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

Acute Alteration of Plasma Renin Activity by Large Doses of Intravenous Prednisolone

Large doses of intravenous glucocorticoids have been used in an attempt to reverse homograft rejection. The intravenous administration of 1 g prednisolone over 1 hr resulted in a significant acute reduction of plasma renin activity in 5 normal subjects tested and in 11 out of 15 patients bearing renal homografts. No definite explanation for failure to respond nor the mechanism of this prednisolone effect is readily at hand. An acute decrease in renin activity could be salutary for the chronically or acutely rejecting patient in that it could reduce vasopressor and salt-retaining effects. However, several of the non-responders had an increase in renin activity which could have been detrimental. © 1972, SAGE Publications. All rights reserved

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

Targeted gold nanoparticles enable molecular CT imaging of cancer: an in vivo study

In recent years, advances in molecular biology and cancer research have led to the identification of sensitive and specific biomarkers that associate with various types of cancer. However, in vivo cancer detection methods with computed tomography, based on tracing and detection of these molecular cancer markers, are unavailable today. This paper demonstrates in vivo the feasibility of cancer diagnosis based on molecular markers rather than on anatomical structures, using clinical computed tomography. Anti-epidermal growth factor receptor conjugated gold nanoparticles (30 nm) were intravenously injected into nude mice implanted with human squamous cell carcinoma head and neck cancer. The results clearly demonstrate that a small tumor, which is currently undetectable through anatomical computed tomography, is enhanced and becomes clearly visible by the molecularly-targeted gold nanoparticles. It is further shown that active tumor targeting is more efficient and specific than passive targeting. This noninvasive and nonionizing molecular cancer imaging tool can facilitate early cancer detection and can provide researchers with a new technique to investigate in vivo the expression and activity of cancer-related biomarkers and molecular processes

Ex vivo perfusion, arteriography, and autotransplantation procedures for kidney salvage

Three kidneys with arterial lesions that would have been difficult or impossible to repair by standard vascular reconstruction were removed, perfused by the Belzer technique, and returned to host after partial or complete autotransplantation. The fact that kidneys can be studied, dissected, repaired, and constantly salvaged with this technique should have important implications in several aspects of urologic operations