Gut microbiota and immune profiling of microbiota-humanised versus wildtype mouse models of hepatointestinal schistosomiasis.

Mounting evidence of the occurrence of direct and indirect interactions between the human blood fluke, Schistosoma mansoni, and the gut microbiota of rodent models raises questions on the potential role(s) of the latter in the pathophysiology of hepatointestinal schistosomiasis. However, substantial differences in both the composition and function between the gut microbiota of laboratory rodents and that of humans hinders an in-depth understanding of the significance of such interactions for human schistosomiasis. Taking advantage of the availability of a human microbiota-associated mouse model (HMA), we have previously highlighted differences in infection-associated changes in gut microbiota composition between HMA and wildtype (WT) mice. To further explore the dynamics of schistosome-microbiota relationships in HMA mice, in this study we (i) characterize qualitative and quantitative changes in gut microbiota composition of a distinct line of HMA mice (D2 HMA) infected with S. mansoni prior to and following the onset of parasite egg production; (ii) profile local and systemic immune responses against the parasite in HMA as well as WT mice and (iii) assess levels of faecal inflammatory markers and occult blood as indirect measures of gut tissue damage. We show that patent S. mansoni infection is associated with reduced bacterial alpha diversity in the gut of D2 HMA mice, alongside expansion of hydrogen sulphide-producing bacteria. Similar systemic humoral responses against S. mansoni in WT and D2 HMA mice, as well as levels of faecal lipocalin and markers of alternatively activated macrophages, suggest that these are independent of baseline gut microbiota composition. Qualitative comparative analyses between faecal microbial profiles of S. mansoni-infected WT and distinct lines of HMA mice reveal that, while infection-induced alterations of the gut microbiota composition are highly dependent on the baseline flora, bile acid composition and metabolism may represent key elements of schistosome-microbiota interactions through the gut-liver axis.

Agency, communion, and cardiovascular reactivity during marital interaction.

The concepts of agency and communion have been used to describe sex differences in vulnerability to specific stressor domains. This study examined blood pressure and heart rate responses of 60 married couples to experimental manipulations of disagreement (i.e., communion stressor) and achievement challenge (i.e., agency stressor). Consistent with predictions, disagreement elicited heightened cardiovascular reactivity among wives, but not husbands. In contrast, the achievement challenge elicited heightened cardiovascular reactivity among husbands, but not wives. Participants' responses to a circumplex measure of interpersonal appraisal were consistent with the interpretation of differential responses to agency and communion stressors. Results are congruent with a situational approach to sex differences in cardiovascular reactivity and illustrate the utility of interpersonal methods in the explication of psychosocial risk for cardiovascular disease.

A novel alpha integrin subunit associates with betaPS and functions in tissue morphogenesis and movement during Drosophila development.

We have identified a novel alpha integrin subunit in Drosophila, that associates with betaPS integrin. We report the temporal expression of the gene encoding this integrin subunit, which we have called alphaPS3, throughout development and the localization of its expression during embryogenesis. AlphaPS3 RNA was localized to tissues undergoing invagination, tissue movement and morphogenesis such as salivary gland, trachea, midgut, dorsal vessel, midline of the ventral nerve cord, amnioserosa and the amnioproctodeal invagination. AlphaPS3 DNA localized to the chromosomal vicinity of scab (scb), previously identified by a failure of dorsal closure. Embryos homozygous for the 119 allele of scb had no detectable alphaPS3 RNA and the 1035 allele of scb contains a P element inserted just 5' of the coding region for the shorter of the gene's two transcripts. Furthermore, mutations in the scb locus exhibit additional defects corresponding to sites of alphaPS3 transcription, including abnormal salivary glands, mislocalization of the pericardial cells and interrupted trachea. Removal of both maternal and zygotic betaPS produced similar defects, indicating that these two integrin subunits associate in vivo and function in the movement and morphogenesis of tissues during development in Drosophila. Phenotypic similarities suggest that laminin A is a potential ligand for this integrin, at least in some tissues.

Partner notification for HIV prevention: a critical reexamination.

The history, current role, and potential enhanced functions of HIV partner notification are reviewed. What is known about the effectiveness of partner notification is summarized and five general findings are reported: (1) many, if not most, HIV-infected individuals will cooperate in notifying at least some of their sex partners of exposure to HIV; (2) sex partners are generally receptive to being notified and will seek HIV testing; (3) patient referral is probably not as effective as provider referral in reaching sex partners; (4) sex partners often are unaware of or misunderstand their HIV risks; and (5) sex partners frequently have high rates of HIV infection. Means for enhancing partner notification are reviewed, including social network interventions, coupling partner notification with behavioral interventions, reaching persons earlier in their HIV infection, using data collected from partner notification as a source of program evaluation information, and addressing important community concerns about partner notification.

Drosophila integrins and their ligands.

The major advance during the past year was the identification of ligands for two of the previously known position-specific integrins in Drosophila. At the same time, two new Drosophila integrin subunits (one alpha and one beta) were discovered, and significant progress was made on developmental genetic analyses of integrin functions, shedding light on the roles of integrins in Drosophila development.

Evaluating the CDC program for HIV counseling and testing.

The Centers for Disease Control is conducting two investigations of the outcomes of HIV counselling and testing services offered persons at high risk for infection with the human immunodeficiency virus (HIV). One investigation is a trial conducted at sexually transmitted disease clinics where an enhanced version of HIV counseling and testing is compared with a standard version. The other investigation is a longitudinal study of the effects of HIV counseling and testing in drug treatment programs that use methadone therapy. In the evaluation, comparisons are being made of different ways of offering HIV counseling and testing and of the effectiveness of the program among persons who know their HIV serostatus and those who do not. The outcome variables include self-reported sexual and drug-using behaviors, together with corroborating laboratory tests, drug treatment compliance, mental health effects, and services utilization. Methodological, practical, and sociopolitical challenges were encountered in the evaluations. Possible solutions to the problems are described. The authors conclude that the designs of the evaluations were appropriate, but that considerable resources are required to carry them out. In settings with low levels of resources, thorough evaluation of the process and an assessment of the immediate outcomes may be the most appropriate evaluation strategy. As HIV counseling and testing are of fundamental importance to national and international HIV prevention efforts, their evaluation is a critical issue.