Biomedical subjects

R K Cavender

Publications and source records attributed to R K Cavender.

3 recordsLinked to original sources

PubMed1995

Tonsillar ectopia and Chiari malformations: monozygotic triplets. Case report.

A unique case of monozygotic triplets, each of whom exhibits variable degrees of tonsillar ectopia, is reported. Patient X presented with a Chiari I malformation and associated syringomyelia; examination of patients Y and Z showed 4 mm and 2.5 mm of tonsillar ectopia, respectively. No such case has been reported in the literature. The discussion defines the current magnetic resonance criteria for diagnosis of hindbrain malformations and addresses the question of whether these disorders represent a spectrum or separate disease entities, with specific emphasis on genetic predisposition. Due to the 100% concordance in this case the presence of a common hereditary factor in the etiology of these malformations is highly suggested.

Adult↗

PubMed1992

Effects of an opiate receptor antagonist on renin release in dogs.

The present experiments were designed to determine whether blockade of endogenous opiate receptors with naloxone would suppress renin release induced by circulating epinephrine or by reductions of renal perfusion pressure. In the first series of experiments, anesthetized dogs were prepared with a flow probe around the left renal artery and a catheter in the left renal vein, permitting measurement of renin secretion before, during, and after 15-min infusions of epinephrine (50 ng.kg-1.min-1 iv). The epinephrine infusions were conducted either before or after blockade of opiate receptors with naloxone (1 mg/kg iv). Naloxone failed to alter the renin secretory response to intravenous epinephrine infusion. In a second series of experiments, anesthetized dogs were uninephrectomized and prepared with a constrictor cuff around the left renal artery and a renal arterial catheter distal to the cuff. After control measurements of renal perfusion pressure and plasma renin activity (PRA), the cuff was constricted at 15-min intervals to produce controlled stepwise reductions of renal perfusion pressure ranging from 15 to 90 mmHg. One-half of the animals was pretreated with naloxone (1 mg/kg iv). Naloxone pretreatment had no effect on the PRA response to reduced renal perfusion pressure at any pressure. The data fail to support the hypothesis that endogenous opioid peptides are modulators in the control of renin release.

Animals↗

PubMed1992

Giant cell tumor of the small bones of the hands and feet: metatarsal giant cell tumor.

Giant cell tumors (GCTs) of the small bones of the hands and feet are very rare. The prevalence of hand involvement is 5.8 percent and of the feet is 3.6 percent. When GCTs occur in these locations, they appear to represent a distinctive more aggressive form of tumor. They occur more often in a younger patient population, are more commonly multifocal, and are associated with higher risks for local recurrence and pulmonary metastasis. This article presents a rare case of GCT of the metatarsal bone and discusses the presentation, distinctive characteristics and treatment of this tumor when it occurs in these locations.

Adult↗