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INTRODUCTION: Men have higher rates of morbidity and mortality across nearly all top ten causes of mortality worldwide. Much of this disparity is attributed to men's lower utilization of routine health services; however, little is known about men's general healthcare utilization in sub-Saharan Africa. METHODS: We analyze the responses of 1,116 men in a community-representative survey of men drawn from a multi-staged sample of residents of 36 villages in Malawi to identify factors associated with men's facility attendance in the last 12 months, either for men's own health (client visit) or to support the health care of someone else (caregiver visit). We conducted single-variable tests of association and multivariable logistic regression with random effects to account for clustering at the village level. RESULTS: Median age of participants was 34, 74% were married, and 82% attended a health facility in the last year (63% as client, 47% as caregiver). Neither gender norm beliefs nor socioeconomic factors were independently associated with attending a client visit. Only problems with quality of health services (adjusted odds ratio [aOR] 0.294, 95% confidence interval [CI] 0.10-0.823) and good health (aOR 0.668, 95% CI 0.462-0.967) were independently associated with client visit attendance. Stronger beliefs in gender norms were associated with caregiver visits (beliefs about acceptability of violence [aOR = 0.661, 95% CI 0.488-0.896], male sexual dominance [aOR = 0.703, 95% CI 0.505-0.978], and traditional women's roles [aOR = 0.718, 95% CI 0.533-0.966]). Older age (aOR 0.542, 95% CI 0.401-0.731) and being married (aOR 2.380, 95% CI 1.196-4.737) were also independently associated with caregiver visits. CONCLUSION: Quality of services offered at local health facilities and men's health status were the only variables associated with client facility visits among men, while harmful gender norms, not being married, and being younger were negatively associated with caregiver visits.
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Cuidadores , Homens , Feminino , Instalações de Saúde , Humanos , Malaui , Masculino , Aceitação pelo Paciente de Cuidados de SaúdeRESUMO
OBJECTIVE: To determine how often men in Malawi attend health facilities and if testing for human immunodeficiency virus (HIV) is offered during facility visits. METHODS: We conducted a cross-sectional, community-representative survey of men (15-64 years) from 36 villages in Malawi. We excluded men who ever tested HIV-positive. Primary outcomes were: health facility visits in the past 12 months (for their own health (client visit) or to support the health services of others (guardian visit)); being offered HIV testing during facility visits; and being tested that same day. We disaggregated all results by HIV testing history: tested ≤ 12 months ago, or in need of testing (never tested or tested > 12 months before). FINDINGS: We included 1116 men in the analysis. Mean age was 34 years (standard deviation: 13.2) and 55% (617/1116) of men needed HIV testing. Regarding facility visits, 82% (920/1116) of all men and 70% (429/617) of men in need of testing made at least one facility visit in the past 12 months. Men made a total of 1973 visits (mean two visits): 39% (765/1973) were as guardians and 84% (1657/1973) were to outpatient departments. Among men needing HIV testing, only 7% (30/429) were offered testing during any visit. The most common reason for not testing was not being offered services (37%; 179/487). CONCLUSION: Men in Malawi attend health facilities regularly, but few of those in need of HIV testing are offered testing services. Health screening services should capitalize on men's routine visits to outpatient departments as clients and guardians.
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Infecções por HIV/diagnóstico , Instalações de Saúde/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Adolescente , Adulto , Estudos Transversais , Feminino , Infecções por HIV/epidemiologia , Humanos , Malaui/epidemiologia , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Gravidez , Adulto JovemRESUMO
In a Policy Forum, Peter Ehrenkranz and colleagues discuss the contribution of CD4 and viral load testing to outcomes for people with HIV in low- and middle-income countries.
