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1.
Open Forum Infect Dis ; 11(7): ofae318, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38983709

RESUMO

The United Nations Program on HIV/AIDS (UNAIDS) targets aim to reduce new HIV infections below 370 000 annually by 2025. However, there were 1.3 million new HIV infections worldwide in 2022. We collected and analyzed data for key variables of the HIV epidemic from UNAIDS and supplemented by PUBMED/EMBASE searches and national reports. A total of 53% of the HIV infections worldwide were in 14 high-prevalence countries in Southern/East Africa-where most of the funding for treatment and prevention is allocated-versus 47% in 54 low-prevalence countries. In 2022, there were more new HIV infections (770 000 vs 468 000), more HIV-related deaths (383 000 vs 225 000), higher rates of mother-to-child transmissions (16% vs 9%) and lower antiretroviral therapy coverage (67% vs 83%) in low-prevalence countries versus high-prevalence countries. To achieve UNAIDS annual new infections target for 2025, ART coverage needs to be optimized worldwide, and preexposure prophylaxis coverage expanded to 74 million people, versus 2.5 million currently treated.

2.
Commun Biol ; 7(1): 900, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048787

RESUMO

A central concept of evolutionary biology, supported by broad scale allometric analyses, asserts that changing morphology should induce downstream changes in locomotor kinematics and energetics, and by inference selective fitness. However, if these mechanistic relationships exist at local intraspecific scales, where they could provide substrate for fundamental microevolutionary processes, is unknown. Here, analyses of selectively-bred duck breeds demonstrate that distinct body shapes incur kinematic shifts during walking, but these do not translate into differences in energetics. A combination of modular relationships between anatomical regions, and a trade-off between limb flexion and trunk pitching, are shown to homogenise potential functional differences between the breeds, accounting for this discrepancy between form and function. This complex interplay between morphology, motion and physiology indicates that understanding evolutionary links between the avian body plan and locomotor diversity requires studying locomotion as an integrated whole and not key anatomical innovations in isolation.


Assuntos
Patos , Animais , Fenômenos Biomecânicos , Patos/fisiologia , Metabolismo Energético , Evolução Biológica , Locomoção/fisiologia , Masculino , Caminhada/fisiologia , Feminino
3.
Nat Commun ; 14(1): 1575, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949094

RESUMO

It is accepted that non-avian theropod dinosaurs, with their long muscular tails and small forelimbs, had a centre-of-mass close to the hip, while extant birds, with their reduced tails and enlarged wings have their mass centred more cranially. Transition between these states is considered crucial to two key innovations in the avian locomotor system: crouched bipedalism and powered flight. Here we use image-based models to challenge this dichotomy. Rather than a phylogenetic distinction between 'dinosaurian' and 'avian' conditions, we find terrestrial versus volant taxa occupy distinct regions of centre-of-mass morphospace consistent with the disparate demands of terrestrial bipedalism and flight. We track this decoupled evolution of body shape and mass distribution through bird evolution, including the origin of centre-of-mass positions more advantageous for flight and major reversions coincident with terrestriality. We recover modularity in the evolution of limb proportions and centre-of-mass that suggests fully crouched bipedalism evolved after powered flight.


Assuntos
Evolução Biológica , Dinossauros , Animais , Filogenia , Somatotipos , Aves , Dinossauros/anatomia & histologia , Fósseis
4.
Open Forum Infect Dis ; 10(1): ofac673, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36632416

RESUMO

A novel injectable pre-exposure prophylaxis, cabotegravir, has greater efficacy and acceptability than oral tenofovir/emtricitabine for prevention of HIV infection. Cabotegravir is currently priced at $22 200 per year, >185 times higher than the $60-$119 estimated cost-effectiveness threshold for middle-income countries (MICs). Following civil society pressure, ViiV provided access to generic versions in 90 countries with the Medicines Patent Pool (MPP), including all African nations. However, several MICs outside Africa have rapidly growing HIV epidemics. We analyzed the ViiV-MPP deal to assess population covered and gross domestic product (GDP) per capita. There were 38 countries excluded from the ViiV-MPP deal despite having a GDP per capita lower than the highest-earning African country. These countries include 2.4 billion people (30% global population), with an incidence of 122 000 (8%). For cabotegravir to have a significant impact on HIV infections, millions will need to be treated at affordable prices in a wide range of countries.

