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Biomedical subjects

R Long

Publications and source records attributed to R Long.

At least 127 records · Page 7Linked to original sources
PubMed1984

Repair of urinary tract fistulas with bulbocavernosus myocutaneous flaps.

Urinary tract fistulas resulting from severe trauma or pelvic irradiation are often associated with extensive tissue loss, scar formation, and fibrosis. Two cases, one with a urethro-vaginal fistula secondary to trauma and one with a vesico-vaginal fistula secondary to irradiation, are presented. In neither case could the bladder, urethra, or vagina be repaired primarily. Using a bulbocavernosus myocutaneous "island" flap, the fistulas were successfully repaired. The anatomy of the graft and the operative procedure are described. This new procedure should be considered in urinary tract fistulas in which there is extensive tissue loss and scarring.

Adult↗
PubMed1983

Role of nitrosation in the mutagenic activity of coal dust: a postulation for gastric carcinogenesis in coal miners.

The mutagenicity of coal dust solvent extracts with and without nitrosation was studied using the Salmonella/microsome assay system. Coal dust solvent extracts were either non-mutagenic or very weakly mutagenic with S9 activation. High mutagenic activities, however, were found when extracts of bituminous, subbituminous, and lignite coal dusts were reacted with nitrite under an acidic condition. Formation of mutagens from coal dust extracts by nitrosation was highest at pH 3.2 and decreased with increasing pH in the reaction mixture. Mutagenic activity appeared to be independent of metabolic activation. The mutagens formed from nitrosation of coal dust extracts induced frameshift mutations. The results reported here may have possible implications for the explanation of an elevated incidence of gastric cancer in coal miners.

Coal↗
PubMed1982

Upper extremity neuropathies following median sternotomy.

The status of 958 patients who underwent median sternotomy between January, 1978, and May, 1981, was analyzed. Fifty-four patients had an upper extremity neuropathy. Among 38 patients who underwent further evaluation, motor and sensory nerve conduction studies localized the injury to the level of the elbow in 13, to the brachial plexus in 10, and to both locations in 6. Ninety-two percent of these 38 patients were asymptomatic 3 months after operation.

Arm↗
PubMed1981

Intractable diarrhoea in a patient with vasoactive intestinal peptide-secreting neuroblastoma. Attempted control by somatostatin.

A 1 1/2 year old child developed profuse watery diarrhoea, shown to be due to excessive plasma vasoactive intestinal peptide (VIP) levels, whilst on treatment for metastatic neuroblastoma. Because it was unresponsive to alternative treatment, an attempt was made to control the diarrhoea with a somatostatin infusion. The attempt failed despite the fact that serum VIP levels were substantially reduced. Possible reasons for failure are discussed and the importance of plasma VIP as a marker for maturation in neuroblastoma emphasised.

Diarrhea↗
PubMed1981

Lack of difference in digoxin urinary excretion with two intravenous infusion rates.

Ten normal subjects were given 0.4 mg digoxin intravenously by bolus injection over 3 to 5 min and by constant-rate infusion for 1 hr. Urinary excretion of digoxin over the next 6 days, as measured by radioimmunoassay, was similar after both the rates of intravenous injection. In one subject, who excreted substantial amounts of digoxin reduction products, no difference was apparent in the amount of reduced metabolites excreted. These results are not in agreement with previous reports of an effect of intravenous infusion rate on urinary digoxin excretion.

Adult↗
PubMed1980

Differentiation between reperfusion and occlusion myocardial necrosis with technetium-99m pyrophospate scans.

Although infarct-avid scanning is used to diagnose myocardial infarction, no distinction is made between two very different mechanisms of myocardial cell death. These are occlusion necrosis and reperfusion necrosis. The former is the major form of cell injury after a sustained occlusion of a coronary artery; the latter occurs immediately after reperfusion of ischemic myocardium. The present study examines whether the technetium pyrophosphate scan becomes positive more rapidly with one form of injury rather than the other. Myocardial damage was produced in dogs by either sustained coronary occlusion (Group I, 6 dogs) or reperfusion (Group II, 18 dogs). Infarct-avid myocardial scans obtained with technetium-99m pyrophosphate were positive in only one of six animals in Group I when isotope was injected 4.5 hours after sustained coronary occlusion. In contrast, 12 or 13 animals (Group IIa) with reperfusion necrosis had a positive scan when isotope was injected 3.5 hours after reperfusion. When isotope was injected only 30 minutes after the onset of reperfusion (Group IIb), only two of five scans were clearly positive. The results indicate that if the interval between myocardial injury and a positive scan is known, inference can be made concerning the predominant type of injury.

Animals↗