Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Wellcome Open Res ; 8: 306, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38031545

RESUMO

Background: There is a need for follow-up of early-life stunting intervention trials into childhood to determine their long-term impact. A holistic school-age assessment of health, growth, physical and cognitive function will help to comprehensively characterise the sustained effects of early-life interventions. Methods: The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe assessed the effects of improved infant and young child feeding (IYCF) and/or improved water, sanitation and hygiene (WASH) on stunting and anaemia at 18 months. Among children enrolled to SHINE, 1,275 have been followed up at 7-8 years of age (1,000 children who have not been exposed to HIV, 268 exposed to HIV antenatally who remain HIV negative and 7 HIV positive children). Children were assessed using the School-Age Health, Activity, Resilience, Anthropometry and Neurocognitive (SAHARAN) toolbox, to measure their growth, body composition, cognitive and physical function. In parallel, a caregiver questionnaire assessed household demographics, socioeconomic status, adversity, nurturing, caregiver support, food and water insecurity. A monthly morbidity questionnaire is currently being administered by community health workers to evaluate school-age rates of infection and healthcare-seeking. The impact of the SHINE IYCF and WASH interventions, the early-life 'exposome', maternal HIV, and contemporary exposures on each school-age outcome will be assessed. We will also undertake an exploratory factor analysis to generate new, simpler metrics for assessment of cognition (COG-SAHARAN), growth (GROW-SAHARAN) and combined growth, cognitive and physical function (SUB-SAHARAN). The SUB-SAHARAN toolbox will be used to conduct annual assessments within the SHINE cohort from ages 8-12 years. Ethics and dissemination: Approval was obtained from Medical Research Council of Zimbabwe (08/02/21) and registered with Pan-African Clinical Trials Registry (PACTR202201828512110, 24/01/22). Primary caregivers provided written informed consent and children written assent. Findings will be disseminated through community sensitisation, peer-reviewed journals and stakeholders including the Zimbabwean Ministry of Health and Child Care.

2.
Wellcome Open Res ; 7: 274, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38910935

RESUMO

Background: Neurodevelopment assessment tools for low-resource settings are urgently needed. However, most available tools were developed in high-income settings and may lack cross-cultural validity. Methods: We piloted and adapted two subtests within the planning domain of the Kaufman Assessment Battery for Children-2nd edition (KABC-II) for use in rural Zimbabwean children aged 7years. After initial assessments of face validity, we created 4 substitutions for the story completion subtest and 7 additions for the pattern reasoning subtest through a co-design process with fieldworkers and child development experts. To assess how successful the changes were, T-tests adjusting for unequal variances were used to compare scores between the original and adapted versions of the same subtest. ANOVA and pairwise analysis was performed to compare the performance of KABC-II subtests across domains. Intraclass correlation coefficient was calculated to explore the variability between domains. Results: Initial test scores on the planning domain were significantly lower than the other three domains of learning, sequential memory and simultaneous reasoning (P<0.001) in 50 children (mean age 7.6(SD 0.2) years). Modified subtests were administered to another 20 children (mean age 7.6(SD 0.2) years), who showed story completion scores that were 0.7 marks higher (95% CI 0.0, 1.4; P=0.05) and pattern reasoning scores 1.8 marks higher (95% CI 0.5, 3.2; P=0.01). Overall, the planning domain mean score increased from 8.1 (SD 2.9) to 10.6 (SD 3.4). The intra class correlation coefficient between all four KABC-II domains was initially 0.43 (95% CI 0.13, 0.64) and after modification was 0.69 (95% CI 0.37, 0.87), suggesting an increase in the construct validity. Conclusions: The KABC-II planning domain was successfully adapted to improve cross-cultural validity. Construct validity was enhanced, based on increased inter-correlations among scales. The process of co-design to modify tests for new settings may be beneficial for other commonly used neurodevelopmental tools.