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Contagem de Linfócito CD4 , Países em Desenvolvimento , Saúde Global , Infecções por HIV/diagnóstico , HIV , Carga Viral , Fármacos Anti-HIV/uso terapêutico , Países em Desenvolvimento/economia , Saúde Global/economia , HIV/efeitos dos fármacos , HIV/crescimento & desenvolvimento , HIV/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Custos de Cuidados de Saúde , Acessibilidade aos Serviços de Saúde , Humanos , Valor Preditivo dos Testes , Prognóstico , Fatores de RiscoRESUMO
Calpains are intracellular Ca(2+)-regulated cysteine proteases that are essential for various cellular functions. Mammalian conventional calpains (calpain-1 and calpain-2) modulate the structure and function of their substrates by limited proteolysis. Thus, it is critically important to determine the site(s) in proteins at which calpains cleave. However, the calpains' substrate specificity remains unclear, because the amino acid (aa) sequences around their cleavage sites are very diverse. To clarify calpains' substrate specificities, 84 20-mer oligopeptides, corresponding to P10-P10' of reported cleavage site sequences, were proteolyzed by calpains, and the catalytic efficiencies (kcat/Km) were globally determined by LC/MS. This analysis revealed 483 cleavage site sequences, including 360 novel ones. Thekcat/Kms for 119 sites ranged from 12.5-1,710 M(-1)s(-1) Although most sites were cleaved by both calpain-1 and -2 with a similarkcat/Km, sequence comparisons revealed distinct aa preferences at P9-P7/P2/P5'. The aa compositions of the novel sites were not statistically different from those of previously reported sites as a whole, suggesting calpains have a strict implicit rule for sequence specificity, and that the limited proteolysis of intact substrates is because of substrates' higher-order structures. Cleavage position frequencies indicated that longer sequences N-terminal to the cleavage site (P-sites) were preferred for proteolysis over C-terminal (P'-sites). Quantitative structure-activity relationship (QSAR) analyses using partial least-squares regression and >1,300 aa descriptors achievedkcat/Kmprediction withr= 0.834, and binary-QSAR modeling attained an 87.5% positive prediction value for 132 reported calpain cleavage sites independent of our model construction. These results outperformed previous calpain cleavage predictors, and revealed the importance of the P2, P3', and P4' sites, and P1-P2 cooperativity. Furthermore, using our binary-QSAR model, novel cleavage sites in myoglobin were identified, verifying our predictor. This study increases our understanding of calpain substrate specificities, and opens calpains to "next-generation,"i.e.activity-related quantitative and cooperativity-dependent analyses.
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Calpaína/química , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Catálise , Humanos , Modelos Moleculares , Proteólise , Relação Quantitativa Estrutura-Atividade , Especificidade por SubstratoRESUMO
CAPN3/p94/calpain-3, a calpain protease family member predominantly expressed in skeletal muscle, possesses unusually rapid and exhaustive autolytic activity. Mutations in the human CAPN3 gene impairing its protease functions cause limb-girdle muscular dystrophy type 2A (LGMD2A); yet, the connection between CAPN3's autolytic activity and the enzyme's function in vivo remain unclear. Here, we demonstrated that CAPN3 protease activity was reconstituted by intermolecular complementation (iMOC) between its two autolytic fragments. Furthermore, the activity of full-length CAPN3 active-site mutants was surprisingly rescued through iMOC with autolytic fragments containing WT amino acid sequences. These results provide evidence that WT CAPN3 can be formed by the iMOC of two different complementary CAPN3 mutants. The finding of iMOC-mediated restoration of calpain activity indicates a novel mechanism for the genotype-phenotype links in LGMD2A.
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Calpaína/metabolismo , Proteínas Musculares/metabolismo , Animais , Células COS , Calpaína/química , Calpaína/genética , Chlorocebus aethiops , Humanos , Proteínas Musculares/química , Proteínas Musculares/genética , Mutação , ProteóliseRESUMO
Compared to other organs, the mouse thymus exhibits a high level of sialidase activity in both the soluble and crude membrane fractions, as measured at neutral pH using 4MU-Neu5Ac as a substrate. The main purpose of the present study was to identify the sialidase with a high level of the activity at neutral pH in the crude membrane. Several parameters were analyzed using the soluble (S) fraction, N and D fractions that were obtained by NP-40 or DOC/NP-40 solubilization from the thymus crude membrane. The main sialidase activity in the N fraction exhibited almost the same pI as that of soluble Neu2 and 60% of the activity was removed from the membrane by three washes with 10 mM Tris-buffer, at pH 7.0. The N fraction preferentially hydrolyzed the sialic acid bond of glycoprotein and exhibited sialidase activity with fetuin at pH 7.0 but not at pH 4.5. The same activity was observed in a plasma membrane-rich fraction. To date, the removal of sialic acid from fetuin at pH 7.0 was reported only with soluble Neu2 and the membrane fraction from Neu2-transfected COS cells. We analyzed the gene that controls the sialidase activity in the crude membrane fraction at pH 7.0 using SMXA recombinant mice and found that compared with other three genes, Neu2 presented the best correlation with the activity level. We suggest that Neu2 is most likely responsible for the main activity in the N fraction, due to its association with the membrane by an unknown mechanism.
