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1.
AIDS Care ; : 1-6, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38295267

RESUMEN

Comprehensive sexuality education (CSE) is seen as a key instrument through which to affect behaviour and improve sexual and reproductive health (SRH) outcomes amongst adolescents. However, few studies have to date evaluated key SRH outcomes following exposure to CSE within a school setting. This study estimates the association between CSE and HIV testing and HIV testing self-efficacy amongst HIV positive adolescent girls. Data were collected from a cross-sectional survey administered in four high HIV prevalence districts . Independent variables included exposure to CSE, with outcome variables measuring uptake of HIV testing in the 12 months preceding the survey, and HIV testing self-efficacy. The sample comprised 505 HIV positive adolescent girls aged 12-19. . Attending CSE was associated with both; being more confident to get an HIV test (AOR: 2.44, 95% CI: 1.47-4.06, p < 0.001) and having ever tested for HIV (AOR: 2.15, 95% CI: 1.39-3.33, p < 0.001) while controlling for numerous variables. Results suggest CSE can play an important role in not only affecting HIV-related behaviours themselves, but also critical factors that affect HIV behaviours, including self-efficacy.

2.
Plant Physiol ; 189(4): 1976-2000, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35486376

RESUMEN

Many plants, including Arabidopsis (Arabidopsis thaliana), accumulate starch in the light and remobilize it to support maintenance and growth at night. Starch synthesis and degradation are usually viewed as temporally separate processes. Recently, we reported that starch is also degraded in the light. Degradation rates are generally low early in the day but rise with time. Here, we show that the rate of degradation in the light depends on time relative to dawn rather than dusk. We also show that degradation in the light is inhibited by trehalose 6-phosphate, a signal for sucrose availability. The observed responses of degradation in the light can be simulated by a skeletal model in which the rate of degradation is a function of starch content divided by time remaining until dawn. The fit is improved by extension to include feedback inhibition of starch degradation by trehalose 6-phosphate. We also investigate possible functions of simultaneous starch synthesis and degradation in the light, using empirically parameterized models and experimental approaches. The idea that this cycle buffers growth against falling rates of photosynthesis at twilight is supported by data showing that rates of protein and cell wall synthesis remain high during a simulated dusk twilight. Degradation of starch in the light may also counter over-accumulation of starch in long photoperiods and stabilize signaling around dusk. We conclude that starch degradation in the light is regulated by mechanisms similar to those that operate at night and is important for stabilizing carbon availability and signaling, thus optimizing growth in natural light conditions.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Carbono/metabolismo , Fosfatos/metabolismo , Fotosíntesis/fisiología , Almidón/metabolismo , Trehalosa/metabolismo
3.
Health Qual Life Outcomes ; 21(1): 94, 2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37605150

RESUMEN

BACKGROUND: Antiretroviral treatment improves health related quality of life (HRQoL) of people with human immunodeficiency virus (PWH). However, one third initiating first-line treatment experience virological failure and the determinants of HRQoL in this key population are unknown. Our study aims to identify determinants of among PWH failing antiretroviral treatment in sub-Saharan Africa. METHODS: We analysed data from a cohort of PWH having virological failure (> 1,000 copies/mL) on first-line ART in South Africa and Uganda. We measured HRQoL using the EuroQOL EQ-5D-3L and used a two-part regression model to obtain by-country analyses for South Africa and Uganda. The first part identifies risk factors that were associated with the likelihood of participants reporting perfect health (utility = 1) versus non-perfect health (utility < 1). The second part identifies risk factors that were associated with the EQ-5 L-3L utility scores for participants reporting non-perfect health. We performed sensitivity analyses to compare the results between the two-part model using tobit models and ordinary least squares regression. RESULTS: In both countries, males were more likely to report perfect health and participants with at least one comorbidity were less likely to report perfect health. In South Africa, participants with side effects and in Uganda those with opportunistic infections were also less likely to report perfect health. In Uganda, participants with 100% ART adherence were more likely to report perfect health. In South Africa, high HIV viral load, experiencing ART side effects, and the presence of opportunistic infections were each associated with lower HRQoL, whereas participants with 100% ART adherence reported higher HRQoL. In Uganda participants with lower CD4 count had lower HRQoL. CONCLUSION: Markers of advanced disease (opportunistic infection, high viral load, low CD4), side effects, comorbidities and lack of ART adherence negatively impacted HRQoL for PWH experiencing virological failure. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02787499.