3.
J Invest Dermatol ; 139(5): 1073-1081, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30472058

RESUMO

MicroRNA-29 (miR-29) negatively regulates fibrosis and is downregulated in multiple fibrotic organs and tissues, including in the skin. miR-29 mimics prevent pulmonary fibrosis in mouse models but have not previously been tested in the skin. This study aimed to identify pharmacodynamic biomarkers of miR-29 in mouse skin, to translate those biomarkers across multiple species, and to assess the pharmacodynamic activity of a miR-29b mimic (remlarsen) in a clinical trial. miR-29 biomarkers were selected based on gene function and mRNA expression using quantitative reverse transcriptase polymerase chain reaction. Those biomarkers comprised multiple collagens and other miR-29 direct and indirect targets and were conserved across species; remlarsen regulated their expression in mouse, rat, and rabbit skin wounds and in human skin fibroblasts in culture, while a miR-29 inhibitor reciprocally regulated their expression. Biomarker expression translated to clinical proof-of-mechanism; in a double-blinded, placebo-randomized, within-subject controlled clinical trial of single and multiple ascending doses of remlarsen in normal healthy volunteers, remlarsen repressed collagen expression and the development of fibroplasia in incisional skin wounds. These results suggest that remlarsen may be an effective therapeutic to prevent formation of a fibrotic scar (hypertrophic scar or keloid) or to prevent cutaneous fibrosis, such as scleroderma.


Assuntos
Matriz Extracelular/metabolismo , MicroRNAs/genética , Dermatopatias/patologia , Animais , Biópsia por Agulha , Modelos Animais de Doenças , Matriz Extracelular/efeitos dos fármacos , Fibrose/genética , Fibrose/patologia , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Camundongos , MicroRNAs/farmacologia , Estudos Prospectivos , Dermatopatias/tratamento farmacológico , Dermatopatias/genética , Resultado do Tratamento
4.
Wound Repair Regen ; 26(4): 311-323, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30118158

RESUMO

There is a strong unmet need for new therapeutics to accelerate wound healing across both chronic and acute indications. It is well established that local tissue hypoxia, vascular insufficiency, and/or insufficient angiogenesis contribute to inadequate wound repair in the context of diabetic foot ulcers as well as to other chronic wounds such as venous stasis and pressure ulcers. microRNA-92a-3p (miR-92a) is a potent antiangiogenic miRNA whose inhibition has led to increases in angiogenesis in multiple organ systems, resulting in an improvement in function following myocardial infarction, limb ischemia, vascular injury, and bone fracture. Due to their pro-angiogenic effects, miR-92a inhibitors offer potential therapeutics to accelerate the healing process in cutaneous wounds as well. This study investigated the effect of a development stage locked nucleic acid-modified miR-92a inhibitor, MRG-110, in excisional wounds in db/db mice and in normal pigs. In both acute and chronic wounds, MRG-110 increased granulation tissue formation as assessed by histology, angiogenesis as assessed by immunohistochemistry and tissue perfusion, and wound healing as measured by time to closure and percent closure over time. The effects of MRG-110 were greater than those that were observed with the positive controls rhVEGF-165 and rhPDGF-BB, and MRG-110 was at least additive with rhPDGF-BB when co-administered in db/db mouse wounds. MRG-110 was found to up-regulate expression of the pro-angiogenic miR-92a target gene integrin alpha 5 in vitro in both human vascular endothelial cells and primary human skin fibroblasts and in vivo in mouse skin, demonstrating its on-target effects in vitro and in vivo. Additional safety endpoints were assessed in both the mouse and pig studies with no safety concerns noted. These studies suggest that MRG-110 has the potential to accelerate both chronic and acute wound healing and these data provide support for future clinical trials of MRG-110.


Assuntos
Indutores da Angiogênese/farmacologia , Pé Diabético/complicações , MicroRNAs/antagonistas & inibidores , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/complicações , Ferimentos e Lesões/tratamento farmacológico , Animais , Células Endoteliais/metabolismo , Feminino , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Tecido de Granulação/patologia , Humanos , Masculino , Camundongos , Modelos Animais , Neovascularização Patológica/patologia , Oligonucleotídeos Antissenso/metabolismo , Transdução de Sinais , Suínos
5.
Compr Rev Food Sci Food Saf ; 16(5): 868-880, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33371618

