Reconstitution of lipoprotein(a) by infusion of human low density lipoprotein into transgenic mice expressing human apolipoprotein(a)

Lipoprotein(a) (Lp(a)) is an atherosclerosis-causing lipoprotein that circulates in human plasma as a complex of low density lipoprotein (LDL) and apolipoprotein(a) (apo(a)). It is not known whether apo(a) attaches to LDL within hepatocytes prior to secretion or in plasma subsequent to secretion. Here we describe the development of a line of mice expressing the human apo(a) transgene under the control of the murine transferrin promoter. The apo(a) was secreted into the plasma, but circulated free of lipoproteins. When human (h)-LDL was injected intravenously, the circulating apo(a) rapidly associated with the lipoproteins, as determined by nondenaturing gel electrophoresis. Human HDL and mouse LDL had no such effect. When h-VLDL was injected, there was a delayed association of apo(a) with the lipoprotein fraction which suggests that apo(a) preferentially associated with a metabolic product of VLDL. The complex of apo(a) with LDL formed both in vivo and in vitro was resistant to boiling in the presence of detergents and denaturants, but was resolved upon disulfide reduction. These studies suggest that apo(a) fails to associate with mouse lipoproteins due to structural differences between human and mouse LDL, and that Lp(a) formation can occur in plasma through the association of apo(a) with circulating LDL

Antiretroviral treatment as prevention: Impact of the 'test and treat' strategy on the tuberculosis epidemic

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Tuberculosis in a South African prison - a transmission modelling analysis

Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a mathematical model was developed to explore the interactions between incarceration conditions and TB control measures. Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and international minimum standards for incarceration. Results. Levels of overcrowding (230%) in communal cells and poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively. Conclusions. Current conditions of detention for awaitingtrial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently

Tuberculosis in a South African prison - a transmission modelling analysis

Background. Prisons are recognised internationally as institutions with very high tuberculosis (TB) burdens where transmission is predominantly determined by contact between infectious and susceptible prisoners. A recent South African court case described the conditions under which prisoners awaiting trial were kept. With the use of these data, a mathematical model was developed to explore the interactions between incarceration conditions and TB control measures. Methods. Cell dimensions, cell occupancy, lock-up time, TB incidence and treatment delays were derived from court evidence and judicial reports. Using the Wells-Riley equation and probability analyses of contact between prisoners, we estimated the current TB transmission probability within prison cells, and estimated transmission probabilities of improved levels of case finding in combination with implementation of national and international minimum standards for incarceration. Results. Levels of overcrowding (230%) in communal cells and poor TB case finding result in annual TB transmission risks of 90% per annum. Implementing current national or international cell occupancy recommendations would reduce TB transmission probabilities by 30% and 50%, respectively. Improved passive case finding, modest ventilation increase or decreased lock-up time would minimally impact on transmission if introduced individually. However, active case finding together with implementation of minimum national and international standards of incarceration could reduce transmission by 50% and 94%, respectively. Conclusions. Current conditions of detention for awaitingtrial prisoners are highly conducive for spread of drug-sensitive and drug-resistant TB. Combinations of simple well-established scientific control measures should be implemented urgently

Apo(a) Expression in Transgenic Mice

Cet article est d’un type particulier, puisque son auteur répond à un auteur du même numéro qui retrace les débats d’une journée d’étude NEQ (Notion en questions), consacrée à l’émergentisme en janvier 2016. Le positionnement du répondant, didacticien de l’intervention, explique sa réaction. Une première partie situe donc l’auteur dans un courant transdisciplinaire où l’émergentisme a sa place dans une perspective plurilingue. La suite est autant une réaction à l’article de Marjolijn Verspoor qu’aux débats de la journée. L’apport des recherches présentées dans l’article initial est d’un grand intérêt, mais leurs limites confirment le besoin d’un travail transdisciplinaire incluant d’ailleurs la discipline des documents académiques.This article has an unusual format as its author responds to another article in the same issue that relates the exchanges that took place during a Notion in Question (NEQ) seminar devoted to « Emergentism » in January 2016. The theoretical position of the respondent, a researcher in language learning and teaching, justifies his response. The first part of the article will describe this transdisciplinary position in which emergentism has a place in a plurilingual perspective. The second part is as much a response to Marjolijn’s Verspoor (MV)’s contribution as to the debates on that day. The results of MV’s research are rich and worthwhile but their very limitations justify the need for transdisciplinary collaboration in which the various fields of research complement each other

