on the patient outcome. Materials & Methods: Between 1998 to Aug 2002, 558 live related renal transplants were performed at our center. The immunosuppression used consisted mainly of cyclosporine, azathioprine and prednisolone, though varied in some patients. These patients were followed for any occurrence of significant gastrointestinal problems. Results: Out of the of 538 renal transplant recipients studied, gastro esophageal ulcerations were seen in 3% patients. Acute pancreatitis was observed in twelve (2.2% patients and four patients had acute intestinal obstruction secondary to fecal impaction. Infectious complications included acute diarrheas in 18% of patients. Three patients developed abdominal tuberculosis. Acute rejection episodes were encountered in 26% of the patients. During these episodes, 58% of patients experienced prolonged ileus. Most of these complications (66% occurred within first one-year post transplant. Three patients presenting with acute intestinal obstruction required laparotomy (two- bands, one-intussusception. There were four mortalities -two patients had severe pancreatitis, one patient had massive upper GI bleed and one succumbed due to perforation peritonitis. Conclusions: Gastrointestinal complications account for significant morbidity and mortality in renal transplant recipients. Paralytic ileus secondary to acute vascular rejection is quite common and resolves spontaneously with recovery of renal function.

  5. 血管内皮生长因子基因转染对犬肾动脉内膜损伤后的作用%Effects of vascular endothelial growth factor gene transfection on injured renal artery intima of dogs

    Institute of Scientific and Technical Information of China (English)

    张良峰; 徐岩; 王昌会


    Objective:To study the expression of vascular endothelial growth factor (VEGF) gene transfection in renal artery intima of dogs and its efficacy to injured renal artery intima. Method: We produced an eukaryotic expression plasmid of pcD2/VEGF121 and pcD2 plasmid through transferring colibacillus XLl-Blue as a large scale by the technique of molecular biology. The 2 sides of renal arteries of 14 dogs were randomly divided into 2 groups: therapy sides and control sides. Renal arteriography of 14 dogs were performed and then the PTC A balloons was sent into renal arteries and injured the renal artery intima by compression of balloon. The balloons coated pcD2/VEGF121 plasmid and pcD2 plasmid was respectively sent into therapy sides, and control sides and transferred the gene to renal artery intima by compression of balloon for 5 minutes. Repeated renal arteriography were performed at 1st week, 6th week and 10th week respectively after operation and then killed dogs to take the injured renal arteries for HE staining and immunohistochemistry after making pathological section. We observed the changes of renal artery intima, the expression of VEGF protein and ultrastructure of renal artery by HE staining, immunohistochemistry and electron microscope to identify the efficacy of VEGF gene to the injured renal artery of dogs. Result:Light stenosis was observed in 2 sides of renal artery at 6th week after operation, and stenosis became significant at 10th week. But there was no significant difference between therapy sides and control sides. Proliferation was observed in 2 sides at 6th week after operation and became significant at 10th week, there was no significant difference between therapy sides and control sides. Expression of VEGF protein in therapy sides was significantly higher in 1st week after operation than control sides, and the difference became weak at 6th week. There was better intima covering in therapy sides than control sides at 10th week. Conclusion: VEGF

  6. The Renal Renin-Angiotensin System (United States)

    Harrison-Bernard, Lisa M.


    The renin-angiotensin system (RAS) is a critical regulator of sodium balance, extracellular fluid volume, vascular resistance, and, ultimately, arterial blood pressure. In the kidney, angiotensin II exerts its effects to conserve salt and water through a combination of the hemodynamic control of renal blood flow and glomerular filtration rate and…

  7. Cyclosporine-induced renal dysfunction in human renal allograft recipients. (United States)

    Kiberd, B A


    Cyclosporine-treated renal allograft recipients frequently suffer CsA-related nephrotoxicity and hypertension. This study demonstrates that glomerular filtration rate is reduced acutely by 13% (P less than 0.02) and renal vascular resistance increased by 30% (P less than 0.05), immediately after patients take their CsA dose. The reduction in GFR is directly related to their trough CsA level (r = 0.82; P less than 0.01). The lower the trough CsA level the greater the fall in GFR after the CsA dose. Plasma renin activity does not increase after the CsA dose (pre-CsA 0.6 +/- 0.2 ng/L/sec vs. post-CsA 0.4 +/- 0.1 ng/L/sec; P = NS), and therefore cannot be responsible for the reduction in renal function. Short-term nifedipine treatment is effective in preventing the acute reduction in GFR (P less than 0.05). This occurred despite no apparent effect of nifedipine in altering trough or post-dose CsA levels. Furthermore nifedipine was effective in lowering both the mean arterial blood pressure (109 mmHg to 94 mmHg; P less than 0.01) and the elevated renal vascular resistance (25% reduction; P less than 0.02) observed in these patients. These results suggest that nifedipine may be a suitable agent for limiting acute CsA nephrotoxicity and for treating CsA-associated hypertension in renal allograft recipients.

  8. Method to measure tone of axial and proximal muscle. (United States)

    Gurfinkel, Victor S; Cacciatore, Timothy W; Cordo, Paul J; Horak, Fay B


    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention.

  9. Production and Perception of Tone 3 Focus in Mandarin Chinese. (United States)

    Lee, Yong-Cheol; Wang, Ting; Liberman, Mark


    This study uses production and perception experiments to explore tone 3 focus in Mandarin Chinese. Overall, contrastive focus in Mandarin is clearly marked with increased duration, intensity, and pitch range: in the experiments, listeners identified focused syllables correctly more than 90% of the time. However, a tone 3 syllable offers a smaller capacity for pitch range expansion under focus, and also yields less intensity increase; in addition, local dissimilation increases the duration, intensity, and pitch range of adjacent syllables within the same phrase as a focused tone 3 syllable. As a result, tone 3 focus was less well identified by listeners (77.1%). We suggest that the relatively poor identification of tone 3 focus is due to the smaller capacity for pitch range expansion, the confusion from within-phrase local dissimilatory effects, and the relatively weak intensity of tone 3. This study demonstrates that even within a language where purely prosodic marking of focus is clear, the location of prosodic focus can be difficult to identify in certain circumstances. Our results underline the conclusion, established in other work, that prosodic marking of focus is not universal, but is expressed through the prosodic system of each language.

  10. Influence of a tone's tonal function on temporal change detection. (United States)

    Lebrun-Guillaud, Géraldine; Tillmann, Barbara


    Music cognition research has provided evidence that the tonal function of a musical event influences perception and memory. Our study investigated whether tonal function influences a basic temporal judgment, notably the detection of a temporal change disrupting a sequence's regularity. The sequences consisted of six musical events presented in isochrony (or with the fifth event occurring earlier or later): Three chords (instilling a tonal context) were followed by a tone (repeated three times). The tones fulfilled one of two tonal functions in the tonal context. Participants had to detect whether the sequence contained a temporal change and were not informed about tonal manipulations. Discrimination performance (as measured by d') showed an influence of tonal function on temporal change detection: Performance was better for the tonic tone (having the most important tonal function in the key) than for the unstable leading tone, the less stable mediant tone, and even than the stable dominant tone. The outcome shows the influence of listeners' tonal knowledge on a perceptual time judgment and suggests that processing of tonal and temporal structures interact at some stage of processing.

  11. Visual emotional context modulates brain potentials elicited by unattended tones. (United States)

    Sugimoto, Sayaka; Nittono, Hiroshi; Hori, Tadao


    To examine whether brain electrical responses to environmental stimuli were influenced by emotional contexts, event-related potentials (ERPs) elicited by nonstartle probe tones were recorded from 13 student volunteers while they were viewing emotionally positive, neutral, and negative slides of the International Affective Picture System. The auditory stimuli consisted of high-deviant (2000 Hz, p=.08), low-deviant (1050 Hz, p=.08), and standard (1000 Hz, p=.84) tones with a mean onset-to-onset interval of 600 ms. Participants were told to ignore the tones. High-deviant tones elicited a larger N1 (peaking around 100 ms) when participants were viewing negative slides than when viewing positive slides. The amplitude of the P2 elicited by standard tones (peaking around 170 ms) was smaller when participants were viewing positive slides than when viewing negative and neutral slides. The amplitude of the mismatch negativity (150-200 ms) tended to reduce during positive slide presentation, but this difference appeared to be due to reduction of the P2 elicited by standard tones. These findings suggest that visually induced emotional states have a sequential effect on auditory information processing, in that the influence of negative emotion appears at an earlier stage than that of positive emotion.

  12. Adipose-Vascular Coupling and Potential Therapeutics. (United States)

    Gollasch, Maik


    Excess visceral adipose tissue is associated with increased risk of high blood pressure, lipid disorders, type 2 diabetes, and cardiovascular disease. Adipose tissue is an endocrine organ with multiple humoral and metabolic roles in regulating whole-body physiology. However, perivascular adipose tissue (PVAT) also plays a functional role in regulating the contractile state of the underlying smooth muscle cell layer. Work during the past decade has shown that this adipose-vascular coupling is achieved by production of numerous substances released from PVAT. Animal disease models have been instrumental in identifying biological and pathophysiological functions of this regulation. These studies have produced strong evidence that alterations in the paracrine control of PVAT in the regulation of arterial tone contribute to vascular dysfunction in obesity, hypertension, and cardiometabolic disease. Perivascular relaxing factors, or perhaps their putative targets, might represent exciting new targets for the prevention and treatment of cardiovascular and metabolic diseases.

  13. Effect of extraluminal ATP application on vascular tone and blood flow in skeletal muscle

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Al-Khazraji, Baraa K; Mortensen, Stefan P


    During skeletal muscle contractions, the concentration of ATP increases in muscle interstitial fluid as measured by microdialysis probes. This increase is associated with the magnitude of blood flow, suggesting that interstitial ATP may be important for contraction-induced vasodilation. However......, interstitial ATP has solely been described to induce vasoconstriction in skeletal muscle. To examine whether interstitial ATP induces vasodilation in skeletal muscle and to what extent this vasoactive effect is mediated by formation of nitric oxide (NO) and prostanoids, three different experimental models were...... studied. The rat gluteus maximus skeletal muscle model was used to study changes in local skeletal muscle hemodynamics. Superfused ATP at concentrations found during muscle contractions (1-10 µM) increased blood flow by up to 400%. In this model, the underlying mechanism was also examined by inhibition...

  14. [Diazepam (valium). Changes in haemodynamics, myocardial oxygen consumption and vascular tone (author's transl)]. (United States)

    Hempelmann, G; Seitz, W; Piepenbrock, S


    In 30 patients with congenital or acquired heart disease the haemodynamic effects of diazepam (Valium) 0.3 mg/kg were investigated during surgical procedures under neuroleptanalgesia. The following parameters were measured or calculated: Heart rate (HR), arterial pressure (-Part, Psyst, Pdiast), pulmonary artery pressure (-PAP), right (-PRA) and left atrial pressure (-PLA), left ventricular pressure (PLV), left ventricular enddiastolic pressure (PLVED), left ventricular peak dp/dt (dp/dtmax), cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke index (SI), total systemic resistance (TSR), total pulmonary resistance (TPR), work index of the right (RVWI) and left ventricle (LVWI). In comparison with a control group (n = 36) diazepam caused a decrease in arterial pressure cardiac index, stroke index, right and left atrial pressure and dp/dtmax. This, however, was mainly attributable to vasodilatation and not to a negative inotropic effect, which is of only minor importance with diazepam. These haemodynamic changes resulted in a reduction in myocardial oxygen consumption. Diazepam is a valuable drug in neuroleptanalgesia, when an increase in blood pressure can not be controlled by fentanyl or droperidol.

  15. Endothelial Mediation of Coronary Vascular Tone: Nitric Oxide Attenuation of Cholinergic Vasospastic Challenge (United States)


    artery. In: Henry, J.L., R. Couture, A.C. Cuello , G. Pelletier, R. Quirom, D. Regoli , eds. Substance P and Neurokinins. New York: Springer- Verlag...1987: 152-157. 44. Hancock, J.C. Hemodynamic actions of substance P in anesthetized rats. In: Henry, J.L., R. Couture, AC. Cuello , G. Pelletier, R

  16. Renal Cysts (United States)

    ... as “simple” cysts, meaning they have a thin wall and contain water-like fluid. Renal cysts are fairly common in ... simple kidney cysts, meaning they have a thin wall and only water-like fluid inside. They are fairly common in ...

