High-fat diet-induced elevation of body weight set point in male mice.

OBJECTIVE: High-fat diets (HFD) are thought to disrupt energy homeostasis to drive overeating and obesity. However, weight loss resistance in individuals with obesity suggests that homeostasis is intact. This study aimed to reconcile this difference by systematically assessing body weight (BW) regulation under HFD. METHODS: Male C57BL/6 N mice were fed diets with varying fat and sugar in different durations and patterns. BW and food intake were monitored. RESULTS: BW gain was transiently accelerated by HFD (≥40%) prior to plateauing. The plateau was consistent regardless of starting age, HFD duration, or fat/sugar content. Reverting to a low-fat diet (LFD) caused transiently accelerated weight loss, which correlated with how heavy mice were before the diet relative to LFD-only controls. Chronic HFD attenuated the efficacy of single or repetitive dieting, revealing a defended BW higher than that of LFD-only controls. CONCLUSIONS: This study suggests that dietary fat modulates the BW set point immediately upon switching from LFD to HFD. Mice defend a new elevated set point by increasing caloric intake and efficiency. This response is consistent and controlled, suggesting that hedonic mechanisms contribute to rather than disrupt energy homeostasis. An elevated floor of the BW set point after chronic HFD could explain weight loss resistance in individuals with obesity.

Nuevos paradigmas: 12 años de trombólisis sistémica. Unidad ACV, Hospital de Clínicas / New paradigms: 12 years of systemic thrombolysis. Stroke Unit, Clinicas Hospital / Novos paradigmas: 12 anos de trombólise sistêmica. Unidade AVC, Hospital de Clínicas

Introducción: el ACV constituye un problema de salud y la trombólisis sistémica una estrategia de reperfusión con alto nivel de evidencia para su tratamiento. Los reportes nacionales sobre su utilización son escasos. Objetivos: comunicar y analizar los resultados de esta terapia en el Hospital de Clínicas. Establecer predictores de buena evolución, hemorragia intracraneana y mortalidad. Métodos: estudio observacional analítico de los pacientes trombolizados en el Hospital de Clínicas (2010-2021). Resultados: se realizó trombólisis sistémica a 268 pacientes. La mediana del NIHSS al ingreso fue 12 puntos. Un 42% fueron infartos totales de la circulación anterior. La cardioembolia constituyó la etiopatogenia más frecuente. El 59,3% de los pacientes fueron externalizados con independencia funcional y 55,2% con déficit neurológico mínimo. Las tasas de hemorragia intracraneana sintomática y mortalidad fueron 7,1% y 18,7% respectivamente. El 57% de los pacientes se trataron con tiempo puerta aguja ≤60 minutos. El porcentaje de trombólisis en el total de ACV fue 18,9%. La edad, NIHSS al ingreso e internación en unidad de ACV se comportaron como variables importantes para predecir buena evolución, hemorragia intracraneana y muerte. Discusión y conclusiones: se comunicó la mayor casuística nacional sobre el tema. Los parámetros de efectividad y seguridad del tratamiento fueron comparables a los reportados internacionalmente. Se destacaron los buenos tiempos puerta aguja y tasa trombólisis sobre ACV totales como indicadores satisfactorios de calidad asistencial. La internación en unidad de ACV se comportó como un factor predictor de independencia funcional y protector frente a mortalidad hospitalaria.

Introduction: Strokes are a health problem and systemic thrombolysis constitutes a reperfusion strategy backed up by significant evidence on its positive therapeutic impact. National reports on its use are scarce. Objectives: To report and analyze results obtained with this therapeutic approach at the Clinicas Hospital. To establish predictive factors for a good evolution, intracranial hemorrhage and mortality. Method: Observational, analytical study of thrombolysed patients at Clinicas Hospital (2010-2021). Results: Systemic thrombolysis was performed in 268 patients. Average NIHSS score was 12 points when admitted to hospital.42 % of cases were total anterior circulation infarct (TACI). Cardioembolic ischaemmic stroke was the most frequent etiopahogenesis. 59.3% of patients were discharged with functional independence and 55.2% had minimal neurologic deficit. Symptomatic intracranial hemorrhage and mortality rates were 7.1% and 18.7% respectively. 57% of patients were assisted within ≤60 minutes they showed up at the ER. Thrombolysis percentage in total number of strokes was 18.9%. Age, NIHSS score upon arrival to hospital and admission to the stroke unit were significant variables to predict a good evolution, intracranial hemorrhage and death. Discussion and conclusions: The large number of cases in the country was reported. Effectiveness and safety parameters for this treatment were comparable to those reported internationally. The good door-to-needle time and thrombolysis rate versus total number of strokes stood out as satisfactory indicators of healthcare quality. Admission to the stroke unit behaved as a predictive factor of functional independence and it protected patients from hospital mortality.

