Influência do corticoide na cicatrização do manguito rotador de ratos

Resumo: Objetivo: O objetivo do presente estudo foi comparar a resistência da cicatrização, com relação a tensão máxima, força máxima e força de ruptura do tendão infra-espinhal de ratos, submetidos a inoculação de corticoides após a lesão e reparos experimentais. Material e método: 60 ratos Wistar foram submetidos a tenotomia do tendão infra-espinhal e suturados. Prévio à cirurgia foram divididos em grupo controle (C) inoculados com soro e grupo de estudo (E) inoculados com corticoides sobre o tendão. Após o reparo os ratos foram sacrificados em grupos de 10 indivíduos do grupo controle e 10 do grupo de estudo em intervalos de 1 semana (C1 e E1), 3 semanas (C3 e E3) e 5 semanas (C5 e E5). Os ratos foram dissecados separando o tendão infra-espinhal com o úmero. As peças de estudo foram submetidas a teste de tração e avaliados: tensão máxima (kgf/cm2), força máxima (kgf) e força de ruptura (kgf) e comparado o grupo de estudo com os respectivos grupos controle. Resultados: Dentre os ratos sacrificados com 1 semana observamos maior tensão máxima do grupo C1 em comparação com o grupo E1. As variáveis força máxima (kgf), força de ruptura (kgf); não diferiram estatisticamente entre os grupos pesquisados. Da mesma forma nos ratos sacrificados com 3 semanas o grupo C3 mostrou apenas resistência maior na tensão máxima em comparação com o grupo E3 (p=0.007), as demais variáveis não apresentaram diferenças. Nos ratos sacrificados com 5 semanas (C5 e E5), nenhum dos parâmetros estudados apresentou diferenças estatísticas. Concluímos que o corticoide diminui a resistência à tensão máxima nos grupos em uma e três semanas em comparação com os respectivos grupos controle. Os demais parâmetros não tiveram diferença entre o grupo de estudo e o grupo controle

The electron–proton bottleneck of photosynthetic oxygen evolution

Photosynthesis fuels life on Earth by storing solar energy in chemical form. Today’s oxygen-rich atmosphere has resulted from the splitting of water at the protein-bound manganese cluster of photosystem II during photosynthesis. Formation of molecular oxygen starts from a state with four accumulated electron holes, the S4 state—which was postulated half a century ago1 and remains largely uncharacterized. Here we resolve this key stage of photosynthetic O2 formation and its crucial mechanistic role. We tracked 230,000 excitation cycles of dark-adapted photosystems with microsecond infrared spectroscopy. Combining these results with computational chemistry reveals that a crucial proton vacancy is initally created through gated sidechain deprotonation. Subsequently, a reactive oxygen radical is formed in a single-electron, multi-proton transfer event. This is the slowest step in photosynthetic O2 formation, with a moderate energetic barrier and marked entropic slowdown. We identify the S4 state as the oxygen-radical state; its formation is followed by fast O–O bonding and O2 release. In conjunction with previous breakthroughs in experimental and computational investigations, a compelling atomistic picture of photosynthetic O2 formation emerges. Our results provide insights into a biological process that is likely to have occurred unchanged for the past three billion years, which we expect to support the knowledge-based design of artificial water-splitting systems

FERREIRA GULLAR: “Não sou viciado em poesia”.

Esta entrevista resultou de uma conversa de mais de três horas, ao longo das quais falou-se sobre os mais variados temas, do estatuto da arte à crise de valores da humanidade, dos textos de circunstância ao equívoco do hermetismo, da prática do ensaísmo à especificidade da poesia

Aplicación de los Modelos de Respuesta Binaria a los Determinantes de la Demanda de Postgrado en Colombia /

Se presenta un análisis de la aplicación de los modelos Logit y Probit a los determinantes de la demanda de postgrados en Colombia en el marco de la teoría del capital humano. Como ejemplo, se utilizan los datos correspondientes a la encuesta de seguimiento a graduados del Ministerio de Educación Nacional (MEN) de 2007. Se examinan las características personales y del entorno laboral de 19.781 profesionales 1 que diligenciaron la encuesta, y su influencia en la probabilidad de tener o no estudios de postgrado a través de los dos tipos de modelos de elección binaria, de los cuales se elige el de mejor especificación. Los resultados de este artículo de reflexión sobre la aplicación de modelos estadísticos para el análisis de la demanda en la Educación Superior, muestran que las características personales y del entorno laboral se explican de manera significativa con la demanda de postgrados, y que algunas de estas tienen un peso mayor en cuanto a sus efectos sobre el comportamiento de la demanda como son: el área del conocimiento del pregrado, el ingreso del individuo y el nivel educativo de los padres.Universidad Autónoma del Carib