  17. Renal failure

    Institute of Scientific and Technical Information of China (English)


    970363 Effect on serum PTH and 1, 25(OH)2 D3levels of rapid correction of metabolic acidosis in CRFpatients with secondary hyperparathyroidism. YUANQunsheng(袁群生), et al. Renal Div, PUMC Hosp,Beijing, 100730. Chin J Nephrol 1996; 12(6): 328-331.

  18. Drug-induced renal injury

    African Journals Online (AJOL)

    Drugs can cause acute renal failure by causing pre-renal, intrinsic or post-renal toxicity. Pre-renal ... incidence of drug dose adjustment in renal impairment in the SAMJ. ... Fever, haemolytic anaemia, thrombocytopenia, renal impairment and.

  19. 47 CFR 11.12 - Two-tone Attention Signal encoder and decoder. (United States)


    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Two-tone Attention Signal encoder and decoder... SYSTEM (EAS) General § 11.12 Two-tone Attention Signal encoder and decoder. Existing two-tone Attention... Attention Signal decoder will no longer be required and the two-tone Attention Signal will be used...

  20. Context, Contrast, and Tone of Voice in Auditory Sarcasm Perception. (United States)

    Voyer, Daniel; Thibodeau, Sophie-Hélène; Delong, Breanna J


    Four experiments were conducted to investigate the interplay between context and tone of voice in the perception of sarcasm. These experiments emphasized the role of contrast effects in sarcasm perception exclusively by means of auditory stimuli whereas most past research has relied on written material. In all experiments, a positive or negative computer-generated context spoken in a flat emotional tone was followed by a literally positive statement spoken in a sincere or sarcastic tone of voice. Participants indicated for each statement whether the intonation was sincere or sarcastic. In Experiment 1, a congruent context/tone of voice pairing (negative/sarcastic, positive/sincere) produced fast response times and proportions of sarcastic responses in the direction predicted by the tone of voice. Incongruent pairings produced mid-range proportions and slower response times. Experiment 2 introduced ambiguous contexts to determine whether a lower context/statements contrast would affect the proportion of sarcastic responses and response time. Results showed the expected findings for proportions (values between those obtained for congruent and incongruent pairings in the direction predicted by the tone of voice). However, response time failed to produce the predicted pattern, suggesting potential issues with the choice of stimuli. Experiments 3 and 4 extended the results of Experiments 1 and 2, respectively, to auditory stimuli based on written vignettes used in neuropsychological assessment. Results were exactly as predicted by contrast effects in both experiments. Taken together, the findings suggest that both context and tone influence how sarcasm is perceived while supporting the importance of contrast effects in sarcasm perception.

  1. Renal dopamine receptors and hypertension. (United States)

    Hussain, Tahir; Lokhandwala, Mustafa F


    Dopamine has been recognized as an important modulator of central as well as peripheral physiologic functions in both humans and animals. Dopamine receptors have been identified in a number of organs and tissues, which include several regions within the central nervous system, sympathetic ganglia and postganglionic nerve terminals, various vascular beds, the heart, the gastrointestinal tract, and the kidney. The peripheral dopamine receptors influence cardiovascular and renal function by decreasing afterload and vascular resistance and promoting sodium excretion. Within the kidney, dopamine receptors are present along the nephron, with highest density on proximal tubule epithelial cells. It has been reported that there is a defective dopamine receptor, especially D(1) receptor function, in the proximal tubule of various animal models of hypertension as well as in humans with essential hypertension. Recent reports have revealed the site of and the molecular mechanisms responsible for the defect in D(1) receptors in hypertension. Moreover, recent studies have also demonstrated that the disruption of various dopamine receptor subtypes and their function produces hypertension in rodents. In this review, we present evidence that dopamine and dopamine receptors play an important role in regulating renal sodium excretion and that defective renal dopamine production and/or dopamine receptor function may contribute to the development of various forms of hypertension.

  2. Gap junctions in the control of vascular function. (United States)

    Figueroa, Xavier F; Duling, Brian R


    Direct intercellular communication via gap junctions is critical in the control and coordination of vascular function. In the cardiovascular system, gap junctions are made up of one or more of four connexin proteins: Cx37, Cx40, Cx43, and Cx45. The expression of more than one gap-junction protein in the vasculature is not redundant. Rather, vascular connexins work in concert, first during the development of the cardiovascular system, and then in integrating smooth muscle and endothelial cell function, and in coordinating cell function along the length of the vessel wall. In addition, connexin-based channels have emerged as an important signaling pathway in the astrocyte-mediated neurovascular coupling. Direct electrical communication between endothelial cells and vascular smooth muscle cells via gap junctions is thought to play a relevant role in the control of vasomotor tone, providing the signaling pathway known as endothelium-derived hyperpolarizing factor (EDHF). Consistent with the importance of gap junctions in the regulation of vasomotor tone and arterial blood pressure, the expression of connexins is altered in diseases associated with vascular complications. In this review, we discuss the participation of connexin-based channels in the control of vascular function in physiologic and pathologic conditions, with a special emphasis on hypertension and diabetes.

  3. Unusual Presentation of Renal Vein Thrombosis in a Preterm Infant. (United States)

    Yang, Chang-Yo; Fu, Ren-Huei; Lien, Reyin; Yang, Peng-Hong


    Neonatal renal vein thrombosis is the most common vascular condition in the newborn kidney, which could lead to serious complication in infants undergoing intensive care. In this study, we report the case of a preterm infant with left renal vein and inferior vena cava thrombosis, presented with gross hematuria, thrombocytopenia, transient hypertension, and adrenal hemorrhage. Supportive care was offered instead of heparin therapy or thrombolytic agents. In conclusion, our case teaches that, despite the lack of a clinically obvious shock event, renal vein thrombosis should be considered in a macrohematuric newborn without renal failure.


    Directory of Open Access Journals (Sweden)

    Arjun Singh


    Full Text Available The auditory sensitivity of 63 patient of chronic renal failure on hemodialysis was assessed in order to know the effect of dialysis on hearing threshold. All selected patient were non diabetic with normal tympanic membrane and with no history of ototoxic drug and any hereditary hearing problems. Pure tone audiometry was done before and after dialys is and all cases were followed for 3 month. A high incidence of high frequency sensorineural hearing loss was obtained which could not be attributed to age , noise exposure and ottotoxicity. An association between high frequency sensorineural hearing loss a nd hemodialysis is thus suggested KEYWORDS: Hemodialysis ; Pure tone audiometry ; High frequency sensorineural hearing loss ; Duration of disease ; Chronic renal failure

  5. Renal failure (chronic)


    Clase, Catherine


    Chronic renal failure is characterised by a gradual and sustained decline in renal clearance or glomerular filtration rate (GFR). Continued progression of renal failure will lead to renal function too low to sustain healthy life. In developed countries, such people will be offered renal replacement therapy in the form of dialysis or renal transplantation. Requirement for dialysis or transplantation is termed end-stage renal disease (ESRD).Diabetes, glomerulonephritis, hypertension, pyelone...

  6. PGI2 synthesis and excretion in dog kidney: evidence for renal PG compartmentalization

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, R.M.; Nasjletti, A.; Heerdt, P.M.; Baer, P.G.


    To assess the concept of compartmentalization of renal prostaglandins (PG), we compared entry of PGE2 and the PGI2 metabolite 6-keto-PGF1 alpha into the renal vascular and tubular compartments, in sodium pentobarbital-anesthetized dogs. Renal arterial 6-keto-PGF1 alpha infusion increased both renal venous and urinary 6-keto-PGF1 alpha outflow. In contrast, renal arterial infusion of arachidonic acid (AA) or bradykinin (BK) increased renal venous 6-keto-PGF1 alpha outflow but had no effect on its urinary outflow. Both urinary and renal venous PGE2 outflows increased during AA or BK infusion. Ureteral stopped-flow studies revealed no postglomerular 6-keto-PGF1 alpha entry into tubular fluid. During renal arterial infusion of (3H)PGI2 and inulin, first-pass 3H clearance was 40% of inulin clearance; 35% of urinary 3H was 6-keto-PGF1 alpha, and two other urinary metabolites were found. During renal arterial infusion of (3H)6-keto-PGF1 alpha and inulin, first-pass 3H clearance was 150% of inulin clearance; 75% of urinary 3H was 6-keto-PGF1 alpha, and only one other metabolite was found. We conclude that in the dog PGE2 synthesized in the kidney enters directly into both the renal vascular and tubular compartments, but 6-keto-PGF1 alpha of renal origin enters directly into only the renal vascular compartment.

  7. Comparative effects of enalapril and nifedipine on renal hemodynamics in hypertensive renal allograft recipients. (United States)

    Abu-Romeh, S H; el-Khatib, D; Rashid, A; Patel, M; Osman, N; Fayyad, M; Scheikhoni, A; Higazi, A S


    The comparative effects of enalapril (E) and nifedipine (N) on renal hemodynamics were assessed in twenty-two moderately hypertensive, cadaveric renal transplant patients who were maintaining stable renal function. Fourteen patients were on cyclosporin (CSA) and eight were receiving azathioprine with prednisolone (AZA). In each patient effective renal plasma flow (ERPF) was determined four times, first baseline, second with E, third as another baseline after a washout period, and fourth with N; and renal vascular resistance (RVR) was derived in each. ERPF and RVR were significantly compromised in the CSA group (202 +/- 55 ml/min and 65 +/- 18 mmHg/ml/min) compared to the AZA group (302 +/- 99 and 43 +/- 15 respectively). During E therapy, RVR further increased in the CSA group to 82 +/- 37 while it decreased in the AZA group to 31 +/- 7 (both changes were significant when compared to their respective baseline values). N, on the other hand, only significantly lowered RVR in the AZA group. Furthermore, two patients, one from each group, developed acute reversible renal failure shortly after E therapy. However, both agents were effective in lowering blood pressure to a comparable degree in both groups. In conclusion, our data showed a somewhat less favourable renal hemodynamic response to short-term enalapril therapy in hypertensive renal transplant patients maintained on CSA. However, the significance of such hemodynamic changes for long-term renal function remains uncertain.

  8. A weak-scattering model for turbine-tone haystacking (United States)

    McAlpine, A.; Powles, C. J.; Tester, B. J.


    Noise and emissions are critical technical issues in the development of aircraft engines. This necessitates the development of accurate models to predict the noise radiated from aero-engines. Turbine tones radiated from the exhaust nozzle of a turbofan engine propagate through turbulent jet shear layers which causes scattering of sound. In the far-field, measurements of the tones may exhibit spectral broadening, where owing to scattering, the tones are no longer narrow band peaks in the spectrum. This effect is known colloquially as 'haystacking'. In this article a comprehensive analytical model to predict spectral broadening for a tone radiated through a circular jet, for an observer in the far field, is presented. This model extends previous work by the authors which considered the prediction of spectral broadening at far-field observer locations outside the cone of silence. The modelling uses high-frequency asymptotic methods and a weak-scattering assumption. A realistic shear layer velocity profile and turbulence characteristics are included in the model. The mathematical formulation which details the spectral broadening, or haystacking, of a single-frequency, single azimuthal order turbine tone is outlined. In order to validate the model, predictions are compared with experimental results, albeit only at polar angle equal to 90°. A range of source frequencies from 4 to 20kHz, and jet velocities from 20 to 60ms-1, are examined for validation purposes. The model correctly predicts how the spectral broadening is affected when the source frequency and jet velocity are varied.

  9. Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Shimojo, G.L.; Palma, R.K.; Brito, J.O.; Sanches, I.C. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil); Irigoyen, M.C. [Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); De Angelis, K. [Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP (Brazil)


    The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.

  10. The prosody of Swedish underived nouns: No lexical tones required

    Directory of Open Access Journals (Sweden)

    Bruce Morén-Duolljá


    Full Text Available This paper provides a detailed representational analysis of the morpho-prosodic system of underived nouns in a dialect of Swedish.  It shows that the morphology, stress and tonal patterns are not as complex as they first appear once the data are looked at in sufficient detail.  Further, it shows that the renowned Swedish "lexical pitch accent" is not the result of lexical tones/tonemes.  Rather, Swedish is like all other languages and uses tones to mark the edges of prosodic constituents on the surface. "Accent 2" occurs when tones mark the edge of a structural uneven trochee (i.e. recursive foot and "accent 1" occurs elsewhere. This analysis is counter all other treatments of North Germanic tones and denies the almost unquestioned assumption that there is an underlying tone specification on roots and/or affixes in many North Germanic varieties. At the same time, it unifies the intuitions behind the three previous approaches found in the literature.

