Avaliação e comparação entre métodos de mensuração de pressão arterial sistólica em gatos hígidos anestesiados / Evaluation and comparison between methods of measurement of systolic blood pressure in healthy anesthetized cats

Foram avaliados e comparados, para fins de validação, dois diferentes métodos de mensuração de pressão arterial sistólica (PAS), não invasivos ou indiretos (oscilométrico e Doppler vascular) com o invasivo ou direto (cateterização arterial - padrão ouro), em 12 gatos hígidos anestesiados de idade variando entre sete meses e dois anos. Em cada animal, procedeu-se à mensuração simultânea da pressão não invasiva e da invasiva. O método oscilométrico foi comparado, por meio de sete medidas consecutivas, com intervalo de 30 segundos entre elas, com o método invasivo, e, logo em seguida, o método Doppler foi comparado ao método invasivo da mesma maneira. Concluiu-se que o método oscilométrico é estatisticamente igual ao método invasivo, enquanto o Doppler difere de ambos. Entretanto, pela forte correlação positiva entre os métodos Doppler e invasivo, foi possível criar um fator de correção (equação de regressão linear) para se determinar o valor da pressão invasiva, a partir do valor obtido pelo método Doppler. Para obtenção de valores mais fidedignos, recomenda-se a utilização desse fator de correção quando o método Doppler for utilizado para mensuração de PAS em gatos anestesiados.

For validation purposes, two different methods of measurement of systolic blood pressure (SBP), noninvasive or indirect (oscillometric and vascular doppler), direct or invasive (arterial catheterization - the gold standard) were evaluated and compared in 12 healthy anesthetized cats, varying between seven months to two years old. In each animal, we proceeded to the simultaneous noninvasive and invasive measurement of pressure. The oscillometric method was compared by means of seven consecutive measurements with an interval of 30 seconds between them, with the invasive method, and soon after, the doppler method was compared to the invasive method in the same way. It was concluded that the oscillometric method is statistically equal to the invasive method, whereas doppler differs from both. However, due to the strong positive correlation between doppler and invasive methods, it was possible to create a correction factor (linear regression) to determine the value of invasive pressure from the value obtained by the doppler method. To obtain more reliable figures, it is recommended to use this correction factor when the doppler method is used to measure SBP in anesthetized cats.

Seleção genômica ampla para curvas de crescimento / Genome Wide Selection for growth curves

Foi proposta uma metodologia para avaliação genética de curvas de crescimento considerando-se informações de marcadores SNPs (Single Nucleotide Polymorphisms). Em um primeiro passo foram ajustados modelos de crescimento não lineares (logístico) aos dados de peso-idade de cada animal, e em um segundo passo as estimativas dos parâmetros de tais modelos foram consideradas como fenótipos em um modelo de regressão (LASSO Bayesiano - BL) cujas covariáveis foram os genótipos dos marcadores SNPs. Este enfoque possibilitou estimar os valores genéticos genômicos (GBV) para peso em qualquer tempo da trajetória de crescimento, refletindo na confecção de curvas de crescimento genômicas, as quais permitiram a identificação de grupos de indivíduos geneticamente superiores em relação à eficiência de crescimento. Os dados simulados utilizados neste estudo foram constituídos de 2000 indivíduos (1000 na população de treinamento e 1000 na população de validação) contendo 453 marcadores SNPs distribuídos sobre cinco cromossomos. Os resultados indicaram a alta eficiência do método BL em predizer GBVs da população de validação com base na população de treinamento (coeficientes de correlação variaram entre 0,79 e 0,93), bem como a alta eficiência na detecção de QTLs, uma vez que os marcadores com maiores efeitos estimados encontravam-se em posições dos cromossomos próximas àquelas nas quais se encontravam os verdadeiros QTLs postulados na simulação.

