Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q92565 (GFR)
 4,179 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Observations on the influence of extrauterine life upon renal functional maturation in the human being were made in 49 newborn infants of 25 to 41 weeks' GA during the first 48 hours of life, and in serial studies of 12 of these infants whose GA at birth was less than or equal to 34 weeks. GFR was found to be uniformly low in infants born prior to 34 weeks' GA, and increased rapidly after 34 weeks' GA. Glucosuria was found to occur commonly in infants less than or equal to 30 weeks' GA. Glomerulotubular balance for glucose was noted in every infant studied, regardless of GA or length of time since birth. Mean values for TRP at every age prior to feeding was greater than or equal to 85%, and decreased concomitantly with the rise in serum phosphate concentrations after feedings were introduced. The urinary excretion of alpha amino nitrogen was greatest in infants less than 34 weeks' GA. These studies suggest that renal functional development in the human infant is closely related to conceptional (GA + postnatal age) age, and that the pattern of renal functional development for the premature infant during extrauterine life is similar to that of the fetus in utero of corresponding conceptional age.
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PMID:Developmental patterns of renal functional maturation compared in the human neonate. 64 17

We report on two brothers with renal hypophosphatemia, intracerebral calcifications, minor facial anomalies, and short distal phalanges. The children presented with recurrent dental abscesses; one had premature closure of the anterior fontanelle. Biochemical findings included hypophosphatemia and elevated serum alkaline phosphatase with normocalcemia. Blood levels of parathyroid hormone, 1,25(OH)2 and 25(OH) vitamin D levels were normal; TRP (the fractional tubular reabsorption of PO4) and TmP/GFR (the tubular maximum rate of PO4 reabsorption in relation to GFR) were low. Both parents had a normal serum phosphate and brain CT scan without evidence of calcifications. This apparently new syndrome of renal hypophosphatemia associated with intracerebral calcifications appears to be inherited as either an autosomal recessive or an X-linked trait.
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PMID:Familial renal hypophosphatemia, minor facial anomalies, intracerebral calcifications, and non-rachitic bone changes: apparently new syndrome? 230 90

Bone mineral content (BMC) was measured with the Norland Cameron apparatus in 120 renal stone formers (RSF) with idiopathic stone disease and in 41 patients with primary hyperparathyroidism. RSF were classified, according to an oral calcium load test, into three groups: no hypercalciuria (HC; 41 cases); absorptive HC (53 cases), and resorptive or renal HC (25 cases). BMC values in RSF as a group were significantly lower than normal (p less than 0.001, Mann-Whitney test) though higher than in hyperparathyroid patients. There was a trend for BMC to decrease from male RSF without HC to patients with renal or resorptive HC. No statistical difference was found between the groups, however, BMC values in absorptive HC were different from normal (p less than 0.001). Why patients with HC are demineralized is unclear since no correlation was found between BMC and basal values of serum phosphate, TRP, calculated TmP/GFR, urinary calcium or hydroxyproline. Nevertheless our results indicate that urolithiasis, and possibly its treatment, is not a benign condition for the skeleton.
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PMID:Bone mineral content in idiopathic renal stone disease and in primary hyperparathyroidism. 682 40

The tubular transport of inorganic phosphate (Pi) is controlled by a parathyroid hormone-independent mechanism that responds to variations in the Pi intake. This adaptation mechanism could also respond to growth-mediated variation in the utilization of Pi by the organism. In the present work we have determined the maximal net Pi reabsorption per volume of glomerular filtrate (max TRPi/ml GF) in the young growing (2-mo) and adult 8- to 9-mo) rats. Max TRP[i/ml GF was significantly lower in intact adult (1.44 +/- 0.06 mumol/ml) compared with intact young growing animals (2.22 +/- 0.12 mumol/ml GF). This difference was maintained after removal of the thyroparathyroid glands; adult, 2.89 +/- 0.25, young, 4.56 +/- 0.25 mumol/ml. It was not associated with a difference in the urinary excretion of cAMP, GFR, renal handling of sodium, plasma calcium, or acid-base status. Administration of growth hormone preparations to adult rats did not raise max TRPi/ml GF to the level observed in young intact animals. With regard to the tubular Pi adaptation to Pi restriction, lowering the phosphorus content in the diet from 0.8 to 0.2 g/100 g resulted in an attenuated and delayed enhancement in max TRPi/ml in adult as compared with the response observed in young growing rats. These results show that the decrease in tubular reabsorption of Pi that occurs when rats become adult in a parathyroid hormone-independent phenomenon. It is suggested that this change is an adaptation of the tubular Pi transport to a reduction in the utilization of Pi in relation to the diminished growth rate of the animals.
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PMID:Tubular handling of Pi in young growing and adult rats. 709 22

