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1.
Environ Res ; 194: 110637, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33373609

RESUMO

By mid-September 2020, over 1.33 million confirmed COVID-19 cases and 32 thousand deaths had been reported in Africa. Global research on COVID-19 went 'viral' with a record 3487 research contributions comprising of 2062 journal papers and 1425 preprints published within the first three months following the outbreak of COVID-19. Surprisingly, the silence of the African research community has been unprecedented - contributing a paltry 0.6% (22 contributions), a figure nearly matched by Colombia (18 publications). Until now, a comprehensive perspective on the reasons for this subdued research response, and COVID-19 themes critical to Africa has been missing. We posit that while a milieu of factors accounts for this silence, unprecedented research opportunities exist to support COVID-19 decision and policy formulation in Africa. The subdued response reflects weak research systems, characterized by deep-rooted challenges, including severe lack of research expertise, funding, and infrastructure, coupled with poor working conditions. Hence, Africa's contribution to research on infectious diseases, including COVID-19, remains weak. Perceptions and attitudes among researchers and policy-makers on COVID-19, and the role of science in decision and policy-making also exist. Moreover, COVID-19 and earlier severe acute respiratory syndromes are considered as 'imported diseases' originating from outside Africa. Thus, notions may exist that the control methods will come from outside Africa through 'technology-transfer' or 'capacity-building'. Yet local COVID-19 research is needed to address knowledge gaps, including; (1) potential novel transmission of SARS-CoV-2, (2) adaption of generic COVID-19 control measures to suit African settings, (3) occurrence and persistence of SARS-CoV-2 in solid waste, wastewaters, on-site sanitation systems, and drinking water, and (4) the 'human factor' including the role of gender, perceptions, myths, attitudes, and religious beliefs in the transmission and control of COVID-19. Therefore, there is a need to: (1) strengthen local research capacity and evaluation systems, (2) consider biosafety and ethical issues, (3) initiate cross-disciplinary research and global collaboration on COVID-19, and (4) integrate science communication in COVID-19 programs.


Assuntos
COVID-19 , África , Colômbia , Surtos de Doenças , Humanos , SARS-CoV-2
2.
Sci Total Environ ; 724: 138186, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32268285

RESUMO

Colombia is the fourth contributor to the Amazon River Basin (ARB) by surface, and the third by mean annual runoff. The Yahuarcaca Lakes System (YLS), consisting of four large interconnected water bodies situated on the floodplain of Amazon River, was identified as one of the key areas for the conservation of freshwater biodiversity in the Colombian ARB. This review aimed to provide a general overview of YLS, present its environmental and biological features, identify main ecological and health threats, and propose mitigation strategies and future research prospects. A systematic search was performed using various databases. In summary, YLS harbors significant biodiversity and provides a number of ecological services for local communities, encompassing fish and drinking water supply and utilization of the floodplain for agriculture. Ensuring its sustainability requires attention from local and international authorities, collaboration with indigenous communities and future interdisciplinary research.

3.
Toxins (Basel) ; 12(2)2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32050689

RESUMO

Selected species of cyanobacteria and green algae have been reported to produce lipophilic polymethoxy-1-alkenes (PMAs) which were shown to exhibit in vivo teratogenicity. Considering that information on PMAs in Arthospira sp. (known commercially as Spirulina) and Chlorella sp. cultivated for food supplement production was essentially lacking, the present study screened Chlorella (n = 10) and Spirulina (n = 13) food supplements registered in the European Union. Mass spectrometry analysis of column fractionated extracts was performed. None of the four variants previously reported in some cyanobacteria and green algae, nor any potentially related structures were detected in the studied samples. Since the isolated lipophilic fractions contained various compounds, they were further screened for in vivo teratogenicity in Danio rerio embryo, and for the potential to induce oxidative stress and genotoxicity in the liver and neurotoxicity in the brain of adult zebrafish. None of the tested food supplements had detectable levels of PMAs or any potentially related structures. No teratogenicity was revealed except for spinal curvature induced by fractions obtained from two Chlorella products. Selected fractions revealed cytotoxicity as indicated by an increased level of reactive oxygen species, catalase activity, lipid peroxidation and increased frequency of DNA strand breaks in hepatic tissue. The majority (60%) of Chlorella fractions induced an increase in cholinesterase activity in zebrafish brain homogenate while exposure to 61.5% of Spirulina fractions was associated with its decrease. The present study confirms that Chlorella and Spirulina food supplements are free of teratogenic PMAs, although the observed in vivo toxicities raise questions regarding the quality of selected products.


Assuntos
Alcenos/análise , Chlorella/química , Suplementos Nutricionais/análise , Spirulina/química , Testes de Toxicidade/métodos , Peixe-Zebra , Alcenos/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Quebras de DNA/efeitos dos fármacos , Suplementos Nutricionais/efeitos adversos , Suplementos Nutricionais/normas , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Estresse Oxidativo/efeitos dos fármacos
4.
Toxins (Basel) ; 12(1)2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861931

RESUMO

Cyanobacterial metabolites are increasingly studied, in regards to their biosynthesis, ecological role, toxicity, and potential biomedical applications. However, the history of cyanotoxins prior to the last few decades is virtually unknown. Only a few paleolimnological studies have been undertaken to date, and these have focused exclusively on microcystins and cylindrospermopsins, both successfully identified in lake sediments up to 200 and 4700 years old, respectively. In this paper, we review direct extraction, quantification, and application of cyanotoxins in sediment cores, and put forward future research prospects in this field. Cyanobacterial toxin research is also compared to other paleo-cyanobacteria tools, such as sedimentary pigments, akinetes, and ancient DNA isolation, to identify the role of each tool in reproducing the history of cyanobacteria. Such investigations may also be beneficial for further elucidation of the biological role of cyanotoxins, particularly if coupled with analyses of other abiotic and biotic sedimentary features. In addition, we identify current limitations as well as future directions for applications in the field of paleolimnological studies on cyanotoxins.


Assuntos
Toxinas Bacterianas/toxicidade , Cianobactérias/metabolismo , Limnologia/métodos , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Paleontologia/métodos , Toxinas de Cianobactérias , Sedimentos Geológicos , Lagos/microbiologia
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