Repeatability of the evaluation of systemic microvascular endothelial function using laser doppler perfusion monitoring: clinical and statistical implications

OBJECTIVE: An awareness of the repeatability of biological measures is required to properly design and calculate sample sizes for longitudinal interventional studies. We investigated the day-to-day repeatability of measures of systemic microvascular reactivity using laser Doppler perfusion monitoring. METHODS: We performed laser Doppler perfusion monitoring in combination with skin iontophoresis using acetylcholine and sodium nitroprusside as well as post-occlusive reactive and thermal hyperemia twice within two weeks. The repeatability was assessed by calculating the within-subject standard deviations, limits of agreement, typical errors and intra-class correlation coefficients between days 1 and 2. The ratio of the within-subject standard deviation to the mean values obtained on days 1 and 2 (within-subject standard deviation/GM) was used to determine the condition with the best repeatability. RESULTS: Twenty-four healthy subjects, aged 24.6 + 3.8 years, were recruited. The area under the curve of the vasodilatory response to post-occlusive reactivity showed marked variability (within-subject standard deviation/GM = 0.83), while the area under the curve for acetylcholine exhibited less variability (within-subject standard deviation/ GM = 0.52) and was comparable to the responses to sodium nitroprusside and thermal treatment (within-subject standard deviations/GM of 0.67 and 0.56, respectively). The area under the blood flow/time curve for vasodilation during acetylcholine administration required the smallest sample sizes, the area under the blood flow/time curve during post-occlusive reactivity required the largest sample sizes, and the area under the blood flow/time curves of vasodilation induced by sodium nitroprusside and thermal treatment required intermediate sizes. CONCLUSIONS: In view of the importance of random error related to the day-to-day repeatability of laser Doppler perfusion monitoring, we propose an original and robust statistical methodology for use in designing prospective clinical studies

Effects of non-supervised low intensity aerobic excise training on the microvascular endothelial function of patients with type 1 diabetes: a non-pharmacological interventional study

Submitted by Sandra Infurna ([email protected]) on 2017-02-28T15:03:25Z No. of bitstreams: 1 diogo_bavel_etal_IOC_2016.pdf: 851035 bytes, checksum: 52be2ee772168f4e825e13c3670c7c02 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-02-28T15:16:31Z (GMT) No. of bitstreams: 1 diogo_bavel_etal_IOC_2016.pdf: 851035 bytes, checksum: 52be2ee772168f4e825e13c3670c7c02 (MD5)Made available in DSpace on 2017-02-28T15:16:31Z (GMT). No. of bitstreams: 1 diogo_bavel_etal_IOC_2016.pdf: 851035 bytes, checksum: 52be2ee772168f4e825e13c3670c7c02 (MD5) Previous issue date: 2016Instituto Nacional de Cardiologia. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Investigação Cardiovascular. Rio de Janeiro, RJ, Brasil / Universidade Estácio de Sá. Escola de Educação Física e Ciências do Esporte. Rio de Janeiro, RJ, Brasil.Instituto Nacional de Cardiologia. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Investigação Cardiovascular. Rio de Janeiro, RJ, Brasil .Universidade do Estado do Rio de Janeiro. Departamento de Medicina. Unidade de Diabetes. Rio de Janeiro, RJ, Brasil.Instituto Nacional de Cardiologia. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Investigação Cardiovascular. Rio de Janeiro, RJ, Brasil

SEASONAL AND SPATIAL PATTERNS OF TOXIGENIC SPECIES OF Dinophysis AND Pseudo-nitzschia IN A SUBTROPICAL BRAZILIAN ESTUARY

