Safety and feasibility of transcranial direct current stimulation in end-stage renal disease patients undergoing hemodialysis: an exploratory study.

INTRODUCTION: Patients with end-stage renal disease often face a challenging routine of hemodialysis, dietary restrictions, and multiple medications, which can affect their hemodynamic function. Home-based, safe, and nonpharmacological approaches such as transcranial direct current stimulation (tDCS) should be combined with conventional treatment. OBJECTIVE: To assess the safety and feasibility of tDCS on blood pressure and heart rate in patients with end-stage renal disease undergoing hemodialysis. METHOD: This is a parallel, randomized, sham-controlled trial. Patients undergoing hemodialysis for more than three months were included. The patients received ten non-consecutive 2mA tDCS sessions on the primary motor cortex . Each session lasted 20 minutes. At baseline and after each of the ten sessions, blood pressure and heart rate of the patients were measured hourly for four hours. RESULTS: Thirty patients were randomized to the active or sham group. The mean difference between the groups was calculated as the mean value of the sham group minus the mean value of the active group. Despite there were no statistical changes for all outcomes considering all 10 sessions, we found differences between groups for systolic -10.93 (-29.1;7.2), diastolic -3.63 (-12.4; 5.1), and mean blood pressure -6.0 (-16.3; 4.2) and hear rate 2.26 (-2.5; 7.1). No serious adverse events were found. The active group showed higher blood pressure values at all points, while heart rate was lower in the active group. CONCLUSION: tDCS is safe and feasible for patients with end-stage renal disease undergoing hemodialysis. Future studies should investigate whether tDCS could potentially induce a hypotensive protective effect during hemodialysis.

Spathaspora brasiliensis sp. nov., Spathaspora suhii sp. nov., Spathaspora roraimanensis sp. nov. and Spathaspora xylofermentans sp. nov., four novel (D)-xylose-fermenting yeast species from Brazilian Amazonian forest.

Four new D-xylose fermenting yeast species of the clade Spathaspora were recovered from rotting-wood samples in a region of Amazonian forest, Northern Brazil. Three species produced unconjugated asci with a single elongated ascospore with curved ends. These species are described as Spathaspora brasiliensis, Spathaspora suhii and Spathaspora roraimanensis. Two isolates of an asexually reproducing species belonging to the Spathaspora clade were also obtained and they are described as Spathaspora xylofermentans. All these species are able to ferment D-xylose during aerobic batch growth in rich YP (1 % yeast extract, 2 % peptone and 2 % D-xylose) medium, albeit with differing efficiencies. The type strains are Spathaspora brasiliensis sp. nov UFMG-HMD19.3 (=CBMAI 1425=CBS 12679), Spathaspora suhii sp. nov. UFMG-XMD16.2 (=CBMAI 1426=CBS 12680), Spathaspora roraimanensis sp. nov. UFMG-XMD23.2 (CBMAI 1427=CBS 12681) and Spathaspora xylofermentans sp. nov. UFMG-HMD23.3 (=CBMAI 1428=CBS 12682).

Candida amazonensis sp. nov., an ascomycetous yeast isolated from rotting wood in the Amazonian forest.

Five strains of a novel yeast species were isolated from rotting wood samples collected in an Amazonian forest site in the state of Roraima, northern Brazil. The sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that this species belongs to the Scheffersomyces clade and is related to Candida coipomoensis, Candida lignicola and Candida queiroziae. The novel species Candida amazonensis sp. nov. is proposed to accommodate these isolates. The type strain of C. amazonensis sp. nov. is UFMG-HMD-26.3(T) ( = CBS 12363(T) = NRRL Y-48762(T)).

Spathaspora arborariae sp. nov., a d-xylose-fermenting yeast species isolated from rotting wood in Brazil.

Four strains of a new yeast species were isolated from rotting wood from two sites in an Atlantic Rain Forest and a Cerrado ecosystem in Brazil. The analysis of the sequences of the D1/D2 domains of the large-subunit rRNA gene showed that this species belongs to the Spathaspora clade. The new species ferments D-xylose efficiently and is related to Candida jeffriesii and Spathaspora passalidarum, both of which also ferment D-xylose. Similar to S. passalidarum, the new species produces unconjugated asci with a single greatly elongated ascospore with curved ends. The type strain of Spathaspora arborariae sp. nov. is UFMG-HM19.1A(T) (=CBS11463(T)=NRRL Y-48658(T)).