Asunto(s)
Infecciones por VIH , Infecciones Oportunistas , Masculino , Humanos , VIH , Calidad de Vida , Sudáfrica/epidemiología , Antirretrovirales , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología
4.
Int J Behav Med ; 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37477850

RESUMEN

BACKGROUND: Several studies have reported on the benefits of social support for health behaviour, including risky sex. Social support may thus be an important resource for promoting individual health and well-being, particularly in regions where HIV rates are high and healthcare resources are scarce. However, prior research on the implications of social support for the health behaviour of young women has yielded mixed and inconclusive findings. Using prospective data from young women in South Africa, this study examines the associations of social support with subsequent sexual practices, health behaviour, and health outcomes. METHOD: We used two rounds of longitudinal data from a sample of n = 1446 HIV-negative emerging adult women, aged 18 to 29 years, who participated in a population-based HIV study in KwaZulu-Natal, South Africa. Applying the analytic template for outcome-wide longitudinal designs, we estimated the associations between combinations of social support (i.e. tangible, educational, emotional) and ten HIV risk-related outcomes. RESULTS: Combinations of tangible, educational, and emotional support, as well as tangible support by itself, were associated with lower risk for several outcomes, whereas educational and emotional support, by themselves or together, showed little evidence of association with the outcomes. CONCLUSION: This study highlights the protective role of tangible support in an environment of widespread poverty, and the additional effect of combining tangible support with non-tangible support. The findings strengthen recent evidence on the benefits of combining support in the form of cash and food with psychosocial care in mitigating risk behaviours associated with HIV and negative health outcomes among young women.

5.
HIV Med ; 23(5): 474-484, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34755438

RESUMEN

OBJECTIVES: HIV virological failure remains a major threat to programme success in sub-Saharan Africa. While HIV drug resistance (HIVDR) and inadequate adherence are the main drivers of virological failure, the individual, clinical and health system characteristics that lead to poor outcomes are not well understood. The objective of this paper is to identify those characteristics among people failing first-line antiretroviral therapy (ART). METHODS: We enrolled a cohort of adults in HIV care experiencing virological failure on first-line ART at five sites and used standard statistical methods to characterize them with a focus on three domains: individual/demographic, clinical, and health system, and compared each by country of enrolment. RESULTS: Of 840 participants, 51% were women, the median duration on ART was 3.2 years [interquartile range (IQR) 1.1, 6.4 years] and the median CD4 cell count prior to failure was 281 cells/µL (IQR 121, 457 cells/µL). More than half of participants [53%; 95% confidence interval (CI) 49-56%] stated that they had > 90% adherence and 75% (95% CI 72-77%) took their ART on time all or most of the time. Conversely, the vast majority (90%; 95% CI 86-92%) with a completed genotypic drug resistance test had any HIV drug resistance. This population had high health system use, reporting a median of 3 (IQR 2.6) health care visits and a median of 1 (IQR 1.1) hospitalization in the preceding 6 months. CONCLUSIONS: Patients failing first-line ART in sub-Saharan Africa generally report high rates of adherence to ART, have extremely high rates of HIV drug resistance and utilize significant health care resources. Health systems interventions to promptly detect and manage treatment failure will be a prerequisite to establishing control of the HIV epidemic.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Adulto , Recuento de Linfocito CD4 , Farmacorresistencia Viral , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Sudáfrica/epidemiología , Insuficiencia del Tratamiento , Uganda/epidemiología , Carga Viral
6.
Global Health ; 18(1): 84, 2022 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-36224610

RESUMEN

BACKGROUND: This study aligns with Sustainable Development Goal 3 which borders on "good health and well-being for people by ensuring healthy lives and promoting well-being for all at all ages". It contributes to the health literature by evaluating the roles of health expenditures and educational quality on three health outcomes (infant mortality, maternal mortality and life expectancy at birth). METHODS: The study uses the panel spatial correlation consistent (PSCC) approach on balanced panel data on 25 selected sub-Saharan African countries from 2000 to 2020 to interrogate the nexus. RESULTS: The following findings are documented. First, health expenditures reveal significant asymmetric quadratic effects on health outcomes. Second, the interactions between health expenditures and educational quality reduce infant and maternal mortalities while enhancing life expectancy. Third, the threshold points from the interaction effects indicate that enhancing educational quality beyond some critical thresholds of 1.51 and 1.49 can induce a drop in maternal and child mortalities while a point beyond 1.84 exerts an improvement in life expectancy. CONCLUSIONS: Hence, policy makers should ensure that both health expenditures and educational quality exceed the established thresholds for sustainable health outcomes.


