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1.
Agric Syst ; 198: 103367, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35125616

RESUMO

CONTEXT: The COVID-19 pandemic caused unprecedented global disruption and continues to wreak havoc. Dire predictions were made about the risks to smallholder farmers in lower- and middle- income, but hard data have been lacking. We present the results from 9201 interviews with smallholder farmers from seven countries. OBJECTIVE: The objectives are to describe: i) how farmers perceive the key effects of the COVID-19 pandemic and containment measures on livelihoods and food security; ii) the effects on agricultural activities; iii) the coping strategies households deployed. METHODS: Household surveys were conducted as part of ongoing monitoring programs during the latter half of 2020. Sites in seven countries were covered: Burundi; Kenya; Rwanda; Tanzania; Uganda; Zambia; and Vietnam. Findings are representative of smallholder farmers across multiple districts per country. RESULTS AND CONCLUSIONS: The effects of the COVID-19 containment measures were widespread and often perceived to be severe. Food purchase, off-farm income, sale of farm produce, and access to crop inputs were all affected. In locations under more stringent restrictions during the time of the survey, up to 80% of households had to reduce food consumption and/or variety. Almost all households with off-farm incomes reported reductions, by half on average. A half to three-quarters of households (depending on the location) with income from farm sales reported losses compared to the pre-pandemic situation. In locations with more relaxed containment measures in place during the time of the survey, less frequent and less severe economic and food security outcomes were perceived by the respondent, with around 20% of households reporting negative outcomes. Mobility restrictions, reduced market access, crashes in sale price for agricultural goods, and soaring prices for food purchase were key factors. Sale prices generally dropped for all agricultural products in any given location, and affected not only high-value perishable products, but also staple crops such as maize and cassava. Depending on the location, between 30% and 90% of the households applied coping strategies in response to the pandemic during 2020. There was an almost complete absence of official aid amongst households interviewed. SIGNIFICANCE: Our results raise the thorny issue of how best to balance containment of disease against the wellbeing of the vulnerable rural population in lower- and middle-income countries. There is a risk that the buffering capacity of rural people will become exhausted. Possible policy measures to limit negative outcomes include i) tiered mobility restrictions with travel allowed for economic reasons; ii) short-term price guarantee schemes to stabilise the food system; iii) direct aid; iv) the timely re-installation of distribution channels for agricultural inputs.

2.
Am J Pathol ; 185(1): 252-65, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25447045

RESUMO

Microphthalmia-associated transcription factor (MITF) acts via pigment epithelium-derived factor (PEDF), an antiangiogenic protein, to regulate retinal pigment epithelium migration. PEDF expression and/or regulation during melanoma development have not been investigated previously. Using immunohistochemistry, we determined expression of PEDF in common and dysplastic melanocytic nevi, melanoma in situ, invasive melanoma, and metastatic melanoma (n = 102). PEDF expression was consistently decreased in invasive and metastatic melanoma, compared with nevi and melanoma in situ (P < 0.0001). PEDF was lost in thicker melanomas (P = 0.003), and correlated with depth of invasion (P = 0.003) and distant metastasis (P = 0.0331), but only marginally with mitotic index, AJCC stage, nodal metastasis, or blood vascular density (0.05 < P < 0.10). Quantitative real-time PCR and microarray analyses confirmed PEDF down-regulation at the mRNA level in several melanoma lines, compared with melanocytes. MITF positively correlated with PEDF expression in invasive melanomas (P = 0.0003). Searching for PEDF regulatory mechanisms revealed two occupied conserved E-boxes (DNA recognition elements) in the first intron of the human and mouse PEDF promoter regions, confirmed by binding assays. Dominant-negative and siRNA approaches in vivo demonstrated direct transcriptional influence of MITF on PEDF, establishing the PEDF gene (SERPINF1) as a MITF target in melanocytes and melanoma cells. These findings suggest that loss of PEDF expression promotes early invasive melanoma growth.


Assuntos
Proteínas do Olho/metabolismo , Regulação Neoplásica da Expressão Gênica , Melanoma/metabolismo , Fator de Transcrição Associado à Microftalmia/metabolismo , Fatores de Crescimento Neural/metabolismo , Serpinas/metabolismo , Neoplasias Cutâneas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Linhagem Celular Tumoral , Feminino , Inativação Gênica , Humanos , Imuno-Histoquímica , Masculino , Melanócitos , Camundongos , Microscopia de Fluorescência , Pessoa de Meia-Idade , Dados de Sequência Molecular , Invasividade Neoplásica , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , RNA Interferente Pequeno/metabolismo , Homologia de Sequência do Ácido Nucleico , Adulto Jovem
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