Introdução: o AVC é um problema de saúde sendo a trombólise sistêmica uma estratégia de reperfusão com alto nível de evidência para seu tratamento. Os dados nacionais sobre seu uso são escassos. Objetivos: comunicar e analisar os resultados desta terapia no Hospital de Clínicas. Estabelecer preditores de boa evolução, hemorragia intracraniana e mortalidade. Métodos: estudo observacional analítico de pacientes trombolisados no Hospital de Clínicas (2010-2021). Resultados: a trombólise sistêmica foi realizada em 268 pacientes. A mediana do índice NIHSS na admissão foi de 12 pontos. 42% eram infartos totais da circulação anterior. A cardioembolia foi a etiopatogenia mais frequente. 59,3% dos pacientes tiveram alta da unidade com independência funcional e 55,2% com déficit neurológico mínimo. As taxas de hemorragia intracraniana sintomática e mortalidade foram de 7,1% e 18,7%, respectivamente. 57% dos pacientes foram tratados com tempo porta-agulha ≤60 minutos. A porcentagem de trombólise no AVC total foi de 18,9%. Idade, NIHSS na admissão e internação na unidade de AVC se comportaram como variáveis importantes para prever boa evolução, hemorragia intracraniana e óbito. Discussão e conclusões: este trabajo inclui a maior casuística nacional sobre o tema. Os parâmetros de eficácia e segurança do tratamento foram comparáveis aos descritos na bibliografia internacional. Foram destacados como indicadores satisfatórios da qualidade do atendimento os bons tempos porta-agulha e taxa de trombólise em relação ao AVC total. A internação em unidade de AVC comportou-se como preditor de independência funcional e protetor contra a mortalidade hospitalar.

Novel segmentation algorithm for high-throughput analysis of spectral domain-optical coherence tomography imaging of teleost retinas.

Spectral domain-optical coherence tomography (SD-OCT) has become an essential tool for assessing ocular tissues in live subjects and conducting research on ocular development, health, and disease. The processing of SD-OCT images, particularly those from non-mammalian species, is a labor-intensive manual process due to a lack of automated analytical programs. This paper describes the development and implementation of a novel computer algorithm for the quantitative analysis of SD-OCT images of live teleost eyes. Automated segmentation processing of SD-OCT images of retinal layers was developed using a novel algorithm based on thresholding. The algorithm measures retinal thickness characteristics in a large volume of imaging data of teleost ocular structures in a short time, providing increased accuracy and repeatability of SD-OCT image analysis over manual measurements. The algorithm also generates hundreds of retinal thickness measurements per image for a large number of images for a given dataset. Meanwhile, heat mapping software that plots SD-OCT image measurements as a color gradient was also created. This software directly converts the measurements of each processed image to represent changes in thickness across the whole retinal scan. It also enables 2D and 3D visualization of retinal thickness across the scan, facilitating specimen comparison and localization of areas of interest. The study findings showed that the novel algorithm is more accurate, reliable, and repeatable than manual SD-OCT analysis. The adaptability of the algorithm makes it potentially suitable for analyzing SD-OCT scans of other non-mammalian species.

Optimización de las variables de extracción de flavonoides a partir de hojas de Annona muricata L / Optimization of variables for extraction of flavonoids from Annona muricata L. leaves

Introducción: la Annona muricata L. (guanábana) se emplea en la etnomedicina para el tratamiento de diferentes enfermedades. Se han determinado la presencia de flavonoides en las hojas, los cuales poseen propiedades antidiabéticas, antioxidantes y antiinflamatorias. Objetivo: evaluar la influencia de parámetros operacionales de extracción en la obtención de flavonoides a partir de las hojas de A. muricata. Métodos: se emplearon hojas secas, previamente molidas como material vegetal y etanol como disolvente. La evaluación de las variables de operación se realizó a partir de un diseño experimental de superficie respuesta compuesto central rotacional 23 con puntos estrellas, seleccionándose los intervalos entre 50 y 70 mL/g para la relación material vegetal-volumen de disolvente, entre 40 y 80 por ciento la concentración de etanol y entre 2 y 3 h el tiempo de extracción. Se determinó la presencia de flavonoides y quercetina en los extractos obtenidos. La cuantificación de flavonoides totales se realizó por un método colorimétrico a 430 nm, expresado como quercetina. Para la mejor condición experimental se realizaron experimentos por triplicado y se comparó con el valor predicho por el diseño encontrándose una buena correlación entre ambos. Resultados: la condición óptima en la extracción de flavonoides totales se obtuvo a una concentración de etanol de un 96 por ciento, una relación de 70 ml/g y un tiempo de 1,6 h. Las variables significativas resultaron los efectos cuadráticos de la relación material vegetal-volumen de disolvente y la concentración de etanol. Conclusiones: se seleccionaron las mejores condiciones de extracción en la obtención de un extracto a partir de hojas de guanábana con presencia de flavonoides, a partir de las cuales se alcanzó un rendimiento del proceso de extracción de 87 por ciento(AU)