Este estudo investigou a distribuição espacial e temporal de espécies toxigênicas de fitoplâncton entre outubro de 2010 e abril de 2012 na Baía de Guaratuba, Estado do Paraná, Brasil, onde as atividades de maricultura têm se intensificado nos últimos anos. As maiores abundâncias de Pseudo-nitzschia calliantha e P. pungens (até 7,3 x 104 células L-1), diatomáceas causadoras do envenenamento amnésico por consumo de molusco (ASP), foram correlacionadas com valores mais elevados de temperatura (de dezembro a abril), salinidade (>;20) e concentrações de silicato (variando de 6,0 a 90,0 µM). A ocorrência destas diatomáceas na baía aparentemente depende do desenvolvimento de mecanismo de inoculação na água costeira adjacente e de seu subsequente transporte pelas correntes de maré para o interior do estuário. Durante o período de estudo, no entanto, a abundância celular de Pseudo-nitzschia permaneceu baixa, provavelmente devido à limitação do crescimento por falta de fosfato, especialmente na área externa. Além disso, espécies nocivas de Dinophysis, um dinoflagelado responsável pela produção de toxinas diarreicas (DSP), foram registradas em todas as campanhas mensais de amostragem. As maiores abundâncias de D. acuminata, D. caudata e D. tripos foram associadas com a camada logo acima da haloclina, nas regiões da baía onde a estratificação da coluna de água foi mais frequente. Em algumas ocasiões, a abundância de células de D. acuminata (até 3,2 x 103 células L-1) em áreas utilizadas para cultivo de moluscos bivalves para consumo humano, superou níveis considerados perigosos. Estes resultados indicam a necessidade de implantação de um programa de monitoramento de microalgas nocivas na Baía de Guaratuba.This study investigated the spatial and temporal distributions of toxigenic phytoplankton species between October 2010 and April 2012 in Guaratuba Bay, Paraná state, Brazil, where aquaculture has been intensified in recent years. The highest abundances of Pseudo-nitzschia calliantha and P. pungens (up to 7.3 x 104 cells L-1), diatoms which cause amnesic shellfish poisoning (ASP), were correlated with higher values of temperature (from December to April, salinity (>;20) and silicate concentrations (ranging from 6.0 to 90.0 µm). The occurrence of these harmful diatoms in the bay also appeared to depend upon the development of seeding mechanisms in the adjacent coastal water and its subsequent advection by tidal currents to the interior of the estuary. During the study period, Pseudo-nitzschia cell abundance remained low to moderate probably as a result of growth limitation by phosphate shortage, especially in the outer area of the estuary. In addition, harmful species of Dinophysis, dinoflagellates responsible for diarrhetic shellfish poisoning (DSP) events, were recorded in every sampling campaign. The highest abundances of D. acuminata, D. caudata and D. tripos were associated with the upper halocline layer in regions of the bay where water column stratification was more frequent. On some occasions, cell abundances of D. acuminata (up to 3.2 x 103 cells L-1) exceeded levels considered harmful in areas used to cultivate bivalve mollusks for human consumption. These novel results strongly indicate the necessity of implementing a monitoring program for harmful microalgae in Guaratuba Bay

Diversity and Toxicity of the Genus Coolia Meunier in Brazil, and Detection of 44-methyl Gambierone in Coolia tropicalis

Coolia is a genus of marine benthic dinoflagellates which is widely distributed in tropical and temperate zones. Toxicity has been reported in selected Coolia species, although the identity of causative compounds is still controversial. In this study, we investigated the taxonomical and toxicological aspects of Coolia species from Brazil. Since light- and electron microscopy-based morphology was not enough to distinguish small-celled species, ITS and LSU D1-D3 phylogenetic analyses were used for species definition. Cultures of Coolia palmyrensis and Coolia santacroce were established from samples collected along the northeastern Brazilian coast, the first record of both species in South Atlantic waters. Cultures of Coolia malayensis and Coolia tropicalis were also established and exhibited acute in vivo toxicity to adults of Artemia salina, while C. palmyrensis and C. santacroce were non-toxic. The presence of 30 yessotoxin analogues, 7 metabolites of Coolia and 44 Gambierdiscus metabolites was screened in 14 strains of Coolia. 44-methyl gambierone (formerly referred to as MTX3) and a new isomer of this compound were detected only in C. tropicalis, using both low- and high-resolution LC-MS/MS. To our knowledge, this is the first report of gambierone analogues in dinoflagellates other than Gambierdiscus; the role of C. tropicalis in ciguatera poisoning thus deserves to be considered in further investigations

Dinoflagelados bênticos em áreas de costões rochosos e recifes : distribuição, toxinas e impactos potenciais

