Lipid metabolism in Chlamydia trachomatis-infected cells: directed trafficking of Golgi-derived sphingolipids to the chlamydial inclusion.

Chlamydia trachomatis undergoes its entire life cycle within an uncharacterized intracellular vesicle that does not fuse with lysosomes. We used a fluorescent Golgi-specific probe, (N-[7-(4-nitrobenzo-2-oxa-1,3-diazole)]) aminocaproylsphingosine (C6-NBD-Cer), in conjunction with conventional fluorescence or confocal microscopy to identify interactions between the Golgi apparatus and the chlamydial inclusion. We observed not only a close physical association between the Golgi apparatus and the chlamydial inclusion but the eventual presence of a metabolite of this fluorescent probe associated with the chlamydiae themselves. Sphingomyelin, endogenously synthesized from C6-NBD-Cer, was specifically transported to the inclusion and incorporated into the cell wall of the intracellular chlamydiae. Incorporation of the fluorescent sphingolipid by chlamydiae was inhibited by brefeldin A. Chlamydiae therefore occupy a vesicle distal to the Golgi apparatus that receives anterograde vesicular traffic from the Golgi normally bound for the plasma membrane. Collectively, the data suggest that the chlamydial inclusion may represent a unique compartment within the trans-Golgi network.

And the poor get children; sex, contraception, and family planning in the working class.

Includes bibliography.

What you should know about emergency contraception /

"1/05."

Multiple genotypes of Chlamydia pneumoniae identified in human carotid plaque

Chlamydia pneumoniae is an obligate intracellular respiratory pathogen that causes 10% of community-acquired pneumonia and has been associated with cardiovascular disease. Both whole-genome sequencing and specific gene typing suggest that there is relatively little genetic variation in human isolates of C. pneumoniae. To date, there has been little genomic analysis of strains from human cardiovascular sites. The genotypes of C. pneumoniae present in human atherosclerotic carotid plaque were analysed and several polymorphisms in the variable domain 4 (VD4) region of the outer-membrane protein-A (ompA) gene and the intergenic region between the ygeD and uridine kinase (ygeD-urk) genes were found. While one genotype was identified that was the same as one reported previously in humans (respiratory and cardiovascular), another genotype was found that was identical to a genotype from non-human sources (frog/koala).

Type III secretion contact-dependent model for the intracellular development of Chlamydia

The medically significant genus Chlamydia is a class of obligate intracellular bacterial pathogens that replicate within vacuoles in host eukaryotic cells termed inclusions. Chlamydia's developmental cycle involves two forms; an infectious extracellular form, known as an elementary body (EB), and a non-infectious form, known as the reticulate body (RB), that replicates inside the vacuoles of the host cells. The RB surface is covered in projections that are in intimate contact with the inclusion membrane. Late in the developmental cycle, these reticulate bodies differentiate into the elementary body form. In this paper, we present a hypothesis for the modulation of these developmental events involving the contact-dependent type III secretion (TTS) system. TTS surface projections mediate intimate contact between the RB and the inclusion membrane. Below a certain number of projections, detachment of the RB provides a signal for late differentiation of RB into EB. We use data and develop a mathematical model investigating this hypothesis. If the hypothesis proves to be accurate, then we have shown that increasing the number of inclusions per host cell will increase the number of infectious progeny EB until some optimal number of inclusions. For more inclusions than this optimum, the infectious yield is reduced because of spatial restrictions. We also predict that a reduction in the number of projections on the surface of the RB (and as early as possible during development) will significantly reduce the burst size of infectious EB particles. Many of the results predicted by the model can be tested experimentally and may lead to the identification of potential targets for drug design. © Society for Mathematical Biology 2006.

