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Sample records for abnormal glomerular filtration

  1. The Glomerular Filtration Barrier: Components and Crosstalk

    PubMed Central

    Menon, Madhav C.; Chuang, Peter Y.; He, Cijiang John

    2012-01-01

    The glomerular filtration barrier is a highly specialized blood filtration interface that displays a high conductance to small and midsized solutes in plasma but retains relative impermeability to macromolecules. Its integrity is maintained by physicochemical and signalling interplay among its three core constituents—the glomerular endothelial cell, the basement membrane and visceral epithelial cell (podocyte). Understanding the pathomechanisms of inherited and acquired human diseases as well as experimental injury models of this barrier have helped to unravel this interdependence. Key among the consequences of interference with the integrity of the glomerular filtration barrier is the appearance of significant amounts of proteins in the urine. Proteinuria correlates with kidney disease progression and cardiovascular mortality. With specific reference to proteinuria in human and animal disease phenotypes, the following review explores the roles of the endothelial cell, glomerular basement membrane, and the podocyte and attempts to highlight examples of essential crosstalk within this barrier. PMID:22934182

  2. Radionuclide measurement of differential glomerular filtration rate

    SciTech Connect

    Powers, T.A.; Stone, W.J.; Grove, R.B.; Plunkett, J.M.; Kadir, S.; Patton, J.A.; Bowen, R.D.

    1981-01-01

    The authors sought to determine whether radionuclides could provide a reasonable estimate of differential renal function in five normal dogs and six dogs with unilateral segmental renal infarction. Glomerular filtration rate (GFR) of each kidney was measured by the standard technique using constant infusions of 99mTc-DTPA, iothalamate, and creatinine following ureteral catheterization. These results were correlated with total GFR estimated by bolus injection of 99mTc-DTPA and analysis of the plasma 99mTc-DTPA disappearance curve obtained by blood sampling. Differential GFR was then calculated by multiplying the total GFR from double exponential analysis of this curve (DTPA2) by each of three measures of differential function. These include the percent differential uptake of 99mTc-DTPA and 99mTc-DMSA in the posterior projection as well as the geometric mean of 99mTc-DMSA uptake. There were good correlations between differential GFR calculated from iothalamate clearances obtained at ureteral catheterization and all noninvasive methods involving radionuclides and DTPA2 (r = 0.85 - 0.99). Single exponential analysis of the 99mTc-DTPA plasma disappearance curve was less satisfactory. The authors suggest that measurement of total and differential GFR calculated from plasma clearance of 99mTc-DTPA and external counting may be a useful method with potential clinical applications.

  3. Estimating Glomerular Filtration Rate in Older People

    PubMed Central

    Fusco, Sergio; Corica, Francesco; Marino, Antonio; Maggio, Marcello; Mari, Vincenzo; Corsonello, Andrea

    2014-01-01

    We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR) in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting. PMID:24772439

  4. Optical, real-time monitoring of the glomerular filtration rate

    NASA Astrophysics Data System (ADS)

    Rabito, Carlos A.; Chen, Yang; Schomacker, Kevin T.; Modell, Mark D.

    2005-10-01

    An easy and accurate assessment of the renal function is a critical requirement for detecting the initial functional decline of the kidney induced by acute or chronic renal disease. A method for measuring the glomerular filtration rate is developed with the accuracy of clearance techniques and the convenience of plasma creatinine. The renal function is measured in rats as the rate of clearance determined from time-resolved transcutaneous fluorescence measurements of a new fluorescent glomerular filtration agent. The agent has a large dose-safety coefficient and the same space distribution and clearance characteristics as iothalamate. This new approach is a convenient and accurate way to perform real-time measurements of the glomerular filtration rate to detect early kidney disease before the renal function becomes severely and irreversibly compromised.

  5. Optimized robust plasma sampling for glomerular filtration rate studies.

    PubMed

    Murray, Anthony W; Gannon, Mark A; Barnfield, Mark C; Waller, Michael L

    2012-09-01

    In the presence of abnormal fluid collection (e.g. ascites), the measurement of glomerular filtration rate (GFR) based on a small number (1-4) of plasma samples fails. This study investigated how a few samples will allow adequate characterization of plasma clearance to give a robust and accurate GFR measurement. A total of 68 nine-sample GFR tests (from 45 oncology patients) with abnormal clearance of a glomerular tracer were audited to develop a Monte Carlo model. This was used to generate 20 000 synthetic but clinically realistic clearance curves, which were sampled at the 10 time points suggested by the British Nuclear Medicine Society. All combinations comprising between four and 10 samples were then used to estimate the area under the clearance curve by nonlinear regression. The audited clinical plasma curves were all well represented pragmatically as biexponential curves. The area under the curve can be well estimated using as few as five judiciously timed samples (5, 10, 15, 90 and 180 min). Several seven-sample schedules (e.g. 5, 10, 15, 60, 90, 180 and 240 min) are tolerant to any one sample being discounted without significant loss of accuracy or precision. A research tool has been developed that can be used to estimate the accuracy and precision of any pattern of plasma sampling in the presence of 'third-space' kinetics. This could also be used clinically to estimate the accuracy and precision of GFR calculated from mistimed or incomplete sets of samples. It has been used to identify optimized plasma sampling schedules for GFR measurement. PMID:22825040

  6. Structural basis for reduced glomerular filtration capacity in nephrotic humans.

    PubMed Central

    Drumond, M C; Kristal, B; Myers, B D; Deen, W M

    1994-01-01

    Previous studies have established that in a variety of human glomerulopathies the reduced glomerular filtration rate (GFR) is due to a marked lowering of the ultrafiltration coefficient (Kf). To identify the factors which lower Kf, we measured the filtering surface area per glomerulus, filtration slit frequency, basement membrane thickness, and GFR and its determinants in patients with minimal change and membraneous nephropathies and in age-matched healthy controls. Overall values of Kf for the two kidneys were calculated from GFR, renal plasma flow rate, systemic colloid osmotic pressure, and three assumed values for the transcapillary pressure difference. "Experimental" values of the glomerular hydraulic permeability (kexp) were then calculated from Kf, glomerular filtering surface area, and estimates of the total number of nephrons of the two kidneys. Independent estimates of the glomerular hydraulic permeability (kmodel) were obtained using a recent mathematical model that is based on analyses of viscous flow through the various structural components of the glomerular capillary wall. Individual values of basement membrane thickness and filtration slit frequency were used as inputs in this model. The results indicate that the reductions of Kf in both nephropathies can be attributed entirely to reduced glomerular hydraulic permeability. The mean values of kexp and kmodel were very similar in both disorders and much smaller in the nephrotic groups than in healthy controls. There was good agreement between kexp and kmodel for any given group of subjects. It was shown that, in both groups of nephrotics, filtration slit frequency was a more important determinant of the water flow resistance than was basement membrane thickness. The decrease in filtration slit frequency observed in both disorders caused the average path length for the filtrate to increase, thereby explaining the decreased hydraulic permeability. Images PMID:8083359

  7. The renal handling of hemoglobin. I. Glomerular filtration.

    PubMed

    Bunn, H F; Esham, W T; Bull, R W

    1969-05-01

    The glomerular filtration of hemoglobin (alpha(2)beta(2)) was studied under conditions in which its dissociation into alphabeta dimers was experimentally altered. Rats receiving hemoglobin treated with the sulfhydryl reagent bis(N-maleimidomethyl) ether (BME) showed a much lower renal excretion and prolonged plasma survival as compared with animals injected with untreated hemoglobin. Plasma disappearance was also prolonged in dogs receiving BME hemoglobin. Gel filtration data indicated that under physiological conditions, BME hemoglobin had impaired subunit dissociation. In addition, BME hemoglobin showed a very high oxygen affinity and a decreased rate of auto-oxidation. Glomerular filtration was enhanced under conditions which favor the dissociation of hemoglobin into dimers. Cat hemoglobin, which forms subunits much more extensively than canine hemoglobin, was excreted more readily by the rat kidney. The renal uptake of (59)Fe hemoglobin injected intra-arterially into rabbits varied inversely with the concentration of the injected dose.

  8. Determinants of glomerular filtration in experimental glomerulonephritis in the rat.

    PubMed Central

    Maddox, D A; Bennett, C M; Deen, W M; Glassock, R J; Knutson, D; Daugharty, T M; Brenner, B M

    1975-01-01

    Pressures and flows were measured in surface glomerular capillaries, efferent arterioles, and proximal tubules of 22 Wistar rats in the early autologous phase of nephrotoxic serum nephritis (NSN). Linear deposits of rabbit and rat IgG and C3 component of complement were demonstrated in glomerular capillary walls by immunofluorescence microscopy. Light microscopy revealed diffuse proliferative glomerulonephritis, and proteinuria was present. Although whole kidney and single nephron glomerular filtration rate (GFR) in NSN (0.8 plus or minus 0.04 SE2 ml/min and 2 plus or minus 2 nl/min, respectively) remained unchanged from values in 16 weight-matched NORMAL HYDROPENIC control rats (0.8 plus or minus 0.08 and 28 plus or minus 2), important alterations in glomerular dynamics were noted. Mean transcapillary hydraulic pressure difference (deltaP) averaged 41 plus or minus 1 mm Hg in NSN versus 32 plus or minus 1 in controls (P LESS THAN 0.005). Oncotic pressures at the afferent (piA) end of the glomerular capillary were similar in both groups ( 16 mm /g) but increased much less by the efferent end (piE) in NSN (to 29 plus or minus 1 mm Hg) than in controls (33 plus or minus 1, P less than 0.025). Hence, equality between deltaP and piE, denoting filtration pressure equilibrium, obtained in control but not in NSN rats. While glomerular plasma flow rate was slightly higher in NSN (88 plus or minus 8 nl/min) than in controls (76 plus or minus 6, P greater than 0.2), the failure to achieve filtration equilibrium in NSN rats was primarily the consequence of a marked fall in the glomerular capillary ultrafiltration coefficient, Kf, to a mean value of 0.03 nl/(s times mm Hg), considerably lower than that found recently for the normal rat, 0.08 nl/(s times mm Hg). Thus, despite extensive glomerular injury, evidenced morphologically and by the low Kf, GFR remained normal. This maintenance of GFR resulted primarily from increases in deltaP, which tended to increase the net driving

  9. Preliminary Findings of Serum Creatinine and Estimated Glomerular Filtration Rate (eGFR) in Adolescents with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Lin, Jin-Ding; Lin, Lan-Ping; Hsieh, Molly; Lin, Pei-Ying

    2010-01-01

    The present study aimed to describe the kidney function profile--serum creatinine and estimated glomerular filtration rate (eGFR), and to examine the relationships of predisposing factors to abnormal serum creatinine in people with intellectual disabilities (ID). Data were collected by a cross-sectional study of 827 aged 15-18 years adolescents…

  10. WT1-Dependent Sulfatase Expression Maintains the Normal Glomerular Filtration Barrier

    PubMed Central

    Schlötzer-Schrehardt, Ursula; Karumanchi, S. Ananth; Shi, Xiaofeng; Zaia, Joseph; Jeruschke, Stefanie; Zhang, Dongsheng; Pavenstaedt, Hermann; Drenckhan, Astrid; Amann, Kerstin; Ng, Carrie; Hartwig, Sunny; Ng, Kar-Hui; Ho, Jacqueline; Kreidberg, Jordan A.; Taglienti, Mary; Royer-Pokora, Brigitte; Ai, Xingbin

    2011-01-01

    Paracrine signaling between podocytes and glomerular endothelial cells through vascular endothelial growth factor A (VEGFA) maintains a functional glomerular filtration barrier. Heparan sulfate proteoglycans (HSPGs), located on the cell surface or in the extracellular matrix, bind signaling molecules such as VEGFA and affect their local concentrations, but whether modulation of these moieties promotes normal crosstalk between podocytes and endothelial cells is unknown. Here, we found that the transcription factor Wilms' Tumor 1 (WT1) modulates VEGFA and FGF2 signaling by increasing the expression of the 6-O-endosulfatases Sulf1 and Sulf2, which remodel the heparan sulfate 6-O-sulfation pattern in the extracellular matrix. Mice deficient in both Sulf1 and Sulf2 developed age-dependent proteinuria as a result of ultrastructural abnormalities in podocytes and endothelial cells, a phenotype similar to that observed in children with WT1 mutations and in Wt1+/− mice. These kidney defects associated with a decreased distribution of VEGFA in the glomerular basement membrane and on endothelial cells. Collectively, these data suggest that WT1-dependent sulfatase expression plays a critical role in maintaining the glomerular filtration barrier by modulating the bioavailability of growth factors, thereby promoting normal crosstalk between podocytes and endothelial cells. PMID:21719793

  11. Effect of angiotensin on glomerular filtration of albumin.

    PubMed

    Eisenbach, G M; Van Liew, J B

    1975-01-01

    Angiotensin-induced proteinuria was examined at the glomerular-tubular level in rats. Ultra-micro-disc electrophoresis was employed to determine albumin concentration of rat proximal tubular fluid samples under control conditions and during the infusion of 0.15 mug/min X 100 g body weight angiotensin II using micropuncture techniques. Under control conditions proximal tubular albumin concentration was 1.32 +/- 0.79 (SD) mg/100 ml (n = 71). There was no correlation between albumin concentration and (TF/P)-inulin ratio indicating an albumin reabsorption in the proximal tubule parallel to fluid reabsorption under control conditions. During angiotensin infusion using re-collection techniques, there is an average increase of 26 times in tubular albumin concentration, indicating an increase in albumin filtered. There was no change in GFR, SNGFR, transit time, (TF/P)-inulin ratio, an increase in urine flow rate, sodium excretion, protein excretion, mean arterial blood pressure during angiotensin infusion. Since effective glomerular filtration pressure was not increased during angiotensin it is concluded that angiotensin-induced proteinuria is due to an increase in filtered protien mediated by a change in glomerular permeability to proteins.

  12. Glomerular filtration rate in cows estimated by a prediction formula.

    PubMed

    Murayama, Isao; Miyano, Anna; Sato, Tsubasa; Iwama, Ryosuke; Satoh, Hiroshi; Ichijyo, Toshihiro; Sato, Shigeru; Furuhama, Kazuhisa

    2014-12-01

    To testify the relevance of Jacobsson's equation for estimating bovine glomerular filtration rate (GFR), we prepared an integrated formula based on its equation using clinically healthy dairy (n=99) and beef (n=63) cows, and cows with reduced renal function (n=15). The isotonic, nonionic, contrast medium iodixanol was utilized as a test tracer. The GFR values estimated from the integrated formula were well consistent with those from the standard multisample method in each cow strain, and the Holstein equation prepared by a single blood sample in Holstein dairy cows. The basal reference GFR value in healthy dairy cows was significantly higher than that in healthy beef cows, presumably due to a breed difference or physiological state difference. It is concluded that the validity for the application of Jacobsson's equation to estimate bovine GFR is proven and it can be used in bovine practices.

  13. Physiology Lab Demonstration: Glomerular Filtration Rate in a Rat.

    PubMed

    Hinojosa-Laborde, Carmen; Jespersen, Brian; Shade, Robert

    2015-01-01

    Measurements of glomerular filtration rate (GFR), and the fractional excretion of sodium (Na) and potassium (K) are critical in assessing renal function in health and disease. GFR is measured as the steady state renal clearance of inulin which is filtered at the glomerulus, but not secreted or reabsorbed along the nephron. The fractional excretion of Na and K can be determined from the concentration of Na and K in plasma and urine. The renal clearance of inulin can be demonstrated in an anesthetized animal which has catheters in the femoral artery, femoral vein and bladder. The equipment and supplies used for this procedure are those commonly available in a research core facility, and thus makes this procedure a practical means for measuring renal function. The purpose of this video is to demonstrate the procedures required to perform a lab demonstration in which renal function is assessed before and after a diuretic drug. The presented technique can be utilized to assess renal function in rat models of renal disease. PMID:26274567

  14. /sup 125/I iothalamate an ideal marker for glomerular filtration

    SciTech Connect

    Odlind, B.; Haellgren, R.S.; Sohtell, M.; Lindstroem, B.

    1985-01-01

    The triiodinated angiographic contrast medium, iothalamate (usually labelled /sup 125/I), has been used extensively as a marker for glomerular filtration. The authors have studied the renal handling of /sup 125/I iothalamate (IOT) in vivo and in vitro in several species. In renal cortical slices from chicken, rabbit, rat, and monkey, the tissue-to-medium ratio of IOT was twice that of /sup 51/Cr-EDTA (EDTA) at 37 degrees C; a difference that was abolished at 0 degree C and markedly reduced by added o-iodohippurate or iodipamide. In five chickens the steady-state renal clearance of IOT (CIOT) was twice that of EDTA (CEDTA) or /sup 3/H inulin (C1); a difference that was abolished by administration of 100 mg/kg/hr of novobiocin, an organic anion transport inhibitor. CEDTA was similar to C1 before as well as after transport inhibition. Utilizing the Sperber technique the mean apparent tubular excretion fraction (ATEF) of IOT was 8%, while that of EDTA was 1%. After novobiocin coinfusion (new steady-state) ATEFIOT was significantly reduced and not different from that of EDTA (-1%). In the same animals the total urinary recovery of IOT was 84 and 57% before and after novobiocin, respectively, while corresponding values for EDTA was unchanged by the inhibitor. In seven rats the renal extraction of IOT was reduced from 29 to 17% by coinfusion of probenecid (5 mg/kg/hr). Corresponding extractions were 82 to 34% and 22% (unchanged) for PAH and EDTA, respectively.

  15. Estimating glomerular filtration rate in a population-based study

    PubMed Central

    Shankar, Anoop; Lee, Kristine E; Klein, Barbara EK; Muntner, Paul; Brazy, Peter C; Cruickshanks, Karen J; Nieto, F Javier; Danforth, Lorraine G; Schubert, Carla R; Tsai, Michael Y; Klein, Ronald

    2010-01-01

    Background: Glomerular filtration rate (GFR)-estimating equations are used to determine the prevalence of chronic kidney disease (CKD) in population-based studies. However, it has been suggested that since the commonly used GFR equations were originally developed from samples of patients with CKD, they underestimate GFR in healthy populations. Few studies have made side-by-side comparisons of the effect of various estimating equations on the prevalence estimates of CKD in a general population sample. Patients and methods: We examined a population-based sample comprising adults from Wisconsin (age, 43–86 years; 56% women). We compared the prevalence of CKD, defined as a GFR of <60 mL/min per 1.73 m2 estimated from serum creatinine, by applying various commonly used equations including the modification of diet in renal disease (MDRD) equation, Cockcroft–Gault (CG) equation, and the Mayo equation. We compared the performance of these equations against the CKD definition of cystatin C >1.23 mg/L. Results: We found that the prevalence of CKD varied widely among different GFR equations. Although the prevalence of CKD was 17.2% with the MDRD equation and 16.5% with the CG equation, it was only 4.8% with the Mayo equation. Only 24% of those identified to have GFR in the range of 50–59 mL/min per 1.73 m2 by the MDRD equation had cystatin C levels >1.23 mg/L; their mean cystatin C level was only 1 mg/L (interquartile range, 0.9–1.2 mg/L). This finding was similar for the CG equation. For the Mayo equation, 62.8% of those patients with GFR in the range of 50–59 mL/min per 1.73 m2 had cystatin C levels >1.23 mg/L; their mean cystatin C level was 1.3 mg/L (interquartile range, 1.2–1.5 mg/L). The MDRD and CG equations showed a false-positive rate of >10%. Discussion: We found that the MDRD and CG equations, the current standard to estimate GFR, appeared to overestimate the prevalence of CKD in a general population sample. PMID:20730018

  16. Glomerular filtration rate, cardiovascular risk factors and insulin resistance.

    PubMed

    Salazar, Martín R; Carbajal, Horacio A; Marillet, Alberto G; Gallo, Delfina M; Valli, María L; Novello, Miguel; Echeverría, Raúl F

    2009-01-01

    The aim of this paper was to study the estimated glomerular filtration rate (eGFR), its changes with age, and its association with systolic blood pressure (SBP) and diastolic BP (DBP), indicators of obesity, dyslipemia, insulin resistance and inflammation on a random population sample. BP, weight, size and waist circumference (WC) were recorded at home. Fasting morning blood samples were analysed. The eGFR was calculated with MDRD (eGFR-MDRD), Cockroft-Gault (eGFR-CG) adjusted to 1.73 m2 and reciprocal of serum creatinine (100/serum cretinine). A total of 1016 individuals, 722 females (41.97 +/- 0.66 years old) and 294 males (42.06 +/- 0.99 years old), completed the laboratory tests. The mean of 100/Scr was 115.13 +/- 0.60 (dl/mg), the mean eGFR-CG was 98.48 +/- 0.82 ml/min/1.73 m2; the mean eGFR-MDRD was 85.15 +/- 0.58 ml/min/1.73 m2. The eGFR-MDRD decreased with age and with the number of risk factors in both sexes. The eGFR-MDRD < 60 ml/min/1.73 m2 adjusted prevalence was 6.2 per 100 inhabitants (CI 95%, 4.7-7.7), 3.6 (CI 95%, 1.5-5.7) in males and 8.6 (CI 95%, 6.6-10.6) in females. The bivariate analysis showed that the eGFR-MDRD correlates inversely with age, SBP, DBP WC, BMI, serum glucose, serum total cholesterol, LDL cholesterol, serum triglycerides, serum uric acid and, in males, with C-reactive-protein. There was no correlation with either insulinemia or HOMA. The mean eGFR value, its association with cardiovascular risk factors and the prevalence of eGFR < 60 ml/min/1.73 m2 found in a rural population of Argentina are similar to those found in other parts of the world. PMID:19897440

  17. Effect of arctiin on glomerular filtration barrier damage in STZ-induced diabetic nephropathy rats.

    PubMed

    Ma, Song-Tao; Liu, Dong-lian; Deng, Jing-jing; Niu, Rui; Liu, Rui-bin

    2013-10-01

    Diabetic nephropathy (DN) is the major life-threatening complication of diabetes. Abnormal permeability of glomerular basement membrane plays an important role in DN pathogenesis. This study was performed to assess the effect of arctiin, the lignan constituent from Arctium lappa L., on metabolic profile and aggravation of renal lesions in a rat model of streptozotocin (STZ)-induced DN. STZ-induced diabetic rats were treated with arctiin at the dosage of 60 or 40 mg/kg/day via intraperitoneal injection for 8 weeks. Blood glucose and 24-h urinary albumin content were measured, and kidney histopathological changes were monitored. RT-PCR and immunohistochemistry were used to detect the mRNA and protein levels of nephrin, podocin and heparanase (HPSE) in the kidney cortex of rats, respectively. Treatment with arctiin significantly decreased the levels of 24-h urinary albumin, prevented the sclerosis of glomeruli and effectively restored the glomerular filtration barrier damage by up-regulating the expression of nephrin and podocin and down-regulating HPSE level. Our studies suggest that arctiin might be beneficial for DN. The effects of arctiin on attenuating albuminuria and glomerulosclerosis are possibly mediated by regulating the expression of nephrin and podocin and HPSE in STZ-induced diabetic rats. PMID:23147865

  18. Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

    SciTech Connect

    Spino, M.; Chai, R.P.; Isles, A.F.; Balfe, J.W.; Brown, R.G.; Thiessen, J.J.; MacLeod, S.M.

    1985-07-01

    A study was conducted to examine renal function in 10 healthy control subjects and eight patients with cystic fibrosis in stable condition. Sequential bolus injections of /sup 99m/Tc-DTPA and /sup 125/I-OIH were administered to assess glomerular filtration rate and effective renal plasma flow, respectively. Blood was subsequently collected for 3 hours, and urine for 24 hours. Renal clearances of both radioisotope markers were virtually identical in patients and controls. Inasmuch as neither glomerular filtration rate nor effective renal plasma flow was enhanced in patients with cystic fibrosis, increased clearance of drugs in these patients is unlikely to be the result of enhanced glomerular filtration or tubular secretion.

  19. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 2: Why to measure glomerular filtration rate with iohexol?

    PubMed Central

    Delanaye, Pierre; Melsom, Toralf; Ebert, Natalie; Bäck, Sten-Erik; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Gaspari, Flavio

    2016-01-01

    A reliable assessment of glomerular filtration rate (GFR) is of paramount importance in clinical practice as well as epidemiological and clinical research settings. It is recommended by Kidney Disease: Improving Global Outcomes guidelines in specific populations (anorectic, cirrhotic, obese, renal and non-renal transplant patients) where estimation equations are unreliable. Measured GFR is the only valuable test to confirm or confute the status of chronic kidney disease (CKD), to evaluate the slope of renal function decay over time, to assess the suitability of living kidney donors and for dosing of potentially toxic medication with a narrow therapeutic index. Abnormally elevated GFR or hyperfiltration in patients with diabetes or obesity can be correctly diagnosed only by measuring GFR. GFR measurement contributes to assessing the true CKD prevalence rate, avoiding discrepancies due to GFR estimation with different equations. Using measured GFR, successfully accomplished in large epidemiological studies, is the only way to study the potential link between decreased renal function and cardiovascular or total mortality, being sure that this association is not due to confounders, i.e. non-GFR determinants of biomarkers. In clinical research, it has been shown that measured GFR (or measured GFR slope) as a secondary endpoint as compared with estimated GFR detected subtle treatment effects and obtained these results with a comparatively smaller sample size than trials choosing estimated GFR. Measuring GFR by iohexol has several advantages: simplicity, low cost, stability and low interlaboratory variation. Iohexol plasma clearance represents the best chance for implementing a standardized GFR measurement protocol applicable worldwide both in clinical practice and in research.

  20. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 2: Why to measure glomerular filtration rate with iohexol?

    PubMed

    Delanaye, Pierre; Melsom, Toralf; Ebert, Natalie; Bäck, Sten-Erik; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Gaspari, Flavio

    2016-10-01

    A reliable assessment of glomerular filtration rate (GFR) is of paramount importance in clinical practice as well as epidemiological and clinical research settings. It is recommended by Kidney Disease: Improving Global Outcomes guidelines in specific populations (anorectic, cirrhotic, obese, renal and non-renal transplant patients) where estimation equations are unreliable. Measured GFR is the only valuable test to confirm or confute the status of chronic kidney disease (CKD), to evaluate the slope of renal function decay over time, to assess the suitability of living kidney donors and for dosing of potentially toxic medication with a narrow therapeutic index. Abnormally elevated GFR or hyperfiltration in patients with diabetes or obesity can be correctly diagnosed only by measuring GFR. GFR measurement contributes to assessing the true CKD prevalence rate, avoiding discrepancies due to GFR estimation with different equations. Using measured GFR, successfully accomplished in large epidemiological studies, is the only way to study the potential link between decreased renal function and cardiovascular or total mortality, being sure that this association is not due to confounders, i.e. non-GFR determinants of biomarkers. In clinical research, it has been shown that measured GFR (or measured GFR slope) as a secondary endpoint as compared with estimated GFR detected subtle treatment effects and obtained these results with a comparatively smaller sample size than trials choosing estimated GFR. Measuring GFR by iohexol has several advantages: simplicity, low cost, stability and low interlaboratory variation. Iohexol plasma clearance represents the best chance for implementing a standardized GFR measurement protocol applicable worldwide both in clinical practice and in research. PMID:27679716

  1. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 2: Why to measure glomerular filtration rate with iohexol?

    PubMed Central

    Delanaye, Pierre; Melsom, Toralf; Ebert, Natalie; Bäck, Sten-Erik; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Gaspari, Flavio

    2016-01-01

    A reliable assessment of glomerular filtration rate (GFR) is of paramount importance in clinical practice as well as epidemiological and clinical research settings. It is recommended by Kidney Disease: Improving Global Outcomes guidelines in specific populations (anorectic, cirrhotic, obese, renal and non-renal transplant patients) where estimation equations are unreliable. Measured GFR is the only valuable test to confirm or confute the status of chronic kidney disease (CKD), to evaluate the slope of renal function decay over time, to assess the suitability of living kidney donors and for dosing of potentially toxic medication with a narrow therapeutic index. Abnormally elevated GFR or hyperfiltration in patients with diabetes or obesity can be correctly diagnosed only by measuring GFR. GFR measurement contributes to assessing the true CKD prevalence rate, avoiding discrepancies due to GFR estimation with different equations. Using measured GFR, successfully accomplished in large epidemiological studies, is the only way to study the potential link between decreased renal function and cardiovascular or total mortality, being sure that this association is not due to confounders, i.e. non-GFR determinants of biomarkers. In clinical research, it has been shown that measured GFR (or measured GFR slope) as a secondary endpoint as compared with estimated GFR detected subtle treatment effects and obtained these results with a comparatively smaller sample size than trials choosing estimated GFR. Measuring GFR by iohexol has several advantages: simplicity, low cost, stability and low interlaboratory variation. Iohexol plasma clearance represents the best chance for implementing a standardized GFR measurement protocol applicable worldwide both in clinical practice and in research. PMID:27679716

  2. Comparative evaluation of quantitative glomerular filtration rate measured by isotopic and nonisotopic methods

    SciTech Connect

    Balachandran, S.; Toguri, A.G.; Petrusick, T.W.; Abbott, L.C.

    1981-04-01

    Good correlation of glomerular filtration rate measured isotopically from plasma disappearance of Tc-99m-DTPA was shown with inulin clearance, creatinine clearance, and graded radionuclide imaging. The isotopic GFR is a simple, urineless technique not requiring continuous infusion that enables one to perform simultaneous renal imaging with one radiotracer.

  3. Comparative evaluation of quantitative glomerular filtration rate measured by isotopic and nonisotopic methods

    SciTech Connect

    Balachandran, S.; Toguri, A.G.; Petrusick, T.W.; Abbott, L.C.

    1981-04-01

    Good correlation of glomerular filtration rate (GFR) measured isotopically from plasma disappearance of Tc-99m-DTPA (Sn) was shown with inulin clearance, creatinine clearance, and graded radionuclide imaging. The isotopic GFR is a simple, urineless technique not requiring continuous infusion that enables one to perform simultaneous renal imaging with one radiotracer.

  4. Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

    NASA Technical Reports Server (NTRS)

    Tempel, G. E.; Musacchia, X. J.; Jones, S. B.

    1977-01-01

    Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

  5. Glomerular endothelial surface layer acts as a barrier against albumin filtration.

    PubMed

    Dane, Martijn J C; van den Berg, Bernard M; Avramut, M Cristina; Faas, Frank G A; van der Vlag, Johan; Rops, Angelique L W M M; Ravelli, Raimond B G; Koster, Bram J; van Zonneveld, Anton Jan; Vink, Hans; Rabelink, Ton J

    2013-05-01

    Glomerular endothelium is highly fenestrated, and its contribution to glomerular barrier function is the subject of debate. In recent years, a polysaccharide-rich endothelial surface layer (ESL) has been postulated to act as a filtration barrier for large molecules, such as albumin. To test this hypothesis, we disturbed the ESL in C57Bl/6 mice using long-term hyaluronidase infusion for 4 weeks and monitored albumin passage using immunolabeling and correlative light-electron microscopy that allows for complete and integral assessment of glomerular albumin passage. ESL ultrastructure was visualized by transmission electron microscopy using cupromeronic blue and by localization of ESL binding lectins using confocal microscopy. We demonstrate that glomerular fenestrae are filled with dense negatively charged polysaccharide structures that are largely removed in the presence of circulating hyaluronidase, leaving the polysaccharide surfaces of other glomerular cells intact. Both retention of native ferritin [corrected] in the glomerular basement membrane and systemic blood pressure were unaltered. Enzyme treatment, however, induced albumin passage across the endothelium in 90% of glomeruli, whereas this could not be observed in controls. Yet, there was no net albuminuria due to binding and uptake of filtered albumin by the podocytes and parietal epithelium. ESL structure and function completely recovered within 4 weeks on cessation of hyaluronidase infusion. Thus, the polyanionic ESL component, hyaluronan, is a key component of the glomerular endothelial protein permeability barrier.

  6. Par3A is dispensable for the function of the glomerular filtration barrier of the kidney.

    PubMed

    Koehler, Sybille; Tellkamp, Frederik; Niessen, Carien M; Bloch, Wilhelm; Kerjaschki, Dontscho; Schermer, Bernhard; Benzing, Thomas; Brinkkoetter, Paul T

    2016-07-01

    Polarity signaling through the atypical PKC (aPKC)-Par polarity complex is essential for the development and maintenance of the podocyte architecture and the function of the glomerular filtration barrier of the kidney. To study the contribution of Par3A in this complex, we generated a novel Pard3 podocyte-specific knockout mouse model by targeting exon 6 of the Pard3 gene. Genetic deletion of Pard3a did not impair renal function, neither at birth nor later in life. Even challenging the animals did not result in glomerular disease. Despite its well-established role in aPKC-mediated signaling, Par3A appears to be dispensable for the function of the glomerular filtration barrier. Moreover, its homolog Pard3b, and not Pard3a, is the dominant Par3 gene expressed in podocytes and found at the basis of the slit diaphragm, where it partially colocalizes with podocin. In conclusion, Par3A function is either dispensable for slit diaphragm integrity, or compensatory mechanisms and a high redundancy of the different polarity proteins, including Par3B, Lgl, or PALS1, maintain the function of the glomerular filtration barrier, even in the absence of Par3A.

  7. Somatostatin analogue, octreotide, reduces increased glomerular filtration rate and kidney size in insulin-dependent diabetes

    SciTech Connect

    Serri, O.; Beauregard, H.; Brazeau, P.; Abribat, T.; Lambert, J.; Harris, A.; Vachon, L. Sandoz Canada Inc., Dorval, Quebec )

    1991-02-20

    To determine whether treatment with a somatostatin analogue can reduce kidney hyperfiltration and hypertrophy in insulin-dependent diabetes mellitus, the authors studied 11 patients with insulin-dependent diabetes mellitus and glomerular hyperfiltration. The patients were assigned randomly to receive continuous subcutaneous infusion of either octreotide, 300 {mu}g/24 h (five patients) or placebo (six patients) for 12 weeks. At baseline, mean glomerular filtration rate and mean total kidney volume were not significantly different in the two groups. However, after 12 weeks of treatment, the mean glomerular filtration rate was significantly lower in the octreotide group than in the placebo group. Furthermore, the mean total kidney volume was significantly lower after treatment in the octreotide group than in the placebo group. Glycemic control did not change significantly in either group. They conclude that subcutaneous infusion of octreotide for 12 weeks reduces increased glomerular filtration rate and kidney size in patients with insulin-dependent diabetes mellitus despite the fact that glycemic control remains unchanged.

  8. Assembly of the glomerular filtration surface. Differentiation of anionic sites in glomerular capillaries of newborn rat kidney

    PubMed Central

    1980-01-01

    Glomerular development was studied in the newborn rat kidney by electron microscopy and cytochemistry. Glomerular structure at different developmental stages was related to the permeability properties of its components and to the differentiation of anionic sites in the glomerular basement membrane (GBM) and on endothelial and epithelia cell surfaces. Cationic probes (cationized ferritin, ruthenium red, colloidal iron) were used to determine the time of appearance and distribution of anionic sites, and digestion with specific enzymes (neuraminidase, heparinase, chondroitinases, hyaluronidases) was used to determine their nature. Native (anionic) ferritin was used to investigate glomerular permeability. The main findings were: (a) The first endothelial fenestrae (which appear before the GBM is fully assembled) possess transient, negatively charged diaphragms that bind cationized ferritin and are impermeable to native ferritin. (b). Two types of glycosaminoglycan particles can be identified by staining with ruthenium red. Large (30-nm) granules are seen only in the cleft of the S-shaped body at the time of mesenchymal migration into the renal vesicle. They consist of hyaluronic acid and possibly also chondroitin sulfate. Smaller (10-15-nm) particles are seen in the earliest endothelial and epithelial basement membranes (S- shaped body stage), become concentrated in the laminae rarae after fusion of these two membranes to form the GBM, and contain heparan sulfate. They are assumed to be precursors of the heparan sulfate-rich granules present in the mature GBM. (c) Distinctive sialic acid-rich, and sialic acid-poor plasmalemmal domains have been delineated on both the epithelial and endothelial cell surfaces. (d) The appearance of sialoglycoproteins on the epithelial cell surface concides with the development of foot processes and filtration slits. (e) Initially the GBM is loosely organized and quite permeable to native ferritin ;it becomes increasinly impermeable to

  9. The effect of intravesical pressure on glomerular filtration rate in patients with myelomeningocele.

    PubMed

    Steinhardt, G F; Goodgold, H M; Samuels, L D

    1988-11-01

    Numerous investigators have demonstrated the development of hydronephrosis and renal deterioration in patients with myelomeningocele who have high pressure bladders. By drawing blood at sequential intervals during 99mtechnetium-diethylenetriaminepentaacetic acid renal scanning we are able to generate nuclide clearance curves that correlate well with glomerular filtration rate. Renal scanning is done most frequently with the bladder catheterized and left to gravity drainage. By filling the bladder under manometric control to a pressure of 35 to 40 cm. water we have followed routine scanning with continued blood sampling to generate nuclide clearance at low and high bladder pressures. In 5 myelomeningocele patients so studied we found consistent and significant decreases in glomerular filtration rate at high bladder pressures. PMID:3184307

  10. Progression of glomerular filtration rate reduction determined in conscious Dahl salt-sensitive hypertensive rats.

    PubMed

    Cowley, Allen W; Ryan, Robert P; Kurth, Terry; Skelton, Meredith M; Schock-Kusch, Daniel; Gretz, Norbert

    2013-07-01

    Sequential changes in glomerular filtration rate during development of hypertension in the conscious Dahl salt-sensitive rats were determined using a new method for measurement. Using a miniaturized device, disappearance curves of fluorescein isothiocyanate-sinistrin were measured by transcutaneous excitation and real-time detection of the emitted light through the skin. Rats with implanted femoral venous catheters (dye injection and sampling) and carotid catheters (mean arterial pressure by telemetry) were studied, while maintained on a 0.4% NaCl diet and on days 2, 5, 7, 14, and 21 after switching to 4.0% (high-salt [HS]) diet. A separate group of rats were maintained on 0.4% for 21 days as a time control. Mean arterial pressure rose progressively from the last day of 0.4% (130±2 mm Hg) reaching significance by day 5 of HS and averaged 162±7 mm Hg by day 21. Urine albumin excretion was significantly elevated (×3) by day 7 of HS in Dahl salt-sensitive rats. Glomerular filtration rate reduced on day 14 of HS falling from 1.53±0.06 mL/min per 100 g body weight to 1.27±0.04. By day 21, glomerular filtration rate had fallen 28% to 1.1±0.04 mL/min per 100 g (t(1/2) 28.4±1.1 minute.) No significant reductions of creatinine clearance were observed throughout the study in response to HS demonstrating the insensitivity of creatinine clearance measurements even with creatinine measured using mass spectrometry. We conclude that the observed reduction of glomerular filtration rate was a consequence and not a cause of the hypertension and that this noninvasive approach could be used in these conscious Dahl salt-sensitive rats for a longitudinal assessment of renal function.

  11. Assessment of glomerular filtration rate measurement with plasma sampling: a technical review.

    PubMed

    Murray, Anthony W; Barnfield, Mark C; Waller, Michael L; Telford, Tania; Peters, A Michael

    2013-06-01

    This article reviews available radionuclide-based techniques for glomerular filtration rate (GFR) measurement, focusing on clinical indications for GFR measurement, ideal GFR radiopharmaceutical tracer properties, and the 2 most common tracers in clinical use. Methods for full, 1-compartment, and single-sample renal clearance characterization are discussed. GFR normalization and the role of GFR measurement in chemotherapy dosing are also considered. PMID:23658207

  12. Obesity in kidney transplant recipients: association with decline in glomerular filtration rate.

    PubMed

    Moreira, Thaís Rodrigues; Bassani, Tayron; de Souza, Gizele; Manfro, Roberto Ceratti; Gonçalves, Luiz Felipe Santos

    2013-10-01

    In this study we aimed to evaluate the influence of obesity in kidney and patient survival and graft function. Retrospective cohort study of kidney transplant recipients performed between 2001 and 2009. The body mass index was calculated at time of transplantation, one and five years after. The main outcomes studied were incidence of delayed graft function, new onset diabetes after transplantation, patient and graft survival, and glomerular filtration rate. The prevalence of obesity and overweight patients were 10.7% and 26.8% respectively, with an increase to 16.9% and 32.5% one year after transplantation. Underweight and obese recipients presented a higher incidence of early graft loss. The incidence of new onset diabetes after transplantation was significantly higher at one and five years in overweight or obese recipients at baseline. Overweight and obese recipients presented significantly lower estimated glomerular filtration rate at five years posttransplantation (p = 0.002). In the Kaplan-Meier analyses no statistically significant differences in patients or grafts survivals were observed. Obese patients have a higher rate of early graft failure and a higher new onset diabetes after transplantation incidence. Also, the finding of decreased glomerular filtration rate is worrisome and perhaps longer follow-up will reveal more graft failures and patients deaths in the group of obese recipients.

  13. Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.

    PubMed

    Moreira, Daniel M; Friedlander, Justin I; Hartman, Christopher; Gershman, Boris; Smith, Arthur D; Okeke, Zeph

    2016-08-01

    The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition. PMID:26573808

  14. Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.

    PubMed

    Moreira, Daniel M; Friedlander, Justin I; Hartman, Christopher; Gershman, Boris; Smith, Arthur D; Okeke, Zeph

    2016-08-01

    The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition.

  15. Assessing glomerular filtration rate in healthy adult potential kidney donors in Bangladesh: a comparison of various prediction equations with measured glomerular filtration rate by diethylentriamine pentaacetic acid renogram.

    PubMed

    Jahan, F; Chowdhury, M N U; Mahbub, T; Arafat, S M; Jahan, S; Hossain, M; Khan, M F

    2013-08-01

    To ensure that potential kidney donors in Bangladesh have no renal impairment, it is extremely important to have accurate methods for evaluating the glomerular filtration rate (GFR). We evaluated the performance of serum creatinine based GFR in healthy adult potential kidney donors in Bangladesh to compare GFR determined by DTPA with that determined by various prediction equations. In this study GFR in 61 healthy adult potential kidney donors were measured with 99mTc-diethylenetriamine penta-acetic acid (DTPA) renogram. We also estimated GFR using a four variable equation modification of diet in renal disease (MDRD), Cockcroft-Gault creatinine clearance (CGCrCl), Cockcroft-Gault glomerular filtration rate (CG-GFR). The mean age of study population was 34.31 +/- 9.46 years and out of them 65.6% was male. In this study mean mGFR was 85.4 +/- 14.8. Correlation of estimated GFR calculated by CG-CrCl, CG-GFR and MDRD were done with measured GFR DTPA using quartile. Kappa values were also estimated which was found to be 0.104 for (p = 0.151), 0.336 for (p = 0.001) and 0.125 for (p = 0.091) respectively. This indicates there is no association between estimated GFR calculated by CG-CrCl, CG-GFR, MDRD with measured GFR DTPA. These results show poor performance of these equations in evaluation of renal function among healthy population and also raise question regarding validity of these equations for assessment of renal function in chronic kidney disease in our population.

  16. Increased tubuloglomerular feed-back mediated suppression of glomerular filtration during acute volume expansion in rats.

    PubMed Central

    Davis, J M; Häberle, D A; Kawata, T; Schmitt, E; Takabatake, T; Wohlfeil, S

    1988-01-01

    1. Volume expansion is currently believed to change the intrinsic properties of the juxtaglomerular apparatus such that the sensitivity of the tubuloglomerular feedback (TGF) mechanism is reduced, thus allowing glomerular filtration rate, and hence salt and water excretion, to rise. Recent studies conflict with this view and indeed the older literature reveals that the rise in glomerular filtration rate (GFR) under these conditions is far more modest than would be expected if TGF control were eliminated. 2. To investigate this problem, TGF control of filtration rate was examined by measuring single-nephron glomerular filtration rate (SNGFR) during loop of Henle perfusion at varying rates in rats under control conditions, after acute, moderate (4% of body weight), iso-oncotic volume expansion and in rats treated with antibodies to atrial natriuretic peptide (ANP) prior to the acute volume expansion. 3. With TGF control of filtration interrupted by filtrate collection from the proximal tubule, SNGFR in the expanded rats was massively increased compared with controls, although SNGFR measured in the distal tubule, and hence with TGF control intact, was only modestly increased, as was whole-kidney filtration rate. Loop perfusion at increasing rates up to 30 nl min-1 progressively decreased SNGFR in controls, and in the expanded rats the range over which control was exerted extended up to 60-80 nl min-1. For changes in loop flow around the spontaneous operating point, the sensitivity of the TGF mechanism, defined as delta SNGFR/delta loop flow, was similar in both groups. Treatment of rats with ANP antibodies prior to volume expansion substantially blunted the changes in renal salt and water excretion and the increase in SNGFR seen in the absence of loop perfusion. 4. These results are not consistent with a diminution of TGF function after volume expansion, rather with an enhancement. The latter is best accounted for by vasodilation of preglomerular resistance vessels on

  17. Autoregulation of renal blood flow and glomerular filtration rate in the pregnant rabbit

    SciTech Connect

    Woods, L.L.; Mizelle, H.L.; Hall, J.E.

    1987-01-01

    The authors purpose was to determine whether renal autoregulatory capability is retained in pregnancy despite the marked renal vasodilation that occurs at this time. Renal blood flow and glomerular filtration rate (GFR) were measured in anesthetized pregnant (22-27 days gestation) and nonpregnant rabbits during step reductions in renal perfusion pressure from control (100 +/- 3 mmHg) to 50 mmHg. Control renal blood flow and GFR were significantly higher in pregnant animals. Filtration fraction was also significantly elevated in pregnant animals. During step reductions in renal perfusion pressure, renal blood flow was well autoregulated down to approx.70 mmHg in both nonpregnant and pregnant animals. Likewise, GFR was also well autoregulated, falling by 10 +/- 2 and 8 +/- 3% in nonpregnant and pregnant animals, respectively, when perfusion pressure was reduced from 90 to 70 mmHg. These results suggest that renal autoregulation is preserved in pregnancy despite the fact that the renal circulation is already markedly vasodilated.

  18. Genetic Modifiers of White Blood Cell Count, Albuminuria and Glomerular Filtration Rate in Children with Sickle Cell Anemia

    PubMed Central

    Flanagan, Jonathan M.; Alvarez, Ofelia A.; Nelson, Stephen C.; Aygun, Banu; Nottage, Kerri A.; George, Alex; Roberts, Carla W.; Piccone, Connie M.; Howard, Thad A.; Davis, Barry R.; Ware, Russell E.

    2016-01-01

    Discovery and validation of genetic variants that influence disease severity in children with sickle cell anemia (SCA) could lead to early identification of high-risk patients, better screening strategies, and intervention with targeted and preventive therapy. We hypothesized that newly identified genetic risk factors for the general African American population could also impact laboratory biomarkers known to contribute to the clinical disease expression of SCA, including variants influencing the white blood cell count and the development of albuminuria and abnormal glomerular filtration rate. We first investigated candidate genetic polymorphisms in well-characterized SCA pediatric cohorts from three prospective NHLBI-supported clinical trials: HUSTLE, SWiTCH, and TWiTCH. We also performed whole exome sequencing to identify novel genetic variants, using both a discovery and a validation cohort. Among candidate genes, DARC rs2814778 polymorphism regulating Duffy antigen expression had a clear influence with significantly increased WBC and neutrophil counts, but did not affect the maximum tolerated dose of hydroxyurea therapy. The APOL1 G1 polymorphism, an identified risk factor for non-diabetic renal disease, was associated with albuminuria. Whole exome sequencing discovered several novel variants that maintained significance in the validation cohorts, including ZFHX4 polymorphisms affecting both the leukocyte and neutrophil counts, as well as AGGF1, CYP4B1, CUBN, TOR2A, PKD1L2, and CD163 variants affecting the glomerular filtration rate. The identification of robust, reliable, and reproducible genetic markers for disease severity in SCA remains elusive, but new genetic variants provide avenues for further validation and investigation. PMID:27711207

  19. Alport syndrome: its effects on the glomerular filtration barrier and implications for future treatment

    PubMed Central

    Savige, Judy

    2014-01-01

    The glomerular filtration barrier comprises a fenestrated capillary endothelium, glomerular basement membrane and podocyte slit diaphragm. Over the past decade we have come to realise that permselectivity depends on size and not necessarily charge, that the molecular sieve depends on the podocyte contractile apparatus and is highly dynamic, and that protein uptake by proximal tubular epithelial cells stimulates signalling and the production of transcription factors and inflammatory mediators. Alport syndrome is the second commonest monogenic cause of renal failure after autosomal dominant polycystic kidney disease. Eighty per cent of patients have X-linked disease caused by mutations in the COL4A5 gene. Most of these result in the replacement of the collagen IV α3α4α5 network with the α1α1α2 heterotrimer. Affected membranes also have ectopic laminin and increased matrix metalloproteinase levels, which makes them more susceptible to proteolysis. Mechanical stress, due to the less elastic membrane and hypertension, interferes with integrin-mediated podocyte–GBM adhesion. Proteinuria occurs when urinary levels exceed tubular reabsorption rates, and initiates tubulointerstitial fibrosis. The glomerular mesangial cells produce increased TGFβ and CTGF which also contribute to glomerulosclerosis. Currently there is no specific therapy for Alport syndrome. However treatment with angiotensin converting enzyme (ACE) inhibitors delays renal failure progression by reducing intraglomerular hypertension, proteinuria, and fibrosis. Our greater understanding of the mechanisms underlying the GBM changes and their consequences in Alport syndrome have provided us with further novel therapeutic targets. PMID:25107927

  20. Shroom3 contributes to the maintenance of the glomerular filtration barrier integrity

    PubMed Central

    Yeo, Nan Cher; O’Meara, Caitlin C.; Bonomo, Jason A.; Veth, Kerry N.; Tomar, Ritu; Flister, Michael J.; Drummond, Iain A.; Bowden, Donald W.; Freedman, Barry I.; Lazar, Jozef; Link, Brian A.

    2015-01-01

    Genome-wide association studies (GWAS) identify regions of the genome correlated with disease risk but are restricted in their ability to identify the underlying causative mechanism(s). Thus, GWAS are useful “roadmaps” that require functional analysis to establish the genetic and mechanistic structure of a particular locus. Unfortunately, direct functional testing in humans is limited, demonstrating the need for complementary approaches. Here we used an integrated approach combining zebrafish, rat, and human data to interrogate the function of an established GWAS locus (SHROOM3) lacking prior functional support for chronic kidney disease (CKD). Congenic mapping and sequence analysis in rats suggested Shroom3 was a strong positional candidate gene. Transferring a 6.1-Mb region containing the wild-type Shroom3 gene significantly improved the kidney glomerular function in FHH (fawn-hooded hypertensive) rat. The wild-type Shroom3 allele, but not the FHH Shroom3 allele, rescued glomerular defects induced by knockdown of endogenous shroom3 in zebrafish, suggesting that the FHH Shroom3 allele is defective and likely contributes to renal injury in the FHH rat. We also show for the first time that variants disrupting the actin-binding domain of SHROOM3 may cause podocyte effacement and impairment of the glomerular filtration barrier. PMID:25273069

  1. Glomerular filtration rate is altered in children with sickle cell disease: a comparison between Hb SS and Hb SC

    PubMed Central

    de Paula, Rafael Pereira; Nascimento, Alana Ferreira; Sousa, Sandra Mara Bispo; Bastos, Paulo Roberto Velasco; Barbosa, Ana Angélica Leal

    2013-01-01

    Background Renal failure is common among older patients with sickle cell disease; this is preceded by subclinical glomerular hyperfiltration. Data about renal function of adults with sickle cell disease have been reported, but data on children is scarce, especially when comparing heterozygotic and homozygotic patients. Objective The goal of this study was to investigate the glomerular filtration rate of heterozygotic and homozygotic children with sickle cell disease. Methods The glomerular filtration rate of 11 children with sickle cell disease [7 homozygotic (SS) and 4 heterozygotic (SC)] with a mean age of 11 years (standard deviation: ± 5 years) was evaluated using standard laboratory techniques. Results are presented as descriptive analysis. Results Our results suggest that glomerular hyperfiltration is present in children with sickle cell disease; this is more evident in homozygotic than heterozygotic children. Conclusion There is evidence of a need to monitor the renal function of children with sickle cell disease when special attention should be paid to homozygotic patients. PMID:24255619

  2. Radioactive chromium-ethylenediaminetetraacetic acid for determination of glomerular filtration rate in rabbits

    SciTech Connect

    Tvedegaard, E.; Kamstrup, O.

    1981-12-01

    Simultaneous determination of the glomerular filtration rate was made by the insulin clearance technique and by analysis of the plasma disappearance curve of radioactive chromium-ethylenediaminetetraacetic acid (/sup 51/Cr-EDTA) following an intravenous injection in 28 anaesthetized rabbits. In some rabbits, the renal function was reduced by previous surgery. The insulin clearances ranged from 2.7 to 17 ml/minute. By a double-exponential analysis of the plasma disappearance curve, the total plasma clearance of /sup 51/Cr-EDTA was found to exceed the inulin clearance by 12%. By the simpler slope-intercept analysis requiring only two blood samples, this value was 32%. The renal clearance of /sup 51/Cr-EDTA was 97% of inulin clearance. In nephrectomized rabbits, plasma clearance of /sup 51/Cr-EDTA was 0.7 ml/minute. At all levels of renal function, measurement of the plasma clearance rate of /sup 51/Cr-EDTA by the single injection technique allowed a fairly reliable estimate of the glomerular filtration rate.

  3. Assessment of glomerular filtration rate utilizing subcutaneously injected 51Cr-EDTA.

    PubMed

    Monteiro, M C; Alonso, G; Ajzen, H; Pereira, A B

    1994-11-01

    1. 51Cr-EDTA injected with lidocaine and epinephrine, as a subcutaneous button, is slowly absorbed, and a plasma level that is relatively stable can be maintained for a time sufficient to permit measurement of the renal clearance of EDTA, which is a measure of glomerular filtration rate (GFR). We studied this procedure in 32 normal volunteers and 24 patients with different glomerulopathies, comparing EDTA and creatinine clearances. In 20 patients these measurements were also compared with inulin clearance. 2. Creatinine clearance overestimates GFR due to tubular secretion of creatinine. This secretion is present even in patients with significantly reduced glomerular filtration rates. As a consequence, the lower the GFR the higher the overestimation will be. 3. A good correlation was obtained between the 51Cr-EDTA and inulin clearance: y(EDTA) = 4.21 + 0.88 x (inulin), r = 0.98. The procedure is simple to perform, and the radiotracer utilized is significantly less expensive than iothalamate. PMID:7549976

  4. Linkage Analysis of Glomerular Filtration Rate in American Indians: The Strong Heart Family Study

    PubMed Central

    Mottl, Amy K.; Vupputuri, Suma; Cole, Shelley A.; Almasy, Laura; Göring, Harald HH; Diego, Vincent P.; Laston, Sandra; Franceschini, Nora; Shara, Nawar; Lee, Elisa T.; Best, Lyle G.; Fabsitz, Richard R.; MacCluer, Jean W.; Umans, Jason G.; North, Kari E.

    2009-01-01

    American Indians have a disproportionately high rate of kidney disease likely due to a combination of increased environmental and genetic risk factors. In an attempt to localize genes influencing kidney disease risk factors, we performed a genome wide scan of estimated glomerular filtration rate on participants of the Strong Heart Family Study. Over 3 600 men and women from 13 American Indian tribes were recruited from 3 centers (Arizona, North and South Dakota, Oklahoma). Using SOLAR 2.1.2, multipoint variance component linkage analysis was performed in each center as well as the entire cohort after controlling for center effects. Two modeling strategies were utilized: model 1 incorporated age, sex and interaction terms and model 2 additionally controlled for diabetic status, systolic and diastolic blood pressure, body mass index, low density lipoproteins, high density lipoproteins, triglycerides and smoking status. Significant evidence for linkage in Arizona lay on 12p12.2 at 39cM nearest marker D12S310 (LOD=3.5). Additional loci with suggestive evidence for linkage were detected at 1p36.31 (LOD=2.0–2.3), 2q33.3 (LOD=1.8) and 9q34.2 (LOD=2.4). No significant evidence for additive interaction with diabetes, hypertension or obesity was noted. In conclusion, we found evidence for linkage of a quantitative trait locus influencing estimated glomerular filtration rate to a region of chromosome 12p in a large cohort of American Indians. PMID:18854848

  5. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 1: How to measure glomerular filtration rate with iohexol?

    PubMed Central

    Delanaye, Pierre; Ebert, Natalie; Melsom, Toralf; Gaspari, Flavio; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Bäck, Sten-Erik

    2016-01-01

    While there is general agreement on the necessity to measure glomerular filtration rate (GFR) in many clinical situations, there is less agreement on the best method to achieve this purpose. As the gold standard method for GFR determination, urinary (or renal) clearance of inulin, fades into the background due to inconvenience and high cost, a diversity of filtration markers and protocols compete to replace it. In this review, we suggest that iohexol, a non-ionic contrast agent, is most suited to replace inulin as the marker of choice for GFR determination. Iohexol comes very close to fulfilling all requirements for an ideal GFR marker in terms of low extra-renal excretion, low protein binding and in being neither secreted nor reabsorbed by the kidney. In addition, iohexol is virtually non-toxic and carries a low cost. As iohexol is stable in plasma, administration and sample analysis can be separated in both space and time, allowing access to GFR determination across different settings. An external proficiency programme operated by Equalis AB, Sweden, exists for iohexol, facilitating interlaboratory comparison of results. Plasma clearance measurement is the protocol of choice as it combines a reliable GFR determination with convenience for the patient. Single-sample protocols dominate, but multiple-sample protocols may be more accurate in specific situations. In low GFRs one or more late samples should be included to improve accuracy. In patients with large oedema or ascites, urinary clearance protocols should be employed. In conclusion, plasma clearance of iohexol may well be the best candidate for a common GFR determination method. PMID:27679715

  6. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 1: How to measure glomerular filtration rate with iohexol?

    PubMed Central

    Delanaye, Pierre; Ebert, Natalie; Melsom, Toralf; Gaspari, Flavio; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Bäck, Sten-Erik

    2016-01-01

    While there is general agreement on the necessity to measure glomerular filtration rate (GFR) in many clinical situations, there is less agreement on the best method to achieve this purpose. As the gold standard method for GFR determination, urinary (or renal) clearance of inulin, fades into the background due to inconvenience and high cost, a diversity of filtration markers and protocols compete to replace it. In this review, we suggest that iohexol, a non-ionic contrast agent, is most suited to replace inulin as the marker of choice for GFR determination. Iohexol comes very close to fulfilling all requirements for an ideal GFR marker in terms of low extra-renal excretion, low protein binding and in being neither secreted nor reabsorbed by the kidney. In addition, iohexol is virtually non-toxic and carries a low cost. As iohexol is stable in plasma, administration and sample analysis can be separated in both space and time, allowing access to GFR determination across different settings. An external proficiency programme operated by Equalis AB, Sweden, exists for iohexol, facilitating interlaboratory comparison of results. Plasma clearance measurement is the protocol of choice as it combines a reliable GFR determination with convenience for the patient. Single-sample protocols dominate, but multiple-sample protocols may be more accurate in specific situations. In low GFRs one or more late samples should be included to improve accuracy. In patients with large oedema or ascites, urinary clearance protocols should be employed. In conclusion, plasma clearance of iohexol may well be the best candidate for a common GFR determination method.

  7. Iohexol plasma clearance for measuring glomerular filtration rate in clinical practice and research: a review. Part 1: How to measure glomerular filtration rate with iohexol?

    PubMed

    Delanaye, Pierre; Ebert, Natalie; Melsom, Toralf; Gaspari, Flavio; Mariat, Christophe; Cavalier, Etienne; Björk, Jonas; Christensson, Anders; Nyman, Ulf; Porrini, Esteban; Remuzzi, Giuseppe; Ruggenenti, Piero; Schaeffner, Elke; Soveri, Inga; Sterner, Gunnar; Eriksen, Bjørn Odvar; Bäck, Sten-Erik

    2016-10-01

    While there is general agreement on the necessity to measure glomerular filtration rate (GFR) in many clinical situations, there is less agreement on the best method to achieve this purpose. As the gold standard method for GFR determination, urinary (or renal) clearance of inulin, fades into the background due to inconvenience and high cost, a diversity of filtration markers and protocols compete to replace it. In this review, we suggest that iohexol, a non-ionic contrast agent, is most suited to replace inulin as the marker of choice for GFR determination. Iohexol comes very close to fulfilling all requirements for an ideal GFR marker in terms of low extra-renal excretion, low protein binding and in being neither secreted nor reabsorbed by the kidney. In addition, iohexol is virtually non-toxic and carries a low cost. As iohexol is stable in plasma, administration and sample analysis can be separated in both space and time, allowing access to GFR determination across different settings. An external proficiency programme operated by Equalis AB, Sweden, exists for iohexol, facilitating interlaboratory comparison of results. Plasma clearance measurement is the protocol of choice as it combines a reliable GFR determination with convenience for the patient. Single-sample protocols dominate, but multiple-sample protocols may be more accurate in specific situations. In low GFRs one or more late samples should be included to improve accuracy. In patients with large oedema or ascites, urinary clearance protocols should be employed. In conclusion, plasma clearance of iohexol may well be the best candidate for a common GFR determination method. PMID:27679715

  8. Glomerular filtration and tubular secretion of MAG-3 in the rat kidney

    SciTech Connect

    Mueller-Suur, R.M.; Mueller-Suur, C. )

    1989-12-01

    Technetium-99m mercaptoacetyltriglycine (MAG-3) has recently been introduced as a new radiopharmaceutical for dynamic renal scintigraphy. To elucidate the mechanism of renal excretion, micropuncture experiments were performed in rat kidneys for direct measurements of glomerular filtration and tubular secretory capacity. Fluid of Bowman space was collected from superficial glomeruli and analyzed for its contents of (99mTc)MAG-3, (125I)hippurate and (3H)inulin during constant infusion of these compounds. The ratio of activity of ultrafiltrate to that of arterial plasma was 0.23 for MAG-3, 0.68 for hippurate and 1.04 for inulin which demonstrates that the filtrated amount of MAG-3 is only 23% of that of inulin, presumably because of higher plasma protein binding which was also measured in vitro and found to be 80 +/- 1.5% for MAG-3 and 32 +/- 2% for (125I)hippurate. Proximal and distal tubules were also micropunctured and their tubular fluid as well as the final urine analyzed for the activity of hippurate and MAG-3. The tubular fluid to plasma ratio values along the nephron and in the final urine were all lower for MAG-3 than for hippurate, indicating a lower secretory capacity. From measurements of whole renal clearance, GFR and plasma protein binding the filtered amount of MAG-3 was 0.26 and of hippurate 0.87 ml/min.g kidney weight (p less than 0.001) and the secreted amount 2.01 and 2.38 ml/min.g kidney weight (p less than 0.05), respectively. We conclude that MAG-3 is predominantly excreted by tubular secretion and that the lower renal clearance of MAG-3 as compared with that of hippurate is a result both of a substantially decreased glomerular filtration and of a lower tubular secretion.

  9. Glomerular filtration rate is associated with burden of coronary atherosclerosis in patients with acute coronary syndrome.

    PubMed

    Duran, Mustafa; Uysal, Onur Kadir; Gunebakmaz, Ozgur; Baran, Oguzhan; Turfan, Murat; Ornek, Ender; Cetin, Mustafa; Murat, Sani Namik; Yarlioglues, Mikail; Karadeniz, Muhammed; Kurtul, Alpaslan; Kaya, Mehmet Gungor

    2014-04-01

    We aimed to elucidate the relationship between mild to moderate renal impairements and burden of atherosclerosis in patients with acute coronary syndrome (ACS). A total of 380 patients with ACS were included in the study. Gensini and SYNTAX scores were also calculated. Kidney function was classified based on estimated glomerular filtration rate (eGFR) into stage 1: eGFR >90, stage 2: 60 to 89, and stage 3: 30 to 60 mL/min per 1.73 m(2). Gensini and SYNTAX scores were higher in stages 2 and 3 than in stage 1. Also, the number of diseased vessels, number of critical lesions (>50 and 70%), left main disease, and number of total occlusion vessels were higher in stages 2 and 3 than in stage 1. Multivariate linear regression analysis demonstrated that a decreased eGFR was an independent risk factor for SYNTAX and Gensini scores together with age and male gender.

  10. An overview of glomerular filtration rate testing in dogs and cats.

    PubMed

    Von Hendy-Willson, Vanessa E; Pressler, Barrak M

    2011-05-01

    Determination of glomerular filtration rate (GFR) is a valuable, yet underused, diagnostic tool for evaluating renal function in dogs and cats. This article first reviews the hormonal and hemodynamic factors which contribute to GFR, followed by a description of considerations when selecting a pharmacokinetic model and methods of animal-to-animal standardization. The best-characterized existing GFR markers, including creatinine, radiolabeled markers, and iohexol, are reviewed in depth, as well as alternative but lesser used techniques. A weighted means analysis of reported GFR measurements in healthy dogs and cats and a review of selected studies that have examined GFR alterations in animals with naturally occurring and experimental diseases provide the reader with preliminary guidelines on expected GFR results in these species and disease conditions. PMID:20541957

  11. Utility of Cystatin C for Estimating Glomerular Filtration Rate in Patients With Muscular Dystrophy.

    PubMed

    Kimura, Koichi; Morita, Hiroyuki; Daimon, Masao; Horio, Masaru; Kawata, Takayuki; Nakao, Tomoko; Hirokawa, Megumi; Kitao, Ruriko; Watanabe, Daisuke; Komori, Tetsuo; Nagata, Tetsuya; Takeda, Shin'ichi; Komaki, Hirofumi; Segawa, Kazuhiko; Nakajima, Takashi; Takenaka, Katsu; Komuro, Issei

    2016-05-25

    Emerging concerns regarding heart failure, arrhythmia, and sudden death in patients with muscular dystrophy are of significant clinical importance. On the other hand, little attention has been paid to renal dysfunction because these patients have low serum creatinine levels. Serum cystatin C, unaffected by muscle quantity, is a potentially superior marker for estimating renal function. Here, we present cases with muscular dystrophy in which estimated glomerular filtration rate (GFR) by cystatin C (eGFRcys) provided good agreement with simultaneously measured GFR by inulin renal clearance (differences less than 20%). Sudden death with acute heart failure occurred in a patient with underlying renal dysfunction and elevated BNP. Neurologists and cardiologists should evaluate renal function using GFR with cystatin C in patients with muscular dystrophy.

  12. Telaprevir decreases estimated glomerular filtration rate in HIV-hepatitis C virus coinfected patients.

    PubMed

    Van den Eynde, Eva; Curto, Jordi; Ferrer, Elena; Imaz, Arkaitz; Saumoy, Maria; Di Yacovo, Silvana; Vila, Antonia; Podzamczer, Daniel

    2015-05-15

    We investigated kidney function outcome in 24 chronic hepatitis C genotype 1 patients coinfected with HIV receiving telaprevir in a single tertiary care hospital in Spain. A statistically significant median (interquartile range) decrease in estimated glomerular filtration rate (eGFR, ml/min/1.73 m) relative to baseline [93.6 (73.0-109.0)] was seen at weeks 4 [86.5 (34.0-112.0), P = 0.014], 8 [90.0 (49.0-111.0), P = 0.026] and 12 [89.5 (54.0-113.0), P = 0.017]. These changes reversed after telaprevir discontinuation. Patients presenting an eGFR decrease had a higher risk of haematological toxicity. PMID:25784438

  13. Experience with the cumulative integral method for measurement of glomerular filtration rate *

    PubMed Central

    Hurley, R. Morrison; Drummond, Keith N.

    1974-01-01

    The glomerular filtration rate (GFR) was estimated using 125I-iothalamate by the cumulative integral method in 95 subjects — 16 normal subjects and 79 patients with suspected or proved renal disease. This method is accurate, simple to perform and theoretically sound. It minimizes errors due to transit time and bladder storage. The normal range of GFR was determined to be 71 ± 10 (two standard deviations) ml/min/m2. In 66 patients serum creatinine levels were compared with the GFR value expressed per square metre. For any given serum creatinine level there is a wide range of GFR values. A serum creatinine value in the normal range, i.e. between 0.7 and 1.3 mg/dl, cannot be used to predict the patient's GFR. The micro blood sampling technique makes this method particularly useful in infants. PMID:4834526

  14. Resolution of the three dimensional structure of components of the glomerular filtration barrier

    PubMed Central

    2014-01-01

    Background The human glomerulus is the primary filtration unit of the kidney, and contains the Glomerular Filtration Barrier (GFB). The GFB had been thought to comprise 3 layers – the endothelium, the basement membrane and the podocyte foot processes. However, recent studies have suggested that at least two additional layers contribute to the function of the GFB, the endothelial glycocalyx on the vascular side, and the sub-podocyte space on the urinary side. To investigate the structure of these additional layers is difficult as it requires three-dimensional reconstruction of delicate sub-microscopic (<1 μm) cellular and extracellular elements. Methods Here we have combined three different advanced electron microscopic techniques that cover multiple orders of magnitude of volume sampled, with a novel staining methodology (Lanthanum Dysprosium Glycosaminoglycan adhesion, or LaDy GAGa), to determine the structural basis of these two additional layers. Serial Block Face Scanning Electron Microscopy (SBF-SEM) was used to generate a 3-D image stack with a volume of a 5.3 x 105 μm3 volume of a whole kidney glomerulus (13% of glomerular volume). Secondly, Focused Ion Beam milling Scanning Electron Microscopy (FIB-SEM) was used to image a filtration region (48 μm3 volume). Lastly Transmission Electron Tomography (Tom-TEM) was performed on a 0.3 μm3 volume to identify the fine structure of the glycocalyx. Results Tom-TEM clearly showed 20 nm fibre spacing in the glycocalyx, within a limited field of view. FIB-SEM demonstrated, in a far greater field of view, how the glycocalyx structure related to fenestrations and the filtration slits, though without the resolution of TomTEM. SBF-SEM was able to determine the extent of the sub-podocyte space and glycocalyx coverage, without additional heavy metal staining. Neither SBF- nor FIB-SEM suffered the anisotropic shrinkage under the electron beam that is seen with Tom-TEM. Conclusions These images demonstrate that the

  15. Benefits of direct glomerular filtration rate (GFR) determination versus creatinine-based tests for evaluating renal function.

    PubMed

    Cimmino, C J

    1998-08-01

    To diagnose renal disease earlier and thereby reduce the number of patients with endstage renal disease, accurate, specific diagnostic tests are necessary. The author explains the benefits of using tests that rely on the glomerular filtration rate measurement rather than on traditional creatinine-based diagnostic tests.

  16. Outcome Assessment of a Computer-Animated Model for Learning about the Regulation of Glomerular Filtration Rate

    ERIC Educational Resources Information Center

    Gookin, Jody L.; McWhorter, Dan; Vaden, Shelly; Posner, Lysa

    2010-01-01

    The regulation of the glomerular filtration rate (GFR) is a particularly important and challenging concept for students to integrate into a memorable framework for building further knowledge and solving clinical problems. In this study, 76 first-year veterinary students and 19 veterinarians in clinical specialty training (house officers)…

  17. Psychosocial stress and changes in estimated glomerular filtration rate among adults with diabetes mellitus

    PubMed Central

    Annor, Francis B.; Masyn, Katherine E.; Okosun, Ike S.; Roblin, Douglas W.; Goodman, Michael

    2015-01-01

    Background Psychosocial stress has been hypothesized to impact renal changes, but this hypothesis has not been adequately tested. The aim of this study was to examine the relationship between psychosocial stress and estimated glomerular filtration rate (eGFR) and to examine other predictors of eGFR changes among persons with diabetes mellitus (DM). Methods Data from a survey conducted in 2005 by a major health maintenance organization located in the southeastern part of the United States, linked to patients’ clinical and pharmacy records (n=575) from 2005 to 2008, was used. Study participants were working adults aged 25–59 years, diagnosed with DM but without advanced microvascular or macrovascular complications. eGFR was estimated using the Modification of Diet in Renal Disease equation. A latent psychosocial stress variable was created from five psychosocial stress subscales. Using a growth factor model in a structural equation framework, we estimated the association between psychosocial stress and eGFR while controlling for important covariates. Results The psychosocial stress variable was not directly associated with eGFR in the final model. Factors found to be associated with changes in eGFR were age, race, insulin use, and mean arterial pressure. Conclusion Among fairly healthy DM patients, we did not find any evidence of a direct association between psychosocial stress and eGFR changes after controlling for important covariates. Predictors of eGFR change in our population included age, race, insulin use, and mean arterial pressure. PMID:26484039

  18. [Consensus document: recommendations for the use of equations to estimate glomerular filtration rate in children].