Asunto(s)
Gastos en Salud , Esperanza de Vida , Niño , Mortalidad del Niño , Humanos , Lactante , Mortalidad Infantil , Recién Nacido , Evaluación de Resultado en la Atención de Salud
7.
BMC Public Health ; 22(1): 973, 2022 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-35568839

RESUMEN

BACKGROUND: HIV incidence among adolescent girls and young women (AGYW) remains high, with their male partners a prominent factor in sustaining these elevated rates. Partnership characteristics remain important metrics for determining HIV risk, with evidence indicating that AGYW engaged in transactional and age-disparate relationships face greater HIV exposure. This study examines the risk posed to AGYW in a relationship with a "Blesser", defined as male who provides his female partner with their material needs or desires in exchange for a sexual relationship, an age-disparate (5 or more years older) partner, and the potential compounded risk of being a relationship with a partner or partners who are considered both a "Blesser" and age-disparate. METHODS: A cross -sectional household based representative sample of AGYW (aged between 12-24 years) were enrolled in the study (n = 18 926) from the districts of City of Johannesburg and Ekurhuleni in the Gauteng province and the Districts of eThekwini and uMgungundlovu in the province of KwaZulu-Natal (KZN) in South Africa between March 13, 2017 to June 22, 2018. Participants completed a structured questionnaire and provided finger-prick blood samples for laboratory measurements. Our analysis used descriptive statistics and multiple binary logistic regressions accounting for survey weights, clustering and stratification. FINDINGS: The median age of the sample was 21 years old (Interquartile range: 19-23) and nearly three quarters (73.7%) were currently attending school. Whilst all relationships exposed AGYW to potential HIV risk, multiple binary logistic regression analysis revealed that AGYW in a relationship with both a Blesser and an age-disparate partner were more likely to be HIV positive (AOR: 3.12, 95% CI: 1.76-5.53, p < 0.001), diagnosed with an STI (AOR: 4.60, 95% CI: 2.99-7.08, p < 0.001), had 2 or more sexual partners in the previous 12 months (AOR: 6.37, 95% CI: 3.85-10.54, p < 0.001), engaged in sexual activity at age 15 or younger (AOR: 3.67, 95% CI: 2.36-5.69, p < 0.001) and more likely to have ever been pregnant (AOR: 2.60, 95% CI: 1.24-5.45, p < 0.05) than those not in a relationship with either a Blesser or age-disparate partner. CONCLUSION: Different relationships present different HIV risk to AGYW. AGYW who had engaged in relationships with both a Blesser and an age-disparate partner were at greater HIV risk when examined against these relationships independent of one another. The data reveals the compounded HIV risk of being in both a transactional and age-disparate relationship.


Asunto(s)
Infecciones por VIH , Adolescente , Adulto , Niño , Estudios Transversales , Femenino , Infecciones por VIH/epidemiología , Humanos , Masculino , Embarazo , Conducta Sexual , Parejas Sexuales , Sudáfrica/epidemiología , Adulto Joven
8.
Ann Intern Med ; 174(12): 1683-1692, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34698502

RESUMEN

BACKGROUND: Virologic failure in HIV predicts the development of drug resistance and mortality. Genotypic resistance testing (GRT), which is the standard of care after virologic failure in high-income settings, is rarely implemented in sub-Saharan Africa. OBJECTIVE: To estimate the effectiveness of GRT for improving virologic suppression rates among people with HIV in sub-Saharan Africa for whom first-line therapy fails. DESIGN: Pragmatic, unblinded, randomized controlled trial. (ClinicalTrials.gov: NCT02787499). SETTING: Ambulatory HIV clinics in the public sector in Uganda and South Africa. PATIENTS: Adults receiving first-line antiretroviral therapy with a recent HIV RNA viral load of 1000 copies/mL or higher. INTERVENTION: Participants were randomly assigned to receive standard of care (SOC), including adherence counseling sessions and repeated viral load testing, or immediate GRT. MEASUREMENTS: The primary outcome of interest was achievement of an HIV RNA viral load below 200 copies/mL 9 months after enrollment. RESULTS: The trial enrolled 840 persons, divided equally between countries. Approximately half (51%) were women. Most (72%) were receiving a regimen of tenofovir, emtricitabine, and efavirenz at enrollment. The rate of virologic suppression did not differ 9 months after enrollment between the GRT group (63% [263 of 417]) and SOC group (61% [256 of 423]; odds ratio [OR], 1.11 [95% CI, 0.83 to 1.49]; P = 0.46). Among participants with persistent failure (HIV RNA viral load ≥1000 copies/mL) at 9 months, the prevalence of drug resistance was higher in the SOC group (76% [78 of 103] vs. 59% [48 of 82]; OR, 2.30 [CI, 1.22 to 4.35]; P = 0.014). Other secondary outcomes, including 9-month survival and retention in care, were similar between groups. LIMITATION: Participants were receiving nonnucleoside reverse transcriptase inhibitor-based therapy at enrollment, limiting the generalizability of the findings. CONCLUSION: The addition of GRT to routine care after first-line virologic failure in Uganda and South Africa did not improve rates of resuppression. PRIMARY FUNDING SOURCE: The President's Emergency Plan for AIDS Relief and the National Institute of Allergy and Infectious Diseases.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Farmacorresistencia Viral , Infecciones por VIH/tratamiento farmacológico , Adulto , Alquinos/uso terapéutico , Benzoxazinas/uso terapéutico , Ciclopropanos/uso terapéutico , Emtricitabina/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sudáfrica , Tenofovir/uso terapéutico , Uganda , Carga Viral
9.
Cult Health Sex ; 24(7): 871-885, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-33840377

