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Biomedical subjects

S Marcus

Publications and source records attributed to S Marcus.

At least 145 records · Page 8Linked to original sources
PubMed1976

Evaluation of tests for infectious mononucleosis through proficiency testing.

Two standard tests for infectious mononucleosis (the Davidsohn differential and the ox cell hemolysin test) and ten slide tests; Monotest (Wampole), Monospot (Ortho), IM Kit (Micro. Res. Corp.) Monosticon (Organon), Diagluto IM (Beckman), Monosticon Dri-Dot (Organon), Bacto-Hetrol (Difco), Mono-Diff (Wampole), Monophile (Bio-Diagnostic Systems) and Rythrotox (BMC) were evaluated as they were used in 50 laboratories within the State of Utah and by two referee laboratories outside the state. The state proficiency testing program for infectious mononucleosis was modified so that the desired evaluation survey data could be obtained. Sensitivity, specificity, reproducibility (within and between shipments) and percent agreement with target results were determined for each test; factors which might have affected the test results were evaluated to determine which were correlated with good performance.

Costs and Cost Analysis↗
PubMed1975

Influence of serum free fatty acid levels on growth hormone secretion in lactating cows.

The influence of intravenous injections or infusions of insulin (0-2 i.u./kg), propranolol (150 mg), 3,5-dimethylpyrazole (3 mg/kg), 3,5-dimethylisoxazole (0-08 mg/kg), glucose (0-5 g/kg), nicotinic acid (120 mg/kg), arginine (0-5 g/kg) or butyrate (0-5 mmol/kg) on plasma glucose levels, and on serum concentrations of growth hormone and free fatty acids of lactating cows was investigated. In all of these experiments we noted an increase in the level of growth hormone. This increase was not a direct consequence of alterations in the glucose concentration, since the growth hormone peak occurred both during a decrease (insulin, 3,5-dimethylisoxazole, nicotinic acid and butyrate tests), and during an increase of the glucose level (glucose, arginine and propranolol tests), whereas the glucose concentration remained unchanged during the 3,5-dimethylpyrazole experiments. However, in each instance a precipitous fall of the free fatty acid level was noted. The glucose, growth hormone, and free fatty acid levels of lactating cows were not affected by either i.v. injection or infusion of saline.

Animals↗
PubMed1971

Separation of mycobacterial soluble antigens by isoelectric focusing.

Ion-exchange chromatography and gel filtration have been reported to yield partial separation of mycobacterial antigens. These procedures were used in combination with isoelectric focusing in an attempt to purify antigens of Mycobacterium tuberculosis strain H37Ra. The fractionating action of isoelectric focusing is dependent upon differences in the isoelectric points of the proteins to be separated. Culture filtrate of M. tuberculosis H37Ra was chromatographed on Sephadex G-200. This resulted in two widely separated peaks. The first peak, presumably containing high-molecular-weight substances, was then fractionated on a diethylaminoethyl Sephadex anion-exchange column. Three peaks were collected, and each was subjected to isoelectric focusing. Each peak was further separated into two or more fractions. The serological reactivity of each fraction was determined by immunodiffusion and immunoelectrophoresis. Sensitized guinea pigs were also skin-tested with the fractions. Two of the fractions contained only a single precipitinogen. One fraction contained two precipitinogens. A fourth fraction contained three precipitinogens and was also the only fraction to display sensitin activity. Four of the fractions were inactive either as precipitinogens or sensitins. The results suggest that the methods described are useful for the separation of mycobacterial antigens.

Journal Article↗
PubMed1970

Extent of specific to nonspecific resistance in mice: parenteral versus aerosol challenge.

Quantitative data were gathered concerning the extent of resistance induced in mice immunized by specific and nonspecific means and subsequently challenged both parenterally and by aerosol. Animals were immunized specifically by subcutaneous or intraperitoneal injection of Formalin-killed Klebsiella pneumoniae type I, which was also employed as a challenge organism. The intraperitoneal ld(50) was 30 bacilli. Nonspecific resistance was induced by injection of a Boivin preparation of Salmonella typhimurium endotoxin. Nonspecific resistance was highest 24 hr after injection of 10 mug of endotoxin. At this time, more than half of the mice survived challenge with 10(2) but not with 10(3)ld(50). Specifically immunized mice were resistant to as much as 10(5)ld(50), depending upon the route of immunization. Potency ratios for parenteral challenge were: nonspecific to normal, 100; specific to normal, 10(4) to 10(5); specific to nonspecific, 10(2) to 10(3). Employing aerosol challenge, specific immunization protected in the ld(100) range; nonspecifically immunized animals showed significant prolongation of survival time, but the 30-day mortality was similar to the control group.

Journal Article↗