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Sample records for renal reabsorptive capacity

  1. Recent advances in renal tubular calcium reabsorption.

    NARCIS (Netherlands)

    Mensenkamp, A.R.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2006-01-01

    PURPOSE OF REVIEW: Knowledge of renal Ca2+ reabsorption has evolved greatly in recent years. This review focuses on two recent discoveries concerning passive and active Ca2+ reabsorption. RECENT FINDINGS: The thiazide diuretics are known for their hypocalciuric effect. Recently, it has been demonstr

  2. Intestinal absorption and renal reabsorption of calcium throughout postnatal development.

    Science.gov (United States)

    Beggs, Megan R; Alexander, R Todd

    2017-04-01

    Calcium is vital for many physiological functions including bone mineralization. Postnatal deposition of calcium into bone is greatest in infancy and continues through childhood and adolescence until peek mineral density is reached in early adulthood. Thereafter, bone mineral density remains static until it eventually declines in later life. A positive calcium balance, i.e. more calcium absorbed than excreted, is crucial to bone deposition during growth and thus to peek bone mineral density. Dietary calcium is absorbed from the intestine into the blood. It is then filtered by the renal glomerulus and either reabsorbed by the tubule or excreted in the urine. Calcium can be (re)absorbed across intestinal and renal epithelia via both transcellular and paracellular pathways. Current evidence suggests that significant intestinal and renal calcium transport changes occur throughout development. However, the molecular details of these alterations are incompletely delineated. Here we first briefly review the current model of calcium transport in the intestine and renal tubule in the adult. Then, we describe what is known with regard to calcium handling through postnatal development, and how alterations may aid in mediating a positive calcium balance. The role of transcellular and paracellular calcium transport pathways and the contribution of specific intestinal and tubular segments vary with age. However, the current literature highlights knowledge gaps in how specifically intestinal and renal calcium (re)absorption occurs early in postnatal development. Future research should clarify the specific changes in calcium transport throughout early postnatal development including mediators of these alterations enabling appropriate bone mineralization. Impact statement This mini review outlines the current state of knowledge pertaining to the molecules and mechanisms maintaining a positive calcium balance throughout postnatal development. This process is essential to achieving

  3. Stokes flow through a slit with periodic reabsorption: An application to renal tubule

    Directory of Open Access Journals (Sweden)

    T. Haroon

    2016-06-01

    Full Text Available This paper is concerned with the Stokes flow of an incompressible viscous fluid through a slit with periodic reabsorption at the walls. The momentum equation for the two dimensional flow is exactly solved in terms of stream function for two different cases of boundary conditions. Dimensional forms of stream function, velocity components, axial flow rate, pressure distribution, mean pressure drop, wall shear stress, fractional reabsorption and leakage flux are obtained. The points of maximum velocity components are also identified for fixed axial distance. Using physiological data of rat kidney, the theoretical values of periodic reabsorption and pressure drop for various values of fractional reabsorption are tabulated. The graphs of flow properties for both the cases are compared with the case of uniform reabsorption. It is shown that the periodic reabsorption parameter for both the cases plays a vital role in altering the flow properties, which are useful in analyzing flow behavior during the reabsorption of glomerular filtrate through a renal tubule in normal and diseased conditions. It is found that 50% reabsorption of fluid from a single nephron can be achieved by setting α=3.197500134cm for one of the cases which indicates that there is a need of artificial kidney for survival. In case 2, a minor treatment is needed as the value of α for 80% reabsorption is not possible. Streamlines are also drawn to analyze the flow behavior through an abnormal renal tubule.

  4. Why Do SGLT2 Inhibitors Inhibit Only 30–50% of Renal Glucose Reabsorption in Humans?

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    Liu, Jiwen; Lee, TaeWeon; DeFronzo, Ralph A.

    2012-01-01

    Sodium glucose cotransporter 2 (SGLT2) inhibition is a novel and promising treatment for diabetes under late-stage clinical development. It generally is accepted that SGLT2 mediates 90% of renal glucose reabsorption. However, SGLT2 inhibitors in clinical development inhibit only 30–50% of the filtered glucose load. Why are they unable to inhibit 90% of glucose reabsorption in humans? We will try to provide an explanation to this puzzle in this perspective analysis of the unique pharmacokineti...

  5. Cubilin is an albumin binding protein important for renal tubular albumin reabsorption.

    Science.gov (United States)

    Birn, H; Fyfe, J C; Jacobsen, C; Mounier, F; Verroust, P J; Orskov, H; Willnow, T E; Moestrup, S K; Christensen, E I

    2000-05-01

    Using affinity chromatography and surface plasmon resonance analysis, we have identified cubilin, a 460-kDa receptor heavily expressed in kidney proximal tubule epithelial cells, as an albumin binding protein. Dogs with a functional defect in cubilin excrete large amounts of albumin in combination with virtually abolished proximal tubule reabsorption, showing the critical role for cubilin in the uptake of albumin by the proximal tubule. Also, by immunoblotting and immunocytochemistry we show that previously identified low-molecular-weight renal albumin binding proteins are fragments of cubilin. In addition, we find that mice lacking the endocytic receptor megalin show altered urinary excretion, and reduced tubular reabsorption, of albumin. Because cubilin has been shown to colocalize and interact with megalin, we propose a mechanism of albumin reabsorption mediated by both of these proteins. This process may prove important for understanding interstitial renal inflammation and fibrosis caused by proximal tubule uptake of an increased load of filtered albumin.

  6. Renal haemodynamics, sodium and water reabsorption during continuous intravenous infusion of recombinant interleukin-2

    DEFF Research Database (Denmark)

    Geertsen, P F; von der Maase, H; Olsen, Niels Vidiendal

    1998-01-01

    ) and 48 h post therapy. Cardiac output was measured by impedance cardiography. Effective renal plasma flow and glomerular filtration rate were determined by the renal clearances of 131I-hippuran and 99mTc-diethylenetriaminepenta-acetic acid (DTPA) respectively. Renal clearance of lithium (CLi) was used....../82) ml/min (P=0.04). The urinary excretion rate of thromboxane B2 and the ratio between excretion rates of thromboxane B2 and 6-keto-prostaglandin-F1alpha increased by 98% (P=0.022) and 175% (P=0.022) respectively. 4. The study suggests a specific recombinant interleukin-2-induced renal vasoconstrictor...... effect. Changes in renal prostaglandin synthesis may contribute to the decrease in renal blood flow. The lithium clearance data suggest that an increased proximal tubular reabsorption rate may contribute to the decreased sodium clearance during recombinant interleukin-2 treatment....

  7. Cubilin Is Essential for Albumin Reabsorption in the Renal Proximal Tubule

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    Amsellem, S.; Gburek, J.; Hamard, G.; Nielsen, R.; Willnow, T.E.; Devuyst, O.; Nexo, E.; Verroust, P. J.; Christensen, E I; Kozyraki, R.

    2010-01-01

    Receptor-mediated endocytosis is responsible for protein reabsorption in the proximal tubule. This process involves two interacting receptors, megalin and cubilin, which form a complex with amnionless. Whether these proteins function in parallel or as part of an integrated system is not well understood. Here, we report the renal effects of genetic ablation of cubilin, with or without concomitant ablation of megalin, using a conditional Cre-loxP system. We observed that proximal tubule cells d...

  8. Cubilin is essential for albumin reabsorption in the renal proximal tubule.

    Science.gov (United States)

    Amsellem, Sabine; Gburek, Jakub; Hamard, Ghislaine; Nielsen, Rikke; Willnow, Thomas E; Devuyst, Olivier; Nexo, Ebba; Verroust, Pierre J; Christensen, Erik I; Kozyraki, Renata

    2010-11-01

    Receptor-mediated endocytosis is responsible for protein reabsorption in the proximal tubule. This process involves two interacting receptors, megalin and cubilin, which form a complex with amnionless. Whether these proteins function in parallel or as part of an integrated system is not well understood. Here, we report the renal effects of genetic ablation of cubilin, with or without concomitant ablation of megalin, using a conditional Cre-loxP system. We observed that proximal tubule cells did not localize amnionless to the plasma membrane in the absence of cubilin, indicating a mutual dependency of cubilin and amnionless to form a functional membrane receptor complex. The cubilin-amnionless complex mediated internalization of intrinsic factor-vitamin B12 complexes, but megalin considerably increased the uptake. Furthermore, cubilin-deficient mice exhibited markedly decreased uptake of albumin by proximal tubule cells and resultant albuminuria. Inactivation of both megalin and cubilin did not increase albuminuria, indicating that the main role of megalin in albumin reabsorption is to drive the internalization of cubilin-albumin complexes. In contrast, cubulin deficiency did not affect urinary tubular uptake or excretion of vitamin D-binding protein (DBP), which binds cubilin and megalin. In addition, we observed cubilin-independent reabsorption of the "specific" cubilin ligands transferrin, CC16, and apoA-I, suggesting a role for megalin and perhaps other receptors in their reabsorption. In summary, with regard to albumin, cubilin is essential for its reabsorption by proximal tubule cells, and megalin drives internalization of cubilin-albumin complexes. These genetic models will allow further analysis of protein trafficking in the progression of proteinuric renal diseases.

  9. Renal tubular reabsorption of sodium and water during infusion of low-dose dopamine in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Using the renal clearance of lithium (CLi) as an index of proximal tubular outflow of sodium and water, together with simultaneous measurements of effective renal plasma flow, glomerular filtration rate (GFR) and sodium clearance (CNa), renal function and the tubular segmental reabsorption rates...... of sodium and water during dopamine infusion (3 micrograms min-1 kg-1) were estimated in 12 normal volunteers. 2. CNa increased by 128% (P less than 0.001). Effective renal plasma flow and GFR increased by 43% (P less than 0.001) and 9% (P less than 0.01), respectively. CLi increased in all subjects by......, on average, 44% (P less than 0.001). Fractional proximal reabsorption [1-(CLi/GFR)] decreased by 13% after dopamine infusion (P less than 0.001), and estimated absolute proximal reabsorption rate (GFR-CLi) decreased by 8% (P less than 0.01). Absolute distal sodium reabsorption rate [(CLi-CNa) x PNa, where...

  10. Renal tubular reabsorption of sodium and water during infusion of low-dose dopamine in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Using the renal clearance of lithium (CLi) as an index of proximal tubular outflow of sodium and water, together with simultaneous measurements of effective renal plasma flow, glomerular filtration rate (GFR) and sodium clearance (CNa), renal function and the tubular segmental reabsorption rates...... of sodium and water during dopamine infusion (3 micrograms min-1 kg-1) were estimated in 12 normal volunteers. 2. CNa increased by 128% (P less than 0.001). Effective renal plasma flow and GFR increased by 43% (P less than 0.001) and 9% (P less than 0.01), respectively. CLi increased in all subjects by......, on average, 44% (P less than 0.001). Fractional proximal reabsorption [1-(CLi/GFR)] decreased by 13% after dopamine infusion (P less than 0.001), and estimated absolute proximal reabsorption rate (GFR-CLi) decreased by 8% (P less than 0.01). Absolute distal sodium reabsorption rate [(CLi-CNa) x PNa, where...

  11. Megalin is essential for renal proximal tubule reabsorption and accumulation of transcobalamin-B(12)

    DEFF Research Database (Denmark)

    Birn, Henrik; Willnow, Thomas E; Nielsen, Rikke;

    2002-01-01

    Megalin has previously been shown to bind and mediate endocytosis of transcobalamin (TC)-B(12). However, the physiological significance of this has not been established, and other TC-B(12) binding proteins have been suggested to mediate renal uptake of this vitamin complex. The present study...... demonstrates by the use of megalin-deficient mice that megalin is, in fact, essential for the normal renal reabsorption of TC-vitamin B(12) and for renal accumulation of this highly conserved vitamin. Megalin-deficient mice excrete increased amounts of TC and B(12) in the urine, revealing a defective renal...... tubular uptake of TC-B(12). The urinary B(12) excretion is increased approximately 4-fold, resulting in an approximately 28-fold higher renal B(12) clearance. This is associated with an approximately 4-fold decrease in B(12) content in megalin-deficient kidney cortex. Thus megalin is important to prevent...

  12. Renal carbonic anhydrases are involved in the reabsorption of endogenous nitrite.

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    Chobanyan-Jürgens, Kristine; Schwarz, Alexandra; Böhmer, Anke; Beckmann, Bibiana; Gutzki, Frank-Mathias; Michaelsen, Jan T; Stichtenoth, Dirk O; Tsikas, Dimitrios

    2012-02-15

    Nitrite (ONO(-)) exerts nitric oxide (NO)-related biological actions and its concentration in the circulation may be of particular importance. Nitrite is excreted in the urine. Hence, the kidney may play an important role in nitrite/NO homeostasis in the vasculature. We investigated a possible involvement of renal carbonic anhydrases (CAs) in endogenous nitrite reabsorption in the proximal tubule. The potent CA inhibitor acetazolamide was administered orally to six healthy volunteers (5 mg/kg) and nitrite was measured in spot urine samples before and after administration. Acetazolamide increased abruptly nitrite excretion in the urine, strongly suggesting that renal CAs are involved in nitrite reabsorption in healthy humans. Additional in vitro experiments support our hypothesis that nitrite reacts with CO(2), analogous to the reaction of peroxynitrite (ONOO(-)) with CO(2), to form acid-labile nitrito carbonate [ONOC(O)O(-)]. We assume that this reaction is catalyzed by CAs and that nitrito carbonate represents the nitrite form that is actively transported into the kidney. The significance of nitrite reabsorption in the kidney and the underlying mechanisms, notably a direct involvement of CAs in the reaction between nitrite and CO(2), remain to be elucidated.

  13. Mangiferin Inhibits Renal Urate Reabsorption by Modulating Urate Transporters in Experimental Hyperuricemia.

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    Yang, Hua; Gao, Lihui; Niu, Yanfen; Zhou, Yuanfang; Lin, Hua; Jiang, Jing; Kong, Xiangfu; Liu, Xu; Li, Ling

    2015-01-01

    Mangiferin, a natural glucosyl xanthone from the leaves of Mangifera indica L., was previously shown to exert potent hypouricemic effects associated with inhibition of the activity of xanthine dehydrogenase/oxidase. The present study aimed to evaluate its uricosuric effect and possible molecular mechanisms underlying the renal urate transporters responsible for urate reabsorption in vivo. Mangiferin (1.5-24.0 mg/kg) was administered intragastrically to hyperuricemic mice and rats induced by the intraperitoneal injection of uric acid and potassium oxonate, respectively. The uricosuric effect was evaluated by determining the serum and urinary urate levels as well as fractional excretion of uric acid (FEUA). The mRNA and protein levels of renal urate-anion transporter 1 (URAT1), organic anion transporter 10 (OAT10), glucose transporter 9 (GLUT9), and PDZ domain-containing protein (PDZK1) were analyzed. The administration of mangiferin significantly decreased the serum urate levels in hyperuricemic mice in a dose- and time-dependent manner. In hyperuricemic rats, mangiferin also reduced the serum urate levels and increased the urinary urate levels and FEUA. These results indicate that mangiferin has uricosuric effects. Further examination showed that mangiferin markedly inhibited the mRNA and protein expression of renal URAT1, OAT10, and GLUT9 in hyperuricemic rats, but did not interfere with PDZK1 expression. Taken together, these findings suggest that mangiferin promotes urate excretion by the kidney, which may be related to the inhibition of urate reabsorption via downregulation of renal urate transporters.

  14. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans.

    Science.gov (United States)

    Lu, Yasong; Griffen, Steven C; Boulton, David W; Leil, Tarek A

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2 modulation.

  15. Chronic glucose infusion causes sustained increases in tubular sodium reabsorption and renal blood flow in dogs.

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    Brands, Michael W; Bell, Tracy D; Rodriquez, Nancy A; Polavarapu, Praveen; Panteleyev, Dmitriy

    2009-02-01

    This study tested the hypothesis that inducing hyperinsulinemia and hyperglycemia in dogs, by infusing glucose chronically intravenously, would increase tubular sodium reabsorption and cause hypertension. Glucose was infused for 6 days (14 mg.kg(-1).min(-1) iv) in five uninephrectomized (UNX) dogs. Mean arterial pressure (MAP) and renal blood flow (RBF) were measured 18 h/day using DSI pressure units and Transonic flow probes, respectively. Urinary sodium excretion (UNaV) decreased significantly on day 1 and remained decreased over the 6 days, coupled with a significant, sustained increase in RBF, averaging approximately 20% above control on day 6. Glomerular filtration rate and plasma renin activity (PRA) also increased. However, although MAP tended to increase, this was not statistically significant. Therefore, the glucose infusion was repeated in six dogs with 70% surgical reduction in kidney mass (RKM) and high salt intake. Blood glucose and plasma insulin increased similar to the UNX dogs, and there was significant sodium retention, but MAP still did not increase. Interestingly, the increases in PRA and RBF were prevented in the RKM dogs. The decrease in UNaV, increased RBF, and slightly elevated MAP show that glucose infusion in dogs caused a sustained increase in tubular sodium reabsorption by a mechanism independent of pressure natriuresis. The accompanying increase in PRA, together with the failure of either RBF or PRA to increase in the RKM dogs, suggests the site of tubular reabsorption was before the macula densa. However, the volume retention and peripheral edema suggest that systemic vasodilation offsets any potential renal actions to increase MAP in this experimental model in dogs.

  16. Local pH domains regulate NHE3-mediated Na+ reabsorption in the renal proximal tubule

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    Burford, James L.; McDonough, Alicia A.; Holstein-Rathlou, Niels-Henrik; Peti-Peterdi, Janos

    2014-01-01

    The proximal tubule Na+/H+ exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base of the brush border, where NHE3 activity is reduced. This NHE3 redistribution is assumed to provoke pressure natriuresis; however, it is unclear how NHE3 redistribution per se reduces NHE3 activity. To investigate if the distribution of NHE3 in the brush border can change the reabsorption rate, we constructed a spatiotemporal mathematical model of NHE3-mediated Na+ reabsorption across a proximal tubule cell and compared the model results with in vivo experiments in rats. The model predicts that when NHE3 is localized exclusively at the base of the brush border, it creates local pH microdomains that reduce NHE3 activity by >30%. We tested the model's prediction experimentally: the rat kidney cortex was loaded with the pH-sensitive fluorescent dye BCECF, and cells of the proximal tubule were imaged in vivo using confocal fluorescence microscopy before and after an increase of blood pressure by ∼50 mmHg. The experimental results supported the model by demonstrating that a rise of blood pressure induces the development of pH microdomains near the bottom of the brush border. These local changes in pH reduce NHE3 activity, which may explain the pressure natriuresis response to NHE3 redistribution. PMID:25298526

  17. Local pH domains regulate NHE3-mediated Na+ reabsorption in the renal proximal tubule

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Burford, James L.; McDonough, Alicia A.

    2014-01-01

    The proximal tubule Na+/H+ exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base o...

  18. Analysis of the effect of canagliflozin on renal glucose reabsorption and progression of hyperglycemia in zucker diabetic Fatty rats.

    Science.gov (United States)

    Kuriyama, Chiaki; Xu, Jun Zhi; Lee, Seunghun Paul; Qi, Jenson; Kimata, Hirotaka; Kakimoto, Tetsuhiro; Nakayama, Keiko; Watanabe, Yoshinori; Taniuchi, Nobuhiko; Hikida, Kumiko; Matsushita, Yasuaki; Arakawa, Kenji; Saito, Akira; Ueta, Kiichiro; Shiotani, Masaharu

    2014-11-01

    Sodium-glucose cotransporter 2 (SGLT2) plays a major role in renal glucose reabsorption. To analyze the potential of insulin-independent blood glucose control, the effects of the novel SGLT2 inhibitor canagliflozin on renal glucose reabsorption and the progression of hyperglycemia were analyzed in Zucker diabetic fatty (ZDF) rats. The transporter activity of recombinant human and rat SGLT2 was inhibited by canagliflozin, with 150- to 12,000-fold selectivity over other glucose transporters. Moreover, in vivo treatment with canagliflozin induced glucosuria in mice, rats, and dogs in a dose-dependent manner. It inhibited apparent glucose reabsorption by 55% in normoglycemic rats and by 94% in hyperglycemic rats. The inhibition of glucose reabsorption markedly reduced hyperglycemia in ZDF rats but did not induce hypoglycemia in normoglycemic animals. The change in urinary glucose excretion should not be used as a marker to predict the glycemic effects of this SGLT2 inhibitor. In ZDF rats, plasma glucose and HbA1c levels progressively increased with age, and pancreatic β-cell failure developed at 13 weeks of age. Treatment with canagliflozin for 8 weeks from the prediabetic stage suppressed the progression of hyperglycemia, prevented the decrease in plasma insulin levels, increased pancreatic insulin contents, and minimized the deterioration of islet structure. These results indicate that selective inhibition of SGLT2 with canagliflozin controls the progression of hyperglycemia by inhibiting renal glucose reabsorption in ZDF rats. In addition, the preservation of β-cell function suggests that canagliflozin treatment reduces glucose toxicity via an insulin-independent mechanism. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

  19. Use systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    Directory of Open Access Journals (Sweden)

    Yasong eLu

    2014-12-01

    Full Text Available In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1 and 2 (SGLT2 along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80% of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al. data (2013, and evaluated against clinical data from the literature (Mogensen, 1971;Wolf et al., 2009;Polidori et al., 2013. The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to

  20. The relationship between the renal reabsorption of cysteine and the lowered urinary pH in diabetics.

    Science.gov (United States)

    Ogawa, Susumu; Takiguchi, Junko; Shimizu, Manami; Nako, Kazuhiro; Okamura, Masashi; Kinouchi, Yoshitaka; Ito, Sadayoshi

    2017-03-22

    In diabetic patients, reduced urinary pH (UpH) is a predictive factor for cardiorenal-vascular disorders. Synthesis of glutathione, an anti-oxidative stress substance, is induced to counteract renal oxidative stress. UpH declines as glutamate is consumed, as does the synthesis of ammonia from glutamate. Glutathione is synthesized from glutamate and cysteine; however, in diabetes, the relationship between lowered UpH and the roles of renal amino acids is unknown. We, therefore, examined the relationship between amino-acid kinetics, UpH, and renal function. This cross-sectional study targeted 100 non-diabetic obese individuals (OG: obese group) and 100 diabetics (DG: diabetic group). We investigated their blood amino acids, urinary amino-acid excretion, the reabsorption rates of various amino acids, and their relationship with the UpH and estimated glomerular filtration rate (eGFR). The DG subjects showed higher blood cysteine concentration, urinary glutamate, and cysteine excretions than the OG subjects. Although the glutamate reabsorption rate declined in the DG subjects, that of cysteine increased due to the lowered eGFR. The DG subjects' urinary cysteine excretion correlated positively with UpH, making this urinary cysteine excretion the sole independent risk factor for lower UpH. In patients with diabetes, the reabsorbed amount of cysteine, not glutamate, regulates the amount of glutathione synthesis in the kidneys. The more an amount of cysteine reabsorption increases concurrently with a decline in eGFR, the more its urinary excretion decreases. Under these conditions, concurrently, the glutamate consumption then increases, resulting in decreased ammonia synthesis and UpH.

  1. Influence of urinary sodium excretion on the clinical assessment of renal tubular calcium reabsorption in hypercalcaemic man.

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    Ralston, S H; Gardner, M D; Dryburgh, F J; Cowan, R A; Boyle, I T

    1986-06-01

    The relation between urinary sodium excretion (NaE) and renal tubular calcium reabsorption (TmCa/GFR) was assessed in patients with hypercalcaemia associated with malignancy and primary hyperparathyroidism. On acute saline loading of seven normally hydrated patients with primary hyperparathyroidism and five patients with malignancy, raised values of TmCa/GFR were reduced to normal in most cases, in association with increases in NaE. The reduction in TmCa/GFR, which occurred, may have been due to a reduction in proximal tubular calcium reabsorption associated with sodium: this would have obscured the effect of humorally mediated increases in distal tubular calcium reabsorption, which are stimulated either by parathyroid hormone or by a putative humoral mediator in hypercalcaemia of malignancy. In patients who were normally hydrated NaE and TmCa/GFR were not significantly correlated. When data were included from patients who were dehydrated and from those undergoing acute saline loading, significant inverse correlations between NaE and TmCa/GFR were observed both in primary hyperparathyroidism (r = -0.49; p less than 0.02) and malignancy (r = -0.60; p less than 0.001). In clinical practice changes in TmCa/GFR associated with sodium seem to be of minor importance under normal circumstances, but they become evident at the upper and lower extremes of urinary sodium excretion. In clinical studies of renal calcium handling urinary sodium excretion must also be assessed, as interpreting TmCa/GFR data is difficult in states of excessive sodium loading or depletion.

  2. Inhibition of renal glucose reabsorption as a novel treatment for diabetes patients

    Directory of Open Access Journals (Sweden)

    Eugenio Cersosimo

    2014-03-01

    Full Text Available The importance of the kidney in glucose homeostasis has been recognized for many years. Recent observations indicating a greater role of renal glucose metabolism in various physiologic and pathologic conditions have rekindled the interest in renal glucose handling as a potential target for the treatment of diabetes. The enormous capacity of the proximal tubular cells to reabsorb the filtered glucose load entirely, utilizing the sodium-glucose co-transporter system (primarily SGLT-2, became the focus of attention. Original studies conducted in experimental animals with the nonspecific SGLT inhibitor phlorizin showed that hyperglycemia after pancreatectomy decreased as a result of forced glycosuria. Subsequently, several compounds with more selective SGLT-2 inhibition properties (“second-generation” were developed. Some agents made it into pre-clinical and clinical trials and a few have already been approved for commercial use in the treatment of type 2 diabetes. In general, a 6-month period of therapy with SGLT-2 inhibitors is followed by a mean urinary glucose excretion rate of ~80 g/day accompanied by a decline in fasting and postprandial glucose with average decreases in HgA1C ~1.0%. Concomitant body weight loss and a mild but consistent drop in blood pressure also have been reported. In contrast, transient polyuria, thirst with dehydration and occasional hypotension have been described early in the treatment. In addition, a significant increase in the occurrence of uro-genital infections, particularly in women has been documented with the use of SGLT-2 inhibitors. Conclusion: Although long-term cardiovascular, renal and bone/mineral effects are unknown SGLT-2 inhibitors, if used with caution and in the proper patient provide a unique insulin-independent therapeutic option in the management of obese type 2 diabetes patients.

  3. Cubilin is an albumin binding protein important for renal tubular albumin reabsorption

    OpenAIRE

    Birn, H.; J. C. Fyfe; Jacobsen, C.; Mounier, F.; Verroust, P. J.; Orskov, H; Willnow, T.E.; Moestrup, S K; Christensen, E I

    2000-01-01

    Using affinity chromatography and surface plasmon resonance analysis, we have identified cubilin, a 460-kDa receptor heavily expressed in kidney proximal tubule epithelial cells, as an albumin binding protein. Dogs with a functional defect in cubilin excrete large amounts of albumin in combination with virtually abolished proximal tubule reabsorption, showing the critical role for cubilin in the uptake of albumin by the proximal tubule. Also, by immunoblotting and immunocytochemistry we show ...

  4. Effect of renal nerve activity on tubular sodium and water reabsorption in dog kidneys as determined by the lithium clearance method

    DEFF Research Database (Denmark)

    Abildgaard, U; Holstein-Rathlou, N H; Leyssac, P P

    1986-01-01

    The reliability of the lithium clearance method in studies of the effect of renal nerve activity upon tubular sodium and water handling in the dog kidney was investigated. Following unilateral acute surgical denervation of the kidney a significant increase in urinary flow rate (40 +/- 7%), sodium...... reabsorption of sodium and water increased significantly by 9 +/- 2% and 8 +/- 2%. Low-frequency electrical stimulation of the distal nerve bundle of the denervated kidney caused a significant decrease in urine flow rate (37 +/- 6%), sodium clearance (31 +/- 4%), lithium clearance (17 +/- 5%) and in fractional...... lithium clearance (18 +/- 5%). Calculated absolute proximal reabsorption rate increased significantly by 17 +/- 3%, while calculated absolute rates of distal sodium and water reabsorption decreased significantly by 16 +/- 5% and 16 +/- 5%. These changes in tubular sodium and water reabsorption during...

  5. Effect of renal venous pressure elevation on tubular sodium and water reabsorption in the dog kidney

    DEFF Research Database (Denmark)

    Abildgaard, U; Amtorp, O; Holstein-Rathlou, N H;

    1988-01-01

    unaffected by acute surgical denervation of the kidneys. In contrast, chronic renal denervation or infusion of phentolamine (5 micrograms kg-1 min-1) into the renal artery eliminated the increase in APR and FPR during RVP elevation to 20 mmHg. Chronic, but not acute renal denervation depleted renal tissue...

  6. Local pH domains regulate NHE3-mediated Na⁺ reabsorption in the renal proximal tubule.

    Science.gov (United States)

    Brasen, Jens Christian; Burford, James L; McDonough, Alicia A; Holstein-Rathlou, Niels-Henrik; Peti-Peterdi, Janos

    2014-12-01

    The proximal tubule Na(+)/H(+) exchanger 3 (NHE3), located in the apical dense microvilli (brush border), plays a major role in the reabsorption of NaCl and water in the renal proximal tubule. In response to a rise in blood pressure NHE3 redistributes in the plane of the plasma membrane to the base of the brush border, where NHE3 activity is reduced. This NHE3 redistribution is assumed to provoke pressure natriuresis; however, it is unclear how NHE3 redistribution per se reduces NHE3 activity. To investigate if the distribution of NHE3 in the brush border can change the reabsorption rate, we constructed a spatiotemporal mathematical model of NHE3-mediated Na(+) reabsorption across a proximal tubule cell and compared the model results with in vivo experiments in rats. The model predicts that when NHE3 is localized exclusively at the base of the brush border, it creates local pH microdomains that reduce NHE3 activity by >30%. We tested the model's prediction experimentally: the rat kidney cortex was loaded with the pH-sensitive fluorescent dye BCECF, and cells of the proximal tubule were imaged in vivo using confocal fluorescence microscopy before and after an increase of blood pressure by ∼50 mmHg. The experimental results supported the model by demonstrating that a rise of blood pressure induces the development of pH microdomains near the bottom of the brush border. These local changes in pH reduce NHE3 activity, which may explain the pressure natriuresis response to NHE3 redistribution.

  7. Targeting renal glucose reabsorption for the treatment of type 2 diabetes mellitus using the SGLT2 inhibitor dapagliflozin.

    Science.gov (United States)

    Jabbour, Serge A; Whaley, Jean M; Tirmenstein, Mark; Poucher, Simon M; Reilly, Timothy P; Boulton, David W; Saye, Joanne; List, James F; Parikh, Shamik

    2012-07-01

    Sodium-glucose co-transporter 2 (SGLT2) plays a key role in glucose homeostasis as the key transporter responsible for most renal glucose reabsorption in the proximal tubules of the kidney. Dapagliflozin is a potent, selective, and reversible inhibitor of SGLT2 that lowers blood glucose levels in an insulin-independent fashion. This novel agent has been studied extensively in patients with type 2 diabetes mellitus (T2DM). In these clinical trials, dapagliflozin significantly decreased glycated hemoglobin and fasting plasma glucose levels when administered alone or as add-on treatment in patients who were already receiving metformin, a sulfonylurea (glimepiride), pioglitazone, or insulin. Moreover, dapagliflozin decreased body weight when taken as monotherapy or in combination with metformin, a sulfonylurea, or insulin, and mitigated weight gain in patients receiving pioglitazone. Consistent with preclinical toxicology studies, dapagliflozin has a manageable adverse event profile that is largely predictable from its mechanism of action. While there are no clinically significant negative effects on renal function or electrolytes, dapagliflozin treatment is associated with increased frequencies of urinary tract infections and vulvovaginitis/balanitis. With a mechanism of action that is distinct from and complementary to that of existing antihyperglycemic therapies, dapagliflozin is an effective antihyperglycemic agent that is well tolerated and may enhance weight loss. As such, dapagliflozin promises to become an important adjunctive therapy for comprehensive treatment of T2DM.

  8. Application of Physiologically-Based Pharmacokinetic Modeling to Explore the Role of Kidney Transporters in Renal Reabsorption of Perfluorooctanoic Acid in the Rat

    Science.gov (United States)

    Worley, Rachel Rogers; Fisher, Jeffrey

    2015-01-01

    Renal elimination and the resulting clearance of perfluorooctanoic acid (PFOA) from the serum exhibit pronounced sex differences in the adult rat. The literature suggests that this is largely due to hormonally regulated expression of organic anion transporters (OATs) on the apical and basolateral membranes of the proximal tubule cells that facilitate excretion and reabsorption of PFOA from the filtrate into the blood. Previously developed PBPK models of PFOA exposure in the rat have not been parameterized to specifically account for transporter-mediated renal elimination. We developed a PBPK model for PFOA in the male and female rat to explore the role of Oat1, Oat3, and Oatp1a1 in sex-specific renal reabsorption and excretion of PFOA. Descriptions of the kinetic behavior of these transporters were extrapolated from in vitro studies and the model was used to simulate time-course serum, liver, and urine data for intravenous (IV) and oral exposures in both sexes. Model predicted concentrations of PFOA in the liver, serum, and urine showed good agreement with experimental data for both the male and female rat indicating that in vitro derived physiological descriptions of transporter-mediated renal reabsorption can successfully predict sex-dependent excretion of PFOA in the rat. This study supports the hypothesis that sex-specific serum half-lives for PFOA are largely driven by expression of transporters in the kidney and contributes to the development of PBPK modeling as a tool for evaluating the role of transporters in renal clearance. PMID:26522833

  9. AKAP220 manages apical actin networks that coordinate aquaporin-2 location and renal water reabsorption.

    Science.gov (United States)

    Whiting, Jennifer L; Ogier, Leah; Forbush, Katherine A; Bucko, Paula; Gopalan, Janani; Seternes, Ole-Morten; Langeberg, Lorene K; Scott, John D

    2016-07-26

    Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation of an "actin barrier" that obstructs the passive transit of AQP2 to the plasma membrane. Bidirectional control of AQP2 trafficking is managed by hormones and signaling enzymes. We have discovered that vasopressin-independent facets of this homeostatic mechanism are under the control of A-Kinase Anchoring Protein 220 (AKAP220; product of the Akap11 gene). CRISPR/Cas9 gene editing and imaging approaches show that loss of AKAP220 disrupts apical actin networks in organoid cultures. Similar defects are evident in tissue sections from AKAP220-KO mice. Biochemical analysis of AKAP220-null kidney extracts detected reduced levels of active RhoA GTPase, a well-known modulator of the actin cytoskeleton. Fluorescent imaging of kidney sections from these genetically modified mice revealed that RhoA and AQP2 accumulate at the apical surface of the collecting duct. Consequently, these animals are unable to appropriately dilute urine in response to overhydration. We propose that membrane-proximal signaling complexes constrained by AKAP220 impact the actin barrier dynamics and AQP2 trafficking to ensure water homeostasis.

  10. Physiology and pathophysiology of the vasopressin-regulated renal water reabsorption.

    NARCIS (Netherlands)

    Boone, M.; Deen, P.M.T.

    2008-01-01

    To prevent dehydration, terrestrial animals and humans have developed a sensitive and versatile system to maintain their water homeostasis. In states of hypernatremia or hypovolemia, the antidiuretic hormone vasopressin (AVP) is released from the pituitary and binds its type-2 receptor in renal

  11. Exaggerated natriuretic response to isotonic volume expansion in hypertensive renal transplant recipients: evaluation of proximal and distal tubular reabsorption by simultaneous determination of renal plasma clearance of lithium and 51Cr-EDTA.

    Science.gov (United States)

    Nielsen, A H; Knudsen, F; Danielsen, H; Pedersen, E B; Fjeldborg, P; Madsen, M; Brøchner-Mortensen, J; Kornerup, H J

    1987-02-01

    In fourteen hypertensive and fourteen normotensive renal transplant recipients, and in a group of thirteen healthy controls, changes in natriuresis, glomerular filtration rate (GFR), and tubular reabsorption of sodium were determined in relation to intravenous infusion of 2 mmol isotonic sodium chloride per kg body weight. An exaggerated natriuresis was demonstrated in the hypertensive renal transplant recipients. This new finding indicates that the augmented natriuresis following plasma volume expansion, which is a characteristic finding in subjects with arterial hypertension, is not mediated by the renal nerves. Investigation of the tubular reabsorption rates of sodium by simultaneous determination of the renal clearance of 51Cr-EDTA and lithium showed that in the hypertensives the changes in tubular handling of sodium were different from those registered in the normotensive subjects. The increased sodium excretion in the hypertensive renal transplant recipients was caused by an increased output of sodium from the proximal tubules which was not fully compensated for by an increased distal reabsorption. Whether this increased delivery of sodium to the distal segments was caused by changes in GFR or in the proximal tubular reabsorption of sodium could not be clarified in the present study and warrants further investigations.

  12. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    OpenAIRE

    Lu, Yasong; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control...

  13. Use systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    OpenAIRE

    Yasong eLu; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control...

  14. Use systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    OpenAIRE

    Yasong eLu; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control...

  15. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    OpenAIRE

    Lu, Yasong; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control...

  16. Fluvastatin modulates renal water reabsorption in vivo through increased AQP2 availability at the apical plasma membrane of collecting duct cells.

    Science.gov (United States)

    Procino, Giuseppe; Barbieri, Claudia; Carmosino, Monica; Tamma, Grazia; Milano, Serena; De Benedictis, Leonarda; Mola, Maria Grazia; Lazo-Fernandez, Yoskaly; Valenti, Giovanna; Svelto, Maria

    2011-11-01

    X-linked nephrogenic diabetes insipidus (XNDI), a severe pathological condition characterized by greatly impaired urine-concentrating ability of the kidney, is caused by inactivating mutations in the V2 vasopressin receptor (V2R) gene. The lack of functional V2Rs prevents vasopressin-induced shuttling of aquaporin-2 (AQP2) water channels to the apical plasma membrane of kidney collecting duct principal cells, thus promoting water reabsorption from urine to the interstitium. At present, no specific pharmacological therapy exists for the treatment of XNDI. We have previously reported that the cholesterol-lowering drug lovastatin increases AQP2 membrane expression in renal cells in vitro. Here we report the novel finding that fluvastatin, another member of the statins family, greatly increases kidney water reabsorption in vivo in mice in a vasopressin-independent fashion. Consistent with this observation, fluvastatin is able to increase AQP2 membrane expression in the collecting duct of treated mice. Additional in vivo and in vitro experiments indicate that these effects of fluvastatin are most likely caused by fluvastatin-dependent changes in the prenylation status of key proteins regulating AQP2 trafficking in collecting duct cells. We identified members of the Rho and Rab families of proteins as possible candidates whose reduced prenylation might result in the accumulation of AQP2 at the plasma membrane. In conclusion, these results strongly suggest that fluvastatin, or other drugs of the statin family, may prove useful in the therapy of XNDI.

  17. Increase in SGLT1-mediated transport explains renal glucose reabsorption during genetic and pharmacological SGLT2 inhibition in euglycemia

    OpenAIRE

    Rieg, Timo; Masuda, Takahiro; Gerasimova, Maria; Mayoux, Eric; Platt, Kenneth; Powell, David R.; Thomson, Scott C.; Koepsell, Hermann; Vallon, Volker

    2013-01-01

    In the kidney, the sodium-glucose cotransporters SGLT2 and SGLT1 are thought to account for >90 and ∼3% of fractional glucose reabsorption (FGR), respectively. However, euglycemic humans treated with an SGLT2 inhibitor maintain an FGR of 40–50%, mimicking values in Sglt2 knockout mice. Here, we show that oral gavage with a selective SGLT2 inhibitor (SGLT2-I) dose dependently increased urinary glucose excretion (UGE) in wild-type (WT) mice. The dose-response curve was shifted leftward and the ...

  18. Recombinant human erythropoietin in humans down-regulates proximal renal tubular reabsorption and causes a fall in glomerular filtration rate

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Aachmann-Andersen, Niels Jacob; Oturai, Peter;

    2010-01-01

    rHuEPO elevates hemoglobin concentration both by increasing red blood cell volume and by a decrease in plasma volume. This study delineates the association of rHuEPO-induced changes in blood volumes with changes in the renin-aldosterone system and renal function. 16 healthy males were given rHuEPO...... tubular outflow and to assess segmental renal tubular handling of sodium and water. rHuEPO-induced increases in hematocrit occurred from day 10 onwards and was caused by both an increase in red cell volume and a fall in plasma volume. Well before that (from day 2 and throughout the treatment time), rHuEPO...... decreased plasma levels of renin and aldosterone (N = 8) by 21 - 33 % (P EPO values returned to baseline. On days 11 and 29 C(Li) increased (P

  19. Predictive capacity of pre-donation GFR and renal reserve capacity for donor renal function after living kidney donation

    NARCIS (Netherlands)

    Rook, M; Hofker, HS; van Son, WJ; van der Heide, JJH; Ploeg, RJ; Navis, GJ

    2006-01-01

    Kidney transplantation from living donors is important to reduce organ shortage. Reliable pre-operative estimation of post-donation renal function is essential. We evaluated the predictive potential of pre-donation glomerular filtration rate (GFR) (iothalamate) and renal reserve capacity for post-do

  20. Effect of cisplatin on renal haemodynamics and tubular function in the dog kidney

    DEFF Research Database (Denmark)

    Daugaard, G; Abildgaard, U; Holstein-Rathlou, N H

    1987-01-01

    Administration of cisplatin (5 mg/kg) to dogs results in polyuric renal failure due initially to a proximal tubular functional impairment. 48-72 h after the cisplatin administration the depressed renal function can be attributed to impairment of proximal as well as distal tubular reabsorptive...... capacities associated with increased renal vascular resistance. The polyuria seems to be due to the impaired reabsorption rate in the distal nephron segments....

  1. Deletion of the angiotensin II type 1 receptor–associated protein enhances renal sodium reabsorption and exacerbates angiotensin II–mediated hypertension

    OpenAIRE

    Ohsawa, Masato; Tamura, Kouichi; Wakui, Hiromichi; Maeda, Akinobu; Dejima, Toru; Kanaoka, Tomohiko; Azushima, Kengo; Uneda, Kazushi; Tsurumi-Ikeya, Yuko; Kobayashi, Ryu; Matsuda, Miyuki; Uchida, Shinichi; Toya, Yoshiyuki; Kobori, Hiroyuki; Nishiyama, Akira

    2014-01-01

    Angiotensin II type 1 receptor (AT1R)–associated protein (ATRAP) promotes AT1R internalization along with suppression of pathological activation of tissue AT1R signaling. However, the functional significance of ATRAP in renal sodium handling and blood pressure regulation under pathological stimuli is not fully resolved. Here we show the blood pressure of mice with a gene-targeted disruption of ATRAP was comparable to that of wild-type mice at baseline. However, in ATRAP-knockout mice, angiote...

  2. RENAL RESERVE FILTRATION CAPACITY IN GROWTH-HORMONE DEFICIENT SUBJECTS

    NARCIS (Netherlands)

    DULLAART, RPF; MEIJER, S; MARBACH, P; SLUITER, WJ

    In normal subjects, the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) acutely increase in response to infusion of amino acids and to low doses of dopamine. It is uncertain whether circulatory growth hormone (GH) is a permissive factor for these stimulatory effects. GFR and

  3. Overall renal and tubular function during infusion of amino acids in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during...... infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal...... tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma...

  4. Overall renal and tubular function during infusion of amino acids in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during...... infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal...... tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma...

  5. Cubilin and amnionless mediate protein reabsorption in Drosophila nephrocytes.

    Science.gov (United States)

    Zhang, Fujian; Zhao, Ying; Chao, Yufang; Muir, Katherine; Han, Zhe

    2013-02-01

    The insect nephrocyte and the mammalian glomerular podocyte are similar with regard to filtration, but it remains unclear whether there is an organ or cell type in flies that reabsorbs proteins. Here, we show that the Drosophila nephrocyte has molecular, structural, and functional similarities to the renal proximal tubule cell. We screened for genes required for nephrocyte function and identified two Drosophila genes encoding orthologs of mammalian cubilin and amnionless (AMN), two major receptors for protein reabsorption in the proximal tubule. In Drosophila, expression of dCubilin and dAMN is specific to nephrocytes, where they function as co-receptors for protein uptake. Targeted expression of human AMN in Drosophila nephrocytes was sufficient to rescue defective protein uptake induced by dAMN knockdown, suggesting evolutionary conservation of Cubilin/AMN co-receptors function from flies to humans. Furthermore, we found that Cubilin/AMN-mediated protein reabsorption is required for the maintenance of nephrocyte ultrastructure and fly survival under conditions of toxic stress. In conclusion, the insect nephrocyte combines filtration with protein reabsorption, using evolutionarily conserved genes and subcellular structures, suggesting that it can serve as a simplified model for both podocytes and the renal proximal tubule.

  6. Bicarbonate reabsorption by the kidney of the newborn rabbit.

    Science.gov (United States)

    van der Heijden, A J; Guignard, J P

    1989-01-01

    Bicarbonate reabsorption by the immature kidney in response to acute acid-base changes was assessed in 50 anesthetized newborn rabbits before the end of nephrogenesis. The normal newborn rabbit (age 5-12 days) is in a state of hypochloremic metabolic alkalosis (PHCO3-, 31.9 +/- 0.6 mmol/l; PCl-, 83.1 +/- 1.0) and excretes a hypertonic (Uosmol = 578 +/- 41 mosmol/kgH2O), alkaline (UpH = 7.40 +/- 0.15) urine containing 50 +/- 9 mmol/l Cl- and 13 +/- 4 mmol/l Na+. The alkalosis is probably generated by an alkaline load contained in the mother's milk and maintained by a state of chloride wasting and volume contraction. In this alkalotic model, bicarbonate reabsorption, expressed per milliliter glomerular filtration rate (GFR), correlates positively with arterial CO2 pressure (PaCO2). The ability of the immature kidney to reclaim filtered bicarbonate in response to an elevation of the plasma carbon dioxide tension remains unlimited up to PaCO2 of 110 mmHg (y = 20.7 + 0.15 x, r = 0.82, P less than 0.001). Hypercapnia is associated with a marked fall in GFR, so that the positive correlation between bicarbonate reabsorption and PaCO2 vanishes when the bicarbonate reabsorption rate is expressed in absolute terms. Bicarbonate reabsorption is strongly dependent on the filtered load during both acutely induced metabolic acidosis and alkalosis. The acid-base state of the newborn rabbit is in sharp contrast with that of most animal species, and the renal handling of bicarbonate as a function of GFR does not show signs of tubular immaturity.

  7. Hereditary tubular transport disorders: implications for renal handling of Ca2+ and Mg2+

    DEFF Research Database (Denmark)

    Dimke, Henrik; Hoenderop, Joost G; Bindels, René J;

    2010-01-01

    The kidney plays an important role in maintaining the systemic Ca2+ and Mg2+ balance. Thus the renal reabsorptive capacity of these cations can be amended to adapt to disturbances in plasma Ca2+ and Mg2+ concentrations. The reabsorption of Ca2+ and Mg2+ is driven by transport of other electrolytes......, sometimes through selective channels and often supported by hormonal stimuli. It is, therefore, not surprising that monogenic disorders affecting such renal processes may impose a shift in, or even completely blunt, the reabsorptive capacity of these divalent cations within the kidney. Accordingly, in Dent......'s disease, a disorder with defective proximal tubular transport, hypercalciuria is frequently observed. Dysfunctional thick ascending limb transport in Bartter's syndrome, familial hypomagnesaemia with hypercalciuria and nephrocalcinosis, and diseases associated with Ca2+-sensing receptor defects, markedly...

  8. Nephrectomy elicits impact of age and BMI on renal hemodynamics : Lower postdonation reserve capacity in older or overweight kidney donors

    NARCIS (Netherlands)

    Rook, M.; Bosma, R. J.; van Son, W. J.; Hofker, H. S.; van der Heide, J. J. Homan; ter Wee, P. M.; Ploeg, R. J.; Navis, G. J.

    2008-01-01

    Renal functional reserve could be relevant for the maintenance of renal function after kidney donation. Low-dose dopamine induces renal vasodilation with a rise in glomerular filtration rate (GFR) in healthy subjects and is thought to be a reflection of reserve capacity (RC). Older age and higher bo

  9. TRPV5-mediated Ca2+ Reabsorption and Hypercalciuria

    Science.gov (United States)

    Renkema, Kirsten Y.; Hoenderop, Joost G. J.; Bindels, René J. M.

    2007-04-01

    The concerted action of the intestine, kidney and bone results in the maintenance of a normal Ca2+ balance, a mechanism that is tightly controlled by the calciotropic hormones vitamin D, parathyroid hormone and calcitonin. Disturbances in the Ca2+ balance have been linked to diverse pathophysiological disorders like urolithiasis, hypertension, electroencephalogram abnormalities and rickets. Importantly, the final amount of Ca2+ that is released from the body is determined in the distal part of the nephron, where active Ca2+ reabsorption occurs. Here, Transient Receptor Potential Vanilloid member 5 (TRPV5), a highly Ca2+-selective channel, has been recognized as the gatekeeper of active Ca2+ reabsorption. The in vivo relevance of TRPV5 has been further investigated by the characterization of TRPV5 knockout (TRPV5-/-) mice, which exhibit severe disturbances in renal Ca2+ handling, such as profound hypercalciuria, intestinal Ca2+ hyperabsorption and reduced bone thickness. Hypercalciuria increases the risk of kidney stone formation in these mice. This review highlights our current knowledge about TRPV5-mediated Ca2+ reabsorption and emphasizes the physiological relevance and the clinical implications related to the TRPV5-/- mice model.

  10. Dietary supplementation with fish oil modifies renal reserve filtration capacity in postoperative, cyclosporin A-treated renal transplant recipients.

    Science.gov (United States)

    Homan van der Heide, J J; Bilo, H J; Donker, A J; Wilmink, J M; Sluiter, W J; Tegzess, A M

    1990-10-01

    The effect of a daily supplementation of 6 g fish oil (30% C20:5 omega-3 = EPA and 20% C22:6 omega-3 = DHA) for 1 month on renal function variables was investigated in a placebo-controlled (6 g coconut oil), prospective, randomized, double-blind study in acute postoperative cyclosporin A (CyA)-treated renal transplant recipients. Seventeen patients ingested placebo capsules (EPA-) and 14 patients fish oil (EPA+). Renal function tests were performed using the simultaneous determination of 125I-iothalamate and 131I-hippuran clearances for glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively. Renal reserve filtration capacity was assessed by dopamine infusion, amino acid infusion, and a combination of both stimuli. After 1 month there were no significant differences in rejection episodes, CyA dose, or CyA levels. In contrast to our earlier observations, serum creatinine, creatinine clearance, GFR, and ERPF did not differ between the EPA- and EPA+ groups. Filtration fraction (FF) differed significantly, being 0.21 in the EPA- group versus 0.26 in the EPA+ group. To exclude the possible influence of a rejection episode, the nonrejecting patients were analyzed separately, creating the subgroups EPA + re - and EPA - re -. These two groups were comparable in age, donor age, and GFR. The EPA + re-group had a significantly lower ERPF (164 ml/min per 1.73 m2) than the EPA-re- group (262 ml/min per 1.73 m2). FF was significantly higher in the EPA+ re-group (0.26) than in the EPA-re-group (0.21).(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Insulin resistance and hyperinsulinaemia in mild to moderate progressive chronic renal failure and its association with aerobic work capacity

    DEFF Research Database (Denmark)

    Eidemak, I; Feldt-Rasmussen, B; Kanstrup, I L;

    1995-01-01

    /I ratio in both groups. In conclusion, not only patients with end-stage chronic renal failure but also those with mild to moderate progressive chronic renal failure are insulin resistant and hyperinsulinaemic. The tissue sensitivity to insulin is correlated to the maximal aerobic work capacity suggesting...

  12. Insulin resistance and hyperinsulinaemia in mild to moderate progressive chronic renal failure and its association with aerobic work capacity

    DEFF Research Database (Denmark)

    Eidemak, I; Feldt-Rasmussen, B; Kanstrup, I L

    1995-01-01

    Tissue sensitivity to insulin and aerobic work capacity was measured in patients with mild to moderate progressive chronic renal failure. Twenty-nine non-diabetic patients with a glomerular filtration rate of 25 ml.min-1.1.73 m-2 (11-43) (median, range) and 15 sex, age, and body mass index matched....../I ratio in both groups. In conclusion, not only patients with end-stage chronic renal failure but also those with mild to moderate progressive chronic renal failure are insulin resistant and hyperinsulinaemic. The tissue sensitivity to insulin is correlated to the maximal aerobic work capacity suggesting...... control subjects with normal renal function were studied. Fasting blood glucose was comparable and in the non-diabetic range in the two groups as was the oral glucose tolerance test. Patients demonstrated hyperinsulinaemia both during fasting (p

  13. [Role of V1- and V2-receptors in mechanism of physiological paradox--an increase of reabsorption of the solute free water and simultaneous rise of diuresis].

    Science.gov (United States)

    Kanashkina, T A; Kuznetsova, A A; Shakhmatova, E I; Natochin, Iu V

    2006-10-01

    In experiments on non-anesthetized rats with administration into stomach of water (5 ml/100 g body mass) direct correlation has been found between an increase of diuresis and excretion of solute free water (r = 0.98, p diuresis and simultaneous rise reabsorption of solute free water (r = 0.8, p diuresis after the vasotocin injection is due to inhibition of sodium re- absorption, with the solute excretion fraction increasing from 2.6 +/- 0.2 % to 11.9 +/- 1.2, p diuresis with the simultaneous increase of reabsorption of solute free water - has been revealed at night hours in children with tendency for nocturnal enuresis (r = 0.64, p diuresis due to a decrease of sodium ion reabsorption in the ascending Henle loop limb. A problem is discussed of the homeostatic significance of a decrease of sodium reabsorption combined with an increase of solute-free water reabsorption; it is suggested that this phenomenon is based on a redistribution of reabsorption inside the nephron - a decrease of ion and water reabsorption in the initial parts of the nephron distal segment and an increase of solute free water reabsorption with the antidiuretic hormone-stimulated high osmotic permeability of terminal parts of renal tubules. An intraperitoneal injection of V1-anatagonist (OPC-21268) decreased the natriuretic component of response to arginine-vasotocin, while injection of V2-antagonist (OPC-31260) eliminated the antidiuretic component.

  14. Losartan reduces oxidative damage to renal DNA and conserves plasma antioxidant capacity in diabetic rats.

    Science.gov (United States)

    Lodovici, Maura; Bigagli, Elisabetta; Tarantini, Francesca; Di Serio, Claudia; Raimondi, Laura

    2015-11-01

    Increased reactive oxygen species (ROS) levels produced by hyperglycemia and angiotensin-II (AT-II) are considered among the pathogenic factors in the malignant transformation of diabetic renal cells. We aimed to investigate the potential role of AT-II in the increased cancer risk seen in diabetes; measuring oxidative damage to renal DNA and protective antioxidant defenses, including adiponectin (Adp) and plasma antioxidant capacity by the Ferric Reducing Ability of Plasma (FRAP) method. In the kidney of streptozotocin (STZ)-induced (55 mg/kg) diabetic rats either treated or not treated for 3 weeks with losartan, an AT-II type 1 receptor antagonist (20 mg/kg/day); we measured 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels, as an index of oxidative DNA damage, circulating Adp and FRAP. Diabetic rats showed significantly higher 8-oxodGuo levels in renal DNA (8.48 ± 0.98 × 10(-6) dG, mean ± SEM n = 11) than normoglycemic ones (1.18 ± 0.04 × 10(-6) dG, mean ± SEM, n=7) and lower plasma Adp and FRAP levels in comparison to normoglycemics. The treatment of diabetic rats with losartan significantly (P Losartan treatment preserves FRAP levels, reduces DNA oxidative injury and thus the carcinogenesis risk. Furthermore, our results indicate that Adp plasma levels are a further marker of oxidative injury to the kidney and confirm that it is an important part of the plasma antioxidant defense.

  15. FARMACOFISIOLOGÍA RENAL

    Directory of Open Access Journals (Sweden)

    Musso CG

    2014-03-01

    Full Text Available Renal physiology plays a key role in the pharmacokinetics of many drugs. Knowledge of the particularities of each nephron function (filtration, secretion, reabsorption and excretion and each of renal tubular transport mechanisms (simple diffusion, facilitated diffusion, facilitated transport, active transport, endocytosis and pinocytosis is fundamental to achieve better management of drug prescriptions.

  16. Renal transepithelial transport of nucleosides.

    Science.gov (United States)

    Nelson, J A; Vidale, E; Enigbokan, M

    1988-01-01

    Previous work from this and other laboratories has suggested that the mammalian kidney has unique mechanisms for handling purine nucleosides. For example, in humans and in mice, adenosine undergoes net renal reabsorption whereas deoxyadenosine is secreted [Kuttesch and Nelson: Cancer Chemother. Pharmacol. 8, 221 (1982)]. The relationships between these renal transport systems and classical renal organic cation and anion, carbohydrate, and cell membrane nucleoside transport carriers are not established. To investigate possible relationships between such carriers, we have tested effects of selected classical transport inhibitors on the renal clearances of adenosine, deoxyadenosine, 5'-deoxy-5-fluorouridine (5'-dFUR), and 5-fluorouracil in mice. The secretion of deoxyadenosine and 5'-dFUR, but not the reabsorption of adenosine or 5-fluorouracil, was prevented by the classical nucleoside transport inhibitors, dipyridamole and nitrobenzylthioinosine. Cimetidine, an inhibitor of the organic cation secretory system, also inhibited the secretion of 5'-dFUR, although it did not inhibit deoxyadenosine secretion in earlier studies [Nelson et al.: Biochem. Pharmacol. 32, 2323 (1983)]. The specific inhibitor of glucose renal reabsorption, phloridzin, failed to inhibit the reabsorption of adenosine or the secretion of deoxyadenosine. Failure of the nucleoside transport inhibitors and phloridzin to prevent adenosine reabsorption suggests that adenosine reabsorption may occur via a unique process. On the other hand, inhibition of the net secretion of deoxyadenosine and 5'-dFUR by dipyridamole and nitrobenzylthioinosine implies a role for the carrier that is sensitive to these compounds in the renal secretion (active transport) of these nucleosides.

  17. Renal aquaporins and sodium transporters with special focus on urinary tract obstruction

    DEFF Research Database (Denmark)

    Frøkiaer, Jørgen; Li, Chunling; Shi, Yimin

    2003-01-01

    seven aquaporins are expressed at distinct sites in the kidney and 4 members of this family (AQP1-4) have been demonstrated to play pivotal roles in the physiology and pathophysiology for renal regulation of body water balance. Osmotic equilibration via renal aquaporins is maintained by active transport...... of NaCl. The major sodium transporters and channels in the individual renal tubule segments have been identified and the regulation of these transporters and channels are fundamental for renal sodium reabsorption and for establishing the driving force. In this mini-review the role of renal aquaporins...... and sodium transporters and channels is briefly described and their key role for the impaired urinary concentrating capacity in response to urinary tract obstruction is reviewed. Thus this review updates previous detailed reviews (1-5)....