    PubMed

    Montañés Bermúdez, R; Gràcia Garcia, S; Fraga Rodríguez, G M; Escribano Subias, J; Diez de Los Ríos Carrasco, M J; Alonso Melgar, A; García Nieto, V

    2014-05-01

    The appearance of the K/DOQI guidelines in 2002 on the definition, evaluation and staging of chronic kidney disease (CKD) have led to a major change in how to assess renal function in adults and children. These guidelines, recently updated, recommended that the study of renal function is based, not only on measuring the serum creatinine concentration, but this must be accompanied by the estimation of glomerular filtration rate (GFR) obtained by an equation. However, the implementation of this recommendation in the clinical laboratory reports in the paediatric population has been negligible. Numerous studies have appeared in recent years on the importance of screening and monitoring of patients with CKD, the emergence of new equations for estimating GFR, and advances in clinical laboratories regarding the methods for measuring plasma creatinine and cystatin C, determined by the collaboration between the departments of paediatrics and clinical laboratories to establish recommendations based on the best scientific evidence on the use of equations to estimate GFR in this population. The purpose of this document is to provide recommendations on the evaluation of renal function and the use of equations to estimate GFR in children from birth to 18 years of age. The recipients of these recommendations are paediatricians, nephrologists, clinical biochemistry, clinical analysts, and all health professionals involved in the study and evaluation of renal function in this group of patients.

  19. Determination of glomerular filtration rate by single-plasma sampling technique following injection of radioiodinated diatrizoate

    SciTech Connect

    Tauxe, W.N.

    1986-01-01

    Measurement of glomerular filtration rate (GFR) based on the radioactivity concentration in a single-plasma sample obtained after the injection of radioiodinated diatrizoate (DTZ) has been described. Simultaneous determinations of GFR by use of DTZ based on multiple-sample plasma disappearance curves and inulin correlate highly. Certain theoretical volumes of distribution (injection dose counts divided by plasma concentration expressed as counts per liter of plasma) correlate highly with GFR determined by the multiple-sample plasma disappearance curves. For patients with relatively high GFR (greater than 100 ml/min) best correlations were obtained at 120 min; for patients with GFR 60-100 ml/min, best correlations were obtained at sampling times of 150 min after injection and for patients with GFR less than 60 ml/min, the ideal sampling time was 230 min after injection. For general use the 180-min sampling time may suffice. Since the formulae were found to produce nearly identical GFR values for data obtained from the use of diethylenetriaminepentaacetic acid and DTZ, the former radiopharmaceutical can probably be substituted for diatrizoate using these formulae and sampling times as long as absence of plasma protein binding of the labeled chelate can be demonstrated.

  20. Transcutaneous measurement of glomerular filtration rate in small rodents: through the skin for the win?

    PubMed

    Ellery, Stacey J; Cai, Xiaochu; Walker, David D; Dickinson, Hayley; Kett, Michelle M

    2015-03-01

    Rodent models of renal physiology and pathology are crucial to our understanding of the molecular, histological and functional sequelae that contribute to kidney diseases. One of the most important measures of renal function is glomerular filtration rate (GFR). While the accurate determination of GFR is pivotal to understanding the progression of disease and/or the benefits of treatment strategies, in rodents the conventional methods for assessment of GFR are inconvenient and cumbersome, not the least because they involve stress and often anaesthesia. The legitimacy of assay-based assessment of plasma and urine markers of GFR in mice has also been heavily scrutinized for their insensitivity to minor declines in GFR and inaccurate detection of renal biomarkers. While infusion-based clearance methods of GFR assessment are thus the gold standard in terms of accuracy, they are limited by the fact that they are primarily non-recovery procedures. This presents a dilemma when trying to document the progression of renal disease, as these measures cannot be taken in the same experimental subject. Here we review a technique of transcutaneous measurement of fluorescein isothiocyanate-labelled sinistrin to calculate GFR in small rodents, using a non-invasive clearance device (NIC-Kidney Device). This is a recently validated non-invasive technique for measuring GFR in small rodents that allows for the real-time measurement of GFR in conscious animals, without the need for plasma and urine assays.

  1. Prediction of hospital mortality by changes in the estimated glomerular filtration rate (eGFR).

    PubMed

    Berzan, E; Mellotte, G; Silke, B

    2015-03-01

    Deterioration of physiological or laboratory variables may provide important prognostic information. We have studied whether a change in estimated glomerular filtration rate (eGFR) value calculated using the (Modification of Diet in Renal Disease (MDRD) formula) over the hospital admission, would have predictive value. An analysis was performed on all emergency medical hospital episodes (N = 61964) admitted between 1 January 2002 and 31 December 2011. A stepwise logistic regression model examined the relationship between mortality and change in renal function from admission to discharge. The fully adjusted Odds Ratios (OR) for 5 classes of GFR deterioration showed a stepwise increased risk of 30-day death with OR's of 1.42 (95% CI: 1.20, 1.68), 1.59 (1.27, 1.99), 2.71 (2.24, 3.27), 5.56 (4.54, 6.81) and 11.9 (9.0, 15.6) respectively. The change in eGFR during a clinical episode, following an emergency medical admission, powerfully predicts the outcome. PMID:25876302

  2. The effect of pseudopregnancy on glomerular filtration rate and salt and water reabsorption in the rat.

    PubMed

    Atherton, J C; Bu'lock, D; Pirie, S C

    1982-03-01

    1. Glomerular filtration rate (G.F.R.) and salt and water reabsorption were measured in age-matched virgin rats and rats at different stages of pseudopregnancy and post-pseudopregnancy. 2. Tubular reabsorption and G.F.R. were significantly higher in later pseudopregnancy. Values at mid-pseudopregnancy were intermediate between virgin controls and late-pseudopregnancy. In post-pseudopregnancy G.F.R. and reabsorption had returned to values not different from the virgins. 3. Expansion of extracellular fluid volume (e.c.f.v.) and elongation of proximal tubules were observed during pseudopregnancy. In post-pseudopregnancy increased tubular length was still apparent but e.c.f.v. was not. 4. The remarkable similarity in the changes in e.c.f.v. and renal functions and structure during pseudopregnancy to those in early pregnancy suggests that the feto-placental unit is not necessary for the pregnancy changes. 5. The differences between the time course of change in plasma progesterone and the time courses of changes in e.c.f.v., renal functions and tubular morphology in late pseudopregnancy suggest that progesterone is not directly involved.

  3. Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus.

    PubMed

    Bakken, Bradley Hartman; McWhorter, Todd J; Tsahar, Ella; Del Rio, Carlos Martínez

    2004-12-01

    Small nectarivorous vertebrates face a quandary. When feeding, they must eliminate prodigious quantities of water; however, when they are not feeding, they are susceptible to dehydration. We examined the role of the kidney in the resolution of this osmoregulatory dilemma. Broad-tailed hummingbirds (Selasphorus platycercus) displayed diurnal variation in glomerular filtration rate (GFR). During the morning, midday and evening, GFRs were 0.9+/-0.6, 1.8+/-0.4 and 2.3+/-0.5 ml h(-1), respectively. At midday, GFR increased linearly with increased water intake. During the evening, hummingbirds decreased renal fractional water reabsorption linearly with increased water intake. Broad-tailed hummingbirds appeared to cease GFR at night (-0.1+/-0.2 ml h(-1)) and decreased GFR in response to short-term ( approximately 1.5 h) water deprivation. GFR seems to be very responsive to water deprivation in hummingbirds. Although hummingbirds and other nectarivorous birds can consume astounding amounts of water, a phylogenetically explicit allometric analysis revealed that their diurnal GFRs are not different from the expectation based on body mass.

  4. Plasma aldosterone and glomerular filtration in hypertensive patients with preserved renal function.

    PubMed

    Roldán, Julián; Morillas, Pedro; Castillo, Jesús; Andrade, Helder; Guillén, Silvia; Núñez, Daniel; Quiles, Juan; Bertomeu, Vicente

    2010-01-01

    There is increasing interest in the role of aldosterone in the pathophysiology of hypertension, cardiovascular disease and deteriorating renal function. The aim of this study was to investigate the relationship between aldosterone and the glomerular filtration rate (GFR) in hypertensive patients with preserved renal function. The study involved 186 consecutive hypertensive patients with a GFR >60 mL/min. The GFR was determined using the Modification of Diet in Renal Disease (MDRD) equation and the patients' plasma aldosterone levels were measured. Patients with a GFR between 60-89 mL/min had a significantly higher plasma aldosterone level than those with a GFR >90 mL/min (20.02 ng/dL vs. 15.3 ng/dL; P< .05). Multivariate analysis showed that the plasma aldosterone level was independently associated with the GFR (B=-7.36; P< .001). In hypertensive patients with preserved kidney function, the plasma aldosterone level was observed to increase as the GFR decreased.

  5. Calculation of relative glomerular filtration rate and correlation with delayed technetium-99m DMSA imaging

    SciTech Connect

    Taylor, A. Jr.; Kipper, M.; Witztum, K.

    1986-01-01

    The relative renal uptake of Tc-99m DMSA was compared with the relative glomerular filtration rate (GFR) in ten patients with serum creatinines ranging from 0.3 to 2.5 mg/dl. Relative GFR was based on the renal uptake of Tc-99m DTPA determined by two methods: 1) integrating the counts from 1 to 3 minutes postinjection and correcting for background. 2) Totalizing the individual renal counts in a single 15-second frame from 2:45 minutes to 3:00 minutes postinjection and correcting for background. The two methods of determining relative DTPA uptake showed excellent correlation, r = 0.98. Relative DMSA uptake determined at 24 hours post-injection using computer-assisted regions of interest showed excellent correlation with the relative GFR determined by either the integral or single-frame method, r = 0.98. The addition of background subtraction for the DMSA images at 24 hours did not improve the correlation.

  6. Association of Glomerular Filtration Rate with Inflammation in Polycystic Ovary Syndrome

    PubMed Central

    Gozukara, Ilay Ozturk; Gozukara, Kerem Han; Kucur, Suna Kabil; Karakılıc, Eda Ulku; Keskin, Havva; Akdeniz, Derya; Aksoy, Ayse Nur; Carlıoglu, Ayse

    2015-01-01

    Background We aimed to estimate the glomerular filtration rate (GFR) in women with polycystic ovary syndrome (PCOS) and to determine the relationship between GFR with C-reactive protein (CRP) and uric acid. Materials and Methods In this cross-sectional study, one-hundred and forty PCOS women and 60 healthy subjects were evaluated. The study was carried out at Endocrinol- ogy Outpatient Clinic, Erzurum Training and Research Hospital, Erzurum, Turkey, from December 2010 to January 2011. GFRs were estimated by Modification of Diet in Renal Disease (MDRD) formula. CRP, urinary albumin excretion (UAE) and uric acid levels were also measured. Results GFRs were significantly higher in PCOS group than control (135.24 ± 25.62 vs. 114.92 ± 24.07 ml/min per 1.73 m2). CRP levels were significantly higher in PCOS patients (4.4 ± 3.4 vs. 2.12 ± 1.5 mg/l). The PCOS group had significantly higher serum uric acid levels (4.36 ± 1.3 mg/dl vs. 3.2 ± 0.73 mg/dl). There was also significantly higher proteinuria level in PCOS patients. Conclusion Even though PCOS patients had higher GFR, serum uric acid and UAE val- ues than control patients, the renal function was within normal limits. Increased GFR in PCOS women positively correlates with elevated serum CRP and uric acid. PMID:26246875

  7. Clinician’s use of automated reports of estimated glomerular filtration rate: A qualitative study

    PubMed Central

    2012-01-01

    Background There is a growing awareness in primary care of the importance of identifying patients with chronic kidney disease (CKD) so that they can receive appropriate clinical care; one method that has been widely embraced is the use of automated reporting of estimated glomerular filtration rate (eGFR) by clinical laboratories. We undertook a qualitative study to examine how clinicians use eGFR in clinical decision making, patient communication issues, barriers to use of eGFR, and suggestions to improve the clinical usefulness of eGFR reports. Methods Our study used qualitative methods with structured interviews among primary care clinicians including both physicians and allied health providers, recruited from Kaiser Permanente Northwest, a non-profit health maintenance organization. Results We found that clinicians generally held favorable views toward eGFR reporting but did not use eGFR to replace serum creatinine in their clinical decision-making. Clinicians used eGFR as a tool to help identify CKD, educate patients about their kidney function and make treatment decisions. Barriers noted by several clinicians included a desire for greater education regarding care for patients with CKD and tools to facilitate discussion of eGFR findings with patients. Conclusions The manner in which clinicians use eGFRs appears to be more complex than previously understood, and our study illustrates some of the efforts that might be usefully undertaken (e.g. specific clinician education) when encouraging further promulgation of eGFR reporting and usage. PMID:23173944

  8. Insulin increases glomerular filtration barrier permeability through PKGIα-dependent mobilization of BKCa channels in cultured rat podocytes.

    PubMed

    Piwkowska, Agnieszka; Rogacka, Dorota; Audzeyenka, Irena; Kasztan, Małgorzata; Angielski, Stefan; Jankowski, Maciej

    2015-08-01

    Podocytes are highly specialized cells that wrap around glomerular capillaries and comprise a key component of the glomerular filtration barrier. They are uniquely sensitive to insulin; like skeletal muscle and fat cells, they exhibit insulin-stimulated glucose uptake and express glucose transporters. Podocyte insulin signaling is mediated by protein kinase G type I (PKGI), and it leads to changes in glomerular permeability to albumin. Here, we investigated whether large-conductance Ca²⁺-activated K⁺ channels (BKCa) were involved in insulin-mediated, PKGIα-dependent filtration barrier permeability. Insulin-induced glomerular permeability was measured in glomeruli isolated from Wistar rats. Transepithelial albumin flux was measured in cultured rat podocyte monolayers. Expression of BKCa subunits was detected by RT-PCR. BKCa, PKGIα, and upstream protein expression were examined in podocytes with Western blotting and immunofluorescence. The BKCa-PKGIα interaction was assessed with co-immunoprecipitation. RT-PCR showed that primary cultured rat podocytes expressed mRNAs that encoded the pore-forming α subunit and four accessory β subunits of BKCa. The BKCa inhibitor, iberiotoxin (ibTX), abolished insulin-dependent glomerular albumin permeability and PKGI-dependent transepithelial albumin flux. Insulin-evoked albumin permeability across podocyte monolayers was also blocked with BKCa siRNA. Moreover, ibTX blocked insulin-induced disruption of the actin cytoskeleton and changes in the phosphorylation of PKG target proteins, MYPT1 and RhoA. These results indicated that insulin increased filtration barrier permeability through mobilization of BKCa channels via PKGI in cultured rat podocytes. This molecular mechanism may explain podocyte injury and proteinuria in diabetes. PMID:25952906

  9. Estimated glomerular filtration rate by serum creatinine or standardized cystatin C in Japanese patients with Graves׳ disease.

    PubMed

    Suzuki, Yoshitake; Matsushita, Kazuyuki; Seimiya, Masanori; Yoshida, Toshihiko; Sawabe, Yuji; Ogawa, Makoto; Nomura, Fumio

    2015-12-01

    Glomerular filtration rate (eGFR) by serum creatinine (eGFRCr) or standardized cystatin C (eGFRCysC) were estimated in Japanese patients with Graves׳ disease (GD) of different sex. Clinical samples were collected from patients with GD with normal renal function to accurately validate eGFRCr and eGFRCysC levels and evaluate how hyperthyroidism affects renal function. Levels of eGFRCr and eGFRCysC showed clinical usefulness in successfully treated euthyroid patients with GD regardless of sex. The article includes detailed experimental methods and data used in our analysis. The data relates to the "Paradoxical effect of thyroid function on the estimated glomerular filtration rate by serum creatinine or standardized cystatin C in Japanese Graves' disease patients" (Suzuki et al., 2015) [1].

  10. Sepsis induces albuminuria and alterations in the glomerular filtration barrier: a morphofunctional study in the rat

    PubMed Central

    2011-01-01

    Introduction Increased vascular permeability represents one of the hallmarks of sepsis. In the kidney, vascular permeability is strictly regulated by the 'glomerular filtration barrier' (GFB), which is comprised of glomerular endothelium, podocytes, their interposed basement membranes and the associated glycocalyx. Although it is likely that the GFB and its glycocalyx are altered during sepsis, no study has specifically addressed this issue. The aim of this study was to evaluate whether albuminuria -- the hallmark of GFB perm-selectivity -- occurs in the initial stage of sepsis and whether it is associated with morphological and biochemical changes of the GFB. Methods Cecal ligation and puncture (CLP) was used to induce sepsis in the rat. Tumor necrosis factor (TNF)-alpha levels in plasma and growth of microorganisms in the peritoneal fluid were evaluated at 0, 3 and 7 hours after CLP or sham-operation. At the same times, kidney specimens were collected and structural and ultrastructural alterations in the GFB were assessed. In addition, several components of GFB-associated glycocalyx, syndecan-1, hyluronan (HA) and sialic acids were evaluated by immunofluorescence, immunohistochemistry and lectin histochemistry techniques. Serum creatinine and creatinine clearance were measured to assess kidney function and albuminuria for changes in GFB permeability. Analysis of variance followed by Tukey's multiple comparison test was used. Results Septic rats showed increased TNF-alpha levels and growth of microorganisms in the peritoneal fluid. Only a few renal corpuscles had major ultrastructural and structural alterations and no change in serum creatinine or creatinine clearance was observed. Contrarily, urinary albumin significantly increased after CLP and was associated with diffuse alteration in the glycocalyx of the GFB, which consisted in a decrease in syndecan-1 expression and in HA and sialic acids contents. Sialic acids were also changed in their structure

  11. Effect of prenatal programming and postnatal rearing on glomerular filtration rate in adult rats.

    PubMed

    Lozano, German; Elmaghrabi, Ayah; Salley, Jordan; Siddique, Khurrum; Gattineni, Jyothsna; Baum, Michel

    2015-03-01

    The present study examined whether a prenatal low-protein diet programs a decrease in glomerular filtration rate (GFR) and an increase in systolic blood pressure (BP). In addition, we examined whether altering the postnatal nutritional environment of nursing neonatal rats affected GFR and BP when rats were studied as adults. Pregnant rats were fed a normal (20%) protein diet or a low-protein diet (6%) during the last half of pregnancy until birth, when rats were fed a 20% protein diet. Mature adult rats from the prenatal low-protein group had systolic hypertension and a GFR of 0.38 ± 0.03 versus 0.57 ± 0.05 ml·min(-1)·100 g body wt(-1) in the 20% group (P < 0.01). In cross-fostering experiments, mothers continued on the same prenatal diet until weaning. Prenatal 6% protein rats cross-fostered to a 20% mother on day 1 of life had a GFR of 0.53 ± 0.05 ml·min(-1)·100 g body wt(-1), which was not different than the 20% group cross-fostered to a different 20% mother (0.45 ± 0.04 ml·min(-1)·100 g body wt(-1)). BP in the 6% to 20% group was comparable with the 20% to 20% group. Offspring of rats fed either 20% or 6% protein diets during pregnancy and cross-fostered to a 6% mother had elevated BP but a comparable GFR normalized to body weight as the 20% to 20% control group. Thus, a prenatal low-protein diet causes hypertension and a reduction in GFR in mature adult offspring, which can be modified by postnatal rearing.

  12. Estimation of Glomerular Filtration Rate Based on Serum Cystatin C versus Creatinine in a Uruguayan Population

    PubMed Central

    Lujambio, Inés; Sottolano, Mariana; Robaina, Sebastián; Carusso, Florencia; da Rosa, Alicia; Ríos, Ana Carina; Olascoaga, Alicia; Gadola, Liliana; Noboa, Oscar; Staessen, Jan A.; Boggia, José

    2014-01-01

    Background. Estimation of glomerular filtration rate (eGFR) from biomarkers has evolved and multiple equations are available to estimate renal function at bedside. Methods. In a random sample of 119 Uruguayans (54.5% women; 56.2 years (mean)), we used Bland and Altman's method and Cohen's kappa statistic to assess concordance on a continuous or categorical (eGFR < 60 versus ≥60 mL/min/1.73 m2) scale between eGFRcys (reference) and eGFR derived from serum creatinine according to the Modification of Diet in Renal Disease (eGFRmdrd) or the Chronic Kidney Disease Epidemiology Collaboration equations (eGFRepi) or from both serum cystatin C and creatinine (eGFRmix). Results. In all participants, eGFRmdrd, eGFRepi, and eGFRmix were, respectively, 9.7, 11.5, and 5.6 mL/min/1.73 m2 higher (P < 0.0001) than eGFRcys. The prevalence of eGFR <60 mL/min/1.73 m2 was the highest for eGFRcys (21.8%), intermediate for eGFRmix (11.8%), and the lowest for eGFRmdrd (5.9%) and eGFRepi (3.4%). Using eGFRcys as reference, we found only fair agreement with the equations based on creatinine (Cohen's kappa statistic 0.15 to 0.23). Conclusion. Using different equations we reached clinically significant differences in the estimation of renal function. eGFRcys provides lower estimates, resulting in higher prevalence of eGFR <60 mL/min/1.73 m2. PMID:25215234

  13. The control of glomerular filtration rate and renal blood flow in chronically volume-expanded rats.

    PubMed Central

    Davis, J M; Häberle, D A; Kawata, T

    1988-01-01

    1. Chronic volume expansion by dietary salt loading practically abolishes tubuloglomerular feed-back (TGF) by means of a humoral inhibitor in tubular fluid. Elimination of the vasoconstrictor influence of feed-back does not, however, increase glomerular filtration rate (GFR) and renal blood flow (RBF), implying that chronic salt loading induces additional preglomerular vasoconstriction. This being so, the feed-back response which, although absent in free-flowing nephrons, can still be elicited by loop of Henle perfusion with Ringer solution, should be essentially normal, except that nephron GFR at any loop perfusion rate should be lower than in controls. Persistence of RBF, GFR and nephron GFR autoregulation would imply that autoregulation is achieved by a preglomerular resistance control system independent of feed-back. 2. These hypotheses were tested by clearance and micropuncture experiments in rats chronically fed a diet containing 40 g NaCl (kg food)-1. 3. RBF and GFR autoregulation indeed persisted, the former down to 90 mmHg compared with 105 mmHg in controls. In controls, nephron GFR measured distally was autoregulated down to 90 mmHg whereas that measured proximally was autoregulated only above 105 mmHg. In high-salt rats nephron GFR from both sites was autoregulated to 90 mmHg. 4. Loop of Henle perfusion with homologous tubular fluid in high-salt rats confirmed attenuation of feed-back. Loop perfusion with Ringer solution yielded a response comparable to that in controls (maximal reduction of nephron GFR to 57%, compared with 56% in controls). Absolute nephron GFR at any loop perfusion rate was lower in high-salt rats than in controls. 5. These observations confirm the initial hypotheses. Considering feed-back and autoregulation as independent, preglomerular resistance control mechanisms, together with elementary haemodynamic considerations, allows formulation of a renal haemodynamics model whose quantitative predictions regarding characteristics of RBF

  14. Glomerular filtration rate in patients with atrial fibrillation and 1-year outcomes

    PubMed Central

    Boriani, Giuseppe; Laroche, Cécile; Diemberger, Igor; Popescu, Mircea Ioachim; Rasmussen, Lars Hvilsted; Petrescu, Lucian; Crijns, Harry J. G. M.; Tavazzi, Luigi; Maggioni, Aldo P.; Lip, Gregory Y. H.

    2016-01-01

    We assessed 1-year outcomes in patients with atrial fibrillation enrolled in the EurObservational Research Programme AF General Pilot Registry (EORP-AF), in relation to kidney function, as assessed by glomerular filtration rate (eGFR). In a cohort of 2398 patients (median age 69 years; 61% male), eGFR (ml/min/1.73 m2) calculated using the CKD-EPI formula was ≥80 in 35.1%, 50–79 in 47.2%, 30–49 in 13.9% and <30 in 3.7% of patients. In a logistic regression analysis, eGFR category was an independent predictor of stroke/TIA or death, with elevated odds ratios associated with severe to mild renal impairment, ie. eGFR < 30 ml/min/1.73 m2 [OR 3.641, 95% CI 1.572–8.433, p < 0.0001], 30–49 ml/min/1.73 m2 [OR 3.303, 95% CI 1.740–6.270, p = 0.0026] or 50–79 ml/min/1.73 m2 [OR 2.094, 95% CI 1.194–3.672, p = 0.0003]. The discriminant capability for the risk of death was tested among various eGFR calculation algorithms: the best was the Cockcroft-Gault equation adjusted for BSA, followed by Cockcroft-Gault equation, and CKD-EPI equation, while the worst was the MDRD equation. In conclusion in this prospective observational registry, renal function was a major determinant of adverse outcomes at 1 year, and even mild or moderate renal impairments were associated with an increased risk of stroke/TIA/death. PMID:27466080

  15. Cystatin C, creatinine, estimated glomerular filtration, and long-term mortality in stroke patients.

    PubMed

    Hojs Fabjan, Tanja; Penko, Meta; Hojs, Radovan

    2014-02-01

    Renal dysfunction is associated with mortality in patients after ischemic stroke. Cystatin C is a potentially superior marker of renal function compared to creatinine and estimated glomerular filtration rate (GFR). In our observational cohort study, 390 Caucasian patients suffered from acute ischemic stroke (mean age 70.9 years; 183 women and 207 men) were included and prospectively followed up to maximal 56 months. Serum creatinine and cystatin C were measured at admission to the hospital; GFR was estimated according to CKD-EPI creatinine and CKD-EPI creatinine/cystatin equations. According to values of serum creatinine, estimated GFR and serum cystatin C patients were divided into quintiles. In the follow-up period, 191 (49%) patients died. For serum cystatin C and estimated GFR based on creatinine and cystatin C, the mortality and the hazard ratios for long-term mortality increased from the first to the fifth quintile nearly linearly. The associations of serum creatinine and estimated GFR categories based on creatinine with long-term mortality were J-shaped. As compared with lowest quintile of serum cystatin C, the fifth quintile was associated with long-term mortality significantly also after multivariate adjustment (age, gender, initial stroke severity, known risk factors for stroke mortality). In contrast, in adjusted analysis serum creatinine and estimated GFR (CKD-EPI creatinine and CKD-EPI creatinine/cystatin) were not associated with long-term mortality. In summary, serum cystatin C was independently and better associated with the risk of long-term mortality in patients suffering from ischemic stroke than were creatinine and estimated GFR using both CKD-EPI equations.

  16. Utility of saliva as a sample to assess renal function and estimated glomerular filtration rate.

    PubMed

    Yajamanam, Naresh; Vinapamula, Kiranmayi S; Sivakumar, V; Bitla, Aparna R; Rao, P V L N Srinivasa

    2016-03-01

    Diagnosis of renal diseases by assessing renal parameters in saliva. Biochemical investigations using serum form important component of monitoring patients with renal disease. Utility of saliva, in diagnosis and monitoring of patients with renal disease and for calculation of estimated glomerular filtration rate (eGFR), was studied. Sixty patients with renal disease and sixty ageand sex-matched healthy controls were studied. Urea, creatinine, sodium, potassium, uric acid, calcium, and phosphorus were measured in both serum and saliva. eGFR was calculated using salivary creatinine. Data were expressed as mean ± standard deviation. Comparison and correlation between groups were assessed by Student's t-test and Pearson correlation, respectively. Bland-Altman plot, mountain plot, and intra-class correlation coefficient were used to test agreement. A P <0.05 was considered statistically significant. Statistical analysis was done using Microsoft excel spreadsheets, Medcalc Version 10.0, and SPSS version 11.5. Salivary levels of urea, creatinine, uric acid, sodium, potassium, and phosphorus were higher in patients compared to controls. Potassium and phosphorus levels were higher (P = 0.001) and creatinine, sodium, calcium, and uric acid levels were lower (P = 0.001) in saliva compared to serum in both patients and controls. Positive correlation was observed between serum and salivary urea and creatinine (P < 0.0001). eGFR values calculated from salivary creatinine showed good agreement with those calculated form serum creatinine. Salivary urea (>6 mmol/L) and creatinine (>14.6 μmol/L) and eGFR calculated from salivary creatinine can be used to identify patients with renal disease.

  17. Single and Transient Ca2+ Peaks in Podocytes do not induce Changes in Glomerular Filtration and Perfusion

    PubMed Central

    Koehler, Sybille; Brähler, Sebastian; Kuczkowski, Alexander; Binz, Julia; Hackl, Matthias J.; Hagmann, Henning; Höhne, Martin; Vogt, Merly C.; Wunderlich, Claudia M.; Wunderlich, F. Thomas; Schweda, Frank; Schermer, Bernhard; Benzing, Thomas; Brinkkoetter, Paul T.

    2016-01-01

    Chronic alterations in calcium (Ca2+) signalling in podocytes have been shown to cause proteinuria and progressive glomerular diseases. However, it is unclear whether short Ca2+ peaks influence glomerular biology and cause podocyte injury. Here we generated a DREADD (Designer Receptor Exclusively Activated by a Designer Drug) knock-in mouse line to manipulate intracellular Ca2+ levels. By mating to a podocyte-specific Cre driver we are able to investigate the impact of Ca2+ peaks on podocyte biology in living animals. Activation of the engineered G-protein coupled receptor with the synthetic compound clozapine-N-oxide (CNO) evoked a short and transient Ca2+ peak in podocytes immediately after CNO administration in vivo. Interestingly, this Ca2+ peak did neither affect glomerular perfusion nor filtration in the animals. Moreover, no obvious alterations in the glomerular morphology could be observed. Taken together, these in vivo findings suggest that chronic alterations and calcium overload rather than an induction of transient Ca2+ peaks contribute to podocyte disease. PMID:27759104

  18. Analgesia dose prescribing and estimated glomerular filtration rate decline: a general practice database linkage cohort study

    PubMed Central

    Nderitu, Paul; Doos, Lucy; Strauss, Vicky Y; Lambie, Mark; Davies, Simon J; Kadam, Umesh T

    2014-01-01

    Objective We aimed to quantify the short-term effect of non-steroidal anti-inflammatory drugs (NSAIDs), aspirin and paracetamol analgesia dose prescribing on estimated glomerular filtration rate (eGFR) decline in the general practice population. Design A population-based longitudinal clinical data linkage cohort study. Setting Two large general practices in North Staffordshire, UK. Participants Patients aged 40 years and over with ≥2 eGFR measurements spaced ≥90 days apart between 1 January 2009 and 31 December 2010 were selected. Exposure Using WHO Defined Daily Dose standardised cumulative analgesia prescribing, patients were categorised into non-user, normal and high-dose groups. Outcome measure The primary outcome was defined as a >5 mL/min/1.73 m2/year eGFR decrease between the first and last eGFR. Logistic regression analyses were used to estimate risk, adjusting for sociodemographics, comorbidity, baseline chronic kidney disease (CKD) status, renin-angiotensin-system inhibitors and other analgesia prescribing. Results There were 4145 patients (mean age 66 years, 55% female) with an analgesia prescribing prevalence of 17.2% for NSAIDs, 39% for aspirin and 22% for paracetamol and stage 3–5 CKD prevalence was 16.1% (n=667). Normal or high-dose NSAID and paracetamol prescribing was not significantly associated with eGFR decline. High-dose aspirin prescribing was associated with a reduced risk of eGFR decline in patients with a baseline (first) eGFR ≥60 mL/min/1.73 m2; OR=0.52 (95% CI 0.35 to 0.77). Conclusions NSAID, aspirin and paracetamol prescribing over 2 years did not significantly affect eGFR decline with a reduced risk of eGFR decline in high-dose aspirin users with well-preserved renal function. However, the long-term effects of analgesia use on eGFR decline remain to be determined. PMID:25138808

  19. Estimated Glomerular Filtration Rate and Mortality among Patients with Coronary Heart Disease

    PubMed Central

    Ding, Ding; Xia, Min; Li, Dan; Yang, Yunou; Li, Qing; Liu, Jiaxing; Chen, Xuechen; Hu, Gang; Ling, Wenhua

    2016-01-01

    Objective The association between estimated glomerular filtration rate (eGFR) and the risk of mortality among patients with coronary heart disease (CHD) is complex and still unclear. The aim of this study was to evaluate the effect of eGFR on the risk prediction of all-cause and cardiovascular disease (CVD) mortality with a long follow-up period among patients with CHD in China. Methods We conducted a prospective cohort study of 3276 Chinese patients with CHD. Cox proportional hazards regression models were used to estimate the association of different levels of eGFR with the risks of mortality. Results During a mean follow-up period of 4.9 years, 293 deaths were identified. The multivariable-adjusted hazard ratios associated with different levels of eGFR (≥90 [reference group], 60–89, 30–59, 15–29 ml/min per 1.73m2) at baseline were 1.00, 1.28 (95% confidence interval [CI], 0.87–1.88), 1.96 (95% CI, 1.31–2.94), and 3.91 (95% CI, 2.15–7.13) (P <0.001) for all-cause mortality, and 1.00, 1.26 (95% CI, 0.78–2.04), 1.94 (95% CI, 1.17–3.20), and 3.77 (95% CI, 1.80–7.89) (P <0.001) for CVD mortality, respectively. After excluding subjects who died during the first 2 years of follow-up (n = 113), the graded associations of eGFR with the risks of all-cause and CVD morality were still present. The addition of eGFR to a model including traditional cardiovascular risk factors resulted in significant improvement in the prediction of all-cause and CVD mortality. Conclusions Reduced eGFR (< 60 ml/min per 1.73 m2) at baseline is associated with increased risks of all-cause and CVD mortality among Chinese patients with CHD. PMID:27537335

  20. Prognostic value of estimated glomerular filtration rate in hospitalized elderly patients.

    PubMed

    De La Higuera, Laura; Riva, Emma; Djade, Codjo Djignefa; Mandelli, Sara; Franchi, Carlotta; Marengoni, Alessandra; Salerno, Francesco; Corrao, Salvatore; Pasina, Luca; Tettamanti, Mauro; Marcucci, Maura; Mannucci, Pier Mannuccio; Nobili, Alessandro

    2014-10-01

    A multicenter observational study, REPOSI (REgistro POliterapie Società Italiana di Medicina Interna), was conducted to assess the prognostic value of glomerular filtration rate (eGFR) on in-hospital mortality, hospital re-admission and death within 3 months, in a sample of elderly patients (n = 1,363) admitted to 66 internal medicine and geriatric wards. Based on eGFR, calculated by the new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, subjects at hospital admission were classified into three groups: group 1 with normal eGFR (≥60 ml/min/1.73 m(2), reference group), group 2 with moderately reduced eGFR (30-59 ml/min/1.73 m(2)) and group 3 with severely reduced eGFR (<30 ml/min/1.73 m(2)). Patients with the lowest eGFR (group 3) on admission were more likely to be older, to have a greater cognitive and functional impairment and a high rate of comorbidities. Multivariable logistic regression analysis showed that severely reduced eGFR at the time of admission was associated with in-hospital mortality (OR 3.00; 95% CI 1.20-7.39, p = 0.0230), but not with re-hospitalization (OR 0.97; 95% CI 0.54-1.76, p = 0.9156) or mortality at 3 months after discharge (OR 1.93; 95% CI 0.92-4.04, p = 0.1582). On the contrary, an increased risk (OR 2.60; 95% CI 1.13-5.98, p = 0.0813) to die within 3 months after discharge was associated with decreased eGFR measured at the time of discharge. Our study demonstrates that severely reduced eGFRs in elderly patients admitted to hospital are strong predictors of the risk of dying during hospitalization, and that this measurement at the time of discharge helps to predict early death after hospitalization.

  1. Verification on the use of the Inoue method for precisely determining glomerular filtration rate in Philippine pediatrics

    NASA Astrophysics Data System (ADS)

    Magcase, M. J. D. J.; Duyan, A. Q.; Carpio, J.; Carbonell, C. A.; Trono, J. D.

    2015-06-01

    The objective of this study is to validate the Inoue method so that it would be the preferential choice in determining glomerular filtration rate (GFR) in Philippine pediatrics. The study consisted of 36 patients ranging from ages 2 months to 19 years old. The subjects used were those who were previously subjected to in-vitro method. The scintigrams of the invitro method was obtained and processed for split percentage uptake and for parameters needed to obtain Inoue GFR. The result of this paper correlates the Inoue GFR and In-vitro method (r = 0.926). Thus, Inoue method is a viable, simple, and practical technique in determining GFR in pediatric patients.

  2. Staging chronic kidney disease and estimating glomerular filtration rate: an opinion paper about the new international recommendations.

    PubMed

    Delanaye, Pierre; Cavalier, Etienne

    2013-10-01

    In January 2013, the international recommendations of the KDIGO (for "Kidney Disease: Improving Global Outcomes") to define chronic kidney disease (CKD) and classify patients in CKD stages have been published. In this opinion article, we will review and discuss the most important guidelines proposed about CKD staging and glomerular filtration rate (GFR) estimating. In particular, we question the choice of fixed knot values at 60 mL/min/1.73 m² to define CKD. We also question the strategies proposed to measure and use cystatin C results.

  3. An orally active adenosine A1 receptor antagonist, FK838, increases renal excretion and maintains glomerular filtration rate in furosemide-resistant rats

    PubMed Central

    Schnackenberg, Christine G; Merz, Emily; Brooks, David P

    2003-01-01

    Loop and thiazide diuretics are common therapeutic agents for the treatment of sodium retention and oedema. However, resistance to diuretics and decreases in renal function can develop during diuretic therapy. Adenosine causes renal vasoconstriction, sodium reabsorption, and participates in the tubuloglomerular feedback mechanism for the regulation of glomerular filtration rate.We tested the hypothesis that the selective adenosine A1 receptor antagonist FK838 is orally active and causes diuresis and natriuresis, but maintains glomerular filtration rate in normal rats or in rats with furosemide resistance.In normal male Sprague – Dawley rats, FK838 dose-dependently increased urine flow and sodium and chloride excretion while sparing potassium. In combination with furosemide, FK838 enhanced the diuretic and natriuretic actions of furosemide to the same extent as hydrochlorothiazide and did not increase the potassium loss in normal rats. In furosemide-resistant rats, FK838 increased urine flow and electrolyte excretion to a greater extent than hydrochlorothiazide. In addition, hydrochlorothiazide significantly decreased glomerular filtration rate, whereas FK838 maintained glomerular filtration rate in furosemide-resistant rats.This study shows that the adenosine A1 receptor antagonist FK838 is orally active and causes potent diuresis and natriuresis and maintains glomerular filtration rate in normal or furosemide-resistant rats. Adenosine A1 receptor antagonists may be novel therapeutics for the treatment of oedema in normal or otherwise diuretic-resistant patients. PMID:12922924

  4. Burden of Hypertension and Abnormal Glomerular Permeability in Hypertensive School Children

    PubMed Central

    Ajite, Adebukola B; Aladekomo, Theophilus A; Aderounmu, Temilade; Olowu, Wasiu A

    2016-01-01

    Background Childhood hypertension has been associated with target-organ damage in young adults. It is often asymptomatic in both children and adolescents; when persistent, and long-standing, it could be a significant risk factor for kidney damage and increased glomerular permeability. Objectives Burden of hypertension and its impact on glomerular permeability were prospectively determined in randomly recruited primary school children. Patients and Methods Blood pressure (BP) measurement was performed by the auscultation method, and abnormal glomerular permeability was assessed by dipstick testing of urine for persistent proteinuria and/or hematuria for ≥ three months in hypertensive children. Results Of 1,335 pupils aged 10.0 ± 2.4 (6.0 - 14.0) years, 33 (2.5%) were hypertensive. Overall mean systolic/diastolic BP was 125.6 ± 6.5/81.7 ± 3.3 (range: 114.0 - 140.0/80.0 - 90.0) mmHg. Nine (27.3%) had combined systolic and diastolic hypertension, 126.7 ± 5.7/80.0 - 80.0 ± 0.0 (120.0 - 130.0/80.0 - 80.0) mmHg. Isolated systolic hypertension, 125.4 ± 6.7 (114.0 - 140.0) mmHg, was present in 14 (42.4%), whereas 10 (30.3%) had isolated diastolic hypertension, 82.0 ± 3.5 (80.0 - 90.0) mmHg. Mean systolic and diastolic BP were 131.0 ± 3.3 (130.0 - 140.0) mmHg and 86.5 ± 4.43 (80.0 - 90.0) mmHg, respectively. According to the dipstick test, none of the hypertensive pupils showed urinalysis evidence of proteinuria and/or hematuria after three months of testing. Conclusions Although the burden of hypertension was 2.5%, the dipstick method did not detect any hypertension-related abnormal glomerular permeability in the school children. PMID:27703956

  5. Relationship of glomerular filtration rate based on serum iodixanol clearance to IRIS staging in cats with chronic kidney disease.

    PubMed

    Iwama, Ryosuke; Sato, Tsubasa; Katayama, Masaaki; Shimamura, Shunsuke; Satoh, Hiroshi; Ichijo, Toshihiro; Furuhama, Kazuhisa

    2015-08-01

    We examined the correlation between the glomerular filtration rate (GFR) estimated from an equation based on the serum iodixanol clearance technique and International Renal Interest Society (IRIS) stages of chronic kidney disease (CKD) in cats. The equation included the injection dose, sampling time, serum concentration and estimated volume of distribution (Vd) of the isotonic, nonionic, contrast medium iodixanol as a test tracer. The percent changes in the median basal GFR values calculated from the equation in CKD cats resembled those of IRIS stages 1-3. These data validate the association between the GFR derived from the simplified equation and IRIS stages based on the serum creatinine concentration in cats with CKD. They describe the GFR ranges determined using single-sample iodixanol clearance for healthy cats and cats with various IRIS stages of CKD. PMID:25864431

  6. The clearance concept with special reference to determination of glomerular filtration rate in patients with fluid retention.

    PubMed

    Henriksen, Ulrik L; Henriksen, Jens H

    2015-01-01

    In subjects without fluid retention, the total plasma clearance of a renal filtration indicator (inulin, (99m) Tc-DTPA, (51) Cr-EDTA) is close to the urinary plasma clearance. Conversely, in patients with fluid retention (oedema, pleural effusions, ascites), there is a substantial discrepancy between the total plasma clearance and the urinary plasma clearance. This is owing to delayed indicator distribution to smaller or larger parts of the interstitial space, which in patients with ascites may simulate a peritoneal dialysator. In patients with fluid retention, urinary plasma clearance should be assessed to obtain a correct measurement of the glomerular filtration rate (GFR). In theory, total plasma clearance with late samples (24-h, 48-h) may be applied in patients with fluid retention, but validation hereof has not been performed. Until such studies are completed, it is recommended that patients with fluid retention have their GFR measured by a urinary plasma clearance technique with controlled quantitative urinary sampling within a few hours after indicator injection.

  7. Reduced glomerular filtration rate, inflammation and HDL cholesterol as main determinants of superoxide production in non-dialysis chronic kidney disease patients.

    PubMed

    Morena, Marion; Patrier, Laure; Jaussent, Isabelle; Bargnoux, Anne-Sophie; Dupuy, Anne-Marie; Badiou, Stéphanie; Leray-Moragues, Hélène; Klouche, Kada; Canaud, Bernard; Cristol, Jean-Paul

    2011-06-01

    Enhanced oxidative stress partly resulting from an over-production of superoxide anion (O(2)(•-)) represents a novel and particular risk factor in chronic kidney disease (CKD) patients. This study was therefore designed to evaluate O(2)(•-) determinants in this population. O(2)(•-) production was evaluated using chemiluminescence method in 136 CKD patients (79M/57F, median age: 69.5 [27.4-94.6]). Renal function (evaluated by the glomerular filtration rate using modification of diet in renal disease (MDRD)), inflammation, lipids, nutritional and bone mineral as well as clinical parameters were evaluated. Potential relationships between O(2)(•-) and these clinico-biological parameters were investigated to identify main determinants of such a pathological process. Enhanced O(2)(•-) production has been observed at the pre-dialysis phase: stages 4 and 5 of CKD (p = 0.0065). In multivariate analysis, low eGFR (MDRD <30 mL/min/1.73 m(2); p = 0.046), high fibrinogen (≥3.7 g/L; p = 0.044) and abnormal HDL cholesterol (<1.42 mmol/L and ≥ 1.75 mmol/L; p = 0.042) were the main determinants of O(2)(•-) production in CKD patients.

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

    SciTech Connect

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

    1989-07-01

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

  9. Measurement of glomerular filtration rate during flight in a migratory bird using a single bolus injection of FITC-inulin.

    PubMed

    Gerson, Alexander R; Guglielmo, Christopher G

    2013-09-15

    During migration, passerine birds typically complete a series of multi-hour flights, each followed by a period of stopover. During flight, rates of respiratory water loss are high, yet these birds show no signs of dehydration after flights. During stopover, birds become hyperphagic to replenish fat reserves, often consuming food with high water content, such as fruit. Thus migratory birds seem to face an osmoregulatory challenge; they must reduce water losses during flight but retain the ability to excrete large quantities of water while maintaining osmotic balance at stopover. Our goal was to measure glomerular filtration rate (GFR) and fractional water reabsorption (FWR) of a migratory bird in free flight, at rest, and during feeding to assess the role of the kidney in maintaining water balance during migration. We used FITC-inulin and one- and two-phase exponential decay models to first validate a technique and then measure GFR in the Swainson's thrush, a small (∼30 g) songbird. Single-phase exponential decay models and the modified slope intercept method overestimated GFR by 26% compared with two-phase exponential decay models. We found no differences in GFR among fed, resting and flying birds, but FWR was significantly higher in resting and flying birds relative to feeding birds. There was no effect of the rate of respiratory water loss on GFR or FWR in flight. These data support the idea that birds in flight do not dramatically alter GFR but rely on increased FWR to minimize excretory water losses.

  10. [Clinical usefulness of the new Japanese glomerular filtration rate equation for initial and individualized dosage adjustment concentrations of vancomycin].

    PubMed

    Kuroda, Naoki; Ueshima, Satoshi; Sato, Tomoaki; Kobiki, Eriko; Kawasaki, Yoichi; Matsunaga, Hisashi; Nakura, Hironori; Sendo, Toshiaki

    2012-01-01

    To clarify whether the new Japanese glomerular filtration rate (eGFR) equation was able to accurately determine the initial and individualized dosage adjustment concentrations of vancomycin (VCM), the predictive performance for VCM concentrations using the eGFR and Cockcroft-Gault (CG) equations was compared. Data were retrospectively collected from clinical records of 90 patients with MRSA infection whose trough and peak VCM concentrations had been determined. The predicted VCM initial and individualized dosage adjustment concentrations were performed with the 2-compartment linear model using pharmacokinetic parameter means and their individual values via Bayesian estimation, respectively. The prediction error (PE) and its absolute value (APE) between the observed and predicted VCM concentrations were calculated as indices of bias and accuracy in predictive performance, respectively. In the initial dosage adjustment of VCM, the PE value, calculated with the eGFR equation in trough and peak VCM concentrations of patients whose BMI were 18.5 kg/m(2) and higher, was significantly smaller than that calculated with the CG equation. In particular, both PE and APE values obtained from the eGFR calculated concentrations from nonelderly patients (younger than 65 years old) were significantly improved compared with those from the CG equation. In the individualized dosage adjustment of VCM, the eGFR equation gave a significantly smaller PE value in nonelderly patients' trough concentrations than the CG equation. These findings provide useful information for adjusting the VCM dosage to achieve optimal therapeutic efficacy in patients with MRSA infection.

  11. Reliability of single kidney glomerular filtration rate measured by a 99mTc-DTPA gamma camera technique

    SciTech Connect

    Rehling, M.; Moller, M.L.; Jensen, J.J.; Thamdrup, B.; Lund, J.O.; Trap-Jensen, J.

    1986-01-01

    The reliability of a previously published method for determination of single kidney glomerular filtration rate (SKGFR) by means of technetium-99m-diethylenetriaminepenta-acetate (99mTc-DTPA) gamma camera renography was evaluated. The day-to-day variation in the calculated SKGFR values was earlier found to be 8.8%. The technique was compared to the simultaneously measured renal clearance of inulin in 19 unilaterally nephrectomized patients with GFR varying from 11 to 76 ml/min. The regression line (y = 1.04 X -2.5) did not differ significantly from the line of identity. The standard error of estimate was 4.3 ml/min. In 17 patients the inter- and intraobserver variation of the calculated SKGFR values was 1.2 ml/min and 1.3 ml/min, respectively. In 21 of 25 healthy subjects studied (age range 27-29 years), total GFR calculated from the renograms was within an established age-dependent normal range of GFR.

  12. Association of glomerular filtration rate with slow coronary flow in patients with normal to mildly impaired renal function.

    PubMed

    Akin, Fatih; Celik, Omer; Ayça, Burak; Yalçin, Ahmet Arif; Altun, Ibrahim; Köse, Nuri

    2014-10-01

    We evaluated the association between estimated glomerular filtration rate (eGFR) and slow coronary flow (SCF) in patients with normal to mildly impaired renal function; 211 patients with angiographically proven SCF and 219 controls were studied. Patients were categorized based on the angiographic findings as with or without SCF. We used the Modification of Diet in Renal Disease equation to calculate eGFR. The frequency of mildly decreased eGFR, serum uric acid levels, and eGFR was higher in the SCF group. Patients with mildly impaired renal function had higher thrombolysis in myocardial infarction frame counts in 3 major coronary arteries. In logistic regression analysis, uric acid (odds ratio [OR] = 1.323, 95% confidence interval [CI] = 1.109-1.572, P = .002) and eGFR (OR = 0.972, 95% CI = 0.957-0.987, P < .001) were independent correlates of SCF. In conclusion, eGFR was significantly correlated with SCF in patients with normal to mildly impaired renal function.

  13. A Comprehensive Software and Database Management System for Glomerular Filtration Rate Estimation by Radionuclide Plasma Sampling and Serum Creatinine Methods.

    PubMed

    Jha, Ashish Kumar

    2015-01-01

    Glomerular filtration rate (GFR) estimation by plasma sampling method is considered as the gold standard. However, this method is not widely used because the complex technique and cumbersome calculations coupled with the lack of availability of user-friendly software. The routinely used Serum Creatinine method (SrCrM) of GFR estimation also requires the use of online calculators which cannot be used without internet access. We have developed user-friendly software "GFR estimation software" which gives the options to estimate GFR by plasma sampling method as well as SrCrM. We have used Microsoft Windows(®) as operating system and Visual Basic 6.0 as the front end and Microsoft Access(®) as database tool to develop this software. We have used Russell's formula for GFR calculation by plasma sampling method. GFR calculations using serum creatinine have been done using MIRD, Cockcroft-Gault method, Schwartz method, and Counahan-Barratt methods. The developed software is performing mathematical calculations correctly and is user-friendly. This software also enables storage and easy retrieval of the raw data, patient's information and calculated GFR for further processing and comparison. This is user-friendly software to calculate the GFR by various plasma sampling method and blood parameter. This software is also a good system for storing the raw and processed data for future analysis.

  14. Associations between proteinuria, systemic hypertension and glomerular filtration rate in dogs with renal and non-renal diseases.

    PubMed

    Wehner, A; Hartmann, K; Hirschberger, J

    2008-02-01

    Proteinuria and systemic hypertension are well recognised risk factors in chronic renal failure (CRF). They are consequences of renal disease but also lead to a further loss of functional kidney tissue. The objectives of this study were to investigate the associations between proteinuria, systemic hypertension and glomerular filtration rate (GFR) in dogs with naturally occurring renal and non-renal diseases, and to determine whether proteinuria and hypertension were associated with shorter survival times in dogs with CRF. Measurements of exogenous creatinine plasma clearance (ECPC), urine protein:creatinine ratio (UPC), and Doppler sonographic measurements of systolic blood pressure (SBP) were made in 60 dogs with various diseases. There was a weak but significant inverse correlation between UPC and ECPC, a significant inverse correlation between SBP and ECPC and a weak but significant positive correlation between UPC and SBP. Some of the dogs with CRF were proteinuric and almost all were hypertensive. Neoplasia was commonly associated with proteinuria in the dogs with a normal ECPC. CRF was the most common cause leading to hypertension. In the dogs with CRF, hypertension and marked proteinuria were associated with significantly shorter survival times.

  15. A Comprehensive Software and Database Management System for Glomerular Filtration Rate Estimation by Radionuclide Plasma Sampling and Serum Creatinine Methods.

    PubMed

    Jha, Ashish Kumar

    2015-01-01

    Glomerular filtration rate (GFR) estimation by plasma sampling method is considered as the gold standard. However, this method is not widely used because the complex technique and cumbersome calculations coupled with the lack of availability of user-friendly software. The routinely used Serum Creatinine method (SrCrM) of GFR estimation also requires the use of online calculators which cannot be used without internet access. We have developed user-friendly software "GFR estimation software" which gives the options to estimate GFR by plasma sampling method as well as SrCrM. We have used Microsoft Windows(®) as operating system and Visual Basic 6.0 as the front end and Microsoft Access(®) as database tool to develop this software. We have used Russell's formula for GFR calculation by plasma sampling method. GFR calculations using serum creatinine have been done using MIRD, Cockcroft-Gault method, Schwartz method, and Counahan-Barratt methods. The developed software is performing mathematical calculations correctly and is user-friendly. This software also enables storage and easy retrieval of the raw data, patient's information and calculated GFR for further processing and comparison. This is user-friendly software to calculate the GFR by various plasma sampling method and blood parameter. This software is also a good system for storing the raw and processed data for future analysis. PMID:26097422

  16. Coffee consumption and cystatin-C-based estimated glomerular filtration rates in healthy young adults: results of a clinical trial.

    PubMed

    Saito, Masafumi; Nemoto, Tohru; Tobimatsu, Satoshi; Ebata, Midori; Le, Yulan; Nakajima, Kei

    2011-01-01

    Recently it has been reported that the estimated glomerular filtration rate (eGFR) is higher in habitual coffee consumers than in noncoffee consumers. However, the causality remains unclear. Therefore, we conducted a clinical trial to investigate the effects of coffee consumption on kidney function. Nineteen asymptomatic nonsmokers aged 21-27 years old participated in this study. They consumed coffee (18 g coffee beans/450 mL per day) or green tea as a comparator for 2 weeks in a crossover design. Although creatinine-based eGFR was not affected after consuming either beverage, all cystatin-C-based eGFRs determined using five different equations were significantly increased after coffee consumption (means: 5.0-7.7%), but not after green tea consumption (means: 0.1-1.6%). Serum adiponectin and magnesium levels increased significantly after coffee consumption (means: 13.6% and 4.3%, resp.), but not after green tea consumption. These findings suggest that even a short period of coffee consumption may increase cystatin-C-based eGFR, along with favorable changes in serum adiponectin, in healthy young adults. PMID:21773013

  17. Subnormal Estimated Glomerular Filtration Rate Strongly Predict Incident Cardiovascular Events in Type 2 Diabetic Chinese Population With Normoalbuminuria

    PubMed Central

    Hsieh, Yi-Ting; Kuo, Jeng-Fu; Su, Shih-Li; Chen, Jung-Fu; Chen, Hung-Chun; Hsieh, Ming-Chia

    2016-01-01

    Abstract No study has evaluated whether subnormal estimated glomerular filtration rate (eGFR) (between 61 and 90 mL/min) and high normal albumin–creatinine ratio (ACR) (<30 mg/g) are associated with cardiovascular (CV) events and mortality in type 2 diabetic (T2DM) patients with normoalbuminuria. We observed a longitudinal cohort study of 1291 T2DM patients with normoalbuminuria who were receiving intensified multifactorial treatment from 2004 to 2008. Cox regression models were used to evaluate eGFR and ACR as the risk factors of major CV events (nonfatal myocardial infarction and stroke) and mortality. During the 4-year period, 56 patients died and 159 patients developed major CV events. We found eGFR, but not ACR, to be associated with major CV events. Compared to those with eGFR higher than 90 mL/min, patients with subnormal eGFR (HR: 3.133, 1.402–7.002, P = 0.005) were at greater risk of incident major CV events. Extremely low eGFR (<30 mL/min) was associated with mortality only in patients under 65 years old. Subnormal eGFR was a strong predictor of major CV events in diabetic patients with normoalbuminuria. Normoalbuminuric diabetic patients with subnormal eGFR may need intensive CV risk factor intervention to prevent and treat CV events. PMID:26765399

  18. Lower glomerular filtration rate is associated with higher systemic vascular resistance in patients without prevalent kidney disease.

    PubMed

    Vääräniemi, Kati; Koskela, Jenni; Tahvanainen, Anna; Tikkakoski, Antti; Wilenius, Matias; Kähönen, Mika; Kööbi, Tiit; Niemelä, Onni; Mustonen, Jukka; Pörsti, Ilkka

    2014-10-01

    The authors examined the association between estimated glomerular filtration rate (eGFR), calculated using the Chronic Kidney Disease Epidemiology Collaboration creatinine-cystatin C equation, and hemodynamics in 556 normotensive or never-treated hypertensive patients without kidney disease (mean age, 46 years). Hemodynamic variables were recorded using pulse wave analysis and whole-body impedance cardiography. The mean eGFR was 98 mL/min/1.73 m(2) (range, 64-145 mL/min/1.73 m(2) and one third of the patients had values below 92, while none had proteinuria. In linear regression analyses adjusted for differences in age, weight:height ratio, low-density lipoprotein cholesterol, and sex, significant associations were found between lower eGFR and higher systolic (P=.001) and diastolic blood pressure (P<.001) and higher systemic vascular resistance (P=.001). There was no association between eGFR and cardiac output or extracellular volume. In the absence of clinical kidney disease, lower eGFR was associated with higher blood pressure and systemic vascular resistance. Therefore, early impairment in kidney function may be involved in the pathogenesis of essential hypertension. PMID:25228202

  19. A Comprehensive Software and Database Management System for Glomerular Filtration Rate Estimation by Radionuclide Plasma Sampling and Serum Creatinine Methods

    PubMed Central

    Jha, Ashish Kumar

    2015-01-01

    Glomerular filtration rate (GFR) estimation by plasma sampling method is considered as the gold standard. However, this method is not widely used because the complex technique and cumbersome calculations coupled with the lack of availability of user-friendly software. The routinely used Serum Creatinine method (SrCrM) of GFR estimation also requires the use of online calculators which cannot be used without internet access. We have developed user-friendly software “GFR estimation software” which gives the options to estimate GFR by plasma sampling method as well as SrCrM. We have used Microsoft Windows® as operating system and Visual Basic 6.0 as the front end and Microsoft Access® as database tool to develop this software. We have used Russell's formula for GFR calculation by plasma sampling method. GFR calculations using serum creatinine have been done using MIRD, Cockcroft-Gault method, Schwartz method, and Counahan-Barratt methods. The developed software is performing mathematical calculations correctly and is user-friendly. This software also enables storage and easy retrieval of the raw data, patient's information and calculated GFR for further processing and comparison. This is user-friendly software to calculate the GFR by various plasma sampling method and blood parameter. This software is also a good system for storing the raw and processed data for future analysis. PMID:26097422

  20. Proteomic analysis of formalin-fixed paraffin-embedded glomeruli suggests depletion of glomerular filtration barrier proteins in two-kidney, one-clip hypertensive rats

    PubMed Central

    Finne, Kenneth; Vethe, Heidrun; Skogstrand, Trude; Leh, Sabine; Dahl, Tone D.; Tenstad, Olav; Berven, Frode S.; Reed, Rolf K.; Vikse, Bjørn Egil

    2014-01-01

    Background It is well known that hypertension may cause glomerular damage, but the molecular mechanisms involved are still incompletely understood. Methods In the present study, we used formalin-fixed paraffin-embedded (FFPE) tissue to investigate changes in the glomerular proteome in the non-clipped kidney of two-kidney one-clip (2K1C) hypertensive rats, with special emphasis on the glomerular filtration barrier. 2K1C hypertension was induced in 6-week-old Wistar Hannover rats (n = 6) that were sacrificed 23 weeks later and compared with age-matched sham-operated controls (n = 6). Tissue was stored in FFPE tissue blocks and later prepared on tissue slides for laser microdissection. Glomeruli without severe morphological damage were isolated, and the proteomes were analysed using liquid chromatography–tandem mass spectrometry. Results 2K1C glomeruli showed reduced abundance of proteins important for slit diaphragm complex, such as nephrin, podocin and neph1. The podocyte foot process had a pattern of reduced abundance of transmembrane proteins but unchanged abundances of the podocyte cytoskeletal proteins synaptopodin and α-actinin-4. Lower abundance of important glomerular basement membrane proteins was seen. Possible glomerular markers of damage with increased abundance in 2K1C were transgelin, desmin and acyl-coenzyme A thioesterase 1. Conclusions Microdissection and tandem mass spectrometry could be used to investigate the proteome of isolated glomeruli from FFPE tissue. Glomerular filtration barrier proteins had reduced abundance in the non-clipped kidney of 2K1C hypertensive rats. PMID:25129444

  1. Comparison of glomerular filtration rate measured between anterior and posterior image processing using Gates’ method in an ectopic pelvic kidney

    PubMed Central

    Li, Na; Li, Baojun; Liang, Wenli

    2016-01-01

    Objective The aim of this study was to evaluate the difference in measured glomerular filtration rate (GFR) of an ectopic pelvic kidney between anterior and posterior image processing using Gates’ method of renal dynamic imaging. Methods A total of 10 patients were studied retrospectively, with a single ectopic kidney in the pelvic cavity and a contralateral kidney at its normal anatomical position confirmed by ultrasound, computed tomography, renal dynamic imaging, etc. All images of ectopic kidneys were processed, and GFRs were measured using anterior and posterior Gates’ method of renal dynamic imaging, respectively. The contralateral normal kidney was only processed on posterior imaging. The total GFRant of one patient, which was equal to the sum of the GFR of a normal kidney on posterior imaging and the GFR of an ectopic kidney on anterior imaging, was compared with the total GFRpost of two kidneys on posterior imaging, with the GFRtwo-sample from the two-sample method, and with the estimated GFR in the Chronic Kidney Disease Epidemiology Collaboration equation. All correlation analyses were carried out between GFRs obtained from three methods, and all patients were followed up. For statistical analysis, nonparametric rank tests were used, Bland-Altman graphs were plotted. Results The mean GFR of the ectopic kidney on anterior imaging was 27.48±12.24 ml/min/1.73 m2. It was higher than the GFR (10.71±4.74 ml/min/1.73 m2) on posterior imaging (t=−2.803, P<0.05). There were statistical differences between the total GFRant and the total GFRtwo-sample (Z=−2.295, P<0.05), between the total GFRant and the total GFRpost (Z=2.599, P<0.01), between the total GFRtwo-sample and the total GFRpost (Z=−2.191, P<0.05), and between the total GFRant and the estimated glomerular filtration rate (Z=−2.803, P<0.01). The bias of the total GFRant was different from that of the total GFRpost (Z=−2.191, P<0.05). There were no differences in the precision and

  2. Comparison between Three Different Equations for the Estimation of Glomerular Filtration Rate in Omani Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Al-Maqbali, Salima R. S.; Mula-Abed, Waad-Allah S.

    2014-01-01

    Objectives: Estimated glomerular filtration rate (eGFR) is an important component of a patient’s renal function profile. The Modification of Diet in Renal Disease (MDRD) equation and the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation are both commonly used. The aim of this study was to compare the performance of the original MDRD186, revised MDRD175 and CKD-EPI equations in calculating eGFR in type 2 diabetes mellitus (T2DM) patients in Oman. Methods: The study included 607 T2DM patients (275 males and 332 females, mean age ± standard deviation 56 ± 12 years) who visited primary health centres in Muscat, Oman, during 2011 and whose renal function was assessed based on serum creatinine measurements. The eGFR was calculated using the three equations and the patients were classified based on chronic kidney disease (CKD) stages according to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines. A performance comparison was undertaken using the weighted kappa test. Results: The median eGFR (mL/min/1.73 m2) was 92.9 for MDRD186, 87.4 for MDRD175 and 93.7 for CKD-EPI. The prevalence of CKD stage 1 was 55.4%, 44.7% and 57% while for stages 2 and 3 it was 43.2%, 54% and 41.8%, based on MDRD186, MDRD175 and CKD-EPI, respectively. The agreement between MDRD186 and CKD-EPI (к 0.868) was stronger than MDRD186 and MDRD175 (к 0.753) and MDRD175 and CKD-EPI (к 0.730). Conclusion: The performances of MDRD186 and CKD-EPI were comparable. Considering that CKD-EPI-based eGFR is known to be close to isotopically measured GFR, the use of MDRD186 rather than MDRD175 may be recommended. PMID:24790742

  3. Assessing Glomerular Filtration Rate in Hospitalized Patients: A Comparison Between CKD-EPI and Four Cystatin C-Based Equations

    PubMed Central

    de la Torre, Judith; Ramos, Natalia; Quiroz, Augusto; Garjau, Maria; Torres, Irina; Azancot, M. Antonia; López, Montserrat; Sobrado, Ana

    2011-01-01

    Summary Background and objectives A specific method is required for estimating glomerular filtration rate GFR in hospitalized patients. Our objective was to validate the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and four cystatin C (CysC)–based equations in this setting. Design, setting, participants, & measurements This was an epidemiologic, cross-sectional study in a random sample of hospitalized patients (n = 3114). We studied the accuracy of the CKD-EPI and four CysC-based equations—based on (1) CysC alone or (2) adjusted by gender; (3) age, gender, and race; and (4) age, gender, race, and creatinine, respectively—compared with GFR measured by iohexol clearance (mGFR). Clinical, biochemical, and nutritional data were also collected. Results The CysC equation 3 significantly overestimated the GFR (bias of 7.4 ml/min per 1.73 m2). Most of the error in creatinine-based equations was attributable to calculated muscle mass, which depended on patient's nutritional status. In patients without malnutrition or reduced body surface area, the CKD-EPI equation adequately estimated GFR. Equations based on CysC gave more precise mGFR estimates when malnutrition, extensive reduction of body surface area, or loss of muscle mass were present (biases of 1 and 1.3 ml/min per 1.73 m2 for equations 2 and 4, respectively, versus 5.9 ml/min per 1.73 m2 for CKD-EPI). Conclusions These results suggest that the use of equations based on CysC and gender, or CysC, age, gender, and race, is more appropriate in hospitalized patients to estimate GFR, since these equations are much less dependent on patient's nutritional status or muscle mass than the CKD-EPI equation. PMID:21852668

  4. Correlation between Serum Lipid Levels and Measured Glomerular Filtration Rate in Chinese Patients with Chronic Kidney Disease

    PubMed Central

    Wang, Caixia; Ye, Zengchun; Li, Shaomin; Liu, Qiong; Lou, Tanqi

    2016-01-01

    Introduction Dyslipidemia is often detected in patients with chronic kidney disease (CKD). Previous studies of the relationship between lipid profiles and kidney function have yielded variable results. We aimed to investigate the correlation between serum lipid levels and kidney function evaluated by measured glomerular filtration rate (mGFR) in Chinese patients with CKD. Methods A cross-sectional study was conducted on 2036 Chinese CKD patients who had mGFR. Linear regression analysis was performed to evaluate the correlation between different serum lipid levels and mGFR, while logistic regression analysis was used to investigate the association between CKD stages and the risk of different types of dyslipidemia. Results The mean age was 55 years and the mean mGFR was 63 mL/min/1.73m2. After adjusting for some confounders (age, gender, body mass index, a history of diabetes, fasting glucose, a history of hypertension, systolic blood pressure, diastolic blood pressure, smoking status, hemoglobin, serum potassium, serum albumin, and serum uric acid), serum triglyceride level showed a negative correlation with mGFR (β = -0.006, P = 0.006) in linear regression analysis, and CKD stages were positively related to the risk of hypertriglyceridemia (odds ratios were 1.329, 1.868, 2.514 and P were 0.046, < 0.001, < 0.001 for CKD stage 2, 3, 4/5, respectively) in logistic regression anlysis. Conclusions Serum triglyceride level is independently association with mGFR. Patients with reduced kidney function are more likely to have higher serum triglyceride levels. Further longitudinal, multicenter and well-conducted studies are needed to provide more evidence. PMID:27695128

  5. Estimation of glomerular filtration rate in healthy cats using single-slice dynamic CT and Patlak plot analysis.

    PubMed

    Granger, L Abbigail; Armbrust, Laura J; Rankin, David C; Ghering, Ronette; Bello, Nora M; Alexander, Kate

    2012-01-01

    Commonly used clinical indicators of renal disease are either insensitive to early dysfunction or have delayed results. Decreased glomerular filtration rate (GFR) indicates renal dysfunction before there is a loss of 50% of functional nephrons. Most tests evaluate global rather than individual kidney function. Dynamic computed tomography (CT) and Patlak plot analysis allows for individual GFR to be tested. Our objectives were to establish a procedure and provide reference values for determination of global GFR in 10 healthy cats using dynamic CT (CTGFR). This method of GFR determination was compared against serum iohexol clearance (SIC). A single CT slice centered on both kidneys and the aorta was acquired every fifth second during and after a bolus injection of iohexol (240 mgI/ml; 300 mgI/kg) for 115 s. Using data from this dynamic acquisition, Patlak plots were obtained, GFR was calculated, and results were compared to global GFR determined by iohexol clearance. The average global CTGFR estimate was 1.84 ml/min x kg (SD = 0.43; range = [1.22, 2.45]). The average global GFR measured using SIC was 2.45 ml/min x kg (SD = 0.58; range = [1.72, 3.69]). GFR measurements estimated by both dynamic CT and SIC were positively associated (estimated Spearman rank correlation coefficient = 0.72; P = 0.0234). The CTGFR method consistently underestimated GFR with a bias of -0.62 (SE = 0.1307) when compared to SIC (P = 0.0011). In healthy cats, CTGFR was capable of determining individual kidney function and appears clinically promising. PMID:22182065

  6. Risk Stratification by 24-Hour Ambulatory Blood Pressure and Estimated Glomerular Filtration Rate in 5322 Subjects From 11 Populations

    PubMed Central

    Boggia, José; Thijs, Lutgarde; Li, Yan; Hansen, Tine W.; Kikuya, Masahiro; Björklund-Bodegård, Kristina; Ohkubo, Takayoshi; Jeppesen, Jørgen; Torp-Pedersen, Christian; Dolan, Eamon; Kuznetsova, Tatiana; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Malyutina, Sofia; Casiglia, Edoardo; Nikitin, Yuri; Lind, Lars; Schwedt, Emma; Sandoya, Edgardo; Kawecka-Jaszcz, Kalina; Filipovský, Jan; Imai, Yutaka; Wang, Jiguang; Ibsen, Hans; O’Brien, Eoin; Staessen, Jan A.

