Knowledge, attitudes and practices on childhood TB among healthcare workers.

BACKGROUND: Increasing childhood TB case detection requires the deployment of diagnostic services at peripheral healthcare level. Capacity and readiness of healthcare workers (HCWs) are key to the delivery of innovative approaches.METHODS: In 2019, HCWs from five district hospitals (DHs) and 20 primary healthcare centres (PHCs) in Cambodia, Cameroon, Cote d´Ivoire, Sierra Leone and Uganda completed a self-administered knowledge-attitudes-practices (KAP) questionnaire on childhood TB. We computed knowledge and attitudes as scores and identified HCW characteristics associated with knowledge scores using linear regression.RESULT: Of 636 eligible HCWs, 497 (78%) participated. Median knowledge scores per country ranged between 7.4 and 12.1 (/18). Median attitude scores ranged between 2.8 and 3.3 (/4). Between 13.3% and 34.4% of HCWs reported diagnosing childhood with (presumptive) TB few times a week. Practising at PHC level, being female, being involved in indirect TB care, having a non-permanent position, having no previous research experience and working in Cambodia, Cameroon, Cote d´Ivoire and Sierra Leone as compared to Uganda were associated with a lower knowledge score.CONCLUSION: HCWs had overall limited knowledge, favourable attitudes and little practice of childhood TB diagnosis. Increasing HCW awareness, capacity and skills, and improving access to effective diagnosis are urgently needed.

[Men who have sex with men (MSM) and HIV infection in Ouagadougou, Burkina Faso: Knowledge, attitudes, practices and seroprevalence survey]. / Les hommes qui ont des rapports sexuels avec d'autres hommes (HSH) et l'infection à VIH à Ouagadougou, Burkina Faso : connaissances, attitudes, pratiques et enquête de séroprévalence.

BACKGROUND: Like many African countries, the issue of sex between men in Burkina Faso remains taboo and sometimes result in social exclusion. This population which is vulnerable to HIV/AIDS is unknown, due to lack of scientific researches. AIM: Our study aimed to characterize knowledge, attitudes and sexual practices and to estimate HIV seroprevalence among men having sex with men (MSM) living in Ouagadougou. METHODS: A cross-sectional study was conducted in order to describe and analyze MSM living in Ouagadougou. They were recruited by snowball sampling, aged at least 18 years, and accepted to participate at the study. Data were collected by qualified interviewers through administered questionnaire face to face. HIV test was systematically proposed. RESULTS: A total of 142 MSM were recruited during the study period. The sample was mostly composed of students or pupils (60.8%), single men (91%), with age range 18-30 years (96.5%). The HIV knowledge median score was 8/10. HIV seroprevalence was 8.9% (4.5-15.4). CONCLUSION: Our study confirms the vulnerability of MSM living in Ouagadougou about HIV/AIDS given the high rate of HIV seroprevalence. Targeted interventions for prevention, care and scientific research are challenges for the authorities to sustain the achievements of the national fight against HIV and AIDS.

Barriers to antiretroviral treatment initiation in rural KwaZulu-Natal, South Africa.

OBJECTIVES: Although antiretroviral therapy (ART) has been freely available since 2004 in South Africa, not all those who are eligible initiate ART. We aimed to investigate individual and household characteristics as barriers to ART initiation in men and women in rural KwaZulu-Natal. METHODS: Adults ≥ 16 years old living within a sociodemographic surveillance area (DSA) who accessed the local HIV programme between 2007 and 2011 were included in the study. Individual and household factors associated with ART initiation within 3 months of becoming eligible for ART were investigated using multivariable logistic regression stratified by sex and after exclusion of individuals who died before initiating ART. RESULTS: Of the 797 men and 1598 women initially included, 8% and 5.5%, respectively, died before ART initiation and were excluded from further analysis. Of the remaining 733 men and 1510 women, 68.2% and 60.2%, respectively, initiated ART ≤ 3 months after becoming eligible (P = 0.34 after adjustment for CD4 cell count). In men, factors associated with a higher ART initiation rate were being a member of a household located < 2 km from the nearest HIV clinic and being resident in the DSA at the time of ART eligibility. In women, ART initiation was more likely in those who were not pregnant, in members of a household where at least one person was on ART and in those with a high wealth index. CONCLUSIONS: In this rural South African setting, barriers to ART initiation differed for men and women. Supportive individual- and household-level interventions should be developed to guarantee rapid ART initiation taking account gender specificities.

