Enfermedad de paget

La enfermedad de Paget, es conocida también como osteitis deformante. Fue primero definida por Sir. James Paget en 1876. Es generalmente considerada como rareza, pero Schomorl, examinando en las autopsias el esqueleto completo, reunión 138 casos en el curso de 5 años

Partial cloning and characterization of an arginine decarboxylase in the kidney

Partial cloning and characterization of an arginine decarboxylase in the kidney. Using homology-based polymerase chain reaction (PCR) amplification, we demonstrate the presence of arginine decarboxylase mRNA in tissues involved in arginine metabolism (brain, kidney, gut, adrenal gland, and liver of the rat) but not in organs (lung, heart, and spleen) in which arginine metabolism is low or absent. The polymerase chain reaction product from the kidney had a nucleotide sequence 61% identical to that of the E. coli biosynthetic arginine decarboxylase. On a whole tissue basis, kidney homogenates were three times more active than brain homogenates at decarboxylating [1-14C]arginine. Subcellular fractionation localized the arginine decarboxylase activity of the kidney to the mitochondria fraction. Agmatine, one of the products of arginine decarboxylation, was found to inhibit nitric oxide formation by post-mitochon-drial supernatants of the brain or kidney. We propose that arginine is metabolized to two structurally different signaling molecules, nitric oxide and agmatine. Furthermore, agmatine can influence the nitric oxide synthase pathway

Exercise training ameliorates progressive renal disease in rats with subtotal nephrectomy

Exercise training ameliorates progressive renal disease in rats with subtotal nephrectomy. To determine the effect of chronic exercise training on renal function in animals with moderate renal insufficiency, rats with 75% renal ablation were either exercise trained by swimming for two months or remained sedentary. Glomerular filtration rate was significantly higher in trained (1.89 ± 0.07 ml/min) than in sedentary rats (1.52 ± 0.11 ml/min). No change was observed in renal blood flow or the degree of hypertension. Proteinuria was reduced in trained (13.6 ± 4.9 mg/24 hr) compared to sedentary animals (33.5 ± 9.2 mg/24 hr). The degree of glomerulosclerosis was much less prominent in trained animals. Plasma, low-density lipoprotein cholesterol-levels and total triglycerides were reduced in trained compared to sedentary rats. This study suggests that chronic exercise training ameliorates the progression of renal disease and improves plasma lipids in rats with moderate renal insufficiency. The mechanism for this improvement in renal function appears to be independent of the influence of systemic blood pressure

Effect of 25-hydroxycholecalciferol on calcium absorption in chronic renal disease