Influência do corticoide na cicatrização do manguito rotador de ratos – Estudo biomecânico

ResumoObjetivocomparar a resistência da cicatrização, com relação a tensão máxima, força máxima e força de ruptura, do tendão infraespinhal de ratos submetidos a inoculação de corticoides após a lesão e a reparos experimentais.Métodosforam submetidos 60 ratos Wistar a tenotomia do tendão infraespinhal e suturados. Previamente à cirurgia foram divididos em grupo controle (C), inoculados com soro, e grupo de estudo (E), inoculados com corticoides sobre o tendão. Após o reparo os ratos foram sacrificados em grupos de 10 indivíduos do grupo controle e 10 do grupo de estudo em intervalos de uma semana (C1 e E1), três semanas (C3 e E3) e cinco semanas (C5 e E5). Os ratos foram dissecados com a separação do tendão infraespinhal do úmero. As peças de estudo foram submetidas a teste de tração e avaliadas – tensão máxima (kgf/cm2), força máxima (kgf) e força de ruptura (kgf) – e comparando os grupos de estudo com os grupos controle.Resultadosdentre os ratos sacrificados com uma semana observamos maior tensão máxima do grupo C1 em comparação com o grupo E1. As variáveis força máxima (kgf) e força de ruptura (kgf) não diferiram estatisticamente entre os grupos pesquisados. Da mesma forma, nos ratos sacrificados com três semanas o grupo C3 mostrou apenas resistência maior na tensão máxima em comparação com o grupo E3 (p=0,007). As demais variáveis não apresentaram diferenças. Nos ratos sacrificados com cinco semanas (C5 e E5), nenhum dos parâmetros estudados apresentou diferenças estatísticas.Conclusãoa inoculação com corticoide sobre o manguito rotador levou a diminuição da resistência a tensão máxima da cicatriz pós reparo cirúrgico experimental em uma e três semanas em comparação com os respectivos grupos controle. Os demais parâmetros não tiveram diferença entre os grupos de estudo e os grupos controle.AbstractObjectiveto compare healing strength of the infraspinatus tendon of rats with corticoid inoculation, regarding maximum tension, maximum force and rupture force, after injury and experimental repair.Methods60 Wistar rats were subjected to tenotomy of the infraspinatus tendon, which was then sutured. Before the surgery, they were divided into a control group (C) inoculated with serum and a study group (S) inoculated with corticoids over the tendon. After repair, the rats were sacrificed in groups of 10 individuals in the control group and 10 in the study group at the times of one week (C1 and S1), three weeks (C3 and S3) and five weeks (C5 and S5). The rats were dissected, separating out the infraspinatus tendon with the humerus. The study specimens were subjected to a traction test, with evaluation of the maximum tension (kgf/cm2), maximum force (kgf) and rupture force (kgf), comparing the study group with the respective control groups.Resultsamong the rats sacrificed one week after the procedure, we observed greater maximum tension in group C1 than in group S1. The variables of maximum force (kgf) and rupture force did not differ statistically between the groups investigated. In the same way, among the rats sacrificed three weeks after the procedure, group C3 only showed greater maximum tension than in group S3 (p=0.007), and the other variables did not present differences. Among the rats sacrificed five weeks after the procedure (C5 and S5), none of the parameters studied presented statistical differences.Conclusionwe concluded that corticoid diminished the resistance to maximum tension in the groups sacrificed one and three weeks after the procedure, in comparison with the respective control groups. The other parameters did not show differences between the study and control groups

Influence of corticoids on healing of the rotator cuff of rats – biomechanical study

AbstractObjectiveto compare healing strength of the infraspinatus tendon of rats with corticoid inoculation, regarding maximum tension, maximum force and rupture force, after injury and experimental repair.Methodsa total of 60 Wistar rats were subjected to tenotomy of the infraspinatus tendon, which was then sutured. Before the surgery, they were divided into a control group (C) inoculated with serum and a study group (S) inoculated with corticoids over the tendon. After repair, the rats were sacrificed in groups of 10 individuals in the control group and 10 in the study group at the times of one week (C1 and S1), three weeks (C3 and S3) and five weeks (C5 and S5). The rats were dissected, separating out the infraspinatus tendon with the humerus. The study specimens were subjected to a traction test, with evaluation of the maximum tension (kgf/cm2), maximum force (kgf) and rupture force (kgf), comparing the study group with the respective control groups.Resultsamong the rats sacrificed one week after the procedure, we observed greater maximum tension in group C1 than in group S1. The variables of maximum force (kgf) and rupture force did not differ statistically between the groups investigated. In the same way, among the rats sacrificed three weeks after the procedure, group C3 only showed greater maximum tension than group S3 (p=0.007), and the other variables did not present differences. Among the rats sacrificed five weeks after the procedure (C5 and S5), none of the parameters studied presented statistical differences.Conclusionwe concluded that corticoid diminished the resistance to maximum tension in the groups sacrificed one and three weeks after the procedure, in comparison with the respective control groups. The other parameters did not show differences between the study and control groups

