This study examines the social and health priorities of older African Americans and Latinos and their attitudes about participation in clinical research. Focus group discussions were conducted with older Latinos and African Americans, and a survey was mailed to key informants from 117 community-based organizations serving primarily older African Americans or Latinos. Results indicate that affordable housing, enough money to meet their needs, adequate transportation, and safer neighborhoods were urgent priorities for older Latinos and African Americans and superseded their health concerns. Distrust of researchers, lack of information, caregiver obligations, fear of experimentation, and lack of benefits were identified as barriers to research participation. Results indicate that community members are willing to participate in research provided they are fully informed of the research and perceive tangible benefits and congruence between the objectives of researchers and participants.

No abstract

The effects of heat on mouse spermatogenesis have been determined using both testis weight and flow cytometrically determined DNA content distribution as experimental end-points. Temperatures of 38-42 degrees C and exposure times of 20-60 min have been tested. The results concerning the testis weight substantially confirm those reported by other authors (Hand et al. 1979). The measurement of DNA content distributions shows a relatively higher depletion, 14 days after treatment, of the cytometric compartment containing elongated spermatids in respect to that containing round spermatids. The analysis of the cytotoxic effects, monitored 14 vs. 28 days after treatment, as a function of the exposure time at a given temperature, or of the temperature for a fixed exposure time, indicates that, in the course of spermatogenesis, late spermatocytes are more sensitive to heat than differentiated spermatogonia. Following the approach based on flow cytometry, the effect of exposures as low as 20 min at 38 degrees C can be appreciated.

No abstract

The relative DNA content of cellular samples from 54 patients affected by breast carcinomas and 20 affected by benign breast lesions (including 11 fibroadenomas) was measured by flow cytometry. All normal tissue samples and 17/20 (85%) specimens from benign lesions exhibited a cytometrically diploid DNA distribution, 3/20 (15%) benign lesions an abnormal DNA content, and 35/54 (65%) carcinomas at least one aneuploid cell subpopulation. Furthermore, 9/54 (17%) tumors were characterized by the presence of more than one aneuploid cell subpopulation. The results also indicate that flow cytometry can be used to recognize lymph nodes infiltrated by aneuploid cells. Statistically significant correlations were evidenced between the occurrence of aneuploidy or the ploidy level measured as DNA index and the nodal infiltration status. The percentage of S cells can also be extracted from DNA content distribution histograms. Statistically significant differences (p less than 0.01) were also observed for the percentage of S cells between normal tissues (6.2 +/- 3.2 SD) and benign lesions (11.1 +/- 6.6 SD), normal tissues (6.2 +/- 3.2 SD) and aneuploid tumors (19.7 +/- 10.3 SD), benign lesions (11.1 +/- 6.6 SD) and aneuploid tumors (19.7 +/- 10.3 SD), and diploid (7.9 +/- 4.0 SD) and aneuploid tumors (19.7 +/- 10.3 SD).