Fibras musculares cardíacas en las cúspides de la valva atrioventricular izquierda humana / Cardiac muscle fibers at the cusps of the human left atrioventricular valve

Las valvas cardíacas y especialmente la valva atrioventricular izquierda (VAVI) ha sido considerada por largo tiempo, como una estructura pasiva. Sin embargo, han surgido nuevas teorías que reconocen a esta estructura como una "valva viva", con un funcionamiento de mayor autonomía y dinámico. En esta línea, existen estudios en donde se ha concluido que la ausencia de tejidos contráctiles en una valva, generan ondulaciones no fisiológicas. Por el contrario, se ha señalado la presencia de tejido contráctil en la valva, lo que refleja una activación ondulante. Basado en lo anterior, el objetivo del presente estudio fue determinar la presencia de fibras musculares cardíacas en las cúspides de la VAVI. Se utilizaron 12 cúspides, 6 anteriores y 6 posteriores, de 7 cadáveres adultos (4) y lactantes (3) de distintas edades, sin patologías cardíacas. Las muestras pertenecían a la Facultad de Medicina de la Universidad Estadual de Ciencias da Saúde de Alagoas, Maceió, Brasil. Estas muestras fueron tratadas con procesamiento histológico de rutina. Los hallazgos morfológicos a un aumento de 4x mostraron células musculares que fueron visibles principalmente por el lado atrial en la totalidad de las cúspides, tanto inmersas en el tejido conectivo denso del anillo fibroso como en el tejido conectivo laxo. Al verificar la naturaleza de las fibras con un aumento mayor (100x), se detectaron estrías transversales en todas las muestras estudiadas, lo cual afirma la presencia de fibras musculares estríadas cardíacas en la VAVI. Los resultados obtenidos aportan al conocimiento de la microestructura y tejido contráctil de las cúspides de la VAVI. Por lo tanto, resulta de gran relevancia seguir profundizando en los conocimientos morfológicos de la VAVI, para sentar una base sólida sobre la microestructura contráctil en los diferentes estadíos del ser humano.

Cardiac valves and particularly, the left atrioventricular valve (LAVV) have long been considered passive structures. Nonetheless, there are more recent hypothesis that recognize this structure as a "living valve", with greater autonomy and dynamic function. Along these lines, some studies have concluded that the absence of contractile tissues in a valve, generates non-physiological undulations. In contrast, the presence of contractile tissue in the valve has been reported, reflecting a waving activation. Based on the above, the objective of the present study was to determine the presence of cardiac muscle fibers in the cusps of the LAVV. 12 cusps, 6 anterior and 6 posterior. Therefore, 7 adult (4) and lactating (3) bodies of different ages without cardiac pathologies were used. The samples belonged to the Faculty of Medicine of the Universidade de Ciencias da Saude de Alagos, Maceió, Brazil. The samples were treated with routine histological processing. Morphological findings at an increase of 4x showed muscle cells that were visible mainly from the atrial side in all the cusps, both immersed in the dense connective tissue of the fibrous ring and in loose connective tissue. Transverse striations were detected in all samples studied, when verifying the nature of the fibers with greater increase (100x), confirming the presence of cardiac striated muscle fibers in the LAVV. The results obtained contribute to the knowledge of the microstructure and contractile tissue of the LAVV cusps. Therefore it is relevant to further morphological knowledge of this valve, in order to build a solid foundation on the contractile microstructure in the different stages of the human development.

The role of ubiquitination and deubiquitination in the regulation of cell junctions

Maintenance of cell junctions plays a crucial role in the regulation of cellular functions including cell proliferation, permeability, and cell death. Disruption of cell junctions is implicated in a variety of human disorders, such as inflammatory diseases and cancers. Understanding molecular regulation of cell junctions is important for development of therapeutic strategies for intervention of human diseases. Ubiquitination is an important type of post-translational modification that primarily regulates endogenous protein stability, receptor internalization, enzyme activity, and protein-protein interactions. Ubiquitination is tightly regulated by ubiquitin E3 ligases and can be reversed by deubiquitinating enzymes. Recent studies have been focusing on investigating the effect of protein stability in the regulation of cell-cell junctions. Ubiquitination and degradation of cadherins, claudins, and their interacting proteins are implicated in epithelial and endothelial barrier disruption. Recent studies have revealed that ubiquitination is involved in regulation of Rho GTPases' biological activities. Taken together these studies, ubiquitination plays a critical role in modulating cell junctions and motility. In this review, we will discuss the effects of ubiquitination and deubiquitination on protein stability and expression of key proteins in the cell-cell junctions, including junction proteins, their interacting proteins, and small Rho GTPases. We provide an overview of protein stability in modulation of epithelial and endothelial barrier integrity and introduce potential future search directions to better understand the effects of ubiquitination on human disorders caused by dysfunction of cell junctions.

