Human naive CD8 T cells down-regulate expression of the WNT pathway transcription factors lymphoid enhancer binding factor 1 and transcription factor 7 (T cell factor-1) following antigen encounter in vitro and in vivo

Abstract The transcription factors lymphoid enhancer binding factor 1 (LEF1) and transcription factor 7 (TCF7) (T cell factor-1 (TCF-1)) are downstream effectors of the WNT signaling pathway, which is a critical regulator of T cell development in the thymus. In this study, we show that LEF1 and TCF7 (TCF-1) are not only expressed in thymocytes, but also in mature T cells. Our data demonstrate that Ag encounter in vivo and engagement of the TCR or IL-15 receptor in vitro leads to the down-regulation of LEF1 and TCF7 (TCF-1) expression in human naive CD8 T cells. We further show that resting T cells preferentially express inhibitory LEF1 and TCF7 (TCF-1) isoforms and that T cell activation changes the isoform balance in favor of stimulatory TCF7 (TCF-1) isoforms. Altogether, our study suggests that proteins involved in the WNT signaling pathway not only regulate T cell development, but also peripheral T cell differentiation.</jats:p

Factors influencing contraception awareness and use: The experiences of young African Australian mothers

The aim of this study was to examine contraception awareness and use among African Australian women in Melbourne, Australia, who have experienced teenage pregnancy, and to explore the social contexts that shape these women's attitudes towards contraception. Among young immigrant and refugee women living in sites of settlement, knowledge and use of contraception are a public health concern. The study used a qualitative research approach and was informed by anthropology, public health and human rights frameworks. Between June 2009 and November 2010, in-depth interviews were conducted in Melbourne, Australia, with 16 African Australian teenagers and women who had experienced teenage pregnancy. In addition, two focus group discussions were held with service providers and African women and five key informant interviews were conducted. Data were transcribed verbatim, coded, and key themes identified and analysed using thematic analysis. The findings revealed that attitudes towards and use of contraception are influenced by parental sexual health literacy and attitudes, gender roles and culturally informed attitudes around motherhood. Service providers should consider the value of whole-of-family and community approaches in order to improve knowledge and decision-making around contraception among young African Australian women

Early motherhood: A qualitative study exploring the experiences of African Australian teenage mothers in greater Melbourne, Australia

BACKGROUND: Motherhood is a significant and important aspect of life for many women around the globe. For women in communities where motherhood is highly desired, motherhood is considered crucial to the woman's identity. Teenage motherhood, occurring at a critical developmental stage of teenagers' lives, has been identified as having adverse social and health consequences. This research aimed to solicit the lived experiences of African Australian young refugee women who have experienced early motherhood in Australia. METHODS: This qualitative research used in-depth interviews. The research methods and analysis were informed by intersectionality theory, phenomenology and a cultural competency framework. Sixteen African born refugee young women who had experienced teenage pregnancy and early motherhood in Greater Melbourne, Australia took part in this research. Interviews were audio recorded, transcribed and data analysed using thematic content analysis. Ethics approval for this research was granted by Victoria University Human Research Ethics committee. RESULTS: Motherhood brings increased responsibilities, social recognition, and a sense of purpose for young mothers. Despite the positive aspects of motherhood, participants faced challenges that affected their lives. Most often, the challenges included coping with increased responsibilities following the birth of the baby, managing the competing demands of schooling, work and taking care of a baby in a site of settlement. The young mothers indicated they received good support from their mothers, siblings and close friends, but rarely from the father of their baby and the wider community. Participants felt that teenage mothers are frowned upon by their wider ethnic communities, which left them with feelings of shame and embarrassment, despite the personal perceived benefits of achieving motherhood. CONCLUSIONS: We propose that service providers and policy makers support the role of the young mothers' own mother, sisters, their grandmothers and aunts following early motherhood. Such support from significant females will help facilitate young mothers' re-engagement with education, work and other aspects of life. For young migrant mothers, this is particularly important in order to facilitate settlement in a new country and reduce the risk of subsequent mistimed pregnancies. Service providers need to expand their knowledge and awareness of the specific needs of refugee teen mothers living in 'new settings'

Molecular signatures distinguish human central memory from effector memory CD8 T cell subsets