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Membrana Celular/enzimologia , Fetuínas/metabolismo , Camundongos/metabolismo , Neuraminidase/química , Neuraminidase/metabolismo , Timo/enzimologia , Sequência de Aminoácidos , Animais , Membrana Celular/química , Membrana Celular/genética , Concentração de Íons de Hidrogênio , Camundongos/genética , Camundongos Endogâmicos C57BL , Neuraminidase/genética , Neuraminidase/isolamento & purificação , Timo/químicaRESUMO
BACKGROUND: The effect of early-term birth on the development of hypoglycaemia in large-for-gestational-age (LGA) neonates is yet to be clarified. This study aimed to clarify the association between hypoglycaemia and early-term birth in LGA neonates. METHODS: This single-centre retrospective cohort study evaluated LGA neonates born at term at Tsurugi Municipal Handa Hospital, Japan. Blood glucose levels were measured immediately and at 1, 2, and 4 hours after birth. The association between early-term birth and hypoglycaemia was evaluated using logistic regression analysis. The prevalence of severe hypoglycaemia and hypoglycaemia according to its timing of development was analysed using Fisher's exact test. RESULTS: In total, 295 neonates were included. Among them, 113 neonates (38.3%) were born at early term and 91 infants (30.8%) had hypoglycaemia. Logistic regression analysis showed a significant association between early-term birth and hypoglycaemia (adjusted odds ratio [95% confidence interval]:2.691 [1.597 to 4.535]). However, there was no significant between-group difference among those with severe hypoglycaemia. CONCLUSIONS: Among LGA neonates, early-term birth is positively associated with neonatal hypoglycaemia. This indicates that among LGA neonates, those born at early term require more careful observation for hypoglycaemia than do those born at later term. J. Med. Invest. 70 : 476-482, August, 2023.
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Hipoglicemia , Nascimento a Termo , Recém-Nascido , Lactente , Humanos , Estudos Retrospectivos , Idade Gestacional , Hipoglicemia/epidemiologia , Hipoglicemia/etiologia , JapãoRESUMO
Calpain-10 (CAPN10) belongs to the calpain superfamily. Genetic polymorphisms of the CAPN10 gene are associated with susceptibility to develop type 2 diabetes mellitus. Although the role of CAPN10 in the pathophysiology of diabetes has been extensively investigated, its biochemical properties are largely unknown. In this report, we made the surprising discovery that CAPN10 cDNA transcripts are subject to cryptic splicing and unexpected protein products were expressed. The same set of splicing products was reproducibly detected in four types of cultured cells including the primary culture of mouse myoblast. At least, one of the products was identical to a natural splicing variant. Sequence analysis of the splicing potential of CAPN10 cDNA, together with mutagenesis studies, resulted in the identification of a powerful splicing acceptor site at the junction of the sequences encoded by exons 9 and 10. We successfully extended the analysis to create expression construct resistant to splicing for both human and mouse CAPN10. The construct allowed us to analyze two major CAPN10 isoforms and reveal their difference in substrate proteolysis and potential cell functions. These results demonstrate that proteins produced from cDNA do not necessarily reflect the original nucleotide sequence. We provide insight into the property of recombinantly expressed CAPN10 proteins in cultured cells circumventing unexpected protein products.
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Processamento Alternativo , Calpaína/genética , Calpaína/metabolismo , Regulação da Expressão Gênica , Animais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Isoformas de Proteínas , Ratos , Ratos WistarRESUMO
INTRODUCTION: Malawi is rapidly closing the gap in achieving the UNAIDS 95-95-95 targets, with 90% of people living with HIV in Malawi aware of their status. As we approach epidemic control, interventions to improve coverage will become more costly. There is, therefore, an urgent need to identify innovative and low-cost strategies to maintain and increase testing coverage without diverting resources from other HIV services. The objective of this study is to model different combinations of facility-based HIV testing modalities and determine the most cost-effective strategy to increase the proportion of men and youth testing for HIV. METHODS: A data-driven individual-based model was parameterized with data from a community-representative survey (socio-demographic, health service utilization and HIV testing history) of men and youth in Malawi (data collected August 2019). In total, 79 different strategies for the implementation of HIV self-testing (HIVST) and provider-initiated-testing-and-counselling at the outpatient department (OPD) were evaluated. Outcomes included percent of men/youth tested for HIV in a 12-month period, cost-effectiveness and human resource requirements. The testing yield was assumed to be constant across the scenarios. RESULTS: Facility-based HIVST offered year-round resulted in the greatest increase in the proportion of men and youth tested in the OPD (from 45% to 72%-83%), was considered cost-saving for HIVST kit priced at $1.00, and generally reduced required personnel as compared to the status quo. At higher HIVST kit prices, and more relaxed eligibility criteria, all scenarios that considered year-round HIVST in the OPD remained on the cost-effectiveness frontier. CONCLUSIONS: Facility-based HIVST is a cost-effective strategy to increase the proportion of men/youth tested for HIV in Malawi and decreases the human resource requirements for HIV testing in the OPD-providing additional healthcare worker time for other priority healthcare activities.
