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Biomedical subjects

S Marcus

Publications and source records attributed to S Marcus.

At least 127 records · Page 7Linked to original sources
PubMed1981

Improvement of early pregnancy diagnosis based on milk progesterone by the use of progestin-impregnated vaginal sponges.

Progestin-impregnated (250 mg medroxyprogesterone) vaginal sponges (PIVS) were inserted 6-7 days post-insemination and removed on the 17th day. Pregnancy was determined by milk progesterone on the 21-24 day post-insemination. It was found that in 52 cows which did not receive PIVS, the rate of false diagnosis of pregnancy was 21%. In 30 cows treated with PIVS, there were no false positives. The diagnosis of non-pregnant was completely accurate in both groups.

Journal Article↗
PubMed1980

Generalized familial benign chronic pemphigus.

This is a report of generalized familial benign chronic pemphigus in a Negro male. The rich staphylococcal and streptococcal flora detected on the skin of this patient may have been a factor in the generalization of the process.

Black People↗
PubMed1980

Statistical study of the Fisher-Race model for human Rh genetics.

The technique of chromosomal positioning of inheritable traits (C.P.I.T.) to project relative positions of two or more traits at more than one gene locus was employed to test the validity of the Fisher-Race model of Rh structure. The results of statistical analysis of two large samples of Rh phenotype distributions suggest that all models based on vertically related, linked alleles are invalid. On the basis of further analysis, Wiener's concept of the structure of the human Rh-Hr gene locus appears most valid among current hypotheses.

Alleles↗
PubMed1979

Projection of individual pyramidal tract neurons to lumbar motor nuclei of the monkey.

The projection of individual pyramidal tract (PT) neurons from the hindlimb area in the precentral gyrus of the cerebral cortex to the lumbar spinal cord was studied in the monkey by systematically searching for sites within identified regions of the spinal gray from which the PT neurons could be antidromically activated by local stimulation. All investigated neurons belonged to the fast conducting fraction of PT neurons. The following results were obtained. 1. Each PT neuron could be activated from more than one region of the spinal gray matter, including identified spinal motor nuclei and areas dorsomedial to these nuclei, but do not the intermediate nucleus or regions dorsal to it. "Passage areas" and "termination areas" were defined. 2. Half of the PT neurons with termination areas within motor nuclei had these areas in more than one nucleus. There were thus strong suggestions for synaptic contacts of some PT neurons with motoneurons of more than one muscle. 3. Four groups of three or four neurons were recorded simultaneously by the same cortical electrode. Comparisons of passage and termination areas within groups revealed both similarities and differences in projections of neighboring neurons. Every neuron was activated from some region(s) where others of the group were not. Common passage areas, or passage and termination areas, for two or three neurons of a group within at least one motor nucleus were found for all groups. Termination areas in the same motor nucleus have been found for the majority of the neurons of only one group. These common projection areas are compatible with, but not prove, that group of adjacent PT neurons has common target cells in the spinal cord.

Animals↗
PubMed1979

The effect of anticancer therapy on peripheral blood T and B lymphocyte counts and function.

Patients categorized according to tumor type were compared to a control non-tumor population. Comparison of relative T cell values among the groups showed no significant differences; however, when absolute numbers of T cells/mm3 were compared, all cancer patients, whether from treated or untreated groups, had significantly depressed T cell values. No significant differences were observed in the relative or absolute numbers of B cells. Comparison of the total lymphocyte response to PHA showed no significant differences among the various cancer groups; however, response in all cancer groups whether from treated or untreated patients, was depressed by comparison to the control group. Patients categorized according to the type of treatment received showed significant depression in the white blood count, lymphocyte count, relative and absolute T cell counts and the absolute B cell count in the postsurgery, postadjunctive therapy group. The pretherapy group also showed significant depression in the absolute number of T cells/mm3 when compared to the controls. Response to PHA correlated with the absolute T cells values.

Antineoplastic Agents↗
PubMed1979

Effects of dark adaptation on spatial and temporal properties of receptive fields in cat lateral geniculate nucleus.

1. We studied the effect of dark adaptation on the spatial organization of receptive fields of single cells in the lateral geniculate nucleus l.g.n. of the cat. 2. Contrary to previous reports, we found that in many l.g.n. cells the ability of the receptive field surround to suppress the response of the centre was diminished following dark adaptation. 3. The degree of reduction of the surround antagonistic strength varied from cell to cell, and was independent of the various classifications of visual neurones (X/Y, ON/OFF, layer, A/layer, A1 and central/peripheral). 4. Most cells also showed an increase in the apparent size of the excitatory centre upon dark adaptation. On the average, the width of the most effective bar stimulus located at the centre of the receptive field increased more than twofold. 5. We also studied the effect of dark adaptation on the temporal properties of l.g.n. receptive fields. In many cells dark adaptation changed the temporal modulation transfer function: it flattened the amplitude function, and changed the phase relationship between the centre response and the surround response. 6. Retinal ganglion cells showed qualitatively similar behaviour to that of l.g.n. neurones. 7. Our data do not support the notion that retinal ganglion cell centres converge on l.g.n. cells to form their surround mechanism.

Action Potentials↗
PubMed1979

A comparison of substance abuse profiles among problem drinkers, problem smokers, and overeaters.

Substance abuse profiles were compared among alcoholics, problem smokers, and overeaters. Fifteen scales were investigated under the rubrics of Motivation, Style (Craving, Loss of Control, and Drug Use) and Effects (Beneficial and Harmful). While all three samples were similar on the Motivation scales, Smokers differed substantially from Alcoholics and Overeaters on the Style scales and in terms of Emotional effects. Smoker were more similar to Alcoholics on perceived beneficial effects, and Alcoholics reported more severe harmful effects. Implications of the results for substance dependency theories and for treatment models were discussed.