Effect of 25-hydroxycholecalciferol on calcium absorption in chronic renal disease. Calcium absorption was measured in eight uremic patients before and after eight days of treatment with 100 or 500 μg of 25-hydroxycholecalciferol (25(OH)D3) per day. Fractional calcium absorption was estimated by administering47Ca i.v. and orally on separate days and counting forearm radioactivity four hours later. Calcium absorption in four patients with residual renal function rose from 16.3 ± 2.5 to 40.8 ± 5.5% after treatment. In order to determine if the increased calcium absorption was mediated by an increase in the production of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) by virtue of increased substrate delivery to the 25-hydroxycholecalciferol-1-hydroxylase system present in the residual renal tissue, identical studies were performed in four anephric patients. Calcium absorption in these patients averaged 15.7 ± 2.2% during the control period and rose to 46.0 ± 11.1% after treatment. Increments in serum calcium after treatment were similar in both groups of patients; the mean concentration rose from 9.6 ± 0.3 to 11.0 ± 0.6 mg/100 ml. The results indicate that 25(OH)D3 can improve calcium absorption in the absence of renal tissue suggesting that its conversion to 1,25(OH)2D3 may not be necessary for its effect on the gastrointestinal tract in the uremic patient.Effet du 25-hydroxycholécalciferol sur l'absorption du calcium au cours de l'insuffisance rénale chronique. L'absorption de calcium a été mesurée chez huit malades urémiques avant et après huit jours de traitement par 100 ou 500 μg de 25(OH)D3 par jour. L'absorption fractionnelle du calcium a été évaluée par l'administration de47Ca, intraveineuse et orale, à des jours différents, et par comptage de l'activité de l'avant-bras quatre heures après. L'absorption du calcium chez quatre malades ayant une fonction rénale résiduelle augmente de 16, 3 ± 2, 5 à 40, 8 ± 5, 5% après traitement. Des études semblables ont été réalisées chez quatre malades anéphriques de façon à apprécier le rôle éventuel, dans l'augmentation de l'absorption intestinale, d'une augmentation de la production de 1,25(OH)2D3 due à l'augmentation de l'apport de substrat à la 25-hydroxycholécalciferol-1-hydroxylase du tissu rénal. L'absorption du calcium chez ces malades est en moyenne de 15, 7 ± 2, 2% pendant la période contrôle et augmente après traitement à 46, 0 ± 11, 1%. Les augmentations du calcium sériques sont semblables dans les deux groupes de malades, la concentration moyenne passe de 9, 6 ± 3 à 11, 0 ± 0, 6 mg/100 ml. Les résultats indiquent que 25(OH)D3 peut améliorer l'absorption du calcium en l'absence de tissu rénal ce qui suggère que sa conversion en 1,25(OH)2D3 peut ne pas être nécessaire à son action sur le tractus gastro-intestinal du malade urémique

Effect of diet, age and sex on the renal response to immune injury in the rat

Effect of diet, age and sex on the glomerular response to immune injury in the rat. We investigated the effect of three factors, namely dietary protein intake, age and sex, on the susceptibility of the renal glomerulus to the binding of antiglomerular basement membrane antibody (anti-GBM) in the early (heterologous) phase of anti-GBM nephritis, and the consequent reduction in glomerular filtration rate (GFR) as measured by inulin clearance (CIn). The effect of diet was examined in ≈ 8 week-old female Munich-Wistar rats fed a 40% high (HP) or a 6% low (LP) protein diet, and that of sex and age in male and female rats, 6 week or 10 month old. Following an intravenous dose (3 to 20 µg/g body wt) of radiolabeled nephritogenic anti-GBM, assessment of glomerular function was followed by quantitation of anti-GBM binding (values corrected for GBM surface area) in isolated glomeruli. At a given plasma level of antibody, the degree of binding of anti-GBM was slightly but significantly higher in HP than LP-fed rats; the decrease in GFR was significantly more pronounced in HP than LP-fed animals. The amount of anti-GBM binding was significantly greater in adult than young animals; however, the consequent decrease in GFR was more pronounced in the young than adult animals. Sex dependency was not discernible in anti-GBM binding or reduction in GFR. In all of the above experimental groups, the degree of anti-GBM binding was closely correlated with the plasma level of anti-GBM, but not with effective renal plasma flow rate, measured by PAH clearance. Separate groups of rats were subjected to experimental manipulation of single nephron GFR, glomerular capillary hydraulic pressure and glomerular plasma flow rate, by partial aortic constriction and saralasin administration. This set of experiments, using a tracer amount of non-nephritogenic anti-GBM, revealed that glomerular anti-GBM binding is independent of any of the above parameters. The studies indicate that dietary protein intake and age, but not sex, are among the factors determining the susceptibility of the glomerulus to acute immune injury. Since the binding of anti-GBM is determined by the affinity property of the glomerulus per se, and not by the prevailing hemodynamic pattern, the observed dependence of susceptibility to functional impairment on age and protein intake appears to also reflect a property of the glomerulus, which is influenced by age and the degree of dietary protein intake

Enfermedad de Paget

La enfermedad de Paget, es conocida también como osteitis deformante. Fue primero definida por Sir. James Paget en 1876. Es generalmente considerada como rareza, pero Schomorl, examinando en las autopsias el esqueleto completo, reunión 138 casos en el curso de 5 años