Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This report examines the correlation between glomerular injury and glomerular dysfunction in murine lupus nephritis. Glomerular filtration rate was measured by the clearance of inulin in conscious NZB/W female mice and shown to vary 12-fold in the animals tested. Detailed morphometric measurements were made on the perfused fixed kidneys. As disease progressed the surface density (Sv) of the open capillary loops decreased by 73%. This drop in Sv correlated with a 4-fold increase in mean glomerular volume (MGV, r = -0.79, p less than 0.0001). The "compensating" increase in MGV maintained or increased filtration surface area despite the loss of some capillary loops to proliferating and/or infiltrating cells. Filtration slit length/glomerulus and the filtration slit number/micron glomerular basement membrane varied 10-fold and were found to correlate directly with glomerular filtration rate (r = 0.64, p less than 0.0007 and r = 0.70, p less than 0.0001, respectively). When linear and multiple regression analyses were applied, all other structural measures, including filtration surface area, correlated with glomerular filtration rate poorly if at all. Glomerular permselective dysfunction (proteinuria) was measured as the fractional clearance of albumin (fractional clearance of albumin) and of IgG. Stepwise multiple regression analysis revealed the percentage of the glomerular basement membrane occupied by dense deposits, slit number/glomerular basement membrane, and glomerular basement membrane thickness statistically explained most (81%) of the variation in fractional clearance of albumin and IgG. These results suggest that epithelial slit length is the most important structural determinant of GFR and that the increase in MGV maintains filtration surface area despite evidence of an extensive inflammatory insult. The mechanism(s) of proteinuria in this model of lupus nephritis are consistent with either a focal increase in GBM permeability due to immune deposits and/or a diffuse increase in permeability due to GBM charge neutralization. The study provides insight as to why previous structure-function reports failed to find correlates of glomerular injury to glomerular dysfunction.
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PMID:Murine lupus nephritis. A structure-function study. 207 65

Two separate experiments were carried out to study the effects of the same acute protein load given at different hours of the day and to assess the ability of proteins from different sources to induce hyperfiltration. In the first experiment, 9 healthy volunteers were kept at strict bedrest for 48 h, during which both a meat high-protein meal (protein load, PL) and a vegetable low-protein meal (control load, CL) were given either at lunch or at suppertime. As compared to a CL, PL determined a significant increase in GFR, total proteinuria (uTP), albuminuria (uA), and urinary retinol-binding protein (uRBP). These effects were much more significant after lunch PL than after supper PL, thus indicating an interaction between the PL and the time of the day. The existence of a circadian rhythm for GFR, uTP, uA, and uRBP was corroborated by spontaneous changes over baseline levels, which also were prominent after lunch CL as compared to those following supper CL. In the second experiment, 7 healthy volunteers ingested at lunch three protein-rich meals at 1-week intervals. The three protein loads consisted of about 80 g protein in the form of cooked red meat, cheese, and soya, respectively. The only significant differences between groups were urea appearance and urea clearance, lower and higher, respectively after soya load. These findings suggest that when evaluating the renal functional reserve after acute protein load both the spontaneous changes and the time-dependent sensitivity of kidney functions to acute challenges should be considered. Finally, the amount rather than quality of dietary proteins seems to be the determinant factor for protein-induced glomerular hyperfiltration.
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PMID:Protein-induced changes in kidney function depend on the time of administration but not on the dietary source. 207 4

Treatment of patients with membranous glomerulonephritis with prednisone on alternate days results in a decreased proteinuria on non-prednisone days. We have studied this phenomenon in more detail in 14 patients (11 M, 3 F) with membranous glomerulonephritis. Mean age +/- SD of the patients was 47 +/- 14 years, mean endogenous creatinine clearance 94 +/- 35 ml/min, and median proteinuria 8.8 g/24 h (range 5.0-30.0 g/24 h). Glomerular filtration rate (GFR, inulin clearance), effective renal plasma flow ERPF, PAH clearance), and proteinuria were measured on a control day (C), and six days after the start of alternate-day prednisone treatment, on the third non-prednisone day (NP3, 24-28 h after the last dose of prednisone). Proteinuria decreased from 6.1 mg/min (3.2-9.8 mg/min) (C) to 2.5 mg/min (1.0-7.7 mg/min) at NP3 (median, interquartile range; P less than 0.01), the percentage decrease averaged 45 +/- 8%. The decrease of proteinuria was correlated with baseline GFR (r = 0.75; P less than 0.01). GFR and ERPF did not change significantly, but filtration fraction decreased significantly from 14.5 +/- 0.8% (C) to 13.5 +/- 0.9% (NP3; P less than 0.05). Fractional excretion of albumin, IgG, and transferrin decreased significantly, by -40 +/- 8%, -52 +/- 6%, and -52 +/- 7% respectively. Fractional excretion of beta 2-microglobulin decreased significantly less by -12 +/- 10%. We conclude that proteinuria is decreased on non-prednisone days in patients with membranous glomerulonephritis treated with alternate-day steroids. The observed decrease of filtration fraction suggests that a reduction of glomerular pressure is involved. In addition, the magnitude of the decrease of proteinuria might indicate a change in glomerular permselectivity characteristics.
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PMID:Decreases of proteinuria during alternate-day prednisone therapy in nephrotic syndrome. 212 25