RESUMEN

The term 'blesser' emerged from social media in South Africa, typically denoting an older man who provides a younger woman with money and/or luxury items in exchange for sex. Within an increasingly consumerist culture, such transactional sexual relationships hold powerful appeal, and remain highly prevalent. An estimated one in three Black South African women have engaged in transactional sex. While these liaisons are associated with negative health outcomes for women, especially in high HIV prevalence settings, attention to how they affect Black women's sexuality is under-studied-especially with respect to emotional and sexual development-an important part of sexual rights and wellbeing. We used qualitative methods to investigate 22 women's experiences with blessers. A sexual rights framework was utilised to explore human rights dimensions. We found women's rights to engage in consensual sex, pursue sexual pleasure and ensure their bodily integrity were compromised. Many participants recognised the psychological costs and limitations of engaging in blesser relationships. Women communicated that they realised such partnerships failed to meet their emotional and relationship needs. Against the backdrop of structural gender inequality, Black South African women's narratives should inform research, programmes and educational interventions aimed at advancing women's sexual development, rights and wellbeing.


Asunto(s)
Infecciones por VIH , Trabajo Sexual , Población Negra , Femenino , Infecciones por VIH/epidemiología , Humanos , Masculino , Trabajo Sexual/psicología , Conducta Sexual/psicología , Sudáfrica/epidemiología
10.
Afr J AIDS Res ; 21(1): 58-64, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35361058

RESUMEN

One of the policy goals of the South African Department of Basic Education's National Policy on HIV, STIs and TB of 2017 is to reduce the incidence of HIV and pregnancy among learners. This is expected to be achieved by improving access to prevention services, including the provision of condoms in schools. This study uses street- level bureaucracy theory to explain how educators can play a more productive role in ensuring that policy goals are achieved. Educators provide their views on their role as condom promotion agents, their perception of demand and utilisation among learners, as well as their insights on suitable distribution mechanisms in the school setting. Trepidation exists among educators about their roles in the promotion and education of condoms. Educator statements suggest that they see the value in their policy-ascribed role to deliver sexual health messages and are also open to performing a role in the distribution of condoms at schools. However, our findings reveal that their role as policy communicators or "street-level bureaucrats" is complicated by inadequate policy guidance. We therefore conclude that to achieve optimal outcomes in terms of safer sexual practices among learners, condom messaging and distribution mechanisms in school settings require evidence-informed implementation strategies.


Asunto(s)
Condones , Infecciones por VIH , Niño , Femenino , Infecciones por VIH/prevención & control , Humanos , Embarazo , Instituciones Académicas , Conducta Sexual , Sudáfrica
11.
J Exp Bot ; 72(10): 3739-3755, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33684221

RESUMEN

Plastid metabolism is critical in both photoautotrophic and heterotrophic plant cells. In chloroplasts, fructose-1,6-bisphosphate aldolase (FBA) catalyses the formation of both fructose 1,6-bisphosphate and sedoheptulose 1,7-bisphosphate within the Calvin-Benson cycle. Three Arabidopsis genes, AtFBA1-AtFBA3, encode plastidial isoforms of FBA, but the contribution of each isoform is unknown. Phylogenetic analysis indicates that FBA1 and FBA2 derive from a recently duplicated gene, while FBA3 is a more ancient paralog. fba1 mutants are phenotypically indistinguishable from the wild type, while both fba2 and fba3 have reduced growth. We show that FBA2 is the major isoform in leaves, contributing most of the measurable activity. Partial redundancy with FBA1 allows both single mutants to survive, but combining both mutations is lethal, indicating a block of photoautotrophy. In contrast, FBA3 is expressed predominantly in heterotrophic tissues, especially the leaf and root vasculature, but not in the leaf mesophyll. We show that the loss of FBA3 affects plastidial glycolytic metabolism of the root, potentially limiting the biosynthesis of essential compounds such as amino acids. However, grafting experiments suggest that fba3 is dysfunctional in leaf phloem transport, and we suggest that a block in photoassimilate export from leaves causes the buildup of high carbohydrate concentrations and retarded growth.