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Infecções por HIV , Adolescente , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Teste de HIV , Humanos , Malaui/epidemiologia , Masculino , Programas de Rastreamento/métodos , Modelos Teóricos , AutotesteRESUMO
Because intracellular [Na(+)] is kept low by Na(+)/K(+)-ATPase, Na(+) dependence is generally considered a property of extracellular enzymes. However, we found that p94/calpain 3, a skeletal-muscle-specific member of the Ca(2+)-activated intracellular "modulator proteases" that is responsible for a limb-girdle muscular dystrophy ("calpainopathy"), underwent Na(+)-dependent, but not Cs(+)-dependent, autolysis in the absence of Ca(2+). Furthermore, Na(+) and Ca(2+) complementarily activated autolysis of p94 at physiological concentrations. By blocking Na(+)/K(+)-ATPase, we confirmed intracellular autolysis of p94 in cultured cells. This was further confirmed using inactive p94:C129S knock-in (p94CS-KI) mice as negative controls. Mutagenesis studies showed that much of the p94 molecule contributed to its Na(+)/Ca(2+)-dependent autolysis, which is consistent with the scattered location of calpainopathy-associated mutations, and that a conserved Ca(2+)-binding sequence in the protease acted as a Na(+) sensor. Proteomic analyses using Cs(+)/Mg(2+) and p94CS-KI mice as negative controls revealed that Na(+) and Ca(2+) direct p94 to proteolyze different substrates. We propose three roles for Na(+) dependence of p94; 1) to increase sensitivity of p94 to changes in physiological [Ca(2+)], 2) to regulate substrate specificity of p94, and 3) to regulate contribution of p94 as a structural component in muscle cells. Finally, this is the first example of an intracellular Na(+)-dependent enzyme.
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Calpaína/metabolismo , Espaço Intracelular/enzimologia , Músculo Esquelético/enzimologia , Sódio/metabolismo , Sequência de Aminoácidos , Animais , Autólise , Sítios de Ligação , Cálcio/metabolismo , Cálcio/farmacologia , Calpaína/química , Calpaína/genética , Ativação Enzimática/efeitos dos fármacos , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Especificidade de Órgãos , Estrutura Terciária de Proteína , Ratos , Sódio/farmacologia , Especificidade por SubstratoRESUMO
INTRODUCTION: Limb-girdle muscular dystrophy type 2A (LGMD2A) is caused by a deficiency of calpain-3/p94. Although the symptoms in most LGMD2A patients are generally homogeneous, some variation in the severity and progression of the disease has been reported. METHODS: We describe 2 patients who carry the same combination of compound heterozygous mutations (pG222R/pR748Q) and whose symptoms are exceptionally benign compared to homozygotes with each missense mutation. RESULTS: The benign phenotype observed in association with the combined pG222R and pR748Q mutations suggested that it may result from a compensatory effect of compound heterozygosity rather than the individual mutations themselves. Our analyses revealed that these two mutations exert different effects on the protease activity of calpain-3, suggesting "molecular complementation" in these patients. CONCLUSION: We propose several hypotheses to explain how this specific combination of mutations may rescue the normal proteolytic activity of calpain-3, resulting in an exceptionally benign phenotype.
