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Biomedical subjects

S Jacobson

Publications and source records attributed to S Jacobson.

At least 217 records · Page 12Linked to original sources
PubMed1981

A rat model of the fetal alcohol syndrome--preliminary histological findings.

A semipurified liquid diet was used to develop a chronic rat model of fetal alcohol syndrome. Adult female rats were fed a control or 40% ethanol (percent of total caloric intake) liquid diet. Additional controls were pair fed to the 40% experimental group. Results of the effects of these diets on the offspring included both qualitative and quantitative changes observed in Golgi study of hippocampal pyramidal neurons.

Animals↗
PubMed1980

The hypothalamic 'tuberoinfundibular' system of the rat as demonstrated by horseradish peroxidase (HRP) microiontophoresis.

Microiontophoresis of horseradish peroxidase (20%) into the median eminence of the rat has allowed visualization of perikarya and axon projections of the tuberoinfundibular system after retrograde transport. Cells projecting to the median eminence were found in the periventricular regions of the hypothalamus and were particularly pronounced in dorsal portions of the rostral arcuate nucleus, the medial division of the paraventricular nucleus, and within the anterior periventricular nucleus. Labeling of perikarya within the ventromedial nucleus was rarely found. No labeling by HRP was found within cells of the dorsomedial, anterior, suprachiasmatic, preoptic, lateral hypothalamic nuclei or within the septal and amygdaloid nuclei. Axons from identifiably cells were located within the periventricular neuropil and contained within the baso-lateral portions of the hypothalamic-hypophysial tract.

Animals↗
PubMed1979

Self-administered nitrous oxide: an adjunct analgesic.

In a pilot study of 26 patients, a mixture of 50% nitrous oxide and 50% oxygen (N2O-O2) appeared to be an effective and safe analgesic for the incision and drainage of closed-space infections. The analgesic effect of N2O-O2, as measured by a Mean Analgesic Index, is augmented by both amnesic and dissociative effects, ie, patients remembered experiencing significantly less pain than they complained of during the procedure (p less than .01) and reported significantly more pain than they appeared to be having, as recorded by an observer (p less than .01). The patient's recollected pain, however, correlated well (r = .68) with the observer's assessment. Forty-two percent of patients had undergone a similar or identical procedure in the past without the benefit of N2O-O2 and made uniformly favorable comparative statement concerning the analgesic effect of the gas.

Abscess↗
PubMed1979

Determinants of spontaneous recovery and persistance in MDCK cells infected with lymphocytic choriomeningitis virus.

MDCK cells that normally would have been killed by standard lymphocytic choriomeningitis (LCM) virus were saved either by pre- or co-infection with defective interfering (DI) virus. The ability of these spared cells to produce virus-specific antigen (as well as infectious virus) and resist being killed by standard virus challenge was followed for at least 35 days. During this period both types of cultures displayed unique cycling patterns for the above characteristics. The most striking difference was the longevity of the infections. Cultures exposed to DI particles prior to standard virus became persistently infected, while co-infection with both virus types led to spontaneous curing with no trace of the previous infection. The basis for these dissimilar outcomes was traced to a hitherto undetected non-defective LCM virus (called SP) in the DI virus stocks used to preinfect MDCK cells. SP virus was not present in standard virus stocks but arose in long-term persistently infected L cells that had been initially infected with standard virus. Cloned SP virus shared species-specific antigens with standard virus, was resistant to inhibition by DI virus and was capable of turning self-curing cultures into cultures persistently synthesizing both DI and SP virus.

Animals↗
PubMed1979

Crohn's disease of the appendix, manifested as acute appendicitis with postoperative fistula.

Two cases are reported of Crohn's disease localized to the appendix and manifested as acute appendicitis; after appendectomy a fistula developed. In none of 18 patients with Crohn's disease reported by other authors, where the appendix was the primary site, did a fistula develop postoperatively. When the appendix is the primary site of Crohn's disease the presence of mild inflammation of adjacent organs such as the terminal ileum may be mistakenly attributed to ordinary appendicitis. If, at exploratory laparotomy performed on a tentative diagnosis of appendicitis, Crohn's disease is suspected in the adjacent intestine, it is proposed that appendectomy should be followed by at least 10 days of total parenteral nutrition to minimize the risk of a fistula developing.

Acute Disease↗
PubMed1979

A rat model (using a semipurified diet) of the fetal alcohol syndrome.

A semipurified liquid diet was used to develop a chronic rat model of the fetal alcohol syndrome. Control female rats gained weight normally, reproduced normally, and gave birth to normal litters on this diet. Increased neonatal mortality, decreased neonatal weights, and altered sex ratios were observed in offspring of experimental alcoholic animals. Preliminary histological results include a mild delay in cell lamination patterns in the cerebral cortex at 4 days postnatal in alcoholic offspring as well as decreased formation of dendritic spines at 7 days postnatal.

