Computer Simulations Applied to Small-Field Dosimetry in Radiotherapy

With the advancement of radiotherapy techniques, we find some challenges in small field dosimetry that are widely used in head and neck treatments, so computer simulations with the Monte Carlo method, already well established in medical physics, are a great tool for  studying small field dosimetry. The present work aims to report the validate of the geometry model used for the simulations of a 6 MV LINAC beam, in addition to estimating the TPS, PDD and PDD 20,10 curves for several regular and small fields, allowing comparisons with experimental data

Enteral tube placement in newborns according to the modified measurement technique

Objective: To evaluate the effectiveness of the enteral tube measurement using the modified nose - ear - xiphoid (NEX) technique by disregarding the tube distal orifices for placement in newborns' neonatal gastric cavity. Methods: A prospective study conducted in a neonatal unit of a teaching hospital in the city of Sao Paulo, based on the radiographic analysis of 60 radiographs of 28 newborns using enteral tubes measured by the modified technique, and who had thoracoabdominal radiography. Results: The correct placement index according to analysis by position was 68.3% and 71.7%, according to evaluators 1 and 2, respectively. In the analysis by vertebrae, 95% of tubes were properly placed in the gastric cavity. There was a statistically significant association between height and location of the enteral tube according to evaluator 2. Conclusion: The evaluated measurement technique presents a risk for inadequate enteral tube placement in newborns, and its application in clinical practice should not be encouraged.Objetivo: Avaliar a efetividade da mensuração de sonda enteral pela técnica modificada, nariz - orelha - apêndice xifoide, com desconto dos orifícios distais da sonda, para posicionamento na câmara gástrica de neonatos. Métodos: Estudo prospectivo, desenvolvido em unidade neonatal de um hospital de ensino do município de São Paulo, a partir da análise radiográfica de 60 radiografias de 28 neonatos em uso de sonda enteral mensurada pela técnica modificada, submetidos à radiografia toracoabdominal. Resultados: O índice de posicionamento correto, de acordo com a análise por posições, foi de 68,3% e 71,7%, segundo os avaliadores 1 e 2, respectivamente, enquanto na análise por vértebras, 95% das sondas estavam adequadamente locadas na câmara gástrica. Ocorreu associação estatisticamente significante entre estatura e localização da sonda enteral, segundo o avaliador 2. Conclusão: A técnica de mensuração avaliada apresenta risco para posicionamento inadequado da sonda enteral utilizada em neonatos, devendo ser desencorajada sua aplicação na prática clínica.Univ Fed Sao Paulo, Escola Paulista Enfermagem, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Enfermagem, Sao Paulo, SP, BrazilWeb of Scienc

In vitro cytotoxicity of chemical preservatives on human fibroblast cells

Preservatives are widely used substances that are commonly added to various cosmetic and pharmaceutical products to prevent or inhibit microbial growth. In this study, we compared the in vitro cytotoxicity of different types of currently used preservatives, including methylparaben, imidazolidinyl urea (IMU), and sodium benzoate, using the human newborn fibroblast cell line CCD 1072Sk. Of the tested preservatives, only IMU induced a reduction in cell viability, as shown using the MIT assay and propidium iodide staining (IMU > methylparaben > sodium benzoate). IMU was shown to promote homeostatic alterations potentially related to the initiation of programed cell death, such as decreased mitochondrial membrane potential and caspase-3 activation, in the treated cells Methylparaben and sodium benzoate were shown to have a very low cytotoxic activity. Taken together, our results suggest that IMU induces programed cell death in human fibroblasts by a canonical intrinsic pathway via mitochondrial perturbation and subsequent release of proapoptotic factors.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)CAPESUniv Anhembi Morumbi, Escola Ciencias Saude, Grp Fitocomplexos & Sinalizacao Celular, Sao Paulo, SP, BrazilInst Osmol & Oleos Essenciais, Monte Verde, MG, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Farmacol, Sao Paulo, SP, BrazilUniv Mogi das Cruzes, Ctr Interdisciplinar Invest Bioquim, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Farmacol, Sao Paulo, SP, BrazilWeb of Scienc

