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Biomedical subjects

B Benjamin

Publications and source records attributed to B Benjamin.

At least 109 records · Page 6Linked to original sources
PubMed1976

Renal gluconeogenesis and increased glucose utilization in shock.

The roles of renal gluconeogenesis and glucose utilization in control, hemorrhaged, and endotoxin-injected animals were investigated using anesthetized, eviscerated, nonnephrectomized and nephrectomized dogs. Results demonstrate an increased glucose utilization in both hemorrhagic and endotoxic shock which was marked after endotoxin. Since blood glucose values dropped more in nephrectomized, hemorrhaged animals, in contrast to the nonnephrectomized, hemorrhaged dogs, the kidneys were assumed to perform a significant gluconeogenic role. The kidneys did not appear to perform gluconeogenesis in endotoxin shock since blood glucose levels were comparable in eviscerated, endotoxin-treated animals whether nephrectomized or not. To ascertain the tissue responsible for the increased glucose utilization in endotoxin shock, a study was performed with endotoxin added to blood in vitro (estimated LD100 concentration). The endotoxin-treated blood (n = 7) demonstrated an increased glucose utilization compared with saline controls (n = 7) (P less than or equal 0.02). Acclerated glucose utilization rates were comparable between the eviscerated, nephrectomized animals and in vitro experiments. These data suggest that excessive glucose demand by certain blood components may partially explain the lethal hypoglycemia of endotoxin shock.

Animals↗
PubMed1976

Effects of glucose or insulin on myocardial performance in endotoxin shock.

Past studies reported by this laboratory have documented myocardial dysfunction and progressively developing hypoglycemia in canine endotoxin shock. The purpose of the present study was to determine the effects of glucose concentrations and insulin infusions on myocardial performance following endotoxin administration. Experiments were carried out on isolated, working canine left ventricular heart preparations exchanging blood with intact dogs. Myocardial function was evaluated following endotoxin and correlated with concentrations of glucose and effects of insulin infusion. Cardiac dysfunction occurred within 2-4 hr postendotoxin and the degree of malfunction was not related to arterial blood glucose concentrations. Maintaining blood glucose at control, preshock, levels by infusion of 50% glucose did not prevent myocardial dysfunction as evidenced by elevations of left ventricular end diastolic pressure, and depressed power. Infusions of insulin reversed cardiac failure and maintained normal performance in spite of wide ranges in glucose concentration (5-120 mg%). Findings suggest that myocardial dysfunction is not precipitated or enhanced by the hypoglycemia of endotoxin shock. The beneficial actions of infused insulin on cardiac performance appear to be elicited on the basis of mechanisms other than myocardial glucose transport.

Animals↗
PubMed1976

Tracheomalacia in association with congenital tracheoesophageal fistula.

Tracheomalacia is an important cause of morbidity and death following correction of congenital tracheoesophageal fistula and is a well defined syndrome which requires recognition and appropriate treatment. The symptoms and signs allow division into mild, moderate, and severe groups. When the clinical features suggest the presence of tracheomalacia, endoscopy should be carried out in order to confirm the diagnosis and document the severity. Mild and moderate cases can be managed conservatively; efficient and regular physiotherapy is the mainstay of treatment. Severe cases warrant consideration for the operation of tracheopexy which may be lifesaving and will certainly reduce the period of hospitalization and will simplify management.

Age Factors↗
PubMed1976

Physiopathologic responses of the rhesus monkey to live Escherichia coli.

The present study was designed to develop an animal model applicable to the clinical patient in the investigation of the pathogenesis of septic shock. The model currently described is a lightly anesthetized, unrestrained monkey, carefully monitored during a 24 hour observation period. Varying doses of live Excherichia coli organisms were infused intravenously during a 30 minute period, and a variety of hemodynamic, respiratory and metabolic parameters were monitored. Doses of organisms varied between 7.6X10(9) and 3.0X10(11) organisms per kilogram of body weight, and there was no obvious correlation between size of dose and survival time. Two of nine experimental monkeys survived the Excherichia coli, while times of death of the remaining monkeys varied between three and 27 hours. Two control monkeys, not administered organisms, survived the 24 hour period with minimal changes in all measured parameters. Results reveal two patterns in response to organism administration. These were early acute death, after three to four hours, and prolonged life, death after 20 to 27 hours. The acute response was characterized by marked systemic hypotension, hypoglycemia, hypoinsulinemia, increased lactate level, decreased pH or respiratory depression. The other type of response involved profound sustained hypotension with hypoglycemia and hypoinsulinemia in most monkeys and elevations in lactate, blood urea nitrogen potassium creatinine, serum glutamicoxalacetic, lactic dehydrogenase and fractionatedlactic dehydrogenase levels. Depressions in respiration were not evident in the group which survived a longer period of time. Renal fibrin thrombi, prominent in baboons administered Escherichia coli, were absent in the rhesus monkey regardless of the size of the dose of organisms. The results of this study suggest the operation of a multifactiorial mechanism in septic shock with interactions between hemodynamic and metabolic factors varying within the species.

Animals↗