Orientador: Prof. Dr. Luiz L. Mafra Jr.Coorientador: Prof. Dr. Luciano F. FernandesTese (doutorado) - Universidade Federal do Paraná, Campus Pontal do Paraná - Centro de Estudos do Mar, Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos. Defesa : Pontal do Paraná, 28/05/2020Inclui referências: p. 126-140Resumo: Dinoflagelados são um grupo de microalgas que, nos sistemas bênticos marinhos, são reconhecidos pela produção de potentes biotoxinas capazes de afetar negativamente os ecossistemas e intoxicar seres humanos por meio do consumo de pescados contaminados. Essas algas estão amplamente distribuídas em todos os mares tropicais e temperados, mas apenas nos últimos dez anos passaram a ser investigadas com maior frequência no Brasil. O presente estudo teve como objetivo investigar características morfológicas, a diversidade filogenética e os aspectos toxinológicos dos gêneros de maior distribuição e abundância conhecida no litoral brasileiro, Coolia, Ostreopsis e Prorocentrum. As espécies Coolia palmyrensis e C. santacroce foram encontradas pela primeira vez no Atlântico Sul, enquanto C. malayensis e C. tropicalis foram bastante tóxicas para indivíduos adultos do microcrustáceo Artemia salina. Foi possível identificar a presença do composto 44-methyl gambirone (previamente conhecido como MTX3) em uma cepa de C. tropicalis. A espécie Ostreopsis cf. ovata foi encontrada ao longo de todo o litoral, e formando eventos de floração no litoral do Paraná. Níveis elevados de potentes neurotoxinas (ovatoxinas) foram encontrados em amostras de campo e em diversos cultivos monoclonais dessa microalga. Contudo, pudemos verificar que existem subclados genéticos de O. cf. ovata pouco tóxicos ou com níveis intracelulares não-detectáveis de toxinas. A distribuição geográfica no Brasil e no mundo, bem como a toxicidade dos clados e subclados genéticos de Ostreopsis spp. foi revista e discutida com base em dados inéditos e na revisão bibliográfica. Por fim, cultivos de oito espécies de Prorocentrum foram estabelecidos, com a citação pioneira das espécies P. leve, P. panamense e Prorocentrum sp. tipo 2 no Atlântico Sul. Esse trabalho mostrou que o litoral brasileiro, sobretudo a região nordeste, abriga uma grande diversidade de espécies de dinoflagelados bênticos. Estudos com tais microalgas no Brasil apresentam, portanto, elevado potencial para resolução de questões acerca desses dinoflagelados ainda não esclarecidas pela ciência. A presença frequente de espécies altamente tóxicas, incluindo algumas pouco estudadas e compreendidas, reforça a necessidade de se avançar na compreensão da ecologia e toxinologia desse grupo de microalgas no litoral brasileiro. Em última análise, os dinoflagelados bênticos apresentam elevado potencial de causar impactos negativos para os ecossistemas e populações humanas no litoral brasileiro. Palavras-chave: Florações de algas nocivas. Microalgas bênticas. Dinoflagelados tóxicos. Biotoxinas marinhas. Coolia. Ostreopsis. Prorocentrum. Toxinologia. Filogenia. Morfologia.Abstract: Marine benthic dinoflagellates are a group of microalgae producing potent biotoxins capable of negatively affecting ecosystems and intoxicating human consumers of contaminated seafood. These algae are widely distributed in all tropical and temperate seas, but they have been only investigated more frequently over the past ten years in Brazil. The present study aimed to investigate morphological characteristics, phylogenetic diversity and toxinological aspects of the most widely distributed and abundant genera, Coolia, Ostreopsis and Prorocentrum. The species Coolia palmyrensis and C. santacroce were found for the first time in the South Atlantic, and C. malayensis and C. tropicalis were highly toxic for adult individuals of the microcrustacean Artemia salina. The presence of the compound 44-methyl gambirone (previously known as MTX-3) was identified in a strain of C. tropicalis. The species Ostreopsis cf. ovata was recorded along the entire coast and forming bloom events on the coast of Paraná State. High levels of potent neurotoxins (ovatoxins) were found in field samples and in several monoclonal cultures of this microalgae. However, we detected the existence of non-toxic or slightly toxic genetic subclades among O. cf. ovata. The global geographic distribution and toxicity of genetic clades and subclades of Ostreopsis spp. was reviewed and discussed herein based on primary data and literature review. Finally, cultures of eight species of Prorocentrum were established, with P. leve, P. panamense and Prorocentrum sp. type 2 recorded for the first time in the South Atlantic. The morphology and phylogeny of strains belonging to the three genera were presented. This work showed that the Brazilian coast, especially the northeast region, have high diversity of benthic dinoflagellates. Studies on this subject in Brazil have, therefore, the potential to solve unclarified scientific questions regarding these dinoflagellates. The frequent presence of highly toxic species, including those less investigated, reinforces the need for advancing our knowledge about this group of microalgae in Brazilian waters. Ultimately, benthic dinoflagellates have a high potential to cause negative impacts to ecosystems and coastal populations in Brazil. Keywords: Harmful algal blooms. Benthic microalgae. Toxic dinoflagellates. Marine biotoxins. Coolia. Ostreopsis. Prorocentrum. Toxinology. Phylogeny. Morpholog

Effects of Metformin on Endothelial Dysfunction of the Renal Circulation Resulting from Acute Hyperglycemia in Non-Diabetic Rabbits