  11. Turbo-per-Tone Equalization for ADSL Systems

    Directory of Open Access Journals (Sweden)

    Marc Moonen


    Full Text Available We study the equalization procedure in discrete multitone (DMT-based systems, in particular, in DMT-based ADSL systems. Traditionally, equalization is performed in the time domain by means of a channel shortening filter. Shifting the equalization operations to the frequency domain, as is done in per-tone equalization, increases the achieved bitrate by 5–10%. We show that the application of the turbo principle to per-tone equalization can provide significant additional gains. In the proposed receiver structure, referred to as a “turbo-per-tone equalization” structure, equalization and decoding are performed in an iterative fashion. Equalization is done by means of a linear minimum mean squared error (MMSE equalizer, using a priori information. We give a description of an efficient implementation of such an equalizer in the per-tone structure. Simulations show that we obtain a bitrate increase of 12–16% compared to the original per-tone equalization-based receiver structure.

  12. Simple reaction time for broadband sounds compared to pure tones. (United States)

    Schlittenlacher, Josef; Ellermeier, Wolfgang; Avci, Gül


    Although many studies have explored the relation between reaction time (RT) and loudness, including effects of intensity, frequency, and binaural summation, comparable work on spectral summation is rare. However, most real-world sounds are not pure tones and typically have bandwidths covering several critical bands. Since comparing to a 1-kHz pure tone, the reference tone, is important for loudness measurement and standardization, the present work focuses on comparing RTs for broadband noise to those for 1-kHz pure tones in three experiments using different spectral and binaural configurations. The results of Experiments 1 and 2 yield good quantitative agreement with spectral loudness summation models for moderate and high sound pressure levels, measured using both pink noise covering almost the entire hearing range and bandpass-filtered pink noise with different center frequencies. However, at lower levels, the RT measurements yield an interaction of level and bandwidth, which is not in line with loudness scaling data. In Experiment 3, which investigated the binaural summation of broadband sounds, the binaural gain for white noise was determined to be 9 dB, which is somewhat larger than what had been found in previous RT measurements using 1-kHz pure tones.

  13. Mandarin Chinese Tone Recognition with an Artificial Neural Network

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHANG Wenle; ZHOU Ning; LEE Chaoyang; LI Yongxin; CHEN Xiuwu; ZHAO Xiaoyan


    Mandarin Chinese tone patterns vary in one of the four ways, i.e, (1) high level; (2) rising; (3) low falling and rising; and (4) high falling. The present study is to examine the efficacy of an artificial neural network in recognizing these tone patterns. Speech data were recorded from 12 children (3-6 years of age) and 15 adults. All subjects were native Mandarin Chinese speakers. The fundamental frequencies (FO) of each monosyllabic word of the speech data were extracted with an autocorrelation method. The pitch data(i.e., the FO contours) were the inputs to a feed-forward backpropagation artificial neural network. The number of inputs to the neural network varied from 1 to 16 and the hidden layer of the network contained neurons that varied from 1 to 16 in number. The output of the network consisted of four neurons representing the four tone patterns of Mandarin Chinese. After being trained with the Levenberg-Marquardt optimization, the neural network was able to successfully classify the tone patterns with an accuracy of about 90% correct for speech samples from both adults and children. The artificial neural network may provide an objective and effective way of assessing tone production in prelingually-deafened children who have received cochlear implants.

  14. Agmatine suppresses peripheral sympathetic tone by inhibiting N-type Ca(2+) channel activity via imidazoline I2 receptor activation. (United States)

    Kim, Young-Hwan; Jeong, Ji-Hyun; Ahn, Duck-Sun; Chung, Seungsoo


    Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension.

  15. Carbon monoxide and bile pigments: surprising mediators of vascular function. (United States)

    Durante, William


    Heme oxygenase (HO) catalyzes the degradation of heme to CO, iron, and biliverdin. Biliverdin is subsequently metabolized to bilirubin by the enzyme biliverdin reductase. Although long considered irrelevant byproducts of heme catabolism, recent studies indicate that CO and the bile pigments biliverdin and bilirubin may play an important physiological role in the circulation. The release of CO by vascular cells may modulate blood flow and blood fluidity by inhibiting vasomotor tone, smooth muscle cell proliferation, and platelet aggregation. CO may also maintain the integrity of the vessel wall by directly blocking vascular cell apoptosis and by inhibiting the release of pro-apoptotic inflammatory cytokines from the vessel wall. These effects of CO are mediated via multiple pathways, including activation of soluble guanylate cyclase, potassium channels, p38 mitogen-activated protein kinase, or inhibition of cytochrome P450. In addition, the release of bile pigments may serve to sustain vascular homeostasis by protecting vascular cells from oxidative stress and by inhibiting the adhesion and infiltration of leukocytes into the vessel wall. Induction of HO-1 gene expression and the subsequent release of CO and bile pigments are observed in numerous vascular disorders and may provide an important adaptive mechanism to preserve homeostasis at sites of vascular injury. Thus, the HO-catalyzed formation of CO and bile pigments by vascular cells may function as a critical endogenous vasoprotective system. Moreover, pharmacological or genetic approaches targeting HO-1 to the vessel wall may represent a novel therapeutic approach in treating vascular disease.

  16. Measurement of intraindividual airway tone heterogeneity and its importance in asthma. (United States)

    Brown, Robert H; Togias, Alkis


    While airways have some degree of baseline tone, the level and variability of this tone is not known. It is also unclear whether there is a difference in airway tone or in the variability of airway tone between asthmatic and healthy individuals. This study examined airway tone and intraindividual airway tone heterogeneity (variance of airway tone) in vivo in 19 individuals with asthma compared with 9 healthy adults. All participants underwent spirometry, body plethysmography, and high-resolution computed tomography at baseline and after maximum bronchodilation with albuterol. Airway tone was defined as the percent difference in airway diameter after albuterol at total lung capacity compared with baseline. The amount of airway tone in each airway varied both within and between subjects. The average airway tone did not differ significantly between the two groups (P = 0.09), but the intraindividual airway tone heterogeneity did (P = 0.016). Intraindividual airway tone heterogeneity was strongly correlated with airway tone (r = 0.78, P tone heterogeneity and conventional lung function outcomes. Intraindividual airway tone heterogeneity appears to be an important characteristic of airway pathophysiology in asthma.

  17. Thrombosis in end-stage renal disease. (United States)

    Casserly, Liam F; Dember, Laura M


    Although renal failure has classically been associated with a bleeding tendency, thrombotic events are common among patients with end-stage renal disease (ESRD). A variety of thrombosis-favoring hematologic alterations have been demonstrated in these patients. In addition, "nontraditional" risk factors for thrombosis, such as hyperhomocysteinemia, endothelial dysfunction, inflammation, and malnutrition, are present in a significant proportion of chronic dialysis patients. Hemodialysis (HD) vascular access thrombosis, ischemic heart disease, and renal allograft thrombosis are well-recognized complications in these patients. Deep venous thrombosis and pulmonary embolism are viewed as rare in chronic dialysis patients, but recent studies suggest that this perception should be reconsidered. Several ESRD treatment factors such as recombinant erythropoietin (EPO) administration, dialyzer bioincompatibility, and calcineurin inhibitor administration may have prothrombotic effects. In this article we review the pathogenesis and clinical manifestations of thrombosis in ESRD and evaluate the evidence that chronic renal failure or its management predisposes to thrombotic events.

  18. 区域性血管床对局部注射胍丁胺的不同反应%Differential responses of regional vascular beds to local injection of agmatine in rats

    Institute of Scientific and Technical Information of China (English)

    李清; 范振中; 王义和; 何瑞荣


    effects completely, while yohimbine led the agmatine-induced effect to a decrease in the PP of renal vascular bed. (3) Agmatine decreased the PP of mesenteric vascular bed in a dose-dependent manner, an effect which was completely blocked by idazoxan, but unaffected by yohimbine. From the results obtained, it is concluded that agmatine differentially affects the vascular tone in the femoral, renal, and mesenteric vascular beds.

  19. 尿毒清对腹膜透析患者残余肾功能及血管内皮生长因子表达的影响%Effects of Niaoduqing on residual renal function in patients undergoing peritoneal dialysis and expression of vascular endothelial growth factor

    Institute of Scientific and Technical Information of China (English)

    陆继芳; 卫志锋; 李多; 郭丽峰; 刘圣君


    目的:观察尿毒清能否保护持续不卧床腹膜透析(continuous ambulatory peritoneal dialysis,CAPD)患者残余肾功能(residual renal function,RRF)及其是否影响血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达。方法选择规律性腹膜透析患者60例,随机分为2组各30例,对照组给予维持 CAPD 方案和相应的对症治疗,治疗组在对照组基础上增加尿毒清口服,随访3个月,监测尿量(urinary volume,UV)、腹膜透析超滤量(ultrafitration,UF)、RRF、尿素清除指数(KT/V)及 VEGF 表达。结果治疗组治疗后 KT/V、RRF、UV均下降而 UF 增加,对照组治疗后 KT/V、RRT、UV、UF 均下降,与治疗前比较差异有统计学意义(P <0.05),2组治疗后各指标差异均有统计学意义(P <0.01);治疗组在治疗后血清和透析液中 VEGF 表达均较治疗前下降(P <0.05),对照组治疗前后血清和透析液中 VEGF 表达差异无统计学意义。结论尿毒清能够保护维持性腹膜透析患者的 RRF,促进毒素排出,并能抑制 VEGF 表达。%Objective To observe the effects of Niaoduqing on residual renal function in patients undergoing peritoneal dialysis and expression of vascular endothelial growth factor (VEGF).Methods Sixty patients undergoing peritoneal dialysis regularly were divided into treatment group(n = 30)and control group(n = 30).The patients of treatment group received Niaoduqing orally for three months,and those of control group did not receive.All patients were provided routine treatment of renal anemia and CAPD.The KT/V,RRF,urinary volume(UV). Ultrafitration(UF)and VEGF changes in two groups were observed.Results UV,KT/V and RRF of treatment group decreased,but UF increased after treatment as compared with before treatment,the differences were significant(P <0.05).The decreases of treatment group were more in degree compared with those of

  20. Serotonylation of vascular proteins important to contraction.

    Directory of Open Access Journals (Sweden)

    Stephanie W Watts

    Full Text Available BACKGROUND: Serotonin (5-hydroxytryptamine, 5-HT was named for its source (sero- and ability to modify smooth muscle tone (tonin. The biological effects of 5-HT are believed to be carried out by stimulation of serotonin receptors at the plasma membrane. Serotonin has recently been shown to be synthesized in vascular smooth muscle and taken up from external sources, placing 5-HT inside the cell. The enzyme transglutaminase uses primary amines such as 5-HT to covalently modify proteins on glutamine residues. We tested the hypothesis that 5-HT is a substrate for transglutaminase in arterial vascular smooth muscle, with protein serotonylation having physiological function. METHODOLOGY/PRINCIPAL FINDINGS: The model was the rat aorta and cultured aortic smooth muscle cells. Western analysis demonstrated that transglutaminase II was present in vascular tissue, and transglutaminase activity was observed as a cystamine-inhibitable incorporation of the free amine pentylamine-biotin into arterial proteins. Serotonin-biotin was incorporated into alpha-actin, beta-actin, gamma-actin, myosin heavy chain and filamin A as shown through tandem mass spectrometry. Using antibodies directed against biotin or 5-HT, immunoprecipitation and immunocytochemistry confirmed serotonylation of smooth muscle alpha-actin. Importantly, the alpha-actin-dependent process of arterial isometric contraction to 5-HT was reduced by cystamine. CONCLUSIONS: 5-HT covalently modifies proteins integral to contractility and the cytoskeleton. These findings suggest new mechanisms of action for 5-HT in vascular smooth muscle and consideration for intracellular effects of primary amines.

  1. Renale Osteopathie


    Horn S


    Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Thera...