Modelación de un sistema de almacenamiento subacuático sostenible para contenedores refrigerados

Los puertos enfrentan desafíos significativos en términos de consumo de energía y emisiones de carbono, especialmente en relación con los contenedores refrigerados. Estos contenedores son responsables de aproximadamente el 50% del consumo total de energía en los puertos y dependen en su mayoría de combustibles fósiles, lo que resulta en altas emisiones de carbono. Para abordar este problema, Bonifacio y Castro (2022) propusieron una solución que contribuyó a un mejor entendimiento de la operación y la problemática. Sin embargo, debido a su inviabilidad económica, se ha desarrollado un nuevo proyecto centrado en el diseño y prueba de una infraestructura de almacenamiento de contenedores refrigerados subacuática revisada. Este proyecto se ha enfocado en el puerto de Santa Marta, donde el 67% de los contenedores son refrigerados. La infraestructura propuesta tiene una capacidad para albergar 800 contenedores distribuidos en 5 niveles de bandejas portacontenedores. Este diseño evita el apilamiento de los contenedores y reduce la temperatura ambiente del almacenamiento, lo que minimiza el consumo de energía fósil. Para evaluar esta solución, se realizó una simulación de eventos discretos utilizando el software especializado para puertos llamado Flexterm. Los resultados de la simulación indican que con esta nueva propuesta se pueden manejar 572 contenedores refrigerados con una duración promedio de 4,32 días. Además, se logra reducir las emisiones de carbono en un 91,44%. En términos financieros, el análisis para la inversión de $36.680.221,72 USD necesaria para implementar esta propuesta muestra una TIR del 35% y un período de recuperación de inversión de 6 años.PregradoIngeniero Industria

Poisoning by Senecio brasiliensis in Horses in Northern Rio Grande do Sul

Background: In various regions of Brazil, horses and cattle are considered the most susceptible animals to plant poisoning. The plants of the genus Senecio are the most important in Rio Grande do Sul because they have the active principle known as the pyrrolizidine alkaloid. Its diagnosis is made through epidemiology, clinical signs and histopathological analysis, either of the tissues obtained by biopsy or necropsy. The objective of this study was to report and characterize the epidemiological, clinical and anatomopathological findings of three cases of natural poisoning by Senecio brasiliensis in horses assisted at the Hospital Veterinário (HV) of the Universidade de Passo Fundo (UPF).Cases: Three traction horses, two males and one female, were admitted at the HV-UPF for clinical care. The animals were presenting anorexia, weight loss, dysmetria, proprioceptive deficit and signs suggestive of colic. The epidemiological study revealed that the sites where these animals were located were infested by Senecio brasiliensis. The support therapy used for equine colic in all three cases was unsuccessful. One of the animals died and the other two were euthanized, all three of them being reffered for necropsy. The post-mortem findings were mainly found in the liver, which showed accentuation of the lobular pattern and the appearance of nutmeg. During necropsy, fragments of organs from thoracic and abdominal cavities and central nervous system were collected and fixed in 10% buffered formalin. Subsequently, the samples were processed chemically, submitted to cuts of five micrometers of thickness and stained with hematoxylin and eosin for microscopic analysis. Microscopically, the liver of all three horses presented megalocytosis, fibrosis and bile ducts hyperplasia. In the central nervous system, spongiosis and the presence of Alzheimer type II astrocytes were observed. Thus, through the association of information, the diagnosis of poisoning by Senecio brasiliensis was achieved.Discussion: The diagnosis of natural poisoning by Senecio brasiliensis was obtained through the epidemiological survey that showed S. brasiliensis in pastures where all three horses were allocated.  Cases of intoxication by S. brasieliensis in cattle are more frequent than in equines, although both species are considered the most susceptible. In horses, the main clinical manifestations observed include neurological disorders, apathy, anorexia, dysphagia, weight loss, subcutaneous edema and icterus. The clinical signs presented by the equines suggested initial signs of colic syndrome, although anorexia, weight loss, dysmetria and proprioceptive deficit are commonly observed in pyrrolizidine alkaloid poisoning in the liver, both in cattle and horses. The pyrrolizidine alkaloids present in the genus Senecio that become toxic when biotransformed in the liver into a pyrrholic form highly reactive that inhibits cell mitosis and leads to the onset of megalocytosis, cell death and liver fibrosis. The necropsy findings and histopathology were characteristic of poisoning in equines, since the predominant macroscopic lesions in the liver were hepatomegaly and accentuation of lobular pattern, whereas microscopically, there was a predominance of hepatic fibrosis, megalocytosis, spongiosis and the incidence of Alzheimer's type II astrocytes in the brain. These lesions are observed both in natural and in experimental cases of poisoning in horses. Thus, through the ante-mortem and complete post-mortem evaluation of the three equines, it was possible to establish the occurrence of natural poisoning by Senecio brasiliensis in Northern Rio Grande do Sul, as well as to characterize the epidemiological, clinical and anatomopathological findings of poisoning in this species