  18. Acute inhibition of NCC does not activate distal electrogenic Na+ reabsorption or kaliuresis.

    Science.gov (United States)

    Hunter, Robert W; Craigie, Eilidh; Homer, Natalie Z M; Mullins, John J; Bailey, Matthew A

    2014-02-15

    Na(+) reabsorption from the distal renal tubule involves electroneutral and electrogenic pathways, with the latter promoting K(+) excretion. The relative activities of these two pathways are tightly controlled, participating in the minute-to-minute regulation of systemic K(+) balance. The pathways are interdependent: the activity of the NaCl cotransporter (NCC) in the distal convoluted tubule influences the activity of the epithelial Na(+) channel (ENaC) downstream. This effect might be mediated by changes in distal Na(+) delivery per se or by molecular and structural adaptations in the connecting tubule and collecting ducts. We hypothesized that acute inhibition of NCC activity would cause an immediate increase in Na(+) flux through ENaC, with a concomitant increase in renal K(+) excretion. We tested this using renal clearance methodology in anesthetized mice, by the administration of hydrochlorothiazide (HCTZ) and/or benzamil (BZM) to exert specific blockade of NCC and ENaC, respectively. Bolus HCTZ elicited a natriuresis that was sustained for up to 110 min; urinary K(+) excretion was not affected. Furthermore, the magnitude of the natriuresis was no greater during concomitant BZM administration. This suggests that ENaC-mediated Na(+) reabsorption was not normally limited by Na(+) delivery, accounting for the absence of thiazide-induced kaliuresis. After dietary Na(+) restriction, HCTZ elicited a kaliuresis, but the natiuretic effect of HCTZ was not enhanced by BZM. Our findings support a model in which inhibition of NCC activity does not increase Na(+) reabsorption through ENaC solely by increasing distal Na(+) delivery but rather by inducing a molecular and structural adaptation in downstream nephron segments.

  19. Renoprotective capacities of non-erythropoietic EPO derivative, ARA290, following renal ischemia/reperfusion injury

    NARCIS (Netherlands)

    van Rijt, Willem G; Nieuwenhuijs-Moeke, Gertrude J; van Goor, Harry; Ottens, Petra J; Ploeg, Rutger J; Leuvenink, Henri G D

    2013-01-01

    Background: ARA290 is a non-erythropoietic EPO derivative which only binds to the cytoprotective receptor complex (EPOR2-beta cR(2)) consisting of two EPO-receptors (EPOR) and two beta common receptors (beta cR). ARA290 is renoprotective in renal ischemia/reperfusion (I/R). In a renal I/R model we f

  20. PGE2 receptor EP3 inhibits water reabsorption and contributes to polyuria and kidney injury in a streptozotocin-induced mouse model of diabetes.

    Science.gov (United States)

    Hassouneh, Ramzi; Nasrallah, Rania; Zimpelmann, Joe; Gutsol, Alex; Eckert, David; Ghossein, Jamie; Burns, Kevin D; Hébert, Richard L

    2016-06-01

    The first clinical manifestation of diabetes is polyuria. The prostaglandin E2 (PGE2) receptor EP3 antagonises arginine vasopressin (AVP)-mediated water reabsorption and its expression is increased in the diabetic kidney. The purpose of this work was to study the contribution of EP3 to diabetic polyuria and renal injury. Male Ep 3 (-/-) (also known as Ptger3 (-/-)) mice were treated with streptozotocin (STZ) to generate a mouse model of diabetes and renal function was evaluated after 12 weeks. Isolated collecting ducts (CDs) were microperfused to study the contribution of EP3 to AVP-mediated fluid reabsorption. Ep 3 (-/-)-STZ mice exhibited attenuated polyuria and increased urine osmolality compared with wild-type STZ (WT-STZ) mice, suggesting enhanced water reabsorption. Compared with WT-STZ mice, Ep 3 (-/-)-STZ mice also had increased protein expression of aquaporin-1, aquaporin-2, and urea transporter A1, and reduced urinary AVP excretion, but increased medullary V2 receptors. In vitro microperfusion studies indicated that Ep 3 (-/-) and WT-STZ CDs responded to AVP stimulation similarly to those of wild-type mice, with a 60% increase in fluid reabsorption. In WT non-injected and WT-STZ mice, EP3 activation with sulprostone (PGE2 analogue) abrogated AVP-mediated water reabsorption; this effect was absent in mice lacking EP3. A major finding of this work is that Ep 3 (-/-)-STZ mice showed blunted renal cyclooxygenase-2 protein expression, reduced renal hypertrophy, reduced hyperfiltration and reduced albuminuria, as well as diminished tubular dilation and nuclear cysts. Taken together, the data suggest that EP3 contributes to diabetic polyuria by inhibiting expression of aquaporins and that it promotes renal injury during diabetes. EP3 may prove to be a promising target for more selective management of diabetic kidney disease.

  1. Hypoxia-inducible factor-1α activation improves renal oxygenation and mitochondrial function in early chronic kidney disease.

    Science.gov (United States)

    Thomas, Joanna L; Pham, Hai; Li, Ying; Hall, Elanore; Perkins, Guy A; Ali, Sameh S; Patel, Hemal H; Singh, Prabhleen

    2017-08-01

    The pathophysiology of chronic kidney disease (CKD) is driven by alterations in surviving nephrons to sustain renal function with ongoing nephron loss. Oxygen supply-demand mismatch, due to hemodynamic adaptations, with resultant hypoxia, plays an important role in the pathophysiology in early CKD. We sought to investigate the underlying mechanisms of this mismatch. We utilized the subtotal nephrectomy (STN) model of CKD to investigate the alterations in renal oxygenation linked to sodium (Na) transport and mitochondrial function in the surviving nephrons. Oxygen delivery was significantly reduced in STN kidneys because of lower renal blood flow. Fractional oxygen extraction was significantly higher in STN. Tubular Na reabsorption was significantly lower per mole of oxygen consumed in STN. We hypothesized that decreased mitochondrial bioenergetic capacity may account for this and uncovered significant mitochondrial dysfunction in the early STN kidney: higher oxidative metabolism without an attendant increase in ATP levels, elevated superoxide levels, and alterations in mitochondrial morphology. We further investigated the effect of activation of hypoxia-inducible factor-1α (HIF-1α), a master regulator of cellular hypoxia response. We observed significant improvement in renal blood flow, glomerular filtration rate, and tubular Na reabsorption per mole of oxygen consumed with HIF-1α activation. Importantly, HIF-1α activation significantly lowered mitochondrial oxygen consumption and superoxide production and increased mitochondrial volume density. In conclusion, we report significant impairment of renal oxygenation and mitochondrial function at the early stages of CKD and demonstrate the beneficial role of HIF-1α activation on renal function and metabolism.

  2. Prevalence of renal dysfunction and its influence on functional capacity in elderly patients with stable chronic heart failure

    Directory of Open Access Journals (Sweden)

    Stanojević Dragana

    2012-01-01

    Full Text Available Bacground/Aim. Chronic heart failure (CHF is highly prevalent and constitutes an important public health problem around the world. In spite of a large number of pharmacological agents that successfully decrease mortality in CHF, the effects on exercise tolerance and quality of life are modest. Renal dysfunction is extremely common in patients with CHF and it is strongly related not only to increased mortality and morbidity but to a significant decrease in exercise tolerance, as well. The aim of our study was to investigate the prevalence and influence of the renal dysfunction on functional capacity in the elderly CHF patients. Methods. We included 127 patients aged over 65 years in a stable phase of CHF. The diagnosis of heart failure was based on the latest diagnostic principles of the European Society of Cardiology. The estimated glomerular filtration rate (eGRF was determined by the abbreviated Modification of Diet in Renal Disease (MDRD2 formula, and patients were categorized using the Kidney Disease Outcomes Quality Initiative (K/DOQI classification system. Functional capacity was determined by the 6 minute walking test (6MWT. Results. Among 127 patients, 90 were men. The average age was 72.5 ± 4.99 years and left ventricular ejection fraction (LVEF was 40.22 ± 9.89%. The average duration of CHF was 3.79 ± 4.84 years. Ninty three (73.2% patients were in New York Heart Association (NYHA class II and 34 (26.8% in NYHA class III. Normal renal function (eGFR ≥ 90 mL/min had 8.9% of participants, 57.8% had eGFR between 60-89 mL/min (stage 2 or mild reduction in GFR according to K/DOQI classification, 32.2% had eGFR between 30-59 mL/min (stage 3 or moderate reduction in GFR and 1.1% had eGFR between 15-29 mL/min (stage 4 or severe reduction in GFR. We found statistically significant correlation between eGFR and 6 minute walking distance (6MWD (r = 0.390, p < 0.001, LVEF (r = 0.268, p < 0.05, NYHA class (ς = -0.269, p < 0.05 and age (r = - 0

  3. Megalin and cubilin in proximal tubule protein reabsorption: from experimental models to human disease.

    Science.gov (United States)

    Nielsen, Rikke; Christensen, Erik Ilsø; Birn, Henrik

    2016-01-01

    Proximal tubule protein uptake is mediated by 2 receptors, megalin and cubilin. These receptors rescue a variety of filtered ligands, including biomarkers, essential vitamins, and hormones. Receptor gene knockout animal models have identified important functions of the receptors and have established their essential role in modulating urinary protein excretion. Rare genetic syndromes associated with dysfunction of these receptors have been identified and characterized, providing additional information on the importance of these receptors in humans. Using various disease models in combination with receptor gene knockout, the implications of receptor dysfunction in acute and chronic kidney injury have been explored and have pointed to potential new roles of these receptors. Based on data from animal models, this paper will review current knowledge on proximal tubule endocytic receptor function and regulation, and their role in renal development, protein reabsorption, albumin uptake, and normal renal physiology. These findings have implications for the pathophysiology and diagnosis of proteinuric renal diseases. We will examine the limitations of the different models and compare the findings to phenotypic observations in inherited human disorders associated with receptor dysfunction. Furthermore, evidence from receptor knockout mouse models as well as human observations suggesting a role of protein receptors for renal disease will be discussed in light of conditions such as chronic kidney disease, diabetes, and hypertension.

  4. Vasodilation and Exercise Capacity in Patients with End-Stage Renal Disease: A Prospective Proof-of-Concept Study.

    Science.gov (United States)

    Habedank, Dirk; Schefold, Joerg C; Bernhardt, Carolin; Karhausen, Tim; Doehner, Wolfram; Anker, Stefan D; Reinke, Petra

    2016-11-01

    Previous data have pointed to the fact that vascular function is significantly impaired in patients with end-stage renal disease (ESRD). We aimed to better characterise vasodilation and exercise capacity in both ESRD and chronic heart failure (CHF) patients. A total of 30 ESRD patients (23 male; mean age 45.7 ± 9.9 years) were included in a prospective proof-of-concept study at a tertiary care academic centre. The patients underwent forearm venous plethysmography with post-ischaemic peak blood flow (PF) and flow-dependent flow (FDF) testing as well as cardiopulmonary exercise testing during the morning of the day following the last haemodialysis. After matching for age, gender, and body mass index, the data were compared to 30 patients with CHF and 20 age-matched healthy controls. PF in ESRD patients was reduced when compared to that in CHF patients (12.5 ± 4.2 vs. 15.6 ± 6.9 ml/100 ml/min; p = 0.048) and healthy controls (26.4 ± 9.3 ml/100 ml/min; p proof-of-concept study, exercise capacity was relatively preserved, while vasodilative capacity was substantially impaired in ESRD patients. Additional studies are warranted to examine the underlying mechanisms and potential clinical implications of our findings.

  5. An experimental renal acidification defect in patients with hereditary fructose intolerance. II. Its distinction from classic renal tubular acidosis; its resemblance to the renal acidification defect associated with the Fanconi syndrome of children with cystinosis.

    Science.gov (United States)

    Morris, R C

    1968-07-01

    In adult patients with hereditary fructose intolerance (HFI) fructose induces a renal acidification defect characterized by (a) a 20-30% reduction in tubular reabsorption of bicarbonate (T HCO(3) (-)) at plasma bicarbonate concentrations ranging from 21-31 mEq/liter, (b) a maximal tubular reabsorption of bicarbonate (Tm HCO(3) (-)) of approximately 1.9 mEq/100 ml of glomerular filtrate, (c) disappearance of bicarbonaturia at plasma bicarbonate concentrations less than 15 mEq/liter, and (d) during moderately severe degrees of acidosis, a sustained capacity to maintain urinary pH at normal minima and to excrete acid at normal rates. In physiologic distinction from this defect, the renal acidification defect of patients with classic renal tubular acidosis is characterized by (a) just less than complete tubular reabsorption of bicarbonate at plasma bicarbonate concentrations of 26 mEq/liter or less, (b) a normal Tm HCO(3) (-) of approximately 2.8 mEq/100 ml of glomerular filtrate, and (c) during acidosis of an even severe degree, a quantitatively trivial bicarbonaturia, as well as (d) a urinary pH of greater than 6. That the fructose-induced renal acidification defect involves a reduced H(+) secretory capacity of the proximal nephron is supported by the magnitude of the reduction in T HCO(3) (-) (20-30%) and the simultaneous occurrence and the persistence throughout administration of fructose of impaired tubular reabsorption of phosphate, alpha amino nitrogen and uric acid.A reduced H(+) secretory capacity of the proximal nephron also appears operative in two unrelated children with hyperchloremic acidosis, Fanconi's syndrome, and cystinosis. In both, T HCO(3) (-) was reduced 20-30% at plasma bicarbonate concentrations ranging from 20-30 mEq/liter. The bicarbonaturia disappeared at plasma bicarbonate concentrations ranging from 15-18 mEq/liter, and during moderate degrees of acidosis, urinary pH decreased to less than 6, and the excretion rate of acid was normal.

  6. Study on the influence of retroperitoneal laparoscopic surgery for the body antioxidant capacity and pain stress state of patients with localized renal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yang-Tao Xu; Yan Pan; Zhi-Qing Sun; Chen-Xi Liu

    2016-01-01

    Objective:To study and analyze the influence of retroperitoneal laparoscopic surgery for the body antioxidant capacity and pain stress state of patients with localized renal carcinoma. Methods:A total of 56 patients with localized renal carcinoma in our hospital from January 2014 to August 2015 who were treated with surgery were divided into two groups according to the differences of surgery, 28 cases in control group were treated with open surgery, 28 cases in observation group were treated with retroperitoneal laparoscopic surgery, then the related indexes of antioxidant capacity and pain stress state of two groups before the surgery and at first, fifth and tenth day after the surgery were compared. Results:The related indexes of antioxidant capacity and pain stress state of two groups before the surgery all had no significant differences, while the related indexes of antioxidant capacity and pain stress state of observation group at first, fifth and tenth day after the surgery were all better than those of control group, the differences were all significant. Conclusion:The influence of retroperitoneal laparoscopic surgery for the body antioxidant capacity and pain stress state of patients with localized renal carcinoma is more active, so it is more suitable for the treatment of localized renal carcinoma.

  7. Relationship between urinary concentrating ability, arginine vasopressin in plasma and blood pressure after renal transplantation.

    Science.gov (United States)

    Pedersen, E B; Danielsen, H; Nielsen, A H; Knudsen, F; Jensen, T; Kornerup, H J; Madsen, M

    1985-06-01

    Arginine vasopressin (AVP) and serum osmolality (Sosm) were determined in plasma before and after a 24-h period of water deprivation in 19 patients with post-renal-transplant hypertension (group I), 14 patients with normal blood pressure after renal transplantation (group II), and 16 healthy control subjects (group III). Urine was collected in four periods of 6 h each for measurement of urine volume (V), urine osmolality (Uosm) and tubular capacity for reabsorption of water (Tc water). AVP and Sosm increased significantly in all groups. The AVP levels were the same in groups I and II, but higher in group I than III both before and after water deprivation. In group II, AVP was higher than in group III only after water deprivation; V was significantly reduced in all groups. In groups I and II, V, Tc water and Uosm were the same. In group III, V was significantly lower than in groups I and II in the last three 6-h periods, and in group III, Tc water was higher in the first 6-h period than in groups I and II. There was a significant positive correlation between AVP and Sosm in all groups. In conclusion, renal water excretion cannot be reduced as rapidly and to the same degree in renal transplant recipients as in control subjects because of a decreased renal capacity for reabsorption of water. The higher AVP level in the transplant recipients may be a compensatory phenomenon for the decreased responsiveness of the renal collecting ducts in the transplanted kidneys. The sensitivity of the osmoreceptors to changes in osmotic stimuli was normal.

  8. Patterned dye structures limit reabsorption in luminescent solar concentrators.

    Science.gov (United States)

    Tsoi, Shufen; Broer, Dirk J; Bastiaansen, Cees W; Debije, Michael G

    2010-11-08

    This work describes a method for limiting internal losses of a luminescent solar concentrator (LSC) due to reabsorption through patterning the fluorescent dye doped coating of the LSC. By engineering the dye coating into regular line patterns with fill factors ranging from 20 - 80%, the surface coverage of the dye molecules were reduced, thereby decreasing the probability of the re-emitted light encountering another dye molecule and the probability of reabsorption. Two types of fluorescent dyes with different quantum yields were used to examine the effects of patterning on LSC performance. The effect of various dimension and geometry of the patterns on the efficiency and edge emission of LSC are presented and analyzed.

  9. Segmental tubular sodium reabsorption in type 1 diabetes

    DEFF Research Database (Denmark)

    Dieperink, H; Eshøj, O; Leyssac, P P

    1993-01-01

    Segmental tubular sodium reabsorption in Type 1 (insulin-dependent) diabetes was measured in 36 patients in a cross-sectional study including one group (n = 13) without significant albuminuria (UalbV 1), one group (n = 16) with albuminuria in the range from 30 to 300 mg 24 h-1......, and a group (n = 7) with nephropathy (UalbV > 300 mg 24 h-1). Lithium clearance was used to measure end proximal delivery. From end proximal delivery, 51Cr-EDTA clearance (GFR) and sodium clearance, segmental tubular reabsorption was calculated. For all patients, GFR was directly correlated with end proximal...... delivery (r = 0.62, p 1, the direct correlation between GFR and end proximal delivery was also significant (r = 0.77, p

  10. Antagonistic Regulation of Parvalbumin Expression and Mitochondrial Calcium Handling Capacity in Renal Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Thomas Henzi

    by adjusting the relative mitochondrial volume and modifying the mitochondrial protein composition conceivably to increase their Ca2+-buffering/sequestration capacity.

  11. [Thyroxine treatment in acute renal failure (author's transl)].

    Science.gov (United States)

    Straub, E

    1975-11-01

    8 patients suffering from acute renal failure (shock kidney) with anuria extending over 3 to 5 days, were treated with L-thyroxine for 5 to 9 days (5-6 mug per kg body weight per day orally). Diuresis was restored within 34 to 46 hrs. Plasma levels of urea and creatinine decreased earlier and much more rapidly to normal than was to be expected from the natural history of the disease, indicating the prompt and extensive increase of glomerular filtration rate. Polyuria seemed less pronounced and also shortened as compared with the ordinary course of that form of sudden renal insufficiency. Obviously, the well-known diuretic response in the normal individual to high doses of thyroid hormones in not a factor in the induction of diuresis in acute renal failure. The tendency with L-thyroxine treatment to dilate the preglomerular arterial vessel is considered a consequence of the stimulation of sodium reabsorption in the upper nephron. High values of RPF and GFR, regularly observed in hyperthyroidism or after L-thyroxine administration, do not depend on any augmentation of cardiac output or on arterial hypertension, since such symptoms were missed in our patients and, in our view, such an interpretation is excluded by the very existence of the so-called autoregulation of the kidney which leaves RPF (and therefore GFR) independent of systemic blood pressure. The same intrarenal feed-back mechanism, normally adapting the glomerular blood supply to the resorptive capacity of the proximal-tubular epithelium (mediation via the juxta-glomerular apparatus), is responsible for the GFR- and RPF-raising effect of exogenous L-thyroxine in the intact kidney as well as in acute renal failure: both sodium reabsorption and sodium filtration are accelerated.--The special conditions under which L-thyroxine interferes with the pathogenetic process of acute renal failure, the latter being characterised by the critical insufficiency of tubular sodium reabsorption and therefore by

  12. Transient receptor potential vanilloid 1 activation by dietary capsaicin promotes urinary sodium excretion by inhibiting epithelial sodium channel α subunit-mediated sodium reabsorption.

    Science.gov (United States)

    Li, Li; Wang, Fei; Wei, Xing; Liang, Yi; Cui, Yuanting; Gao, Feng; Zhong, Jian; Pu, Yunfei; Zhao, Yu; Yan, Zhencheng; Arendshorst, William J; Nilius, Bernd; Chen, Jing; Liu, Daoyan; Zhu, Zhiming

    2014-08-01

    High salt (HS) intake contributes to the development of hypertension. Epithelial sodium channels play crucial roles in regulating renal sodium reabsorption and blood pressure. The renal transient receptor potential vanilloid 1 (TRPV1) cation channel can be activated by its agonist capsaicin. However, it is unknown whether dietary factors can act on urinary sodium excretion and renal epithelial sodium channel (ENaC) function. Here, we report that TRPV1 activation by dietary capsaicin increased urinary sodium excretion through reducing sodium reabsorption in wild-type (WT) mice on a HS diet but not in TRPV1(-/-) mice. The effect of capsaicin on urinary sodium excretion was involved in inhibiting αENaC and its related with-no-lysine kinase 1/serum- and glucocorticoid-inducible protein kinase 1 pathway in renal cortical collecting ducts of WT mice. Dietary capsaicin further reduced the increased αENaC activity in WT mice attributed to the HS diet. In contrast, this capsaicin effect was absent in TRPV1(-/-) mice. Immunoprecipitation study indicated αENaC specifically coexpressed and functionally interact with TRPV1 in renal cortical collecting ducts of WT mice. Additionally, ENaC activity and expression were suppressed by capsaicin-mediated TRPV1 activation in cultured M1-cortical collecting duct cells. Long-term dietary capsaicin prevented the development of high blood pressure in WT mice on a HS diet. It concludes that TRPV1 activation in the cortical collecting ducts by capsaicin increases urinary sodium excretion and avoids HS diet-induced hypertension through antagonizing αENaC-mediated urinary sodium reabsorption. Dietary capsaicin may represent a promising lifestyle intervention in populations exposed to a high dietary salt intake.

  13. Cellular transport of l-arginine determines renal medullary blood flow in control rats, but not in diabetic rats despite enhanced cellular uptake capacity.

    Science.gov (United States)

    Persson, Patrik; Fasching, Angelica; Teerlink, Tom; Hansell, Peter; Palm, Fredrik

    2017-02-01

    Diabetes mellitus is associated with decreased nitric oxide bioavailability thereby affecting renal blood flow regulation. Previous reports have demonstrated that cellular uptake of l-arginine is rate limiting for nitric oxide production and that plasma l-arginine concentration is decreased in diabetes. We therefore investigated whether regional renal blood flow regulation is affected by cellular l-arginine uptake in streptozotocin-induced diabetic rats. Rats were anesthetized with thiobutabarbital, and the left kidney was exposed. Total, cortical, and medullary renal blood flow was investigated before and after renal artery infusion of increasing doses of either l-homoarginine to inhibit cellular uptake of l-arginine or N(ω)-nitro- l-arginine methyl ester (l-NAME) to inhibit nitric oxide synthase. l-Homoarginine infusion did not affect total or cortical blood flow in any of the groups, but caused a dose-dependent reduction in medullary blood flow. l-NAME decreased total, cortical and medullary blood flow in both groups. However, the reductions in medullary blood flow in response to both l-homoarginine and l-NAME were more pronounced in the control groups compared with the diabetic groups. Isolated cortical tubular cells displayed similar l-arginine uptake capacity whereas medullary tubular cells isolated from diabetic rats had increased l-arginine uptake capacity. Diabetics had reduced l-arginine concentrations in plasma and medullary tissue but increased l-arginine concentration in cortical tissue. In conclusion, the reduced l-arginine availability in plasma and medullary tissue in diabetes results in reduced nitric oxide-mediated regulation of renal medullary hemodynamics. Cortical blood flow regulation displays less dependency on extracellular l-arginine and the upregulated cortical tissue l-arginine may protect cortical hemodynamics in diabetes.

  14. Effects of renal sympathetic denervation on exercise blood pressure, heart rate, and capacity in patients with resistant hypertension.

    Science.gov (United States)

    Ewen, Sebastian; Mahfoud, Felix; Linz, Dominik; Pöss, Janine; Cremers, Bodo; Kindermann, Ingrid; Laufs, Ulrich; Ukena, Christian; Böhm, Michael

    2014-04-01

    Renal denervation reduces office blood pressure in patients with resistant hypertension. This study investigated the effects of renal denervation on blood pressure, heart rate, and chronotropic index at rest, during exercise, and at recovery in 60 patients (renal denervation group=50, control group=10) with resistant hypertension using a standardized bicycle exercise test protocol performed 6 and 12 months after renal denervation. After renal denervation, exercise blood pressure at rest was reduced from 158±3/90±2 to 141±3/84±4 mm Hg (PExercise blood pressure tended to be lower at all stages of exercise at 6- and 12-month follow-up in patients undergoing renal denervation, although reaching statistical significance only at mild-to-moderate exercise levels (75-100 W). At recovery after 1 minute, blood pressure decreased from 201±4/95±2 to 177±4/88±2 (PHeart rate was reduced after renal denervation from 71±3 bpm at rest, 128±5 bpm at maximum workload, and 96±5 bpm at recovery after 1 minute to 66±2 (Pexercise time increased from 6.59±0.33 to 8.4±0.32 (Pheart rate during exercise, improved mean workload, and increased exercise time without impairing chronotropic competence.

  15. Everything you need to know about distal renal tubular acidosis in autoimmune disease

    NARCIS (Netherlands)

    T. Both (Tim); R. Zietse (Bob); E.J. Hoorn (Ewout); P.M. van Hagen (Martin); V.A.S.H. Dalm (Virgil); J.A.M. van Laar (Jan); P.L.A. van Daele (Paul)

    2014-01-01

    textabstractRenal acid-base homeostasis is a complex process, effectuated by bicarbonate reabsorption and acid secretion. Impairment of urinary acidification is called renal tubular acidosis (RTA). Distal renal tubular acidosis (dRTA) is the most common form of the RTA syndromes. Multiple pathophysi

  16. Increased Milk Protein Concentration in a Rehydration Drink Enhances Fluid Retention Caused by Water Reabsorption in Rats.

    Science.gov (United States)

    Ito, Kentaro; Saito, Yuri; Ashida, Kinya; Yamaji, Taketo; Itoh, Hiroyuki; Oda, Munehiro

    2015-01-01

    A fluid-retention effect is required for beverages that are designed to prevent dehydration. That is, fluid absorbed from the intestines should not be excreted quickly; long-term retention is desirable. Here, we focused on the effect of milk protein on fluid retention, and propose a new effective oral rehydration method that can be used daily for preventing dehydration. We first evaluated the effects of different concentrations of milk protein on fluid retention by measuring the urinary volumes of rats fed fluid containing milk protein at concentrations of 1, 5, and 10%. We next compared the fluid-retention effect of milk protein-enriched drink (MPD) with those of distilled water (DW) and a sports drink (SD) by the same method. Third, to investigate the mechanism of fluid retention, we measured plasma insulin changes in rats after ingesting these three drinks. We found that the addition of milk protein at 5 or 10% reduced urinary volume in a dose-dependent manner. Ingestion of the MPD containing 4.6% milk protein resulted in lower urinary volumes than DW and SD. MPD also showed a higher water reabsorption rate in the kidneys and higher concentrations of plasma insulin than DW and SD. These results suggest that increasing milk protein concentration in a beverage enhances fluid retention, which may allow the possibility to develop rehydration beverages that are more effective than SDs. In addition, insulin-modifying renal water reabsorption may contribute to the fluid-retention effect of MPD.

  17. Inherited forms of renal hypomagnesemia: an update.

    NARCIS (Netherlands)

    Knoers, N.V.A.M.

    2009-01-01

    The kidney plays an important role in ion homeostasis in the human body. Several hereditary disorders characterized by perturbations in renal magnesium reabsorption leading to hypomagnesemia have been described over the past 50 years, with the most important of these being Gitelman syndrome, familia

  18. Lithium clearance and renal tubular sodium handling during acute and long-term nifedipine treatment in essential hypertension

    DEFF Research Database (Denmark)

    Bruun, N E; Ibsen, H; Skøtt, P

    1988-01-01

    1. In two separate studies the lithium clearance method was used to evaluate the influence of acute and long-term nifedipine treatment on renal tubular sodium reabsorption. 2. In the acute study, after a 4 week placebo period two doses of 20 mg of nifedipine decreased supine blood pressure from 155...... reabsorption did not change. Sodium clearance, fractional sodium excretion, potassium clearance, plasma volume and extracellular fluid volume were also unchanged. 4. In conclusion, we found no changes of renal tubular sodium reabsorption during acute nifedipine treatment, whereas long-term nifedipine treatment...

  19. Assessment of the place of tubular reabsorption of phosphorus in the diagnosis of osteopenia of prematurity

    Science.gov (United States)

    Acar, Duygu Besnili; Kavuncuoğlu, Sultan; Çetinkaya, Merih; Petmezci, Ercüment; Dursun, Mesut; Korkmaz, Orhan; Altuncu, Emel Kayrak

    2015-01-01

    Aim: In this study, we aimed to investigate the utility of tubular reabsorption of phosphorus in the diagnosis of osteopenia of prematurity in addition to biochemical markers. Materials and Method: Premature babies with a gestational age of ≤32 weeks and/or a birth weight of ≤1 500 g who were hospitalized in the neonatal intensive care unit between June 2009 and March 2011 were included in the study. These babies were evaluated at the 40th gestational week and serum calcium, phosphorus, alkaline phosphatase, urea, creatinine, urinary calcium and phosphorus levels were measured and tubular reabsorption of phosphorus was determined. The subjects who had bone graphy findings and/or an alkaline phosphatase level of >400IU/L and a phosphorus value of 499 IU were compared with the newborns who were found to have a tubular reabsorption of phosphorus of ≥%95 for the objective of evaluating the specificity and sensitivity of tubular reabsorption of phosphorus, the sensitivity, specificity, positive predictive value and negative predictive value of tubular reabsorption of phosphorus in the diagnosis of osteopenia were found to be 27%, 82%, 17% and 89%, respectively. When the osteopenic and non-osteopenic patients were compared in terms of the levels of tubular reabsorption of phosphorus, no statistically significant difference was found. Conclusions: It was thought that it was not appropriate to use tubular reabsorption of phosphorus alone in the diagnosis of osteopenia of prematurity. PMID:26078696

  20. Characterization and reduction of reabsorption losses in luminescent solar concentrators.

    Science.gov (United States)

    Wilson, Lindsay R; Rowan, Brenda C; Robertson, Neil; Moudam, Omar; Jones, Anita C; Richards, Bryce S

    2010-03-20

    The effects of excitation wavelength on the optical properties (emission spectrum and quantum yield) of a luminescent solar concentrator (LSC) containing a fluorescent organic dye (Lumogen F Rot 305) are studied. Excitation at wavelengths on the long-wavelength edge of the absorption spectrum of the dye results in redshifted emission, but the quantum yield remains constant at 100%. The origin of this effect and its consequences are discussed. The extent of the long-wavelength tail of the absorption spectrum of the dye is determined and the importance in reabsorption losses is shown. The optical efficiencies and photon transport probabilities of LSCs containing either an organic dye or a rare-earth lanthanide complex are compared using ray-tracing simulations and experiment. The optical efficiency is shown to depend strongly on the Stokes shift of the fluorophore. The lanthanide complex, which has a very large Stokes shift, exhibits a higher optical efficiency than the dye (64% cf. 50%), despite its lower quantum yield (86% cf. 100%).

  1. Zero-reabsorption doped-nanocrystal luminescent solar concentrators.

    Science.gov (United States)

    Erickson, Christian S; Bradshaw, Liam R; McDowall, Stephen; Gilbertson, John D; Gamelin, Daniel R; Patrick, David L

    2014-04-22

    Optical concentration can lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without tracking, but they have been plagued by luminophore self-absorption losses when employed on practical size scales. Here, we introduce doped semiconductor nanocrystals as a new class of phosphors for use in luminescent solar concentrators. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn(2+)-doped ZnSe nanocrystals that show no luminescence reabsorption. Optical quantum efficiencies of 37% are measured, yielding a maximum projected energy concentration of ∼6× and flux gain for a-Si photovoltaics of 15.6 in the large-area limit, for the first time bounded not by luminophore self-absorption but by the transparency of the waveguide itself. Future directions in the use of colloidal doped nanocrystals as robust, processable spectrum-shifting phosphors for luminescent solar concentration on the large scales required for practical application of this technology are discussed.

  2. Observations on the mechanism and location of ascites reabsorption in man

    Energy Technology Data Exchange (ETDEWEB)

    Rector, W.G. Jr.; Ibarra, F.

    1987-04-01

    Animal data indicate that ascites is reabsorbed by a lymphatic mechanism and that these vessels are subdiaphragmatic in location. We evaluated the relative role of lymphatics in ascites reabsorption in man by comparing the ascites clearance and plasma appearance rates of intraperitoneally injected radiolabeled albumin to those of intraperitoneally injected labeled autologous red blood cells, which require, owing to their large size, lymphatic removal, in patients with cirrhosis and ascites. To evaluate the location of reabsorption, we repeated these measurements after replacing ascites in the subdiaphragmatic region with 500-1000 ml of intraperitoneally injected air, reasoning that this maneuver should slow or eliminate ascites reabsorption occurring at this site. We found that the transfer rates of albumin and red cells out of ascites were similar and that creation of pneumoperitoneum did not influence these rates. These data confirm that ascites protein reabsorption occurs via a lymphatic mechanism in man. They suggest, however, that these vessels may not be subdiaphragmatic in location.

  3. Delivery dependence of early proximal bicarbonate reabsorption in the rat in respiratory acidosis and alkalosis.

    Science.gov (United States)

    Santella, R N; Maddox, D A; Gennari, F J

    1991-01-01

    In the intact rat kidney, bicarbonate reabsorption in the early proximal tubule (EP) is strongly dependent on delivery. Independent of delivery, metabolic acidosis stimulates EP bicarbonate reabsorption. In this study, we investigated whether systemic pH changes induced by acute or chronic respiratory acid-base disorders also affect EP HCO3- reabsorption, independent of delivery (FLHCO3, filtered load of bicarbonate). Hypercapnia was induced in rats acutely (1-3 h) and chronically (4-5 d) by increasing inspired PCO2. Hypocapnia was induced acutely (1-3 h) by mechanical hyperventilation, and chronically (4-5 d) using hypoxemia to stimulate ventilation. When compared with normocapneic rats with similar FLHCO3, no stimulation of EP or overall proximal HCO3 reabsorption was found with either acute hypercapnia (PaCO2 = 74 mmHg, pH = 7.23) or chronic hypercapnia (PaCO2 = 84 mmHg, pH = 7.31). Acute hypocapnia (PaCO2 = 29 mmHg, pH = 7.56) did not suppress EP or overall HCO3 reabsorption. Chronic hypocapnia (PaCO2 = 26 mmHg, pH = 7.54) reduced proximal HCO3 reabsorption, but this effect was reversed when FLHCO3 was increased to levels comparable to euvolemic normocapneic rats. Thus, when delivery is accounted for, we could find no additional stimulation of proximal bicarbonate reabsorption in respiratory acidosis and, except at low delivery rates, no reduction in bicarbonate reabsorption in respiratory alkalosis. PMID:1991847

  4. Methylene blue solder re-absorption in microvascular anastomoses

    Science.gov (United States)

    Birch, Jeremy F.; Hepplewhite, J.; Frier, Malcolm; Bell, Peter R. F.

    2003-06-01

    Soldered vascular anastomoses have been reported using several chromophores but little is known of the optimal conditions for microvascular anastomosis. There are some indications of the optimal protein contents of a solder, and the effects of methylene blue on anastomotic strength. The effects of varying laser power density in vivo have also been described, showing a high rate of thrombosis with laser power over 22.9Wcm-2. However no evidence exists to describe how long the solder remains at the site of the anastomosis. Oz et al reported that the fibrin used in their study had been almost completely removed by 90 days but without objective evidence of solder removal. In order to address the issue of solder re-absorption from the site of an anastomosis we used radio-labelled albumin (I-125) incorporated into methylene blue based solder. This was investigated in both the situation of the patent and thrombosed anastomosis with anastomoses formed at high and low power. Iodine-125 (half life: 60.2 days) was covalently bonded to porcine albumin and mixed with the solder solution. Radio-iodine has been used over many years to determine protein turnover using either I-125 or I-131. Iodine-125 labelled human albumin is regularly used as a radiopharmaceutical tool for the determination of plasma volume. Radio-iodine has the advantages of not affecting protein metabolism and the label is rapidly excreted after metabolic breakdown. Labelling with chromium (Cr-51) causes protein denaturation and is lost from the protein with time. Labelled albumin has been reported in human studies over a 21-day period, with similar results reported by Matthews. Most significantly McFarlane reported a different rate of catabolism of I-131 and I-125 over a 22-day period. The conclusion from this is that the rate of iodine clearance is a good indicator of protein catabolism. In parallel with the surgery a series of blank standards were prepared with a known mass of solder to correct for isotope

  5. Effects of photon reabsorption phenomena in confocal micro-photoluminescence measurements in crystalline silicon

    Science.gov (United States)

    Roigé, A.; Alvarez, J.; Jaffré, A.; Desrues, T.; Muñoz, D.; Martín, I.; Alcubilla, R.; Kleider, J.-P.

    2017-02-01

    Confocal micro-photoluminescence (PL) spectroscopy has become a powerful characterization technique for studying novel photovoltaic (PV) materials and structures at the micrometer level. In this work, we present a comprehensive study about the effects and implications of photon reabsorption phenomena on confocal micro-PL measurements in crystalline silicon (c-Si), the workhorse material of the PV industry. First, supported by theoretical calculations, we show that the level of reabsorption is intrinsically linked to the selected experimental parameters, i.e., focusing lens, pinhole aperture, and excitation wavelength, as they define the spatial extension of the confocal detection volume, and therefore, the effective photon traveling distance before collection. Second, we also show that certain sample properties such as the reflectance and/or the surface recombination velocity can also have a relevant impact on reabsorption. Due to the direct relationship between the reabsorption level and the spectral line shape of the resulting PL emission signal, reabsorption phenomena play a paramount role in certain types of micro-PL measurements. This is demonstrated by means of two practical and current examples studied using confocal PL, namely, the estimation of doping densities in c-Si and the study of back-surface and/or back-contacted Si devices such as interdigitated back contact solar cells, where reabsorption processes should be taken into account for the proper interpretation and quantification of the obtained PL data.

  6. Angiotensin II AT1 receptor blockade decreases vasopressin-induced water reabsorption and AQP2 levels in NaCl-restricted rats

    DEFF Research Database (Denmark)

    Kwon, Tae-Hwan; Nielsen, Jakob; Knepper, M.A.

    2005-01-01

    Vasopressin and ANG II, which are known to play a major role in renal water and sodium reabsorption, are mainly coupled to the cAMP/PKA and phosphoinositide pathways, respectively. There is evidence for cross talk between these intracellular signaling pathways. We therefore hypothesized that vaso......Vasopressin and ANG II, which are known to play a major role in renal water and sodium reabsorption, are mainly coupled to the cAMP/PKA and phosphoinositide pathways, respectively. There is evidence for cross talk between these intracellular signaling pathways. We therefore hypothesized......) vehicle infusion as the control (n = 8). All rats were maintained on a NaCl-deficient diet (0.1 meq Na+·200 g body wt−1·day−1) during the experiment. DDAVP treatment alone resulted in a significant decrease in urine output (3.1 ± 0.2 ml/day) compared with controls (11.5 ± 2.2 ml/day, P ... the urine output was significantly increased in response to DDAVP and candesartan cotreatment (9.8 ± 1.0 ml/day, P alone (3...

  7. Testosterone increases urinary calcium excretion and inhibits expression of renal calcium transport proteins.

    NARCIS (Netherlands)

    Hsu, Y.J.; Dimke, H.; Schoeber, J.P.H.; Hsu, S.C.; Lin, S.H.; Chu, P.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2010-01-01

    Although gender differences in the renal handling of calcium have been reported, the overall contribution of androgens to these differences remains uncertain. We determined here whether testosterone affects active renal calcium reabsorption by regulating calcium transport proteins. Male mice had hig

  8. Taurine and the renal system

    Science.gov (United States)

    2010-01-01

    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

  9. Regulation of renal function and blood pressure control by P2 purinoceptors in the kidney.

    Science.gov (United States)

    Van Beusecum, Justin; Inscho, Edward W

    2015-04-01

    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.

  10. PEGylation of the peptide Bac7(1-35) reduces renal clearance while retaining antibacterial activity and bacterial cell penetration capacity.

    Science.gov (United States)

    Benincasa, Monica; Zahariev, Sotir; Pelillo, Chiara; Milan, Annalisa; Gennaro, Renato; Scocchi, Marco

    2015-05-05

    The proline-rich antibacterial peptide Bac7(1-35) protects mice against Salmonella typhimurium infection, despite its rapid clearance. To overcome this problem the peptide was linked to a polyethylene glycol (PEG) molecule either via a cleavable ester bond or via a non-hydrolysable amide bond. Both the PEGylated conjugates retained most of the in vitro activity against S. typhimurium. In addition, the ester bond was cleaved in human serum or plasma, releasing a carboxymethyl derivative of Bac7(1-35) which accounts for a higher activity of this peptide with relative to the other, non-hydrolysable form. Both PEGylated peptides maintained the capacity of the unconjugated form to kill bacteria without permeabilizing the bacterial membranes, by penetrating into cells. They exploited the same transporter as unmodified Bac7(1-35), suggesting it has the capacity to internalize quite sizeable cargo if this is linked to Bac7 fragment. PEGylation allows the peptide to have a wide distribution in mice, and a slow renal clearance, indicating that this strategy would improve the bioavailability of Bac7, and in principle of other antimicrobial peptides. This can be an equally important issue to reducing cytotoxicity for therapeutic use of these antibacterials.

  11. Reabsorption of ascites and the factors that affect this process in cirrhosis.

    Science.gov (United States)

    Akay, Sinan; Ozutemiz, Omer; Kilic, Murat; Karasu, Zeki; Akyildiz, Murat; Karasulu, Ercument; Baka, Meral; Doganavsargil, Basak; Ersoz, Galip; Ulukaya, Sezgin; Alper, Isik; Ates, Utku; Batur, Yucel

    2008-10-01

    Ascites is one of the main features of liver decompensation in cirrhosis, and it is considered to be a dynamic process. In this study, we aimed to (1) measure the reabsorption rate of ascites; (2) evaluate whether these findings were related to features of ascites, hemodynamics, and serum measurements; and (3) examine morphologic changes in the diaphragm of cirrhotic patients. In all, 42 cirrhotic patients with ascites were enrolled in the study to comprise our study group. Using the dextran 70 test, patient ascites volumes and reabsorption rates were measured. Biopsies from the peritoneal side of the diaphragm were also processed for scanning electron microscopy and lymphatic immunohistochemical studies from the cirrhotic patients and control cadavers. The mean ascites reabsorption rate was 4.5 +/- 4.5 (0.18-14.6) mL/min, which correlated significantly with the calculated ascites volume (r = 0.75, P ascites viscosity was 1.07 +/- 0.07 (0.99-1.17) centipoise, which demonstrated a high degree of negative correlation with the ascites reabsorption rate (r = -0.77, P ascites reabsorption rates than patients without this particular history. The size of lymphatic stomata in scanning electron microscopy depictions was increased, and lymphatic lacunae were dilated in immunohistochemical studies in the cirrhotic patients with ascites. However, these findings were not uniform in every cirrhotic patient with ascites. The volume and viscosity of ascites seem to influence its reabsorption rate. Additionally, previous episodes of spontaneous bacterial peritonitis may be responsible for the decreased ascites reabsorption rates observed in certain patient populations.

  12. Renal Glycosuria without Hyperglycemia in Cyclosporine-Treated Rats

    Directory of Open Access Journals (Sweden)

    Chang Hwa Lee

    2012-06-01

    Conclusion: Glycosuria may occur without hyperglycemia in cyclosporine administration. We suggest that cyclosporine may decrease tubular reabsorption of glucose in renal tubular epithelial cells, and then glycosuria could be induced by the altered glucose transporter expressions. We will analyze the glucose transporters in proximal tubule of rat kidney.

  13. Renal phenotypic investigations of megalin-deficient patients

    DEFF Research Database (Denmark)

    Storm, Tina; Tranebjærg, Lisbeth; Frykholm, Carina

    2013-01-01

    causes the extremely rare Donnai-Barrow/Facio-Oculo-Acustico-Renal (DB/FOAR) syndrome characterized by a characteristic and multifaceted phenotype including low-molecular-weight proteinuria. In this study, we examined the role of megalin for tubular protein reabsorption in humans through analysis...

  14. Fluid reabsorption in proximal convoluted tubules of mice with gene deletions of claudin-2 and/or aquaporin1.

    Science.gov (United States)

    Schnermann, Jurgen; Huang, Yuning; Mizel, Diane

    2013-11-01

    Deletions of claudin-2 (Cldn2) and aquaporin1 (AQP1) reduce proximal fluid reabsorption (PFR) by about 30% and 50%, respectively. Experiments were done to replicate these observations and to determine in AQP1/claudin-2 double knockout mice (DKO) if the effects of deletions of these established water pores are additive. PFR was determined in inactin/ketamine-anesthetized mice by free-flow micropuncture using single-nephron I(125)-iothalamate (io) clearance. Animal means of PFR [% of glomerular filtration rate (GFR)] derived from TF/Piothalamate ratios in 12 mice in each of four groups [wild type (WT), Cldn2(-/-), AQP1(-/-), and DKO) were 45.8 ± 0.85 (51 tubules), 35.4 ± 1 (54 tubules; P PFR and SNGFR was maintained in mutant mice, but the slope of this relationship was reduced in the absence of Cldn2 and/or AQP1. Transtubular osmotic pressure differences were not different between WT and Cldn2(-/-) mice, but markedly increased in DKO. In conclusion, the deletion of Cldn2, AQP1, or of both Cldn2 and AQP1 reduces PFR by 22.7%, 19.6%, and 26%, respectively. Our data are consistent with an up to 25% paracellular contribution to PFR. The reduced osmotic water permeability caused by absence of AQP1 augments luminal hypotonicity. Aided by a fall in filtered load, the capacity of non-AQP1-dependent transcellular reabsorption is sufficient to maintain PFR without AQP1 and claudin-2 at 75% of control.

  15. FGF23 regulates renal sodium handling and blood pressure

    OpenAIRE

    Andrukhova, Olena; Slavic, Svetlana; Smorodchenko, Alina; Zeitz, Ute; Shalhoub, Victoria; Lanske, Beate; Pohl, Elena E.; Erben, Reinhold G.

    2014-01-01

    Fibroblast growth factor-23 (FGF23) is a bone-derived hormone regulating renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. Here, we show that FGF23 directly regulates the membrane abundance of the Na+:Cl− co-transporter NCC in distal renal tubules by a signaling mechanism involving the FGF receptor/αKlotho complex, extracellular signal-regulated kinase 1/2 (ERK1/2), serum/glucocorticoid-regulated kinase 1 (SGK1), and with-no lysine kinase-4 (WNK4). Renal sodium (...

  16. Evaluation of plasma concentrations of homocysteine, IL-6, TNF-alpha, hs-CRP, and total antioxidant capacity in patients with end-stage renal failure.

    Directory of Open Access Journals (Sweden)

    Mahin Babaei

    2014-12-01

    Full Text Available It has been proved that hyperhomocysteinemia has a high prevalence in patients with end-stage renal disease (ESRD, which may contribute to the high cardiovascular risk in these patients. Cardiovascular disease is the first cause of high mortality rate in ESRD patients. The aim of the present study was to assess five important factors in patients with ESRD (the amount of homocysteine, IL-6, TNF-alpha, hs-CRP, and Total Antioxidant Capacity. These factors were surveyed in ESRD patients to compare with healthy subjects. In a cross-sectional study, we enrolled 80 patients on maintenance hemodialysis and measured the inflammatory and oxidative stress indicators. The plasma samples were assayed for five above mentioned variables using standard protocols. Two-hour post hemodialysis plasma samples were also assayed for TAC. Plasma levels of inflammation markers, IL-6 and hs-CRP, homocysteine were significantly increased in ESRD group versus control group. This increase was also found in TNF-α levels as compared to the controls, but the differences were not statistically significant. Also, the post dialysis samples had significantly lower levels of TAC as compared to predialysis ones.

  17. Evaluation of plasma concentrations of homocysteine, IL-6, TNF-alpha, hs-CRP, and total antioxidant capacity in patients with end-stage renal failure.

    Science.gov (United States)

    Babaei, Mahin; Dashti, Nasrin; Lamei, Navid; Abdi, Khosrou; Nazari, Farhad; Abbasian, Sepideh; Gerayeshnejad, Siavash

    2014-01-01

    It has been proved that hyperhomocysteinemia has a high prevalence in patients with end-stage renal disease (ESRD), which may contribute to the high cardiovascular risk in these patients. Cardiovascular disease is the first cause of high mortality rate in ESRD patients. The aim of the present study was to assess five important factors in patients with ESRD (the amount of homocysteine, IL-6, TNF-alpha, hs-CRP, and Total Antioxidant Capacity). These factors were surveyed in ESRD patients to compare with healthy subjects. In a cross-sectional study, we enrolled 80 patients on maintenance hemodialysis and measured the inflammatory and oxidative stress indicators. The plasma samples were assayed for five above mentioned variables using standard protocols. Two-hour post hemodialysis plasma samples were also assayed for TAC. Plasma levels of inflammation markers, IL-6 and hs-CRP, homocysteine were significantly increased in ESRD group versus control group. This increase was also found in TNF-α levels as compared to the controls, but the differences were not statistically significant. Also, the post dialysis samples had significantly lower levels of TAC as compared to predialysis ones.

  18. Role of claudins in renal calcium handling

    Directory of Open Access Journals (Sweden)

    Armando Luis Negri

    2015-07-01

    Full Text Available Paracellular channels occurring in tight junctions play a major role in transepithelial ionic flows. This pathway includes a high number of proteins, such as claudins. Within renal epithelium, claudins result in an ionic selectivity in tight junctions. Ascending thick limb of loop of Henle (ATLH is the most important segment for calcium reabsorption in renal tubules. Its cells create a water-proof barrier, actively transport sodium and chlorine through a transcellular pathway, and provide a paracellular pathway for selective calcium reabsorption. Several studies have led to a model of paracellular channel consisting of various claudins, particularly claudin-16 and 19. Claudin-16 mediates cationic paracellular permeability in ATLH, whereas claudin-19 increases cationic selectivity of claudin-16 by blocking anionic permeability. Recent studies have shown that claudin-14 promoting activity is only located in ATLH. When co-expressed with claudin-16, claudin-14 inhibits the permeability of claudin-16 and reduces paracellular permeability to calcium. Calcium reabsorption process in ATLH is closely regulated by calcium sensor receptor (CaSR, which monitors circulating Ca levels and adjusts renal excretion rate accordingly. Two microRNA, miR-9 and miR-374, are directly regulated by CaSR. Thus, miR-9 and miR-374 suppress mRNA translation for claudin-14 and induce claudin-14 decline.

  19. Molecular clock is involved in predictive circadian adjustment of renal function.

    Science.gov (United States)

    Zuber, Annie Mercier; Centeno, Gabriel; Pradervand, Sylvain; Nikolaeva, Svetlana; Maquelin, Lionel; Cardinaux, Léonard; Bonny, Olivier; Firsov, Dmitri

    2009-09-22

    Renal excretion of water and major electrolytes exhibits a significant circadian rhythm. This functional periodicity is believed to result, at least in part, from circadian changes in secretion/reabsorption capacities of the distal nephron and collecting ducts. Here, we studied the molecular mechanisms underlying circadian rhythms in the distal nephron segments, i.e., distal convoluted tubule (DCT) and connecting tubule (CNT) and the cortical collecting duct (CCD). Temporal expression analysis performed on microdissected mouse DCT/CNT or CCD revealed a marked circadian rhythmicity in the expression of a large number of genes crucially involved in various homeostatic functions of the kidney. This analysis also revealed that both DCT/CNT and CCD possess an intrinsic circadian timing system characterized by robust oscillations in the expression of circadian core clock genes (clock, bma11, npas2, per, cry, nr1d1) and clock-controlled Par bZip transcriptional factors dbp, hlf, and tef. The clock knockout mice or mice devoid of dbp/hlf/tef (triple knockout) exhibit significant changes in renal expression of several key regulators of water or sodium balance (vasopressin V2 receptor, aquaporin-2, aquaporin-4, alphaENaC). Functionally, the loss of clock leads to a complex phenotype characterized by partial diabetes insipidus, dysregulation of sodium excretion rhythms, and a significant decrease in blood pressure. Collectively, this study uncovers a major role of molecular clock in renal function.

  20. The Association of Albuminuria With Tubular Reabsorption of Uric Acid: Results From a General Population Cohort

    Science.gov (United States)

    Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

    2014-01-01

    Background Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and Results Included were 7688 participants of the PREVEND Study, an observational, general population‐based cohort study. Linear regression analyses were used to test associations of baseline albuminuria with baseline serum uric acid concentration and tubular uric acid reabsorption (calculated as [100−fractional uric acid excretion]%). Cox regression analyses were used to study the association of baseline serum uric acid and albuminuria with incident cardiovascular morbidity and mortality. In cross‐sectional analyses, albuminuria was associated positively with serum uric acid concentration, both crude and after adjustment for potential confounders (both Puric acid reabsorption, again both crude and after adjustment for potential confounders (both Puric acid were associated with incident cardiovascular events (Hazard Ratios 1.09 [1.03 to 1.17], P=0.01 and 1.19 [1.09 to 1.30], Puric acid being less predictive for cardiovascular morbidity and mortality in the presence of high albuminuria and vice versa. Conclusions Albuminuria is strongly associated with tubular uric acid reabsorption, and consequently with serum uric acid concentration. This phenomenon may explain in part why albuminuria is associated with cardiovascular outcome. PMID:24772520

  1. The Association of Albuminuria With Tubular Reabsorption of Uric Acid : Results From a General Population Cohort

    NARCIS (Netherlands)

    Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

    2014-01-01

    Background-Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and Results-Include

  2. Interdependence of reabsorption and internal energy losses in luminescent solar concentrators

    Science.gov (United States)

    Digaum, Jennefir; Kuebler, Stephen M.

    2014-03-01

    As a complementary device to photovoltaic (PV) cells, luminescent solar concentrators (LSCs) can reduce the cost of solar energy by replacing the expensive PV material with inexpensive energy-harvesting plastic or glass matrix. However, due to its low efficiency, LSCs are still not commercially viable. The low efficiency is due to the various losses associated with light harvesting and trapping. Most of these losses come from reabsorption and escape of reemitted energy from the LSC device. State-of-the-art LSC technology focuses on decreasing reabsorption loss by employing luminophores with a large Stokes shift. But these materials typically have low quantum yield. Increasing the Stokes shift of the luminophore reduces reabsorption but introduces substantial loss due to low quantum yield and the Stokes shift of the re-emitted photons. The interdependence of these losses is studied computationally using a ray-tracing model that accounts for reabsorption, Stokes shift, escape cone loss, and matrix loss. It is shown that using high Stokesshift luminophores does not give the highest energy efficiency. Higher energy efficiency is obtained by optimizing the Stokes shift. Even greater performance can be achieved by employing high-quantum-yield dyes with intermediate Stokes shift. LSC devices based on this approach could be nearly twice as efficient as those based on conventional luminophores, such as Rhodamine B.

  3. Morphological and functional characteristics of the kidney of cartilaginous fishes: with special reference to urea reabsorption.

    Science.gov (United States)

    Hyodo, Susumu; Kakumura, Keigo; Takagi, Wataru; Hasegawa, Kumi; Yamaguchi, Yoko

    2014-12-15

    For adaptation to high-salinity marine environments, cartilaginous fishes (sharks, skates, rays, and chimaeras) adopt a unique urea-based osmoregulation strategy. Their kidneys reabsorb nearly all filtered urea from the primary urine, and this is an essential component of urea retention in their body fluid. Anatomical investigations have revealed the extraordinarily elaborate nephron system in the kidney of cartilaginous fishes, e.g., the four-loop configuration of each nephron, the occurrence of distinct sinus and bundle zones, and the sac-like peritubular sheath in the bundle zone, in which the nephron segments are arranged in a countercurrent fashion. These anatomical and morphological characteristics have been considered to be important for urea reabsorption; however, a mechanism for urea reabsorption is still largely unknown. This review focuses on recent progress in the identification and mapping of various pumps, channels, and transporters on the nephron segments in the kidney of cartilaginous fishes. The molecules include urea transporters, Na(+)/K(+)-ATPase, Na(+)-K(+)-Cl(-) cotransporters, and aquaporins, which most probably all contribute to the urea reabsorption process. Although research is still in progress, a possible model for urea reabsorption in the kidney of cartilaginous fishes is discussed based on the anatomical features of nephron segments and vascular systems and on the results of molecular mapping. The molecular anatomical approach thus provides a powerful tool for understanding the physiological processes that take place in the highly elaborate kidney of cartilaginous fishes.

  4. Renal control of calcium, phosphate, and magnesium homeostasis.

    Science.gov (United States)

    Blaine, Judith; Chonchol, Michel; Levi, Moshe

    2015-07-01

    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.

  5. Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

    NARCIS (Netherlands)

    ter Maaten, JC; Bakker, SJL; Serne, EH; ter Wee, PM; Gans, ROB

    1999-01-01

    Background. Insulin induces increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects coul

  6. Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

    NARCIS (Netherlands)

    ter Maaten, JC; Bakker, SJL; Serne, EH; ter Wee, PM; Gans, ROB

    1999-01-01

    Background. Insulin induces increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects coul

  7. Primary clear cell renal carcinoma cells display minimal mitochondrial respiratory capacity resulting in pronounced sensitivity to glycolytic inhibition by 3-Bromopyruvate.

    Science.gov (United States)

    Nilsson, H; Lindgren, D; Mandahl Forsberg, A; Mulder, H; Axelson, H; Johansson, M E

    2015-01-08

    Changes of cellular metabolism are an integral property of the malignant potential of most cancer cells. Already in the 1930s, Otto Warburg observed that tumor cells preferably utilize glycolysis and lactate fermentation for energy production, rather than the mitochondrial oxidative phosphorylation dominating in normal cells, a phenomenon today known as the Warburg effect. Even though many tumor types display a high degree of aerobic glycolysis, they still retain the activity of other energy-producing metabolic pathways. One exception seems to be the clear cell variant of renal cell carcinoma, ccRCC, where the activity of most other pathways than that of glycolysis has been shown to be reduced. This makes ccRCC a promising candidate for the use of glycolytic inhibitors in treatment of the disease. However, few studies have so far addressed this issue. In this report, we show a strikingly reduced mitochondrial respiratory capacity of primary human ccRCC cells, resulting in enhanced sensitivity to glycolytic inhibition by 3-Bromopyruvate (3BrPA). This effect was largely absent in established ccRCC cell lines, a finding that highlights the importance of using biologically relevant models in the search for new candidate cancer therapies. 3BrPA markedly reduced ATP production in primary ccRCC cells, followed by cell death. Our data suggest that glycolytic inhibitors such as 3BrPA, that has been shown to be well tolerated in vivo, should be further analyzed for the possible development of selective treatment strategies for patients with ccRCC.