Safety and feasibility of transcranial direct current stimulation in end-stage renal disease patients undergoing hemodialysis: an exploratory study / Segurança e viabilidade da estimulação transcraniana por corrente contínua em pacientes com doença renal em estágio terminal submetidos à hemodiálise: um estudo exploratório

Abstract Introduction: Patients with end-stage renal disease often face a challenging routine of hemodialysis, dietary restrictions, and multiple medications, which can affect their hemodynamic function. Home-based, safe, and nonpharmacological approaches such as transcranial direct current stimulation (tDCS) should be combined with conventional treatment. Objective: To assess the safety and feasibility of tDCS on blood pressure and heart rate in patients with end-stage renal disease undergoing hemodialysis. Method: This is a parallel, randomized, sham-controlled trial. Patients undergoing hemodialysis for more than three months were included. The patients received ten non-consecutive 2mA tDCS sessions on the primary motor cortex . Each session lasted 20 minutes. At baseline and after each of the ten sessions, blood pressure and heart rate of the patients were measured hourly for four hours. Results: Thirty patients were randomized to the active or sham group. The mean difference between the groups was calculated as the mean value of the sham group minus the mean value of the active group. Despite there were no statistical changes for all outcomes considering all 10 sessions, we found differences between groups for systolic -10.93 (-29.1;7.2), diastolic -3.63 (-12.4; 5.1), and mean blood pressure -6.0 (-16.3; 4.2) and hear rate 2.26 (-2.5; 7.1). No serious adverse events were found. The active group showed higher blood pressure values at all points, while heart rate was lower in the active group. Conclusion: tDCS is safe and feasible for patients with end-stage renal disease undergoing hemodialysis. Future studies should investigate whether tDCS could potentially induce a hypotensive protective effect during hemodialysis.

Resumo Introdução: Pacientes com doença renal em estágio terminal (DRET) geralmente enfrentam uma rotina desafiadora de hemodiálise, restrições alimentares e diversos medicamentos, podendo afetar sua função hemodinâmica. Abordagens domiciliares, seguras e não farmacológicas, como a estimulação transcraniana por corrente contínua (ETCC), devem ser combinadas com tratamento convencional. Objetivo: Avaliar segurança e viabilidade da ETCC na pressão arterial e frequência cardíaca em pacientes com DRET em hemodiálise. Método: Estudo paralelo, randomizado, controlado por placebo. Foram incluídos pacientes em hemodiálise por mais de três meses. Os pacientes receberam dez sessões não consecutivas de ETCC de 2mA no córtex motor primário. Cada sessão durou 20 minutos. No início do estudo e após cada uma das dez sessões, a pressão arterial e frequência cardíaca dos pacientes foram medidas a cada hora durante quatro horas. Resultados: Trinta pacientes foram randomizados para grupo ativo ou sham. A diferença média entre grupos foi calculada como valor médio do grupo sham menos valor médio do grupo ativo. Apesar de não haver alterações estatísticas para todos os desfechos considerando as 10 sessões, encontramos diferenças entre os grupos para pressão arterial sistólica -10,93 (-29,1; 7,2), diastólica -3,63 (-12,4; 5,1) e média -6,0 (-16,3; 4,2) e frequência cardíaca 2,26 (-2,5; 7,1). Não encontramos eventos adversos graves. O grupo ativo apresentou valores maiores de pressão arterial em todos os pontos, enquanto a frequência cardíaca foi menor no grupo ativo. Conclusão: ETCC é segura e viável para pacientes com DRET submetidos à hemodiálise. Estudos futuros devem investigar se a ETCC pode potencialmente induzir um efeito hipotensor protetor durante a hemodiálise.

Diversity and physiological characterization of D-xylose-fermenting yeasts isolated from the Brazilian Amazonian Forest.

BACKGROUND: This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates. METHODOLOGY/PRINCIPAL FINDINGS: A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB)-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L) culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g) and productivities (0.62 g/L · h to 0.75 g/L · h). Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g), with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g) and productivity (0.2 g/L · h), while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates.