PubMed Health⌕ Search

Biomedical subjects

K Grossman

Publications and source records attributed to K Grossman.

7 recordsLinked to original sources
PubMed1996

The output of the hippocampus is inhibited during social behavior in the male rat.

During sexual behavior in the male rat, peptidergic cells in the medial amygdaloid nucleus become active and release a vasopressin-like peptide. The present experiments were designed to examine hippocampal changes as a result of this peptide's action during sexual behaviors. Chronic field-potential recordings from the hippocampus of male rats were acquired in a wide variety of social and nonsocial circumstances. Hippocampal responses that resemble the known action of the vasopressin-like peptide were seen only with social stimuli such as sexual stimuli and stimuli that led to aggressive behavior between males. The results show that the occasions of peptide action in the hippocampus correlate with the occasions of peptide release as determined by recording from the peptidergic cell bodies. The results are interpreted to indicate that the amygdala projection to the hippocampus has a special role to play in social behavior.

Animals↗
PubMed1996

Upregulation of prostate-specific membrane antigen after androgen-deprivation therapy.

OBJECTIVES: To determine the expression of prostate-specific membrane antigen (PSMA) before and after androgen-deprivation therapy and to compare PSMA expression with prostate-specific antigen (PSA) expression. METHODS: We studied specimens from 20 patients with prostate cancer undergoing medical or surgical castration or combination androgen-deprivation therapy in whom matched pretreatment and post-treatment tissue specimens were available and 16 patients in whom only a post-treatment specimen was available. The expression of PSMA and PSA in the tissue specimens was determined by immunoperoxidase staining. The extent of staining was calculated by multiplying the percent of antigen-positive tumor cells by the staining intensity to arrive at a stain index for each biomarker. An in vitro study assessed the concentration of PSMA and PSA in extracts of LNCaP cells cultured in the presence or absence of androgen as determined by immunoassays and Western blot analysis. RESULTS: PSMA reactivity was found to be increased in 55% (11 of 20) of post-treatment primary tissues and 100% (4 of 4) of post-treatment metastatic specimens. In contrast, PSA expression was found to be decreased in 70% (14 of 20) of post-treatment primary and 100% (4 of 4) of post-treatment metastatic specimens. Neither type of androgen-deprivation treatment nor tissue sensitivity to androgen deprivation appeared to influence degree of biomarker expression. PSMA was found to be downregulated and PSA upregulated when LNCaP cells were cultured in the presence of testosterone or dihydrotestosterone. CONCLUSIONS: The enhanced expression of PSMA in tissues and LNCaP cells after androgen deprivation suggests that PSMA is upregulated in the majority of prostate carcinomas after androgen treatment. The high expression in metastatic tissues strongly suggests that PSMA may be a clinically useful target for antibody-and genetic-directed therapy of prostate cancer that recurs after androgen deprivation. The mechanism whereby androgens suppress the expression of PSMA, and the association of PSMA with the development of hormone-independent prostate cancers, will require further study.

Androgen Antagonists↗
PubMed1991

Evidence for nerve growth factor-mediated paracrine effects in human epidermis.

Nerve growth factor (NGF) is critical to the development and maintenance of the peripheral nervous system, but its possible roles in other organ systems are less well characterized. We have recently shown that human epidermal melanocytes, pigment cells derived from the neural crest, express the NGF receptor (p75 NGF-R) in vitro (Peacocke, M., M. Yaar, C. P. Mansur, M. V. Chao, and B. A. Gilchrest. 1988. Proc. Natl. Acad. Sci. USA. 85:5282-5286). Using cultured human skin-derived cells we now demonstrate that the melanocyte p75 NGF-R is functional, in that NGF stimulation modulates melanocyte gene expression; that exposure to an NGF gradient is chemotactic for melanocytes and enhances their dendricity; and that keratinocytes, the dominant epidermal cell type, express NGF messenger RNA and hence are a possible local source of NGF for epidermal melanocytes in the skin. These combined data suggest a paracrine role for NGF in human epidermis.

Base Sequence↗
PubMed1991

Initiation of dates and anxiety among college men and women.

A dating questionnaire was completed by 248 undergraduate college students who were either dating someone in an exclusive relationship or were not going steady. Responses to this questionnaire by students not going steady with someone indicated that 54 college-age men were more active at initiating and more successful at getting dates than the 70 women. However, between one-half and three-fourths of the college women reported having initiated dates with men. Both sexes experienced considerable anxiety while initiating a date which suggests a self-help system might be designed to ameliorate this problem.

Adult↗