  8. Impact of Reabsorption on the Emission Spectra and Recombination Dynamics of Hybrid Perovskite Single Crystals.

    Science.gov (United States)

    Diab, Hiba; Arnold, Christophe; Lédée, Ferdinand; Trippé-Allard, Gaëlle; Delport, Géraud; Vilar, Christèle; Bretenaker, Fabien; Barjon, Julien; Lauret, Jean-Sébastien; Deleporte, Emmanuelle; Garrot, Damien

    2017-07-06

    Understanding the surface properties of organic-inorganic lead-based perovskites is of high importance to improve the device's performance. Here, we have investigated the differences between surface and bulk optical properties of CH3NH3PbBr3 single crystals. Depth-resolved cathodoluminescence was used to probe the near-surface region on a depth of a few microns. In addition, we have studied the transmitted luminescence through thicknesses between 50 and 600 μm. In both experiments, the expected spectral shift due to the reabsorption effect has been precisely calculated. We demonstrate that reabsorption explains the important variations reported for the emission energy of single crystals. Single crystals are partially transparent to their own luminescence, and radiative transport is the dominant mechanism for propagation of the excitation in thick crystals. The transmitted luminescence dynamics are characterized by a long rise time and a lengthening of their decay due to photon recycling and light trapping.

  9. A hypothesis linking sodium and lithium reabsorption in the distal nephron

    DEFF Research Database (Denmark)

    Thomsen, Klaus; Shirley, DG

    2006-01-01

      A hypothesis is proposed linking Na(+) and Li(+) reabsorption in the distal nephron. The handling of these two ions in the distal nephron is related because they share the same apical membrane entry mechanism: the amiloride-sensitive Na(+) channel (ENaC). However, the two ions exit the cell...... through different transport mechanisms: Na(+) via the Na(+)-K(+)-ATPase and Li(+) via the Na(+)/H(+) exchanger. Studies in rats have shown that under normal circumstances hardly any Li(+) is reabsorbed in the distal nephron, so that the urinary excretion of Li(+), expressed as a fraction of the delivery...... to the early distal tubule (FE(Li dist)), amounts to approximately 0.97. In contrast, during severe dietary Na(+) restriction, FE(Li dist) decreases to 0.50-0.60. Our hypothesis is that the absence of distal Li(+) reabsorption during intake of a normal diet can be explained by a negative driving force for Li...

  10. A hypothesis linking sodium and lithium reabsorption in the distal nephron

    DEFF Research Database (Denmark)

    Thomsen, Klaus; Shirley, DG

    2006-01-01

    to the early distal tubule (FE(Li dist)), amounts to approximately 0.97. In contrast, during severe dietary Na(+) restriction, FE(Li dist) decreases to 0.50-0.60. Our hypothesis is that the absence of distal Li(+) reabsorption during intake of a normal diet can be explained by a negative driving force for Li......(+) entrance across the apical membrane in those segments in which ENaC is active. Method. We propose a model that incorporates this concept. RESULTS: The model indicates that the lowering of FE(Li dist) during dietary Na(+) restriction can be explained by activation of apical ENaC in extra sub......-segments further downstream. In these extra sub-segments the driving force for Li(+) reabsorption is positive, leading to significant Li(+) reabsorption. During dietary K(+) restriction, FE(Li dist) is reduced to 0.35-0.55. The model shows that this reduction in FE(Li dist) can be explained by hyperpolarization...

  11. Effects of hyperventilation and hypocapnic/normocapnic hypoxemia on renal function and lithium clearance in humans

    DEFF Research Database (Denmark)

    Christensen, H; Klausen, T; Fogh-Andersen, N;

    1998-01-01

    Using the renal clearance of lithium as an index of proximal tubular outflow, this study tested the hypothesis that acute hypocapnic hypoxemia decreases proximal tubular reabsorption to the same extent as hypocapnic normoxemia (hyperventilation) and that this response is blunted during normocapni...

  12. Kidney-on-a-chip technology for renal proximal tubule tissue reconstruction

    NARCIS (Netherlands)

    Nieskens, T.T.G.; Wilmer, M.J.G.

    2016-01-01

    The renal proximal tubule epithelium is responsible for active secretion of endogenous and exogenous waste products from the body and simultaneous reabsorption of vital compounds from the glomerular filtrate. The complexity of this transport machinery makes investigation of processes such as tubular

  13. Renal acidification defects in medullary sponge kidney

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1988-01-01

    Thirteen patients with medullary sponge kidney underwent a short ammonium chloride loading test to investigate their renal acidification capacity. All but 1 presented with a history of recurrent renal calculi and showed bilateral widespread renal medullary calcification on X-ray examination. Nine...... of renal calculi in medullary sponge kidney, have considerable therapeutic implications....

  14. Renal effects of methoxyverapamil in anesthetized rats.

    Science.gov (United States)

    Brown, B; Churchill, P

    1983-05-01

    The purpose of these experiments was to determine the renal effects of methoxyverapamil (D-600). Three groups of rats were anesthetized with sodium pentobarbital and given 0, 0.85 or 1.69 nmol/min of methoxyverapamil i.v. Increases in urine flow and Na, K and Ca excretory rates occurred, in an apparently dose-dependent manner. Plasma Na and arterial renin concentration decreased at both doses and, at the higher dose, mean arterial blood pressure and effective renal plasma flow decreased while plasma K increased. Plasma Ca, glomerular filtration rate, filtration fraction and total renal plasma flow were not affected. The findings that methoxyverapamil increased urine flow and electrolyte excretion without changing glomerular filtration rate are consistent with the hypothesis that methoxyverapamil acts directly on tubular reabsorptive mechanisms. These effects, and the effect on plasma renin concentration, could contribute to the beneficial effects of this and other Ca entry antagonists in the treatment of hypertension.

  15. Renal Proteome in Mice with Different Susceptibilities to Fluorosis

    Science.gov (United States)

    Peres-Buzalaf, Camila; Salvato, Fernanda; Labate, Carlos Alberto; Everett, Eric T.; Whitford, Gary Milton; Buzalaf, Marília Afonso Rabelo

    2013-01-01

    A/J and 129P3/J mouse strains have different susceptibilities to dental fluorosis due to their genetic backgrounds. They also differ with respect to several features of fluoride (F) metabolism and metabolic handling of water. This study was done to determine whether differences in F metabolism could be explained by diversities in the profile of protein expression in kidneys. Weanling, male A/J mice (susceptible to dental fluorosis, n = 18) and 129P3/J mice (resistant, n = 18) were housed in pairs and assigned to three groups given low-F food and drinking water containing 0, 10 or 50 ppm [F] for 7 weeks. Renal proteome profiles were examined using 2D-PAGE and LC-MS/MS. Quantitative intensity analysis detected between A/J and 129P3/J strains 122, 126 and 134 spots differentially expressed in the groups receiving 0, 10 and 50 ppmF, respectively. From these, 25, 30 and 32, respectively, were successfully identified. Most of the proteins were related to metabolic and cellular processes, followed by response to stimuli, development and regulation of cellular processes. In F-treated groups, PDZK-1, a protein involved in the regulation of renal tubular reabsorption capacity was down-modulated in the kidney of 129P3/J mice. A/J and 129P3/J mice exhibited 11 and 3 exclusive proteins, respectively, regardless of F exposure. In conclusion, proteomic analysis was able to identify proteins potentially involved in metabolic handling of F and water that are differentially expressed or even not expressed in the strains evaluated. This can contribute to understanding the molecular mechanisms underlying genetic susceptibility to dental fluorosis, by indicating key-proteins that should be better addressed in future studies. PMID:23308176

  16. Renal proteome in mice with different susceptibilities to fluorosis.

    Directory of Open Access Journals (Sweden)

    Juliane Guimarães Carvalho

    Full Text Available A/J and 129P3/J mouse strains have different susceptibilities to dental fluorosis due to their genetic backgrounds. They also differ with respect to several features of fluoride (F metabolism and metabolic handling of water. This study was done to determine whether differences in F metabolism could be explained by diversities in the profile of protein expression in kidneys. Weanling, male A/J mice (susceptible to dental fluorosis, n = 18 and 129P3/J mice (resistant, n = 18 were housed in pairs and assigned to three groups given low-F food and drinking water containing 0, 10 or 50 ppm [F] for 7 weeks. Renal proteome profiles were examined using 2D-PAGE and LC-MS/MS. Quantitative intensity analysis detected between A/J and 129P3/J strains 122, 126 and 134 spots differentially expressed in the groups receiving 0, 10 and 50 ppmF, respectively. From these, 25, 30 and 32, respectively, were successfully identified. Most of the proteins were related to metabolic and cellular processes, followed by response to stimuli, development and regulation of cellular processes. In F-treated groups, PDZK-1, a protein involved in the regulation of renal tubular reabsorption capacity was down-modulated in the kidney of 129P3/J mice. A/J and 129P3/J mice exhibited 11 and 3 exclusive proteins, respectively, regardless of F exposure. In conclusion, proteomic analysis was able to identify proteins potentially involved in metabolic handling of F and water that are differentially expressed or even not expressed in the strains evaluated. This can contribute to understanding the molecular mechanisms underlying genetic susceptibility to dental fluorosis, by indicating key-proteins that should be better addressed in future studies.

  17. Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption

    DEFF Research Database (Denmark)

    Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

    1997-01-01

    to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between...... convolution of halothane-anesthetized Sprague-Dawley rats. Four parameters that depend on the rate of proximal fluid reabsorption were measured: proximal intratubular pressure (Pprox), early and late proximal flow rate, and early distal NaCl concentration. Pprox decreased by 0.5 +/- 0.1 mmHg, late proximal...... flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load...

  18. PTH modulation of NCC activity regulates TRPV5 Ca2+ reabsorption.

    Science.gov (United States)

    Hoover, Robert S; Tomilin, Viktor; Hanson, Lauren; Pochynyuk, Oleh; Ko, Benjamin

    2016-01-15

    Since parathyroid hormone (PTH) is known to increase transient receptor potential vanilloid (TRPV)5 activity and decrease Na(+)-Cl(-) cotransporter (NCC) activity, we hypothesized that decreased NCC-mediated Na(+) reabsorption contributes to the enhanced TRPV5 Ca(2+) reabsorption seen with PTH. To test this, we used mDCT15 cells expressing functional TRPV5 and ruthenium red-sensitive (45)Ca(2+) uptake. PTH increased (45)Ca(2+) uptake to 8.8 ± 0.7 nmol·mg(-1)·min(-1) (n = 4, P NCC activity from 75.4 ± 2.7 to 20.3 ± 1.3 nmol·mg(-1)·min(-1) (n = 4, P NCC is required for RasGRP1 knockdown to impact the PTH effect on TRPV5 activity. Knockdown of with no lysine kinase (WNK)4 resulted in an attenuation of the increase in PTH-mediated TRPV5 activity. TRPV5 activity increased by 36% compared with 45% in control (n = 4, P NCC activity contributes to the response to PTH, implying a role for hormonal modulation of NCC activity in distal Ca(2+) handling.

  19. CNNM2, encoding a basolateral protein required for renal Mg2+ handling, is mutated in dominant hypomagnesemia

    NARCIS (Netherlands)

    Stuiver, M.; Lainez, S.; Will, C.; Terryn, S.; Gunzel, D.; Debaix, H.; Sommer, K.; Kopplin, K.; Thumfart, J.; Kampik, N.B.; Querfeld, U.; Willnow, T.E.; Nemec, V.; Wagner, C.A.; Hoenderop, J.G.J.; Devuyst, O.; Knoers, N.V.A.M.; Bindels, R.J.M.; Meij, I.C.; Muller, D.

    2011-01-01

    Familial hypomagnesemia is a rare human disorder caused by renal or intestinal magnesium (Mg(2+)) wasting, which may lead to symptoms of Mg(2+) depletion such as tetany, seizures, and cardiac arrhythmias. Our knowledge of the physiology of Mg(2+) (re)absorption, particularly the luminal uptake of

  20. Angiotensin II signaling increases activity of the renal Na-Cl cotransporter through a WNK4-SPAK-dependent pathway.

    NARCIS (Netherlands)

    San-Cristobal, P.; Pacheco-Alvarez, D.; Richardson, C.; Ring, A.M.; Vazquez, N.; Rafiqi, F.H.; Chari, D.; Kahle, K.T.; Leng, Q.; Bobadilla, N.A.; Hebert, S.C.; Alessi, D.R.; Lifton, R.P.; Gamba, G.

    2009-01-01

    Mutations in the kinase WNK4 cause pseudohypoaldosteronism type II (PHAII), a syndrome featuring hypertension and high serum K(+) levels (hyperkalemia). WNK4 has distinct functional states that regulate the balance between renal salt reabsorption and K(+) secretion by modulating the activities of

  1. Angiotensin II signaling increases activity of the renal Na-Cl cotransporter through a WNK4-SPAK-dependent pathway.

    NARCIS (Netherlands)

    San-Cristobal, P.; Pacheco-Alvarez, D.; Richardson, C.; Ring, A.M.; Vazquez, N.; Rafiqi, F.H.; Chari, D.; Kahle, K.T.; Leng, Q.; Bobadilla, N.A.; Hebert, S.C.; Alessi, D.R.; Lifton, R.P.; Gamba, G.

    2009-01-01

    Mutations in the kinase WNK4 cause pseudohypoaldosteronism type II (PHAII), a syndrome featuring hypertension and high serum K(+) levels (hyperkalemia). WNK4 has distinct functional states that regulate the balance between renal salt reabsorption and K(+) secretion by modulating the activities of re

  2. Altered renal sodium handling and risk of incident hypertension: Results of the Olivetti Heart Study

    Science.gov (United States)

    D’Elia, Lanfranco; Cappuccio, Francesco P.; Iacone, Roberto; Russo, Ornella; Galletti, Ferruccio; Strazzullo, Pasquale

    2017-01-01

    Renal tubular sodium (Na) handling plays a key role in blood pressure (BP) regulation. Several cross-sectional studies reported a positive association between higher proximal tubule fractional reabsorption of Na and BP, but no prospective investigation has been reported of this possible association. Hence, the purpose of this study was to estimate the predictive role of renal Na handling on the risk of incident hypertension and the changes in BP occurring in the 8-year follow-up observation of a sample of initially normotensive men (The Olivetti Heart Study). The study included 294 untreated normotensive non-diabetic men with normal renal function examined twice (1994–95 and 2002–04). Renal tubular Na handling was estimated by exogenous lithium clearance. Fractional reabsorption of Na in proximal and distal tubules was calculated and included in the analysis. At baseline, there was no association between BP and either proximal or distal fractional reabsorption of Na. At the end of the 8-year follow-up, direct associations were observed between baseline proximal (but not distal) Na fractional reabsorption and the changes occurred in systolic and diastolic BP over time (+2.79 and +1.53 mmHg, respectively, per 1SD difference in proximal Na-FR; phypertension, independently of potential confounders (OR: 1.34, 95%CI:1.06–1.70). The results of this prospective investigation strongly suggest a causal relationship between an enhanced rate of Na reabsorption in the proximal tubule and the risk of incident hypertension in initially normotensive men. PMID:28196131

  3. [Reabsorption of yellow fluorescent protein in the Rana temporaria kidney by receptor-mediated endocytosis].

    Science.gov (United States)

    Seliverstova, E V; Prutskova, N P

    2014-01-01

    The absorption of yellow fluorescent protein (YFP) and the expression of the endocytic receptors, megalin and cubilin, were investigated in the renal proximal tubules (PT) in frogs Rana temporaria after parenteral YFP injections. The methods of confocal microscopy and immunohistochemistry were used. The dynamics of YFP absorption was analyzed 2 h after injection. The logarithmic time dependence of the accumulation of YFP-containing endocytic vesicles in PT cells and the completion of absorption process 90-120 min after injection were shown. Unlike substantial megalin and cubilin expression 15-30 min after YFP introduction, immunolabeled endocytic receptors were not detected in PT cells after 2 h. The re-injection of YFP led to the appearance of apical endocytic vesicles containing megalin or cubilin colocalized with YFP. At the same time, the decrease of YFP uptake associated with reduction in the number of receptor-containing vesicles was demonstrated, suggesting a failure of megalin and cubilin expression. The decrease of absorption capacity of PT cells after YFP re-injection was similar to that found previously under conditions of the competitive absorption of green fluorescent protein (GFP) and YFP injected in different sequences. The data are the further demonstration of the proposed mechanism limiting the tubular protein absorption in the frog kidney and suggest the involvement of megalin and cubilin in uptake and vesicular transport of YFP.

  4. Effect of inhibition of converting enzyme on renal hemodynamics and sodium management in polycystic kidney disease.

    Science.gov (United States)

    Torres, V E; Wilson, D M; Burnett, J C; Johnson, C M; Offord, K P

    1991-10-01

    We compared the tubular transport of sodium and the erythrocyte sodium-lithium countertransport activity in hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD) and in normotensive control subjects. In addition, we assessed the effects of inhibition of converting enzyme on renal hemodynamics and sodium excretion in hypertensive patients with ADPKD to provide information on mechanisms responsible for the increased renal vascular resistance and filtration fraction and the adjustment of the pressure-natriuresis relationship during saline expansion, observed in patients with ADPKD, hypertension, and preserved renal function. In comparison with normotensive control subjects, the hypertensive patients with ADPKD had lower renal plasma flows, higher renal vascular resistances and filtration fractions, and similar proximal and distal fractional reabsorptions of sodium. The administration of enalapril resulted in significant increases in the renal plasma flow and significant reductions in mean arterial pressure, renal vascular resistance, and filtration fraction, but the glomerular filtration rate remained unchanged. Despite the significant reduction in mean arterial pressure during inhibition of converting enzyme, the distal fractional reabsorption of sodium decreased while the total fractional excretion of sodium remained unchanged or increased slightly. No significant differences were detected between the normotensive control subjects and the hypertensive patients with ADPKD in erythrocyte sodium-lithium countertransport activity, plasma renin activity, plasma aldosterone concentration, or atrial natriuretic factor. These results suggest that the renal renin-angiotensin system plays a central role in the alterations in renal hemodynamics and sodium management associated with the development of hypertension in ADPKD.

  5. Trauma renal Renal trauma

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior

    1999-02-01

    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

  6. The effect of nifedipine on graft function in renal allograft recipients treated with cyclosporin A.

    Science.gov (United States)

    Propper, D J; Whiting, P H; Power, D A; Edward, N; Catto, G R

    1989-08-01

    The effect of the calcium channel antagonist nifedipine on renal allograft function was assessed in two groups of renal transplant recipients at least one year after transplantation. Group 1 comprised 10 patients receiving low-dose prednisolone and cyclosporin A, and Group 2 comprised 9 patients receiving low-dose prednisolone and azathioprine. Before commencing nifedipine, creatinine and sodium clearance rates and the fractional excretion of sodium were similar in both two groups. Lithium clearance rates and the fractional excretion of lithium were, however, significantly lower (p less than 0.01) in Group 1 than in Group 2. The absolute reabsorption of sodium from the distal nephron (p less than 0.01), the absolute reabsorption of water from the distal nephron segment (p less than 0.01) and the fractional reabsorption of sodium from the distal tubule relative to the delivery of sodium from the proximal tubule (p less than 0.05) were also lower in Group 1. After seven days of nifedipine treatment (10 mg/8 h) there was a significant fall in sodium clearance (p less than 0.01) and fractional sodium excretion (p less than 0.05), and an increase in the fractional distal reabsorption of sodium relative to the delivery of sodium from the proximal tubule (p less than 0.01), and the fractional distal reabsorption of water relative to the delivery of water from the proximal tubule (p less than 0.02), in Group 1 but not Group 2. The only alterations observed in Group 2 were an increase in fractional lithium excretion (p less than 0.05), and a significant fall in the absolute proximal tubular reabsorption of iso-osmotic fluids (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Renal arteriography

    Science.gov (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, ...

  8. Localisation and mechanism of renal retention of radiolabelled somatostatin analogues

    Energy Technology Data Exchange (ETDEWEB)

    Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Barone, Raffaella [UCL, Centre of Nuclear Medicine and Laboratory of PET, Brussels (Belgium); Visser, Theo J. [Erasmus MC, Department of Internal Medicine, Rotterdam (Netherlands)

    2005-10-01

    Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scintigraphy and radionuclide therapy. The kidney is the most important critical organ during such therapy owing to the reabsorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake after intravenous injection of radiolabelled somatostatin analogues. The multi-ligand megalin/cubilin receptor complex, responsible for reabsorption of many peptides and proteins in the kidney, is an interesting candidate for renal endocytosis of these peptide analogues. For localisation studies, ex vivo autoradiography and micro-autoradiography of rat kidneys were performed 1-24 h after injection of radiolabelled somatostatin analogues and compared with the renal anti-megalin immunohistochemical staining pattern. To confirm a role of megalin in the mechanism of renal retention of [{sup 111}In-DTPA]octreotide, the effects of three inhibitory substances were explored in rats. Renal ex vivo autoradiography showed high cortical radioactivity and lower radioactivity in the outer medulla. The distribution of cortical radioactivity was inhomogeneous. Micro-autoradiography indicated that radioactivity was only retained in the proximal tubules. The anti-megalin immunohistochemical staining pattern showed a strong similarity with the renal [{sup 111}In-DTPA]octreotide ex vivo autoradiograms. Biodistribution studies showed that co-injection of positively charged d-lysine reduced renal uptake to 60% of control. Sodium maleate reduced renal [{sup 111}In-DTPA]octreotide uptake to 15% of control. Finally, cisplatin pre-treatment of rats reduced kidney uptake to 70% of control. Renal retention of [{sup 111}In-DTPA]octreotide is confined to proximal tubules in the rat kidney, in which megalin-mediated endocytosis may play an important part. (orig.)

  9. The cytochrome P-450 inhibitor cobalt chloride prevents inhibition of renal Na,K-ATPase and redistribution of apical NHE-3 during acute hypertension

    DEFF Research Database (Denmark)

    Zhang, Y B; Magyar, C E; Holstein-Rathlou, N H

    1998-01-01

    Acute systolic arterial hypertension provokes a rapid decrease in proximal tubule sodium reabsorption and diuresis associated with inhibition of renal cortex Na,K-ATPase activity and redistribution of apical membrane Na/H exchanger (NHE-3) to heavier density membranes containing markers of interm......Acute systolic arterial hypertension provokes a rapid decrease in proximal tubule sodium reabsorption and diuresis associated with inhibition of renal cortex Na,K-ATPase activity and redistribution of apical membrane Na/H exchanger (NHE-3) to heavier density membranes containing markers...... reabsorption and diuresis and abolishes Na,K-ATPase inhibition and NHE-3 redistribution during acute hypertension, evidence that these responses may be mediated by cytochrome P-450 arachidonate metabolites....

  10. Renal neurohormonal regulation in heart failure decompensation.

    Science.gov (United States)

    Jönsson, Sofia; Agic, Mediha Becirovic; Narfström, Fredrik; Melville, Jacqueline M; Hultström, Michael

    2014-09-01

    Decompensation in heart failure occurs when the heart fails to balance venous return with cardiac output, leading to fluid congestion and contributing to mortality. Decompensated heart failure can cause acute kidney injury (AKI), which further increases mortality. Heart failure activates signaling systems that are deleterious to kidneys such as renal sympathetic nerve activity (RSNA), renin-angiotensin-aldosterone system, and vasopressin secretion. All three reduce renal blood flow (RBF) and increase tubular sodium reabsorption, which may increase renal oxygen consumption causing AKI through renal tissue hypoxia. Vasopressin contributes to venous congestion through aquaporin-mediated water retention. Additional water retention may be mediated through vasopressin-induced medullary urea transport and hyaluronan but needs further study. In addition, there are several systems that could protect the kidneys and reduce fluid retention such as natriuretic peptides, prostaglandins, and nitric oxide. However, the effect of natriuretic peptides and nitric oxide are blunted in decompensation, partly due to oxidative stress. This review considers how neurohormonal signaling in heart failure drives fluid retention by the kidneys and thus exacerbates decompensation. It further identifies areas where there is limited data, such as signaling systems 20-HETE, purines, endothelin, the role of renal water retention mechanisms for congestion, and renal hypoxia in AKI during heart failure.

  11. On determinants of glomerular filtration rate after inhibition of proximal tubular reabsorption

    DEFF Research Database (Denmark)

    Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

    1994-01-01

    The carbonic anhydrase inhibitor acetazolamide (ACZ) inhibits the absolute rate of proximal reabsorption (APR), causes a reduction in glomerular filtration rate (GFR), and activates the tubuloglomerular feedback mechanism (TGF) resulting in afferent vasoconstriction. The quantitative importance...... vasoconstriction seen after carbonic anhydrase inhibition fails to restore GFR to its control value. This is due to the high flow resistance in the distal nephron segments during the increased tubular flow rates seen after ACZ. The high distal flow resistance causes a parallel change in Pgc and Pprox and thus...... leaves delta P nearly unchanged. The present study highlights the importance of the distal flow resistance in determining delta P and therefore GFR during conditions where tubular flow rate is increased....

  12. Core/shell quantum dot based luminescent solar concentrators with reduced reabsorption and enhanced efficiency.

    Science.gov (United States)

    Coropceanu, Igor; Bawendi, Moungi G

    2014-07-09

    CdSe/CdS core/shell quantum dots (QDs) have been optimized toward luminescent solar concentration (LSC) applications. Systematically increasing the shell thickness continuously reduced reabsorption up to a factor of 45 for the thickest QDs studied (with ca. 14 monolayers of CdS) compared to the initial CdSe cores. Moreover, an improved synthetic method was developed that retains a high-fluorescence quantum yield, even for particles with the thickest shell volume, for which a quantum yield of 86% was measured in solution. These high quantum yield thick shell quantum dots were embedded in a polymer matrix, yielding highly transparent composites to serve as prototype LSCs, which exhibited an optical efficiency as high as 48%. A Monte Carlo simulation was developed to model LSC performance and to identify the major loss channels for LSCs incorporating the materials developed. The results of the simulation are in excellent agreement with the experimental data.

  13. Tuning luminescence and reducing reabsorption of CdSe quantum disks forluminescent solar concentrators.

    Science.gov (United States)

    Lin, Huichuan; Xie, Peng; Liu, Yong; Zhou, Xiang; Li, Baojun

    2015-08-21

    Cadmium selenide (CdSe) quantum disks (QDs) have been synthesized for application in luminescent solar concentrators (LSCs). Luminescence tuning and reabsorption reduction of the QDs were achieved by controlling their size using a hot injection method. The overlap of the absorption and photoluminescence spectra of the as-prepared CdSe QDs was negligible. The as-prepared CdSe QDs were incorporated into polymethylmethacrylate without aggregation and luminescence quenching. The obtained highly transparent composites with non-affecting light-emitting properties were used as LSCs. The placement of a CdSe QDs doped LSC prototype (10 × 1 × 0.1 cm) on a Si-cell resulted in a 201% increase in the electrical power output of the Si-cell compared with that of the bare Si-cell.

  14. The role of plasma volume, plasma renin and the sympathetic nervous system in the posture-induced decline in renal lithium clearance in man.

    Science.gov (United States)

    Smith, D F; Shimizu, M

    1978-01-01

    Excretion of lithium in urine was studied in 2 healthy males while recumbent and while upright, either walking or standing quietly. An oral dose of 24.3 mmol of Lit was taken as three lithium carbonate tablets 13 h before clearance tests. Renal lithium clearance decreased and lithium fractional reabsorption increased while upright. Standing immersed to the neck in water, which prevents the fall in plasma volume upon changing posture from recumbent to upright, prevented the fall in renal lithium clearance as well as the rise in lithium fractional reabsorption while upright. Oral doses of guanethidine (total dose of 200 mg) or oxprenolol (total dose of 140 mg) taken to prevent high levels of sympathetic nervous system activity and plasma renin, respectively, failed to prevent the fall in renal lithium clearance or the rise in lithium fractional reabsorption upon changing posture from recumbent to upright. The findings indicate that the fall in renal lithium clearance and the rise in lithium fractional reabsorption upon changing posture from recumbent to upright is related to the fall in plasma volume but not to high levels of sympathetic nervous system activity or plasma renin activity.

  15. Renal Osteodystrophy

    Directory of Open Access Journals (Sweden)

    Aynur Metin Terzibaşoğlu

    2004-12-01

    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.

  16. Força muscular respiratória e capacidade funcional na insuficiência renal terminal Respiratory muscle strength and functional capacity in end-stage renal disease (ESRD

    Directory of Open Access Journals (Sweden)

    Thiago Dipp

    2010-08-01

    Full Text Available OBJETIVO: Verificar a associação da força muscular respiratória com a capacidade funcional, força proximal de membros inferiores e variáveis bioquímicas em pacientes em hemodiálise (HD. MÉTODOS: Participaram deste estudo 30 indivíduos (18 homens, com 53,4 ± 12,9 anos e tempo de HD de 41,1 ± 55,7 meses. Foram avaliados pressão inspiratória máxima (PImax, pressão expiratória máxima (PEmax, distância percorrida no teste de caminhada de seis minutos (6MWT, número de repetições no teste de sentar-e-levantar em 30 segundos (TSL e registrados os exames bioquímicos de rotina no serviço. RESULTADOS: Houve diminuição da PEmax em relação aos valores preditos (p = 0,015 e redução na distância percorrida no 6MWT quando comparados com equações de predição (p OBJECTIVE: to evaluate the association of respiratory muscle strength with functional capacity, lower limb strength and biochemical variables in hemodialysis (HD patients. METHODS: a cross-sectional study involving 30 patients (18 male, 53.4 ± 12.9 years, 41.1 ± 55.7 months on HD therapy. Maximal inspiratory pressure (PImax, maximal expiratory pressure (PEmax, distance completed in a six-minute walk test (6MWT and number of repetitions in sit-and-stand test (STST were evaluated. The biochemical variables were recorded in the database routine work service. RESULTS: LogEPmax and 6MWT values were significantly lower than the predicted values (p = 0.015; p < 0.001, respectively. logPImax and logPEmax were correlated with number of repetitions in STST (r = 0.476, p = 0.008; r = 0.540, p = 0.002, respectively and with phosphorus blood levels (r = 0.422, p = 0.020; r = 0.639, p < 0.001, respectively. 6MWT was correlated with logPEmax (r = 0.511; p = 0.004 and with number of repetitions in STST (r = 0.561; p = 0.001. CONCLUSION: PEmax reduction in patients with ESRD on HD is associated with functional capacity, lower limb strength and phosphorus blood levels, and may at least

  17. Icodextrin re-absorption varies with age in children on automated peritoneal dialysis.

    Science.gov (United States)

    Dart, Allison; Feber, Janusz; Wong, Hubert; Filler, Guido

    2005-05-01

    Information on the use of Icodextrin in children remains scarce; however, it is believed that the characteristics are similar across all ages. We report the use of Icodextrin in a cohort of pediatric automated peritoneal dialysis (APD) patients younger than those previously reported (n=8, median age of 2.8, range 0.02-17.1 years). Net Icodextrin daytime dwell ultrafiltration was calculated in each patient for every day on therapy as ml/h/m2. Half of the patients showed re-absorption even when reducing Icodextrin dwells from a median of 10 to 6 h. All four patients who re-absorbed the Icodextrin (ranging from -23.7+/-7.5 to -2.5+/-6.0 ml/h/m2) were treated with cyclic nocturnal APD, and three of these four patients were high transporters on the peritoneal equilibration test (PET). Icodextrin fluid removal correlated significantly with age (Spearman rank r=0.8571, P=0.0107). The data suggest that Icodextrin behaves differently in young children.

  18. Caffeine-induced diuresis and natriuresis is independent of renal tubular NHE3

    OpenAIRE

    Fenton, Robert A.; Poulsen, Søren B.; de la Mora Chavez, Samantha; Soleimani, Manoocher; Busslinger, Meinrad; Dominguez Rieg, Jessica A.; Rieg, Timo

    2015-01-01

    Caffeine is one of the most widely consumed behavioral substances. We have previously shown that caffeine- and theophylline-induced inhibition of renal reabsorption causes diuresis and natriuresis, an effect that requires functional adenosine A1 receptors. In this study, we tested the hypothesis that blocking the Gi protein-coupled adenosine A1 receptor via the nonselective adenosine receptor antagonist caffeine changes Na+/H+ exchanger isoform 3 (NHE3) localization and phosphorylation, resul...

  19. Renal morphology of Bradypus torquatus

    Directory of Open Access Journals (Sweden)

    Pedro Kastein Faria da Cunha Bianchi

    2012-11-01

    Full Text Available Among the Xenarthras, sloths present a hydric ingestion restricted to water from leaves, fruits, and vegetables. As a first approach to verify whether these animals have some morphophysiological difference which could justify or compensate this low hydric ingestion, the renal anatomy of these animals was investigated, particularly that of maned sloth (Bradypus torquatus. Kidneys from these animals were macroscopically analyzed, through light microscopy and scanning electron microscopy. The Bradypus torquatus kidneys are bean-shaped paired organs, located dorso-cranially to the pelvic girdle, between the peritoneum and the posterior abdominal wall. The use of histological techniques allowed us to identify, in the cortical region, the renal corpuscles and tubules, and, in the medullary region, a significant amount of interstitial tissue with a collecting duct. The results of this study showed that, although Bradypus torquatus doesn’t drink water directly, its kidneys doesn’t differ from that of most mammals, presenting the same anatomical structure, suggesting that these animals fully reach their hydric needs, basically by consuming leaves, fruits, and sprouts. Nevertheless, in order to confirm this hypothesis, studies on the effectiveness of water reabsorption, such as the renin-angiotensin-aldosterone system, must be carried out.

  20. Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique.

    Science.gov (United States)

    Tuğcu-Demiröz, Fatmanur; Gonzalez-Alvarez, Isabel; Gonzalez-Alvarez, Marta; Bermejo, Marival

    2014-10-01

    The aim of the present study was to develop a method for water flux reabsorption measurement in Doluisio's Perfusion Technique based on the use of phenol red as a non-absorbable marker and to validate it by comparison with gravimetric procedure. The compounds selected for the study were metoprolol, atenolol, cimetidine and cefadroxil in order to include low, intermediate and high permeability drugs absorbed by passive diffusion and by carrier mediated mechanism. The intestinal permeabilities (Peff) of the drugs were obtained in male and female Wistar rats and calculated using both methods of water flux correction. The absorption rate coefficients of all the assayed compounds did not show statistically significant differences between male and female rats consequently all the individual values were combined to compare between reabsorption methods. The absorption rate coefficients and permeability values did not show statistically significant differences between the two strategies of concentration correction. The apparent zero order water absorption coefficients were also similar in both correction procedures. In conclusion gravimetric and phenol red method for water reabsorption correction are accurate and interchangeable for permeability estimation in closed loop perfusion method.

  1. Renal perfusion scintiscan

    Science.gov (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 ...

  2. New molecular players facilitating Mg(2+) reabsorption in the distal convoluted tubule.

    NARCIS (Netherlands)

    Glaudemans, B.; Knoers, N.V.A.M.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2010-01-01

    The renal distal convoluted tubule (DCT) has an essential role in maintaining systemic magnesium (Mg(2+)) concentration. The DCT is the final determinant of plasma Mg(2+) levels, as the more distal nephron segments are largely impermeable to Mg(2+). In the past decade, positional candidate strategie

  3. New molecular players facilitating Mg(2+) reabsorption in the distal convoluted tubule.

    NARCIS (Netherlands)

    Glaudemans, B.; Knoers, N.V.A.M.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2010-01-01

    The renal distal convoluted tubule (DCT) has an essential role in maintaining systemic magnesium (Mg(2+)) concentration. The DCT is the final determinant of plasma Mg(2+) levels, as the more distal nephron segments are largely impermeable to Mg(2+). In the past decade, positional candidate strategie

  4. Endocytic receptor LRP2/megalin-of holoprosencephaly and renal Fanconi syndrome.

    Science.gov (United States)

    Willnow, Thomas E; Christ, Annabel

    2017-08-01

    Megalin (or LRP2) is an endocytic receptor that plays a central role in embryonic development and adult tissue homeostasis. Loss of this receptor in congenital or acquired diseases results in multiple organ dysfunctions, including forebrain malformation (holoprosencephaly) and renal reabsorption defects (renal Fanconi syndrome). Here, we describe current concepts of the mode of receptor action that include co-receptors and a repertoire of different ligands, and we discuss how these interactions govern functional integrity of the kidney and the brain, and cause disease when defective.

  5. RENAL CRYOABLATION

    Directory of Open Access Journals (Sweden)

    A. V. Govorov

    2012-01-01

    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.

  6. Renal angiomyolipoma

    DEFF Research Database (Denmark)

    Holm-Nielsen, P; Sørensen, Flemming Brandt

    1988-01-01

    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...

  7. Renal Cancer in the Elderly.

    Science.gov (United States)

    González León, Tania; Morera Pérez, Maricela

    2016-01-01

    The increase of the aging population corresponds with the rise of renal cancer in elderly patients. The distinction between functional and chronological age, quality of life, and survival estimate are important issues, among others, that should be considered in the management of renal cancer in elderly patients. We made this review with the purpose of synthesizing the most updated criteria regarding indications and outcomes of the different therapeutic options in the management of elderly patients with renal cancer, beginning from the physiologic considerations that characterize them, their capacity to tolerate different therapeutic possibilities, and the prognosis of the patients' risks and comorbidity assessment.

  8. Renal tubular acidosis.

    Science.gov (United States)

    Rothstein, M; Obialo, C; Hruska, K A

    1990-12-01

    Renal tubular acidosis refers to a group of disorders that result from pure tubular damage without concomitant glomerular damage. They could be hereditary (primary) or acquired (secondary to various disease states like sickle cell disease, obstructive uropathy, postrenal transplant, autoimmune disease, or drugs). The hallmark of the disorder is the presence of hyperchloremic metabolic acidosis with, or without, associated defects in potassium homeostasis, a UpH greater than 5.5 in the presence of systemic acidemia, and absence of an easily identifiable cause of the acidemia. There are three physiologic types whose basic defects are impairment of or a decrease in acid excretion, i.e., type 1 (dRTA); a failure in bicarbonate reabsorption, i.e., type 2 (pRTA); and deficiency of buffer or impaired generation of NH4+, i.e., type 4 RTA. Several pathophysiologic mechanisms have been postulated for these various types. pRTA is the least common of all in the adult population. It rarely occurs as an isolated defect. It is frequently accompanied by diffuse proximal tubule transport defects with aminoaciduria, glycosuria, hyperphosphaturia, and so forth (Fanconi syndrome). dRTA is associated with a high incidence of nephrolithiasis, nephrocalcinosis, osteodystrophy, and growth retardation (in children). Osteodystrophy also occurs in pRTA to a lesser degree and is believed to be secondary to hypophosphatemia. Patients with type 4 RTA usually have mild renal insufficiency from either diabetes mellitus or interstitial nephritis. Acute bicarbonate loading will result in a high fractional excretion of bicarbonate greater than 15% (FEHCO3- greater than 15%) in patients with pRTA, but FEHCO3- less than 3% in patients with dRTA. Type I patients will also have a low (U - B) PCO2 with bicarbonate loading. They are also unable to lower their urine pH to less than 5.5 with NH4Cl loading. The treatment of these patients involves avoidance of precipitating factors when possible, treatment

  9. Antidiuretic effects of a factor in brain/corpora cardiaca/corpora allata extract on fluid reabsorption across the cryptonephric complex of Manduca sexta.

    Science.gov (United States)

    Liao, S; Audsley, N; Schooley, D A

    2000-02-01

    Extracts of the brain/corpora cardiaca/corpora allata (Br/CC/CA) complex of Manduca sexta larvae elicit an antidiuretic effect, measured by an increase in fluid reabsorption across the cryptonephric complex of larval M. sexta. Separation of the extract by reversed-phase liquid chromatography gave two fractions with antidiuretic effects. The more potent of these two factors was further characterized for its effects on the cryptonephric complex. Its antidiuretic effect is not inhibited by bumetanide, a drug that inhibits M. sexta diuretic hormone (Mas-DH)-stimulated fluid reabsorption. These data indicate that the mechanism of the antidiuretic effect of the factor is different from that of Mas-DH on the cryptonephric complex. The basal reabsorption of the cryptonephric complex is blocked when treated on the lumen side with bafilomycin A(1), an inhibitor of the H(+)-ATPase, or with amiloride, an inhibitor of the H(+)/K(+) antiporter. However, the antidiuretic-factor-stimulated fluid reabsorption is not affected by either bafilomycin A(1) or amiloride. The increase in reabsorption triggered by the semi-purified factor can be inhibited by Cl(-) channel blockers or by removing Cl(-) from the lumen side of the cryptonephric complex. It appears that this factor activates a Cl(-) pump associated with the cryptonephric complex. Forskolin mimics the effect of this factor on fluid reabsorption, and the effect of forskolin is not inhibited by bumetanide. A selective and potent inhibitor of protein kinase A, H-89, also inhibits antidiuretic-factor-stimulated fluid reabsorption. Addition of the factor to cryptonephric complexes maintained in vitro caused a significant increase in cyclic AMP levels extracted from these tissues compared with values for controls. These data suggest that the antidiuretic effect of the factor in Br/CC/CA extract is mediated by cyclic AMP.

  10. Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport

    Directory of Open Access Journals (Sweden)

    Nobuhiko Satoh

    2015-01-01

    Full Text Available A serine/threonine kinase Akt is a key mediator in various signaling pathways including regulation of renal tubular transport. In proximal tubules, Akt mediates insulin signaling via insulin receptor substrate 2 (IRS2 and stimulates sodium-bicarbonate cotransporter (NBCe1, resulting in increased sodium reabsorption. In insulin resistance, the IRS2 in kidney cortex is exceptionally preserved and may mediate the stimulatory effect of insulin on NBCe1 to cause hypertension in diabetes via sodium retention. Likewise, in distal convoluted tubules and cortical collecting ducts, insulin-induced Akt phosphorylation mediates several hormonal signals to enhance sodium-chloride cotransporter (NCC and epithelial sodium channel (ENaC activities, resulting in increased sodium reabsorption. Serum- and glucocorticoid-inducible kinase 1 (SGK1 mediates aldosterone signaling. Insulin can stimulate SGK1 to exert various effects on renal transporters. In renal cortical collecting ducts, SGK1 regulates the expression level of ENaC through inhibition of its degradation. In addition, SGK1 and Akt cooperatively regulate potassium secretion by renal outer medullary potassium channel (ROMK. Moreover, sodium-proton exchanger 3 (NHE3 in proximal tubules is possibly activated by SGK1. This review focuses on recent advances in understanding of the roles of Akt and SGK1 in the regulation of renal tubular transport.

  11. Mechanism of increased renal clearnace of amylase/creatinine in acute pancreatitis.

    Science.gov (United States)

    Johnson, S G; Ellis, C J; Levitt, M D

    1976-11-25

    We investigated three possible causes of the increased ratio of amylase/creatinine clearance observed in acute pancreatitis. The presence of rapidly cleared isoamylase was excluded by studies of serum and urine, which demonstrated no anomalous isoamylases. In pancreatitis, the ratios (+/-1 S.E.M.) of both pancreatic isoamylase (9.2+/-0.6 per cent) and salivary isoamylase (8.6+/-1.6 per cent) were significantly (P less than 0.01) elevated over respective control values (2.4+/-0.2 and 1.8+/-0.2 per cent). Increased glomerular permeability to amylase was excluded by the demonstration of normal renal clearance of dextrans. We tested tubular reabsorption of protein by measuring the renal clearance of beta2-microglobulin, which is relatively freely filtered at the glomerulus and then avidly reabsorbed by the normal tubule. During acute pancreatitis the ratio of the renal clearance of beta2-microglobulin to that of creatinine was 1.22+/-0.52 per cent, an 80-fold increase over normal (0.015+/-0.002 per cent), with a rapid return toward normal during convalescence. Presumably, this reversible renal tubular defect also reduces amylase reabsorption and accounts for the elevated renal clearance of amylase/creatinine observed in acute pancreatitis.

  12. A new human NHERF1 mutation decreases renal phosphate transporter NPT2a expression by a PTH-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Marie Courbebaisse

    Full Text Available BACKGROUND: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1 binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. METHODS: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. RESULTS: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. CONCLUSIONS: Our results indicate that the PDZ1 domain is critical for NHERF1-NPT2a interaction in humans and for the control of NPT2a expression at the plasma membrane. Thus we have identified a new mechanism of renal phosphate loss and shown that different mutations in NHERF1 can alter renal phosphate reabsorption via distinct mechanisms.

  13. Determinants of renal tissue hypoxia in a rat model of polycystic kidney disease.

    Science.gov (United States)

    Ow, Connie P C; Abdelkader, Amany; Hilliard, Lucinda M; Phillips, Jacqueline K; Evans, Roger G

    2014-11-15

    Renal tissue oxygen tension (PO2) and its determinants have not been quantified in polycystic kidney disease (PKD). Therefore, we measured kidney tissue PO2 in the Lewis rat model of PKD (LPK) and in Lewis control rats. We also determined the relative contributions of altered renal oxygen delivery and consumption to renal tissue hypoxia in LPK rats. PO2 of the superficial cortex of 11- to 13-wk-old LPK rats, measured by Clark electrode with the rat under anesthesia, was higher within the cysts (32.8 ± 4.0 mmHg) than the superficial cortical parenchyma (18.3 ± 3.5 mmHg). PO2 in the superficial cortical parenchyma of Lewis rats was 2.5-fold greater (46.0 ± 3.1 mmHg) than in LPK rats. At each depth below the cortical surface, tissue PO2 in LPK rats was approximately half that in Lewis rats. Renal blood flow was 60% less in LPK than in Lewis rats, and arterial hemoglobin concentration was 57% less, so renal oxygen delivery was 78% less. Renal venous PO2 was 38% less in LPK than Lewis rats. Sodium reabsorption was 98% less in LPK than Lewis rats, but renal oxygen consumption did not significantly differ between the two groups. Thus, in this model of PKD, kidney tissue is severely hypoxic, at least partly because of deficient renal oxygen delivery. Nevertheless, the observation of similar renal oxygen consumption, despite markedly less sodium reabsorption, in the kidneys of LPK compared with Lewis rats, indicates the presence of inappropriately high oxygen consumption in the polycystic kidney.

  14. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    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

  15. Renal fallure

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    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

  16. Renal cancer.

    NARCIS (Netherlands)

    Corgna, E.; Betti, M.; Gatta, G.; Roila, F.; Mulder, P.H.M. de

    2007-01-01

    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

  17. Renal cancer

    NARCIS (Netherlands)

    Corgna, Enrichetta; Betti, Maura; Gatta, Gemma; Roila, Fausto; De Mulder, Pieter H. M.

    2007-01-01

    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

  18. Renal phenotypic investigations of megalin-deficient patients: novel insights into tubular proteinuria and albumin filtration.

    Science.gov (United States)

    Storm, Tina; Tranebjærg, Lisbeth; Frykholm, Carina; Birn, Henrik; Verroust, Pierre J; Nevéus, Tryggve; Sundelin, Birgitta; Hertz, Jens Michael; Holmström, Gerd; Ericson, Katharina; Christensen, Erik I; Nielsen, Rikke

    2013-03-01

    The reabsorption of filtered plasma proteins, hormones and vitamins by the renal proximal tubules is vital for body homeostasis. Studies of megalin-deficient mice suggest that the large multi-ligand endocytic receptor megalin plays an essential role in this process. In humans, dysfunctional megalin causes the extremely rare Donnai-Barrow/Facio-Oculo-Acustico-Renal (DB/FOAR) syndrome characterized by a characteristic and multifaceted phenotype including low-molecular-weight proteinuria. In this study, we examined the role of megalin for tubular protein reabsorption in humans through analysis of proximal tubular function in megalin-deficient patients. Direct sequencing of the megalin-encoding gene (LRP2) was performed in a family in which three children presented with classical DB/FOAR manifestations. Renal consequences of megalin deficiency were investigated through immunohistochemical analyses of renal biopsy material and immunoblotting of urine samples. In the patients, a characteristic urinary protein profile with increased urinary excretion of vitamin D-binding protein, retinol-binding protein and albumin was associated with absence of, or reduced, proximal tubular endocytic uptake as shown by renal immunohistochemistry. In the absence of tubular uptake, urinary albumin excretion was in the micro-albuminuric range suggesting that limited amounts of albumin are filtered in human glomeruli. This study demonstrated that megalin plays an essential role for human proximal tubular protein reabsorption and suggests that only limited amounts of albumin is normally filtered in the human glomeruli. Finally, we propose that the characteristic urinary protein profile of DB/FOAR patients may be utilized as a diagnostic marker of megalin dysfunction.

  19. New molecular players facilitating Mg(2+) reabsorption in the distal convoluted tubule.

    Science.gov (United States)

    Glaudemans, Bob; Knoers, Nine V A M; Hoenderop, Joost G J; Bindels, René J M

    2010-01-01

    The renal distal convoluted tubule (DCT) has an essential role in maintaining systemic magnesium (Mg(2+)) concentration. The DCT is the final determinant of plasma Mg(2+) levels, as the more distal nephron segments are largely impermeable to Mg(2+). In the past decade, positional candidate strategies in families with inherited forms of hypomagnesemia have led to the identification of genes involved in Mg(2+) handling. A large fraction of this resides in the DCT, namely, (i) the transient receptor potential channel melastatin subtype 6 (TRPM6), a divalent cation-permeable channel located at the luminal membrane of the DCT, facilitates Mg(2+) entry from the pro-urine into the cell; (ii) the epidermal growth factor is a novel hormone regulating active Mg(2+) transport through TRPM6; (iii) the voltage-gated K(+) channel, Kv1.1, establishes a favorable luminal membrane potential for TRPM6-mediated Mg(2+) transport; (iv) the Na(+)/K(+)-ATPase gamma-subunit (gamma-Na(+)/K(+)-ATPase) was identified as mutated protein in a family with isolated dominant hypomagnesemia. The molecular mechanism by which gamma-Na(+)/K(+)-ATPase is involved in DCT Mg(2+) handling remains unknown; (v) a high percentage of patients with mutations in the renal transcription factor HNF1B (hepatocyte nuclear factor 1 homeobox B) gene develop hypomagnesemia; and (vi) Gitelman and EAST/SeSAME syndrome patients suffer from a similar tubulopathy due to mutations in NCC (NaCl cotransporter) and Kir4.1, respectively. In these patients, decreased expression of TRPM6 is proposed to cause hypomagnesemia. Insights into the molecular mechanisms of the identified genes, as well as the identification of novel genes, will further improve our knowledge about renal Mg(2+) handling.

  20. Effect of ambient pressure and radiation reabsorption of atmosphere on the flame spreading over thermally thin combustibles in microgravity

    Institute of Scientific and Technical Information of China (English)

    杜文峰; 胡文瑞

    2003-01-01

    For the flame spread over thermally thin combustibles in an atmosphere, if the atmosphere cannot emit and absorb the thermal radiation (e.g. for atmosphere of O2-N2), the conductive heat transfer from the flame to the fuel surface dominates the flame spread at lower ambient atmosphere. As the ambient pressure increases, the flame spread rate increases, and the radiant heat transfer from the flame to the fuel surface gradually becomes the dominant driving force for the flame spread. In contrast, if the atmosphere is able to emit and absorb the thermal radiation (e.g. for atmosphere of O2-CO2), at lower pressure, the heat transfer from flame to the fuel surface is enhanced by the radiation reabsorption of the atmosphere at the leading edge of the flame, and both conduction and thermal radiation play important roles in the mechanism of flame spread. With the increase in ambient pressure, the oxygen diffuses more quickly from ambient atmosphere into the flame, the chemical reaction in the flame is enhanced, and the flame spread rate increases. When the ambient pressure is greater than a critical value, the thermal radiation from the flame to the solid surface is hampered by the radiation reabsorption of ambient atmosphere with the further increase in ambient pressure. As a result, with the increase in ambient pressure, the flame spread rate decreases and the heat conduction gradually dominates the flame spread over the fuel surface.

  1. Renal teratogens.

    Science.gov (United States)

    Morgan, Thomas M; Jones, Deborah P; Cooper, William O

    2014-09-01

    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.

  2. Blood Pressure and the Renal Actions of AT2 Receptors.

    Science.gov (United States)

    Carey, Robert M

    2017-03-01

    Angiotensin type-2 receptors (AT2Rs) in the renal proximal tubule inhibit sodium (Na+) reabsorption by inducing renal cyclic GMP formation and internalizing and inhibiting major Na+ transporters Na+-H+ exchanger-3 (NHE-3) and Na+/K+ATPase (NKA). Instead of angiotensin II (Ang II), angiotensin III (Ang III) is the predominant endogenous agonist for this response. Exogenous non-peptide AT2R agonist Compound-21 induces natriuresis and lowers blood pressure (BP) in normal and Ang II-infused hypertensive rodents. Spontaneously hypertensive rats (SHR; both pre-hypertensive and hypertensive) have defective natriuretic responses to Ang III, suggesting a defect in AT2R-mediated natriuresis in SHR that leads to hypertension. The mechanisms of deficient AT2R-mediated natriuresis in SHR are unknown but could involve either pre-receptor or receptor/post-receptor defects.

  3. Sarcoidose renal

    Directory of Open Access Journals (Sweden)

    AQUINO MARIA ENEDINA CLAUDINO DE

    2001-01-01

    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.

  4. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    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

  5. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    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

  6. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    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-

  7. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    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

  8. Renal Hemangiopericytoma

    Directory of Open Access Journals (Sweden)

    İbrahim Halil Bozkurt

    2015-03-01

    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.

  9. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station...

  10. Markers of renal function tests

    Directory of Open Access Journals (Sweden)

    Shivaraj Gowda

    2010-04-01

    Full Text Available Background: The markers of renal function test assess the normal functioning of kidneys. These markers may be radioactive and non radioactive. They indicate the glomerular filtration rate, concentrating and diluting capacity of kidneys (tubular function. If there is an increase or decrease in the valves of these markers it indicates dysfunction of kidney. Aim: The aim of this review is to compare and analyze the present and newer markers of renal function tests which help in diagnosis of clinical disorders. Material & Methods: An extensive literature survey was done aiming to compare and compile renal function tests makers required in diagnosis of diseases. Results: Creatinine, urea, uric acid and electrolytes are makers for routine analysis whereas several studies have confirmed and consolidated the usefulness of markers such as cystatin C and β-Trace Protein. Conclusion: We conclude that further investigation is necessary to define these biomarkers in terms of usefulness in assessing renal function.

  11. Photon Emission and Reabsorption Processes in CH3NH3PbBr3 Single Crystals Revealed by Time-Resolved Two-Photon-Excitation Photoluminescence Microscopy

    Science.gov (United States)

    Yamada, Takumi; Yamada, Yasuhiro; Nakaike, Yumi; Wakamiya, Atsushi; Kanemitsu, Yoshihiko

    2017-01-01

    The dynamical processes of radiative recombination of photocarriers and reabsorption of emitted photons in CH3NH3PbBr3 single crystals are studied using time-resolved two-photon-excitation photoluminescence (PL) microscopy. We find that the PL spectrum and its decay dynamics depend on the excitation-depth profile. As the excitation depth increases, the PL spectrum becomes asymmetric, the peak energy redshifts, and the PL decay time becomes longer. These observations can be well explained by a simple model including photon recycling (photon emission and reabsorption) in thick samples with strong band-to-band transitions and high radiative recombination efficiencies.

  12. Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

    Directory of Open Access Journals (Sweden)

    J.B. Graceli

    2013-07-01

    Full Text Available The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na+ and Cl- reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg-1·day-1, sc and progesterone (OVP, 1.7 mg·kg-1·day-1, sc. We assessed Na+ and Cl- fractional excretion (FENa+ and FECl- , respectively and renal and plasma catecholamine release concentrations. FENa+ , FECl- , water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FENa+ , FECl- , water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g. Furthermore, combining OVX + D (OD: 111.9±25.4 decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function.

  13. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  14. Role of adenosine in tubuloglomerular feedback and acute renal failure.

    Science.gov (United States)

    Osswald, H; Vallon, V; Mühlbauer, B

    1996-12-01

    1. Adenosine (ADO) can induce renal vasoconstriction and a fall in glomerular filtration rate. When the rate of ATP hydrolysis prevails over the rate of ATP synthesis the kidney generates ADO at an enhanced rate. 2. Tubuloglomerular feedback (TGF) is the vascular response to changes of the NaCl concentration in the tubular fluid at the macula densa segment, which is the result of transepithelial electrolyte reabsorption by the proximal tubule and the loop of Henle. 3. TGF can be inhibited by ADO-A1 receptor antagonists and is potentiated by substances that can elevate extracellular ADO concentrations. These observations led to the hypothesis that ADO is an element of the signal transmission processes in the juxtaglomerular apparatus. 4. Renal ischaemia and nephrotoxic substances can induce acute renal failure (ARF). ADO receptor antagonists have been shown to ameliorate renal function in several different models of ARF in laboratory animals and humans. 5. A number of factors, such as extracellular volume contraction, low NaCl diet, angiotensin II and cyclooxygenase inhibitors enhance to a similar extent: (a) the renal vascular response to endogenous and exogenous ADO; (b) the TGF response of the nephron; and (c) the severity of ARF. All three phenomena are susceptible to antagonism by ADO receptor antagonists. 6. Therefore, we conclude that ADO plays a significant role in normal and pathological states of kidney function.

  15. Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Michael [Aarhus Univ. Hospital (Denmark). MR Research Centre; Aarhus Univ. (Denmark). Inst. of Experimental Clinical Medicine; Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231; Laustsen, Christoffer [Aarhus Univ. Hospital (Denmark). MR Research Centre; Perot, Vincent; Grenier, Nicolas [Hopital Pellegrin, CHU Bordeaux (France). Service d' Imagerie Diagnostique et Therapeutique de l' Adulte; Basseau, Fabrice; Moonen, Chrit [Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231

    2010-07-01

    Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2{sup *}, and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2{sup *} was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

  16. Re-absorption process in the upconversion green emission of the erbium ion-doped fluorozirconate glass system

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, G.K., E-mail: gersonkc@gmail.co [Departamento de Fisica, UEPG, Bloco L, Av. Carlos Cavalcanti, 4748, 84030-000 Ponta Grossa, PR (Brazil); Koepp, F.M. [COPEL-R. Joaquim Nabuco 184, 84025-900 Ponta Grossa, PR (Brazil); Viatroski, M.A.; Novatski, A.; Gomez, S.L.; Jurelo, A.R.; Flemming, J. [Departamento de Fisica, UEPG, Bloco L, Av. Carlos Cavalcanti, 4748, 84030-000 Ponta Grossa, PR (Brazil); Bonardi, C. [UTFPr-Av Monteiro Lobato, s/n-km 04, CEP: 84016-210 Ponta Grossa, PR (Brazil)

    2010-04-15

    In this paper we report the upconversion emission for the {sup 4}S{sub 3/2}->{sup 4}I{sub 15/2} Stark components of Er{sup 3+} ion-doped fluorozirconate glass at T=2 K. The spectrum shows only seven peaks, one less than expected theoretically, being missing the peak at the wave number 17,996 cm{sup -1} (lambda=555 nm). This result is compared with the luminescence for the same transition at the same conditions which exhibits the eight expected lines. Such a discrepancy is attributed to a re-absorption process (ESRA) between the energy levels {sup 4}I{sub 13/2} and {sup 2}H{sub 9/2}.

  17. Efeitos negativos da insuficiência renal crônica sobre a função pulmonar e a capacidade funcional Negative effects of chronic kidney failure on lung function and functional capacity

    OpenAIRE

    2010-01-01

    OBJETIVO: Avaliar a função pulmonar e a capacidade funcional em pacientes com insuficiência renal crônica (IRC) em hemodiálise e em pacientes após transplante renal. MÉTODOS: Foram avaliados 72 indivíduos, sendo 32 pacientes com IRC em hemodiálise (GD) há mais de 6 meses, 10 pacientes transplantados renais (GT) há, pelo menos, 6 meses e 30 sujeitos saudáveis para grupo controle (GC). Todos os grupos foram avaliados utilizando espirometria, pressões inspiratória (PImax) e expiratória (PEmax) m...