Ocular parameters of biological ageing in HIV-infected individuals in South Africa: relationship with chronological age and systemic biomarkers of ageing

HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two ‘cellular’ biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend = 0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection

Potential utility of empirical tuberculosis treatment for HIV-infected patients with advanced immunodeficiency in high TB-HIV burden settings

The human immunodeficiency virus (HIV) and HIV-associated tuberculosis (TB-HIV) epidemics remain uncontrolled in many resource-limited regions, especially in sub-Saharan Africa. The scale of these epidemics requires the consideration of innovative bold interventions and 'out-of-the-box' thinking. To this end, a symposium entitled 'Controversies in HIV' was held at the 40th Union World Conference on Lung Health in Cancun, Mexico, in December 2009. The first topic debated, entitled 'Annual HIV testing and immediate start of antiretroviral therapy for all HIV-infected persons', received much attention at international conferences and in the literature in 2009. The second topic forms the subject of this article. The rationale for the use of empirical TB treatment is premised on the hypothesis that in settings worst affected by the TB-HIV epidemic, a subset of HIV-infected patients have such a high risk of undiagnosed TB and of associated mortality that their prognosis may be improved by immediate initiation of empirical TB treatment used in conjunction with antiretroviral therapy. In addition to morbidity and mortality reduction, additional benefits may include prevention of nosocomial TB transmission and TB preventive effect. Potential adverse consequences, however, may include failure to consider other non-TB diagnoses, drug co-toxicity, compromised treatment adherence, and logistical and resource challenges. There may also be general reluctance among national TB programmes to endorse such a strategy. Following fruitful debate, the conclusion that this strategy should be carefully evaluated in randomised controlled trials was strongly supported. This paper provides an in-depth consideration of this proposed intervention. © 2011 The Union.Articl

New world mucosal and cutaneous leishmaniasis: an emerging health problem among British travellers.

BACKGROUND: Mucosal leishmaniasis (ML) is an important complication of new world cutaneous leishmaniasis (CL) caused by species of the Leishmania Viannia subgenus. Previous reports of ML among travellers to Latin America are few. AIMS: To determine the annual number of cases of CL due to L. Viannia species diagnosed at this institution and to correlate this with changing patterns of travel. Secondly, to document the clinical presentation, diagnosis, treatment and outcome of ML at this institution. DESIGN: Retrospective observational study. METHODS: Data were collected from a clinical database, laboratory records, patient case notes and an international passenger survey. RESULTS: Between 1995 and 2003, the annual number of cases of CL (total 79) steadily increased from 4 per year to 18 per year; the estimated number of travellers from the UK to Latin America increased 3.5-fold. Six cases of ML were diagnosed among British travellers in 1995 (1), 1997 (1) and 2002 (4). These infections were acquired in Bolivia (3), Colombia (2) and Belize (1). Nasopharyngeal symptoms developed 0-15 months after returning to the UK. Four patients had concurrent CL at diagnosis. Diagnosis of ML was delayed up to 6 months from the onset of symptoms. Mucosal biopsies from all 6 patients were PCR-positive for L. (Viannia) DNA; microscopy and culture were less sensitive. ML relapsed in one patient following treatment. DISCUSSION: Increasing travel to Latin America from the UK was associated with an increasing number of diagnoses of L. Viannia CL. ML is likely to emerge as a more frequently imported infection among such travellers. Familiarity with these diseases is important for prompt diagnosis and optimal management