Contraception and heterosex: an intimate relationship

Whilst the importance of contraception within heterosex has long been accepted, particularly in relation to the prevention of HIV/AIDS, the way in which the use, or non-use, of contraception re/constructs heterosexual encounters themselves has had far less attention. The embodied nature of both the risk of pregnancy, and most contraceptive technologies leads women to assert a right to bodily autonomy. Yet this assertion conflicts with their expectation of equitable coupledom within heterosexuality and their routine consideration of men’s preferences. This article will argue that the use of contraception is an intricate part of heterosexual practices, and shows how normative ideas about heterosexuality leave men as appearing as an absent presence within women’s contraceptive decisions.

Every child a wanted child: mid-life women's experiences of contraception

This paper is based on qualitative research which found that the contraceptive pill had achieved a "hegemonic status" among some British women in their thirties. In addition, despite the risk of sexually transmitted diseases, the idea of using condoms was very unpopular, and the research suggests that this is linked to a reluctance to rely on male cooperation over contraception. This paper will further argue that the women generally chose methods that they felt would be in their own best interests, and were often exercising considerable agency within the constraints of their relationships. Moreover, by accepting the responsibility for contraception, the women not only gained sole control over their fertility, but contraception may be an area within heterosexuality where women can exercise power.

Embodied expertise: women's perceptions of the contraception consultation

This research, based on qualitative interviews and non-participant observation, emerges from a larger study investigating what factors influence the ‘contraceptive careers’ of British women in their 30s. The women informants recognized that contraceptive products often impacted on their health, but viewed them as distinct from ‘medical matters’. Rather than doctors being seen as having expertise, it was women health professionals, be they nurses, midwives, health visitors or doctors, who were perceived as the ones who ‘know’ about contraception, through an assumption that they are contraception users.This embodied knowledge is valued by the women above their formal medical training. I will also show how general practice surgeries and family planning clinics were viewed as gendered spaces, which altered the expectations and experiences of the women during contraceptive consultations. This study found that as ‘real’ expertise over contraception stems from embodied rather than textual knowledge, the women’s choices were grounded by a gendered sense of trust.

I got pregnant, I was so like ... crying inside...: experiences of women of Pakistani ancestry seeking contraception in the UK

South Asian women in Britain are less likely to use contraception than women in other ethnic groups. Previous studies have identified a lack of knowledge combined with low levels of English language and/or literacy as barriers to using contraception, but have not examined in detail women's experiences of accessing services. This qualitative study focused on the experiences of 19 Muslim women of Pakistani ancestry and the views of six health and community workers. The findings detail considerable institutional barriers to accessing contraceptive services, such as a lack of information and the paternalistic attitudes of some health professionals. The study suggests that, although all the women were motivated to access and use contraception, their ability to make informed choices was often limited. It was only when the women encountered advocates, who might be professionals or from their social networks, that they could begin to take control of their fertility. This study is consistent with earlier research and shows that lack of access to contraceptive services can have high personal and social costs for South Asian women.

Simplified preparation of human arterial sections for PCR analysis of Chlamydia pneumoniae and human DNA

AIMS: To investigate multiple techniques for the preparation of solid tissue for polymerase chain reaction (PCR) analysis, and to identify the most simple techniques for routine use in the laboratory. METHODS: Techniques for the preparation of arterial tissue samples including homogenisation, ultrafiltration, and treatments involving proteinase K, Gene Clean, lectin, and Fe3+ specific chelators were evaluated using the PCR to amplify both Chlamydia pneumoniae and human DNA. RESULTS: Treatment with either Gene-Clean or lectin and the Fe3+ specific chelator deferoxamine mesylate removed PCR inhibitors from tissue homogenates. Homogenisation followed by GeneClean treatment resulted in the amplification of C pneumoniae DNA from within a section of atherosclerotic carotid artery, implying that C pneumoniae elementary bodies had been disrupted. In eight further clinical samples from patients not known to have C pneumoniae infection, human DNA was amplified and no cross contamination was observed between samples. These samples contained no evidence of C pneumoniae by PCR. CONCLUSIONS: A simple preparation of solid tissue for PCR analysis, involving homogenisation followed by GeneClean treatment has been developed, and is effective for the amplification of both C pneumoniae and human DNA.