RESUMEN
Human tissue transglutaminase (TGM2) is a calcium-dependent crosslinking enzyme involved in the posttranslational modification of intra- and extracellular proteins and implicated in several neurodegenerative diseases. To find specific inhibitors to TGM2, two structurally diverse chemical libraries (LOPAC and Prestwick) were screened. We found that ZM39923, a Janus kinase inhibitor, and its metabolite ZM449829 were the most potent inhibitors with IC(50) of 10 and 5 nM, respectively. In addition, two other inhibitors, including tyrphostin 47 and vitamin K(3), were found to have an IC(50) in the micromolar range. These agents used in part a thiol-dependent mechanism to inhibit TGM2, consistent with the activation of TGM2 by reduction of an intramolecular disulfide bond. These inhibitors were tested in a polyglutamine-expressing Drosophila model of neurodegeneration and found to improve survival. The TGM2 inhibitors we discovered may serve as valuable lead compounds for the development of orally active TGM2 inhibitors to treat human diseases.
Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Transglutaminasas/antagonistas & inhibidores , Animales , Calcio/farmacología , Técnicas Químicas Combinatorias , Modelos Animales de Enfermedad , Drosophila melanogaster/efectos de los fármacos , Drosophila melanogaster/enzimología , Evaluación Preclínica de Medicamentos , Factor XIIIa/antagonistas & inhibidores , Factor XIIIa/metabolismo , Proteínas de Unión al GTP , Guanosina Trifosfato/metabolismo , Humanos , Enfermedad de Machado-Joseph/enzimología , Estructura Molecular , Naftoquinonas/química , Naftoquinonas/farmacología , Octoxinol , Proteína Glutamina Gamma Glutamiltransferasa 2 , Transglutaminasas/metabolismo , Tirfostinos/químicaRESUMEN
OBJECTIVE: This is the first large-scale assessment of the implementation of HIV Rapid Test Quality Improvement Initiative in South Africa. METHODS: We used a quasi-experimental one group post-test only design. The intervention implemented starting April 2014 comprised health-care worker training on quality assurance (QA) of HIV rapid testing and enrolment of the facilities in proficiency testing (PT), targeting 2,077 healthcare facilities in 32 high HIV burden districts. Following the intervention, two consecutive rounds of site assessments were undertaken. The first, conducted after a median of 7.5 months following the training, included 1,915 facilities that participated in the QA training, while the second, conducted after a median of one-year following the first-round assessment included 517 (27.0%) of the 1,915 facilities. In both assessments, the Stepwise-Process-for-Improving-the-quality-of-HIV-Rapid-Testing (SPI-RT) checklist was used to score facilities' performance in 7 domains: training, physical facility, safety, pre-testing, testing, post-testing and external quality assessment. Facilities' level of readiness for national certification was assessed. RESULT: Between 2016 and 2017, there were four PT cycles. PT participation increased from 32.4% (620/1,915) in 2016 to 91.5% (1,753/1,915) in 2017. In each PT cycle, PT results were returned by 76%-87% of facilities and a satisfactory result (>80%) was achieved by ≥95% of facilities. In the SPI-RT assessment, in round-one, 22.3% of facilities were close to or eligible for national certification-this significantly increased to 38.8% in round-two (P-value<0.001). The median SPI-RT score for the domains HIV pre-testing (83.3%) and post-testing (72.2%) remained the same between the two rounds. The median score for the testing domain increased by 5.6% (to 77.8%). CONCLUSION: Facilities performance on the domains that are critical for accuracy of diagnosis (i.e. pre-testing, testing and post-testing) remained largely unchanged. This study provided several recommendations to improve QA implementation in South Africa, including the need to improve routine use of internal quality control for corrective actions.