Hypertension and renal mass reduction induce glomerular hypertension (GH), hyperfiltration (HF) and renal injury. GH may contribute to allograft loss in post-transplant hypertensive patients (PT x HT). HF and GH may be evaluated by renal response to acute protein intake (API). Since ACE inhibition may prevent GH, the effects of fosinopril (Fos) were evaluated in 10 PT X HT on azathioprine and prednisone. Patients received 5 to 40 mg/day of Fos during 12 months. Baseline MAP (111.1 +/- 2.9 mm Hg) was significantly reduced by 10 to 12 mm Hg, rising to 114.7 +/- 2.7 mm Hg after Fos was administered. GFR (63.7 +/- 5.9 ml/min) decreased after 4 (48.1 +/- 4.6, P less than 0.05) and 12 months (50.7 +/- 4.6, P less than 0.05), rising to 59.4 +/- 5.6 after Fos was given. There was no GFR response to API before and after one month of Fos, however, a clear response became apparent at 4 (+ 27% P less than 0.05), and 12 months (+ 18%, P less than 0.05), disappearing after Fos discontinuation. Proteinuria (918.8 +/- 710.6 mg/d) decreased after 4 (72.3 +/- 21.6 mg/d, P less than 0.05) and 12 months, rising to 297.8 +/- 172.3 mg/day after therapy. GFR response to API in 22 controls and 17 uninephrectomized donors was 13 and 11%, respectively. Lack of response to API in PT x HT suggests HF and GH. Reduction of GFR, restoration of response to API and reduction of proteinuria, indicate that ACE inhibition with fosinopril ameliorates HF and GH. This effect may be beneficial in preventing hemodynamic-mediated allograft injury.
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PMID:Fosinopril prevents hyperfiltration and decreases proteinuria in post-transplant hypertensives. 214 57

Diabetic nephropathy is now the leading cause of renal failure in patients referred for uremia therapy. The diabetic patient is a complicated treatment problem from the first detection of microalbuminmuria, at which time decisions regarding choice of antihypertensive and strictness of metabolic control assume increasing importance. At present, our policy is to advocate strict control of blood pressure, aiming for a systolic blood pressure of less than 140 mm Hg and a diastolic blood pressure of less than 80 mm Hg. We attempt to maintain hemoglobin Alc levels at less than 8%, if the patient does not develop frequent episodes of hypoglycemia. We extend these recommendations to the patient with frank proteinuria, nephrotic syndrome and early uremia, understanding that strict metabolic control may be impossible as patients lose GFR. In addition, we recommend avoidance of a high protein diet in the early nephropathic diabetic, with diet of approximately 1 gm/kg/d. As renal failure progresses, we embark on an analysis of the patient's abilities, lifestyle, and social support. At a GFR of approximately 10 mL/min, we initiate preparations for uremia therapy. If a willing and appropriate living related kidney donor is available, the patient is referred for cardiovascular evaluation and kidney transplantation performed subsequently. If no donor is immediately available, we refer the patient for vascular access placement and/or insertion of a Tenckhoff peritoneal catheter, if preferred. Most of these predialysis patients also undergo screening for placement on the cadaveric kidney transplant list, including cardiac work-up as is done for the patients who receive living-related renal transplants. Because of the long waiting list in Brooklyn, and the universal shortage of organ donors, many of these patients eventually end up on dialysis for some period of time. Other extrarenal problems (urologic, ophthalmologic) are addressed at initial referral and followed up, in hopes of maintaining the patient in optimal physical shape as uremia progresses. The care of the diabetic patient with ESRD ideally involves a consortium of caregivers. We include a nurse-educator familiar with options for uremia therapy, a podiatrist, a cardiologist, and often a urologist, an endocrinologist, and a gastroenterologist. In addition, a social worker is helpful to assess psychologic difficulties in adjustment to uremia, socioeconomic considerations, and rehabilitation status. Finally, the nephrologist, as coordinator of this team works with the vascular or transplant surgeon, to facilitate the transition to ESRD and its therapy.
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PMID:Care of the diabetic patient with end-stage renal disease. 219 Feb 84