Since the effects of cyclosporine on mineral and bone metabolism are controversial, we studied calcium regulating hormones, calcium-phosphorus (Ca-P) metabolism, and bone remodeling, assessed by serum osteocalcin, in long-term renal transplant recipients (RT). Forty-seven normocalcemic patients with good renal function receiving cyclosporine (CT, n = 27) or not (NC, n = 20) were studied at baseline and after an oral Ca load. CT and NC had similar age, daily dose of steroids, GFR level, and duration of transplantation. Baseline evaluation included 24-hr urinary Ca, P, TRP, TmP/GFR, fasting serum intact PTH, 1,25-(OH)2D, 25OHD, osteocalcin, Ca, and P. Subjects of the two groups had excessive secretion of PTH, tubular P wasting, and high serum osteocalcin level, as is usual in RT. However, there was no difference between CT and NC regarding any baseline variable. Ten CT and ten NC, matched for duration of transplantation and serum PTH level, ingested 1g Ca to achieve an acute dynamic study of PTH secretion and Ca-P metabolism. In both CT and NC, this Ca load caused the same decreases in serum PTH (P < 0.001), NcAMP (P < 0.05), and urinary P (P < 0.001) and the same increases in serum and urinary Ca (P < 0.001), and in both TmP/GFR and TRP (P < 0.001). These results strongly suggest that cyclosporine treatment had no significant effect on calcium-regulating hormone secretion, P-Ca metabolism, and bone remodeling level. We therefore consider that cyclosporine is unlikely to have any prominent role in the abnormalities of bone endocrine and mineral metabolism that are common in long-term kidney recipients.
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PMID:Lack of evidence that cyclosporine treatment impairs calcium-phosphorus homeostasis and bone remodeling in normocalcemic long-term renal transplant recipients. 760 39

To assess the effects of growth hormone (GH) on serum 1,25-dihydroxyvitamin D [1,25(OH)2D], we performed the following prospective crossover study in six healthy, young, adult, white men. During each of two admissions for 2 1/2 days to a general clinical research center, subjects were placed on a daily dietary calcium intake of 400 mg. Serum calcium, phosphorus, 1,25(OH)2D, immunoreactive intact parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP3), tubular reabsorption of phosphate (TMP/GFR) were measured. Recombinant human GH (rhGH, Humatrope) (25 microg/kg/day subcutaneously for 1 week) was administered prior to and during one of the admissions. Results are expressed as mean +/- SEM. Whereas serum 1,25(OH)2D (58.9 +/- 7.7 versus 51.6 +/- 7.4 pg/ml, P< 0.01), serum phosphorus (4.5 +/- 0.1 versus 3.7 +/- 0.1 mg/dl, P < 0.01), TRP (92.0 +/- 0.5 versus 87.8 +/- 0.7 mg/dl, P < 0.005), TMP/GFR (4.6 +/- 0.1 versus 3.5 +/- 0.2, P < 0.005), and urinary calcium (602 +/- 49 versus 346 +/- 25 mg/day, P < 0.001) increased significantly, serum PTH decreased significantly (19.9 +/- 1.9 versus 26.8 +/- 4.0 pg/ml, P < 0.05) and serum calcium did not change when subjects received rhGH. These findings indicate that in humans, GH affects serum 1,25(oh)2D independently of circulating PTH and that this effect is mediated by IGF-I. We propose, therefore, that one potential mechanism by which GH stimulates increases in bone mass is via modest increases in serum 1,25(OH)2D.
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PMID:Increased serum 1,25-dihydroxyvitamin D after growth hormone administration is not parathyroid hormone-mediated. 931 96

The aim of the study was to elucidate whether cyclosporine- and tacrolimus-based immunosuppression impairs tubular reabsorption of phosphate after kidney transplantation. Sixty cadaveric allograft recipients were included in the study. Forty patients receiving triple immunosupression with cyclosporine, azathioprine, and prednisone were studied for 1, 6, 12 months (groups A1 and A2, 20 patients) and for 24, 30, and 36 months (groups B1 and B2, 20 patients) after transplantation. Twenty patients who received tacrolimus with steroid withdrawal after 3 months were included in the study (group C). Recipients from groups A2 and B2 were treated additionally with vitamin D and calcium carbonate. Serum iPTH, 25-OHD, 1.25(OH)(2)D concentrations were determined, and TRP (mmol/L) and TmP/GFR (mmol/L) were calculated using Walton-Bijvoet nomogram. Higher values of total calcium serum concentration in group A were detected. Lower inorganic phosphate serum concentrations were detected in groups A and C, in contrast to group B where they remained within normal values. TmP/GFR values were significantly higher in group C in the first and third examination in comparison with patients of group A. Moreover, TRP index values were significantly higher than analogous values of groups A and B. Tacrolimus-treated patients exhibit significantly faster recovery from tubular phosphate reabsorption impairment compared to cyclosporine-treated recipients. No correlation between iPTH, 25-OHD, 1,25(OH)(2)D concentration, and tubular dysfunction parameters was observed. Amelioration of phosphate handling, in spite of hyperparathyroidism intensity, can follow early steroid avoidance.
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PMID:Tacrolimus decreases tubular phosphate wasting in renal allograft recipients. 1452 92