Asunto(s)
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Fructosa-Bifosfato Aldolasa/genética , Fructosa-Bifosfato Aldolasa/metabolismo , Fotosíntesis , Filogenia , Plastidios/metabolismo
12.
AIDS Behav ; 25(2): 397-413, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32812124

RESUMEN

Differentiated service delivery holds great promise for streamlining the delivery of health services for HIV. This study used a discrete choice experiment to assess preferences for differentiated HIV treatment delivery model characteristics among 500 virally suppressed adults on antiretroviral therapy in Harare, Zimbabwe. Treatment model characteristics included location, consultation type, healthcare worker cadre, operation times, visit frequency and duration, and cost. A mixed effects logit model was used for parameter estimates to identify potential preference heterogeneity among participants, and interaction effects were estimated for sex and age as potential sources of divergence in preferences. Results indicated that participants preferred health facility-based services, less frequent visits, individual consultations, shorter waiting times, lower cost and, delivered by respectful and understanding healthcare workers. Some preference heterogeneity was found, particularly for location of service delivery and group vs. individual models; however, this was not fully explained by sex and age characteristics of participants. In urban areas, facility-based models, such as the Fast Track model requiring less frequent clinic visits, are likely to better align with patient preferences than some of the other community-based or group models that have been implemented. As Zimbabwe scales up differentiated treatment models for stable patients, a clear understanding of patient preferences can help in designing services that will ensure optimal utilization and improve the efficiency of service delivery.


RESUMEN: La entrega de servicios diferenciados representa una gran promesa para optimizar la prestación de servicios sanitarios para el VIH. Este estudio utilizó un experimento de elecciones discretas para evaluar las preferencias en cuanto a las características de los modelos diferenciados de prestación de tratamiento para el VIH entre 500 adultos con supresión viral bajo tratamiento antirretroviral en Harare, Zimbabue. Las características de los modelos de tratamientos incluyeron el lugar, el tipo de consulta, la estructura en la que estaba inserto el trabajador sanitario, los tiempos operativos, la frecuencia y duración de las visitas y los costos. Se utilizó un modelo de probabilidad de efectos mixtos para las estimaciones de los parámetros para identificar una posible heterogeneidad en las preferencias entre los participantes, y se estimaron los efectos de las interacciones por el sexo y la edad como fuentes potenciales de diferencia en las preferencias. Los resultados indicaron que los participantes preferían servicios basados en centros de salud, visitas menos frecuentes, consultas individuales, tiempos de espera más cortos y menores costos, proporcionados por trabajadores sanitarios respetuosos y comprensivos. Se hallaron algunas heterogeneidades en las preferencias, particularmente para el lugar de la prestación del servicio y para los modelos grupales frente a individuales; sin embargo, esto no se explicó totalmente por las características de sexo y edad de los participantes. En áreas urbanas, los modelos basados en los centros, como el modelo de atención rápida (Fast Track), que requieren visitas menos frecuentes a la clínica, probablemente concuerden mejor con las preferencias de los pacientes que los otros modelos grupales o comunitarios que se han propuesto. A medida que en Zimbabue se amplíen los modelos de tratamiento diferenciado para los pacientes estables, un claro conocimiento de las preferencias de los pacientes puede ayudar a diseñar servicios que garantizarán una utilización óptima y mejorarán la eficiencia de la prestación de servicios.


Asunto(s)
Infecciones por VIH/terapia , Prioridad del Paciente , Adulto , Atención Ambulatoria , Conducta de Elección , Infecciones por VIH/tratamiento farmacológico , Humanos , Zimbabwe
13.
AIDS Care ; 33(1): 70-79, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32036678

RESUMEN

Early antiretroviral therapy (ART) initiation is essential, but linkage to care following community-based services is often poor, and inadequately understood. This study examined factors influencing linkage to care following home-based HIV-testing services (HBHTS) in a hyper-endemic setting in South Africa. HBHTS was offered to participants (N = 10,236) enrolled in the second HIV Incidence Provincial Surveillance System survey (2015-2016), KwaZulu-Natal. Follow-up telephone surveys with 196 of the 313 individuals diagnosed HIV-positive through HBHTS were used to measure linkage to care (i.e., a clinic visit within 12 weeks) and ART-initiation. Among newly diagnosed individuals (N = 183), 55% linked to care, and 21% of those who were ART-eligible started treatment within 12 weeks. Linkage to care was less likely among participants who had doubted their HIV-diagnosis (aOR:0.46, 95%CI: 0.23-0.93) and more likely among participants who had disclosed their HIV-status (aOR:2.31, 95%CI: 1.07-4.97). Reasons for not linking to care included no time (61%), only wanting to start treatment when sick (48%), fear of side-effects (33%), and not believing the HIV-diagnosis (16%). Results indicate that HBHTS needs to be paired with targeted interventions to facilitate early linkage to care. Interventions are required to counter denial of HIV status and facilitate early linkage to care among healthier individuals.