    2013-01-01

    No previous study addressed whether in the general population estimated glomerular filtration rate (eGFR [Chronic Kidney Disease Epidemiology Collaboration formula]) adds to the prediction of cardiovascular outcome over and beyond ambulatory blood pressure. We recorded health outcomes in 5322 subjects (median age, 51.8 years; 43.1% women) randomly recruited from 11 populations, who had baseline measurements of 24-hour ambulatory blood pressure (ABP24) and eGFR. We computed hazard ratios using multivariable-adjusted Cox regression. Median follow-up was 9.3 years. In fully adjusted models, which included both ABP24 and eGFR, ABP24 predicted (P≤0.008) both total (513 deaths) and cardiovascular (206) mortality; eGFR only predicted cardiovascular mortality (P=0.012). Furthermore, ABP24 predicted (P≤0.0056) fatal combined with nonfatal events as a result of all cardiovascular causes (555 events), cardiac disease (335 events), or stroke (218 events), whereas eGFR only predicted the composite cardiovascular end point and stroke (P≤0.035). The interaction terms between ABP24 and eGFR were all nonsignificant (P≥0.082). For cardiovascular mortality, the composite cardiovascular end point, and stroke, ABP24 added 0.35%, 1.17%, and 1.00% to the risk already explained by cohort, sex, age, body mass index, smoking and drinking, previous cardiovascular disease, diabetes mellitus, and antihypertensive drug treatment. Adding eGFR explained an additional 0.13%, 0.09%, and 0.14%, respectively. Sensitivity analyses stratified for ethnicity, sex, and the presence of hypertension or chronic kidney disease (eGFR <60 mL/min per 1.73 m2) were confirmatory. In conclusion, in the general population, eGFR predicts fewer end points than ABP24. Relative to ABP24, eGFR is as an additive, not a multiplicative, risk factor and refines risk stratification 2- to 14-fold less. PMID:23172928

  7. Association between the Delta Estimated Glomerular Filtration Rate and the Prevalence of Monoclonal Gammopathy of Undetermined Significance in Korean Males

    PubMed Central

    Chun, Sail; Min, Won-Ki

    2014-01-01

    Background. We investigated the association between the reduction in the estimated glomerular filtration rate (eGFR) and the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in Korean males. Methods. We enrolled 723 healthy Korean males. Serum creatinine concentration, serum electrophoresis, serum immunofixation, and the serum free light chain assay were performed. We calculated delta eGFR per year (ΔeGFR/yr). The prevalence of MGUS was compared based on the ΔeGFR/yr and age group. Results. Thirteen (1.8%) of 723 participants exhibited the monoclonal band on serum immunofixation. Prevalence of MGUS by age group was 0.00% (0/172 for 40 years), 1.63% (6/367 for 60 years), and 3.80% (7/184 for >60 years). The median decrease in ΔeGFR/yr was 5.3%. The prevalence of MGUS in participants in their 50s with >5.3% decline in ΔeGFR/yr was significantly higher than those with <5.3% decrease in ΔeGFR/yr (3.16% versus 0.00%; P = 0.049). The prevalence of MGUS in participants in their 50s with >5.3% decrease in ΔeGFR/yr was similar to that of healthy males in their 60s. Conclusion. Using the rate of reduction in ΔeGFR/yr in healthy Korean males who had their serum creatinine level checked regularly may increase the MGUS detection rate in clinical practice. PMID:24895568

  8. Fully automatic region of interest selection in glomerular filtration rate estimation from 99mTc-DTPA renogram.

    PubMed

    Lin, Kun-Ju; Huang, Jia-Yann; Chen, Yung-Sheng

    2011-12-01

    Glomerular filtration rate (GFR) is a common accepted standard estimation of renal function. Gamma camera-based methods for estimating renal uptake of (99m)Tc-diethylenetriaminepentaacetic acid (DTPA) without blood or urine sampling have been widely used. Of these, the method introduced by Gates has been the most common method. Currently, most of gamma cameras are equipped with a commercial program for GFR determination, a semi-quantitative analysis by manually drawing region of interest (ROI) over each kidney. Then, the GFR value can be computed from the scintigraphic determination of (99m)Tc-DTPA uptake within the kidney automatically. Delineating the kidney area is difficult when applying a fixed threshold value. Moreover, hand-drawn ROIs are tedious, time consuming, and dependent highly on operator skill. Thus, we developed a fully automatic renal ROI estimation system based on the temporal changes in intensity counts, intensity-pair distribution image contrast enhancement method, adaptive thresholding, and morphological operations that can locate the kidney area and obtain the GFR value from a (99m)Tc-DTPA renogram. To evaluate the performance of the proposed approach, 30 clinical dynamic renograms were introduced. The fully automatic approach failed in one patient with very poor renal function. Four patients had a unilateral kidney, and the others had bilateral kidneys. The automatic contours from the remaining 54 kidneys were compared with the contours of manual drawing. The 54 kidneys were included for area error and boundary error analyses. There was high correlation between two physicians' manual contours and the contours obtained by our approach. For area error analysis, the mean true positive area overlap is 91%, the mean false negative is 13.4%, and the mean false positive is 9.3%. The boundary error is 1.6 pixels. The GFR calculated using this automatic computer-aided approach is reproducible and may be applied to help nuclear medicine physicians in

  9. Glomerular Filtration Rate and Urine Albumin to Creatinine Ratio Associated With Hearing Impairment Among Korean Adults With Diabetes

    PubMed Central

    Cho, Yunji; Kim, Do Hoon; Choi, June; Lee, Joo Kyung; Roh, Yong-Kyun; Nam, Hyo-Yun; Nam, Ga-Eun; Kim, Dong-Won; Lee, Seung-Hyun; Lee, Chung-Woo; Han, Kyungdo; Park, Yong-Gyu

    2016-01-01

    Abstract The objective of this study was to examine the association of estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (ACR) with hearing impairment among diabetic adults in Korea. The study was based on data from Korea National Health and Nutrition Examination Survey 2011 to 2012. Participants were 1206 diabetic adults, aged over 19 years, who completed audiometric testing supervised by nationally certified clinicians. Hearing impairment was defined in three grades: no hearing impairment (pure-tone average 0–25 dB), slight hearing impairment (26–40 dB), and disabling hearing impairment (>40 dB) in the better ear at frequencies 0.5, 1, 2, 3, 4 and 6 kHz. Using logistic regression, risk of hearing impairment was assessed after having controlled for confounding factors. Higher levels of ACR and lower levels of eGFR correlated with an increase in percentage of disabling hearing impairment both unilaterally and bilaterally (P < 0.001). Controlling for possible confounding covariates, odds ratios for hearing impairment showed tendency to increase in higher ACR groups (P for trend = 0.029). Similar pattern was examined between eGFR and hearing impairment (P for trend = 0.006). Odds ratios were 1.981 (1.146, 3.424) for ACR Q4 and 2.773 (1.286, 5.983) for eGFR < 60 mL/min. Fall in eGFR and rise in ACR correlated with severity of hearing impairment. The association existed independently of age, sex, body mass index (BMI), smoking, drinking, exercise, new onset of diabetes, education, income, mental stress, noise exposure, and metabolic syndrome. PMID:27124027

  10. Low glomerular filtration rate is a risk factor for ribavirin-associated anaemia in old patients with chronic hepatitis C.

    PubMed

    Borroni, G; Cazzaniga, M; Andreoletti, M; Ceriani, R; Guerzoni, P; Omazzi, B; Pich, M G L; Prada, A; Spinzi, G; Terreni, N; Salerno, F

    2013-04-01

    Elderly patients with chronic hepatitis C have a reduced responsiveness to antiviral therapy with Peg-interferon and ribavirin. The dose reduction or the discontinuation of ribavirin due to the occurrence of anaemia is one of the most important causes for the low sustained viral response observed in older patients. We aimed to evaluate the relationship between baseline renal function and the early onset of ribavirin-associated anaemia in older (≥60 years) patients. Using data from 348 patients with chronic hepatitis C consecutively treated with peg-interferon plus ribavirin, we investigated which factors were associated with the occurrence of anaemia in elderly patients (≥60 years). Ribavirin-induced anaemia occurred in 40.5% of patients. Older patients showed a rate of anaemia significantly higher than younger patients (51.5% vs 36.3%; P = 0.009). Consequently, the rate of ribavirin dose reduction or discontinuation due to anaemia was 35.1% in older patients and 23.5% in younger patients (P = 0.029). A significantly higher proportion of older patients had a low baseline glomerular filtration rate (GFR) compared with younger patients (56.7% vs 27.1%; P < 0.001). At the multivariate regression analysis, low baseline GFR (<70 mL/min) was associated with an increased risk of ribavirin-associated anaemia only in the older patients (OR: 3.526; 95% CI: 1.385-8.979; P = 0.008). In this subset, baseline GFR was significantly correlated with both absolute (r = -0.320; P < 0.001) and relative (r = -0.324; P < 0.001) haemoglobin decrease within the first 8 weeks of treatment. In patients aged >60 years, a low pre-treatment GFR was strongly associated with the risk to develop ribavirin-related anaemia with consequent reduction in ribavirin doses. PMID:23490395

  11. The effects of amino acid loading on glomerular filtration in dogs on different protein diets: a controlled study.

    PubMed

    Fine, A

    1988-08-01

    Considerable variation in both the magnitude and pattern of response of glomerular filtration rate (GFR) to protein loading in omnivores has been reported in the literature. These experiments were designed to examine, under carefully controlled conditions, the effects of different acute protein loads given to a group of dogs placed on a normal protein (NP) intake for 4 weeks and to the same dogs when on a low protein (LP) intake for the same duration. GFR did not change when the dogs were changed from NP to LP diets, 3.0 + 0.2 (NP) vs. 3.2 + 0.3 (LP) mL.min-1.kg-1. Intravenous amino acid was infused at 15, 25, and 40 mL/h on different days. Regardless of whether on a low or high protein diet, the GFR did not change. Another set of experiments was performed in another Canadian centre 2000 miles away. In these studies with dogs on a similar normal protein diet, a striking rise in GFR occurred following amino-acid infusion at 25 mL/h, 3.1 + 0.3 vs. 4.8 + 0.6 mL.min-1.kg-1 (p less than 0.001). These results demonstrate, at least in the dog, that contrary to previous reports, dietary protein changes do not affect the GFR. Furthermore, the GFR response to an acute intravenous protein load does not depend on the amount of protein given nor the previous protein diet but appears to be possibly dependent on other factors that may be environmental or congenital.

  12. Abnormal development of glomerular endothelial and mesangial cells in mice with targeted disruption of the lama3 gene.

    PubMed

    Abrass, C K; Berfield, A K; Ryan, M C; Carter, W G; Hansen, K M

    2006-09-01

    Mice with targeted disruption of the lama3 gene, which encodes the alpha3 chain of laminin-5 (alpha3beta3gamma2, 332), develop a blistering skin disease similar to junctional epidermolysis bullosa in humans. These animals also develop abnormalities in glomerulogenesis. In both wild-type and mutant animals (lama3(-/-)), podocytes secrete glomerular basement membrane and develop foot processes. Endothelial cells migrate into this scaffolding and secrete a layer of basement membrane that fuses with the one formed by the podocyte. In lama3(-/-) animals, glomerular maturation arrests at this stage. Endothelial cells do not attenuate, develop fenestrae, or form typical lumens, and mesangial cells (MCs) were not identified. LN alpha3 subunit (LAMA3) protein was identified in the basement membrane adjacent to glomerular endothelial cells (GEnCs) in normal rats and mice. In developing rat glomeruli, the LAMA3 subunit was first detectable in the early capillary loop stage, which corresponds to the stage at which maturation arrest was observed in the mutant mice. Lama3 mRNA and protein were identified in isolated rat and mouse glomeruli and cultured rat GEnCs, but not MC. These data document expression of LAMA3 in glomeruli and support a critical role for it in GEnC differentiation. Furthermore, LAMA3 chain expression and/or another product of endothelial cells are required for MC migration into the developing glomerulus. PMID:16850021

  13. Glomerular filtration rate

    MedlinePlus

    ... formulas are used for adults and children. The formula includes some or all of the following: Age Blood creatinine measurement Ethnicity Gender Height Weight The creatinine clearance test , which involves a 24- ...

  14. Canine Systemic Lupus Erythematosus. TRANSMISSION OF SEROLOGIC ABNORMALITIES BY CELL-FREE FILTRATES

    PubMed Central

    Lewis, Robert M.; Andre-Schwartz, Janine; Harbis, Gerald S.; Hirsch, Martin S.; Black, Paul H.; Schwartz, Robert S.

    1973-01-01

    The presence of viruses was sought in a colony of dogs bred from parents with systemic lupus crythematosus (SLE). Cell-free filtrates prepared from the spleens of these animals were injected into newborn dogs, mice, and rats. The canine recipients developed antinuclear antibody (ANA) and positive lupus erythematosus (LE) cell tests: ANA and, in some cases, antinative DNA antibodies were produced by the murine recipients: no abnormalities were detected in the rats. Serial passage of spleen cells or cell-free filtrates of spleen tissue in syngeneic mice reduced the time required for appearance of ANA from 9 to 4 mo. Some murine recipients of the canine filtrate developed malignant lymphomas. Murine leukemia viruses were identified in these tumors by electron microscopic, virologic, and serologic technics. These neoplasms, but not other tumors known to contain murine leukemia viruses, were associated with the production of ANA. Puppies inoculated with the canine filtrate-induced mouse lymphoma developed ANA and positive LE cell tests within 4 mo. The results were interpreted to indicate the presence in canine SLE of a virus capable of: (a) inducing the serologic abnormalities of SLE in normal dogs and mice: (b) activating latent murine leukemia viruses: and (c) spreading by both horizonal and vertical routes. Images PMID:4124208

  15. Heparin-binding EGF-like growth factor contributes to reduced glomerular filtration rate during glomerulonephritis in rats

    PubMed Central

    Feng, Lili; Garcia, Gabriela E.; Yang, Young; Xia, Yiyang; Gabbai, Francis B.; Peterson, Orjan W.; Abraham, Judith A.; Blantz, Roland C.; Wilson, Curtis B.

    2000-01-01

    Heparin-binding epidermal growth factor–like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, is expressed during inflammatory and pathological conditions. We have cloned the rat HB-EGF and followed the expression of HB-EGF in rat kidneys treated with anti– glomerular basement membrane (anti–GBM) antibody (Ab) to induce glomerulonephritis (GN). We observed glomerular HB-EGF mRNA and protein within 30 minutes of Ab administration and showed by in situ hybridization that glomerular HB-EGF mRNA expression was predominantly in mesangial and epithelial cells. Expression of HB-EGF correlated with the onset of decreased renal function in this model. To test the direct effect of HB-EGF on renal function, we infused the renal cortex with active rHB-EGF, prepared from transfected Drosophila melanogaster cells. This treatment induced a significant decrease in single nephron GFR (SNGFR), single nephron plasma flow, and glomerular ultrafiltration coefficient and an increase in the glomerular capillary hydrostatic pressure gradient. In addition, anti–HB-EGF Ab administered just before anti-GBM Ab blocked the fall in SNGFR and GFR at 90 minutes without any change in the glomerular histologic response. These studies suggest that HB-EGF expressed early in the anti-GBM Ab GN model contributes to the observed acute glomerular hemodynamic alterations. PMID:10675360

  16. Effect of Proteinuria and Glomerular Filtration Rate on Renal Outcome in Patients with Biopsy-Proven Benign Nephrosclerosis

    PubMed Central

    Sumida, Keiichi; Hoshino, Junichi; Ueno, Toshiharu; Mise, Koki; Hayami, Noriko; Suwabe, Tatsuya; Kawada, Masahiro; Imafuku, Aya; Hiramatsu, Rikako; Hasegawa, Eiko; Yamanouchi, Masayuki; Sawa, Naoki; Fujii, Takeshi; Ohashi, Kenichi; Takaichi, Kenmei; Ubara, Yoshifumi

    2016-01-01

    Background Reduced estimated glomerular filtration rate (eGFR) and proteinuria are risk factors for end-stage renal disease (ESRD), of which benign nephrosclerosis is a common cause. However, few biopsy-based studies have assessed these associations. Methods We performed retrospective cohort study of 182 Japanese patients who underwent renal biopsy from June 1985 through March 2014 and who were diagnosed with benign nephrosclerosis. Competing risk regression analyses were used to investigate the effect of eGFR and proteinuria levels at the time of renal biopsy on the risk for renal events (ESRD or a 50% decline in eGFR from baseline). Results During a median 5.8-year follow-up, 63 (34.6%) patients experienced renal events. The incidence of renal events increased with lower baseline eGFR and greater baseline proteinuria levels. After adjustment for baseline covariates, lower eGFR levels (subhazard ratios [SHRs], 1.30; 95% confidence interval [CI], 1.01–1.67, per 10 mL/min/1.73 m2) and higher proteinuria levels (SHR, 1.52; 95% CI, 1.23–1.87, per 1.0 g/day) at the time of renal biopsy were associated independently with higher risk for renal events. Lower levels of serum albumin (SHR, 2.07; 95% CI, 1.20–3.55 per 1.0 g/dL) were also associated with renal events. Patients with both eGFR <30 mL/min/1.73 m2 and proteinuria ≥0.5 g/day had a 26.7-fold higher risk (95% CI, 3.97–179.4) of renal events than patients with both eGFR ≥60 mL/min/1.73 m2 and proteinuria <0.5 g/day. Conclusions Reduced eGFR and increased proteinuria as well as lower serum albumin at the time of renal biopsy are independent risk factors for renal events among patients with biopsy-proven benign nephrosclerosis. PMID:26809068

  17. Renal evaluation in the healthy green iguana (Iguana iguana): assessment of plasma biochemistry, glomerular filtration rate, and endoscopic biopsy.

    PubMed

    Hernandez-Divers, Stephen J; Stahl, Scott J; Stedman, Nancy L; Hernandez-Divers, Sonia M; Schumacher, Juergen; Hanley, Christopher S; Wilson, Heather; Vidyashankar, Anand N; Zhao, Ying; Rumbeiha, Wilson K

    2005-06-01

    Plasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (+/- SD) values for packed cell volume (30 +/- 3%), total protein (62 +/- 7 g/L, 6.2 +/- 0.7 g/dl), albumin (25 +/- 2 g/L, 2.5 +/- 0.2 g/dl), globulin (37 +/- 6 g/L, 3.7 +/- 0.6 g/ dl), total calcium (3.0 +/- 0.2 mmol/L, 12.0 +/- 0.7 mg/dl), ionized calcium (1.38 +/- 0.1 mmol/L), phosphorus (1.32 +/- 0.28 mmol/L, 4.1 +/- 0.9 mg/dl), uric acid (222 +/- 100 micromol/L, 3.8 +/- 1.7 mg/dl), sodium (148 +/- 3 mmol/L or mEq/ L), and potassium (2.6 +/- 0.4 mmol/L or mEq/L) were considered within normal limits. Values for urea were low (< 1.4 mmol/L, < 4 mg/dl) with 70% of samples below the detectable analyzer range. After the i.v. injection of 75 mg/ kg iohexol into the caudal (ventral coccygeal or tail) vein, serial blood collections were performed over 32 hr. Iohexol assays by high-performance liquid chromatography produced plasma iohexol clearance graphs for each lizard. A three-compartment model was used to fit area under the curve values and to obtain the glomerular filtration rate (GFR) using regression analysis. The mean GFR (SD) was 16.56 +/- 3.90 ml/kg/hr, with a 95% confidence interval of 14.78-18.34 ml/kg/hr. Bilateral endoscopic renal evaluation and biopsy provided tissue samples of excellent diagnostic quality, which correlated with tissue harvested at necropsy and evaluated histologically. None of the 23 animals demonstrated any adverse effects of iohexol clearance or endoscopy. Recommended diagnostics for the evaluation of renal function and disease in the green iguana include plasma biochemical profiles, iohexol clearance, endoscopic examination, and renal biopsy.

  18. Comparison of plasma clearance of exogenous creatinine, exo-iohexol, and endo-iohexol over a range of glomerular filtration rates expected in cats.

    PubMed

    van Hoek, Ingrid M; Lefebvre, Hervé P; Paepe, Dominique; Croubels, Siska; Biourge, Vincent; Daminet, Sylvie

    2009-12-01

    The study investigated plasma clearance of exogenous creatinine (PECCT), exo-iohexol (PexICT) and endo-iohexol (PenICT) in six healthy cats, four cats with chronic kidney disease (CKD) and six hyperthyroid (HT) cats to assess potential differences in glomerular filtration rate (GFR) measurement over a wide range of GFR values. The PECCT, PexICT and PenICT were performed in a combined protocol. There was a significant difference between PexICT and PenICT and PECCT in healthy cats. Differences between clearance techniques are suggested to be correlated to range in GFRs and should be taken into account when GFR is measured. PMID:19679501

  19. Ramadan fasting and chronic kidney disease: does estimated glomerular filtration rate change after and before Ramadan? Insights from a mini meta-analysis

    PubMed Central

    Bragazzi, Nicola Luigi

    2015-01-01

    Ramadan fasting represents one of the five pillars of the Islam creed. Even though patients are exempted from this religious duty, they may be eager to share this particular moment of the year with their family and peers, taking part in the intense spiritual ceremonies and events that characterize this month. However, there are no guidelines or standardized protocols that can help physicians to properly address the issue of patients with chronic kidney disease fasting in Ramadan and correctly advising them. For this purpose, we carried out a systematic review and a meta-analysis to see whether glomerular filtration rate value changed before and after Ramadan. Our main findings are that: chronic kidney disease patients can safely fast during Ramadan since glomerular filtration rate does not change in a statistically significant way and, even though most studies have been carried out during Ramadan falling in cold seasons, the sensitivity analysis did not reveal any impact of seasonality. Further research in the field is needed. PMID:26082658

  20. Additive effect of polymorphisms in the β2 -adrenoceptor and NADPH oxidase p22 phox genes contributes to the loss of estimated glomerular filtration rate in Chinese.

    PubMed

    Wang, Tao; Zhang, Yan; Ma, JingTao; Feng, Zhen; Niu, Kai; Liu, Bing

    2014-09-01

    Because increased oxidative stress may mediate the detrimental actions of enhanced sympathetic nervous activity on renal function and vice versa, we investigated the effect of the polymorphic Arg16Gly in the β2 -adrenoceptor (ADRB2) gene, Trp64Arg in the β3 -adrenoceptor (ADRB3) gene and C242T in the NADPH oxidase p22phox (CYBA) gene on estimated glomerular filtration rate (eGFR) in a Chinese population. Initially recruited from different outpatient services of HeBei General Hospital in northern China, 668 individuals were finally included in the study, with complete demographic information. Laboratory tests were performed and estimated glomerular filtration rate (eGFR) was derived from the Modification of Diet in Renal Disease (MDRD) equation for the Chinese population. Plasma noradrenaline levels and genotype were determined by HPLC and the TaqMan method, respectively. Only across the Arg16Gly polymorphism did eGFR show significant difference: it was lower in individuals with the Gly16Gly variation, who also had the highest plasma noradrenaline levels. This polymorphism remained a significant determinant of eGFR after multivariate analysis. Of importance, the multifactor dimensionality reduction method further detected a significant synergism between the Arg16Gly and C242T polymorphisms in reducing eGFR. These observations clarify the effects of the studied polymorphisms on eGFR and exemplify gene-gene interactions influencing renal function.

  1. [Prevalence of diabetic retinopathy and distal symmetrical diabetic polyneuropathy, and glomerular filtration screening upon the diagnosis of type 2 diabetes mellitus - a cohort study].

    PubMed

    Buková, L; Galajda, P; Mokáň, M

    2013-11-01

    The prospective cohort study analyzes the prevalence of microvascular complications at the time of dia-gnosis type 2 diabetes (DM 2). We were monitoring 200 outpatients (117 men and 83 women, aged from 30 to 92 years) with newly diagnosed and previously untreated type 2 diabetes mellitus during the period of August 2007 -  August 2011 accidentally sending GP or internists. Prevalence of diabetic retinopathy in men was 0.85% and in women 1.2%. The prevalence of diabetic distal symetric polyneuropathy in men was 53% and in women 62%. The median of glomerular filtration based on a simplified MDRD 4 equation (according to the study Modification of Diet in Renal Disease) was 1.27 ± 0.6 ml/ s/ 1.73 m2 for men and 1.05 ± 0.32 ml/ s/ 1.73 m2 for women. At baseline, 16.6% of men and 46.2% of women enrolled in our cohort study had glomerular filtration rate < 1 ml/ s/ 1.73 m2. PMID:24279438

  2. Gender differences in age-related decline in glomerular filtration rates in healthy people and chronic kidney disease patients

    PubMed Central

    2010-01-01

    Background Since men with chronic kidney disease (CKD) progress faster than women, an accurate assessment of CKD progression rates should be based on gender differences in age-related decline of glomerular filtration rate (GFR) in healthy individuals. Methods A Chinese sample population from a stratified, multistage, and clustered CKD screening study was classified into healthy, at-risk, and CKD groups. The gender differences in estimated GFR (eGFR) and age-related eGFR decline were calculated for each group after controlling for blood pressure, fasting glucose levels, serum lipids levels, education level, and smoking status. After referencing to the healthy group, gender-specific multivariate-adjusted rates of decline in eGFR and differences in the rates of decline were calculated for both CKD and at-risk groups. Results The healthy, at-risk, and CKD groups consisted of 4569, 7434, and 1573 people, respectively. In all the 3 groups, the multivariate-adjusted eGFRs in men were lower than the corresponding eGFRs in women. In addition, in the healthy and at-risk groups, the rates of decline in eGFR in men were lower than the corresponding rates of decline in women (healthy group: 0.51 mL·min-1·1.73 m-2·yr-1 vs. 0.74 mL·min-1·1.73 m-2·yr-1 and at-risk group: 0.60 mL·min-1·1.73 m-2·yr-1 vs. 0.73 mL·min-1·1.73 m-2·yr-1). However, in the CKD group, the rates of decline in eGFR in men were similar to those in women (0.96 mL·min-1·1.73 m-2·yr-1 vs. 0.91 mL·min-1·1.73 m-2·yr-1). However, after referencing to the healthy group, the rates of decline in eGFR in men in the at-risk and CKD groups were greater faster than the corresponding rates in women (at-risk group: 0.10 mL·min-1·1.73 m-2·yr-1 vs. -0.03 mL·min-1·1.73 m-2·yr-1 and CKD group: 0.44 mL·min-1·1.73 m-2·yr-1 vs. 0.15 mL·min-1·1.73 m-2·yr-1). Conclusion To accurately assess gender differences in CKD progression rates, gender differences in age-related decline in GFR should be considered

  3. Effects of Moderate-to-Severe Impairment of the Estimated Glomerular Filtration Rate and of Proteinuria on the Central Hemodynamics and Arterial Stiffness in Middle-Aged Healthy Japanese Men

    PubMed Central

    Tomiyama, Hirofumi; Odaira, Mari; Matsumoto, Chisa; Yamada, Jiko; Yoshida, Masanobu; Shiina, Kazuki; Yamashina, Akira

    2011-01-01

    We evaluated the effects of moderate-to-severe impairment of the estimated glomerular filtration rate (eGFR: 15 to 59 mL/min per 1.73 m2) and of proteinuria on the central hemodynamics and the pulse wave velocity (PWV) in 2244 middle-aged healthy Japanese men who were not receiving any medications for cardiovascular diseases or cardiovascular risk factors. The adjusted value of the radial augmentation index was higher in the subjects with proteinuria than in those without proteinuria. On the other hand, this value was similar between the subjects with and without moderate-to-severe impairment of the eGFR. Not only proteinuria but also moderate-to-severe impairment of the eGFR was associated with increase in the adjusted value of the brachial-ankle PWV. Thus, proteinuria was found to be an independent risk factor for abnormal central hemodynamics and increased stiffness of the large- to middle-sized arteries, while moderate-to-severe impairment of the eGFR was associated with an increase of the arterial stiffness, but not with abnormality of the central hemodynamics. PMID:21423551

  4. Temporal behavior of peripheral organ distribution volume in mammillary systems. II. Application to background correction in separate glomerular filtration rate estimation in man

    SciTech Connect

    Decostre, P.L.; Salmon, Y. )

    1990-10-01

    An original approach to background subtraction is presented for 99mTc-DTPA separate glomerular filtration rate (SGFR) estimation in man. The method is based on the properties of the peripheral organ distribution volume (PODV) in mammillary systems. These PODV properties allow easy separation of the components of the renogram, i.e., interstitial fluid, plasma and renal activities. The proposed algorithm takes advantage of the linear time dependence of the kidney distribution volume, during the renal uptake phase, to correct for the plasma residual activity, which always remains after classical background correction. Theoretically, the ratio between kidney uptake and SGFR should be identical for both left and right kidneys, even for very asymmetrical kidney functions. This is best verified when the proposed plasma residual activity correction is applied.

  5. Genotype/phenotype correlations of NPHS1 and NPHS2 mutations in nephrotic syndrome advocate a functional inter-relationship in glomerular filtration.

    PubMed

    Koziell, Ania; Grech, Victor; Hussain, Sagair; Lee, Gary; Lenkkeri, Ulla; Tryggvason, Karl; Scambler, Peter

    2002-02-15

    Mutations of the novel renal glomerular genes NPHS1 and NPHS2 encoding nephrin and podocin cause two types of severe nephrotic syndrome presenting in early life, Finnish type congenital nephrotic syndrome (CNF) and a form of autosomal recessive familial focal segmental glomerulosclerosis (SRN1), respectively. To investigate the mechanisms by which mutations might cause glomerular protein leak, we analysed NPHS1/NPHS2 genotype/phenotype relationships in 41 non-Finnish CNF patients, four patients with congenital (onset 0 to 3 months) focal segmental glomerulosclerosis and five patients with possible SRN1 (onset 6 months to 2 years). We clarify the range of NPHS1 mutations in CNF, detecting mutation 'hot-spots' within the NPHS1 coding sequence. In addition, we describe a novel discordant CNF phenotype characterized by variable clinical severity, apparently influenced by gender. Moreover, we provide evidence that CNF may be genetically heterogeneous by detection of NPHS2 mutations in some CNF patients in whom NPHS1 mutations were not found. We confirm an overlap in the NPHS1/NPHS2 mutation spectrum with the characterization of a unique di-genic inheritance of NPHS1 and NPHS2 mutations, which results in a 'tri-allelic' hit and appears to modify the phenotype from CNF to one of congenital focal segmental glomerulosclerosis (FSGS). This may result from an epistatic gene interaction, and provides a rare example of multiple allelic hits being able to modify an autosomal recessive disease phenotype in humans. Our findings provide the first evidence for a functional inter-relationship between NPHS1 and NPHS2 in human nephrotic disease, thus underscoring their critical role in the regulation of glomerular filtration. PMID:11854170

  6. Knockdown of ApoL1 in Zebrafish Larvae Affects the Glomerular Filtration Barrier and the Expression of Nephrin

    PubMed Central

    Kotb, Ahmed M.; Simon, Ole; Blumenthal, Antje; Vogelgesang, Silke; Dombrowski, Frank; Amann, Kerstin; Zimmermann, Uwe; Endlich, Karlhans; Endlich, Nicole

    2016-01-01

    APOL1, a secreted high-density lipoprotein, is expressed in different human tissues. Genetic variants of APOL1 are described to be associated with the development of end stage renal diseases in African Americans. In human kidney, APOL1 is mainly expressed in podocytes that are responsible for proper blood filtration. Since mice do not express ApoL1, the zebrafish is an ideal model to study the role of ApoL1. Injection of morpholinos against zApoL1 into zebrafish eggs and larvae, respectively, induces severe edema indicating a leakage of the filtration barrier. This was demonstrated in zApoL1 knockdown larvae by intravascular injection of fluorescently-labeled 10- and 500-kDa dextrans and by clearance of the vitamin D-binding protein from the circulation. Immunohistochemistry and RT-PCR revealed the reduction of nephrin, a podocyte-specific protein essential for blood filtration. Coinjection of human nephrin mRNA rescued the zApoL1 knockdown induced phenotype. Reduced APOL1 and nephrin levels were also found in biopsies of patients suffering from end stage renal diseases. Our results demonstrate that zApoL1 is essential for proper blood filtration in the zebrafish glomerulus and that zApoL1 affects the expression of nephrin. PMID:27138898

  7. Knockdown of ApoL1 in Zebrafish Larvae Affects the Glomerular Filtration Barrier and the Expression of Nephrin.

    PubMed

    Kotb, Ahmed M; Simon, Ole; Blumenthal, Antje; Vogelgesang, Silke; Dombrowski, Frank; Amann, Kerstin; Zimmermann, Uwe; Endlich, Karlhans; Endlich, Nicole

    2016-01-01

    APOL1, a secreted high-density lipoprotein, is expressed in different human tissues. Genetic variants of APOL1 are described to be associated with the development of end stage renal diseases in African Americans. In human kidney, APOL1 is mainly expressed in podocytes that are responsible for proper blood filtration. Since mice do not express ApoL1, the zebrafish is an ideal model to study the role of ApoL1. Injection of morpholinos against zApoL1 into zebrafish eggs and larvae, respectively, induces severe edema indicating a leakage of the filtration barrier. This was demonstrated in zApoL1 knockdown larvae by intravascular injection of fluorescently-labeled 10- and 500-kDa dextrans and by clearance of the vitamin D-binding protein from the circulation. Immunohistochemistry and RT-PCR revealed the reduction of nephrin, a podocyte-specific protein essential for blood filtration. Coinjection of human nephrin mRNA rescued the zApoL1 knockdown induced phenotype. Reduced APOL1 and nephrin levels were also found in biopsies of patients suffering from end stage renal diseases. Our results demonstrate that zApoL1 is essential for proper blood filtration in the zebrafish glomerulus and that zApoL1 affects the expression of nephrin. PMID:27138898

  8. Decreased arterial elasticity in children with nondialysis chronic kidney disease is related to blood pressure and not to glomerular filtration rate.

    PubMed

    Sinha, Manish D; Keehn, Louise; Milne, Laura; Sofocleous, Paula; Chowienczyk, Phil J

    2015-10-01

    We compared large artery mechanical properties in children with nondialysis stages of chronic kidney disease with those in children with normal renal function, examining the potential effect of blood pressure (BP) components and level of renal dysfunction. Common carotid artery mechanical properties, carotid-femoral pulse wave velocity, and carotid and peripheral BP were measured in children (n=226) with nondialysis chronic kidney disease (n=188; 11.9±3.7 years; 26%, 25%, 30%, 16%, and 3% in stages 1, 2, 3, 4 and 5, respectively) and healthy controls (n=38; 11.5±3.3 years). In children with nondialysis chronic kidney disease when compared with healthy controls, at similar levels of peripheral and carotid BP, carotid artery diastolic diameter and wall thickness were similar. In those with suboptimal BP (≥75th percentile), indices of arterial elasticity indicated greater stiffness than in healthy normotensive controls (distensibility: 92±31 versus 114±33 kPa(-1)×10(-3), P=0.03; compliance: 2.1±0.7 versus 2.6±0.7 m(2) kPa(-1)×10(-6), P=0.02; Young elastic modulus: 0.151±0.068 versus 0.109±0.049 kPa×10(3), P=0.02; and wall stress: 83.6±23.5 versus 68.7±14.9 kPa, P=0.02). In all children, mechanical properties were independently related to carotid and peripheral BP components but not to estimated glomerular filtration rate. In children with nondialysis chronic kidney disease, changes in elastic properties of the carotid artery are primarily related to BP and not to glomerular renal function.

  9. A Pilot Study to Evaluate Renal Hemodynamics in Cirrhosis by Simultaneous Glomerular Filtration Rate, Renal Plasma Flow, Renal Resistive Indices and Biomarkers Measurements

    PubMed Central

    Mindikoglu, Ayse L.; Dowling, Thomas C.; Wong-You-Cheong, Jade J.; Christenson, Robert H.; Magder, Laurence S.; Hutson, William R.; Seliger, Stephen L.; Weir, Matthew R.

    2014-01-01

    Background Renal hemodynamic measurements are complicated to perform in patients with cirrhosis; yet they provide the best measure of risk to predict hepatorenal syndrome (HRS). Currently, there are no established biomarkers of altered renal hemodynamics in cirrhosis validated by measured renal hemodynamics. Methods In this pilot study, simultaneous measurements of glomerular filtration rate (GFR), renal plasma flow (RPF), renal resistive indices and biomarkers were performed to evaluate renal hemodynamic alterations in 10 patients with cirrhosis (3 patients without ascites, 5 with diuretic sensitive and 2 diuretic refractory ascites). Results Patients with diuretic refractory ascites had the lowest mean GFR (36.5 ml/min/1.73m2) and RPF (133.6 ml/min/1.73m2) when compared to those without ascites (GFR=82.9 ml/min/1.73m2, RPF=229.9 ml/min/1.73m2) and with diuretic-sensitive ascites (GFR=82.3 ml/min/1.73m2, RPF=344.1 ml/min/1.73m2). A higher mean filtration fraction (FF= GFR/RPF=0.36) was noted among those without ascites compared to those with ascites. Higher FF in patients without ascites is most likely secondary to the vasoconstriction in the efferent glomerular arterioles (normal FF≃0.20). In general, renal resistive indices were inversely related to FF. While patients with ascites had lower FF and higher right kidney main and arcuate artery resistive indices, those without ascites had higher FF and lower right kidney main and arcuate artery resistive indices. While cystatin C and beta-2 microglobulin performed better compared to Cr in estimating RPF; beta-trace protein, beta-2 microglobulin, SDMA, and (SDMA+ADMA) performed better in estimating right kidney arcuate artery resistive index. Conclusion The results of this pilot study showed that identification of non-invasive biomarkers of reduced RPF and increased renal resistive indices can identify cirrhotics at risk for HRS at a stage more amenable to therapeutic intervention, and reduce mortality from kidney

  10. Associations of Perfluoroalkyl Substances (PFAS) with Lower Birth Weight: An Evaluation of Potential Confounding by Glomerular Filtration Rate Using a Physiologically Based Pharmacokinetic Model (PBPK)

    PubMed Central

    Loccisano, Anne E.; Morken, Nils-Halvdan; Yoon, Miyoung; Wu, Huali; McDougall, Robin; Maisonet, Mildred; Marcus, Michele; Kishi, Reiko; Miyashita, Chihiro; Chen, Mei-Huei; Hsieh, Wu-Shiun; Andersen, Melvin E.; Clewell, Harvey J.; Longnecker, Matthew P.

    2015-01-01

    Background Prenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration rate (GFR), which is related to PFAS concentration and birth weight. Objectives We used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR. Methods We modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data. Results The reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g (95% CI: –3.40, –2.04), and for perfluorooctanoic acid (PFOA) was 7.13 g (95% CI: –8.46, –5.80); results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g (95% CI: –21.66, –7.78) and 14.72 g (95% CI: –8.92, –1.09) reductions in birth weight, respectively. Conclusion Results of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy. Citation Verner MA, Loccisano AE, Morken NH, Yoon M, Wu H, Mc

  11. Impact of urine concentration adjustment method on associations between urine metals and estimated glomerular filtration rates (eGFR) in adolescents.

    PubMed

    Weaver, Virginia M; Vargas, Gonzalo García; Silbergeld, Ellen K; Rothenberg, Stephen J; Fadrowski, Jeffrey J; Rubio-Andrade, Marisela; Parsons, Patrick J; Steuerwald, Amy J; Navas-Acien, Ana; Guallar, Eliseo

    2014-07-01

    Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, blood lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m(2); 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary.

  12. The impact of serum uric acid on the natural history of glomerular filtration rate: a retrospective study in the general population

    PubMed Central

    Xu, Ying; Liu, Xiang; Sun, Xiaohe

    2016-01-01

    Serum uric acid (SUA) level has been proposed to have important connections with chronic kidney disease (CKD), while the impact of SUA level on the natural history of glomerular filtration rate (GFR) decline remains unknown. The present study aims to study the association of the SUA level with the GFR decline in a general population. Two thousand, seven hundred and eighty-nine subjects who visited the Health Checkup Clinic both at 2008 and 2013 were identified. A significant inverse correlation was observed between change in SUA from 2008–2013 (ΔSUA) and change in eGFR (ΔeGFR) during the same period. Multivariate regression analysis of ΔeGFR indicated that the increase in SUA over time were a negative predictor of the change in eGFR. Our result indicates that the decline of eGFR over years is larger in subjects with an increased SUA level, which helps to underline the importance of SUA level management in the context of kidney function preservation. PMID:27069799

  13. Comparison of the performance of the updated Schwartz, combined Schwartz and the Grubb glomerular filtration rate equations in a general pediatric population.

    PubMed

    Gheissari, Alaleh; Roomizadeh, Peyman; Kelishadi, Roya; Abedini, Amin; Haghjooy-Javanmard, Shaghayegh; Abtahi, Seyed-Hossein; Mehdikhani, Bahareh

    2014-09-01

    To determine the performance of the updated Schwartz, combined Schwartz and Grubb glomerular filtration rate (GFR) equations in a relatively large number of healthy children with no known renal disease, we studied 712 students aged between seven and 18 years from the Isfahan province of Iran by random cluster sampling between 2009 and 2010. Blood investigations included blood urea nitrogen, creatinine and cystatin C. For each participant, GFR was calculated based on the three equations. We used Bland-Altman plots and weighted kappa statistics to compare the performance of the study equations. The mean age of the children was 12.2 ± 2.4 years. A high concordance in estimating GFR (mean difference: 0 ± 12.7 mL/min/1.73 m 2 ) and a very good agreement in defining chronic kidney disease (CKD) and non-CKD individuals (weighted kappa: 0.85; 95% confidence intervals: 0.69-1) were observed between the updated Schwartz and the combined Schwartz equations. Poor agreement was observed between the Grubb equation and two Schwartz equations in estimating GFR and defining CKD. There was no systematic deviation between the updated Schwartz and the combined Schwartz equations in children with normal renal function. The Grubb equation was highly inconsistent with both Schwartz equations in this population. We conclude that the updated Schwartz equation is simpler and more accessible than the combined Schwartz equation in daily clinical practice and CKD screening programs.

  14. Intermediate Volume on Computed Tomography Imaging Defines a Fibrotic Compartment that Predicts Glomerular Filtration Rate Decline in Autosomal Dominant Polycystic Kidney Disease Patients

    PubMed Central

    Caroli, Anna; Antiga, Luca; Conti, Sara; Sonzogni, Aurelio; Fasolini, Giorgio; Ondei, Patrizia; Perico, Norberto; Remuzzi, Giuseppe; Remuzzi, Andrea

    2011-01-01

    Total kidney and cyst volumes have been used to quantify disease progression in autosomal dominant polycystic kidney disease (ADPKD), but a causal relationship with progression to renal failure has not been demonstrated. Advanced image processing recently allowed to quantify extracystic tissue, and to identify an additional tissue component named “intermediate,” appearing hypoenhanced on contrast-enhanced computed tomography (CT). The aim of this study is to provide a histological characterization of intermediate volume, investigate its relation with renal function, and provide preliminary evidence of its role in long-term prediction of functional loss. Three ADPKD patients underwent contrast-enhanced CT scans before nephrectomy. Histological samples of intermediate volume were drawn from the excised kidneys, and stained with hematoxylin and eosin and with saturated picrosirius solution for histological analysis. Intermediate volume showed major structural changes, characterized by tubular dilation and atrophy, microcysts, inflammatory cell infiltrate, vascular sclerosis, and extended peritubular interstitial fibrosis. A significant correlation (r = −0.69, P < 0.001) between relative intermediate volume and baseline renal function was found in 21 ADPKD patients. Long-term prediction of renal functional loss was investigated in an independent cohort of 13 ADPKD patients, followed for 3 to 8 years. Intermediate volume, but not total kidney or cyst volume, significantly correlated with glomerular filtration rate decline (r = −0.79, P < 0.005). These findings suggest that intermediate volume may represent a suitable surrogate marker of ADPKD progression and a novel therapeutic target. PMID:21683674

  15. The effect of celiprolol on glomerular filtration rate and renal blood flow in patients with chronic renal impairment and healthy volunteers.

    PubMed Central

    Robson, R A; Bridgman, P G; Wells, J E; Bailey, R R; Lynn, K L

    1992-01-01

    A double-blind, placebo controlled study investigated the effects of celiprolol, 200 mg daily for 7 days, on glomerular filtration rate (GFR) and estimated renal blood flow (ERBF) in eight healthy volunteers and eight patients with chronic renal insufficiency. In healthy volunteers the mean difference in GFR was 4.8 ml min-1 (95% CI -8.2 to 17.7 ml min-1) and the mean difference in ERBF was 49.8 ml min-1 (95% CI -47.5 to 147 ml min-1) after celiprolol. In patients with chronic renal insufficiency the mean difference in GFR was -2.1 ml min-1 (95% CI -64.6 to 65.8 ml min-1). The study had sufficient power to detect a 15% change in GFR for normals and 10% for patients, and for ERBF, changes of 14% and 23% were detectable. Celiprolol at a dose of 200 mg daily for 7 days can be used in patients with chronic renal insufficiency without adversely affecting GFR or ERBF. PMID:1349496

  16. Use of gadolinium diethylene triamine penta-acetic acid, as measured by ELISA, in the determination of glomerular filtration rates in cats.

    PubMed

    Sox, Erika M; Chiotti, Ruthanne; Goldstein, Richard E

    2010-10-01

    The goal of this study was to evaluate a commercially available assay for gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) for use in estimating glomerular filtration rate (GFR) in cats (Gd-DTPA GFR) with a wide range of GFRs. Eighteen adult cats (11 healthy and seven with chronic kidney disease) were included. Plasma concentrations of Gd-DTPA following intravenous injection were measured with an ELISA kit (FIT-GFR). Results for Gd-DTPA GFR were compared with simultaneously obtained values for plasma clearance of iohexol (iohexol GFR), plasma blood urea nitrogen (BUN) and creatinine concentrations. A negative correlation existed between iohexol GFR and plasma concentrations of BUN and creatinine. A positive correlation existed between Gd-DTPA GFR and iohexol GFR. There was no correlation between Gd-DTPA GFR and plasma concentrations of BUN and creatinine. In this study plasma clearance of Gd-DTPA assayed by FIT-GFR did not appear to provide a sufficiently accurate estimation of GFR in cats when compared with plasma clearance of iohexol, and plasma concentrations of BUN and creatinine. PMID:20724186

  17. Impact of urine concentration adjustment method on associations between urine metals and estimated glomerular filtration rates (eGFR) in adolescents☆

    PubMed Central

    Weaver, Virginia M.; Vargas, Gonzalo García; Silbergeld, Ellen K.; Rothenberg, Stephen J.; Fadrowski, Jeffrey J.; Rubio-Andrade, Marisela; Parsons, Patrick J.; Steuerwald, Amy J.; Navas-Acien, Ana; Guallar, Eliseo

    2014-01-01

    Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, blood lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m2; 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary. PMID:24815335

  18. Results of the first-in-human clinical trial for MB-102, a novel fluorescent tracer agent for real-time measurement of glomerular filtration rate

    NASA Astrophysics Data System (ADS)

    Dorshow, Richard B.; Debreczeny, Martin P.; Dowling, Thomas C.

    2015-03-01

    The fluorescent tracer agent 2,5-bis[N-(1-carboxy-2-hydroxy)]carbamoyl-3,6-diaminopyrazine, designated MB-102, has been developed with properties and attributes necessary for use as a direct measure of glomerular filtration rate (GFR). Comparison to known standard exogenous GFR agents in animal models has demonstrated an excellent correlation. A clinical trial to demonstrate this same correlation in humans is in progress. This clinical trial is the first in a series of trials necessary to obtain regulatory clearance from the FDA. We report herein the comparison of plasma pharmacokinetics between MB-102 and the known standard exogenous GFR agent Iohexol in healthy subjects with normal renal function. Post simultaneous administration of both agents, blood samples over a period of 12 hours were collected from each subject to assess pharmacokinetic parameters including GFR. Urine samples were collected over this same period to assess percent injected dose recovered in the urine. Results indicate MB-102 is a GFR agent in humans from the comparison to the standard agent.

  19. Association Between Contrast Media Volume-Glomerular Filtration Rate Ratio and Contrast-Induced Acute Kidney Injury After Primary Percutaneous Coronary Intervention.

    PubMed

    Celik, Omer; Ozturk, Derya; Akin, Fatih; Ayca, Burak; Yalcın, Ahmet Arif; Erturk, Mehmet; Bıyık, Ismail; Ayaz, Ahmet; Akturk, Ibrahim Faruk; Enhos, Asım; Aslan, Serkan

    2015-07-01

    We hypothesized that contrast media volume-estimated glomerular filtration rate (CV-e-GFR) ratio may be a predictor of contrast media-induced acute kidney injury (CI-AKI). We investigated the associations between CV-e-GFR ratio and CI-AKI in 597 patients undergoing primary percutaneous coronary intervention (pPCI). An absolute ≥0.3 mg/dL increase in serum creatinine compared with baseline levels within 48 hours after the procedure was considered as CI-AKI; 78 (13.1%) of the 597 patients experienced CI-AKI. The amount of contrast during procedure was higher in the CI-AKI group than in those without CI-AKI (153 vs 135 mL, P = .003). The CV-e-GFR ratio was significantly higher in patients with CI-AKI than without (2.3 vs 1.5, P < .001). In multivariate analysis, independent predictors of CI-AKI were low left ventricular ejection fraction (P = .018, odds ratio [OR] = 0.966), e-GFR <60 mL/min (P = .012, OR = 2.558), and CV-e-GFR >2 (P < .001, OR = 5.917). In conclusion, CV-e-GFR ratio is significantly associated with CI-AKI after pPCI.

  20. Flow Mediated Dilatation Is Reduced with the Progressive Stages of Glomerular Filtration Rate and Albuminuria in Type 2 Diabetic Patients without Coronary Heart Disease

    PubMed Central

    Ito, Hiroyuki; Nakashima, Mina; Meguro, Kentaro; Furukawa, Haruki; Yamashita, Hitomi; Takaki, Akifusa; Yukawa, Chizuko; Omoto, Takashi; Shinozaki, Masahiro; Nishio, Shinya; Abe, Mariko; Antoku, Shinichi; Mifune, Mizuo; Togane, Michiko

    2015-01-01

    We aimed to clarify the usefulness of measuring the flow mediated dilatation (FMD) in patients with type 2 diabetes mellitus without and with coronary heart disease (CHD). The FMD was measured in 480 patients with type 2 diabetes and in 240 nondiabetic subjects. The FMD was significantly lower in the subjects with CHD (n = 145, 5.4 ± 3.2%) than in those without CHD (n = 95, 6.9 ± 3.5%) among the nondiabetic subjects. The FMD was also lower in the subjects both with CHD (n = 161, 5.6 ± 2.8%) and without CHD (n = 319, 6.1 ± 3.3%) among the patients with diabetes compared to those without both diabetes and CHD. The FMD showed a significant positive correlation with the estimated glomerular filtration rate (eGFR) in the diabetic patients without CHD, while there was no significant association in those with CHD. The FMD was significantly lower with the progressive stages of the GFR or albuminuria in the patients without CHD among those with diabetes, although the FMD was not different in those with CHD. In conclusion, the FMD is considered to be useful for the detection of atherosclerosis in patients with type 2 diabetes, even if overt macroangiopathy is not diagnosed. PMID:26064988

  1. Tamm-Horsfall Protein Regulates Circulating and Renal Cytokines by Affecting Glomerular Filtration Rate and Acting as a Urinary Cytokine Trap*

    PubMed Central

    Liu, Yan; El-Achkar, Tarek M.; Wu, Xue-Ru

    2012-01-01

    Although few organ systems play a more important role than the kidneys in cytokine catabolism, the mechanism(s) regulating this pivotal physiological function and how its deficiency affects systemic cytokine homeostasis remain unclear. Here we show that elimination of Tamm-Horsfall protein (THP) expression from mouse kidneys caused a marked elevation of circulating IFN-γ, IL1α, TNF-α, IL6, CXCL1, and IL13. Accompanying this were enlarged spleens with prominent white-pulp macrophage infiltration. Lipopolysaccharide (LPS) exacerbated the increase of serum cytokines without a corresponding increase in their urinary excretion in THP knock-out (KO) mice. This, along with the rise of serum cystatin C and the reduced inulin and creatinine clearance from the circulation, suggested that diminished glomerular filtration may contribute to reduced cytokine clearance in THP KO mice both at the baseline and under stress. Unlike wild-type mice where renal and urinary cytokines formed specific in vivo complexes with THP, this “trapping” effect was absent in THP KO mice, thus explaining why cytokine signaling pathways were activated in renal epithelial cells in such mice. Our study provides new evidence implicating an important role of THP in influencing cytokine clearance and acting as a decoy receptor for urinary cytokines. Based on these and other data, we present a unifying model that underscores the role of THP as a major regulator of renal and systemic immunity. PMID:22451664

  2. Dietary acid reduction with fruits and vegetables or bicarbonate attenuates kidney injury in patients with a moderately reduced glomerular filtration rate due to hypertensive nephropathy.

    PubMed

    Goraya, Nimrit; Simoni, Jan; Jo, Chanhee; Wesson, Donald E

    2012-01-01

    The neutralization of dietary acid with sodium bicarbonate decreases kidney injury and slows the decline of the glomerular filtration rate (GFR) in animals and patients with chronic kidney disease. The sodium intake, however, could be problematic in patients with reduced GFR. As alkali-induced dietary protein decreased kidney injury in animals, we compared the efficacy of alkali-inducing fruits and vegetables with oral sodium bicarbonate to diminish kidney injury in patients with hypertensive nephropathy at stage 1 or 2 estimated GFR. All patients were evaluated 30 days after no intervention; daily oral sodium bicarbonate; or fruits and vegetables in amounts calculated to reduce dietary acid by half. All patients had 6 months of antihypertensive control by angiotensin-converting enzyme inhibition before and during these studies, and otherwise ate ad lib. Indices of kidney injury were not changed in the stage 1 group. By contrast, each treatment of stage 2 patients decreased urinary albumin, N-acetyl β-D-glucosaminidase, and transforming growth factor β from the controls to a similar extent. Thus, a reduction in dietary acid decreased kidney injury in patients with moderately reduced eGFR due to hypertensive nephropathy and that with fruits and vegetables was comparable to sodium bicarbonate. Fruits and vegetables appear to be an effective kidney protective adjunct to blood pressure reduction and angiotensin-converting enzyme inhibition in hypertensive and possibly other nephropathies.

  3. Intermediate volume on computed tomography imaging defines a fibrotic compartment that predicts glomerular filtration rate decline in autosomal dominant polycystic kidney disease patients.

    PubMed

    Caroli, Anna; Antiga, Luca; Conti, Sara; Sonzogni, Aurelio; Fasolini, Giorgio; Ondei, Patrizia; Perico, Norberto; Remuzzi, Giuseppe; Remuzzi, Andrea

    2011-08-01

    Total kidney and cyst volumes have been used to quantify disease progression in autosomal dominant polycystic kidney disease (ADPKD), but a causal relationship with progression to renal failure has not been demonstrated. Advanced image processing recently allowed to quantify extracystic tissue, and to identify an additional tissue component named "intermediate," appearing hypoenhanced on contrast-enhanced computed tomography (CT). The aim of this study is to provide a histological characterization of intermediate volume, investigate its relation with renal function, and provide preliminary evidence of its role in long-term prediction of functional loss. Three ADPKD patients underwent contrast-enhanced CT scans before nephrectomy. Histological samples of intermediate volume were drawn from the excised kidneys, and stained with hematoxylin and eosin and with saturated picrosirius solution for histological analysis. Intermediate volume showed major structural changes, characterized by tubular dilation and atrophy, microcysts, inflammatory cell infiltrate, vascular sclerosis, and extended peritubular interstitial fibrosis. A significant correlation (r = -0.69, P < 0.001) between relative intermediate volume and baseline renal function was found in 21 ADPKD patients. Long-term prediction of renal functional loss was investigated in an independent cohort of 13 ADPKD patients, followed for 3 to 8 years. Intermediate volume, but not total kidney or cyst volume, significantly correlated with glomerular filtration rate decline (r = -0.79, P < 0.005). These findings suggest that intermediate volume may represent a suitable surrogate marker of ADPKD progression and a novel therapeutic target.

  4. Feasibility study of high-resolution DCE-MRI for glomerular filtration rate (GFR) measurement in a routine clinical modal.

    PubMed

    Zhang, Yu-Dong; Wu, Chen-Jiang; Zhang, Jing; Wang, Xiao-Ning; Liu, Xi-Sheng; Shi, Hai-Bin

    2015-10-01

    Dynamic contrast enhanced (DCE) MR renography has been identified as an interesting tool to determine single-kidney GFR. However, a fundamental issue for the applicability of MR-based estimate of single-kidney GFR is selecting a balance between spatial and temporal resolution of DCE-MRI data. The purpose is to assess the feasibility of GFR estimate from high-resolution (HR) dynamic contrast-enhanced (DCE) MRI in a routine clinical modal. Standard MR renography (2.4s/phase, total 4min; 4-ml Gd) and five-phase, HR-based imaging protocol (0, 30, 70, 120, and 240s; 0.05mmol/kg Gd) were prospectively performed in twelve volunteers who were scheduled for routine renal MRI. Data were plotted with Patlak, two-compartment modified Tofts model (2CTM), and two-compartment filtration model (2CFM) for GFR estimate. During all the measurements, only the signal intensities in the aorta and whole kidney parenchyma were considered. Standard 2CFM and 2CTM produced lower residuals over the fitted interval than HR-based measures (p<0.05); and HR-bases 2CFM and 2CTM did not reflect significant correlation to standard values. Standard Patlak plots with 0-240s data points produced significantly lower GFR and higher residuals than that plots with 0-120s data points (p<0.05). HR-based Patlak plots with 0, 30, 70, and 120s data points significantly correlated with reference values (Pearson ρ=0.97, p<0.01), and produced a 33.2% underestimation of reference value, which was better than that plots with 0, 30, 70, 120, and 240s data points (ρ=0.92, p<0.01; 58.6% underestimation of reference value). It concludes that it is feasible to estimate GFR with HR-based DCE-MRI and appreciate kinetic model. Patlak plots from 0, 30, 70, and 120s data points is better than plots from 0, 30, 70, 120, and 240s data points.

  5. Initial formal toxicity evaluation of APC-2, a novel fluorescent tracer agent for real-time measurement of glomerular filtration rate in preparation for a first-in-man clinical trial

    NASA Astrophysics Data System (ADS)

    Bugaj, Joseph E.; Dorshow, Richard B.

    2014-03-01

    The fluorescent tracer agent 2,5-bis[N-(1-carboxy-2-hydroxy)]carbamoyl-3,6-diaminopyrazine, designated APC-2, has been developed with properties and attributes necessary for use as a direct measure of glomerular filtration rate (GFR). Comparison to known standard exogenous GFR agents in animal models has demonstrated an excellent correlation. A clinical trial to demonstrate this same correlation in humans is in preparation. A battery of formal toxicity tests necessary for regulatory clearance to proceed with a clinical trial has been recently completed on this new fluorescent tracer agent. These include single dose toxicity studies in rats and dogs to determine overall toxicity and toxicokinetics of the compound. Blood compatibility, mutation assay, chromosomal aberration assay, and several other assays were also completed. Toxicity assessments were based on mortality, clinical signs, body weight, food consumption and anatomical pathology. Blood samples were collected to assess pharmacokinetic parameters including half-life, area under the curve, and clearance. Urine samples were collected to assess distribution. Doses of up to 200-300 times the estimated human dose were administered. No test-article related effects were noted on body weight, food consumption, ophthalmic observations and no abnormal pathology was seen in either macroscopic or microscopic evaluations of any organs or tissues. All animals survived to scheduled sacrifice. Transient discoloration of skin and urine was noted at the higher dose levels in both species as expected from a highly fluorescent compound and was not considered pathological. Thus initial toxicology studies of this new fluorescent tracer agent APC-2 have resulted in no demonstrable pathological test article concerns.

  6. Glomerular Filtration Rate and Urine Albumin to Creatinine Ratio Associated With Hearing Impairment Among Korean Adults With Diabetes: A Nationwide Population-Based Study.

    PubMed

    Cho, Yunji; Kim, Do Hoon; Choi, June; Lee, Joo Kyung; Roh, Yong-Kyun; Nam, Hyo-Yun; Nam, Ga-Eun; Kim, Dong-Won; Lee, Seung-Hyun; Lee, Chung-Woo; Han, Kyungdo; Park, Yong-Gyu

    2016-04-01

    The objective of this study was to examine the association of estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (ACR) with hearing impairment among diabetic adults in Korea. The study was based on data from Korea National Health and Nutrition Examination Survey 2011 to 2012. Participants were 1206 diabetic adults, aged over 19 years, who completed audiometric testing supervised by nationally certified clinicians. Hearing impairment was defined in three grades: no hearing impairment (pure-tone average 0-25 dB), slight hearing impairment (26-40 dB), and disabling hearing impairment (>40 dB) in the better ear at frequencies 0.5, 1, 2, 3, 4 and 6 kHz. Using logistic regression, risk of hearing impairment was assessed after having controlled for confounding factors. Higher levels of ACR and lower levels of eGFR correlated with an increase in percentage of disabling hearing impairment both unilaterally and bilaterally (P < 0.001). Controlling for possible confounding covariates, odds ratios for hearing impairment showed tendency to increase in higher ACR groups (P for trend = 0.029). Similar pattern was examined between eGFR and hearing impairment (P for trend = 0.006). Odds ratios were 1.981 (1.146, 3.424) for ACR Q4 and 2.773 (1.286, 5.983) for eGFR < 60 mL/min. Fall in eGFR and rise in ACR correlated with severity of hearing impairment. The association existed independently of age, sex, body mass index (BMI), smoking, drinking, exercise, new onset of diabetes, education, income, mental stress, noise exposure, and metabolic syndrome. PMID:27124027

  7. Proteinuria and Reduced Estimated Glomerular Filtration Rate Independently Predict Risk for Acute Myocardial Infarction: Findings from a Population-Based Study in Keelung, Taiwan

    PubMed Central

    Chang, Shu-Hsuan; Tsai, Chia-Ti; Yen, Amy Ming-Fang; Lei, Meng-Huan; Chen, Hsiu-Hsi; Tseng, Chuen-Den

    2015-01-01

    Background The aim of this study was to evaluate the independent roles of proteinuria and reduced estimated glomerular filtration rate (GFR) in the development of acute myocardial infarction in a northern Taiwanese population. Methods We conducted a community-based prospective cohort study in Keelung, the northernmost county of Taiwan. A total of 63,129 subjects (63% women) ≥ 20 years of age who had no history of coronary heart disease were recruited and followed-up. Univariate and multivariate proportional hazards regression analysis was performed to assess the association between proteinuria and estimated GFR and the risk of acute myocardial infarction. Results There were 305 new cases of acute myocardial infarction (114 women and 191 men) documented during a four-year follow-up period. After adjustment of potential confounding covariates, heavier proteinuria (dipstick urinalysis reading 3+) and estimated GFR of less than 60 ml/min/1.73 m2 independently predicted increased risk of developing acute myocardial infarction. The adjusted hazard ratio (aHR) of heavier proteinuria for occurrence of acute myocardial infarction was 1.85 [95% confidence intervals (CI), 1.17-2.91, p < 0.01] (vs. the reference group: negative dipstick proteinuria). The aHR of estimated GFR of 30-59 ml/min/1.73 m2 for occurrence of acute myocardial infarction was 2.4 (95% CI, 1.31-4.38, p < 0.01) (vs. the reference group: estimated GFR ≥ 90 ml/ min/1.73 m2), and that of estimated GFR of 15-29 ml/min/1.73 m2 was 5.26 (95% CI, 2.26-12.26, p < 0.01). Conclusions We demonstrated that both heavier proteinuria and lower estimated GFR are significant independent predictors of developing future acute myocardial infarction in a northern Taiwanese population. PMID:27122856

  8. Impact of nucleos(t)ide analogues on the estimated glomerular filtration rate in patients with chronic hepatitis B: a prospective cohort study in China.

    PubMed

    Qi, X; Wang, J-Y; Mao, R-C; Zhang, J-M

    2015-01-01

    Chronic hepatitis B therapy with nucleos(t)ide analogues, particularly tenofovir or adefovir, may affect renal function. To date, there has not been a head-to-head controlled study to assess estimated glomerular filtration rate (eGFR) fluctuations in nucleos(t)ide-treated CHB patients. We aimed to evaluate the long-term effects of nucleos(t)ide on eGFR in Chinese patients with chronic hepatitis B. This prospective cohort study included 275 patients. Patient subgroups included those treated with lamivudine (n = 50), adefovir (n = 60), telbivudine (n = 68) and entecavir (n = 61); untreated patients (n = 36) served as control. After an average follow-up duration of 23 months, eGFR calculated by Cockcroft-Gault and Modification of Diet in Renal Disease formulas increased by 18.35 mL/min and 19.34 mL/min (P < 0.0001) in the telbivudine group, respectively, and decreased by 10.95 mL/min and 12.17 mL/min (P = 0.0001) in the adefovir group, respectively. Even if renal function was normal or mildly impaired at baseline, eGFR increased significantly more in the telbivudine group than in the other groups (P < 0.001). More patients in the adefovir group (23%) had a ≥20% decrease in eGFR than the other groups (P < 0.0001). More patients in the telbivudine group (31%) had a ≥20% increase in eGFR than the other groups (P < 0.0001). In conclusion, prolonged telbivudine therapy resulted in improved eGFR, while adefovir therapy was associated with decreased eGFR. Lamivudine and entecavir therapy did not significantly influence eGFR.

  9. Self-reported sleep duration is associated with reduced glomerular filtration rate among adults with hypertension: a population-based study from rural northeast China.

    PubMed

    Guo, Xiaofan; Yu, Shasha; Li, Zhao; Guo, Liang; Zheng, Liqiang; Yang, Hongmei; Zou, Lu; Hu, Wenyu; Zhou, Ying; Zhu, Luoning; Zhang, Yonghong; Sun, Yingxian

    2015-06-01

    Short sleep duration has been found recently to be a predictor of proteinuria. However, population-based investigations addressing the association between self-reported sleep duration and glomerular filtration rate (GFR) among hypertensive patients are lacking. We therefore sought to investigate the extent to which self-reported sleep duration might be associated with reduced GFR in a large hypertensive population in rural northeast China. A total of 5555 hypertensive participants, aged ≥35 years, in rural areas of Liaoning Province, China, were screened between January 2012 and August 2013, using a stratified, cluster multi-stage sampling scheme. Anthropometric measurements, self-reported sleep duration, blood biochemical indexes and other health-related variables were collected by medically trained personnel. Reduced GFR was defined as the estimated GFR (eGFR) < 60 mL min(-1) 1.73 m(2). On average, participants slept for 6.9 ± 1.6 h per night. Mean self-reported sleep duration decreased with eGFR (P < 0.001). For both genders, a lower prevalence of reduced GFR was observed among participants who slept ≤6 h per night in total. In the multivariable regression model, after adjustments for age, gender, ethnicity, lifestyle factors, clinical correlates, depressive symptoms and general quality of life, participants who slept for 6 h or less per night were associated with a higher risk of reduced GFR [odds ratio (OR: 1.70, 95% confidence interval (CI): 1.05-2.73] compared with the reference group (self-reported sleep duration >7 and ≤8 h day(-1) ). We concluded that short self-reported sleep duration (≤6 h per night) was related significantly to an increased risk of reduced GFR in a hypertensive population. This novel risk factor should be taken into consideration during daily management of hypertension to prevent chronic kidney disease.

  10. Enzymatic creatinine assays allow estimation of glomerular filtration rate in stages 1 and 2 chronic kidney disease using CKD-EPI equation.

    PubMed

    Kuster, Nils; Cristol, Jean-Paul; Cavalier, Etienne; Bargnoux, Anne-Sophie; Halimi, Jean-Michel; Froissart, Marc; Piéroni, Laurence; Delanaye, Pierre

    2014-01-20

    The National Kidney Disease Education Program group demonstrated that MDRD equation is sensitive to creatinine measurement error, particularly at higher glomerular filtration rates. Thus, MDRD-based eGFR above 60 mL/min/1.73 m² should not be reported numerically. However, little is known about the impact of analytical error on CKD-EPI-based estimates. This study aimed at assessing the impact of analytical characteristics (bias and imprecision) of 12 enzymatic and 4 compensated Jaffe previously characterized creatinine assays on MDRD and CKD-EPI eGFR. In a simulation study, the impact of analytical error was assessed on a hospital population of 24084 patients. Ability using each assay to correctly classify patients according to chronic kidney disease (CKD) stages was evaluated. For eGFR between 60 and 90 mL/min/1.73 m², both equations were sensitive to analytical error. Compensated Jaffe assays displayed high bias in this range and led to poorer sensitivity/specificity for classification according to CKD stages than enzymatic assays. As compared to MDRD equation, CKD-EPI equation decreases impact of analytical error in creatinine measurement above 90 mL/min/1.73 m². Compensated Jaffe creatinine assays lead to important errors in eGFR and should be avoided. Accurate enzymatic assays allow estimation of eGFR until 90 mL/min/1.73 m² with MDRD and 120 mL/min/1.73 m² with CKD-EPI equation.

  11. Impact of urine concentration adjustment method on associations between urine metals and estimated glomerular filtration rates (eGFR) in adolescents

    SciTech Connect

    Weaver, Virginia M.; Vargas, Gonzalo García; Silbergeld, Ellen K.; Rothenberg, Stephen J.; Fadrowski, Jeffrey J.; Rubio-Andrade, Marisela; Parsons, Patrick J.; Steuerwald, Amy J.; and others

    2014-07-15

    Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, blood lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m{sup 2}; 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary. - Highlights: • Positive associations between urine metals and creatinine-based eGFR are unexpected. • Optimal approach to urine concentration adjustment for urine biomarkers uncertain. • We compared urine concentration adjustment methods. • Positive associations observed only with urine creatinine adjustment. • Additional research using non-creatinine-based methods of adjustment needed.

  12. Correlation between cystatin C-based formulas, Schwartz formula and urinary creatinine clearance for glomerular filtration rate estimation in children with kidney disease

    PubMed Central

    Safaei-Asl, Afshin; Enshaei, Mercede; Heydarzadeh, Abtin; Maleknejad, Shohreh

    2016-01-01

    Introduction: Assessment of glomerular filtration rate (GFR) is an important tool for monitoring renal function. Objectives: Regarding to limitations in available methods, we intended to calculate GFR by cystatin C (Cys C) based formulas and determine correlation rate of them with current methods. Patients and Methods: We studied 72 children (38 boys and 34 girls) with renal disorders. The 24 hour urinary creatinine (Cr) clearance was the gold standard method. GFR was measured with Schwartz formula and Cys C-based formulas (Grubb, Hoek, Larsson and Simple). Then correlation rates of these formulas were determined. Results: Using Pearson correlation coefficient, a significant positive correlation between all formulas and the standard method was seen (R2 for Schwartz, Hoek, Larsson, Grubb and Simple formula was 0.639, 0.722, 0.705, 0.712, 0.722, respectively) (P<0.001). Cys C-based formulas could predict the variance of standard method results with high power. These formulas had correlation with Schwarz formula by R2 0.62-0.65 (intermediate correlation). Using linear regression and constant (y-intercept), it revealed that Larsson, Hoek and Grubb formulas can estimate GFR amounts with no statistical difference compared with standard method; but Schwartz and Simple formulas overestimate GFR. Conclusion: This study shows that Cys C–based formulas have strong relationship with 24 hour urinary Cr clearance. Hence, they can determine GFR in children with kidney injury, easier and with enough accuracy. It helps the physician to diagnosis of renal disease in early stages and improves the prognosis. PMID:27689114

  13. Drug dosing in patients with renal insufficiency in a hospital setting using electronic prescribing and automated reporting of estimated glomerular filtration rate.

    PubMed

    Nielsen, Anita L; Henriksen, Daniel P; Marinakis, Christianna; Hellebek, Annemarie; Birn, Henrik; Nybo, Mads; Søndergaard, Jens; Nymark, Anita; Pedersen, Court

    2014-05-01

    In patients with impaired renal function, drug dose adjustment is often required. Non-adherence to clinical prescribing recommendations may result in severe adverse events. In previous studies, the prevalence rate of non-adherence to recommended dosing has been reported to be 19-67%. Using the clinical support system Renbase(®) as reference, we investigated the use and dosing of drugs in patients with impaired renal function in a university hospital setting using electronic prescription and automatic reporting of estimated glomerular filtration rate (eGFR). In all, 232 patients with an eGFR in the range of 10-49 ml/min./1.73 m(2) were included. We identified 436 episodes with administration of renal risk drugs (prescribed to 183 patients): 410 drugs required dose adjustment according to the eGFR and 26 should be avoided. In total, the use or dosing of 66 (15%) of the 436 renal risk drugs was not in agreement with recommendations in Renbase(®) . This reflects less disagreement with expert guidelines than reported previously, indicating a possible beneficial effect of electronic prescribing and reporting of eGFR. However, we also found that disagreement to some extent reflected inappropriate drug use. We conclude that despite implementation of electronic prescribing and automated reporting of eGFR, patients with renal insufficiency may still be exposed to inappropriate drug use, with potential increased risk of adverse effects. Initiatives to reduce medication errors such as the use of electronic decision support systems should be explored.

  14. Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate.

    PubMed

    Goraya, Nimrit; Simoni, Jan; Jo, Chan-Hee; Wesson, Donald E

    2014-11-01

    Alkali therapy of metabolic acidosis in patients with chronic kidney disease (CKD) with plasma total CO2 (TCO2) below 22 mmol/l per KDOQI guidelines appears to preserve estimated glomerular filtration rate (eGFR). Since angiotensin II mediates GFR decline in partial nephrectomy models of CKD and even mild metabolic acidosis increases kidney angiotensin II in animals, alkali treatment of CKD-related metabolic acidosis in patients with plasma TCO2 over 22 mmol/l might preserve GFR through reduced kidney angiotensin II. To test this, we randomized 108 patients with stage 3 CKD and plasma TCO2 22-24 mmol/l to Usual Care or interventions designed to reduce dietary acid by 50% using sodium bicarbonate or base-producing fruits and vegetables. All were treated to achieve a systolic blood pressure below 130 mm Hg with regimens including angiotensin converting enzyme inhibition and followed for 3 years. Plasma TCO2 decreased in Usual Care but increased with bicarbonate or fruits and vegetables. By contrast, urine excretion of angiotensinogen, an index of kidney angiotensin II, increased in Usual Care but decreased with bicarbonate or fruits and vegetables. Creatinine-calculated and cystatin C-calculated eGFR decreased in all groups, but loss was less at 3 years with bicarbonate or fruits and vegetables than Usual Care. Thus, dietary alkali treatment of metabolic acidosis in CKD that is less severe than that for which KDOQI recommends therapy reduces kidney angiotensin II activity and preserves eGFR.

  15. Areca Nut Chewing and an Impaired Estimated Glomerular Filtration Rate as Significant Risk Factors for Non-Muscle-Invasive Bladder Cancer Recurrence

    PubMed Central

    Cao, Jian; Xu, Ran; Zhao, Xiaokun; Zhong, Zhaohui; Zhang, Lei; Zhu, Xuan; Wu, Shuiqing; Ai, Kai

    2016-01-01

    The present study sought to investigate the predictive value of preoperative clinicopathological variables, with a special focus on areca nut chewing, on disease recurrence and progression in patients with non-muscle-invasive bladder cancer (NMIBC). Data from 242 patients diagnosed with NMIBC between 2008 and 2013 were analyzed retrospectively. Fifteen clinicopathological variables were analyzed to evaluate their prognostic value. During a mean observation period of 21 months, disease recurrence occurred in 140 patients (57.9%). On multivariate analysis, heavy-areca nut chewing (HR = 2.18, 95% CI: 1.37–3.47), current smoking (HR = 3.09, 95% CI: 1.99–4.80), moderately impaired estimated glomerular filtration rate (eGFR) (HR = 1.76, 95% CI: 1.09–2.83), severely impaired eGFR (HR = 3.32, 95% CI: 1.70–6.48) and tumor grade (HR = 1.94, 95% CI: 1.36–2.77) were independent factors for recurrence, based on which a risk factor model was developed to stratify patients into high, medium and low risk groups. In conclusion, our study suggests that in addition to quitting smoking, quitting areca nut chewing may also reduce the risk of first recurrence in NMBIC patients, monitoring and preserving their renal function may be beneficial as well. Further prospective studies are needed to verify the prognostic significance of these factors and the risk stratification model in this population. PMID:27385379

  16. Pathogenesis of glomerular haematuria.

    PubMed

    Yuste, Claudia; Gutierrez, Eduardo; Sevillano, Angel Manuel; Rubio-Navarro, Alfonso; Amaro-Villalobos, Juan Manuel; Ortiz, Alberto; Egido, Jesus; Praga, Manuel; Moreno, Juan Antonio

    2015-05-01

    Haematuria was known as a benign hallmark of some glomerular diseases, but over the last decade, new evidences pointed its negative implications on kidney disease progression. Cytotoxic effects of oxidative stress induced by hemoglobin, heme, or iron released from red blood cells may account for the tubular injury observed in human biopsy specimens. However, the precise mechanisms responsible for haematuria remain unclear. The presence of red blood cells (RBCs) with irregular contours and shape in the urine indicates RBCs egression from the glomerular capillary into the urinary space. Therefore glomerular haematuria may be a marker of glomerular filtration barrier dysfunction or damage. In this review we describe some key issues regarding epidemiology and pathogenesis of haematuric diseases as well as their renal morphological findings. PMID:25949932

  17. Association of estimated glomerular filtration rate with all‐cause and cardiovascular mortality: the role of malnutrition–inflammation–cachexia syndrome

    PubMed Central

    Ou, Shuo‐Ming; Chen, Yung‐Tai; Hung, Szu‐Chun; Shih, Chia‐Jen; Lin, Chi‐Hung; Chiang, Chih‐Kang

    2016-01-01

    Abstract Background Previous studies have demonstrated that high estimated glomerular filtration rate (eGFR) is paradoxically associated with an increased risk of mortality, and the association becomes more predominant in older people. However, the role of malnutrition–inflammation–cachexia syndrome (MICS) in the association between eGFR and mortality has never been explored. Methods We conducted a community‐based cohort study using data from the Taipei City Elderly Health Examination Database, collected during the period 2001–10. All participants aged ≥65 years were included and stratified by the absence or presence of MICS, which is defined as the presence of at least one of the following markers: body mass index <22 kg/m2, serum albumin <3.0 mg/dL, or Geriatric Nutritional Risk Index (GNRI) <98. The study endpoints were all‐cause and cardiovascular mortality. Results A total of 131 354 participants were identified and categorized according to the chronic kidney disease stage based on eGFR. Compared with the reference eGFR of 60–89 mL/min/1.73 m2, the overall and cardiovascular mortality risks were markedly high in the groups with eGFR of <30 mL/min/1.73 m2 [overall: adjusted hazard ratio (aHR), 1.86; 95% confidence interval (CI), 1.72–2.00; cardiovascular: aHR, 1.87; 95% CI, 1.60–2.19] and ≥90 mL/min/1.73 m2 (overall: aHR, 1.23; 95% CI, 1.13–1.34; cardiovascular: aHR, 1.28; 95% CI, 1.06–1.54). In the absence of MICS, high eGFR was associated with lower mortality risk (aHR, 0.71; 95% CI, 0.62–0.80), and the U‐shaped relationship disappeared. Subgroup analyses produced consistent results. Conclusions MICS could influence the association observed between high eGFR and mortality in older people, particularly in those with low body mass index, albumin level, GNRI, and very low serum creatinine level. PMID:27493868

  18. Effect of A Reduction in glomerular filtration rate after NEphrectomy on arterial STiffness and central hemodynamics: Rationale and design of the EARNEST study☆

    PubMed Central

    Moody, William E.; Tomlinson, Laurie A.; Ferro, Charles J.; Steeds, Richard P.; Mark, Patrick B.; Zehnder, Daniel; Tomson, Charles R.; Cockcroft, John R.; Wilkinson, Ian B.; Townend, Jonathan N.

    2014-01-01

    Background There is strong evidence of an association between chronic kidney disease (CKD) and cardiovascular disease. To date, however, proof that a reduction in glomerular filtration rate (GFR) is a causative factor in cardiovascular disease is lacking. Kidney donors comprise a highly screened population without risk factors such as diabetes and inflammation, which invariably confound the association between CKD and cardiovascular disease. There is strong evidence that increased arterial stiffness and left ventricular hypertrophy and fibrosis, rather than atherosclerotic disease, mediate the adverse cardiovascular effects of CKD. The expanding practice of live kidney donation provides a unique opportunity to study the cardiovascular effects of an isolated reduction in GFR in a prospective fashion. At the same time, the proposed study will address ongoing safety concerns that persist because most longitudinal outcome studies have been undertaken at single centers and compared donor cohorts with an inappropriately selected control group. Hypotheses The reduction in GFR accompanying uninephrectomy causes (1) a pressure-independent increase in aortic stiffness (aortic pulse wave velocity) and (2) an increase in peripheral and central blood pressure. Methods This is a prospective, multicenter, longitudinal, parallel group study of 440 living kidney donors and 440 healthy controls. All controls will be eligible for living kidney donation using current UK transplant criteria. Investigations will be performed at baseline and repeated at 12 months in the first instance. These include measurement of arterial stiffness using applanation tonometry to determine pulse wave velocity and pulse wave analysis, office blood pressure, 24-hour ambulatory blood pressure monitoring, and a series of biomarkers for cardiovascular and bone mineral disease. Conclusions These data will prove valuable by characterizing the direction of causality between cardiovascular and renal disease. This

  19. Glomerular filtration rate after alpha-radioimmunotherapy with 211At-MX35-F(ab')2: a long-term study of renal function in nude mice.

    PubMed

    Bäck, Tom; Haraldsson, Börje; Hultborn, Ragnar; Jensen, Holger; Johansson, Martin E; Lindegren, Sture; Jacobsson, Lars

    2009-12-01

    Besides bone marrow, the kidneys are often dose-limiting organs in internal radiotherapy. The effects of high-linear energy transfer (LET) radiation on the kidneys after alpha-radioimmunotherapy (alpha-RIT) with the alpha-particle emitter, (211)At, were studied in nude mice by serial measurements of the glomerular filtration rate (GFR). The renal toxicity was evaluated at levels close to the dose limit for the bone marrow and well within the range for therapeutic efficacy on tumors. Astatinated MX35-F(ab')(2) monoclonal antibodies were administered intravenously to nude mice. Both non-tumor-bearing animals and animals bearing subcutaneous xenografts of the human ovarian cancer cell line, OVCAR-3, were used. The animals received approximately 0.4, 0.8, or 1.2 MBq in one, two, or three fractions. The mean absorbed doses to the kidneys ranged from 1.5 to 15 Gy. The renal function was studied by serial GFR measurements, using plasma clearance of (51)Cr-EDTA, up to 67 weeks after the first astatine injection. A dose-dependent effect on GFR was found and at the time interval 8-30 weeks after the first administration of astatine, the absorbed doses causing a 50% decrease in GFR were 16.4 +/- 3.3 and 14.0 +/- 4.1 Gy (mean +/- SEM), tumor- and non-tumor-bearing animals, respectively. The reduction in GFR progressed with time, and at the later time interval, (31-67 weeks) the corresponding absorbed doses were 7.5 +/- 2.4 and 11.3 +/- 2.3 Gy, respectively, suggesting that the effects of radiation on the kidneys were manifested late. Examination of the kidney sections showed histologic changes that were overall subdued. Following alpha-RIT with (211)At-MX35-F(ab')(2) at levels close to the dose limit of severe myelotoxicity, the effects found on renal function were relatively small, with only minor to moderate reductions in GFR. These results suggest that a mean absorbed dose to the kidneys of approximately 10 Gy is acceptable, and that the kidneys would not be the primary

  20. Accuracy of GFR estimation formula in determination of glomerular filtration rate in kidney donors: Comparison with 24 h urine creatinine clearance.

    PubMed

    Hafeez, Abdul Rauf; Idrees, Muhammad Khalid; Akhtar, Syed Fazal

    2016-03-01

    To determine the accuracy of estimated glomerular filtration rate (eGFR) using the modification of diet in renal disease (MDRD), Cockcroft-Gault (CG), and chronic kidney disease epidemiology (CKD-EPI) formulas in potential kidney donors compared with 24-h urine creatinine clearance, we studied 207 potential live kidney donors in our center. There were 126 (60.9%) males and 81 (39.1%) females. Male:female ratio was 1.6:1. The age of the donors ranged from 18-58 years, with mean age of 35.30 ± 9.23 years and most of the individuals were below 40 years of age. The body mass index (BMI) was calculated and venous blood samples were obtained for the measurement of serum creatinine and every study participant was instructed to collect 24-h urine. GFR was calculated based on 24-h urine creatinine clearance and the formulas. The accuracy of GFR estimation formula was taken as positive if the GFR calculated by the formulas and urine creatinine clearance fell between 90-120 mL/min/1.73 m(2). The accuracy of the MDRD formula was 48.8% and the CG formula was 41.5% whereas the accuracy of the CKD-EPI formula was 78.2%. The accuracy of the eGFR using the MDRD formula was significantly higher in males than females (57.9% vs. 33.3% P = 0.001), while there was no statistically significant difference in the eGFR between them in case of the use of the CG and the CKD-EPI formulas. BMI and obesity had no effect on the accuracy of eGFR by the use of the different formulas. The performance of GFR estimation formulas was sub optimal and these either underestimated and/or over-estimated the GFR in healthy subjects. CKD-EPI is closer to 24 -h urinary creatinine clearance in the calculation of eGFR. However, none of the eGFR formulas can be used in renal transplant donors because of their low accuracy, and 24-h urine creatinine clearance should be used for evaluation of the GFR in this population.

  1. Measurement of glomerular filtration rate by dynamic contrast-enhanced magnetic resonance imaging using a subject-specific two-compartment model.

    PubMed

    Tipirneni-Sajja, Aaryani; Loeffler, Ralf B; Oesingmann, Niels; Bissler, John; Song, Ruitian; McCarville, Beth; Jones, Deborah P; Hudson, Melissa; Spunt, Sheri L; Hillenbrand, Claudia M

    2016-04-01

    Measuring glomerular filtration rate (GFR) by dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) as part of standard of care clinicalMRIexams (e.g., in pediatric solid tumor patients) has the potential to reduce diagnostic burden. However, enthusiasm for this relatively newGFRtest may be curbed by the limited amount of cross-calibration studies with referenceGFRtechniques and the vast variety ofMRtracer model algorithms causing confusion on the choice of model. To advanceMRI-basedGFRquantification via improvedGFRmodeling and comparison with associated(99m)Tc-DTPA-GFR, 29 long-term Wilms' tumor survivors (19.0-43.3 years, [median 32.0 ± 6.0 years]) treated with nephrectomy, nonnephrotoxic chemotherapy ± radiotherapy underwentMRIwith Gd-DTPAadministration and a(99m)Tc-DTPA GFRtest. ForDCE-MRI-basedGFRestimation, a subject-specific two-compartment (SS-2C) model was developed that uses individual hematocrit values, automatically defines subject-specific uptake intervals, and fits tracer-uptake curves by incorporating these measures. The association between reference(99m)Tc-DTPA GFRandMR-GFRs obtained bySS-2C, three published 2C uptake, and inflow-outflow models was investigated via linear regression analysis. Uptake intervals varied from 64 sec to 141 sec [96 sec ± 21 sec] and hematocrit values ranged from 30% to 49% [41% ± 4%]; these parameters can therefore not be assumed as constants in 2C modeling. OurMR-GFRestimates using theSS-2C model showed accordingly the highest correlation with(99m)Tc-DTPA-GFRs (R(2) = 0.76,P < 0.001) compared with other models (R(2)-range: 0.36-0.66). In conclusion,SS-2C modeling ofDCE-MRIdata improved the association betweenGFRobtained by(99m)Tc-DTPAand Gd-DTPA DCE-MRIto such a degree that this approach could turn into a viable, diagnosticGFRassay without radiation exposure to the patient.

  2. Relationship between Kidney Dysfunction and Ischemic Stroke Outcomes: Albuminuria, but Not Estimated Glomerular Filtration Rate, Is Associated with the Risk of Further Vascular Events and Mortality after Stroke

    PubMed Central

    Lee, Dong-Geun

    2016-01-01

    Background and Objective Estimated glomerular filtration rate (eGFR) and albuminuria are known to be associated with ischemic stroke outcomes. In this study, we investigated the longitudinal relationships of the two markers with mortality, vascular events and functional outcomes in a stroke cohort. Methods A total of 295 patients with acute ischemic stroke were prospectively recruited in a single center between May 2012 and February 2015. Renal dysfunction was defined as a decreased eGFR (<60 mL/min/1.73 m2) or albuminuria (urine albumin-to-creatinine ratio ≥ 30 mg/g). Good functional outcome at 6 months was defined as a modified Rankin scale score ≤ 2, and the occurrence of major vascular events (stroke, acute coronary syndrome or peripheral artery occlusion) or death was monitored. The associations between renal dysfunction and mortality, major vascular events, and 6-month functional outcome were evaluated by the Cox proportional hazards model and logistic regression analysis. Unadjusted and adjusted hazards ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs) were obtained. A Kaplan–Meier survival curve for composite adverse events (major vascular events or death) was also computed according to the presence or absence of albuminuria. Results Albuminuria, not eGFR, was significantly associated with mortality (P = 0.028; HR 2.15; 95% CI 1.09–4.25) and major vascular events (P = 0.044; HR 2.24; 95% CI 1.02–4.94) in the multivariate Cox proportional hazards models adjusting for age, sex, diabetes, hypertension, current smoking, atrial fibrillation, previous stroke, alcohol history, initial National Institutes of Health Stroke Scale (NIHSS) score and eGFR. In addition, albuminuria was negatively associated with 6-month functional outcome in the multivariate logistic regression analysis adjusting for age, sex, diabetes, hypertension, current smoking, atrial fibrillation, previous stroke, alcohol history and eGFR (P = 0.001; OR 0.36; 95% CI 0

  3. [Measurement of glomerular filtration rate (GFR) after administration of iodine contrast medium with the Renalyzer PRX90 in healthy cats and cats with kidney diseases].

    PubMed

    Meyer-Lindenberg, A; Westhoff, A; Wohlsein, P; Pohlenz, J; Nolte, I

    1998-09-01

    In the present study, the measurement of the glomerular filtration rate (GFR) in the cat with the aid of an iodine contrast medium clearance with the renalyzer PRX90 is introduced. Investigations on the accuracy of measurement showed that even repeated measurement of plasma samples after two days of storage at room temperature yielded reproducible clearance results. Also, partial dilution of the plasma sample (2 ml with 1 ml Aqua bidest.) to reduce the volume of blood withdrawn still produced reliable results. Further dilution of the plasma volume (1 ml with 2 ml Aqua bidest.) however did not allow for accurate measurements. A total of 59 cats of different age and sex were included in the study. 31 cats had healthy kidneys with urea and creatinine values within the reference range, unchanged urine findings and physiologic urine protein patterns (SDS-PAGE). These cats served as reference group. The GFR reference value ascertained for these animals was 2.1 ml/min/kg BW (mean = 3.45 ml/min/kg with s = +/- 1.0 ml/min/kg). 28 cats had elevated values of urea and creatinine in the blood, as well as partially changed urine findings. For further diagnosis of renal disease, separation of urine proteins was done with the SDS-PAGE in the PhastSystem, which in all cases yielded a pathologic urine protein pattern. In 11 cases the renal disease could be further confirmed by histological investigation. GFR in these patients was clearly lowered compared with healthy cats, with measured values between 0 and 1.8 ml/min/kg. It can be concluded that the renalyzer allows reliable determination of the GFR also in the cat. To what extent measurement of the GFR is also helpful to diagnose nephropathies in the stage of compensation needs to be further investigated. In cats with high grade uremia and a GFR below 1 ml/min however, an exact calculation is not possible, since the accuracy of measurement within this range is inadequate. Thus, in severe disease no correct assessment is possible

  4. Volume-independent reductions in glomerular filtration rate in acute chloride-depletion alkalosis in the rat. Evidence for mediation by tubuloglomerular feedback.

    PubMed Central

    Galla, J H; Bonduris, D N; Sanders, P W; Luke, R G

    1984-01-01

    We have recently described reduced superficial nephron glomerular filtration rate (SNGFR) in chloride-depletion alkalosis (CDA) without volume depletion. To elucidate the mechanism of this phenomenon, we studied three degrees of increasing severity of CDA (groups CDA-1, 2, and 3) produced by one or two peritoneal dialyses against 0.15 M NaHCO3 and electrolyte infusions of different Cl and HCO3 content in Sprague-Dawley rats; control rats (CON) were dialyzed against and infused with Ringers-HCO3. Extracellular fluid (ECF) volume was assessed by blood pressure, hematocrit, plasma protein concentration, and 125I-albumin space; none of these variables differed among the four groups. Micropuncture of the latest proximal and earliest distal convolutions was carried out. As CDA intensified from CON to CDA-3 (plasma tCO2 25 +/- 1 to 43 +/- 1 meq/L; P less than 0.01), distally determined SNGFR declined progressively (40.9 +/- 1.7 to 28.3 +/- 1.8 nl/min; P less than 0.01), while in early distal tubule fluid, flow rate (8.6 +/- 0.7 to 3.4 +/- 0.6 nl/min) and Cl concentration (36 +/- 2 to 19 +/- 3 meq/L) decreased and osmolality (110 +/- 5 to 208 +/- 12 mosmol/kg) increased (P less than 0.01), and, in the loop segment, Cl reabsorption decreased progressively (2,009 +/- 112 to 765 +/- 128 peq/min; P less than 0.01). In early distal tubule fluid, Cl concentration correlated positively and osmolality negatively with distally determined SNGFR (P less than 0.05). Proximally determined SNGFRs did not differ among the four groups. Proximal tubule stop-flow pressure responses to increasing rates of orthograde perfusion of the loop segment from 0 to 40 nl/min did not differ between groups CON and CDA-2. We interpret these data to show that reductions in SNGFR in CDA in the rat can occur by tubuloglomerular feedback (TGF) in the absence of differences in ECF volume or of alterations in TGF sensitivity during metabolic alkalosis. Of the proposed signals for TGF sensed by the macula densa

  5. Glomerular filtration rate after alpha-radioimmunotherapy with 211At-MX35-F(ab')2: a long-term study of renal function in nude mice.

    PubMed

    Bäck, Tom; Haraldsson, Börje; Hultborn, Ragnar; Jensen, Holger; Johansson, Martin E; Lindegren, Sture; Jacobsson, Lars

    2009-12-01

    Besides bone marrow, the kidneys are often dose-limiting organs in internal radiotherapy. The effects of high-linear energy transfer (LET) radiation on the kidneys after alpha-radioimmunotherapy (alpha-RIT) with the alpha-particle emitter, (211)At, were studied in nude mice by serial measurements of the glomerular filtration rate (GFR). The renal toxicity was evaluated at levels close to the dose limit for the bone marrow and well within the range for therapeutic efficacy on tumors. Astatinated MX35-F(ab')(2) monoclonal antibodies were administered intravenously to nude mice. Both non-tumor-bearing animals and animals bearing subcutaneous xenografts of the human ovarian cancer cell line, OVCAR-3, were used. The animals received approximately 0.4, 0.8, or 1.2 MBq in one, two, or three fractions. The mean absorbed doses to the kidneys ranged from 1.5 to 15 Gy. The renal function was studied by serial GFR measurements, using plasma clearance of (51)Cr-EDTA, up to 67 weeks after the first astatine injection. A dose-dependent effect on GFR was found and at the time interval 8-30 weeks after the first administration of astatine, the absorbed doses causing a 50% decrease in GFR were 16.4 +/- 3.3 and 14.0 +/- 4.1 Gy (mean +/- SEM), tumor- and non-tumor-bearing animals, respectively. The reduction in GFR progressed with time, and at the later time interval, (31-67 weeks) the corresponding absorbed doses were 7.5 +/- 2.4 and 11.3 +/- 2.3 Gy, respectively, suggesting that the effects of radiation on the kidneys were manifested late. Examination of the kidney sections showed histologic changes that were overall subdued. Following alpha-RIT with (211)At-MX35-F(ab')(2) at levels close to the dose limit of severe myelotoxicity, the effects found on renal function were relatively small, with only minor to moderate reductions in GFR. These results suggest that a mean absorbed dose to the kidneys of approximately 10 Gy is acceptable, and that the kidneys would not be the primary

  6. Polymorphisms of the UCP2 Gene Are Associated with Glomerular Filtration Rate in Type 2 Diabetic Patients and with Decreased UCP2 Gene Expression in Human Kidney

    PubMed Central

    de Souza, Bianca Marmontel; Michels, Marcus; Sortica, Denise Alves; Bouças, Ana Paula; Rheinheimer, Jakeline; Buffon, Marjoriê Piuco; Bauer, Andrea Carla; Canani, Luís Henrique; Crispim, Daisy

    2015-01-01

    Introduction Uncoupling protein 2 (UCP2) reduces production of reactive oxygen species (ROS) by mitochondria. ROS overproduction is one of the major contributors to the pathogenesis of chronic diabetic complications, such as diabetic kidney disease (DKD). Thus, deleterious polymorphisms in the UCP2 gene are candidate risk factors for DKD. In this study, we investigated whether UCP2 -866G/A, Ala55Val and Ins/Del polymorphisms were associated with DKD in patients with type 2 diabetes mellitus (T2DM), and whether they had an effect on UCP2 gene expression in human kidney tissue biopsies. Materials and Methods In a case-control study, frequencies of the UCP2 -866G/A, Ala55Val and Ins/Del polymorphisms as well as frequencies of the haplotypes constituted by them were analyzed in 287 T2DM patients with DKD and 281 T2DM patients without this complication. In a cross-sectional study, UCP2 gene expression was evaluated in 42 kidney biopsy samples stratified according to the presence of the UCP2 mutated -866A/55Val/Ins haplotype. Results In the T2DM group, multivariate logistic regression analysis showed that the -866A/55Val/Ins haplotype was an independent risk factor for DKD (OR = 2.136, 95% CI 1.036–4.404), although neither genotype nor allele frequencies of the individual polymorphisms differed between case and control groups. Interestingly, T2DM patients carrying the mutated haplotype showed decreased estimated glomerular filtration rate (eGFR) when compared to subjects with the reference haplotype (adjusted P= 0.035). In kidney biopsy samples, UCP2 expression was significantly decreased in UCP2 mutated haplotype carriers when compared to kidneys from patients with the reference haplotype (0.32 ± 1.20 vs. 1.85 ± 1.16 n fold change; adjusted P< 0.000001). Discussion Data reported here suggest that the UCP2 -866A/55Val/Ins haplotype is associated with an increased risk for DKD and with a lower eGFR in T2DM patients. Furthermore, this mutated haplotype was associated

  7. Assessment of glomerular filtration rate in transplant recipients with severe renal insufficiency by Nankivell, Modification of Diet in Renal Disease (MDRD), and Cockroft-Gault equations.

    PubMed

    Rodrigo, E; Fernández-Fresnedo, G; Ruiz, J C; Piñera, C; Heras, M; de Francisco, A L M; Sanz de Castro, S; Cotorruelo, J G; Zubimendi, J A; Arias, M

    2003-08-01

    Measurement of glomerular filtration rate (GFR) is time consuming and cumbersome. Several formulas have been developed to predict creatinine clearance (CrCl) or GFR using serum creatinine (Cr) concentrations and demographic characteristics. However, few studies have been performed to discern the best formula to estimate GFR in kidney transplantation. In this study, Cockroft-Gault (CG), Nankivell, and Levey (MDRD) formulas were tested to predict GFR in 125 cadaveric renal transplant patients with severe renal insufficiency (GFR less than 30 mL/min per 1.73 m2). The GFR was estimated as the average Cr and urea clearances. The mean GFR estimated by averaged Cr and urea clearances (22.18+/-5.23 mL/min per 1.73 m2) was significantly different from the mean values yielded by the MDRD formula (20.42+/-6.65 mL/min per 1.73 m2, P=.000), the Nankivell formula (30.14+/-11.98 mL/min per 1.73 m2, P=.000), and the CG formula (29.42+/-8.64 mL/min per 1.73 m2, P=.000). The MDRD formula showed a better correlation (R=0.741, P=.000) than the CG (R=0.698, P=.000) and the Nankivell formulas (R=0.685, P=.000). Analysis of differences using the Bland-Altmann method demonstrated that MDRD gave the lowest bias (MDRD: -1.65+/-4.4 mL/min per 1.73 m2; CG: 7.33+/-6.24 mL/min per 1.73 m2; Nankivell: 8.05+/-9.23 mL/min per 1.73 m2) and narrower limits of agreement (Nankivell: -10.41-26.51 mL/min per 1.73 m2; CG: -5.15-19.81 mL/min per 1.73 m2; MDRD: -10.61-7.31 mL/min per 1.73 m2). In transplant patients with severe renal insufficiency, the MDRD equation seems better than the other formulas to estimate GFR.

  8. Multicenter Study of Creatinine- and/or Cystatin C-Based Equations for Estimation of Glomerular Filtration Rates in Chinese Patients with Chronic Kidney Disease

    PubMed Central

    Zhang, Lin; Li, Xue-mei; Yang, Yu-wei; Zeng, Ping; Guo, Xiu-zhi; Qin, Yan; Liu, Hong-chun; Han, Xing-min; Li, Yan-peng; Xu, Wei; Sun, Shu-yan; Wang, Li-qiang; Quan, Hui; Xia, Li-jun; Hu, Hong-zhang; Zhong, Fang-cai; Duan, Rong

    2013-01-01

    Objective To establish equations for the estimation of glomerular filtration rates (eGFRs) based on serum creatinine (SCr) and/or serum cystatin C (SCysC) in Chinese patients with chronic kidney disease (CKD), and to compare the new equations with both the reference GFR (rGFR) and the literature equations to evaluate their applicability. Methods The 788 Chinese CKD patients were randomly divided into two groups, the training group and the testing group, to establish new eGFR-formulas based on serum CysC and to validate the established formulas, respectively. 99mTc-DTPA clearance (as the rGFR), serum Cr, and serum CysC were determined for all patients, and GFR was calculated using the Cockcroft-Gault equation (eGFR1), the MDRD formula (eGFR2), the CKD-EPI formulas (eGFR3, eGFR4), and the Chinese eGFR Investigation Collaboration formulas (eGFR5, eGFR6). The accuracy of each eGFR was compared with the rGFR. Results The training and testing groups' mean GFRs were 50.84±31.36 mL/min/1.73 m2 and 54.16±29.45 mL/min/1.73 m2, respectively. The two newly developed eGFR formulas were fitted using iterative computation: and . Significant correlation was observed between each eGFR and the rGFR. However, proportional errors and constant errors were observed between rGFR and eGFR1, eGFR2, eGFR4, eGFR5 or eGFR6, and constant errors were observed between eGFR3 and rGFR, as revealed by the Passing & Bablok plot analysis. The Bland-Altman analysis illustrated that the 95% limits of agreement of all equations exceeded the previously accepted limits of <60 mL/min •1.73 m2, except the equations of eGFR7 and eGFR8. Conclusion The newly developed formulas, eGFR7 and eGFR8, provide precise and accurate GFR estimation using serum CysC detection alone or in combination with serum Cr detection. Differences in detection methods should be carefully considered when choosing literature eGFR equations to avoid misdiagnosis and mistreatment. PMID:23526939

  9. Relationship between glomerular filtration rate and plasma N-terminal pro B-type natriuretic peptide concentrations in dogs with chronic kidney disease.

    PubMed

    Miyagawa, Y; Tominaga, Y; Toda, N; Takemura, N

    2013-08-01

    Plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations increase in dogs with azotemia. However, the correlation between glomerular filtration rate (GFR) and NT-proBNP concentrations in dogs has not been evaluated. The objective of this study was to evaluate the correlation between GFR and plasma NT-proBNP concentrations in dogs with chronic kidney disease (CKD). In this retrospective cross-sectional study, plasma creatinine (Cre) and NT-proBNP concentrations, plasma iohexol clearance (PCio) values and blood pressure were measured in dogs with CKD. Dogs were classified according to PCio values into D group (dogs with decreased PCio values), and N group (dogs with normal PCio values). Dogs were further categorized on the basis of their systolic blood pressure and PCio values into NT-D group (normotensive dogs with decreased PCio values), NT-N group (normotensive dogs with normal PCio values), HT-D group (hypertensive dogs with decreased PCio values) and HT-N group (hypertensive dogs with normal PCio values). Significant correlations were observed between plasma NT-proBNP and Cre concentrations (r=0.360, P<0.05) and PCio values (r=-0.470, P<0.01). Plasma NT-proBNP concentrations were significantly higher in the D group than in the N group (P<0.001). Plasma NT-proBNP concentrations were significantly higher in the HT-D group than in the other three groups (P ≤ 0.007). No differences in plasma NT-proBNP concentrations were observed between the NT-D and HT-N groups (P=0.28). Plasma NT-proBNP concentrations were significantly lower in the NT-N group than in the other three groups (P ≤ 0.043). Our findings suggest that decreased GFR might be associated with increased plasma NT-proBNP concentrations in dogs, similar to that in humans. In addition, the complication of hypertension in CKD might be associated with further increases in plasma NT-proBNP concentrations. In conclusion, the effects of GFR and blood pressure on the plasma NT

  10. [Methods for determining the glomerular filtration rate in experiments with small animals: position report of the Animal Experiment Diagnosis of Kidney Function Study Group of the Society of Nephrology of East Germany].

    PubMed

    Hagemann, I; Wüstenberg, P W

    1987-10-01

    The methods of the investigation of the glomerular filtration rate (GFR) in the animal experiment on cats and rats used at present are demonstrated as survey and the results of the basic investigations are compared. The values in cats lie between 20 and 30 ml/min/100 g kidney, in rats GFR values are between 0.6 and 1.0 ml/min/100 g body mass and 0.6-0.3 ml/min/1 g kidney. The basic values are essentially influenced by the experimental conditions and determination methods so that only clearance values within the working team concerned are comparable. PMID:3433988

  11. Association of Estimated Glomerular Filtration Rate with Hemoglobin Level in Korean Adults: The 2010–2012 Korea National Health and Nutrition Examination Survey

    PubMed Central

    Han, Sang Youb; Oh, Se Won; Hong, Jae Won; Yi, Seong Yoon; Noh, Jung Hyun; Lee, Hye Ran; Kim, Dong-Jun

    2016-01-01

    Purpose Little is known about anemia in patients with early renal dysfunction. We aimed to investigate the association of hemoglobin level and anemia prevalence with estimated glomerular filtration rate (eGFR) decline using a nation-wide representative sample of the adult Korean population. Methods In total, 17,373 participants (7,296 men; weighted n = 18,330,187; mean age, 44.2±0.3 years; 9,886 women, weighted n = 18,317,454; mean age, 46.9±0.3 years) were included. eGFR was divided into 5 groups: Group 1, ≥105; Group 2, 90–104; 75–89; Group 4, 60–74; and Group 5, <60 mL/min/1.73m2. Results The weighted anemia prevalence rates were 2.6% in men and 12.8% in women. In men, the weighted hemoglobin level increased with a decrease in eGFR; this value peaked at an eGFR of 60–89 mL/min/1.73m2 and decreased thereafter at an eGFR of <60 mL/min/1.73m2 (15.19±0.03, 15.35±0.03, 15.53±0.03, 15.52±0.06, and 14.90±0.12 g/dL from Groups 1 to 5) after adjustment for age, college graduation, cancer history, current smoking, waist circumference, serum cholesterol level, serum triglyceride level, and diastolic blood pressure. In women, the weighted hemoglobin level increased with a decrease in eGFR; this value peaked with an eGFR of 75–89 mL/min/1.73m2 and decreased thereafter (12.90±0.03, 13.08±0.02, 13.20±0.04, 13.14±0.05, and 12.47±0.11 g/dL from Groups 1 to 5) after adjustment for menstruation, pregnancy, estrogen replacement, and the above-mentioned variables. In both sexes, the weighted prevalence of anemia with an eGFR of 60–104 mL/min/1.73m2 was significantly lower than that with an eGFR of ≥105 mL/min/1.73m2 (men, 3.2±0.4%, 1.9±0.3%, 1.8±0.3%, 2.0±0.9%, and 18.1±3.1%; women, 14.0±0.8%, 11.2±0.7%, 10.5±1.0%, 13.2±1.6%, and 32.3±3.2% from Groups 1 to 5). Conclusions We noted a compensatory increase in the hemoglobin level with a minor decline in kidney function (in the range of eGFR ≥60 mL/min/1.73m2) prior to a marked decrease in

  12. Estimated Glomerular Filtration Rate Trajectories in HIV-Infected Subjects Treated With Different Ritonavir-Boosted Protease Inhibitors and Tenofovir Disoproxil Fumarate or Abacavir

    PubMed Central

    Gianotti, Nicola; Galli, Laura; Poli, Andrea; Salpietro, Stefania; Nozza, Silvia; Carbone, Alessia; Merli, Marco; Ripa, Marco; Lazzarin, Adriano; Castagna, Antonella

    2016-01-01

    Abstract The aim of the study was to evaluate in human immunodeficiency virus (HIV)-infected patients estimated glomerular filtration rate (eGFR) trajectories during treatment with different protease inhibitors (PIs) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus tenofovir (TDF) or abacavir (ABC) and lamivudine or emtricitabine (xTC). Retrospective study of patients followed at a single clinical center; all patients who started TDF or ABC for the first time with a NNRTI or lopinavir/r (LPV/r) or atazanavir/r (ATV/r) or darunavir/r (DRV/r), for whom at least 1 eGFR value before the start and during the studied treatment was known, were included in this analysis. eGFR was calculated by means of the CKD-EPI formula. Univariate and multivariate mixed linear model (MLM) was applied to estimate eGFR slope with the considered antiretroviral treatment. In the 1658 patients treated with TDF/xTC (aged 43 [37–48] years, with an eGFR of 105 [96; 113] mL/min/1.73 m2, 80% males, 92% Caucasians, 10% coinfected with HCV, 4% with diabetes, 11% with hypertension, 38% naive for antiretroviral therapy (ART), 37% with HIV-RNA <50 copies/mL) the median follow-up was 2.5 (1.2–4.6) years. Their adjusted eGFR slopes (95% CI) were −1.26 (−1.58; −0.95), −0.43 (−1.20; +0.33), −0.86 (−1.28; −0.44), and −0.20 (−0.42; +0.02) mL/min/1.73 m2 per year in patients treated with ATV/r, DRV/r, LPV/r, and NNRTI, respectively. Patients receiving ATV/r or LPV/r had a greater adjusted decline in eGFR compared with those receiving NNRTIs (difference −1.06 [−1.44; −0.69] mL/min/1.73 m2 per year, P <0.001; and −0.66 [−1.13; −0.20] mL/min/1.73 m2 per year, P = 0.005, respectively); adjusted eGFR slopes were similar in patients receiving DRV/r and in those receiving NNRTIs. Patients receiving ATV/r had a greater adjusted eGFR decline than those treated with DRV/r (difference −0.83 [−1.65; −0.02] mL/min/1.73 m2 per year; P = 0.04), but not

  13. Estimated Glomerular Filtration Rate Trajectories in HIV-Infected Subjects Treated With Different Ritonavir-Boosted Protease Inhibitors and Tenofovir Disoproxil Fumarate or Abacavir.

    PubMed

    Gianotti, Nicola; Galli, Laura; Poli, Andrea; Salpietro, Stefania; Nozza, Silvia; Carbone, Alessia; Merli, Marco; Ripa, Marco; Lazzarin, Adriano; Castagna, Antonella

    2016-05-01

    The aim of the study was to evaluate in human immunodeficiency virus (HIV)-infected patients estimated glomerular filtration rate (eGFR) trajectories during treatment with different protease inhibitors (PIs) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus tenofovir (TDF) or abacavir (ABC) and lamivudine or emtricitabine (xTC).Retrospective study of patients followed at a single clinical center; all patients who started TDF or ABC for the first time with a NNRTI or lopinavir/r (LPV/r) or atazanavir/r (ATV/r) or darunavir/r (DRV/r), for whom at least 1 eGFR value before the start and during the studied treatment was known, were included in this analysis. eGFR was calculated by means of the CKD-EPI formula. Univariate and multivariate mixed linear model (MLM) was applied to estimate eGFR slope with the considered antiretroviral treatment.In the 1658 patients treated with TDF/xTC (aged 43 [37-48] years, with an eGFR of 105 [96; 113] mL/min/1.73 m, 80% males, 92% Caucasians, 10% coinfected with HCV, 4% with diabetes, 11% with hypertension, 38% naive for antiretroviral therapy (ART), 37% with HIV-RNA <50 copies/mL) the median follow-up was 2.5 (1.2-4.6) years. Their adjusted eGFR slopes (95% CI) were -1.26 (-1.58; -0.95), -0.43 (-1.20; +0.33), -0.86 (-1.28; -0.44), and -0.20 (-0.42; +0.02) mL/min/1.73 m per year in patients treated with ATV/r, DRV/r, LPV/r, and NNRTI, respectively. Patients receiving ATV/r or LPV/r had a greater adjusted decline in eGFR compared with those receiving NNRTIs (difference -1.06 [-1.44; -0.69] mL/min/1.73 m per year, P <0.001; and -0.66 [-1.13; -0.20] mL/min/1.73 m per year, P = 0.005, respectively); adjusted eGFR slopes were similar in patients receiving DRV/r and in those receiving NNRTIs. Patients receiving ATV/r had a greater adjusted eGFR decline than those treated with DRV/r (difference -0.83 [-1.65; -0.02] mL/min/1.73 m per year; P = 0.04), but not than those receiving LPV/r; no significant difference was

  14. Estimated Glomerular Filtration Rate Trajectories in HIV-Infected Subjects Treated With Different Ritonavir-Boosted Protease Inhibitors and Tenofovir Disoproxil Fumarate or Abacavir.

    PubMed

    Gianotti, Nicola; Galli, Laura; Poli, Andrea; Salpietro, Stefania; Nozza, Silvia; Carbone, Alessia; Merli, Marco; Ripa, Marco; Lazzarin, Adriano; Castagna, Antonella

    2016-05-01

    The aim of the study was to evaluate in human immunodeficiency virus (HIV)-infected patients estimated glomerular filtration rate (eGFR) trajectories during treatment with different protease inhibitors (PIs) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus tenofovir (TDF) or abacavir (ABC) and lamivudine or emtricitabine (xTC).Retrospective study of patients followed at a single clinical center; all patients who started TDF or ABC for the first time with a NNRTI or lopinavir/r (LPV/r) or atazanavir/r (ATV/r) or darunavir/r (DRV/r), for whom at least 1 eGFR value before the start and during the studied treatment was known, were included in this analysis. eGFR was calculated by means of the CKD-EPI formula. Univariate and multivariate mixed linear model (MLM) was applied to estimate eGFR slope with the considered antiretroviral treatment.In the 1658 patients treated with TDF/xTC (aged 43 [37-48] years, with an eGFR of 105 [96; 113] mL/min/1.73 m, 80% males, 92% Caucasians, 10% coinfected with HCV, 4% with diabetes, 11% with hypertension, 38% naive for antiretroviral therapy (ART), 37% with HIV-RNA <50 copies/mL) the median follow-up was 2.5 (1.2-4.6) years. Their adjusted eGFR slopes (95% CI) were -1.26 (-1.58; -0.95), -0.43 (-1.20; +0.33), -0.86 (-1.28; -0.44), and -0.20 (-0.42; +0.02) mL/min/1.73 m per year in patients treated with ATV/r, DRV/r, LPV/r, and NNRTI, respectively. Patients receiving ATV/r or LPV/r had a greater adjusted decline in eGFR compared with those receiving NNRTIs (difference -1.06 [-1.44; -0.69] mL/min/1.73 m per year, P <0.001; and -0.66 [-1.13; -0.20] mL/min/1.73 m per year, P = 0.005, respectively); adjusted eGFR slopes were similar in patients receiving DRV/r and in those receiving NNRTIs. Patients receiving ATV/r had a greater adjusted eGFR decline than those treated with DRV/r (difference -0.83 [-1.65; -0.02] mL/min/1.73 m per year; P = 0.04), but not than those receiving LPV/r; no significant difference was

  15. Comparison of the Schwartz and CKD-EPI Equations for Estimating Glomerular Filtration Rate in Children, Adolescents, and Adults: A Retrospective Cross-Sectional Study

    PubMed Central

    Selistre, Luciano; Rabilloud, Muriel; Cochat, Pierre; de Souza, Vandréa; Iwaz, Jean; Lemoine, Sandrine; Beyerle, Françoise; Poli-de-Figueiredo, Carlos E.; Dubourg, Laurence

    2016-01-01

    Background Estimating kidney glomerular filtration rate (GFR) is of utmost importance in many clinical conditions. However, very few studies have evaluated the performance of GFR estimating equations over all ages and degrees of kidney impairment. We evaluated the reliability of two major equations for GFR estimation, the CKD-EPI and Schwartz equations, with urinary clearance of inulin as gold standard. Methods and Findings The study included 10,610 participants referred to the Renal and Metabolic Function Exploration Unit of Edouard Herriot Hospital (Lyon, France). GFR was measured by urinary inulin clearance (only first measurement kept for analysis) then estimated with isotope dilution mass spectrometry (IDMS)–traceable CKD-EPI and Schwartz equations. The participants’ ages ranged from 3 to 90 y, and the measured GFRs from 3 to 160 ml/min/1.73 m2. A linear mixed-effects model was used to model the bias (mean ratio of estimated GFR to measured GFR). Equation reliability was also assessed using precision (interquartile range [IQR] of the ratio) and accuracy (percentage of estimated GFRs within the 10% [P10] and 30% [P30] limits above and below the measured GFR). In the whole sample, the mean ratio with the CKD-EPI equation was significantly higher than that with the Schwartz equation (1.17 [95% CI 1.16; 1.18] versus 1.08 [95% CI 1.07; 1.09], p < 0.001, t-test). At GFR values of 60–89 ml/min/1.73 m2, the mean ratios with the Schwartz equation were closer to 1 than the mean ratios with the CKD-EPI equation whatever the age class (1.02 [95% CI 1.01; 1.03] versus 1.15 [95% CI 1.13; 1.16], p < 0.001, t-test). In young adults (18–40 y), the Schwartz equation had a better precision and was also more accurate than the CKD-EPI equation at GFR values under 60 ml/min/1.73 m2 (IQR: 0.32 [95% CI 0.28; 0.33] versus 0.40 [95% CI 0.36; 0.44]; P30: 81.4 [95% CI 78.1; 84.7] versus 63.8 [95% CI 59.7; 68.0]) and also at GFR values of 60–89 ml/min/1.73 m2. In all patients

  16. Glomerular nephrotoxicity of aminoglycosides

    SciTech Connect

    Martinez-Salgado, Carlos Lopez-Hernandez, Francisco J.; Lopez-Novoa, Jose M.

    2007-08-15

    Aminoglycoside antibiotics are the most commonly used antibiotics worldwide in the treatment of Gram-negative bacterial infections. However, aminoglycosides induce nephrotoxicity in 10-20% of therapeutic courses. Aminoglycoside-induced nephrotoxicity is characterized by slow rises in serum creatinine, tubular necrosis and marked decreases in glomerular filtration rate and in the ultrafiltration coefficient. Regulation of the ultrafiltration coefficient depends on the activity of intraglomerular mesangial cells. The mechanisms responsible for tubular nephrotoxicity of aminoglycosides have been intensively reviewed previously, but glomerular toxicity has received less attention. The purpose of this review is to critically assess the published literature regarding the toxic mechanisms of action of aminoglycosides on renal glomeruli and mesangial cells. The main goal of this review is to provide an actualized and mechanistic vision of pathways involved in glomerular toxic effects of aminoglycosides.

  17. Glomerular disease.

    PubMed

    Vaden, Shelly L

    2011-08-01

    Glomerular diseases are a leading cause of chronic kidney disease in dogs but seem to be less common in cats. Glomerular diseases are diverse, and a renal biopsy is needed to determine the specific glomerular disease that is present in any animal. Familial glomerulopathies occur in many breeds of dogs. However, most dogs with glomerular disease have acquired glomerular injury that is either immune-complex mediated or due to systemic factors, both of which are believed to be the result of a disease process elsewhere in the body (i.e., neoplastic, infectious, and noninfectious inflammatory disorders). A thorough clinical evaluation is indicated in all dogs suspected of having glomerular disease and should include an extensive evaluation for potential predisposing disorders. Nonspecific management of dogs with glomerular disease can be divided into 3 major categories: (1) treatment of potential predisposing disorders, (2) management of proteinuria, and (3) management of uremia and other complications of glomerular disease and chronic kidney disease. Specific management of specific glomerular diseases has not been fully studied in dogs. However, it may be reasonable to consider immunosuppressive therapy in dogs that have developed a form of glomerulonephritis secondary to a steroid-responsive disease (e.g., systemic lupus erythematosus) or have immune-mediated lesions that have been documented in renal biopsy specimens. Appropriate patient monitoring during therapy is important for maximizing patient care. The prognosis for dogs and cats with glomerular disease is variable and probably dependent on a combination of factors. The purpose of this article is to discuss the general diagnosis and management of dogs with glomerular disease. PMID:21782143

  18. Associations of blood lead, cadmium, and mercury with estimated glomerular filtration rate in the Korean general population: Analysis of 2008-2010 Korean National Health and Nutrition Examination Survey data

    SciTech Connect

    Kim, Yangho; Lee, Byung-Kook

    2012-10-15

    Introduction: The objective of this study was to evaluate associations between blood lead, cadmium, and mercury levels with estimated glomerular filtration rate in a general population of South Korean adults. Methods: This was a cross-sectional study based on data obtained in the Korean National Health and Nutrition Examination Survey (KNHANES) (2008-2010). The final analytical sample consisted of 5924 participants. Estimated glomerular filtration rate (eGFR) was calculated using the MDRD Study equation as an indicator of glomerular function. Results: In multiple linear regression analysis of log2-transformed blood lead as a continuous variable on eGFR, after adjusting for covariates including cadmium and mercury, the difference in eGFR levels associated with doubling of blood lead were -2.624 mL/min per 1.73 m Superscript-Two (95% CI: -3.803 to -1.445). In multiple linear regression analysis using quartiles of blood lead as the independent variable, the difference in eGFR levels comparing participants in the highest versus the lowest quartiles of blood lead was -3.835 mL/min per 1.73 m Superscript-Two (95% CI: -5.730 to -1.939). In a multiple linear regression analysis using blood cadmium and mercury, as continuous or categorical variables, as independent variables, neither metal was a significant predictor of eGFR. Odds ratios (ORs) and 95% CI values for reduced eGFR calculated for log2-transformed blood metals and quartiles of the three metals showed similar trends after adjustment for covariates. Discussion: In this large, representative sample of South Korean adults, elevated blood lead level was consistently associated with lower eGFR levels and with the prevalence of reduced eGFR even in blood lead levels below 10 {mu}g/dL. In conclusion, elevated blood lead level was associated with lower eGFR in a Korean general population, supporting the role of lead as a risk factor for chronic kidney disease.

  19. Effect of background region of interest and time-interval selection on glomerular filtration ratio estimation by percentage dose uptake of (99m)Tc-DTPA in comparison with (51)Cr-EDTA clearance in healthy cats.

    PubMed

    Debruyn, Katrien; Vandermeulen, Eva; Saunders, Jimmy H; Dobbeleir, André A; Ham, Hamphrey R; Peremans, Kathelijne

    2013-08-01

    Evaluation of glomerular function is a useful part of the diagnostic approach in animals suspected of having renal disease. Time-interval and background region of interest (bg ROI) selection are determining factors when calculating the glomerular filtration ratio (GFR) based on percentage uptake of (99m)technetium-labelled diethylene triamine penta-acetic acid ((99m)Tc-DTPA). Therefore, three different time intervals (60-120 s, 120-180 s, 60-180 s) and three different bg ROIs (C-shape, caudolateral, cranial + caudal) were investigated. In addition, global GFRs based on percentage dose uptake of (99m)Tc-DTPA for the different time-intervals and bg ROIs were compared with the global GFR based on (51)chromium-ethylene diaminic tetra-acetic acid ((51)Cr-EDTA) plasma clearance in nine healthy European domestic shorthair cats. Paired Student's t-tests and linear regression analysis were used to analyse the data. Different time intervals seemed to cause significant variation (P <0.01) in absolute GFR values, regardless of the choice of bg ROI. Significant differences (P <0.01) between bg ROIs were only observed in the 120-180s time interval between the C-shape and cranial + caudal bg ROI, and between the caudolateral and cranial + caudal bg ROI. The caudolateral bg ROI in the 60-180 s time interval showed the highest correlation coefficient (r = 0.882) between (99m)Tc-DTPA and (51)Cr-EDTA, although a significant difference (P <0.05) was present between both techniques. PMID:23349527

  20. Effective plasma volume in cirrhosis with ascites. Evidence that a decreased value does not account for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR during drug-induced diuresis

    PubMed Central

    Lieberman, Fred L.; Ito, Sosuke; Reynolds, Telfer B.

    1969-01-01

    A reduction in effective (nonportal) plasma volume is considered the basis for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR occurring during drug-induced diuresis in patients with cirrhosis and ascites. In the present study the concept of a reduced effective plasma volume in cirrhosis is challenged by two lines of evidence, even though effective plasma volume itself could not be measured. (a) Total plasma volume failed to rise in 10 patients with the spontaneous loss of ascites, the appearance of sodium in the urine, and a rise in GFR. Portal pressure remained constant in these patients as ascites left, suggesting that effective plasma volume had not increased while portal plasma volume decreased. (b) Reduction of GFR could not be prevented in five patients with cirrhosis and ascites while total plasma volume was prevented from falling with albumin infusions during drug-induced diuresis. Reduction of GFR during drug-induced diuresis in 15 patients with cirrhosis and ascites was completely reversed with saline infusion despite continued diuresis with the identical drugs, excluding drug nephrotoxicity as the cause for the reduced GFR. The ascites of cirrhosis might no longer be regarded as a cause of effective plasma volume contraction, stimulating renal sodium retention and a reduction in GFR. More likely, this form of ascites is a result of plasma volume expansion and sodium retention. The causes for renal sodium retention and a spontaneous reduction in GFR remain unknown. The cause for a fall in GFR during drug-induced diuresis also remains unknown, but effective plasma volume contraction and drug nephrotoxicity seem excluded. Images PMID:5771197

  1. Individualizing Pharmacotherapy in Patients with Renal Impairment: The Validity of the Modification of Diet in Renal Disease Formula in Specific Patient Populations with a Glomerular Filtration Rate below 60 Ml/Min. A Systematic Review

    PubMed Central

    Kramers, Cornelis; Derijks, Hieronymus J.; Wensing, Michel; Wetzels, Jack F. M.

    2015-01-01

    Background The Modification of Diet in Renal Disease (MDRD) formula is widely used in clinical practice to assess the correct drug dose. This formula is based on serum creatinine levels which might be influenced by chronic diseases itself or the effects of the chronic diseases. We conducted a systematic review to determine the validity of the MDRD formula in specific patient populations with renal impairment: elderly, hospitalized and obese patients, patients with cardiovascular disease, cancer, chronic respiratory diseases, diabetes mellitus, liver cirrhosis and human immunodeficiency virus. Methods and Findings We searched for articles in Pubmed published from January 1999 through January 2014. Selection criteria were (1) patients with a glomerular filtration rate (GFR) < 60 ml/min (/1.73m2), (2) MDRD formula compared with a gold standard and (3) statistical analysis focused on bias, precision and/or accuracy. Data extraction was done by the first author and checked by a second author. A bias of 20% or less, a precision of 30% or less and an accuracy expressed as P30% of 80% or higher were indicators of the validity of the MDRD formula. In total we included 27 studies. The number of patients included ranged from 8 to 1831. The gold standard and measurement method used varied across the studies. For none of the specific patient populations the studies provided sufficient evidence of validity of the MDRD formula regarding the three parameters. For patients with diabetes mellitus and liver cirrhosis, hospitalized patients and elderly with moderate to severe renal impairment we concluded that the MDRD formula is not valid. Limitations of the review are the lack of considering the method of measuring serum creatinine levels and the type of gold standard used. Conclusion In several specific patient populations with renal impairment the use of the MDRD formula is not valid or has uncertain validity. PMID:25741695

  2. Abnormalities in signaling pathways in diabetic nephropathy

    PubMed Central

    Brosius, Frank C; Khoury, Charbel C; Buller, Carolyn L; Chen, Sheldon

    2010-01-01

    Diabetic nephropathy (DN) is characterized by a plethora of signaling abnormalities that together ultimately result in the clinical and pathologic hallmarks of DN, namely progressive albuminuria followed by a gradual decline in glomerular filtration rate leading to kidney failure, and accompanied by podocyte loss, progressive glomerular sclerosis and, ultimately, progressive tubulointerstitial fibrosis. Over the past few years, the general understanding of the abnormalities in signaling pathways that lead to DN has expanded considerably. In this review, some of the important pathways that appear to be involved in driving this process are discussed, with special emphasis on newer findings and insights. Newer concepts regarding signaling changes in bradykinin, mTOR, JAK/STAT, MCP-1, VEGF, endothelial nitric oxide synthase, activated protein C and other pathways are discussed. PMID:20224802

  3. Exploratory Analysis for the Evaluation of Estimated Glomerular Filtration Rate, Cholesterol and Triglycerides after Switching from Tenofovir/Emtricitabine plus Atazanavir/Ritonavir (ATV/r) to Abacavir/Lamivudine plus ATV/r in Patients with Preserved Renal Function

    PubMed Central

    Postorino, Maria Concetta; Quiros-Roldan, Eugenia; Maggiolo, Franco; Di Giambenedetto, Simona; Ladisa, Nicoletta; Lapadula, Giuseppe; Lorenzotti, Silvia; Sighinolfi, Laura; Castelnuovo, Filippo; Di Pietro, Massimo; Gotti, Daria; Mazzini, Nicola; Torti, Carlo

    2016-01-01

    Background and Objectives: Renal toxicity due to tenofovir (TDF) has been largely described in patients with HIV infection. However, other antiretroviral drugs (such as atazanavir [ATV], especially when boosted by ritonavir, ATV/r) could perpetuate some degrees of renal impairment with or without TDF co-administration. Also, possible benefits of stopping TDF in patients without renal diseases is not well known. This study aimed at exploring evolution of renal function and lipid profile after switching from tenofovir/emtricitabine (TDF/FTC) to abacavir/lamivudine (ABC/3TC), maintaining the ATV/r component of the regimen. Methods: Patients in the Italian MASTER Cohort, who switched from TDF/FTC plus ATV/r to ABC/3TC plus ATV/r were included, provided that major renal diseases were not diagnosed before switching (i.e., baseline). Serum creatinine, estimated glomerular filtration rate (eGFR), total cholesterol, HDL and triglycerides were evaluated at baseline and at month 18 after switching. Results: 126 patients were selected (80% males). Patients were mostly Italians (92%). 79% had undetectable HIV-RNA and 44% were co-infected by HBV and/or HCV. Median age at switch was 47 years (IQR 43-55). A small but significant decrease in serum creatinine [from 1.06 mg/dl (SD: 0.3) to 0.94 mg/dl (SD: 0.2); p<0.001] with an improvement in eGFR [from 86.8 ml/min (SD: 33) to 96.4 ml/min (SD: 37); p<0.001] were observed in per protocol analysis at month 18. Also ITT analysis showed a decrease in mean serum creatinine [from 1.08 mg/dl (SD: 0.35) to 0.95 mg/dl (SD: 0.24); p<0.001] with an improvement in mean eGFR [from 86.9 ml/min/1.73m2 (SD: 24.11) to 95.8 ml/min/1.73m2 (SD: 19.99); p<0.001]. Total cholesterol increased [from 188 mg/dl (SD: 42) to 206 mg/dl (SD: 44); p<0.001] but also HDL increased as well [from 46 mg/dl (SD: 14) to 54 mg/dl (SD: 19); p=0.015]. An increase in triglycerides concentration was observed [from 162 mg/dl (SD: 144) to 214 mg/dl (SD: 109); p=0.027] in per

  4. Documentation of angiotensin II receptors in glomerular epithelial cells

    NASA Technical Reports Server (NTRS)

    Sharma, M.; Sharma, R.; Greene, A. S.; McCarthy, E. T.; Savin, V. J.; Cowley, A. W. (Principal Investigator)

    1998-01-01

    Angiotensin II decreases glomerular filtration rate, renal plasma flow, and glomerular capillary hydraulic conductivity. Although angiotensin II receptors have been demonstrated in mesangial cells and proximal tubule cells, the presence of angiotensin II receptors in glomerular epithelial cells has not previously been shown. Previously, we have reported that angiotensin II caused an accumulation of cAMP and a reorganization of the actin cytoskeleton in cultured glomerular epithelial cells. Current studies were conducted to verify the presence of angiotensin II receptors by immunological and non-peptide receptor ligand binding techniques and to ascertain the activation of intracellular signal transduction in glomerular epithelial cells in response to angiotensin II. Confluent monolayer cultures of glomerular epithelial cells were incubated with angiotensin II, with or without losartan and/or PD-123,319 in the medium. Membrane vesicle preparations were obtained by homogenization of washed cells followed by centrifugation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of membrane proteins followed by multiscreen immunoblotting was used to determine the presence of angiotensin II receptor type 1 (AT1) or type 2 (AT2). Angiotensin II-mediated signal transduction in glomerular epithelial cells was studied by measuring the levels of cAMP, using radioimmunoassay. Results obtained in these experiments showed the presence of both AT1 and AT2 receptor types in glomerular epithelial cells. Angiotensin II was found to cause an accumulation of cAMP in glomerular epithelial cells, which could be prevented only by simultaneous use of losartan and PD-123,319, antagonists for AT1 and AT2, respectively. The presence of both AT1 and AT2 receptors and an increase in cAMP indicate that glomerular epithelial cells respond to angiotensin II in a manner distinct from that of mesangial cells or proximal tubular epithelial cells. Our results suggest that glomerular epithelial

  5. The cell biology of renal filtration

    PubMed Central

    Quaggin, Susan E.

    2015-01-01

    The function of the kidney, filtering blood and concentrating metabolic waste into urine, takes place in an intricate and functionally elegant structure called the renal glomerulus. Normal glomerular function retains circulating cells and valuable macromolecular components of plasma in blood, resulting in urine with just trace amounts of proteins. Endothelial cells of glomerular capillaries, the podocytes wrapped around them, and the fused extracellular matrix these cells form altogether comprise the glomerular filtration barrier, a dynamic and highly selective filter that sieves on the basis of molecular size and electrical charge. Current understanding of the structural organization and the cellular and molecular basis of renal filtration draws from studies of human glomerular diseases and animal models of glomerular dysfunction. PMID:25918223

  6. Overexpression of VEGF165b in Podocytes Reduces Glomerular Permeability

    PubMed Central

    Qiu, Yan; Ferguson, Joanne; Oltean, Sebastian; Neal, Chris R.; Kaura, Amit; Bevan, Heather; Wood, Emma; Sage, Leslie M.; Lanati, Silvia; Nowak, Dawid G.; Salmon, Andy H.J.; Bates, David

    2010-01-01

    The observation that therapeutic agents targeting vascular endothelial growth factor-A (VEGF-A) associate with renal toxicity suggests that VEGF plays a role in the maintenance of the glomerular filtration barrier. Alternative mRNA splicing produces the VEGFxxxb family, which consists of antiangiogenic peptides that reduce permeability and inhibit tumor growth; the contribution of these peptides to normal glomerular function is unknown. Here, we established and characterized heterozygous and homozygous transgenic mice that overexpress VEGF165b specifically in podocytes. We confirmed excess production of glomerular VEGF165b by reverse transcriptase–PCR, immunohistochemistry, and ELISA in both heterozygous and homozygous animals. Macroscopically, the mice seemed normal up to 18 months of age, unlike the phenotype of transgenic podocyte-specific VEGF164-overexpressing mice. Animals overexpressing VEGF165b, however, had a significantly reduced normalized glomerular ultrafiltration fraction with accompanying changes in ultrastructure of the glomerular filtration barrier on the vascular side of the glomerular basement membrane. These data highlight the contrasting properties of VEGF splice variants and their impact on glomerular function and phenotype. PMID:20688932

  7. De Novo Glomerular Diseases after Renal Transplantation

    PubMed Central

    Moroni, Gabriella; Glassock, Richard J.

    2014-01-01

    Glomerular diseases developing in the kidney allograft are more often recurrences of the original disease affecting the native kidneys. However, in an undefined number of cases de novo, glomerular diseases unrelated to the original disease in the native kidneys can develop in the transplanted kidney. The clinical presentation and histologic features of de novo diseases are often similar to those features observed in patients with primary or secondary GN in the native kidneys. However, in transplanted kidneys, the glomerular, vascular, and tubulointerstitial changes are often intertwined with structural abnormalities already present at the time of transplant or caused by antibody- or cell-mediated allograft rejection, immunosuppressive drugs, or superimposed infection (most often of a viral nature). The pathophysiology of de novo glomerular diseases is quite variable. In rare cases of de novo minimal change disease, circulating factors increasing the glomerular permeability likely participate. Maladaptive hemodynamic changes and tissue fibrosis caused by calcineurin inhibitors or other factors may be involved in the pathogenesis of de novo FSGS. The exposure of cryptic podocyte antigens may favor the development of de novo membranous nephropathy. Many cases of de novo membranoproliferative GN are related to hepatitis C virus infection. Patients with Alport syndrome lacking antigenic epitopes in their glomerular basement membrane may develop antibodies against these glomerular basement membrane antigens expressed in the transplanted kidney. Infection may cause acute GN to have a heterogeneous clinical presentation and outcome. De novo pauci-immune GN in renal transplant is rare. Preexisting or acquired intolerance to glucose may, in the long term, cause diabetic nephropathy. The prognosis of de novo diseases depends on the type of GN, the severity of lesions caused by the alloimmune response, or the efficacy of immunosuppressive therapy. In most cases, the management

  8. Glomerular hemodynamics in persistent renovascular hypertension in the rat.

    PubMed

    Herrera-Acosta, J; Gabbai, F; Franco, M; Tapia, E; Linfa, G; Díaz, L; Campos, J

    1983-01-01

    We studied the glomerular hemodynamics and activity of the tubuloglomerular feedback system (TGFS) in Wistar rats with persistent hypertension 60 days after removal of the clipped kidney in the Goldblatt (two-kidney, one clip) hypertension model. Ten hypertensive rats (HBP) were compared with 12 normotensive ones (NBP). Micropuncture studies revealed that values for the single nephron glomerular filtration rate (SNGFR), glomerular plasma flow (QA), and afferent oncotic pressure (PAR.A) were similar in both groups, whereas glomerular capillary pressure (PGC) and effective filtration pressure (EFP) were higher in the HBP group (p less than 0.05). A slight but insignificant increase in afferent resistance was present in the HBP group. A positive correlation was found between mean arterial pressure and stop flow pressure (SFP) (r = 0.64, p less than 0.05) but not with SNGFR, suggesting a reduction in the ultrafiltration coefficient in hypertensive rats. This was further supported by studies of the activity of the TGFS, which demonstrated that interrupting flow to the macula densa was followed by a smaller increment in SNGFR in HBP, in spite of a similar rise in SFP. The mechanism responsible for decreasing glomerular permeability is unknown but could be related to structural changes in glomerular capillary or to an increase in intrarenal angiotensin II, as has been demonstrated previously in this model. It is suggested that these adaptations occurring in the kidney exposed to hypertension can contribute to the maintenance of elevated arterial pressure after removing the stenotic kidney.

  9. Filtration Fundamentals.

    ERIC Educational Resources Information Center

    Ward, Ken; Hunsaker, Scot

    1997-01-01

    Examines how choice of commercial swimming-pool filtration systems is driven by the project-specific needs of the pools. Also highlighted are definitions of specific terms used when discussing filtration systems. Questions that pool designers can answer to make filtration-system purchasing decisions are listed. (GR)

  10. Water Filtration

    ERIC Educational Resources Information Center

    Jacobsen, Erica K.

    2004-01-01

    A water filtration column is devised by students using a two-liter plastic bottle containing gravel, sand, and activated charcoal, to test the filtration potential of the column. Results indicate that the filtration column eliminates many of the contaminating materials, but does not kill bacteria.

  11. The Beneficial Role of Retinoids in Glomerular Disease

    PubMed Central

    Mallipattu, Sandeep K.; He, John Cijiang

    2015-01-01

    The primary etiology of CKD is a direct consequence of initial dysfunction and injury of the glomerulus, the main filtration system. Podocytes are terminally differentiated epithelial cells in the glomerulus, whose major function is the maintenance of this renal filtration barrier. Podocyte injury is implicated in many glomerular diseases including focal segmental glomerular sclerosis and HIV-associated nephropathy. In many of these diseased conditions, the podocyte can either undergo dedifferentiation and proliferation, apoptosis, or cell detachment. Regardless of the initial type of injury, the podocyte ultimately loses its functional capacity to maintain the glomerular filtration barrier. Significant injury resulting in a loss of the podocytes and failure to maintain the renal filtration barrier contributes to progressive kidney disease. Consequently, therapies that prevent podocyte injury and promote their regeneration will have a major clinical impact on glomerular disease. Retinoic acid (RA), which is a derivative of vitamin A, has many cellular functions including induction of cell differentiation, regulation of apoptosis, and inhibition of inflammation and proliferation. RA is required for kidney development and is essential for cellular differentiation in the setting of podocyte injury. The mechanism by which RA directs its beneficial effects is multifactorial, ranging from its anti-inflammatory and anti-fibrotic effects to a direct effect of upregulating podocyte differentiation markers in the podocyte. The focus of this review is to provide an overview of RA in kidney development and glomerular disease. We also highlight the key mechanism(s) by which RA restores podocyte differentiation markers and ameliorates glomerular disease. PMID:25853135

  12. Review series: The cell biology of renal filtration.

    PubMed

    Scott, Rizaldy P; Quaggin, Susan E

    2015-04-27

    The function of the kidney, filtering blood and concentrating metabolic waste into urine, takes place in an intricate and functionally elegant structure called the renal glomerulus. Normal glomerular function retains circulating cells and valuable macromolecular components of plasma in blood, resulting in urine with just trace amounts of proteins. Endothelial cells of glomerular capillaries, the podocytes wrapped around them, and the fused extracellular matrix these cells form altogether comprise the glomerular filtration barrier, a dynamic and highly selective filter that sieves on the basis of molecular size and electrical charge. Current understanding of the structural organization and the cellular and molecular basis of renal filtration draws from studies of human glomerular diseases and animal models of glomerular dysfunction.

  13. Repeat Catheter Ablation of Long-standing Persistent Atrial Fibrillation in Patients with a Total Atrial Fibrillation Duration of More Than 2 Years: Effects of the CHA2DS2-VASc Score and Estimated Glomerular Filtration Rate on the Outcomes.

    PubMed

    Wang, Qian; Jiang, Shi-Li; Liu, Xu; Yang, Yi-Qing

    2016-01-01

    Objective Little is known about the outcome of repeat catheter ablation of long-standing persistent atrial fibrillation (AF) in patients with a total AF duration of more than 2 years. The main objective of this study was to explore the results and factors affecting the clinical success rate of these repeat procedures. Methods We enrolled 99 patients with a total AF duration of more than 2 years and recurrent atrial arrhythmias after the initial catheter ablation of long-standing persistent AF. The enrolled patients were divided into two groups named the AF-recurrence group (50 patients) and the atrial tachycardia (AT)-recurrence group (49 patients) and all underwent a strict follow-up. The quality of life (QOL) and AF-related symptom classification were assessed at baseline and at 24 months post re-ablation. Results After a mean follow-up of 31 months, 30 (30.3%) patients were free from arrhythmia recurrence, and the success rate in the AT-recurrence group was higher than that in the AF-recurrence group (32.7% vs. 28.0%, p=0.614). A Cox regression analysis revealed a CHA2DS2-VASc score ≥3 to be a predictor of recurrence. AF recurrent patients with an abnormal renal function were more prone to undergo a failed procedure. However, an abnormal renal function had no effect on the outcome of the repeat procedure for patients with AT recurrence. At the 24-month follow-up, patients maintaining sinus rhythm (SR) had a significantly improved QOL and AF-related symptoms. Conclusion The success rate of repeat procedures for long-standing persistent AF and a total AF duration of more than 2 years is poor for patients with a CHA2DS2-VASc score ≥3. An impaired renal function has an unfavorable effect on the outcome for patients with AF recurrence. For patients maintaining SR, both the QOL and AF symptomatology improve significantly. PMID:27629945

  14. Ornithine decarboxylase, kidney size, and the tubular hypothesis of glomerular hyperfiltration in experimental diabetes

    PubMed Central

    Thomson, Scott C.; Deng, Aihua; Bao, Dingjiu; Satriano, Joseph; Blantz, Roland C.; Vallon, Volker

    2001-01-01

    In early diabetes, the kidney grows and the glomerular filtration rate (GFR) increases. This growth is linked to ornithine decarboxylase (ODC). The study of hyperfiltration has focused on microvascular abnormalities, but hyperfiltration may actually result from a prior increase in capacity for proximal reabsorption which reduces the signal for tubuloglomerular feedback (TGF). Experiments were performed in Wistar rats after 1 week of streptozotocin diabetes. Kidney weight, ODC activity, and GFR were correlated in diabetic and control rats given difluoromethylornithine (DFMO; Marion Merrell Dow, Cincinnati, Ohio, USA) to inhibit ODC. We assessed proximal reabsorption by micropuncture, using TGF as a tool for manipulating single-nephron GFR (SNGFR), then plotting proximal reabsorption versus SNGFR. ODC activity was elevated 15-fold in diabetic kidneys and normalized by DFMO, which also attenuated hyperfiltration and hypertrophy. Micropuncture data revealed an overall increase in proximal reabsorption in diabetic rats too great to be accounted for by glomerulotubular balance. DFMO prevented the overall increase in proximal reabsorption. These data confirm that ODC is required for the full effect of diabetes on kidney size and proximal reabsorption in early streptozotocin diabetes and are consistent with the hypothesis that diabetic hyperfiltration results from normal physiologic actions of TGF operating in a larger kidney, independent of any primary malfunction of the glomerular microvasculature. PMID:11160138

  15. TGF-β–Activated Kinase 1 Is Crucial in Podocyte Differentiation and Glomerular Capillary Formation

    PubMed Central

    Lee, So-Young; Wang, Zhibo; Ding, Yan; Haque, Nadeem; Zhang, Jiwang; Zhou, Jing

    2014-01-01

    TGF-β–activated kinase 1 (TAK1) is a key intermediate in signal transduction induced by TGF-β or inflammatory cytokines, such as TNF-α and IL-1, which are potent inducers of podocyte injury responses that lead to proteinuria and glomerulosclerosis. Nevertheless, little is known about the physiologic and pathologic roles of TAK1 in podocytes. To examine the in vivo role of TAK1, we generated podocyte-specific Tak1 knockout mice (Nphs2-Cre+:Tak1fx/fx; Tak1∆/∆). Targeted deletion of Tak1 in podocytes resulted in perinatal lethality, with approximately 50% of animals dying soon after birth and 90% of animals dying within 1 week of birth. Tak1∆/∆ mice developed proteinuria from P1 and exhibited delayed glomerulogenesis and reduced expression of Wilms’ tumor suppressor 1 and nephrin in podocytes. Compared with Tak1fx/fx mice, Tak1∆/∆ mice exhibited impaired formation of podocyte foot processes that caused disruption of the podocyte architecture with prominent foot process effacement. Intriguingly, Tak1∆/∆ mice displayed increased expression of vascular endothelial growth factor within the glomerulus and abnormally enlarged glomerular capillaries. Furthermore, 4- and 7-week-old Tak1∆/∆ mice with proteinuria had increased collagen deposition in the mesangium and the adjacent tubulointerstitial area. Thus, loss of Tak1 in podocytes is associated with the development of proteinuria and glomerulosclerosis. Taken together, our data show that TAK1 regulates the expression of Wilms’ tumor suppressor 1, nephrin, and vascular endothelial growth factor and that TAK1 signaling has a crucial role in podocyte differentiation and attainment of normal glomerular microvasculature during kidney development and glomerular filtration barrier homeostasis. PMID:24652804

  16. Glomerular pathology and the progression of chronic kidney disease.

    PubMed

    Lemley, Kevin V

    2016-06-01

    Structural studies of the glomerulus, largely undertaken in animal models, have informed our understanding of the progression of chronic kidney disease (CKD) for decades. A fundamental tenet of that understanding is that a loss of podocytes underlies progression in many or most cases of progressive CKD. Recent attempts have been made to reconcile earlier findings from glomerular physiology (the primacy of glomerular capillary hypertension in causation of secondary glomerular sclerosis) with structural findings and have suggested a more detailed model of the mechanisms underlying podocyte detachment as viable cells. A new appreciation of the main locus of mechanical challenges to the podocyte (in the filtration slit) may both explain the renoprotective action of some current therapies and help to suggest novel therapeutic strategies. PMID:27122538

  17. Tissue transglutaminase inhibition as treatment for diabetic glomerular scarring: it's good to be glueless.

    PubMed

    Schelling, Jeffrey R

    2009-08-01

    Diabetic nephropathy is characterized by enhanced glomerular and tubulointerstitial deposition of extracellular matrix proteins, which are bound together by tissue transglutaminase (TG2). Huang et al. demonstrate that infusion of a novel TG2 inhibitor in diabetic rats prevented renal scarring and albuminuria and preserved glomerular filtration rate. These studies confirm the role of TG2 in the pathogenesis of diabetic nephropathy and add to an emerging literature that demonstrates that TG2 is an attractive therapeutic target for sclerosing kidney diseases.