RESUMO

Sodium benzoate and potassium sorbate are extremely useful agents for food and beverage preservation, yet concerns remain over their complete safety. Benzoate can react with the ascorbic acid in drinks to produce the carcinogen benzene. A few children develop allergy to this additive while, as a competitive inhibitor of D-amino acid oxidase, benzoate can also influence neurotransmission and cognitive functioning. Model organism and cell culture studies have raised some issues. Benzoate has been found to exert teratogenic and neurotoxic effects on zebrafish embryos. In addition, benzoate and sorbate are reported to cause chromosome aberrations in cultured human lymphocytes; also to be potently mutagenic toward the mitochondrial DNA in aerobic yeast cells. Whether the substantial human consumption of these compounds could significantly increase levels of such damages in man is still unclear. There is no firm evidence that it is a risk factor in type 2 diabetes. The clinical administration of sodium benzoate is of proven benefit for many patients with urea cycle disorders, while recent studies indicate it may also be advantageous in the treatment of multiple sclerosis, schizophrenia, early-stage Alzheimer's disease and Parkinson's disease. Nevertheless, exposure to high amounts of this agent should be approached with caution, especially since it has the potential to generate a shortage of glycine which, in turn, can negatively influence brain neurochemistry. We discuss here how a small fraction of the population might be rendered-either through their genes or a chronic medical condition-particularly susceptible to any adverse effects of sodium benzoate.

6.
Antiviral Res ; 131: 92-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27126613

RESUMO

The yellow fever virus (YFV) vaccine 17D-204 is considered safe and effective, yet rare severe adverse events (SAEs), some resulting in death, have been documented following vaccination. Individuals exhibiting post-vaccinal SAEs are ideal candidates for antiviral monoclonal antibody (MAb) therapy; the time until appearance of clinical signs post-exposure is usually short and patients are quickly hospitalized. We previously developed a murine-human chimeric monoclonal antibody (cMAb), 2C9-cIgG, reactive with both virulent YFV and 17D-204, and demonstrated its ability to prevent and treat YF disease in both AG129 mouse and hamster models of infection. To counteract possible selection of 17D-204 variants that escape neutralization by treatment with a single MAb (2C9-cIgG), we developed a second cMAb, 864-cIgG, for use in combination with 2C9-cIgG in post-vaccinal therapy. MAb 864-cIgG recognizes/neutralizes only YFV 17D-204 vaccine substrain and binds to domain III (DIII) of the viral envelope protein, which is different from the YFV type-specific binding site of 2C9-cIgG in DII. Although it neutralized 17D-204 in vitro, administration of 864-cIgG had no protective capacity in the interferon receptor-deficient AG129 mouse model of 17D-204 infection. The data presented here show that although DIII-specific 864-cIgG neutralizes virus infectivity in vitro, it does not have the ability to abrogate disease in vivo. Therefore, combination of 864-cIgG with 2C9-cIgG for treatment of YF vaccination SAEs does not appear to provide an improvement on 2C9-cIgG therapy alone.


Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacina contra Febre Amarela/imunologia , Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Vírus da Febre Amarela/imunologia , Animais , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Modelos Animais de Doenças , Humanos , Imunização Passiva , Camundongos , Testes de Neutralização , Receptores de Interferon/deficiência , Receptores de Interferon/genética , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo , Febre Amarela/terapia , Vacina contra Febre Amarela/efeitos adversos
7.
Vaccine ; 30(21): 3180-7, 2012 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-22425792