[HIV seroprevalence and associated factors among men who have sex with men in Togo]. / Séroprévalence du VIH et facteurs associés chez les hommes ayant des rapports sexuels avec d'autres hommes au Togo.

BACKGROUND: Limited data are available on HIV infection among vulnerable populations in sub-saharan African countries, especially among men who have sex with men (MSM). The aim of this study was to estimate HIV prevalence and the factors associated with HIV infection among MSM in Togo in 2011. METHOD: A cross-sectional survey was carried out among MSM aged at least 18years old, living in Togo for at least 3months. They were recruited through the snowball method in six cities of Togo from November 2011 to January 2012. A survey form was used and an HIV screening test was proposed to the participants. The HIV prevalence was estimated with a 95% confidence interval. Univariate and multivariate analyses were performed to identify factors associated with HIV infection. RESULTS: A total of 758 MSM were enrolled in this study, including 498 (67.5%) from Lomé, the capital of Togo. The median age was 24years with an interquartile range of [21-27years] and 271 MSM (35.7%) were students. The vast majority of MSM were Togolese (90.3%) and 14.6% were married or committed to a woman. HIV testing was accepted by 488 MSM (64.3%) but only 408 (53.8%) finally accepted a blood sample collection. The prevalence of HIV infection was 19.6% [95% confidence interval, 15.9-23.8]. In multivariate analysis, three factors were associated with HIV infection: living in Lomé, with an HIV prevalence of 29.8% against 4.3% in the other cities of Togo [adjusted odds ratio (aOR)=9.68; P<0.001]; having a good knowledge of HIV transmission modes (aOR=0.59; P=0.049); and not having a regular sex partner (aOR=1.69; P=0.049). CONCLUSION: One MSM out of five was HIV-infected. Intervention programs targeting this vulnerable population are urgently needed, to reduce HIV incidence in Togo.

[Enhanced prenatal HIV couple oriented counselling session and couple communication about HIV (ANRS 12127 Prenahtest Trial)]. / Intervention de conseil VIH prénatal orienté vers le couple et communication conjugale autour du VIH (Essai ANRS 12127 Prenahtest).

BACKGROUND: The Prenahtest study investigated the efficacy of a couple-oriented HIV counselling session (COC) in encouraging couple HIV counselling and testing, and improving intra-couple communication about sexual and reproductive health. We report here on the effect of COC on intra-couple communication about HIV. METHODS: Within this 4-country trial (India, Georgia, Dominican Republic and Cameroon), 484 to 491 pregnant women per site were recruited and individually randomized to receive either the COC intervention, enhanced counselling with role playing, or standard post-test HIV counselling. Women were interviewed at recruitment, before HIV testing (T0), and 2 to 8 weeks after post-test HIV counselling (T1). Four dichotomous variables documented intra-couple communication about HIV at T1: 1) discussion about HIV, 2) discussion about condom use, 3) suggesting HIV testing and 4) suggesting couple HIV counselling to the partner. An intra-couple HIV communication index was created: low degree of communication ("yes" response to zero or one of the four variables), intermediate degree of communication ("yes" to two or three variables) or high degree of communication ("yes" to the four variables). To estimate the impact of COC on the intra-couple HIV communication index, multivariable logistic regressions were conducted. RESULTS: One thousand six hundred and seven women were included in the analysis of whom 54 (3.4%) were HIV-infected (49 in Cameroon). In the four countries, the counselling group was associated with intra-couple HIV communication (P≤0.03): women allocated to the COC group were significantly more likely to report high or intermediate degrees of intra-couple communication about HIV (versus low degree of communication) than women allocated to standard counselling. CONCLUSION: COC improved short-term communication about HIV within couples in different sociocultural contexts, a positive finding for a couple approach to HIV prevention.