  2. Renale Knochenerkrankungen

    Directory of Open Access Journals (Sweden)

    Mayer G


    Full Text Available Störungen des Mineral- und Knochenstoffwechsels sind bei fast allen Patienten mit chronischen Nierenerkrankungen anzutreffen. Pathogenetisch spielt eine Neigung zur Phosphatretention bei einer Reduktion der glomerulären Filtrationsrate die zentrale Rolle. Neben typischen, aber sehr variablen Veränderungen der Knochenstruktur (renale Osteopathie besteht auch eine sehr enge Assoziation zwischen diesen Störungen und dem massiv erhöhten kardiovaskulären Risiko der Patienten.

  3. On the origin of impinging tones at low supersonic flow

    CERN Document Server

    Wilke, Robert


    Impinging compressible jets may cause deafness and material fatigue due to immensely loud tonal noise. It is generally accepted that a feedback mechanism similar to the screech feedback loop is responsible for impinging tones. The close of the loop remained unclear. One hypothesis hold up in the literature explains the emanated sound with the direct interaction of vortices and the wall. Other explanations name the standoff shock oscillations as the origin of the tones. Using direct numerical simulations (DNS) we were able to identify the source mechanism for under-expanded impinging jets with a nozzle pressure ratio (NPR) of 2.15 and a plate distance of 5 diameters. We found two different types of interactions between vortices and shocks to be responsible for the generation of the impinging tones. They are not related to screech.

  4. Complex-tone pitch representations in the human auditory system

    DEFF Research Database (Denmark)

    Bianchi, Federica

    ) listeners and the effect of musical training for pitch discrimination of complex tones with resolved and unresolved harmonics. Concerning the first topic, behavioral and modeling results in listeners with sensorineural hearing loss (SNHL) indicated that temporal envelope cues of complex tones...... for the individual pitch-discrimination abilities, the musically trained listeners still allocated lower processing effort than did the non-musicians to perform the task at the same performance level. This finding suggests an enhanced pitch representation along the auditory system in musicians, possibly as a result......Understanding how the human auditory system processes the physical properties of an acoustical stimulus to give rise to a pitch percept is a fascinating aspect of hearing research. Since most natural sounds are harmonic complex tones, this work focused on the nature of pitch-relevant cues...

  5. Musical Tone Law Method for the Structural Damage Detection

    Directory of Open Access Journals (Sweden)

    Weisong Yang


    Full Text Available Damage detection tests of inclined cables, steel pipes, spherical shells, and an actual cable-stayed bridge were conducted based on the proposed musical tone law method. The results show that the musical tone law method could be used in the damage detection of isotropic material structures with simple shape, like cables, pipes, plates, and shells. Having distinct spectral lines like a comb with a certain interval distribution rule is the main characteristic of the music tone law. Damage detection baseline could be established by quantizing the fitting relationship between modal orders and the corresponding frequency values. The main advantage of this method is that it could be used in the structural damage detection without vibration information of an intact structure as a reference.

  6. Phonology in the Lexical Processing of Chinese: Priming Tone Neighbors

    Institute of Scientific and Technical Information of China (English)

    Zhou Xiaolin


    Using both visual-visual and auditory-visual priming lexical decision tasks, this study investigated phonological processing in reading logographic Chinese. Compound words sharing segmental templates but differing in lexical tones were used as primes and targets while their relative frequency was manipulated. It was found that tone neighbours did not prime each other significantly and the SOA of 100 msec in visual-visual priming. When the SOA was increased to 357 msec, or when primes were presented auditorily, the processing of target words was significantly delayed by their tone neighbours. Larger inhibitory effects were observed for low frequency targets with high frequency primes. It was argued that although phonological information is automatically activated and this activation affects access to semantics in reading Chinese,phonological mediation is not the only or the main ~urce of constraints on semantic activation.

  7. Effects of deoxycholylglycine, a conjugated secondary bile acid, on myogenic tone and agonist-induced contraction in rat resistance arteries.

    Directory of Open Access Journals (Sweden)

    Sandeep Khurana

    Full Text Available BACKGROUND: Bile acids (BAs regulate cardiovascular function via diverse mechanisms. Although in both health and disease serum glycine-conjugated BAs are more abundant than taurine-conjugated BAs, their effects on myogenic tone (MT, a key determinant of systemic vascular resistance (SVR, have not been examined. METHODOLOGY/PRINCIPAL FINDINGS: Fourth-order mesenteric arteries (170-250 µm isolated from Sprague-Dawley rats were pressurized at 70 mmHg and allowed to develop spontaneous constriction, i.e., MT. Deoxycholylglycine (DCG; 0.1-100 µM, a glycine-conjugated major secondary BA, induced reversible, concentration-dependent reduction of MT that was similar in endothelium-intact and -denuded arteries. DCG reduced the myogenic response to stepwise increase in pressure (20 to 100 mmHg. Neither atropine nor the combination of L-NAME (a NOS inhibitor plus indomethacin altered DCG-mediated reduction of MT. K(+ channel blockade with glibenclamide (K(ATP, 4-aminopyradine (K(V, BaCl(2 (K(IR or tetraethylammonium (TEA, K(Ca were also ineffective. In Fluo-2-loaded arteries, DCG markedly reduced vascular smooth muscle cell (VSM Ca(2+ fluorescence (∼50%. In arteries incubated with DCG, physiological salt solution (PSS with high Ca(2+ (4 mM restored myogenic response. DCG reduced vascular tone and VSM cytoplasmic Ca(2+ responses (∼50% of phenylephrine (PE- and Ang II-treated arteries, but did not affect KCl-induced vasoconstriction. CONCLUSION: In rat mesenteric resistance arteries DCG reduces pressure- and agonist-induced vasoconstriction and VSM cytoplasmic Ca(2+ responses, independent of muscarinic receptor, NO or K(+ channel activation. We conclude that BAs alter vasomotor responses, an effect favoring reduced SVR. These findings are likely pertinent to vascular dysfunction in cirrhosis and other conditions associated with elevated serum BAs.

  8. Vascular development in Arabidopsis. (United States)

    Ye, Zheng-Hua; Freshour, Glenn; Hahn, Michael G; Burk, David H; Zhong, Ruiqin


    Vascular tissues, xylem and phloem, form a continuous network throughout the plant body for transport of water, minerals, and food. Characterization of Arabidopsis mutants defective in various aspects of vascular formation has demonstrated that Arabidopsis is an ideal system for investigating the molecular mechanisms controlling vascular development. The processes affected in these mutants include initiation or division of procambium or vascular cambium, formation of continuous vascular cell files, differentiation of procambium or vascular cambium into vascular tissues, cell elongation, patterned secondary wall thickening, and biosynthesis of secondary walls. Identification of the genes affected by some of these mutations has revealed essential roles in vascular development for a cytokinin receptor and several factors mediating auxin transport or signaling. Mutational studies have also identified a number of Arabidopsis mutants defective in leaf venation pattern or vascular tissue organization in stems. Genetic evidence suggests that the vascular tissue organization is regulated by the same positional information that determines organ polarity.

  9. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.


    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile

  10. Obesity and renal hemodynamics

    NARCIS (Netherlands)

    Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.


    Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile inde

  11. [Nucleotide receptors and renal function]. (United States)

    Jankowski, Maciej


    Kidney plays a key role in homeostasis of human body. It has heterogenic structure and is characterized by complicated vascular beds and numbers of sympathetic nerves endings. Nucleotides receptors are involved in the regulation of blood flow, a fundamental process for renal function. Plasma is filtrated in renal glomerulus and activity of nucleotides receptors located on cells of glomerular filter modifies the physi- cochemical properties of filter and affects the filtration process. Electrolytes, water and low molecular weight molecules are reabsorbed from tubular fluid or secreted into fluid in proximal and distal tubules. Glomerular filtration rate and activity of tubular processes are regulated via nucleotides receptors by glomerulotubularbalance and tubuloglomerular feedback. Nucleotides receptors are involved in systemic regulation of blood pressure and carbohydrate metabolism.

  12. Neurophysiological and Behavioral Responses of Mandarin Lexical Tone Processing. (United States)

    Yu, Yan H; Shafer, Valerie L; Sussman, Elyse S


    Language experience enhances discrimination of speech contrasts at a behavioral- perceptual level, as well as at a pre-attentive level, as indexed by event-related potential (ERP) mismatch negativity (MMN) responses. The enhanced sensitivity could be the result of changes in acoustic resolution and/or long-term memory representations of the relevant information in the auditory cortex. To examine these possibilities, we used a short (ca. 600 ms) vs. long (ca. 2,600 ms) interstimulus interval (ISI) in a passive, oddball discrimination task while obtaining ERPs. These ISI differences were used to test whether cross-linguistic differences in processing Mandarin lexical tone are a function of differences in acoustic resolution and/or differences in long-term memory representations. Bisyllabic nonword tokens that differed in lexical tone categories were presented using a passive listening multiple oddball paradigm. Behavioral discrimination and identification data were also collected. The ERP results revealed robust MMNs to both easy and difficult lexical tone differences for both groups at short ISIs. At long ISIs, there was either no change or an enhanced MMN amplitude for the Mandarin group, but reduced MMN amplitude for the English group. In addition, the Mandarin listeners showed a larger late negativity (LN) discriminative response than the English listeners for lexical tone contrasts in the long ISI condition. Mandarin speakers outperformed English speakers in the behavioral tasks, especially under the long ISI conditions with the more similar lexical tone pair. These results suggest that the acoustic correlates of lexical tone are fairly robust and easily discriminated at short ISIs, when the auditory sensory memory trace is strong. At longer ISIs beyond 2.5 s language-specific experience is necessary for robust discrimination.

  13. Neurophysiological and Behavioral Responses of Mandarin Lexical Tone Processing (United States)

    Yu, Yan H.; Shafer, Valerie L.; Sussman, Elyse S.


    Language experience enhances discrimination of speech contrasts at a behavioral- perceptual level, as well as at a pre-attentive level, as indexed by event-related potential (ERP) mismatch negativity (MMN) responses. The enhanced sensitivity could be the result of changes in acoustic resolution and/or long-term memory representations of the relevant information in the auditory cortex. To examine these possibilities, we used a short (ca. 600 ms) vs. long (ca. 2,600 ms) interstimulus interval (ISI) in a passive, oddball discrimination task while obtaining ERPs. These ISI differences were used to test whether cross-linguistic differences in processing Mandarin lexical tone are a function of differences in acoustic resolution and/or differences in long-term memory representations. Bisyllabic nonword tokens that differed in lexical tone categories were presented using a passive listening multiple oddball paradigm. Behavioral discrimination and identification data were also collected. The ERP results revealed robust MMNs to both easy and difficult lexical tone differences for both groups at short ISIs. At long ISIs, there was either no change or an enhanced MMN amplitude for the Mandarin group, but reduced MMN amplitude for the English group. In addition, the Mandarin listeners showed a larger late negativity (LN) discriminative response than the English listeners for lexical tone contrasts in the long ISI condition. Mandarin speakers outperformed English speakers in the behavioral tasks, especially under the long ISI conditions with the more similar lexical tone pair. These results suggest that the acoustic correlates of lexical tone are fairly robust and easily discriminated at short ISIs, when the auditory sensory memory trace is strong. At longer ISIs beyond 2.5 s language-specific experience is necessary for robust discrimination. PMID:28321179

  14. Q fever: a case with a vascular infection complication (United States)

    Edouard, Sophie; Labussiere, Anne-Sophie; Guimard, Yves; Fournier, Pierre-Edouard; Raoult, Didier


    The most common clinical presentation of chronic Q fever is endocarditis with infections of aneurysms or vascular prostheses being the second most common presentation. Here, the authors report a case of vascular chronic Q fever. In this patient, a renal artery aneurysm was discovered by abdominal and pelvic CT during a systematic investigation to identify predisposing factors to chronic Q fever because of high antibody titres in a patient with valve disease. PMID:22767654

  15. Implementation and preliminary evaluation of 'C-tone': A novel algorithm to improve lexical tone recognition in Mandarin-speaking cochlear implant users. (United States)

    Ping, Lichuan; Wang, Ningyuan; Tang, Guofang; Lu, Thomas; Yin, Li; Tu, Wenhe; Fu, Qian-Jie


    Because of limited spectral resolution, Mandarin-speaking cochlear implant (CI) users have difficulty perceiving fundamental frequency (F0) cues that are important to lexical tone recognition. To improve Mandarin tone recognition in CI users, we implemented and evaluated a novel real-time algorithm (C-tone) to enhance the amplitude contour, which is strongly correlated with the F0 contour. The C-tone algorithm was implemented in clinical processors and evaluated in eight users of the Nurotron NSP-60 CI system. Subjects were given 2 weeks of experience with C-tone. Recognition of Chinese tones, monosyllables, and disyllables in quiet was measured with and without the C-tone algorithm. Subjective quality ratings were also obtained for C-tone. After 2 weeks of experience with C-tone, there were small but significant improvements in recognition of lexical tones, monosyllables, and disyllables (P C-tone were greater for disyllables than for monosyllables. Subjective quality ratings showed no strong preference for or against C-tone, except for perception of own voice, where C-tone was preferred. The real-time C-tone algorithm provided small but significant improvements for speech performance in quiet with no change in sound quality. Pre-processing algorithms to reduce noise and better real-time F0 extraction would improve the benefits of C-tone in complex listening environments. Chinese CI users' speech recognition in quiet can be significantly improved by modifying the amplitude contour to better resemble the F0 contour.