5.
BMJ Glob Health ; 6(12)2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34937701

RESUMO

OBJECTIVES: The Oxford-AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19, Vaxzevira or Covishield) builds on two decades of research and development (R&D) into chimpanzee adenovirus-vectored vaccine (ChAdOx) technology at the University of Oxford. This study aimed to approximate the funding for the R&D of ChAdOx and the Oxford-AstraZeneca vaccine and to assess the transparency of funding reporting mechanisms. METHODS: We conducted a scoping review and publication history analysis of the principal investigators to reconstruct R&D funding the ChAdOx technology. We matched award numbers with publicly accessible grant databases. We filed freedom of information (FOI) requests to the University of Oxford for the disclosure of all grants for ChAdOx R&D. RESULTS: We identified 100 peer-reviewed articles relevant to ChAdOx technology published between January 2002 and October 2020, extracting 577 mentions of funding bodies from acknowledgements. Government funders from overseas (including the European Union) were mentioned 158 times (27.4%), the UK government 147 (25.5%) and charitable funders 138 (23.9%). Grant award numbers were identified for 215 (37.3%) mentions; amounts were publicly available for 121 (21.0%). Based on the FOIs, until December 2019, the biggest funders of ChAdOx R&D were the European Commission (34.0%), Wellcome Trust (20.4%) and Coalition for Epidemic Preparedness Innovations (17.5%). Since January 2020, the UK government contributed 95.5% of funding identified. The total identified R&D funding was £104 226 076 reported in the FOIs and £228 466 771 reconstructed from the literature search. CONCLUSION: Our study approximates that public and charitable financing accounted for 97%-99% of identifiable funding for the ChAdOx vaccine technology research at the University of Oxford underlying the Oxford-AstraZeneca vaccine until autumn 2020. We encountered a lack of transparency in research funding reporting.


Assuntos
COVID-19 , ChAdOx1 nCoV-19 , Vacinas contra COVID-19 , Humanos , SARS-CoV-2
6.
Invest Ophthalmol Vis Sci ; 58(7): 3046-3054, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28622396

RESUMO

Purpose: The mutation R345W in EFEMP1 (fibulin-3) causes macular degeneration. This study sought to determine whether proteoglycan content and diffusion across Bruch's membrane are altered in Efemp1ki/ki mice carrying this mutation or in Efemp1-/- mice. Methods: Proteoglycans in mouse Bruch's membranes were stained with Cupromeronic Blue (CB). Heparan sulfated proteoglycan (HSPG) and chondroitin/dermatan sulfate proteoglycan (C/DSPG) distributions were visualized following treatments with chondroitinase ABC (C-ABC) or nitrous acid. Total sulfated glycosaminoglycans (sGAGs) in Bruch's membrane/choroid (BrM/Ch) were measured with dimethylmethylene blue (DMMB). Matrix metalloprotease (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-3 were examined by immunofluorescence and quantified using Image J. Molecules with different Stokes radius (Rs) were allowed simultaneously to diffuse through mouse BrM/Ch mounted in a modified Ussing chamber. Samples were quantified using gel exclusion chromatography. Results: HSPGs and C/DSPGs were markedly increased in Efemp1ki/ki Bruch's membrane, and MMP-2 and MMP-9 were decreased, but TIMP-3 was increased. Diffusion across Efemp1ki/ki Bruch's membrane was impaired. In contrast, the proteoglycan amount in Efemp1-/- Bruch's membrane was not significantly different, but the size of proteoglycans was much larger. MMP-2, MMP-3, and TIMP-3 levels were similar to that of Efemp1+/+ mice, but they were localized diffusely in retinal pigment epithelium (RPE) cells instead of Bruch's membrane. Diffusion across Efemp1-/- Bruch's membrane was enhanced. Conclusions: Mutant fibulin-3 causes proteoglycan accumulation, reduction of MMP-2 and MMP-9, but increase of TIMP-3, and impairs diffusion across Bruch's membrane. Fibulin-3 ablation results in altered sizes of proteoglycans, altered distributions of MMP-2, MMP-9, and TIMP-3, and enhances diffusion across Bruch's membrane.