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Calpaína/genética , Triagem de Portadores Genéticos , Proteínas Musculares/genética , Distrofia Muscular do Cíngulo dos Membros/genética , Mutação de Sentido Incorreto/genética , Fenótipo , Índice de Gravidade de Doença , Adulto , Animais , Células COS , Chlorocebus aethiops , Feminino , Humanos , Masculino , Distrofia Muscular do Cíngulo dos Membros/diagnósticoRESUMO
(1) Background: Men frequent outpatient departments (OPD) but are underrepresented in HIV testing services throughout sub-Saharan Africa. (2) Methods: We conducted a secondary analysis on data from a community-based survey with men in rural Malawi to assess factors associated with HIV testing, and being offered testing, during men's OPD visits. We include OPD visits made by men in-need of testing as our unit of observation. Multilevel mixed-effects logistic regression models were conducted. (3) Results: 782 men were eligible for these analyses, with 1575 OPD visits included (median two visits per man; IQR 1-3). 17% of OPD visits resulted in HIV testing. Being offered testing (aOR 42.45; 95% CI 15.13-119.10) and satisfaction with services received (aOR 3.27; 95% CI 1.28-8.33) were significantly associated with HIV testing. 14% of OPD visits resulted in being offered HIV testing. Being married/steady relationship (aOR 2.53; 95% CI 1.08-5.91) and having a sexual partner living with HIV (aOR 8.22; 95% CI 1.67-40.49) were significantly associated with being offered testing. (4) Conclusion: Being offered HIV testing was the strongest factor associated with testing uptake, while HIV status of sexual partner had the strongest association with being offered testing. Implementation of provider-initiated-testing should be prioritized for male OPD visits.
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OBJECTIVES: Near-point-of-care (POC) testing for early infant diagnosis (EID) and viral load expedites clinical action and improves outcomes but requires capital investment. We assessed whether excess capacity on existing near-POC devices used for TB diagnosis could be leveraged to increase near-POC HIV molecular testing, termed integrated testing, without compromising TB services. DESIGN: Preimplementation/postimplementation studies in 10 health facilities in Malawi and 8 in Zimbabwe. METHODS: Timeliness of EID and viral load test results and clinical action were compared between centralized and near-POC testing using Somers' D tests (continuous indicators) and risk ratios (RR, binary indicators); TB testing/treatment rates and timeliness were analyzed preintegration/postintegration. RESULTS: With integration, average device utilization increased but did not exceed 55%. Despite the addition of HIV testing, TB test volumes, timeliness, and treatment initiations were maintained. Although few HIV-positive infants were identified, near-POC EID testing improved treatment initiation within 1 month by 57% compared with centralized EID [Malawi RR: 1.57, 95% confidence interval (CI) 0.98-2.52], and near-POC viral load testing significantly increased the proportion of patients with elevated viral load receiving clinical action within 1 month (Zimbabwe RR: 5.26, 95% CI 3.38-8.20; Malawi RR: 3.90, 95% CI 2.58-5.91). CONCLUSION: Integrating TB/HIV testing using existing multidisease platforms is feasible and enables increased access to rapid diagnostics without disrupting existing TB services. Our results serve as an example of a novel, efficient implementation model that can increase access to critical testing services across disease silos and should be considered for additional clinical applications.
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Infecções por HIV , Tuberculose , Diagnóstico Precoce , Estudos de Viabilidade , Infecções por HIV/diagnóstico , Teste de HIV , Humanos , Lactente , Malaui , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Tuberculose/diagnóstico , ZimbábueRESUMO
INTRODUCTION: Point-of-care (POC) early infant diagnosis (EID) testing has been shown to dramatically decrease turnaround times from sample collection to caregiver result receipt and time to ART initiation for HIV-positive infants compared to centralized laboratory testing. As governments in sub-Saharan Africa implement POC EID technologies, we report on the feasibility and effectiveness of POC EID testing and the impact of same-day result delivery on rapid ART initiation within national programmes across six countries. METHODS: This pre-/post-evaluation compared centralized laboratory-based (pre) with POC (post) EID testing in 52 facilities across Cameroon, Democratic Republic of Congo, Ethiopia, Kenya, Senegal and Zimbabwe between April 2017 and October 2019 (country-dependent). Data were collected retrospectively from routine records at health facilities for all infants tested under two years of age. Hazard ratios and 95% confidence intervals were calculated to compare time-to-event outcomes, visualized with Kaplan-Meier curves, and the Somers' D test was used to compare continuous outcomes. RESULTS: Data were collected for 2892 EID tests conducted on centralized laboratory-based platforms and 4610 EID tests on POC devices with 127 (4%) and 192 (4%) HIV-positive infants identified, respectively. POC EID significantly reduced the time from sample collection to caregiver result receipt (POC median: 0 days, IQR: 0 to 0 vs. centralized: 35 days, IQR: 26 to 56) and time from sample collection to ART initiation for HIV-positive infants (POC median: 1 day, IQR: 0 to 7 vs. centralized: 39 days, IQR: 26 to 57). With POC testing, 72% of infants received results on the same day as sample collection; HIV-positive infants with a same-day diagnosis had six times the rate of ART initiation compared to those diagnosed one or more days after sample collection (HR: 6.39; 95% CI: 3.44 to 11.85). CONCLUSIONS: Same-day diagnosis and treatment initiation for infants is possible with POC EID within routine government-led and -supported public sector healthcare facilities in resource-limited settings. Given that POC EID allows for rapid ART initiation, aligning to the World Health Organization's recommendation of ART initiation within seven days, its use in public sector programmes has the potential to reduce overall mortality for infants with HIV through early treatment initiation.