Community-based assessment of infant feeding practices within a programme for prevention of mother-to-child HIV transmission in rural Zimbabwe.

OBJECTIVE: To describe the infant feeding practices and attitudes of women who used prevention of mother-to-child transmission of HIV (PMTCT) services in rural Zimbabwe. DESIGN: A cross-sectional study including structured interviews and focus group discussions was conducted between June 2003 and February 2004. SETTING: The study took place in Murambinda Mission Hospital (Buhera District, Manicaland Province), the first site offering PMTCT services in rural Zimbabwe. SUBJECTS: The interviews targeted HIV-infected and HIV-negative women who received prenatal HIV counselling and testing and minimal infant feeding counselling, and who delivered between 15 August 2001 and 15 February 2003. The focus groups were conducted among young and elderly men and women. RESULTS: Overall, 71 HIV-infected and 93 HIV-negative mothers were interviewed in clinics or at home. Most infants (97%) had ever been breast-fed. HIV-negative mothers introduced fluids/foods other than breast milk significantly sooner than HIV-infected mothers (median 4.0 vs. 6.0 months, P = 0.005). Infants born to HIV-negative mothers were weaned significantly later than HIV-exposed infants (median 19.0 vs. 6.0 months, P = 10(-5)). More than 90% of mothers reported that breast-feeding their infant was a personal decision, a third of whom also mentioned having taken into account health workers' messages. CONCLUSION: The HIV-infected mothers interviewed were gradually implementing infant feeding practices recommended in the context of HIV. Increased infant feeding support capacity in resource-limited rural populations is required, i.e. training of counselling staff, decentralised follow-up and weaning support.

Improved knowledge and practices among end-users of mother-to-child transmission of HIV prevention services in rural Zimbabwe.

OBJECTIVE: To evaluate the influence of a prevention of mother-to-child transmission of HIV advocacy and mobilization campaign on awareness and knowledge levels within the community. METHOD: We used a knowledge, attitudes and practices survey to collect baseline data in November 2002 and again in July 2004 for evaluation purposes. RESULTS: A total of 351 women attending healthcare services were interviewed each time. The proportion of women aware of the service increased from 48.0% in 2002 to 82.8% in 2004 (OR = 4.9, 95% CI 3.3-7.3, P = 0.001). Exclusive breastfeeding was identified as a mother-to-child transmission risk factor by 27.1% in 2002 and by 55.8% of respondents in 2004 (OR = 2.9, CI 2.1-4.2, P = 0.001). Although most interviewees agreed that the prevention of sexual transmission of HIV was the best strategy for prevention of mother-to-child transmission of HIV (88.3% in 2002 and 96.4% in 2004), few reported having ever used a male condom (24.8% in 2002 vs. 29.8% in 2004, P = 0.16). DISCUSSION: Prevention of mother-to-child transmission of HIV strategies at both individual and community level were still insufficiently understood and applied. Targeted educational messages and communication for social change need to be combined. Knowledge, attitudes and practices surveys can be used to monitor programme progress.

Cubilin dysfunction causes abnormal metabolism of the steroid hormone 25(OH) vitamin D(3).

Steroid hormones are central regulators of a variety of biological processes. According to the free hormone hypothesis, steroids enter target cells by passive diffusion. However, recently we demonstrated that 25(OH) vitamin D(3) complexed to its plasma carrier, the vitamin D-binding protein, enters renal proximal tubules by receptor-mediated endocytosis. Knockout mice lacking the endocytic receptor megalin lose 25(OH) vitamin D(3) in the urine and develop bone disease. Here, we report that cubilin, a membrane-associated protein colocalizing with megalin, facilitates the endocytic process by sequestering steroid-carrier complexes on the cellular surface before megalin-mediated internalization of the cubilin-bound ligand. Dogs with an inherited disorder affecting cubilin biosynthesis exhibit abnormal vitamin D metabolism. Similarly, human patients with mutations causing cubilin dysfunction exhibit urinary excretion of 25(OH) vitamin D(3). This observation identifies spontaneous mutations in an endocytic receptor pathway affecting cellular uptake and metabolism of a steroid hormone.