Assuntos
Lâmina Basilar da Corioide/metabolismo , DNA/genética , Proteínas da Matriz Extracelular/genética , Degeneração Macular/genética , Mutação , Proteoglicanas/metabolismo , Envelhecimento/genética , Animais , Lâmina Basilar da Corioide/patologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Proteínas da Matriz Extracelular/metabolismo , Degeneração Macular/diagnóstico , Degeneração Macular/metabolismo , Camundongos , Camundongos Mutantes
7.
Mol Vis ; 23: 228-241, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28465655

RESUMO

PURPOSE: To examine the effects of autophagy deficiency induced by RPE-specific deletion of Atg5 or Atg7 in mice as a function of age. METHODS: Conditional knockout mice with a floxed allele of Atg5 or Atg7 were crossed with inducible VMD2-rtTA/Cre transgenic mice. VMD2-directed RPE-specific Cre recombinase expression was induced with doxycycline feeding in the resulting mice. Cre-mediated deletion of floxed Atg5 or Atg7 resulted in RPE-specific inactivation of the Atg5 or Atg7 gene. Plastic and thin retinal sections were analyzed with light and electron microscopy for histological changes. Photoreceptor outer segment (POS) thickness in plastic sections was measured using the Adobe Photoshop CS4 extended ruler tool. Autophagic adaptor p62/SQSTM1 and markers for oxidatively damaged lipids, proteins, and DNA were examined with immunofluorescence staining of cryosections. Fluorescence signals were quantified using Image J software. RESULTS: Accumulation of p62/SQSTM1 reflecting autophagy deficiency was observed in the RPE of the Atg5ΔRPE and Atg7ΔRPE mice. 3-nitrotyrosine, advanced glycation end products (AGEs), and 8-hydroxy-2'-deoxyguanosine (8-OHdG), markers for oxidatively damaged proteins and DNA, were also found to accumulate in the RPE of these mice. We observed retinal degeneration in 35% of the Atg5ΔRPE mice and 45% of the Atg7ΔRPE mice at 8 to 24 months old. Degeneration severity and the number of mice with degeneration increased with age. The mean POS thickness of these mice was 25 µm at 8-12 months, 15 µm at 13-18 months, and 3 µm at 19-24 months, compared to 35 µm, 30 µm, and 24 µm in the wild-type mice, respectively. Early age-related macular degeneration (AMD)-like RPE defects were found in all the Atg5ΔRPE and Atg7ΔRPE mice 13 months old or older, including vacuoles, uneven RPE thickness, diminished basal infoldings, RPE hypertrophy/hypotrophy, pigmentary irregularities, and necrosis. The severity of the RPE defects increased with age and in the mice with retinal degeneration. RPE atrophy and choroidal neovascularization (CNV) were occasionally observed in the Atg5ΔRPE and Atg7ΔRPE mice with advanced age. CONCLUSIONS: Autophagy deficiency induced by RPE-specific deletion of Atg5 or Atg7 predisposes but does not necessarily drive the development of AMD-like phenotypes or retinal degeneration.