  18. Chronic high glucose inhibits albumin reabsorption by lysosomal alkalinization in cultured porcine proximal tubular epithelial cells (LLC-PK1).

    Science.gov (United States)

    Ishibashi, Fukashi

    2006-06-01

    Lysosomal acidification is a key step of albumin reabsorption in proximal tubular epithelial cells (PTECs). This study was performed to examine the influence of chronic high glucose on lysosomal acidification in cultured PTECs. Porcine PTECs (LLC-PK(1) cells) were cultured in 16.7 mM (300 mg/dl) glucose (HG) alone or with 0.5 mM phlorizin for 24 weeks and subsequently for 12 weeks in 5.5 mM (100 mg/dl) glucose (NG). Chronic HG inhibited the fluorescein isothiocyanate (FITC)-albumin (A) uptake progressively, while phlorizin reversed the inhibition. NG for 12 weeks after HG normalized the uptake. The time-dependent uptake of FITC-A was inhibited by HG and bafilomycin A(1) (BafA(1)) after 15 min and by 4,4'-diisothiocyanato-2,2'-disulfonic acid (DIDS) and N-ethyl-N-isopropyl-amiloride (EIPA) after 3 min. Cellular ATP was depleted by HG and restored by NG. Lysosomal pH, assessed by an acidotropic fluorescent probe, was alkalinized (pH 4.5-7.8) with 5.5-27.8 mM glucose and normalized by subsequent NG. BafA(1) alkalinized lysosomes, and the concentration required to 50% change for the pH and 50% inhibition of FITC-A uptake was similar. EIPA inhibited FITC-A uptake, but did not influence lysosomal pH. DIDS inhibited FITC-A uptake, and unexpectedly lowered lysosomal pH. Real time PCR showed that HG reduced the mRNA level for vacuolar H(+)-ATPase, but did not alter those of chloride channel-5 and Na(+)-H(+)-exchanger-3. In conclusion, the chronic HG inhibits albumin reabsorption by lysosomal alkalinization in PTECs, probably due to ATP depletion and down-regulation of vacuolar H(+)-ATPase.

  19. Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

    Science.gov (United States)

    Maeda, M; Otsuki, M; Okano, K; Yamasaki, T; Baba, S

    1981-01-01

    Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function.

  20. The Potential Role of Catheter-Based Renal Sympathetic Denervation in Chronic and End-Stage Kidney Disease.

    Science.gov (United States)

    Sata, Yusuke; Schlaich, Markus P

    2016-07-01

    Sympathetic activation is a hallmark of chronic and end-stage renal disease and adversely affects cardiovascular prognosis. Hypertension is present in the vast majority of these patients and plays a key role in the progressive deterioration of renal function and the high rate of cardiovascular events in this patient cohort. Augmentation of renin release, tubular sodium reabsorption, and renal vascular resistance are direct consequences of efferent renal sympathetic nerve stimulation and the major components of neural regulation of renal function. Renal afferent nerve activity directly influences sympathetic outflow to the kidneys and other highly innervated organs involved in blood pressure control via hypothalamic integration. Renal denervation of the kidney has been shown to reduce blood pressure in many experimental models of hypertension. Targeting the renal nerves directly may therefore be specifically useful in patients with chronic and end-stage renal disease. In this review, we will discuss the potential role of catheter-based renal denervation in patients with impaired kidney function and also reflect on the potential impact on other cardiovascular conditions commonly associated with chronic kidney disease such as heart failure and arrhythmias.

  1. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive...... carrying capacity (SCC) and assimilative carrying capacity (ACC). The act mandates that the latter two aspects must be taken into consideration in the local spatial plans. The present study aimed at developing a background for a national guideline for carrying capacity in Indonesian provinces and districts...... standard or governmental political objective exists. In most cases it was possible to select a set of indicators, including thresholds that are workable in a carrying capacity planning at the local administrative levels. Not all relevant sectors at the decentralized level were included. Indicators of SCC...

  2. Renal Cysts

    Science.gov (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 ...

  3. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    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.

  4. 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.

  5. Renal uptake of myoglobin is mediated by the endocytic receptors megalin and cubilin

    DEFF Research Database (Denmark)

    Gburek, Jakub; Birn, Henrik; Verroust, Pierre J;

    2003-01-01

    and cubilin are involved in renal reabsorption of myoglobin. Both receptors were captured from solubilized renal brush-border membranes by affinity chromatography using myoglobin-Sepharose. Myoglobin bound to purified megalin and cubilin with Kd values of 2.0 and 3 microM, respectively, as evaluated...... by surface plasmon resonance analysis. Apomyoglobin bound to megalin with the same affinity, and the affinity of apomyoglobin to cubilin was reduced (Kd = 5 microM). Radioiodinated myoglobin could be displaced by apomyoglobin in inhibition studies using isolated renal brush-border membranes (Ki approximately...... was demonstrated by use of kidney-specific megalin knockout mice. Injected myoglobin was extensively reabsorbed by megalin-expressing proximal tubular cells, whereas there was very little uptake in the megalin-deficient cells. In conclusion, this study establishes the molecular mechanism of myoglobin uptake...

  6. The effect of nifedipine on renal function in normotensive cyclosporin-A-treated renal allograft recipients.

    Science.gov (United States)

    McNally, P G; Walls, J; Feehally, J

    1990-01-01

    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.

  7. Effects of "in vivo" administration of baclofen on rat renal tubular function.

    Science.gov (United States)

    Donato, Verónica; Pisani, Gerardo Bruno; Trumper, Laura; Monasterolo, Liliana Alicia

    2013-09-05

    The effects of the in vivo administration of baclofen on renal tubular transport and aquaporin-2 (AQP2) expression were evaluated. In conscious animals kept in metabolic cages, baclofen (0.01-1mg/kg, s.c.) induced a dose-dependent increment in the urine flow rate (UFR) and in sodium and potassium excretion, associated with an increased osmolal clearance (Closm), a diminished urine to plasma osmolality ratio (Uosm/Posm) and a decrease in AQP2 expression. The above mentioned baclofen effects on functional parameters were corroborated by using conventional renal clearance techniques. Additionally, this model allowed the detection of a diminution in glucose reabsorption. Some experiments were performed with water-deprived or desmopressin-treated rats kept in metabolic cages. Either water deprivation or desmopressin treatment decreased the UFR and increased the Uosm/Posm. Baclofen did not change the Uosm/Posm or AQP2 expression in desmopressin-treated rats; but it increased the UFR and diminished the Uosm/Posm and AQP2 expression in water-deprived animals. These results indicate that in vivo administration of baclofen promotes alterations in proximal tubular transport, since glucose reabsorption was decreased. The distal tubular function was also affected. The increased Closm indicates an alteration in solute reabsorption at the ascending limb of the Henle's loop. The decreased Uosm/Posm and AQP2 expression in controls and in water-deprived, but not in desmopressin-treated rats, lead us to speculate that some effect of baclofen on endogenous vasopressin availability could be responsible for the impaired urine concentrating ability, more than any disturbance in the responsiveness of the renal cells to the hormone.

  8. Renal sodium handling in children with nephrotic relapse: relation to hypovolaemic symptoms.

    Science.gov (United States)

    Van de Walle, J G; Donckerwolcke, R A; Greidanus, T B; Joles, J A; Koomans, H A

    1996-11-01

    We studied renal sodium handling during water diuresis in children in the early phase of relapse of minimal lesion nephrotic syndrome (MLNS). Findings were related to presence or absence of symptoms suggestive of hypovolaemia, and to neurohumoral factors, and were compared to results of similar studies in the same children in remission. Nine children (aged 7.8 +/- 3.1 years) presented with hypovolaemic symptoms, and 10 (7.4 +/- 4.3 years) without such symptoms. Both groups displayed severe proteinuria, hypoproteinaemia and oedema. Symptomatic patients showed tendency for a low glomerular filtration rate, and significantly impaired urine dilution, decreased fractional sodium and lithium excretions, and elevated diluting segment reabsorption [CH2O/(CH2O + CNa)] and sodium/potassium exchange [UK/(UK + UNa)]. In the non-symptomatic patients these parameters were normal. Plasma renin and aldosterone were significantly elevated in the symptomatic children, and strongly correlated with all parameters of tubule sodium reabsorption. Weaker associations were found for plasma noradrenaline and atrial natriuretic peptide. Vasopressin was also relatively high in the symptomatic group, but showed no association with impaired urine dilution. The diffusely stimulated tubular sodium reabsorption in the symptomatic children, in association with stimulated neurohumoral factors, indicates that secondary sodium retention contributes to oedema formation in at least a subset of children developing a nephrotic relapse. This may be limited to the early stage, and be more pronounced in some patients than in others. The tubular defect responsible for maintenance of oedema in stabilized MLNS remains unclear.

  9. Regulation of blood pressure and renal function by NCC and ENaC: lessons from genetically engineered mice.

    Science.gov (United States)

    Verouti, Sophia N; Boscardin, Emilie; Hummler, Edith; Frateschi, Simona

    2015-04-01

    The activity of the thiazide-sensitive Na(+)/Cl(-) cotransporter (NCC) and of the amiloride-sensitive epithelial Na(+) channel (ENaC) is pivotal for blood pressure regulation. NCC is responsible for Na(+) reabsorption in the distal convoluted tubule (DCT) of the nephron, while ENaC reabsorbs the filtered Na(+) in the late DCT and in the cortical collecting ducts (CCD) providing the final renal adjustment to Na(+) balance. Here, we aim to highlight the recent advances made using transgenic mouse models towards the understanding of the regulation of NCC and ENaC function relevant to the control of sodium balance and blood pressure. We thus like to pave the way for common mechanisms regulating these two sodium-transporting proteins and their potential implication in structural remodeling of the nephron segments and Na(+) and Cl(-) reabsorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Dopamine and angiotensin type 2 receptors cooperatively inhibit sodium transport in human renal proximal tubule cells.

    Science.gov (United States)

    Gildea, John J; Wang, Xiaoli; Shah, Neema; Tran, Hanh; Spinosa, Michael; Van Sciver, Robert; Sasaki, Midori; Yatabe, Junichi; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2012-08-01

    Little is known regarding how the kidney shifts from a sodium and water reclaiming state (antinatriuresis) to a state where sodium and water are eliminated (natriuresis). In human renal proximal tubule cells, sodium reabsorption is decreased by the dopamine D(1)-like receptors (D(1)R/D(5)R) and the angiotensin type 2 receptor (AT(2)R), whereas the angiotensin type 1 receptor increases sodium reabsorption. Aberrant control of these opposing systems is thought to lead to sodium retention and, subsequently, hypertension. We show that D(1)R/D(5)R stimulation increased plasma membrane AT(2)R 4-fold via a D(1)R-mediated, cAMP-coupled, and protein phosphatase 2A-dependent specific signaling pathway. D(1)R/D(5)R stimulation also reduced the ability of angiotensin II to stimulate phospho-extracellular signal-regulated kinase, an effect that was partially reversed by an AT(2)R antagonist. Fenoldopam did not increase AT(2)R recruitment in renal proximal tubule cells with D(1)Rs uncoupled from adenylyl cyclase, suggesting a role of cAMP in mediating these events. D(1)Rs and AT(2)Rs heterodimerized and cooperatively increased cAMP and cGMP production, protein phosphatase 2A activation, sodium-potassium-ATPase internalization, and sodium transport inhibition. These studies shed new light on the regulation of renal sodium transport by the dopaminergic and angiotensin systems and potential new therapeutic targets for selectively treating hypertension.

  11. Is the renal kallikrein-kinin system a factor that modulates hypercalciuria?

    Directory of Open Access Journals (Sweden)

    Armando Luis Negri

    2017-01-01

    Full Text Available Renal tubular calcium reabsorption is one of the principal factors that determine serum calcium concentration and calcium excretion. Calcium excretion is regulated by the distal convoluted tubule and connecting tubule, where the epithelial calcium channel TRPV5 can be found, which limits the rate of transcellular calcium transport. The dynamic presence of the TRPV5 channel on the surface of the tubular cell is mediated by an endosomal recycling process. Different intrarenal factors are involved in calcium channel fixation in the apical membrane, including the anti-ageing hormone klotho and tissue kallikrein (TK. Both proteins are synthesised in the distal tubule and secreted in the tubular fluid. TK stimulates active calcium reabsorption through the bradykinin receptor B2 that compromises TRPV5 activation through the protein kinase C pathway. TK-deficient mice show hypercalciuria of renal origin comparable to that seen in TRPV5 knockout mice. There is a polymorphism with loss of function of the human TK gene R53H (allele H that causes a marked decrease in enzymatic activity. The presence of the allele H seems to be common at least in the Japanese population (24%. These individuals have a tendency to greater calcium and sodium excretion in urine that is more evident during furosemide infusion. Future studies should analyse if manipulating the renal kallikrein-kinin system can correct idiopathic hypercalciuria with drugs other than thiazide diuretics.

  12. Renal failure (chronic)

    OpenAIRE

    Clase, Catherine

    2011-01-01

    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...

  13. OBESITY-INDUCED HYPERTENSION: INTERACTION OF NEUROHUMORAL AND RENAL MECHANISMS

    Science.gov (United States)

    Hall, John E.; do Carmo, Jussara M.; da Silva, Alexandre A.; Wang, Zhen; Hall, Michael E.

    2015-01-01

    Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65–75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include 1) physical compression of the kidneys by fat in and around the kidneys, 2) activation of the renin-angiotensin-aldosterone system (RAAS), and 3) increased sympathetic nervous system (SNS) activity. Activation of the RAAS system is likely due, in part, to renal compression as well as SNS activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for SNS activation in obesity have not been fully elucidated but appear to require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes, and inflammation. Unless effective anti-obesity drugs are developed, the impact of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase. PMID:25767285

  14. Drosophila provides rapid modeling of renal development, function, and disease.

    Science.gov (United States)

    Dow, Julian A T; Romero, Michael F

    2010-12-01

    The evolution of specialized excretory cells is a cornerstone of the metazoan radiation, and the basic tasks performed by Drosophila and human renal systems are similar. The development of the Drosophila renal (Malpighian) tubule is a classic example of branched tubular morphogenesis, allowing study of mesenchymal-to-epithelial transitions, stem cell-mediated regeneration, and the evolution of a glomerular kidney. Tubule function employs conserved transport proteins, such as the Na(+), K(+)-ATPase and V-ATPase, aquaporins, inward rectifier K(+) channels, and organic solute transporters, regulated by cAMP, cGMP, nitric oxide, and calcium. In addition to generation and selective reabsorption of primary urine, the tubule plays roles in metabolism and excretion of xenobiotics, and in innate immunity. The gene expression resource FlyAtlas.org shows that the tubule is an ideal tissue for the modeling of renal diseases, such as nephrolithiasis and Bartter syndrome, or for inborn errors of metabolism. Studies are assisted by uniquely powerful genetic and transgenic resources, the widespread availability of mutant stocks, and low-cost, rapid deployment of new transgenics to allow manipulation of renal function in an organotypic context.

  15. Obesity-induced hypertension: interaction of neurohumoral and renal mechanisms.

    Science.gov (United States)

    Hall, John E; do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Hall, Michael E

    2015-03-13

    Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65% to 75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include (1) physical compression of the kidneys by fat in and around the kidneys, (2) activation of the renin-angiotensin-aldosterone system, and (3) increased sympathetic nervous system activity. Activation of the renin-angiotensin-aldosterone system is likely due, in part, to renal compression, as well as sympathetic nervous system activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for sympathetic nervous system activation in obesity have not been fully elucidated but may require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes mellitus, and inflammation. Unless effective antiobesity drugs are developed, the effect of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase.

  16. Severe hypophosphatemic osteomalacia with Fanconi syndrome, renal tubular acidosis, vitamin D deficiency and primary biliary cirrhosis.

    Science.gov (United States)

    Bando, Hironori; Hashimoto, Naoko; Hirota, Yushi; Sakaguchi, Kazuhiko; Hisa, Itoko; Inoue, Yoshifumi; Imanishi, Yasuo; Seino, Susumu; Kaji, Hiroshi

    2009-01-01

    A 49-year-old woman was admitted to our hospital for back pain with marked thoracic and extremity deformities leading to bed-rest for three years. She was diagnosed with hypophosphatemic osteomalacia based on her symptoms, X-ray and bone scintigram, high serum alkaline phosphatase level, and low serum levels of both phosphorus and 1,25 dihydroxyvitamin D(3) with inhibition of phosphorus reabsorption. Fanconi syndrome with renal tubular acidosis, vitamin D deficiency and primary biliary cirrhosis were related to the pathogenesis of osteomalacia in this case. Several causal diseases may be concomitantly responsible for acceleration of the severity of osteomalacia in this patient.

  17. Mini-review: regulation of the renal NaCl cotransporter by hormones.

    Science.gov (United States)

    Rojas-Vega, Lorena; Gamba, Gerardo

    2016-01-01

    The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone.

  18. Chronic nitric oxide synthase inhibition ecacerbates renal dysfunction in cirrhotic rats

    DEFF Research Database (Denmark)

    Græbe, Martin; Miller, Lone Brønd; Christensen, Sten;

    2004-01-01

    (CBL). Three weeks of daily sodium balance studies showed that CBL rats developed sodium retention compared with sham-operated rats and that l-NAME treatment dose dependently deteriorated cumulative sodium balance by reducing urinary sodium excretion. Five weeks after CBL, renal clearance studies were...... performed, followed by Western blotting of the electroneutral type 3 sodium/proton exchanger (NHE3) and the Na-K-ATPase present in proximal tubules. Untreated CBL rats showed a decreased proximal reabsorption with a concomitant reduction of NHE3 and Na-K-ATPase levels, indicating that tubular segments...

  19. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive...... and ACC may increase the political focus on resources and environmental issues and may help to move local authorities towards a more holistic spatial planning approach. A carrying capacity approach could be an inspiration for local spatial planning in developing countries. A spatial planning act...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  20. Pharmacokinetics, pharmacodynamics, and tolerability of verinurad, a selective uric acid reabsorption inhibitor, in healthy adult male subjects

    Directory of Open Access Journals (Sweden)

    Shen Z

    2017-07-01

    Full Text Available Zancong Shen,1 Michael Gillen,2 Jeffrey N Miner,1 Gail Bucci,1 David M Wilson,1 Jesse W Hall1 1Ardea Biosciences, Inc., San Diego, CA, 2AstraZeneca, Gaithersburg, MD, USA Purpose: Verinurad (RDEA3170 is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. The aim of this study was to evaluate the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in healthy adult males.Subjects and methods: This was a Phase I, randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Panels of eight male subjects received a single oral dose of verinurad or placebo in either a fasted or fed state; panels of 10–12 male subjects received ascending doses of once-daily verinurad or placebo in a fasted state for 10 days. Serial blood and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse event (AE reports, laboratory tests, vital signs, and electrocardiograms (ECGs.Results: A total of 81 adult males completed the study. Following single doses of verinurad, maximum observed plasma concentration (Cmax and area under the plasma concentration–time curve (AUC increased in a dose-proportional manner; Cmax occurred at 0.5–0.75 hours and 1.25 hours in the fasted and fed states, respectively. Food decreased AUC by 23% and Cmax by 37%-53%. There was a modest accumulation of verinurad following multiple daily doses. Verinurad reduced serum urate levels by up to 62% (40 mg, single dose and 61% (10 mg, multiple dose. The increase in urinary excretion of uric acid was greatest in the first 6 hours after dosing and was still evident ≥24 hours for verinurad doses ≥2 mg. Verinurad was well tolerated at all doses. No serious AEs, severe AEs, discontinuations due to AEs, or clinically significant laboratory or ECG abnormalities were reported.Conclusion: Single and multiple doses of verinurad were well tolerated

  1. Regulation of renal Na-(K)-Cl cotransporters by vasopressin.

    Science.gov (United States)

    Bachmann, Sebastian; Mutig, Kerim

    2017-08-01

    Vasopressin (AVP) induces antidiuresis, thus playing an essential role in body water and electrolyte homeostasis. Its antidiuretic effects are mediated chiefly by V2 vasopressin receptors (V2R) expressed along the distal nephron and collecting duct epithelia. NaCl reabsorption in the distal nephron, which includes the thick ascending limb (TAL) and distal convoluted tubule (DCT), largely depends on the activity of two structurally related Na-(K)-Cl cotransporters, NKCC2 in TAL and NCC in DCT. AVP-induced activation of these transporters contributes to urine concentration and renal electrolyte reabsorption. Previous work has specified molecular pathways mediating the effects of V2R activation in TAL and DCT, and protein networks involved in intracellular trafficking and phosphoregulation of the two transporters have been identified. This review summarizes recent progress in understanding AVP signalling mechanisms that are responsible for the activation of NKCC2 and NCC. Implications in the pathophysiology of diseases such as nephrogenic diabetes insipidus, diabetes mellitus and salt-sensitive hypertension are discussed in this context.

  2. Renale Osteopathie

    OpenAIRE

    Horn S

    2001-01-01

    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...

  3. Renale Knochenerkrankungen

    Directory of Open Access Journals (Sweden)

    Mayer G

    2008-01-01

    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.

  4. Repercussões da insuficiência renal crônica na capacidade de exercício, estado nutricional, função pulmonar e musculatura respiratória de crianças e adolescentes Consequences of chronic renal insufficiency on the exercise capacity, nutritional status, pulmonary function and respiratory musculature of children and adolescents

    OpenAIRE

    2008-01-01

    OBJETIVO: Avaliar a capacidade funcional, função pulmonar, musculatura respiratória e estado nutricional de crianças e adolescentes portadores de insuficiência renal crônica (IRC) em tratamento conservador. MÉTODOS: Este estudo foi realizado com 30 voluntários, divididos em dois grupos: Portadores de IRC em tratamento conservador (Grupo IRC) e grupo sem comprometimento da função renal (Grupo Controle). Os voluntários foram submetidos à avaliação fisioterapêutica, espirometria, avaliação de fo...

  5. 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.

    2006-01-01

    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

  6. 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.

    2006-01-01

    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

  7. Renal parameter estimates in unrestrained dogs

    Science.gov (United States)

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

    1974-01-01

    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.

  8. NaHCO3 and NaC1 tolerance in chronic renal failure.

    Science.gov (United States)

    Husted, F C; Nolph, K D; Maher, J F

    1975-08-01

    In patients with chronic renal failure, NaHCO3 therapy may correct or prevent acidemia. It has been proposed that the NaHCO3 required will not result in clinically significant Na retention comparable to that from similar increases in NaC1 intake. In each of ten patients with chronic renal failure, creatinine clearance (Ccr) range 2.5-16.8 ml/min, on an estimated 10-meq Na and C1 diet, electrolyte excretion was compared on NaHCO3 vs NaC1 supplements of 200 meq/day. Periods of NaHCO3 and NaC1 (in alternate order for successive patients) lasted 4 days, separated by reequilibration to base-line weight. Mean +/- SEM excretion (ex) of Na, C1, and HCO3 and deltaCcr and deltaweight (day 4-1) are compared below for the 4th day of NaC1 vs. NaHCO3 intake. Mean Ccr +/-SEM on day 4 of NaC1 and NaHCO3 were 10.8 +/-1.6 and 9.0 +/-1.4 ml/min, respectively (P less than 0.02). Mean systolic blood pressure (but not diastolic) increased significantly on NaC1 (P less than 0.05). No significant blood pressure changes were seen on NaHCO3. Net positive HCO3 balance occurred on NaHCO3 as indicated above and reflected a rise in mean serum HCO3 from 19 to 30 meq/liter (day 1 vs. 4) (P less than 0.01). Mechanisms for the greater excretion of Na on NaHCO3 may relate to C1 wasting as noted above on low C1 intake and limited HCO3 reabsorptive capacity. Thus, Na excretion by day 4 was greater on NaHCO3 than on NaHCO3 did Na excretion near intake (210 meq/day).

  9. Analytical model of photon reabsorption in ZnO quantum dots with size and concentration dependent dual-color photoluminescence

    Science.gov (United States)

    Fan, Baolu; Guo, Xiaoxiao; Zhang, Yumeng; Fan, Jiyang

    2017-02-01

    We investigate the concentration and size dependent UV/green photoluminescence properties of the ZnO quantum dots (QDs) with sizes in the strong confinement regime. The luminescence characteristics of an ensemble of colloidal semiconductor QDs with quantum confinement effect depend sensitively on particle concentration but this has only been qualitatively understood. By taking ZnO QDs as an ideal prototype, we construct a material-independent theoretical model to study the photon reabsorption phenomenon. The theoretical result agrees well with the experiment. This model can be used to quantitatively study the concentration-dependent luminescence properties of any collection of QDs with considerable size dispersion. On the other hand, the origin of green emission in ZnO QDs remains debated. The comparative study of the size dependence of UV and green emissions in conjunction with the effective-mass approximation calculation suggests that the green emission in the ZnO QDs originates from the conduction band to the deep level transition.

  10. Evaluation of Pharmacokinetic Interactions Between Lesinurad, a New Selective Urate Reabsorption Inhibitor, and Commonly Used Drugs for Gout Treatment.

    Science.gov (United States)

    Shen, Zancong; Tieu, Kathy; Wilson, David; Bucci, Gail; Gillen, Michael; Lee, Caroline; Kerr, Bradley

    2017-01-11

    Lesinurad is a novel selective uric acid reabsorption inhibitor approved for treatment of hyperuricemia associated with gout in combination with xanthine oxidase inhibitors (XOIs). Open-label pharmacokinetic studies were performed in volunteers or subjects with hyperuricemia (serum uric acid ≥ 8 mg/dL) to investigate interactions of lesinurad (with and without concurrent XOIs) with colchicine and 2 nonsteroidal anti-inflammatory drugs: naproxen and indomethacin. Colchicine studies included consecutive 7-day treatment periods of (1) allopurinol 300 mg, allopurinol 300 mg plus lesinurad 400 or 600 mg, and continued lesinurad 400 or 600 mg; or (2) febuxostat 40 or 80 mg, febuxostat 40 or 80 mg plus lesinurad 400 mg, and continued febuxostat 40 or 80 mg plus lesinurad 600 mg. Naproxen and indomethacin studies included lesinurad 400 mg on day 1, naproxen 250 mg twice daily or indomethacin 25 mg twice daily on days 2-6, and lesinurad 400 mg plus continued naproxen or indomethacin on days 7-13 and the morning of day 14. Lesinurad did not alter the pharmacokinetics of naproxen and modestly altered exposure to colchicine (AUC decrease of ≤ 25%) and indomethacin (AUC increase of ∼35%). Indomethacin did not alter the pharmacokinetics of lesinurad, whereas naproxen modestly decreased the Cmax of lesinurad by ∼27%.

  11. Quantification of re-absorption and re-emission processes to determine photon recycling efficiency in perovskite single crystals

    Science.gov (United States)

    Fang, Yanjun; Wei, Haotong; Dong, Qingfeng; Huang, Jinsong

    2017-02-01

    Photon recycling, that is, iterative self-absorption and re-emission by the photoactive layer itself, has been speculated to contribute to the high open-circuit voltage in several types of high efficiency solar cells. For organic-inorganic halide perovskites that have yielded highly efficient photovoltaic devices, however, it remains unclear whether the photon recycling effect is significant enough to improve solar cell efficiency. Here we quantitatively evaluate the re-absorption and re-emission processes to determine photon recycling efficiency in hybrid perovskite with its single crystals by measuring the ratio of the re-emitted photons to the initially excited photons, which is realized by modulating their polarization to differentiate them. The photon recycling efficiencies are revealed to be less than 0.5% in CH3NH3PbI3 and CH3NH3PbBr3 single crystals under excitation intensity close to one sun, highlighting the intrinsically long carrier recombination lifetime instead of the photon-recycling-induced photon propagation as the origin of their long carrier diffusion length.

  12. [Immunoglobulin filtration and reabsorption as possible factors in the pathogenesis of chronic glomerulonephritis. Clinical, immunomorphological and histoenzymological research].

    Science.gov (United States)

    Nabokov, A V; Travkina, E S; Zel'tser, G L; Nevorotin, A I

    1992-01-01

    Kidney biopsy specimens obtained from a group of individuals with chronic glomerulonephritis (CGN) have been processed for light and electron microscopic immunolocalization of total immunoglobulins (Igs). In a few cases, acid phosphatase (ACPase), a lysosomal enzyme marker, was ultrastructurally visualized. In the glomeruli, horseradish peroxidase-stained Igs were revealed in capillary lumina, urinary spaces and in transit through occasional loci of the glomerular basal membranes while ACPase-containing lysosomes resided both within and outside the cells. In the proximal tubules, Igs were traced in the endocytic vesicles and vacuoles, the latter also being positive for ACPase. Statistically significant relationships have been revealed between the number of IGs-labeled proximal tubules and some clinical or pathomorphological stigmata of CGN, in particular, proteinuria and arterial hypertension levels, marked interstitial sclerosis, etc. The data obtained are discussed in regard to the mechanisms of increased macromolecular filtration and the different proteinuria selectivity levels as well as the development of interstitial sclerosis as a result of the elevated reabsorption and incomplete lysosomal degradation of Igs in CGN.

  13. Bilateral Renal Mass-Renal Disorder: Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ozlem Tiryaki

    2013-01-01

    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.

  14. Distal renal tubular acidosis

    Science.gov (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 ...

  15. Proximal renal tubular acidosis

    Science.gov (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 ...

  16. Multiple Drug Transporters Are Involved in Renal Secretion of Entecavir.

    Science.gov (United States)

    Yang, Xi; Ma, Zhiyuan; Zhou, Sisi; Weng, Yayun; Lei, Hongmei; Zeng, Su; Li, Liping; Jiang, Huidi

    2016-10-01

    Entecavir (ETV) is a first-line antiviral agent for the treatment of chronic hepatitis B virus infection. Renal excretion is the major elimination path of ETV, in which tubular secretion plays the key role. However, the secretion mechanism has not been clarified. We speculated that renal transporters mediated the secretion of ETV. Therefore, the aim of our study was to elucidate which transporters contribute to the renal disposition of ETV. Our results revealed that ETV (50 μM) remarkably reduced the accumulation of probe substrates in MDCK cells stably expressing human multidrug and toxin efflux extrusion proteins (hMATE1/2-K), organic cation transporter 2 (hOCT2), and carnitine/organic cation transporters (hOCTNs) and increased the substrate accumulation in cells transfected with multidrug resistance-associated protein 2 (hMRP2) or multidrug resistance protein 1 (hMDR1). Moreover, ETV was proved to be a substrate of the above-described transporters. In transwell studies, the transport of ETV in MDCK-hOCT2-hMATE1 showed a distinct directionality from BL (hOCT2) to AP (hMATE1), and the cellular accumulation of ETV in cells expressing hMATE1 was dramatically lower than that of the mock-treated cells. The accumulation of ETV in mouse primary renal tubular cells was obviously affected by inhibitors of organic anion transporter 1/3 (Oat1/3), Oct2, Octn1/2, and Mrp2. Therefore, the renal uptake of ETV is likely mediated by OAT1/3 and OCT2 while the efflux is mediated by MATEs, MDR1, and MRP2, and OCTN1/2 may participate in both renal secretion and reabsorption. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Systemic and renal-specific sympathoinhibition in obesity hypertension.

    Science.gov (United States)

    Lohmeier, Thomas E; Iliescu, Radu; Liu, Boshen; Henegar, Jeffrey R; Maric-Bilkan, Christine; Irwin, Eric D

    2012-02-01

    Chronic pressure-mediated baroreflex activation suppresses renal sympathetic nerve activity. Recent observations indicate that chronic electric activation of the carotid baroreflex produces sustained reductions in global sympathetic activity and arterial pressure. Thus, we investigated the effects of global and renal specific suppression of sympathetic activity in dogs with sympathetically mediated, obesity-induced hypertension by comparing the cardiovascular, renal, and neurohormonal responses to chronic baroreflex activation and bilateral surgical renal denervation. After control measurements, the diet was supplemented with beef fat, whereas sodium intake was held constant. After 4 weeks on the high-fat diet, when body weight had increased ≈50%, fat intake was reduced to a level that maintained this body weight. This weight increase was associated with an increase in mean arterial pressure from 100±2 to 117±3 mm Hg and heart rate from 86±3 to 130±4 bpm. The hypertension was associated with a marked increase in cumulative sodium balance despite an approximately 35% increase in glomerular filtration rate. The importance of increased tubular reabsorption to sodium retention was further reflected by ≈35% decrease in fractional sodium excretion. Subsequently, both chronic baroreflex activation (7 days) and renal denervation decreased plasma renin activity and abolished the hypertension. However, baroreflex activation also suppressed systemic sympathetic activity and tachycardia and reduced glomerular hyperfiltration while increasing fractional sodium excretion. In contrast, glomerular filtration rate increased further after renal denervation. Thus, by improving autonomic control of cardiac function and diminishing glomerular hyperfiltration, suppression of global sympathetic activity by baroreflex activation may have beneficial effects in obesity beyond simply attenuating hypertension.

  18. INTERMEDIATE SYNDROME: A TYPICAL PATTERN OF PRE-RENAL ACUTE RENAL FAILURE IN THE ELDERLY

    Directory of Open Access Journals (Sweden)

    Greloni G

    2004-01-01

    Full Text Available Acute renal failure is a frequent entity in the elderly. This is due on one hand to the structural and physiological changes of the aged kidney, and on the other hand to the exposure of this population to polypharmacy and their reduced capability to metabolize drugs. In the present report we present a case of a seventy year-old woman who developed acute renal failure secondary to severe dehydration with a clinical and laboratory pattern of intermediate syndrome: laboratory results compatible with parenchymal renal insufficiency (elevated urinary sodium, plasma urea and creatinine, but with a positive response to hydration. The main characteristics of the aged kidney that predispose to the development of an intermediate syndrome are: the vascular dysautonomy and reduced capability of sodium and water reabsorption. The intermediate syndrome is a typical pattern of pre-renal insufficiency in the elderly. RESUMEN: La insuficiencia renal aguda es frecuente en el anciano. Esto se debe por un lado a los cambios estructurales y funcionales propios del riñón senil, y por otro a la gran exposición que esta población tiene a la polifarmacia, y su reducida capacidad para metabolizar los medicamentos. En este reporte presentamos el caso de una mujer de 70 años que desarrolló una insuficiencia renal aguda secundaria a severa deshidratación, mostrando un patrón clínico y de laboratorio propio de un sindrome intermedio: laboratorios compatibles con una insuficiencia renal parenquimatosa (sodio urinario, uremia y creatininemia elevadas, pero con una respuesta favorable a la hidratación. Las principales características del riñón senil que predisponen al desarrollo del sindrome intermedio: son la disautonomía vascular y la reducida capacidad en la recuperación de sodio y agua El sindrome intermedio es un patrón típico de insuficiencia prerrenal en el anciano.

  19. Renal catabolism of albumin – current views and controversies

    Directory of Open Access Journals (Sweden)

    Jakub Gburek

    2011-10-01

    Full Text Available Albumin is the main protein of blood plasma, lymph, cerebrospinal fluid and interstitial fluid. The protein assists in many important body functions, including maintenance of proper colloidal osmotic pressure, transport of important metabolites and antioxidant action. Synthesis of albumin takes place mainly in the liver, and its catabolism occurs mostly in vascular endothelium of muscle, skin and liver as well as in the kidney tubular epithelium. Renal catabolism of albumin consists of glomerular filtration and tubular reabsorption. The tubular processes include endocytosis via the multiligand scavenger receptor tandem megalin and cubilin-amnionless complex. Possible ways of further catabolism of this protein are lysosomal proteolysis to amino acids and short peptides, recycling of degradation products into the bloodstream and tubular lumen or transcytosis of whole molecules. The article discusses the molecular aspects of these processes and presents the controversies arising in the light of the last decade of research.

  20. Renal tuberculosis

    Directory of Open Access Journals (Sweden)

    Džamić Zoran

    2016-01-01

    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

  1. Magnesium loss in cyclosporine-treated patients is related to renal epidermal growth factor downregulation.

    Science.gov (United States)

    Ledeganck, Kristien J; De Winter, Benedicte Y; Van den Driessche, Annelies; Jürgens, Angelika; Bosmans, Jean-Louis; Couttenye, Marie M; Verpooten, Gert A

    2014-05-01

    Cyclosporine (CsA) treatment is associated with hypomagnesaemia due to a renal Mg(2+) leak. In animal studies a role for the Mg(2+) channel TRPM6 localized in the distal convoluted tubule and stimulated by epidermal growth factor (EGF) is suggested. We hypothesize that CsA-induced hypomagnesaemia is due to a renal magnesium leak, also in patients, resulting from a downregulation of the renal EGF production, thereby inhibiting the activation of TRPM6. Renal transplant patients treated with CsA (n = 55) and 35 chronic kidney disease (CKD) patients were included. At three time points, with an interval of at least 1 month, blood and urine samples were taken to determine creatinine, Mg(2+), sodium and EGF. Serum Mg(2+) was significantly lower in the CsA group versus the CKD group with significantly more CsA-treated patients developing hypomagnesaemia. Although the fractional excretion (FE) Mg(2+) did not differ significantly between the two groups, subanalysis of the patients with hypomagnesaemia showed a significantly higher FE Mg(2+) in CsA-treated patients compared with CKD patients (P = 0.05). The urinary EGF excretion was significantly decreased in the CsA group and was a predictor of the FE Mg(2+) in the two groups. Serum sodium was significantly decreased in the CsA group simultaneously with an increased FE Na(+). In CsA-treated patients, the association of a low urinary EGF excretion and a decreased renal Mg(2+) reabsorption is in accordance with in vitro and animal studies. In the whole study population, log urinary EGF excretion is an independent predictor of the FE Mg(2+), supporting the role of EGF in magnesium reabsorption.

  2. Renale Osteopathie

    Directory of Open Access Journals (Sweden)

    Horn S

    2001-01-01

    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.

  3. Renal disease in pregnancy.

    Science.gov (United States)

    Thorsen, Martha S; Poole, Judith H

    2002-03-01

    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. Calcineurin inhibitors and male fertility after renal transplantation - a review.

    Science.gov (United States)

    Georgiou, G K; Dounousi, E; Harissis, H V

    2016-06-01

    Renal transplantation and restoration of renal function are associated with significant favourable changes regarding the reproductive capacity of male patients with previous end-stage renal disease. However, there is evidence that some of the immunosuppressive agents may impair male fertility after all. Calcineurin inhibitors (CNIs), cyclosporine A and tacrolimus (FK506), which constitute the cornerstone of immunosuppression regimen following renal transplantation, have been implicated in causing an overall decline in the fertilisation capacity of male renal transplant recipients (RTRs). In this review, data from human clinical studies are collectively presented in an effort to estimate the potential adverse effects of CNIs on the masculine reproductive organs, the hormonal axis of males, the process of spermatogenesis and generally the male RTRs capacity to fertilise. © 2015 Blackwell Verlag GmbH.

  5. Renal calculus

    CERN Document Server

    Pyrah, Leslie N

    1979-01-01

    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...

  6. Resistance of the rat to development of lead-induced renal functional deficits

    Energy Technology Data Exchange (ETDEWEB)

    O' Flaherty, E.J.; Adams, W.D.; Hammond, P.B.; Taylor, E.

    1986-01-01

    Lead nephropathy, characterized functionally by depression of effective renal plasma flow (ERPF), glomerular filtration rate (GFR), and maximum glucose reabsorption rate, is associated with prolonged occupational exposure to lead. Production of comparable lead-related renal functional deficits in rats has been difficult to achieve. The authors have examined in rats some of the factors that might be expected to influence the development of lead-induced renal functional damage, using GFR (as inulin clearance). ERPF (as para-aminohippurate clearance), and maximum glucose readsorption rates as indices of renal functional competence. Although lead produces a significant weight loss, this can be accounted for by reduced food intake and is not associated with reduction in renal function. Even exposure to large amounts of lead in conjunction with other factors; such as controlled diet (NIH-07 and AIN-76) and early age of initial exposure, that might have been expected to increase the rats' susceptibility has not resulted in the development of renal functional deficits. It is unlikely that the rat can be successfully explored as an animal model of human lead nephropathy with accompanying functional deficits.

  7. Pharmacokinetics, pharmacodynamics, and tolerability of verinurad, a selective uric acid reabsorption inhibitor, in healthy adult male subjects.

    Science.gov (United States)

    Shen, Zancong; Gillen, Michael; Miner, Jeffrey N; Bucci, Gail; Wilson, David M; Hall, Jesse W

    2017-01-01

    Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. The aim of this study was to evaluate the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in healthy adult males. This was a Phase I, randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Panels of eight male subjects received a single oral dose of verinurad or placebo in either a fasted or fed state; panels of 10-12 male subjects received ascending doses of once-daily verinurad or placebo in a fasted state for 10 days. Serial blood and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse event (AE) reports, laboratory tests, vital signs, and electrocardiograms (ECGs). A total of 81 adult males completed the study. Following single doses of verinurad, maximum observed plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) increased in a dose-proportional manner; Cmax occurred at 0.5-0.75 hours and 1.25 hours in the fasted and fed states, respectively. Food decreased AUC by 23% and Cmax by 37%-53%. There was a modest accumulation of verinurad following multiple daily doses. Verinurad reduced serum urate levels by up to 62% (40 mg, single dose) and 61% (10 mg, multiple dose). The increase in urinary excretion of uric acid was greatest in the first 6 hours after dosing and was still evident ≥24 hours for verinurad doses ≥2 mg. Verinurad was well tolerated at all doses. No serious AEs, severe AEs, discontinuations due to AEs, or clinically significant laboratory or ECG abnormalities were reported. Single and multiple doses of verinurad were well tolerated, absorption was rapid, and exposure was dose proportional. Verinurad increased urinary uric acid elimination and resulted in sustained reductions in serum urate. These data support further clinical evaluation of once-daily verinurad as a treatment for

  8. Causes of frequency and nocturia after renal transplantation.

    NARCIS (Netherlands)

    Weide, M.J.A. van der; Achterberg, T. van; Smits, J.P.J.M.; Heesakkers, J.P.F.A.; Bemelmans, B.L.H.; Hilbrands, L.B.

    2008-01-01

    OBJECTIVE: To explore the role of bladder capacity, bladder pain, dysfunctional voiding, urgency, urinary tract infections (UTIs), and urinary output as potential causes of frequency and nocturia after renal transplantation. PATIENTS AND METHODS: Data were gathered from 52 adult renal transplant

  9. Causes of frequency and nocturia after renal transplantation

    NARCIS (Netherlands)

    Weide, M.J.A. van der; Achterberg, T. van; Smits, J.P.J.M.; Heesakkers, J.P.F.A.; Bemelmans, B.L.H.; Hilbrands, L.B.

    2008-01-01

    OBJECTIVE: To explore the role of bladder capacity, bladder pain, dysfunctional voiding, urgency, urinary tract infections (UTIs), and urinary output as potential causes of frequency and nocturia after renal transplantation. PATIENTS AND METHODS: Data were gathered from 52 adult renal transplant

  10. Causes of frequency and nocturia after renal transplantation.

    NARCIS (Netherlands)

    Weide, M.J.A. van der; Achterberg, T. van; Smits, J.P.J.M.; Heesakkers, J.P.F.A.; Bemelmans, B.L.H.; Hilbrands, L.B.

    2008-01-01

    OBJECTIVE: To explore the role of bladder capacity, bladder pain, dysfunctional voiding, urgency, urinary tract infections (UTIs), and urinary output as potential causes of frequency and nocturia after renal transplantation. PATIENTS AND METHODS: Data were gathered from 52 adult renal transplant pat

  11. Causes of frequency and nocturia after renal transplantation

    NARCIS (Netherlands)

    Weide, M.J.A. van der; Achterberg, T. van; Smits, J.P.J.M.; Heesakkers, J.P.F.A.; Bemelmans, B.L.H.; Hilbrands, L.B.

    2008-01-01

    OBJECTIVE: To explore the role of bladder capacity, bladder pain, dysfunctional voiding, urgency, urinary tract infections (UTIs), and urinary output as potential causes of frequency and nocturia after renal transplantation. PATIENTS AND METHODS: Data were gathered from 52 adult renal transplant pat

  12. Bone marrow-derived cells in renal repair

    NARCIS (Netherlands)

    Broekema, Martine

    2007-01-01

    The kidney can recover after acute renal injury due to its highly effective endogenous regenerative capacity. However, under certain conditions the balance between injury and repair can get disturbed. This can ultimately lead to chronic renal failure, which is an increasing problem in the clinical s

  13. Aromatase deficiency causes altered expression of molecules critical for calcium reabsorption in the kidneys of female mice *.

    NARCIS (Netherlands)

    Oz, O.K.; Hajibeigi, A.; Howard, K.; Cummins, C.L.; Abel, M. van; Bindels, R.J.M.; Word, R.A.; Kuro-o, M.; Pak, C.Y.; Zerwekh, J.E.

    2007-01-01

    Kidney stones increase after menopause, suggesting a role for estrogen deficiency. ArKO mice have hypercalciuria and lower levels of calcium transport proteins, whereas levels of the klotho protein are elevated. Thus, estrogen deficiency is sufficient to cause altered renal calcium handling. INTRODU

  14. Hypercalcaemia of malignancy: evidence for a nonparathyroid humoral agent with an effect on renal tubular handling of calcium.

    Science.gov (United States)

    Ralston, S H; Fogelman, I; Gardner, M D; Dryburgh, F J; Cowan, R A; Boyle, I T

    1984-02-01

    The renal handling of calcium was examined in 31 patients with hypercalcaemia of malignancy. Results were compared with those from patients with primary hyperparathyroidism, and normal controls rendered hypercalcaemic by calcium infusion. On relating the urinary calcium excretion indices to serum calcium values, inappropriately low rates of urinary calcium excretion were generally found in patients with malignancy associated hypercalcaemia. Further, the pattern of urinary calcium excretion in these subjects was similar to that found in patients with primary hyperparathyroidism. These observations suggest that, in many solid tumours, the development of hypercalcaemia may be attributable to a humoral mediator with a parathyroid hormone-like effect on renal tubular calcium reabsorption. The relatively frequent occurrence of hypercalcaemia in malignant disease thus may be partially explained by the presence of this humoral agent, which may impair the renal excretion of an increase in filtered calcium load, whether due to bone metastases, or humorally mediated osteolysis.

  15. Renal actinomycosis with concomitant renal vein thrombosis.

    Science.gov (United States)

    Chang, Dong-Suk; Jang, Won Ik; Jung, Ji Yoon; Chung, Sarah; Choi, Dae Eun; Na, Ki-Ryang; Lee, Kang Wook; Shin, Yong-Tai

    2012-02-01

    Renal actinomycosis is a rare infection caused by fungi of the genus Actinomyces. A 74-year-old male was admitted to our hospital because of gross hematuria with urinary symptoms and intermittent chills. Computed tomography of the abdomen showed thrombosis in the left renal vein and diffuse, heterogeneous enlargement of the left kidney. After nephrectomy, sulfur granules with chronic suppurative inflammation were seen microscopically, and the histopathological diagnosis was renal actinomycosis. Our case is the first report of renal actinomycosis with renal vein thrombosis.

  16. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

    Directory of Open Access Journals (Sweden)

    E.V. Seliverstova

    2015-04-01

    Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

  17. TRANSPLANTE RENAL

    Directory of Open Access Journals (Sweden)

    Soraia Geraldo Rozza Lopes

    2014-01-01

    Full Text Available El objetivo del estudio fue comprender el significado de espera del trasplante renal para las mujeres en hemodiálisis. Se trata de un estudio cualitativo-interpretativo, realizado con 12 mujeres en hemodiálisis en Florianópolis. Los datos fueron recolectados a través de entrevistas en profundidad en el domicilio. Fue utilizado el software Etnografh 6.0 para la pre-codificación y posterior al análisis interpretativo emergieron dos categorías: “las sombras del momento actual”, que mostró que las dificultades iniciales de la enfermedad están presentes, pero las mujeres pueden hacer frente mejor a la enfermedad y el tratamiento. La segunda categoría, “la luz del trasplante renal”, muestra la esperanza impulsada por la entrada en la lista de espera para un trasplante.

  18. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930564 Dwell times affect the local host de-fence mechanism of peritoneal dialysis patients.WANG Tao(汪涛),et al.Renal Instit,SunYatsen Med Univ,Guangzhou,510080.Chin JNephrol 1993;9(2):75—77.The effect of different intraperitoneal awelltimes on the local host defence in 6 peritonealdialysis patients was studied.A significant de-crease in the number of peritoneal cells,IgG con-centration and the phagoeytosis and bactericidalactivity of macrophages was determined when thedwell time decreased from 12 to 4 hs or form 4 to0.5hs,but the peroxidase activity in macrophagesincreased significantly.All variables,except theperoxidase activity in macrophages,showed nosignificant difference between patients of high or

  19. Traumatismo renal

    OpenAIRE

    Rocha, Sofia Rosa Moura Gomes da

    2009-01-01

    Introdução: A realização deste trabalho visa a elaboração de uma revisão sistematizada subordinada à temática da traumatologia renal. Objectivos: Os principais objectivos deste trabalho são: apurar a etiologia, definir a classificação, analisar o diagnóstico e expôr o tratamento e as complicações. Desenvolvimento: Os traumatismos são a principal causa de morte antes dos 40 anos. O rim é o órgão do aparelho génito-urinário mais frequentemente atingido. Os traumatismos renais são mais fre...

  20. Non-urate transporter 1-related renal hypouricemia and acute renal failure in an Israeli-Arab family.

    Science.gov (United States)

    Bahat, Hilla; Dinour, Dganit; Ganon, Liat; Feldman, Leonid; Holtzman, Eli J; Goldman, Michael

    2009-05-01

    Idiopathic renal hypouricemia (IRHU) is a rare hereditary disease, predisposing the individual to exercise-induced acute renal failure (EIARF) and nephrolithiasis, and it is characterized by increased clearance of renal uric acid. Most of the described patients are Japanese, who have loss-of-function mutations in the SLC22A12 gene coding for the human urate transporter 1 (URAT1) gene. An 18-year-old youth, who was admitted for EIARF due to IRHU, and six consanguineous Israeli-Arab family members were included in the study. The family members were tested for fractional excretion of uric acid and molecular analysis of the URAT1 gene. Four family members, including the proband, had very low levels of blood uric acid and high rate of fractional excretion (FE urate> 100%) of uric acid. Genetic analysis of the affected family members did not reveal a mutation in the coding regions and intron-exon boundaries of SCL22A12. Haplotype analysis excluded SCL22A12 involvement in the pathogenesis, suggesting a different gene as a cause of the disease. We herein describe the first Israeli-Arab family with IRHU. A non-URAT1 genetic defect that causes decreased reabsorption or, more probably, increased secretion of uric acid, induces IRHU. Further studies are required in order to elucidate the genetic defect.

  1. ANCA-Associated Glomerulonephritis: Risk Factors for Renal Relapse

    Science.gov (United States)

    Göçeroğlu, Arda; Berden, Annelies E.; Fiocco, Marta; Floßmann, Oliver; Westman, Kerstin W.; Ferrario, Franco; Gaskin, Gill; Pusey, Charles D.; Hagen, E. Christiaan; Noël, Laure-Hélène; Rasmussen, Niels; Waldherr, Rüdiger; Walsh, Michael; Bruijn, Jan A.; Jayne, David R. W.; Bajema, Ingeborg M.

    2016-01-01

    Relapse in ANCA-associated vasculitis (AAV) has been studied previously, but there are few studies on renal relapse in particular. Identifying patients at high risk of renal relapse may aid in optimizing clinical management. We investigated which clinical and histological parameters are risk factors for renal relapse in ANCA-associated glomerulonephritis (AAGN). Patients (n = 174) were newly diagnosed and had mild–moderate or severe renal involvement. Data were derived from two trials of the European Vasculitis Society: MEPEX and CYCAZAREM. The Cox regression model was used to identify parameters increasing the instantaneous risk (= rate) of renal relapse (useful for instant clinical decisions). For identifying predictors of renal relapse during follow-up, we used Fine & Gray’s regression model. Competing events were end-stage renal failure and death. The cumulative incidence of renal relapse at 5 years was 9.5% (95% CI: 4.8–14.3%). In the Cox model, sclerotic class AAGN increased the instantaneous risk of renal relapse. In Fine & Gray’s model, the absence of interstitial infiltrates at diagnosis was predictive for renal relapse. In this study we used two different models to identify possible relationships between clinical and histopathological parameters at time of diagnosis of AAV with the risk of experiencing renal relapse. Sclerotic class AAGN increased the instantaneous risk of renal relapse. This association is most likely due to the high proportion of sclerosed glomeruli reducing the compensatory capacity. The absence of interstitial infiltrates increased the risk of renal relapse which is a warning sign that patients with a relatively benign onset of disease may also be prone to renal relapse. Renal relapses occurring in patients with sclerotic class AAGN and renal relapses occurring in patients without interstitial infiltrates were mutually exclusive, which may indicate that they are essentially different. PMID:27973575

  2. Comparative study of renal sodium transport between ouabain-hypertensive rats and ouabain-nonhypertensive rats

    Institute of Scientific and Technical Information of China (English)

    GE Heng; Lü Zhuo-ren

    2006-01-01

    Objective: To compare renal sodium transport, using fractional excretions of lithium(FEii)as a marker of proximal tubule sodium reabsorption, between hypertensive and non-hypertensive ouabaintreated rats and further to elucidate the role of ouabain in pathogenesis of hypertension. Methods:Thirty male Sprague-Dawley rats weighting 180-200 g were randomly divided into normal control group and ouabain treated group. Rats were infused with 1 ml/kg · d normal saline or 27.8 μg/kg · d ouabain intraperitoneally once a day respectively. Systolic blood pressure (SBP), heart rate and body weight were recorded weekly. Rats were sacrificed 6 weeks after treatment. Blood and 24-hour urine sample were collected to measure the serum and urinary concentration of sodium, trace lithium and creatinine. Endogenous creatinine clearance rate (Ccr), fractional excretions of sodium (FENa), fractional excretions of lithium (FELi) and fractional reabsorption of sodium in the postproximal tubules (FDRNa) were calculated.Ouabain levels of plasma and renal tissue, plasma renin activity, angiotensin Ⅱ and aldosterone concentration were determined. Results: 65% of the ouabain-treated rats achieved significantly higher SBP after 4weeks, compared with that of the saline control groups or self baseline (P<0. 01). But in the other 35%of the ouabain-treated rats, their SBP was similar with control group during the experiment (P>0. 05).The body weight, heart rate and food intake between the 3 groups were no significant differences (P>0.05). FELi and FDRNa were significantly lower in ouabain-hypertensive group compared with ouabain-nonhypertensive group and control group(P<0.01 and P<0.05). The FELi and FDRNa of ouabain-nonhypertensive groups were similar with control group(P>0.05). Ccr and FENa were comparable between the 3 groups (P>0. 05). Plasma and renal tissue ouabain levels, plasma renin activity, angiotensin Ⅱ and aldosterone contents in ouabain-hypertensive rats were

  3. Effect of sludge ice cooling on renal function and renal histology in the dog.

    Science.gov (United States)

    Verbaeys, A; Oosterlinck, W; Lameire, N; Cuvelier, C; De Sy, W A

    1981-01-01

    The effect of sludge ice surface cooling on the compensatory hypertrophied dog kidney was investigated. Renal function was measured prior to and on days 1, 3 and 7 after the cooling procedure by means of inulin clearance, PAH clearance and sodium excretion capacity during normal hydration and after volume expansion. No alteration in renal function was shown. No freezing lesions or thromboses were seen on histological examination.

  4. Molecular analysis of the SGLT2 gene in patients with renal glucosuria

    DEFF Research Database (Denmark)

    Santer, René; Kinner, Martina; Lassen, Christoph L.

    2003-01-01

    heterozygous for an SGLT2 mutation resulting in glucosuria in the range of 14.6 to 202 g/1.73 m(2)/d (81 - 1120 mmol/1.73 m(2)/d). Some, but not all, of their heterozygous family members had an increased glucose excretion of up to 4.4 g/1.73 m(2)/d (24 mmol/1.73 m(2)/d). Likewise, in index cases...... with glucosuria below 10 g/1.73 m(2)/d (55 mmol/1.73 m(2)/d) an SGLT2 mutation, if present, was always detected in the heterozygous state. We conclude that SGLT2 plays an important role in renal tubular glucose reabsorption. Inheritance of renal glucosuria shows characteristics of a codominant trait with variable...

  5. Demeclocycline Attenuates Hyponatremia by Reducing Aquaporin-2 Expression in the Renal Inner Medulla

    DEFF Research Database (Denmark)

    Kortenoeven, Marleen L. A.; Sinke, Anne P.; Hadrup, Niels;

    2013-01-01

    Binding of vasopressin to its type-2 receptor in renal collecting ducts induces cAMP signaling, transcription and translocation of aquaporin-2 (AQP2) water channels to the plasma membrane and water reabsorption from the pro-urine. Demeclocycline is currently used to treat hyponatremia in patients...... urine volume, decreased urine osmolality and reverted hyponatremia in an SIADH rat model. AQP2 and adenylate cyclase 5/6 abundances were reduced in the inner medulla, but increased in the cortex and outer medulla, in the absence of any sign of toxicity. In conclusion, our in vitro and in vivo data...... indicate that demeclocycline mainly attenuates hyponatremia in SIADH by reducing adenylate cyclase 5/6 expression, and consequently cAMP generation, AQP2 gene transcription and AQP2 abundance in the renal inner medulla, coinciding with a reduced vasopressin-escape response in the other collecting duct...

  6. Acute effect of cisplatin on renal hemodynamics and tubular function in dog kidneys

    DEFF Research Database (Denmark)

    Daugaard, G; Abildgaard, U; Holstein-Rathlou, N H

    1986-01-01

    The present study was designed to investigate the early hemodynamic and tubular effects of cisplatin administration on dogs. To localize the nephrotoxic actions of cisplatin, we have taken advantage of the lithium clearance method. After infusion of 5 mg of cisplatin per kg, an immediate and sign.......56 +/- 0.04 and from 4.76 +/- 0.32 mmol/min to 3.92 +/- 0.23 mmol/min, respectively. The results show that administration of cisplatin causes an acute, mainly proximal tubular impairment in dogs without alterations in renal hemodynamics......./min) and fractional lithium clearance (from 0.31 +/- 0.03 to 0.44 +/- 0.04) was seen. This occurred without measurable changes in glomerular filtration rate and renal blood flow. The calculated fractional as well as absolute rates of proximal reabsorption of sodium decreased significantly from 0.68 +/- 0.03 to 0...

  7. A novel description of FDG excretion in the renal system: application to metformin-treated models

    Science.gov (United States)

    Garbarino, S.; Caviglia, G.; Sambuceti, G.; Benvenuto, F.; Piana, M.

    2014-05-01

    This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increase of the bladder’s volume during the FDG excretion process. From the computational viewpoint, the reconstruction of the tracer kinetic parameters is obtained by solving the maximum likelihood problem iteratively, using a non-stationary, steepest descent approach that explicitly accounts for the Poisson nature of nuclear medicine data. The reliability of the method is validated against two sets of synthetic data realized according to realistic conditions. Finally we applied this model to describe FDG excretion in the case of animal models treated with metformin. In particular we show that our approach allows the quantitative estimation of the reduction of FDG de-phosphorylation induced by metformin.