The sortilin cytoplasmic tail conveys Golgi-endosome transport and binds the VHS domain of the GGA2 sorting protein.

Sortilin belongs to a growing family of multiligand type-1 receptors with homology to the yeast receptor Vps10p. Based on structural features and sortilin's intracellular predominance, we have proposed it to be a sorting receptor for ligands in the synthetic pathway as well as on the cell membrane. To test this hypothesis we examine here the cellular trafficking of chimeric receptors containing constructs of the sortilin tail. We report that sorting signals conforming to YXX and dileucine motifs mediate rapid endocytosis of sortilin chimeras, which subsequently travel to the trans-Golgi network, showing little or no recycling. Furthermore, we found that cation-independent mannose 6-phosphate receptor (MPR300)-sortilin chimeras, expressed in mannose 6-phosphate receptor knockout cells, were almost as efficient as MPR300 itself for transport of newly synthesized beta-hexosaminidase and beta-glucuronidase to lysosomes, and established that the sortilin tail contains potent signals for Golgi-endosome sorting. Finally, we provide evidence suggesting that sortilin is the first example of a mammalian receptor targeted by the recently described GGA family of cytosolic sorting proteins, which condition the Vps10p-mediated sorting of yeast carboxypeptidase Y.

Activation and functional characterization of the mosaic receptor SorLA/LR11.

We previously isolated and sequenced the approximately 250-kDa type 1 receptor sorLA/LR11, a mosaic protein with elements characterizing the Vps10p domain receptor family as well as the low density lipoprotein receptor family. The N terminus of the Vps10p domain comprises a consensus sequence for cleavage by furin ((50)RRKR(53)) that precedes a truncation found in sorLA isolated from human brain. Here we show that sorLA, like sortilin-1/neurotensin receptor-3, whose lumenal domain consists of a Vps10p domain only, is synthesized as a proreceptor that is cleaved by furin in late Golgi compartments. We show that the truncation conditions the Vps10p domain for propeptide inhibitable binding of neuropeptides and the receptor-associated protein. We further demonstrate that avid binding of the receptor-associated protein, apolipoprotein E, and lipoprotein lipase not inhibited by propeptide occurs to sites located in other lumenal domains. In transfected cells, about 10% of full-length sorLA were expressed on the cell surface capable of mediating endocytosis. However, the major pool of receptors was found in late Golgi compartments, suggesting possible interaction with newly synthesized ligands. The results show that sorLA, following activation by truncation, binds multiple ligands and may mediate both endocytosis and sorting.

Contribution of the carboxy-terminal domain of lipoprotein lipase to interaction with heparin and lipoproteins.

The C-terminal domain of lipoprotein lipase (LPL) is involved in several important interactions. To assess its contribution to the binding ability of full-length LPL we have determined kinetic constants using biosensor technique. The affinity of the C-terminal domain for heparin was about 500-fold lower than that of full-length LPL (K(d) = 1.3 microM compared to 3.1 nM). Replacement of Lys403, Arg405 and Lys407 by Ala abolished the heparin affinity, whereas replacement of Arg420 and Lys422 had little effect. The C-terminal domain increased binding of chylomicrons and VLDL to immobilized heparin relatively well, but was less than 10% efficient in binding of LDL compared to full-length LPL. Deletion of residues 390-393 (WSDW) did not change the affinity to heparin and only slightly decreased the affinity to lipoproteins. We conclude that the C-terminal folding domain contributes only moderately to the heparin affinity of full-length LPL, whereas the domain appears important for tethering triglyceride-rich lipoproteins to heparin-bound LPL.

Trichosanthin interacts with and enters cells via LDL receptor family members.