Asunto(s)
Serodiagnóstico del SIDA/normas , Infecciones por VIH/diagnóstico , Humanos , Ensayos de Aptitud de Laboratorios , Garantía de la Calidad de Atención de Salud , Control de Calidad , Mejoramiento de la Calidad , SudáfricaRESUMEN
The gap in HIV testing remains significant and new modalities such as HIV self-testing (HIVST) have been recommended to reach key and under-tested populations. In December 2016, the World Health Organization (WHO) released the Guidelines on HIV Self-Testing and Partner Notification: A Supplement to the Consolidated Guidelines on HIV Testing Services (HTS) and urged member countries to develop HIVST policy and regulatory frameworks. In South Africa, HIVST was included as a supplementary strategy in the National HIV Testing Services Policy in 2016, and recently, guidelines for HIVST were included in the South African National Strategic Plan for HIV, sexually transmitted infections and tuberculosis 2017-2022. This document serves as an additional guidance for the National HIV Testing Services Policy 2016, with specific focus on HIVST. It is intended for policy advocates, clinical and non-clinical HTS providers, health facility managers and healthcare providers in private and public health facilities, non-governmental, community-based and faith-based organisations involved in HTS and outreach, device manufacturers, workplace programmes and institutes of higher education.
Asunto(s)
Vacunas contra el SIDA/síntesis química , Vacunas contra el SIDA/uso terapéutico , Síndrome de Inmunodeficiencia Adquirida/terapia , Conducta Cooperativa , Programas Nacionales de Salud/organización & administración , Síndrome de Inmunodeficiencia Adquirida/inmunología , África , Investigación Biomédica/organización & administración , Diseño de Fármacos , Eficiencia Organizacional , VIH-1/inmunología , Promoción de la Salud/organización & administración , Derechos Humanos , Humanos , Modelos Biológicos , Programas Nacionales de Salud/legislación & jurisprudencia , Organización Mundial de la Salud/organización & administraciónRESUMEN
Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. Here we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm(3)) during melting and solidification. We also show complementary x-ray results from a small volume (<1 mm(3)), bridging four orders of magnitude. Real-time imaging will enable efficient process development and the control of structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.
RESUMEN
The search for a safe effective HIV vaccine has been a centerpiece of HIV research for almost 2 decades. More than 60 clinical HIV vaccine trials have been conducted to date. Several promising candidate HIV vaccines are in advanced clinical development. To date, however, no trial has included adolescents, one of the most important target groups for any preventive HIV vaccine. To license a vaccine for use in this age group, efficacy data or, at a minimum, bridging safety and immunogenicity data in this population are needed. To accomplish this, several critical issues and special challenges in the development and implementation of HIV vaccine trials in adolescents must be addressed, including regulatory considerations, potential differentials in safety and immunogenicity, alternative trial design strategies, recruitment and retention challenges, community involvement models, and approaches to informed consent/assent. This article examines these issues and proposes specific next steps to facilitate the routine inclusion of this high-priority population in preventive HIV vaccine trials as early and seamlessly as possible.
Asunto(s)
Vacunas contra el SIDA/uso terapéutico , Política de Salud , Proyectos de Investigación , Vacunas contra el SIDA/efectos adversos , Vacunas contra el SIDA/inmunología , Adolescente , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: A number of countries in sub-Saharan Africa are preparing for HIV vaccine efficacy trials. Social and behavioural factors related to HIV transmission require examination in each setting where these trials are considered. As part of this, several countries have also recently begun preparatory research investigating relevant social and behavioural issues. There is a need for a review of the literature to help focus such research efforts in Sub-Saharan Africa. OBJECTIVES: To examine key social and behavioural issues that may impact on the conduct of HIV vaccine efficacy trials in sub-Saharan Africa. DESIGN: Literature review METHODS: Major databases (PubMed, PsychInfo, EBSCOhost, and AIDSline) were searched for literature that discussed social and behavioural issues related to HIV vaccine trials. Three areas are highlighted as being particularly significant for HIV vaccine research: (1) willingness to participate in future HIV vaccine efficacy trials, (2) retention of participants in studies, and (3) sexual risk reporting during trials. For each of these topics, major findings from both developed and developing countries are described and avenues for further research are discussed. RESULTS: There are few data from Sub-Saharan Africa regarding willingness to participate in HIV vaccine trials. Data on participant retention rates varies widely, and maintaining large cohorts of individuals within Phase III trials presents an important challenge. In addition, the possible impact of trial participation on sexual disinhibition, and response bias on sexual risk-reporting remain as issues for HIV vaccine trials in African contexts. CONCLUSION: Social and behavioural research forms an important part of preparations for HIV vaccine efficacy trials, and there is a clear need for more research of this type in Sub-Saharan Africa. Innovative approaches are required to address issues such as willingness to participate in vaccine research, participant retention during efficacy trials, and the accurate reporting by participants of sexual risk behaviours.