Differential effects of TPA and retinoic acid on cell-cell communication in human bronchial epithelial cells.

Understanding how normal and immortalized bronchial epithelial cells respond to modulators of gap junctional communication will increase our understanding of the process of tumor promotion. In the present study we compared to effects of retinoic acid (RA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) on the rate of fluorescent dye transfer via gap junctions in primary human tracheo-bronchial epithelial cells (TBE) and SV40 large T-antigen immortalized, non-tumorigenic bronchial epithelial cells (BEAS-2B). RA in the physiological range (0.001-1 microM) inhibited cell proliferation (DNA synthesis, mitotic index) more in primary TBE cells than BEAS-2B cells. Also in RA-treated cells, decreased cell proliferation was coupled to decreased gap junctional communication (GJC) in TBE but not in BEAS-2B cells. TPA strongly suppressed GJC and proliferation in primary TBE cells, whereas BEAS-2B exhibited increased GJC and retained a significant fraction of cells undergoing DNA synthesis. Our studies show that an uncoupling of GJC and cell proliferation is associated with a differential response to the growth inhibitory effects of RA and phorbol esters in immortalized compared to primary human bronchial epithelial cells.     

WISC-R Verbal/Performance Discrepancies in Pediatric Cancer Patients

Intelligence testing was completed on 38 newly diagnosed pediatriconcology patients and 29 hemophilia patients between 6 and I7years of age. A low Verbal/high Performance intelligence testpattern was displayed by 39% of the oncology patients as comparedto an expected frequency of 12/14% in the hemophilia controls.Increased amounts of prednisone, vincristine, and number ofdays between diagnosis and intelligence testing correlated withthe Verbal-Performance (V-P) discrepancy scores in the oncologypatients. These findings and previous studies suggest the needfor monitoring the intellectual, emotional, linguistic, andneuropsychological status of pediatric oncology patients beginningat the time of diagnosis.     

Polyorna virus adsorbs to specific sialyloligosaccharide receptors on erythrocytes

Hemagglutination by polyoma virus has been shown to require sialic acid residues on cell surface oligosaccharides. This report presents evidence which suggests that adsorbtion of polyoma virus to erythrocytes is not due simply to a nonspecific electrostatic interaction with negatively charged sialic acids but rather requires the presence of specific sialyloligosaccharide structures. Newcastle disease virus (NDV) neuraminidase hydrolyzes sialic acids in the sequences NeuAcα2,3Gal and NeuAcα2,8NeuAc. Erythrocytes treated with NDV lost 40% of their surface sialic acid, retained full hemagglutination by certain influenza viruses which also bind sialyloligosaccharides, and yet were not agglutinated by polyoma virus. Erythrocytes treated with Vibrio cholerae neuraminidase, which removes virtually all sialic acid, were no longer agglutinated by influenza virus or polyoma virus. Selective replacement of sialic acid on V. cholerae neuraminidase-treated cells with purified β-galactoside α-2,3-sialytransferase in the sequence NeuAcα2, 3Gal completely restored hemagglutination by polyoma virus. In contrast, replacement of sialic acid by other sialyitransferases in the sequences NeuAcα2,6Gal or NeuAcα2,6GalNAc does not restore hemagglutination by polyoma virus.     

Blood endotyping distinguishes the profile of vitiligo from that of other inflammatory and autoimmune skin diseases

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The effects of school-based intervention programs on aggressive behavior: a meta-analysis

Research on the effectiveness of school-based programs for preventing or reducing aggressive behavior was synthesized with a meta-analysis. Changes in aggressive behavior between pretest and posttest were analyzed for developmental patterns and characteristics associated with differential effects. Control groups showed little change in aggressive behavior, but there were significant reductions among intervention groups. Most studies were conducted on demonstration programs; the few studies of routine practice programs showed much smaller effects. Among demonstration programs, positive outcomes were associated with a variety of study, subject, and intervention characteristics. Most notably, higher risk youth showed greater reductions in aggressive behavior, poorly implemented programs produced smaller effects, and different types of programs were generally similar in their effectiveness, other things equal.     

