Insights from the amphioxus genome on the origin of vertebrate neural crest

The emergence of the neural crest has been proposed to play a key role in early vertebrate evolution by remodeling the chordate head into a "new head" that enabled early vertebrates to shift from filter feeding to active predation. Here we show that the genome of the basal chordate, amphioxus, contains homologs of most vertebrate genes implicated in a putative neural crest gene regulatory network (NC-GRN) for neural crest development. Our survey of gene expression shows that early inducing signals, neural plate border patterning genes, and melanocyte differentiation genes appear conserved. Furthermore, exogenous BMP affects expression of amphioxus neural plate border genes as in vertebrates, suggesting that conserved signals specify the neural plate border throughout chordates. In contrast to this core conservation, many neural crest specifier genes are not expressed at the amphioxus neural plate/tube border, raising the intriguing possibility that this level of the network was co-opted during vertebrate evolution. Consistent with this, the regulatory region of AmphiFoxD, homologous to the vertebrate neural crest specifier FoxD3, drives tissue-specific reporter expression in chick mesoderm, but not neural crest. Thus, evolution of a new regulatory element may have allowed co-option of this gene to the NC-GRN.     

Understanding the needs of relatives of patients within a special hospital for mentally disordered offenders: a basis for improved services

This paper outlines one component of a major research study, which will forn the basis for a new service for relatives of schizophrenia sufferers within a special hospital The aim of this initial component has been twofold firstly to identify and understand the needs of relatives in terms of their present knowledge and understanding of schizophrenia, and secondly to establish what stress the relatives are presently experiencing in maintaining contact with patients and whether this stress may have an impact on the management of schizophrenia at the hospital A purposive sample of 17 relatives were interviewed using two semi-structured interview protocols All interviews were audio-taped and later transcribed for analysis The data have provided an illuminating insight into the thoughts and feelings of relatives and indicate many ways in which a service for relatives could be tailored It is apparent that many relatives are currently not being supported, involved or allowed to contribute to the care of their family member at Ashworth Hospital This present situation is stressful for relatives and is likely to have a detrimental effect on the course of schizophrenia in patients at Ashworth Hospital     

Substituent effects on partition coefficients of barbituric acids

Precise partition coefficients in 1-octanol-water at 25 degrees C were determined for three 2-thiobarbituric acids and 14 barbituric acids with a wider range of substituents. The experimental log P values (log Pexp) of barbituric acids were correlated with the carbon number and the branching effect of the C5 substituent(s) by linear regression analysis. The carbon number term makes a major contribution to the partition coefficients. The contribution of the polar effect of the C5 substituents was insignificant in contrast to a previous report. Hydrophobic constants (pi) were determined for allyl, phenyl, and chloro-substituents, and these empirical pi values gave much closer predicted calculated log P (log Pcalc) values when applied to the reported log Pexp values.     

Patient discomfort during screen-film mammography

Vigorous compression is required to minimize radiation dose and maximize image quality for screen-film mammography. Of 356 women who adequately completed a questionnaire following mammography, 171 (48%) reported mammography to be comfortable, 135 (38%) uncomfortable but tolerable, 39 (11%) very uncomfortable, and only 11 (3%) found the examination to be intolerable. Only 14 women (4%) indicated that they would not return for mammography at our facility in the future. Because of this high level of acceptance of compression by women, technologists and radiologists should not hesitate to use vigorous compression to optimize image quality and decrease radiation dose to the patient.     

Function of the interleukin-2 (IL-2) receptor gamma-chain in biologic responses of X-linked severe combined immunodeficient B cells to IL-2, IL-4, IL-13, and IL-15

The interleukin-2 (IL-2) receptor gamma-chain is a common component of several members of the cytokine receptor superfamily including those for IL-2, IL-4, IL-7, IL-9, IL-15, and possibly IL-13, and has recently been renamed the common gamma-chain (gamma c-chain). Transfection experiments have shown that the gamma c-chain participates in signal transduction by IL-2, IL-4 and IL-7, but a functional role for the gamma c-chain in biological responses by normal T cells and B cells to these cytokines has not been established. In this study, we have used X- linked severe combined immunodeficiency (X-SCID) as a naturally occurring gamma c-chain gene disruption model to examine the role of the gamma c-chain in human B-cell responses to IL-2, IL-4, IL-13, and IL-15. Our experiments show that B cells from two X-SCID patients with characterized gamma c-chain gene mutations do not respond to IL-2 or IL- 15, but respond as well or better than normal B cells to both IL-4 and IL-13 in assays for B-cell activation, proliferation, and IgE secretion. This finding raises important questions about the function of the gamma c-chain in receptors for IL-4 and IL-13, and the nature of the immune defect in X-SCID.