Asunto(s)
Serodiagnóstico del SIDA/estadística & datos numéricos , Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/epidemiología , Aceptación de la Atención de Salud/estadística & datos numéricos , Derivación y Consulta/estadística & datos numéricos , Adolescente , Adulto , Terapia Antirretroviral Altamente Activa , Servicios de Salud Comunitaria , Escolaridad , Femenino , Inseguridad Alimentaria , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Servicios de Atención de Salud a Domicilio , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Sudáfrica/epidemiología , Resultado del Tratamiento , Adulto Joven
14.
Proc Natl Acad Sci U S A ; 115(42): E9953-E9961, 2018 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-30275313

RESUMEN

In shade-intolerant plants, the perception of proximate neighbors rapidly induces architectural changes resulting in elongated stems and reduced leaf size. Sensing and signaling steps triggering this modified growth program have been identified. However, the underlying changes in resource allocation that fuel stem growth remain poorly understood. Through 14CO2 pulse labeling of Brassica rapa seedlings, we show that perception of the neighbor detection signal, low ratio of red to far-red light (R:FR), leads to increased carbon allocation from the major site of photosynthesis (cotyledons) to the elongating hypocotyl. While carbon fixation and metabolite levels remain similar in low R:FR, partitioning to all downstream carbon pools within the hypocotyl is increased. Genetic analyses using Arabidopsis thaliana mutants indicate that low-R:FR-induced hypocotyl elongation requires sucrose transport from the cotyledons and is regulated by a PIF7-dependent metabolic response. Moreover, our data suggest that starch metabolism in the hypocotyl has a growth-regulatory function. The results reveal a key mechanism by which metabolic adjustments can support rapid growth adaptation to a changing environment.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Brassicaceae/crecimiento & desarrollo , Carbono/metabolismo , Cotiledón/crecimiento & desarrollo , Hipocótilo/crecimiento & desarrollo , Hojas de la Planta/crecimiento & desarrollo , Plantones/crecimiento & desarrollo , Arabidopsis/metabolismo , Brassicaceae/metabolismo , Cotiledón/metabolismo , Hipocótilo/metabolismo , Luz , Fitocromo , Hojas de la Planta/metabolismo , Plantones/metabolismo , Transducción de Señal
15.
BMC Womens Health ; 20(1): 7, 2020 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-31948429

RESUMEN

BACKGROUND: Young women in sub-Saharan Africa remain at the epicentre of the HIV epidemic, with surveillance data indicating persistent high levels of HIV incidence. In South Africa, adolescent girls and young women (AGYW) account for a quarter of all new HIV infections. Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) is a strategy introduced by the United States President's Emergency Plan for AIDS Relief (PEPFAR) aimed at reducing HIV incidence among AGYW in 10 countries in sub-Saharan Africa by 25% in the programme's first year, and by 40% in the second year. This study will assess the change in HIV incidence and reduction in risk associated behaviours that can be attributed to the DREAMS initiative in South Africa, using a population-based cross-sectional survey. METHODS: Data will be collected from a household-based representative sample of AGYW (between the ages 12-24 years) in four high prevalence districts (more than 10% of the population have HIV in these districts) in South Africa in which DREAMS has been implemented. A stratified cluster-based sampling approach will be used to select eligible participants for a cross-sectional survey with 18,500, to be conducted over 2017/2018. A questionnaire will be administered containing questions on sexual risk behaviour, selected academic and developmental milestones, prevalence of gender based violence, whilst examining exposure to DREAMS programmes. Biological samples, including two micro-containers of blood and self-collected vulvovaginal swab samples, are collected in each survey to test for HIV infection, HIV incidence, sexually transmitted infections (STIs) and pregnancy. This study will measure trends in population level HIV incidence using the Limiting antigen (LAg) Avidity Enzyme Immuno-Assay (EIA) and monitor changes in HIV incidence. DISCUSSION: Ending the HIV/AIDS pandemic by 2030 requires the continual monitoring and evaluation of prevention programmes, with the aim of optimising efforts and ensuring the achievement of epidemic control. This study will determine the impact DREAMS interventions have had on HIV incidence among AGYW in a 'real world, non-trial setting'.