  16. The Theory of Adaptive Dispersion and Acoustic-phonetic Properties of Cross-language Lexical-tone Systems (United States)

    Alexander, Jennifer Alexandra

    Lexical-tone languages use fundamental frequency (F0/pitch) to convey word meaning. About 41.8% of the world's languages use lexical tone (Maddieson, 2008), yet those systems are under-studied. I aim to increase our understanding of speech-sound inventory organization by extending to tone-systems a model of vowel-system organization, the Theory of Adaptive Dispersion (TAD) (Liljencrants and Lindblom, 1972). This is a cross-language investigation of whether and how the size of a tonal inventory affects (A) acoustic tone-space size and (B) dispersion of tone categories within the tone-space. I compared five languages with very different tone inventories: Cantonese (3 contour, 3 level tones); Mandarin (3 contour, 1 level tone); Thai (2 contour, 3 level tones); Yoruba (3 level tones only); and Igbo (2 level tones only). Six native speakers (3 female) of each language produced 18 CV syllables in isolation, with each of his/her language's tones, six times. I measured tonal F0 across the vowel at onset, midpoint, and offglide. Tone-space size was the F0 difference in semitones (ST) between each language's highest and lowest tones. Tone dispersion was the F0 distance (ST) between two tones shared by multiple languages. Following the TAD, I predicted that languages with larger tone inventories would have larger tone-spaces. Against expectations, tone-space size was fixed across level-tone languages at midpoint and offglide, and across contour-tone languages (except Thai) at offglide. However, within each language type (level-tone vs. contour-tone), languages with smaller tone inventories had larger tone spaces at onset. Tone-dispersion results were also unexpected. The Cantonese mid-level tone was further dispersed from a tonal baseline than the Yoruba mid-level tone; Cantonese mid-level tone dispersion was therefore greater than theoretically necessary. The Cantonese high-level tone was also further dispersed from baseline than the Mandarin high-level tone -- at midpoint

  17. Review of Surgical Techniques of Experimental Renal Transplantation in Rats. (United States)

    Shrestha, Badri; Haylor, John


    Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.

  18. Player Collaboration in the Explorative Sound Environment ToneInk

    DEFF Research Database (Denmark)

    Hansen, Anne-Marie S.; Andersen, Hans Jørgen; Raudaskoski, Pirkko Liisa


    In the present paper, ToneInk, a prototype of a music based play scenario that investigates player collaboration, is introduced. ToneInk is an explorative sound environment that differs from the majority of music based games in that players can collaborate and be creative in the way they express...... mutual awareness, and in general were more passive when they needed to monitor a screen interface that supported the sound environment. Player collaboration was strongest when players negotiated rhythm, while the negotiation of melody was temporally offset and consisted of long individual explorations....

  19. D-2-like receptor stimulation decreases effective renal plasma flow and glomerular filtration rate in spontaneously hypertensive rats

    NARCIS (Netherlands)

    de Vries, PAM; de Jong, PE; de Zeeuw, D; Navis, GJ


    In spontaneously hypertensive rats (SHRs) the dopaminergic D-1-like renal vasodilator response is impaired. The renal vascular response to D-2-like receptor stimulation in vivo is incompletely known. Therefore, renal hemodynamics were studied in conscious SHRs during continuous infusion of D-2-like

  20. Arterial spin labeling MR imaging for characterisation of renal masses in patients with impaired renal function: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Pedrosa, Ivan [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); UT Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Rafatzand, Khashayar; Robson, Philip; Alsop, David C. [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); Wagner, Andrew A. [Beth Israel Deaconess Medical Center and Harvard Medical School, Surgery, Division of Urology, Boston, MA (United States); Atkins, Michael B. [Beth Israel Deaconess Medical Center and Harvard Medical School, Hematology/Oncology, Boston, MA (United States); Rofsky, Neil M. [University of Texas Southwestern Medical Center, Departments of Radiology, Dallas, TX (United States)


    To retrospectively evaluate the feasibility of arterial spin labeling (ASL) magnetic resonance imaging (MRI) for the assessment of vascularity of renal masses in patients with impaired renal function. Between May 2007 and November 2008, 11/67 consecutive patients referred for MRI evaluation of a renal mass underwent unenhanced ASL-MRI due to moderate-to-severe chronic or acute renal failure. Mean blood flow in vascularised and non-vascularised lesions and the relation between blood flow and final diagnosis of malignancy were correlated with a 2-sided homogeneous variance t-test and the Fisher Exact Test, respectively. A p value <0.05 was considered statistically significant. Seventeen renal lesions were evaluated in 11 patients (8 male; mean age = 70 years) (range 57-86). The median eGFR was 24 mL/min/1.73 m{sup 2} (range 7-39). The average blood flow of 11 renal masses interpreted as ASL-positive (134 +/- 85.7 mL/100 g/min) was higher than that of 6 renal masses interpreted as ASL-negative (20.5 +/- 8.1 mL/100 g/min)(p = 0.015). ASL-positivity correlated with malignancy (n = 3) or epithelial atypia (n = 1) at histopathology or progression at follow up (n = 7). ASL detection of vascularity in renal masses in patients with impaired renal function is feasible and seems to indicate neoplasia although the technique requires further evaluation. (orig.)

  1. Vascular Adventitia Calcification and Its Underlying Mechanism.

    Directory of Open Access Journals (Sweden)

    Na Li

    Full Text Available Previous research on vascular calcification has mainly focused on the vascular intima and media. However, we show here that vascular calcification may also occur in the adventitia. The purpose of this work is to help elucidate the pathogenic mechanisms underlying vascular calcification. The calcified lesions were examined by Von Kossa staining in ApoE-/- mice which were fed high fat diets (HFD for 48 weeks and human subjects aged 60 years and older that had died of coronary heart disease, heart failure or acute renal failure. Explant cultured fibroblasts and smooth muscle cells (SMCswere obtained from rat adventitia and media, respectively. After calcification induction, cells were collected for Alizarin Red S staining. Calcified lesions were observed in the aorta adventitia and coronary artery adventitia of ApoE-/-mice, as well as in the aorta adventitia of human subjects examined. Explant culture of fibroblasts, the primary cell type comprising the adventitia, was successfully induced for calcification after incubation with TGF-β1 (20 ng/ml + mineralization media for 4 days, and the phenotype conversion vascular adventitia fibroblasts into myofibroblasts was identified. Culture of SMCs, which comprise only a small percentage of all cells in the adventitia, in calcifying medium for 14 days resulted in significant calcification.Vascular calcification can occur in the adventitia. Adventitia calcification may arise from the fibroblasts which were transformed into myofibroblasts or smooth muscle cells.

  2. Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke. (United States)

    Coucha, Maha; Li, Weiguo; Johnson, Maribeth H; Fagan, Susan C; Ergul, Adviye


    The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or N(ω)-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group (P nitration improved the myogenic tone of vessels from ischemic (P Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs vessel reactivity in both hemispheres via nitration. We suggest that sham operation rather than the nonischemic side should be used as a control in preclinical stroke studies.

  3. Increased pulmonary arteriolar tone associated with lung oxidative stress and nitric oxide in a mouse model of Alzheimer's disease. (United States)

    Roberts, Andrew M; Jagadapillai, Rekha; Vaishnav, Radhika A; Friedland, Robert P; Drinovac, Robert; Lin, Xingyu; Gozal, Evelyne


    Vascular dysfunction and decreased cerebral blood flow are linked to Alzheimer's disease (AD). Loss of endothelial nitric oxide (NO) and oxidative stress in human cerebrovascular endothelium increase expression of amyloid precursor protein (APP) and enhance production of the Aβ peptide, suggesting that loss of endothelial NO contributes to AD pathology. We hypothesize that decreased systemic NO bioavailability in AD may also impact lung microcirculation and induce pulmonary endothelial dysfunction. The acute effect of NO synthase (NOS) inhibition on pulmonary arteriolar tone was assessed in a transgenic mouse model (TgAD) of AD (C57BL/6-Tg(Thy1-APPSwDutIowa)BWevn/Mmjax) and age-matched wild-type controls (C57BL/6J). Arteriolar diameters were measured before and after the administration of the NOS inhibitor, L-NAME Lung superoxide formation (DHE) and formation of nitrotyrosine (3-NT) were assessed as indicators of oxidative stress, inducible NOS (iNOS) and tumor necrosis factor alpha (TNF-α) expression as indicators of inflammation. Administration of L-NAME caused either significant pulmonary arteriolar constriction or no change from baseline tone in wild-type (WT) mice, and significant arteriolar dilation in TgAD mice. DHE, 3-NT, TNF-α, and iNOS expression were higher in TgAD lung tissue, compared to WT mice. These data suggest L-NAME could induce increased pulmonary arteriolar tone in WT mice from loss of bioavailable NO In contrast, NOS inhibition with L-NAME had a vasodilator effect in TgAD mice, potentially caused by decreased reactive nitrogen species formation, while significant oxidative stress and inflammation were present. We conclude that AD may increase pulmonary microvascular tone as a result of loss of bioavailable NO and increased oxidative stress. Our findings suggest that AD may have systemic microvascular implications beyond central neural control mechanisms.

  4. Role of Microvascular Tone and Extracellular Matrix Contraction in the Regulation of Interstitial Fluid: Implications for Aortic Dissection. (United States)

    Mallat, Ziad; Tedgui, Alain; Henrion, Daniel


    The pathophysiology of aortic dissection is poorly understood, and its risk is resistant to medical treatment. Most studies have focused on a proposed pathogenic role of transforming growth factor-β in Marfan disease and related thoracic aortic aneurysms and aortic dissections. However, clinical testing of this concept using angiotensin II type 1 receptor antagonists to block transforming growth factor-β signaling fell short of promise. Genetic mutations that predispose to thoracic aortic aneurysms and aortic dissections affect components of the extracellular matrix and proteins involved in cellular force generation. Thus, a role for dysfunctional mechanosensing in abnormal aortic wall remodeling is emerging. However, how abnormal mechanosensing leads to aortic dissection remains a mystery. Here, we review current knowledge about the regulation of interstitial fluid dynamics and myogenic tone and propose that alteration in contractile force reduces vascular tone in the microcirculation (here, aortic vasa vasorum) and leads to elevations of blood flow, transmural pressure, and fluid flux into the surrounding aortic media. Furthermore, reduced contractile force in medial smooth muscle cells coupled with alteration of structural components of the extracellular matrix limits extracellular matrix contraction, further promoting the formation of intramural edema, a critical step in the initiation of aortic dissection. The concept is supported by several pathophysiological and clinical observations. A direct implication of this concept is that drugs that lower blood pressure and limit interstitial fluid accumulation while preserving or increasing microvascular tone would limit the risk of dissection. In contrast, drugs that substantially lower microvascular tone would be ineffective or may accelerate the disease and precipitate aortic dissection.

