Acute effect of prednisolone on renal handling of sodium.

The effect of prednisolone on renal handling of sodium (Na) was studied in rats under three experimental conditions: 1) hydropenia, 2) water diuresis, and 3) distal tubular blockade (DTB). Prednisolone, 0.25 mg/100 g per hr, was infused directly into left renal artery and urine was collected separately from each kidney. Predominantly unilateral increases in urine flow (V) and Na excretion were noticed in all experiments during prednisolone infusion. In the hydropenic rats the maximal increments on the infused side were, for V (mean ± SD), from 9.3 ± 1.5 to 21.4 ± 0.8 μl/min (P < 0.001); for C(Na)/C(In), from 0.28 ± 0.11 to 2.97 ± 0.71 % (P < 0.005); and for [Formula: see text] , from 2.93 ± 2.26 to 5.32 ± 1.92% (P < 0.05). In the rats with water diuresis, the maximal increases were, for V/C(In), from 5.87 ± 1.97 to 10.1 ± 6.0% (P < 0.005); for C(H(2)O)/C(In), from 4.09 ± 0.68 to 6.00 ± 0.44% (P < 0.0005); and for C(Na)/C(In), from 0.22 ± 0.07 to 0.70 ± 0.38% (P < 0.01). In DTB-rats the maximal increases were for V from 48.6 ± 9.0 to 72.7 ± 14.1 μl/min (P < 0.0005) and for C(Na)/C(In) from 9.42 ± 2.97 to 20.23 ± 7.34% (P < 0.005). In the contralateral kidney these changes were less pronounced. These observations suggest that prednisolone depresses directly Na reabsorption. The association of natriuresis with augmented [Formula: see text] and C(H(2)O)/C(In) during hydropenia and water diuresis, respectively, and the increases in V and C(Na)/C(In) during DTB, all are consistent with inhibition of Na reabsorption in the proximal tubule

Alopecia, ascites, and incomplete regeneration after 85 to 90 per cent liver resection

A nineteen year old female underwent 85 to 90 per cent partial hepatectomy to treat a minimal deviation hepatoma. Observations afterwards suggested that the limit of resection compatible with survival had been reached. She recovered perfect health after many months, although liver regeneration was not complete. Severe but eventually reversible alopecia and ascites developed postoperatively, undoubtedly as a complication of the massive hepatic resection. © 1975

Liver transplantation in biliary atresia with concomitant hepatoma.

Two cases are reported in which the very infrequently reported association was found of liver cell carcinoma and biliary cirrhosis secondary to congenital biliary atresia. A search of the literature revealed 4 previous reports of cases with similar pathology. Our 2 patients were both operated upon within the first few months of life, at which time congenital biliary atresia was documented, and in 1 instance temporarily corrected. They ran a progressive downhill course until they both received replacement livers, one at 4 years of age and the other at 12, at which times hepatoma was found in the excised cirrhotic livers. One patient is in good health 18 months post-transplantation. The other developed metastases but died of gastro-intestinal bleeding and pneumonia 76 days post-transplantation

Serum parathyroid hormone levels and renal handling of phosphorus in patients with chronic renal disease

In eight patients with advanced renal insufficiency (inulin clearance 1.4-9.1 ml/min), concentrations of serum calcium (S[Ca]) and phosphorus (S[P]) were maintained normal (S[Ca] > 9.0 mg/100 ml, (S[P] < 3.5 mg/100 ml) for at least 20 consecutive days with phosphate binding antacids and oral calcium carbonate. The initial serum levels of immunoreactive parathyroid hormone (S-PTH) were elevated in three (426-9230 pg/ml), normal in four (one after subtotal parathyroidectomy), and not available in one. The initial fractional excretion of filtered phosphorus was high in all and ranged from 0.45-1.05. Following sustained normo-calcemia and normo-phosphatemia, S-PTH was reduced below control levels in all patients; being normal in six and elevated in two. decreased below control levels in all patients; it remained high in six (of which five had normal S-PTH) and was normal in two (of which one had elevated S-PTH). The observed relationship between S-PTH and could either reflect the inability of the radioimmunoassay for PTH employed to measure a circulating molecular species of PTH which was present in which case the actual levels of S-PTH were higher than those measured, and/or it could be indicative of the presence of additional important factor(s) (other than S-PTH) which inhibit tubular reabsorption of phosphorus in advanced chronic renal failure. © 1972 by The Endocrine Society

Structure and dielectric properties of polar fluids with extended dipoles: results from numerical simulations

The strengths and short-comings of the point-dipole model for polar fluids of spherical molecules are illustrated by considering the physically more relevant case of extended dipoles formed by two opposite charges $\pm q$ separated by a distance $d$ (dipole moment $\mu=q d$). Extensive Molecular Dynamics simulations on a high density dipolar fluid are used to analyse the dependence of the pair structure, dielectric constant \eps and dynamics as a function of the ratio $d/\sigma$ (\sig is the molecular diameter), for a fixed dipole moment $\mu$. The point dipole model is found to agree well with the extended dipole model up to d/\sig \simeq 0.3. Beyond that ratio, \eps shows a non-trivial variation with d/\sig. When d/\sig>0.6, a transition is observed towards a hexagonal columnar phase; the corresponding value of the dipole moment, \mu^2/\sig^3 k T=3, is found to be substantially lower than the value of the point dipole required to drive a similar transition.Comment: 10 pages, 11 figures; Paper submitted to Molecular Physic