Asunto(s)
Infecciones por VIH , Servicios Preventivos de Salud , Conducta de Reducción del Riesgo , Conducta Sexual , Adolescente , Estudios Transversales , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Infecciones por VIH/psicología , Humanos , Incidencia , Estudios Longitudinales , Prevalencia , Servicios Preventivos de Salud/métodos , Servicios Preventivos de Salud/organización & administración , Sudáfrica/epidemiología , Adulto Joven
16.
BMC Health Serv Res ; 20(1): 76, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32013946

RESUMEN

BACKGROUND: Interventions targeting community health workers (CHWs) aim to optimise the delivery of health services to underserved rural areas. Whilst interventions are evaluated against their objectives, there remains limited evidence on the economic costs of these interventions, and the practicality and value of scale up. The aim of this paper is to undertake a cost analysis on a CHW training and supervision intervention using exclusive breastfeeding rates amongst mothers as an outcome measure. METHODS: This is a retrospective cost analysis, from an implementer's perspective, of a cluster randomised controlled trial investigating the effectiveness of a continuous quality improvement (CQI) intervention aimed at CHWs providing care and support to pregnant women and women with babies aged < 1 year in South Africa. RESULTS: One of the outcomes of the RCT revealed that the prevalence of exclusive breastfeeding (EBF) significantly improved, with the cost per mother EBF in the control and intervention arm calculated at US$760,13 and US$1705,28 respectively. The cost per additional mother practicing EBF was calculated to be US$7647, 88, with the supervision component of the intervention constituting 64% of the trial costs. In addition, women served by the intervention CHWs were more likely to have received a CHW visit and had significantly better knowledge of childcare practices. CONCLUSION: Whilst the cost of this intervention is high, adapted interventions could potentially offer an economical alternative for achieving selected maternal and child health (MCH) outcomes. The results of this study should inform future programmes aimed at providing adapted training and supervision to CHWs with the objective of improving community-level health outcomes.


Asunto(s)
Lactancia Materna/estadística & datos numéricos , Agentes Comunitarios de Salud/economía , Agentes Comunitarios de Salud/organización & administración , Capacitación en Servicio/economía , Madres/psicología , Costos y Análisis de Costo , Femenino , Humanos , Lactante , Embarazo , Mejoramiento de la Calidad , Estudios Retrospectivos , Sudáfrica
17.
Afr J AIDS Res ; 19(2): 147-155, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32780676

RESUMEN

HIV prevalence among truckers in Africa is high and testing rates suboptimal. With numerous African countries having approved HIV self-testing kits, more information on how to design acceptable and accessible self-testing programs for high-risk populations is necessary. We explored views about self-testing via in-depth interviews with 24 truckers participating in a randomised controlled trial who refused HIV testing. A social-ecological lens was used to guide data analysis and frame study findings. While most participants said that they would use an HIV self-test, perceived barriers and facilitators were identified at multiple levels. Many participants noted lack of time to test or obtain a self-test kit as a major barrier (intrapersonal) and varied in their views about self-testing with a partner (interpersonal). Participants offered programmatic/policy recommendations, suggesting that they preferred accessing self-test kits in settings where training could be provided. Participants believed they should be able to pick up multiple test kits at the same time and that the test kits should be free or low cost. These study findings will help guide the design of self-testing programs for truckers and other mobile populations.


Asunto(s)
Conducción de Automóvil , Infecciones por VIH/diagnóstico , Tamizaje Masivo/métodos , Adulto , Conducción de Automóvil/psicología , Conducción de Automóvil/estadística & datos numéricos , Infecciones por VIH/epidemiología , Accesibilidad a los Servicios de Salud , Humanos , Kenia/epidemiología , Masculino , Investigación Cualitativa , Autoadministración , Parejas Sexuales
18.
J Exp Bot ; 70(6): 1829-1841, 2019 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-30785201

RESUMEN

Carbon isotope (13C) fractionations occurring during and after photosynthetic CO2 fixation shape the carbon isotope composition (δ13C) of plant material and respired CO2. However, responses of 13C fractionations to diel variation in starch metabolism in the leaf are not fully understood. Here we measured δ13C of organic matter (δ13COM), concentrations and δ13C of potential respiratory substrates, δ13C of dark-respired CO2 (δ13CR), and gas exchange in leaves of starch-deficient plastidial phosphoglucomutase (pgm) mutants and wild-type plants of four species (Arabidopsis thaliana, Mesembryanthemum crystallinum, Nicotiana sylvestris, and Pisum sativum). The strongest δ13C response to the pgm-induced starch deficiency was observed in N. sylvestris, with more negative δ13COM, δ13CR, and δ13C values for assimilates (i.e. sugars and starch) and organic acids (i.e. malate and citrate) in pgm mutants than in wild-type plants during a diel cycle. The genotype differences in δ13C values could be largely explained by differences in leaf gas exchange. In contrast, the PGM-knockout effect on post-photosynthetic 13C fractionations via the plastidic fructose-1,6-bisphosphate aldolase reaction or during respiration was small. Taken together, our results show that the δ13C variations in starch-deficient mutants are primarily explained by photosynthetic 13C fractionations and that the combination of knockout mutants and isotope analyses allows additional insights into plant metabolism.