  8. LP-925219 maximizes urinary glucose excretion in mice by inhibiting both renal SGLT1 and SGLT2

    OpenAIRE

    Powell, David R.; Smith, Melinda G; Doree, Deon D; Harris, Angela L; Xiong, Wendy W; Mseeh, Faika; Wilson, Alan; Gopinathan, Suma; Diaz, Damaris; Goodwin, Nicole C.; Harrison, Bryce; Strobel, Eric; Rawlins, David B.; Carson, Ken; Zambrowicz, Brian

    2015-01-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of oral anti-diabetic agents that improve glycemic control by inhibiting SGLT2-mediated renal glucose reabsorption. Currently available agents increase urinary glucose excretion (UGE) to 50% of filtered glucose when SGLT2 is completely inhibited. This led us to test whether LP-925219, a small molecule dual SGLT1/SGLT2 inhibitor, increases UGE to maximal values in wild-type (WT) mice. We first tested LP-925219 inhibition of gluc...

  9. Canagliflozin use in patients with renal impairment-Utility of quantitative clinical pharmacology analyses in dose optimization.

    Science.gov (United States)

    Khurana, Manoj; Vaidyanathan, Jayabharathi; Marathe, Anshu; Mehrotra, Nitin; Sahajwalla, Chandrahas G; Zineh, Issam; Jain, Lokesh

    2015-06-01

    Canagliflozin (INVOKANA™) is approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus (T2DM). Canagliflozin inhibits renal sodium-glucose co-transporter 2 (SGLT2), thereby, reducing reabsorption of filtered glucose and increasing urinary glucose excretion. Given the mechanism of action of SGLT2 inhibitors, we assessed the interplay between renal function, efficacy (HbA1c reduction), and safety (renal adverse reactions). The focus of this article is to highlight the FDA's quantitative clinical pharmacology analyses that were conducted to support the regulatory decision on dosing in patients with renal impairment (RI). The metrics for assessment of efficacy for T2DM drugs is standard; however, there is no standard method for evaluation of renal effects for diabetes drugs. Therefore, several analyses were conducted to assess the impact of canagliflozin on renal function (as measured by eGFR) based on available data. These analyses provided support for approval of canagliflozin in T2DM patients with baseline eGFR ≥ 45 mL/min/1.73 m(2) , highlighting a data-driven approach to dose optimization. The availability of a relatively rich safety dataset (ie, frequent and early measurements of laboratory markers) in the canagliflozin clinical development program enabled adequate assessment of benefit-risk balance in various patient subgroups based on renal function. © 2015, The American College of Clinical Pharmacology.

  10. Capacity and Capacity Utilization in Fishing Industries

    OpenAIRE

    Kirkley, James E; Squires, Dale

    1999-01-01

    Excess capacity of fishing fleets is one of the most pressing problems facing the world's fisheries and the sustainable harvesting of resource stocks. Considerable confusion persists over the definition and measurement of capacity and capacity utilization in fishing. Fishing capacity and capacity utilization, rather than capital (or effort) utilization, provide the appropriate framework. This paper provides both technological-economic and economic definitions of capacity and excess capacity i...

  11. Renal functional reserve and renal recovery after acute kidney injury.

    Science.gov (United States)

    Sharma, Aashish; Mucino, Marìa Jimena; Ronco, Claudio

    2014-01-01

    Renal functional reserve (RFR) represents the capacity of the kidney to increase glomerular filtration rate (GFR) in response to certain physiological or pathological stimuli or conditions. Once baseline GFR is determined, RFR can be assessed clinically after an oral protein load or intravenous amino acid infusion. In clinical practice, baseline GFR displays variable levels due to diet or other factors. RFR is the difference between peak 'stress' GFR induced by the test (p.o. or i.v.) and the baseline GFR. In clinical scenarios where hyperfiltration is present (high baseline GFR due to pregnancy, hypertension or diabetic nephropathy, in solitary kidney or kidney donors), RFR may be fully or partially used to achieve normal or supranormal renal function. Since commonly used renal function markers, such as GFR, may remain within normal ranges until 50% of nephrons are lost or in patients with a single remnant kidney, the RFR test may represent a sensitive and early way to assess the functional decline in the kidney. RFR assessment may become an important tool to evaluate the ability of the kidney to recover completely or partially after a kidney attack. In case of healing with a defect and progressive fibrosis, recovery may appear complete clinically, but a reduced RFR may be a sign of a maladaptive repair or subclinical loss of renal mass. Thus, a reduction in RFR may represent the equivalent of renal frailty or susceptibility to insults. The main aim of this article is to review the concept of RFR, its utility in different clinical scenarios, and future perspective for its use.

  12. Influence of volume expansion on NaC1 reabsorption in the diluting segments of the nephron: a study using clearance methods.

    Science.gov (United States)

    Danovitch, G M; Bricker, N S

    1976-09-01

    Whether volume expansion influences NaC1 reabsorption by the diluting segment of the nephron remains a matter of controversy. In the present studies this question has been examined in normal unanesthetized dogs, undergoing maximal water diuresis. Free water clearance (CH2O/GFR) has been used as the index of NaC1 reabsorption in the diluting segment. Three expressions have been employed for "distal delivery" of NaC1: a) V/GFR, designated as the "volume term"; b) (CNa/GFR + CH2O/GFR), the "sodium term;" and c) (CC1/GFR + CH2O/GFR), the "chloride term". The validity of these terms is discussed. Three techniques were used to increase distal delivery: 1) the administration of acetazolamide to dogs in which extracellular fluid (ECF) volume was not expanded (grop 1); 2) "moderate" volume expansion (group 2); and 3) "marked" volume expansion (group 3). CH2O/GFR increased progressively with rising values for "distal delivery" regardless of which term was used to calculate the latter. With all three delivery terms, differences in distal NaC1 reabsorption emerged between the two volume-expanded groups, though only with the "chloride" term did substantial differences also emerge between the nonexpanded group 1 dogs and both volume-expanded groups. In group 1, values for CH2O/GFR increased in close to a linear fashion up to distal delivery values equal to 24% of the volume of glomerular filtrate. However, at high rates of distal delivery the rate of rise of CH2O/GFR was less in group 2 than in group 1 and the depression of values was even greater in group 3. Within the limits of the techniques used, the data suggest that volume expansion inhibits fractional NaC1 reabsorption in the diluting segment of the nephron in a dose-related fashion. The "chloride" term was found to be superior to the "volume" and "sodium" terms in revealing these changes.

  13. LUMINESCENCE LIFETIME MEASUREMENTS OF YB3+ IONS IN LI2ZN2(MOO43 CRYSTAL BY USING METHOD ELIMINATING REABSORPTION EFFECT

    Directory of Open Access Journals (Sweden)

    S. V. Kurilchik

    2011-01-01

    Full Text Available The experimental setup for luminescence decay time measurements of rear-earth ions in condensed matters  (crystals,  glasses  and solutions  has  been  developed.  Fluorescence decay time  of  Yb3+  ions  in Yb3+:Li2Zn2(MoO43 crystal was measured in the spectral range near 1 µm by using special method eliminating effects of reabsorption.

  14. The use of biomarkers for assessing HAART-associated renal toxicity in HIV-infected patients.

    Science.gov (United States)

    del Palacio, María; Romero, Sara; Casado, Jose L

    2012-09-01

    Renal toxicity has become an important issue in HIV-infected patients receiving highly active antiretroviral therapy (HAART). Several biomarkers are available for monitoring renal function, although no consensus exists on how best to apply these tools in HIV infection. The best biomarker is the glomerular filtration rate (GFR), and several creatinine-based estimates equations of GFR are widely used in HIV infection, with clinical advantages for the equation developed by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). Although serum cystatin C has been proposed as a more sensitive marker of renal dysfunction in HIV infection, it may be affected by ongoing inflammation. Tubular dysfunction can be simple or complex, depending on whether the tubular transport of one or more substances is affected. Multiple renal tubular dysfunction or Fanconi syndrome is characterized by alterations in the reabsorption of glucose, amino acids, phosphate and often also bicarbonate. Therefore, Fanconi syndrome would be the tip of the iceberg, and the most unusual and severe manifestation. In the last years, several low molecular weight proteins as markers of tubular alteration, including retinol-binding protein, b2-microglobulin, and neutrophil gelatinase associated lipocalin have become available. Different studies have shown differences in urine concentrations of these proteins in patients receiving tenofovir, but again, no consistent data have shown their clinical usefulness in predicting the clinical consequences of tubular alteration. Thus, we review findings from recent studies performed in this area to describe the performance of new biomarkers for renal damage in HIV-infected patients.

  15. Applications of urinary proteomics in renal disease research using animal models.

    Science.gov (United States)

    Lv, Yang; Cai, Guangyan; Chen, Xiangmei

    2015-01-01

    Animal models of renal disease are essential tools in research on kidney disease and have provided valuable insights into pathogenesis. Use of animal models minimises inter-individual differences, allows specific pathological changes to be examined, and facilitates collection of tissue samples. Thus, mechanistic research and identification of biomarkers are possible. Various animal models manifesting specific pathological lesions can be used to investigate acute or chronic kidney disease (CKD). Urine, a terminal metabolic product, is produced via glomerular filtration, reabsorption, and excretion in the tubular and collecting ducts, reflecting the functions of glomeruli or tubular tissue stimulated in various ways or subject to disease. Almost 70 % of urinary proteins originate from the kidney (the other 30 % come from plasma), and urinary sampling is important to noninvasively detect renal disease. Proteomics is powerful when used to screen urine components. Increasingly, urine proteomics is used to explore the pathogenesis of kidney disease in animals and to identify novel biomarkers of renal disease. In this section, we will introduce the field of urinary proteomics as applied in different models of animal renal disease and the valuable role played by proteomics in noninvasive diagnosis and rational treatment of human renal disease.

  16. Fluorescently Labeled Cyclodextrin Derivatives as Exogenous Markers for Real-Time Transcutaneous Measurement of Renal Function.

    Science.gov (United States)

    Huang, Jiaguo; Weinfurter, Stefanie; Pinto, Pedro Caetano; Pretze, Marc; Kränzlin, Bettina; Pill, Johannes; Federica, Rodeghiero; Perciaccante, Rossana; Ciana, Leopoldo Della; Masereeuw, Rosalinde; Gretz, Norbert

    2016-10-19

    Evaluation of renal function is crucial for a number of clinical situations. Here, we reported a novel exogenous fluorescent marker (FITC-HPβCD) to real-time assess renal function by using a transcutaneous fluorescent detection technique. FITC-HPβCD was designed based on the principle of renal clearance of designed drugs. It displays favorable fluorescent properties, high hydrophilicity, low plasma protein binding, and high stability in porcine liver esterase as well as in plasma and nontoxicity. More importantly, FITC-HPβCD can be efficiently and rapidly filtered by glomerulus and completely excreted into urine without proximal tubular reabsorption or secretion in rat models. Additionally, the marker was well-tolerated, with nearly 100% urinary recovery of the given doses, and no metabolism were found. Relying on this novel kidney function marker and transcutaneous devices, we demonstrate a rapid, robust, and convenient approach for real-time assessing renal function without the need of time-consuming blood and urine sample preparation. Our work provides a promising tool for noninvasive real-time monitoring of renal function in vivo.

  17. Ectopic germinal center and megalin defect in primary Sjogren syndrome with renal Fanconi syndrome.

    Science.gov (United States)

    Wang, Jing; Wen, Yubing; Zhou, Mengyu; Shi, Xiaoxiao; Jiang, Lanping; Li, Mingxi; Yu, Yang; Li, Xuemei; Li, Xuewang; Zhang, Wen; Lundquist, Andrew L; Chen, Limeng

    2017-06-02

    This study reports the clinical and pathological features of 12 cases of primary Sjogren syndrome (pSS) with renal involvement presenting with proximal tubular dysfunction in a single center, and investigates the possible correlation of ectopic germinal center formation and megalin/cubilin down-expression. Clinical and pathological records were reviewed. Immunohistochemistry was carried out to detect megalin, cubilin, CD21 and IL-17 expression. Patients presented with different degrees of proximal renal tubule lesion and decreased estimated glomerular filtration rate (eGFR). Renal biopsy revealed tubulointerstitial nephritis, with tubular epithelial cell degeneration, tubular atrophy, interstitial inflammation and focal fibrosis. Immunohistochemistry revealed decreased expression of megalin and cubilin, two important multiligand protein receptors on the brush border of proximal tubular epithelial cells. IL-17 secreted by Th17 subtype effector T cells was diffusely detected in the renal proximal tubule, with a negative correlation of IL-17 and megalin expression. In addition, ectopic germinal centers characterized by CD21(+) follicular dendritic cells were present in the renal interstitium. In patients with a decreased eGFR, treatment with 4 weeks of glucocorticoid therapy resulted in an improved eGFR in 75% of patients. We report 12 cases of pSS characterized by Fanconi syndrome. The decreased megalin and cubilin expression may contribute to the proximal tubular reabsorption defect, possibly secondary to Th17 infiltration and formation of ectopic germinal centers.

  18. Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

    Energy Technology Data Exchange (ETDEWEB)

    Graceli, J.B. [Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Cicilini, M.A.; Bissoli, N.S.; Abreu, G.R.; Moysés, M.R. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil)

    2013-07-02

    The maintenance of extracellular Na{sup +} and Cl{sup -} concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na{sup +} and Cl{sup -} reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg{sup -1}·day{sup -1}, sc) and progesterone (OVP, 1.7 mg·kg{sup -1}·day{sup -1}, sc). We assessed Na{sup +} and Cl{sup -} fractional excretion (FE{sub Na{sup {sub +}}} and FE{sub Cl{sup {sub -}}}, respectively) and renal and plasma catecholamine release concentrations. FE{sub Na{sup {sub +}}}, FE{sub Cl{sup {sub -}}}, water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FE{sub Na{sup {sub +}}}, FE{sub Cl{sup {sub -}}}, water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen

  19. Renal tubular dysfunction with nephrocalcinosis in a patient with beta thalassemia minor

    Directory of Open Access Journals (Sweden)

    Prabahar Murugesan

    2008-01-01

    Full Text Available Thalassemia is a hereditary anemia resulting from defect in hemoglobin production. Beta thalassemia is due to impaired production of beta globin chains, leading to a relative excess of alpha globin chains. The term beta thalassemia minor is used to describe heterozygotes, who carry one normal beta globin allele and one beta thalassemic allele. The vast majority of these patients are asymptomatic. However, a variety of renal tubular abnormalities including hypercalciuria, hypo-magnesemia with renal magnesium wasting, decreased tubular absorption of phosphorus, hypo-uricemia with renal uric acid wasting, renal glycosuria and tubular proteinuria have been described even in patients with beta thalassemia minor. We here in report a 24-year old female patient who was found to have thalassemia minor and nephrocalcinosis with evidence of renal tubular dysfunction. Investigations revealed normal renal function, hypercalciuria, reduced tubular reabsorption of phos-phorus, hypomagnesemia and renal magnesium wasting. Screening for aminoaciduria was found to be negative. An acid loading test revealed normal urinary acidification. Ultrasonogram of the abdomen revealed nephrocalcinosis and splenomegaly. Detailed work up for anemia showed normal white cell and platelet count while peripheral smear showed microcytic hypochromic anemia with few target cells. Hemoglobin electrophoresis revealed hemoglobin A of 92%, hemoglobin A2 of 6.2% and hemo-globin F of 1.8% consistent with beta thalassemia minor. Her parental screening was normal. A diag-nosis of beta thalassemia minor with renal tubular dysfunction was made and the patient was started on thiazide diuretics to reduce hypercalciuria and advised regular follow-up.

  20. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  1. Renal arteries (image)

    Science.gov (United States)

    A renal angiogram is a test used to examine the blood vessels of the kidneys. The test is performed ... main vessel of the pelvis, up to the renal artery that leads into the kidney. Contrast medium ...

  2. Synthesis of Reabsorption-Suppressed Type-II/Type-I ZnSe/CdS/ZnS Core/Shell Quantum Dots and Their Application for Immunosorbent Assay

    Science.gov (United States)

    Wang, Sheng; Li, Jin Jie; Lv, Yanbing; Wu, Ruili; Xing, Ming; Shen, Huaibin; Wang, Hongzhe; Li, Lin Song; Chen, Xia

    2017-06-01

    We report a phosphine-free one-pot method to synthesize ZnSe/CdS/ZnS core-shell quantum dots (QDs) with composite type-II/type-I structures and consequent reabsorption suppression properties. The as-synthesized QDs possess high efficient red emission (with quantum yield of 82%) and high optical stability. Compared to type-I QDs, the ZnSe/CdS/ZnS QDs show larger Stokes shift and lower reabsorption which can reduce the emission loss and improve the level of fluorescence output. The ZnSe/CdS/ZnS QDs are used as fluorescent labels to exploit their application in fluorescence-linked immunosorbent assay (FLISA) for the first time in the detection of C-reactive protein (CRP) with a limit of detection (LOD) of 0.85 ng/mL, which is more sensitive than that of CdSe/ZnS type-I QDs based FLISA (1.00 ng/mL). The results indicate that the ZnSe/CdS/ZnS type-II/type-I QDs may be good candidates for applications in biomedical information detection.

  3. [Renal leiomyoma. Case report].

    Science.gov (United States)

    Joual, A; Guessous, H; Rabii, R; Benjelloun, M; Benlemlih, A; Skali, K; el Mrini, M; Benjelloun, S

    1999-01-01

    The authors report a case of renal leiomyoma observed in a 56-year-old man. This cyst presented in the from of loin pain. Computed tomography revealed a homogeneous renal tumor. Treatment consisted of radical nephrectomy. Histological examination of the specimen showed benign renal leiomyoma.

  4. Renal inflammatory myofibroblastic tumor

    DEFF Research Database (Denmark)

    Heerwagen, S T; Jensen, C; Bagi, P

    2007-01-01

    Renal inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor of controversial etiology with a potential for local recurrence after incomplete surgical resection. The radiological findings in renal IMT are not well described. We report two cases in adults with a renal mass treated...

  5. Effects of renal function on pharmacokinetics and pharmacodynamics of lesinurad in adult volunteers

    Directory of Open Access Journals (Sweden)

    Gillen M

    2016-11-01

    Full Text Available Michael Gillen,1 Shakti Valdez,2 Dongmei Zhou,2 Bradley Kerr,2 Caroline A Lee,2 Zancong Shen2 1AstraZeneca LP, Gaithersburg, MD, 2Ardea Biosciences, Inc., San Diego, CA, USA Introduction: Lesinurad is a selective uric acid reabsorption inhibitor approved for the treatment of gout in combination with a xanthine oxidase inhibitor (XOI in patients who have not achieved target serum uric acid (sUA levels with an XOI alone. Most people with gout have chronic kidney disease. The pharmacokinetics, pharmacodynamics, and safety of lesinurad were assessed in subjects with impaired renal function. Methods: Two Phase I, multicenter, open-label, single-dose studies enrolled subjects with normal renal function (estimated creatinine clearance [eCrCl] >90 mL/min; N=12 or mild (eCrCl 60–89 mL/min; N=8, moderate (eCrCl 30–59 mL/min; N=16, or severe (eCrCl <30 mL/min; N=6 renal impairment. Subjects were given a single oral lesinurad dose of 200 mg (N=24 or 400 mg (N=18. Blood and urine samples were analyzed for plasma lesinurad concentrations and serum and urine uric acid concentrations. Safety was assessed by adverse events and laboratory data. Results: Mild, moderate, and severe renal impairment increased lesinurad plasma area under the plasma concentration–time curve by 34%, 54%–65%, and 102%, respectively. Lesinurad plasma Cmax was unaffected by renal function status. Lower renal clearance and urinary excretion of lesinurad were associated with the degree of renal impairment. The sUA-lowering effect of a single dose of lesinurad was similar between mild renal impairment and normal function, reduced in moderate impairment, and greatly diminished in severe impairment. Lesinurad increased urinary urate excretion in normal function and mild renal impairment; the increase was less with moderate or severe renal impairment. Lesinurad was well tolerated by all subjects. Conclusion: Lesinurad exposure increased with decreasing renal function; however, the

  6. Development of a Physiologically Based Computational Kidney Model to Describe the Renal Excretion of Hydrophilic Agents in Rats

    Science.gov (United States)

    Niederalt, Christoph; Wendl, Thomas; Kuepfer, Lars; Claassen, Karina; Loosen, Roland; Willmann, Stefan; Lippert, Joerg; Schultze-Mosgau, Marcus; Winkler, Julia; Burghaus, Rolf; Bräutigam, Matthias; Pietsch, Hubertus; Lengsfeld, Philipp

    2013-01-01

    A physiologically based kidney model was developed to analyze the renal excretion and kidney exposure of hydrophilic agents, in particular contrast media, in rats. In order to study the influence of osmolality and viscosity changes, the model mechanistically represents urine concentration by water reabsorption in different segments of kidney tubules and viscosity dependent tubular fluid flow. The model was established using experimental data on the physiological steady state without administration of any contrast media or drugs. These data included the sodium and urea concentration gradient along the cortico-medullary axis, water reabsorption, urine flow, and sodium as well as urea urine concentrations for a normal hydration state. The model was evaluated by predicting the effects of mannitol and contrast media administration and comparing to experimental data on cortico-medullary concentration gradients, urine flow, urine viscosity, hydrostatic tubular pressures and single nephron glomerular filtration rate. Finally the model was used to analyze and compare typical examples of ionic and non-ionic monomeric as well as non-ionic dimeric contrast media with respect to their osmolality and viscosity. With the computational kidney model, urine flow depended mainly on osmolality, while osmolality and viscosity were important determinants for tubular hydrostatic pressure and kidney exposure. The low diuretic effect of dimeric contrast media in combination with their high intrinsic viscosity resulted in a high viscosity within the tubular fluid. In comparison to monomeric contrast media, this led to a higher increase in tubular pressure, to a reduction in glomerular filtration rate and tubular flow and to an increase in kidney exposure. The presented kidney model can be implemented into whole body physiologically based pharmacokinetic models and extended in order to simulate the renal excretion of lipophilic drugs which may also undergo active secretion and reabsorption

  7. Genetic diagnosis of X-linked dominant hypophosphatemic rickets in a cohort study: Tubular reabsorption of phosphate and 1,25(OH2D serum levels are associated with PHEX mutation type

    Directory of Open Access Journals (Sweden)

    García-Miñaur Sixto

    2011-09-01

    Full Text Available Abstract Background Genetic Hypophosphatemic Rickets (HR is a group of diseases characterized by renal phosphate wasting with inappropriately low or normal 1,25-dihydroxyvitamin D3 (1,25(OH2D serum levels. The most common form of HR is X-linked dominant HR (XLHR which is caused by inactivating mutations in the PHEX gene. The purpose of this study was to perform genetic diagnosis in a cohort of patients with clinical diagnosis of HR, to perform genotype-phenotype correlations of those patients and to compare our data with other HR cohort studies. Methods Forty three affected individuals from 36 non related families were analyzed. For the genetic analysis, the PHEX gene was sequenced in all of the patients and in 13 cases the study was complemented by mRNA sequencing and Multiple Ligation Probe Assay. For the genotype-phenotype correlation study, the clinical and biochemical phenotype of the patients was compared with the type of mutation, which was grouped into clearly deleterious or likely causative, using the Mann-Whitney and Fisher's exact test. Results Mutations in the PHEX gene were identified in all the patients thus confirming an XLHR. Thirty four different mutations were found distributed throughout the gene with higher density at the 3' end. The majority of the mutations were novel (69.4%, most of them resulted in a truncated PHEX protein (83.3% and were family specific (88.9%. Tubular reabsorption of phosphate (TRP and 1,25(OH2D serum levels were significantly lower in patients carrying clearly deleterious mutations than in patients carrying likely causative ones (61.39 ± 19.76 vs. 80.14 ± 8.80%, p = 0.028 and 40.93 ± 30.73 vs. 78.46 ± 36.27 pg/ml, p = 0.013. Conclusions PHEX gene mutations were found in all the HR cases analyzed, which was in contrast with other cohort studies. Patients with clearly deleterious PHEX mutations had lower TRP and 1,25(OH2D levels suggesting that the PHEX type of mutation might predict the XLHR

  8. Postpartum renal vein thrombosis.

    Science.gov (United States)

    Rubens, D; Sterns, R H; Segal, A J

    1985-01-01

    Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two postpartum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.

  9. An experimental renal acidification defect in patients with hereditary fructose intolerance. I. Its resemblance to renal tubular acidosis.

    Science.gov (United States)

    Morris, R C

    1968-06-01

    In three unrelated patients with hereditary fructose intolerance (HFI), but in none of five normal subjects, the experimental administration of fructose invariably induced a reversible dysfunction of the renal tubule with biochemical and physiological characteristics of renal tubular acidosis. During a state of ammonium chloride-induced acidosis, (a) urinary pH was greater than six and the rate of excretion of net acid (titratable acid plus ammonium minus bicarbonate) was inappropriately low, (b) the glomerular filtration rate remained unchanged or decreased modestly, and (c) urinary excretion of titratable acid increased briskly with diuresis of infused phosphate, although urinary pH changed little. The tubular dysfunction, which also includes impaired tubular reabsorption of alpha amino nitrogen and phosphate, persisted throughout administration of fructose and disappeared afterward. The tubular dysfunction was not causally dependent on hypoglucosemia, ammonium chloride-induced acidosis or osmotic diuresis. Rather, it appeared causally related to the fructose-induced metabolic abnormality of patients with HFI. The causal enzymatic defect, the virtual absence of fructose-1-phosphate aldolase, occurs in the kidney as well as in the liver of patients with HFI.

  10. Renal infarction resulting from traumatic renal artery dissection.

    Science.gov (United States)

    Kang, Kyung Pyo; Lee, Sik; Kim, Won; Jin, Gong Yong; Na, Ki Ryang; Yun, Il Yong; Park, Sung Kwang

    2008-06-01

    Renal artery dissection may be caused by iatrogenic injury, trauma, underlying arterial diseases such as fibromuscular disease, atherosclerotic disease, or connective tissue disease. Radiological imaging may be helpful in detecting renal artery pathology, such as renal artery dissection. For patients with acute, isolated renal artery dissection, surgical treatment, endovascular management, or medical treatment have been considered effective measures to preserve renal function. We report a case of renal infarction that came about as a consequence of renal artery dissection.

  11. Renal xenobiotic transporters are differentially expressed in mice following cisplatin treatment.

    Science.gov (United States)

    Aleksunes, Lauren M; Augustine, Lisa M; Scheffer, George L; Cherrington, Nathan J; Manautou, José E

    2008-09-04

    The goal of this study was to identify alterations in mRNA and protein expression of various xenobiotic transport proteins in mouse kidney during cisplatin-induced acute renal failure. For this purpose, male C57BL/6J mice received a single dose of cisplatin (18 mg/kg, i.p.) or vehicle. Four days later, tissues were collected for assessment of plasma BUN, histopathological analysis of renal lesions, and mRNA and Western blot analysis of renal transporters including organic anion and cation transporters (Oat, Oct), organic anion transporting polypeptides (Oatp), multidrug resistance-associated proteins (Mrp), multidrug resistance proteins (Mdr), breast cancer resistance protein (Bcrp) and multidrug and toxin extrusion proteins (Mate). Cisplatin treatment caused necrosis of renal proximal tubules along with elevated plasma BUN and renal kidney injury molecule-1 mRNA expression. Cisplatin-induced renal injury increased mRNA and protein levels of the efflux transporters Mrp2, Mrp4, Mrp5, Mdr1a and Mdr1b. Uptake transporters Oatp2a1 and Oatp2b1 mRNA were also up-regulated following cisplatin. By contrast, expression of Oat1, Oat2, Oct2 and Oatp1a1 mRNA was reduced in cisplatin-treated mice. Expression of several uptake and efflux transporters was unchanged in cisplatin-treated mice. Apical staining of Mrp2 and Mrp4 proteins was enhanced in proximal tubules from cisplatin-treated mice. Collectively, these expression patterns suggest coordinated regulation of uptake and efflux pathways during cisplatin-induced renal injury. Reduced expression of basolateral and apical uptake transporters along with enhanced transcription of export transporters likely represents an adaptation to lower intracellular accumulation of chemicals, prevent their reabsorption and enhance urinary clearance.

  12. Renal uptake of myoglobin is mediated by the endocytic receptors megalin and cubilin.

    Science.gov (United States)

    Gburek, Jakub; Birn, Henrik; Verroust, Pierre J; Goj, Bogusława; Jacobsen, Christian; Moestrup, Søren K; Willnow, Thomas E; Christensen, Erik I

    2003-09-01

    Nephrotoxicity of myoglobin is well recognized as playing a part in the development of acute renal failure in settings of myoglobinuria. However, the molecular mechanism of myoglobin uptake in renal proximal tubules has not been clarified. Here, we report that the endocytic receptors megalin and cubilin are involved in renal reabsorption of myoglobin. Both receptors were captured from solubilized renal brush-border membranes by affinity chromatography using myoglobin-Sepharose. Myoglobin bound to purified megalin and cubilin with Kd values of 2.0 and 3 microM, respectively, as evaluated by surface plasmon resonance analysis. Apomyoglobin bound to megalin with the same affinity, and the affinity of apomyoglobin to cubilin was reduced (Kd = 5 microM). Radioiodinated myoglobin could be displaced by apomyoglobin in inhibition studies using isolated renal brush-border membranes (Ki approximately 2 microM). Receptor-associated protein as well as antibodies directed against megalin and cubilin markedly inhibited the uptake of fluorescent-labeled myoglobin by cultured yolk sac BN-16 cells. The significance of megalin- and cubilin-mediated endocytosis for myoglobin uptake in vivo was demonstrated by use of kidney-specific megalin knockout mice. Injected myoglobin was extensively reabsorbed by megalin-expressing proximal tubular cells, whereas there was very little uptake in the megalin-deficient cells. In conclusion, this study establishes the molecular mechanism of myoglobin uptake in the renal proximal tubule involving the endocytic receptors megalin and cubilin. Identification of the receptors for tubular uptake of myoglobin may be essential for development of new therapeutic strategies for myoglobinuric acute renal failure.

  13. Kidney-on-a-chip technology for renal proximal tubule tissue reconstruction.

    Science.gov (United States)

    Nieskens, Tom T G; Wilmer, Martijn J

    2016-11-05

    The renal proximal tubule epithelium is responsible for active secretion of endogenous and exogenous waste products from the body and simultaneous reabsorption of vital compounds from the glomerular filtrate. The complexity of this transport machinery makes investigation of processes such as tubular drug secretion a continuous challenge for researchers. Currently available renal cell culture models often lack sufficient physiological relevance and reliability. Introducing complex biological culture systems in a 3D microfluidic design improves the physiological relevance of in vitro renal proximal tubule epithelium models. Organ-on-a-chip technology provides a promising alternative, as it allows the reconstruction of a renal tubule structure. These microfluidic systems mimic the in vivo microenvironment including multi-compartmentalization and exposure to fluid shear stress. Increasing data supports that fluid shear stress impacts the phenotype and functionality of proximal tubule cultures, for which we provide an extensive background. In this review, we discuss recent developments of kidney-on-a-chip platforms with current and future applications. The improved proximal tubule functionality using 3D microfluidic systems is placed in perspective of investigating cellular signalling that can elucidate mechanistic aberrations involved in drug-induced kidney toxicity. Copyright © 2016. Published by Elsevier B.V.

  14. Heterozygous disruption of renal outer medullary potassium channel in rats is associated with reduced blood pressure.

    Science.gov (United States)

    Zhou, Xiaoyan; Zhang, Zuo; Shin, Myung Kyun; Horwitz, Sarah Beth; Levorse, John M; Zhu, Lei; Sharif-Rodriguez, Wanda; Streltsov, Denis Y; Dajee, Maya; Hernandez, Melba; Pan, Yi; Urosevic-Price, Olga; Wang, Li; Forrest, Gail; Szeto, Daphne; Zhu, Yonghua; Cui, Yan; Michael, Bindhu; Balogh, Leslie Ann; Welling, Paul A; Wade, James B; Roy, Sophie; Sullivan, Kathleen A

    2013-08-01

    The renal outer medullary potassium channel (ROMK, KCNJ1) mediates potassium recycling and facilitates sodium reabsorption through the Na(+)/K(+)/2Cl(-) cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Human genetic studies indicate that ROMK homozygous loss-of-function mutations cause type II Bartter syndrome, featuring polyuria, renal salt wasting, and hypotension; humans heterozygous for ROMK mutations identified in the Framingham Heart Study have reduced blood pressure. ROMK null mice recapitulate many of the features of type II Bartter syndrome. We have generated an ROMK knockout rat model in Dahl salt-sensitive background by using zinc finger nuclease technology and investigated the effects of knocking out ROMK on systemic and renal hemodynamics and kidney histology in the Dahl salt-sensitive rats. The ROMK(-/-) pups recapitulated features identified in the ROMK null mice. The ROMK(+/-) rats, when challenged with a 4% salt diet, exhibited a reduced blood pressure compared with their ROMK(+/+) littermates. More importantly, when challenged with an 8% salt diet, the Dahl salt-sensitive rats with 50% less ROMK expression showed increased protection from salt-induced blood pressure elevation and signs of protection from renal injury. Our findings in ROMK knockout Dahl salt-sensitive rats, together with the previous reports in humans and mice, underscore a critical role of ROMK in blood pressure regulation.

  15. Effects of halothane-nitrous oxide inhalation anesthesia and Inactin on overall renal and tubular function in Sprague-Dawley and Wistar rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Christensen, P; Leyssac, P P

    1982-01-01

    Real function, plasma renin concentration (PRC) and prostaglandin (PG) excretion rate was studied in groups of Sprague-Dawley (SPRD) and Wistar (WIST) rats anesthetized with either Halothane-N2O or Inactin. Conscious rats were used as controls. A. In Halothane-N2O anesthesia inulin clearance (CIN......) and absolute proximal reabsorption rate (APR) was moderately decreased (by about 20%), while renal plasma flow (RPF), urine flow and solute excretion remained unchanged as compared to conscious rats. There was a linear relationship between the reciprocal of the proximal occlusion time (OT) and CIN in Halothane...

  16. Refractory anemia leading to renal hemosiderosis and renal failure

    OpenAIRE

    Sujatha Siddappa; K M Mythri; Kowsalya, R.; Ashish Parekh

    2011-01-01

    Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  17. Refractory anemia leading to renal hemosiderosis and renal failure

    Directory of Open Access Journals (Sweden)

    Sujatha Siddappa

    2011-01-01

    Full Text Available Renal hemosiderosis is a rare cause of renal failure and, as a result, may not be diagnosed unless a detailed history, careful interpretation of blood parameters and renal biopsy with special staining is done. Here, we present a rare case of renal hemosiderosis presenting with renal failure.

  18. Renal replacement therapy for acute renal failure.

    Science.gov (United States)

    Macedo, E; Bouchard, J; Mehta, R L

    2009-09-01

    Renal replacement therapy became a common clinical tool to treat patients with severe acute kidney injury (AKI) since the 1960s. During this time dialytic options have expanded considerably; biocompatible membranes, bicarbonate dialysate and dialysis machines with volumetric ultrafiltration control have improved the treatment for acute kidney injury. Along with advances in methods of intermittent hemodialysis, continuous renal replacement therapies have gained widespread acceptance in the treatment of dialysis-requiring AKI. However, many of the fundamental aspects of the renal replacement treatment such as indication, timing of dialytic intervention, and choice of dialysis modality are still controversial and may influence AKI patient's outcomes. This review outlines current concepts in the use of dialysis techniques for AKI and suggests an approach for selecting the optimal method of renal replacement therapy.

  19. Single sublethal dose of microcystin-LR is responsible for different alterations in biochemical, histological and physiological renal parameters.

    Science.gov (United States)

    Lowe, J; Souza-Menezes, J; Freire, D S; Mattos, L J; Castiglione, R C; Barbosa, C M L; Santiago, L; Ferrão, F M; Cardoso, L H D; da Silva, R T; Vieira-Beiral, H J; Vieyra, A; Morales, M M; Azevedo, S M F O; Soares, R M

    2012-05-01

    Microcystins (MCYSTs) are very stable cyclic peptidic toxins produced by cyanobacteria. Their effects on hepatic tissue have been studied extensively, and they are considered to be a potent hepatotoxin. However, several effects of MCYST on other organs have also been described, but generally in studies using higher doses of MCYST. In the present work, we investigated the effect of a single sublethal dose of MCYST-LR (55 μg/kg) in Wistar rats and analyzed different aspects that influenced renal physiology, including toxin accumulation, excretion, histological morphology, biochemical responses and oxidative damage in the kidney. After 24 h of exposure to MCYST-LR, it was possible to observe an increased glomerular filtration rate (6.28 ± 1.56 vs 2.16 ± 0.48 μl/min per cm(2)) compared with the control group. Increase of interstitial space and collagen deposition corresponded to a fibrotic response to the increased production of reactive oxygen species. The observed decrease of Na(+) reabsorption was due to inhibition of the activity of both Na(+) pumps in proximal tubules cells. We suggested that this modulation is mediated by the effect of MCYST as a phosphatase protein inhibitor that maintains the sustained kinase-mediated regulatory phosphorylation of the ATPases. The observed alteration of Na(+) active transporters lead to damage of renal function, since are involved in regulation of water and solute reabsorption in proximal tubules. The results of this report reinforce the importance of understanding the molecular effects of a single sublethal dose of MCYST-LR, which, in this study, was responsible for macro-alterations found in the renal parenchyma and renal physiology in rats.

  20. Renal function after renal artery stenting

    Institute of Scientific and Technical Information of China (English)

    George S. Hanzel; Mark Downes; Peter A. McCullough

    2005-01-01

    @@ Atherosclerotic renal artery stenosis (ARAS), a common clinical finding, is increasing in prevalence as the population ages. ARAS is seen in ~ 7% of persons over 65 years of age1 and in ~ 20% of patients at the time of coronary angiography.2 It is an important cause of chronic kidney disease and may result in 11-14% of cases of end stage renal disease.3

  1. Imaging of renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

    2003-05-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

  2. Renal tubular function in children with beta-thalassemia minor.

    Science.gov (United States)

    Kalman, Süleyman; Atay, A Avni; Sakallioglu, Onur; Ozgürtaş, Taner; Gök, Faysal; Kurt, Ismail; Kürekçi, A Emin; Ozcan, Okan; Gökçay, Erdal

    2005-10-01

    beta-thalassemia minor is a common heterozygous haemoglobinopathy that is characterized by both microcytosis and hypochromia. It requires no treatment. It has been postulated that low-grade haemolysis, tubular iron deposition and toxins derived from erythrocytes might cause renal tubular damage in adult patients with beta-thalassemia minor. Our aim was to investigate the renal tubular functions in children with beta-thalassemia minor and to determine its possible harmful effects. The study was conducted on 32 children (14 female and 18 male) at the age of 5.8 +/- 3.1 years (range 2-14 years) with beta-thalassemia minor. The patients were classified as anaemic (haemoglobin (Hb) 11 g/dL) (Group 2, n = 18). A control group was formed with 18 healthy children whose ages and sexes match those in other groups (Group 3, n = 18). Fractional excretion of sodium (FE(Na), %), fractional excretion of magnesium (FE(Mg), %), fractional excretion of uric acid (FE(UA), %) and tubular phosphorus reabsorption (TPR,%) were calculated with standard formulas. Urinary calcium excretion (mg/kg per 24 h), zinc (Zn) (microg/dL), glucosuria (mg/dL), beta-2 microglobulin (mg/dL) and N-acetyl-beta-D-glycosaminidase (NAG, U/mmol creatinine) levels were measured through biochemical methods. There was no statistically significant difference among the three groups in terms of the results of FE(Na) (%), FE(Mg) (%), FE(UA) (%), TPR (%), calciuria (mg/kg per 24 h), NAG, urine Zn, proteinuria, glucosuria or urine beta- 2 microglobulin levels (P > 0.05). On the contrary of children with beta-thalassemia major, renal tubular dysfunction has not been determined in children with beta-thalassemia minor in the present study.

  3. Dopamine-mediated inhibition of renal Na+/K+-ATPase in HK-2 cells is reduced by ouabain.

    Science.gov (United States)

    Zhang, Yu-Rong; Yuan, Zu-Yi

    2010-05-01

    1. Abnormal renal sodium handling is considered a major contributing factor in hypertension associated with chronic ouabain treatment. However, the molecular mechanisms involved in abnormal renal sodium handling have not been elucidated. Therefore, we investigated whether chronic ouabain treatment perturbs dopamine D(1) receptor function. 2. The expression and phosphorylation levels of the D(1) receptor in cells of the human proximal tubule cell line (HK-2) were determined using western blot analysis and reverse transcription polymerase chain reaction. The activity of the renal sodium/potassium pump (Na(+)/K(+)-ATPase) was measured using a colourimetric assay, and cyclic adenosine monophosphate accumulation was determined by performing a radioimmunoassay. 3. We showed that chronic ouabain treatment decreased the protein and mRNA expression levels of the D(1) receptor and increased the basal phosphorylation of the D(1) receptor in HK-2 cells. We also showed that in the presence of ouabain, HK-2 cells did not reveal the cyclic adenosine monophosphate accumulation and Na(+)/K(+)-ATPase inhibition induced by the D(1) receptor agonist fenoldopam. 4. We hypothesize that the ouabain-induced decrease in renal D(1) receptor function is responsible for the increase in renal sodium reabsorption, which eventually leads to ouabain-induced hypertension.

  4. Incidental renal neoplasms

    DEFF Research Database (Denmark)

    Rabjerg, Maj; Mikkelsen, Minne Nedergaard; Walter, Steen;

    2014-01-01

    On the basis of associations between tumor size, pathological stage, histological subtype and tumor grade in incidentally detected renal cell carcinoma vs symptomatic renal cell carcinoma, we discussed the need for a screening program of renal cell carcinoma in Denmark. We analyzed a consecutive...... series of 204 patients with renal tumors in 2011 and 2012. The tumors were classified according to detection mode: symptomatic and incidental and compared to pathological parameters. Eighty-nine patients (44%) were symptomatic, 113 (55%) were incidental. Information was not available in two patients...

  5. Insuficiencia renal aguda.

    OpenAIRE

    Carlos Hernán Mejía

    2009-01-01

    Acute renal failure (ARF) is a clinic syndrome characterized by decline in renal function occurring over a short time period. Is a relatively common complication in hospitalized critically ill patients and is associated with high morbidity and mortality. ARF has often a multi-factorial etiology syndrome usually approached diagnostically as pre-renal, post-renal, or intrinsic ARF. Most intrinsic ARF is caused by ischemia or nephrotoxins and is classically associated with acute tubular necrosis...

  6. Isolated Renal Hydatidosis Presenting as Renal Mass: A Diagnostic Dilemma

    Directory of Open Access Journals (Sweden)

    Datteswar Hota

    2015-07-01

    Full Text Available Hydatid disease is a parasitic infestation by larval form of Echinococcus granulosus. Isolated renal involvement is extremely rare. There are no specific signs and symptoms of renal hydatidosis. However it may present as palpable mass, flank pain, hematuria, malaise, fever, and hydatiduria or as a complication of it such as infection, abscess, hemorrhage, necrosis and pelviureteric junction obstruction, renal failure etc. Except hydatiduria, none are pathognomonic for renal hydatidosis. There is no literature on renal hydatidosis presenting as renal mass we report 2 cases of isolated renal hydatidosis, which mimicked a renal mass on imaging study.

  7. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...... metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available...

  8. Renal pelvis or ureter cancer

    Science.gov (United States)

    Transitional cell cancer of the renal pelvis or ureter; Kidney cancer - renal pelvis; Ureter cancer ... Cancer can grow in the urine collection system, but it is uncommon. Renal pelvis and ureter cancers ...

  9. Renal Primordia Activate Kidney Regenerative Events in a Rat Model of Progressive Renal Disease

    Science.gov (United States)

    Imberti, Barbara; Corna, Daniela; Rizzo, Paola; Xinaris, Christodoulos; Abbate, Mauro; Longaretti, Lorena; Cassis, Paola; Benedetti, Valentina; Benigni, Ariela; Zoja, Carlamaria; Remuzzi, Giuseppe; Morigi, Marina

    2015-01-01

    New intervention tools for severely damaged kidneys are in great demand to provide patients with a valid alternative to whole organ replacement. For repairing or replacing injured tissues, emerging approaches focus on using stem and progenitor cells. Embryonic kidneys represent an interesting option because, when transplanted to sites such as the renal capsule of healthy animals, they originate new renal structures. Here, we studied whether metanephroi possess developmental capacity when transplanted under the kidney capsule of MWF male rats, a model of spontaneous nephropathy. We found that six weeks post-transplantation, renal primordia developed glomeruli and tubuli able to filter blood and to produce urine in cyst-like structures. Newly developed metanephroi were able to initiate a regenerative-like process in host renal tissues adjacent to the graft in MWF male rats as indicated by an increase in cell proliferation and vascular density, accompanied by mRNA and protein upregulation of VEGF, FGF2, HGF, IGF-1 and Pax-2. The expression of SMP30 and NCAM was induced in tubular cells. Oxidative stress and apoptosis markedly decreased. Our study shows that embryonic kidneys generate functional nephrons when transplanted into animals with severe renal disease and at the same time activate events at least partly mimicking those observed in kidney tissues during renal regeneration. PMID:25811887

  10. The renal channelopathies.

    Science.gov (United States)

    Loudon, K W; Fry, A C

    2014-07-01

    Specific channels permit movement of selected ions through cellular membranes, and are of vital importance in a number of physiological processes, particularly in excitable tissues such as nerve and muscle, but also in endocrine organs and in epithelial biology. Disorders of channel proteins are termed channelopathies, and their importance is increasingly recognised within medicine. In the kidney, ion channels have critical roles enabling sodium and potassium reuptake or excretion along the nephron, in magnesium homeostasis, in the control of water reabsorption in the collecting duct, and in determining glomerular permeability. In this review, we assess the channelopathies encountered in each nephron segment, and see how their molecular and genetic characterisation in the past 20-30 years has furthered our understanding of normal kidney physiology and disease processes, aids correct diagnosis and promises future therapeutic opportunities. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  11. Diagnóstico de la enfermedad renal crónica como trazador de la capacidad técnica en la atención médica en 20 estados de México The diagnosis of Chronic Kidney Disease as a tracer of the technical capacity in care facilities of 20 Mexican states

    Directory of Open Access Journals (Sweden)

    Reyna Lizette Pacheco-Domínguez

    2011-01-01

    Full Text Available OBJETIVO. Evaluar el conocimiento y la capacidad técnica de los médicos de primer nivel de atención en el manejo de los pacientes con diabetes mellitus e hipertensión arterial y de pacientes en riesgo de desarrollar enfermedad renal crónica (ERC y utilizar la enfermedad terminal de esta última como trazador de la calidad de la atención primaria en el sistema de salud mexicano. MATERIAL Y MÉTODOS. Se realizó un estudio transversal en los servicios de salud de las secretarías de salud en 20 estados de junio a diciembre de 2008. Se construyó un cuestionario con dos casos clínicos. RESULTADOS. El promedio de calificación de los 149 médicos evaluados fue de 53.7 Los médicos que trabajan en las unidades de mayor tamaño tienden a tener mayor antigüedad y obtuvieron las calificaciones más bajas. CONCLUSIÓN. La utilización del diagnóstico de la ERC como un trazador permite detectar la capacidad de los médicos en el primer nivel de atención y el potencial del uso de esta metodología para evaluar procesos críticos en el sistema de salud.OBJECTIVE. To assess knowledge and technical capacity of primary care physicians in the management of patients with diabetes mellitus and high blood pressure as well as patients at risk of developing chronic kidney disease, and to use the latter condition as a tracer of the quality of primary care of the Mexican health system. MATERIAL AND METHODS. A cross-sectional study included 149 primary health physicians in primary care units from state health care services in 20 states. An instrument with two clinical cases was applied. RESULTS. The average score of the physicians evaluated was 53.7 out of 100. Those physicians working in larger size units and graduated before the year 2000 tend to receive lower scores. CONCLUSIONS. The use of chronic kidney disease as a tracer of the technical capacity of the Mexican health care system is useful to understand the problems of primary care in the country

  12. Expression profiles of genes involved in xenobiotic metabolism and disposition in human renal tissues and renal cell models

    Energy Technology Data Exchange (ETDEWEB)

    Van der Hauwaert, Cynthia; Savary, Grégoire [EA4483, Université de Lille 2, Faculté de Médecine de Lille, Pôle Recherche, 59045 Lille (France); Buob, David [Institut de Pathologie, Centre de Biologie Pathologie Génétique, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Leroy, Xavier; Aubert, Sébastien [Institut de Pathologie, Centre de Biologie Pathologie Génétique, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Institut National de la Santé et de la Recherche Médicale, UMR837, Centre de Recherche Jean-Pierre Aubert, Equipe 5, 59045 Lille (France); Flamand, Vincent [Service d' Urologie, Hôpital Huriez, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Hennino, Marie-Flore [EA4483, Université de Lille 2, Faculté de Médecine de Lille, Pôle Recherche, 59045 Lille (France); Service de Néphrologie, Hôpital Huriez, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille (France); Perrais, Michaël [Institut National de la Santé et de la Recherche Médicale, UMR837, Centre de Recherche Jean-Pierre Aubert, Equipe 5, 59045 Lille (France); and others

    2014-09-15

    Numerous xenobiotics have been shown to be harmful for the kidney. Thus, to improve our knowledge of the cellular processing of these nephrotoxic compounds, we evaluated, by real-time PCR, the mRNA expression level of 377 genes encoding xenobiotic-metabolizing enzymes (XMEs), transporters, as well as nuclear receptors and transcription factors that coordinate their expression in eight normal human renal cortical tissues. Additionally, since several renal in vitro models are commonly used in pharmacological and toxicological studies, we investigated their metabolic capacities and compared them with those of renal tissues. The same set of genes was thus investigated in HEK293 and HK2 immortalized cell lines in commercial primary cultures of epithelial renal cells and in proximal tubular cell primary cultures. Altogether, our data offers a comprehensive description of kidney ability to process xenobiotics. Moreover, by hierarchical clustering, we observed large variations in gene expression profiles between renal cell lines and renal tissues. Primary cultures of proximal tubular epithelial cells exhibited the highest similarities with renal tissue in terms of transcript profiling. Moreover, compared to other renal cell models, Tacrolimus dose dependent toxic effects were lower in proximal tubular cell primary cultures that display the highest metabolism and disposition capacity. Therefore, primary cultures appear to be the most relevant in vitro model for investigating the metabolism and bioactivation of nephrotoxic compounds and for toxicological and pharmacological studies. - Highlights: • Renal proximal tubular (PT) cells are highly sensitive to xenobiotics. • Expression of genes involved in xenobiotic disposition was measured. • PT cells exhibited the highest similarities with renal tissue.

  13. Activation of purinergic receptors (P2) in the renal medulla promotes endothelin-dependent natriuresis in male rats.

    Science.gov (United States)

    Gohar, Eman Y; Speed, Joshua S; Kasztan, Malgorzata; Jin, Chunhua; Pollock, David M

    2016-08-01

    Renal endothelin-1 (ET-1) and purinergic signaling systems regulate Na(+) reabsorption in the renal medulla. A link between the renal ET-1 and purinergic systems was demonstrated in vitro, however, the in vivo interaction between these systems has not been defined. To test whether renal medullary activation of purinergic (P2) receptors promotes ET-dependent natriuresis, we determined the effect of increased medullary NaCl loading on Na(+) excretion and inner medullary ET-1 mRNA expression in anesthetized adult male Sprague-Dawley rats in the presence and absence of purinergic receptor antagonism. Isosmotic saline (NaCl; 284 mosmol/kgH2O) was infused into the medullary interstitium (500 μl/h) during a 30-min baseline urine collection period, followed by isosmotic or hyperosmotic saline (1,800 mosmol/kgH2O) for two further 30-min urine collection periods. Na(+) excretion was significantly increased during intramedullary infusion of hyperosmotic saline. Compared with isosmotic saline, hyperosmotic saline infused into the renal medulla caused significant increases in inner medullary ET-1 mRNA expression. Renal intramedullary infusion of the P2 receptor antagonist suramin inhibited the increase in Na(+) excretion and inner medullary ET-1 mRNA expression induced by NaCl loading in the renal medulla. Activation of medullary P2Y2/4 receptors by infusion of UTP increased urinary Na(+) excretion. Combined ETA and ETB receptor blockade abolished the natriuretic response to intramedullary infusion of UTP. These data demonstrate that activation of medullary P2 receptors promotes ET-dependent natriuresis in male rats, suggesting that the renal ET-1 and purinergic signaling systems interact to efficiently facilitate excretion of a NaCl load.

  14. Acute SGLT inhibition normalizes O2 tension in the renal cortex but causes hypoxia in the renal medulla in anaesthetized control and diabetic rats.

    Science.gov (United States)

    O'Neill, Julie; Fasching, Angelica; Pihl, Liselotte; Patinha, Daniela; Franzén, Stephanie; Palm, Fredrik

    2015-08-01

    Early stage diabetic nephropathy is characterized by glomerular hyperfiltration and reduced renal tissue Po2. Recent observations have indicated that increased tubular Na(+)-glucose linked transport (SGLT) plays a role in the development of diabetes-induced hyperfiltration. The aim of the present study was to determine how inhibition of SLGT impacts upon Po2 in the diabetic rat kidney. Diabetes was induced by streptozotocin in Sprague-Dawley rats 2 wk before experimentation. Renal hemodynamics, excretory function, and renal O2 homeostasis were measured in anesthetized control and diabetic rats during baseline and after acute SGLT inhibition using phlorizin (200 mg/kg ip). Baseline arterial pressure was similar in both groups and unaffected by SGLT inhibition. Diabetic animals displayed reduced baseline Po2 in both the cortex and medulla. SGLT inhibition improved cortical Po2 in the diabetic kidney, whereas it reduced medullary Po2 in both groups. SGLT inhibition reduced Na(+) transport efficiency [tubular Na(+) transport (TNa)/renal O2 consumption (Qo2)] in the control kidney, whereas the already reduced TNa/Qo2 in the diabetic kidney was unaffected by SGLT inhibition. In conclusion, these data demonstrate that when SGLT is inhibited, renal cortex Po2 in the diabetic rat kidney is normalized, which implies that increased proximal tubule transport contributes to the development of hypoxia in the diabetic kidney. The reduction in medullary Po2 in both control and diabetic kidneys during the inhibition of proximal Na(+) reabsorption suggests the redistribution of active Na(+) transport to less efficient nephron segments, such as the medullary thick ascending limb, which results in medullary hypoxia.

  15. [Hemorrhagic bilateral renal angiomyolipoma].

    Science.gov (United States)

    Benjelloun, Mohamed; Rabii, Redouane; Mezzour, Mohamed Hicham; Joual, Abdenbi; Bennani, Saâd; el Mrini, Mohamed

    2003-09-01

    Renal angiomyolipoma is a rare benign tumour, often associated with congenital diseases especially de Bourneville's tuberous sclerosis. Bilateral angiomyolipoma is exceptional. The authors report a case of bilateral renal angiomyolipoma in a 33-year-old patient presenting with haemorrhagic shock. In the light of this case and a review of the literature, the authors discuss the diagnostic and therapeutic aspects of this disease.

  16. Alterações renais nas doenças falciformes Renal abnormalities in sickle cell disease

    Directory of Open Access Journals (Sweden)

    Isis Q. Magalhães

    2007-09-01

    abnormalities, hemodynamic changes and renal hormone synthesis alterations (erythropoietin, renin, prostaglandins. These changes appear in childhood with consequences including chronic anemia, increased blood flow and vaso-occlusion, especially within the renal medulla. In SS disease, the glomerular filtration rate (GFR is markedly higher in young patients but this drops with age. As a consequence of abnormalities in the distal nephron function there is reduced capacity of urine acidification, potassium excretion and hyposthenuria. Among the clinical effects of the latter are polyuria, nocturia, enuresis and a susceptability for dehydration. Abnormalities of the proximal tubular function include increased reabsorption of phosphates and b2 microglobulin and incresed secretion of uric acid and creatinine. For this reason, creatinine clearance significantly overestimates the glomerular filtration rate making creatinine learance inappropriate to detect early renal function impairment. Proteinuria occurs in 29-50% of over 10-years-old SS patients with 2/3 progressing to chronic renal failure. The use of angiotensin-converting enzyme inhibitor proves to be successful to reduce proteinuria which may have an impact of the progression of renal failure. Microalbuminuria is a sensitive marker of sickle nephropathy that precedes proteinuria. In pediatric population a prevalence of 19% of microbuminuria was observed; a percentage that increases with age and has a positive association with lower hemoglobin levels, higher leucocyte counts and acute chest syndrome. Screening for microalbuminuria is recommended from the age of 10 years old. A multicentric trial is ongoing with the aim of demonstrate potential benefits of early hydroxyurea therapy in the prevention of chronic organic lesions. (BabyHUG.

  17. Influence of dietary protein on renal function in dogs.

    Science.gov (United States)

    Bovée, K C

    1991-11-01

    Two previously published studies in dogs with reduced renal function are reviewed. In the first study, renal function and biochemical responses to dietary changes were studied in four dogs with stable chronic renal failure. The objective was to determine if dogs with moderate stable failure adjust to diets with varied protein and electrolyte content. These dogs were found to have the capacity to adapt to a wide range of dietary protein and electrolyte intake. The only exception was found in dogs fed a reduced-protein diet, which failed to appropriately adjust renal tubular excretion of sodium and phosphate. The only advantage of reduced dietary protein in this study was a reduction in blood urea nitrogen (BUN). Disadvantages of reduced-protein diets were reduced glomerular filtration rate (GFR) and renal plasma flow. In the second study, the hypothesis that large amounts of dietary protein sustain renal hyperfunction and produce progressive glomerulosclerosis in dogs as previously reported in rats was tested. Results failed to find a pattern of deterioration of renal function over 4 y. Light microscopic changes and electron microscopy also failed to find glomerular injury similar to that reported in rodents. These results do not support the hypothesis that feeding a high protein diet had a significant adverse effect on renal function or morphology.

  18. Primary renal hydatidosis

    Directory of Open Access Journals (Sweden)

    Johnsy Merla Joel

    2016-01-01

    Full Text Available Echinococcosis or hydatidosis caused by the tapeworm, Echinococcus granulosus, has the highest prevalence in endemic regions and sheep farming areas. The most common organ involved is the liver (50–75% followed by the lungs (15–20% and other organs (10–20%. Primary involvement of the kidney without the involvement of the liver and lungs, i.e., isolated renal hydatid disease is extremely rare even in endemic areas. The incidence of renal echinococcosis is 2–4%. Renal hydatid cysts usually remain asymptomatic for many years and are multiloculated. A 63-year-old male presented with left loin pain. Computed tomography scan abdomen revealed a presumptive diagnosis of renal hydatid disease. The nephrectomy specimen received in histopathology confirmed the diagnosis. We describe a rare case of primary renal hydatidosis.

  19. Renal replacement therapy after cardiac surgery; renal function recovers

    DEFF Research Database (Denmark)

    Steinthorsdottir, Kristin Julia; Kandler, Kristian; Agerlin Windeløv, Nis

    2013-01-01

    To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy.......To assess renal outcome in patients discharged from hospital following cardiac surgery-associated acute kidney injury (CSA-AKI) with need for renal replacement therapy....

