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Biomedical subjects

S Levine

Publications and source records attributed to S Levine.

At least 415 records · Page 23Linked to original sources
PubMed1981

Long-term effects of early iron deficiency on consummatory behavior in the rat.

Two experiments were designed to investigate the effects of early iron deficiency on consummatory behavior in the adult rat. In experiment 1, animals were placed in a novel chamber, either with or without water available. Although there were no effects of iron deficiency per se, the data suggested that decreased caloric intake experienced early in life may have different long-term consequences for males and females. While ad lib control males, and females in all diet conditions, exhibited less elevation of plasma corticosterone when water was available in the novel chamber, calorically restricted males appeared unable to use the cues or reinforcement provided by consummatory behavior to reduce arousal. In Experiment 2, a conditioned taste aversion situation involving conflict, we were able to separate effects due to early iron deficiency from those due to early caloric restriction. When reexposed to milk, calorically restricted (weight control) males exhibited an attenuated plasma corticoid response, compared to that of ad lib control males, while weight control females resembled ad lib control females in their response. Thus, as in Experiment 1, early caloric restriction affected males more than females. Early iron deficiency, however, markedly altered pituitary-adrenal responsiveness in both males and females. Not only was the response to reexposure completely reversed in rehabilitated males and females, but also, the corticoid response to deprivation was increased in rehabilitated males and decreased in rehabilitated females. Taken together with previous data, these results suggest that early iron deficiency alters both behavioral and physiological arousal or responsiveness, and may do so differentially in males than females.

Animals↗
PubMed1981

Hippocampal lesion effects on conditioned taste aversion and pituitary-adrenal activity in rats.

A series of experiments examined the effects of hippocampal lesions on conditioned taste aversion (CTA) and pituitary-adrenal activity. Experiment 1 examined recovery from a conditioned taste aversion under conditions of free extinction. Hippocampal and unoperated rats recovered from the aversion at the same rate. Further, this experiment showed that the suppression in drinking in both groups produced by lithium chloride (LiCl) injection was a conditioned taste aversion (was dependent upon the pairing of the taste stimulus with LiCl) and not enhanced neophobia. In Experiment 2 there were no behavioral effects of the lesion in a forced extinction CTA paradigm. In addition, hippocampal lesions failed to alter pituitary-adrenal responsiveness to LiCl. In the same experiment, pituitary-adrenal responsiveness of hippocampectomized rats, when re-exposed to the taste paired earlier with LiCl, was altered. Hippocampal lesions eliminated the elevation in corticosterone shown by unoperated control and neocortical-lesioned rats. The third experiment replicated this finding showing again that hippocampal-lesioned rats failed to show the forced extinction elevation in corticosterone when exposed to the aversive taste (Experiment 3). These data were integrated with other reports of behavioral and pituitary-adrenal alterations in hippocampal-lesioned rats.

Animals↗
PubMed1981

Clinical applications of the radioimmunoassay of secretory tuberculoprotein.

A radioimmunoassay that measures a specific secretory tuberculoprotein was used to detect Mycobacterium tuberculosis in 9 of 30 liquid cultures of sputum. The accumulation of immunoreactive material in liquid cultures containing isoniazid was shown to reflect in vitro susceptibility of mycobacteria to the antibiotic effects of the drug.

Bacterial Proteins↗
PubMed1981

Antigen and polypeptide synthesis by temperature-sensitive mutants of respiratory syncytial virus.

A revised nomenclature for the polypeptides of respiratory syncytial (RS) virus has been devised on the basis of comparison of the Long, A2 and RSN-2 strains by slab-gel electrophoresis. Seven polypeptides, now designated VP200, VGP48, VPN41, VPP32, VPM27, VP25 and VP10, were observed in preparations of all three strains of RS virus, irrespective of the host cell of origin. In addition, a slowly migrating glycopolypeptide GP1 was prominent in partially purified RS virus of the Long and A2 strains obtained from Hep-2 cells, and to a lesser extent from BS-C-1 cells. In the case of the RSN-2 strain, this polypeptide was only resolved clearly in virus obtained from Hep-2 cells. GP1 was an atypical glycopolypeptide in that 35S-methionine incorporation was poor relative to 3H-glucosamine incorporation. The ts mutants of RS virus exhibited four distinct phenotypes with respect to intracellular polypeptide synthesis and antigen production of 39 degrees C. Mutants ts 17 (complementation group B') and ts 19 (group E) were almost completely restricted, suggesting defective early functions. Mutants ts A1 (group A), ts A7 (group C) and ts 1 (group D) synthesized antigen and polypeptides normally, but the amount of antigen at the cell surface was reduced, suggesting maturation defects. In addition, the VPP32 of ts 1 (group D) exhibited an aberrant mobility, confirming its viral specificity. The remaining mutants, representing groups B, F and G exhibited generally impaired synthesis at 39 degrees C. Absence of surface filaments in ts mutant-infected cells at 39 degrees C confirmed their virus-specific nature.

Antigens, Viral↗
PubMed1981

Dissociation of adrenal corticosteroid production from ACTH in water-restricted female rats.

These experiments were undertaken to investigate the mechanism whereby a precipitous drop in plasma corticosterone concentration is brought about following drinking in rats on a restricted water schedule. No alteration in adrenocorticotrophic hormone (ACTH) output was found, nor was catabolism of corticosterone sufficient to account for the drop. It is concluded that corticosterone level is controlled under these conditions by a mechanism independent of ACTH concentration.