Submitted by Sandra Infurna ([email protected]) on 2019-06-18T12:15:02Z No. of bitstreams: 1 SolangeCaillaux_EduardoTibirca_etal_IOC_2005.pdf: 191616 bytes, checksum: 706673feaafdd7a5f5d467f8b647f2b5 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-06-18T12:22:24Z (GMT) No. of bitstreams: 1 SolangeCaillaux_EduardoTibirca_etal_IOC_2005.pdf: 191616 bytes, checksum: 706673feaafdd7a5f5d467f8b647f2b5 (MD5)Made available in DSpace on 2019-06-18T12:22:24Z (GMT). No. of bitstreams: 1 SolangeCaillaux_EduardoTibirca_etal_IOC_2005.pdf: 191616 bytes, checksum: 706673feaafdd7a5f5d467f8b647f2b5 (MD5) Previous issue date: 2005Universidade do Estado do Rio de Janeiro. Departamento de Medicina. Disciplina de Diabetes. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Fisiologia e Farmacodinâmica. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Fisiologia e Farmacodinâmica. Rio de Janeiro, RJ. Brasil.Objetivo: Avaliar o efeito da metformina (Met) na disfunção endotelial da circulação renal de coelhos não diabéticos induzida por concentrações de glicose usualmente observadas em pacientes com diabetes tipo 2 (DM2) em tratamento ambulatorial. Metodologia: Rins isolados de coelhos não diabéticos foram expostos por 3h a concentrações normais (100mg/dl) e elevadas (270mg/dl) de glicose na presença ou ausência de Met (100μM). Os níveis de glicose utilizados correspondem à mediana da glicemia pós-prandial (270mg/dl) obtida 2h após o café da manhã em 780 pacientes com DM2 atendidos em nosso serviço. A reatividade vascular (RV) dependente do endotélio (DE) foi avaliada com acetilcolina (ACh) e independente do endotélio (IE) com nitroprussiato de sódio (NPS). Resultado: Houve redução significativa na vasodilatação DE no grupo com infusão elevada de glicose em comparação ao controle (redução máxima na pressão de perfusão de respectivamente 25 ± 3 vs. 41 ± 3%; p< 0,01). No grupo de infusão com concentrações elevadas de glicose associada à infusão contínua de Met, a resposta vasodilatadora DE foi restaurada sem haver diferença significativa com o grupo controle (redução da pressão de perfusão respectivamente de 43 ± 1,5% e 41 ± 3%, p> 0,05). A Met não alterou a vasodilatação induzida pela ACh na presença de níveis normais de glicose. Finalmente, a vasodilatação renal induzida por NPS não foi modificada pela infusão conjunta de glicose e Met. Conclusão: Níveis de glicose observados em pacientes com DM2 em tratamento ambulatorial são capazes de provocar alterações agudas na RV no modelo experimental estudado, sendo estes efeitos totalmente abolidos pela Met. Os mecanismos envolvidos nesta ação protetora da Met merecem investigações específicas.Objective: To assess the effects of metformin (Met) on the endothelial dysfunction of the renal circulation of non-diabetic rabbits acutely induced by levels of glucose usually observed in diabetic patients in daily clinical practice. Methods: Isolated perfused kidneys from non-diabetic rabbits were exposed for 3h to normal (100mg/dl – control group) or high (270mg/dl) D-glucose with or without Met (100μM). The glucose levels used correspond to 2h post-breakfast median values (272mg/dl) obtained from a cohort of 780 type 2 diabetic (DM2) outpatients seen in our service. Vascular reactivity was evaluated with endothelium-dependent (ED) [acetylcholine - ACh] and independent (EI) [sodium nitroprusside - SNP] vasodilating agents. Results: Kidneys perfused with high glucose had ED maximal vasodilation blunted in comparison to controls (respectively 25 ± 3 and 41 ± 3%; p< 0.01). A 3h Met infusion restored the vasodilating effect of ACh in the renal circulation in the presence of high glucose, no different from controls (respectively 43 ± 1.5 vs. 41 ± 3% p> 0.05). Met did not affect maximum vasodilation induced by ACh in the presence of normal glucose levels. Finally, renal vasodilation induced by SNP was not modified by simultaneous infusion of glucose and Met. Conclusions: Acute hyperglycemia corresponding to the range observed in patients with DM2 induces endothelial dysfunction in the renal circulation of normal rabbits. Acute treatment with Met was able to protect the renal circulation against the effects of high glucose. The mechanisms involved in this protector effect deserve further investigation

Increased functional and structural skin capillary density in type 1 diabetes patients with vascular complications

Abstract The present study was designed to study skin capillary density and recruitment of the upper and lower extremities in patients with type 1 diabetes with vascular complications, when compared to patients without complications and healthy subjects. We used intravital video-microscopy to measure basal and maximal (during venous congestion) skin capillary densities as well as capillary recruitment using post-occlusive reactive hyperemia (PORH) in the dorsum of the fingers and toes. Our results showed that besides microvascular vasodilation and loss of autoregulatory capacity, patients with type 1 diabetes with vascular complications present increased skin capillary density in both extremities.</p