Retinal pigment epithelium cells can influence endothelial cell plasminogen activators

Endothelial cells from both human retinal microvessels (HME) and fetal bovine aortic endothelium (FBAE) were grown in aggregate cultures alone, or with either retinal pigment epithelium (RPE) cells or fibroblasts. The levels of plasminogen activator (PA) and plasminogen activator inhibitor (PAI) in the conditioned media of the various aggregate types were measured. High PA levels were detected in the conditioned medium of pure endothelial cell aggregates (equal to 140% and 124% of urokinase control for HME and FBAE, respectively), and high PAI levels were associated with pure RPE aggregates (inhibiting 93% of the urokinase control). The conditioned medium of pure fibroblast aggregates had very low levels of either PA or PAI. When RPE cells were aggregated with FBAE or HME cells into mixed (heterogenous) aggregates, the PA measured in the conditioned medium was equal to 22% and 30% of the urokinase control, respectively. The PA level in the conditioned medium of mixed fibroblast-FBAE cell aggregates was higher, 104% of the control, and the difference was statistically significant (P less than 0.001). Co-incubation of pure RPE aggregates with pure FBAE aggregates or with pure HME aggregates resulted in PA activity in the conditioned medium that was equal to 110% and 96% of the control, respectively. The PA level found when pure FBAE cell aggregates were co-incubated with pure fibroblast aggregates was higher, 134% of the control, and the difference was statistically significant (P less than 0.001). Our results indicate that RPE cells can reduce endothelial cell PA, probably through both direct contact between the cells and PAI production. Fibroblasts did not have this influence on endothelial cell PA.     

Community psychiatry then and now: An introduction

Allen R. Dyer is Professor of Psychiatry at Albany Medical College and Professor of Health Policy and Management at the State University of New York at Albany, Albany, New York. Effective March 1, 1992, he becomes Professor and Chairman, Department of Psychiatry and Behavioral Sciences, James H. Quillen College of Medicine, East Tennessee State University.     

No more Hiroshimas

Dyer reports on the ninth World Congress of International Physicians for the Prevention of Nuclear War (IPPNW), held in Hiroshima, Japan, in October 1989. Taking as their theme "No more Hiroshimas," IPPNW participants visited the sites of the only acts of nuclear war -- the 1945 U.S. bombings of Hiroshima and Nagasaki that ended World War II. Scientific sessions updated information on the health effects of radiation. The congress issued an appeal for "a new agenda of moral priorities" that urges the implementation of five measures: the immediate cessation of all nuclear testing; a halt to the production of bomb-grade fissile material; conversion of secret weapons laboratories to open scientific institutes addressing environmental issues; reallocation of 50% of military spending to health and environmental projects; and the establishment of a U.N. Peace Research Centre at Hiroshima and a scholarship program to educate future world leaders about nuclear war.     

Neurobehavioral phenotype in carriers of the fragile X premutation

There have been contradictory findings in the fragile X (fraX) literature about possible neurocognitive and psychological symptoms due to the fraX premutation (pM). The purpose of the present study was to investigate the relationship between CGG repeat length and neurobehavioral functioning in carriers of the fraX pM. Eighty‐five female carriers of the pM with allele sizes ranging from 59–166 were administered a comprehensive IQ test (WAIS‐III) and completed a questionnaire designed to measure psychopathology (Symptom Checklist (SCL)‐90‐R). No relationship between allele size and cognition was identified. A significant negative relationship between allele size and age was found, as well as a positive relationship between allele size and depression. Follow‐up analyses separating small and large allele sizes (below and above 100 CGG repeats) indicated that individuals with larger allele sizes scored significantly higher on the Interpersonal Sensitivity and Depression subscales of the SCL‐90‐R. Despite the limitation of few individuals with high CGG repeat lengths, our findings suggest that females with larger premutated alleles (≥ 100 repeats) display some clinical manifestations of fraX syndrome. © 2001 Wiley‐Liss, Inc.