  20. Capacity Statement for Railways

    DEFF Research Database (Denmark)

    Landex, Alex

    2007-01-01

    The subject “Railway capacity” is a combination of the capacity consumption and how the capacity is utilized. The capacity utilization of railways can be divided into 4 core elements: The number of trains; the average speed; the heterogeneity of the operation; and the stability. This article...... describes how the capacity consumption for railways can be worked out and analytical measurements of how the capacity is utilized. Furthermore, the article describes how it is possible to state and visualize railway capacity. Having unused railway capacity is not always equal to be able to operate more...

  1. Role of bone marrow-derived stem cells, renal progenitor cells and ...

    African Journals Online (AJOL)

    Hayam Abdel Meguid El Aggan

    2013-04-06

    Apr 6, 2013 ... renal blood flow; MoAbs, monoclonal antibodies; PE, phycoerythrin; ... entiated cells typically characterized by their capacity for self renewal, ability to give rise to multiple .... tion, was done by the spectrophotometric method.31.

  2. Renal neuroendocrine tumors

    Directory of Open Access Journals (Sweden)

    Brian R Lane

    2009-01-01

    Full Text Available Objectives: Neuroendocrine tumors (NETs are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC, and large cell neuroendocrine carcinoma (LCNEC are exceedingly rare. Materials and Methods: The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature. Results: Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease. Conclusions: A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

  3. Pregnancy and renal transplantation.

    Science.gov (United States)

    Başaran, O; Emiroğlu, R; Seçme, S; Moray, G; Haberal, M

    2004-01-01

    Ovarian dysfunction, anovulatory vaginal bleeding, amenorrhea, high prolactin levels, and loss of libido are the causes of infertility in women with chronic renal failure. After renal transplantation, endocrine function generally improves after recovery of renal function. In this study we retrospectively evaluated the prepregnancy and postdelivery renal function, outcome of gestation, as well as maternal and fetal complications for eight pregnancies in eight renal transplant recipients between November 1975 and March 2003 of 1095 among 1425. Eight planned pregnancies occurred at a mean of 3.6 years posttransplant. Spontaneous abortion occured in the first trimester in one case. One intrauterine growth retardation was observed with a full-term pregnancy; one intrauterine growth retardation and preterm delivery; one preeclampsia with preterm delivery and urinary tract infection; and one preeclampsia with preterm delivery and oligohydramnios. The mean gestation period was 35.5 +/- 3.0 weeks (31.2 to 38.0). Pregnancy had no negative impact on renal function during a 2-year follow-up. No significant proteinuria or acute rejection episodes were observed. Among the seven deliveries, no congenital anomaly was documented and no postpartum problems for the child and the mother were observed. Our study suggests that successful pregnancy is possible in renal transplant recipients. In cases with good graft function and absence of severe proteinuria or hypertension, pregnancy does not affect graft function or patient survival; however, fetal problems are encountered such as intrauterine growth retardation, low birth weight, and preeclampsia.

  4. Renal autotransplantation: current perspectives.

    Science.gov (United States)

    Stewart, B H; Banowsky, L H; Hewitt, C B; Straffon, R A

    1976-01-01

    Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included severe ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.

  5. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  6. Midterm renal functions following acute renal infarction

    Directory of Open Access Journals (Sweden)

    Sakir Ongun

    2015-10-01

    Full Text Available The aim of this study was to explore clinical features of renal infarction (RI that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA only, whereas patients with atrial fibrillation (AF or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8% with RI had atrial fibrillation (AF as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9% had elevated serum lactate dehydrogenase (LDH, 18 patients (78.2% had leukocytosis, and 16 patients (69.5% had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m2 at admission and increased to 82.3 ± 23.4 mL/min/1.73 m2 at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  7. Midterm renal functions following acute renal infarction.

    Science.gov (United States)

    Ongun, Sakir; Bozkurt, Ozan; Demir, Omer; Cimen, Sertac; Aslan, Guven

    2015-10-01

    The aim of this study was to explore clinical features of renal infarction (RI) that may have a role in diagnosis and treatment in our patient cohort and provide data on midterm renal functions. Medical records of patients with diagnosis of acute RI, established by contrast enhanced computed tomography (CT) and at least 1 year follow-up data, who were hospitalized in our clinic between 1998 and 2012 were retrospectively reviewed; including descriptive data, clinical signs and symptoms, etiologic factors, laboratory findings, and prescribed treatments. Patients with solitary infarct were treated with acetylsalicylic acid (ASA) only, whereas patients with atrial fibrillation (AF) or multiple or global infarct were treated with anticoagulants. Estimated Glomerular Filtration Rate (eGFR) referring to renal functions was determined by the Modification of Diet in Renal Disease (MDRD) formula. Twenty-seven renal units of 23 patients with acute RI were identified. The mean age was 59.7 ± 15.7 years. Fourteen patients (60.8%) with RI had atrial fibrillation (AF) as an etiologic factor of which four had concomitant mesenteric ischemia at diagnosis. At presentation, 20 patients (86.9%) had elevated serum lactate dehydrogenase (LDH), 18 patients (78.2%) had leukocytosis, and 16 patients (69.5%) had microscopic hematuria. Two patients with concomitant mesenteric ischemia and AF passed away during follow up. Mean eGFR was 70.8 ± 23.2 mL/min/1.73 m(2) at admission and increased to 82.3 ± 23.4 mL/min/1.73 m(2) at 1 year follow up. RI should be considered in patients with persistent flank or abdominal pain, particularly if they are at high risk of thromboembolism. Antiplatelet and/or anticoagulant drugs are both effective treatment options according to the amplitude of the infarct for preserving kidney functions.

  8. Inactivation of the Na-Cl co-transporter (NCC) gene is associated with high BMD through both renal and bone mechanisms: analysis of patients with Gitelman syndrome and Ncc null mice.

    Science.gov (United States)

    Nicolet-Barousse, Laurence; Blanchard, Anne; Roux, Christian; Pietri, Laurence; Bloch-Faure, May; Kolta, Sami; Chappard, Christine; Geoffroy, Valérie; Morieux, Caroline; Jeunemaitre, Xavier; Shull, Gary E; Meneton, Pierre; Paillard, Michel; Houillier, Pascal; De Vernejoul, Marie-Christine

    2005-05-01

    Chronic thiazide treatment is associated with high BMD. We report that patients and mice with null mutations in the thiazide-sensitive NaCl cotransporter (NCC) have higher renal tubular Ca reabsorption, higher BMD, and lower bone remodeling than controls, as well as abnormalities in Ca metabolism, mainly caused by Mg depletion. Chronic thiazide treatment decreases urinary Ca excretion (UVCa) and increases BMD. To understand the underlying mechanisms, Ca and bone metabolism were studied in two models of genetic inactivation of the thiazide-sensitive NaCl cotransporter (NCC): patients with Gitelman syndrome (GS) and Ncc knockout (Ncc(-/-)) mice. Ca metabolism was analyzed in GS patients and Ncc(-/-) mice under conditions of low dietary Ca. BMD was measured by DXA in patients and mice, and bone histomorphometry was analyzed in mice. GS patients had low plasma Mg. They exhibited reduced UVCa, but similar serum Ca and GFR as control subjects, suggesting increased renal Ca reabsorption. Blood PTH was lower despite lower serum ionized Ca, and Mg repletion almost corrected both relative hypoparathyroidism and low UVCa. BMD was significantly increased in GS patients at both lumbar (+7%) and femoral (+16%) sites, and osteocalcin was reduced. In Ncc(-/-) mice, serum Ca and GFR were unchanged, but UVCa was reduced and PTH was elevated; Mg repletion largely corrected both abnormalities. Trabecular and cortical BMD were higher than in Ncc(+/+) mice (+4% and +5%, respectively), and despite elevated PTH, were associated with higher cortical thickness and lower endosteal osteoclastic surface. Higher BMD is observed in GS patients and Ncc(-/-) mice. Relative hypoparathyroidism (human) and bone resistance to PTH (mice), mainly caused by Mg depletion, can explain the low bone remodeling and normal/low serum Ca despite increased renal Ca reabsorption.

  9. Lactulose and renal failure.

    Science.gov (United States)

    Vogt, B; Frey, F J

    1997-01-01

    The introduction of lactulose as a new therapeutic agent for treatment of hepatic encephalopathy was a major breakthrough in this field. It was hypothesized that lactulose might prevent postoperative renal impairment after biliary surgery in patients with obstructive jaundice. The presumable mechanism purported was the diminished endotoxinemia by lactulose. Unfortunately, such a reno-protective effect has not been shown conclusively until now in clinical studies. In chronic renal failure lactulose is known to promote fecal excretion of water, sodium, potassium, amonium, urea, creatinine and protons. Thus, lactulose could be useful for the treatment of chronic renal failure. However, compliance to the therapy represents a major problem.

  10. Renal tubule cell repair following acute renal injury.

    Science.gov (United States)

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

    1995-01-01

    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.

  11. Megalin and cubilin: synergistic endocytic receptors in renal proximal tubule.

    Science.gov (United States)

    Christensen, E I; Birn, H

    2001-04-01

    The multiligand, endocytic receptors megalin and cubilin are colocalized in the renal proximal tubule. They are heavily expressed in the apical endocytic apparatus. Megalin is a 600-kDa transmembrane protein belonging to the low-density lipoprotein-receptor family. The cytoplasmic tail contains three NPXY motifs that mediate the clustering in coated pits and are possibly involved in signaling functions. Cubilin, also known as the intestinal intrinsic factor-cobalamin receptor, is a 460-kDa receptor with no transmembrane domain and no known signal for endocytosis. Because the two receptors bind each other with high affinity and colocalize in several tissues, it is highly conceivable that megalin mediates internalization of cubilin and its ligands. Both receptors are important for normal tubular reabsorption of proteins, including albumin. Among the proteins normally filtered in the glomeruli, cubilin has been shown to bind albumin, immunoglobulin light chains, and apolipoprotein A-I. The variety of filtered ligands identified for megalin include vitamin-binding proteins, hormones, enzymes, apolipoprotein H, albumin, and beta(2)- and alpha(1)-microglobulin. Loss of these proteins and vitamins in the urine of megalin-deficient mice illustrates the physiological importance of this receptor.

  12. Study of the Distribution of Radiative Defects and Reabsorption of the UV in ZnO Nanorods-Organic Hybrid White Light Emitting Diodes (LEDs).

    Science.gov (United States)

    Hussain, Ijaz; Bano, Nargis; Hussain, Sajjad; Soomro, Yousuf; Nur, Omer; Willander, Magnus

    2011-07-08

    In this study, the low temperature aqueous chemical growth (ACG) method was employed to synthesized ZnO nanorods to process-organic hybrid white light emitting diodes (LEDs) on glass substrate. Electroluminescence spectra of the hybrid white LEDs demonstrate the combination of emission bands arising from radiative recombination of the organic and ZnO nanorods (NRs). Depth resolved luminescence was used for probing the nature and spatial distribution of radiative defects, especially to study the re-absorption of ultraviolet (UV) in this hybrid white LEDs structure. At room temperature the cathodoluminescence (CL) spectra intensity of the deep band emission (DBE) is increased with the increase of the electron beam penetration depth due to the increase of defect concentration at the ZnO NRs/Polyfluorene (PFO) interface and probably due to internal absorption of the UV. A strong dependency between the intensity ratio of the UV to the DBE bands and the spatial distribution of the radiative defects in ZnO NRs has been found. The comparison of the CL spectra from the PFO and the ZnO NRs demonstrate that PFO has a very weak violet-blue emission band, which confirms that most of the white emission components originate from the ZnO NRs.

  13. Study of the Distribution of Radiative Defects and Reabsorption of the UV in ZnO Nanorods-Organic Hybrid White Light Emitting Diodes (LEDs

    Directory of Open Access Journals (Sweden)

    Yousuf Soomro

    2011-07-01

    Full Text Available In this study, the low temperature aqueous chemical growth (ACG method was employed to synthesized ZnO nanorods to process-organic hybrid white light emitting diodes (LEDs on glass substrate. Electroluminescence spectra of the hybrid white LEDs demonstrate the combination of emission bands arising from radiative recombination of the organic and ZnO nanorods (NRs. Depth resolved luminescence was used for probing the nature and spatial distribution of radiative defects, especially to study the re-absorption of ultraviolet (UV in this hybrid white LEDs structure. At room temperature the cathodoluminescence (CL spectra intensity of the deep band emission (DBE is increased with the increase of the electron beam penetration depth due to the increase of defect concentration at the ZnO NRs/Polyfluorene (PFO interface and probably due to internal absorption of the UV. A strong dependency between the intensity ratio of the UV to the DBE bands and the spatial distribution of the radiative defects in ZnO NRs has been found. The comparison of the CL spectra from the PFO and the ZnO NRs demonstrate that PFO has a very weak violet-blue emission band, which confirms that most of the white emission components originate from the ZnO NRs.

  14. Photon Reabsorption in Mixed CsPbCl3:CsPbI3 Perovskite Nanocrystal Films for Light-Emitting Diodes

    Science.gov (United States)

    2017-01-01

    Cesium lead halide nanocrystals, CsPbX3 (X = Cl, Br, I), exhibit photoluminescence quantum efficiencies approaching 100% without the core–shell structures usually used in conventional semiconductor nanocrystals. These high photoluminescence efficiencies make these crystals ideal candidates for light-emitting diodes (LEDs). However, because of the large surface area to volume ratio, halogen exchange between perovskite nanocrystals of different compositions occurs rapidly, which is one of the limiting factors for white-light applications requiring a mixture of different crystal compositions to achieve a broad emission spectrum. Here, we use mixtures of chloride and iodide CsPbX3 (X = Cl, I) perovskite nanocrystals where anion exchange is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3 to CsPbI3 in solution and within a poly(methyl methacrylate) matrix via photon reabsorption, which also occurs in electrically excited crystals in bulk heterojunction LEDs. PMID:28316756

  15. Correlations between caries status and salivary flow rate,pH and buffer capacity in patients with end-stage renal disease%终末期肾脏病病人的唾液流率、pH值和缓冲能力与龋病的关系

    Institute of Scientific and Technical Information of China (English)

    房付春; 吴补领; 高杰; 麻丹丹; 岳静; 陈婷; 王小勇

    2012-01-01

    AIM: To investigate the caries status in patients with end-stage renal disease (ESRD) under- going hemodialysis and its correlation with salivary parameters. METHODS: Serenty-six patients with ESRD were included in (he study. The dental caries and salivary parameters were determined and then compared with those of healthy controls. The correlations between decayed, missing and filled teeth ( DMFT) value and salivary parameters in ESRD patients were analyzed. RESULTS: The caries indices had no significant difference between the two groups. The salivary flow rate (SFR) of the patients was less than that of the controls, but salivary pH and salivary buffer capacity ( SBC) were higher (all P 0.05) but there was a negative correlation with SBC (r = -0.322, P-0.005) in these patients. CONCLUSION: The increased SBC may be an important factor for the decreased caries prevalence in patients with ESRD .%目的:调查行血液透析治疗的终末期肾脏病病人的龋病状况和唾液性质,并分析两者的关系.方法:比较病患组(76例)和对照组(76例)的龋病状况、唾液流率、pH值和缓冲能力;并通过Pearson相关性检验分析病患组龋失补指数值与其唾液性质的关系.结果:两组间的龋病指标值无显著差异(P>0.05),病患组的唾液流率显著低于对照组、pH值和缓冲能力显著高于对照组,差异均有统计学意义(P<0.05),同时病患组中的龋失补指数值与唾液流率和pH值呈负相关,但无显著性(P>0.05),与唾液缓冲能力呈显著负相关(r=-0.322,P=0.005).结论:终末期肾脏病病人,唾液缓冲能力的增加可能是其患龋病率相对较低的重要因素.

  16. Effect of metabolic acidosis on renal tubular sodium handling in rats as determined by lithium clearance

    Directory of Open Access Journals (Sweden)

    Menegon L.F.

    1998-01-01

    Full Text Available Systemic metabolic acidosis is known to cause a decrease in salt and water reabsorption by the kidney. We have used renal lithium clearance to investigate the effect of chronic, NH4Cl-induced metabolic acidosis on the renal handling of Na+ in male Wistar-Hannover rats (200-250 g. Chronic acidosis (pH 7.16 ± 0.13 caused a sustained increase in renal fractional Na+ excretion (267.9 ± 36.4%, accompanied by an increase in fractional proximal (113.3 ± 3.6% and post-proximal (179.7 ± 20.2% Na+ and urinary K+ (163.4 ± 5.6% excretion when compared to control and pair-fed rats. These differences occurred in spite of an unchanged creatinine clearance and Na+ filtered load. A lower final body weight was observed in the acidotic (232 ± 4.6 g and pair-fed (225 ± 3.6 g rats compared to the controls (258 ± 3.7 g. In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 ± 0.05 g compared to the other experimental groups (control, 1.46 ± 0.05 g; pair-fed, 1.4 ± 0.05 g. We suggest that altered renal Na+ and K+ handling in acidotic rats may result from a reciprocal relationship between the level of metabolism in renal tubules and ion transport.

  17. Renal scintigraphy in veterinary medicine.

    Science.gov (United States)

    Tyson, Reid; Daniel, Gregory B

    2014-01-01

    Renal scintigraphy is performed commonly in dogs and cats and has been used in a variety of other species. In a 2012 survey of the members of the Society of Veterinary Nuclear Medicine, 95% of the respondents indicated they perform renal scintigraphy in their practice. Renal scintigraphy is primarily used to assess renal function and to evaluate postrenal obstruction. This article reviews how renal scintigraphy is used in veterinary medicine and describes the methods of analysis. Species variation is also discussed.

  18. A bioartificial renal tubule device embedding human renal stem/progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anna Giovanna Sciancalepore

    Full Text Available We present a bio-inspired renal microdevice that resembles the in vivo structure of a kidney proximal tubule. For the first time, a population of tubular adult renal stem/progenitor cells (ARPCs was embedded into a microsystem to create a bioengineered renal tubule. These cells have both multipotent differentiation abilities and an extraordinary capacity for injured renal cell regeneration. Therefore, ARPCs may be considered a promising tool for promoting regenerative processes in the kidney to treat acute and chronic renal injury. Here ARPCs were grown to confluence and exposed to a laminar fluid shear stress into the chip, in order to induce a functional cell polarization. Exposing ARPCs to fluid shear stress in the chip led the aquaporin-2 transporter to localize at their apical region and the Na(+K(+ATPase pump at their basolateral portion, in contrast to statically cultured ARPCs. A recovery of urea and creatinine of (20±5% and (13±5%, respectively, was obtained by the device. The microengineered biochip here-proposed might be an innovative "lab-on-a-chip" platform to investigate in vitro ARPCs behaviour or to test drugs for therapeutic and toxicological responses.

  19. Expression of renal cubilin and its potential role in tubulointerstitial inflammation induced by albumin overload

    Institute of Scientific and Technical Information of China (English)

    Jurong YANG; Yani HE; Haiying SHEN; Hanlu DING; Kailong LI; Huiming WANG

    2008-01-01

    Sustained proteinuria is an independent risk factor leading to kidney fibrosis and end-stage renal fail-ure. Over-reabsorption of filtered proteins, notably albu-min, has been proved to trigger interstitial inflammation and fibrosis in proteinuric renal disease. Cubilin, an endo-cytic receptor expressed on the renal tubular brush bor-der, is responsible for albumin reabsorption in physiologic condition. However, little is known about whether it is required for activation of tubular cells induced by albu-min overload. In this work, we investigated the change of cubilin expression and its potential role in albumin-induced up-regulation of chemokines synthesis in vivo and in vitro. Twenty-six patients with nephrotic syndrome were enrolled in this study. Proximal tubule uptake of albumin, expression of apical membrane cubilin and infiltrating cells in kidney interstitium were determined by immunocytochemistry. In vitro, the transcription of cubilin in HK2 cells after exposure to albumin was ana-lyzed by real-time PCR. Endocytosis of albumin in HK2 cells was examined by fluorescent microscope. The influ-ence of inhibition of cubilin on albumin-induced expres-sions of monocyte chemoattractant protein 1 (MCP-1) and regulated upon activation normal T-cell expressed and secreted (RANTES) was investigated by Western blot. The intensity of luminal cubilin and tubular accu-mulation of albumin were significantly increased in nephrotic kidneys. The expression of MCP-1 and RANTES was up-regulated, and there were spatial rela-tionships in localization between these chemokines and cubilin as well as intracellular albumin in kidney tissues. Infiltration of CD-3 and ED-1-positive cells was predom-inant in tubulointerstitial areas displaying signs of increases of cubilin expression and albumin accumula-tion. In vitro, the transcription of cubilin mRNA in HK2 cells was enhanced after 24 h exposure to albumin in a dose-dependent manner. Inhibition of endocytosis of albumin by antisense

  20. Primary renal synovial sarcoma

    Directory of Open Access Journals (Sweden)

    Girish D. Bakhshi

    2012-03-01

    Full Text Available Primary Renal Sarcoma is rare tumor comprising only 1% of all renal tumours. Synovial sarcomas are generally deep-seated tumors arising in the proximity of large joints of adolescents and young adults and account for 5-10% of all soft tissue tumours. Primary synovial sarcoma of kidney is rare and has poor prognosis. It can only be diagnosed by immunohistochemistry. It should be considered as a differential in sarcomatoid and spindle cell tumours. We present a case of 33-year-old female, who underwent left sided radical nephrectomy for renal tumour. Histopathology and genetic analysis diagnosed it to be primary renal synovial sarcoma. Patient underwent radiation therapy and 2 years follow up is uneventful. A brief case report with review of literature is presented.

  1. Renal protection in diabetes

    DEFF Research Database (Denmark)

    Parving, H H; Tarnow, L; Rossing, P

    1996-01-01

    BACKGROUND: The combination of diabetes and hypertension increases the chances of progressive renal disorder and, ultimately, renal failure. Roughly 40% of all diabetics, whether insulin-dependent or not, develop diabetic nephropathy. Diabetic nephropathy is the single most important cause of end......-stage renal disease in the Western world and accounts for more than a quarter of all end-stage renal diseases. Diabetic nephropathy is a major cause of increased morbidity and mortality in diabetic patients. Increased arterial blood pressure is an early and common phenomenon in incipient and overt diabetic...... nephropathy. The relationship between arterial blood pressure and diabetic nephropathy is a complex one, with diabetic nephropathy increasing blood pressure and blood pressure accelerating the course of nephropathy. OVERVIEW: Calcium antagonists antagonize preglomerular vasoconstriction. Additional putative...

  2. Renal primitive neuroectodermal tumors.

    Science.gov (United States)

    Bartholow, Tanner; Parwani, Anil

    2012-06-01

    Primitive neuroectodermal tumors exist as a part of the Ewing sarcoma/primitive neuroectodermal tumor family. These tumors most commonly arise in the chest wall and paraspinal regions; cases with a renal origin are rare entities, but have become increasingly reported in recent years. Although such cases occur across a wide age distribution, the average age for a patient with a renal primitive neuroectodermal tumor is the mid- to late 20s, with both males and females susceptible. Histologically, these tumors are characterized by pseudorosettes. Immunohistochemically, CD99 is an important diagnostic marker. Clinically, these are aggressive tumors, with an average 5-year disease-free survival rate of only 45% to 55%. Given that renal primitive neuroectodermal tumor bears many similarities to other renal tumors, it is important to review the histologic features, immunostaining profile, and genetic abnormalities that can be used for its correct diagnosis.

  3. Renal vein thrombosis

    Science.gov (United States)

    ... Saunders; 2012:chap 34. Read More Acute kidney failure Arteriogram Blood clots Dehydration Nephrotic syndrome Pulmonary embolus Renal Tumor Review Date 5/19/2015 Updated by: Charles Silberberg, ...

  4. Eligibility for renal denervation

    DEFF Research Database (Denmark)

    Persu, Alexandre; Jin, Yu; Baelen, Marie;

    2014-01-01

    -resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according......Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after...... undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility...

  5. Complete renal recovery from severe acute renal failure after thrombolysis of bilateral renal vein thrombosis.

    Science.gov (United States)

    Ramadoss, Suresh; Jones, Robert G; Foggensteiner, Lukas; Willis, Andrew P; Duddy, Martin J

    2012-10-01

    A previously healthy young man presented with acute renal failure due to extensive spontaneous deep vein thrombosis, including the inferior vena cava (IVC) and both renal veins. The patient was treated with selectively delivered thrombolytic therapy over a 7-day-period, which resulted in renal vein patency and complete recovery of renal function. A stent was placed over a segment stenosis of the IVC. No thrombophilic factors were identified. Bilateral renal vein thrombosis in young fit individuals is an unusual cause of acute renal failure. Thrombolytic therapy, even with delay, can completely restore renal function.

  6. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

  7. Circadian exosomal expression of renal thiazide-sensitive NaCl cotransporter (NCC) and prostasin in healthy individuals.

    Science.gov (United States)

    Castagna, Annalisa; Pizzolo, Francesca; Chiecchi, Laura; Morandini, Francesca; Channavajjhala, Sarath Kiran; Guarini, Patrizia; Salvagno, Gianluca; Olivieri, Oliviero

    2015-06-01

    A circadian timing system is involved in the maintenance of fluid and electrolyte balance and blood pressure control. Aldosterone and vasopressin modulate ion transporters and channels crucial in sodium (Na) and water reabsorption such as the epithelium Na channel and the renal thiazide-sensitive NaCl cotransporter (NCC). We analyzed in urinary exosomes the intraday variations of NCC and prostasin expression and the association with electrolytes and water balance parameters. Blood and urine samples were collected at five time points during the day from five healthy subjects. Blood renin, aldosterone, cortisol, ACTH, and plasmatic and urinary Na, potassium, creatinine, adiuretin (ADH), NCC, and prostasin were evaluated. ACTH and cortisol showed a circadian pattern, similarly to aldosterone, while exosomal NCC and prostasin pattern were similar to urinary ADH, decreased in the morning and subsequently increased in the afternoon and evening. In urinary exosomes, NCC and prostasin had a diurnal pattern parallel to ADH and aquaporin 2, confirming that, in healthy subjects, both prostasin and NCC relate to water balance. These results provide suggestions for a possible chronotherapeutic approach in patients treated with thiazides, diuretic drugs acting as specific inhibitors of NCC-mediated Na reabsorption. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Renal papillary necrosis

    Directory of Open Access Journals (Sweden)

    Stephen A. Geller

    2013-12-01

    Full Text Available In 1877, Dr. Nikolaus Friedreich (1825-1882; student of Virchow who became Professor of Pathology at Heidelberg and who also described Friedreich’s ataxia first described renal papillary necrosis (RPN in patients with prostatic hypertrophy and secondary hydronephrosis. Thereafter in 1937, Froboese and Günther emphasized the association of this entity with diabetes mellitus. These authors also observed renal papillary necrosis in cases of urinary tract obstruction even in the absence of diabetes mellitus.

  9. [Hyperuricemia and renal risk].

    Science.gov (United States)

    Viazzi, Francesca; Bonino, Barbara; Ratto, Elena; Desideri, Giovambattista; Pontremoli, Roberto

    2015-01-01

    Recent studies have revealed an association between elevated levels of uric acid and conditions correlated to chronic kidney diseases such as hypertension, cardiovascular and cerebral disease, insulin resistance. Several pathogenetic mechanisms at cellular and tissue levels could justify a direct correlation between serum uric acid levels and renal damage. Growing evidence indicating a correlation between urate lowering therapy and renal morbidity could encourage the use of urate lowering therapy in primary or secondary prevention in chronic kidney disease.

  10. NKCC2 activity is inhibited by the Bartter's syndrome type 5 gain-of-function CaR-A843E mutant in renal cells.

    Science.gov (United States)

    Carmosino, Monica; Gerbino, Andrea; Hendy, Geoffrey N; Torretta, Silvia; Rizzo, Federica; Debellis, Lucantonio; Procino, Giuseppe; Svelto, Maria

    2015-04-01

    The gain-of-function A843E mutation of the calcium sensing receptor (CaR) causes Bartter syndrome type 5. Patients carrying this CaR variant show a remarkably reduced renal NaCl reabsorption in the thick ascending limb (TAL) of Henle's loop resulting in renal loss of NaCl in the absence of mutations in renal Na(+) and Cl(-) ion transporters. The molecular mechanisms underlying this clinical phenotype are incompletely understood. We investigated, in human embryonic kidney 293 (HEK 293) cells and porcine kidney epithelial (LLC-PK1) cells, the functional cross-talk of CaR-A843E with the Na(+):K(+):2Cl(-) co-transporter, NKCC2, which provides NaCl reabsorption in the TAL. The expression of the CaR mutant did not alter the apical localisation of NKCC2 in LLC-PK1 cells. However, the steady-state NKCC2 phosphorylation and activity were decreased in cells transfected with CaR-A843E compared with the control wild-type CaR (CaR WT)-transfected cells. Of note, low-Cl(-)-dependent NKCC2 activation was also strongly inhibited upon the expression of CaR-A843E mutant. The use of either P450 ω-hydroxylase (CYP4)- or phospholipase A2 (PLA2)-blockers suggests that this effect is likely mediated by arachidonic acid (AA) metabolites. The data suggested that the activated CaR affects intracellular pathways modulating NKCC2 activity rather than NKCC2 intracellular trafficking in renal cells, and throw further light on the pathological role played by active CaR mutants in Bartter syndrome type 5. © 2015 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  11. Laparoscopic Renal Cryoablation

    Science.gov (United States)

    Schiffman, Marc; Moshfegh, Amiel; Talenfeld, Adam; Del Pizzo, Joseph J.

    2014-01-01

    In light of evidence linking radical nephrectomy and consequent suboptimal renal function to adverse cardiovascular events and increased mortality, research into nephron-sparing techniques for renal masses widely expanded in the past two decades. The American Urological Association (AUA) guidelines now explicitly list partial nephrectomy as the standard of care for the management of T1a renal tumors. Because of the increasing utilization of cross-sectional imaging, up to 70% of newly detected renal masses are stage T1a, making them more amenable to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. Cryosurgery has emerged as a leading option for renal ablation, and compared with surgical techniques it offers benefits in preserving renal function with fewer complications, shorter hospitalization times, and allows for quicker convalescence. A mature dataset exists at this time, with intermediate and long-term follow-up data available. Cryosurgical recommendations as a first-line therapy are made at this time in limited populations, including elderly patients, patients with multiple comorbidities, and those with a solitary kidney. As more data emerge on oncologic efficacy, and technical experience and the technology continue to improve, the application of this modality will likely be extended in future treatment guidelines. PMID:24596441

  12. Neonatal renal vein thrombosis.

    Science.gov (United States)

    Brandão, Leonardo R; Simpson, Ewurabena A; Lau, Keith K

    2011-12-01

    Neonatal renal vein thrombosis (RVT) continues to pose significant challenges for pediatric hematologists and nephrologists. The precise mechanism for the onset and propagation of renal thrombosis within the neonatal population is unclear, but there is suggestion that acquired and/or inherited thrombophilia traits may increase the risk for renal thromboembolic disease during the newborn period. This review summarizes the most recent studies of neonatal RVT, examining its most common features, the prevalence of acquired and inherited prothrombotic risk factors among these patients, and evaluates their short and long term renal and thrombotic outcomes as they may relate to these risk factors. Although there is some consensus regarding the management of neonatal RVT, the most recent antithrombotic therapy guidelines for the management of childhood thrombosis do not provide a risk-based algorithm for the acute management of RVT among newborns with hereditary prothrombotic disorders. Whereas neonatal RVT is not a condition associated with a high mortality rate, it is associated with significant morbidity due to renal impairment. Recent evidence to evaluate the effects of heparin-based anticoagulation and thrombolytic therapy on the long term renal function of these patients has yielded conflicting results. Long term cohort studies and randomized trials may be helpful to clarify the impact of acute versus prolonged antithrombotic therapy for reducing the morbidity that is associated with neonatal RVT.

  13. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

    OpenAIRE

    Zhi-xiang Yuan; Jingxin Mo; Guixian Zhao; Gang Shu; Hua-lin Fu; Wei Zhao

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rati...

  14. RENAL MALIGNANT NEOPLASMS: RENAL CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    Elisangela Giachini

    2017-06-01

    Full Text Available The aim of this study is to evaluate the incidence and prevalence of malignant kidney tumors, to contribute to identifying factors which the diagnosis of renal cell carcinomas. Through this study, we understand that kidney disease over the years had higher incidence rates, especially in adults in the sixth decade of life. The renal cell carcinoma (RCC is the third most common malignancy of the genitourinary tract, affecting 2% to 3% of the population. There are numerous ways of diagnosis; however, the most important are ultrasonography, magnetic resonance imaging and computed tomography. In general most of the patients affected by the CCR, have a good prognosis when diagnosed early and subjected to an effective treatment. This study conducted a literature review about the CCR, through this it was possible to understand the development needs of the imaging methods used for precise diagnosis and classification of RCC through the TNM system.

  15. Discontinuous symplectic capacities

    NARCIS (Netherlands)

    Zehmisch, K.; Ziltener, F.J.

    2014-01-01

    We show that the spherical capacity is discontinuous on a smooth family of ellipsoidal shells. Moreover, we prove that the shell capacity is discontinuous on a family of open sets with smooth connected boundaries.

  16. Responsibility and Capacities

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    That responsible moral agency presupposes certain mental capacities, constitutes a widely accepted view among theorists. Moreover, it is often assumed that degrees in the development of the relevant capacities co-vary with degrees of responsibility. In this article it is argued that, the move from...... the view that responsibility requires certain mental capacities to the position that degrees of responsibility co-vary with degrees of the development of the mental capacities, is premature....

  17. CDMA systems capacity engineering

    CERN Document Server

    Kim, Kiseon

    2004-01-01

    This new hands-on resource tackles capacity planning and engineering issues that are crucial to optimizing wireless communication systems performance. Going beyond the system physical level and investigating CDMA system capacity at the service level, this volume is the single-source for engineering and analyzing systems capacity and resources.

  18. Malignant renal tumors in children

    Directory of Open Access Journals (Sweden)

    Justin Scott Lee

    2015-05-01

    Full Text Available Renal malignancies are common in children. While the majority of malignant renal masses are secondary to Wilms tumor, it can be challenging to distinguish from more aggressive renal masses. For suspicious renal lesions, it is crucial to ensure prompt diagnosis in order to select the appropriate surgical procedure and treatment. This review article will discuss the common differential diagnosis that can be encountered when evaluating a suspicious renal mass in the pediatric population. This includes clear cell sarcoma of the kidney, malignant rhabdoid tumor, renal medullary carcinoma and lymphoma. 

  19. Effect of inhibition of nitric oxide synthase on blood pressure and renal sodium handling in renal denervated rats

    Directory of Open Access Journals (Sweden)

    F. Xavier

    2000-03-01

    unchanged creatinine clearance and Na+ filtered load. These results suggest that bilateral renal denervation delayed and attenuated the L-NAME-induced hypertension by promoting an additional decrease in tubule sodium reabsorption in the post-proximal segments of nephrons. Much of the hypertension caused by chronic NO synthesis inhibition is thus dependent on renal nerve activity.

  20. Changes in the rate of formation and resistance to reabsorption of cerebrospinal fluid during deliberate hypotension induced with adenosine or hemorrhage.

    Science.gov (United States)

    Shapira, Y; Artru, A A; Lam, A M

    1992-03-01

    Adenosine is recommended for induction of deliberate hypotension. Although its effects on brain vasculature and metabolism and intracranial pressure have been reported, its effects on cerebrospinal fluid dynamics have not. In this study the rate of cerebrospinal fluid formation (Vf), resistance to reabsorption of cerebrospinal fluid (Ra), and electroencephalogram (EEG) activity were determined in rabbits before and during decrease of cerebral perfusion pressure (CPP) with intravenous (iv) adenosine or hemorrhage. In the adenosine group (n = 6), Vf and Ra were determined at control CPP, at CPP of 50, 35, and 28 mmHg achieved with iv adenosine, and at CPP greater than 60 mmHg achieved with iv adenosine combined with iv phenylephrine. In the hemorrhage group (n = 6), Vf and Ra were determined at the first four experimental conditions only. Control values for Vf (9 +/- 3 and 9 +/- 4 microliter.min-1, mean +/- SD) and Ra (428 +/- 567 and 412 +/- 144 cmH2O.ml-1.min) did not differ between groups. In the adenosine group, Vf did not change significantly when CPP was decreased. However, in the hemorrhage group, Vf decreased significantly at CPP of 50 and 35 mmHg and became unmeasurable at CPP of 28 mmHg. Ra did not change significantly in either group. An increase of low-frequency (0.5-3.0 Hz) EEG activity and/or decrease of higher-frequency (3.5-30 Hz) EEG activity occurred at CPP of 28 mmHg in the adenosine group and at CPP of 35 mmHg in the hemorrhage group.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Eco-friendly luminescent solar concentrators with low reabsorption losses and resistance to concentration quenching based on aqueous-solution-processed thiolate-gold nanoclusters

    Science.gov (United States)

    Huang, H. Y.; Cai, K. B.; Chang, L. Y.; Chen, P. W.; Lin, T. N.; Lin, C. A. J.; Shen, J. L.; Talite, M. J.; Chou, W. C.; Yuan, C. T.

    2017-09-01

    Heavy-metal-containing quantum dots (QDs) with engineered electronic states have been served as luminophores in luminescent solar concentrators (LSCs) with impressive optical efficiency. Unfortunately, those QDs involve toxic elements and need to be synthesized in a hazardous solvent. Recently, biocompatible, eco-friendly gold nanoclusters (AuNCs), which can be directly synthesized in an aqueous solution, have gained much attention for promising applications in ‘green photonics’. Here, we explored the solid-state photophysical properties of aqueous-solution-processed, glutathione-stabilized gold nanoclusters (GSH-AuNCs) with a ligand-to-metal charge-transfer (LMCT) state for developing ‘green’ LSCs. We found that such GSH-AuNCs exhibit a large Stokes shift with almost no spectral overlap between the optical absorption and PL emission due to the LMCT states, thus, suppressing reabsorption losses. Compared with GSH-AuNCs in solution, the photoluminescence quantum yields (PL-QYs) of the LSCs can be enhanced, accompanied with a lengthened PL lifetime owing to the suppression of non-radiative recombination rates. In addition, the LSCs do not suffer from severe concentration-induced PL quenching, which is a common weakness for conventional luminophores. As a result, a common trade-off between light-harvesting efficiency and solid-state PL-QYs can be bypassed due to nearly-zero spectral overlap integral between the optical absorption and PL emission. We expect that GSH-AuNCs hold great promise for serving as luminophores for ‘green’ LSCs by further enhancing solid-state PL-QYs.

  2. Renal stem cells and their implications for kidney cancer.

    Science.gov (United States)

    Axelson, Håkan; Johansson, Martin E

    2013-02-01

    The renal cell carcinomas (RCC) denote a diverse set of neoplasias with unique genetic and histological features. The RCCs emanate from the renal tubule, a highly heterogeneous epithelial structure, and depending on which cell is malignified the resulting cancer displays unique characteristics. Notwithstanding this, the cells of origin for the RCC forms are far from established, and only inferred by the accumulated weight of marker similarities, not always providing an unequivocal picture. The tubular epithelium is normally mitotically quiescent, but demonstrates a considerable regenerative capacity upon renal injury. Recently the hypothesis that regeneration is driven by adult stem cells has been added experimental support, providing further complexity to the issue of renal carcinogenesis. Whether these cells are linked to RCC is an open question. In the present review we therefore present the prevailing theories regarding kidney regeneration, since a better understanding of this process might be of relevance when considering the different malignancies that arise from kidney epithelium. Our own results show that papillary renal cell carcinoma displays considerable similarities to proximal tubular progenitor cells and we suggest that this tumor form may develop in a multi-step fashion via benign renal adenomas. The putative connection between renal stem cells and carcinomas is, however, not clarified, since the current understanding of the renal stem cell system is not complete. It is clear that the efforts to isolate and characterize renal progenitor/stem cells suffer from numerous technical limitations and that it remains likely that the kidney harbors different stem cell pools with a restricted differentiation potential.

  3. Percutaneous renal tumour biopsy.

    Science.gov (United States)

    Delahunt, Brett; Samaratunga, Hemamali; Martignoni, Guido; Srigley, John R; Evans, Andrew J; Brunelli, Matteo

    2014-09-01

    The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed.

  4. Can renal infarction occur after renal cyst aspiration? Case report.

    Science.gov (United States)

    Emre, Habib; Soyoral, Yasemin Usul; Tanik, Serhat; Gecit, Ilhan; Begenik, Huseyin; Pirincci, Necip; Erkoc, Reha

    2011-01-01

    Renal infarction (RI) is a rarely seen disorder, and the diagnosis is often missed. The two major causes of RI are thromboemboli originhating from a thrombus in the heart or aorta, and in-situ thrombosis of a renal artery. We report a case of RI that developed due to renal artery and vein thrombosis, as confirmed by pathological evaluation of the nephrectomy material, three weeks after renal cyst aspiration.

  5. Imaging chronic renal disease and renal transplant in children

    Energy Technology Data Exchange (ETDEWEB)

    Carmichael, Jim; Easty, Marina [Great Ormond Street Hospital, Radiology Department, London (United Kingdom)

    2010-06-15

    At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants. (orig.)

  6. Renal sympathetic denervation: MDCT evaluation of the renal arteries.

    LENUS (Irish Health Repository)

    Hutchinson, Barry D

    2013-08-01

    Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

  7. Screening renal stone formers for distal renal tubular acidosis

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...

  8. Renal Tumor Biopsy Technique

    Institute of Scientific and Technical Information of China (English)

    Lei Zhang; Xue-Song Li; Li-Qun Zhou

    2016-01-01

    Objective:To review hot issues and future direction of renal tumor biopsy (RTB) technique.Data Sources:The literature concerning or including RTB technique in English was collected from PubMed published from 1990 to 2015.Study Selection:We included all the relevant articles on RTB technique in English,with no limitation of study design.Results:Computed tomography and ultrasound were usually used for guiding RTB with respective advantages.Core biopsy is more preferred over fine needle aspiration because of superior accuracy.A minimum of two good-quality cores for a single renal tumor is generally accepted.The use of coaxial guide is recommended.For biopsy location,sampling different regions including central and peripheral biopsies are recommended.Conclusion:In spite of some limitations,RTB technique is relatively mature to help optimize the treatment of renal tumors.

  9. Dyslipoproteinemia in renal transplantation.

    Directory of Open Access Journals (Sweden)

    Gunjotikar R

    1994-01-01

    Full Text Available Twenty-seven live related donor renal allograft recipients were evaluated for dyslipoproteinemia. Twenty-two patients received dual immunosuppression with prednisolone and azathioprine. Five patients received cyclosporin as well. Total cholesterol (Tch, triglycerides (TG, HDL cholesterol (HDLch, LDL cholesterol (LDLch and VLDL cholesterol (VLDLch levels were estimated. Fifteen (56% patients showed significant lipoprotein abnormalities. Renal allograft recipients showed significantly lower levels of Tch (p < 0.05 and LDLch (p < 0.05 and higher levels of TG (p < 0.005 and HDLch (p < 0.05. Diet and beta blockers did not influence lipoprotein levels. A significant negative correlation was noted between post-transplant duration and Tch, TG and VLDLch levels. Increased TG levels were associated with increase in weight and higher daily prednisolone dosage at the time of evaluation. The study confirms the existence of dyslipoproteinemia in renal allograft recipients.

  10. Renal (Kidney) Manifestations in TSC

    Science.gov (United States)

    ... International TSC Research Conference Text Size Get Involved RENAL (KIDNEY) MANIFESTATIONS IN TSC Download a PDF of ... sclerosis complex (TSC) will develop some form of renal (kidney) disease during their lifetime. There are three ...

  11. Renal involvement in antiphospholipid syndrome.

    Science.gov (United States)

    Pons-Estel, Guillermo J; Cervera, Ricard

    2014-02-01

    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.

  12. [Renal transplantation and urinary lithiasis].

    Science.gov (United States)

    Lechevallier, E; Saussine, C; Traxer, O

    2008-12-01

    Renal lithiasis in renal donors is rare. A renal stone in a donor, or in a renal transplant, is not a contraindication for harvesting nor transplantation. If possible, the stone must be removed at the time of the transplantation. The risk of lithiasis is increased in the renal transplant recipient, with a frequency of 2-6%. Metabolic abnormalities for lithiasis are frequent and can be induced by the immunosuppressive treatment, anticalcineurins. Lithiasis can have a poor prognosis in the renal recipient with a risk for infection or renal dysfunction. Small (renal transplant can be followed-up. Stones of 0.5-1.5cm need an extracorporeal lithotripsy with a previous safety JJ stent. Stones greater than 1.5cm can be treated by ureteroscopy or percutaneous surgery.

  13. Oral health status in children with renal disorders.

    Science.gov (United States)

    Subramaniam, P; Gupta, M; Mehta, A

    2012-01-01

    Advances in pediatric nephrology have resulted in increased survival rates of children with renal disorders. Renal disease is characterized by multiple organ involvement, including soft and hard tissues of the oral cavity. Data regarding the oral health status of Indian children with renal disorders is scarce. Thus, the aim of this study was to assess the oral health status of children with renal disorders in Jaipur city, India. Thirty six children in the age-group of 4-14 years, diagnosed with renal disorders were selected Data pertaining to demographics, medication history, body mass index and blood investigations were obtained from the hospital records. The World Health Organization (WHO) criteria were used to diagnose dental caries. Enamel defects were recorded according to Developmental Defects of Enamel index. Oral hygiene status, salivary pH and buffering capacity were also assessed. The mean blood hemoglobin value was 9.75 gm/dl, blood urea nitrogen 43.06 gm/dl and serum creatinine 1.5 mg/dl. Enamel defects were seen in 58.3% of children. Their mean deft and DMFT scores were 1.5 and 0.5, respectively. The mean Oral Hygiene Index-Simplified (OHI-S) score was 1.56. Gingival overgrowth was not present. Mean salivary pH was 6.92 and buffering capacity of stimulated saliva was 9.86. It is necessary for pediatric dentists to follow preventive oral health regimens that are tailored to these patients.

  14. Renal denervation and hypertension.

    Science.gov (United States)

    Schlaich, Markus P; Krum, Henry; Sobotka, Paul A; Esler, Murray D

    2011-06-01

    Essential hypertension remains one of the biggest challenges in medicine with an enormous impact on both individual and society levels. With the exception of relatively rare monogenetic forms of hypertension, there is now general agreement that the condition is multifactorial in nature and hence requires therapeutic approaches targeting several aspects of the underlying pathophysiology. Accordingly, all major guidelines promote a combination of lifestyle interventions and combination pharmacotherapy to reach target blood pressure (BP) levels in order to reduce overall cardiovascular risk in affected patients. Although this approach works for many, it fails in a considerable number of patients for various reasons including drug-intolerance, noncompliance, physician inertia, and others, leaving them at unacceptably high cardiovascular risk. The quest for additional therapeutic approaches to safely and effectively manage hypertension continues and expands to the reappraisal of older concepts such as renal denervation. Based on the robust preclinical and clinical data surrounding the role of renal sympathetic nerves in various aspects of BP control very recent efforts have led to the development of a novel catheter-based approach using radiofrequency (RF) energy to selectively target and disrupt the renal nerves. The available evidence from the limited number of uncontrolled hypertensive patients in whom renal denervation has been performed are auspicious and indicate that the procedure has a favorable safety profile and is associated with a substantial and presumably sustained BP reduction. Although promising, a myriad of questions are far from being conclusively answered and require our concerted research efforts to explore the full potential and possible risks of this approach. Here we briefly review the science surrounding renal denervation, summarize the current data on safety and efficacy of renal nerve ablation, and discuss some of the open questions that need

  15. Renal Artery Stent Outcomes

    Science.gov (United States)

    Murphy, Timothy P.; Cooper, Christopher J.; Matsumoto, Alan H.; Cutlip, Donald E.; Pencina, Karol M.; Jamerson, Kenneth; Tuttle, Katherine R.; Shapiro, Joseph I.; D’Agostino, Ralph; Massaro, Joseph; Henrich, William; Dworkin, Lance D.

    2016-01-01

    BACKGROUND Multiple randomized clinical trials comparing renal artery stent placement plus medical therapy with medical therapy alone have not shown any benefit of stent placement. However, debate continues whether patients with extreme pressure gradients, stenosis severity, or baseline blood pressure benefit from stent revascularization. OBJECTIVES The study sought to test the hypothesis that pressure gradients, stenosis severity, and/or baseline blood pressure affects outcomes after renal artery stent placement. METHODS Using data from 947 patients with a history of hypertension or chronic kidney disease from the largest randomized trial of renal artery stent placement, the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) study, we performed exploratory analyses to determine if subsets of patients experienced better outcomes after stent placement than the overall cohort. We examined baseline stenosis severity, systolic blood pressure, and translesion pressure gradient (peak systolic and mean) and performed interaction tests and Cox proportional hazards analyses for the occurrence of the primary endpoint through all follow-up, to examine the effect of these variables on outcomes by treatment group. RESULTS There were no statistically significant differences in outcomes based on the examined variables nor were there any consistent nonsignificant trends. CONCLUSIONS Based on data from the CORAL randomized trial, there is no evidence of a significant treatment effect of the renal artery stent procedure compared with medical therapy alone based on stenosis severity, level of systolic blood pressure elevation, or according to the magnitude of the transstenotic pressure gradient. (Benefits of Medical Therapy Plus Stenting for Renal Atherosclerotic Lesions [CORAL]; NCT00081731) PMID:26653621

  16. Capacity at Railway Stations

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations do have other challenges regarding capacity than open lines as it is here the traffic is dispatched. The UIC 406 capacity method that can be used to analyse the capacity consumption can be exposed in different ways at stations which may lead to different results. Therefore, stations need...... special focus when conducting UIC 406 capacity analyses.This paper describes how the UIC 406 capacity method can be expounded for stations. Commonly for the analyses of the stations it is recommended to include the entire station including the switch zone(s) and all station tracks. By including the switch...... is changed, this paper recommends that the railway lines are not always be divided. In case trains turn around on open (single track) line, the capacity consumption may be too low if a railway line is divided. The same can be the case if only few trains are overtaken at an overtaking station. For dead end...

  17. Evaluation of railway capacity

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.; Schittenhelm, Bernd

    2006-01-01

    This paper describes the relatively new UIC 406 method for calculating capacity consumption on railway lines. The UIC 406 method is an easy and effective way of calculating the capacity consumption, but it is possible to expound the UIC 406 method in different ways which can lead to different...... capacity consumptions. This paper describes the UIC 406 method and how it is expounded in Denmark. The paper describes the importance of choosing the right length of the line sections examined and how line sections with multiple track sections are examined. Furthermore, the possibility of using idle...... capacity to run more trains is examined. The paper presents a method to examine the expected capacity utilization of future timetables. The method is based on the plan of operation instead of the exact (known) timetable. At the end of the paper it is described how it is possible to make capacity statements...

  18. Renal Failure in Pregnancy.

    Science.gov (United States)

    Balofsky, Ari; Fedarau, Maksim

    2016-01-01

    Renal failure during pregnancy affects both mother and fetus, and may be related to preexisting disease or develop secondary to diseases of pregnancy. Causes include hypovolemia, sepsis, shock, preeclampsia, thrombotic microangiopathies, and renal obstruction. Treatment focuses on supportive measures, while pharmacologic treatment is viewed as second-line therapy, and is more useful in mitigating harmful effects than treating the underlying cause. When supportive measures and pharmacotherapy prove inadequate, dialysis may be required, with the goal being to prolong pregnancy until delivery is feasible. Outcomes and recommendations depend primarily on the underlying cause.

  19. Renal lithiasis and nutrition.

    Science.gov (United States)

    Grases, Felix; Costa-Bauza, Antonia; Prieto, Rafel M

    2006-09-06

    Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified through diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins) and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine) is discussed.

  20. Pediatric Renal Neoplasms.

    Science.gov (United States)

    Ranganathan, Sarangarajan

    2009-03-01

    Renal tumors in childhood consist of a diverse group of tumors ranging from the most common Wilms' tumor, to the uncommon and often fatal rhabdoid tumor. Diagnosis is based on morphologic features and aided by ancillary techniques such as immunohistochemistry and cytogenetics. Molecular techniques have helped identify a group of pediatric renal cell carcinomas that have specific translocations, called translocation-associated carcinomas. Differential diagnosis of the various tumors is discussed. Pathogenesis and nephroblastomatosis, the precursor lesions of Wilms tumor, also are discussed briefly, as are the handling of these tumor specimens and prognostic factors. Copyright © 2009 Elsevier Inc. All rights reserved.

  1. Gravidez e transplante renal

    OpenAIRE

    Andrade, Joana Rita Ferreira

    2014-01-01

    Enquadramento: A gravidez é rara em mulheres com Doença Renal Crónica, sobretudo em estadio avançado, em virtude de várias condicionantes como a disfunção ovárica, hemorragias vaginais anovulatórias e amenorreia. Contudo, após transplante renal é possível alimentar o sonho de constituir família, mas é preciso considerar os riscos aumentados para o enxerto e a maior susceptibilidade para complicações da gravidez. Objectivo: Avaliar os riscos e identificar as variáveis que influenciam o suce...

  2. Renal lithiasis and nutrition

    Directory of Open Access Journals (Sweden)

    Prieto Rafel M

    2006-09-01

    Full Text Available Abstract Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified trough diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine is discussed.

  3. Capacity Building in Vietnam

    OpenAIRE

    Adam McCarty

    2001-01-01

    This report is the outcome of a study commissioned to examine the capacity building needs in Vietnam, and is a supplementary document to the Asian Development Bank's Country Operational Strategy for Vietnam. Vietnam's needs in terms of capacity building are particularly important given that is it a transitional economy and also one with little institutional experience in dealing with the international donor community. This paper examines the international awareness of capacity building and ca...

  4. The clinical physiology of water metabolism. Part II: Renal mechanisms for urinary concentration; diabetes insipidus.

    Science.gov (United States)

    Weitzman, R E; Kleeman, C R

    1979-12-01

    The renal reabsorption of water independent of solute is the result of the coordinated function of the collecting duct and the ascending limb of the loop of Henle. The unique juxtaposition of the ascending and descending portions of the loop of Henle and of the vasa recta permits the function of a counter-current multiplier system in which water is removed from the tubular lumen and reabsorbed into the circulation. The driving force for reabsorption is the osmotic gradient in the renal medulla which is dependent, in part, on chloride (followed by sodium) pumping from the thick ascending loop of Henle. Urea trapping is also thought to play an important role in the generation of a hypertonic medullary interstitium. Arginine vasopressin (AVP) acts by binding to receptors on the cell membrane and activating adenylate cyclase. This, inturn, results in the intracellular accumulation of cyclic adenosine monophosphate (AMP) which in some fashion abruptly increases the water permeability of the luminal membrane of cells in the collecting duct. As a consequence, water flows along an osmotic gradient out of the tubular lumen into the medullary interstitium. Diabetes insipidus is the clinical condition associated with either a deficiency of or a resistance to AVP. Central diabetes insipidus is due to diminished release of AVP following damage to either the neurosecretory nuclei or the pituitary stalk. Possible causes include idiopathic, familial, trauma, tumor, infection or vascular lesions. Patients present with polyuria, usually beginning over a period of a few days. The diagnosis is made by showing that urinary concentration is impaired after water restriction but that there is a good response to exogenous vasopressin therapy. Nephrogenic diabetes insipidus can be identified by a patient's lack of response to AVP. Nephrogenic diabetes insipidus is caused by a familial defect, although milder forms can be acquired as a result of various forms of renal disease. Central

  5. Connexin 30 deficiency impairs renal tubular ATP release and pressure natriuresis.

    Science.gov (United States)

    Sipos, Arnold; Vargas, Sarah L; Toma, Ildikó; Hanner, Fiona; Willecke, Klaus; Peti-Peterdi, János

    2009-08-01

    In the renal tubule, ATP is an important regulator of salt and water reabsorption, but the mechanism of ATP release is unknown. Several connexin (Cx) isoforms form mechanosensitive, ATP-permeable hemichannels. We localized Cx30 to the nonjunctional apical membrane of cells in the distal nephron and tested whether Cx30 participates in physiologically important release of ATP. We dissected, partially split open, and microperfused cortical collecting ducts from wild-type and Cx30-deficient mice in vitro. We used PC12 cells as ATP biosensors by loading them with Fluo-4/Fura Red to measure cytosolic calcium and positioning them in direct contact with the apical surface of either intercalated or principal cells. ATP biosensor responses, triggered by increased tubular flow or by bath hypotonicity, were approximately three-fold greater when positioned next to intercalated cells than next to principal cells. In addition, these responses did not occur in preparations from Cx30-deficient mice or with purinergic receptor blockade. After inducing step increases in mean arterial pressure by ligating the distal aorta followed by the mesenteric and celiac arteries, urine output increased 4.2-fold in wild-type mice compared with 2.6-fold in Cx30-deficient mice, and urinary Na(+) excretion increased 5.2-fold in wild-type mice compared with 2.8-fold in Cx30-deficient mice. Furthermore, Cx30-deficient mice developed endothelial sodium channel-dependent, salt-sensitive elevations in mean arterial pressure. Taken together, we suggest that mechanosensitive Cx30 hemichannels have an integral role in pressure natriuresis by releasing ATP into the tubular fluid, which inhibits salt and water reabsorption.

  6. Branchio-oto-renal syndrome.

    Science.gov (United States)

    Jalil, Jawad; Basheer, Faisal; Shafique, Mobeen

    2014-05-01

    The association of branchial arch anomalies (branchial cysts, branchial fistulas), hearing loss and renal anomalies constitutes the branchio-oto-renal (BOR) syndrome also known as Melnick Fraser syndrome. We present a case of this rare disorder in a girl child who presented with profound deafness, preauricular pits, branchial sinuses and renal hypoplasia.

  7. Drug-induced renal disease.

    Science.gov (United States)

    Curtis, J R

    1979-11-01

    The clinical manifestations of drug-induced renal disease may include all the manifestations attributed to natural or spontaneous renal diseases such as acute renal failure, chronic renal failure, acute nephritic syndrome, renal colic, haematuria, selective tubular defects, obstructive nephropathy, etc. It is therefore vital in any patient with renal disease whatever the clinical manifestations might be, to obtain a meticulous drug and toxin inventory. Withdrawal of the offending drug may result in amelioration or cure of the renal disorder although in the case of severe renal failure it may be necessary to utilise haemodialysis or peritoneal dialysis to tide the patient over the period of acute renal failure. Analgesic nephropathy is an important cause of terminal chronic renal failure and it is therefore vital to make the diagnosis as early as possible. The pathogenesis of some drug-induced renal disorders appears to be immunologically mediated. There are many other pathogenetic mechanisms involved in drug-induced renal disorders and some drugs may under appropriate circumstances be responsible for a variety of different nephrotoxic effects. For example, the sulphonamides have been incriminated in examples of crystalluria, acute interstitial nephritis, acute tubular necrosis, generalised hypersensitivity reactions, polyarteritis nodosa and drug-induced lupus erythematosus.

  8. Management of chronic renal failure.

    NARCIS (Netherlands)

    de Zeeuw, D.; Apperloo, AJ; de Jong, P.