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Continuidade da Assistência ao Paciente , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Testes Imediatos , Diagnóstico Precoce , Feminino , Programas Governamentais , Humanos , Lactente , Masculino , Avaliação de Programas e Projetos de Saúde , Estudos RetrospectivosRESUMO
INTRODUCTION: In many low- and middle-income countries, HIV viral load (VL) testing occurs at centralized laboratories and time-to-result-delivery is lengthy, preventing timely monitoring of HIV treatment adherence. Near point-of-care (POC) devices, which are placed within health facility laboratories rather than clinics themselves (i.e. "true" POC), can offer VL in conjunction with centralized laboratories to expedite clinical decision making and improve outcomes, especially for patients at high risk of treatment failure. We assessed impacts of near-POC VL testing on result receipt and clinical action in public sector programmes in Cameroon, Democratic Republic of Congo, Kenya, Malawi, Senegal, Tanzania and Zimbabwe. METHODS: Routine health data were collected retrospectively after introducing near-POC VL testing at 57 public sector health facilities (2017 to 2019, country-dependent). Where possible, key indicators were compared to data from patients receiving centralized laboratory testing using hazard ratios and the Somers' D test. RESULTS: Data were collected from 6795 tests conducted on near-POC and 17614 tests on centralized laboratory-based platforms. Thirty-one percent (2062/6694) of near-POC tests were conducted for high-risk populations: pregnant and breastfeeding women, children and those with suspected failure. Compared to conventional testing, near-POC improved the median time from sample collection to return of results to patient [six vs. sixty-eight days, effect size: -32.2%; 95% CI: -41.0% to -23.4%] and to clinical action for individuals with an elevated HIV VL [three vs. fourty-nine days, effect size: -35.4%; 95% CI: -46.0% to -24.8%]. Near-POC VL results were two times more likely to be returned to the patient within 90 days compared to centralized tests [50% (1781/3594) vs. 27% (4172/15271); aHR: 2.22, 95% CI: 2.05 to 2.39]. Thirty-seven percent (340/925) of patients with an elevated near-POC HIV VL result had documented clinical follow-up actions within 30 days compared to 7% (167/2276) for centralized testing. CONCLUSIONS: Near-POC VL testing enabled rapid test result delivery for high-risk populations and led to significant improvements in the timeliness of patient result receipt compared to centralized testing. While there was some improvement in time-to-clinical action with near-POC VL testing, major gaps remained. Strengthening of systems supporting the utilization of results for patient management are needed to truly capitalize on the benefits of decentralized testing.
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Infecções por HIV/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Carga Viral , Adolescente , Adulto , África Subsaariana , Idoso , Criança , Pré-Escolar , Feminino , Infecções por HIV/tratamento farmacológico , Instalações de Saúde , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Gravidez , Prática de Saúde Pública , Estudos Retrospectivos , Carga Viral/métodos , Adulto JovemRESUMO
Calpain-3 (CAPN3), a 94-kDa member of the calpain protease family, is abundant in skeletal muscle. Mutations in the CAPN3 gene cause limb girdle muscular dystrophy type 2A, indicating that CAPN3 plays important roles in muscle physiology. CAPN3 has several unique features. A crystallographic study revealed that its C-terminal penta-EF-hand domains form a homodimer, suggesting that CAPN3 functions as a homodimeric protease. To analyze complex formation of CAPN3 in a more convenient manner, we performed blue native polyacrylamide gel electrophoresis and found that the observed molecular weight of native CAPN3, as well as recombinant CAPN3, was larger than 240 kDa. Further analysis by cross-linking and sequential immunoprecipitation revealed that CAPN3 in fact forms a homotrimer. Trimer formation was abolished by the deletion of the PEF domain, but not the CAPN3-specific insertion sequences NS, IS1, and IS2. The PEF domain alone formed a homodimer, as reported, but addition of the adjacent CBSW domain to its N-terminus reinforced the trimer-forming property. Collectively, these results suggest that CAPN3 forms a homotrimer in which the PEF domain's dimer-forming ability is influenced by other domains.