  5. The renin-angiotensin system in thyroid disorders and its role in cardiovascular and renal manifestations. (United States)

    Vargas, Félix; Rodríguez-Gómez, Isabel; Vargas-Tendero, Pablo; Jimenez, Eugenio; Montiel, Mercedes


    Thyroid disorders are among the most common endocrine diseases and affect virtually all physiological systems, with an especially marked impact on cardiovascular and renal systems. This review summarizes the effects of thyroid hormones on the renin-angiotensin system (RAS) and the participation of the RAS in the cardiovascular and renal manifestations of thyroid disorders. Thyroid hormones are important regulators of cardiac and renal mass, vascular function, renal sodium handling, and consequently blood pressure (BP). The RAS acts globally to control cardiovascular and renal functions, while RAS components act systemically and locally in individual organs. Various authors have implicated the systemic and local RAS in the mediation of functional and structural changes in cardiovascular and renal tissues due to abnormal thyroid hormone levels. This review analyzes the influence of thyroid hormones on RAS components and discusses the role of the RAS in BP, cardiac mass, vascular function, and renal abnormalities in thyroid disorders.

  6. Mechanisms of K(+) induced renal vasodilation in normo- and hypertensive rats in vivo

    DEFF Research Database (Denmark)

    Magnusson, Linda Helena Margaretha; Sørensen, Charlotte Mehlin; Braunstein, T H;


    Aim: We investigated the mechanisms behind K(+) -induced renal vasodilation in vivo in normotensive Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). Methods: Renal blood flow (RBF) was measured utilizing an ultrasonic Doppler flow probe. Renal vascular resistance (RVR) was calc......Aim: We investigated the mechanisms behind K(+) -induced renal vasodilation in vivo in normotensive Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). Methods: Renal blood flow (RBF) was measured utilizing an ultrasonic Doppler flow probe. Renal vascular resistance (RVR......) was calculated as the ratio of mean arterial pressure (MAP) and RBF (RVR = MAP/RBF). Test drugs were introduced directly into the renal artery. Inward rectifier K(+) (K(ir) ) channels and Na(+) ,K(+) -ATPase were blocked by Ba(2+) and ouabain (estimated plasma concentrations ~20 and ~7 µm) respectively. Results...

  7. Bilateral Renal Mass-Renal Disorder: Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ozlem Tiryaki


    Full Text Available A 30-year-old woman has presented complaining of weakness and fatigue to her primary care physician. The renal sonography is a routine step in the evaluation of new onset renal failure. When the renal masses have been discovered by sonography in this setting, the functional imaging may be critical. We reported a case about bilateral renal masses in a young female patient with tuberculosis and renal insufficiency. Magnetic resonance (MR has revealed the bilateral renal masses in patient, and this patient has been referred to our hospital for further management. The patient’s past medical and surgical history was unremarkable.

  8. Distal renal tubular acidosis (United States)

    Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA ... excreting it into the urine. Distal renal tubular acidosis (Type I RTA) is caused by a defect ...

  9. Proximal renal tubular acidosis (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  10. Elevated Plasma Homocysteine Level in Vascular Dementia Reflects the Vascular Disease Process

    Directory of Open Access Journals (Sweden)

    Karin Nilsson


    Full Text Available Background: Patients with vascular dementia (VaD exhibit particularly elevated levels of plasma total homocysteine (tHcy compared to patients with other psychogeriatric diseases. Methods: We investigated the main determinants (age, renal impairment, cobalamin/folate status and presence of extracerebral vascular disease of plasma tHcy in 525 patients with VaD. Furthermore, 270 patients with depression were used as a reference group to reveal the potential specificity of elevated plasma tHcy in patients with VaD. Results: Elevated plasma tHcy levels in patients with VaD could only partly be attributed to cobalamin/folate deficiency or renal impairment. Plasma tHcy might also be related to the vascular disease process since patients with depression and vascular disease exhibited similar plasma tHcy levels to patients with VaD. Conclusion: Our findings suggest that elevated plasma tHcy might be a sensitive marker for the vascular disease process in patients with VaD and that the level also is a reflection of changes in the other main determinants of plasma tHcy.

  11. Branding of vascular surgery. (United States)

    Perler, Bruce A


    The Society for Vascular Surgery surveyed primary care physicians (PCPs) to understand how PCPs make referral decisions for their patients with peripheral vascular disease. Responses were received from 250 PCPs in 44 states. More than 80% of the respondents characterized their experiences with vascular surgeons as positive or very positive. PCPs perceive that vascular surgeons perform "invasive" procedures and refer patients with the most severe vascular disease to vascular surgeons but were more than twice as likely to refer patients to cardiologists, believing they are better able to perform minimally invasive procedures. Nevertheless, PCPs are receptive to the notion of increasing referrals to vascular surgeons. A successful branding campaign will require considerable education of referring physicians about the totality of traditional vascular and endovascular care increasingly provided by the contemporary vascular surgical practice and will be most effective at the local grassroots level.

  12. Renal hemodynamics in hypertensive renal allograft recipients: effects of calcium antagonists and ACE inhibitors. (United States)

    Grekas, D; Dioudis, C; Kalevrosoglou, I; Alivanis, P; Derveniotis, V; Tourkantonis, A


    Hypertension present in more than 50% of successfully renal transplanted patients and its prevalence has slightly increased since the introduction of cyclosporine A. Twenty patients, 9 women and 11 men aged from 30 to 58 years, with stable cadaveric renal allograft function and moderate to severe hypertension, were included in the study. Renal artery graft stenosis causing hypertension were excluded. All patients were given triple drug immunosuppressive treatment with methylprednisolone, azathioprine and cyclosporine A (CsA) and their hypertension was treated with a nifedipine dose of 20 mg twice daily. To evaluate the effect of ACE inhibitors on renal hemodynamics and hypertension, a 4 mg/daily dose of perindopril was added to the above regimen for two months. Effective renal plasma flow (ERPF) decreased from 208 +/- 54 to 168 +/- 61 ml/min and renal vascular resistance (RVR) increased from 75 +/- 12 to 88 +/- 17 mm Hg/ml/min (P nifedipine. It is suggested that the combination of both antihypertensive agents was more effective than monotherapy with nifedipine in controlling blood pressure, but less favorable on the renal hemodynamic response in hypertensive renal transplant patients who were maintained on CsA.

  13. Renal tuberculosis

    Directory of Open Access Journals (Sweden)

    Džamić Zoran


    Full Text Available Tuberculosis is still a significant health problem in the world, mostly in developing countries. The special significance lies in immunocompromised patients, particularly those suffering from the HIV. Urogenital tuberculosis is one of the most common forms of extrapulmonary tuberculosis, while the most commonly involved organ is the kidney. Renal tuberculosis occurs by hematogenous dissemination of mycobacterium tuberculosis from a primary tuberculosis foci in the body. Tuberculosis is characterized by the formation of pathognomonic lesions in the tissues - granulomata. These granulomata may heal spontaneously or remain stable for years. In certain circumstances in the body associated with immunosuppression, the disease may be activated. Central caseous necrosis occurs within tuberculoma, leading to formation of cavities that destroy renal parenchyma. The process may gain access to the collecting system, forming the caverns. In this way, infection can be spread distally to renal pelvis, ureter and bladder. Scaring of tissue by tuberculosis process may lead to development of strictures of the urinary tract. The clinical manifestations are presented by nonspecific symptoms and signs, so tuberculosis can often be overlooked. Sterile pyuria is characteristic for urinary tuberculosis. Dysuric complaints, flank pain or hematuria may be presented in patients. Constitutional symptoms of fever, weight loss and night sweats are presented in some severe cases. Diagnosis is made by isolation of mycobacterium tuberculosis in urine samples, by cultures carried out on standard solid media optimized for mycobacterial growth. Different imaging studies are used in diagnostics - IVU, CT and NMR are the most important. Medical therapy is the main modality of tuberculosis treatment. The first line anti-tuberculosis drugs include isoniazid, rifampicin, pyrazinamide and ethambutol. Surgical treatment is required in some cases, to remove severely damaged kidney, if

  14. Representing morphological tone in a computational grammar of Hausa

    Directory of Open Access Journals (Sweden)

    Berthold Crysmann


    Full Text Available In this paper I shall discuss the representation of morphological tone in Hausa, as implemented in a computational grammar of the language, referred to as HaG, which has been developed within the framework of Head-driven Phrase Structure Grammar. Based on an in-depth study of segmental and suprasegmental properties manipulated by morphological processes, I shall argue that two fundamental insights from Autosegmental Phonology needs to be seamlessly integrated into typed feature structure grammars of languages with grammatical tone, namely (i the systematic separation of tonal and metrical information from the string of consonants and vowels, and (ii the possibility of tonal spreading, i.e. the possibility for a tonal specification to be assigned to an arbitrary number of adjacent tone-bearing units (syllables. To this end, I present a formalisation of tonal melodies in terms of typed list constraints that implement a notion of tonal spreading, allowing for an underspecified description of tonal melodies, independent of the number of tone-bearing units. I shall finally show that this minimal encoding is sufficient and flexible enough to capture the range of suprasegmental phenomena in Hausa.

  15. The Role of Tone in Some Cushitic Languages. (United States)

    Appleyard, David L.


    The morphological function of tone/accent is examined in a number of Cushitic languages, with the objective of determining whether any comparative statement can be made validly at the group level. Three languages, the Somali dialect cluster, Afar, and Oromo, are the basis for the study. Patterns in case, gender, and the jussive form are analyzed.…

  16. Consonance perception of complex-tone dyads and chords

    DEFF Research Database (Denmark)

    Rasmussen, Marc; Santurette, Sébastien; MacDonald, Ewen


    Sensory consonance and dissonance are perceptual attributes of musical intervals conveying pleasant- ness, tension, and harmony in musical phrases. For complex-tone dyads, corresponding to two musical notes played simultaneously, consonance is known to vary with the ratio in fundamental frequency...... for a potential role of frequency selectivity for consonance perception of dyads, might not hold for chords...

  17. Fan Noise Source Diagnostic Test: Tone Modal Structure Results (United States)

    Heidelberg, Laurence J.


    This investigation is part of a test series that was extremely comprehensive and included aerodynamic and acoustic testing of a fan stage using two different fan rotors and three different stator designs. The test series is known as the Source Diagnostic Test (SDT) and was conducted by NASA Glenn as part of the Advanced Subsonic Technology (AST) Noise Reduction Program. Tone mode measurements of one of the rotors with three different stators were made. The stator designs involve changes in vane count and sweep at constant solidity. The results of both inlet and exhaust tone mode measurements are presented in terms of mode power for both circumferential and radial mode orders. The results show benefits of vane sweep to be large, up to 13 dB in total tone power. At many conditions, the increase in power due to cutting on the rotor/stator interaction is more than offset by vane sweep. The rotor locked mode is shown as an important contributor to tone power when the blade tip speed is near and above Mach one. This is most evident in the inlet when the direct rotor field starts to cut on.

  18. Context, Contrast, and Tone of Voice in Auditory Sarcasm Perception (United States)

    Voyer, Daniel; Thibodeau, Sophie-Hélène; Delong, Breanna J.


    Four experiments were conducted to investigate the interplay between context and tone of voice in the perception of sarcasm. These experiments emphasized the role of contrast effects in sarcasm perception exclusively by means of auditory stimuli whereas most past research has relied on written material. In all experiments, a positive or negative…

  19. STEM Tones Pre-Activate Suffixes in the Brain (United States)

    Söderström, Pelle; Horne, Merle; Roll, Mikael


    Results from the present event-related potentials (ERP) study show that tones on Swedish word stems can rapidly pre-activate upcoming suffixes, even when the word stem does not carry any lexical meaning. Results also show that listeners are able to rapidly restore suffixes which are replaced with a cough. Accuracy in restoring suffixes correlated…

  20. Perceptual Weights for Loudness Judgments of 6-Tone Complexes

    DEFF Research Database (Denmark)

    Jesteadt, Walt; Valente, Daniel L.; Joshi, Suyash Narendra

    of SPL or SL values was tested. Both tasks used two-interval forced-choice trials, with level “jitter” introduced by selecting the level of each tone from a normal distribution with specified mean level and standard deviation of 5 dB. Subjects were instructed to indicate which complex was louder......In a series of studies, 6 subjects with normal hearing (NH) and 3 with sensorineural hearing loss (SNHL) judged the overall loudness of 6-tone complexes comprised of octave frequencies from 0.25 to 8 kHz. In two tasks, tones were equated in level in dB SPL or in sensation level (SL) and a range....... In the “loudness” task there was no difference in mean level across the two intervals. In the “sample discrimination” task, the two complexes differed by an average of 5 dB. For both tasks, perceptual weights were derived by correlating the differences in level between matched-frequency tones in the complexes...