Assuntos
Proteína 5 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/genética , Autofagia , Deleção de Genes , Degeneração Macular/genética , Degeneração Retiniana/genética , Epitélio Pigmentado da Retina/patologia , Alelos , Animais , Biomarcadores/metabolismo , Eletrorretinografia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Degeneração Macular/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Degeneração Retiniana/patologia , Epitélio Pigmentado da Retina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
J Health Care Poor Underserved ; 28(1): 63-70, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28238987

RESUMO

BACKGROUND: Within Zambia there is a shortage of health workers in rural areas. This study aims to identify motivating factors for retaining rural health workers. METHODS: Sixty rural health workers completed surveys and 46 were interviewed. They rated the importance of six motivating factors and discussed these and other factors in interviews. An interview was conducted with a Government Human Resources Manager (HR Manager) to elicit contextual information. RESULTS: All six factors were identified as being very important motivators, as were two additional factors. Additional career training was identified by many as the most important factor. Comparison of results and the HR Manager interview revealed that workers lacked knowledge about opportunities and that the HR manager was aware of barriers to career development. CONCLUSION: The Zambian government might better motivate and retain rural health workers by offering them any combination of identified factors, and by addressing the barriers to career development.


Assuntos
Pessoal de Saúde/psicologia , Mão de Obra em Saúde/organização & administração , Motivação , Seleção de Pessoal/organização & administração , Serviços de Saúde Rural/organização & administração , Comunicação , Feminino , Instalações de Saúde/normas , Conhecimentos, Atitudes e Prática em Saúde , Habitação/normas , Humanos , Entrevistas como Assunto , Masculino , Salários e Benefícios , Desenvolvimento de Pessoal/organização & administração , Zâmbia
9.
Invest Ophthalmol Vis Sci ; 56(12): 7604-10, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26618653

RESUMO

PURPOSE: Following decapitation, the planarian Schmidtea mediterranea regenerates its head and eyes. The gene ovo is required for eye maintenance and regeneration in response to wounding. In this study, we investigated whether eye regeneration in S. mediterranea could occur absent a wound healing response. METHODS: One hundred twenty S. mediterranea were treated with ovo RNA interference (RNAi) or control (unc-22) RNAi by feeding double-stranded RNA (dsRNA). Following eye loss, ovo RNAi treatment was halted and replaced with control RNAi treatment. Quantitative real-time PCR (qPCR) was used to monitor ovo expression. Eye functionality was monitored via a phototaxis assay. Photoreceptor neurons were visualized via immunofluorescence staining of arrestin. RESULTS: Treatment with ovo RNAi caused eyes to gradually shrink until they were completely absent. One hundred percent of ovo RNAi-treated planarians lost both eyes within 137 days of treatment onset. ovo RNAi-treated planarians were unable to regenerate eyes in response to decapitation. Upon removal of ovo RNAi, eyes became visible as small pigmented spots in the head within 28 days. The eyes slowly developed, appearing to gain pigmented cells first and then nonpigmented photoreceptors. Phototaxis assays demonstrated functional eye loss and eye restoration. ovo mRNA was significantly decreased following treatment with ovo RNAi and significantly increased following removal of ovo RNAi. Arrestin staining was present in the eyes, optic nerves, and optic chiasm of worms with regenerated eyes but not in eyeless worms. CONCLUSIONS: S. mediterranea have the ability to generate functional eyes in the absence of a wound healing response. This ability requires the expression of ovo.


Assuntos
Regeneração Nervosa/fisiologia , Neurônios/metabolismo , Células Fotorreceptoras/metabolismo , Fatores de Transcrição/genética , Transcriptoma/fisiologia , Animais , Neurônios/citologia , Células Fotorreceptoras/citologia , Planárias/genética , Planárias/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/metabolismo
10.
Invest Ophthalmol Vis Sci ; 56(8): 4619-30, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26200502