RESUMO

Yellow fever virus (YFV), a member of the genus Flavivirus, is a mosquito-borne pathogen that requires wild-type (wt), virulent strains to be handled at biosafety level (BSL) 3, with HEPA-filtration of room air exhaust (BSL3+). YFV is found in tropical regions of Africa and South America and causes severe hepatic disease and death in humans. Despite the availability of effective vaccines (17D-204 or 17DD), YFV is still responsible for an estimated 200,000 cases of illness and 30,000 deaths annually. Besides vaccination, there are no other prophylactic or therapeutic strategies approved for use in human YF. Current small animal models of YF require either intra-cranial inoculation of YF vaccine to establish infection, or use of wt strains (e.g., Asibi) in order to achieve pathology. We have developed and characterized a BSL2, adult mouse peripheral challenge model for YFV infection in mice lacking receptors for interferons α, ß, and γ (strain AG129). Intraperitoneal challenge of AG129 mice with 17D-204 is a uniformly lethal in a dose-dependent manner, and 17D-204-infected AG129 mice exhibit high viral titers in both brain and liver suggesting this infection is both neurotropic and viscerotropic. Furthermore the use of a mouse model permitted the construction of a 59-biomarker multi-analyte profile (MAP) using samples of brain, liver, and serum taken at multiple time points over the course of infection. This MAP serves as a baseline for evaluating novel therapeutics and their effect on disease progression. Changes (4-fold or greater) in serum and tissue levels of pro- and anti-inflammatory mediators as well as other factors associated with tissue damage were noted in AG129 mice infected with 17D-204 as compared to mock-infected control animals.


Assuntos
Modelos Animais de Doenças , Receptores de Interferon/deficiência , Febre Amarela/patologia , Febre Amarela/virologia , Vírus da Febre Amarela/patogenicidade , Animais , Biomarcadores/análise , Encéfalo/virologia , Contenção de Riscos Biológicos , Injeções Intraperitoneais , Fígado/virologia , Camundongos , Camundongos Knockout , Análise de Sobrevida , Carga Viral , Febre Amarela/mortalidade
8.
Antiviral Res ; 94(1): 1-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22366350

RESUMO

Yellow fever virus (YFV), a member of the genus Flavivirus, is a mosquito-borne virus found in tropical regions of Africa and South America that causes severe hepatic disease and death in humans. Despite the availability of effective vaccines, YFV is responsible for an estimated 200,000 cases and 30,000 deaths annually. There are currently no prophylactic or therapeutic strategies approved for use in human YFV infections. Furthermore, implementation of YFV 17D-204 vaccination campaigns has become problematic due to an increase in reported post-vaccinal adverse events. We have created human/murine chimeric MAbs of a YFV-reactive murine monoclonal antibody (mMAb), 2C9, that was previously shown to protect mice from lethal YFV infection and to have therapeutic activity. The new chimeric (cMAbs) were constructed by fusion of the m2C9 IgG gene variable regions with the constant regions of human IgG and IgM and expressed in Sp2 murine myelomas. The 2C9 cMAbs (2C9-cIgG and 2C9-cIgM) reacted with 17D-204 vaccine strain in an enzyme-linked immunosorbent assay and neutralized virus in vitro similarly to the parent m2C9. Both m2C9 and 2C9-cIgG when administered prophylactically 24h prior to infection protected AG129 mice from peripheral 17D-204 challenge at antibody concentrations ≥1.27 µg/mouse; however, the 2C9-cIgM did not protect even at a dose of 127 µg/mouse. The 17D-204 infection of AG129 mice is otherwise uniformly lethal. While the m2C9 was shown previously to be therapeutically effective in YFV-infected BALB/c mice at day 4 post-infection, the m2C9 and 2C9-cIgG demonstrated therapeutic activity only when administered 1 day post-infection in 17D-204-infected AG129 mice.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Imunoglobulina G/uso terapêutico , Imunoglobulina M/uso terapêutico , Febre Amarela/tratamento farmacológico , Febre Amarela/prevenção & controle , Vírus da Febre Amarela/efeitos dos fármacos , Animais , Anticorpos Monoclonais Humanizados/genética , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Antivirais , Modelos Animais de Doenças , Humanos , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Imunoglobulina M/genética , Imunoglobulina M/imunologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Knockout , Febre Amarela/imunologia , Febre Amarela/virologia , Vírus da Febre Amarela/fisiologia
9.
BMC Microbiol ; 10: 130, 2010 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-20426860

