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Biomedical subjects

V Silverman

Publications and source records attributed to V Silverman.

3 recordsLinked to original sources

Corneal epithelial wound healing: a tissue culture assay on the effect of antibiotics.

The effects of gentamicin, tobramycin and the fluorquinolone, ofloxacin on corneal epithelial wound healing were determined using an in vitro model of wound healing. Wounds were created in rabbit corneal epithelial cultures which were then exposed to various concentrations of the antibiotics. Effects on wound healing were measured by comparing migration rates between 6 and 18 hours and wound areas at various antibiotic concentrations over 36 hours. Gentamicin at concentrations of 0.5, 1.0, 1.5 and 2.0 mg/ml was found to statistically significantly effect wound healing compared to controls. Tobramycin on the other hand was found to have minimal effect on wound healing up to 2.0 mg/ml. Ofloxacin at concentrations greater than or equal to 0.05 mg/ml had statistically significant effects on wound-healing.

Analysis of Variance↗

A controlled study of the effects of thyrotoxicosis and propranolol treatment on mineral metabolism and parathyroid hormone immunoreactivity.

We studied mineral metabolism in 15 thyrotoxic patients and 15 controls matched for sex, age, and weight. Thyrotoxic subjects showed significantly higher serum calcium, phosphate, alkaline phosphatase, and globulin and lower serum creatinine, magnesium, and albumin. Parathyroid hormone immunoreactivity (iPTH) was measured with three different antisera. Thyrotoxic patients showed markedly reduced iPTH values in the most sensitive assay, a midregion-specific assay based on homologous antiserum BG-6. Antiserum 211/32 gave slightly reduced iPTH values, but antiserum NG-1 gave values that were increased by 65%. The limited sensitivity of these later two antisera, like that of others used earlier for such studies, may have blunted the apparent fall in iPTH (antiserum 211/32) or predisposed the assay to a systematic artifact (antiserum NG-1). These results show that for use in the evaluation of hypercalcemia in thyrotoxic patients, a PTH assay must first be characterized as to the expected result in uncomplicated thyrotoxicosis. Twelve of the thyrotoxic subjects entered a random order cross-over study in which propranolol and placebo were given in double-masked fashion for 6 consecutive days each. Overall, the drug did not alter calcium, phosphate, or magnesium metabolism. It lowered serum calcium only in two overtly hypercalcemic subjects, whose urinary calcium excretion did not decline. These results confirm that propranolol may reduce elevated serum calcium levels in thyrotoxicosis and suggest that in this setting the drug may have a direct or indirect effect on renal calcium metabolism.

Adult↗

Hypercalcemia after acute renal failure.

In a patient recovering from acute renal failure, hypercalcemia abruptly developed at a time when the serum creatinine level remained high (5 mg/dl) but well after the serum phosphate level had been restored to normal by oral aluminum hydroxide therapy. The renal damage had been severe, with oliguria lasting six weeks. Parathyroid hormone (PTH) immunoreactivity was measured with two different "carboxyterminal" PTH assays, giving high-normal or slightly mild renal failure could have accounted for the increased immunoreactivity. After five months of hypercalcemia, prednisone was administered and produced a prompt and sustained normalization of serum calcium. This prolonged variant of hypercalcemia after renal failure is not well recognized in the literature. The response to glucocorticoids suggests that abnormal metabolism of vitamin D or osteoclast activating factor might be involved in its genesis.

Absorption↗