Adrenal Glands↗
PubMed1981

Relationship between cyclooxygenase activity (COA) inhibition and stimulation of ventilation by salicylate.

Recent investigations have demonstrated that inhibition of the cyclooxygenase enzyme of the prostaglandin synthetase complex accounts for most of the pharmacological effects of salicylate. To determine whether inhibition of cyclooxygenase activity (COA) plays a role in stimulation of ventilation (VE) by salicylate, sodium salicylate and other more potent inhibitors of COA (i.e., indomethacin and ibuprofen) were infused into anesthetized dogs. These experimental intravascular infusions lasted 1 hr; VE and oxygen consumption (VO2) were continuously measured. In the initial series of experiments, all COA inhibitors were infused at a rate of 25 mumol/kg/min. It was noted that only salicylate elicited consistent increases in either VE or VO2. The possibility that high infusion rates of potent COA inhibitors may prevent stimulation of VE by some additional toxic effect was explored in a second series of experiments in which we infused the minimal amount of COA inhibitors necessary to completely inhibit cyclooxygenase in other experimental situations. In these experiments, it was noted that none of the COA inhibitors (i.e., salicylate, meclofenamate, indomethacin or ibuprofen) stimulated either VE or VO2. These observations suggest that salicylate stimulates VE by a mechanism other than inhibition of prostaglandin synthetase. Because salicylate-induced increases in VE and VO2 followed a similar time course, these results are consistent with our concept that stimulation of VE by salicylate is related to tissue hypermetabolism.

Animals↗
PubMed1981

[Present status of transurethral laser technique in the treatment of urethral strictures (author's transl)].

The main difference between the conventional methods of urethrotomy and the laser method is that the scar tissue of the urethral stricture is not cut but removed by evaporisation. At present only neodymium: YAG and argon ion lasers are available for clinical endoscopic use. For the purpose of removing tissue neodymium: YAG lasers need irrigation with a gas in contrast to argon ion lasers that can be utilized with the well known water irrigation. Certain considerations and experiences suggest the carbon dioxide lasers to be the best ones for evaporating stricture tissue since they cause very limited zones of necrosis with immediate sealing of the wound edges. Transurethral carbon dioxide laser application, however, is still at an experimental stage, since convenient light transmission systems are not available for clinical use at the present time.

Argon↗
PubMed1980

Infant responsiveness to maternal cues in mice of 2 inbred lines.

The present study examined the responsiveness of 19- and 20-day-old C57BL/6J (C) and A/J (A) mouse pups to maternal cues. The C pups were found to spend more time near their C or A foster mother than they did near a virgin female. The A pups showed no such preference. Attempts to increase the motivation of A pups to approach the mother did not produce any preference for maternal cues, However, when the bedding on which odorous substances had been permitted to accumulate for an extended period of time was used as choice stimuli, pups of both lines showed a preference for the bedding of the mother as opposed to that of a virgin female. These results support findings with other rodents of a change in the female's odor during lactation which increases her attractiveness to her pups; and they demonstrate a genetic difference between pups of 2 inbred strains in their approach to maternal cues.

Animals↗
PubMed1980

Maternal behavior, pup vocalizations, and pup temperature changes following handling in mice of 2 inbred strains.

A cross-fostering design was used to examine maternal behavior, pup vocalizations, and pup temperature changes following an infantile procedure in C57BL/6J (C) and A/J (A) mice. In Experiment I, maternal behavior of C and A mothers after infantile handling differed in a number of ways irrespective of the strain of the foster pups. In addition, A pups were retrieved faster but licked less than were C pups by mothers of both strains. Handling appeared to increase the probability that strain differences would occur in that no differences between the lines, in either the behavior of the mothers or the capacity of the pups to elicit maternal behavior, were found during observations made just prior to daily handling. These observations also revealed that mothers of both strains treated same-strain foster pups differently than they treated foster pups of another strain. In Experiment II, A pups were found to emit more ultrasound following handling than were C pups, suggesting that retrieval but not pup-licking was stimulated by ultrasonic signals. Measurement of pup temperature during and following the handling procedure showed that (1) strain differences in ultrasonic signaling were not related to strain differences in the degree of hypothermia experienced by the pups; (2) recovery of body temperature following handling was slow for pups of both strains, and depended to some degree on the strain of the pups' foster mother; and (3) development of thermoregulation occurred more rapidly in C than A pups.

Animals↗
PubMed1980

Crime or affliction? Rape in an African community.

Amongst the Gusii of southwestern Kenya instances of rape are frequently reported; this was true also in the colonial period and yet it seems that those cases which come to the notice of the authorities are few compared with the numbers which actually occur. While certain features of the traditional culture seem to have encouraged violent sexual assault, because in a patrilocal society miscreants are likely to victimize their relatives, that is women who are sexually taboo, the crime is considered a sacrilegious matter to be dealt with in the family, not by the secular authorities. Given the sacrilegious nature of the act the Gusii are convinced that such behavior is involuntary and that the criminal is not a criminal but an afflicted person, motivated by the malevolence of the ancestral spirits or of jealous neighbors and kin. The author uses case material to illustrate various aspects of the Gusii belief system in regard to criminal behavior in general and rape in particular.

Adolescent↗