The relationship between blood pressure and progression of nephropathy was studied (the mean follow-up period of 32.6 +/- 17.9 (S.D.) months in 20 Type 2 (non-insulin-dependent) diabetic patients with clinical nephropathy (proteinuria greater than 0.5 g/day) and preserved renal function (serum creatinine level less than 150 mumol/liter). Fifteen hypertensive patients under antihypertensive treatment were divided into 2 groups: those with the mean diastolic blood pressure greater than or equal to 90 mmHg and/or the mean systolic blood pressure greater than or equal to 150 mmHg during the follow-up period were designated as Group A (n = 6) and the remainders as Group B (n = 9). Five normotensive patients without any anti-hypertensive treatment throughout the follow-up period served as a control group (Group C). The decline rate in GFR was significantly greater (p less than 0.05) in Group A (1.15 +/- 0.39 (S.E.) ml/min/month) than those in Groups B (0.33 +/- 0.08 ml/min/month) and C (0.40 +/- 0.09 ml/min/month), respectively. The decline rate in GFR showed significant positive correlations both with systolic (rS = 0.553, p less than 0.05) and diastolic (rS = 0.493, p less than 0.05) blood pressures in the 15 hypertensive patients. The age, initial glomerular filtration rate, duration of diabetes and mean HbA1c level during the observation period were comparable in Groups A, B and C, respectively. The results indicate that an uncontrolled hypertension is associated with a rapid progression of kidney impairment in Type 2 diabetic patients with overt nephropathy, as has been suggested in Type 1 (insulin-dependent) diabetic patients.
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PMID:Uncontrolled hypertension is associated with a rapid progression of nephropathy in type 2 diabetic patients with proteinuria and preserved renal function. 225 4

It has been suggested that angiotensin II (ANG II) activation after renal ablation contributes to the altered glomerular dynamics and proteinuria that characterizes this model of chronic renal failure. In the present study, male Munich-Wistar rats underwent 75% renal ablation (Nx group). Two weeks later, micropuncture studies were performed in sham-operated rats (sham group) and Nx group rats during intravenous infusion of either a vehicle or two ANG II inhibitors, namely [Sar1, Ala8]ANG II or MK-421 administered at a rate of 0.3 and 1 mg.kg body wt-1.h-1, respectively. Acute ANG II inhibition in sham group had no effect on mean arterial pressure (MAP), glomerular dynamics, or proteinuria. In contrast, in Nx group ANG II inhibition lessened glomerular hypertension (from 64.7 +/- 1.0 to 55.4 +/- 1.7 mmHg, P less than 0.0001) the result of postglomerular vasodilation (P less than 0.01), normalized the glomerular ultrafiltration coefficient (from 0.038 +/- 0.002 to 0.005 +/- 0.002 nl.s-1.mmHg-1, P less than 0.0001), and attenuated proteinuria (from 42.1 +/- 6.5 to 28.1 +/- 5.4 micrograms/min, P less than 0.01). MAP, single-nephron GFR and plasma flow were unaffected. These results suggest that ANG II activity is enhanced in nephrectomy, contributing in a major way to altered glomerular dynamics and proteinuria.
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PMID:Angiotensin II control of the renal microcirculation in rats with reduced renal mass. 230 95

Alpha-1-microglobulin (alpha-1-m) is a low molecular weight glycoprotein (mw 25-33 KD) that is filtered through the glomeruli and reabsorbed in the proximal parts of the renal tubules where it is catabolized. Normal ranges were established for alpha-1-m (100 healthy controls) in serum (20-42 mg/l) and urine (3.5-8 mg/l). Alpha-1-m was then measured in 341 urine samples whose protein pattern had been classified as "pathologic" and "normal" according to microelectrophoresis. Increased alpha-1-m concentrations were found in 266 out of 280 pathologic urines (5% false negative) and in 3 out of 61 normal urines (4% false positive). Beta-2-microglobulin (beta-2-m), total protein or protein test strips showed a poorer correlation to the electrophoretic results. Measurement of alpha-1-m is, therefore, the most sensitive of these methods for the detection of proteinuria. In 90 patients with low molecular weight proteinuria and either with or without renal insufficiency alpha-1-m concentrations were determined in both urine and serum. While all patients had elevated urinary alpha-1-m concentrations, increased serum values were only found in renal insufficiency (Ccrea less than 100 ml/min). Independently of these results, we were also able to establish that increased alpha-1-m levels are found at decreased glomerular filtration rates (Ccrea less than 70 ml/min). Pathologic alpha-1-m concentrations therefore only allow the conclusion of isolated tubular impairment when the GFR is greater than 70 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Alpha 1-microglobulin in the urine and serum in proteinuria and kidney insufficiency]. 241 44

