TNF-α and TGF-ß synergistically stimulate elongation of human endothelial cells without transdifferentiation to smooth muscle cell phenotype.

We earlier reported synergy between tumor necrosis factor-α (TNF-α) and transforming growth factor-ß1 (TGF-ß1) for apoptosis in human umbilical vein endothelium (HUVEC). Here, we study morphological change by circularity measurement of HUVEC surviving this cytokine induced synergistic apoptosis. Contrasting with reports by others studying bovine endothelium, HUVEC did not change morphology in response to TGF-ß1. TNF-α markedly elongated cells (p<0.001) and this further increased with combination of the two cytokines (p<0.001), while elongation was accompanied by increased actin stress fibres. Transdifferentiation of HUVEC to a smooth muscle cell phenotype as reported elsewhere was excluded in the current study.

Interspecific nest parasitism by Pseudabispa paragioides, a solitary Australian wasp.

In morphology, coloration, and size, Pseudabispa wasps (Hymenoptera: Vespidae: Eumeninae) closely resemble mason wasps in the genus Abispa, and their distributions overlap. Although these two genera are among the largest solitary wasps in Australia, the biology of Pseudabispa was not previously known. Field observations from near Katherine, Northern Territory, strongly suggest that P. paragioides (Meade-Waldo) females attack and kill female A. ephippium (Fabricius) and usurp their nests, then appropriate cells, mass provision them with caterpillars acquired by theft from still other nests, and close them with mud taken from the host nest. Despite an abundance of potentially available cells in nests of three other large solitary wasps common at the same site, P. paragioides was found associated only with nests of A. ephippium. This unusual report of apparently forcible and lethal interspecific nest takeover for a non-social wasp parallels behaviors previously known only from socially parasitic eusocial Hymenoptera. Exploitation by P. paragioides may help explain why its host displays some of the most highly developed parental care known in any solitary eumenid, and why its nests are spaced widely from one another.

Biology of the parasitoid Melittobia (Hymenoptera: Eulophidae).

As parasitoids upon solitary bees and wasps and their nest cohabitants, Melittobia have an intricate life history that involves both female cooperation and variably expressed male siblicidal conflict. Inter- and intrasexual dimorphism includes blind, flightless males and (probably nutritionally determined) short- and long-winged females. Thought to be highly inbred, Melittobia do not conform to local mate competition (LMC) theory but exhibit simple forms of many social insect traits, including overlapping adult generations, different female phenotypes, close kinship ties, parental care, and altruistic cooperative escape behaviors. Most host records and research findings are based on only 3 species--M. acasta, M. australica, and M. digitata--but any of the 12 species could have pest potential due to their polyphagy, explosive population growth, cryptic habits, and behavioral plasticity. Readily cultured in the laboratory, Melittobia offer considerable potential as a model for genetic, developmental, and behavioral studies.

Social workers' views of the etiology of mental disorders: results of a national study.

Research on many mental disorders conducted since the 1990s strongly suggests a biological component to etiology. These developments should inform the decisions clinical social workers make regarding their interventions with clients. Several recent research reports, however, suggest that social workers may underestimate the influence of biological factors in some mental disorders. Because the measures of practitioners' views developed for those studies were not sensitive to disorder-specific responses for a range of mental illnesses, the usefulness of their findings may be questioned. The authors present the results of a national study of social workers in which disorder-specific measures of mental illness were used to determine more clearly whether social workers are making research-based assessments of mental illnesses etiology. It was found that social workers attribute causality of four disorders in a manner consistent with current research.

Synergistic induction of apoptosis in human endothelial cells by tumour necrosis factor-alpha and transforming growth factor-beta.

Serum deprivation stimulates endothelial apoptosis while albumin inhibits this and has been proposed as important in confining apoptotic remodelling to poorly perfused vessels. Tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta are also reported to induce endothelial apoptosis. To investigate the comparative roles of these stimuli, the effect of TNF-alpha and TGF-beta, alone or in combination, in the presence or absence of serum or albumin was studied. There was strong synergy between the cytokines in inducing human umbilical vein endothelial cell apoptosis, but only in the absence of serum. Synergy was destroyed by boiling cytokines and was not affected by polymyxin B. Dose response experiments revealed greater activity of TGF-beta(1) than TGF-beta(2). The synergy was protein synthesis dependent and apoptosis was confirmed by DNA gel electrophoresis, transmission electron microscopy and FACS analysis. Data suggests a role for synergistic activation of endothelial cell apoptosis by TNF-alpha and TGF-beta(1) but perhaps only in poorly perfused vessels deprived of serum factors.