Abstract Memory T cells are heterogeneous in terms of their phenotype and functional properties. We investigated the molecular profiles of human CD8 naive central memory (TCM), effector memory (TEM), and effector memory RA (TEMRA) T cells using gene expression microarrays and phospho-protein-specific intracellular flow cytometry. We demonstrate that TCM have a gene expression and cytokine signaling signature that lies between that of naive and TEM or TEMRA cells, whereas TEM and TEMRA are closely related. Our data define the molecular basis for the different functional properties of central and effector memory subsets. We show that TEM and TEMRA cells strongly express genes with known importance in CD8 T cell effector function. In contrast, TCM are characterized by high basal and cytokine-induced STAT5 phosphorylation, reflecting their capacity for self-renewal. Altogether, our results distinguish TCM and TEM/TEMRA at the molecular level and are consistent with the concept that TCM represent memory stem cells.</jats:p

Ancient Amazonian populations left lasting impacts on forest structure

Amazonia contains a vast expanse of contiguous tropical forest and is influential in global carbon and hydrological cycles. Whether ancient Amazonia was highly disturbed or modestly impacted, and how ancient disturbances have shaped current forest ecosystem processes, is still under debate. Amazonian Dark Earths (ADEs), which are anthropic soil types with enriched nutrient levels, are one of the primary lines of evidence for ancient human presence and landscape modifications in settings that mostly lack stone structures and which are today covered by vegetation. We assessed the potential of using moderate spatial resolution optical satellite imagery to predict ADEs across the Amazon Basin. Maximum entropy modeling was used to develop a predictive model using locations of ADEs across the basin and satellite‐derived remotely sensed indices. Amazonian Dark Earth sites were predicted to be primarily along the main rivers and in eastern Amazonia. Amazonian Dark Earth sites, when compared with randomly selected forested sites located within 50 km of ADE sites, were less green canopies (lower normalized difference vegetation index) and had lower canopy water content. This difference was accentuated in two drought years, 2005 and 2010. This is contrary to our expectation that ADE sites would have nutrient‐rich soils that support trees with greener canopies and forests on ADE soils being more resilient to drought. Biomass and tree height were lower on ADE sites in comparison with randomly selected adjacent sites. Our results suggested that ADE‐related ancient human impact on the forest is measurable across the entirety of the 6 million km2 of Amazon Basin using remotely sensed data

The UK register of HIV seroconverters: Methods and analytical issues

A Register of HIV-infected persons who have had a negative antibody test within 3 years of their first antibody positive test (seroconverters) is being set up in the UK to monitor the distribution of times from HIV seroconversion to AIDS (the incubation period) and to death. It will also provide a national resource for use by those designing studies in this group of individuals. Clinicians caring for HIV-positive persons in Genito-Urinary Medicine, Infectious Disease and other departments throughout the UK were asked to participate by providing information on eligible subjects. Most laboratories undertaking HIV antibody testing were also contacted and asked to provide the name of the attending clinician for all seroconverters identified through the HIV laboratory reporting systems of the PHLS Communicable Disease Surveillance Centre (CDSC) and the Scottish Centre for Infection and Environmental Health (SCIEH) and for any other seroconverters known to them but not identified by CDSC or SCIEH. Data items sought for the Register include: sex, ethnic group, probable route of HIV transmission, annual CD4 counts, details of therapy and prophylaxis prescribed, AIDS-defining events and vital status. Follow up information is collected annually. Wherever possible, all seroconverters known to a clinic have been identified, whether currently alive or dead, either from clinic records or laboratory reporting or both. The objective is to establish and update a complete register of seroconverters on a long-term basis to provide reliable estimates of the incubation period on which future projections of AIDS cases in the UK can be made

Climate Variability and Ross River Virus Transmission in Townsville Region, Australia 1985 to 1996

Background How climate variability affects the transmission of infectious diseases at a regional level remains unclear. In this paper, we assessed the impact of climate variation on the Ross River virus (RRv) transmission in the Townsville region, Queensland, north-east Australia. Methods Population-based information was obtained on monthly variations in RRv cases, climatic factors, sea level, and population growth between 1985 and 1996. Cross-correlations were computed for a series of associations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity and high tide) and the monthly incidence of RRv disease over a range of time lags. The impact of climate variability on RRv transmission was assessed using the seasonal auto-regressive integrated moving average (SARIMA) model. Results There were significant correlations of the monthly incidence of RRv to rainfall, maximum temperature, minimum temperature and relative humidity, all at a lag of 2 months, and high tide in the current month. The results of SARIMA models show that monthly average rainfall (β=0.0012, p=0.04) and high tide (β=0.0262, p=0.01) were significantly associated with RRv transmission, although temperature and relative humidity did not seem to have played an important role in the Townsville region. Conclusions Rainfall, and high tide were likely to be key determinants of RRv transmission in the Townsville region