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Biomedical subjects

R L Hirsch

Publications and source records attributed to R L Hirsch.

84 records · Page 5Linked to original sources
PubMed1968

Experimental cholelithiasis in the rabbit induced by cholestanol feeding: effect of neomycin treatment on bile composition and gallstone formation.

Fed cholestanol is converted by the rabbit to 5alpha-bile acids which coprecipitate with the normally occurring 5beta-bile acids to form gallstones composed of calcium and sodium glycoallodeoxycholate and glycodeoxycholate. The present study shows that oral administration of large doses of neomycin prevents gallstone formation in the cholestanol-fed rabbit and reduces the elevated concentration of allodeoxycholic acid in bile, with a reciprocal increase in allocholic acid concentration. The reduction in the concentration of allodeoxycholic acid and in the incidence of gallstones is proportional to the dose of neomycin; at a concentration of allodeoxycholic acid below about 20% of total bile acids, gallstone formation does not occur. Neomycin probably exerts its action by modifying the anerobic intestinal flora which dehydroxylate allocholic acid to allodeoxycholic acid; if so, this suggests that both hepatic and bacterial transformations are essential steps in the pathogenesis of cholestanol-induced cholelithiasis. The bile of rabbits on a normal diet contains allodeoxycholic acid (5% of total bile acids). A similar decrease in allodeoxycholic acid concentration and reciprocal increase in allocholic acid concentration is observed when neomycin is administered to rabbits on a normal diet.

Animals↗
PubMed1966

Movement of lipids into and out of the blood during hyperlipidemia induced in rabbits by pituitary extract and fraction H.

Rabbits were rendered hyperlipidemic by the subcutaneous injection of an alkaline aqueous extract of mammalian pituitary gland or a partially purified, concentrated fraction derived therefrom, designated Fraction H. Eight hours after the injection of Fraction H, arteriovenous (A-V) differences in plasma triglyceride (TG) were measured across five body areas. A large negative A-V difference in plasma TG was consistently found across the liver (increase in plasma concentration), and a moderate positive A-V difference across the perirenal fat depot (decrease in plasma concentration). Most values obtained across the intestines and mesentery and the leg were positive. Differences across the kidney were mostly small and almost equally divided between positive and negative values. Similar results were obtained 7-12 and 16-18 hr after injection of the pituitary extract. It is concluded that the liver is the principal source of the TG for this kind of hyperlipidemia, and that the plasma TG levels are reduced principally in passage through adipose tissue. A consistent negative A-V difference in plasma free fatty acid concentration (net increase) was found across the kidney 7-12 hr after injection, suggesting that the kidney hydrolyzes its accumulated TG and mobilizes it in the form of free fatty acids.

Animals↗
PubMedDate not supplied

Admissions for suspected snake bite to the Perth adult teaching hospitals, 1979 to 1988.

OBJECTIVE: To describe the epidemiology of snake bite in Perth, and the likelihood of envenomation. DESIGN: Information from case notes was retrospectively analysed. SETTING: Emergency medicine, teaching hospitals. PATIENTS: All patients admitted to the three adult teaching hospitals in Perth for suspected snake bite from 1979 to 1988. MAIN OUTCOME MEASURE: Systemic envenomation, was accepted as present if there were definite symptoms, signs or laboratory evidence (vomiting, abdominal pain, ptosis, convulsions, difficulty with breathing or swallowing, coagulopathy, haemolysis, rhabdomyolysis or renal failure). RESULTS: Ninety-nine patients were definitely bitten, with 53 envenomed, including three snake handlers. Thirty others may have been envenomed. Nearly half (44%) of the 82 patients with witnessed snake bite were envenomed. The dugite (Pseudonaja affinis) caused most cases of envenomation, most often producing coagulopathy only. The remainder were probably due to bites by the tiger snake (Notechis after occidentalis) and gwardar (Pseudonaja nuchalis), with one by a sea snake. The Commonwealth Serum Laboratories Snake Venom Detection Kit (VDK) enabled identification of the genus in 36% of definite cases of snake bite, and in 51% of cases of envenomation. It may occasionally produce false-positive results. The VDK is of greatest value in establishing the genus of snake in envenomed patients. CONCLUSIONS: It is suggested that a mixture of brown and tiger snake antivenom be used to treat patients envenomed by an unidentified snake in the Perth metropolitan area. This does not apply to patients bitten elsewhere in Western Australia or transferred to Perth from country regions where other snakes are more prevalent.

Adolescent↗
PubMedDate not supplied

Resources and responsibility for professional education in blood transfusion therapy.

Two current problems in blood transfusion services are the widespread lack of information on this subject among practicing physicians, house staff, and medical students, and the dearth of broadly trained, full-time professionals in the field. Our most important and urgent responsibility is to train physicians who seek full-time careers in any aspect of blood transfusion services, blood center management, hospital transfusion services, research, or combination thereof. Successful training programs require sufficient space, personnel, and funds. In addition, blood centers have a responsibility to educate practicing physicians and house staff by formal teaching sessions, or informally when problems arise. Medical school curricula usually contain little on blood banking; exposure to some basic immunohematology or a visit to a blood center will help sensitize students to the availability of blood. Hospital administrators, regional medical society officers, and corporate medical directors, informed of the blood centers' activities, can help improve relationships between center, hospital, and community.

Blood Banks↗