RESUMO

BACKGROUND: The RNA interference (RNAi) pathway acts as an innate antiviral immune response in Aedes aegypti, modulating arbovirus infection of mosquitoes. Sindbis virus (SINV; family: Togaviridae, genus: Alphavirus) is an arbovirus that infects Ae. aegypti in the laboratory. SINV strain TR339 encounters a midgut escape barrier (MEB) during infection of Ae. aegypti. The nature of this barrier is not well understood. To investigate the role of the midgut as the central organ determining vector competence for arboviruses, we generated transgenic mosquitoes in which the RNAi pathway was impaired in midgut tissue of bloodfed females. We used these mosquitoes to reveal effects of RNAi impairment in the midgut on SINV replication, midgut infection and dissemination efficiencies, and mosquito longevity. RESULTS: As a novel tool for studying arbovirus-mosquito interactions, we engineered a transgenic mosquito line with an impaired RNAi pathway in the midgut of bloodfed females by silencing expression of the Aa-dcr2 gene. In midgut tissue of the transgenic Carb/dcr16 line, Aa-dcr2 expression was reduced approximately 50% between 1-7 days post-bloodmeal (pbm) when compared to the recipient mosquito strain. After infection with SINV-TR339EGFP, Aa-dcr2 expression levels were enhanced in both mosquito strains. In the RNAi pathway impaired mosquito strain SINV titers and midgut infection rates were significantly higher at 7 days pbm. There was also a strong tendency for increased virus dissemination rates among the transgenic mosquitoes. Between 7-14 days pbm, SINV was diminished in midgut tissue of the transgenic mosquitoes. Transgenic impairment of the RNAi pathway and/or SINV infection did not affect longevity of the mosquitoes. CONCLUSIONS: We showed that RNAi impaired transgenic mosquitoes are a useful tool for studying arbovirus-mosquito interactions at the molecular level. Following ingestion by Ae. aegypti, the recombinant SINV-TR339EGFP was confronted with both MEB and a midgut infection barrier (MIB). Impairment of the RNAi pathway in the midgut strongly reduced both midgut barriers for the virus. This confirms that the endogenous RNAi pathway of Ae. aegypti modulates vector competence for SINV in the midgut. The RNAi pathway acts as a gatekeeper to the incoming virus by affecting infection rate of the midgut, intensity of infection, and dissemination from the midgut to secondary tissues.


Assuntos
Aedes/imunologia , Aedes/virologia , Interações Hospedeiro-Patógeno , Interferência de RNA , Sindbis virus/imunologia , Sindbis virus/patogenicidade , Animais , Animais Geneticamente Modificados , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/virologia , Genes
10.
J Med Entomol ; 46(4): 909-18, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19645297

RESUMO

Aedes densonucleosis virus (family Parcoviridae, genus Brevidensovirus, AeDNV) is a mosquito pathogen that increases Aedes aegypti larval mortality and reduces adult life span. We conducted three laboratory population cage trials, each lasting 16-25 wk. We tested two broad hypotheses. First, Ae. aegypti raised in containers seeded with 10(8) AeDNV genome equivalents/ml (geq/ ml), a concentration feasible for field application, increase AeDNV to concentrations that cause significant adult and larval mortality. Second, infected female mosquitoes disperse AeDNV to uninfected larval habitats. In hypothesis 1, we addressed the rate at which infected larvae secrete virus, how AeDNV titers change in seeded containers over time, whether AeDNV decays over time, and whether AeDNV exposed populations are reduced. In hypothesis 2, we monitored AeDNV concentrations in novel containers after oviposition by infected females. Both hypotheses were supported. Larvae increased AeDNV, secreting virus at a rate of 2.14 x 10(6) geq/larva/d when exposed to 10(8) geq/ml. AeDNV titers reached an asymptote of 10(10) geq/ml by week 10 in seeded containers. AeDNV decayed by 1 log every 4 d as indicated by a reduction in larval mortality. Adult population size was reduced in treated populations. Infected females dispersed AeDNV to novel containers, with titers reaching 10(8) geq/ml. The parameters were used in a Leslie-Lewis matrix model. This model predicted that AeDNV negatively affects Ae. aegypti densities and population structure and thus vectorial capacity.


Assuntos
Aedes/virologia , Densovirinae/fisiologia , Replicação Viral , Aedes/crescimento & desenvolvimento , Animais , Feminino , Larva/virologia , Modelos Biológicos , Controle de Mosquitos/métodos , Densidade Demográfica , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...