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Calpaína/metabolismo , Proteínas Musculares/metabolismo , Distrofia Muscular do Cíngulo dos Membros/metabolismo , Animais , Calpaína/química , Calpaína/genética , Linhagem Celular , Motivos EF Hand , Feminino , Predisposição Genética para Doença/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Musculares/química , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Distrofia Muscular do Cíngulo dos Membros/genética , Mutagênese Insercional , Mutação , Domínios ProteicosRESUMO
Calpain-1 and calpain-2 are highly structurally similar isoforms of calpain. The calpains, a family of intracellular cysteine proteases, cleave their substrates at specific sites, thus modifying their properties such as function or activity. These isoforms have long been considered to function in a redundant or complementary manner, as they are both ubiquitously expressed and activated in a Ca2+- dependent manner. However, studies using isoform-specific knockout and knockdown strategies revealed that each calpain species carries out specific functions in vivo. To understand the mechanisms that differentiate calpain-1 and calpain-2, we focused on the efficiency and longevity of each calpain species after activation. Using an in vitro proteolysis assay of troponin T in combination with mass spectrometry, we revealed distinctive aspects of each isoform. Proteolysis mediated by calpain-1 was more sustained, lasting as long as several hours, whereas proteolysis mediated by calpain-2 was quickly blunted. Calpain-1 and calpain-2 also differed from each other in their patterns of autolysis. Calpain-2-specific autolysis sites in its PC1 domain are not cleaved by calpain-1, but calpain-2 cuts calpain-1 at the corresponding position. Moreover, at least in vitro, calpain-1 and calpain-2 do not perform substrate proteolysis in a synergistic manner. On the contrary, calpain-1 activity is suppressed in the presence of calpain-2, possibly because it is cleaved by the latter protein. These results suggest that calpain-2 functions as a down-regulation of calpain-1, a mechanism that may be applicable to other calpain species as well.
Assuntos
Calpaína/metabolismo , Troponina T/metabolismo , Autólise , Calpaína/genética , Ativação Enzimática , Estabilidade Enzimática , Células HCT116 , Células HEK293 , Células HeLa , Humanos , Proteólise , Especificidade por Substrato , Fatores de TempoRESUMO
BACKGROUND: Globally, nearly 22 million HIV-infected patients are currently accessing antiretroviral treatment; however, almost one million people living with HIV died of AIDS-related illnesses in 2018. Advanced HIV disease remains a significant issue to curb HIV-related mortality. METHODS: We analyzed 864,389 CD4 testing records collected by 1,016 Alere Pima Analyzers implemented at a variety of facilities, including peripheral facilities, between January 2012 and December 2016 across four countries in sub-Saharan Africa. Routinely collected data and programmatic records were used to analyze the median CD4 counts and proportions of patients with advanced HIV disease by country, facility type, and year. RESULTS: Median CD4 counts were between 409-444 cells/ul each year since 2012 with a median in 2016 of 444 cells/ul (n = 319,829). The proportion of test results returning CD4 counts above 500 cells/ul has increased slowly each year with 41.8% (95% CI: 41.6-41.9%) of tests having a CD4 count above 500 cells/ul in 2016. Median CD4 counts were similar across facility types. The proportion of test results indicating advanced HIV disease has remained fairly consistent: 19.4% (95% CI: 18.8-20.1%) in 2012 compared to 16.1% (95% CI: 16.0-16.3%) in 2016. The proportion of test results indicating advanced HIV disease annually ranged from 14.5% in Uganda to 29.8% in Cameroon. 6.9% (95% CI: 6.8-7.0%) of test results showed very advanced HIV disease (CD4<100 cells/ul) in 2016. CONCLUSIONS: The proportion of CD4 test results indicating advanced disease was relatively high and consistent across four high HIV burden countries.