  1. Renale Osteopathie

    Directory of Open Access Journals (Sweden)

    Horn S


    Full Text Available Die renale Osteopathie umfaßt Erkrankungen des Knochens, die bei Patienten mit chronischen Nierenerkrankungen auftreten, wie den sekundären bzw. tertiären Hyperparathyreoidismus, die adynamische Knochenerkrankung und die Osteopathie nach Nierentransplantation. Durch die Identifikation des Kalzium-Sensing-Rezeptors bzw. des Vitamin D-Rezeptors hat sich unser Verständnis der Zusammenhänge in den letzten Jahren erheblich verbessert. Neue Medikamente versprechen effizientere Prophylaxe- und Therapiemöglichkeiten. Wir beeinflussen dadurch nicht nur die Morbidität und Lebensqualität, sondern auch die Mortalität unserer Patienten.

  2. Effects of ligustrazine on hemodynamics and contractile function of coronary vascular ring in dogs with renal hypertension%川芎嗪对肾性高血压犬血流动力学及冠状动脉血管环功能的影响

    Institute of Scientific and Technical Information of China (English)

    唐瑭; 陈德森; 刘刚


    目的 观察川芎嗪对肾性高血压犬血流动力学及冠状动脉环舒缩功能的影响.方法 以直接测压法测定犬在给予川芎嗪(0.2g/kg小剂量组和0.6g/kg大剂量组)前及给药后0.5,1,2,4h共5个时间点的左室内压力峰值(LVSP)、左室内压力最大上升速率(+LV dp/dtmax)、平均动脉压(MAP)、脉压(PP).以去甲肾上腺素(NE)和氯化钾(KCl)分别灌流模型组犬离体冠状动脉环,测定川芎嗪对犬冠状动脉环半抑制浓度(IC50),观察川芎嗪对NE及KCl致肾性高血压的冠状动脉环收缩的影响.结果 给药后1,2h 2个时间点测定的川芎嗪有较明显的剂量依赖性地降低肾性高血压犬LVSP、+LV dp/dtmax、MAP的作用;抑制NE和KCl引起的离体冠脉收缩,NE及KCl IC50分别为(1.06±0.65)×10-4mol/L和(1.51±0.26)×10-4mol/L.1×10-4和5×10-4mol/L川芎嗪可使NE引起的内源性钙收缩张力由(1.45±0.18)g分别下降至(0.94±0.42)g和(0.63±0.25)g,外源性钙收缩张力由(2.15±0.47)g降至(1.21±0.42)g和(0.89±0.25)g.结论 川芎嗪对肾性高血压犬有降压作用,并可抑制NE和KCl引起的冠脉收缩,其作用机制与抑制平滑肌细胞电压依赖性钙通道和受体操纵钙通道介导的外钙内流和内钙释放,降低心肌收缩力进而影响心功能有关.%Objective It is to explore the effects of ligustrazine on hemodynamics and contractile function of coronary vascular ring in renal hypertensive dogs. Methods The direct manometric method was used to determine the left intraventricular pressure peak value ( LVSP ), maximum rising rate of left ventricular pressure ( + LV dp/dtmax ), mean arterial pressure ( MAP ) , pulse pressure ( PP ) in canines before giving ligustrazine 0. 2 g/kg or 0. 6 g/kg and after 30 min, 1, 2, 4 h respectively. In norepinephrine( NE ) - and potassium chloride ( KC1 )-induced renal hypertension canines, half inhibitory concentration ( IC50 ) of coronary vascular ring was determined after perfusing

  3. Renal disease in pregnancy. (United States)

    Thorsen, Martha S; Poole, Judith H


    Anatomic and physiologic adaptations within the renal system during pregnancy are significant. Alterations are seen in renal blood flow and glomerular filtration, resulting in changes in normal renal laboratory values. When these normal renal adaptations are coupled with pregnancy-induced complications or preexisting renal dysfunction, the woman may demonstrate a reduction of renal function leading to an increased risk of perinatal morbidity and mortality. This article will review normal pregnancy adaptations of the renal system and discuss common pregnancy-related renal complications.

  4. Woodwind Tone Hole Acoustics and the Spectrum Transformation Function. (United States)

    Keefe, Douglas Howard

    This report describes an investigation of woodwind musical instrument tone holes and their effect on the radiated spectrum, the total dissipation, the stability of oscillation, the psychoacoustical cues important in perception, and the tuning and response of the instrument. Varying tone hole proportions significantly affect the radiative and frictional damping near a single hole, the mutual interactions between holes, the onset of streaming and turbulence near the holes, and the perceived woodwind timbre. The interconnections between related fields are explored through a brief review of sound production in woodwinds plus more extensive reviews of room and psychological acoustics. A theoretical and experimental discussion of the spectrum transformation function from the mouthpiece into the room relates all these fields. Also, considered are differences between cylindrical and conical bore woodwinds, the systematic shifts in saxophone spectra produced by the beating of the reed, the coupling of many closely spaced tone holes to the room excitation, the role of the player, and the results pertaining to computer music synthesis. The complicated acoustical flow inside the main air column near a single tone hole has been examined using a Green function, integral equation approach. A variational formulation allows explicit calculation of the open and closed hole impedance parameters needed in the transmission line description of a woodwind, and experiments have verified the theory in detail. Major acoustical topics considered are listed below. The effective length t(,e) of an open hole, relevant for instrument design and modification, is calculated and measured in terms of the main bore diameter 2a, hole diameter 2b, and the height t of the hole chimney; the effect of a hanging pad is a semi-empirical correction on t(,e). When the fundamental plane-wave mode of the main air column oscillation is at a pressure node, both the open and closed hole series impedances are

  5. Protease-Activated Receptor 2 Promotes Pro-Atherogenic Effects through Transactivation of the VEGF Receptor 2 in Human Vascular Smooth Muscle Cells


    Indrakusuma, Ira; Romacho, Tania; Eckel, Jürgen


    Background: Obesity is associated with impaired vascular function. In the cardiovascular system, protease-activated receptor 2 (PAR2) exerts multiple functions such as the control of the vascular tone. In pathological conditions, PAR2 is related to vascular inflammation. However, little is known about the impact of obesity on PAR2 in the vasculature. Therefore, we explored the role of PAR2 as a potential link between obesity and cardiovascular diseases. Methods: C57BL/6 mice were fed with eit...

  6. Anatomic variations of the renal vessels: focus on the precaval right renal artery. (United States)

    Bouali, Ourdia; Labarre, David; Molinier, François; Lopez, Raphaël; Benouaich, Vincent; Lauwers, Frédéric; Moscovici, Jacques


    The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

  7. Development of a robust reverse tone pattern transfer process (United States)

    Khusnatdinov, Niyaz; Doyle, Gary; Resnick, Douglas J.; Ye, Zhengmao; LaBrake, Dwayne; Milligan, Brennan; Alokozai, Fred; Chen, Jerry


    Pattern transfer is critical to any lithographic technology, and plays a significant role in defining the critical features in a device layer. As both the memory and logic roadmaps continue to advance, greater importance is placed on the scheme used to do the etching. For many critical layers, a need has developed which requires a multilayer stack to be defined in order to perform the pattern transfer. There are many cases however, where this standard approach does not provide the best results in terms of critical dimension (CD) fidelity and CD uniformity. As an example, when defining a contact pattern, it may be advantageous to apply a bright field mask (in order to maximize the normalized inverse log slope (NILS)) over the more conventional dark field mask. The result of applying the bright field mask in combination with positive imaging resist is to define an array of pillar patterns, which then must be converted back to holes before etching the underlying dielectric material. There have been several publications on tone reversal that is introduced in the resist process itself, but often an etch transfer process is applied to reverse the pattern tone. The purpose of this paper is to describe the use of a three layer reverse tone process (RTP) that is capable of reversing the tone of every printed feature type. The process utilizes a resist pattern, a hardmask layer and an additional protection layer. The three layer approach overcomes issues encountered when using a single masking layer. Successful tone reversal was demonstrated both on 300mm wafers and imprint masks, including the largest features in the pattern, with dimensions as great as 60 microns. Initial in-field CD uniformity is promising. CDs shifted by about 2.6nm and no change was observed in either LER or LWR. Follow-up work is required to statistically qualify in-field CDU and also understand both across wafer uniformity and feature linearity.

  8. Transonic Tones and Excess Broadband Noise in Overexpanded Supersonic Jets (United States)

    Zaman, Khairul B. M. Q.


    Noise characteristics of convergent-divergent (C-D) nozzles in the overexpanded regime are the focus of this paper. The flow regime is encountered during takeoff and landing of certain airplanes and also with rocket nozzles in launch-pad environment. Experimental results from laboratory-scale single nozzles are discussed. The flow often undergoes a resonance accompanied by emission of tones (referred to as transonic tones). The phenomenon is different from the well-known screech tones. Unlike screech, the frequency increases with increasing supply pressure. There is a staging behavior odd harmonic stages occur at lower pressures while the fundamental occurs in a range of relatively higher pressures. A striking feature is that tripping of the nozzle s internal boundary layer tends to suppress the resonance. However, even in the absence of tones the broadband levels are found to be high. That is, relative to a convergent case and at same pressure ratio, the C-D nozzles are found to be noisier, often by more than 10dB. This excess broadband noise (referred to as EBBN) is further explored. Its characteristics are found to be different from the well-known broadband shockassociated noise ( BBSN ). For example, while the frequency of the BBSN peak varies with observation angle no such variation is noted with EBBN. The mechanisms of the transonic tone and the EBBN are not completely understood yet. They appear to be due to unsteady shock motion inside the nozzle. The shock drives the flow downstream like a vibrating diaphragm, and resonance takes place similarly as with acoustic resonance of a conical section having one end closed and the other end open. When the boundary layer is tripped, apparently a breakdown of azimuthal coherence suppresses the resonance. However, there is still unsteady shock motion albeit with superimposed randomness. Such random motion of the internal shock and its interaction with the separated boundary layer produces the EBBN.

  9. Additional renal arteries: incidence and morphometry. (United States)

    Satyapal, K S; Haffejee, A A; Singh, B; Ramsaroop, L; Robbs, J V; Kalideen, J M


    Advances in surgical and uro-radiological techniques dictate a reappraisal and definition of renal arterial variations. This retrospective study aimed at establishing the incidence of additional renal arteries. Two subsets were analysed viz.: a) Clinical series--130 renal angiograms performed on renal transplant donors, 32 cadaver kidneys used in renal transplantation b) Cadaveric series--74 en-bloc morphologically normal kidney pairs. The sex and race distribution was: males 140, females 96; African 84, Indian 91, White 43 and "Coloured" 18, respectively. Incidence of first and second additional arteries were respectively, 23.2% (R: 18.6%; L: 27.6%) and 4.5% (R: 4.7%; L: 4.4%). Additional arteries occurred more frequently on the left (L: 32.0%; R: 23.3%). The incidence bilaterally was 10.2% (first additional arteries, only). The sex and race incidence (first and second additional) was: males, 28.0%, 5.1%; females, 16.4%, 3.8% and African 31.1%, 5.4%; Indian 13.5%, 4.5%; White 30.9%, 4.4% and "Coloured" 18.5%, 0%; respectively. Significant differences in the incidence of first additional arteries were noted between sex and race. The morphometry of additional renal arteries were lengths (cm) of first and second additional renal arteries: 4.5 and 3.8 (right), 4.9 and 3.7 (left); diameters: 0.4 and 0.3 (right), 0.3 and 0.3 (left). Detailed morphometry of sex and race were also recorded. No statistically significant differences were noted. Our results of the incidence of additional renal arteries of 27.7% compared favourably to that reported in the literature (weighted mean 28.1%). The study is unique in recording detailed morphometry of these vessels. Careful techniques in the identification of this anatomical variation is important since it impacts on renal transplantation surgery, vascular operations for renal artery stenosis, reno-vascular hypertension, Takayasu's disease, renal trauma and uro-radiological procedures.

