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Biomedical subjects

S M Hirsch

Publications and source records attributed to S M Hirsch.

8 recordsLinked to original sources
PubMed1992

Nucleolar organizer regions in squamous cell carcinoma of the head and neck.

Nucleolar organizer regions are collections of nucleolar proteins associated with ribosomal genes that can be visualized in histologic sections using a silver colloid stain, thus the term silver-staining nucleolar organizer region (AgNOR). In some tissues, the number of AgNORs per nucleus correlates with cellular proliferation and, independently, with malignant change. AgNORs were studied in 66 paraffin-embedded head and neck squamous cell carcinomas and in 12 samples of normal tonsillar squamous epithelium. Carcinomas had a significantly higher mean AgNOR count than the benign epithelium (P less than .0001). Among carcinomas, mean AgNOR count increased with stage of the disease (P less than .001), but there was no significant correlation with histologic grade or DNA ploidy as determined by flow cytometry. These data suggest that AgNOR count should be evaluated as a possible aid in differentiating benign from malignant squamous epithelial proliferations in the head and neck, and also possibly as a prognostic marker in these carcinomas.

Aneuploidy↗
PubMed1979

Survey research and the silent majority.

A survey conducted at the New York University Dental Center demonstrated that significant differences exist between patients who are ready participants in research efforts and those who require the more persistent attention of the researcher. In addition, patients who were questioned while in treatment emphasized different reasons for selecting a dental school for treatment than did those patients who were interviewed prior to beginning treatment. The importance of collecting data from a truly random sample of patients is stressed and elaborated with reference to the marketing implications of the results. Strategies for patient recruitment and retention require knowledge that is complete and does not suffer from systematic absences in the data base. Careful data collection methods are described and advocated.

Academic Medical Centers↗
PubMed1976

Ontogeny of defensive reactions in Norway rats.

Young rats of several ages were presented with stimuli (a caged domestic cat, a footshock, and a suddenly moving object) known to be aversive to adults and disruptive of behavior in mature animals. Twenty-day-old rats were relatively unaffected by these events, while rats aged 30 days and older tended to reduce their locomotion and freeze upon the presentation of these cues. These data are consistent with Bolles' hypothesis that shock-elicited responses are innate defensive reactions. We also suggest that the inefficient passive avoidance learning in juvenile rats may result from their deficit in shock-induced freezing.

Age Factors↗