Adult↗
PubMed1978

Mitogenic factor from chronically infected guinea pigs.

A lymphokine produced by antigen stimulated lymphocytes, induces blastogenesis in cultures of lymphocytes which are not sensitive to the specific antigen. The in vitro production of this factor (MF) was accomplished utilizing peritoneal exudate (PE) cells from Coccidioides immitis infected guinea pigs. Production of MF by lymphoid cultures paralleled skin test reactivity of the donor animal. Removal of adherent cells from the PE population did not decrease the production of MF; conversely, a more significant production of MF was effected by the adherent cell depleted populations. Maximal production of MF was achieved at non-adherent cell concentrations from 4 X 10(6) to 8 X 10(6) cells/ml. Cell concentrations below 4 X 10(6)/ml produced material which inhibited DNA synthesis in test cultures. MF was separated from the inhibitory substance(s) by column chromatography of the crude preparations on Sephadex G-75. Inhibitor(s) eluted in the void volume (VO), and the MF eluted in an effluent volume (Ve) which was greater than the total bed volume (Vt) suggesting that MF is adsorbed by Sephadex beads.

Animals↗
PubMed1978

Pattern of projections of individual pyramidal tract neurons to the spinal cord of the monkey.

The results suggest : (1) that PT neurons sending axons to motor nuclei innervating distal forelimb muscles branch less than other PT neurons; (2) that a group of PT neurons located close together may influence various species of motoneurons, but that this influence is the strongest on motoneurons of one species; (3) that individual PT neurons terminate only on a small fraction of a given motoneuron group.

Efferent Pathways↗
PubMed1977

Release of neurophysins I and II during and after parturition in cows.

Bovine neurophysin I and neurophysin II (bNpI and bNpII) have been assayed by radioimmunoassay in the jugular venous blood of cows during parturition. In general, low bNpI levels were detected on the day before labour began and during the first stage of labour. Neurophysin I was present in appreciable quantities in blood taken during the second stage of labour and in most cows the concentrations rose to a maximum during the expulsive stage. After delivery, the concentration of bNpI in the blood diminished. This pattern of release is similar to that reported for oxytocin at parturition in cows. As with bNpI, maximum levels of bNpII occurred during the expulsive stage of labour in some animals. In others, bNpII concentrations were very low or absent. Low concentrations of bNpII were found at the other stages of labour. Examination of the results from individual animals indicated that the release of the two neurophysins can be independent.

Animals↗
PubMed1977

Faces of Freud.

Explore the source record for details and available documents.

Historiography↗
PubMed1977

Tests alternative to the rabbit bioassay for pyrogens.

The rabbit bioassay is currently the only legally acceptable method to test for pyrogenic contamination of parenteral preparations and medical devices designed to enter the parenterum. However, research efforts have recently made available alternative procedures to test for pyrogens which may have significant value in quality control. Part of the reluctance to accept tests other than the rabbit test may be due to the low visibility of emerging understanding of a significant theory of testing in which it is contended that the parameters of sensitivity and specificity are inversely related and that accuracy is an ideal. The rabbit pyrogen assay will detect 1 to 10 ng of enterobacteriaceal endotoxin (ET). The limulus test will detect 0.01 to 0.1 ng/ml of ET; some of the other tests approach the rabbit assay in sensitivity. Since it is current dogma that pyrogen is equivalent to ET, the basis for the use of ET to standardize pyrogen tests is rationalized. The source of ET in practice is bacterial contamination; therefore, numbers of bacteria that contaminate parenteral preparations can be directly related to potential pyrogenicity. Further, viable counts of bacteria in parenteral preparations, prior to sterilization, is a reliable test for pyrogens. Other tests such as nitroblue tetrazolium reduction and actinomycin-D enhancement of lethality of pyrogen for mice deserve consideration in quality control procedures. The limulus test, the most practical of currently available alternative tests for detection of ET and therefore, of pyrogen has application where the rabbit test cannot be used. Therefore, control personnel must learn of the availability, performance and interpretation of the limulus test. Practical considerations must govern the choice of an alternative test when the use of a test other than the rabbit bioassay is indicated.

Animals↗
PubMed1976

Influences of stress, age and sex on serum growth hormone and free fatty acid levels in cattle.

The serum growth hormone (BGH) and free fatty acid (FFA) concentrations of large groups of calves (male and female ranging in age from 8 to 14 days and from 3 to 6 months old), bulls, oxen, heifers and cows under normal conditions were compared with the serum BGH and FFA values of corresponding large groups of animals under stress conditions. Stress was caused by transport, as it routinely occurs, and was further reinforced by a stay of several hours in unfamiliar surroundings. Stress provokes a significant increase in serum FFA in all groups and induced a significant decrease in serum BGH in all groups, with the exception of the non-pregnant heifers. The male and female calves which were 8 to 14 days old, had significantly higher BGH levels than the older animals. The female calves from 3 to 6 months of age, and the heifers had significantly lower BGH levels than the cows. The males had higher serum BGH values than the females, but a significant difference could be demonstrated only between the male and female calves of both age-groups. The oxen, which were 1 to 3 years old, had significantly higher BGH levels than the non-pregnant heifers of the same age. It appeared that gestation had no influence on the serum BGH and FFA levels of both heifers and cows.

Age Factors↗