Evaluation of erythrocyte filtrability and its relation to globular membrane (Na+, K+)--dependent ATPase in hypertensive patients

The values of erythrocyte filtration index and erythrocyte membrane (Na+, K+) – dependent ATPase activity were evaluated in 21 hypertensive patients (12 men and 9 women) aged 46.3 ± 9.7 years. The patients suffered from essential hypertension and the blood pressure values recorded were 171.9 ± 21.3 mmHg systolic and 110.6 ± 12.2 mmHg diastolic. The activity of erythrocyte membrane Na+, K+ ATPase is significantly lower (p < 0.001) among the patients (0.074 ± 0.029 μmoles Pi/mg prot/h) than in the healthy controls (0.160 ± 0.045 μmoles Pi/mg prot/h). The rate of erythrocyte filtrability was also significantly lower (p < 0.001) in respect to the controls (12.84 ± 2.40 μl. seg.-1 and (15.80 ± 1.75, respectively). However, no correlation was found between the two parameters evaluated.This study was supported by a grant from INIC (MbL2)

Microviscosity of erythrocyte membrane in hypertensive patients

Twenty eight ambulatory patients (16 men and 12 women), suffering from essential hypertension, whose ages averaged 46.9 ± 9.6 years, were studied; the patients presented blood pressure values of 174.0 ± 22.7 mmHg systolic and 110.5 ± 11.7 mmHg diastolic. It was detected a significant rise of erythrocyte membrane microviscosity (p < 0.01) and a significant decrease of erythrocyte filtrability (p < 0.001). However, no significant correlation was observed between these two parameters. The results obtained suggest that essential hypertension induces or may be associated to intrinsic abnormalities of erythrocyte membrane eventually acting on globular flexibility

The relation between the erythrocyte nitric oxide and hemorheological parameters

© 2006 – IOS Press and the authors. All rights reservedWe stimulated human erythrocytes obtained from patients with hypercholesterolemia (HC; n = 42), renal transplantation (RT; n = 18) and hypertension (HT; n = 10) with acetylcholine (ACh 10 μM) and measured the amperometric NO production, comparing with the NO levels achieved on erythrocytes of healthy persons (n = 27). We also measured the hemoglobin, hematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity and fibrinogen concentration from human blood samples. The erythrocytes NO levels were of 2.5 ± 0.7 nM (P = 0.038, HC), 2.4 ± 1.1 nM (RT) and 2.2 ± 0.8 nM (HT) against the 2.0 ± 0.8 nM for the control groups. For each group and at each shear stress value, the erythrocytes deformability decreases with the increase of the NO concentration after ACh stimulation. We observed a significant increase of the control values on the erythrocyte aggregation results on each patient group. Besides the lower erythrocyte deformability obtained on HC, RT and HT blood samples, the erythrocytes produced higher NO levels after ACh stimulation than the healthy ones. The power of erythrocyte hemorheological behaviour could be compensated by the NO production at the presence of acetylcholine. We can hypothesises that cholinergic drugs could be used as co-adjuvants of specific therapeutics compounds on these studied diseases.This work was supported by “Fundação para a Ciência e Tecnologia”, Portugal

Phase Contrast X-Ray Synchrotron Microtomography for Virtual Dissection of the Head of <i>Rhodnius prolixus</i>

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Vitamin D-related polymorphisms and vitamin D levels as risk biomarkers of COVID-19 disease severity

© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Vitamin D is a fundamental regulator of host defences by activating genes related to innate and adaptive immunity. Previous research shows a correlation between the levels of vitamin D in patients infected with SARS-CoV-2 and the degree of disease severity. This work investigates the impact of the genetic background related to vitamin D pathways on COVID-19 severity. For the first time, the Portuguese population was characterized regarding the prevalence of high impact variants in genes associated with the vitamin D pathways. This study enrolled 517 patients admitted to two tertiary Portuguese hospitals. The serum concentration of 25 (OH)D, was measured in the hospital at the time of patient admission. Genetic variants, 18 variants, in the genes AMDHD1, CYP2R1, CYP24A1, DHCR7, GC, SEC23A, and VDR were analysed. The results show that polymorphisms in the vitamin D binding protein encoded by the GC gene are related to the infection severity (p = 0.005). There is an association between vitamin D polygenic risk score and the serum concentration of 25 (OH)D (p = 0.04). There is an association between 25 (OH)D levels and the survival and fatal outcomes (p = 1.5e-4). The Portuguese population has a higher prevalence of the DHCR7 RS12785878 variant when compared with its prevalence in the European population (19% versus 10%). This study shows a genetic susceptibility for vitamin D deficiency that might explain higher severity degrees in COVID-19 patients. These results reinforce the relevance of personalized strategies in the context of viral diseases.This project was supported by the “Fundação para a Ciência e Tecnologia”, program “Research 4 Covid-19 Apoio especial a projetos de implementação rápida para soluções inovadoras de resposta à pandemia de COVID-19”. It was also partially supported by each institution.info:eu-repo/semantics/publishedVersio

Erythrocyte acetylcholinesterase in essential hypertension

© by Springer-Verlag 1980Red cell acetylcholinesterase activity (AChE) has been studied in 58 patients suffering from essential hypertension; diastolic blood pressure values were about 130mm or higher in 45 patients (group A) and lower in 13 (group B). The very significant increase (p<0.001) of AChE activity in group A has been forced by the severity of systemic lesions. Meanwhile, the AChE values have been slightly increased, but not statistically significant in the patients of group B. These results are supporting the hypothesis that the blood pressure control can be mediated or normalized, at least in part, by cholinergic mechanisms.This work was supported by Instituto Nacional de Investigação Científica (project LMC-10)