In vitro cytotoxicity of chemical preservatives on human fibroblast cells

Preservatives are widely used substances that are commonly added to various cosmetic and pharmaceutical products to prevent or inhibit microbial growth. In this study, we compared the in vitro cytotoxicity of different types of currently used preservatives, including methylparaben, imidazolidinyl urea (IMU), and sodium benzoate, using the human newborn fibroblast cell line CCD1072Sk. Of the tested preservatives, only IMU induced a reduction in cell viability, as shown using the MTT assay and propidium iodide staining (IMU>;methylparaben>;sodium benzoate). IMU was shown to promote homeostatic alterations potentially related to the initiation of programed cell death, such as decreased mitochondrial membrane potential and caspase-3 activation, in the treated cells. Methylparaben and sodium benzoate were shown to have a very low cytotoxic activity. Taken together, our results suggest that IMU induces programed cell death in human fibroblasts by a canonical intrinsic pathway via mitochondrial perturbation and subsequent release of proapoptotic factors

Efficacy and safety of very early mobilization after thrombolysis in acute ischemic stroke: a randomized clinical trial.

Stroke has a deleterious impact on human health due to its high incidence, degree of disabling sequelae and mortality, constituting one of the main causes of death and disability worldwide. This study aimed to assess the efficacy and safety of very early mobilization (VEMG) after thrombolysis in functional recovery in patients with acute ischemic stroke. The present study was an open, prospective, randomized study, with no blinded outcome, carried out in the stroke unit of a tertiary referral hospital located in Salvador-Bahia, Brazil. The primary outcome was the level of functional independence. Secondary outcomes were functional mobility, balance, complications within 7 days of hospitalization and 90 days after hospital discharge, and length of stay. A total of 104 patients with ischemic stroke who received thrombolytic treatment between August 2020 and July 2021 were prospectively recruited to the study. Of these, 51 patients received VEMG within 24 h of the ictus and another 53 patients receiving usual care (UCG) with mobilization 24 h after the ictus. When compared to the usual care, the VEMG group was not associated with a significant reduction in the risk of the primary outcome (relative risk [95% confidence intervals]: 0.74 [0.339-1.607]) or any of the secondary outcomes. In this study, the strategy of early mobilization after thrombolysis in ischemic stroke was safe, but without evidence of short-term benefit. Brazilian Registry of Clinical Trials under the registry (registry number: RBR-8bgcs3). [Abstract copyright: © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.

Selection of okra parents based on performance and genetic divergence

A total of 200 okra accessions with wide variability and a potential for genetic improvement were stored in the Vegetables Germplasm Bank of the Federal University of Viçosa (UFV-BGH) in Viçosa, Minas Gerais State, Brazil. The objective of this work was to select parents by genetic divergence and behavior per se in 70 okra accessions from the BGH-UFV by quantitative and qualitative descriptors of economic interest. Analysis of individual and combined variance, by clustering of means by Scott-Knott test, of the accessions by Tocher’s method and selection based on qualitative descriptors and behavior per se using the methodology of sum of inverted positions was made. The variability of the characteristics of the accessions as verified by the Scott-Knott test formed different groups and subgroups by Tocher’s method. Fifteen accessions were selected with the qualitative descriptors, and based on the sum of inverted positions for quantitative descriptors the BGH-132, BGH-547, BGH-693, BGH-740, BGH-961, BGH-7863, BGH- 7865, BGH-3196 and BGH-4890 okra accessions were selected as potential parents.Key words: Abelmoschus esculentus (L.) Moench, germplasm bank, genetic resource, genetic improvement

Is there still room to explore cyclodextrin glycosyltransferase-producers in Brazilian biodiversity?

In the present work, different Brazilian biomes aiming to identify and select cyclodextrin glycosyltransferase-producer bacteria are explored. This enzyme is responsible for converting starch to cyclodextrin, which are interesting molecules to carry other substances of economic interest applied by textile, pharmaceutical, food, and other industries. Based on the enzymatic index, 12 bacteria were selected and evaluated, considering their capacity to produce the enzyme in culture media containing different starch sources. It was observed that the highest yields were presented by the bacteria when grown in cornstarch. These bacteria were also characterized by sequencing of the 16S rRNA region and were classified as Bacillus, Paenibacillus, Gracilibacillus and Solibacillus.publishersversionpublishe