Animals↗
PubMed1978

Afferent and efferent subcortical projections of behaviorally defined sectors of prefrontal granular cortex.

Although the functional significance of the midprincipalis region is well known, the afferent and efferent connections of this zone, in comparison to the anterior and posterior portions of the cortex lining the principal sulcus, are poorly understood. In 3 animals the retrograde tracer HRP and the anterograde tracers, tritiated proline, lysine and leucine, were injected into the sulcal cortex lining the principal sulcus. The cortex forming the banks of the principal sulcus was divided into anterior, middle and posterior sectors with one animal used for each zone. As expected from previous studies, the heaviest afferents to the cortex forming the principal sulcus were from the parvocellular portions of the medical dorsal nucleus. The medial pulvinar nucleus and the nucleus limitans projected to only the anterior and posterior portions of the cortex lining the principal sulcus. Projections were seen to all 3 sectors from the anterior, midline, intralaminar and lateral thalamic nuclei. Although cells were seen in the hypothalamus following injections in all 3 sectors of the cortex lining the principal sulcus, the heaviest hypothalamic projections were noted after injections into the mid-sector of the cortex. These HRP-positive cells were in the dorsal and lateral hypothalamic area, dorsal medial nucleus and in the lateral mammillary nucleus. These findings link the midprincipalis region with the prefrontolimbic circuit, and suggest that the midprincipalis region, n. medialis dorsalis, the mammillary bodies and perhaps the cingulate gyrus constitute part of an anatomical circuit concerned with memory processes.

Afferent Pathways↗
PubMed1978

Morphological, biochemical, ultrastructural, tissue culture and clinical observations of typical and aggressive craniopharyngiomas.

Craniopharyngiomas are tumors of the suprasellar area, which are often cystic, encapsulated and slow-growing. Certain of these tumors can behave in an aggressive manner and either invade surrounding structures or recur. In order to determine characteristics which may aid in distinguishing typical from atypical lesions, a study of biopsy and tissue culture specimens from 25 human craniopharyngiomas was undertaken. Tissue culture observations reveal two distinct cell populations. Typical lesions grew in culture in an orderly epithelial pattern and had desmosome-tonofibril aggregates and smooth surface topography demonstrable by electron microscopy. In the atypical tumors the cell growth was irregular, with mitotic activity, cholesterol crystals and features characteristic of neoplastic transformation, such as surface microvilli, an increase of cytoplasmic basophilia, size and number of nucleoli and retraction of cytoplasm. Correlation with the clinical status of the patients suggests that tumors of the four patients which exhibited atypical features in culture behaved more aggressively.

Adolescent↗
PubMed1978

Dominance and effects of strange conspecifics on aggressive interactions in the hermit crab Pagurus longicarpus (say).

Dominance orders in the hermit crab Pagurus longicarpus were observed in the laboratory. Groups of four crabs formed loose dominance hierarchies as determined by repeated display and retreat behaviour. Stronger dominance orders were inversely correlated with the frequency of aggressive interactions. Recognition of individuals, as measured by frequency and intensity of aggressive encounters between familiar crabs and introduced strangers, was not important in maintaining dominance orders. Rather, P. longicarpus recognized the aggressive state of conspecifics, as shown by frequencies of aggressive encounters after individuals of different dominance rankings were exchanged between established hierarchies.

Aggression↗
PubMed1978

Resistance of SJL mice to immunosuppression by antibodies.

Immunosuppressive antisera that specifically inhibit induction of tuberculin-type delayed hypersensitivity in mice to the antigens chicken conalbumin and methylated human serum albumin were compared for activity in CF-1, CAF1, and SJL mice. These contrasensitizing antisera were effective in CF-1 and CAF1 mice of various ages. But in SJL mice they were ineffective if the animals were older than 8 weeks and were only moderately effective if the animals were younger. The antibodies of these antisera responsible for specific immunosuppression could be absorbed onto adherent peritoneal exudate cells taken from DAF1 but not SJL mice. They could be eluted from the CAF1 cells at 56 degrees C. These results and other data that are discussed suggest that SJL resistance to immunosuppression by contrasensitizing antibodies is related to a macrophage abnormality. The results also help explain earlier findings that SJL mice are unusually easy to sensitize and unusually resistant to tolerogenesis. This strain of mice should be especially useful for studying the mechanisms of afferent immunosuppression in immunologic enhancement-like forms of tolerance.

Aging↗