  18. Outcome of the acute glomerular injury in proliferative lupus nephritis

    SciTech Connect

    Chagnac, A.; Kiberd, B.A.; Farinas, M.C.; Strober, S.; Sibley, R.K.; Hoppe, R.; Myers, B.D. )

    1989-09-01

    Treatment with total lymphoid irradiation (TLI) and corticosteroids markedly reduced activity of systemic lupus erythematosis in 10 patients with diffuse proliferative lupus nephritis (DPLN) complicated by a nephrotic syndrome. Physiologic and morphometric techniques were used serially before, and 12 and 36 mo post-TLI to characterize the course of glomerular injury. Judged by a progressive reduction in the density of glomerular cells and immune deposits, glomerular inflammation subsided. A sustained reduction in the fractional clearance of albumin, IgG and uncharged dextrans of radius greater than 50 A, pointed to a parallel improvement in glomerular barrier size-selectivity. Corresponding changes in GFR were modest, however. A trend towards higher GFR at 12 mo was associated with a marked increase in the fraction of glomerular tuft area occupied by patent capillary loops as inflammatory changes receded. A late trend toward declining GFR beyond 12 mo was associated with progressive glomerulosclerosis, which affected 57% of all glomeruli globally by 36 mo post-TLI. Judged by a parallel increase in volume by 59%, remaining, patent glomeruli had undergone a process of adaptive enlargement. We propose that an increasing fraction of glomeruli continues to undergo progressive sclerosis after DPLN has become quiescent, and that the prevailing GFR depends on the extent to which hypertrophied remnant glomeruli can compensate for the ensuing loss of filtration surface area.

  19. Effect of saline adaptation and renal portal sodium infusion on glomerular size distributions and kidney function in domestic fowl.

    PubMed

    Wideman, R F; Satnick, J L; Mitsos, W J; Bennett, K R; Smith, S R

    1987-02-01

    Experiments were designed to evaluate acute and chronic effects of sodium on glomerular size distributions and kidney function of Single Comb White Leghorns. Chicks were raised on either tap water (control) or .6% NaCl (saline) drinking water. Kidney function studies were conducted when the birds reached 14 to 16 weeks of age. Saline-adapted birds had significantly lower glomerular filtration rates and significantly higher sodium and potassium excretion rates when compared with birds raised on tap water. Acute effects of sodium on kidney function were assessed by infusing 25 mM tetrasodium pyrophosphate unilaterally into the renal portal system. For birds raised on tap water, unilateral sodium infusion caused a significant unilateral reduction in the glomerular filtration rate. However, neither the acute nor the chronic reductions in glomerular filtration rates in response to sodium were associated with a reduction in the number of filtering nephrons. Saline-adapted birds had significantly hypertrophied glomeruli.

  20. TNF-mediated damage to glomerular endothelium is an important determinant of acute kidney injury in sepsis.

    PubMed

    Xu, Chang; Chang, Anthony; Hack, Bradley K; Eadon, Michael T; Alper, Seth L; Cunningham, Patrick N

    2014-01-01

    Severe sepsis is often accompanied by acute kidney injury (AKI) and albuminuria. Here we studied whether the AKI and albuminuria associated with lipopolysaccharide (LPS) treatment in mice reflects impairment of the glomerular endothelium with its associated endothelial surface layer. LPS treatment decreased the abundance of endothelial surface layer heparan sulfate proteoglycans and sialic acid, and led to albuminuria likely reflecting altered glomerular filtration permselectivity. LPS treatment decreased the glomerular filtration rate (GFR), while also causing significant ultrastructural alterations in the glomerular endothelium. The density of glomerular endothelial cell fenestrae was 5-fold lower, whereas the average fenestrae diameter was 3-fold higher in LPS-treated than in control mice. The effects of LPS on the glomerular endothelial surface layer, endothelial cell fenestrae, GFR, and albuminuria were diminished in TNF receptor 1 (TNFR1) knockout mice, suggesting that these LPS effects are mediated by TNF-α activation of TNFR1. Indeed, intravenous administration of TNF decreased GFR and led to loss of glomerular endothelial cell fenestrae, increased fenestrae diameter, and damage to the glomerular endothelial surface layer. LPS treatment decreased kidney expression of vascular endothelial growth factor (VEGF). Thus, our findings confirm the important role of glomerular endothelial injury, possibly by a decreased VEGF level, in the development and progression of AKI and albuminuria in the LPS model of sepsis in the mouse.

  1. Glomerular hemodynamics in established glycerol-induced acute renal failure in the rat.

    PubMed Central

    Wolfert, A I; Oken, D E

    1989-01-01

    The glomerular dynamic correlates of failed filtration were studied in volume replete rats with established glycerol-induced acute renal failure (ARF). Over one-half of all nephrons formed virtually no filtrate, while the single nephron glomerular filtration rate (SNGFR) of fluid-filled nephrons, measured at the glomerulotubular junction to preclude the possibility of covert tubular leakage, averaged one-sixth of control (P less than 0.001). Even that low mean value was elevated by a few nephrons with a near normal SNGFR. Renal failure thus reflected both total filtration failure in the majority of nephrons and massively reduced filtration in most of the remainder. Glomerular capillary pressure (Pg) averaged some 14 mmHg below control (P less than 0.001), whereas the arterial colloid osmotic and Bowman's space pressures were not significantly altered. Renocortical and whole kidney blood flow were also unchanged. Marked internephron functional heterogeneity precluded estimates of the ultrafiltration coefficient. However, the fall in SNGFR correlated well with the markedly depressed Pg and afferent net filtration pressure (delta PnetA, P less than 0.001), which in turn were caused by increased preglomerular resistance and a reciprocal fall in efferent arteriolar resistance. This complex change in intrarenal resistances was largely, if not entirely, responsible for failed filtration in this ARF model. PMID:2592568

  2. Ultrastructural co-localisation of vimentin and cytokeratin in visceral glomerular epithelial cells of dogs with glomerulonephritis.

    PubMed

    Vilafranca, M; Ferrer, L; Wohlsein, P; Trautwein, G; Sanchez, J; Navarro, J A

    1995-07-01

    The expression of cytokeratin and vimentin was studied in the glomerular epithelial cells of canine kidneys with and without glomerular abnormalities. Using ultrastructural, immunogold single and double labelling techniques, cytokeratin and vimentin were found together in the visceral glomerular epithelial cells (vGECs) of abnormal kidneys. In normal kidneys, the vGECs expressed only vimentin, and cytokeratin was found exclusively in parietal glomerular epithelial cells (pGECs). These results confirm previous findings in the same animals, obtained by immunohistological staining techniques.

  3. NHANES III: influence of race on GFR thresholds and detection of metabolic abnormalities.

    PubMed

    Foley, Robert N; Wang, Changchun; Ishani, Areef; Collins, Allan J

    2007-09-01

    Whether the creatinine-based glomerular filtration rate (GFR) thresholds used to define chronic kidney disease (CKD) identify metabolic abnormalities similarly in minority and nonminority populations is unknown. We addressed this question among adult participants in the Third National Health and Nutrition Examination Survey (NHANES III) (n = 15,837). GFR was estimated from serum creatinine values and metabolic abnormalities were defined by 5th or 95th percentile values. After adjustment for age, demographic characteristics, and GFR, black participants were significantly more likely than white participants to have abnormal levels of systolic and diastolic blood pressure, hemoglobin, phosphorus, and uric acid. Hispanic subjects were significantly more likely to have abnormal levels of systolic blood pressure, hemoglobin, bicarbonate, and phosphorus. Among participants with GFR < 60 mL/min per 1.73 m(2), black participants were significantly more likely to have abnormal levels of systolic and diastolic blood pressure, hemoglobin, and uric acid; Hispanic subjects were significantly more likely to have abnormal systolic blood pressure levels. Metabolic abnormalities were more common in minority populations, and low GFR appeared to have a multiplicative effect. Defining CKD using a single GFR threshold may be disadvantageous for minority populations because metabolic abnormalities are present at higher levels of GFR.

  4. Persistent haematuria and proteinuria due to glomerular disease in related Abyssinian cats.

    PubMed

    White, Joanna D; Norris, Jacqueline M; Bosward, Katrina L; Fleay, R; Lauer, Chris; Malik, Richard

    2008-07-01

    Eight cases of glomerular disease in young, related Abyssinian cats are described. Haematuria was the most consistent feature. Six cats developed the nephrotic syndrome. The short-term prognosis was good for cats with haematuria and fair for cats with the nephrotic syndrome as oedema resolved in three of the six cats. Light microscopic examination of renal biopsies from three cats was considered normal or revealed only mild abnormalities. In the three cases subjected to necropsy, histological abnormalities included mild mesangial hypercellularity and adhesions between the glomerular tuft and Bowman's capsule consistent with a focal proliferative glomerulopathy. Further investigation into this glomerulopathy will require ultrastructural and immunohistochemical studies to characterise the glomerular abnormality and genetic analyses to investigate its potential to be an inherited disease. Glomerular disease, potentially a familial one, should be considered in the investigation of persistent haematuria or proteinuria in Abyssinian and related cats. PMID:18455462

  5. Podocyte pathology and nephropathy - sphingolipids in glomerular diseases.

    PubMed

    Merscher, Sandra; Fornoni, Alessia

    2014-01-01

    Sphingolipids are components of the lipid rafts in plasma membranes, which are important for proper function of podocytes, a key element of the glomerular filtration barrier. Research revealed an essential role of sphingolipids and sphingolipid metabolites in glomerular disorders of genetic and non-genetic origin. The discovery that glucocerebrosides accumulate in Gaucher disease in glomerular cells and are associated with clinical proteinuria initiated intensive research into the function of other sphingolipids in glomerular disorders. The accumulation of sphingolipids in other genetic diseases including Tay-Sachs, Sandhoff, Fabry, hereditary inclusion body myopathy 2, Niemann-Pick, and nephrotic syndrome of the Finnish type and its implications with respect to glomerular pathology will be discussed. Similarly, sphingolipid accumulation occurs in glomerular diseases of non-genetic origin including diabetic kidney disease (DKD), HIV-associated nephropathy, focal segmental glomerulosclerosis (FSGS), and lupus nephritis. Sphingomyelin metabolites, such as ceramide, sphingosine, and sphingosine-1-phosphate have also gained tremendous interest. We recently described that sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is expressed in podocytes where it modulates acid sphingomyelinase activity and acts as a master modulator of danger signaling. Decreased SMPDL3b expression in post-reperfusion kidney biopsies from transplant recipients with idiopathic FSGS correlates with the recurrence of proteinuria in patients and in experimental models of xenotransplantation. Increased SMPDL3b expression is associated with DKD. The consequences of differential SMPDL3b expression in podocytes in these diseases with respect to their pathogenesis will be discussed. Finally, the role of sphingolipids in the formation of lipid rafts in podocytes and their contribution to the maintenance of a functional slit diaphragm in the glomerulus will be discussed. PMID:25126087

  6. The effect of abnormal birth history on ambulatory blood pressure and disease progression in children with chronic kidney disease

    PubMed Central

    Flynn, Joseph T; Ng, Derek K; Chan, Grace J; Samuels, Joshua; Furth, Susan; Warady, Bradley; Greenbaum, Larry A.

    2014-01-01

    Objective To examine the associations between abnormal birth history (birth weight [BW] <2500 grams, gestational age <36 weeks, or small for gestational age), BP, and renal function among 332 participants (97 with abnormal and 235 with normal birth history) in the Chronic Kidney Disease in Children (CKiD) Study, a cohort of children with chronic kidney disease (CKD). Study design Casual and 24-hour ambulatory BP were obtained. Glomerular filtration rate (GFR) was determined by iohexol disappearance. Confounders (birth and maternal characteristics, socioeconomic status) were used to generate predicted probabilities of abnormal birth history for propensity score matching. Weighted linear and logistic regression models with adjustment for quintiles of propensity scores and CKD diagnosis were used to assess the impact of birth history on BP and GFR. Results Age at enrollment, percent with glomerular disease, and baseline GFR were similar between the groups. Those with abnormal birth history were more likely to be female, of Black race or Hispanic ethnicity, to have low household income, or part of a multiple birth. Unadjusted BP measurements, baseline GFR and change in GFR did not differ significantly between the groups; no differences were seen after adjusting for confounders by propensity score matching. Conclusions Abnormal birth history does not appear to have exerted a significant influence on BP or GFR in this cohort of children with CKD. The absence of an observed association is likely secondary to the dominant effects of underlying CKD and its treatment. PMID:24698454

  7. Intraglomerular microcirculation: measurements of single glomerular loop flow in rats.

    PubMed

    Steinhausen, M; Zimmerhackl, B; Thederan, H; Dussel, R; Parekh, N; Esslinger, H U; von Hagens, G; Komitowski, D; Dallenbach, F D

    1981-08-01

    With the use of a new fluorescent microscopic technique, we were able to measure the mean intracapillary velocities and pressures of single capillary loops of renal glomeruli of living rats. The technique involved photographing and recording the flow of fluorescent latex particles through the glomerular loops with a television monitor. In 25 rats the single glomerular loop flow velocity was 781 +/- (SD) 271 micrometers . sec-1. The mean diameter of the capillary loops measured 8.4 +/- 1.4 micrometers; their lengths were 72.3 +/- 37.5 micrometers. From the decrease in velocity of flow along the capillary loop, we were able to evaluate the filtration equivalent for the capillary surface. It was possible to measure intracapillary pressures of single glomerular loops continuously under microscopic control. High intracapillary pressures correlated with high intracapillary velocities. From the data we obtained, we were unable to calculate a filtration equilibrium at the ends of the observed capillary loops. For further correlations, we injected the glomeruli we had studied in the living state and examined them with the scanning electron microscope.

  8. Predictors of Rapid Progression of Glomerular and Non-Glomerular Kidney Disease in Children: The CKiD Cohort

    PubMed Central

    Warady, Bradley A.; Abraham, Alison G.; Schwartz, George J.; Wong, Craig S.; Muñoz, Alvaro; Betoko, Aisha; Mitsnefes, Mark; Kaskel, Frederick; Greenbaum, Larry A.; Mak, Robert H.; Flynn, Joseph; Moxey-Mims, Marva M.; Furth, Susan

    2015-01-01

    Background Few studies have prospectively evaluated the progression of chronic kidney disease (CKD) in children and factors associated with progression. Study Design Prospective assessment of risk factors for the composite event of renal replacement therapy (RRT) or 50% glomerular filtration rate (GFR) decline. Setting and Participants 496 children with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study. Outcomes Parametric failure time models were used to characterize adjusted associations between baseline levels and changes of predictors and the time to composite event. Results The cohort consisted of 398 children with non-glomerular and 98 children with glomerular disease, of whom 29% and 41%, respectively progressed to the composite event after a median follow-up of 5.2 and 3.7 years. Demographic, clinical characteristics and outcomes differed substantially according to underlying diagnosis, hence risk factors for progression were assessed in stratified analyses and formal interactions by diagnosis were performed. Among non-glomerular patients and after adjusting for baseline GFR, times to the composite event were significantly reduced with Up/c > 2 mg/mg, hypoalbuminemia, elevated blood pressure, dyslipidemia, male gender and anemia by 79%, 69%, 38%, 40%, 38% and 45%, respectively. Among patients with glomerular disease, Up/c > 0.5 mg/mg, hypoalbuminemia and elevated blood pressure significantly reduced times to the composite event by 94%, 71% and 67%, respectively. Variables expressing change in patient clinical status over the initial year of the study contributed significantly to the model which was cross validated internally. Limitations small number of events in glomerular patients and use of internal cross validation. Conclusions Characterization and modeling of risk factors for CKD progression can be used to predict the extent to which these factors, either alone or in combination, would shorten the time to RRT/50% decline of GFR in

  9. Glomerular involvement in the arthrogryposis, renal dysfunction and cholestasis syndrome

    PubMed Central

    Holme, Amelia; Hurcombe, Jennifer A.; Straatman-Iwanowska, Anna; Inward, Carol I.; Gissen, Paul; Coward, Richard J.

    2013-01-01

    Background Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome is a multisystem autosomal-recessive disorder caused by defects in the VPS33B and VIPAR genes, involved in localization of apical membrane proteins. Affected children usually die by 1 year of age, often secondary to infective complications. The classic renal manifestation previously described in ARC syndrome is proximal–tubular dysfunction. The aim of this study is to gain further insight into the renal manifestations of this syndrome. Methods Clinical review of three cases of ARC syndrome presenting to a tertiary centre. Together with measurement of VPS33B and VIPAR protein expression in the human glomerulus. Results The cases demonstrated severe failure to thrive and in addition to commonly described features profound proteinuria and albuminuria, together with hypoalbuminaemia, suggesting glomerular involvement of this syndrome. Western blotting of conditionally immortalized human glomerular cells and ex vivo immunofluorescent analysis of the human glomerulus revealed that VPS33B and VIPAR were highly expressed in glomerular endothelium, and podocytes, but not in the mesangium. Conclusions ARC syndrome affects the glomerulus as well as the proximal tubule in the kidney. Our molecular studies suggest that both cell types that constitute the glomerular filtration barrier are affected in this condition, providing an explanation for the albuminuria that we have observed in our cases. PMID:26019847

  10. The Structural and Functional Organization of the Podocyte Filtration Slits Is Regulated by Tjp1/ZO-1

    PubMed Central

    Itoh, Masahiko; Nakadate, Kazuhiko; Horibata, Yasuhiro; Matsusaka, Taiji; Xu, Jianliang; Hunziker, Walter; Sugimoto, Hiroyuki

    2014-01-01

    Blood filtration in the kidney glomerulus is essential for physiological homeostasis. The filtration apparatus of the kidney glomerulus is composed of three distinct components: the fenestrated endothelial cells, the glomerular basement membrane, and interdigitating foot processes of podocytes that form the slit diaphragm. Recent studies have demonstrated that podocytes play a crucial role in blood filtration and in the pathogenesis of proteinuria and glomerular sclerosis; however, the molecular mechanisms that organize the podocyte filtration barrier are not fully understood. In this study, we suggest that tight junction protein 1 (Tjp1 or ZO-1), which is encoded by Tjp1 gene, plays an essential role in establishing the podocyte filtration barrier. The podocyte-specific deletion of Tjp1 down-regulated the expression of podocyte membrane proteins, impaired the interdigitation of the foot processes and the formation of the slit diaphragm, resulting in glomerular dysfunction. We found the possibility that podocyte filtration barrier requires the integration of two independent units, the pre-existing epithelial junction components and the newly synthesized podocyte-specific components, at the final stage in glomerular morphogenesis, for which Tjp1 is indispensable. Together with previous findings that Tjp1 expression was decreased in glomerular diseases in human and animal models, our results indicate that the suppression of Tjp1 could directly aggravate glomerular disorders, highlights Tjp1 as a potential therapeutic target. PMID:25184792

  11. The prevalence of hematologic and metabolic abnormalities during chronic kidney disease stages in different ethnic groups.

    PubMed

    Barbour, S J; Er, L; Djurdjev, O; Karim, M A; Levin, A

    2008-07-01

    We conducted an observational cross-sectional study to determine if the prevalence of hematologic and metabolic abnormalities in chronic kidney disease (CKD) varied in different ethnic groups. We used a CKD provincial database where a complete data set at the time of registration was available as well as an estimated glomerular filtration rate (eGFR), which showed using the abbreviated MDRD formula that the patients had CKD of stages 3-5. We included patients with self-reported race of Caucasian, Oriental Asian, or South Asian. Primary outcomes were the prevalence of at least one of the following: anemia, hypocalcemia, hyperphosphatemia, hyperparathyroidism, hypoalbuminemia, and three or more laboratory abnormalities. All definitions were consistent with K/DOQI guidelines. When compared with Caucasians, Oriental Asians and South Asians had a higher prevalence of many of the metabolic abnormalities during most stages of CKD and were more likely to have any abnormality at all levels of eGFR. The prevalence of three or more laboratory abnormalities was higher in Oriental Asians at all stages and in South Asians at some levels of eGFR. These results were unchanged or exaggerated when controlled for age, gender, diabetes, and a primary diagnosis of renal disease. Hence, it appears that South Asians and Oriental Asians have more laboratory abnormalities compared with Caucasians at most levels of eGFR.

  12. Effect of the antiglucocorticoid RU-486 on glomerular hemodynamics in remnant nephrons.

    PubMed

    Cardoso, L R; Oliveira, A V; Santos, O F; Boim, M A; Razvickas, C V; Ajzen, H; Schor, N

    1997-01-01

    Endogenous glucocorticoid (GC) has been proposed to play a role in the adaptive functions of remnant nephron and participates in the progression of renal disease. The effect of GC blockade by RU-486 (20 mg/kg), an anti-GC agent, on the progression of chronic renal failure (CRF) was evaluated in Munich-Wistar rats. CRF was induced by 5/6 nephrectomy. Global renal function, glomerular hemodynamics, proteinuria and renal histopathology studies were performed after 60 days of CRF induction. RU administration in control or CRF groups did not induce significant changes in total renal function, mean arterial or intraglomerular hydraulic pressures, 24-hour proteinuria or sclerosis index. However, RU induced a significant reduction in single-nephron glomerular filtration rate in the superficial nephrons in both groups' control (decreases 20%) and CRF (decreases 57%), without changing total glomerular filtration rate, when compared with vehicle administration. These reductions were due to a decline in glomerular plasma flow rate (QA) and in glomerular ultrafiltration coefficient (Kf). These data suggest that GC played a role in the adaptive hyperfiltration associated with the compensatory mechanism but did not participate in the genesis of proteinuria or glomerulosclerosis in this experimental model. PMID:9208281

  13. Novel Biomarkers in Glomerular Disease

    PubMed Central

    Caliskan, Yasar; Kiryluk, Krzysztof

    2014-01-01

    Glomerular diseases are major contributors to the global burden of end stage kidney disease. The clinical course and outcome of these disorders are extremely variable and difficult to predict. The clinical trajectories range from a benign and spontaneously remitting condition to a symptomatic and rapidly progressive disease. The diagnosis is based entirely on the evaluation of kidney biopsy, but this invasive procedure carries multiple risks and often fails to predict the clinical course or responsiveness to treatment. However, more recent advances in genetics and molecular biology facilitated elucidation of novel pathogenic mechanisms of these disorders. These discoveries fuel the development of novel biomarkers and offer prospects of non-invasive diagnosis and improved prognostication. Our review focuses on the most promising novel biomarkers that have recently emerged for the major types of glomerular diseases, including IgA nephropathy, membranous nephropathy, focal segmental glomerulosclerosis, and membranoproliferative glomerulonephritis. PMID:24602470

  14. The effects of PTK787/ZK222584, an inhibitor of VEGFR and PDGFRβ pathways, on intussusceptive angiogenesis and glomerular recovery from Thy1.1 nephritis.

    PubMed

    Wnuk, Monika; Hlushchuk, Ruslan; Tuffin, Gérald; Huynh-Do, Uyen; Djonov, Valentin

    2011-04-01

    The aim of our study was to investigate the phenomenon of intussusceptive angiogenesis with a focus on its molecular regulation by vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor β (PDGFRβ) pathways and biological significance for glomerular recovery after acute injury. Glomerular healing by intussusception was examined in a particular setting of Thy1.1 nephritis, where the lysis of mesangial cells results in an initial collapse and successive rebuilding of glomerular capillary structure. Restoration of capillary structure after induction of Thy1.1 nephritis occurred by intussusceptive angiogenesis resulting in i) rapid expansion of the capillary plexus with reinstatement of the glomerular filtration surface and ii) restoration of the archetypical glomerular vascular pattern. Glomerular capillaries of nephritic rats after combined VEGFR2 and PDGFRβ inhibition by PTK787/ZK222584 (PTK/ZK) were tortuous and irregular. However, the onset of intussusceptive angiogenesis was influenced only after long-term PTK/ZK treatment, providing an important insight into differential molecular regulation between sprouting and intussusceptive angiogenesis. PTK/ZK treatment abolished α-smooth muscle actin and tensin expression by injured mesangial cells, impaired glomerular filtration of microspheres, and led to the reduction of glomerular volume and the presence of multiple hemorrhages detectable in the tubular system. Collectively, treatment of nephritic patients with PTK/ZK compound is not recommended. PMID:21435466

  15. Early renal abnormalities as an indicator of cardiovascular risk in type 2 diabetes.

    PubMed

    Viazzi, Francesca; Bonino, Barbara; Ratto, Elena; De Cosmo, Salvatore; Pontremoli, Roberto

    2014-12-01

    Accurate assessment of cardiovascular (CV) risk is a prerequisite for devising effective therapeutic strategies in patients with type 2 diabetes (T2DM) as it allows to refine prognosis and treatment targets as well as the cost-benefit ratio for specific pharmacological interventions. The presence of subclinical vascular organ damage plays a well known role in determining overall risk and a wider use of low cost, easy to perform diagnostic tools to stratify CV risk is very much needed. Besides their well known prognostic value for progression to end stage renal disease (ESRD), subclinical renal abnormalities such as microalbuminuria and/or a slight reduction in estimation of glomerular filtration rate (eGFR), have been shown to be powerful, independent predictors of CV diseases in patients with T2DM. Through the combined evaluation of these two biomarkers of chronic kidney disease (CKD), clinicians can usefully and reliably get a perspective on global and CV outcome of their diabetic patients.

  16. The Prediction of Key Cytoskeleton Components Involved in Glomerular Diseases Based on a Protein-Protein Interaction Network

    PubMed Central

    Ju, Wenjun; Li, Xuejuan; Li, Shao; Ding, Jie

    2016-01-01

    Maintenance of the physiological morphologies of different types of cells and tissues is essential for the normal functioning of each system in the human body. Dynamic variations in cell and tissue morphologies depend on accurate adjustments of the cytoskeletal system. The cytoskeletal system in the glomerulus plays a key role in the normal process of kidney filtration. To enhance the understanding of the possible roles of the cytoskeleton in glomerular diseases, we constructed the Glomerular Cytoskeleton Network (GCNet), which shows the protein-protein interaction network in the glomerulus, and identified several possible key cytoskeletal components involved in glomerular diseases. In this study, genes/proteins annotated to the cytoskeleton were detected by Gene Ontology analysis, and glomerulus-enriched genes were selected from nine available glomerular expression datasets. Then, the GCNet was generated by combining these two sets of information. To predict the possible key cytoskeleton components in glomerular diseases, we then examined the common regulation of the genes in GCNet in the context of five glomerular diseases based on their transcriptomic data. As a result, twenty-one cytoskeleton components as potential candidate were highlighted for consistently down- or up-regulating in all five glomerular diseases. And then, these candidates were examined in relation to existing known glomerular diseases and genes to determine their possible functions and interactions. In addition, the mRNA levels of these candidates were also validated in a puromycin aminonucleoside(PAN) induced rat nephropathy model and were also matched with existing Diabetic Nephropathy (DN) transcriptomic data. As a result, there are 15 of 21 candidates in PAN induced nephropathy model were consistent with our predication and also 12 of 21 candidates were matched with differentially expressed genes in the DN transcriptomic data. By providing a novel interaction network and prediction, GCNet

  17. [Glomerular disease and living donor kidney transplantation].

    PubMed

    Guerra, Rita; Rodríguez, Alejandra; Campistol, Josep M

    2005-01-01

    Glomerular diseases are an important and frequent cause of renal transplant graft loss in the mid-long term, mainly due to primary renal disease recurrence. Glomerular diseases have particular connotations in living donor kidney transplantation, due to the risk of primary disease recurrence and subsequent graft loss, and also the risk of development of glomerular disease related donors have for their genetic similitude. The incidence of glomerular disease recurrence after transplantation varies with type, being especially frequent in IgA nephropathy and type II membranous proliferative glomerulopathy. The difference between histological and clinical recurrence should always be established, being much more frequent the first. Renal biopsy is the essential diagnostic test to detect and confirm the existence of glomerular disease after transplant, with immunofluorescence study being necessary to determine the type of glomerular disease.

  18. Complement deposition in glomerular diseases.

    PubMed

    di Belgiojoso, G B; Tarantino, A; Durante, A; Guerra, L

    1975-01-01

    Biopsies from 400 patients affected by glomerular diseases, both "primary" and secondary to systemic diseases, have been studied by immunofluorescence. Staining was performed for immunoglobulins fibrogen and C1q, C4, C3 and C3A. C1q, C4 and C3 were positive in a high percentage of cases in focal glomerulosclerosis, membranoproliferative glomerulonephritis, lupus nephritis and essential cryoglobulinaemia glomerulonephritis. C1q and C4 were very rarely present in focal proliferative glomerulonephritis and rheumatoid purpura glomerulonephritis. C3A was found frequently only in acute glomerulonephritis. Results are discussed with reference to their diagnostic value and to information about mechanisms of complement activation.

  19. Haematuria as a risk factor for chronic kidney disease progression in glomerular diseases: A review.

    PubMed

    Moreno, Juan Antonio; Yuste, Claudia; Gutiérrez, Eduardo; Sevillano, Ángel M; Rubio-Navarro, Alfonso; Amaro-Villalobos, Juan Manuel; Praga, Manuel; Egido, Jesús

    2016-04-01

    Haematuria has long been considered to be a benign condition associated with glomerular diseases. However, new evidences suggest that haematuria has a pathogenic role in promoting kidney disease progression. An increased risk for end-stage renal disease has been reported in adolescents and young adults with persistent microscopic haematuria. A persistent impairment of renal function has been also reported following macroscopic haematuria-associated acute kidney injury in immunoglobulin A nephropathy. Haematuria-induced renal damage has been related to oxidant, cytotoxic and inflammatory effects induced by haemoglobin or haem released from red blood cells. The pathophysiological origin of haematuria may be due to a more fragile and easily ruptured glomerular filtration barrier, as reported in several glomerular diseases. In this review we describe a number of the key issues associated with the epidemiology and pathogenesis of haematuria-associated diseases, provide an update of recent knowledge on the role of haematuria on renal function outcome and discuss specific therapeutic approaches in this setting. KEY SUMMARY POINTS: 1. Glomerular haematuria is a common observation in a number of renal diseases that may lead to persistent renal injury. 2. Haematuria in children differs from that in adults in specific aspects, particularly in the frequency of glomerular diseases and renal disease outcome. 3. Regular follow-up of renal function in children with isolated microhaematuria may be recommended. PMID:25980470

  20. A nanoporous surface is essential for glomerular podocyte differentiation in three-dimensional culture

    PubMed Central

    Zennaro, Cristina; Rastaldi, Maria Pia; Bakeine, Gerald James; Delfino, Riccarda; Tonon, Federica; Farra, Rossella; Grassi, Gabriele; Artero, Mary; Tormen, Massimo; Carraro, Michele

    2016-01-01

    Although it is well recognized that cell–matrix interactions are based on both molecular and geometrical characteristics, the relationship between specific cell types and the three-dimensional morphology of the surface to which they are attached is poorly understood. This is particularly true for glomerular podocytes – the gatekeepers of glomerular filtration – which completely enwrap the glomerular basement membrane with their primary and secondary ramifications. Nanotechnologies produce biocompatible materials which offer the possibility to build substrates which differ only by topology in order to mimic the spatial organization of diverse basement membranes. With this in mind, we produced and utilized rough and porous surfaces obtained from silicon to analyze the behavior of two diverse ramified cells: glomerular podocytes and a neuronal cell line used as a control. Proper differentiation and development of ramifications of both cell types was largely influenced by topographical characteristics. Confirming previous data, the neuronal cell line acquired features of maturation on rough nanosurfaces. In contrast, podocytes developed and matured preferentially on nanoporous surfaces provided with grooves, as shown by the organization of the actin cytoskeleton stress fibers and the proper development of vinculin-positive focal adhesions. On the basis of these findings, we suggest that in vitro studies regarding podocyte attachment to the glomerular basement membrane should take into account the geometrical properties of the surface on which the tests are conducted because physiological cellular activity depends on the three-dimensional microenvironment. PMID:27757030

  1. Effects of Therapy on Urine Neutrophil Gelatinase-Associated Lipocalin in Nondiabetic Glomerular Diseases with Proteinuria

    PubMed Central

    Vanavanan, Somlak; Chittamma, Anchalee; Phakdeekitcharoen, Bunyong; Lertrit, Amornpan; Sathirapongsasuti, Nuankanya

    2016-01-01

    Urine neutrophil gelatinase-associated lipocalin (NGAL) is widely used as a biomarker for acute kidney injury. Cross-sectional studies have shown that NGAL may be elevated in glomerular diseases, but there is limited information on the value of NGAL in predicting treatment response or on the changes of NGAL levels after therapy. We prospectively evaluated the effects of therapy on NGAL in nondiabetic glomerular diseases. Urine NGAL was collected at biopsy and follow-up at 12 months. At baseline, NGAL in glomerular disease patients (n = 43) correlated with proteinuria, but not with glomerular filtration rate (GFR). After therapy with renin-angiotensin blockers and/or immune modulating agents, change of NGAL correlated with change of proteinuria, but not with change of GFR. NGAL at baseline was not different between patients in complete remission (CR) at follow-up compared to those not in remission (NR). Compared to baseline, NGAL at follow-up decreased in CR (n = 10), but not in NR. Change of NGAL was greater in CR than NR. In conclusion, the change of urine NGAL correlated with the change of proteinuria. Baseline NGAL was not a predictor of complete remission. Future studies will be necessary to determine the role of NGAL as a predictor of long term outcome in proteinuric glomerular diseases. PMID:27525120

  2. Rotary filtration system

    DOEpatents

    Herman, David T.; Maxwell, David N.

    2011-04-19

    A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

  3. Relationship of abnormal Tamm-Horsfall glycoprotein localization to renal morphology and function.

    PubMed

    Chambers, R; Groufsky, A; Hunt, J S; Lynn, K L; McGiven, A R

    1986-07-01

    Tamm-Horsfall glycoprotein (TH) distribution was studied using a biotin-avidin immunoperoxidase technique in renal biopsies from 166 consecutive patients and 8 normal kidneys. Tubulointerstitial damage was independently assessed and graded. In 109 patients TH antibodies were measured by ELISA and in 30 of these urinary TH and beta 2-microglobulin excretions were measured by radioimmunoassay. In 124 biopsies only distal tubular epithelium and casts were stained. Glomerular space (8) or interstitial (34) deposits were seen in 42 biopsies; 16/68 with glomerulonephritis, 4/14 with systemic vasculitis, 12/33 with chronic interstitial nephritis, 1/8 with acute interstitial nephritis, 9/43 with other nephropathies. There was no correlation between TH distribution and the degree of tubulointerstitial damage (p greater than 0.5), urinary TH excretion (p greater than 0.05), urinary beta 2-microglobulin excretion (p greater than 0.05), glomerular filtration rate, urinary concentrating ability, or the incidence of pyuria. TH antibodies did not correlate with TH distribution (p greater than 0.5) or the degree of tubulointerstitial damage. Abnormal TH distribution showed no statistical relationship to the degree of tubulointerstitial damage, changes in renal function or levels of TH antibodies.

  4. Glomerular hemodynamics during abortion induced by RU 486 and sepsis in rats.

    PubMed

    Boim, M A; Draibe, S A; Ramos, O L; Ajzen, H; Ulmann, A; Schor, N

    1994-06-01

    1. Acute renal failure is a very common consequence of septic abortion. Whole kidney and glomerular hemodynamics were evaluated in virgin (V), pregnant (PREG) and aborted (ABOR) euvolemic Munich-Wistar rats before and after E. coli (0111-B4) endotoxin (LPS) infusion in order to evaluate the effect of septic abortion on the renal microcirculation. 2. Abortion induced by RU 486 blunted the increase in glomerular filtration rate (GFR) induced by normal pregnancy (0.86 +/- 0.03 vs 0.63 +/- 0.07 ml/min, P < 0.05). In virgin rats, RU 486 did not modify the parameters of renal function. Significant alterations occurred in whole kidney and single nephron function. However, the changes in whole kidney function in the ABOR group were significantly higher than those observed for the V group (reductions in GFR were 42% in V and 80% in ABOR, RPF decreased 34% in V and 76% in ABOR, TRVR increased 82% in V and 400% in ABOR). 3. Mean single nephron glomerular filtration rate (SNGFR) was reduced in all groups after LPS (44% in V, 43% in V+RU, 55% in PREG, 60% in ABOR), due to significant decreases in glomerular plasma flow rate, QA (42% in V, 55% in V+RU, 53% in PREG, 57% in ABOR) and in glomerular ultrafiltration coefficient, Kf (46% in V, 47% in V+RU, 45% in PREG, 67% in ABOR). 4. These data show that LPS induced significant alterations in renal function in all groups. However, aborted rats were more sensitive to the effects of LPS than V rats. These results indicate that abortion may potentiate the effects of endotoxemia on renal function elevating the extent of acute renal failure and thus the mortality rate. PMID:7894359

  5. Glomerular hemodynamic alterations during acute hyperinsulinemia in normal and diabetic rats

    NASA Technical Reports Server (NTRS)

    Tucker, B. J.; Anderson, C. M.; Thies, R. S.; Collins, R. C.; Blantz, R. C.

    1992-01-01

    Treatment of insulin dependent diabetes invariably requires exogenous insulin to control blood glucose. Insulin treatment, independent of other factors associated with insulin dependent diabetes, may induce changes that affect glomerular function. Due to exogenous delivery of insulin in insulin dependent diabetes entering systemic circulation prior to the portal vein, plasma levels of insulin are often in excess of that observed in non-diabetics. The specific effects of hyperinsulinemia on glomerular hemodynamics have not been previously examined. Micropuncture studies were performed in control (non-diabetic), untreated diabetic and insulin-treated diabetic rats 7 to 10 days after administration of 65 mg/kg body weight streptozotocin. After the first period micropuncture measurements were obtained, 5 U of regular insulin (Humulin-R) was infused i.v., and glucose clamped at euglycemic values (80 to 120 mg/dl). Blood glucose concentration in non-diabetic controls was 99 +/- 6 mg/dl. In control rats, insulin infusion and glucose clamp increased nephron filtration rate due to decreases in both afferent and efferent arteriolar resistance (afferent greater than efferent) resulting in increased plasma flow and increased glomerular hydrostatic pressure gradient. However, insulin infusion and glucose clamp produced the opposite effect in both untreated and insulin-treated diabetic rats with afferent arteriolar vasoconstriction resulting in decreases in plasma flow, glomerular hydrostatic pressure gradient and nephron filtration rate. Thromboxane A2 (TX) synthetase inhibition partially decreased the vasoconstrictive response due to acute insulin infusion in diabetic rats preventing the decrease in nephron filtration rate.(ABSTRACT TRUNCATED AT 250 WORDS).

  6. 7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHEAST, SHOWING PUMP NO. 1 AND METERING EQUIPMENT - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  7. 8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING SOUTHWEST, SHOWING MEZZANINE WITH FILTER TANKS AT REAR - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  8. Ernest Henry Starling (1866-1927) on the glomerular and tubular functions of the kidney.

    PubMed

    Fine, Leon G

    2014-01-01

    Around the turn of the 20th century, Ernest Henry Starling (1866-1927) made many fundamental contributions to the understanding of human physiology. With a deep interest in how fluid balance is regulated, he naturally turned to explore the intricacies of kidney function. Early in his career he focused upon the process of glomerular filtration and was able to substantiate the view of Carl Ludwig that this process can be explained entirely upon the basis of hydrostatic and oncotic pressure gradients across the glomerular capillary wall and that the process can be regulated by alterations in the tone of the afferent and efferent arterioles. To explore renal tubular function he employed a heart-lung-kidney model in the dog and was able to infer that certain substances are reabsorbed by the tubules (e.g. sodium chloride) and certain by tubular secretion (e.g. uric acid, indigo carmine dye). By temporarily blocking tubular function using hydrocyanic acid he was able to conclude that secreted substances must be taken up on the peritubular side of the cell and concentrated within the cell to drive the secretory process. Finally, he was able to appreciate that the kidney is an organ which is regulated according to the needs of the organism and that the processes of glomerular filtration, tubular secretion and reabsorption are all subject to regulatory influences, which have evolved to conserve the normal chemical composition of the cells and fluids of the body. PMID:24970544

  9. Renal abnormalities among HIV-infected, antiretroviral naive children, Harare, Zimbabwe: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Data on the prevalence of renal and urine abnormalities among HIV-infected children in Sub-Saharan Africa are limited. We set out to determine the prevalence of proteinuria; low estimated glomerular filtration rate (eGFR), urinary tract infection and associated factors among HIV-infected antiretroviral therapy (ART) naive children, aged 2–12 years, attending the paediatric HIV clinic at a tertiary hospital in Harare. Methods Consecutive ART naive children attending the clinic between June and October 2009 were recruited. Detailed medical history was obtained and a complete physical examination was performed. Children were screened for urinary tract infection and for significant persistent proteinuria. Serum creatinine was used to estimate GFR using the modified Counahan-Barratt formula. The Student’s t-test was used to analyse continuous variables and the chi-square or Fisher’s exact test was used to analyse categorical data. Logistic regression was performed to assess the relationship between study factors and urine abnormalities, persistent proteinuria and the eGFR. Results Two hundred and twenty children were enrolled into the study. The median age was 90 months (Q1=65.5; Q3=116.5). The prevalence of urinary tract infection was 9.5%. Escherichia coli was the predominant organism. There was uniform resistance to cotrimoxazole. Persistent proteinuria (urine protein to creatinine ratio greater than 0.2, a week apart) was found in 5% of the children. Seventy-five children (34.6%) had mild to moderate renal impairment shown by a low eGFR (30 to <90ml/min/1.73m2). Persistent proteinuria was more likely to be found in children who were wasted, weight-for-height (WHZ) z-score <−2 (p=0.0005). Children with WHO clinical stage 4 were more likely to have a low eGFR than children with less advanced stages (OR 2.68; CI 1.24-5.80). Urine abnormalities were more likely to be observed in children with WHO clinical stages 3 and 4 (OR 2.20; CI 1

  10. Anti-glomerular basement membrane blood test

    MedlinePlus

    GBM antibody test; Antibody to human glomerular basement membrane; Anti-GBM antibodies ... Normally, there are none of these antibodies in the blood. Normal ... labs use different measurements or test different samples. Talk ...

  11. Glomerulo-tubular junction stenosis as a factor contributing to glomerular obsolescence in IgA nephropathy.

    PubMed

    Sato, Mitsuhiro; Hotta, Osamu; Taguma, Yoshio

    2002-05-01

    Periglomerular fibrosis (PF) is an interstitial injury observed in various renal diseases. It is speculated that this lesion, by occluding the glomerulo-tubular junction (GTJ) and causing atubular glomeruli, may result functionally in a reduction of the glomerular filtration rate (GFR) and may be a factor contributing to the progression of renal disease. In the present study, 340 renal biopsy specimens were analysed to determine whether or not there was nephron injury derived from such a mechanism, as well as direct glomerular injury, in IgA nephropathy (IgAN). The patients were divided into five groups according to the degree of glomerular sclerosis. The average age was lower in groups with milder sclerosis and serum creatinine (Cr) was elevated in groups with more severe sclerosis. Because the GTJ was assumed to disappear when an atubular glomerulus was formed, the ratio of the number of glomeruli with discernible GTJ to the total number of glomeruli was evaluated. As glomerular sclerosis progressed, discernible GTJ reduced significantly (p <0.001) and the degree of PF increased significantly (p <0.05). By serial section study in cases with pronounced PF, transitions between the stages of stenosis of the GTJ and atubular glomeruli were observed. It is speculated that the occlusion of the GTJ eventually hyalinizes the glomerulus; in such cases, glomerular obsolescence of the collapse type might be formed. On the other hand, obsolescence of the mesangial proliferative type might be formed in the hyalinization derived from direct glomerular injury. In this context, glomerular obsolescence of the collapse type was observed more frequently and was accompanied by more increased PF than obsolescence of the mesangial proliferative type (p <0.001). These results suggest that in addition to direct glomerular injury, nephron injury derived from interstitial damage of this type plays an important contributory role in the progression of IgAN.

  12. Ethanol at low concentrations protects glomerular podocytes through alcohol dehydrogenase and 20-HETE.

    PubMed

    McCarthy, Ellen T; Zhou, Jianping; Eckert, Ryan; Genochio, David; Sharma, Rishi; Oni, Olurinde; De, Alok; Srivastava, Tarak; Sharma, Ram; Savin, Virginia J; Sharma, Mukut

    2015-01-01

    Clinical studies suggest cardiovascular and renal benefits of ingesting small amounts of ethanol. Effects of ethanol, role of alcohol dehydrogenase (ADH) or of 20-hydroxyeicosatetraenoic acid (20-HETE) in podocytes of the glomerular filtration barrier have not been reported. We found that mouse podocytes at baseline generate 20-HETE and express ADH but not CYP2e1. Ethanol at high concentrations altered the actin cytoskeleton, induced CYP2e1, increased superoxide production and inhibited ADH gene expression. Ethanol at low concentrations upregulated the expression of ADH and CYP4a12a. 20-HETE, an arachidonic acid metabolite generated by CYP4a12a, blocked the ethanol-induced cytoskeletal derangement and superoxide generation. Ethanol at high concentration or ADH inhibitor increased glomerular albumin permeability in vitro. 20-HETE and its metabolite produced by ADH activity, 20-carboxy-arachidonic acid, protected the glomerular permeability barrier against an ADH inhibitor, puromycin or FSGS permeability factor. We conclude that ADH activity is required for glomerular function, 20-HETE is a physiological substrate of ADH in podocytes and that podocytes are useful biosensors to understand glomeruloprotective effects of ethanol.

  13. Atubular glomeruli and glomerulotubular junction abnormalities in diabetic nephropathy.

    PubMed

    Najafian, Behzad; Kim, Youngki; Crosson, John T; Mauer, Michael

    2003-04-01

    Atubular glomeruli (AG) have been described in several renal disorders. However, little attention has been paid to AG in diabetic nephropathy (DN). Preliminary studies suggested that tip lesions were frequently present in type 1 diabetic (D) patients with proteinuria. The aim of this study was to determine the frequency of AG and their possible relationship with tip lesions in DN. Renal biopsies from eight proteinuric type 1 D patients with normal to moderately reduced GFR (76 +/- 26 ml/min per 1.73 m(2)) and eight normal subjects were studied by light (LM) and electron microscopy (EM). Glomerular volume, volume of the glomerular corpuscle, which is tuft, and the fractional volumes of proximal, distal, and atrophic tubules per cortex were estimated using appropriate stereologic methods. Glomerulotubular junctions were examined on serial sections and classified into glomeruli attached to: normal tubules (NT); short atrophic tubules (SAT); long atrophic tubules (LAT); atrophic tubules with no observable glomerular opening (ATNO); and atubular glomeruli (AG). EM studies showed typical diabetic changes in biopsies, including increased GBM width (P < 0.00001) and mesangial fractional volume (P < 0.0001) and decreased filtration surface density (P < 0.01) compared with normal subjects. Seventeen percent of glomeruli in the D patients were atubular, and 51% were attached to atrophic tubules. Tip lesions were present in all SAT, 64% of LAT, 82% of ATNO, and only 9% of NT and were never observed in normal subjects. The relative volume of AG was smaller than glomeruli in other categories (P < 0.05). Fractional volume of proximal (P < 0.01) and distal (P <0.01) tubules per cortex were decreased, while fractional volume of cortical interstitium (P <0.00001) and atrophic tubules (P <0.01) were increased in D patients. Fractional volume of atrophic tubules, %AG, and percent of glomeruli with tip lesion explained 94% of the GFR variability in diabetic patients (P <0.05). Thus, AG

  14. Magnetic-seeding filtration

    SciTech Connect

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  15. Trends in medical filtration.

    PubMed

    Hogan, Brendan

    2002-06-01

    Advances in materials, mould tooling and control systems are offering the industry greater design choices in filtration as well as the potential to reduce manufacturing costs. This article describes what is possible.

  16. Requirement for Class II Phosphoinositide 3-Kinase C2α in Maintenance of Glomerular Structure and Function▿

    PubMed Central

    Harris, David P.; Vogel, Peter; Wims, Marie; Moberg, Karen; Humphries, Juliane; Jhaver, Kanchan G.; DaCosta, Christopher M.; Shadoan, Melanie K.; Xu, Nianhua; Hansen, Gwenn M.; Balakrishnan, Sanjeevi; Domin, Jan; Powell, David R.; Oravecz, Tamas

    2011-01-01

    An early lesion in many kidney diseases is damage to podocytes, which are critical components of the glomerular filtration barrier. A number of proteins are essential for podocyte filtration function, but the signaling events contributing to development of nephrotic syndrome are not well defined. Here we show that class II phosphoinositide 3-kinase C2α (PI3KC2α) is expressed in podocytes and plays a critical role in maintaining normal renal homeostasis. PI3KC2α-deficient mice developed chronic renal failure and exhibited a range of kidney lesions, including glomerular crescent formation and renal tubule defects in early disease, which progressed to diffuse mesangial sclerosis, with reduced podocytes, widespread effacement of foot processes, and modest proteinuria. These findings were associated with altered expression of nephrin, synaptopodin, WT-1, and desmin, indicating that PI3KC2α deficiency specifically impacts podocyte morphology and function. Deposition of glomerular IgA was observed in knockout mice; importantly, however, the development of severe glomerulonephropathy preceded IgA production, indicating that nephropathy was not directly IgA mediated. PI3KC2α deficiency did not affect immune responses, and bone marrow transplantation studies also indicated that the glomerulonephropathy was not the direct consequence of an immune-mediated disease. Thus, PI3KC2α is critical for maintenance of normal glomerular structure and function by supporting normal podocyte function. PMID:20974805

  17. Requirement for class II phosphoinositide 3-kinase C2alpha in maintenance of glomerular structure and function.

    PubMed

    Harris, David P; Vogel, Peter; Wims, Marie; Moberg, Karen; Humphries, Juliane; Jhaver, Kanchan G; DaCosta, Christopher M; Shadoan, Melanie K; Xu, Nianhua; Hansen, Gwenn M; Balakrishnan, Sanjeevi; Domin, Jan; Powell, David R; Oravecz, Tamas

    2011-01-01

    An early lesion in many kidney diseases is damage to podocytes, which are critical components of the glomerular filtration barrier. A number of proteins are essential for podocyte filtration function, but the signaling events contributing to development of nephrotic syndrome are not well defined. Here we show that class II phosphoinositide 3-kinase C2α (PI3KC2α) is expressed in podocytes and plays a critical role in maintaining normal renal homeostasis. PI3KC2α-deficient mice developed chronic renal failure and exhibited a range of kidney lesions, including glomerular crescent formation and renal tubule defects in early disease, which progressed to diffuse mesangial sclerosis, with reduced podocytes, widespread effacement of foot processes, and modest proteinuria. These findings were associated with altered expression of nephrin, synaptopodin, WT-1, and desmin, indicating that PI3KC2α deficiency specifically impacts podocyte morphology and function. Deposition of glomerular IgA was observed in knockout mice; importantly, however, the development of severe glomerulonephropathy preceded IgA production, indicating that nephropathy was not directly IgA mediated. PI3KC2α deficiency did not affect immune responses, and bone marrow transplantation studies also indicated that the glomerulonephropathy was not the direct consequence of an immune-mediated disease. Thus, PI3KC2α is critical for maintenance of normal glomerular structure and function by supporting normal podocyte function.

  18. Water sample filtration unit

    USGS Publications Warehouse

    Skougstad, M.W.; Scarbro, G.F.

    1968-01-01

    A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

  19. Water Filtration Products

    NASA Technical Reports Server (NTRS)

    1986-01-01

    American Water Corporation manufactures water filtration products which incorporate technology originally developed for manned space operations. The formula involves granular activated charcoal and other ingredients, and removes substances by catalytic reactions, mechanical filtration, and absorption. Details are proprietary. A NASA literature search contributed to development of the compound. The technology is being extended to a deodorizing compound called Biofresh which traps gas and moisture inside the unit. Further applications are anticipated.

  20. Monosodium Titanate Sludge Filtration

    SciTech Connect

    Dworjanyn, L.O.

    2000-11-07

    Good filterability of tetraphenylborate (TPB) slurry is attributed to the hydrophobic nature of crystalline organic TPB that forms a firm but porous filter cake, allowing salt solution to pass through without unduly compressing the cake. Addition of inorganic sludge or monosodium titanate (MST) has an adverse effect on filtration, but the overall filtration rate with TPB is satisfactory. Poor cross-flow filtration performance for the Salt Disposition Alternatives requiring MST filtration is attributed primarily to the difficulty in filtering the residual inorganic sludge rich in iron and aluminum precipitates. Ferric hydrolysis products and colloids form a bulky and sticky filter cake significantly reducing filtration rate. Similarly poor filtration rates were observed in the BNFL ferric/ferrous precipitation process, necessitating a change to permanganate precipitation. This report, based on a few sludge settling observations, does not resolve the MST/Sludge filterability issue. However, it does identify the need for a change in emphasis from cross-flow optimization to understanding and controlling the chemistry and physics of alkaline inorganic particle suspensions and filterability. Promising potential exists to identify or develop surfactants or flocculants to enhance filterability of SRS sludge and monosodium titanate. Additional work is needed to provide a basic understanding of the nature of caustic sludge filter cake formation.

  1. Connecting tubule glomerular feedback antagonizes tubuloglomerular feedback in vivo.

    PubMed

    Wang, H; Garvin, J L; D'Ambrosio, M A; Ren, Y; Carretero, O A

    2010-12-01

    In vitro experiments showed that the connecting tubule (CNT) sends a signal that dilates the afferent arteriole (Af-Art) when Na(+) reabsorption in the CNT lumen increases. We call this process CNT glomerular feedback (CTGF) to differentiate it from tubuloglomerular feedback (TGF), which is a cross talk between the macula densa (MD) and the Af-Art. In TGF, the MD signals the Af-Art to constrict when NaCl transport by the MD is enhanced by increased luminal NaCl. CTGF is mediated by CNT Na(+) transport via epithelial Na(+) channels (ENaC). However, we do not know whether CTGF occurs in vivo or whether it opposes the increase in Af-Art resistance caused by TGF. We hypothesized that CTGF occurs in vivo and opposes TGF. To test our hypothesis, we conducted in vivo micropuncture of individual rat nephrons, measuring stop-flow pressure (P(SF)) as an index of glomerular filtration pressure. To test whether activation of CTGF opposes TGF, we used benzamil to block CNT Na(+) transport and thus CTGF. CTGF inhibition with the ENaC blocker benzamil (1 μM) potentiated the decrease in P(SF) at 40 and 80 nl/min. Next, we tested whether we could augment CTGF by inhibiting NaCl reabsorption in the distal convoluted tubule with hydrochlorothiazide (HCTZ, 1 mM) to enhance NaCl delivery to the CNT. In the presence of HCTZ, benzamil potentiated the decrease in P(SF) at 20, 40, and 80 nl/min. We concluded that in vivo CTGF occurs and opposes the vasoconstrictor effect of TGF. PMID:20826574

  2. Human glomerular epithelial cell proteoglycans

    SciTech Connect

    Thomas, G.J.; Jenner, L.; Mason, R.M.; Davies, M. )

    1990-04-01

    Proteoglycans synthesized by cultures of human glomerular epithelial cells have been isolated and characterized. Three types of heparan sulfate were detected. Heparan sulfate proteoglycan I (HSPG-I; Kav 6B 0.04) was found in the cell layer and medium and accounted for 12% of the total proteoglycans synthesized. HSPG-II (Kav 6B 0.25) accounted for 18% of the proteoglycans and was located in the medium and cell layer. A third population (9% of the proteoglycan population), heparan sulfate glycosaminoglycan (HS-GAG; Kav 6B 0.4-0.8), had properties consistent with single glycosaminoglycan chains or their fragments and was found only in the cell layer. HSPG-I and HSPG-II from the cell layer had hydrophobic properties; they were released from the cell layer by mild trypsin treatment. HS-GAG lacked these properties, consisted of low-molecular-mass heparan sulfate oligosaccharides, and were intracellular. HSPG-I and -II released to the medium lacked hydrophobic properties. The cells also produced three distinct types of chondroitin sulfates. The major species, chondroitin sulfate proteoglycan I (CSPG-I) eluted in the excluded volume of a Sepharose CL-6B column, accounted for 30% of the proteoglycans detected, and was found in both the cell layer and medium. Cell layer CSPG-I bound to octyl-Sepharose. It was released from the cell layer by mild trypsin treatment. CSPG-II (Kav 6B 0.1-0.23) accounted for 10% of the total 35S-labeled macromolecules and was found predominantly in the culture medium. A small amount of CS-GAG (Kav 6B 0.25-0.6) is present in the cell extract and like HS-GAG is intracellular. Pulse-chase experiments indicated that HSPG-I and -II and CSPG-I and -II are lost from the cell layer either by direct release into the medium or by internalization where they are metabolized to single glycosaminoglycan chains and subsequently to inorganic sulfate.

  3. Leveraging melanocortin pathways to treat glomerular diseases

    PubMed Central

    Gong, Rujun

    2013-01-01

    The melanocortin system is a neuroimmunoendocrine hormone system that constitutes the fulcrum in the homeostatic control of a diverse array of physiological functions, including melanogenesis, inflammation, immunomodulation, adrenocortical steroidogenesis, hemodynamics, natriuresis, energy homeostasis, sexual function and exocrine secretion. The kidney is a quintessential effector organ of the melanocortin hormone system with melanocortin receptors abundantly expressed by multiple renal paranchymal cells, including podocytes, mesangial cells, glomerular endothelial cells and renal tubular cells. Converging evidence unequivocally demonstrates that the melanocortin based therapy by using the melanocortin peptide adrenocorticotropic hormone (ACTH) is prominently effective in inducing remission of steroid resistant nephrotic syndrome caused by a variety of glomerular diseases, including membranous nephropathy and podocytopathies such as minimal change disease and focal segmental glomerulosclerosis, suggesting a steroidogenic independent melanocortin mechanism. Mechanistically, ACTH and other melanocortin peptides as well as synthetic melanocortin analogues possess potent proteinuria reducing and renoprotective effects that could be attributable to both direct protection of glomerular cells and systemic immunomodulation. Thus, leveraging melanocortin signaling pathways by using either the existing U.S. Food and Drug Administration approved melanocorin peptide ACTH or novel synthetic melanocortin analogues represents a promising and pragmatic therapeutic strategy for glomerular diseases. This review article introduces the biophysiology of melanocortin hormone system with emphasis on the kidney as the target organ, discusses the existing clinical and experimental data on melanocortin treatments for glomerular diseases, elucidates the potential mechanisms of action, and describes the potential side effects of melanocortin based therapy. PMID:24602463

  4. Measuring glomerular number from kidney MRI images

    NASA Astrophysics Data System (ADS)

    Thiagarajan, Jayaraman J.; Natesan Ramamurthy, Karthikeyan; Kanberoglu, Berkay; Frakes, David; Bennett, Kevin; Spanias, Andreas

    2016-03-01

    Measuring the glomerular number in the entire, intact kidney using non-destructive techniques is of immense importance in studying several renal and systemic diseases. Commonly used approaches either require destruction of the entire kidney or perform extrapolation from measurements obtained from a few isolated sections. A recent magnetic resonance imaging (MRI) method, based on the injection of a contrast agent (cationic ferritin), has been used to effectively identify glomerular regions in the kidney. In this work, we propose a robust, accurate, and low-complexity method for estimating the number of glomeruli from such kidney MRI images. The proposed technique has a training phase and a low-complexity testing phase. In the training phase, organ segmentation is performed on a few expert-marked training images, and glomerular and non-glomerular image patches are extracted. Using non-local sparse coding to compute similarity and dissimilarity graphs between the patches, the subspace in which the glomerular regions can be discriminated from the rest are estimated. For novel test images, the image patches extracted after pre-processing are embedded using the discriminative subspace projections. The testing phase is of low computational complexity since it involves only matrix multiplications, clustering, and simple morphological operations. Preliminary results with MRI data obtained from five kidneys of rats show that the proposed non-invasive, low-complexity approach performs comparably to conventional approaches such as acid maceration and stereology.

  5. Urine synaptopodin excretion is an important marker of glomerular disease progression

    PubMed Central

    Kwon, Soon Kil; Kim, Seung Jung; Kim, Hye-Young

    2016-01-01

    Background/Aims: Podocytes play an important role in maintaining the glomerular filtration barrier and in formation of the slit diaphragm. Podocyte loss is associated with chronic kidney disease progression, but it is not clear whether urinary podocyte proteins in urine reflect the clinical extent of glomerular damage. We investigated the correlation between the amounts of urinary podocyte proteins and renal function and albuminuria. Methods: The study enrolled 33 patients with diabetic kidney disease or glomerular disease and measured urinary podocytes proteins using Western blotting. Urinary podocyte proteins were measured according to the density of the bands on Western blotting. We measured serum creatinine and the spot urine albumin/creatinine ratio as markers of renal damage, and compared the correlation of urinary podocyte protein in the glomerular disease patients. Results: The mean patient age was 49.3 ± 16.5 years, the mean serum creatinine level was 2.30 ± 1.76 mg/dL, and the mean albumin/creatinine ratio was 4.85 ± 3.52. Among the podocyte proteins, urine synaptopodin showed strong correlation with serum creatinine by multivariate regression analysis (p < 0.001) and showed linear correlation (r = 0.429, p < 0.01). Urine podocyte proteins were increased in patients with diabetes, and synaptopodin showed the greatest significant difference (7.68 ± 5.61 vs. 2.56 ± 3.11, p < 0.001), but this might be associated with renal impairment. The urine albumin excretion did not differ between the diabetics and non-diabetics (p = 0.73). Conclusions: Urine synaptopodin is associated with serum creatinine elevation in the patients with glomerulonephritis including diabetic kidney disease regardless of urine albumin excretion. We suggest that the urine synaptopodin level can predict glomerular damage independently of the urine albumin excretion. PMID:27604800

  6. Racial and socioeconomic factors in glomerular disease.

    PubMed

    Halevy, D; Radhakrishnan, J; Appel, G B

    2001-07-01

    The influence of racial and socioeconomic factors on the incidence, prognosis, and response to therapy of many diseases has long been noted. Although glomerular diseases comprise 10% to over 16% of the dialysis and renal transplant populations, respectively, only recently have racial and socioeconomic factors been evaluated. Several glomerular diseases are associated with a striking African-American predominance. These include idiopathic focal sclerosis, and especially its collapsing variant, human immunodeficiency virus (HIV)-associated nephropathy, and severe lupus nephritis. In many of these entities the renal disease is also more aggressive and rapidly progressive than in other populations. Recent data points to genetic-biologic as well as social and economic factors that may be responsible for these findings. Studies dealing with the therapy of glomerular lesions must be stratified for racial and social background differences to avoid bias in outcome. Whether racial and socioeconomic data should be used in treating individual patients, and how, remains an area of controversy.

  7. Waste water filtration enhancement

    SciTech Connect

    Martin, H.L.

    1989-01-01

    Removal of submicron particles from process solutions and waste water is now economically achievable using a new Tyvek{reg sign} media in conventional filtration equipment. This new product greatly enhances filtration and allows use of the much improved filter aids and polymers which were recently developed. It has reduced operating costs and ensures a clean effluent discharge to the environment. This significant technical development is especially important to those who discharge to a small stream with low 7Q10 flow and must soon routinely pass the Toxicity tests that are being required by many States for NPDES permit renewal. The Savannah River Plant produces special nuclear materials for the US Government. Aluminum forming and metal finishing operations in M-Area, that manufacture fuel and target assemblies for the nuclear reactors, discharge to a waste water treatment facility using BAT hydroxide precipitation and filtration. The new Tyvek{reg sign} media and filter aids have achieved 55% less solids in the filtrate discharged to Tims Branch Creek, 15% less hazardous waste (dry filter cake), 150%-370% more filtration capacity, 74% lower materials purchase cost, 10% lower total M-Area manufacturing cost, and have improved safety. Performance with the improved polymers is now being evaluated.

  8. Renal glomerular fibrosis in a cat.

    PubMed

    Nakamura, S; Shibata, S; Shirota, K; Abe, K; Uetsuka, K; Nakayama, H; Goto, N; Doi, K

    1996-11-01

    Renal glomerular fibrosis was observed in a 1-year-old spayed female Japanese domestic cat that showed clinically advanced renal failure. In the glomeruli, increased homogeneous materials were stained strongly with aniline blue by Masson's trichrome and positive for anti-type III collagen antibody by immunohistochemical staining, causing mesangial sclerosis and capillary collapse. By electron microscopy, randomly arranged fibrils were observed in the expanded subendothelial and mesangial areas, and the fibrils showed periodicity characteristic of collagen fibers in longitudinal sections. These findings of glomerular lesions closely resemble those of human "collagenofibrotic glomerulonephropathy," which has recently been described as a new type of glomerulonephropathy. PMID:8952029

  9. HANAC Syndrome Col4a1 Mutation Causes Neonate Glomerular Hyperpermeability and Adult Glomerulocystic Kidney Disease.

    PubMed

    Chen, Zhiyong; Migeon, Tiffany; Verpont, Marie-Christine; Zaidan, Mohamad; Sado, Yoshikazu; Kerjaschki, Dontscho; Ronco, Pierre; Plaisier, Emmanuelle

    2016-04-01

    Hereditary angiopathy, nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is an autosomal dominant syndrome caused by mutations in COL4A1 that encodes the α1 chain of collagen IV, a major component of basement membranes. Patients present with cerebral small vessel disease, retinal tortuosity, muscle cramps, and kidney disease consisting of multiple renal cysts, chronic kidney failure, and sometimes hematuria. Mutations producing HANAC syndrome localize within the integrin binding site containing CB3[IV] fragment of the COL4A1 protein. To investigate the pathophysiology of HANAC syndrome, we generated mice harboring the Col4a1 p.Gly498Val mutation identified in a family with the syndrome. Col4a1 G498V mutation resulted in delayed glomerulogenesis and podocyte differentiation without reduction of nephron number, causing albuminuria and hematuria in newborns. The glomerular defects resolved within the first month, but glomerular cysts developed in 3-month-old mutant mice. Abnormal structure of Bowman's capsule was associated with metalloproteinase induction and activation of the glomerular parietal epithelial cells that abnormally expressed CD44,α-SMA, ILK, and DDR1. Inflammatory infiltrates were observed around glomeruli and arterioles. Homozygous Col4a1 G498V mutant mice additionally showed dysmorphic papillae and urinary concentration defects. These results reveal a developmental role for the α1α1α2 collagen IV molecule in the embryonic glomerular basement membrane, affecting podocyte differentiation. The observed association between molecular alteration of the collagenous network in Bowman's capsule of the mature kidney and activation of parietal epithelial cells, matrix remodeling, and inflammation may account for glomerular cyst development and CKD in patients with COL4A1-related disorders.

  10. Glomerular lesions induced in the rabbit by physicochemically altered homologous IgG.

    PubMed Central

    Cavalot, F.; Miyata, M.; Vladutiu, A.; Terranova, V.; Dubiski, S.; Burlingame, R.; Tan, E.; Brentjens, J.; Milgrom, F.; Andres, G.

    1992-01-01

    Immunization of rabbits with physicochemically altered homologous or even autologous IgG induces formation of antibodies combining with IgG of rabbit and of foreign species. Cardiac but not renal lesions were reported in such animals. This study examined the nephritogenic potential of the immune response to cationized or heat-aggregated homologous IgG of b9 or b4 allotype in rabbits of the b4 allotype. Rabbits injected with either b9 or b4 cationized IgG produced antibodies reactive with rabbit and human IgG and with histones; they also developed abnormal glomerular deposits of IgG b4 and C3 corresponding to alterations of the glomerular basement membranes (GBM). Rabbits injected with either b9 or b4 aggregated IgG developed antibodies reactive with rabbit and human IgG and abnormal glomerular deposits of IgG b4 and C3 in the GBM and in the mesangium with subendothelial and mesangial electron-dense deposits. Some rabbits in both groups had proliferative and exudative glomerulonephritis and proteinuria. The results showed that immunization of rabbits with physicochemically altered homologous IgG induces an immune response to rabbit and human IgG and to histones as well as glomerular deposits of autologous IgG and C3 and other glomerular lesions. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 PMID:1546743

  11. Microfluidic colloid filtration

    PubMed Central

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

    2016-01-01

    Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level. PMID:26927706

  12. Microfluidic colloid filtration

    NASA Astrophysics Data System (ADS)

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

    2016-03-01

    Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level.

  13. Microfluidic colloid filtration.

    PubMed

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J C; Wessling, Matthias

    2016-01-01

    Filtration of natural and colloidal matter is an essential process in today's water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a "cake layer"--often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level. PMID:26927706

  14. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect

    Daniel J. Stepan; Bradley G. Stevens; Melanie D. Hetland

    1999-10-01

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc).

  15. Filtration by eyelashes

    NASA Astrophysics Data System (ADS)

    Vistarakula, Krishna; Bergin, Mike; Hu, David

    2010-11-01

    Nearly every mammalian and avian eye is rimmed with lashes. We investigate experimentally the ability of lashes to reduce airborne particle deposition in the eye. We hypothesize that there is an optimum eyelash length that maximizes both filtration ability and extent of peripheral vision. This hypothesis is tested using a dual approach. Using preserved heads from 36 species of animals at the American Museum of Natural History, we determine the relationship between eye size and eyelash geometry (length and spacing). We test the filtration efficacy of these geometries by deploying outdoor manikins and measuring particle deposition rate as a function of eyelash length.

  16. Magnetic-seeding filtration

    SciTech Connect

    Depaoli, D.

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  17. Small charged macromolecules for assessing glomerular disease

    SciTech Connect

    McAfee, J.G.; Subramanian, G.; Schneider, R.F.; Thomas, F.D.; Lyons, B.; Roskopf, M.; Zapf-Longo, C.

    1985-05-01

    Only about 50% of patients with biopsy-proven glomerular disease have shown significant depression of inulin or creatinine clearance. Previously discussed was a greater difference in clearance of unlabeled charged dextrans than with inulin or neutral dextrans between rats with glomerular damage and normal controls. The charged macromolecules reflected the early loss of the normal anionic charge of the glomerulus in disease. The authors have explored this principle for radionuclide studies. After limited coupling with the cyclic diahydride of DTPA, the In-111 labeled aminated dextran was injected IV simultaneously with Tc-99m DTPA in Sprague-Dawley rats. Glomerular damage was induced with IV puromycin aminonucleoside (5 mg/100g body wt) 9 days previously, for comparison with normal controls. Plasma clearance was determined from multiple blood samples over 2 hours. Urine and organs were assayed after sacrifice 2 hours after injection. The results are presented in this paper. If these results prove valid for man, radiolabeled charged small macromolecules should improve the assessment of spontaneous glomerulopathies compared to conventional ''glomerular'' agents.

  18. Epidemiology of Glomerular Disease in Southern Arizona

    PubMed Central

    Murugapandian, Sangeetha; Mansour, Iyad; Hudeeb, Mohammad; Hamed, Khaled; Hammode, Emad; Bijin, Babitha; Daheshpour, Sepehr; Thajudeen, Bijin; Kadambi, Pradeep

    2016-01-01

    Abstract Glomerulonephritis stands third in terms of the etiologies for end-stage kidney disease in the USA. The aim of this study was to look at the patterns of biopsy-proven glomerulonephritis based on data from a single center. Kidney biopsy specimens of all patients above the age of 18 years, over a 10-year period, who had diagnosis of nondiabetic glomerular disease, were selected for the study. The most common histopathological diagnosis was focal and segmental glomerulosclerosis (FSGS) (22.25%, 158/710) followed by membranous nephropathy (20.28%, 144/710) and immunoglobulin (Ig)A nephropathy (19.71%, 140/710). There was male preponderance in all histological variants except IgA nephropathy, lupus nephritis, and pauci-immune glomerulonephritis. The race distribution was uneven, and all histological variants, except minimal change disease and lupus nephritis, were more commonly seen in whites. In a separate analysis of the histological pattern in Hispanics, lupus nephritis was the most common pathology (28.70%, 62/216) followed by FSGS (18.05%, 39/216). In American Indian population, the most common pathology was IgA nephropathy (33.33%, 8/24) followed by FSGS (16.67%, 4/24). This study highlights the histopathological patterns of glomerular disease in southern Arizona. The data suggest regional and ethnic variations in glomerular disease that may point towards genetic or environmental influence in the pathogenesis of glomerular diseases. PMID:27149502

  19. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  20. Alterations in glomerular and tubular dynamics at 1 and 14 days simulated microgravity and after acute return to orthostasis

    NASA Technical Reports Server (NTRS)

    Tucker, Bryan J.; Mendonca, Margarida M.

    1995-01-01

    Head-down tilt (HDT) is utilized to simulate microgravity and produces a cephalad fluid shift, which results in alterations in fluid and electrolyte balance. These changes in volume homeostasis are due, in part, to alterations in multiple volume control mechanisms in which renal function is a major participant. We have previously demonstrated that glomerular filtration rate increases early in HDT and eventually returns to values not different from non-tilt measurements. This early increase in glomerular filtration rate was also demonstrated during days 2 and 8 of the SLS-1 mission. However, urine flow and electrolyte excretion does not parallel the alternations in glomerular filtration rate and the site of this change in nephron fluid reabsorption pattern has not been previously examined. Through determination of the location of alterations in tubular fluid reabsorption within the nephron, a more detailed hypothesis can be forwarded as to which specific neuro-humoral agents participating in control or renal function in microgravity conditions. the importance of this type of examination is that measurements in circulating neuro-humoral agents and urinary excretion patterns alone are not accurate predictors of how renal functional response may alter to head-down tilt or other models of simulated weightlessness. To examine this issue, renal micropuncture techniques were utilized in Munich-Wistar rats submitted 24 hour and 14 day head-down tilt, measuring all the determinants of glomerular ultrafiltration and obtaining data regarding segmental tubular fluid reabsorption. Following these measurements, the rats were returned to an orthostatic position and after 60 minutes, the measurements were repeated.

  1. Water Treatment Technology - Filtration.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

  2. Pathogenetic role of glomerular CXCL13 expression in lupus nephritis

    PubMed Central

    Worthmann, K; Gueler, F; von Vietinghoff, S; Davalos-Mißlitz, A; Wiehler, F; Davidson, A; Witte, T; Haller, H; Schiffer, M; Falk, C S; Schiffer, L

    2014-01-01

    Podocytes maintain the structure and function of the glomerular filtration barrier. However, podocytes have recently been implicated in the innate immune response, and their function as non-haematopoietic antigen-presenting cells was highlighted. We have shown previously that excessive expression of the chemokine CXCL13 is a distinctive early event for nephritis in a murine model of systemic lupus erythematosus (SLE). Furthermore, we found that CXCL13 is elevated significantly in the serum of patients with SLE-nephritis. In this study, we were able to show for the first time that (i) CXCL13 is expressed locally in glomeruli in a model for SLE-nephritis in mice and that (ii) incubation of human podocytes with CXCL13 induces receptor stimulation of CXCR5 with activation of signalling pathways, resulting in (iii) secretion of proinflammatory cytokines and chemokines in culture supernatant. This cytokine/chemokine cocktail can lead to (iv) a neutrophil respiratory burst in isolated human granulocytes. Taken together, our results provide further evidence that CXCL13 is involved in the pathogenesis of glomerulonephritis and that podocytes can play an active role in local proinflammatory immune responses. Thus, CXCL13 could be a direct target for the therapy of glomerulonephritis in general and for SLE-nephritis in particular. PMID:24827905

  3. Characterization of glomerular epithelial cell matrix receptors.

    PubMed Central

    Adler, S.

    1992-01-01

    Integrin matrix receptors on glomerular epithelial cells (GEC) may play an important role in adhesion of GEC to the glomerular basement membrane (GBM) and in the maintenance of normal glomerular permeability. Therefore, the author determined the types of matrix receptors present on cultured rat GEC and examined their interactions with several components of the extracellular matrix. Beta 1 integrin matrix receptors were detected on all three glomerular cell types in rat kidney in vivo and at areas of cell-cell contact on cultured GEC. Glomerular epithelial cell adhesion to types I and IV collagen was slightly greater than to laminin and fibronectin. Adhesion to fibronectin was significantly inhibited by a synthetic peptide containing the RGD adhesion sequence. Immunoprecipitation of lysates of surface-iodinated GEC showed the presence of alpha 3 beta 1 integrin. Chromatography of lysates on immobilized collagen showed alpha 3 beta 1 integrin and a 70- to 75-kd protein band as the collagen receptors on GEC. Chromatography on the 120-kd cell-binding fragment of fibronectin disclosed only alpha 3 beta 1 as a specific fibronectin receptor. Antibody to the beta 1 integrin chain inhibited adhesion to laminin and collagen. These studies demonstrate that in vitro, as in vivo, GEC appear to express only alpha 3 beta 1 integrin. Furthermore, this matrix receptor is capable of mediating GEC adhesion to collagen, fibronectin, and laminin, components of the GBM, and presumably plays a similar role in promoting GEC adhesion to GBM in vivo. Images Figure 1 Figure 4 Figure 5 Figure 6 Figure 7 PMID:1325740

  4. Organization of the pronephric filtration apparatus in zebrafish requires Nephrin, Podocin and the FERM domain protein Mosaic eyes

    PubMed Central

    Kramer-Zucker, Albrecht G.; Wiessner, Stephanie; Jensen, Abbie M.; Drummond, Iain A.

    2010-01-01

    Podocytes are specialized cells of the kidney that form the blood filtration barrier in the kidney glomerulus. The barrier function of podocytes depends upon the development of specialized cell–cell adhesion complexes called slit-diaphragms that form between podocyte foot processes surrounding glomerular blood vessels. Failure of the slit-diaphragm to form results in leakage of high molecular weight proteins into the blood filtrate and urine, a condition called proteinuria. In this work, we test whether the zebrafish pronephros can be used as an assay system for the development of glomerular function with the goal of identifying novel components of the slit-diaphragm. We first characterized the function of the zebrafish homolog of Nephrin, the disease gene associated with the congenital nephritic syndrome of the Finnish type, and Podocin, the gene mutated in autosomal recessive steroid-resistant nephrotic syndrome. Zebrafish nephrin and podocin were specifically expressed in pronephric podocytes and required for the development of pronephric podocyte cell structure. Ultrastructurally, disruption of nephrin or podocin expression resulted in a loss of slit-diaphragms at 72 and 96 h post-fertilization and failure to form normal podocyte foot processes. We also find that expression of the band 4.1/FERM domain gene mosaic eyes in podocytes is required for proper formation of slit-diaphragm cell–cell junctions. A functional assay of glomerular filtration barrier revealed that absence of normal nephrin, podocin or mosaic eyes expression results in loss of glomerular filtration discrimination and aberrant passage of high molecular weight substances into the glomerular filtrate. PMID:16102746

  5. Long-term observations on tubular and glomerular function in cadmium-exposed persons

    SciTech Connect

    Piscator, M.

    1984-03-01

    Four groups of cadmium-exposed persons, from different workplaces and with different types of exposure, have been followed for periods of 9-20 years. In one group the total observation time is over 30 years, since they were included in Friberg's original study. The studies include determination of inulin or creatinine clearance, protein excretion and specific indicators of renal tubular dysfunction. The results indicate that once tubular dysfunction is established, it is irreversible, even when it is minor. In some persons it was noted that the development of renal dysfunction seemed to be a multistage process. The initial stage is characterized by an increased excretion of low molecular weight proteins like ..beta../sub 2/-microglobulin and ribonuclease. After a period of several years with no or low exposure, there was a relatively sharp increase in excretion of total proteins and albumin and a decrease in glomerular filtration rate. This is interpreted as being the result of further increases in renal concentration of cadmium and in spread of cadmium along the tubules. Metallothionein absorption in the tubules, its catabolism and synthesis must play an important role for the development and progress of the tubular dysfunction. It was not possible to show that a decrease in glomerular filtration rate occurs before low molecular weight proteinuria. 15 references, 2 figures, 2 tables.

  6. Craniofacial Abnormalities

    MedlinePlus

    ... of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ... palate, are among the most common of all birth defects. Others are very rare. Most of them affect ...

  7. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  8. Walking abnormalities

    MedlinePlus

    ... include: Arthritis of the leg or foot joints Conversion disorder (a psychological disorder) Foot problems (such as a ... injuries. For an abnormal gait that occurs with conversion disorder, counseling and support from family members are strongly ...

  9. Nail abnormalities

    MedlinePlus

    Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails ... Just like the skin, the fingernails tell a lot about your health: ... the fingernail. These lines can occur after illness, injury to ...

  10. Liquid filtration simulation

    SciTech Connect

    Corey, I.; Bergman, W.

    1996-06-01

    We have a developed a computer code that simulates 3-D filtration of suspended particles in fluids in realistic filter structures. This code, being the most advanced filtration simulation package developed to date, provides LLNL and DOE with new capabilities to address problems in cleaning liquid wastes, medical fluid cleaning, and recycling liquids. The code is an integrated system of commercially available and LLNL-developed software; the most critical are the computational fluid dynamics (CFD) solver and the particle transport program. For the CFD solver, we used a commercial package based on Navier-Stokes equations and a LLNL-developed package based on Boltzman-lattice gas equations. For the particle transport program, we developed a cod based on the 3-D Langevin equation of motion and the DLVO theory of electrical interactions. A number of additional supporting packages were purchased or developed to integrate the simulation tasks and to provide visualization output.

  11. Influence of running different distances on renal glomerular and tubular impairment in humans.

    PubMed

    Poortmans, J R; Mathieu, N; De Plaen, P

    1996-01-01

    Strenuous exercise has been claimed to modify renal glomerular and tubular function, the relative involvement of the two sites being unknown. These changes may be assessed by the determination of plasma high and low molecular mass proteins. A group of 13 man performed five runs (100, 400, 800, 1,500, 3,000 m) at maximal speed. The excretion rates and renal clearances of creatinine, albumin (Alb), beta 2-microglobulin (beta 2-m) and retinol-binding protein (RBP) were determined before and after each run. The glomerular filtration rate remained stable during the shorter runs and declined by about 40% during the longer runs. The excretion rate for Alb rose from 10-fold above the basal value (6 micrograms.min-1) for the 100 m to 49-fold for the 800 m and then declined for distances up to 3,000 m. The beta 2-m and RBP had a lesser initial increase, 3.5-(rest 55 ng.min-1) and 7.6-(rest 116 ng.min-1) fold, respectively, for the 100 m run and thereafter showed a higher excretion rate than Alb for the 400 m and 800 m runs. The renal clearances of these high (Alb) and low molecular mass (beta 2-m and RBP) proteins followed the changes observed for excretion rates. There was a linear relationship (r2 = 0.996) between plasma lactate concentration and total protein excretion in the postexercise period when taking all five runs into consideration. Glomerular permeability was primarily affected by the 100-m run while the longer runs modified both the glomerular and the tubular sites. To conclude, the present study demonstrated a differential response of the kidney to strenuous exercise with respect to the intensity and duration of the events. PMID:8925826

  12. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or...

  13. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or...

  14. Sex Differences in Associations Among Obesity, Metabolic Abnormalities, and Chronic Kidney Disease in Japanese Men and Women

    PubMed Central

    Sakurai, Masaru; Kobayashi, Junji; Takeda, Yasuo; Nagasawa, Shin-Ya; Yamakawa, Junichi; Moriya, Junji; Mabuchi, Hiroshi; Nakagawa, Hideaki

    2016-01-01

    Aims The present study aimed to investigate relationships among abdominal obesity, metabolic abnormalities, and the prevalence of chronic kidney disease (CKD) in relatively lean Japanese men and women. Participants and methods The participants included 8133 men and 15 934 women between 40 and 75 years of age recruited from the government health check-up center in Kanazawa City, Japan. The prevalence of abdominal obesity, high blood pressure, dyslipidemia, and high fasting plasma glucose levels were assessed according to the Japanese criteria for metabolic syndrome. The estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease equation for the Japanese population, and participants with an eGFR <60 mL/min/1.73 m2 and/or proteinuria were diagnosed with CKD. Results Overall, 23% of males and 14% of females met criteria for CKD. Having more numerous complicated metabolic abnormalities was significantly associated with a higher odds ratio (OR) of CKD for men and women, irrespective of abdominal obesity. However, there was a sex difference in the OR of CKD for obese participants without metabolic abnormalities, such that abdominal obesity without metabolic abnormalities was significantly associated with a higher OR for men (multivariate-adjusted OR 1.63; 95% confidence interval [CI], 1.16–2.28) but not for women (OR 1.01; 95% CI, 0.71–1.44). Conclusions The present findings demonstrated that obesity without metabolic abnormalities was associated with a higher risk of CKD in men but not women in a relatively lean Japanese population. PMID:27087606

  15. Quantification of single-kidney glomerular filtration rate with electron-beam computed tomography

    NASA Astrophysics Data System (ADS)

    Lerman, Lilach O.; Ritman, Erik L.; Pelaez, Laura I.; Sheedy, Patrick F., II; Krier, James D.

    2000-04-01

    The ability to accurately and noninvasively quantify single- kidney GFR could be invaluable for assessment of renal function. We developed a model that enables this measurement with EBCT. To examine the reliability of this method, EBCT renal flow and volume studies after contrast media administration were performed in pigs with unilateral renal artery stenosis (Group 1), controls (Group 2), and simultaneously with inulin clearance (Group 3). Renal flow curves, obtained from the bilateral renal cortex and medulla, depicted transit of the contrast through the vascular and tubular compartments, and were fitted using extended gamma- variate functions. Renal blood flow was calculated as the sum of products of cortical and medullary perfusions and volumes. Normalized GFR (mL/min/cc) was calculated using the rate (maximal slope) of proximal tubular contrast accumulation, and EBCT-GFR as normalized GFR* cortical volume. In Group 1, the decreased GFR of the stenotic kidney correlated well with its decreased volume and RBF, and with the degree of stenosis (r equals -0.99). In Group 3, EBCT-GFR correlated well with inulin clearance (slope 1.1, r equals 0.81). This novel approach can be very useful for quantification of concurrent regional hemodynamics and function in the intact kidneys, in a manner potentially applicable to humans.

  16. Urinary CYP Eicosanoid Excretion Correlates with Glomerular Filtration in African-Americans with Chronic Kidney Disease

    PubMed Central

    Dreisbach, Albert W; Smith, Stanley V; Kyle, Patrick B; Ramaiah, Manjunath; Amenuke, Margaret; Garrett, Michael R; Lirette, Seth T; Griswold, Michael E; Roman, Richard J

    2015-01-01

    Previous studies have indicated that cytochrome P450 (CYP) metabolites of arachidonic acid (AA), i.e., 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs), play an important role in the regulation of renal tubular and vascular function. The present study for the first time profiled HETEs and epoxygenase derived dihydroxyeicosatetraenoic acid diHETEs levels in spot urines and plasma in 262 African American patients from the University of Mississippi Chronic Kidney Disease Clinic and 31 African American controls. Significant correlations in eGFR and urinary 20-HETE/creatinine and 19-HETE/ creatinine levels were observed. The eGFR increased by 17.47 [p=0.001] and 60.68 [(p=0.005] ml/min/ for each ng/mg increase in 20-HETE and 19-HETE levels, respectively. Similar significant positive associations were found between the other urinary eicosanoids and eGFR and also with 19-HETE/urine creatinine concentration and proteinuria. We found that approximately 80% of plasma HETEs and 30% diHETEs were glucuronidated and the fractional excretion of 20-HETE was less than 1%. These results suggest that there is a significant hepatic source of urinary 20-HETE glucuronide and EETs with extensive renal biotransformation to metabolites which may play a role in the pathogenesis of CKD. PMID:25151892

  17. Effect of proteinuria and glomerular filtration rate on cardiovascular risk in essential hypertension.

    PubMed

    Segura, Julian; Campo, Carlos; Ruilope, Luis M

    2004-11-01

    Changes in renal function related with essential hypertension are associated with an elevated cardiovascular morbidity and mortality. Indices of altered renal function (e.g., microalbuminuria, increased serum creatinine concentrations, decrease in estimated creatinine clearance or GFR, and overt proteinuria) are independent predictors of cardiovascular morbidity and mortality. The Framingham Heart Study documented the relevance of proteinuria for cardiovascular prognosis in the community. The INSIGHT Study assessed the role of proteinuria as a risk factor in essential hypertension. The presence of proteinuria at baseline turned out to be a very potent predictor for the development of cardiovascular events and death in patients with essential hypertension and one or more associated cardiovascular risk factors. Recent data indicate that minor derangements of renal function, including proteinuria, are associated, both in the community and in the hypertensive population, with the clustering of cardiovascular risk factors observed in metabolic syndrome that promote progression of atherosclerosis. Renal function has to be routinely evaluated in every hypertensive patient, and the presence of minor alterations considered in the stratification of cardiovascular risk in hypertensive patients.

  18. Urinary CYP eicosanoid excretion correlates with glomerular filtration in African-Americans with chronic kidney disease.

    PubMed

    Dreisbach, Albert W; Smith, Stanley V; Kyle, Patrick B; Ramaiah, Manjunath; Amenuke, Margaret; Garrett, Michael R; Lirette, Seth T; Griswold, Michael E; Roman, Richard J

    2014-10-01

    Previous studies have indicated that cytochrome P450 (CYP) metabolites of arachidonic acid (AA), i.e., 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs), play an important role in the regulation of renal tubular and vascular function. The present study for the first time profiled HETEs and epoxygenase derived dihydroxyeicosatetraenoic acid diHETEs levels in spot urines and plasma in 262 African American patients from the University of Mississippi Chronic Kidney Disease Clinic and 31 African American controls. Significant correlations in eGFR and urinary 20-HETE/creatinine and 19-HETE/creatinine levels were observed. The eGFR increased by 17.47 [p=0.001] and 60.68 [(p=0.005]ml/min/for each ng/mg increase in 20-HETE and 19-HETE levels, respectively. Similar significant positive associations were found between the other urinary eicosanoids and eGFR and also with 19-HETE/urine creatinine concentration and proteinuria. We found that approximately 80% of plasma HETEs and 30% diHETEs were glucuronidated and the fractional excretion of 20-HETE was less than 1%. These results suggest that there is a significant hepatic source of urinary 20-HETE glucuronide and EETs with extensive renal biotransformation to metabolites which may play a role in the pathogenesis of CKD.

  19. A comparison of prediction equations for estimating glomerular filtration rate in adults without kidney disease.

    PubMed

    Lin, Julie; Knight, Eric L; Hogan, Mary Lou; Singh, Ajay K

    2003-10-01

    The ability of the Modification of Renal Disease (MDRD) equation to predict GFR when compared with multiple other prediction equations in healthy subjects without known kidney disease was analyzed. Between May 1995 and December 2001, a total of 117 healthy individuals underwent (125)I-iothalamate or (99m)Tc-diethylenetriamine-pentaacetic acid (DTPA) renal studies as part of a routine kidney donor evaluation at either Brigham and Women's Hospital or Boston Children's Hospital. On chart review, 100 individuals had sufficient data for analysis. The MDRD 1, MDRD 2 (simplified MDRD equation), Cockcroft-Gault (CG), Cockcroft-Gault corrected for GFR (CG-GFR), and other equations were tested. The median absolute difference in ml/min per 1.73 m(2) between calculated and measured GFR was 28.7 for MDRD 1, 18.5 for MDRD 2, 33.1 for CG, and 28.6 for CG-GFR in the (125)I-iothalamate group and was 31.1 for MDRD 1, 38.2 for MDRD 2, 22.0 for CG, and 31.1 for CG-GFR in the (99m)Tc-DTPA group. Bias was -0.5, -3.3, 25.6, and 5.0 for MDRD 1, MDRD 2, CG, and CG-GFR, respectively, in subjects who received (125)I-iothalamate and -33.2, -36.5, 6.0, and -15.0 for MDRD 1, MDRD 2, CG, and CG-GFR, respectively, in those who received (99m)Tc-DTPA studies. Precision testing, as measured by linear regression, yielded R(2) values of 0.04 for CG, 0.05 for CG-GFR, 0.15 for MDRD 1, and 0.14 for MDRD in those who underwent (125)I-iothalamate studies and 0.18 for CG, 0.21 for CG-GFR, 0.40 for MDRD 1, and 0.38 for MDRD 2 for those who underwent (99m)Tc-DTPA studies. The MDRD equations were more accurate within 30 and 50% of the measured GFR compared with the CG and CG-GFR equations. When compared with the CG equation, the MDRD equations are more precise and more accurate for predicting GFR in healthy adults. The MDRD equations, however, consistently underestimate GFR, whereas the CG equations consistently overestimate measured GFR in people with normal renal function. In potential kidney donors, prediction equations may not be sufficient for estimating GFR; radioisotope studies may be needed for a better assessment of GFR. Further studies are needed to derive and assess GFR prediction equations in people with normal or mildly impaired renal function. PMID:14514734

  20. Detection of diffuse glomerular lesions in rats: II. Comparison of indium-111 cationic small macromolecules with technetium-99m DTPA

    SciTech Connect

    McAfee, J.G.; Thomas, F.D.; Subramanian, G.; Schneider, R.D.; Lyons, B.; Roskopf, M.; Zapf-Longo, C.; Whaley, D.

    1986-04-01

    Dextrans with average molecular weights of 5000, 10,000, and 17,500 and inulin were rendered cationic by amination with 2-bromoethylamine hydrobromide. After limited coupling with DTPA cyclic dianhydride, they were labeled with 111In. A good correlation was found between their early renal uptake quantitated by camera-computer techniques and their renal clearance from multiple plasma samples in rats with glomerular damage induced by puromycin aminonucleoside and controls. However, there was poor correlation between the early renal uptake of these agents and the clearance of simultaneously injected (/sup 99m/Tc)DTPA. The 2-hr organ distribution and urinary excretion of these agents were compared with the corresponding values of DTPA. The differences in clearance between rats with glomerular damage and controls were greater with aminated dextran (mol wt 5000) than with DTPA, confirming previous work with infusions of nonradioactive charged dextrans and neutral inulin. The cationic dextrans appear to reflect the presence or absence of the normal anionic charge of the glomerular membrane as well as changes in filtration rate. Aminated inulin did not differentiate between controls and rats with glomerular disease any better than DTPA, probably because the number of amino groups conjugated was insufficient to produce the charge effect.

  1. NF-κB signaling maintains the survival of cadmium-exposed human renal glomerular endothelial cells

    PubMed Central

    Zhang, Hongyan; Li, Liqun; Wang, Yifan; Dong, Fengyun; Chen, Xiaocui; Liu, Fuhong; Xu, Dongmei; Yi, Fan; Kapron, Carolyn M.; Liu, Ju

    2016-01-01

    The kidney is one of the primary organs targeted by cadmium (Cd), a widely distributed environmental pollutant. The glomerular endothelium is the major component of the glomerular filtration barrier. However, the effects of Cd on glomerular endothelial cells remain largely unknown. For this purpose, we aimed to determine the effects of low dose Cd on the survival of human renal glomerular endothelial cells (HRGECs). Cultured HRGECs were exposed to 4 µM cadmium chloride (CdCl2) and examined at different time-points. We found that Cd activates the nuclear factor-κB (NF-κB) pathway without inducing the apoptosis of HRGECs. Pre-treating the cells with pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, prior to Cd exposure triggered extensive cell death (73.5%). In addition, Cd activates the c-Jun N-terminal kinase (JNK) pathway, and inhibition of the NF-κB pathway significantly elevates Cd-induced JNK phosphorylation in HRGECs (p<0.01). The combination treatment of PDTC and SP600125, a JNK pathway inhibitor, increased the survival of Cd-stimulated HRGECs compared with those cells treated with PDTC alone (p<0.05). Taken together, these findings demonstrate that the NF-κB pathway plays an essential role in maintaining the survival of Cd-exposed HRGECs. PMID:27315281

  2. NF-κB signaling maintains the survival of cadmium-exposed human renal glomerular endothelial cells.

    PubMed

    Zhang, Hongyan; Li, Liqun; Wang, Yifan; Dong, Fengyun; Chen, Xiaocui; Liu, Fuhong; Xu, Dongmei; Yi, Fan; Kapron, Carolyn M; Liu, Ju

    2016-08-01

    The kidney is one of the primary organs targeted by cadmium (Cd), a widely distributed environmental pollutant. The glomerular endothelium is the major component of the glomerular filtration barrier. However, the effects of Cd on glomerular endothelial cells remain largely unknown. For this purpose, we aimed to determine the effects of low dose Cd on the survival of human renal glomerular endothelial cells (HRGECs). Cultured HRGECs were exposed to 4 µM cadmium chloride (CdCl2) and examined at different time-points. We found that Cd activates the nuclear factor-κB (NF-κB) pathway without inducing the apoptosis of HRGECs. Pre-treating the cells with pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, prior to Cd exposure triggered extensive cell death (73.5%). In addition, Cd activates the c-Jun N-terminal kinase (JNK) pathway, and inhibition of the NF-κB pathway significantly elevates Cd-induced JNK phosphorylation in HRGECs (p<0.01). The combination treatment of PDTC and SP600125, a JNK pathway inhibitor, increased the survival of Cd-stimulated HRGECs compared with those cells treated with PDTC alone (p<0.05). Taken together, these findings demonstrate that the NF-κB pathway plays an essential role in maintaining the survival of Cd-exposed HRGECs. PMID:27315281

  3. Dynamic optical filtration

    NASA Technical Reports Server (NTRS)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  4. Dynamic Optical Filtration

    NASA Technical Reports Server (NTRS)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  5. Magnetic flocculation and filtration

    SciTech Connect

    Yiacoumi, Sotira; Chin, Ching-Ju; Yin, Tung-Yu; Tsouris, C., DePaoli, D.W.; Chattin, M.R.; Spurrier, M.

    1996-10-01

    A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

  6. Magnetic-seeding filtration

    SciTech Connect

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  7. Cross talk between miR-214 and PTEN attenuates glomerular hypertrophy under diabetic conditions

    PubMed Central

    Wang, Xiaoxia; Shen, E.; Wang, Yanzhe; Li, Junhui; Cheng, Dongsheng; Chen, Yuqiang; Gui, Dingkun; Wang, Niansong

    2016-01-01

    Glomerular mesangial cells (MCs) hypertrophy is one of the earliest pathological abnormalities in diabetic nephropathy (DN), which correlates with eventual glomerulosclerosis. This study aimed to investigate the therapeutic role of miRNA in diabetic glomerular MCs hypertrophy and synthesis of extracellular matrix (ECM). Microarray analysis revealed a significant up-regulation of miR-214 in the renal cortex of diabetic db/db mice, which was confirmed by real-time PCR of isolated glomeruli and primary cultured human MCs. In vitro studies showed that inhibition of miR-214 significantly reduced expression of α-SMA, SM22 and collagen IV, and partially restored phosphatase and tensin homolog (PTEN) protein level in high glucose-stimulated human MCs. Furthermore, we identified PTEN as the target of miR-214 by a luciferase assay in HEK293 cells. Moreover, overexpression of PTEN ameliorated miR-214-mediated diabetic MC hypertrophy while knockdown of PTEN mimicked the MC hypertrophy. In vivo study further confirmed that inhibition of miR-214 significantly decreased the expression of SM22, α-SMA and collagen IV, partially restored PTEN level, and attenuated albuminuria and mesangial expansion in db/db mice. In conclusion, cross talk between miR-214 and PTEN attenuated glomerular hypertrophy under diabetic conditions in vivo and in vitro. Therefore, miR-214 may represent a novel therapeutic target for DN. PMID:27549568

  8. Cross talk between miR-214 and PTEN attenuates glomerular hypertrophy under diabetic conditions.

    PubMed

    Wang, Xiaoxia; Shen, E; Wang, Yanzhe; Li, Junhui; Cheng, Dongsheng; Chen, Yuqiang; Gui, Dingkun; Wang, Niansong

    2016-01-01

    Glomerular mesangial cells (MCs) hypertrophy is one of the earliest pathological abnormalities in diabetic nephropathy (DN), which correlates with eventual glomerulosclerosis. This study aimed to investigate the therapeutic role of miRNA in diabetic glomerular MCs hypertrophy and synthesis of extracellular matrix (ECM). Microarray analysis revealed a significant up-regulation of miR-214 in the renal cortex of diabetic db/db mice, which was confirmed by real-time PCR of isolated glomeruli and primary cultured human MCs. In vitro studies showed that inhibition of miR-214 significantly reduced expression of α-SMA, SM22 and collagen IV, and partially restored phosphatase and tensin homolog (PTEN) protein level in high glucose-stimulated human MCs. Furthermore, we identified PTEN as the target of miR-214 by a luciferase assay in HEK293 cells. Moreover, overexpression of PTEN ameliorated miR-214-mediated diabetic MC hypertrophy while knockdown of PTEN mimicked the MC hypertrophy. In vivo study further confirmed that inhibition of miR-214 significantly decreased the expression of SM22, α-SMA and collagen IV, partially restored PTEN level, and attenuated albuminuria and mesangial expansion in db/db mice. In conclusion, cross talk between miR-214 and PTEN attenuated glomerular hypertrophy under diabetic conditions in vivo and in vitro. Therefore, miR-214 may represent a novel therapeutic target for DN. PMID:27549568

  9. Filtration: Principles and practices. 2. edition

    SciTech Connect

    Matteson, M.J.; Orr, C.

    1998-12-31

    This new book is the most authoritative and comprehensive guide to essential, state-of-the-art data. It provides the very latest theoretical and practical data on filtration for gas and liquids. The 2nd edition has been revised and updated to include several new chapters which detail filtration in the mineral industry, high-efficiency air filtration, cartridge filters, and ultrafiltration. The contents include: Gas filtration theory; Liquid-filtration theory; Filter media; Industrial gas filtration; Filtration pretreatment; Filtration in the chemical process industry; Ultrafiltration; Filtration in the mineral industry; Filtration in heating, ventilating, and air conditioning; Cartridge filtration; High-efficiency air filtration; Analytical applications of filtration; and Filter evaluation and testing.

  10. Filtration in industrial hygiene.

    PubMed

    Brown, R C

    2001-01-01

    Filters used in industrial hygiene are of two basic types, corresponding with the two basic airborne hazards: particulate and vapor. They are as different in their construction as they are in their purpose, and each gives negligible protection against the other hazard. By use of the correct type, adequate filtration efficiency can usually be achieved. Most particulate filters are made from fibers, and finer fibers result in higher efficiency. Filters can capture particles much smaller than the fiber diameter, as a result of diffusional motion of the airborne particles and, in the case of filters that hold a permanent electric charge, electrostatic attraction. Most vapor filters are made from granules of activated carbon, which have an extremely large effective surface area, where molecules of contaminant are adsorbed. The performance of all filters tends to alter as the filter material becomes loaded. Electrically neutral particulate filters become more efficient but at the expense of increased resistance to airflow. Particulate filters that act by electric forces may become less efficient, and are often less inclined to clog. Vapor filters usually have a high initial efficiency, but the penetration of vapor increases as the filters become saturated with adsorbed vapor, and the performance of these filters is normally expressed in terms of their lifetime rather than their efficiency. It is important that the choice of a filter should be made with close reference to the situation in which it is to be used, and optimum respiratory protection should be sought, rather than maximum filtration efficiency. Special problems of filters are illustrated by some case histories, and finally the use of filters as size selectors for dust samplers is briefly described. PMID:11669390

  11. A PERSPECTIVE OF RIVERBANK FILTRATION

    EPA Science Inventory

    Riverbank filtration is a process in which pumping of wells located along riverbanks induce a portion of the river water to flow toward the pumping wells. The process has many similarities to the slow sand filtration process. River water contaminants are attenuated due to a combi...

  12. Nebivolol Attenuates Redox-Sensitive Glomerular and Tubular Mediated Proteinuria in Obese Rats

    PubMed Central

    Habibi, Javad; Hayden, Melvin R.; Sowers, James R.; Pulakat, Lakshmi; Tilmon, Roger D.; Manrique, Camila; Lastra, Guido; DeMarco, Vincent G.

    2011-01-01

    Obesity and insulin resistance-related proteinuria is associated with oxidative stress and impaired tissue bioavailable nitric oxide. Recent data suggest that nicotinamide adenine dinucleotide phosphate oxidase-mediated oxidative injury to the proximal tubule, like that seen in the glomerulus, contributes to proteinuria in insulin-resistant states. The vasodilator β-blocker nebivolol reduces nicotinamide adenine dinucleotide phosphate oxidase activity, increases bioavailable nitric oxide, and improves insulin sensitivity. To test the hypothesis that a treatment strategy that reduces oxidative stress and attenuates obesity-associated increases in glomerular and proximal tubule derived protein, we treated young Zucker obese (ZO) and age-matched Zucker lean male rats with nebivolol (10 mg · kg−1 · d−1) for 21 d. Compared with Zucker lean, ZO controls exhibited increased proteinuria and γ-glutamyl transpeptidase, reductions in systemic insulin sensitivity in association with increased renal renin, (pro)renin receptor, angiotensin II type 1 receptor, and mineralocorticoid receptor immunostaining, oxidative stress, and glomerular tubular structural abnormalities that were substantially improved with in vivo nebivolol treatment. Nebivolol treatment also led to improvements in glomerular podocyte foot-process effacement and improvement in podocyte-specific proteins (nephrin and synaptopodin) as well as proximal tubule-specific proteins (megalin and lysosomal-associated membrane protein-2) and proximal tubule ultrastructural remodeling in the ZO kidney. Our findings support the notion that obesity and insulin resistance lead to increased glomerulotubular oxidative stress and resultant glomerular and tubular sources of excess urine protein. Furthermore, the results of this study suggest the beneficial effect of nebivolol on proteinuria was derived from improvements in weight and insulin sensitivity and reductions in renal oxidative stress in a state of obesity and

  13. Detection of Goodpasture antigen in fractions prepared from collagenase digests of human glomerular basement membrane.

    PubMed Central

    Fish, A J; Lockwood, M C; Wong, M; Price, R G

    1984-01-01

    Preparations of human glomerular basement membrane (GBM) were digested with collagenase, and a Goodpasture (GP) antigen rich pool from gel filtration column runs was identified by antibody inhibition radioimmunoassay. The components of the GP antigen pool were separated on polyacrylamide gels, and transferred to nitrocellulose sheets by the 'western' blotting technique. The blots were separately reacted with thirteen GP sera as primary antibody, followed by peroxidase labelled goat anti-human IgG and revealed 45-50K (two bands) and 25-28K (one-three bands) components. No corresponding reactivity was observed using convalescent GP sera or other control sera (normal human serum, rapidly progressive glomerulonephritis with or without pulmonary haemorrhage, and lupus erythematosus) as primary antibody. Images Fig. 3 PMID:6319059

  14. Partial characterization of proteoglycans synthesized by human glomerular epithelial cells in culture

    SciTech Connect

    Klein, D.J.; Oegema, T.R. Jr.; Fredeen, T.S.; van der Woude, F.; Kim, Y.; Brown, D.M. )

    1990-03-01

    Confluent adult and fetal human glomerular epithelial cells were incubated for 24 h in the presence of (3H)-amino acids and (35S)sulfate. Two heparan-35SO4 proteoglycans were released into the culture medium. These 35S-labeled proteoglycans eluted as a single peak from anion exchange chromatographic columns, but were separable by gel filtration on Sepharose CL-6B columns. The larger heparan-35SO4 proteoglycan eluted with the column void volume and at a Kav of 0.26 from Sepharose CL-4B columns. The most abundant medium heparan-35SO4 proteoglycan was a high buoyant density proteoglycan similar in hydrodynamic size (Sepharose CL-6B Kav 0.23) to those previously described in glomerular basement membranes and isolated glomeruli. Heparan-35SO4 chains from both proteoglycans were 36 kDa. A smaller proportion of Sepharose CL-6B excluded dermatan-35SO4 proteoglycan was also synthesized by these cells. The predominant protein cores of both medium heparan-35SO4 proteoglycans were approximately 230 and 180 kDa. A hybrid chondroitin/dermatan-heparan-35SO4 proteoglycan with an 80-kDa protein core copurified with the smaller medium heparan-35SO4 proteoglycan. This 35S-labeled proteoglycan appeared as a diffuse, chondroitinase ABC sensitive 155-kDa fluorographic band in sodium dodecyl sulfate-polyacrylamide gels after the Sepharose CL-6B Kav 0.23 35S-labeled proteoglycan fraction was digested with heparitinase. The heparitinase generated heparan sulfate proteoglycan protein cores and the 155-kDa hybrid proteoglycan fragment had molecular weights similar to those previously identified in rat glomerular basement membrane and glomeruli using antibodies against a basement membrane tumor proteoglycan precursor.

  15. Early-onset podocyte injury and glomerular sclerosis in osborne-mendel rats.

    PubMed

    Yasuno, Kyohei; Ishihara, Shoko; Saito, Rio; Ishikawa, Makoto; Kato, Takashi; Kobayashi, Ryosuke; Baba, Tomoshige; Kawano, Kazuya; Ogihara, Kikumi; Kamiie, Junichi; Shirota, Kinji

    2010-10-01

    Progressive glomerular injury associated with early-onset proteinuria was investigated in male Osborne-Mendel (OM) rats aged 5 to 20 weeks. Age-matched male Fischer 344 (F344) rats were used for comparison. OM rats developed mild hypertension and selective proteinuria (albuminuria) from 5 weeks of age, and non-selective proteinuria from 7 weeks of age. Light microscopy of OM kidney revealed hyaline droplets in the podocyte at 5 weeks of age and vacuolation of podocytes and adhesion of the capillary loop to the Bowman's capsule at 7 weeks of age. Segmental glomerulosclerosis developed in OM rats from 15 weeks of age, and global sclerosis appeared at 20 weeks of age. Desmin, a marker of podocye injury, was expressed in podocytes from 10 weeks of age, and the intensity of expression increased with age. Ultrastructurally, damage to podocytes such as effacement of foot processes, decreasing number of filtration slits, and rearrangement of the actin cytoskeleton were observed from 5 weeks of age in OM rat. Glomerular volume in OM rats increased with age and was consistently higher than in age-matched F344 rats. The number of WT-1-positive podocytes and vimentin-positive podocyte area were lower in OM rats and decreased with age. These findings suggest that glomerulonephropathy in male OM rats is associated with glomerular hypertrophy, progressive podocytopathy, and a reduction in podocyte number and area. Renal injury in OM rats was associated with development of early-onset proteinuria and was more progressive than in age-matched F344 rats.

  16. MC1R is dispensable for the proteinuria reducing and glomerular protective effect of melanocortin therapy

    PubMed Central

    Qiao, Yingjin; Berg, Anna-Lena; Wang, Pei; Ge, Yan; Quan, Songxia; Zhou, Sijie; Wang, Hai; Liu, Zhangsuo; Gong, Rujun

    2016-01-01

    Melanocortin therapy by using adrenocorticotropic hormone (ACTH) or non-steroidogenic melanocortin peptides attenuates proteinuria and glomerular injury in experimental glomerular diseases and induces remission of nephrotic syndrome in patients with diverse glomerulopathies, even those resistant to steroids. The underlying mechanism remains elusive, but the role of melanocortin 1 receptor (MC1R) has been implicated and was examined here. Four patients with congenital red hair color and nephrotic syndrome caused by idiopathic membranous nephropathy or focal segmental glomerulosclerosis were confirmed by gene sequencing to bear dominant-negative MC1R mutations. Despite prior corticosteroid resistance, all patients responded to ACTH monotherapy and ultimately achieved clinical remission, inferring a steroidogenic-independent and MC1R-dispensable anti-proteinuric effect of melanocortin signaling. In confirmatory animal studies, the protective effect of [Nle4, D-Phe7]-α-melanocyte stimulating hormone (NDP-MSH), a potent non-steroidogenic pan-melanocortin receptor agonist, on the lipopolysaccharide elicited podocytopathy was completely preserved in MC1R-null mice, marked by reduced albuminuria and diminished histologic signs of podocyte injury. Moreover, in complementary in vitro studies, NDP-MSH attenuated the lipopolysaccharide elicited apoptosis, hypermotility and impairment of filtration barrier function equally in primary podocytes derived from MC1R-null and wild-type mice. Collectively, our findings suggest that melanocortin therapy confers a proteinuria reducing and podoprotective effect in proteinuric glomerulopathies via MC1R-independent mechanisms. PMID:27270328

  17. A reassessment of soluble urokinase-type plasminogen activator receptor in glomerular disease

    PubMed Central

    Spinale, Joann M.; Mariani, Laura H.; Kapoor, Shiv; Zhang, Jidong; Weyant, Robert; Song, Peter X.; Wong, Hetty N.; Troost, Jonathan P.; Gadegbeku, Crystal A.; Gipson, Debbie S.; Kretzler, Matthias; Nihalani, Deepak; Holzman, Lawrence B.

    2014-01-01

    It has been suggested that soluble urokinase receptor (suPAR) is a causative circulating factor for and a biomarker of focal and segmental glomerulosclerosis (FSGS). Here we undertook validation of these assumptions in both mouse and human models. Injection of recombinant suPAR in wild-type mice did not induce proteinuria within 24 hours. Moreover, a disease phenotype was not seen in an inducible transgenic mouse model that maintained elevated suPAR concentrations for 6 weeks. Plasma and urine suPAR concentrations were evaluated as clinical biomarkers in 241 patients with glomerular disease from the prospective, longitudinal multi-center observational NEPTUNE cohort. The serum suPAR concentration at baseline inversely correlated with estimated glomerular filtration rate (eGFR) and the urine suPAR/creatinine ratio positively correlated with the urine protein/creatinine ratio. After adjusting for eGFR and urine protein, neither the serum nor urine suPAR level was an independent predictor of FSGS histopathology. A multivariable mixed-effects model of longitudinal data evaluated the association between the change in serum suPAR concentration from baseline with eGFR. After adjusting for baseline suPAR concentration, age, gender, proteinuria and time, the change in suPAR from baseline was associated with eGFR, but this association was not different for patients with FSGS as compared to other diagnoses. Thus, these results do not support a pathological role for suPAR in FSGS. PMID:25354239

  18. Renal scintigraphy in insulin-dependent diabetes mellitus: Early glomerular and urologic dysfunction

    SciTech Connect

    Poirier, J.Y.; Moisan, A.; Le Cloirec, J.; Siemen, C.; Yaouanq, J.; Edan, G.; Herry, J.Y. )

    1990-07-01

    Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by intravenous injection of 99mTc-diethylenetriaminepentaacetic acid (DTPA) and 131I-Hippuran in 115 insulin-dependent diabetic patients with albumin excretion rates (AER) less than 200 micrograms/min, and in 45 normal subjects. Separate kidney function and urinary elimination were estimated by renography. GFR was increased in the diabetic patients (152 +/- 24 ml/min/1.73 m2 vs. 128 +/- 15) and correlated significantly with RPF (r = 0.5; p less than 10(-9)). No relationship was found between GFR and the duration of diabetes, blood glucose, HbA1c, or AER. Fifty patients were hyperfiltering with RPF and filtration fraction higher than those in the normofiltering group. Slow intrarenal or pyeloureteral elimination, either unilateral or bilateral, was observed in 3 controls and 60 diabetic subjects (24 hyperfiltering; 36 normofiltering) and did not disappear with the patient in the standing position. In these 60 patients, mean age, duration of diabetes, blood glucose, HbA1c, 24 h albumin excretion rate, and frequency of peripheral or autonomic neuropathy did not differ from patients with normal scintigraphy; GFR was lower in the group with slow elimination, but not significantly so. 99mTc-DTPA renal uptake was symmetric in all the controls; asymmetric renal uptake with asymmetric GFR was observed in 13 patients (7 hyperfiltering; 6 normofiltering) and often associated with slower elimination. No evidence for renal stenotic atheroma or parenchymatous disease was found on the angiopyleoureterography. The results suggest that incipient uropathy is a very common phenomenon that occurs irrespective of glomerular dysfunction.

  19. Gallium 67 scintigraphy in glomerular disease

    SciTech Connect

    Bakir, A.A.; Lopez-Majano, V.; Levy, P.S.; Rhee, H.L.; Dunea, G.

    1988-12-01

    To evaluate the diagnostic usefulness of gallium 67 scintigraphy in glomerular disease, 45 patients with various glomerulopathies, excluding lupus nephritis and renal vasculitis, were studied. Persistent renal visualization 48 hours after the gallium injection, a positive scintigram, was graded as + (less than), ++ (equal to), and +++ (greater than) the hepatic uptake. Positive scintigrams were seen in ten of 16 cases of focal segmental glomerulosclerosis, six of 11 cases of proliferative glomerulonephritis, and one case of minimal change, and one of two cases of membranous nephropathy; also in three of six cases of sickle glomerulopathy, two cases of diabetic neuropathy, one of two cases of amyloidosis, and one case of mild chronic allograft rejection. The 25 patients with positive scans were younger than the 20 with negative scans (31 +/- 12 v 42 +/- 17 years; P less than 0.01), and exhibited greater proteinuria (8.19 +/- 7.96 v 2.9 +/- 2.3 S/d; P less than 0.01) and lower serum creatinine values (2 +/- 2 v 4.1 +/- 2.8 mg/dL; P less than 0.01). The amount of proteinuria correlated directly with the intensity grade of the gallium image (P less than 0.02), but there was no correlation between the biopsy diagnosis and the outcome of the gallium scan. It was concluded that gallium scintigraphy is not useful in the differential diagnosis of the glomerular diseases under discussion. Younger patients with good renal function and heavy proteinuria are likely to have a positive renal scintigram regardless of the underlying glomerulopathy.

  20. Role of porosity in filtration. 12: Filtration with sedimentation

    SciTech Connect

    Tiller, F.M.; Hsyung, N.B.; Cong, D.Z.

    1995-05-01

    Filtration on horizontal surfaces facing upward is accompanied by sedimentation. Materials balances that are based solely on the volume of filtrate and neglect sedimentation flux lead to an understatement of the solids deposited in the cake and potentially large errors in calculated values of the average specific resistance {alpha}{sub av} neglecting sedimentation was 3.75 times greater than the value including the effect of sedimentation. In addition to errors due to neglect of sedimentation, CATSCAN studies show that the slurry concentration above the cake increases with time, contrary to usual assumptions. In a manner similar to batch sedimentation in a closed cylinder, characteristics of constant composition arose from the cake surface. Approximate predictions based on a combination of traditional sedimentation and filtration theory were in accord with the CATSCAN data. Existing filtration theory must be substantially modified to account for the effect of sedimentation.

  1. Glycosaminoglycan Regulation by VEGFA and VEGFC of the Glomerular Microvascular Endothelial Cell Glycocalyx in Vitro

    PubMed Central

    Foster, Rebecca R.; Armstrong, Lynne; Baker, Siân; Wong, Dickson W.L.; Wylie, Emma C.; Ramnath, Raina; Jenkins, Robert; Singh, Anurag; Steadman, Robert; Welsh, Gavin I.; Mathieson, Peter W.; Satchell, Simon C.

    2014-01-01

    Damage to endothelial glycocalyx impairs vascular barrier function and may contribute to progression of chronic vascular disease. An early indicator is microalbuminuria resulting from glomerular filtration barrier damage. We investigated the contributions of hyaluronic acid (HA) and chondroitin sulfate (CS) to glomerular microvascular endothelial cell (GEnC) glycocalyx and examined whether these are modified by vascular endothelial growth factors A and C (VEGFA and VEGFC). HA and CS were imaged on GEnCs and their resynthesis was examined. The effect of HA and CS on transendothelial electrical resistance (TEER) and labeled albumin flux across monolayers was assessed. Effects of VEGFA and VEGFC on production and charge characteristics of glycosaminoglycan (GAG) were examined via metabolic labeling and liquid chromatography. GAG shedding was quantified using Alcian Blue. NDST2 expression was examined using real-time PCR. GEnCs expressed HA and CS in the glycocalyx. CS contributed to the barrier to both ion (TEER) and protein flux across the monolayer; HA had only a limited effect. VEGFC promoted HA synthesis and increased the charge density of synthesized GAGs. In contrast, VEGFA induced shedding of charged GAGs. CS plays a role in restriction of macromolecular flux across GEnC monolayers, and VEGFA and VEGFC differentially regulate synthesis, charge, and shedding of GAGs in GEnCs. These observations have important implications for endothelial barrier regulation in glomerular and other microvascular beds. PMID:23770346

  2. Phenotypic Expression of ADAMTS13 in Glomerular Endothelial Cells

    PubMed Central

    Tati, Ramesh; Kristoffersson, Ann-Charlotte; Ståhl, Anne-lie; Mörgelin, Matthias; Motto, David; Satchell, Simon; Mathieson, Peter; Manea-Hedström, Minola; Karpman, Diana

    2011-01-01

    Background ADAMTS13 is the physiological von Willebrand factor (VWF)-cleaving protease. The aim of this study was to examine ADAMTS13 expression in kidneys from ADAMTS13 wild-type (Adamts13+/+) and deficient (Adamts13−/−) mice and to investigate the expression pattern and bioactivity in human glomerular endothelial cells. Methodology/Principal Findings Immunohistochemistry was performed on kidney sections from ADAMTS13 wild-type and ADAMTS13-deficient mice. Phenotypic differences were examined by ultramorphology. ADAMTS13 expression in human glomerular endothelial cells and dermal microvascular endothelial cells was investigated by real-time PCR, flow cytometry, immunofluorescence and immunoblotting. VWF cleavage was demonstrated by multimer structure analysis and immunoblotting. ADAMTS13 was demonstrated in glomerular endothelial cells in Adamts13+/+ mice but no staining was visible in tissue from Adamts13−/− mice. Thickening of glomerular capillaries with platelet deposition on the vessel wall was detected in Adamts13−/− mice. ADAMTS13 mRNA and protein were detected in both human endothelial cells and the protease was secreted. ADAMTS13 activity was demonstrated in glomerular endothelial cells as cleavage of VWF. Conclusions/Significance Glomerular endothelial cells express and secrete ADAMTS13. The proteolytic activity could have a protective effect preventing deposition of platelets along capillary lumina under the conditions of high shear stress present in glomerular capillaries. PMID:21720563

  3. Phagocytosis by glomerular endothelial cells in infection-related glomerulopathy.

    PubMed

    van Velthuysen, M L; Mayen, A E; Prins, F A; de Heer, E; Bruijn, J A; Fleuren, G J

    1994-01-01

    Glomerulonephritis in BALB/c mice following infection with Trypanosoma brucei is characterized by albuminuria and glomerular deposition of immunoglobulins. Electron-dense deposits are present in the mesangium, as well as subendothelially and subepithelially along the glomerular capillary wall. In this study the nature of intracytoplasmic, electron-dense, round structures observed in glomerular endothelial cells was investigated by immunoelectron-microscopy and enzyme histochemistry. The presence of these structures was related in time with the development of proteinuria. Mice from the C57BL10 strain, which upon infection develop glomerular immune complexes without proteinuria, were examined as well. The results demonstrated that the first endothelial changes, occurring 3-4 weeks after infection, were swelling of endothelial cells containing intracytoplasmic, electron-dense, round structures. These changes were seen prior to the onset of proteinuria, and were not present in glomeruli of mice that did not develop proteinuria. The endothelial granules were shown to contain immunoglobulins and typical lysosomal enzymes, providing evidence for phagocytosis by the glomerular endothelial cells. Liver endothelial cells did not show comparable changes. Thus, local phagocytosis by glomerular endothelial cells is shown to be a specific event in the development of glomerular disease. PMID:7800204

  4. Glomerular Polycystic Kidney Disease in a Dog (Blue Merle Collie)

    PubMed Central

    Chalifoux, A.; Phaneuf, J. -B.; Olivieri, M.; Gosselin, Y.

    1982-01-01

    Glomerular polycystic kidney disease was diagnosed in an 11 month old, female, Blue Merle Collie. Clinical signs (polyuria, polydipsia, vomiting, diarrhea, partial anorexia) and laboratory work (blood urea nitrogen, creatinine, serum phosphorus, specific gravity, proteinuria, nonregenerative anemia) indicated chronic renal failure. However, after the study of a biopsy specimen, a definitive diagnosis was reached and the prognosis was determined. Necropsy findings and histopathological studies revealed: presence of glomerular cysts, atrophy of glomerular tufts and sclerosis of the interstitial tissue. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:17422209

  5. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  6. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  7. A flexible, multilayered protein scaffold maintains the slit in between glomerular podocytes

    PubMed Central

    Grahammer, Florian; Wigge, Christoph; Schell, Christoph; Kretz, Oliver; Patrakka, Jaakko; Schneider, Simon; Klose, Martin; Arnold, Sebastian J.; Habermann, Anja; Bräuniger, Ricarda; Rinschen, Markus M.; Völker, Linus; Bregenzer, Andreas; Rubbenstroth, Dennis; Boerries, Melanie; Kerjaschki, Dontscho; Miner, Jeffrey H.; Walz, Gerd; Benzing, Thomas; Fornoni, Alessia; Frangakis, Achilleas S.; Huber, Tobias B.

    2016-01-01

    Vertebrate life critically depends on renal filtration and excretion of low molecular weight waste products. This process is controlled by a specialized cell-cell contact between podocyte foot processes: the slit diaphragm (SD). Using a comprehensive set of targeted KO mice of key SD molecules, we provided genetic, functional, and high-resolution ultrastructural data highlighting a concept of a flexible, dynamic, and multilayered architecture of the SD. Our data indicate that the mammalian SD is composed of NEPHRIN and NEPH1 molecules, while NEPH2 and NEPH3 do not participate in podocyte intercellular junction formation. Unexpectedly, homo- and heteromeric NEPHRIN/NEPH1 complexes are rarely observed. Instead, single NEPH1 molecules appear to form the lower part of the junction close to the glomerular basement membrane with a width of 23 nm, while single NEPHRIN molecules form an adjacent junction more apically with a width of 45 nm. In both cases, the molecules are quasiperiodically spaced 7 nm apart. These structural findings, in combination with the flexibility inherent to the repetitive Ig folds of NEPHRIN and NEPH1, indicate that the SD likely represents a highly dynamic cell-cell contact that forms an adjustable, nonclogging barrier within the renal filtration apparatus. PMID:27430022

  8. Prevalence of asymptomatic urinary abnormalities among adolescents.

    PubMed

    Fouad, Mohamed; Boraie, Maher

    2016-05-01

    To determine the prevalence of asymptomatic urinary abnormalities in adolescents, first morning clean mid-stream urine specimens were obtained from 2500 individuals and examined by dipstick and light microscopy. Adolescents with abnormal screening results were reexamined after two weeks and those who had abnormal results twice were subjected to systemic clinical examination and further clinical and laboratory investigations. Eight hundred and three (32.1%) individuals had urinary abnormalities at the first screening, which significantly decreased to 345 (13.8%) at the second screening, (P <0.001). Hematuria was the most common urinary abnormalities detected in 245 (9.8%) adolescents who had persistent urine abnormalities; 228 (9.1%) individuals had non glomerular hematuria. The hematuria was isolated in 150 (6%) individuals, combined with leukocyturia in 83 (3.3%) individuals, and combined with proteinuria in 12 (0.5%) individuals. Leukocyturia was detected in 150 (6%) of all studied adolescents; it was isolated in 39 (1.6%) individuals and combined with proteinuria in 28 (1.1%) of them. Asymptomatic bacteriuria was detected in 23 (0.9%) of all studied adolescents; all the cases were females. Proteinuria was detected in 65 (2.6%) of all the studied adolescents; 45 (1.8%) individuals had <0.5 g/day and twenty (0.8%) individuals had 0.5-3 g/day. Asymptomatic urinary abnormalities were more common in males than females and adolescents from rural than urban areas (P <0.01) and (P <0.001), respectively. The present study found a high prevalence of asymptomatic urinary abnormalities among adolescents in our population.

  9. Filtration: An investment in IAQ

    SciTech Connect

    Burroughs, H.E.B.

    1997-08-01

    Air filtration is a forgotten component in the resiliency engineering equation. This under-utilized asset is becoming more understandable and user-friendly, bringing about giant strides in application technology in commercial buildings for IAQ resiliency. Filtration and air cleaning are highly developed and well-established technologies in industrial and specialized application areas. These include a variety of clean room applications as well as a wide array of highly sophisticated industrial needs for varying degrees and types of cleansed air sources. Application areas include pharmaceutical, health care, process control, and electronic protection, to name a few. Yet filtration generally remains an under-utilized technology in the field of indoor environmental quality in commercial buildings. Although source control is clearly the preferred technique for controlling air contaminants, air cleaning can provide a spectrum of valuable and cost-effective tactics to achieve and maintain an acceptable indoor environment.

  10. Wound modulation after filtration surgery.

    PubMed

    Seibold, Leonard K; Sherwood, Mark B; Kahook, Malik Y

    2012-11-01

    Filtration surgery is the standard invasive procedure for the management of intraocular pressure in advanced glaucoma. The key to a successful outcome is to modulate the normal wound healing cascade that leads to closure of the newly created aqueous outflow pathway. Antifibrotic agents such as mitomycin C and 5-fluorouracil have been increasingly used to modulate the wound healing process and increase surgical success. Although these agents have proven efficacy, they also increase the risk of complications. Efforts have centered on the identification of novel agents and techniques that can influence wound modulation without these complications. We detail new agents and methods under investigation to control wound healing after filtration surgery. PMID:23068975

  11. Filtrates and Residues: Gel Filtration--An Innovative Separation Technique.

    ERIC Educational Resources Information Center

    Blumenfeld, Fred; Gardner, James

    1985-01-01

    Gel filtration is a form of liquid chromatography that separates molecules primarily on the basis of their size. Advantages of using this technique, theoretical aspects, and experiments (including procedures used) are discussed. Several questions for students to answer (with answers) are also provided. (JN)

  12. Integrated pore blockage-cake filtration model for crossflow filtration

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Russell, Renee L.; Shimskey, Rick W.; Smith, Harry D.; Peterson, Reid A.

    2011-07-01

    Crossflow filtration is to be a key process in the treatment and disposal of approximately 60,000 metric tons of high-level radioactive waste stored at the Hanford Site in Richland, Washington. Pacific Northwest National Laboratory is assessing filter performance with waste simulant materials that mimic the chemical and physical properties of Hanford tank waste. Prior simulant studies indicated that waste filtration performance may be limited by pore and cake fouling. To limit the shutdown of waste treatment operations, the pre-treatment facility plans to recover filter flux losses from cake formation and filter fouling by frequently backpulsing the filter elements. The objective of the current paper is to develop a simple model of flux decline resulting from cake and pore fouling and potential flux recovery through backpulsing of the filters for Hanford waste filtration operations. To this end, a model capable of characterizing the decline in waste-simulant filter flux as a function of both irreversible pore blockage and reversible cake formation is proposed. This model is used to characterize the filtration behavior of Hanford waste simulants in both continuous and backpulsed operations. The model is then used to infer the optimal backpulse frequency under specific operating conditions.

  13. Health benefits of particle filtration

    EPA Science Inventory

    This product was developed under an interagency agreement between the U.S. EPA and the U.S. Department of Energy - Lawrence Berkeley National Laboratory (LBNL). The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews o...

  14. ITP Filtrate Benzene Removal Alternatives

    SciTech Connect

    Dworjanyn, L.O.

    1993-05-21

    Existing ITP filtrate hold tanks may provide sufficient capacity and residence time to strip dissolved benzene from the incoming filtrate using nitrogen sparging in the bottom of the old tanks. This is based on equilibrium supported by late Wash test data using aged washed slurry. Theoretical considerations indicate that benzene stripping will be more difficult from the ITP unwashed high salt filtrates due to reduced mass transfer. Therefore experimental sparging data is needed to quantify the theoretical effects.Foaming limits which dictate allowable sparging rate will also have to be established. Sparging in the hold tanks will require installation of sintered metal spargers, and possibly stirrers and foam monitoring/disengagement equipment. The most critical sparging needs are at the start of the precipitation/concentration cycle, when the filtrate flux rate is the highest,and at the end of wash cycle where Henry`s equilibrium constant falls off,requiring more gas to sparge the dissolved benzene. With adequate recycle (for proper distribution) or sparging in the old tanks, the 30 inch column could be used for the complete ITP process. A courser packing would reduce back pressure while enabling benzene stripping. The Late Wash Tests indicate adequate benzene stripping even at reduced gas flow. This will require experimental verification under ITP conditions. Using the 30 in. column vs 18 in. during the wash cycle will enhance stripping without need for additional sparging provided the minimum flow requirements are met.

  15. Filtration combustion: Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  16. MICROBIOLOGICAL REMOVAL BY FILTRATION PROCESSES

    EPA Science Inventory

    Filtration ws originally used to remove contaminants that affect the appearance, odor, and taste of drinking water. Later it was demonstrated that bacteria in drinking water were causative agents of disease. Water treatment technology improved with the addition of disinfection, c...

  17. Improving IAQ Via Air Filtration.

    ERIC Educational Resources Information Center

    Monk, Brian

    1999-01-01

    Provides tips on using air filtration to control indoor air quality in educational facilities, including dedicated spaces with unique air quality conditions such as in libraries, museums and archival storage areas, kitchens and dining areas, and laboratories. The control of particulate contaminants, gaseous contaminants, and moisture buildup are…

  18. Podometrics as a Potential Clinical Tool for Glomerular Disease Management.

    PubMed

    Kikuchi, Masao; Wickman, Larysa; Hodgin, Jeffrey B; Wiggins, Roger C

    2015-05-01

    Chronic kidney disease culminating in end-stage kidney disease is a major public health problem costing in excess of $40 billion per year with high morbidity and mortality. Current tools for glomerular disease monitoring lack precision and contribute to poor outcome. The podocyte depletion hypothesis describes the major mechanisms underlying the progression of glomerular diseases, which are responsible for more than 80% of cases of end-stage kidney disease. The question arises of whether this new knowledge can be used to improve outcomes and reduce costs. Podocytes have unique characteristics that make them an attractive monitoring tool. Methodologies for estimating podocyte number, size, density, glomerular volume and other parameters in routine kidney biopsies, and the rate of podocyte detachment from glomeruli into urine (podometrics) now have been developed and validated. They potentially fill important gaps in the glomerular disease monitoring toolbox. The application of these tools to glomerular disease groups shows good correlation with outcome, although data validating their use for individual decision making is not yet available. Given the urgency of the clinical problem, we argue that the time has come to focus on testing these tools for application to individualized clinical decision making toward more effective progression prevention.

  19. Podometrics as a potential clinical tool for glomerular disease management

    PubMed Central

    Kikuchi, Masao; Wickman, Larysa; Hodgin, JB; Wiggins, Roger C.

    2015-01-01

    Chronic Kidney Disease culminating in End Stage Kidney Disease is a major public health problem costing in excess of $40 billion per year with high morbidity and mortality. Current tools for glomerular disease monitoring lack precision and contribute to poor outcome. The podocyte depletion hypothesis describes the major mechanisms underlying progression of glomerular diseases responsible for >80% of ESKD. The question arises whether this new knowledge can be used to improve outcomes and reduce costs. Podocytes have unique characteristics that make them an attractive monitoring tool. Methodologies for estimating podocyte number, size, density, glomerular volume and other parameters in routine kidney biopsies, and the rate of podocyte detachment from glomeruli into urine (“podometrics”), have now been developed and validated. They potentially fill important gaps in the glomerular disease monitoring toolbox. Application of these tools to glomerular disease groups demonstrates good correlation with outcome, although data validating their use for individual decision-making is not yet available. Given the urgency of the clinical problem we argue that the time has come to focus on testing these tools for application to individualized clinical decision-making towards more effective progression prevention. PMID:26215862

  20. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  1. What makes red cells dysmorphic in glomerular haematuria?

    PubMed

    Rath, B; Turner, C; Hartley, B; Chantler, C

    1992-09-01

    Although red cell morphology has been used to localise the site of haematuria in the urinary tract, the cause of red cell deformity is still speculative. We have conducted experiments in vitro using venous red cells which indicate that hypochromia depends mainly upon sodium concentration and occurs when this falls below 75 mmol/l. We simulated the passage of red cells through the renal tubule by sequentially treating them with fluids of composition similar to those in different tubular segments, and produced anisocytosis and hypochromia but not the typical "bizarre deformity"--the hallmark of glomerular haematuria. We conclude that dual injury is required to produce the "typical" dysmorphic red cells in glomerular haematuria. First, mechanical damage caused by passage of red blood cells through the glomerular basement membrane followed by a second, osmotic, injury sustained by red cells during passage through the hypotonic tubular segment. PMID:1457323

  2. Immunology of anti-glomerular basement membrane disease.

    PubMed

    Salama, Alan D; Pusey, Charles D

    2002-05-01

    Anti-glomerular basement membrane disease is a form of autoimmune glomerulonephritis often accompanied by lung haemorrhage. It is characterized by circulating and deposited antibodies that bind basement membrane components in the glomerulus and lung alveolus. Since early descriptions of the deposition of immunoglobulin on the glomerular basement membrane, work has focused on the binding properties of the autoantibodies, and this has led to the identification of the autoantigen as the non-collagenous region of the alpha 3 chain of type IV collagen. Despite being thought of as a prototypic antibody mediated autoimmune disease, it is becoming apparent that both humoral and cellular immune mechanisms act in concert to initiate and perpetuate disease. Recent data have shed light on the molecular pathogenesis of anti-glomerular basement membrane disease and provided a more complete framework on which to build our understanding of autoimmune renal disease. This should lead to novel approaches to immunotherapy for patients with glomerulonephritis. PMID:11981257

  3. Glomerular thrombi in renal allografts associated with cyclosporin treatment.

    PubMed Central

    Neild, G H; Reuben, R; Hartley, R B; Cameron, J S

    1985-01-01

    We have found glomerular capillary thrombi or afferent arteriolar thrombosis in eight renal biopsy specimens from seven renal allograft recipients. All patients were receiving cyclosporin and prednisolone. Biopsies were performed either routinely one and four weeks after transplantation or during periods of renal dysfunction. None of the patients whose biopsy material contained glomerular thrombi was considered, in retrospect, to have been undergoing rejection at the time of biopsy. Thrombi consisted of finely granular material partially obstructing glomerular capillaries. By light microscopy the staining characteristics of the thrombi were compatible with platelet-fibrin aggregates, and this was confirmed by immunoperoxidase examination. Such thrombi have not previously been seen in biopsy material from patients treated with prednisolone and azathioprine, except rarely associated with acute vascular injection. In none of these patients was there haematological evidence of the haemolytic uraemic syndrome as has been reported in bone marrow recipients treated with cyclosporin. Images PMID:3882763

  4. Differential diagnosis of glomerular disease: a systematic and inclusive approach

    PubMed Central

    Hebert, Lee A.; Parikh, Samir; Prosek, Jason; Nadasdy, Tibor; Rovin, Brad H.

    2013-01-01

    Background Glomerular disease is a complex and evolving topic. In evaluating a specific case it is not unusual for the clinician to ask: Am I missing something? Should I biopsy? When? Should I treat first, then biopsy? This work, which is both evidence based and experience based, is intended to address each of these concerns, and many other issues relevant to the differential diagnosis of glomerular disease. Summary The central approach is the use of diagnostic algorithms that are based on quantitative measures routinely obtained early in the course of the diagnostic evaluation. The algorithms are designed to be easy to navigate, systematic, and inclusive. Also provided is a detailed and prioritized list of recommended diagnostic testing, and the rationale for each test. Key message This work is intended to facilitate accurate diagnosis in the individual patient presenting with evidence of glomerular disease. PMID:24052039

  5. Increasing or stabilizing renal epoxyeicosatrienoic acid production attenuates abnormal renal function and hypertension in obese rats.

    PubMed

    Huang, Hui; Morisseau, Christophe; Wang, JingFeng; Yang, Tianxin; Falck, John R; Hammock, Bruce D; Wang, Mong-Heng

    2007-07-01

    Since epoxyeicosatrienoic acids (EETs) affect sodium reabsorption in renal tubules and dilate the renal vasculature, we have examined their effects on renal hemodynamics and sodium balance in male rats fed a high-fat (HF) diet by fenofibrate, a peroxisome proliferator-activated receptor-alpha (PPAR-alpha) agonist and an inducer of cytochrome P-450 (CYP) epoxygenases; by N-methanesulfonyl-6-(2-proparyloxyphenyl)hexanamide (MSPPOH), a selective EET biosynthesis inhibitor; and by 12-(3-adamantane-1-yl-ureido)dodecanoic acid (AUDA), a selective inhibitor of soluble epoxide hydrolase. In rats treated with fenofibrate (30 mg.kg(-1).day(-1) ig) or AUDA (50 mg/l in drinking water) for 2 wk, mean arterial pressure, renal vascular resistance, and glomerular filtration rate were lower but renal blood flow was higher than in vehicle-treated control rats. In addition, fenofibrate and AUDA decreased cumulative sodium balance in the HF rats. Treatment with MSPPOH (20 mg.kg(-1).day(-1) iv) + fenofibrate for 2 wk reversed renal hemodynamics and sodium balance to the levels in control HF rats. Moreover, fenofibrate caused a threefold increase in renal cortical CYP epoxygenase activity, whereas the fenofibrate-induced elevation of this activity was attenuated by MSPPOH. Western blot analysis showed that fenofibrate induced the expression of CYP epoxygenases in renal cortex and microvessels and that the induction effect of fenofibrate was blocked by MSPPOH. These results demonstrate that the fenofibrate-induced increase of CYP epoxygenase expression and the AUDA-induced stabilization of EET production in the kidneys cause renal vascular dilation and reduce sodium retention, contributing to the improvement of abnormal renal hemodynamics and hypertension in HF rats.

  6. Comparison of different normalization strategies for the analysis of glomerular microRNAs in IgA nephropathy

    PubMed Central

    Bockmeyer, Clemens L.; Säuberlich, Karen; Wittig, Juliane; Eßer, Marc; Roeder, Sebastian S.; Vester, Udo; Hoyer, Peter F.; Agustian, Putri A.; Zeuschner, Philip; Amann, Kerstin; Daniel, Christoph; Becker, Jan U.

    2016-01-01

    Small nucleolar RNAs (snoRNAs) have been used for normalization in glomerular microRNA (miRNA) quantification without confirmation of validity. Our aim was to identify glomerular reference miRNAs in IgA nephropathy. We compared miRNAs in human paraffin-embedded renal biopsies from patients with cellular-crescentic IgA-GN (n = 5; crescentic IgA-GN) and non-crescentic IgA-GN (n = 5; IgA-GN) to mild interstitial nephritis without glomerular abnormalities (controls, n = 5). Laser-microdissected glomeruli were used for expression profiling of 762 miRNAs by low-density TaqMan arrays (cards A and B). The comparison of different normalization methods (GeNormPlus, NormFinder, global mean and snoRNAs) in crescentic IgA-GN, IgA-GN and controls yielded similar results. However, levels of significance and the range of relative expression differed. In median, two normalization methods demonstrated similar results. GeNormPlus and NormFinder gave different top ranked reference miRNAs. Stability ranking for snoRNAs varied between cards A and B. In conclusion, we suggest the geometric mean of the most stable reference miRNAs found in GeNormPlus (miR-26b-5p), NormFinder (miR-28-5p) and snoRNAs (RNU44) as reference. It should be considered that significant differences could be missed using one particular normalization method. As a starting point for glomerular miRNA studies in IgA nephropathy we provide a library of miRNAs. PMID:27553688

  7. Comparison of different normalization strategies for the analysis of glomerular microRNAs in IgA nephropathy.

    PubMed

    Bockmeyer, Clemens L; Säuberlich, Karen; Wittig, Juliane; Eßer, Marc; Roeder, Sebastian S; Vester, Udo; Hoyer, Peter F; Agustian, Putri A; Zeuschner, Philip; Amann, Kerstin; Daniel, Christoph; Becker, Jan U

    2016-08-24

    Small nucleolar RNAs (snoRNAs) have been used for normalization in glomerular microRNA (miRNA) quantification without confirmation of validity. Our aim was to identify glomerular reference miRNAs in IgA nephropathy. We compared miRNAs in human paraffin-embedded renal biopsies from patients with cellular-crescentic IgA-GN (n = 5; crescentic IgA-GN) and non-crescentic IgA-GN (n = 5; IgA-GN) to mild interstitial nephritis without glomerular abnormalities (controls, n = 5). Laser-microdissected glomeruli were used for expression profiling of 762 miRNAs by low-density TaqMan arrays (cards A and B). The comparison of different normalization methods (GeNormPlus, NormFinder, global mean and snoRNAs) in crescentic IgA-GN, IgA-GN and controls yielded similar results. However, levels of significance and the range of relative expression differed. In median, two normalization methods demonstrated similar results. GeNormPlus and NormFinder gave different top ranked reference miRNAs. Stability ranking for snoRNAs varied between cards A and B. In conclusion, we suggest the geometric mean of the most stable reference miRNAs found in GeNormPlus (miR-26b-5p), NormFinder (miR-28-5p) and snoRNAs (RNU44) as reference. It should be considered that significant differences could be missed using one particular normalization method. As a starting point for glomerular miRNA studies in IgA nephropathy we provide a library of miRNAs.

  8. Validation of sterilizing grade filtration.

    PubMed

    Jornitz, M W; Meltzer, T H

    2003-01-01

    Validation consideration of sterilizing grade filters, namely 0.2 micron, changed when FDA voiced concerns about the validity of Bacterial Challenge tests performed in the past. Such validation exercises are nowadays considered to be filter qualification. Filter validation requires more thorough analysis, especially Bacterial Challenge testing with the actual drug product under process conditions. To do so, viability testing is a necessity to determine the Bacterial Challenge test methodology. Additionally to these two compulsory tests, other evaluations like extractable, adsorption and chemical compatibility tests should be considered. PDA Technical Report # 26, Sterilizing Filtration of Liquids, describes all parameters and aspects required for the comprehensive validation of filters. The report is a most helpful tool for validation of liquid filters used in the biopharmaceutical industry. It sets the cornerstones of validation requirements and other filtration considerations. PMID:14620854

  9. High Temperature Particle Filtration Technology

    SciTech Connect

    Besmann, T.M.

    2001-11-13

    High temperature filtration can serve to improve the economic, environmental, and energy performance of chemical processes. This project was designed to evaluate the stability of filtration materials in the environments of the production of dimethyldichlorosilane (DDS). In cooperation with Dow Corning, chemical environments for the fluidized bed reactor where silicon is converted to DDS and the incinerator where vents are cornbusted were characterized. At Oak Ridge National Laboratory (ORNL) an exposure system was developed that could simulate these two environments. Filter samples obtained from third parties were exposed to the environments for periods up to 1000 hours. Mechanical properties before and after exposure were determined by burst-testing rings of filter material. The results indicated that several types of filter materials would likely perform well in the fluid bed environment, and two materials would be good candidates for the incinerator environment.

  10. Centrifugal membrane filtration -- Task 9

    SciTech Connect

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  11. Hot gas filtration technical issues

    SciTech Connect

    Pontius, D.H.

    1995-11-01

    The primary objective of this research has been to provide an understanding of factors pertinent to the development of an effective filtration system for removing particles from high-temperature, high-pressure gas streams in advanced power generation systems under development by the Department of Energy. Information used to define the filtration system issues was compiled from the Morgantown Energy Technology Center (METC) Contractors Conferences, specific tasks assigned to Southern Research Institute, meetings with METC personnel and contractors, and other conferences and workshops organized by METC. Initial research and pilot scale installations have shown that there are some potential problem areas. Thick ash deposits have formed, bridging from passive surfaces to the filter material and between filter candles. A great number of ceramic filters have broken in various experimental and demonstration devices, especially during long-term testing. This paper reviews particulate characteristics (effects on filtration processes, conventional fly ash, gasifier char, PFBC ash, and detailed studies of PFBC ash) and ceramic filter materials (general issues, thermal stress, clay-bonded SiC filter materials, and monolithic ceramic materials).

  12. Cake Filtration in Viscoelastic Polymer Solutions

    NASA Astrophysics Data System (ADS)

    Surý, Alexander; Machač, Ivan

    2009-07-01

    In this contribution, the filtration equations for a cake filtration in viscoelastic fluids are presented. They are based on a capillary hybrid model for the flow of a power law fluid. In order to express the elastic pressure drop excess in the flow of viscoelastic filtrate through the filter cake and filter screen, modified Deborah number correction functions are included into these equations. Their validity was examined experimentally. Filtration experiments with suspensions of hardened polystyrene particles (Krasten) in viscoelastic aqueous solutions of polyacryl amides (0.4% and 0.6%wt. Kerafloc) were carried out at a constant pressure on a cylindrical filtration unit using filter screens of different resistance.

  13. Glomerular hyperfiltration and metabolic syndrome: results from the FIrenze-BAgno A Ripoli (FIBAR) Study.

    PubMed

    Monami, Matteo; Pala, Laura; Bardini, Gianluca; Francesconi, Paolo; Cresci, Barbara; Marchionni, Niccolò; Rotella, Carlo Maria; Mannucci, Edoardo

    2009-09-01

    Metabolic syndrome (MS) has been associated with microalbuminuria and kidney disease. In the present cohort study, different methods for the estimation of glomerular filtration rate (GFR) on the basis of serum creatinine were compared with respect to their association with MS and their predictive value for incident diabetes mellitus. The present analysis was performed on the cohort of subjects enrolled in the FIBAR study, a screening program for diabetes. GFR was estimated (eGFR) using three different methods: Cockroft-Gault (CG) formula, using actual body weight (CAW), CG formula using ideal body weight (CIW), and Modification of Diet in Renal Disease formula (M). The study was performed on 2,694 nondiabetic subjects, without history of renal insufficiency or serum creatinine at baseline >1.5 mg/dl. Mean follow-up was 27.8 +/- 11.5 months. Elevated eGFR, estimated with different methods, was associated with increased prevalence of most components of MS; however, an association between elevated clearance and MS was observed only when using CAW, which overestimates filtration in obese subjects. During follow-up, 40 new cases of diabetes were recorded (0.5/100 patient*years). After adjusting for age and sex, the HR (with 95% confidence intervals) for diabetes for patients in the highest quintile of eGFR was 1.14 [0.44-2.99], 0.89 [0.31-2.51], and 1.01 [0.42-2.41] for formula CAW, CIW, and M, respectively (all p > 0.7). Elevated eGFR, estimated through methods which do not produce a systematic overestimate in obese subjects, is not associated with the diagnosis of MS, and does not predict diabetes.

  14. Relation Between Filtration and Soil Consolidation Theories

    NASA Astrophysics Data System (ADS)

    Strzelecki, Tomasz; Strzelecki, Michał

    2015-03-01

    This paper presents a different, than commonly used, form of equations describing the filtration of a viscous compressible fluid through a porous medium in isothermal conditions. This mathematical model is compared with the liquid flow equations used in the theory of consolidation. It is shown that the current commonly used filtration model representation significantly differs from the filtration process representation in Biot's and Terzaghi's soil consolidation models, which has a bearing on the use of the methods of determining the filtration coefficient on the basis of oedometer test results. The present analysis of the filtration theory equations should help interpret effective parameters of the non-steady filtration model. Moreover, equations for the flow of a gas through a porous medium and an interpretation of the filtration model effective parameters in this case are presented.

  15. Renin lineage cells repopulate the glomerular mesangium after injury.

    PubMed

    Starke, Charlotte; Betz, Hannah; Hickmann, Linda; Lachmann, Peter; Neubauer, Björn; Kopp, Jeffrey B; Sequeira-Lopez, Maria Luisa S; Gomez, R Ariel; Hohenstein, Bernd; Todorov, Vladimir T; Hugo, Christian P M

    2015-01-01

    Mesangial cell injury has a major role in many CKDs. Because renin-positive precursor cells give rise to mesangial cells during nephrogenesis, this study tested the hypothesis that the same phenomenon contributes to glomerular regeneration after murine experimental mesangial injury. Mesangiolysis was induced by administration of an anti-mesangial cell serum in combination with LPS. In enhanced green fluorescent protein-reporter mice with constitutively labeled renin lineage cells, the size of the enhanced green fluorescent protein-positive area in the glomerular tufts increased after mesangial injury. Furthermore, we generated a novel Tet-on inducible triple-transgenic LacZ reporter line that allowed selective labeling of renin cells along renal afferent arterioles of adult mice. Although no intraglomerular LacZ expression was detected in healthy mice, about two-thirds of the glomerular tufts became LacZ positive during the regenerative phase after severe mesangial injury. Intraglomerular renin descendant LacZ-expressing cells colocalized with mesangial cell markers α8-integrin and PDGF receptor-β but not with endothelial, podocyte, or parietal epithelial cell markers. In contrast with LacZ-positive cells in the afferent arterioles, LacZ-positive cells in the glomerular tuft did not express renin. These data demonstrate that extraglomerular renin lineage cells represent a major source of repopulating cells for reconstitution of the intraglomerular mesangium after injury.

  16. Renin Lineage Cells Repopulate the Glomerular Mesangium after Injury

    PubMed Central

    Starke, Charlotte; Betz, Hannah; Hickmann, Linda; Lachmann, Peter; Neubauer, Björn; Kopp, Jeffrey B.; Sequeira-Lopez, Maria Luisa S.; Gomez, R. Ariel; Hohenstein, Bernd; Hugo, Christian P.M.

    2015-01-01

    Mesangial cell injury has a major role in many CKDs. Because renin-positive precursor cells give rise to mesangial cells during nephrogenesis, this study tested the hypothesis that the same phenomenon contributes to glomerular regeneration after murine experimental mesangial injury. Mesangiolysis was induced by administration of an anti-mesangial cell serum in combination with LPS. In enhanced green fluorescent protein–reporter mice with constitutively labeled renin lineage cells, the size of the enhanced green fluorescent protein–positive area in the glomerular tufts increased after mesangial injury. Furthermore, we generated a novel Tet-on inducible triple-transgenic LacZ reporter line that allowed selective labeling of renin cells along renal afferent arterioles of adult mice. Although no intraglomerular LacZ expression was detected in healthy mice, about two-thirds of the glomerular tufts became LacZ positive during the regenerative phase after severe mesangial injury. Intraglomerular renin descendant LacZ-expressing cells colocalized with mesangial cell markers α8-integrin and PDGF receptor-β but not with endothelial, podocyte, or parietal epithelial cell markers. In contrast with LacZ-positive cells in the afferent arterioles, LacZ-positive cells in the glomerular tuft did not express renin. These data demonstrate that extraglomerular renin lineage cells represent a major source of repopulating cells for reconstitution of the intraglomerular mesangium after injury. PMID:24904091

  17. Nephron filtration rate and proximal tubular fluid reabsorption in the Akita mouse model of type I diabetes mellitus

    PubMed Central

    Schnermann, Jurgen

    2013-01-01

    An increase of glomerular filtration rate (hyperfiltration) is an early functional change associated with type I or type II diabetes mellitus in patients and animal models. The causes underlying glomerular hyperfiltration are not entirely clear. There is evidence from studies in the streptozotocin model of diabetes in rats that an increase of proximal tubular reabsorption results in the withdrawal of a vasoconstrictor input exerted by the tubuloglomerular feedback (TGF) mechanism. In the present study, we have used micropuncture to assess single nephron function in wild type (WT) mice and in two strains of type I diabetic Ins2+/- mice in either a C57Bl/6 (Akita) or an A1AR-/- background (Akita/A1AR-/-) in which TGF is non-functional. Kidney glomerular filtration rate (GFR) of anesthetized mice was increased by 25% in Akita mice and by 52% in Akita/A1AR-/-, but did not differ between genotypes when corrected for kidney weight. Single nephron GFR (SNGFR) measured by end-proximal fluid collections averaged 11.8 ± 1 nl/min (n=17), 13.05 ± 1.1 nl/min (n=23; p=0.27), and 15.4 ± 0.84 nl/min (n=26; p=0.009 compared to WT; p=0.09 compared to Akita) in WT, Akita, and Akita/A1AR-/- mice respectively. Proximal tubular fluid reabsorption was not different between WT and diabetic mice and correlated with SNGFR in all genotypes. We conclude that glomerular hyperfiltration is a primary event in the Akita model of type I diabetes, perhaps driven by an increased filtering surface area, and that it is ameliorated by TGF to the extent that this regulatory system is functional. PMID:24358878

  18. Contribution of glomerular morphometry to the diagnosis of pediatric nephropathies.

    PubMed

    Marini, Mariana Barreto; Rocha, Laura Penna; Machado, Juliana Reis; Ramalho, Fernando Silva; Dos Reis, Marlene Antônia; Corrêa, Rosana Rosa Miranda

    2016-05-01

    Only a few studies describe histopathological changes in renal biopsies performed in pediatric patients. This study was conducted to identify an association between morphometric data in renal biopsies and renal function of these patients. Fifty-nine individuals with ages between 2 and 18 years old were selected, who were divided into six groups consisting of frequent nephropathies in children and adolescents and one control group. Proteinuria, urea, and creatinine values of the patients were recorded. Interactive image analysis software Leica QWin[®]was used for morpho- metric analysis of Bowman's capsule, glomerular capillary tuft, and Bowman's space area. The mean glomerular tuft area was higher in the membranous glomerulopathy group than in the podo- cytopathy group (57,101 ± 25,094 vs. 27,420 c ± 6279 µm(2); P <0.05). The median of Bowman's space area was higher in the control group than in the podocytopathy group and in the thin basement membrane/Alport syndrome group [12,210 (7676-26,945) vs. 5801 (3031-7852) µm(2); P <0.01 and 12210 (7676-26,945) vs. 4183 (3797-7992) µm(2); P <0.01, respectively]. There was a positive and significant correlation between Bowman's capsule area and the levels of proteinuria, creatinine, and urea of the patients, as well as between the glomerular tuft area and the levels of proteinuria, creatinine, and urea in the patients, regardless of their nephropathy. Glomerular morphometry may contribute to the diagnosis of some glomerulopathies and the association between glomerular morphometric parameters, and laboratory data may promote a better understanding of the prognosis of these patients. PMID:27215240

  19. Interaction between alpha 2-adrenergic and angiotensin II systems in the control of glomerular hemodynamics as assessed by renal micropuncture in the rat

    NASA Technical Reports Server (NTRS)

    Thomson, S. C.; Gabbai, F. B.; Tucker, B. J.; Blantz, R. C.

    1992-01-01

    The hypothesis that renal alpha 2 adrenoceptors influence nephron filtration rate (SNGFR) via interaction with angiotensin II (AII) was tested by renal micropuncture. The physical determinants of SNGFR were assessed in adult male Munich Wistar rats 5-7 d after ipsilateral surgical renal denervation (DNX). DNX was performed to isolate inhibitory central and presynaptic alpha 2 adrenoceptors from end-organ receptors within the kidney. Two experimental protocols were employed: one to test whether prior AII receptor blockade with saralasin would alter the glomerular hemodynamic response to alpha 2 adrenoceptor stimulation with the selective agonist B-HT 933 under euvolemic conditions, and the other to test whether B-HT 933 would alter the response to exogenous AII under conditions of plasma volume expansion. In euvolemic rats, B-HT 933 caused SNGFR to decline as the result of a decrease in glomerular ultrafiltration coefficient (LpA), an effect that was blocked by saralasin. After plasma volume expansion, B-HT 933 showed no primary effect on LpA but heightened the response of arterial blood pressure, glomerular transcapillary pressure gradient, and LpA to AII. The parallel results of these converse experiments suggest a complementary interaction between renal alpha 2-adrenergic and AII systems in the control of LpA.

  20. Water Filtration Using Plant Xylem

    PubMed Central

    Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2014-01-01

    Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

  1. Water filtration using plant xylem.

    PubMed

    Boutilier, Michael S H; Lee, Jongho; Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2014-01-01

    Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees--a readily available, inexpensive, biodegradable, and disposable material--can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm(3) of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings.

  2. Assessments of factors that affect glomerular filtration rate and indirect markers of renal function in dogs and cats.

    PubMed

    Miyagawa, Yuichi; Takemura, Naoyuki; Hirose, Hisashi

    2010-09-01

    Chronic kidney disease is one of the most common disorders in dogs and cats. The plasma urea nitrogen (P-UN) and creatinine (P-Cre) concentrations are not sufficiently sensitive for early diagnosis of renal dysfunction. Although urine and plasma clearance methods allow earlier detection of reductions in the GFR, it is difficult to estimate a mildly reduced GFR from the values obtained by these methods, as they are also affected by physiological factors, such as body weight (BW) and age. The present study is a retrospective survey designed to assess the factors that affect markers of kidney function and to revaluate the clinical utility of the markers, including P-UN, P-Cre and GFR determined by plasma iohexol clearance (PCio) in dogs and cats. The P-UN, P-Cre and PCio values in dogs and the P-Cre and PCio values in cats were significantly correlated with BW (P<0.001). PCio in smaller dogs (≤ 15.0 kg) was significantly and inversely correlated with age. In smaller dogs, increase of P-UN alone might warrant a suspicion of a decreased GFR, but in contrast, P-Cre may be inefficient for detecting renal dysfunction or determining the severity of CKD compared with that in larger dogs (≥ 15.1 kg). P-Cre in larger dogs correlated better with PCio than in smaller dogs, suggesting that P-Cre in larger dogs was a more sensitive marker of reduced GFR. PMID:20410678

  3. Assessing glomerular filtration rate (GFR) in elderly Chinese patients with chronic kidney disease (CKD): a comparison of various predictive equations.

    PubMed

    Xun, Liu; Cheng, Wang; Hua, Tang; Chenggang, Shi; Zhujiang, Chen; Zengchun, Ye; Tanqi, Lou

    2010-01-01

    The aim of this study was to evaluate the applicability of formulas based on serum creatinine (SC) levels in elderly Chinese patients with CKD. A total of 103 elderly CKD patients were investigated. The GFR was estimated with Cockcroft-Gault-equation, MDRD1-equation, abbreviated MDRD-equation, Jelliffe-1973-equation, Mawer-equation, Hull-equation, Jelliffe-1971-equation, SC-reciprocal-equation, Gate-equation and Bjornsson-equation. The accuracy of estimated GFR (eGFR) values was compared with the 99mTc-DTPA-GFR (standardized GFR=sGFR) in elderly CKD patients. Bland-Altman analysis demonstrated that Hull-equation, Cockcroft-Gault-equation and Bjornsson-equation were better than the other ones. However, the agreement limits of all the equations exceeded the prior acceptable tolerances defined as 60 ml/min/(1.73 m(2)). Linear regressions showed that the slopes of Jelliffe-1973-equation, Cockcroft-Gault-equation and Bjornsson-equation were closer to the identical line. The median of difference of MDRD1-equation, abbreviated MDRD-equation and Gate-equation were smaller. Accuracy of Jelliffe-1973-equation, Cockcroft-Gault-equation and Hull-equation were better than those of the other equations. But 30% accuracy of all the equations were less than 70%. When compared the bias as well as accuracy of eGFR with sGFR values in different stages of CKD, GFR estimated by MDRD1-equation, Hull-equation, Cockcroft-Gault-equation and Jelliffe-1973-equation showed good results. These results suggested that when SC was checked with enzymatic method, GFR-estimation equations may show great bias in elderly Chinese CKD patients. Further improved formulas are needed to evaluate renal function in elderly Chinese patients with CKD. PMID:19615764

  4. Clinical Commentary: How to Choose Blood Pressure Goals and Treatment: Influence of Estimated Glomerular Filtration Rate and Albuminuria

    PubMed Central

    Weir, Matthew R.

    2008-01-01

    Objective measures of cardiovascular disease are often lacking until patients develop symptoms associated with either coronary, cerebral or peripheral vascular disease. Estimating risk for cardiovascular disease is often based on classic Framingham Heart Study criteria, such as age, gender, blood pressure, cholesterol, glucose levels and family history. Moreover, there is a well described continuous relationship between blood pressure, cholesterol, and glucose and risk for cardiovascular events. Estimating GFR, using simple formulae, and screening quantitatively for albuminuria may provide an important opportunity for identifying patients at increased risk for cardiovascular events. These safe, simple and cost-effective measures of estimating cardiovascular disease risk can be used not only to estimate cardiovascular disease burden, but also to gauge the adequacy of response to cardiovascular risk-reducing therapies. PMID:18596856

  5. Podocyte Number in Children and Adults: Associations with Glomerular Size and Numbers of Other Glomerular Resident Cells.

    PubMed

    Puelles, Victor G; Douglas-Denton, Rebecca N; Cullen-McEwen, Luise A; Li, Jinhua; Hughson, Michael D; Hoy, Wendy E; Kerr, Peter G; Bertram, John F

    2015-09-01

    Increases in glomerular size occur with normal body growth and in many pathologic conditions. In this study, we determined associations between glomerular size and numbers of glomerular resident cells, with a particular focus on podocytes. Kidneys from 16 male Caucasian-Americans without overt renal disease, including 4 children (≤3 years old) to define baseline values of early life and 12 adults (≥18 years old), were collected at autopsy in Jackson, Mississippi. We used a combination of immunohistochemistry, confocal microscopy, and design-based stereology to estimate individual glomerular volume (IGV) and numbers of podocytes, nonepithelial cells (NECs; tuft cells other than podocytes), and parietal epithelial cells (PECs). Podocyte density was calculated. Data are reported as medians and interquartile ranges (IQRs). Glomeruli from children were small and contained 452 podocytes (IQR=335-502), 389 NECs (IQR=265-498), and 146 PECs (IQR=111-206). Adult glomeruli contained significantly more cells than glomeruli from children, including 558 podocytes (IQR=431-746; P<0.01), 1383 NECs (IQR=998-2042; P<0.001), and 367 PECs (IQR=309-673; P<0.001). However, large adult glomeruli showed markedly lower podocyte density (183 podocytes per 10(6) µm(3)) than small glomeruli from adults and children (932 podocytes per 10(6) µm(3); P<0.001). In conclusion, large adult glomeruli contained more podocytes than small glomeruli from children and adults, raising questions about the origin of these podocytes. The increased number of podocytes in large glomeruli does not match the increase in glomerular size observed in adults, resulting in relative podocyte depletion. This may render hypertrophic glomeruli susceptible to pathology.

  6. Pig manure treatment and purification by filtration.

    PubMed

    Makara, A; Kowalski, Z

    2015-09-15

    This study aimed to develop a new, complex pig manure treatment and filtration process. The final scheme, called the AMAK process, comprised the following successive steps: mineralization with mineral acids, alkalization with lime milk, superphosphate addition, a second alkalization, thermal treatment, and pressure filtration. The proposed method produced a filtrate with 95%, 80%, and 96% reductions in chemical oxygen demand, nitrogen content, and phosphorus content, respectively. An advantage of the proposed method was that it incorporated a crystalline phase into the solid organic part of the manure, which enabled high filtration rates (>1000 kg m(-2) h(-1)) and efficient separation. The process also eliminated odor emissions from the filtrate and sediment. The treated filtrate could be used to irrigate crops or it could be further treated in conventional biological wastewater treatment plants. The sediment could be used for producing mineral-organic fertilizer. The AMAK process is inexpensive, and it requires low investment costs. PMID:26197426

  7. Membrane filtration of food suspensions.

    PubMed Central

    Sharpe, A N; Peterkin, P I; Dudas, I

    1979-01-01

    Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before filtration had little effect on filterability. Brand of membrane filter, flow direction, pressure differential, age (microbiological quality) of the food, duration of the blending process, temperature, and concentration of food in the suspension had significant and often predictable effects. Preparation of suspensions by Stomacher (relative to rotary blender) addition of surfactant (particularly at elevated temperature) and prior incubation with proteases sometimes had dramatic effects of filterability. In contrast to popular opinion, foods can be membrane filtered in quantities pertinent to the maximums used in conventional plating procedures. Removal of growth inhibitors and food debris is possible by using membrane filters. Lowering of the limits of detection of microorganisms by concentration on membrane filters can be considered feasible for many foods. The data are particularly relevant to the use of hydrophobic grid-membrane filters (which are capable of enumerating up to 9 X 10(4) organisms per filter) in instrumented methods of food microbiological analysis. Images PMID:760637

  8. Nonwoven filtration mat production by electrospinning method

    NASA Astrophysics Data System (ADS)

    Lackowski, M.; Krupa, A.; Jaworek, A.

    2011-06-01

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  9. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  10. Coexistent Wegener's granulomatosis and anti-glomerular basement membrane disease.

    PubMed

    Wahls, T L; Bonsib, S M; Schuster, V L

    1987-02-01

    Wegener's granulomatosis and Goodpasture's syndrome represent two major causes of a pulmonary-renal syndrome. We describe the clinical course and morphologic features of a patient in whom pulmonary manifestations of Wegener's granulomatosis developed and were followed six months later by anti-glomerular basement membrane disease. Although we regard this as a unique and probably fortuitous association, a genetic predisposition or a secondary form of anti-GBM disease cannot be excluded. PMID:3542802

  11. Renal biopsy and pathologic evaluation of glomerular disease.

    PubMed

    Lees, George E; Cianciolo, Rachel E; Clubb, Fred J

    2011-08-01

    Presence of suspected primary glomerular disease is the most common and compelling reason to consider renal biopsy. Pathologic findings in samples from animals with nephritic or nephrotic glomerulopathies, as well as from animals with persistent subclinical glomerular proteinuria that is not associated with advanced chronic kidney disease, frequently guide treatment decisions and inform prognosis when suitable specimens are obtained and examined appropriately. Ultrasound-guided needle biopsy techniques generally are satisfactory; however, other methods of locating or approaching the kidney, such as manual palpation (e.g., in cats), laparoscopy, or open surgery, also can be used. Visual assessment of the tissue content of needle biopsy samples to verify that they are renal cortex (i.e., contain glomeruli) as they are obtained is a key step that minimizes the submission of uninformative samples for examination. Adequate planning for a renal biopsy also requires prior procurement of the fixatives and preservatives needed to process and submit samples that will be suitable for electron microscopic examination and immunostaining, as well as for light microscopic evaluation. Finally, to be optimally informative, renal biopsy specimens must be processed by laboratories that routinely perform the required specialized examinations and then be evaluated by experienced veterinary nephropathologists. The pathologic findings must be carefully integrated with one another and with information derived from the clinical investigation of the patient's illness to formulate the correct diagnosis and most informative guidance for therapeutic management of the animal's glomerular disease. PMID:21782145

  12. Involvement of glomerular SREBP-1c in diabetic nephropathy

    SciTech Connect

    Ishigaki, Naomi; Yamamoto, Takashi; Shimizu, Yoshio; Kobayashi, Kazuto; Yatoh, Shigeru; Sone, Hirohito; Takahashi, Akimitsu; Suzuki, Hiroaki; Yamagata, Kunihiro; Yamada, Nobuhiro; Shimano, Hitoshi

    2007-12-21

    The role of glomerular SREBP-1c in diabetic nephropathy was investigated. PEPCK-promoter transgenic mice overexpressing nuclear SREBP-1c exhibited enhancement of proteinuria with mesangial proliferation and matrix accumulation, mimicking diabetic nephropathy, despite the absence of hyperglycemia or hyperlipidemia. Isolated transgenic glomeruli had higher expression of TGF{beta}-1, fibronectin, and SPARC in the absence of marked lipid accumulation. Gene expression of P47phox, p67phox, and PU.1 were also activated, accompanying increased 8-OHdG in urine and kidney, demonstrating that glomerular SREBP-1c could directly cause oxidative stress through induced NADPH oxidase. Similar changes were observed in STZ-treated diabetic mice with activation of endogenous SREBP-1c. Finally, diabetic proteinuria and oxidative stress were ameliorated in SREBP-1-null mice. Adenoviral overexpression of active and dominant-negative SREBP-1c caused consistent reciprocal changes in expression of both profibrotic and oxidative stress genes in MES13 mesangial cells. These data suggest that activation of glomerular SREBP-1c could contribute to emergence and/or progression of diabetic nephropathy.

  13. Ocular abnormalities in thin basement membrane disease

    PubMed Central

    Colville, D.; Savige, J.; Branley, P.; Wilson, D.

    1997-01-01

    AIM/BACKGROUND—Alport syndrome is an X linked disease that results in renal failure, deafness, and ocular abnormalities including a dot and fleck retinopathy and anterior lenticonus. The ultrastructural appearance of the glomerular basement membrane in thin basement membrane disease (TBMD) resembles that seen in some patients with Alport syndrome, and in some cases this disease is inherited too. The aim of this study was to determine whether patients with TBMD have any ocular abnormalities.
METHODS—The eyes of 17 unrelated individuals with TBMD were studied by slit-lamp, including biomicroscopic fundus examination with a 78 D lens, by direct ophthalmoscopy, and by fundal photographs. The findings were compared with those in patients with IgA glomerulonephritis or Alport syndrome, and in normals.
RESULTS—No patient with TBMD had a dot and fleck retinopathy or anterior lenticonus. A corneal dystrophy (n = 2) or pigmentation (n = 1), and retinal pigment epithelial clumping and maculopathy (n = 1) were noted. Corneal, lens, and retinal dots were found in five (29%), three (18%), and 16 (94%) patients, respectively, but these were also demonstrated in individuals with other renal diseases and in normal individuals.
CONCLUSIONS—The dot and fleck retinopathy and anterior lenticonus typical of Alport syndrome do not occur in TBMD. The protein abnormality and genetic defect in TBMD are not known, but the lack of ocular lesions suggests that the abnormal protein in this disease is more sparsely distributed or less important in the basement membranes of the eye than of the kidney. Alternatively, the protein may be less affected by the mutations responsible for TBMD.

 PMID:9227202

  14. ANF inhibits vasopressin-induced Ca/sup 2 +/ mobilization and contraction in glomerular mesangial cells

    SciTech Connect

    Meyer-Lehnert, H.; Tsai, P.; Caramelo, C.; Schrier, R.W.

    1988-10-01

    It has been suggested that atrial natriuretic factor (ANF) may increase glomerular filtration rate (GFR) via alteration of the glomerular ultrafiltration area, which is at least in part regulated by the contractile state of mesangial cells. The present study therefore investigated the effect of ANF (atriopeptin III) on arginine vasopressin (AVP)-induced Ca2+ mobilization and contraction in cultured rat mesangial cells. AVP (10(-8) M) increased intracellular Ca2+ (( Ca2+)i) as measured by the quin2 method (142.1 +/- 3.7 vs. 297.9 +/- 8.9 nM, P less than 0.001). This effect, however, was diminished by 10(-8) M ANF (297.9 +/- 8.9 vs. 233.1 +/- 9.3 nM, P less than 0.0025). ANF alone did not affect basal (Ca2+)i. AVP-stimulated 45Ca2+ efflux (cpm.mg prot-1.30 s-1) from mesangial cells within 30 s (1,432 +/- 70 basal vs. 2,751 +/- 287 AVP at 30 s, P less than 0.001). This effect of AVP on 45Ca2+ efflux was also inhibited by ANF (1,403 +/- 62 basal vs. 1,584 +/- 87 AVP and ANF, NS); ANF alone had no effect on spontaneous 45Ca2+ efflux. Furthermore, ANF inhibited AVP-induced 45Ca2+ uptake, which is purportedly one of the major determinants of the sustained phase of cell contraction. Cell contraction was assessed by digital imaging analysis. AVP (10(-7) M) caused contraction of 33.8 +/- 2.0% of the cells, but the contractile response decreased to 20.7 +/- 2.3% in the presence of 10(-9) M ANF and was virtually abolished in the presence of 10(-8) M ANF. Guanosine 3',5'-cyclic monophosphate (cGMP) has been proposed as the second messenger for ANF. ANF (10(-7) M) stimulated cGMP production significantly (0.54 +/- 0.12 vs. 22.30 +/- 5.91 pmol.mg prot-1.10 min-1, P less than 0.01), but it had no effect on cGMP at concentrations of 10(-8) M and below. 8-Bromo-cGMP (8-BrcGMP) attenuated the stimulatory effect of AVP on (Ca2+)i, 45Ca2+ efflux, and 45Ca2+ uptake.

  15. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system that uses a surface water source or a ground water source under the direct influence of surface...

  16. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system that uses a surface water source or a ground water source under the direct influence of surface...

  17. Effect of puromycin aminonucleoside on HSPG core protein content of glomerular epithelial cells

    SciTech Connect

    Kasinath, B.S.; Singh, A.K.; Kanwar, Y.S.; Lewis, E.J. )

    1988-10-01

    It has been suggested that the glomerular basement membrane heparan sulfate proteoglycan (HSPG) is an important determinant of the glomerular permselectivity barrier. Derangements in the content of basement membrane heparan sulfate have been implicated in alterations in glomerular permselectivity seen in many glomerular diseases such as aminonucleoside nephrosis. The cellular origin and metabolism of the glomerular basement membrane HSPG have not been studied in detail. The authors have detected the expression of the proteoglycan by cloned glomerular visceral epithelial cells of the rat by employing a specific antibody against the core protein of HSPG isolated from the rat glomerular basement membrane. These findings suggest that in the rat in vivo glomerular visceral epithelial cells are one source of heparan sulfate present in the glomerular basement membrane. The effect of puromycin aminonucleoside (PAN) on the HSPG core protein content of the cloned glomerular epithelial cells was studied. By a quantitative immunoperoxidase method, the aminonucleoside caused a 28% reduction in the core protein content of the epithelial cells following 72 h of incubation. However, the content of Heymann nephritis-related antigen, Fx1A was unchanged. Studies employing ({sup 3}H)leucine incorporation showed that PAN was a weak inhibitor of de novo protein synthesis at 24 h of incubation, with complete recovery at 48 and 72 h. These data suggest that PAN effect on heparan sulfate core protein cannot be attributed to generalized inhibition of protein synthesis. The precise mechanism underlying the aminonucleoside effect on heparan sulfate core protein remains to be elucidated.

  18. Tertiary filtration in small wastewater treatment plants.

    PubMed

    Naddeo, V; Belgiorno, V

    2007-01-01

    Tertiary filtration can be proposed in small wastewater treatment plants with impact on protected water bodies. Rotating disk filters may be adopted, in respect to conventional sand filters, when low availability of space and low investment costs are the prevailing conditions. The overall objective of this research was to evaluate the filtration efficiency of rotating disk filters; to compare effectiveness with traditional sand filters; to analyse thoroughly the importance of particle size distribution in wastewater tertiary filtration. In the experimental activity, conventional wastewater quality parameters were investigated and particle size distribution (PSD) was characterized to discuss the filter effectiveness. The effect of design and operation parameters of tertiary filters were discussed related to particle removal curves derived from particles counts. Analysis of particle size distribution can be very useful to help comprehension of filtration processes, design of filtration treatments and to decide the best measures to improve filter performance.

  19. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... The appearance of normal teeth varies, especially the molars. ... conditions. Specific diseases can affect tooth shape, tooth ...

  20. Rutin Prevents High Glucose-Induced Renal Glomerular Endothelial Hyperpermeability by Inhibiting the ROS/Rhoa/ROCK Signaling Pathway.

    PubMed

    Wang, Xiaoming; Zhao, Xiaohong; Feng, Ting; Jin, Gang; Li, Zhenjiang

    2016-09-01

    Diabetic nephropathy is a progressive kidney disease caused by damage to the capillaries in the glomeruli. Endothelial dysfunction is an early sign of diabetic cardiovascular disease and may contribute to progressive diabetic nephropathy. Hyperglycemia-induced endothelial hyperpermeability is crucial to diabetic nephropathy. Rutin has beneficial effects on diabetic nephropathy, but the exact mechanisms of its protective effect remain elusive. The aim of this study was to assess the role of pretreatment with rutin in an in vitro model of hyperglycemia-induced barrier dysfunction in human renal glomerular endothelial cells. Human renal glomerular endothelial cells were exposed to rutin and/or hyperglycemia for 24 h. Hyperglycemia increased permeability and decreased the junction protein occludin in the cell-cell junction area and the total expression in human renal glomerular endothelial cells, whereas rutin treatment significantly corrected these abnormalities. Furthermore, hyperglycemia-induced activation of RhoA/ROCK was reversed by treatment with rutin or the knockdown of ROCK2. Interestingly, rutin prevented hyperglycemia-induced hyperpermeability, and dysfunction of the tight junction, a high level of reactive oxygen species, and activation of RhoA/ROCK were significantly abolished with the knockdown of Nrf2. In conclusion, rutin significantly prevented hyperglycemia-disrupted renal endothelial barrier function by inhibiting the RhoA/ROCK signaling pathway through decreasing reactive oxygen species, which was mediated by the activation of Nrf2. Our results may explain, at least in part, some beneficial effects of rutin that may be applicable to the treatment of vascular disorders in diabetic nephropathy. PMID:27552253

  1. 10. OBLIQUE DETAIL VIEW OF PUMP NO. 1 IN FILTRATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. OBLIQUE DETAIL VIEW OF PUMP NO. 1 IN FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHEAST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  2. 12. View west of access bridge to top of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View west of access bridge to top of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  3. 14. View of damage to southeast corner of filtration building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. View of damage to southeast corner of filtration building. Note construction of concrete over brick. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  4. 32. Piping under central corridor of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  5. 8. Detail view of southwest corner of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Detail view of southwest corner of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  6. 13. View of west entrance to central corridor of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View of west entrance to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  7. 7. View east of southeast corner of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View east of southeast corner of filtration bed building. Laboratory building is at center left of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  8. 4. View south of rear of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View south of rear of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  9. 31. Piping under central corridor of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  10. 11. View of east entry to central corridor of filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View of east entry to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  11. 1. Perspective view southwest of filtration bed with earth mounded ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Perspective view southwest of filtration bed with earth mounded over facility. Armory Street appears in the foreground. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  12. Zea mays L. extracts modify glomerular function and potassium urinary excretion in conscious rats.

    PubMed

    Velazquez, D V O; Xavier, H S; Batista, J E M; de Castro-Chaves, C

    2005-05-01

    reabsorptions--I and II--increased (96.5 +/- 1.5, n = 12, to 97.8 +/- 0.9%; n = 13; p<0.01; and 8.2 +/- 3.5, n = 12, to 12.2 +/- 3.4%, n = 13, p<0.01, respectively). To summarize, in water-loaded conscious rats (2.5 ml/100 body wt.), corn silk aqueous extract is diuretic at a dose of 500 mg/kg body wt. and kaliuretic at doses of 350 and 500 mg/kg body wt. In water-loaded conscious rats (5.0 ml/100 g body wt.), corn silk aqueous extract is kaliuretic at a dose of 500 mg/kg body wt., but glomerular filtration and filtered load decrease without affecting proximal tubular function, Na+, or uric acid excretion.

  13. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  14. Morphological abnormalities among lampreys

    USGS Publications Warehouse

    Manion, Patrick J.

    1967-01-01

    The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the normal tail. The point of origin varied; the extra tails occurred on dorsal, ventral, or lateral surfaces. Some of the extra tails were misshaped and curled, but others were normal in shape and pigment pattern. Other abnormalities in larval sea lampreys were malformed or twisted tails and bodies. The cause of the structural abnormalities is unknown. The presence of extra caudal fins could be genetically controlled, or be due to partial amputation or injury followed by abnormal regeneration. Few if any lampreys with structural abnormalities live to sexual maturity.

  15. Modeling of compressible cake filtration

    SciTech Connect

    Abbound, N.M. . Dept. of Civil Engineering); Corapcioglu, M.Y. . Dept. of Civil Engineering)

    1993-10-15

    The transport of suspended solid particles in a liquid through porous media has importance from the viewpoint of engineering practice and industrial applications. Deposition of solid particles on a filter cloth or on a pervious porous medium forms the filter cakes. Following a literature survey, a governing equation for the cake thickness is obtained by considering an instantaneous material balance. In addition to the conservation of mass equations for the liquid, and for suspended and captured solid particles, functional relations among porosity, permeability, and pressure are obtained from literature and solved simultaneously. Later, numerical solutions for cake porosity, pore pressure, cake permeability, velocity of solid particles, concentration of suspended solid particles, and net rate of deposition are obtained. At each instant of time, the porosity decreases throughout the cake from the surface to the filter septum where it has the smallest value. As the cake thickness increases, the trends in pressure variation are similar to data obtained by other researchers. This comparison shows the validity of the theory and the associated solution presented. A sensitivity analysis shows higher pressure values at the filter septum for a less pervious membrane. Finally, a reduction in compressibility parameter provides a thicker cake, causes more particles to be captured inside the cake, and reduces the volumetric filtrate rate. The increase of solid velocity with the reduction in compressibility parameter shows that more rigid cakes compress less.

  16. Filtrating forms of soil bacteria

    NASA Astrophysics Data System (ADS)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  17. Protein- and diabetes-induced glomerular hyperfiltration: role of glucagon, vasopressin, and urea.

    PubMed

    Bankir, Lise; Roussel, Ronan; Bouby, Nadine

    2015-07-01

    A single protein-rich meal (or an infusion of amino acids) is known to increase the glomerular filtration rate (GFR) for a few hours, a phenomenon known as "hyperfiltration." It is important to understand the factors that initiate this upregulation because it becomes maladaptive in the long term. Several mediators and paracrine factors have been shown to participate in this upregulation, but they are not directly triggered by protein intake. Here, we explain how a rise in glucagon and in vasopressin secretion, directly induced by protein ingestion, might be the initial factors triggering the hepatic and renal events leading to an increase in the GFR. Their effects include metabolic actions in the liver and stimulation of sodium chloride reabsorption in the thick ascending limb. Glucagon is not only a glucoregulatory hormone. It is also important for the excretion of nitrogen end products by stimulating both urea synthesis in the liver (along with gluconeogenesis from amino acids) and urea excretion by the kidney. Vasopressin allows the concentration of nitrogenous end products (urea, ammonia, etc.) and other protein-associated wastes in a hyperosmotic urine, thus allowing a very significant water economy characteristic of all terrestrial mammals. No hyperfiltration occurs in the absence of one or the other hormone. Experimental results suggest that the combined actions of these two hormones, along with the complex intrarenal handling of urea, lead to alter the composition of the tubular fluid at the macula densa and to reduce the intensity of the signal activating the tubuloglomerular feedback control of GFR, thus allowing GFR to raise. Altogether, glucagon, vasopressin, and urea contribute to set up the best compromise between efficient urea excretion and water economy.

  18. Statin-sensitive endocytosis of albumin by glomerular podocytes.

    PubMed

    Eyre, Jeanette; Ioannou, Kyriakos; Grubb, Blair D; Saleem, Moin A; Mathieson, Peter W; Brunskill, Nigel J; Christensen, Erik I; Topham, Peter S

    2007-02-01

    Glomerular podocytes are critical regulators of glomerular permeability via the slit diaphragm and may play a role in cleaning the glomerular filter. Whether podocytes are able to endocytose proteins is uncertain. We studied protein endocytosis in conditionally immortalized mouse and human podocytes using FITC-albumin by direct quantitative assay and by fluorescence microscopy and electron microscopy in mouse podocytes. Furthermore, in vivo uptake was studied in human, rat, and mouse podocytes. Both mouse and human podocytes displayed specific one-site binding for FITC-albumin with K(d) of 0.91 or 0.44 mg/ml and B(max) of 3.15 or 0.81 microg/mg cell protein, respectively. In addition, they showed avid endocytosis of FITC-albumin with K(m) of 9.48 or 4.5 mg/ml and V(max) of 474.3 or 97.4 microg.mg cell protein(-1).h(-1), respectively. Immunoglobulin and transferrin were inefficient competitors of this process, indicating some specificity for albumin. Accumulation of endocytosed albumin could be demonstrated in intracellular vesicles by fluorescence confocal microscopy and electron microscopy. Endocytosis was sensitive to pretreatment with simvastatin. In vivo accumulation of albumin was found in all three species but was most pronounced in the rat. We conclude that podocytes are able to endocytose protein in a statin-sensitive manner. This function is likely to be highly significant in health and disease. In addition, protein endocytosis by podocytes may represent a useful, measurable phenotypic characteristic against which potentially injurious or beneficial interventions can be assessed. PMID:17032937

  19. Polymorphonuclear leukocytes increase glomerular albumin permeability via hypohalous acid.

    PubMed

    Li, J Z; Sharma, R; Dileepan, K N; Savin, V J

    1994-10-01

    Acute glomerulonephritis is characterized by the presence of neutrophils within glomeruli and the generation of reactive oxygen species (ROS) by activated polymorphonuclear leukocytes (PMNs). Hydrogen peroxide (H2O2) and other ROS including hypothalous acids have been implicated in PMN mediated injury. To determine the role of specific ROS in PMN mediated glomerular injury, isolated rat glomeruli were incubated for 30 minutes at 37 degrees C with H2O2, with H2O2 and myeloperoxidase, or with activated PMNs. Scavengers of ROS were included in some experiments. PMNs were harvested from rat peritoneal cavity and activated with phorbol myristate acetate (PMA). Glomerular albumin permeability (Palbumin) was calculated from the volume response to an oncotic gradient. Palbumin of glomeruli incubated with H2O2 (10(-3) or 10(-1) M) was not increased, while Palbumin after incubation with H2O2 and MPO was markedly increased (0.94 +/- 0.004). Palbumin after incubation with PMA, or with non-activated PMNs was not different from that of control glomeruli, Palbumin of the glomeruli incubated with activated PMNs increased (0.85 +/- 0.01, P < 0.001). This increase in Palbumin was inhibited by superoxide dismutase, catalase, or taurine (Palbumin = 0.035 +/- 0.06, -0.39 +/- 0.10, 0.028 +/- 0.06, respectively) and ameliorated by sodium azide (Palbumin = 0.21 +/- 0.03). In contrast, dimethyl sulfoxide did not prevent the increase in Palbumin (Palbumin = 0.92 +/- 0.01). Our results show that the hypohalous acid derived from that of H2O2-MPO-halide system is capable of increasing Palbumin. We conclude that hypohalous acid may be the primary mediator of the immediate increase in glomerular protein permeability induced by PMNs. PMID:7861697

  20. Tensin2-deficient mice on FVB/N background develop severe glomerular disease

    PubMed Central

    UCHIO-YAMADA, Kozue; MONOBE, Yoko; AKAGI, Ken-ichi; YAMAMOTO, Yoshie; OGURA, Atsuo; MANABE, Noboru

    2016-01-01

    Tensin2 (Tns2) is an essential component for the maintenance of glomerular basement membrane (GBM) structures. Tns2-deficient mice were previously shown to develop mild glomerular injury on a DBA/2 background, but not on a C57BL/6J or a 129/SvJ background, suggesting that glomerular injury by the deletion of Tns2 was strongly dependent on the genetic background. To further understand the mechanisms for the onset and the progression of glomerular injury by the deletion of Tns2, we generated Tns2-deficient mice on an FVB/N (FVB) strain, which is highly sensitive to glomerular disease. Tns2-deficient mice on FVB (FVBGN) developed severe nephrotic syndrome, and female FVBGN mice died within 8 weeks. Ultrastructural analysis revealed that FVBGN mice exhibited severe glomerular defects with mesangial process invasion of glomerular capillary tufts, lamination and thickening of the GBM and subsequent podocyte foot process effacement soon after birth. Aberrant laminin components containing α1, α2 and β1 chains, which are normally expressed in the mesangium, accumulated in the GBM of FVBGN, suggesting that these components originated from mesangial cells that invaded glomerular capillary tufts. Compared to Tns2-deficient mice on the other backgrounds in previous reports, FVBGN mice developed earlier onset of glomerular defects and rapid progression of renal failure. Thus, this study further extended our understanding of the possible genetic background effect on the deterioration of nephrotic syndrome by Tns2 deficiency. PMID:26854109

  1. Reduction in glomerular pore size is not restricted to pregnant women. Evidence for a new syndrome: 'Shrunken pore syndrome'.

    PubMed

    Grubb, Anders; Lindström, Veronica; Jonsson, Magnus; Bäck, Sten-Erik; Åhlund, Tomas; Rippe, Bengt; Christensson, Anders

    2015-07-01

    The plasma levels of cystatin C, β2-microglobulin, beta-trace protein, retinol binding protein (RBP) and creatinine were determined in plasma samples from 111 randomly selected patients with eGFRcystatin C ≤ 60% of eGFRcreatinine and from 55 control patients with 0.9eGFRcreatinine ≤ eGFRcystatin C ≤ 1.1eGFRcreatinine (eGFRcystatin C ≈ eGFRcreatinine). The concentration ratios of cystatin C/creatinine, β2-microglobulin/creatinine, beta-trace protein/creatinine and RBP/creatinine were significantly higher in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine than in patients with eGFRcystatin C ≈ eGFRcreatinine. When the patients were divided into three groups with different estimated GFR intervals (≤ 40, 40-60 and ≥ 60 mL/min/1.73m(2)) the concentration ratios of cystatin C/creatinine, β2-microglobulin/creatinine, and beta-trace protein/creatinine were significantly higher in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine than in patients with eGFRcystatin C ≈ eGFRcreatinine for all GFR intervals. Similar results were obtained when the population without pregnant women was studied as well as the subpopulations of men or of non-pregnant women. Populations of pre-eclamptic women and pregnant women in the third trimester display similar results. Since the production of these four proteins with sizes similar to that of cystatin C is not co-regulated, the most likely explanation for the simultaneous increase of their creatinine-ratios in patients with eGFRcystatin C ≤ 60% of eGFRcreatinine is that their elimination by glomerular filtration is decreased. We suggest that this is due to a reduction in pore diameter of the glomerular membrane and propose the designation 'Shrunken pore syndrome' for this pathophysiological state.

  2. Glomerular microcapillary thrombosis demonstrated by the new technique of immunocathodoluminescence.

    PubMed Central

    Schmidt, E. H.; Bröcker, W.; Wagner, H.; Pfefferkorn, G.; Beller, F. K.

    1975-01-01

    Fluorescein-labeled antigen-antibody complexes could be made visible by scanning electron microscopy using an intensifying device. This new method of immunocathodoluminescence was demonstrated on cryostat sections of rat kidneys containing glomerular fibrin as the result of endotoxin infusion. The resulting photographs correspond with those obtained by immunofluorescent microscopy. The advantage of this technique is, however, the larger depth of focus. By using thinner cyostat sections it is expected that the higher resolution of scanning microscopy will provide even better details in three dimensions. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:1101704

  3. Drug-Induced Glomerular Disease: Immune-Mediated Injury

    PubMed Central

    Markowitz, Glen S.; Radhakrishnan, Jai

    2015-01-01

    Drug-induced autoimmune disease was initially described decades ago, with reports of vasculitis and a lupus-like syndrome in patients taking hydralazine, procainamide, and sulfadiazine. Over the years, multiple other agents have been linked to immune-mediated glomerular disease, often with associated autoantibody formation. Certain clinical and laboratory features may distinguish these entities from their idiopathic counterparts, and making this distinction is important in the diagnosis and management of these patients. Here, drug-induced, ANCA-associated vasculitis, drug-induced lupus, and drug-associated membranous nephropathy are reviewed. PMID:26092827

  4. Atypical anti-glomerular basement membrane disease: lessons learned

    PubMed Central

    Glassock, Richard J.

    2016-01-01

    Anti-glomerular basement membrane (GBM) disease usually pursues a self-limited course, at least from the immunological perspective. In addition, circulating antibodies to cryptic, conformational epitopes within the NC1 domain of the alpha 3 chain of Type IV Collagen are commonly found at the zenith of the clinical disease. However, exceptions to these general rules do occur, as exemplified by two remarkable cases reported in this issue of the Clinical Kidney Journal. The possible explanations for and the lessons learned from these uncommon occurrences are discussed in this short commentary. PMID:27679709

  5. A neural network model for olfactory glomerular activity prediction

    NASA Astrophysics Data System (ADS)

    Soh, Zu; Tsuji, Toshio; Takiguchi, Noboru; Ohtake, Hisao

    2012-12-01

    Recently, the importance of odors and methods for their evaluation have seen increased emphasis, especially in the fragrance and food industries. Although odors can be characterized by their odorant components, their chemical information cannot be directly related to the flavors we perceive. Biological research has revealed that neuronal activity related to glomeruli (which form part of the olfactory system) is closely connected to odor qualities. Here we report on a neural network model of the olfactory system that can predict glomerular activity from odorant molecule structures. We also report on the learning and prediction ability of the proposed model.

  6. Atypical anti-glomerular basement membrane disease: lessons learned

    PubMed Central

    Glassock, Richard J.

    2016-01-01

    Anti-glomerular basement membrane (GBM) disease usually pursues a self-limited course, at least from the immunological perspective. In addition, circulating antibodies to cryptic, conformational epitopes within the NC1 domain of the alpha 3 chain of Type IV Collagen are commonly found at the zenith of the clinical disease. However, exceptions to these general rules do occur, as exemplified by two remarkable cases reported in this issue of the Clinical Kidney Journal. The possible explanations for and the lessons learned from these uncommon occurrences are discussed in this short commentary.

  7. Abnormal uterine bleeding.

    PubMed

    Jennings, J C

    1995-11-01

    Physicians who care for female patients cannot avoid the frequent complaint of abnormal uterine bleeding. Knowledge of the disorders that cause this problem can prevent serious consequences in many patients and improve the quality of life for many others. The availability of noninvasive and minimally invasive diagnostic studies and minimally invasive surgical treatment has revolutionized management of abnormal uterine bleeding. Similar to any other disorder, the extent to which a physician manages abnormal uterine bleeding depends on his or her own level of comfort. When limitations of either diagnostic or therapeutic capability are encountered, consultation and referral should be used to the best interest of patients.

  8. Filtration in coal liquefaction - Influence of filtration conditions in non-hydrogenated systems

    NASA Astrophysics Data System (ADS)

    Clarke, J. W.; Rantell, T. D.

    1980-01-01

    A series of experiments has been carried out to study the effects of filtration conditions upon the rate of filtration of non-hydrogenated coal digests. The results show the dependence of cake resistivity on both the filtration temperature and pressure. Filter cakes were found to be compressible, resulting in smaller increases in rate with increasing pressure than with incompressible cakes. The filtration temperature determines the packing of residual solids in the cake which in turn affects the cake resistivity. An empirical relation has been derived between filtration temperature and resistivity. With increasing temperature there is an increase in filtration rate due to the reduced viscosity, but a reduction owing to a higher packing density of solids in the filter cake.

  9. New developments in slow sand filtration

    SciTech Connect

    Fox, K.R.

    1993-01-01

    Recent regulations promulgated by the U.S. Environmental Protection Agency (EPA), including the Surface Water Treatment Rule, have helped to renew the interest in the use of slow sand filtration (SSF) for treating surface waters for small communities. Slow sand filtration is not a new process, but is one that has been used to treat water effectively since the early 1800's. Interest in slow sand filtration in the United States has increased dramatically in the past thirteen years. New analytical techniques, such as particle counting, improved turbidity, improved growth media for microbiological analysis, and advanced techniques for measuring organic constituents allowed for more detailed studies than were possible in the early 1900's. The new work led to the publication of design manuals and task committee reports describing slow sand filtration in detail.

  10. Dust filtration in hot coal gas

    SciTech Connect

    Schreurs, H.C.E.

    1995-12-31

    Cleaning up coal gas at high temperatures means a fundamental change to the complete system of an Integrated Coal Gasification Combined Cycle. Coal ash is one of the components that asks for a complete different kind of treating. Several types of dust filtration are available for cleaning up hot coal gas. Several difficulties arise when cleaning up hot coal gas for dust. The paper will deal with the possibilities of the dust cleaning (place, technics), the difficulties (material, efficiencies, residue handling) and the cleaning conditions. It will given an overview of the boundary conditions of dust filtration with respect to slag and ash formation in the gasifier and the coal gas treatment and use after the filtration. Evaluation will show the development path for hot dust filtration, divided into several steps for correct risk analysis. Both former system and feasibility studies on hot gas clean up and ongoing studies and research, all conducted under Novem-assignment, will be reported on.

  11. Effect of selenium-deficient diet in experimental glomerular disease.

    PubMed

    Baliga, R; Baliga, M; Shah, S V

    1992-07-01

    We examined the effect of a selenium-deficient diet on two experimental models of glomerular disease, the puromycin aminonucleoside (PAN)-induced nephrotic syndrome, a model of minimal change disease, and passive Heymann nephritis, a complement-dependent and neutrophil-independent model that resembles membranous nephropathy. The specific activity of selenium-dependent glutathione peroxidase was markedly reduced in the liver, the kidney cortex, and in glomeruli in weanling male Sprague-Dawley rats placed on a selenium-deficient diet for 6 wk compared with rats fed a selenium-replete diet, with no significant differences in the specific activities of superoxide dismutase or catalase. PAN-injected selenium-deficient rats had a marked and significantly greater proteinuria throughout the course of the experiment compared with PAN-injected selenium-replete rats with no significant histological differences. In the passive Heymann nephritis model induced by injecting anti-Fx1A immunoglobulin G, rats fed a selenium-deficient diet had significantly higher urinary protein (day 5: 91 +/- 16 mg/24 h, n = 10) compared with rats fed a selenium-replete diet (52 +/- 5 mg/24 h, n = 11) with no differences in the amount of antibody deposited in the kidney. The most likely explanation for the effect of a selenium-deficient diet is that selenium deficiency resulted in a marked reduction of glutathione peroxidase, thus indicating an important role of glutathione peroxidase in these models of glomerular injury.

  12. A Compendium of Urinary Biomarkers Indicative of Glomerular Podocytopathy

    PubMed Central

    2013-01-01

    It is well known that glomerular podocyte injury and loss are present in numerous nephropathies and that the pathophysiologic consecution of disease hinges upon the fate of the podocyte. While multiple factors play a hand in glomerulopathy progression, basic logic lends that if one monitors the podocyte's status, that may reflect the status of disease. Recent investigations have focused on what one can elucidate from the noninvasive collection of urine, and have proven that certain, specific biomarkers of podocytes can be readily identified via varying techniques. This paper has brought together all described urinary biomarkers of podocyte injury and is made to provide a concise summary of their utility and testing in laboratory and clinical theatres. While promising in the potential that they hold as tools for clinicians and investigators, the described biomarkers require further comprehensive vetting in the form of larger clinical trials and studies that would give their value true weight. These urinary biomarkers are put forth as novel indicators of glomerular disease presence, disease progression, and therapeutic efficacy that in some cases may be more advantageous than the established parameters/measures currently used in practice. PMID:24327929

  13. Etiopathology of chronic tubular, glomerular and renovascular nephropathies: Clinical implications

    PubMed Central

    2011-01-01

    Chronic kidney disease (CKD) comprises a group of pathologies in which the renal excretory function is chronically compromised. Most, but not all, forms of CKD are progressive and irreversible, pathological syndromes that start silently (i.e. no functional alterations are evident), continue through renal dysfunction and ends up in renal failure. At this point, kidney transplant or dialysis (renal replacement therapy, RRT) becomes necessary to prevent death derived from the inability of the kidneys to cleanse the blood and achieve hydroelectrolytic balance. Worldwide, nearly 1.5 million people need RRT, and the incidence of CKD has increased significantly over the last decades. Diabetes and hypertension are among the leading causes of end stage renal disease, although autoimmunity, renal atherosclerosis, certain infections, drugs and toxins, obstruction of the urinary tract, genetic alterations, and other insults may initiate the disease by damaging the glomerular, tubular, vascular or interstitial compartments of the kidneys. In all cases, CKD eventually compromises all these structures and gives rise to a similar phenotype regardless of etiology. This review describes with an integrative approach the pathophysiological process of tubulointerstitial, glomerular and renovascular diseases, and makes emphasis on the key cellular and molecular events involved. It further analyses the key mechanisms leading to a merging phenotype and pathophysiological scenario as etiologically distinct diseases progress. Finally clinical implications and future experimental and therapeutic perspectives are discussed. PMID:21251296

  14. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  15. Abnormal Uterine Bleeding

    MedlinePlus

    ... Abnormal uterine bleeding is any bleeding from the uterus (through your vagina) other than your normal monthly ... or fibroids (small and large growths) in the uterus can also cause bleeding. Rarely, a thyroid problem, ...

  16. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... as cancer of the uterus, cervix, or vagina • Polycystic ovary syndrome How is abnormal bleeding diagnosed? Your health care ... before the fetus can survive outside the uterus. Polycystic Ovary Syndrome: A condition characterized by two of the following ...

  17. 6. Detail view northeast of rear of filtration bed building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail view northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  18. 5. View northeast of rear of filtration bed building. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at extreme center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  19. 10. View west of east entry to filtration beds. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View west of east entry to filtration beds. Note monitor roof and clerestory windows over central corridor. Laboratory building is sited over the center of the filtration bed building at extreme left center of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  20. Three-dimensional electron microscopy reveals the evolution of glomerular barrier injury

    PubMed Central

    Randles, Michael J.; Collinson, Sophie; Starborg, Tobias; Mironov, Aleksandr; Krendel, Mira; Königshausen, Eva; Sellin, Lorenz; Roberts, Ian S. D.; Kadler, Karl E.; Miner, Jeffrey H.; Lennon, Rachel

    2016-01-01

    Glomeruli are highly sophisticated filters and glomerular disease is the leading cause of kidney failure. Morphological change in glomerular podocytes and the underlying basement membrane are frequently observed in disease, irrespective of the underlying molecular etiology. Standard electron microscopy techniques have enabled the identification and classification of glomerular diseases based on two-dimensional information, however complex three-dimensional ultrastructural relationships between cells and their extracellular matrix cannot be easily resolved with this approach. We employed serial block face-scanning electron microscopy to investigate Alport syndrome, the commonest monogenic glomerular disease, and compared findings to other genetic mouse models of glomerular disease (Myo1e−/−, Ptpro−/−). These analyses revealed the evolution of basement membrane and cellular defects through the progression of glomerular injury. Specifically we identified sub-podocyte expansions of the basement membrane with both cellular and matrix gene defects and found a corresponding reduction in podocyte foot process number. Furthermore, we discovered novel podocyte protrusions invading into the glomerular basement membrane in disease and these occurred frequently in expanded regions of basement membrane. These findings provide new insights into mechanisms of glomerular barrier dysfunction and suggest that common cell-matrix-adhesion pathways are involved in the progression of disease regardless of the primary insult. PMID:27725732

  1. Soluble interleukin-2 receptor in patients with glomerular diseases.

    PubMed Central

    Chen, H. S.; Wu, M. S.; Yen, T. S.; Chen, W. Y.

    1995-01-01

    In this study, we measured the soluble interleukin-2 receptor (sIL-2R) level to evaluate the cellular immune status in 61 patients with different types of glomerular diseases; 40 healthy volunteers were used as control. All patients with glomerular diseases had levels of serum sIL-2R significantly higher than those of the controls (766 +/- 59 vs 280 +/- 23 U/ml; p < 0.05). Even patients with normal renal function still had higher serum sIL-2R levels than the controls, no matter to which subgroups they belonged (primary glomerulonephritis, lupus nephritis or diabetic nephropathy). Serum sIL-2R levels were similar among the three subgroups. The serum levels of sIL-2R correlated well with age and were significantly higher in older patients, although this was not observed in the control group. Serum sIL-2R levels were significantly higher in patients with active urinary sediment and in patients with impaired renal function and showed a significant negative correlation with creatinine clearance (r = -0.56; p < 0.05). Although urinary and serum sIL-2R levels were quite well correlated, (r = 0.35; p < 0.05), the urinary levels of sIL-2R did not differ in patients with different disease activity or different renal functions although they had a significant correlation with 24-hour urinary protein (r = 0.39; p < 0.05). Patients with nephrotic syndrome also had higher urinary sIL-2R levels than other patients (529 +/- 106 vs 280 +/- 31 U/ml; p < 0.05). We conclude that greater T-cell activation might contribute to the pathogenesis of different glomerulonephritis entities, and serum levels of sIL-2R can serve as a useful clinical marker of glomerulonephritis activity. Renal function influenced the serum levels of sIL-2R significantly. This factor must be considered when we interpret the data. Urinary sIL-2R levels did not reflect the disease activity as well. This might be due to the secondary influence of the extent of the glomerular protein leak. Further investigation is

  2. ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice.

    PubMed

    Jones, Frances E; Bailey, Matthew A; Murray, Lydia S; Lu, Yinhui; McNeilly, Sarah; Schlötzer-Schrehardt, Ursula; Lennon, Rachel; Sado, Yoshikazu; Brownstein, David G; Mullins, John J; Kadler, Karl E; Van Agtmael, Tom

    2016-02-01

    Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies.

  3. Cytomegalovirus-Associated CD4(+) CD28(null) Cells in NKG2D-Dependent Glomerular Endothelial Injury and Kidney Allograft Dysfunction.

    PubMed

    Shabir, S; Smith, H; Kaul, B; Pachnio, A; Jham, S; Kuravi, S; Ball, S; Chand, S; Moss, P; Harper, L; Borrows, R

    2016-04-01

    Emerging data suggest that expansion of a circulating population of atypical, cytotoxic CD4(+) T cells lacking costimulatory CD28 (CD4(+) CD28(null) cells) is associated with latent cytomegalovirus (CMV) infection. The purpose of the current study was to increase the understanding of the relevance of these cells in 100 unselected kidney transplant recipients followed prospectively for a median of 54 months. Multicolor flow cytometry of peripheral blood mononuclear cells before transplantation and serially posttransplantation was undertaken. CD4(+) CD28(null) cells were found predominantly in CMV-seropositive patients and expanded in the posttransplantation period. These cells were predominantly effector-memory phenotype and expressed markers of endothelial homing (CX3CR1) and cytotoxicity (NKG2D and perforin). Isolated CD4(+) CD27(-) CD28(null) cells proliferated in response to peripheral blood mononuclear cells previously exposed to CMV-derived (but not HLA-derived) antigens and following such priming incubation with glomerular endothelium resulted in signs of endothelial damage and apoptosis (release of fractalkine and von Willebrand factor; increased caspase 3 expression). This effect was mitigated by NKG2D-blocking antibody. Increased CD4(+) CD28(null) cell frequencies were associated with delayed graft function and lower estimated glomerular filtration rate at end follow-up. This study suggests an important role for this atypical cytotoxic CD4(+) CD28(null) cell subset in kidney transplantation and points to strategies that may minimize the impact on clinical outcomes.

  4. Effect of column filtration upon the quality parameters of fresh dog semen.

    PubMed

    Mogas, T; Rigau, T; Piedrafita, J; Bonet, S; Rodríguez-Gil, J E

    1998-12-01

    We filtered dog semen through various resin columns to obtain a quick, simple system for improving semen quality. Fresh ejaculates were filtered through columns with either glasswool or a chemically-inert polypropylene network disc. The columns were filled with Sephadex G-15 (nonionic resin), Sephadex A-50 (anionic-exchange resin), Sephadex C-50 (cationic-exchange resin) or a combination of Sephadex A-50 and C-50. Filtration through glasswool improved semen quality, with a significant (P < 0.001) increase in the percentage of viability and decrease in the percentage of altered acrosomes (P < 0.001) and total abnormalities (P < 0.001). Total motility was not modified, but curvilinear velocity or linearity of the movement were improved using the glasswool bed. The effect of the glasswool was so intense that it masked the effects of the filtration resins. Substitution of glasswool by polypropylene discs resulted in an unmasking of the effects of the resins, although the polypropylene exerted slight effects on semen. Elution of the spermatozoa through Sephadex G-15 or Sephadex C-50 resulted in a decrease of altered acrosomes. However, filtration through Sephadex A-50 increased viability and decreased the percentage of altered acrosomes and total abnormalities. Combined filtration through Sephadex A-50 and C-50 yielded the combined results observed with the resins individually. Ultrastructural imaging of the interaction between spermatozoa and the beds and resins showed that the cells were loosely deposited upon the glasswool fibers and the Sephadex G-15 particles, whereas close interaction was observed between spermatozoa and Sephadex A-50 and C-50 particles. The whole of the sperm cell bound to C-50 particles, whereas spermatozoa were specifically bonded to A-50 particles in the apical region of the head and in segments of the tail, which were periodically distributed. The data suggest that filtration through glasswool or an anionic resin-exchange can significantly

  5. Novel procedures accurately measure drilling mud dynamic filtration

    SciTech Connect

    Chenevert, M.E.; Al-Abri, S. ); Jin, L. )

    1994-04-25

    New equipment and test procedures can determine dynamic mud cake properties such as equilibrium cake thickness, porosity, permeability, compressibility, and erosion resistance. The following were developed to study dynamic filtration: a dynamic filtration cell; a recommended filtration medium; a mud cake thickness device; mud cake porosity determination method; calculation methods for shear rate determination beneath a rotating cone; determination of equilibrium cake thickness, erosion resistance, and compressibility; and preferred filtration display techniques. The article describes the equipment, test procedures, and typical filtration results.

  6. COMPARATIVE EVALUATION OF R3f GARNET BEAD FILTRATION AND MULTIMEDIA FILTRATION SYSTEMS; FINAL REPORT

    EPA Science Inventory

    This report summarizes the results of tests conducted to date at the EPA T&E Facility on the R3f filtration system utilizing fine beads (such as garnet beads or glass beads) and a conventional multimedia filtration system. Both systems have been designed and built by Enprotec, a...

  7. Dynamic filtration of invert-emulsion muds

    SciTech Connect

    Jiao, D.; Sharma, M.M. )

    1993-09-01

    Dynamic-filtration experiments conducted on oil-based muds show that the dynamic-filtration rate is much higher than API filtration rates. The use of water-wet solids results in very poor-quality external mudcakes and high fluid-loss rates. Better external mudcakes are formed by mixing equal parts organophilic clay and mud. Filtration-loss-control additives (asphalt mineral pitches) do not reduce the equilibrium filtration rate, but do reduce spurt loss and limit solids invasion. In brine-saturated rocks, the invasion rate for oil-based muds is significantly smaller than for water-based muds because capillary pressure prevents the oil phase from entering the core in oil-based muds. Oil-based mudcakes are softer and more shear-sensitive than water-based mudcakes. Scanning electron microscope (SEM) photomicrographs indicate that oil-based mudcakes consist of individual water droplets coated with clay particles. This cake structure gives rise to the low permeability and shear sensitivity of oil-based muds.

  8. Actin filament organization of foot processes in vertebrate glomerular podocytes.

    PubMed

    Ichimura, Koichiro; Kurihara, Hidetake; Sakai, Tatsuo

    2007-09-01

    We investigated the actin filament organization and immunolocalization of actin-binding proteins (alpha-actinin and cortactin) in the podocyte foot processes of eight vertebrate species (lamprey, carp, newt, frog, gecko, turtle, quail, and rat). Three types of actin cytoskeleton were found in these foot processes. (1) A cortical actin network with cortactin filling the space between the plasma membrane and the other actin cytoskeletons described below was found in all of the species examined here. The data indicated that the cortical actin network was the minimal essential actin cytoskeleton for the formation and maintenance of the foot processes in vertebrate podocytes. (2) An actin bundle with alpha-actinin existing along the longitudinal axis of foot process above the level of slit diaphragms was only observed in quail and rat. (3) An actin fascicle consisting of much fewer numbers of actin filaments than that of the actin bundle was observed in the species other than quail and rat, but at various frequencies. These findings suggest that the actin bundle is an additional actin cytoskeleton reflecting a functional state peculiar to quail and rat glomeruli. Considering the higher intraglomerular pressure and the extremely thin filtration barrier in birds and mammals, the foot processes probably mainly protect the thinner filtration barrier from the higher internal pressure occurring in quail and rat glomeruli. Therefore, we consider that the actin bundle plays a crucial role in the mechanical protection of the filtration barrier. Moreover, the actin fascicle may be a potential precursor of the actin bundle.

  9. Histiocytic and Nonhistiocytic Glomerular Lesions: Foam Cells and Their Mimickers.

    PubMed

    Kaur, Amulyajit; Sethi, Sanjeev

    2016-02-01

    Numerous histiocytes are sometimes noted in glomeruli, giving rise to a foamy-appearing glomerulus. Foamy-appearing glomeruli may also be noted in conditions that do not contain numerous histiocytes. These disease entities are rare, have different underlying causes and pathophysiology, and can cause a diagnostic dilemma. We have observed this histiocytic/foamy glomerular change on the kidney biopsy specimen in 5 different disease entities: crystal-storing histiocytosis, histiocytic glomerulopathy associated with macrophage-activating syndrome, thrombotic microangiopathy, lecithin-cholesterol acyltransferase deficiency, and lipoprotein glomerulopathy. We describe and compare the kidney biopsy findings of these histiocytic and foamy-appearing entities. It is important to recognize the kidney biopsy findings of these rare conditions to correctly evaluate and identify the cause and manage these patients. PMID:26606995

  10. Glomerular diseases and cancer: evaluation of underlying malignancy.

    PubMed

    Pani, Antonello; Porta, Camillo; Cosmai, Laura; Melis, Patrizia; Floris, Matteo; Piras, Doloretta; Gallieni, Maurizio; Rosner, Mitchell; Ponticelli, Claudio

    2016-04-01

    Onconephrology is an emerging medical subspecialty focused on the numerous interconnections between cancer and kidney diseases. Patient with malignancies commonly experience kidney problems including acute kidney injury, tumor lysis syndrome, fluid and electrolyte disorders and chronic kidney disease, often as a consequence of the anti-cancer treatment. Conversely, a number of glomerulopathies, tubulopathies and vascular renal diseases can early signal the presence of an underlying cancer. Furthermore, the administration of immunosuppressive drugs, especially cytotoxic drugs and calcineurin inhibitors, may strongly impair the immune response increasing the risk of cancer. The objective of this review article is to: (i) discuss paraneoplastic glomerular disease, (ii) review cancer as an adverse effect of immunosuppressive agents used to treat glomerulopathies, and (iii) in the absence of international approved guidelines, propose a screening program based on expert opinion aimed at guiding nephrologists to early detect malignancies during their clinical practice. PMID:26498294

  11. High glucose causes dysfunction of the human glomerular endothelial glycocalyx.

    PubMed

    Singh, A; Fridén, V; Dasgupta, I; Foster, R R; Welsh, G I; Tooke, J E; Haraldsson, B; Mathieson, P W; Satchell, S C

    2011-01-01

    The endothelial glycocalyx is a gel-like layer which covers the luminal side of blood vessels. The glomerular endothelial cell (GEnC) glycocalyx is composed of proteoglycan core proteins, glycosaminoglycan (GAG) chains, and sialoglycoproteins and has been shown to contribute to the selective sieving action of the glomerular capillary wall. Damage to the systemic endothelial glycocalyx has recently been associated with the onset of albuminuria in diabetics. In this study, we analyze the effects of high glucose on the biochemical structure of the GEnC glycocalyx and quantify functional changes in its protein-restrictive action. We used conditionally immortalized human GEnC. Proteoglycans were analyzed by Western blotting and indirect immunofluorescence. Biosynthesis of GAG was analyzed by radiolabeling and quantified by anion exchange chromatography. FITC-albumin was used to analyze macromolecular passage across GEnC monolayers using an established in vitro model. We observed a marked reduction in the biosynthesis of GAG by the GEnC under high-glucose conditions. Further analysis confirmed specific reduction in heparan sulfate GAG. Expression of proteoglycan core proteins remained unchanged. There was also a significant increase in the passage of albumin across GEnC monolayers under high-glucose conditions without affecting interendothelial junctions. These results reproduce changes in GEnC barrier properties caused by enzymatic removal of heparan sulfate from the GEnC glycocalyx. They provide direct evidence of high glucose-induced alterations in the GEnC glycocalyx and demonstrate changes to its function as a protein-restrictive layer, thus implicating glycocalyx damage in the pathogenesis of proteinuria in diabetes.