The type-I ribosome-inactivating protein trichosanthin displays selective cytotoxicity, suggesting specific mechanisms for entry into cells. Here we show that trichosanthin binds specifically to the endocytic receptors LRP and megalin, and that binding as well as uptake into cells is inhibited by the receptor-associated protein (RAP). The results suggest that the known abortifacient and renotoxic actions of trichosanthin are caused by LRP-mediated uptake in trophoblasts and megalin-mediated uptake in proximal tubule epithelial cells, respectively.

alpha-synuclein binds to Tau and stimulates the protein kinase A-catalyzed tau phosphorylation of serine residues 262 and 356.

alpha-Synuclein has been implicated in the pathogenesis of several neurodegenerative disorders based on the direct linking of missense mutations in alpha-synuclein to autosomal dominant Parkinson's disease and its presence in Lewy-like lesions. To gain insight into alpha-synuclein functions, we have investigated whether it binds neuronal proteins and modulates their functional state. The microtubule-associated protein tau was identified as a ligand by alpha-synuclein affinity chromatography of human brain cytosol. Direct binding assays using (125)I-labeled human tau40 demonstrated a reversible binding with a IC(50) about 50 pM. The interacting domains were localized to the C terminus of alpha-synuclein and the microtubule binding region of tau as determined by protein fragmentation and the use of recombinant peptides. High concentrations of tubulin inhibited the binding between tau and alpha-synuclein. Functionally, alpha-synuclein stimulated the protein kinase A-catalyzed phosphorylation of tau serine residues 262 and 356 as determined using a phospho-epitope-specific antibody. We propose that alpha-synuclein modulates the phosphorylation of soluble axonal tau and thereby indirectly affects the stability of axonal microtubules.

Sortilin/neurotensin receptor-3 binds and mediates degradation of lipoprotein lipase.

Lipoprotein lipase and the receptor-associated protein (RAP) bind to overlapping sites on the low density lipoprotein receptor-related protein/alpha2-macroglobulin receptor (LRP). We have investigated if lipoprotein lipase interacts with the RAP binding but structurally distinct receptor sortilin/neurotensin receptor-3. We show, by chemical cross-linking and surface plasmon resonance analysis, that soluble sortilin binds lipoprotein lipase with an affinity similar to that of LRP. The binding was inhibited by heparin and RAP and by the newly discovered sortilin ligand neurotensin. In 35S-labeled 3T3-L1 adipocytes treated with the cross-linker dithiobis(succinimidyl propionate), lipoprotein lipase-containing complexes were isolated by anti-sortilin antibodies. To elucidate function in cells, sortilin-negative Chinese hamster ovary cells were transfected with full-length sortilin and shown to express about 8% of the receptors on the cell surface. These cells degraded 125I-labeled lipoprotein lipase much faster than the wild-type cells. The degradation was inhibited by unlabeled lipoprotein lipase, indicating a saturable pathway, and by RAP and heparin. Moreover, inhibition by the weak base chloroquine suggested that degradation occurs in an acidic vesicle compartment. The results demonstrate that sortilin is a multifunctional receptor that binds lipoprotein lipase and, when expressed on the cell surface, mediates its endocytosis and degradation.

Propeptide cleavage conditions sortilin/neurotensin receptor-3 for ligand binding.

We recently reported the isolation and sequencing of sortilin, a new putative sorting receptor that binds receptor-associated protein (RAP). The luminal N-terminus of sortilin comprises a consensus sequence for cleavage by furin, R41WRR44, which precedes a truncation originally found in sortilin isolated from human brain. We now show that the truncation results from cellular processing. Sortilin is synthesized as a proform which, in late Golgi compartments, is converted to the mature receptor by furin-mediated cleavage of a 44 residue N-terminal propeptide. We further demonstrate that the propeptide exhibits pH-dependent high affinity binding to fully processed sortilin, that the binding is competed for by RAP and the newly discovered sortilin ligand neurotensin, and that prevention of propeptide cleavage essentially prevents binding of RAP and neurotensin. The findings evidence that the propeptide sterically hinders ligands from gaining access to overlapping binding sites in prosortilin, and that cleavage and release of the propeptide preconditions sortilin for full functional activity. Although proteolytic processing is involved in the maturation of several receptors, the described exposure of previously concealed ligand-binding sites after furin-mediated cleavage of propeptide represents a novel mechanism in receptor activation.