RESUMO

PURPOSE: Mutations in BEST1, encoding bestrophin-1 (Best1), cause autosomal recessive bestrophinopathy (ARB). Encoding bestrophin-1 is a pentameric anion channel localized to the basolateral plasma membrane of the RPE. Here, we characterize the effects of the mutations R141H (CGC > CAC) and I366fsX18 (c.1098_1100+7del), identified in a patient in our practice, on Best1 trafficking, oligomerization, and channel activity. METHODS: Currents of Cl- were assessed in transfected HEK293 cells using whole-cell patch clamp. Best1 localization was assessed by confocal microscopy in differentiated, human-induced pluripotent stem cell-derived RPE (iPSC-RPE) cells following expression of mutants via adenovirus-mediated gene transfer. Oligomerization was evaluated by coimmunoprecipitation in iPSC-RPE and MDCK cells. RESULTS: Compared to Best1, Best1 I366fsX18 currents were increased while Best1 R141H Cl- currents were diminished. Coexpression of Best1 R141H with Best1 or Best1 I366fsX18 resulted in rescued channel activity. Overexpressed Best1, Best1 R141H, and Best1 I366fsX18 were all properly localized in iPSC-RPE cells; Best1 R141H and Best1 I366fsX18 coimmunoprecipitated with endogenous Best1 in iPSC-RPE cells and with each other in MDCK cells. CONCLUSIONS: The first 366 amino acids of Best1 are sufficient to mediate channel activity and homo-oligomerization. The combination of Best1 and Best1 R141H does not cause disease, while Best1 R141H together with Best1 I366fsX18 causes ARB. Since both combinations generate comparable Cl- currents, this indicates that ARB in this patient is not caused by a loss of channel activity. Moreover, Best1 I366fsX18 differs from Best1 in that it lacks most of the cytosolic C-terminal domain, suggesting that the loss of this region contributes significantly to the pathogenesis of ARB in this patient.


Assuntos
Canais de Cloreto/genética , DNA/genética , Oftalmopatias Hereditárias/genética , Proteínas do Olho/genética , Regulação da Expressão Gênica , Mutação , Doenças Retinianas/genética , Epitélio Pigmentado da Retina/ultraestrutura , Adolescente , Bestrofinas , Western Blotting , Membrana Celular/metabolismo , Canais de Cloreto/biossíntese , Canais de Cloreto/metabolismo , Análise Mutacional de DNA , Oftalmopatias Hereditárias/metabolismo , Oftalmopatias Hereditárias/patologia , Proteínas do Olho/biossíntese , Feminino , Angiofluoresceinografia , Fundo de Olho , Genes Recessivos , Células HEK293/metabolismo , Células HEK293/ultraestrutura , Humanos , Microscopia Confocal , Microscopia Eletrônica , Microscopia de Fluorescência , Técnicas de Patch-Clamp , Doenças Retinianas/metabolismo , Doenças Retinianas/patologia , Epitélio Pigmentado da Retina/metabolismo
11.
J Mol Biol ; 390(5): 902-12, 2009 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-19481093

RESUMO

Voltage-dependent K(+) (Kv) channels form the basis of the excitability of nerves and muscles. KvAP is a well-characterized archeal Kv channel that has been widely used to investigate many aspects of Kv channel biochemistry, biophysics, and structure. In this study, a minimal kinetic gating model for KvAP function in two different phospholipid decane bilayers is developed. In most aspects, KvAP gating is similar to the well-studied eukaryotic Shaker Kv channel: conformational changes occur within four voltage sensors, followed by pore opening. Unlike the Shaker Kv channel, KvAP possesses an inactivated state that is accessible from the pre-open state of the channel. Changing the lipid composition of the membrane influences multiple gating transitions in the model, but, most dramatically, the rate of recovery from inactivation. Inhibition by the voltage sensor toxin VSTx1 is most easily explained if VSTx1 binds only to the depolarized conformation of the voltage sensor. By delaying the voltage sensor's return to the hyperpolarized conformation, VSTx1 favors the inactivated state of KvAP.


Assuntos
Archaea/metabolismo , Ativação do Canal Iônico , Bicamadas Lipídicas/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilgliceróis/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Alcanos/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Cinética , Peptídeos/farmacologia , Superfamília Shaker de Canais de Potássio/metabolismo , Venenos de Aranha/farmacologia
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