Mechanism of the attenuated cardiac response to beta-adrenergic stimulation in chronic hypoxia.

A blunting of the chronotropic and inotropic responses of the heart to beta-adrenergic stimulation occurs following chronic exposure to hypobaric hypoxia. To pursue the mechanism(s) involved, observations were made in six intact, conscious goats at sea level and in another six goats maintained in a decompression chamber at 445 Torr (approximately 4,300m) for 10 days (Pao2 = 43 Torr). No significant group differences in cardiac frequency and various indices of myocardial performance (peak dP/dt, time-to-peak dP/dt, Vmax) were demonstrable either before or after cholinergic blockade with intravenous atropine methyl bromide, 1 mg/kg.

Urethral prosthesis for treatment of prostatic abscess in a dog.

A dog with a prostatic abscess was treated successfully with surgical implantation of a urethral prosthesis after 6 recurring episodes of abscess formation failed to respond to antibiotic therapy, surgical drainage, and bilateral marsupialization.

Intraoperative ureteral trauma: a radiologic approach.

Thirty-two patients with inadvertent intraoperative ureteral trauma or ligation are presented. One-third of the injuries were due to general surgical procedures such as lumbar sympathectomy, aortoiliac bypass and colectomy. Because of postoperative pain, discomfort and sedation, these injuries are frequently unrecognized for long periods.

Survey for positive Limulus amoebocyte lysate test in plasma from humans and common research animals.

A survey for positive Limulus amoebocyte lysate tests was conducted on apparently healthy humans, mongrel dogs, rats, mice, rabbits, and squirrel monkeys. Only mongrel dog (45.8%) and human (32.

Cerebral metastasis from a malignant thymoma.

A 14-year-old girl was found to have a solitary metastatic thymoma in the occipital lobe of the brain eight years following thoracotomy for removal of a malignant thymoma. Histologically, the lesions appear identical. Initial neurological examination was normal.

Recurrent intestinal intussusceptions in the dog.

Intestinal intussusceptions in 2 young dogs recurred within 3 days of initial surgical reduction. Subsequent recurrence was prevented by intestinal resection and creation of multiple intestinal adhesions in 1 dog and by creation of adhesions alone in the other.

An anesthetized dog heatstroke model.

This study was undertaken to develop an anesthetized dog heatstroke model. Forty-six animals were anesthetized with pentobarbital sodium (25 mg/kg) intravenously, and maintained at an ambient temperature of (42-46 degrees C) with a water-heated blanket over 2.5-3.

Leukocyte urea cycle enzymes in hyperammonemia.

All enzymes of the urea cycle are demonstrable in circulating leukocytes. They show the same relative activities as those in liver except for argininosuccinate synthetase + lyase (combined) which seems to be disproportionately active. To see whether leukocytes reflect liver activity, blood from patients with three hepatic urea cycle disorders was tested.

Hyperornithinemia, hyperammonemia, and homocitrullinuria associated with decreased carbamyl phosphate synthetase I activity.

Six subjects from three sibships with hyperornithinemia, homocitrullinuria, and hyperammonemia are described. Assays of liver biopsy in one showed decreased CPS I and leukocyte assays indicate a similar defect in all six. Loading studies with ornithine and citrulline are consistent with a block early in the urea cycle between ornithine and citrulline.

Treatment of hyperparathyroidism by percutaneous embolization of a mediastinal adenoma.

Percutaneous embolization of parathyroid adenomas was attempted in three hypercalcemic patients with previously unsuccessful neck explorations. Two adenomas were in the mediastinum and the third was within the thyroid lobe. Autologous clot, Gelfoam, and silicone rubber were used to obstruct feeding arteries.

Cardiovascular responsiveness to beta-adrenergic stimulation and blockade in chronic hypoxia.

Previous studies have shown that exposure to high altitude results in an initial increase in heart rate, followed by a return to sea-level values within several days; circulating catecholamines rise progressively during this time. Nine conscious dogs were studied in normoxia (N) and after 10 days' exposure to 445 torr (CH). The mean (plus or minus SE) hematocrit was higher in CH (50 plus or minus 2 vs.