    1992-01-01

    There is growing evidence that treatment of patients with renal function impairment will undergo a major shift within the next few years. Along with more or less successful attempts to alleviate the signs and symptoms of reduced renal function, new insights into renal pathophysiology as well as new

  9. New options for the management of hyperparathyroidism after renal transplantation.

    Science.gov (United States)

    Douthat, Walter Guillermo; Chiurchiu, Carlos Raul; Massari, Pablo Ulises

    2012-06-24

    The persistence and severity of hyperparathyroidism (HPT) post-renal transplantation is relatively frequent and primarily associated with the timing and its magnitude in the pre-transplant period and with the presence of parathyroid adenomas. HPT after renal transplantation is clinically manifested with hypercalcemia, hypophosphatemia, bone pain, fractures, and in more serious cases with cardiovascular calcifications that affect the survival. The primary clinical objective for patients with secondary HPT after renal transplantation is to obtain a level of parathyroid hormone (PTH) adequate to the renal transplanted function and to normalize levels of calcium, phosphorus and vitamin D. In many cases during this period, the development of hypercalcemia and/or hypophosphatemia makes it necessary to take different therapeutic measures. The use of vitamin D or its analogues has been extrapolated from the management of pre-transplant HPT obtaining variable outcomes, although its use is limited by its capacity to produce hypercalcemia. Calcimimetics are drugs that have proven be effective in reducing PTH levels in patients with HPT on dialysis and has been effective in reducing up to 50% PTH levels in moderate to severe HPT in post-renal transplantation.When HPT persists after renal transplantation and does not respond to medical treatment, invasive management by percutaneous ethanol injection therapy of parathyroid glands or parathyroidectomy should be considered. The emergence of new methods for the management of HPT expands the availability of therapeutic tools for transplant patients.

  10. Renal glucose handling in diabetes and sodium glucose cotransporter 2 inhibition

    Directory of Open Access Journals (Sweden)

    Resham Raj Poudel

    2013-01-01

    Full Text Available The kidneys play a major role in glucose homeostasis through its utilization, gluconeogenesis, and reabsorption via sodium glucose cotransporters (SGLTs. The defective renal glucose handling from upregulation of SGLTs, mainly the SGLT2, plays a fundamental role in the pathogenesis of type 2 diabetes mellitus. Genetic mutations in a SGLT2 isoform that results in benign renal glycosuria, as well as clinical studies with SGLT2 inhibitors in type 2 diabetes support the potential of this approach. These studies indicate that inducing glycosuria by suppressing SGLT2 can reduce plasma glucose and A1c levels, as well as decrease weight, resulting in improved β-cell function and enhanced insulin sensitivity in liver and muscle. Because the mechanism of SGLT2 inhibition is independent of insulin secretion and sensitivity, these agents can be combined with other antidiabetic agents, including exogenous insulin. This class represents a novel therapeutic approach with potential for the treatment of both type 2 and type 1 diabetes.

  11. Syndrome of inappropriate antidiuretic hormone secretion and cerebral/renal salt wasting syndrome: similarities and differences.

    Science.gov (United States)

    Oh, Ji Young; Shin, Jae Il

    2014-01-01

    Hyponatremia (sodium levels of cerebral edema and brain herniation; therefore, prompt diagnosis and proper treatment is important in preventing morbidity and mortality. Among various causes of hyponatremia, diagnosing syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral/renal salt wasting syndrome (C/RSW) is difficult due to many similarities. SIADH is caused by excess of renal water reabsorption through inappropriate antidiuretic hormone secretion, and fluid restriction is the treatment of choice. On the other hand, C/RSW is caused by natriuresis, which is followed by volume depletion and negative sodium balance and replacement of water and sodium is the mainstay of treatment. Determinating volume status in hyponatremic patients is the key point in differential between SIADH and C/RSW. However, in most situations, differential diagnosis of these two diseases is difficult because they overlap in many clinical and laboratory aspects, especially to assess differences in volume status of these patients. Although distinction between the SIADH and C/RSW is difficult, improvement of hypouricemia and an increased fractional excretion of uric acid after the correction of hyponatremia in SIADH, not in C/RSW, may be one of the helpful points in discriminating the two diseases. In this review, we compare these two diseases regarding the pathophysiologic mechanisms, diagnosis, and therapeutic point of view.

  12. Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells.

    Science.gov (United States)

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

    2014-03-01

    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.

  13. Hydrogen Sulfide Inhibits High-Salt Diet-Induced Renal Oxidative Stress and Kidney Injury in Dahl Rats

    Directory of Open Access Journals (Sweden)

    Pan Huang

    2016-01-01

    Full Text Available Background. The study was designed to investigate if H2S could inhibit high-salt diet-induced renal excessive oxidative stress and kidney injury in Dahl rats. Methods. Male salt-sensitive Dahl and SD rats were used. Blood pressure (BP, serum creatinine, urea, creatinine clearance rate, and 24-hour urine protein were measured. Renal ultra- and microstructures were observed. Collagen-I and -III contents the oxidants and antioxidants levels in renal tissue were detected. Keap1/Nrf2 association and Keap1 s-sulfhydration were detected. Results. After 8 weeks of high-salt diet, BP was significantly increased, renal function and structure were impaired, and collagen deposition was abundant in renal tissues with increased renal MPO activity, H2O2, MDA, GSSG, and •OH contents, reduced renal T-AOC and GSH contents, CAT, GSH-PX and SOD activity, and SOD expressions in Dahl rats. Furthermore, endogenous H2S in renal tissues was decreased in Dahl rats. H2S donor, however, decreased BP, improved renal function and structure, and inhibited collagen excessive deposition in kidney, in association with increased antioxidative activity and reduced oxidative stress in renal tissues. H2S activated Nrf2 by inducing Keap1 s-sulfhydration and subsequent Keap1/Nrf2 disassociation. Conclusions. H2S protected against high-salt diet-induced renal injury associated with enhanced antioxidant capacity and inhibited renal oxidative stress.

  14. SINDROME INTERMEDIO: UN PATRÓN TÍPICO DE INSUFICIENCIA RENAL AGUDA EN EL ANCIANO

    Directory of Open Access Journals (Sweden)

    Algranati L

    2004-01-01

    Full Text Available Acute renal failure is a frequent entity in the elderly. This is due on one hand to the structural and physiological changes of the aged kidney, and on the other hand to the exposure of this population to polypharmacy and their reduced capability to metabolize drugs. In the present report we present a case of a seventy year-old woman who developed acute renal failure secondary to severe dehydration with a clinical and laboratory pattern of intermediate syndrome: laboratory results compatible with parenchymal renal insufficiency (elevated urinary sodium, plasma urea and creatinine, but with a positive response to hydration. The main characteristics of the aged kidney that predispose to the development of an intermediate syndrome are: the vascular dysautonomy and reduced capability of sodium and water reabsorption. The intermediate syndrome is a typical pattern of pre-renal insufficiency in the elderly. RESUMEN: La insuficiencia renal aguda es frecuente en el anciano. Esto se debe por un lado a los cambios estructurales y funcionales propios del riñón senil, y por otro a la gran exposición que esta población tiene a la polifarmacia, y su reducida capacidad para metabolizar los medicamentos. En este reporte presentamos el caso de una mujer de 70 años que desarrolló una insuficiencia renal aguda secundaria a severa deshidratación, mostrando un patrón clínico y de laboratorio propio de un sindrome intermedio: laboratorios compatibles con una insuficiencia renal parenquimatosa (sodio urinario, uremia y creatininemia elevadas, pero con una respuesta favorable a la hidratación. Las principales características del riñón senil que predisponen al desarrollo del sindrome intermedio: son la disautonomía vascular y la reducida capacidad en la recuperación de sodio y agua El sindrome intermedio es un patrón típico de insuficiencia prerrenal en el anciano.

  15. [Hypertension and renal disease

    DEFF Research Database (Denmark)

    Kamper, A.L.; Pedersen, E.B.; Strandgaard, S.

    2009-01-01

    hypertension. Mild degrees of chronic kidney disease (CKD) can be detected in around 10% of the population, and detection is important as CKD is an important risk factor for atherosclerotic cardiovascular disease. Conversely, heart failure may cause an impairment of renal function. In chronic progressive...

  16. Insuficiencia renal aguda.

    Directory of Open Access Journals (Sweden)

    Carlos Hernán Mejía

    2009-10-01

    Full Text Available La insuficiencia renal aguda se diagnostica aproximadamente en 5% de los pacientes hospitalizados. Sus principales causas se relacionan con la alteración del flujo sanguíneo renal, sea por depleción de volumen, baja perfusión renal o por distribución intrarrenal inadecuada y obstrucción del árbol urinario. El diagnóstico parte de la historia clínica y un buen examen físico que corrobore el estado de volemia del paciente y se complementa con el uso adecuado de los índices urinarios (excreción de sodio y osmolaridad, el uroanálisis y la ecografía renal. Su tratamiento consiste en una adecuada recuperación del volumen, manejo de los diuréticos, soporte nutricional, conservación del equilibrio hidroelectrolítico y brindar terapia de diálisis si hay toxicidad urémica, hipercaliemia severa (>6.5 mEq/l, acidosis metabólica o sobrecarga severa de volumen.

  17. Management of Renal Cysts

    Science.gov (United States)

    Nalbant, Ismail; Can Sener, Nevzat; Firat, Hacer; Yeşil, Süleyman; Zengin, Kürşad; Yalcınkaya, Fatih; Imamoglu, Abdurrahim

    2015-01-01

    Background and Objectives: Renal cysts have a high prevalence in the general population, and their estimated incidence increases with age. Renal cyst aspiration (usually with sclerotherapy) or open/laparoscopic decortication is a generally effective and safe method in the treatment of symptomatic simple renal cysts. The success rates of laparoscopic decortication and percutaneous aspiration-sclerotherapy were compared to assist in the decision making for the procedure. Methods: A total of 184 patients with symptomatic simple renal cysts were treated with either laparoscopic decortication in 149 cases or percutaneous aspiration-sclerotherapy in 35 cases. The follow-up period was approximately 35 months, and the symptomatic and radiologic success rates of the 2 techniques were compared retrospectively. Results: Laparoscopic decortication was found to have high success rates, a low recurrence rate, and minimal morbidity. Percutaneous aspiration-sclerotherapy is an outpatient procedure with a minimally higher recurrence rate. Conclusion: When a symptomatic cyst is encountered and treatment of the cyst is indicated, laparoscopic decortication is a more efficient method that offers better results than percutaneous aspiration-sclerotherapy. PMID:25848184

  18. Rupture of Renal Transplant

    Directory of Open Access Journals (Sweden)

    Shona Baker

    2015-01-01

    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.

  19. Primary renal graft thrombosis

    NARCIS (Netherlands)

    Bakir, N; Sluiter, WJ; Ploeg, RJ; van Son, WJ; Tegzess, Adam

    1996-01-01

    Background. Renal allograft thrombosis is a serious complication of kidney transplantation that ultimately leads to graft loss. Its association with acute and hyperacute rejection is well documented; however, in a large proportion of patients the precise cause remains obscure. The exact incidence an

  20. Effect of progesterone on renal sodium handling in man: relation to aldosterone excretion and plasma renin activity.

    Science.gov (United States)

    Oparil, S; Ehrlich, E N; Lindheimer, M D

    1975-08-01

    1. The effect of progesterone on renal haemodynamics and intrarenal sodium handing was evaluated in thirteen normal men on a constant diet. Clearances were measured during maximal water diuresis and again 4-7 days later, this time 3 h after progesterone was given intramuscularly. Seven additional studies were performed 3 days after progesterone administration. Another four tests were performed on volunteers who had manifested renal 'escape' from the sodium-retaining effect of deoxycorticosterone acetate. 2. In acute progesterone studies glomerular filtration rate was unchanged, whereas effective renal plasma flow increased, so that filtration fraction decreased significantly. A similar in crease in urinary sodium occurred whether subjects received a low or high sodium diet. Indices which related to the distal delivery of filtrate (fractional urine flow and the sum of fractional free water and sodium clearances) increased significantly in both groups. The progesterone-induced increase in sodium excretion was not related to changes in plasma renin activity, renin substrate or urinary aldosterone. After 3 days of progesterone, the increase of sodium excretion was less than in the acute studies and urinary aldosterone increased tow- to four-fold. Progesterone failed to produce an acute increse in urinary sodium in subjects hyperexpanded by administration of exogenous mineralocorticoids. 3. Results suggest that the acute natriuretic action of progesterone is in part independent of aldosterone inhibition and that progesterone may inhibit sodium reabsorption at proximal as well as distal sites in the nephron.

  1. Liquid heat capacity lasers

    Science.gov (United States)

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  2. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical...

  3. Lipopolysaccharide impairs amyloid beta efflux from brain: altered vascular sequestration, cerebrospinal fluid reabsorption, peripheral clearance and transporter function at the blood–brain barrier

    Directory of Open Access Journals (Sweden)

    Erickson Michelle A

    2012-06-01

    Full Text Available Abstract Background Defects in the low density lipoprotein receptor-related protein-1 (LRP-1 and p-glycoprotein (Pgp clearance of amyloid beta (Aβ from brain are thought to contribute to Alzheimer’s disease (AD. We have recently shown that induction of systemic inflammation by lipopolysaccharide (LPS results in impaired efflux of Aβ from the brain. The same treatment also impairs Pgp function. Here, our aim is to determine which physiological routes of Aβ clearance are affected following systemic inflammation, including those relying on LRP-1 and Pgp function at the blood–brain barrier. Methods CD-1 mice aged between 6 and 8 weeks were treated with 3 intraperitoneal injections of 3 mg/kg LPS at 0, 6, and 24 hours and studied at 28 hours. 125I-Aβ1-42 or 125I-alpha-2-macroglobulin injected into the lateral ventricle of the brain (intracerebroventricular (ICV or into the jugular vein (intravenous (IV was used to quantify LRP-1-dependent partitioning between the brain vasculature and parenchyma and peripheral clearance, respectively. Disappearance of ICV-injected 14 C-inulin from brain was measured to quantify bulk flow of cerebrospinal fluid (CSF. Brain microvascular protein expression of LRP-1 and Pgp was measured by immunoblotting. Endothelial cell localization of LRP-1 was measured by immunofluorescence microscopy. Oxidative modifications to LRP-1 at the brain microvasculature were measured by immunoprecipitation of LRP-1 followed by immunoblotting for 4-hydroxynonenal and 3-nitrotyrosine. Results We found that LPS: caused an LRP-1-dependent redistribution of ICV-injected Aβ from brain parenchyma to brain vasculature and decreased entry into blood; impaired peripheral clearance of IV-injected Aβ; inhibited reabsorption of CSF; did not significantly alter brain microvascular protein levels of LRP-1 or Pgp, or oxidative modifications to LRP-1; and downregulated LRP-1 protein levels and caused LRP-1 mislocalization in cultured brain

  4. Value for railway capacity

    DEFF Research Database (Denmark)

    Sameni, Melody Khadem; Preston, John M.

    2012-01-01

    Growth in rail traffic has not been matched by increases in railway infrastructure. Given this capacity challenge and the current restrictions on public spending, the allocation and the utilization of existing railway capacity are more important than ever. Great Britain has had the greatest growth...... in rail passenger kilometers of European countries since 1996. However, costs are higher and efficiency is lower than European best practice. This paper provides an innovative methodology for assessing the efficiency of passenger operators in capacity utilization. Data envelopment analysis (DEA) is used...... to analyze the efficiency of operators in transforming inputs of allocated capacity of infrastructure and franchise payments into valuable passenger service outputs while avoiding delays. By addressing operational and economic aspects of capacity utilization simultaneously, the paper deviates from existing...

  5. ``Aggressive`` renal angiomyolipoma

    Energy Technology Data Exchange (ETDEWEB)

    Cittadini, G. Jr. [Univ. of Genoa (Italy). Dept. of Radiology; Pozzi Mucelli, F. [Univ. of Trieste (Italy). Dept. of Radiology; Danza, F.M. [Catholic Sacro Cuore Univ., Rome (Italy). Dept. of Radiology; Derchi, L.E. [Univ. of Genoa (Italy). Dept. of Radiology; Pozzi Mucelli, R.S. [Univ. of Trieste (Italy). Dept. of Radiology

    1996-11-01

    We describe the US and CT examinations of 4 patients with renal angiomyolipoma with an `aggressive` appearance, and review the literature. The imaging findings in 4 patients with benign renal angiomyolipomas associated with thrombosis of the renal vein and/or inferior vena cava are presented. CT demonstrated fat densities within both tumor and thrombus. In one patient, small lymph nodes with low density internal areas were detected in the para-aortic region. When considering our patients together with those reported in the literature, we found that most angiomyolipomas with venous invasion were large and centrally located within the kidney. Venous thrombosis was observed in 9 lesions of the right kidney, and in only 4 of the left one. One patient only had symptoms due to the thrombus; 10 had problems due to the tumor; and 3 were asymptomatic. Only 4 patients with pararenal enlarged lymph nodes have been reported on in the imaging literature. Fat-containing nodes were detected by CT in one case only; the others had enlarged nodes of soft-tissue density. In one patient the diagnosis of hamartomatous lymph node invasion was established by angiography. In patients with renal angiomyolipoma, demonstration of both fatty thrombus and the fatty infiltration of lymph nodes of the renal hilum cannot be regarded as an indication of malignancy, but only of local aggessive behavior. Conservative treatment seems possible. Detection of enlarged lymph nodes of soft tissue density may cause difficult diagnostic problems, with the diagnosis addressed only by the presence of associated lesions. (orig./MG).

  6. Chronic renal disease in pregnancy.

    Science.gov (United States)

    Ramin, Susan M; Vidaeff, Alex C; Yeomans, Edward R; Gilstrap, Larry C

    2006-12-01

    The purpose of this review was to examine the impact of varying degrees of renal insufficiency on pregnancy outcome in women with chronic renal disease. Our search of the literature did not reveal any randomized clinical trials or meta-analyses. The available information is derived from opinion, reviews, retrospective series, and limited observational series. It appears that chronic renal disease in pregnancy is uncommon, occurring in 0.03-0.12% of all pregnancies from two U.S. population-based and registry studies. Maternal complications associated with chronic renal disease include preeclampsia, worsening renal function, preterm delivery, anemia, chronic hypertension, and cesarean delivery. The live birth rate in women with chronic renal disease ranges between 64% and 98% depending on the severity of renal insufficiency and presence of hypertension. Significant proteinuria may be an indicator of underlying renal insufficiency. Management of pregnant women with underlying renal disease should ideally entail a multidisciplinary approach at a tertiary center and include a maternal-fetal medicine specialist and a nephrologist. Such women should receive counseling regarding the pregnancy outcomes in association with maternal chronic renal disease and the effect of pregnancy on renal function, especially within the ensuing 5 years postpartum. These women will require frequent visits and monitoring of renal function during pregnancy. Women whose renal disease is further complicated by hypertension should be counseled regarding the increased risk of adverse outcome and need for blood pressure control. Some antihypertensives, especially angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, should be avoided during pregnancy, if possible, because of the potential for both teratogenic (hypocalvaria) and fetal effects (renal failure, oliguria, and demise).

  7. CUTANEOUS MANIFESTATIONS OF CHRONIC RENAL FAILURE AND RENAL TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    R. Suganya Gnanadeepam

    2017-07-01

    Full Text Available BACKGROUND The kidney and the skin are the two large networks of the body with abundant blood supply associated with various cutaneous manifestations. This study aims to detect the various cutaneous manifestations and its incidence in patients with chronic renal failure and renal transplantation. MATERIALS AND METHODS This study was done for a period of 1 year from January 2016 to December 2016 at Nephrology OPD ward and Medicine wards, Government KAPV Medical College Hospital, Trichy. During this period, 100 patients who had the presence of skin manifestations were selected and studied (80 renal failure patients and 20 renal transplantation patients. RESULTS Most of the specific cutaneous manifestations of chronic renal failure and renal transplantation were noted in this study. Pruritus and xerosis were the most common manifestations noted in chronic renal failure while infections was commonly noted in renal transplantation patients. CONCLUSION Pruritus and xerosis were the most common among the specific cutaneous manifestations in chronic renal failure followed by nail abnormalities and pigmentary changes. Cutaneous manifestations of renal transplantation were mostly due to infections of which fungal infection is the most common followed by viral infection.

  8. Transarterial embolization for serious renal hemorrhage following renal biopsy.

    Science.gov (United States)

    Zeng, Dan; Liu, Guihua; Sun, Xiangzhou; Zhuang, Wenquan; Zhang, Yuanyuan; Guo, Wenbo; Yang, Jianyong; Chen, Wei

    2013-01-01

    The goal of this study is to evaluate the feasibility and efficacy of percutaneous transarterial embolization for the treatment of serious renal hemorrhage after renal biopsy. Nine patients with renal hemorrhage had frank pain and gross hematuria as main symptoms after renal biopsy. Intrarenal arterial injuries and perinephric hematoma were confirmed by angiography in all cases. The arterial injuries led to two types of renal hemorrhage, Type I: severe renal injure or intrarenal renal artery rupture (n=5), with contrast medium spilling out of the artery and spreading into renal pelvis or kidney capsule in angiography; Type II, pseudo aneurysm or potential risk of intrarenal artery injure (n=4), where contrast medium that spilled out of intraartery was retained in the parenchyma as little spots less than 5 mm in diameter in angiography. Transcatheter superselective intrarenal artery embolization was performed with coils or microcoils (Type I intrarenal artery injure) and polyvinyl alcohol particles (Type II injure). The intrarenal arterial injuries were occluded successfully in all patients. Light or mild back or abdominal pain in the side of the embolized kidney was found in three patients following embolization procedures and disappeared 3 days later. Serum creatinine and perinephric hematoma were stable, and gross hematuresis stopped immediately (n=4) or 3-5 days (n=3) after embolization. In conclusions, transcatheter superselective intrarenal artery embolization as a minimally invasive therapy is safe and effective for treatment of serious renal hemorrhage following percutaneous renal biopsy.

  9. Renal proximal tubule Na,K-ATPase is controlled by CREB-regulated transcriptional coactivators as well as salt-inducible kinase 1.

    Science.gov (United States)

    Taub, Mary; Garimella, Sudha; Kim, Dongwook; Rajkhowa, Trivikram; Cutuli, Facundo

    2015-12-01

    Sodium reabsorption by the kidney is regulated by locally produced natriuretic and anti-natriuretic factors, including dopamine and norepinephrine, respectively. Previous studies indicated that signaling events initiated by these natriuretic and anti-natriuretic factors achieve their effects by altering the phosphorylation of Na,K-ATPase in the renal proximal tubule, and that protein kinase A (PKA) and calcium-mediated signaling pathways are involved. The same signaling pathways also control the transcription of the Na,K-ATPase β subunit gene atp1b1 in renal proximal tubule cells. In this report, evidence is presented that (1) both the recently discovered cAMP-regulated transcriptional coactivators (CRTCs) and salt-inducible kinase 1 (SIK1) contribute to the transcriptional regulation of atp1b1 in renal proximal tubule (RPT) cells and (2) renal effectors, including norepinephrine, dopamine, prostaglandins, and sodium, play a role. Exogenously expressed CRTCs stimulate atp1b1 transcription. Evidence for a role of endogenous CRTCs includes the loss of transcriptional regulation of atp1b1 by a dominant-negative CRTC, as well as by a CREB mutant, with an altered CRTC binding site. In a number of experimental systems, SIK phosphorylates CRTCs, which are then sequestered in the cytoplasm, preventing their nuclear effects. Consistent with such a role of SIK in primary RPT cells, atp1b1 transcription increased in the presence of a dominant-negative SIK1, and in addition, regulation by dopamine, norepinephrine, and monensin was disrupted by a dominant-negative SIK1. These latter observations can be explained if SIK1 is phosphorylated and inactivated in the presence of these renal effectors. Our results support the hypothesis that Na,K-ATPase in the renal proximal tubule is regulated at the transcriptional level via SIK1 and CRTCs by renal effectors, in addition to the previously reported control of the phosphorylation of Na,K-ATPase.

  10. Vedr.: Military capacity building

    DEFF Research Database (Denmark)

    Larsen, Josefine Kühnel; Struwe, Lars Bangert

    2013-01-01

    Military capacity building has increasingly become an integral part of Danish defence. Military capacity is a new way of thinking Danish defence and poses a new set of challenges and opportunities for the Danish military and the Political leadership. On the 12th of december, PhD. Candidate Josefine...... Kühnel Larsen and researcher Lars Bangert Struwe of CMS had organized a seminar in collaboration with Royal Danish Defense Colleg and the East African Security Governance Network. The seminar focused on some of the risks involved in Military capacity building and how these risks are dealt with from...

  11. Vedr.: Military capacity building

    DEFF Research Database (Denmark)

    Larsen, Josefine Kühnel; Struwe, Lars Bangert

    2013-01-01

    Kühnel Larsen and researcher Lars Bangert Struwe of CMS had organized a seminar in collaboration with Royal Danish Defense Colleg and the East African Security Governance Network. The seminar focused on some of the risks involved in Military capacity building and how these risks are dealt with from......Military capacity building has increasingly become an integral part of Danish defence. Military capacity is a new way of thinking Danish defence and poses a new set of challenges and opportunities for the Danish military and the Political leadership. On the 12th of december, PhD. Candidate Josefine...

  12. H+, Water and Urea Transport in the Inner Medullary Collecting Duct and Their Role in the Prevention and Pathogenesis of Renal Stone Disease

    Science.gov (United States)

    Wall, Susan M.; Klein, Janet D.

    2008-09-01

    The inner medullary collecting duct (IMCD) is the final site within the kidney for the reabsorption of urea, water and electrolytes and for the secretion of H+ before the luminal fluid becomes the final urine. Transporters expressed in the IMCD contribute to the generation of the large ion gradients that exist between the interstitium and the collecting duct lumen. Thus, the luminal fluid within the human IMCD can reach an osmolality of 1200 mOsm/kg H2O and a pH of 4. This ability of the human nephron to concentrate and acidify the urine might predispose to stone formation. However, under treatment conditions that predispose to stone formation, such as during hypercalciuria, the kidney mitigates stone formation by reducing solute concentration by reducing H2O reabsorption. Moreover, the kidney attenuates stone formation by tightly controlling acid-base balance, which prevents the bone loss, hypocitraturia and hypercalciuria observed during metabolic acidosis by augmenting net H+ excretion by tightly regulating H+ transporter function and through luminal buffering, particularly with NH3. This article will review the ion transporters present in the mammalian IMCD and their role in the prevention and in the pathogenesis of renal stone formation.

  13. Iodinated contrast media and the role of renal replacement therapy.

    Science.gov (United States)

    Weisbord, Steven D; Palevsky, Paul M

    2011-05-01

    Iodinated contrast media are among the most commonly used pharmacologic agents in medicine. Although generally highly safe, iodinated contrast media are associated with several adverse effects, most significantly the risk of acute kidney injury, particularly in patients with underlying renal dysfunction. By virtue of their pharmacokinetic characteristics, these contrast agents are efficiently cleared by hemodialysis and to a lesser extent, hemofiltration. This has led to research into the capacity for renal replacement therapies to prevent certain adverse effects of iodinated contrast. This review examines the molecular and pharmacokinetic characteristics of iodinated contrast media and critically analyzes data from past studies on the role of renal replacement therapy to prevent adverse effects of these diagnostic agents. Published by Elsevier Inc.

  14. Problemas renales de la cirrosis Renal problems of cirrhosis

    Directory of Open Access Journals (Sweden)

    Alvaro García

    1992-02-01

    Full Text Available Presentamos una revisión actualizada y condensada acerca de los problemas renales más relevantes que ocurren en la cirrosis tales como las alteraciones en el manejo del sodio y del agua, el tratamiento de la ascitis y el edema y el enfoque de la falla renal que ocurre en esta enfermedad, es decir síndrome hepato-renal y necrosis tubular aguda.

    We present a condensed and updated review on the most common renal problems occurring in cirrhosis such as the handling of sodium and water, the treatment of ascites and edema and the approach to the renal failure that frequently takes place in this disease, namely hepato-renal syndrome and acute tubular necrosis.

  15. MR imaging findings of renal infarction induced by renal artery

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Woo; Kim, Suck; Kim, Yong Woo; Hu, Jin Sam; Choi, Sang Yoel; Moon, Tae Yong; Lee, Suck Hong; Kim, Byung Su; Lee, Chang Hun [Pusan National Univ., Pusan (Korea, Repulic of). Coll. of Medicine

    1998-02-01

    To assess the usefulness of diffusion-weighted imaging (DWI) in evaluating serial parenchymal changes in renal infarction induced by renal artery ligation, by comparing this with the conventional spin echo technique and correlating the results with the histopathological findings. In 22 rabbits, renal infarction was induced by ligation of the renal artery. Spin-echo T1-weighted imaging (T1WI), turbo spin-echo (TSE) T2-weighted imaging (T2WI), and DWI were performed, using a 1.5-T superconductive unit, at 30 minutes, 1 hour, 2,3,6, 12 and 24 hours, and 2, 3, 7 and 20 days after left renal artery ligation. Changes in signal intensity on T1WI, T2WI, and DWI were correlated with histopathologic findings. Diffusion-weighted imaging is useful for the detection of hyperacute renal infarction, and the apparent diffusion coefficient may provide additional information concerning its evolution. (author). 21 refs., 9 figs.

  16. Renal subcapsular haematoma: an unusual complication of renal artery stenting

    Institute of Scientific and Technical Information of China (English)

    XIA Dan; CHEN Shan-wen; ZHANG Hong-kun; WANG Shuo

    2011-01-01

    After successful renal artery angioplasty and stent placement, a patient in a fully anticoagulated state developed hypotension and flank pain. Computed tomography (CT) of the abdomen revealed a large renal subcapsular haematoma which was successfully managed conservatively without embolotherapy and surgical intervention. To prevent hemorrhage after renal artery stenting, it is necessary to underscore the importance of reducing the contrast volume and pressure of angiography, controlling systemic blood pressure, and monitoring guide wire position at all times.

  17. CO diffusion capacity

    Energy Technology Data Exchange (ETDEWEB)

    Mielke, U.

    1979-01-01

    We measured in 287 persons the pulmonary CO diffusion capacity with the steady-state and the single breath methods, applying apnoeic periods of 4 and 10 seconds duration. The aspects methodical significance, polyclinical applicability and pathognostic relevance with respect to other approved pulmonary functional tests are discussed. Differing pulmonary diffusion capacity values found in normal persons or in patients suffering from silicosis, pulmonary fibrosis, Boeck's disease or rheumatoid arthritis, were investigated and critically evaluated.

  18. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  19. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  20. Dopamins renale virkninger

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal

    1990-01-01

    Dopamine is an endogenic catecholamine which, in addition to being the direct precursor of noradrenaline, has also an effect on peripheral dopaminergic receptors. These are localized mainly in the heart, splanchnic nerves and the kidneys. Dopamine is produced in the kidneys and the renal metaboli...... dialysis unnecessary in a number of patients on account of increased diuresis and natriuresis. The effect of GFR and the significance for the prognosis are not known....

  1. Renal lithiasis and nutrition

    OpenAIRE

    Prieto Rafel M; Costa-Bauza Antonia; Grases Felix

    2006-01-01

    Abstract Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified trough diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins) and each type of...

  2. Nutrition and renal disease.

    Directory of Open Access Journals (Sweden)

    Iris de Castaño

    2009-11-01

    Full Text Available Kidney plays an important roll in body homeostasis through excretory, metabolic and endocrine functions. Kidneys filter fluids and solutes and reabsorbed water , electrolytes an minerals. Urine volume and solute excretion are adjusted to keep composition of the extracellular space, serum osmolarity and intravascular volume in constant balance. Kidneys also regulate acid base equilibrium, hormone metabolism and excretion and amino acid concentration. Vitamin D hydroxylation takes place in the kidney, this is the active form of this vitamin, which inhibits PTH. In addition they produce erythropoietin which control hemoglobin concentration in erythrocytes. When renal insufficiency develops, and glormerular filtration rate is between 50 to 75% of normal, this functions are decreased .When renal function is less than 10%, this functions ceased. In children small changes in water, solute, acid base, calcium and phosphorus can alter normal growth and development. If kidneys can not maintain internal equilibrium, specific nutrients should be used. Compensation should be done according to age, type or renal disease and level of glomerular filtration rate.

  3. Renal artery aneurysm mimicking renal calculus with hydronephrosis.

    Science.gov (United States)

    Chen, Shanwen; Meng, Hongzhou; Cao, Min; Shen, Baihua

    2013-06-01

    A 51-year-old woman was found to have a left renal calculus with hydronephrosis. She underwent unsuccessful extracorporeal shock wave lithotripsy, leading to the recommendation that percutaneous lithotomy was necessary to remove the renal calculus. In view of the unusual shape of the calculus and absence of abnormalities in urine sediment, preoperative computed tomography and renal angiography were performed, which instead showed a calcified left renal artery aneurysm. Subsequent efforts to perform an aneurysmectomy also failed, eventually necessitating left nephrectomy. This case illustrates the pitfalls in the diagnosis of a renal artery aneurysm, which is a relatively common condition that may have unusual presentations. Hence, it is suggested that the possibility of a renal artery aneurysm be considered in the differential diagnosis when one detects a renal calculus with an unusual appearance. In addition, we propose that 3-dimensional reconstruction computed tomography be performed before considering surgical options for such renal calculi to rule out the possibility of a renal artery aneurysm.

  4. Renal scintigraphy in infants with antenatally diagnosed renal pelvis dilatation

    Directory of Open Access Journals (Sweden)

    Ajdinović Boris

    2008-01-01

    Full Text Available Background/Aim. Ureteropelvic junction obstruction and vesicoureteral reflux are the most frequent entities identified on the basis of antenatal hydronephrosis. The aim of this study was to determine the incidence and pattern of abnormal renal scintigraphy findings in postnatal investigation of children with antenatal hydronephrosis. Methods. Twenty four infants (19 boys and five girls presented with antenatal hydronephrosis and mild to moderate hydronephrosis on ultrasound in newborn period were referred for renal scintigraphy. Ten patients with vesicoureteral reflux documented on micturating cystoureterography underwent 99mTc-DMSA renal scintigraphy and 14 patients were subjected to 99mTc-DTPA scintigraphy. Results. Anteroposterior pelvic diameter on ultrasound ranged from 11 to 24 mm. Renal DMSA scans identified congenital scars in two boys with bilateral reflux of grade V and unilateral reflux of grade III. Relative kidney uptake (RKU less than 40% was found in three, and poor kidney function (RKU less than 10% in two patients. Significant obstruction was shown on DTPA diuretic renal scintigraphy in 6/14 patients. Some slowing in dranaige (T1/2 greater than 10 minutes with no reduction in differential renal function was identified in three patients. Differential renal function less than 10% was obtained in one case. Conclusion. A high percent of abnormal renal scintigraphy findings was obtained. Renal scintigraphy was useful in determination of underlying cause of antenatally detected hydronephrosis.

  5. Efficacy of ultrasonography-guided renal biopsy for the evaluation of renal dysfunction following renal transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jae; Choi, Chul Soon; Min, Seon Jeong; Lee, Gyung Kyu; Lee, Eil Seong; Kang, Ik Won; Bae, Sang Hoon [Hallym University College of Medicine, Chuncheon (Korea, Republic of)

    2003-12-15

    To evaluate the usefulness and complications of renal biopsy under ultrasonography-guidance in renal dysfunction after renal transplantation. Ultrasonography-guided renal biopsy was done in 47 patients with the transplanted kidney. The subjects consisted of 30 males and 17 females, age ranged from 16 to 66 years (average age=38 years). Biopsies were done once in 27 patients, twice in 17 patients, three times in 3 patients, a total of 70 biopsies. The success rate of renal biopsy for the accurate pathologic diagnosis and the incidence and types of complications following biopsy were evaluated. The success rate of renal biopsy for the accurate pathologic diagnosis was 96%(67/70). Pathologic diagnosis included 27 cases of acute rejection (39%), 8 cases of acute tubular necrosis (11%), 4 cases of acute rejection and acute tubular necrosis (6%), 4 cases of cyclosporin toxicity (6%), 4 cases of primary disease recurrence (6%), 4 cases of infection (6%) and others. Complications after renal biopsy included 15 cases of microscopic hematuria (21%), 1 case of gross hematuria with spontaneous cessation and 1 case of life threatening hemorrhage. Ultrasonography-guided renal biopsy is a safe and effective diagnostic method for the evaluation of renal dysfunction following renal transplantation.

  6. Trasplante renal Kidney transplant

    Directory of Open Access Journals (Sweden)

    P. Martín

    2006-08-01

    Full Text Available El trasplante renal es la terapia de elección para la mayoría de las causas de insuficiencia renal crónica terminal porque mejora la calidad de vida y la supervivencia frente a la diálisis. El trasplante renal de donante vivo es una excelente alternativa para el paciente joven en situación de prediálisis porque ofrece mejores resultados. El tratamiento inmunosupresor debe ser individualizado buscando la sinergia inmunosupresora y el mejor perfil de seguridad, y debe adaptarse a las diferentes etapas del trasplante renal. En el seguimiento del trasplante renal hay que tener muy en cuenta los factores de riesgo cardiovascular y los tumores puesto que la muerte del paciente con injerto funcionante es la segunda causa de pérdida del injerto tras el primer año del trasplante. La función alterada del injerto es un factor de mortalidad cardiovascular independiente que requerirá seguimiento y control de todas sus complicaciones para retrasar la entrada en diálisis.The kidney transplant is the therapy of choice for the majority of the causes of chronic terminal kidney insufficiency, because it improves the quality of life and survival in comparison with dialysis. A kidney transplant from a live donor is an excellent alternative for the young patient in a state of pre-dialysis because it offers the best results. Immunosuppressive treatment must be individualised, seeking immunosuppressive synergy and the best safety profile, and must be adapted to the different stages of the kidney transplant. In the follow-up to the kidney transplant, cardiovascular risk factors and tumours must be especially taken into account, given that the death of the patient with a working graft is the second cause of loss of the graft following the first year of the transplant. The altered function of the graft is a factor of independent cardiovascular mortality that will require follow-up and the control of all its complications to postpone the entrance in dialysis.

  7. Supra-Acetabular Brown Tumor due to Primary Hyperparathyroidism Associated with Chronic Renal Failure

    Directory of Open Access Journals (Sweden)

    Rosaria M. Ruggeri

    2010-01-01

    Full Text Available A 63-year-old woman presented to the Orthopedic Unit of our hospital complaining of right hip pain of 6 months'duration associated with a worsening limp. Her past medical history included chronic renal insufficiency. Physical examination revealed deep pain in the iliac region and severe restriction of the right hip's articular function in the maximum degrees of range of motion. X-rays and CT scan detected an osteolytic and expansive lesion of the right supra-acetabular region with structural reabsorption of the right iliac wing. 99mTc-MDP whole-body bone scan showed an abnormal uptake in the right iliac region. Bone biopsy revealed an osteolytic lesion with multinucleated giant cells, indicating a brown tumor. Serum intact PTH was elevated (1020 pg/ml; normal values, 12 62 pg/ml, but her serum calcium was normal (total = 9.4 mg/dl, nv 8.5–10.5; ionized = 5.0 mg/dl, nv 4.2–5.4 due to the coexistence of chronic renal failure. 99mTc-MIBI scintigraphy revealed a single focus of sestamibi accumulation in the left retrosternal location, which turned out to be an intrathoracic parathyroid adenoma at surgical exploration. After surgical removal of the parathyroid adenoma, PTH levels decreased to 212 pg/ml. Three months after parathyroidectomy, the imaging studies showed complete recovery of the osteolytic lesion, thus avoiding any orthopedic surgery. This case is noteworthy because (1 primary hyperparathyroidism was not suspected due to the normocalcemia, likely attributable to the coexistence of chronic renal failure; and (2 it was associated with a brown tumor of unusual location (right supra-acetabular region.

  8. Renal medullary ETB receptors produce diuresis and natriuresis via NOS1.

    Science.gov (United States)

    Nakano, Daisuke; Pollock, Jennifer S; Pollock, David M

    2008-05-01

    Endothelin-1 (ET-1) plays an important role in the regulation of salt and water excretion in the kidney. Considerable in vitro evidence suggests that the renal medullary ET(B) receptor mediates ET-1-induced inhibition of electrolyte reabsorption by stimulating nitric oxide (NO) production. The present study was conducted to test the hypothesis that NO synthase 1 (NOS1) and protein kinase G (PKG) mediate the diuretic and natriuretic effects of ET(B) receptor stimulation in vivo. Infusion of the ET(B) receptor agonist sarafotoxin S6c (S6c: 0.45 microg x kg(-1) x h(-1)) in the renal medulla of anesthetized, male Sprague-Dawley rats markedly increased the urine flow (UV) and urinary sodium excretion (UNaV) by 67 and 120%, respectively. This was associated with an increase in medullary cGMP content but did not affect blood pressure. In addition, S6c-induced diuretic and natriuretic responses were absent in ET(B) receptor-deficient rats. Coinfusion of N(G)-propyl-l-arginine (10 microg x kg(-1) x h(-1)), a selective NOS1 inhibitor, suppressed S6c-induced increases in UV, UNaV, and medullary cGMP concentrations. Rp-8-Br-PET-cGMPS (10 microg x kg(-1) x h(-1)) or RQIKIWFQNRRMKWKK-LRK(5)H-amide (18 microg x kg(-1) x h(-1)), a PKG inhibitor, also inhibited S6c-induced increases in UV and UNaV. These results demonstrate that renal medullary ET(B) receptor activation induces diuretic and natriuretic responses through a NOS1, cGMP, and PKG pathway.

  9. Functional coupling of renal K+ and Na+ handling causes high blood pressure in Na+ replete mice.

    Science.gov (United States)

    Vitzthum, Helga; Seniuk, Anika; Schulte, Laura Helene; Müller, Maxie Luise; Hetz, Hannah; Ehmke, Heimo

    2014-03-01

    A network of kinases, including WNKs, SPAK and Sgk1, is critical for the independent regulation of K+ and Na+ transport in the distal nephron. Angiotensin II is thought to act as a key hormone in orchestrating these kinases to switch from K+ secretion during hyperkalaemia to Na+ reabsorption during intravascular volume depletion, thus keeping disturbances in electrolyte and blood pressure homeostasis at a minimum. It remains unclear, however, how K+ and Na+ transport are regulated during a high Na+ intake, which is associated with suppressed angiotensin II levels and a high distal tubular Na+ load. We therefore investigated the integrated blood pressure, renal, hormonal and gene and protein expression responses to large changes of K+ intake in Na+ replete mice. Both low and high K+ intake increased blood pressure and caused Na+ retention. Low K+ intake was accompanied by an upregulation of the sodium-chloride cotransporter (NCC) and its activating kinase SPAK, and inhibition of NCC normalized blood pressure. Renal responses were unaffected by angiotensin AT1 receptor antagonism, indicating that low K+ intake activates the distal nephron by an angiotensin-independent mode of action. High K+ intake was associated with elevated plasma aldosterone concentrations and an upregulation of the epithelial sodium channel (ENaC) and its activating kinase Sgk1. Surprisingly, high K+ intake increased blood pressure even during ENaC or mineralocorticoid receptor antagonism, suggesting the contribution of aldosterone-independent mechanisms. These findings show that in a Na+ replete state, changes in K+ intake induce specific molecular and functional adaptations in the distal nephron that cause a functional coupling of renal K+ and Na+ handling, resulting in Na+ retention and high blood pressure when K+ intake is either restricted or excessively increased.

  10. The influence of percutaneous nephrolithotomy on human systemic stress response, SIRS and renal function.

    Science.gov (United States)

    Shen, Pengfei; Wei, Wuran; Yang, Xiaochun; Zeng, Hao; Li, Xiong; Yang, Jie; Wang, Jia; Huang, Jiaoti

    2010-10-01

    The objective of this study is to investigate the influences of percutaneous nephrolithotomy (PNL) and open surgery nephrolithotomy on the systemic stress response, SIRS and renal function. Forty patients with kidney calculi were enrolled in the study. Twenty cases were randomized to the PNL group and the other twenty cases to the open surgery group. Levels of C-reactive protein (CRP), interleukin-6(IL-6), β(2)-microglobulin (β(2)-MG), respiration rate, heart rate, body temperature and white blood cell counts were examined. CRP and IL-6 were measured in all patients pre-operatively and on post-operative days 1, 3 and 6, respectively. There was significant difference in their pre- and post-operation levels (P SIRS in PNL group and 12 cases in open surgery group; there was significant difference between the two groups (P 0.05). Urine β(2)-MG levels were also measured. There was significant difference between pre- and the first day post-PNL (P 0.05). There was significant difference between pre- and first and third day post-open surgery (P 0.05). There was significant difference between two groups at the first, third and sixth days (P SIRS, but the degree of SIRS in PNL group was lesser than the other group. Both the groups have no obvious effect on glomerular filtration function after operation and have effect on renal tubular reabsorption in the early stage after operation; but the recovery of the PNL group is faster than the open surgery group. It is thus shown that PNL is much safer and more feasible and has lesser effect on renal function.

  11. Haemostatic aspects of renal transplantation.

    Science.gov (United States)

    Sørensen, P J; Schmidt, E B; Knudsen, F; Nielsen, A H; Kristensen, S D; Dyerberg, J; Kornerup, H J

    1988-01-01

    Platelet function and protein C activity and antigen level was studied in 31 renal transplant recipients and 10 healthy controls. The patients were divided into three groups: (I) cyclosporin treated, (II) azathioprine treated, and (III) azathioprine treated patients with chronic rejection. The platelet function in the renal transplant patients was normal and there was no difference between groups I and II. The specific activity of protein C was decreased in patients after renal transplantation and decreasing protein C activity and progressive renal failure was found to be positively correlated in the azathioprine treated groups.

  12. Renal replacement therapy in ICU

    Directory of Open Access Journals (Sweden)

    C Deepa

    2012-01-01

    Full Text Available Diagnosing and managing critically ill patients with renal dysfunction is a part of the daily routine of an intensivist. Acute kidney insufficiency substantially contributes to the morbidity and mortality of critically ill patients. Renal replacement therapy (RRT not only does play a significant role in the treatment of patients with renal failure, acute as well as chronic, but also has spread its domains to the treatment of many other disease conditions such as myaesthenia gravis, septic shock and acute on chronic liver failure. This article briefly outlines the role of renal replacement therapy in ICU.

  13. Renal myxoma: a case report

    Directory of Open Access Journals (Sweden)

    Carlos Henrique C Souza

    2015-04-01

    Full Text Available Myxomas are rare tumors that can appear in many anatomical locations. There are only 14 cases of renal involvement documented in the literature. This article reports a case of renal myxoma in an elderly woman with recurrent cystitis. After five years of follow-up, the computed tomography (CT revealed a large solid tumor mass in the left kidney. Tumor resection was performed preserving the affected kidney with histopathological diagnosis of renal myxoma. The objective of this study is to report a rare case of renal myxoma, emphasizing the importance of the differential diagnosis from other benign and malignant mesenchymal tumors.

  14. Sporotrichosis in Renal Transplant Patients

    Directory of Open Access Journals (Sweden)

    Paulo Gewehr

    2013-01-01

    Full Text Available The current report describes two renal transplant recipients who presented with sporotrichosis. In addition, the authors review the general aspects of sporotrichosis in renal transplant recipients reported in the literature. Sporotrichosis is a rare fungal infection in transplant patients and has been reported primarily in renal transplant recipients not treated with antifungal prophylaxis. Extracutaneous forms of sporotrichosis without skin manifestations and no previous history of traumatic injuries have been described in such patients and are difficult to diagnose. Renal transplant recipients with sporotrichosis described in the present report were successfully treated with antifungal therapy including amphotericin B deoxycholate, lipid amphotericin B formulations, fluconazole and itraconazole.

  15. CT features of renal infarction

    Energy Technology Data Exchange (ETDEWEB)

    Suzer, Okan; Shirkhoda, Ali; Jafri, S. Zafar; Madrazo, Beatrice L.; Bis, Kostaki G.; Mastromatteo, James F

    2002-10-01

    Purpose: To demonstrate the different patterns of renal infarction to avoid pitfalls. To present 'flip-flop enhancement' pattern in renal infarction. Materials and methods: Retrospective review of a total of 41 renal infarction in 37 patients were done. These patients underwent initial CT and the diagnosis of renal infarction was confirmed with either follow up CT or at surgery. Results: Twenty-three patients had wedge-shaped focal infarcts, nine patients had global and five patients had multifocal infarcts of the kidneys. Cortical rim sign was seen predominantly with global infarcts. In five patients, a 'flip-flop enhancement' pattern was observed. In two patients, planned renal biopsies due to tumefactive renal lesions were cancelled because of 'flip-flop enhancement' pattern on follow up CTs. Conclusion: Although most of our cases were straightforward for the diagnosis of renal infarction, cases with tumefactive lesions and global infarctions without the well-known cortical rim sign were particularly challenging. We describe a new sign, flip-flop enhancement pattern, which we believe solidified the diagnosis of renal infarction in five of our cases. The authors recommend further investigations for association of flip-flop enhancement and renal infarction.

  16. Hemorrhagic Fever with Renal Syndrome (HFRS)

    Science.gov (United States)

    ... this page: About CDC.gov . Share Compartir Hemorrhagic Fever with Renal Syndrome (HFRS) On this Page What ... is HFRS prevented? Suggested Reading What is hemorrhagic fever with renal syndrome? Hemorrhagic fever with renal syndrome ( ...

  17. Renal cirsoid arteriovenous malformation masquerading as neoplasia.

    Science.gov (United States)

    Silverthorn, K; George, D

    1988-12-01

    A woman with renal colic and microscopic hematuria had filling defects in the left renal collecting system detected on excretory urography. A nephrectomy, performed because of suspected malignancy, might have been averted by renal angiography.

  18. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  19. Dual capacity reciprocating compressor

    Science.gov (United States)

    Wolfe, Robert W.

    1984-01-01

    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  20. Capacity Maximizing Constellations

    Science.gov (United States)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  1. Weather and road capacity

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian

    2014-01-01

    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore......, the capacity of the highway seems to be reduced in bad weather and there are indications that travel time variability is also increased, at least in free-flow conditions. Heavy precipitation reduces speed and capacity by around 5-8%, whereas snow primarily reduces capacity. Other weather variables......-parametrically against traffic density and in step 2 the residuals from step 1 are regressed linearly against the weather variables. The choice of a non-parametric method is made to avoid constricting ties from a parametric specification and because the focus here is not on the relationship between traffic flow...

  2. Tumor Seeding With Renal Cell Carcinoma After Renal Biopsy

    OpenAIRE

    M.F.B. Andersen; Norus, T.P.

    2016-01-01

    Tumor seeding following biopsy of renal cell carcinoma is extremely rare with an incidence of 1:10.000. In this paper two cases with multiple recurrent RRC metastasis in the biopsy tract following biopsy of renal tumor is presented and the current literature is shortly discussed.

  3. Renal blood flow in experimental septic acute renal failure

    NARCIS (Netherlands)

    Langenberg, C.; Wan, L.; Egi, M.; May, C. N.; Bellomo, R.

    2006-01-01

    Reduced renal blood flow (RBF) is considered central to the pathogenesis of septic acute renal failure (ARF). However, no controlled experimental studies have continuously assessed RBF during the development of severe septic ARF. We conducted a sequential animal study in seven female Merino sheep. F

  4. Renal vein oxygen saturation in renal artery stenosis

    DEFF Research Database (Denmark)

    Nielsen, K; Rehling, M; Henriksen, Jens Henrik Sahl

    1992-01-01

    Renal vein oxygen-saturation was measured in 56 patients with arterial hypertension and unilateral stenosis or occlusion of the renal artery. Oxygen-saturation in blood from the ischaemic kidney (84.4%, range 73-93%) was significantly higher than that from the 'normal' contralateral kidney (81...

  5. The renal scan in pregnant renal transplant patients

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, H.A.; Ziessman, H.A.; Fahey, F.H.; Collea, J.V.; Alijani, M.R.; Helfrich, G.B.

    1985-05-01

    With the greater frequency of renal transplant surgery, more female pts are becoming pregnant and carrying to term. In the renal allograft blood vessels and ureter may be compressed resulting in impaired renal function and/or, hypertension. Toxemia of pregnancy is seen more frequently than normal. Radionuclide renal scan monitoring may be of significant value in this high risk obstetrical pt. After being maintained during the pregnancy, renal function may also deteriorate in the post partum period. 5 pregnant renal transplant pts who delivered live babies had renal studies with Tc-99m DTPA to assess allograft perfusion and function. No transplanted kidney was lost during or after pregnancy as a result of pregnancy. No congenital anomalies were associated with transplant management. 7 studies were performed on these 5 pts. The 7 scans all showed the uterus/placenta. The bladder was always distorted. The transplanted kidney was rotated to a more vertical position in 3 pts. The radiation dose to the fetus is calculated at 0.024 rad/mCi administered. This study demonstrates the anatomic and physiologic alterations expected in the transplanted kidney during pregnancy when evaluated by renal scan and that the radiation burden may be acceptable in management of these pts.

  6. Expression of renal distal tubule transporters TRPM6 and NCC in a rat model of cyclosporine nephrotoxicity and effect of EGF treatment.

    Science.gov (United States)

    Ledeganck, Kristien J; Boulet, Gaëlle A; Horvath, Caroline A; Vinckx, Marleen; Bogers, Johannes J; Van Den Bossche, Rita; Verpooten, Gert A; De Winter, Benedicte Y

    2011-09-01

    Renal magnesium (Mg(2+)) and sodium (Na(+)) loss are well-known side effects of cyclosporine (CsA) treatment in humans, but the underlying mechanisms still remain unclear. Recently, it was shown that epidermal growth factor (EGF) stimulates Mg(2+) reabsorption in the distal convoluted tubule (DCT) via TRPM6 (Thébault S, Alexander RT, Tiel Groenestege WM, Hoenderop JG, Bindels RJ. J Am Soc Nephrol 20: 78-85, 2009). In the DCT, the final adjustment of renal sodium excretion is regulated by the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which is activated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to gain more insight into the molecular mechanisms of CsA-induced hypomagnesemia and hyponatremia. Therefore, the renal expression of TRPM6, TRPM7, EGF, EGF receptor, claudin-16, claudin-19, and the NCC, and the effect of the RAAS on NCC expression, were analyzed in vivo in a rat model of CsA nephrotoxicity. Also, the effect of EGF administration on these parameters was studied. CsA significantly decreased the renal expression of TRPM6, TRPM7, NCC, and EGF, but not that of claudin-16 and claudin-19. Serum aldosterone was significantly lower in CsA-treated rats. In control rats treated with EGF, an increased renal expression of TRPM6 together with a decreased fractional excretion of Mg(2+) (FE Mg(2+)) was demonstrated. EGF did not show this beneficial effect on TRPM6 and FE Mg(2+) in CsA-treated rats. These data suggest that CsA treatment affects Mg(2+) homeostasis via the downregulation of TRPM6 in the DCT. Furthermore, CsA downregulates the NCC in the DCT, associated with an inactivation of the RAAS, resulting in renal sodium loss.

  7. Renal posttransplant's vascular complications

    Directory of Open Access Journals (Sweden)

    Bašić Dragoslav

    2003-01-01

    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

  8. [Renal abnormalities in ankylosing spondylitis].

    Science.gov (United States)

    Samia, Barbouch; Hazgui, Faiçal; Abdelghani, Khaoula Ben; Hamida, Fethi Ben; Goucha, Rym; Hedri, Hafedh; Taarit, Chokri Ben; Maiz, Hedi Ben; Kheder, Adel

    2012-07-01

    We will study the epidemiologic, clinical, biological, therapeutic, prognostic characteristics and predictive factors of development of nephropathy in ankylosing spondylitis patients. We retrospectively reviewed the medical record of 32 cases with renal involvement among 212 cases of ankylosing spondylitis followed in our service during the period spread out between 1978 and 2006. The renal involvement occurred in all patients a mean of 12 years after the clinical onset of the rheumatic disease. Thirty-two patients presented one or more signs of renal involvement: microscopic hematuria in 22 patients, proteinuria in 23 patients, nephrotic syndrome in 11 patients and decreased renal function in 24 patients (75%). Secondary renal amyloidosis (13 patients), which corresponds to a prevalence of 6,1% and tubulointerstitial nephropathy (7 patients) were the most common cause of renal involvement in ankylosing spondylitis followed by IgA nephropathy (4 patients). Seventeen patients evolved to the end stage renal disease after an average time of 29.8 ± 46 months. The average follow-up of the patients was 4,4 years. By comparing the 32 patients presenting a SPA and renal disease to 88 with SPA and without nephropathy, we detected the predictive factors of occurred of nephropathy: tobacco, intense inflammatory syndrome, sacroileite stage 3 or 4 and presence of column bamboo. The finding of 75% of the patients presented a renal failure at the time of the diagnosis of renal involvement suggests that evidence of renal abnormality involvement should be actively sought in this disease. Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  9. Renal metabolism of calcitonin

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, R.E.; Hjelle, J.T.; Mahoney, C.; Deftos, L.J.; Lisker, W.; Kato, P.; Rabkin, R.

    1988-04-01

    The kidneys account for approximately two-thirds of the metabolism of calcitonin, but relatively little is known regarding the details thereof. To further characterize this process, we examined the renal handling and metabolism of human calcitonin (hCT) by the isolated perfused rat kidney. We also studied the degradation of radiolabeled salmon calcitonin (sCT) by subcellular fractions prepared from isolated rabbit proximal tubules. The total renal (organ) clearance of immunoreactive hCT by the isolated kidney was 1.96 +/- 0.18 ml/min. This was independent of the perfusate total calcium concentration from 5.5 to 10.2 mg/dl. Total renal clearance exceeded the glomerular filtration rate (GFR, 0.68 +/- 0.05 ml/min), indicating filtration-independent removal. Urinary calcitonin clearance as a fraction of GFR averaged 2.6%. Gel filtration chromatography of medium from isolated kidneys perfused with /sup 125/I-labeled sCT showed the principal degradation products to be low molecular weight forms eluting with monoiodotyrosine. Intermediate size products were not detected. In the subcellular fractionation experiments, when carried out at pH 5.0, calcitonin hydrolysis exclusively followed the activities of the lysosomal enzyme N-acetyl-beta-glucosaminidase. Typically, at pH 7.5, 42% of total degradation occurred in the region of the brush-border enzyme alanyl aminopeptidase and 29% occurred in the region of the cytosolic enzyme phosphoglucomutase. Although 9% of the calcitonin-degrading activity was associated with basolateral membrane fractions, most of this activity could be accounted for by the presence of brush-border membranes.

  10. Citrato y litiasis renal

    Directory of Open Access Journals (Sweden)

    Elisa E. Del Valle

    2013-08-01

    Full Text Available El citrato es un potente inhibidor de la cristalización de sales de calcio. La hipocitraturia es una alteración bioquímica frecuente en la formación de cálculos de calcio en adultos y especialmente en niños. El pH ácido (sistémico, tubular e intracelular es el principal determinante de la excreción de citrato en la orina. Si bien la mayoría de los pacientes con litiasis renal presentan hipocitraturia idiopática, hay un número de causas para esta anormalidad que incluyen acidosis tubular renal distal, hipokalemia, dietas ricas en proteínas de origen animal y/o dietas bajas en álcalis y ciertas drogas, como la acetazolamida, topiramato, IECA y tiazidas. Las modificaciones dietéticas que benefician a estos pacientes incluyen: alta ingesta de líquidos y frutas, especialmente cítricos, restricción de sodio y proteínas, con consumo normal de calcio. El tratamiento con citrato de potasio es efectivo en pacientes con hipocitraturia primaria o secundaria y en aquellos desordenes en la acidificación, que provocan un pH urinario persistentemente ácido. Los efectos adversos son bajos y están referidos al tracto gastrointestinal. Si bien hay diferentes preparaciones de citrato (citrato de potasio, citrato de sodio, citrato de potasio-magnesio en nuestro país solo está disponible el citrato de potasio en polvo que es muy útil para corregir la hipocitraturia y el pH urinario bajo, y reducir marcadamente la recurrencia de la litiasis renal.