Asunto(s)
Isótopos de Carbono/metabolismo , Fotosíntesis , Almidón/deficiencia , Tracheophyta/metabolismo , Arabidopsis/metabolismo , Mesembryanthemum/metabolismo , Pisum sativum/metabolismo , Nicotiana/metabolismo
19.
Sex Transm Infect ; 95(6): 443-448, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30737260

RESUMEN

OBJECTIVE: There is an urgent need to understand high HIV-infection rates among young women in sub-Saharan Africa. While age-disparate partnerships have been characterised with high-risk sexual behaviours, the mechanisms through which these partnerships may increase HIV-risk are not fully understood. This study assessed the association between age-disparate partnerships and herpes simplex virus type-2 (HSV-2) infection, a factor known to increase HIV-infection risk. METHODS: Cross-sectional face-to-face questionnaire data, and laboratory HSV-2 and HIV antibody data were collected among a representative sample in the 2014/2015 household survey of the HIV Incidence Provincial Surveillance System in KwaZulu-Natal, South Africa. Among 15-24-year-old women who reported having ever had sex (n=1550), the association between age-disparate partnerships (ie, male partner ≥5 years older) and HSV-2 antibody status was assessed using multivariable Poisson regression models with robust variance. Analyses were repeated among HIV-negative women. RESULTS: HSV-2 prevalence was 55% among 15-24-year-old women. Women who reported an age-disparate partnership with their most recent partner were more likely to test HSV-2 positive compared with women with age-similar partners (64% vs 51%; adjusted prevalence ratio (aPR):1.19 (95% CI 1.07 to 1.32, p<0.01)). HSV-2 prevalence was also significantly higher among HIV-negative women who reported age-disparate partnerships (51% vs 40 %; aPR:1.25 (95% CI 1.05 to 1.50, p=0.014)). CONCLUSIONS: Results indicate that age-disparate partnerships are associated with a greater risk of HSV-2 among young women. These findings point towards an additional mechanism through which age-disparate partnerships could increase HIV-infection risk. Importantly, by increasing the HSV-2 risk, age-disparate partnerships have the potential to increase the HIV-infection risk within subsequent partnerships, regardless of the partner age-difference in those relationships.


Asunto(s)
Infecciones por VIH/epidemiología , Herpes Genital/epidemiología , Adolescente , Adulto , Factores de Edad , Anticuerpos Antivirales/sangre , Estudios Transversales , Femenino , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/sangre , Infecciones por VIH/complicaciones , Infecciones por VIH/psicología , Herpes Genital/complicaciones , Herpes Genital/psicología , Herpes Genital/virología , Herpesvirus Humano 2/clasificación , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/inmunología , Herpesvirus Humano 2/aislamiento & purificación , Humanos , Masculino , Factores de Riesgo , Conducta Sexual , Parejas Sexuales , Sudáfrica/epidemiología , Adulto Joven
20.
AIDS Behav ; 23(11): 3119-3128, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30771133

RESUMEN

Short Message Service (SMS) offers an innovative method of promoting sexual health to key and vulnerable populations who are users of mobile phones and are at high risk of HIV infection. This cluster randomised control trial tests the effectiveness of a SMS intervention in reducing HIV risk behaviours and improving HIV testing behaviours among truck drivers, sex workers and community residents located near Roadside Wellness Clinics (RWCs) in three southern African countries. The SMS arm received 35 HIV risk reduction and HIV testing SMSs over a 6-month period. The SMS intervention had no significant impact on sexual risk behaviours. However, participants in the SMS arm were more likely to have tested for HIV in the previous 6 months (86.1% vs. 77.7%; AOR 1.71, 95% CI 1.11-2.66). The results indicate that the general SMS intervention, which provide health promoting information, improved HIV testing rates in key and vulnerable populations in southern Africa.


Asunto(s)
Teléfono Celular , Infecciones por VIH/prevención & control , Tamizaje Masivo/estadística & datos numéricos , Conducta de Reducción del Riesgo , Envío de Mensajes de Texto , Adulto , Anciano , Femenino , Infecciones por VIH/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Mozambique , Proyectos de Investigación , Asunción de Riesgos , Trabajadores Sexuales , Conducta Sexual , Sudáfrica , Poblaciones Vulnerables , Zimbabwe
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