Apparent mitochondrial asymmetry in Xenopus eggs.

Cell polarity is manifest along the animal/vegetal axis in eggs of the frog, Xenopus laevis. Along this axis, maternal cytoplasmic components are asymmetrically distributed and are thought to underlie specification of distinct cell fates. To ascertain the molecular identities of such cytoplasmic components, we have used a monoclonal antibody that specifically stains the vegetal hemisphere of Xenopus eggs. The antigenic protein Vp67 (vegetal protein of 67 kDa) was identified through purification and cloning as a Xenopus homolog of the mitochondrial protein dihydrolipoamide acetyltransferase, a component of the pyruvate dehydrogenase complex. The identification of Vp67 as a mitochondrial protein could indicate that populations of mitochondria are asymmetrically distributed in Xenopus eggs.     

Medical students' attitudes in a PBL curriculum: trust, altruism, and cynicism.

PURPOSE: Studies have shown that medical students become more cynical and less altruistic as they advance in training. However, these studies were conducted in traditional medical schools, and many used unvalidated tools. This study examined students' attitudes in a problem-based learning (PBL) curriculum using reliable and valid measures. METHOD: Medical students and PGY-1 residents at Mercer University School of Medicine in Macon, Georgia, completed Wrightsman's Philosophies of Human Natures Scale (PHNS) in 1999 and 2000. Chronbach's alpha assessed internal reliability among subscales, and test-retest reliability coefficients confirmed acceptable reliability. For 114 students who completed both surveys, changes in PHNS scores were analyzed, with particular attention to the subscales of trustworthiness, altruism, and cynicism. RESULTS: Students assessed at the beginning of their second year increased the extent to which they believed people are trustworthy and increased their beliefs in how altruistic people are. They also showed a significant decrease in cynicism. There was not a significant change in trustworthiness, altruism, or cynicism among the participants beyond first year. In general, female students held less cynical views about others and believed people to be more trustworthy. CONCLUSIONS: Contrary to prior reports, this study found that more advanced trainees were not more cynical or less altruistic than their more junior counterparts. Indeed, a significant and positive change of attitudes among the participants during their first year of medical school refuted earlier reports. Thus, results of earlier studies and the effect of a PBL curriculum on attitudes of medical students need to be re-examined.     

Survival rates in NYC in the era of combination ART

BACKGROUND: Since the advent of combined antiretroviral therapy in 1996, substantial decreases in HIV-related morbidity and mortality have been observed in the United States and other developed countries. To assess the effects on overall survival and for specific AIDS-defining illnesses (ADIs), survival among persons with AIDS (PWAs) in New York City (NYC) before and after the introduction of combination therapy was investigated. METHODS: Survival among 79,878 PWAs diagnosed between 1990 and 1998 and reported through March 2001 was estimated. Cumulative survival at 24 months among PWAs was estimated by actuarial methods, and Cox proportional hazards model adjusted for covariates was used to estimate the relative hazard (RH) of death for specific ADIs over time. RESULTS: Overall cumulative survival at 24 months increased from 43% among PWAs diagnosed during 1990-1995 to 76% for those diagnosed 1996-1998. Improving survival for all ADIs was found among PWAs diagnosed after 1995, but changes for immunoblastic lymphoma, primary lymphoma of the brain, and invasive cervical cancer were only moderate and were statistically (p >.05) insignificant. Burkitt lymphoma, immunoblastic lymphoma, invasive cervical cancer, and primary lymphoma of the brain had the highest RH of death among PWAs diagnosed after 1995. CONCLUSIONS: Substantial improvements in survival after 1995 were found for all PWAs but varied by gender, race, risk, socioeconomic status, and specific ADIs. Consistent with other studies, neoplastic ADIs have shown less improvement than other diseases after 1995. The relatively poor outcome of PWAs with neoplastic diseases requires further investigation.