Metastatic Vulvar Squamous Cell Carcinoma in a Mare

Background: Squamous cell carcinoma (SCC) is a common cutaneous neoplasm in horses, which mainly affects the external genitalia, oral cavity, and periocular region. The development of SCC metastases is rare in these animals, and the most common occurrence is a marked local infiltration. Exposure to ultraviolet rays and skin depigmentation are the main etiological factors of SCC. Definitive diagnosis of the neoplasm is performed through histological examination of lesions. The present report describes the clinical, anatomopathological, and immunohistochemical (IHC) aspects of a case of metastatic SCC, with the vulva as the primary site in a mare. Case: A 17-year-old mare, mixed breed, was referred to the Veterinary Hospital of the Universidade de Passo Fundo (UPF), with history of areas of depigmented skin (pinto coat), and  clinical history of anorexia, frequent episodes of colic, and recumbency. During clinical evaluation, heart rate (68 bpm), rectal temperature (38.4ºC), and respiratory rate (48 mpm) were elevated, and the oral mucosa was pale. The mare also had an ulcerated tumor mass involving the vulva, which extended to the inguinal region and involved the mammary gland. A cytological aspirate of the vulvar tumor was performed, in which no neoplastic cells were found. Next, a biopsy of 2 distinct areas of the vulva was performed. The material was sent for anatomopathological examination, which showed markedly pleomorphic malignant squamous cells, with individual keratinization and high mitotic index, organized in trabeculae with rare keratin pearl-like formations. The exam allowed the diagnosis of SCC Grade II. Due to the poor prognosis and high cost of treatment, the owner consented to euthanasia and necropsy examination. During necropsy, the vulvar tumor mass was grayish, firm to hard, infiltrative, and had friable areas. Tumor foci suggestive of metastasis were also observed in inguinal, mesenteric, mediastinal and renal lymph nodes, adrenal glands, lung, pericardium, medullary canal, intercostal muscles, right 15th rib, and tissue surrounding the azygos vein. Samples from all organs were collected for anatomopathological examination. Diagnosis of metastatic vulvar SCC was confirmed through histological and IHC studies, which evaluated the expression of cytokeratins (AE1/AE3), as well as the proliferative activity of neoplastic cells through the PCNA marker. Discussion: The diagnosis of metastatic SCC was obtained through the observed clinical, necroscopic, histological, and IHC characteristics. This neoplasm usually appears in depigmented regions exposed to ultraviolet light, and older animals are more likely to be affected. The mare in the present case had areas of depigmented skin (pinto coat). The animal was kept in a paddock outdoor and exposed to constant solar radiation. Although rare in horses, manifestation of anorexia, progressive weight loss, and frequent colic episodes and recumbency may be closely related to the multiple sites of metastasis in the present case. The main histological findings of the neoplasm were the dense proliferation of malignant squamous cells with individual keratinization, arranged in a trabecular pattern and with rare formations of keratin pearls, in line with previous studies. During IHC evaluation, the neoplastic cells showed expression of cytokeratins (AE1/AE3), as well as high proliferative activity evidenced by the PCNA marker. Given this background, the present report describes the clinical, anatomopathological, and IHC aspects of a case of metastatic SCC with a primary site in the vulva of a mare. Keywords: equine, genital neoplasm, tumor embolism, squamous cell carcinoma, metastasis, immunohistochemistry