Dynorphin is an opioid peptide distributed throughout the central nervous system. Using a highly specific and sensitive radioimmunoassay for dynorphin we have examined the effect of stress on ir-dynorphin levels in the cortex and hypothalamus of the rat. Stresses related to food ingestion, i.e. starvation (72 hr), mild tail-pinch and insulin (10 U/kg) induced hypoglycemia all produced alterations in ir-dynorphin levels in the cortex. In contrast, restraint stress and 10-minute swim stress produced no changes in ir-dynorphin levels in either the hypothalamus or the cortex. Two hour exposure at 4 degrees C resulted in a fall in ir-dynorphin levels in the hypothalamus. Taken together with previously reported pharmacological effects of dynorphin-(1-13), these results suggest a possible physiological role for dynorphin in appetite and temperature regulation.

Animals↗

PubMedDate not supplied

Measurement of fat absorption utilizing 131iodine-triolein and nonabsorbable radioactive markers.

To eliminate many of the practical problems inherent in the collection of feces and in the chemical determination of fecal fat, a radioactive marker (131Ba) was combined with a labeled fat (131l-triolein) to measure fat absorption in man. The ratios of radioactivity of 131Ba/131l in a prepared capsule and that found in a random "grab" stool specimen after oral administration of the capsule were compared to determine the amount of fat absorbed. In an initial 36 patients, this double-label technique accurately separated normal from abnormal fat absorption as determined by the usual methods of quantitative fecal fat measurement. Results in an additional 102 patients and in 26 normals accurately reflected their clinical states. In addition, in vitro studies demonstrated more complete recovery of added lipid (99 percent) by radioactive techniques than by chemical analysis (86 per cent). The double-label technique not only seems more accurate than usual quantitative fecal fat determinations, but also greatly simplifies the measurement of fat absorption in man by eliminating the need for special diets, quantitative stool collections, and chemical analysis of stool.

Barium↗

PubMedDate not supplied

Radionuclide methods in the assessment of left ventricular function.

The recent introduction of newer scintillation cameras, convenient radiopharmaceuticals and innovative data-processing systems has hastened the use of radionuclide methods in the evaluation of cardiac function. This review familiarizes the primary internist with physics and instrumentation required in understanding cardiovascular nuclear images. Basic principles underlying the gated cardiac blood-pool scan and the first-pass study are described. Authoritative references are given to readers seeking more complete information. The major emphasis of the review, however, is on the clinical applications of these techniques. The role of these noninvasive methods in myocardial infarction, diagnosis and prognosis of ischemic heart disease, assessment of cardiomyopathies, study of idiopathic hypertrophic subaortic stenosis and left atrial myxoma is discussed. Finally, mention is made of newer applications: evaluation of nitroglycerin action on viable but ischemic myocardium and determination of the hemodynamic effects of propranolol in patients with coronary-artery disease.

Angiocardiography↗

PubMedDate not supplied

The effect of intravenous sodium diatrizoate on the function of the transplanted canine kidney.

The response of the canine renal autograft and allograft was measured following intravenous injection of 1 cc/kg 50% sodium diatrizoate (50% Hypaque). There was no significant effect on glomerular filtration rate or renal plasma flow immediately after injection; likewise there was no significant change in GFR 24 hours following injection compared to control animals.

Animals↗

PubMedDate not supplied

Pharmacokinetics of bleomycin after im administration in man.

The pharmacokinetics of bleomycin were studied after im injection in patients with malignant lymphoma. Mean peak serum concentrations of 0.133, 0.326, and 0.587 milliunits/ml were obtained approximately 1 hour after injection of 2, 5, and 10 units/m2, respectively. The mean half-life was 155 minutes, with a range of 65--235 minutes. Thirty-three percent of the administered dose was recovered in the urine after 4 hours. The urinary excretion of bleomycin was 61% during the 24 hours after injection, with some variability that was not explained by differences in dose or creatinine clearance.

Aged↗