  11. Renal calculus disease.

    Science.gov (United States)

    Schulsinger, D A; Sosa, R E

    1998-03-01

    We have seen an explosion in technical innovations for the management of urolithiasis. Today, the endourologist possesses an assortment of minimally invasive tools to treat renal stones. Most patients receive fast, safe and effective treatment in the outpatient setting. Despite the many technical advances, however, anatomical malformations and complex stones still provide significant challenges in diagnosis, access to a targeted stone, fragmentation, and clearance of the resulting fragments. This review examines a variety of urinary stone presentations and treatment strategies for cost-effective management.

  12. [Pulmonary-renal syndrome].

    Science.gov (United States)

    Risso, Jorge A; Mazzocchi, Octavio; De All, Jorge; Gnocchi, César A

    2009-01-01

    The pulmonary-renal syndrome is defined as a combination of diffuse alveolar hemorrhage and glomerulonephritis. The coexistence of these two clinical conditions is due to diseases with different pathogenic mechanisms. Primary systemic vasculitis and Goodpasture syndrome are the most frequent etiologies. Systemic lupus erythematosus, connective tissue diseases, negative anti neutrophil cytoplasmic antibody vasculitis and those secondary to drugs are far less common causes. An early diagnosis based on clinical, radiologic, laboratory and histologic criteria enables early treatment, thus diminishing its high morbidity-mortality rate. Therapy is based on high doses of corticosteroids, immunosuppressants, tumor necrosis factor inhibitors and plasmapheresis.

  13. Role of Erythropoietin in Renal Anemia Therapy

    African Journals Online (AJOL)

    Keywords: Chronic renal failure, Renal anemia, Erythropoietin resistance. Tropical Journal of ... gastrointestinal reaction, which can increase the iron utilization and improve iron reserves, overcoming the reticuloendothelial system iron.

  14. Acute Renal Failure in the Neonate.

    Science.gov (United States)

    Khan, Owais A; Hageman, Joseph R; Clardy, Christopher

    2015-10-01

    Acute renal failure (ARF) in a neonate is a serious condition that impacts 8% to 24% of hospitalized neonates. There is a need for prompt evaluation and treatment to avoid additional complications. In this review, a neonate was found to have renal failure associated with renal vein thrombosis. There are varying etiologies of ARF. Causes of ARF are typically divided into three subsets: pre-renal, renal or intrinsic, and post-renal. Treatment of ARF varies based on the cause. Renal vein thrombosis is an interesting cause of renal or intrinsic ARF and can be serious, often leading to a need for dialysis.

  15. Leiomyosarcoma of the renal vein

    Directory of Open Access Journals (Sweden)

    Lemos Gustavo C.

    2003-01-01

    Full Text Available Leiomyosarcoma of the renal vein is a rare tumor of complex diagnosis. We presented a case of renal vein leiomyosarcoma detected in a routine study. The primary treatment was complete surgical removal of the mass. In cases where surgical removal is not possible the prognosis is poor, with high rates of local recurrence and distant spread.

  16. Ultrasonography in chronic renal failure

    Energy Technology Data Exchange (ETDEWEB)

    Buturovic-Ponikvar, Jadranka E-mail: jadranka.buturovic@mf.uni-lj.si; Visnar-Perovic, Alenka

    2003-05-01

    Many chronic renal diseases lead to the final common state of decrease in renal size, parenchymal atrophy, sclerosis and fibrosis. The ultrasound image show a smaller kidney, thinning of the parenchyma and its hyperechogenicity (reflecting sclerosis and fibrosis). The frequency of renal cysts increases with the progression of the disease. Ultrasound generally does not allow for the exact diagnosis of an underlying chronic disease (renal biopsy is usually required), but it can help to determine an irreversible disease, assess prognosis and avoid unnecessary diagnostic or therapeutic procedures. The main exception in which the ultrasound image does not show a smaller kidney with parenchymal atrophy is diabetic nephropathy, the leading cause of chronic and end-stage renal failure in developed countries in recent years. In this case, both renal size and parenchymal thickness are preserved until end-stage renal failure. Doppler study of intrarenal vessels can provide additional information about microvascular and parenchymal lesions, which is helpful in deciding for or against therapeutic intervention and timely planning for optimal renal replacement therapy option.

  17. Renal replacement therapy in Europe

    DEFF Research Database (Denmark)

    Pippias, Maria; Stel, Vianda S; Abad Diez, José Maria

    2015-01-01

    BACKGROUND: This article summarizes the 2012 European Renal Association-European Dialysis and Transplant Association Registry Annual Report (available at www.era-edta-reg.org) with a specific focus on older patients (defined as ≥65 years). METHODS: Data provided by 45 national or regional renal r...

  18. Testamentary capacity and delirium.

    Science.gov (United States)

    Liptzin, Benjamin; Peisah, Carmelle; Shulman, Kenneth; Finkel, Sanford

    2010-09-01

    With the aging of the population there will be a substantial transfer of wealth in the next 25 years. The presence of delirium can complicate the evaluation of an older person's testamentary capacity and susceptibility to undue influence but has not been well examined in the existing literature. A subcommittee of the IPA Task Force on Testamentary Capacity and Undue Influence undertook to review how to assess prospectively and retrospectively testamentary capacity and susceptibility to undue influence in patients with delirium. The subcommittee identified questions that should be asked in cases where someone changes their will or estate plan towards the end of their life in the presence of delirium. These questions include: was there consistency in the patient's wishes over time? Were these wishes expressed during a "lucid interval" when the person was less confused? Were the patient's wishes clearly expressed in response to open-ended questions? Is there clear documentation of the patient's mental status at the time of the discussion? This review with some case examples provides guidance on how to consider the question of testamentary capacity or susceptibility to undue influence in someone undergoing an episode of delirium.

  19. Flood Bypass Capacity Optimization

    Science.gov (United States)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  20. Renal (tissue) kallikrein-kinin system in the kidney and novel potential drugs for salt-sensitive hypertension.

    Science.gov (United States)

    Katori, Makoto; Majima, Masataka

    2014-01-01

    A large variety of antihypertensive drugs, such as angiotensin converting enzyme inhibitors, diuretics, and others, are prescribed to hypertensive patients, with good control of the condition. In addition, all individuals are generally believed to be salt sensitive and, thus, severe restriction of salt intake is recommended to all. Nevertheless, the physiological defense mechanisms in the kidney against excess salt intake have not been well clarified. The present review article demonstrated that the renal (tissue) kallikrein-kinin system (KKS) is ideally situated within the nephrons of the kidney, where it functions to inhibit the reabsorption of NaCl through the activation of bradykinin (BK)-B2 receptors localized along the epithelial cells of the collecting ducts (CD). Kinins generated in the CD are immediately inactivated by two kidney-specific kinin-inactivating enzymes (kininases), carboxypeptidase Y-like exopeptidase (CPY), and neutral endopeptidase (NEP). Our work demonstrated that ebelactone B and poststatin are selective inhibitors of these kininases. The reduced secretion of the urinary kallikrein is linked to the development of salt-sensitive hypertension, whereas potassium ions and ATP-sensitive potassium channel blockers ameliorate salt-sensitive hypertension by accelerating the release of renal kallikrein. On the other hand, ebelactone B and poststatin prolong the life of kinins in the CD after excess salt intake, thereby leading to the augmentation of natriuresis and diuresis, and the ensuing suppression of salt-sensitive hypertension. In conclusion, accelerators of the renal kallikrein release and selective renal kininase inhibitors are both novel types of antihypertensive agents that may be useful for treatment of salt-sensitive hypertension.

  1. Neutrophils accentuate renal cold ischemia-reperfusion injury. Dose-dependent protective effect of a platelet-activating factor receptor antagonist.

    Science.gov (United States)

    Riera, M; Torras, J; Herrero, I; Valles, J; Paubert-Braquet, M; Cruzado, J M; Alsina, J; Grinyo, J M

    1997-02-01

    This study was undertaken to evaluate whether the renal damage induced by cold ischemia-reperfusion was worsened by neutrophils (PMN), and if blockade of platelet-activating factor (PAF) could effectively decrease this injury. After flushing with EuroCollins, 85 kidneys from Sprague-Dawley rats underwent either no cold ischemia or a 4-h cold ischemia, and then were reperfused for 75 min at 37 degrees C and 100 mm Hg in an isolated perfusion circuit. Reperfusion was performed with a Krebs-Henseleit solution containing 4.5% albumin, with and without human PMN (7.5 x 10(5) cells/ml) and with and without addition of a PAF receptor antagonist (BN 52021). Hemodynamic and functional parameters were continuously assessed during reperfusion. At end of the study, PAF production was evaluated. Presence of PMN during reperfusion of nonischemic kidneys produced no alteration of functional parameters or PAF production. After 4-h cold ischemia, the presence of PMN during reperfusion produced a significant worsening of plasma flow rate, glomerular filtration rate and sodium reabsorption in comparison with kidneys reperfused without PMN. Also, higher production of PAF was observed in the kidneys reperfused with PMN than in the kidneys reperfused without PMN. After 4-h cold ischemia, addition of BN 52021 during reperfusion in the presence of PMN significantly increased the plasma flow rate, glomerular filtration rate and sodium reabsorption in comparison with kidneys reperfused without this PAF antagonist. This effect was dose dependent. After 4-h cold ischemia, addition of BN 52021 during reperfusion in the absence of PMN produced no significant effect on functional parameters in comparison with kidneys reperfused without this PAF antagonist. These results indicate that PMN contribute to renal cold ischemia-reperfusion injury evaluated in the isolated perfused kidney. Treatment with a PAF receptor antagonist attenuated this injury in a dose-dependent manner, which suggests that it

  2. Inhibition of kidney proximal tubular glucose reabsorption does not prevent against diabetic nephropathy in type 1 diabetic eNOS knockout mice.

    Directory of Open Access Journals (Sweden)

    Muralikrishna Gangadharan Komala

    Full Text Available BACKGROUND AND OBJECTIVE: Sodium glucose cotransporter 2 (SGLT2 is the main luminal glucose transporter in the kidney. SGLT2 inhibition results in glycosuria and improved glycaemic control. Drugs inhibiting this transporter have recently been approved for clinical use and have been suggested to have potential renoprotective benefits by limiting glycotoxicity in the proximal tubule. We aimed to determine the renoprotective benefits of empagliflozin, an SGLT2 inhibitor, independent of its glucose lowering effect. RESEARCH DESIGN AND METHODS: We induced diabetes using a low dose streptozotocin protocol in 7-8 week old endothelial nitric oxide (eNOS synthase knockout mice. We measured fasting blood glucose on a monthly basis, terminal urinary albumin/creatinine ratio. Renal histology was assessed for inflammatory and fibrotic changes. Renal cortical mRNA transcription of inflammatory and profibrotic cytokines, glucose transporters and protein expression of SGLT2 and GLUT1 were determined. Outcomes were compared to diabetic animals receiving the angiotensin receptor blocker telmisartan (current best practice. RESULTS: Diabetic mice had high matched blood glucose levels. Empagliflozin did not attenuate diabetes-induced albuminuria, unlike telmisartan. Empagliflozin did not improve glomerulosclerosis, tubular atrophy, tubulointerstitial inflammation or fibrosis, while telmisartan attenuated these. Empagliflozin did not modify tubular toll-like receptor-2 expression in diabetic mice. Empagliflozin did not reduce the upregulation of macrophage chemoattractant protein-1 (MCP-1, transforming growth factor β1 and fibronectin mRNA observed in the diabetic animals, while telmisartan decreased transcription of MCP-1 and fibronectin. Empagliflozin increased GLUT1 mRNA expression and telmisartan increased SGLT2 mRNA expression in comparison to untreated diabetic mice. However no significant difference was found in protein expression of GLUT1 or SGLT2 among the

  3. Successful renal transplantation during pregnancy.

    Science.gov (United States)

    Hold, Phoebe M; Wong, Christopher F; Dhanda, Raman K; Walkinshaw, Steve A; Bakran, Ali

    2005-09-01

    Little is known about the implications of performing a renal transplant on a patient who is already pregnant. This case study reports a successful outcome of pregnancy, diagnosed coincidentally following renal transplantation at 13 weeks gestation. The recipient was a 23-year-old woman with chronic kidney disease who received a live-related renal transplant from her father. Pregnancy was discovered at routine ultrasound scanning of the renal allograft at 5 days posttransplant and estimated at 13 weeks gestation. She received ciclosporin monotherapy as immunosuppression throughout the pregnancy, and was given valacyclovir as prophylaxis against cytomegalovirus (CMV) infection. Renal function remained stable throughout the pregnancy, which progressed normally, resulting in the vaginal delivery of a healthy, liveborn male infant at 37 weeks gestation. This case study demonstrates that transplantation during pregnancy can have a successful outcome.

  4. Characterization of complex renal cysts

    DEFF Research Database (Denmark)

    Graumann, Ole; Osther, Susanne Sloth; Osther, Palle Jörn Sloth

    2010-01-01

    Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically ...... of this "new" classification strategy is, however, still missing. Data on other imaging modalities are too limited for conclusions to be drawn.......Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically...... available data on the Bosniak classification. Material and methods. All publications from an Entrez Pubmed search were reviewed, focusing on clinical applicability and the use of imaging modalities other than CT to categorize complex renal cysts. Results. Fifteen retrospective studies were found. Most...

  5. Ciprofloxacin-Induced Renal Failure

    Directory of Open Access Journals (Sweden)

    Audra Fuller

    2015-10-01

    Full Text Available Acute renal failure (ARF is a common diagnosis in hospitalized patients, particularly in intensive care units (ICU. Determining the cause and contributing factors associated with ARF is crucial during treatment. The etiology is complex, and several factors often contribute to its development. Medications can cause acute tubular necrosis, acute interstitial nephritis, and crystal-induced or post-obstructive nephropathy. There have been several case reports of ARF secondary to fluoroquinolones. Here we report the development of acute renal failure within a few days of initiating oral ciprofloxacin therapy and briefly describe the different types of renal failure secondary to fluoroquinolone administration. Clinical studies demonstrate that using fluoroquinolones with other potentially nephrotoxic medications requires monitoring of renal function to limit the renal toxicity with these medications. Also, the risk-benefit profile of patients requiring fluoroquinolones should be considered.

  6. Development of the renal arterioles.

    Science.gov (United States)

    Sequeira Lopez, Maria Luisa S; Gomez, R Ariel

    2011-12-01

    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.

  7. Hypertension in Renal Allograft Recipients

    Directory of Open Access Journals (Sweden)

    Waiser Johannes

    1999-01-01

    Full Text Available Hypertension is a frequent complication after renal transplantation. It contributes to the considerable cardiovascular morbidity and mortality in renal allograft recipients. Additionally, it has a major impact on long-term allograft survival. The pathogenesis of post transplant hypertension is multifactorial. Besides common risk factors, renal allograft recipients accumulate specific risk factors related to the original renal disease, renal transplantation per se and the immunosuppressive regimen. Chronic allograft dysfunction is the main cause of post transplant hypertension. The introduction of calcineurin inhibitors, such as cyclosporine, has increased the prevalence of hypertension. At present, the growing manual of diagnostic and therapeutic tools enables us to adapt better antihypertensive therapy. Tight monitoring, individualization of the immunosuppressive protocol, inclusion of non-pharmacological measures and aggressive antihypertensive treatment should help to minimize the negative implications of post transplant hypertension. Probably, this goal can only be reached by "normalization" of systolic and diastolic blood pressure to below 135/85 mmHg.

  8. Current status of renal biopsy for small renal masses.

    Science.gov (United States)

    Ha, Seung Beom; Kwak, Cheol

    2014-09-01

    Small renal masses (SRMs) are defined as radiologically enhancing renal masses of less than 4 cm in maximal diameter. The incidence of renal cell carcinoma (RCC) has increased in recent years, which is mainly due to the rise in incidental detection of localized SRMs. However, the cancer-specific mortality rate is not increasing. This discrepancy may be dependent on the indolent nature of SRMs. About 20% of SRMs are benign, and smaller masses are likely to have pathologic characteristics of low Fuhrman grade and clear cell type. In addition, SRMs are increasingly detected in elderly patients who are likely to have comorbidities and are a high-risk group for active treatment like surgery. As the information about the nature of SRMs is improved and management options for SRMs are expanded, the current role of renal mass biopsy for SRMs is also expanding. Traditionally, renal mass biopsy has not been accepted as a standard diagnostic tool in the clinical scenario because of several issues about safety and accuracy. However, current series on SRM biopsy have reported high diagnostic accuracy with rare complications. Studies of modern SRM biopsy have reported diagnostic accuracy greater than 90% with very high specificity. Also, current series have shown very rare morbid cases caused by renal mass biopsy. Currently, renal biopsy of SRMs can be recommended in most cases except when patients have imaging or clinical characteristics indicative of pathology and in cases in which conservative management is not considered.

  9. Current Status of Renal Biopsy for Small Renal Masses

    Science.gov (United States)

    Ha, Seung Beom

    2014-01-01

    Small renal masses (SRMs) are defined as radiologically enhancing renal masses of less than 4 cm in maximal diameter. The incidence of renal cell carcinoma (RCC) has increased in recent years, which is mainly due to the rise in incidental detection of localized SRMs. However, the cancer-specific mortality rate is not increasing. This discrepancy may be dependent on the indolent nature of SRMs. About 20% of SRMs are benign, and smaller masses are likely to have pathologic characteristics of low Fuhrman grade and clear cell type. In addition, SRMs are increasingly detected in elderly patients who are likely to have comorbidities and are a high-risk group for active treatment like surgery. As the information about the nature of SRMs is improved and management options for SRMs are expanded, the current role of renal mass biopsy for SRMs is also expanding. Traditionally, renal mass biopsy has not been accepted as a standard diagnostic tool in the clinical scenario because of several issues about safety and accuracy. However, current series on SRM biopsy have reported high diagnostic accuracy with rare complications. Studies of modern SRM biopsy have reported diagnostic accuracy greater than 90% with very high specificity. Also, current series have shown very rare morbid cases caused by renal mass biopsy. Currently, renal biopsy of SRMs can be recommended in most cases except when patients have imaging or clinical characteristics indicative of pathology and in cases in which conservative management is not considered. PMID:25237457

  10. Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells.

    Science.gov (United States)

    Yuan, Zhi-Xiang; Mo, Jingxin; Zhao, Guixian; Shu, Gang; Fu, Hua-Lin; Zhao, Wei

    2016-01-01

    Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rationale for therapies targeting this aggressive cell population. Precise identification of renal CSC populations and the complete cell hierarchy will accurately inform characterization of disease subtypes. This will ultimately contribute to more personalized and targeted therapies. Here, we summarize potential targeting strategies for renal cancer cells and renal CSCs, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors (mTOR), interleukins, CSC marker inhibitors, bone morphogenetic protein-2, antibody drug conjugates, and nanomedicine. In conclusion, targeting therapies for RCC represent new directions for exploration and clinical investigation and they plant a seed of hope for advanced clinical care.

  11. Spontaneous renal artery dissection complicating with renal infarction.

    Science.gov (United States)

    Tsai, Tsung-Han; Su, Jung-Tsung; Hu, Sung-Yuan; Chao, Chih-Chung; Tsan, Yu-Tse; Lin, Tzu-Chieh

    2010-12-01

    Spontaneous renal artery dissection (SRAD) is a rare entity. We reported a 30-year-old healthy man presenting with sudden onset of left flank pain. Abdominal plain film and sonography were unremarkable. The contrast-enhanced abdominal computed tomographic (CT) scan demonstrated a dissecting intimal flap of the left distal renal artery (RA) complicating infarction. Selective angiography of the renal artery disclosed a long dissection of left distal RA with a patent true lumen and occlusion of left accessory RA. Conservative treatment with control of blood pressure and antiplatelet agent was prescribed. The patient was discharged with an uneventful condition on day 5.

  12. Renal histology and immunopathology in distal renal tubular acidosis.

    Science.gov (United States)

    Feest, T G; Lockwood, C M; Morley, A R; Uff, J S

    1978-11-01

    Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

  13. Effects of supplemental recombinant bovine somatotropin and mist-fan cooling on the renal tubular handling of sodium in different stages of lactation in crossbred Holstein cattle.

    Science.gov (United States)

    Boonsanit, Dolrudee; Chanpongsang, Somchai; Chaiyabutr, Narongsak

    2012-08-01

    The effect of supplementary administration of recombinant bovine somatotrophin (rbST) on the renal tubular handling of sodium in crossbred 87.5% Holstein cattle housed in normal shade (NS) or mist-fan cooled (MF) barns was evaluated. The cows were injected with 500 mg rbST at three different stages of lactation. The MF barn housed cows showed a slightly decreased ambient temperature and temperature humidity index, but an increased relative humidity. Rectal temperature and respiration rates were significantly lower in cooled cows. The rbST treated cows, housed in NS or MF barns, showed markedly increased milk yields, total body water, extracellular fluid and plasma volume levels, along with a reduced rate of urine flow and urinary excretion of sodium, potassium and chloride ions and osmolar clearance, in all three stages of lactation. Renal tubular sodium and water reabsorption were increased after rbST administration without any alteration in the renal hemodynamics. Lithium clearance data suggested that the site of response is in the proximal nephron segment, which may be mediated via increases in the plasma levels of aldosterone and IGF-1, but not vasopressin, during rbST administration.

  14. Building Partner Capacity

    Science.gov (United States)

    2015-02-01

    In a similar manner, globalization has also created new realities, such as in the case of food production where choice now affects demand as much as...quantity did in the past. “Two major factors drive food requirements [and market prices]: a growing global population and prosperity that expands...argued earlier, to expend effort in other nations without consideration of building capacity and resiliency risks strategic failure and wastage of

  15. Markets and Institutional Capacity

    DEFF Research Database (Denmark)

    Ingemann, Jan Holm

    2010-01-01

    Adequate explanations concerning the introduction of production and consumption of organic food in Denmark imply the necessity to engage a certain understanding of markets. Markets should subsequently not be seen as entities nor places but as complex relations between human actors. Further, the e......, the establishment, maintenance and development of markets are depending on the capacity of the actors to enter into continuous and enhancing interplay....

  16. Renal involvement in antiphospholipid syndrome.

    Science.gov (United States)

    Sciascia, Savino; Cuadrado, Maria José; Khamashta, Munther; Roccatello, Dario

    2014-05-01

    Antiphospholipid syndrome (APS) is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for antiphospholipid antibodies (aPLs). APS can be isolated (known as primary APS) or associated with other autoimmune diseases, such as systemic lupus erythematosus (SLE; known as secondary APS). The kidney is a major target organ in APS and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal arteries, glomerular capillaries and renal veins); events reflect the site and size of the involved vessels. Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal prognosis is affected by the presence of aPLs in patients with lupus nephritis and can be poor. In patients with SLE and aPLs, biopsy should be performed because inflammatory and thrombotic lesions require different therapeutic approaches. Renal involvement in patients with definite APS is treated by anticoagulation with long-term warfarin. The range of renal manifestations associated with APS is broadening and, therefore, aPLs have increasing relevance in end-stage renal disease, transplantation and pregnancy.

  17. Renal Toxicities of Targeted Therapies.

    Science.gov (United States)

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

    2015-12-01

    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.

  18. Malignancy and chronic renal failure.

    Science.gov (United States)

    Peces, Ramon

    2003-01-01

    Increased incidence of cancer at various sites is observed in patients with end-stage renal disease (ESRD). Certain malignant diseases, such as lymphomas and carcinomas of the kidney, prostate, liver and uterus, show an enhanced prevalence compared with the general population. In particular, renal cell carcinoma (RCC) shows an excess incidence in ESRD patients. A multitude of factors, directly or indirectly associated with the renal disease and the treatment regimens, may contribute to the increased tumor formation in these patients. Patients undergoing renal replacement therapy (RRT) are prone to develop acquired cystic kidney disease (ACKD), which may subsequently lead to the development of RCC. In pre-dialysis patients with coexistent renal disease, as in dialysis and transplant patients, the presence of ACKD may predispose to RCC. Previous use of cytotoxic drugs (eg, cyclophosphamide) or a history of analgesic abuse, are additional risk factors for malignancy. Malignancy following renal transplantation is an important medical problem during the follow-up. The most common malignancies are lymphoproliferative disorders (early after transplantation) and skin carcinomas (late after transplantation). Another important confounder for risk of malignancy after renal transplantation is the type of immunosuppression. The type of malignancy is different in various countries and dependent on genetic and environmental factors. Finally, previous cancer treatment in a uremic patient on the transplant waiting list is of great importance in relation to waiting time and post-malignancy screening.

  19. Wegener's granulomatosis with renal involvement: patient survival and correlations between initial renal function, renal histology, therapy and renal outcome.

    Science.gov (United States)

    Andrassy, K; Erb, A; Koderisch, J; Waldherr, R; Ritz, E

    1991-04-01

    Patient survival and renal outcome were followed in 25 patients with biopsy confirmed Wegener's granulomatosis and renal involvement. Fourteen out of 25 patients required dialysis on admission, 11/25 patients did not. All patients were treated with a novel protocol comprising methylprednisolone and cyclophosphamide. The median follow-up observation was 36 months (12-113 months). With the exception of 1 patient (who died from causes not related to Wegener's granulomatosis) all patients are alive. Among the patients initially requiring dialysis (n = 14) 4 are in terminal renal failure after 0, 7, 21 and 38 months respectively. In the nondialysis group (n = 11) only 1 patient subsequently required chronic dialysis 30 months after clinical admission. Renal failure was due to non-compliance with immunosuppressive therapy in at least 2 patients. Percentage of obsolescent glomeruli and the degree of tubulointerstitial lesions, but not active glomerular lesions (crescents, necroses) predicted renal outcome. The major cause of renal functional impairment was relapse of Wegener's granulomatosis usually within 2 years after clinical remission. Therefore prolonged treatment with cyclophosphamide for at least 2 years after clinical remission is recommended. Two patients with initially negative immunohistology had a second renal biopsy which revealed de novo appearance of mesangial IgA deposits.

  20. Hyperparathyroidism of Renal Disease

    Science.gov (United States)

    Yuen, Noah K; Ananthakrishnan, Shubha; Campbell, Michael J

    2016-01-01

    Renal hyperparathyroidism (rHPT) is a common complication of chronic kidney disease characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Patients with rHPT experience increased rates of cardiovascular problems and bone disease. The Kidney Disease: Improving Global Outcomes guidelines recommend that screening and management of rHPT be initiated for all patients with chronic kidney disease stage 3 (estimated glomerular filtration rate, < 60 mL/min/1.73 m2). Since the 1990s, improving medical management with vitamin D analogs, phosphate binders, and calcimimetic drugs has expanded the treatment options for patients with rHPT, but some patients still require a parathyroidectomy to mitigate the sequelae of this challenging disease. PMID:27479950

  1. Citrato y litiasis renal

    OpenAIRE

    2013-01-01

    El citrato es un potente inhibidor de la cristalización de sales de calcio. La hipocitraturia es una alteración bioquímica frecuente en la formación de cálculos de calcio en adultos y especialmente en niños. El pH ácido (sistémico, tubular e intracelular) es el principal determinante de la excreción de citrato en la orina. Si bien la mayoría de los pacientes con litiasis renal presentan hipocitraturia idiopática, hay un número de causas para esta anormalidad que incluyen acidosis tubular rena...

  2. Angio-embolization of a renal pseudoaneurysm complicating a percutaneous renal biopsy: a case report.

    Science.gov (United States)

    Rafik, Hicham; Azizi, Mounia; El Kabbaj, Driss; Benyahia, Mohammed

    2015-01-01

    We report the treatment of a bleeding renal pseudoaneurysm by angio-embolization. A 21 years old woman developed macroscopic haematuria following renal biopsy. Renal angio-scan showed a 1.4 cm renal pseudoaneurysm in the left kidney. The presence of pseudoaneurysm was confirmed by selective renal angiography. Successful embolization was performed using gelatine sponge particles.

  3. Successful management of neonatal renal venous thrombosis.

    Science.gov (United States)

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

    2014-10-01

    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.

  4. Diagnosis and treatment of renal artery stenosis.

    NARCIS (Netherlands)

    Plouin, P.F.; Bax, L.

    2010-01-01

    A reduction in the diameter of the renal arteries can lead to hypertension, renal dysfunction and/or pulmonary edema. About 90% of patients with renal artery stenosis have atherosclerosis, and 10% have fibromuscular dysplasia. Atherosclerotic renal artery stenosis is a common condition that typicall

  5. Renal acidification defects in medullary sponge kidney

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1988-01-01

    patients had some form of renal acidification defect; 8 had the distal type of renal tubular acidosis, 2 the complete and 6 the incomplete form. One patient had proximal renal tubular acidosis. These findings, which suggest that renal acidification defects play an important role in the pathogenesis...

  6. Renal allograft rejection. Unusual scintigraphic findings

    Energy Technology Data Exchange (ETDEWEB)

    Desai, A.G.; Park, C.H.

    1986-11-01

    During sequential renal imagining for evaluation of clinically suspected rejection, focal areas of functioning renal tissue were seen in two cases of renal transplant in the midst of severe and irreversible renal allograft rejection. A probable explanation for this histopathologically confirmed and previously unreported finding is discussed.

  7. Competence building capacity shortage

    Energy Technology Data Exchange (ETDEWEB)

    Doorman, Gerard; Wangensteen, Ivar; Bakken, Bjoern

    2005-02-01

    The objective of the project 'Competence Building Capacity Shortage' has been 'to increase knowledge about central approaches aimed at solving the peaking capacity problem in restructured power systems'. With respect to reserve markets, a model was developed in the project to analyze the relations between reserve requirements and prices in the spot and reserve markets respectively. A mathematical model was also developed and implemented, which also includes the balance market, and has a good ability to predict the relations between these markets under various assumptions. With some further development, this model can be used fore realistic analyses of these markets in a Nordic context. It was also concluded that certain system requirements with respect to frequency and time deviation can be relaxed without adverse effects. However, the requirements to system bias, Frequency Activated Operating Reserves and Frequency Activated Contingency Reserves cannot be relaxed, the latter because they must cover the dimensioning fault in the system. On the other hand, Fast Contingency Reserves can be reduced by removing requirements to national balances. Costs can furthermore be reduced by increasingly adapting a Nordic as opposed to national approach. A model for stepwise power flow was developed in the project, which is especially useful to analyze slow power system dynamics. This is relevant when analysing the effects of reserve requirements. A model for the analysis of the capacity balance in Norway and Sweden was also developed. This model is useful for looking at the future balance under various assumptions regarding e.g. weather conditions, demand growth and the development of the generation system. With respect to the present situation, if there is some price flexibility on the demand side and system operators are able to use reserves from the demand side, the probability for load shedding during the peak load hour is close to zero under the weather

  8. Renal rickets-practical approach

    Directory of Open Access Journals (Sweden)

    Manisha Sahay

    2013-01-01

    Full Text Available Rickets/osteomalacia is an important problem in a tropical country. Many cases are due to poor vitamin D intake or calcium deficient diets and can be corrected by administration of calcium and vitamin D. However, some cases are refractory to vitamin D therapy and are related to renal defects. These include rickets of renal tubular acidosis (RTA, hypophosphatemic rickets, and vitamin D dependent rickets (VDDR. The latter is due to impaired action of 1α-hydroxylase in renal tubule. These varieties need proper diagnosis and specific treatment.

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

    Directory of Open Access Journals (Sweden)

    G.V. Soundra Pandyan

    2006-01-01

    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.

  10. Renal function, aldosterone, and vasopressin excretion following repeated long-distance running.

    Science.gov (United States)

    Wade, C E; Dressendorfer, R H; O'Brien, J C; Claybaugh, J R

    1981-04-01

    Renal and endocrine responses were studied in 10 male runners during a 20-day 500-km race. Overnight urine and prerun blood samples were taken prior to running on days 1, 2, 5, 8, 14, 17, and 20. Day 13 followed 70 h of rest. Urine flow rate, osmotic clearance, tubular free water reabsorption, urinary vasopressin excretion rate, and body weight were not significantly changed. Creatinine clearance was constant except for an elevation on day 5. Plasma osmolality was elevated on days 2, 14, and 17. Plasma sodium was increased (P less than 0.05) on days 2 and 13 but reduced on day 20. The percentage of filtered sodium excreted was significantly reduced on all nights following running and elevated on recovery day 13. Urinary aldosterone excretion rate was significantly elevated 162, 117, and 97% on days 5, 8, and 20 and returned to control levels on day 13 after 70 h of rest. These data suggest that in response to repeated long-distance running normal fluid balance is regained within 12 h. However, it is necessary to conserve sodium for at least 24 h after exercise as evidenced by the decrease in the percent filtered sodium excreted and continued elevation of aldosterone excretion.

  11. Management of renal disease in pregnancy.

    Science.gov (United States)

    Podymow, Tiina; August, Phyllis; Akbari, Ayub

    2010-06-01

    Although renal disease in pregnancy is uncommon, it poses considerable risk to maternal and fetal health. This article discusses renal physiology and assessment of renal function in pregnancy and the effect of pregnancy on renal disease in patients with diabetes, lupus, chronic glomerulonephritis, polycystic kidney disease, and chronic pyelonephritis. Renal diseases occasionally present for the first time in pregnancy, and diagnoses of glomerulonephritis, acute tubular necrosis, hemolytic uremic syndrome, and acute fatty liver of pregnancy are described. Finally, therapy of end-stage renal disease in pregnancy, dialysis, and renal transplantation are reviewed.

  12. Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Zhenzhen Qiu

    2017-01-01

    Full Text Available Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients’ health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits.

  13. Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis.

    Science.gov (United States)

    Qiu, Zhenzhen; Zheng, Kai; Zhang, Haoxiang; Feng, Ji; Wang, Lizhi; Zhou, Hao

    2017-01-01

    Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits.

  14. [Spontaneous renal artery dissection with renal infarction: a case report].

    Science.gov (United States)

    Oki, Takashi; Adachi, Hiroyuki; Tahara, Hideo; Kino, Sigeo

    2011-11-01

    A 58-year-old woman visited our hospital with nausea and right flank pain. At first abdominal ultrasonography was performed, suggesting a right renal infarction. Computed tomography (CT) study of the abdomen with intravenous contrast was performed to determine the cause of the symptoms. The scan revealed poor enhancement in the lower half of the right kidney. She was diagnosed with a right renal infarction. She was initially treated with anticoagulant therapy, but 5 days later, she complained of nausea. This time, CT demonstrated exacerbation of a right renal infarction with renal artery dissection. Based on this finding, we performed a right nephrectomy. The result of pathology was segmental arterial mediolysis. She was discharged 12 days after the surgery and is doing well at 6 months after discharge. Spontaneous renal artery dissection is a rare disease. It constitutes approximately 0.05% of arteriographic dissections. In addition, spontaneous renal artery dissection shows nonspecific symptoms. Together, these two factors may cause a delay in diagnosis.

  15. An unusual cause of acute renal failure: renal lymphoma.

    Science.gov (United States)

    Ozaltin, Fatih; Yalçin, Bilgehan; Orhan, Diclehan; Sari, Neriman; Caglar, Melda; Besbas, Nesrin; Bakkaloglu, Aysin

    2004-08-01

    Renal involvement is a common finding in non-Hodgkin's lymphoma (NHL). Acute renal failure at initial presentation due to lymphomatous infiltration of the kidneys has been described infrequently. We report a 17-year-old male who presented with acute renal failure due to massive lymphomatous infiltration of the kidneys, which necessitated hemodialysis. The diagnosis of B-cell NHL was established by tru-cut biopsy of the kidneys and the patient had an excellent response to high-dose chemotherapy with no major complication. The presence of extrarenal involvement in the testes and the retroperitoneal lymph nodes made the diagnosis of primary renal lymphoma debatable. However, considering the delay in diagnosis and the high proliferative rate of B-cell NHL, we might postulate that the disease had originated primarily in the kidneys. We recommend that in NHL cases with severe renal involvement, full-dose chemotherapy should be instituted with meticulous clinical and laboratory follow-up in order to improve clinical and renal failure status rapidly and to avoid further dissemination of NHL.

  16. Physiologically based pharmacokinetic-pharmacodynamic modeling to predict concentrations and actions of sodium-dependent glucose transporter 2 inhibitor canagliflozin in human intestines and renal tubules.

    Science.gov (United States)

    Mori, Kazumi; Saito, Ryuta; Nakamaru, Yoshinobu; Shimizu, Makiko; Yamazaki, Hiroshi

    2016-11-01

    Canagliflozin is a recently developed sodium-glucose cotransporter (SGLT) 2 inhibitor that promotes renal glucose excretion and is considered to inhibit renal SGLT2 from the luminal side of proximal tubules. Canagliflozin reportedly inhibits SGLT1 weakly and suppresses postprandial plasma glucose, suggesting that it also inhibits intestinal SGLT1. However, it is difficult to measure the drug concentrations of these assumed sites of action directly. The pharmacokinetic-pharmacodynamic (PK/PD) relationships of canagliflozin remain poorly characterized. Therefore, a physiologically based pharmacokinetic (PBPK) model of canagliflozin was developed based on clinical data from healthy volunteers and it was used to simulate luminal concentrations in intestines and renal tubules. In small intestine simulations, the inhibition ratios for SGLT1 were predicted to be 40%-60% after the oral administration of clinical doses (100-300 mg/day). In contrast, inhibition ratios of canagliflozin for renal SGLT2 and SGLT1 were predicted to be approximately 100% and 0.2%-0.4%, respectively. These analyses suggest that canagliflozin only inhibits SGLT2 in the kidney. Using the simulated proximal tubule luminal concentrations of canagliflozin, the urinary glucose excretion rates in canagliflozin-treated diabetic patients were accurately predicted using the renal glucose reabsorption model as a PD model. Because the simulation of canagliflozin pharmacokinetics was successful, this PBPK methodology was further validated by successfully simulating the pharmacokinetics of dapagliflozin, another SGLT2 inhibitor. The present results suggest the utility of this PBPK/PD model for predicting canagliflozin concentrations at target sites and help to elucidate the pharmacological effects of SGLT1/2 inhibition in humans. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Early and late renal adverse effects after potentially nephrotoxic treatment for childhood cancer.

    Science.gov (United States)

    Knijnenburg, Sebastiaan L; Mulder, Renée L; Schouten-Van Meeteren, Antoinette Y N; Bökenkamp, Arend; Blufpand, Hester; van Dulmen-den Broeder, Eline; Veening, Margreet A; Kremer, Leontien C M; Jaspers, Monique W M

    2013-10-08

    analysis. The prevalence of impairment of tubular phosphate reabsorption was mostly higher (range 0% to 62.5%; 11/57 studies). Higher cumulative ifosfamide dose, concomitant cisplatin treatment, nephrectomy and longer follow-up duration were significant risk factors for impaired tubular phosphate reabsorption in multivariate analyses.Treatment with cisplatin and carboplatin was associated with a significantly lower serum magnesium level in multivariate analysis, and the prevalence of hypomagnesaemia ranged between 0% and 37.5% in the eight studies investigating serum magnesium.Hypertension was investigated in 24 of the 57 studies. Reported prevalences ranged from 0% to 18.2%. A higher body mass index was the only significant risk factor noted in more than one multivariate analysis. Other reported factors that significantly increased the risk of hypertension were use of total body irradiation, abdominal irradiation, acute kidney injury, unrelated or autologous stem cell donor type, growth hormone therapy and older age at screening. Previous infection with hepatitis C significantly decreased the risk of hypertension.Because of the profound heterogeneity of the studies, it was not possible to perform any meta-analysis. The prevalence of renal adverse events after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region and/or nephrectomy ranged from 0% to 84%. With currently available evidence, it was not possible to draw any conclusions with regard to prevalence of and risk factors for renal adverse effects. Future studies should focus on adequate study design and reporting and should deploy multivariate risk factor analysis to correct for possible confounding. Until more evidence becomes available, CCS should be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

  18. Hyporeninemic hypoaldosteronism in diabetic patients with chronic renal failure.

    Science.gov (United States)

    Grande Villoria, J; Macias Nunez, J F; Miralles, J M; De Castro del Pozo, S; Tabernero Romo, J M

    1988-01-01

    Plasma renin activity, plasma aldosterone levels and renal tubular capacity to excrete hydrogen ions were studied in 13 patients suffering from diabetes mellitus with a creatinine clearance of less than 40 ml/min. The results were compared with those obtained in a control group, in a group of nondiabetic subjects with chronic renal failure (CRF) and in a group of diabetic patients without CRF. Twelve of the thirteen diabetic patients with CRF had data characteristic of hyporeninemic hypoaldosteronism associated with type IV renal tubular acidosis. On comparing the results with those of the other two groups of patients, it was observed that the manifestations of the latter two groups considered separately were different from those of the problem group, although in the diabetic patients with normal glomerular filtration rate (GFR) hyporeninism but not hypoaldosteronism was present accompanied by a lower net acid excretion (p less than 0.001) due to a lower excretion of NH4 (p less than 0.05) and titratable acid (p less than 0.001) when the patients were challenged with an NH4Cl overload. We believe that a conjunction of diabetes and renal failure is necessary for the diabetic patients with a decrease in GFR to show hyporeninemic hypoaldosteronism and type IV tubular acidosis.

  19. Quantum reading capacity

    Science.gov (United States)

    Pirandola, Stefano; Lupo, Cosmo; Giovannetti, Vittorio; Mancini, Stefano; Braunstein, Samuel L.

    2011-11-01

    The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory (Pirandola 2011 Phys. Rev. Lett. 106 090504). In the case of optical memories, such as CDs and DVDs, this discrimination involves lossy bosonic channels and can be remarkably boosted by the use of nonclassical light (quantum reading). Here we generalize these concepts by extending the model of memory from single-cell to multi-cell encoding. In general, information is stored in a block of cells by using a channel-codeword, i.e. a sequence of channels chosen according to a classical code. Correspondingly, the readout of data is realized by a process of ‘parallel’ channel discrimination, where the entire block of cells is probed simultaneously and decoded via an optimal collective measurement. In the limit of a large block we define the quantum reading capacity of the memory, quantifying the maximum number of readable bits per cell. This notion of capacity is nontrivial when we suitably constrain the physical resources of the decoder. For optical memories (encoding bosonic channels), such a constraint is energetic and corresponds to fixing the mean total number of photons per cell. In this case, we are able to prove a separation between the quantum reading capacity and the maximum information rate achievable by classical transmitters, i.e. arbitrary classical mixtures of coherent states. In fact, we can easily construct nonclassical transmitters that are able to outperform any classical transmitter, thus showing that the advantages of quantum reading persist in the optimal multi-cell scenario.

  20. Enhancing human capacities

    CERN Document Server

    Savulescu, Julian; Kahane, Guy

    2011-01-01

    Enhancing Human Capacities is the first to review the very latest scientific developments in human enhancement. It is unique in its examination of the ethical and policy implications of these technologies from a broad range of perspectives. Presents a rich range of perspectives on enhancement from world leading ethicists and scientists from Europe and North America The most comprehensive volume yet on the science and ethics of human enhancement Unique in providing a detailed overview of current and expected scientific advances in this area Discusses both general conceptual and ethical issues

  1. Stages of Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  2. Renal Disease and Adult Vaccination

    Science.gov (United States)

    ... Resources for Healthcare Professionals Renal Disease and Adult Vaccination Recommend on Facebook Tweet Share Compartir Vaccines are ... have immunity to this disease Learn about adult vaccination and other health conditions Asplenia Diabetes Type 1 ...

  3. Renal infarction complicating fibromuscular dysplasia.

    Science.gov (United States)

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

    2014-01-01

    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. Drugs in pregnancy. Renal disease.

    Science.gov (United States)

    Marsh, J E; Maclean, D; Pattison, J M

    2001-12-01

    The management of pregnant women with renal impairment presents a major challenge to obstetricians, nephrologists, and ultimately paediatricians. As renal failure progresses there is an increase in both maternal and fetal complications. Often these women have intercurrent medical conditions and, prior to conception, are receiving a broad range of prescribed medications. A successful obstetric outcome relies upon careful pre-pregnancy counselling and planning, obsessive monitoring during pregnancy, and close liaison between different specialist teams. Experience is mounting in the management of pregnant transplant recipients, but the introduction of newer immunosuppressive agents which have great promise in prolonging graft survival present new problems for those recipients of a kidney transplant who are planning to conceive. We review drug prescription for pregnant patients with renal impairment, end-stage renal failure, or a kidney transplant.

  5. Transcatheter embolisation of renal angiomyolipoma.

    LENUS (Irish Health Repository)

    Leong, S

    2010-06-01

    Angiomyolipomas (AML) are rare benign renal tumours which are associated with aneurysms that can cause haemorrhage. Embolisation of AML greater than 4 cm with a variety of embolic agents is now the first-line treatment in these cases.

  6. Cryoablation for Small Renal Masses

    Directory of Open Access Journals (Sweden)

    J. L. Dominguez-Escrig

    2008-01-01

    Full Text Available Advances in imaging techniques (CT and MRI and widespread use of imaging especially ultrasound scanning have resulted in a dramatic increase in the detection of small renal masses. While open partial nephrectomy is still the reference standard for the management of these small renal masses, its associated morbidity has encouraged clinicians to exploit the advancements in minimally invasive ablative techniques. The last decade has seen the rapid development of laparoscopic partial nephrectomy and novel ablative techniques such as, radiofrequency ablation (RFA, high-intensity focused ultrasound (HIFU, and cryoablation (CA. In particular, CA for small renal masses has gained popularity as it combines nephron-sparing surgery with a minimally invasive approach. Studies with up to 5-year followup have shown an overall and cancer-specific 5-year survival of 82% and 100%, respectively. This manuscript will focus on the principles and clinical applications of cryoablation of small renal masses, with detailed review of relevant literature.

  7. Renal replacement therapy in Europe

    DEFF Research Database (Denmark)

    Noordzij, Marlies; Kramer, Anneke; Abad Diez, José M

    2014-01-01

    BACKGROUND: This article provides a summary of the 2011 ERA-EDTA Registry Annual Report (available at www.era-edta-reg.org). METHODS: Data on renal replacement therapy (RRT) for end-stage renal disease (ESRD) from national and regional renal registries in 30 countries in Europe and bordering the .......6-47.0], and on dialysis 39.3% (95% CI 39.2-39.4). The unadjusted 5-year patient survival after the first renal transplantation performed between 2002 and 2006 was 86.7% (95% CI 86.2-87.2) for kidneys from deceased donors and 94.3% (95% CI 93.6-95.0) for kidneys from living donors....

  8. Pregnancy in renal transplant recipients.

    Science.gov (United States)

    Fuchs, Karin M; Wu, Danny; Ebcioglu, Zeynep

    2007-12-01

    Women with renal disease face increasing infertility and high-risk pregnancy as they approach end-stage renal disease due to uremia. Renal transplantation has provided these patients the ability to return to a better quality of life, and for a number of women who are of child bearing age with renal disease, it has restored their fertility and provided the opportunity to have children. But, although fertility is restored, pregnancy in these women still harbors risk to the mother, graft, and fetus. Selected patients who have stable graft function can have successful pregnancies under the supervision of a multidisciplinary team involving maternal fetal medicine specialists and transplant nephrologists. Careful observation and management are required to optimize outcome for mother and fetus.

  9. Antibiotic managment in renal failure.

    Science.gov (United States)

    Winter, R E

    1976-06-01

    This is a brief compilation of the work of many investigators. It includes facts about toxicity and recommendations about antibiotic management in patients with renal failure. As new data are accrued, changes in these recommendations will be necessary.

  10. Mucormycosis (zygomycosis) of renal allograft.

    Science.gov (United States)

    Gupta, Krishan L; Joshi, Kusum; Kohli, Harbir S; Jha, Vivekanand; Sakhuja, Vinay

    2012-12-01

    Fungal infection is relatively common among renal transplant recipients from developing countries. Mucormycosis, also known as zygomycosis, is one of the most serious fungal infections in these patients. The most common of presentation is rhino-cerebral. Isolated involvement of a renal allograft is very rare. A thorough search of literature and our medical records yielded a total of 24 cases with mucormycosis of the transplanted kidney. There was an association with cytomegalovirus (CMV) infection and anti-rejection treatment in these patients and most of these transplants were performed in the developing countries from unrelated donors. The outcome was very poor with an early mortality in 13 (54.5%) patients. Renal allograft mucormycosis is a relatively rare and potentially fatal complication following renal transplantation. Early diagnosis, graft nephrectomy and appropriate antifungal therapy may result in an improved prognosis for these patients.

  11. Functional and histopathological changes in dog kidneys after administration of cisplatin

    DEFF Research Database (Denmark)

    Daugaard, G; Abildgaard, U; Larsen, S

    1987-01-01

    significantly from 3.9 +/- 0.2 to 11.7 +/- 1.4 mmol/l and 96 +/- 3 to 178 +/- 10 mumol/l, respectively. Mean values of renal blood flow, glomerular filtration rate, filtration fraction and lithium clearance in cisplatin-treated animals (143 +/- 14 ml/min, 10.7 +/- 1.1. ml/min, 0.14 +/- 0.01 and 6.3 +/- 0.6 ml...... tubular reabsorptive capacities associated with increased renal vascular resistance. The polyuria seems to be due to impaired reabsorption rates in the distal nephron segments, which will affect the concentration mechanism....

  12. Acute renal dysfunction in liver diseases

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    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.

  13. Renal plasticity in response to feeding in the Burmese python, Python molurus bivittatus.

    Science.gov (United States)

    Esbaugh, A J; Secor, S M; Grosell, M

    2015-10-01

    Burmese pythons are sit-and-wait predators that are well adapted to go long periods without food, yet subsequently consume and digest single meals that can exceed their body weight. These large feeding events result in a dramatic alkaline tide that is compensated by a hypoventilatory response that normalizes plasma pH; however, little is known regarding how plasma HCO3(-) is lowered in the days post-feeding. The current study demonstrated that Burmese pythons contain the cellular machinery for renal acid-base compensation and actively remodel the kidney to limit HCO3(-) reabsorption in the post-feeding period. After being fed a 25% body weight meal plasma total CO2 was elevated by 1.5-fold after 1 day, but returned to control concentrations by 4 days post-feeding (d pf). Gene expression analysis was used to verify the presence of carbonic anhydrase (CA) II, IV and XIII, Na(+) H(+) exchanger 3 (NHE3), the Na(+) HCO3(-) co-transporter (NBC) and V-type ATPase. CA IV expression was significantly down-regulated at 3 dpf versus fasted controls. This was supported by activity analysis that showed a significant decrease in the amount of GPI-linked CA activity in isolated kidney membranes at 3 dpf versus fasted controls. In addition, V-type ATPase activity was significantly up-regulated at 3 dpf; no change in gene expression was observed. Both CA II and NHE3 expression was up-regulated at 3 dpf, which may be related to post-prandial ion balance. These results suggest that Burmese pythons actively remodel their kidney after feeding, which would in part benefit renal HCO3(-) clearance.

  14. The potential role of regucalcin in kidney cell regulation: Involvement in renal failure (Review).

    Science.gov (United States)

    Yamaguchi, Masayoshi

    2015-11-01

    The kidneys play a physiologic role in the regulation of urine formation and nutrient reabsorption in the proximal tubule epithelial cells. Kidney development has been shown to be regulated through calcium (Ca2+) signaling processes that are present through numerous steps of tubulogenesis and nephron induction during embryonic development of the kidneys. Ca2+-binding proteins, such as calbindin-D28k and regucalcin are important proteins that are commonly used as biomarkers in pronephric tubules, and the ureteric bud and metanephric mesenchyme. Previous research on regucalcin focused on Ca2+ sensors that are involved in renal organogenesis and the link between Ca2+-dependent signals and polycystins. Moreover, regucalcin has been highlighted to play a multifunctional role in kidney cell regulation. The regucalcin gene, which is localized on the X chromosome, is regulated through various transcription factors. Regucalcin has been found to regulate intracellular Ca2+ homeostasis in kidney proximal tubule epithelial cells. Regucalcin has been demonstrated to regulate the activity of various enzymes that are involved in intracellular signaling pathways. It has been noted that regucalcin suppresses DNA synthesis and regulates the gene expression of various proteins related to mineral transport, transcription factors, cell proliferation and apoptosis. The overexpression of regucalcin has been shown to exert suppressive effects on cell proliferation and apoptotic cell death, which are stimulated by various stimulatory factors. Moreover, regucalcin gene expression was found to to be involved in various pathophysiological states, including renal failure. This review discusses recent findings concerning the potential role of regucalcin as a regulatory protein in the kidney proximal tubule epithelial cells.

  15. Determinations of renal cortical and medullary oxygenation using BOLD Magnetic Resonance Imaging and selective diuretics

    Science.gov (United States)

    Warner, Lizette; Glockner, James F.; Woollard, John; Textor, Stephen C.; Romero, Juan C.; Lerman, Lilach O.

    2010-01-01

    Objective This study was undertaken to test the hypothesis that blood O2 level dependent magnetic resonance imaging (BOLD MRI) can detect changes in cortical proximal tubule (PT) and medullary thick ascending limb of Henle (TAL) oxygenation consequent to successive administration of furosemide and acetazolamide (Az). Assessment of PT and TAL function could be useful to monitor renal disease states in vivo. Therefore, the adjunct use of diuretics that inhibit Na+ reabsorption selectively in PT and TAL, Az and furosemide, respectively, may help discern tubular function by using BOLD MRI to detect changes in tissue oxygenation. Material and Methods BOLD MRI signal R2* (inversely related to oxygenation) and tissue oxygenation with intrarenal O2 probes were measured in pigs that received either furosemide (0.5mg/kg) or Az (15mg/kg) alone, Az sequentially after furosemide (n=6 each, 15-minute intervals), or only saline vehicle (n=3). Results R2* decreased in the cortex of Az-treated and medulla of furosemide-treated kidneys, corresponding to an increase in their tissue O2 assessed with probes. However, BOLD MRI also showed decreased cortical R2* following furosemide that was additive to the Az-induced decrease. Az administration, both alone and after furosemide, also decreased renal blood flow (−26±3.5 and −29.2±3%, respectively, p<0.01). Conclusion These results suggest that an increase in medullary and cortical tissue O2 elicited by selective diuretics is detectable by BOLD MRI, but may be complicated by hemodynamic effects of the drugs. Therefore, the BOLD MRI signal may reflect functional changes additional to oxygenation, and needs to be interpreted cautiously. PMID:20856128

  16. Renal and systemic acid-base effects of chronic dichloroacetate administration in dogs.

    Science.gov (United States)

    Hulter, H N; Glynn, R D; Sebastian, A

    1980-10-01

    Dichloroacetate (DCA) increases metabolic disposal of lactic acid secondary to activation of pyruvate dehydrogenase and consequent acceleration of pyruvate oxidation. DCA has thus been proposed as a therapeutic agent for clinical states of lactic acidosis. Yet, DCA has a potential metabolic acidosis-producing effect by virtue of reported effects of (A) increasing blood ketoacid concentration, (B) decreasing tubular reabsorption of filtered ketoacid anions, and (C) decreasing renal NH3 production. In the present study chronic administration of DCA, 50 mg/kg p.o. daily for 6-8 days, resulted in a cumulative increase in renal net acid excretion (NAE) (sigma delta NAE, +61 meq, p UpH, +0.18 +/- 0.07, p < 0.05). The increase in NAE was accompanied by a nearly identical increase in urinary anion gap (UAG) (UAG = [NH4+ + Na+ + K+] - [Cl- + HCO3- + HPO4(2-) + H2PO4-]). The increase in UAG was caused by increased urinary total organic anions, accounted for at least in part by a significant increase in urinary acetoacetate. No significant increase in urinary potassium or sodium excretion occurred. A change in plasma acid-base composition occurred that was consistent with a mild respiratory acidosis without associated primary metabolic acidosis or alkalosis. These findings indicate that chronic DCA administration results in (1) increased steady state endogenous noncarbonic organic acid production, and (2) retention of carbonic acid. Further investigation of the potential metabolic and respiratory acidosis-producing effects of DCA is required to determine its clinical efficacy in the treatment of clinical lactic acidosis.

  17. Gastrointestinal and renal responses to variable water intake in whitebellied sunbirds and New Holland honeyeaters.

    Science.gov (United States)

    Purchase, Cromwell; Napier, Kathryn R; Nicolson, Susan W; McWhorter, Todd J; Fleming, Patricia A

    2013-05-01

    Nectarivores face a constant challenge in terms of water balance, experiencing water loading or dehydration when switching between food plants or between feeding and fasting. To understand how whitebellied sunbirds and New Holland honeyeaters meet the challenges of varying preformed water load, we used the elimination of intramuscular-injected [(14)C]-l-glucose and (3)H2O to quantify intestinal and renal water handling on diets varying in sugar concentration. Both sunbirds and honeyeaters showed significant modulation of intestinal water absorption, allowing excess water to be shunted through the intestine when on dilute diets. Despite reducing their fractional water absorption, both species showed linear increases in water flux and fractional body water turnover as water intake increased (both afternoon and morning), suggesting that the modulation of fractional water absorption was not sufficient to completely offset dietary water loads. In both species, glomerular filtration rate was independent of water gain (but was higher for the afternoon), as was renal fractional water reabsorption (measured in the afternoon). During the natural overnight fast, both sunbirds and honeyeaters arrested whole kidney function. Evaporative water loss in sunbirds was variable but correlated with water gain. Both sunbirds and honeyeaters appear to modulate intestinal water absorption as an important component of water regulation to help deal with massive preformed water loads. Shutting down glomerular filtration rate during the overnight fast is another way of saving energy for osmoregulatory function. Birds maintain osmotic balance on diets varying markedly in preformed water load by varying both intestinal water absorption and excretion through the intestine and kidneys.

  18. On renal pathophysiology in preeclampsia

    OpenAIRE

    2014-01-01

    Preeclampsia is a complication of pregnancy which can suddenly change from a relatively mild phenotype into a life-threatening situation. One of the organs that is always involved during preeclampsia is the kidney. The placenta plays an important role in the renal pathophysiology of preeclampsia. The placenta produces excessive amounts of anti-angiogenic factors which are associated with systemic endothelial dysfunction. Although the underlying mechanisms of renal injury during preeclampsia r...

  19. [Heterolateral renal dystopia (2 cases)].

    Science.gov (United States)

    Anastasov, G; Peneva, S; Mushmov, D; Salambashev, L

    1982-01-01

    The authors observed two cases with crossed renal dystopia, to which venous urography, renal scintigraphy, echographic and gamma-chamber investigations were performed. The venous urography, in case of the appropriate symptomatics, is stressed to be able to establish the presence of heterolateral dystopia by as far as the distributional function of the anomaly is concerned--the gamma-chamber investigation is with the highest information value.

  20. [Unusual elements in renal calculi].

    Science.gov (United States)

    Rodríguez-Miñón Cifuentes, J L; Salvador, E; Traba Villameytide, M L

    2006-01-01

    A group of 54 renal calculi were spontaneously passed renal stone after a nephritic colic. Two groups of calculi were found: papillary and non-papillary calculi. All calculi were analyzed by infrared spectroscopy and electronic microscopy scan (EMS) and EDAX. When the stones were analyzed with EDAX, elements such as C, N, O, Na, S, Mg, Al, Si, Cl, K, Ca, Mn, Fe, Ni, Zn were detected. The possible origin of these elements is discussed in this work.