A methodology was proposed for the genetic evaluation of growth curves considering SNP (Single Nucleotide Polymorphisms) markers. At the first step, nonlinear regression growth models (Logistic) were fitted to the weight-age of each animal, and on second step the parameter estimates of the Logistic model were used as phenotype in a regression model (Bayesian LASSO - BL) which covariates were given by SNP genotypes. This approach allows the estimation of GBV (Genomic Breeding Values) for weight at either time of growth trajectory, allowing also the production of genomic growth curves, which selected groups of individuals with larger growth efficiency. The simulated data set was constituted of 2,000 individuals (being 1,000 in the training and 1,000 in the validation population) each one with 453 SNP markers distributed along 5 chromosomes. The results indicated high efficiency of the BL method to predict GBV in the validation population using information from the training population (correlation coefficients varying between 0.79 and 0.93). The BL also presented high efficiency to detect QTL, once the most expressive estimated SNP effects were located at positions closed to true QTL position fixed in the simulation.

Resistance exercise training does not affect plasma irisin levels of hemodialysis patients.

Irisin, a hormone secreted by myocytes induced in exercise, acts as a muscle-derived energy-expenditure signal that binds to undetermined receptors on the white adipose tissue surface, stimulating its browning and uncoupling protein 1 (UCP1) expression. The purpose of this study was to assess the effect of an intradialytic resistance exercise training program (RETP) on plasma irisin levels of hemodialysis (HD) patients and compare the baseline plasma irisin levels of HD patients to healthy subjects. This longitudinal study enrolled 26 patients undergoing HD (50% men, 44.8±14.1 years, body mass index (BMI) 23.5±3.9 kg/m²). The healthy subjects group consisted of 11 women and 7 men with mean age of 50.9±6.6 years and BMI, 24.2±2.7 kg/m². Anthropometric and biochemistry parameters (Irisin by Enzyme-Linked Immunosorbent Assay) were measured at the baseline and after 6 months of RETP (in both lower limbs). There was no difference regarding gender, age, and BMI between HD patients and healthy subjects. Plasma irisin levels in HD patients were lower than in healthy subjects (71.0±41.6 vs. 101.3±12.5 ng/ml, p<0.05). Although the muscle mass increased in consequence of exercise [evaluated by arm muscle area from 27.9 (24.1) to 33.1 (19.0) cm²], plasma irisin did not differ significantly after exercises (71.0±41.6 vs. 73.3±36.0 ng/ml). HD patients seem to have lower plasma irisin when compared to healthy subjects. Moreover, a resistance exercise training program was unable to augment plasma irisin despite increasing muscle mass.

Sucralose sweetener in vivo effects on blood constituents radiolabeling, red blood cell morphology and radiopharmaceutical biodistribution in rats.

Effects of sucralose sweetener on blood constituents labelled with technetium-99m ((99m)Tc) on red blood cell (RBC) morphology, sodium pertechnetate (Na(99m)TcO(4)) and diethylenetriaminepentaacetic acid labeled with (99m)Tc ((99m)Tc-DTPA) biodistribution in rats were evaluated. Radiolabeling on blood constituents from Wistar rats was undertaken for determining the activity percentage (%ATI) on blood constituents. RBC morphology was also evaluated. Na(99m)TcO(4) and (99m)Tc-DTPA biodistribution was used to determine %ATI/g in organs. There was no alteration on RBC blood constituents and morphology %ATI. Sucralose sweetener was capable of altering %ATI/g of the radiopharmaceuticals in different organs. These findings are associated to the sucralose sweetener in specific organs.

Cinnamomum zeylanicum extract on the radiolabelling of blood constituents and the morphometry of red blood cells: in vitro assay.

Effects of Cinnamomum zeylanicum (cinnamon) on the labelling of blood constituents with technetium-99m(99mTc) and on the morphology of red blood cells were studied. Blood samples from Wistar rats were incubated with cinnamon extract for 1 hour or with 0.9% NaCl, as control. Labelling of blood constituents with 99mTc was performed. Plasma (P) and blood cells (BC), soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions were separated. The radioactivity in each fraction was counted and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphological analysis of the red blood cells was evaluated. The data showed that the cinnamon extract decreased significantly (p<0.05) the %ATI on BC, IF-P and IF-BC. No modifications were verified on shape of red blood cells. Cinnamon extracts could alter the labelling of blood constituents with 99mTc, and although our results were obtained with animals, precaution is suggested in interpretations of nuclear medicine examinations involving the labelling of blood constituents in patients who are using cinnamon.