We examined the effect of glomerular immune complex (IC) deposition on glomerular eicosanoid synthesis and the role of the eicosanoids in glomerular pathophysiology. Rats received daily 10 mg i.v. injections of native bovine gamma-globulin (NBGG) or cationic bovine gamma-globulin (CBGG) for 21 days; age-matched controls were maintained. Immunofluorescence and electron microscopy showed mesangial deposits of IC in the NBGG group and capillary wall deposits in the CBGG group, without light or electron microscopic evidence of leukocyte infiltration. One week after the last antigen dose, GFR was similar in all three groups, but RPF increased in the rats given CBGG; (8.37 +/- 0.90 vs. control 5.54 +/- 0.56 ml/min, P less than 0.05). Glomerular synthesis of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) was normal in animals that received NBGG. Rats given CBGG had increased glomerular production of PGE2, (2.23 +/- 0.37 vs. control 1.03 +/- 0.16 ng/mg glomerular dry wt, P less than 0.05) and TxB2 (3.12 +/- 0.50 vs. control 0.48 +/- 0.07 ng/mg glomerular dry wt, P less than 0.001). Proteinuria only developed in the rats given CBGG, 86.6 +/- 18 mg/24 hr, which correlated with glomerular TxA2 synthesis, r = 0.82, P = 0.01. Acute administration of the TxA2 synthesis inhibitor, UK-38,485, and a TxA2 receptor antagonist, EP-092, to rats given CBGG did not affect GFR or RPF. The cyclo-oxygenase inhibitor, indomethacin, reduced both GFR and RPF by up to 40% in CBGG-immunized rats. Oral administration of UK-38,485 for six days to nephrotic rats did not result in a statistically significant reduction of proteinuria despite 85% inhibition of glomerular TxB2. We conclude that cationic antigen induces a glomerular disease pathologically similar to membranous nephropathy. The increment of RPF is most probably due to increased glomerular PGE2. The increased TxA2 has no effect on glomerular hemodynamics and probably is not a component in the pathogenesis of proteinuria.
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PMID:Immune complex effects on glomerular eicosanoid production and renal hemodynamics. 244 Nov 6

The present study was undertaken to determine the effects of prostaglandin synthesis inhibition on glomerular hemodynamics in nephrotoxic serum nephritis and to elucidate the mechanisms by which prostaglandin synthesis inhibition reduces proteinuria in nephritic rats. Dextran sieving studies were performed before and after intravenous administration of indomethacin to control rats and to nephritic rats with heavy proteinuria. Indomethacin did not significantly alter mean arterial pressure, glomerular filtration rate or proteinuria in control rats nor were significant changes in dextran sieving observed. By contrast, in nephritic rats indomethacin significantly reduced glomerular filtration rate (2.58 +/- 0.50 vs. 1.39 +/- 0.27 ml/min, P less than 0.001), proteinuria (0.198 +/- 0.079 vs. 0.048 +/- 0.019 mg/min, P less than 0.05) and filtration rate-corrected proteinuria (0.059 +/- 0.033 vs. 0.031 +/- 0.013 mg/ml GFR, P less than 0.05). The fractional clearance of neutral dextrans with molecular radii exceeding 42 A were elevated above control values in nephritic rats (P less than 0.05). After administration of indomethacin, the fractional clearance of neutral dextrans uniformly declined toward control values and remained elevated only for molecular radii exceeding 54 A. Assessment of glomerular hemodynamics in nephritic rats before and after indomethacin showed significant declines in single nephron filtration rate (31.5 +/- 3.0 vs. 21.2 +/- 2.5 nl/min, P less than 0.02), glomerular plasma flow rate (99.5 +/- 6.7 vs. 68.5 +/- 7.8 nl/min, P less than 0.05) and glomerular ultrafiltration coefficient (0.0430 +/- 0.0033 vs. 0.0339 +/- 0.0032 nl.sec-1.mm Hg-1, p less than 0.05). Indomethacin did not significantly change these parameters in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of indomethacin on glomerular permselectivity and hemodynamics in nephrotoxic serum nephritis. 247 51


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