Assuntos
Instituições de Assistência Ambulatorial , Infecções por HIV/diagnóstico , Atenção Primária à Saúde , África Subsaariana/epidemiologia , Contagem de Linfócito CD4 , Camarões , Coleta de Dados , Infecções por HIV/sangue , Infecções por HIV/epidemiologia , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , UgandaRESUMO
BACKGROUND: Since 2010, point-of-care (POC) CD4 testing platforms have been introduced in both urban and rural settings to expand access to testing by bringing diagnostic services closer to patients. We conducted an analysis of routinely collected CD4 testing data to determine the invalid result rates associated with POC CD4 testing. METHODS: We analyzed 981,152 CD4 testing records collected from Alere Pima Analyzers between January 2011 and December 2016 across five countries in sub-Saharan Africa. Routinely collected data and programmatic records were used to determine the rate of invalid test results per month, by facility type, and by operator based on cumulative usage during the study period. In addition, frequency of invalid test types and utilization of control beads were assessed. RESULTS: Across the five countries, 75,530 invalid messages were returned, resulting in an overall invalid result rate of 7.7%. The invalid result rate by country ranged from 6.6% to 11.2%. Invalid result rates were consistent across facility types. Invalid result rates were inversely correlated with operator usage: low volume operators (<50 tests over study period) experienced an invalid result rate of 10.2%, while high volume operators (>500 tests over study period) experienced an invalid result rate of 5.5%. Two invalid result types (exposure position control and reagent control) accounted for nearly 50% of invalid results. Routine data showed that control beads were run on 88.3% of days that the device was used. CONCLUSIONS: Our analysis found that the rate of invalid results was consistent across all types of health facilities, indicating that decentralization of POC CD4 testing to lower level health facilities did not exhibit high invalid result rates or increase cartridge wastage. Additionally, invalid result rates were inversely correlated to operator usage, with high-volume operators experiencing lower invalid result rates than low-volume operators. POC CD4 testing can, therefore, be performed in decentralized national testing programs; however, adequate training, quality assurance, routine monitoring, and ongoing mentorship should also be implemented for success.
Assuntos
Infecções por HIV/imunologia , Testes Imediatos , Tecnologia sem Fio/instrumentação , África Subsaariana , Contagem de Linfócito CD4 , Estudos Transversais , Humanos , Saúde Pública , Reprodutibilidade dos Testes , Estudos Retrospectivos , Serviços de Saúde RuralRESUMO
INTRODUCTION: As prevalence of undiagnosed HIV declines, it is unclear whether testing programmes will be cost-effective. To guide their HIV testing programmes, countries require appropriate metrics that can be measured. The cost-per-diagnosis is potentially a useful metric. METHODS: We simulated a series of setting-scenarios for adult HIV epidemics and ART programmes typical of settings in southern Africa using an individual-based model and projected forward from 2018 under two policies: (i) a minimum package of "core" testing (i.e. testing in pregnant women, for diagnosis of symptoms, in sex workers, and in men coming forward for circumcision) is conducted, and (ii) core-testing as above plus additional testing beyond this ("additional-testing"), for which we specify different rates of testing and various degrees to which those with HIV are more likely to test than those without HIV. We also considered a plausible range of unit test costs. The aim was to assess the relationship between cost-per-diagnosis and the incremental cost-effectiveness ratio (ICER) of the additional-testing policy. The discount rate used in the base case was 3% per annum (costs in 2018 U.S. dollars). RESULTS: There was a strong graded relationship between the cost-per-diagnosis and the ICER. Overall, the ICER was below $500 per-DALY-averted (the cost-effectiveness threshold used in primary analysis) so long as the cost-per-diagnosis was below $315. This threshold cost-per-diagnosis was similar according to epidemic and programmatic features including the prevalence of undiagnosed HIV, the HIV incidence and a measure of HIV programme quality (the proportion of HIV diagnosed people having a viral load <1000 copies/mL). However, restricting to women, additional-testing did not appear cost-effective even at a cost-per-diagnosis of below $50, while restricting to men additional-testing was cost-effective up to a cost-per-diagnosis of $585. The threshold cost per diagnosis for testing in men to be cost-effective fell to $256 when the cost-effectiveness threshold was $300 instead of $500, and to $81 when considering a discount rate of 10% per annum. CONCLUSIONS: For testing programmes in low-income settings in southern African there is an extremely strong relationship between the cost-per-diagnosis and the cost-per-DALY averted, indicating that the cost-per-diagnosis can be used to monitor the cost-effectiveness of testing programmes.