There is evidence that low birth weight caused by intrauterine growth retardation adversely affects normal renal development. Very little information on this issue is available on children born very prematurely. This investigation examined clinical and functional renal parameters in 40 children (23 boys, 17 girls) ranging in age between 6.1 and 12.4 years and weighing less than 1000 g at birth. Results were compared to those obtained in 43 healthy children of similar age and gender. Study subjects were significantly smaller and thinner than control subjects (mean height SDS: -0.36 vs. +0.70; and mean BMI SDS: -0.56 vs. +1.18). Systolic, diastolic, and mean blood pressures did not differ from those of controls. Renal sonography revealed no abnormality, and mean percentiles for renal length and volume appeared normal. In comparison with controls, plasma creatinine concentration (0.62+/-0.1 vs. 0.53+/-0.1 mg/dl) and estimated creatinine clearance (117+/-17 vs. 131+/-17 ml min(-1) 1.73 m(-2)) differed significantly. No significant differences were observed in microalbuminuria values, but five study subjects (12.5%) presented values above the upper limit of normality. A defect in tubular phosphate transport was also evident: TmP/GFR (3.6+/-0.4 vs. 4.2+/-0.8 mg/dl) and TRP (83+/-5% vs. 90+/-4%) were significantly lower, and urinary P excretion, estimated by the ratio UP/UCr, was significantly higher (1.2+/-0.4 vs. 0.9+/-0.4 mg/mg) than controls. Urinary calcium excretion, estimated by the UCa/UCr ratio, was also significantly higher (0.15+/-0.07 vs. 0.12+/-0.09 mg/mg). These data clearly demonstrate that both GFR and tubular phosphate transport are significantly diminished in school-age children born with extreme prematurity, probably as a consequence of impaired postnatal nephrogenesis.
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PMID:Long-term renal follow-up of extremely low birth weight infants. 1625 1

The aim of the study was to assess impaired tubular phosphate reabsorption and renal function among patients on cyclosporine- or tacrolimus-based immunosuppression for 2 years after kidney transplantation. Among 60 cadaveric kidney allograft recipients observed for 48 months, 40 received cyclosporine, azathioprine, and prednisone (group A and B). Group C consisted of 20 patients receiving tacrolimus with steroid withdrawal at 3 months after transplantation. Renal function and calcium-phosphate metabolism-iPTH, 25-OHD, 1,25(OH)(2)D concentration, phosphate reabsorption (TRP; mmol/L), and tubular maximum phosphate reabsorption per glomerular filtration rate (TmPO(4)/GFR; mmol/L)-were assessed at 1, 6, 12, 18, and 24 months (groups A and C) or 24, 30, 36, 42, and 48 months (group B). Renal function after 24 months of observation was significantly better among tacrolimus-treated patients (serum creatinine concentration mumol/L; C: 94.6 +/- 16.8 vs A: 110.5 +/- 22.1 vs B: 121.1 +/- 30.9; P < .05). Among tacrolimus-treated recipients, TRP and TmPO(4)/GFR remained within normal values during the whole observation period. In groups A and B, TRP improved during the first year of observation; after 2 years it reached values observed in group C (TRP: A: 0.67 +/- 0.1; B: 0.72 +/- 0.13; C: 0.76 +/- 0.07; P = NS), whereas TmPO(4)/GFR remained low in group A after 2 years (A: 0.78 +/- 0.19; B: 0.91 +/- 0.25; C: 0.94 +/- 0.15; P < .05). Tacrolimus-treated patients exhibit significantly faster recovery from tubular phosphate reabsorption impairment compared with cyclosporine-treated recipients. Tacrolimus-based immunosuppression led to better kidney allograft function during 2-year observation.
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PMID:Renal function and tubular phosphate handling in long-term cyclosporine- and tacrolimus-based immunosuppression in kidney transplantation. 1650 80

The aim of this study was to determine the long term outcome of renal glomerular and tubular functions in children receiving an LT for WD. Renal functions were examined in nine children with WD before and long after LT and compared with those of nine liver transplanted children with hepatic diseases other than WD. The duration of follow-up was at least two yr for both groups. GFR, fractional TRP and tubular maximum rate of phosphate reabsorption in relation to GFR (TP/GFR) as well as daily protein and Ca excretion were studied in both groups before and after LT. Pretransplant mean GFR, TRP and TP/GFR were significantly lower in the study group than the controls. A significant increase in the post-transplant TRP and TP/GFR was observed in the study group and the difference between the groups disappeared during the long term follow-up. Urinary protein excretion decreased in both groups after LT. Tubular dysfunction is frequent in patients with WD. LT for hepatic failure secondary to WD is a lifesaving procedure correcting the underlying hepatic defect as well as renal defects.
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PMID:Long term follow-up of glomerular and tubular functions in liver transplanted patients with Wilson's disease. 1828 8


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