  10. Renal calculus

    CERN Document Server

    Pyrah, Leslie N


    Stone in the urinary tract has fascinated the medical profession from the earliest times and has played an important part in the development of surgery. The earliest major planned operations were for the removal of vesical calculus; renal and ureteric calculi provided the first stimulus for the radiological investigation of the viscera, and the biochemical investigation of the causes of calculus formation has been the training ground for surgeons interested in metabolic disorders. It is therefore no surprise that stone has been the subject of a number of monographs by eminent urologists, but the rapid development of knowledge has made it possible for each one of these authors to produce something new. There is still a technical challenge to the surgeon in the removal of renal calculi, and on this topic we are always glad to have the advice of a master craftsman; but inevitably much of the interest centres on the elucidation of the causes of stone formation and its prevention. Professor Pyrah has had a long an...

  11. Implicit target substitution and sequencing for lexical tone production in Chinese: an FMRI study. (United States)

    Chang, Hui-Chuan; Lee, Hsin-Ju; Tzeng, Ovid J L; Kuo, Wen-Jui


    In this study, we examine the neural substrates underlying Tone 3 sandhi and tone sequencing in Mandarin Chinese using fMRI. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (i.e., 33→23). According to current speech production models, target substitution is expected to engage the posterior inferior frontal gyrus. Since Tone 3 sandhi is, to some extent, independent of segments, which makes it more similar to singing, right-lateralized activation in this region was predicted. As for tone sequencing, based on studies in sequencing, we expected the involvement of the supplementary motor area. In the experiments, participants were asked to produce twelve four-syllable sequences with the same tone assignment (the repeated sequences) or a different tone assignment (the mixed sequences). We found right-lateralized posterior inferior frontal gyrus activation for the sequence 3333 (Tone 3 sandhi) and left-lateralized activation in the supplementary motor area for the mixed sequences (tone sequencing). We proposed that tones and segments could be processed in parallel in the left and right hemispheres, but their integration, or the product of their integration, is hosted in the left hemisphere.

  12. Implicit target substitution and sequencing for lexical tone production in Chinese: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Hui-Chuan Chang

    Full Text Available In this study, we examine the neural substrates underlying Tone 3 sandhi and tone sequencing in Mandarin Chinese using fMRI. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (i.e., 33→23. According to current speech production models, target substitution is expected to engage the posterior inferior frontal gyrus. Since Tone 3 sandhi is, to some extent, independent of segments, which makes it more similar to singing, right-lateralized activation in this region was predicted. As for tone sequencing, based on studies in sequencing, we expected the involvement of the supplementary motor area. In the experiments, participants were asked to produce twelve four-syllable sequences with the same tone assignment (the repeated sequences or a different tone assignment (the mixed sequences. We found right-lateralized posterior inferior frontal gyrus activation for the sequence 3333 (Tone 3 sandhi and left-lateralized activation in the supplementary motor area for the mixed sequences (tone sequencing. We proposed that tones and segments could be processed in parallel in the left and right hemispheres, but their integration, or the product of their integration, is hosted in the left hemisphere.

  13. Perceptual evidence for protracted development in monosyllabic Mandarin lexical tone production in preschool children in Taiwan. (United States)

    Wong, Puisan


    This study used the same methodology in Wong [J. Speech Lang. Hear. Res. 55, 1423-1437 (2012b)] to examine the perceived accuracy of monosyllabic Mandarin tones produced by 4- and 5-year-old Mandarin-speaking children growing up in Taiwan and combined the findings with those of 3-year-olds reported in Wong [J. Speech Lang. Hear. Res. 55, 1423-1437 (2012b)] to track the development of monosyllabic tone production in preschool children. Tone productions of adults and children were collected in a picture naming task and low-pass filtered to remove lexical information and reserve tone information. Five native-speakers categorized the target tones in the filtered productions. Children's tone accuracy was compared to adults' to determine mastery and developmental changes. The results showed that preschool children in Taiwan have not fully mastered the production of monosyllabic Mandarin tones. None of the tones produced by the children in the three age groups reached adult-like accuracy. Little developmental change was found in children's tone accuracy during the preschool years. A similar order of accuracy of the tones was observed across the three age groups and the order appeared to follow the order of articulatory complexity in producing the tones. The findings suggest a protracted course of development in children's acquisition of Mandarin tones and that tone development may be constrained by physiological factors.

  14. Lexical tone and stuttering loci in Mandarin: evidence from preschool children who stutter. (United States)

    Chou, Fang-Chi; Zebrowski, Patricia; Yang, Shu-Lan


    The purpose of this study was to examine the relationship between stuttering loci and lexical tone in Mandarin-speaking preschoolers. Conversational samples from 20 Taiwanese children who stutter (CWS; M = 4:9; range = 3:2-6:4) were analysed for frequency and type of speech disfluency and lexical tone associated with stuttering-like disfluencies (SLDs). Results indicated that SLDs were significantly more likely to be produced on Mandarin syllables carrying Tone 3 and Tone 4 syllables compared to syllables carrying either Tone 1 or Tone 2. Post-hoc analyses revealed: (1) no significant differences in the stuttering frequencies between Tone 1 and Tone 2, or between Tone 3 and Tone 4, and (2) a higher incidence of stuttering on syllables carrying Tone 3 and Tone 4 embedded in conflicting (as opposed to compatible) tonal contexts. Results suggest that the higher incidence of stuttering on Mandarin syllables carrying either Tone 3 or 4 may be attributed to the increased level of speech motor demand underlying rapid F0 change both within and across syllables.

  15. Abdominal aortic surgery and renal anomalies

    Directory of Open Access Journals (Sweden)

    Ilić Nikola


    Full Text Available Introduction. Kidney anomalies present a challenge even for the most experienced vascular surgeon in the reconstruction of the aortoilliac segment. The most significant anomalies described in the surgery of the aortoilliac segment are a horse-shoe and ectopic kidney. Objective. The aim of this retrospective study was to analyze experience on 40 patients with renal anomalies, who underwent surgery of the aortoilliac segment and to determine attitudes on conventional surgical treatment. Methods. In the period from 1992 to 2009, at the Clinic for Vascular Surgery of the Clinical Centre of Belgrade we operated on 40 patients with renal anomalies and aortic disease (aneurysmatic and obstructive. The retrospective analysis involved standard epidemiological data of each patient (gender, age, risk factors for atherosclerosis, type of anomaly, type of aortic disease, presurgical parameter values of renal function, type of surgical approach (laparatomy or retroperitoneal approach, classification of the renal isthmus, reimplantation of renal arteries and perioperative morbidity and mortality. Results. Twenty patients were males In 30 (70% patients we diagnosed a horse-shoe kidney and in 10 (30% ectopic kidney. In the cases of ruptured aneurysm of the abdominal aorta the diagnosis was made by ultrasound findings. Pre-surgically, renal anomalies were confirmed in all patients, except in those with a ruptured aneurysm who underwent urgent surgery. In all patients we applied medial laparatomy, except in those with a thoracoabdominal aneurysm type IV, when the retroperitonal approach was necessary. On average the patients were under follow-up for 6.2 years (from 6 months to 17 years. Conclusion. Under our conditions, the so-called double clamp technique with the preservation of the kidney gave best results in the patients with renal anomalies and aortic disease.

  16. Manifestation of peripherial coding in the effect of increasing loudness and enhanced discrimination of the intensity of tone bursts before and after tone burst noise (United States)

    Rimskaya-Korsavkova, L. K.


    To find the possible reasons for the midlevel elevation of the Weber fraction in intensity discrimination of a tone burst, a comparison was performed for the complementary distributions of spike activity of an ensemble of space nerves, such as the distribution of time instants when spikes occur, the distribution of interspike intervals, and the autocorrelation function. The distribution properties were detected in a poststimulus histogram, an interspike interval histogram, and an autocorrelation histogram—all obtained from the reaction of an ensemble of model space nerves in response to an auditory noise burst-useful tone burst complex. Two configurations were used: in the first, the peak amplitude of the tone burst was varied and the noise amplitude was fixed; in the other, the tone burst amplitude was fixed and the noise amplitude was varied. Noise could precede or follow the tone burst. The noise and tone burst durations, as well as the interval between them, was 4 kHz and corresponded to the characteristic frequencies of the model space nerves. The profiles of all the mentioned histograms had two maxima. The values and the positions of the maxima in the poststimulus histogram corresponded to the amplitudes and mutual time position of the noise and the tone burst. The maximum that occurred in response to the tone burst action could be a basis for the formation of the loudness of the latter (explicit loudness). However, the positions of the maxima in the other two histograms did not depend on the positions of tone bursts and noise in the combinations. The first maximum fell in short intervals and united intervals corresponding to the noise and tone burst durations. The second maximum fell in intervals corresponding to a tone burst delay with respect to noise, and its value was proportional to the noise amplitude or tone burst amplitude that was smaller in the complex. An increase in tone burst or noise amplitudes was caused by nonlinear variations in the two

  17. End-stage renal disease causes an imbalance between endothelial and smooth muscle progenitor cells

    NARCIS (Netherlands)

    Westerweel, Peter E; Hoefer, Imo E; Blankestijn, Peter J; de Bree, Petra; Groeneveld, Dafna; van Oostrom, Olivia; Braam, Branko; Koomans, Hein A; Verhaar, Marianne C


    Patients with end-stage renal disease (ESRD) on hemodialysis have an increased risk of cardiovascular disease (CVD). Circulating endothelial progenitor cells (EPC) contribute to vascular regeneration and repair, thereby protecting against CVD. However, circulating smooth muscle progenitor cells (SPC

  18. Reduced plasma total homocysteine concentrations in Type 1 diabetes mellitus is determined by increased renal clearance.

    NARCIS (Netherlands)

    Veldman, B.A.J.; Vervoort, G.M.M.; Blom, H.J.; Smits, P.


    INTRODUCTION: Elevated plasma levels of total homocysteine are related to the development of vascular complications. Patients with diabetes mellitus are particularly at risk for the development of these complications. Several factors determine plasma total homocysteine including renal function.

  19. The intensitive DL of tones: dependence of signal/masker ratio on tone level and on spectrum of added noise. (United States)

    Greenwood, D D


    In Greenwood [J. Acoust. Soc. Am. 33, 484-502 (1961a)] the ratio of masked signal threshold to masker level (S/M) decreased about 4 dB at a masker level of about 50 dB SL, the 'transition' level, when noise bands were subcritical but not when supercritical. Schlauch et al. [J. Acoust. Soc. Am. 71, S73 (1982)] report a related result. A pilot study [Greenwood, Harvard Psychoacoustic Lab. Status Report 37, 8-9 (1961)] in which pure tones masked identical tones in-phase showed a larger change in S/M. Detailed tone-tone growth-of-masking curves from over a dozen subjects in 1967-69, and in 1960, are reported here. A transition in slope, of variable abruptness, often begins to occur at about 50 dB SL, dropping S/M ratio by 6 to 8 dB or more [Rabinowitz et al., J. Acoust. Soc. Am. 35, 1053 (1976)]; the curves sometimes possess two segments, sometimes are simply convex. All have overall slopes less than 1.0, known also as the 'near miss'. Consistent with other results [Zwicker, Acustica 6, 365-396 (1956); Viemeister, J. Acoust. Soc. Am. 51, 1265-1296 (1972); Moore and Raab, J. Acoust. Soc. Am. 55, 1049-1060 (1974)], addition of low-level wide-band and high-pass noise was found to counteract the change in S/M, i.e., to raise the high-level section of the growth-of-masking curve. However, the ability of narrow 'band-pass' noise to exert this effect was greatest when added at a frequency ratio (band/masking-tone) of 1.3 to 1.5, which seems more closely to link the effects of added noise to the effects of increasing a masking band from sub- to supercritical width (above). Interpretation of the decrease in DL with level begins by noting that the 'transition' level correlates approximately with the level at which a primary unit population excited by a given pure tone begins rapidly to expand basally. Underlying this, the basalward shift of a tone's displacement envelope peak accelerates at about the same level [Rhode, J. Acoust. Soc. Am. 49, 1218-1231 (1971); Sellick et al., J

  20. tion of vascular malformations

    African Journals Online (AJOL)

    classification of vascular anomalies outside of the central ... The current classification of CNS vascular ... tural proteins within the wall of caver- .... ing (or established) loss of function or a threat to ..... natural history of the strawberry nevus. Arch.