Introduction: Annona muricata L. (soursop) is used in ethnomedicine for the treatment of various diseases. Leaves of this species have been found to contain flavonoids, which are compounds with antidiabetic, antioxidant and anti-inflammatory properties. Objective: evaluate the influence of operational parameters on the extraction of flavonoids from A. muricata leaves. Methods: dry ground leaves were used as plant material and ethanol as solvent. Evaluation of the operational variables was based on a 23 experimental rotatable response surface central composite design with star points, selecting the intervals between 50 and 70 ml/g for the plant material / solvent volume ratio, 40 percent to 80 percent for ethanol concentration and 2 to 3 h for extraction time. Flavonoids and quercetin were found in the extracts obtained. Total flavonoids were quantified using a colorimetric method at 430 nm, expressed as quercetin. Experiments were conducted in triplicate to determine the best experimental condition. Comparison with the design value predicted showed a good correlation between the two.Results: the optimal condition for extraction of total flavonoids was reached at an ethanol concentration of 96 percent, a 70 ml/g ratio and a time of 1.6 h. The variables found to be significant were the quadratic effects of the plant material/solvent volume ratio and ethanol concentration. Conclusions: a selection was made of the best conditions to obtain an extract from soursop leaves containing flavonoids, in which an extraction output of 87 percent was achieved in the extraction process(AU)

Optimización de las variables de extracción de flavonoides a partir de hojas de Annona muricata L / Optimization of variables for extraction of flavonoids from Annona muricata L. leaves

Introducción: la Annona muricata L. (guanábana) se emplea en la etnomedicina para el tratamiento de diferentes enfermedades. Se han determinado la presencia de flavonoides en las hojas, los cuales poseen propiedades antidiabéticas, antioxidantes y antiinflamatorias. Objetivo: evaluar la influencia de parámetros operacionales de extracción en la obtención de flavonoides a partir de las hojas de A. muricata. Métodos: se emplearon hojas secas, previamente molidas como material vegetal y etanol como disolvente. La evaluación de las variables de operación se realizó a partir de un diseño experimental de superficie respuesta compuesto central rotacional 23 con puntos estrellas, seleccionándose los intervalos entre 50 y 70 mL/g para la relación material vegetal-volumen de disolvente, entre 40 y 80 por ciento la concentración de etanol y entre 2 y 3 h el tiempo de extracción. Se determinó la presencia de flavonoides y quercetina en los extractos obtenidos. La cuantificación de flavonoides totales se realizó por un método colorimétrico a 430 nm, expresado como quercetina. Para la mejor condición experimental se realizaron experimentos por triplicado y se comparó con el valor predicho por el diseño encontrándose una buena correlación entre ambos. Resultados: la condición óptima en la extracción de flavonoides totales se obtuvo a una concentración de etanol de un 96 por ciento, una relación de 70 ml/g y un tiempo de 1,6 h. Las variables significativas resultaron los efectos cuadráticos de la relación material vegetal-volumen de disolvente y la concentración de etanol. Conclusiones: se seleccionaron las mejores condiciones de extracción en la obtención de un extracto a partir de hojas de guanábana con presencia de flavonoides, a partir de las cuales se alcanzó un rendimiento del proceso de extracción de 87 por ciento(AU)

Introduction: Annona muricata L. (soursop) is used in ethnomedicine for the treatment of various diseases. Leaves of this species have been found to contain flavonoids, which are compounds with antidiabetic, antioxidant and anti-inflammatory properties. Objective: evaluate the influence of operational parameters on the extraction of flavonoids from A. muricata leaves. Methods: dry ground leaves were used as plant material and ethanol as solvent. Evaluation of the operational variables was based on a 23 experimental rotatable response surface central composite design with star points, selecting the intervals between 50 and 70 ml/g for the plant material / solvent volume ratio, 40 percent to 80 percent for ethanol concentration and 2 to 3 h for extraction time. Flavonoids and quercetin were found in the extracts obtained. Total flavonoids were quantified using a colorimetric method at 430 nm, expressed as quercetin. Experiments were conducted in triplicate to determine the best experimental condition. Comparison with the design value predicted showed a good correlation between the two. Results: the optimal condition for extraction of total flavonoids was reached at an ethanol concentration of 96 percent, a 70 ml/g ratio and a time of 1.6 h. The variables found to be significant were the quadratic effects of the plant material / solvent volume ratio and ethanol concentration. Conclusions: a selection was made of the best conditions to obtain an extract from soursop leaves containing flavonoids, in which an extraction output of 87 percent was achieved in the extraction process(AU)