  12. [Hair shaft abnormalities].

    PubMed

    Itin, P H; Düggelin, M

    2002-05-01

    Hair shaft disorders may lead to brittleness and uncombable hair. In general the hair feels dry and lusterless. Hair shaft abnormalities may occur as localized or generalized disorders. Genetic predisposition or exogenous factors are able to produce and maintain hair shaft abnormalities. In addition to an extensive history and physical examination the most important diagnostic examination to analyze a hair shaft problem is light microscopy. Therapy of hair shaft disorders should focus to the cause. In addition, minimizing traumatic influences to hair shafts, such as dry hair with an electric dryer, permanent waves and dyes is important. A short hair style is more suitable for such patients with hair shaft disorders.

  13. The Perspective of Riverbank Filtration in China

    NASA Astrophysics Data System (ADS)

    Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

    2014-12-01

    Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

  14. Quantifying oil filtration effects on bearing life

    NASA Technical Reports Server (NTRS)

    Needelman, William M.; Zaretsky, Erwin V.

    1991-01-01

    Rolling-element bearing life is influenced by the number, size, and material properties of particles entering the Hertzian contact of the rolling element and raceway. In general, rolling-element bearing life increases with increasing level of oil filtration. Based upon test results, two equations are presented which allow for the adjustment of bearing L(sub 10) or catalog life based upon oil filter rating. It is recommended that where no oil filtration is used catalog life be reduced by 50 percent.

  15. Vacuum distillation/vapor filtration water recovery

    NASA Technical Reports Server (NTRS)

    Honegger, R. J.; Neveril, R. B.; Remus, G. A.

    1974-01-01

    The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

  16. High-efficiency filtration meets IAQ goals

    SciTech Connect

    Aaronson, E.L. ); Fencl, F. )

    1994-12-01

    This article describes multi-stage filtration system which provided initial cost savings and is expected to save even more in energy costs while fulfilling IAQ requirements. The use of high-efficiency filtration has enabled the city of Kansas City, Mo., to save an estimated $500,000 in initial HVAC system costs for its Bartle Hall expansion project, which is currently under construction. Once operational, the new HVAC system, with its high-efficiency filters, is expected to save thousands of dollars per week more in energy costs while also delivering superior indoor air quality (IAQ).

  17. Filtration of A Hanford AN-104 Sample

    SciTech Connect

    Poirier, MichaelR

    2004-03-01

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter.Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  18. Filtration of a Hanford AN-104 Sample

    SciTech Connect

    POIRIER, MICHAEL

    2004-04-19

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's 241-AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter. Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  19. Subfractionation, characterization and in-depth proteomic analysis of glomerular membrane vesicles in human urine

    PubMed Central

    Hogan, Marie C.; Johnson, Kenneth L.; Zenka, Roman M.; Charlesworth, M. Cristine; Madden, Benjamin J.; Mahoney, Doug W.; Oberg, Ann L.; Huang, Bing Q.; Nesbitt, Lisa L.; Bakeberg, Jason L.; Bergen, H. Robert; Ward, Christopher J.

    2014-01-01

    Urinary exosome-like vesicles (ELVs) are a heterogenous mixture (diameter 40–200nm) containing vesicles shed from all segments of the nephron including glomerular podocytes. Contamination with Tamm Horsfall protein (THP) oligomers has hampered their isolation and proteomic analysis. Here we improved ELV isolation protocols employing density centrifugation to remove THP and albumin, and isolated a glomerular membranous vesicle (GMV) enriched subfraction from 7 individuals identifying 1830 proteins and in 3 patients with glomerular disease identifying 5657 unique proteins. The GMV fraction was composed of podocin/podocalyxin positive irregularly shaped membranous vesicles and podocin/podocalyxin negative classical exosomes. Ingenuity pathway analysis identified integrin, actin cytoskeleton and RhoGDI signaling in the top three canonical represented signaling pathways and 19 other proteins associated with inherited glomerular diseases. The GMVs are of podocyte origin and the density gradient technique allowed isolation in a reproducible manner. We show many nephrotic syndrome proteins, proteases and complement proteins involved in glomerular disease are in GMVs and some were shed in the disease state (nephrin, TRPC6 and INF2 and PLA2R). We calculated sample sizes required to identify new glomerular disease biomarkers, expand the ELV proteome and provide a reference proteome in a database that may prove useful in the search for biomarkers of glomerular disease. PMID:24196483

  20. Genetic Background is a Key Determinant of Glomerular Extracellular Matrix Composition and Organization.

    PubMed

    Randles, Michael J; Woolf, Adrian S; Huang, Jennifer L; Byron, Adam; Humphries, Jonathan D; Price, Karen L; Kolatsi-Joannou, Maria; Collinson, Sophie; Denny, Thomas; Knight, David; Mironov, Aleksandr; Starborg, Toby; Korstanje, Ron; Humphries, Martin J; Long, David A; Lennon, Rachel

    2015-12-01

    Glomerular disease often features altered histologic patterns of extracellular matrix (ECM). Despite this, the potential complexities of the glomerular ECM in both health and disease are poorly understood. To explore whether genetic background and sex determine glomerular ECM composition, we investigated two mouse strains, FVB and B6, using RNA microarrays of isolated glomeruli combined with proteomic glomerular ECM analyses. These studies, undertaken in healthy young adult animals, revealed unique strain- and sex-dependent glomerular ECM signatures, which correlated with variations in levels of albuminuria and known predisposition to progressive nephropathy. Among the variation, we observed changes in netrin 4, fibroblast growth factor 2, tenascin C, collagen 1, meprin 1-α, and meprin 1-β. Differences in protein abundance were validated by quantitative immunohistochemistry and Western blot analysis, and the collective differences were not explained by mutations in known ECM or glomerular disease genes. Within the distinct signatures, we discovered a core set of structural ECM proteins that form multiple protein-protein interactions and are conserved from mouse to man. Furthermore, we found striking ultrastructural changes in glomerular basement membranes in FVB mice. Pathway analysis of merged transcriptomic and proteomic datasets identified potential ECM regulatory pathways involving inhibition of matrix metalloproteases, liver X receptor/retinoid X receptor, nuclear factor erythroid 2-related factor 2, notch, and cyclin-dependent kinase 5. These pathways may therefore alter ECM and confer susceptibility to disease.

  1. Modulation of heparan sulfate in the glomerular endothelial glycocalyx decreases leukocyte influx during experimental glomerulonephritis.

    PubMed

    Rops, Angelique L W M M; Loeven, Markus A; van Gemst, Jasper J; Eversen, Iris; Van Wijk, Xander M; Dijkman, Henry B; van Kuppevelt, Toin H; Berden, Jo H M; Rabelink, Ton J; Esko, Jeffrey D; van der Vlag, Johan

    2014-11-01

    The glomerular endothelial glycocalyx is postulated to be an important modulator of permeability and inflammation. The glycocalyx consists of complex polysaccharides, the main functional constituent of which, heparan sulfate (HS), is synthesized and modified by multiple enzymes. The N-deacetylase-N-sulfotransferase (Ndst) enzymes initiate and dictate the modification process. Here we evaluated the effects of modulation of HS in the endothelial glycocalyx on albuminuria and glomerular leukocyte influx using mice deficient in endothelial and leukocyte Ndst1 (TEKCre+/Ndst1flox/flox). In these mice, glomerular expression of a specific HS domain was significantly decreased, whereas the expression of other HS domains was normal. In the endothelial glycocalyx, this specific HS structure was not associated with albuminuria or with changes in renal function. However, glomerular leukocyte influx was significantly reduced during antiglomerular basement membrane nephritis, which was associated with less glomerular injury and better renal function. In vitro decreased adhesion of wild-type and Ndst1-deficient granulocytes to Ndst1-silenced glomerular endothelial cells was found, accompanied by a decreased binding of chemokines and L-selectin. Thus, modulation of HS in the glomerular endothelial glycocalyx significantly reduced the inflammatory response in antiglomerular basement membrane nephritis.

  2. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU....74 (a)(1) and (c)(1). (2) The turbidity level of representative samples of a system's filtered water... filtration, the turbidity level of representative samples of a system's filtered water must be less than...

  3. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU....74 (a)(1) and (c)(1). (2) The turbidity level of representative samples of a system's filtered water... filtration, the turbidity level of representative samples of a system's filtered water must be less than...

  4. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU....74 (a)(1) and (c)(1). (2) The turbidity level of representative samples of a system's filtered water... filtration, the turbidity level of representative samples of a system's filtered water must be less than...

  5. Design parameters for rotating cylindrical filtration

    NASA Technical Reports Server (NTRS)

    Schwille, John A.; Mitra, Deepanjan; Lueptow, Richard M.

    2002-01-01

    Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. c2002 Elsevier Science B.V. All rights reserved.

  6. Design parameters for rotating cylindrical filtration.

    PubMed

    Schwille, John A; Mitra, Deepanjan; Lueptow, Richard M

    2002-07-15

    Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. PMID:12238523

  7. Gel Filtration Chromatography: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Hurlbut, Jeffrey A.; Schonbeck, Niels D.

    1984-01-01

    Describes a rapid, visual demonstration of protein separation by gel filtration chromatography. The procedure separates two highly colored proteins of different molecular weights on a Sephadex G-75 in 45 minutes. This time includes packing the column as well. Background information, reagents needed, procedures used, and results obtained are…

  8. Contamination control through filtration of microorganisms

    NASA Technical Reports Server (NTRS)

    Stabekis, P. D.; Lyle, R. G.

    1972-01-01

    A description is given of the various kinds of gas and liquid filters used in decontamination and sterilization procedures. Also discussed are filtration mechanisms, characteristics of filter materials, and the factors affecting filter performance. Summaries are included for filter testing and evaluation techniques and the possible application of the filters to spacecraft sterilization.

  9. Design parameters for rotating cylindrical filtration.

    PubMed

    Schwille, John A; Mitra, Deepanjan; Lueptow, Richard M

    2002-07-15

    Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions.

  10. Plasma discharge self-cleaning filtration system

    DOEpatents

    Cho, Young I.; Fridman, Alexander; Gutsol, Alexander F.; Yang, Yong

    2014-07-22

    The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter.

  11. DEMONSTRATION BULLETIN: MEMBRANE FILTRATION - SBP TECHNOLOGIES, INC.

    EPA Science Inventory

    SBP Technologies Inc. (SBP) has developed a membrane-based separation technology that can reduce the volume of contaminated groundwater requiring treatment. The SBP Filtration Unit consists of porous, sintered, stainless steel tubes arranged in a shell-and-tube module configurati...

  12. Protective Role of Growth Hormone against Hyperhomocysteinemia Induced Glomerular Injury

    PubMed Central

    Li, Caixia; Xia, Min; Abais, Justine M.; Liu, Xiaocheng; Li, Ningjun; Boini, Krishna M.; Li, Pin-Lan

    2013-01-01

    The present study investigated the protective role of growth hormone (GH) against hyperhomocysteinemia (hHcys)-induced activations of reactive oxygen species (ROS)/hypoxia-inducible factor (HIF)-1α, epithelial-mesenchymal transition (EMT) and consequent glomerular injury. A hyperhomocysteinemia (hHcys) model was induced by folate free (FF) diet in mice. The urine protein excretion significantly increased while plasma GH levels dramatically decreased in hHcys. Real time RT-PCR showed that GH receptor (GHR) level increased in the cortex of hHcys mice, which mainly occurred in podocytes as shown by confocal microscopy. Recombinant mouse growth hormone (rmGH) treatment (0.02 mg/kg, once a day for 6 weeks) significantly restored the plasma GH, inhibited GHR up-regulation and attenuated proteinuria. Correspondingly, rmGH treatment also blocked hHcys-induced decrease in the expression of podocin, a podocyte slit diaphragm molecule, and inhibited the increases in the expression of desmin, a podocyte injury marker. It was also demonstrated that in hHcys the expression of epithelial markers, p-cadherin and ZO-1, decreased, while the expression of mesenchymal markers, FSP-1 and α-SMA, increased in podocytes, which together suggest the activation of EMT in podocytes. NADPH oxidase (Nox)-dependent superoxide anion (O2·−) and HIF-1α level in the hHcys mice cortex was markedly enhanced. These hHcys-induced EMT enhancement and Nox-dependant O2·−/HIF-1α activation were significantly attenuated by rmGH treatment. HIF-1α level increased in Hcys-treated cultured podocytes, which were blocked by rmGH treatment. Meanwhile, Hcys-induced EMT in cultured podocytes was significantly reversed by HIF-1α siRNA. All these results support the view that GH ameliorates hHcys-induced glomerular injury by reducing Nox-dependent O2·−/HIF-1α signal pathway and EMT. PMID:23529346

  13. Morphological abnormalities in elasmobranchs.

    PubMed

    Moore, A B M

    2015-08-01

    A total of 10 abnormal free-swimming (i.e., post-birth) elasmobranchs are reported from The (Persian-Arabian) Gulf, encompassing five species and including deformed heads, snouts, caudal fins and claspers. The complete absence of pelvic fins in a milk shark Rhizoprionodon acutus may be the first record in any elasmobranch. Possible causes, including the extreme environmental conditions and the high level of anthropogenic pollution particular to The Gulf, are briefly discussed.

  14. Chromosome abnormalities in glioma

    SciTech Connect

    Li, Y.S.; Ramsay, D.A.; Fan, Y.S.

    1994-09-01

    Cytogenetic studies were performed in 25 patients with gliomas. An interesting finding was a seemingly identical abnormality, an extra band on the tip of the short arm of chromosome 1, add(1)(p36), in two cases. The abnormality was present in all cells from a patient with a glioblastoma and in 27% of the tumor cells from a patient with a recurrent irradiated anaplastic astrocytoma; in the latter case, 7 unrelated abnormal clones were identified except 4 of those clones shared a common change, -Y. Three similar cases have been described previously. In a patient with pleomorphic astrocytoma, the band 1q42 in both homologues of chromosome 1 was involved in two different rearrangements. A review of the literature revealed that deletion of the long arm of chromosome 1 including 1q42 often occurs in glioma. This may indicate a possible tumor suppressor gene in this region. Cytogenetic follow-up studies were carried out in two patients and emergence of unrelated clones were noted in both. A total of 124 clonal breakpoints were identified in the 25 patients. The breakpoints which occurred three times or more were: 1p36, 1p22, 1q21, 1q25, 3q21, 7q32, 8q22, 9q22, 16q22, and 22q13.

  15. [Congenital foot abnormalities].

    PubMed

    Delpont, M; Lafosse, T; Bachy, M; Mary, P; Alves, A; Vialle, R

    2015-03-01

    The foot may be the site of birth defects. These abnormalities are sometimes suspected prenatally. Final diagnosis depends on clinical examination at birth. These deformations can be simple malpositions: metatarsus adductus, talipes calcaneovalgus and pes supinatus. The prognosis is excellent spontaneously or with a simple orthopedic treatment. Surgery remains outstanding. The use of a pediatric orthopedist will be considered if malposition does not relax after several weeks. Malformations (clubfoot, vertical talus and skew foot) require specialized care early. Clubfoot is characterized by an equine and varus hindfoot, an adducted and supine forefoot, not reducible. Vertical talus combines equine hindfoot and dorsiflexion of the forefoot, which is performed in the midfoot instead of the ankle. Skew foot is suspected when a metatarsus adductus is resistant to conservative treatment. Early treatment is primarily orthopedic at birth. Surgical treatment begins to be considered after walking age. Keep in mind that an abnormality of the foot may be associated with other conditions: malposition with congenital hip, malformations with syndromes, neurological and genetic abnormalities. PMID:25524290

  16. 11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), LOOKING NORTHWEST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  17. 9. VIEW OF UPPER LEVEL OF FILTRATION ROOM SHOWING TANKS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF UPPER LEVEL OF FILTRATION ROOM SHOWING TANKS AND CONTROL VALVES, LOOKING NORTH - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  18. 12. OBLIQUE VIEW OF NORTH WORK ROOM IN FILTRATION PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. OBLIQUE VIEW OF NORTH WORK ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHWEST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  19. 7. WEYMOUTH FILTRATION PLANT, BUILDING 1 INTERIOR: LA VERNE CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. WEYMOUTH FILTRATION PLANT, BUILDING 1 INTERIOR: LA VERNE CONTROL ROOM, REGULATES DISTRIBUTION OF WATER, CONTROLS POWER HOUSES. - F. E. Weymouth Filtration Plant, 700 North Moreno Avenue, La Verne, Los Angeles County, CA

  20. 3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF THE FILTRATION APPARATUS. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  1. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  2. American Society of Nephrology Quiz and Questionnaire 2015: Glomerular Diseases.

    PubMed

    Bomback, Andrew S; Perazella, Mark A; Choi, Michael J

    2016-05-01

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the annual Kidney Week meeting of the American Society of Nephrology. Once again, the conference hall was overflowing with audience members and eager quiz participants. Topics covered by the expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and kidney transplantation. Complex cases representing each of these categories, along with single-best-answer questions, were prepared and submitted by the panel of experts. Before the meeting, training program directors of United States nephrology fellowship programs and nephrology fellows answered the questions through an Internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on a series of case-oriented questions prepared and discussed by the experts. They compared their answers in real time using their cell phones with a special app with the answers of the nephrology fellows and training program directors. The correct and incorrect answers were then discussed after the results of the questionnaire were displayed. As always, the audience, lecturers, and moderators enjoyed this educational session. This article recapitulates the session and reproduces its educational value for Clinical Journal of the American Society of Nephrology readers. Enjoy the clinical cases and expert discussions.

  3. Glomerular basement membrane thickness among the Saudi population.

    PubMed

    Kfoury, Hala

    2016-01-01

    The aim of this work was to determine the mean glomerular basement membrane (GBM) thickness in the Saudi population. We calculated the average GBM thickness in patients diagnosed with minimal change disease, and the ultrastructural analysis of at least three glomeruli was reviewed using a digital camera installed in an electron microscope. There were a total of 53 cases from 53 Saudi patients aged 2-70 years old. The mean GBM thickness for all cases was 323.6 ± 49.5 nm. There was no significant statistical difference in the mean GBM thickness between males and females. There were significant differences in the mean GBM thickness between all age groups, except for between the age groups 18-60 and >60 years old, where GBM thickness did not differ significantly. Age was significantly correlated with definite progression or diminution in the thickness of the GBM. The mean GBM thickness in our Saudi sample population was comparable to the very few reported measurements in the literature. There was no significant association between GBM thickness and gender; however, GBM thickness is directly proportional to age, up to 60 years old.

  4. American Society of Nephrology Quiz and Questionnaire 2015: Glomerular Diseases.

    PubMed

    Bomback, Andrew S; Perazella, Mark A; Choi, Michael J

    2016-05-01

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the annual Kidney Week meeting of the American Society of Nephrology. Once again, the conference hall was overflowing with audience members and eager quiz participants. Topics covered by the expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and kidney transplantation. Complex cases representing each of these categories, along with single-best-answer questions, were prepared and submitted by the panel of experts. Before the meeting, training program directors of United States nephrology fellowship programs and nephrology fellows answered the questions through an Internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on a series of case-oriented questions prepared and discussed by the experts. They compared their answers in real time using their cell phones with a special app with the answers of the nephrology fellows and training program directors. The correct and incorrect answers were then discussed after the results of the questionnaire were displayed. As always, the audience, lecturers, and moderators enjoyed this educational session. This article recapitulates the session and reproduces its educational value for Clinical Journal of the American Society of Nephrology readers. Enjoy the clinical cases and expert discussions. PMID:26847362

  5. American Society of Nephrology Quiz and Questionnaire 2014: Glomerular Diseases

    PubMed Central

    Perazella, Mark A.; Choi, Michael J.

    2015-01-01

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the Annual Kidney Week Meeting of the American Society of Nephrology. Once again, the conference hall was overflowing with audience members and eager quiz participants. Topics covered by the expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and transplantation. Complex cases representing each of these categories along with single best answer questions were prepared and submitted by the panel of experts. Before the meeting, program directors of United States nephrology training programs and nephrology fellows answered the questions through an internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on a series of case-oriented questions that were prepared and discussed by the experts. They compared their answers in real time using audience response devices with the answers of the nephrology fellows and training program directors. The correct and incorrect answers were then discussed after the audience responses, and the results of the questionnaire were displayed. As always, the audience, lecturers, and moderators enjoyed this educational session. This article recapitulates the session and reproduces its educational value for the readers of CJASN. Enjoy the clinical cases and expert discussions. PMID:25667164

  6. Value of electron microscopy in the diagnosis of glomerular diseases.

    PubMed

    Darouich, Sihem; Goucha, Rym Louzir; Jaafoura, Mohamed Habib; Moussa, Fatma Ben; Zekri, Semy; Maiz, Hédi Ben

    2010-04-01

    To evaluate the contribution of electron microscopy to the final diagnosis of glomerulopathies, the authors established a prospective study during the first semester of 2006. A total of 52 kidney biopsies were performed with 3 samples for light microscopy, immunofluorescence, and electron microscopy. Among these renal biopsies, only 20 were examined with electron microscopy because the diagnosis made on the basis of conventional methods had remained unclear or doubtful. In 18 cases, electron microscopy was undertaken for the investigation of primary kidney disease. The 2 remaining cases were transplant biopsies. In this series of 20 patients, there were 3 children with an average age of 9 years and 17 adults with an average age of 35.5 years. Fifteen patients (75%) were nephrotic. The study revealed that electron microscopy was essential for diagnosis in 8 cases (40%) and was helpful in 12 cases (60%). In conclusion, the results showed that the ultrastructural study provides essential or helpful information in many cases of glomerular diseases, and therefore electron microscopy should be considered an important tool of diagnostic renal pathology. As was recommended, it is important to reserve renal tissue for ultrastructural study unless electron microscopy can be routinely used in all biopsies. Thus, this technique could be performed wherever a renal biopsy has to be ultrastructurally evaluated.

  7. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  8. Filtration Combustion in Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard

    1999-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS, a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized, as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS. Nevertheless, the two applications have much in common, so that what is learned in one application can be used to advantage in the other. We have

  9. 21. Overflow pipe in filtration bed. Located at each corner ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Overflow pipe in filtration bed. Located at each corner of the bed, the pipes drain off any excess water and maintain a limit on water depth. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  10. 15. View west of central corridor between filtration beds which ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View west of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  11. 30. Valves under central corridor of filtration bed building. Main ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Valves under central corridor of filtration bed building. Main flood valves is at left and crossover valve is a right. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  12. 3. View southeast of northwest corner of filtration bed. Laboratory ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View southeast of northwest corner of filtration bed. Laboratory building is at center right of photograph. East rock appears directly behind the laboratory building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  13. 16. View west from center of central corridor between filtration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. View west from center of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  14. 20. View of sand filtration bed. Wheelbarrow was used to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. View of sand filtration bed. Wheelbarrow was used to remove schmutzdeck (top, dirty sand layer containing particulate contamination, dead microorganisms and debris) for cleaning and or disposal. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  15. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  16. 2. View east of filtration bed building. Access bridge to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View east of filtration bed building. Access bridge to earth covering over reinforced concrete roof is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  17. Endothelin A receptor activation on mesangial cells initiates Alport glomerular disease.

    PubMed

    Dufek, Brianna; Meehan, Daniel T; Delimont, Duane; Cheung, Linda; Gratton, Michael Anne; Phillips, Grady; Song, Wenping; Liu, Shiguang; Cosgrove, Dominic

    2016-08-01

    Recent work demonstrates that Alport glomerular disease is mediated through a biomechanical strain-sensitive activation of mesangial actin dynamics. This occurs through a Rac1/CDC42 cross-talk mechanism that results in the invasion of the subcapillary spaces by mesangial filopodia. The filopodia deposit mesangial matrix proteins in the glomerular basement membrane, including laminin 211, which activates focal adhesion kinase in podocytes culminating in the up-regulation of proinflammatory cytokines and metalloproteinases. These events drive the progression of glomerulonephritis. Here we test whether endothelial cell-derived endothelin-1 is up-regulated in Alport glomeruli and further elevated by hypertension. Treatment of cultured mesangial cells with endothelin-1 activates the formation of drebrin-positive actin microspikes. These microspikes do not form when cells are treated with the endothelin A receptor antagonist sitaxentan or under conditions of small, interfering RNA knockdown of endothelin A receptor mRNA. Treatment of Alport mice with sitaxentan results in delayed onset of proteinuria, normalized glomerular basement membrane morphology, inhibition of mesangial filopodial invasion of the glomerular capillaries, normalization of glomerular expression of metalloproteinases and proinflammatory cytokines, increased life span, and prevention of glomerulosclerosis and interstitial fibrosis. Thus endothelin A receptor activation on mesangial cells is a key event in initiation of Alport glomerular disease in this model.

  18. Podocyte EphB4 signaling helps recovery from glomerular injury.

    PubMed

    Wnuk, Monika; Hlushchuk, Ruslan; Janot, Mathilde; Tuffin, Gérald; Martiny-Baron, Georg; Holzer, Philipp; Imbach-Weese, Patricia; Djonov, Valentin; Huynh-Do, Uyen

    2012-06-01

    Eph receptor tyrosine kinases and their ligands (ephrins) have a pivotal role in the homeostasis of many adult organs and are widely expressed in the kidney. Glomerular diseases beginning with mesangiolysis can recover, with podocytes having a critical role in this healing process. We studied here the role of Eph signaling in glomerular disease recovery following mesangiolytic Thy1.1 nephritis in rats. EphB4 and ephrinBs were expressed in healthy glomerular podocytes and were upregulated during Thy1.1 nephritis, with EphB4 strongly phosphorylated around day 9. Treatment with NPV-BHG712, an inhibitor of EphB4 phosphorylation, did not cause glomerular changes in control animals. Nephritic animals treated with vehicle did not have morphological evidence of podocyte injury or loss; however, application of this inhibitor to nephritic rats induced glomerular microaneurysms, podocyte damage, and loss. Prolonged NPV-BHG712 treatment resulted in increased albuminuria and dysregulated mesangial recovery. Additionally, NPV-BHG712 inhibited capillary repair by intussusceptive angiogenesis (an alternative to sprouting angiogenesis), indicating a previously unrecognized role of podocytes in regulating intussusceptive vessel splitting. Thus, our results identify EphB4 signaling as a pathway allowing podocytes to survive transient capillary collapse during glomerular disease.

  19. Increased olfactory bulb acetylcholine bi-directionally modulates glomerular odor sensitivity

    PubMed Central

    Bendahmane, Mounir; Ogg, M. Cameron; Ennis, Matthew; Fletcher, Max L.

    2016-01-01

    The glomerular layer of the olfactory bulb (OB) receives heavy cholinergic input from the horizontal limb of the diagonal band of Broca (HDB) and expresses both muscarinic and nicotinic acetylcholine (ACh) receptors. However, the effects of ACh on OB glomerular odor responses remain unknown. Using calcium imaging in transgenic mice expressing the calcium indicator GCaMP2 in the mitral/tufted cells, we investigated the effect of ACh on the glomerular responses to increasing odor concentrations. Using HDB electrical stimulation and in vivo pharmacology, we find that increased OB ACh leads to dynamic, activity-dependent bi-directional modulation of glomerular odor response due to the combinatorial effects of both muscarinic and nicotinic activation. Using pharmacological manipulation to reveal the individual receptor type contributions, we find that m2 muscarinic receptor activation increases glomerular sensitivity to weak odor input whereas nicotinic receptor activation decreases sensitivity to strong input. Overall, we found that ACh in the OB increases glomerular sensitivity to odors and decreases activation thresholds. This effect, along with the decreased responses to strong odor input, reduces the response intensity range of individual glomeruli to increasing concentration making them more similar across the entire concentration range. As a result, odor representations are more similar as concentration increases. PMID:27165547

  20. World Small Animal Veterinary Association Renal Pathology Initiative: Classification of Glomerular Diseases in Dogs.

    PubMed

    Cianciolo, R E; Mohr, F C; Aresu, L; Brown, C A; James, C; Jansen, J H; Spangler, W L; van der Lugt, J J; Kass, P H; Brovida, C; Cowgill, L D; Heiene, R; Polzin, D J; Syme, H; Vaden, S L; van Dongen, A M; Lees, G E

    2016-01-01

    Evaluation of canine renal biopsy tissue has generally relied on light microscopic (LM) evaluation of hematoxylin and eosin-stained sections ranging in thickness from 3 to 5 µm. Advanced modalities, such as transmission electron microscopy (TEM) and immunofluorescence (IF), have been used sporadically or retrospectively. Diagnostic algorithms of glomerular diseases have been extrapolated from the World Health Organization classification scheme for human glomerular disease. With the recent establishment of 2 veterinary nephropathology services that evaluate 3-µm sections with a panel of histochemical stains and routinely perform TEM and IF, a standardized objective species-specific approach for the diagnosis of canine glomerular disease was needed. Eight veterinary pathologists evaluated 114 parameters (lesions) in renal biopsy specimens from 89 dogs. Hierarchical cluster analysis of the data revealed 2 large categories of glomerular disease based on the presence or absence of immune complex deposition: The immune complex-mediated glomerulonephritis (ICGN) category included cases with histologic lesions of membranoproliferative or membranous patterns. The second category included control dogs and dogs with non-ICGN (glomerular amyloidosis or focal segmental glomerulosclerosis). Cluster analysis performed on only the LM parameters led to misdiagnosis of 22 of the 89 cases-that is, ICGN cases moved to the non-ICGN branch of the dendrogram or vice versa, thereby emphasizing the importance of advanced diagnostic modalities in the evaluation of canine glomerular disease. Salient LM, TEM, and IF features for each pattern of disease were identified, and a preliminary investigation of related clinicopathologic data was performed. PMID:25957358

  1. World Small Animal Veterinary Association Renal Pathology Initiative: Classification of Glomerular Diseases in Dogs.

    PubMed

    Cianciolo, R E; Mohr, F C; Aresu, L; Brown, C A; James, C; Jansen, J H; Spangler, W L; van der Lugt, J J; Kass, P H; Brovida, C; Cowgill, L D; Heiene, R; Polzin, D J; Syme, H; Vaden, S L; van Dongen, A M; Lees, G E

    2016-01-01

    Evaluation of canine renal biopsy tissue has generally relied on light microscopic (LM) evaluation of hematoxylin and eosin-stained sections ranging in thickness from 3 to 5 µm. Advanced modalities, such as transmission electron microscopy (TEM) and immunofluorescence (IF), have been used sporadically or retrospectively. Diagnostic algorithms of glomerular diseases have been extrapolated from the World Health Organization classification scheme for human glomerular disease. With the recent establishment of 2 veterinary nephropathology services that evaluate 3-µm sections with a panel of histochemical stains and routinely perform TEM and IF, a standardized objective species-specific approach for the diagnosis of canine glomerular disease was needed. Eight veterinary pathologists evaluated 114 parameters (lesions) in renal biopsy specimens from 89 dogs. Hierarchical cluster analysis of the data revealed 2 large categories of glomerular disease based on the presence or absence of immune complex deposition: The immune complex-mediated glomerulonephritis (ICGN) category included cases with histologic lesions of membranoproliferative or membranous patterns. The second category included control dogs and dogs with non-ICGN (glomerular amyloidosis or focal segmental glomerulosclerosis). Cluster analysis performed on only the LM parameters led to misdiagnosis of 22 of the 89 cases-that is, ICGN cases moved to the non-ICGN branch of the dendrogram or vice versa, thereby emphasizing the importance of advanced diagnostic modalities in the evaluation of canine glomerular disease. Salient LM, TEM, and IF features for each pattern of disease were identified, and a preliminary investigation of related clinicopathologic data was performed.

  2. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  3. Exercises to Improve Gait Abnormalities

    MedlinePlus

    ... Home About iChip Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

  4. Abnormal ionization in sonoluminescence

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Juan; An, Yu

    2015-04-01

    Sonoluminescence is a complex phenomenon, the mechanism of which remains unclear. The present study reveals that an abnormal ionization process is likely to be present in the sonoluminescing bubble. To fit the experimental data of previous studies, we assume that the ionization energies of the molecules and atoms in the bubble decrease as the gas density increases and that the decrease of the ionization energy reaches about 60%-70% as the bubble flashes, which is difficult to explain by using previous models. Project supported by the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110031) and the National Natural Science Foundation of China (Grant No. 11334005).

  5. Diatomite releases silica during spirit filtration.

    PubMed

    Gómez, J; Gil, M L A; de la Rosa-Fox, N; Alguacil, M

    2014-09-15

    The purpose of this study was to ascertain whether diatomite is an inert filter aid during spirit filtration. Surely, any compound with a negative effect on the spirit composition or the consumer's health could be dissolved. In this study different diatomites were treated with 36% vol. ethanol/water mixtures and the amounts and structures of the extracted compounds were determined. Furthermore, Brandy de Jerez was diatomite- and membrane-filtered at different temperatures and the silicon content was analysed. It was found that up to 0.36% by weight of diatomite dissolved in the aqueous ethanol and amorphous silica, in the form of hollow spherical microparticles, was the most abundant component. Silicon concentrations in Brandy de Jerez increased by up to 163.0% after contact with diatomite and these changes were more marked for calcined diatomite. In contrast, reductions of more than 30% in silicon concentrations were achieved after membrane filtration at low temperatures.

  6. Cellular proliferation after experimental glaucoma filtration surgery

    SciTech Connect

    Jampel, H.D.; McGuigan, L.J.; Dunkelberger, G.R.; L'Hernault, N.L.; Quigley, H.A.

    1988-01-01

    We used light microscopic autoradiography to determine the time course of cellular incorporation of tritiated thymidine (a correlate of cell division) following glaucoma filtration surgery in seven eyes of four cynomolgus monkeys with experimental glaucoma. Incorporation of tritiated thymidine was detected as early as 24 hours postoperatively. Peak incorporation occurred five days postoperatively and had returned to baseline levels by day 11. Cells incorporating tritiated thymidine included keratocytes, episcleral cells, corneal and capillary endothelial cells, and conjunctival and corneal epithelial cells. Transmission electron microscopy was correlated with the autoradiographic results to demonstrate that fibroblasts were dividing on the corneoscleral margin. These findings have potential clinical implications for the use of antiproliferative agents after filtration surgery.

  7. Ultrasonic filtration of industrial chemical solutions

    NASA Technical Reports Server (NTRS)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  8. Optimal filtration of the atmospheric parameters profiles

    NASA Technical Reports Server (NTRS)

    Zuev, V. E.; Glazov, G. N.; Igonin, G. M.

    1986-01-01

    The idea of optimal Marcovian filtration of fluctuating profiles from lidar signals is developed but as applied to a double-frequency sounding which allows the use of large cross sections of elastic scattering and correct separation of the contributions due to aerosol and Rayleigh scatterings from the total lidar return. The filtration efficiency is shown under different conditions of sounding using a computer model. The accuracy of restituted profiles (temperature, pressure, density) is determined by the elements of a posteriori matrix K. The results obtained allow the determination of the lidar power required for providing the necessary accuracy of restitution of the atmospheric parameter profiles at chosen wavelengths of sounding in the ultraviolet and visible range.

  9. Filtration kinetics of chitosan separation by electrofiltration.

    PubMed

    Gözke, Gözde; Kirschhöfer, Frank; Heissler, Stefan; Trutnau, Mirko; Brenner-Weiss, Gerald; Ondruschka, Jelka; Obst, Ursula; Posten, Clemens

    2012-02-01

    Downstream processing of chitosan requires several technological steps that contribute to the total production costs. Precipitation and especially evaporation are energy-consuming processes, resulting in higher costs and limiting industrial scale production. This study investigated the filtration kinetics of chitosan derived from cell walls of fungi and from exoskeletons of arthropods by electrofiltration, an alternative method, thus reducing the downstream processing steps and costs. Experiments with different voltages and pressures were conducted in order to demonstrate the effect of both parameters on filtration kinetics. The concentration of the biopolymer was obtained by the average factor of 40 by applying an electric field of 4 V/mm and pressure of 4 bars. A series of analytical experiments demonstrated the lack of structural and functional changes in chitosan molecules after electrofiltration. These results, combined with the reduction of energy and processing time, define the investigated method as a promising downstream step in the chitosan production technology.

  10. Abnormal hematological indices in cirrhosis

    PubMed Central

    Qamar, Amir A; Grace, Norman D

    2009-01-01

    Abnormalities in hematological indices are frequently encountered in cirrhosis. Multiple causes contribute to the occurrence of hematological abnormalities. Recent studies suggest that the presence of hematological cytopenias is associated with a poor prognosis in cirrhosis. The present article reviews the pathogenesis, incidence, prevalence, clinical significance and treatment of abnormal hematological indices in cirrhosis. PMID:19543577

  11. Granular filtration in a fluidized bed

    SciTech Connect

    Mei, J.S.; Yue, P.C.; Halow, J.S.

    1995-12-01

    Successful development of advanced coal-fired power conversion systems often require reliable and efficient cleanup devices which can remove particulate and gaseous pollutants from high-temperature high-pressure gas streams. A novel filtration concept for particulate cleanup has been developed at the Morgantown Energy Technology Center (METC) of the U.S. Department of Energy. The filtration system consists of a fine metal screen filter immersed in a fluidized bed of granular material. As the gas stream passes through the fluidized bed, a layer of the bed granular material is entrained and deposited at the screen surface. This material provides a natural granular filter to separate fine particles from the gas stream passing through the bed. Since the filtering media is the granular material supplied by the fluidized bed, the filter is not subjected to blinding like candle filters. Because only the inflowing gas, not fine particle cohesive forces, maintains the granular layer at the screen surface, once the thickness and permeability of the granular layer is stabilized, it remains unchanged as long as the in-flowing gas flow rate remains constant. The weight of the particles and the turbulent nature of the fluidized bed limits the thickness of the granular layer on the filter leading to a self-cleaning attribute of the filter. This paper presents work since then on a continuous filtration system. The continuous filtration testing system consisted of a filter, a two-dimensional fluidized-bed, a continuous powder feeder, a laser-based in-line particle counting, sizing, and velocimeter (PCSV), and a continuous solids feeding/bed material withdrawal system. The two-dimensional, transparent fluidized-bed allowed clear observation of the general fluidized state of the granular material and the conditions under which fines are captured by the granular layer.

  12. Tailoring wall permeabilities for enhanced filtration

    NASA Astrophysics Data System (ADS)

    Herterich, J. G.; Vella, D.; Field, R. W.; Hankins, N. P.; Griffiths, I. M.

    2015-05-01

    The build-up of contaminants at the wall of cross-flow membrane filtration systems can be detrimental to the operation of such systems because of, amongst other things, the osmotic backflow it may induce. In this paper, we propose a strategy to avoid the negative effects of backflow due to osmosis by using 2D channels bounded by walls with a combination of permeable and impermeable segments. We show that preventing flow through the final portion of the channel can increase the efficiency of filtration and we determine the optimal fraction occupied by the permeable wall that maximizes efficiency. Our analysis uses a combination of numerical techniques and asymptotic analysis in the limit of low wall permeabilities. Finally, we consider how the energy cost of filtration depends on the Péclet number and show that the energy cost per unit of filtered water may be minimized by appropriately choosing both the Péclet number and the permeable-region fraction.

  13. Purification of Carbon Nanotubes by Magnetic Filtration

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Luzzi, D. E.

    2004-03-01

    Great effort has been expended in the development of methods to purify raw carbon nanotube materials by chemical treatment, washing, mechanical filtration or heat treatment in a vacuum or oxidative environment. These techniques are limited by incomplete removal of catalyst nanoparticles and by damage to the nanotubes that often results. Incomplete removal is due to the very nature of the catalyst nanoparticles which are often encapsulated inside a protective amorphous carbon or graphitic coating. We have applied magnetic filtration as a means to effectively remove the ferromagnetic catalyst nanoparticles achieving reductions of >90% by weight. In this method, SWNT solution is filtered through a column containing Fe or Ni beads in the presence of a magnetic field, by which the catalyst is attracted to the beads. We present the efficacy of various purification schemes using magnetic filtration alone, or combined with chemical-based or annealing-based oxidative treatments. The quality of the nanotube materials is quantitatively assessed using Raman spectroscopy, thermo-gravimetric analysis and electron microscopy.

  14. Acoustic filtration and sedimentation of soot particles

    NASA Astrophysics Data System (ADS)

    Martin, K. M.; Ezekoye, O. A.

    Removal of soot particles from a static chamber by an intense acoustic field is investigated. Combustion of a solid fuel fills a rectangular chamber with small soot particles, which sediment very slowly. The chamber is then irradiated by an intense acoustic source to produce a three dimensional standing wave field in the chamber. The acoustic excitation causes the soot particles to agglomerate, forming larger particles which sediment faster from the system. The soot also forms 1-2 cm disks, with axes parallel to the axis of the acoustic source, which are levitated by the sound field at half-wavelength spacing within the chamber. Laser extinction measurements are made to determine soot volume fractions as a function of exposure time within the chamber. The volume fraction is reduced over time by sedimentation and by particle migration to the disks. The soot disks are considered to be a novel mechanism for particle removal from the air stream, and this mechanism has been dubbed acoustic filtration. An experimental method is developed for comparing the rate of soot removal by sedimentation alone with the rate of soot removal by sedimentation and acoustic filtration. Results show that acoustic filtration increases the rate of soot removal by a factor of two over acoustically-induced sedimentation alone.

  15. Filtration behavior of slurries with varying compressibilities

    SciTech Connect

    Massuda, M.; Bridger, K.; Harvey, M.; Tiller, F.M.

    1988-10-01

    A novel filtration apparatus allows simultaneous measurements of filtrate volume, hydraulic pressure and cake thickness using slurry volumes on the order of 100 cm/sup 3/. Differences in interparticle interactions were studied by varying the barium chloride concentration of 0.38-..mu..m polystyrene latex and filtering at pressures between 2 and 100 psi. Cakes formed from these slurries are highly compressible for concentrations between 0.01M and 0.10M, moderately compressible for the 0.005M concentration, and incompressible for the 0.001M concentration. Plots of filtrate volume versus cake thickness were linear for the incompressible cakes, whereas the compressible cakes showed significant deviations, which were pressure dependent. The pressure distribution for the incompressible cake was found to be essentially linear as predicted from the resistance plots assuming constant ..cap alpha.. and epsilon. For the highly compressible cakes, most of the pressure drop appears to occur near the cake/medium interface with only small changes occurring at the top of the cake.

  16. Spirometric abnormalities among welders

    SciTech Connect

    Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. )

    1991-10-01

    A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

  17. Filtration Combustion in Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard J.

    2001-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS , a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to ensure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS nevertheless, the two applications have much in common so that what is learned fit make application can be used to advantage in the other. In porous

  18. Characterization of Filtration Scale-Up Performance

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Luna, Maria L.; Cantrell, Kirk J.; Peterson, Reid A.; Bonebrake, Michael L.; Shimskey, Rick W.; Jagoda, Lynette K.

    2009-03-09

    The scale-up performance of sintered stainless steel crossflow filter elements planned for use at the Pretreatment Engineering Platform (PEP) and at the Waste Treatment and Immobilization Plant (WTP) were characterized in partial fulfillment (see Table S.1) of the requirements of Test Plan TP RPP WTP 509. This test report details the results of experimental activities related only to filter scale-up characterization. These tests were performed under the Simulant Testing Program supporting Phase 1 of the demonstration of the pretreatment leaching processes at PEP. Pacific Northwest National Laboratory (PNNL) conducted the tests discussed herein for Bechtel National, Inc. (BNI) to address the data needs of Test Specification 24590-WTP-TSP-RT-07-004. Scale-up characterization tests employ high-level waste (HLW) simulants developed under the Test Plan TP-RPP-WTP-469. The experimental activities outlined in TP-RPP-WTP-509 examined specific processes from two broad areas of simulant behavior: 1) leaching performance of the boehmite simulant as a function of suspending phase chemistry and 2) filtration performance of the blended simulant with respect to filter scale-up and fouling. With regard to leaching behavior, the effect of anions on the kinetics of boehmite leaching was examined. Two experiments were conducted: 1) one examined the effect of the aluminate anion on the rate of boehmite dissolution and 2) another determined the effect of secondary anions typical of Hanford tank wastes on the rate of boehmite dissolution. Both experiments provide insight into how compositional variations in the suspending phase impact the effectiveness of the leaching processes. In addition, the aluminate anion studies provide information on the consequences of gibbsite in waste. The latter derives from the expected fast dissolution of gibbsite relative to boehmite. This test report concerns only results of the filtration performance with respect to scale-up. Test results for boehmite

  19. Removal of pathogens using riverbank filtration

    NASA Astrophysics Data System (ADS)

    Cote, M. M.; Emelko, M. B.; Thomson, N. R.

    2003-04-01

    Although more than hundred years old, in situ or Riverbank Filtration (RBF) has undergone a renewed interest in North America because of its potential as a surface water pre-treatment tool for removal of pathogenic microorganisms. A new RBF research field site has been constructed along the banks of the Grand River in Kitchener, Ontario, Canada to assess factors influencing pathogen removal in the subsurface. Implementation of RBF and appropriate design of subsequent treatment (UV, chlorination, etc.) processes requires successful quantification of in situ removals of Cryptosporidium parvum or a reliable surrogate parameter. C.~parvum is often present in surface water at low indigenous concentrations and can be difficult to detect in well effluents. Since releases of inactivated C.~parvum at concentrations high enough for detection in well effluents are cost prohibitive, other approaches for demonstrating effective in situ filtration of C.~parvum must be considered; these include the use of other microbial species or microspheres as indicators of C.~parvum transport in the environment. Spores of Bacillus subtilis may be considered reasonable indicators of C.~parvum removal by in situ filtration because of their size (˜1 μm in diameter), spherical shape, relatively high indigenous concentration is many surface waters, and relative ease of enumeration. Based on conventional particle filtration theory and assuming equivalent chemical interactions for all particle sizes, a 1 μm B.~subtilis spore will be removed less readily than a larger C. parvum oocyst (4-6 μm) in an ideal granular filter. Preliminary full-scale data obtained from a high rate RBF production well near the new RBF test site demonstrated greater than 1 log removal of B.~subtilis spores. This observed spore removal is higher than that prescribed by the proposed U.S. Long Term 2 Enhanced Surface Water Treatment Rule for C.~parvum. To further investigate the removal relationship between C

  20. ETA receptor specific stimulation of glomerular inflammation and injury in streptozotocin-induced diabetic rats

    PubMed Central

    Saleh, M. A.; Boesen, E. I.; Pollock, J. S.; Savin, V. J.; Pollock, D. M.

    2013-01-01

    Aims/hypothesis ETA receptor activation increases glomerular permeability to albumin (Palb) and elevates pre-inflammatory markers in hyperglycaemic (HG) rats. Methods Male Sprague-Dawley rats were given streptozotocin (STZ), n=32 or saline (sham,), n=32. Half of the animals in each group received the ETA-selective antagonist, ABT-627 (atrasentan; p.o.), beginning immediately after hyperglycaemia was confirmed. Glomeruli were isolated by sieving techniques and Palb determined from the change in glomerular volume induced by oncotic gradients of albumin. Glomerular nephrin expression was assessed by immunofluorescence, whereas urinary nephrin was measured by immunoassay. Results Three and six weeks after STZ injection, proteinuria was significantly increased compared to sham controls and was significantly reduced by ABT-627 treatment. Palb was also increased at 3 and 6 wk post-STZ; ABT-627 had no effect on Palb or protein excretion in sham rats. In glomeruli isolated from HG rats, incubation with BQ-123, a selective ETA antagonist, reduced Palb, whereas BQ-788, a selective ETB antagonist had no effect (n=6 rats/group, 5-8 glomeruli/rat). Glomerular and plasma content of soluble inter-cellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1) were significantly increased 6 wk after STZ (ELISA). ABT-627 attenuated these increases. After 6 weeks of hyperglycaemia, glomerular nephrin expression was decreased with a concurrent increase in urinary nephrin excretion; ABT-627 prevented glomerular nephrin loss in the HG rats (n=5-8 rats in the eight groups). Conclusions/Interpretation These observations support the hypothesis that ET-1, via the ETA receptor, directly increases glomerular permeability to albumin, possibly via nephrin loss, as well as early inflammation in the HG rat. PMID:21191784

  1. Modulation of hemodynamic and vascular filtration changes in diabetic rats by dietary myo-inositol

    SciTech Connect

    Pugliese, G.; Tilton, R.G.; Speedy, A.; Santarelli, E.; Eades, D.M.; Province, M.A.; Kilo, C.; Sherman, W.R.; Williamson, J.R. )

    1990-03-01

    To assess the potential of myo-inositol-supplemented diets to prevent diabetes-induced vascular functional changes, we examined the effects of diets supplemented with 0.5, 1, or 2% myo-inositol on blood flow and vascular filtration function in nondiabetic control rats and rats with streptozocin-induced diabetes (STZ-D). After 1 mo of diabetes and dietary myo-inositol supplementation, (1) 131I-labeled bovine serum albumin (BSA) permeation of vessels was assessed in multiple tissues, (2) glomerular filtration rate (GFR) was estimated as renal plasma clearance of 57Co-labeled EDTA, (3) regional blood flows were measured with 15-microns 85Sr-labeled microspheres, and (4) endogenous albumin and IgG urinary excretion rates were quantified by radial immunodiffusion assay. In STZ-D rats, 131I-BSA tissue clearance increased significantly (2- to 4-fold) in the anterior uvea, choroid-sclera, retina, sciatic nerve, aorta, new granulation tissue, diaphragm, and kidney but was unchanged in skin, forelimb muscle, and heart. myo-Inositol-supplemented diets reduced diabetes-induced increases in 131I-BSA clearance (in a dose-dependent manner) in all tissues; however, only in new granulation tissue and diaphragm did the 2% myo-inositol diet completely normalize vascular albumin permeation. Diabetes-induced increases in GFR and in urinary albumin and IgG excretion were also substantially reduced or normalized by dietary myo-inositol supplements. Increased blood flow in anterior uvea, choroid-sclera, kidney, new granulation tissue, and skeletal muscle in STZ-D rats also was substantially reduced or normalized by the 2% myo-inositol diet. myo-Inositol had minimal if any effects on the above parameters in control rats.

  2. A Rare Stapes Abnormality

    PubMed Central

    Kanona, Hala; Virk, Jagdeep Singh; Kumar, Gaurav; Chawda, Sanjiv; Khalil, Sherif

    2015-01-01

    The aim of this study is to increase awareness of rare presentations, diagnostic difficulties alongside management of conductive hearing loss and ossicular abnormalities. We report the case of a 13-year-old female reporting progressive left-sided hearing loss and high resolution computed tomography was initially reported as normal. Exploratory tympanotomy revealed an absent stapedius tendon and lack of connection between the stapes superstructure and footplate. The footplate was fixed. Stapedotomy and stapes prosthesis insertion resulted in closure of the air-bone gap by 50 dB. A review of world literature was performed using MedLine. Middle ear ossicular discontinuity can result in significant conductive hearing loss. This can be managed effectively with surgery to help restore hearing. However, some patients may not be suitable or decline surgical intervention and can be managed safely conservatively. PMID:25628909

  3. Increased Goodpasture Antigen-Binding Protein Expression Induces Type IV Collagen Disorganization and Deposit of Immunoglobulin A in Glomerular Basement Membrane

    PubMed Central

    Revert, Fernando; Merino, Ramón; Monteagudo, Carlos; Macias, Jesús; Peydró, Amando; Alcácer, Javier; Muniesa, Pedro; Marquina, Regina; Blanco, Mario; Iglesias, Marcos; Revert-Ros, Francisco; Merino, Jesús; Saus, Juan

    2007-01-01

    Increased expression of Goodpasture antigen-binding protein (GPBP), a protein that binds and phosphorylates basement membrane collagen, has been associated with immune complex-mediated pathogenesis. However, recent reports have questioned this biological function and proposed that GPBP serves as a cytosolic ceramide transporter (CERTL). Thus, the role of GPBP in vivo remains unknown. New Zealand White (NZW) mice are considered healthy animals although they convey a genetic predisposition for immune complex-mediated glomerulonephritis. Here we show that NZW mice developed age-dependent lupus-prone autoimmune response and immune complex-mediated glomerulonephritis characterized by elevated GPBP, glomerular basement membrane (GBM) collagen disorganization and expansion, and deposits of IgA on disrupted GBM. Transgenic overexpression of human GPBP (hGPBP) in non-lupus-prone mice triggered similar glomerular abnormalities including deposits of IgA on a capillary GBM that underwent dissociation, in the absence of an evident autoimmune response. We provide in vivo evidence that GPBP regulates GBM collagen organization and its elevated expression causes dissociation and subsequent accumulation of IgA on the GBM. Finally, we describe a previously unrecognized pathogenic mechanism that may be relevant in human primary immune complex-mediated glomerulonephritis. PMID:17916599

  4. Aberrant Blood Vessel Formation Connecting the Glomerular Capillary Tuft and the Interstitium Is a Characteristic Feature of Focal Segmental Glomerulosclerosis-like IgA Nephropathy

    PubMed Central

    Lim, Beom Jin; Kim, Min Ju; Hong, Soon Won; Jeong, Hyeon Joo

    2016-01-01

    Background: Segmental glomerulosclerosis without significant mesangial or endocapillary proliferation is rarely seen in IgA nephropathy (IgAN), which simulates idiopathic focal segmental glomerulosclerosis (FSGS). We recently recognized aberrant blood vessels running through the adhesion sites of sclerosed tufts and Bowman’s capsule in IgAN cases with mild glomerular histologic change. Methods: To characterize aberrant blood vessels in relation to segmental sclerosis, we retrospectively reviewed the clinical and histologic features of 51 cases of FSGS-like IgAN and compared them with 51 age and gender-matched idiopathic FSGS cases. Results: In FSGS-like IgAN, aberrant blood vessel formation was observed in 15.7% of cases, 1.0% of the total glomeruli, and 7.3% of the segmentally sclerosed glomeruli, significantly more frequently than in the idiopathic FSGS cases (p = .009). Aberrant blood vessels occasionally accompanied mild cellular proliferation surrounding penetrating neovessels. Clinically, all FSGS-like IgAN cases had hematuria; however, nephrotic range proteinuria was significantly less frequent than idiopathic FSGS. Conclusions: Aberrant blood vessels in IgAN are related to glomerular capillary injury and may indicate abnormal repair processes in IgAN. PMID:27068024

  5. Regression of superficial glomerular podocyte injury in type 2 diabetic rats with overt albuminuria: effect of angiotensin II blockade

    PubMed Central

    Ihara, Genei; Kiyomoto, Hideyasu; Kobori, Hiroyuki; Nagai, Yukiko; Ohashi, Naro; Hitomi, Hirofumi; Nakano, Daisuke; Pelisch, Nicolas; Hara, Taiga; Mori, Takefumi; Ito, Sadayoshi; Kohno, Masakazu; Nishiyama, Akira

    2010-01-01

    Objective Clinical studies indicate that the remission, regression or both of nephrotic-range albuminuria are exerted by angiotensin II receptor blockers (ARBs) in diabetes. The current study was performed to test the hypothesis that these effects of ARBs are associated with regression of glomerular podocyte injury. Methods We examined the effects of an ARB, olmesartan, on glomerular podocyte injury in type 2 diabetic Otsuka–Long–Evans–Tokushima-Fatty rats with overt albuminuria. Results At baseline (55-week-old), diabetic Otsuka–Long–Evans–Tokushima-Fatty rats showed severe albuminuria with desmin-positive areas (an index of podocyte injury) in both superficial and juxtamedullary glomeruli, and podocyte injury was much greater in juxtamedullary than in superficial glomeruli. At 75-week-old, Otsuka–Long–Evans–Tokushima-Fatty rats had developed more severe albuminuria and superficial glomerular podocyte injury, whereas juxtamedullary glomerular podocyte injury did not advance further. Olmesartan (10 mg/kg per day) decreased albuminuria and superficial glomerular desmin staining to levels that were lower than those at baseline, whereas advanced juxtamedullary glomerular podocyte injury was not changed. Conclusion The current study demonstrates for the first time that juxtamedullary glomerular podocyte injury reaches a severe condition at an earlier time than superficial glomerular podocyte injury during the progression of overt albuminuria in type 2 diabetic rats. Our data also support the hypothesis that the antialbuminuric effects of ARBs are associated with regression of superficial glomerular podocyte injury in type 2 diabetes with nephrotic-range albuminuria. PMID:20706133

  6. Short- and long-term follow-up of glomerular and tubular renal markers of kidney function in hyperthyroid cats after treatment with radioiodine.

    PubMed

    van Hoek, I; Lefebvre, H P; Peremans, K; Meyer, E; Croubels, S; Vandermeulen, E; Kooistra, H; Saunders, J H; Binst, D; Daminet, S

    2009-01-01

    Hyperthyroidism can mask co-existing chronic kidney disease (CKD). Previous studies showed that post-treatment renal azotemia can be predicted by pre-treatment assessment of glomerular filtration rate (GFR). We hypothesized that treatment of hyperthyroidism may have different effects on glomerular and tubular function and these changes might be predicted by additional pre-treatment variables than GFR. Serum total T4 (TT4), creatinine and blood urea nitrogen (BUN), blood pressure (BP), body weight (BW), GFR, urine specific gravity (USG), urinary protein/creatinine ratio (UPC) and retinol binding protein/creatinine ratio (uRBP/c) were evaluated before and 1, 4, 12 and 24 weeks post-treatment with radioiodine ((131)I) in 21 non-azotemic hyperthyroid cats. Cats were divided 24 weeks post-treatment into group A (normal kidney function, n=16) and group B (impaired kidney function, n=5). Serum TT4, GFR, UPC and uRBP/c decreased significantly after treatment for the complete group and group A (P<0.05), although GFR and uRBP/c did not change in group B. Serum creatinine and BW increased significantly from 1 week after treatment (P<0.05). There was no change in BUN, USG or BP. Pre-treatment serum TT4, GFR and USG differed significantly between group A and B (P<0.05). GFR at 4 weeks after treatment and maximum decrease in GFR could be partially predicted by a formula using pre-treatment GFR, serum TT4, serum creatinine, BUN and/or USG. Significant changes in kidney function occur within 4 weeks post-treatment and none thereafter. Pre-treatment measurement of GFR, USG and serum TT4 can have possible predictive value regarding the development of post-treatment renal azotemia. PMID:19010632

  7. Converting enzyme inhibition and the glomerular hemodynamic response to glycine in diabetic rats.

    PubMed

    Slomowitz, L A; Peterson, O W; Thomson, S C

    1999-07-01

    GFR normally increases during glycine infusion. This response is absent in humans and rats with established diabetes mellitus. In diabetic patients, angiotensin-converting enzyme inhibition (ACEI) restores the effect of glycine on GFR. To ascertain the glomerular hemodynamic basis for this effect of ACEI, micropuncture studies were performed in male Wistar-Froemter rats after 5 to 6 wk of insulin-treated streptozotocin diabetes. The determinants of single-nephron GFR (SNGFR) were assessed in each rat before and during glycine infusion. Studies were performed in diabetics, diabetics after 5 d of ACEI (enalapril in the drinking water), and weight-matched controls. Diabetic rats manifest renal hypertrophy and glomerular hyperfiltration but not glomerular capillary hypertension. ACEI reduced glomerular capillary pressure, increased glomerular ultrafiltration coefficient, and did not mitigate hyperfiltration. In controls, glycine increased SNGFR by 30% due to increased nephron plasma flow. In diabetics, glycine had no effect on any determinant of SNGFR. In ACEI-treated diabetics, the SNGFR response to glycine was indistinguishable from nondiabetics, but the effect of glycine was mediated by greater ultrafiltration pressure rather than by greater plasma flow. These findings demonstrate that: (1) The absent response to glycine in established diabetes does not indicate that renal functional reserve is exhausted by hyperfiltration; and (2) ACEI restores the GFR response to glycine in established diabetes, but this response is mediated by increased ultrafiltration pressure rather than by increased nephron plasma flow.

  8. Nephritogenic Lupus Antibodies Recognize Glomerular Basement Membrane-Associated Chromatin Fragments Released from Apoptotic Intraglomerular Cells

    PubMed Central

    Kalaaji, Manar; Mortensen, Elin; Jørgensen, Leif; Olsen, Randi; Rekvig, Ole Petter

    2006-01-01

    Antibodies to dsDNA represent a classification criterion for systemic lupus erythematosus. Subpopulations of these antibodies are involved in lupus nephritis. No known marker separates nephritogenic from non-nephritogenic anti-dsDNA antibodies. It is not clear whether specificity for glomerular target antigens or intrinsic antibody-affinity for dsDNA or nucleosomes is a critical parameter. Furthermore, it is still controversial whether glomerular target antigen(s) is constituted by nucleosomes or by non-nucleosomal glomerular structures. Previously, we have demonstrated that antibodies eluted from murine nephritic kidneys recognize nucleosomes, but not other glomerular antigens. In this study, we determined the structures that bind nephritogenic autoantibodies in vivo by transmission electron microscopy, immune electron microscopy, and colocalization immune electron microscopy using experimental antibodies to dsDNA, to histones and transcription factors, or to laminin. The data obtained are consistent and point at glomerular basement membrane-associated nucleosomes as target structures for the nephritogenic autoantibodies. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling or caspase-3 assays demonstrate that lupus nephritis is linked to intraglomerular cell apoptosis. The data suggest that nucleosomes are released by apoptosis and associate with glomerulus basement membranes, which may then be targeted by pathogenic anti-nucleosome antibodies. Thus, apoptotic nucleosomes may represent both inducer and target structures for nephritogenic autoantibodies in systemic lupus erythematosus. PMID:16723695

  9. Glomerular alterations in uranyl acetate-induced acute renal failure in rabbits

    SciTech Connect

    Kobayashi, S.; Nagase, M.; Honda, N.; Hishida, A.

    1984-12-01

    The study was performed to elucidate the progression and regression of superficial and inner glomerular alterations in uranyl acetate-induced renal failure in rabbits. Fifteen hours after the drug injection, creatinine clearance (CCr) decreased to 55% of controls with slightly elevated plasma creatinine concentration (initiation stage). After 5 days, urine flow and CCr decreased to approximately zero, with severe azotemia (maintenance stage). Scanning electron microscopic observations in these stages revealed a flattening and spreading of podocyte cell bodies associated with loss of epithelial foot processes, and reduction in the density of endothelial fenestrae. These changes were more advanced in the maintenance stage. Glomerular and fenestral diameters did not significantly change in the initiation stage but increased in the maintenance stage. There was no significant difference in these morphologic alterations, however, between the superficial and inner glomeruli. Glomerular alterations reverted to normal within 14 days, with good recovery of glomerular function. The findings show no significant difference in the progression or regression of the glomerular changes between the superficial and deep cortex. These morphologic changes may play a role in the reduction of CCr observed in this model.

  10. Nephritogenic lupus antibodies recognize glomerular basement membrane-associated chromatin fragments released from apoptotic intraglomerular cells.

    PubMed

    Kalaaji, Manar; Mortensen, Elin; Jørgensen, Leif; Olsen, Randi; Rekvig, Ole Petter

    2006-06-01

    Antibodies to dsDNA represent a classification criterion for systemic lupus erythematosus. Subpopulations of these antibodies are involved in lupus nephritis. No known marker separates nephritogenic from non-nephritogenic anti-dsDNA antibodies. It is not clear whether specificity for glomerular target antigens or intrinsic antibody-affinity for dsDNA or nucleosomes is a critical parameter. Furthermore, it is still controversial whether glomerular target antigen(s) is constituted by nucleosomes or by non-nucleosomal glomerular structures. Previously, we have demonstrated that antibodies eluted from murine nephritic kidneys recognize nucleosomes, but not other glomerular antigens. In this study, we determined the structures that bind nephritogenic autoantibodies in vivo by transmission electron microscopy, immune electron microscopy, and colocalization immune electron microscopy using experimental antibodies to dsDNA, to histones and transcription factors, or to laminin. The data obtained are consistent and point at glomerular basement membrane-associated nucleosomes as target structures for the nephritogenic autoantibodies. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling or caspase-3 assays demonstrate that lupus nephritis is linked to intraglomerular cell apoptosis. The data suggest that nucleosomes are released by apoptosis and associate with glomerulus basement membranes, which may then be targeted by pathogenic anti-nucleosome antibodies. Thus, apoptotic nucleosomes may represent both inducer and target structures for nephritogenic autoantibodies in systemic lupus erythematosus.

  11. Distinct pathogenic effects of group B coxsackieviruses on human glomerular and tubular kidney cells.

    PubMed Central

    Conaldi, P G; Biancone, L; Bottelli, A; De Martino, A; Camussi, G; Toniolo, A

    1997-01-01

    The six group B coxsackieviruses (CVBs) are highly prevalent human pathogens that cause viremia followed by involvement of different organs. Clinical and experimental evidence suggests that CVBs can induce kidney injury, but the susceptibility of human renal cells to these viruses is unknown. By using pure cultures of human glomerular and tubular cells, we demonstrated that all CVBs are capable of productively infecting renal cells of three different histotypes. Distinct pathogenic effects were observed. Proximal tubular epithelial cells and, to a lesser extent, glomerular podocytes were highly susceptible to CVBs; in both cases, infection led to cytolysis. In contrast, glomerular mesangial cells supported the replication of the six CVBs but failed to develop overt cytopathologic changes. Mesangial cells continued to produce infectious progeny for numerous serial subcultures (i.e., more than 50 days), especially with type 1, 3, 4, and 5 viruses. In the above cells, persistent infection induced the de novo synthesis of platelet-derived growth factor A/B and enhanced the release of transforming growth factor beta1/2. These two factors are important mediators of progression from glomerular inflammation to glomerulosclerosis. CVB replication appeared also to impair the phagocytic and contractile activity of mesangial cells. Loss of these properties--which are important in glomerular physiopathology--may contribute to the development of progressive nephropathy. The results show that CVBs induce distinct effects in different types of cultured renal cells and suggest that CVB infections may be associated with both acute and progressive renal injury. PMID:9371576

  12. Breakthrough of cyanobacteria in bank filtration.

    PubMed

    Pazouki, Pirooz; Prévost, Michèle; McQuaid, Natasha; Barbeau, Benoit; de Boutray, Marie-Laure; Zamyadi, Arash; Dorner, Sarah

    2016-10-01

    The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, 0.73 ≤ r(2) ≤ 0.94). Log removals from bank filtration estimated from taxonomic counts ranged from 0.96 ± (0.5) and varied according to the species of cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p < 0.05) than larger cells. Travel times from the lakes to the wells were estimated as 2 days for Lake B and 10 days for Lake A. Cyanobacterial species in the wells were most closely related to species found in Lake B. Thus, a travel time of less than 1 week permitted the breakthrough of cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins.

  13. Breakthrough of cyanobacteria in bank filtration.

    PubMed

    Pazouki, Pirooz; Prévost, Michèle; McQuaid, Natasha; Barbeau, Benoit; de Boutray, Marie-Laure; Zamyadi, Arash; Dorner, Sarah

    2016-10-01

    The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, 0.73 ≤ r(2) ≤ 0.94). Log removals from bank filtration estimated from taxonomic counts ranged from 0.96 ± (0.5) and varied according to the species of cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p < 0.05) than larger cells. Travel times from the lakes to the wells were estimated as 2 days for Lake B and 10 days for Lake A. Cyanobacterial species in the wells were most closely related to species found in Lake B. Thus, a travel time of less than 1 week permitted the breakthrough of cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins. PMID:27343842

  14. Investigation of Microgranular Adsorptive Filtration System

    NASA Astrophysics Data System (ADS)

    Cai, Zhenxiao

    Over the past few decades, enormous advances have been made in the application of low-pressure membrane filtration to both drinking water and wastewater treatment. Nevertheless, the full potential of this technology has not been reached, due primarily to limitations imposed by membrane fouling. In drinking water treatment, much of the fouling is caused by soluble and particulate natural organic matter (NOM). Efforts to overcome the problem have focused on removal of NOM from the feed solution, usually by addition of conventional coagulants like alum and ferric chloride (FeCl3) or adsorbents like powdered activated carbon (PAC). While coagulants and adsorbents can remove a portion of the NOM, their performance with respect to fouling control has been inconsistent, often reducing fouling but sometimes having no effect or even exacerbating fouling. This research investigated microgranular adsorptive filtration (muGAF), a process that combines three existing technologies---granular media filtration, packed bed adsorption, and membrane filtration---in a novel way to reduce membrane fouling while simultaneously removing NOM from water. In this technology, a thin layer of micron-sized adsorbent particles is deposited on the membrane prior to delivering the feed to the system. The research reported here represents the first systematic study of muGAF, and the results demonstrate the promising potential of this process. A new, aluminum-oxide-based adsorbent---heated aluminum oxide particles (HAOPs)---was synthesized and shown to be very effective for NOM removal as well as fouling reduction in muGAF systems. muGAF has also been demonstrated to work well with powdered activated carbon (PAC) as the adsorbent, but not as well as when HAOPs are used; the process has also been successful when used with several different membrane types and configurations. Experiments using a wide range of operational parameters and several analytical tools lead to the conclusion that the fouling

  15. Electrospinning of nanofibers for filtration media

    NASA Astrophysics Data System (ADS)

    Park, Hyoungjun

    Since particulate impurity is regarded as the primary cause of lung diseases, purification of air has been a crucial issue. Filtration is the most conventional method to obtain clean air, whereby particulate matter is collected on a fibrous media. The use of fibrous filters is prevalent because of their high filtration efficiency and low pressure drop. Fibrous filters were fabricated via the electrospinning process which can be used to produce continuous submicron-diameter sized fibers. Polyacrylonitrile (PAN) nanofibers with a mean fiber diameter of 224 nm were electrospun to form fibermats. Filtration tests on fibermats of PAN were conducted to confirm that filters of thinner fibers result in higher collection efficiencies and lower pressure drops than that of thicker fibers as predicted by the theoretical filtration mechanism. Results showed that electrospun PAN nanofibermats had a superior quality factor of 0.067+/-0 compared to 0.031+/-0.001 by the current state-of-the-art microfiber-based high particulate air (HEPA) filtration media. The verified theory implies that nanofibermats of other types of materials could also be considered as promising filtration media since filtration performance is independent of the material used. As materials for advanced next-generation filtration media, ceramics are favored over polymeric materials due to their robustness against environmental factors such as ultraviolet rays, abrasive particles, and high temperature all of which degrade and damage the fibrous structure. Amidst various ceramic materials, the anatase phase of TiO2 was selected due to its mechanical property and versatility as a photocatalyst and microwave-absorbing material. Anatase TiO2 fibers were fabricated by electrospinning followed by heat treatment at 500°C for 3 hours. However, early precipitation or gelation of the organic solvent-based TiO2 sol posed a practical challenge in the sample preparation. In order to enhance stability of the precursor sol, a

  16. Ictal Cardiac Ryhthym Abnormalities

    PubMed Central

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic–clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  17. Ictal Cardiac Ryhthym Abnormalities.

    PubMed

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic-clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  18. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  19. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential). PMID:261653

  20. Abnormal uterine bleeding.

    PubMed

    Whitaker, Lucy; Critchley, Hilary O D

    2016-07-01

    Abnormal uterine bleeding (AUB) is a common and debilitating condition with high direct and indirect costs. AUB frequently co-exists with fibroids, but the relationship between the two remains incompletely understood and in many women the identification of fibroids may be incidental to a menstrual bleeding complaint. A structured approach for establishing the cause using the Fédération International de Gynécologie et d'Obstétrique (FIGO) PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system will facilitate accurate diagnosis and inform treatment options. Office hysteroscopy and increasing sophisticated imaging will assist provision of robust evidence for the underlying cause. Increased availability of medical options has expanded the choice for women and many will no longer need to recourse to potentially complicated surgery. Treatment must remain individualised and encompass the impact of pressure symptoms, desire for retention of fertility and contraceptive needs, as well as address the management of AUB in order to achieve improved quality of life. PMID:26803558