Termorregulação de pintos de um dia submetidos a ambiente térmico simulado de transporte / Thermoregulation of day-old chickens submitted to simulated transport thermal environment

Objetivou-se, por meio deste trabalho, avaliar a termorregulação de pintos de um dia, mantidos em caixas de transporte, sob condição térmica simulada de transporte. Dois experimentos replicados executados em dias diferentes foram conduzidos em câmara climática. Para cada um dos experimentos, foram utilizados 360 pintos de um dia. Esses animais foram submetidos às condições de frio, conforto e calor, durante uma hora em cada tratamento. Os animais foram mantidos em caixas de transporte de pintos de um dia com quatro compartimentos, sendo cada um deles com 10 animais, totalizando 40 animais por caixa. Foram utilizadas três caixas empilhadas, simulando o que ocorre no caminhão de transporte. Para avaliação fisiológica, foram realizadas as seguintes medidas: frequência respiratória, peso, temperaturas superficial e cloacal. No geral, o posicionamento das caixas não alterou profundamente o conforto térmico dos pintos de um dia. Com relação às faixas térmicas, a condição de frio foi a que mais afetou as respostas fisiológicas, com destaque para as temperaturas superficial média e cloacal. No entanto, com o aumento do tempo de exposição, possivelmente o tratamento térmico por calor possa ter mais efeito sobre a termorregulação desses animais.

An experiment was conducted to assess the thermoregulation of day-old chickens, placed in transport boxes, under simulated transport thermal condition. Two replicated trials were done in two different days in a windowless environmentally controlled chamber. For each one, a total of 360 one-day-old broiler chicks were used. These animals were submitted to three thermal conditions (cold, thermoneutral and heat), for 1 h each. The birds were placed in boxes for day-old chick transport, divided in 40 chicks per box, with three boxes stacked vertically, for each treatment (120 chicks per treatment). Body weight, respiratory frequency, mean surface and cloacal temperature were monitored in a sample of 20 animals per box, with measurements were made before and after the treatments. The box placement had a negligible effect on the thermal comfort of birds. The mean surface and cloacal temperature responses were markedly affected by the cold treatment. However, with an increasing exposure time, the heat treatment might possibly have a clear evidence on the thermoregulation of day-old chickens.

Campilobacteriose genital bovina e tricomonose genital bovina: epidemiologia, diagnóstico e controle / Bovine genital campylobacteriosis and bovine genital trichomonosis: epidemiology, diagnosis and control

A presente atualização trata de duas das mais importantes doenças sexualmente transmitidas de bovinos, a campilobacteriose genital bovina e a tricomonose genital bovina. São abordados aspectos relacionados à epidemiologia destas doenças, principalmente em relação a sua distribuição no Brasil. Também são revisados aspectos importantes de diagnóstico, incluindo as técnicas e interpretação dos resultados, além de medidas de controle para ambas as doenças.

The present update deals with two of the most important sexually transmitted diseases of cattle: bovine genital campylobacteriosis and bovine genital trichomonosis. Epidemiological aspects, mainly their distribution in Brazil, alongside with their diagnosis in cattle are presented and commented. The main points in their diagnoses, including the description of the techniques and the interpretation of the results are also reviewed. Finally the control and prevention of both diseases are discussed.

High levels of serum mannose-binding lectin are associated with the severity of clinical signs of leptospirosis

The clinical heterogeneity observed in leptospirosis may be associated with host factors or bacteria virulence. Human serum mannose-binding lectin (MBL) recognizes many pathogens, and low levels of this lectin are associated with susceptibility to infection. MBL is also implicated in the modulation of the inflammatory process. We determined the levels of serum MBL during leptospirosis infection. A double-antibody sandwich ELISA was used to detect the immunoreactive serum MBL. The ELISA plates were coated with monoclonal antibody to MBL and bound MBL or recombinant human MBL were detected by rabbit anti-human MBL serum. HRPO-conjugated goat anti-rabbit antibody was used for detection of the reaction. Two groups of patients seen at referral hospitals in Recife, PE, Brazil, were divided according to the year of infection, 2001 (N = 61) or 2002 (N = 57) and compared in terms of disease severity and levels of serum MBL. A group of healthy volunteers (N = 97) matched by age, gender, and ethnic background was used as control. Patients infected in 2001 had more severe outcomes than those infected in 2002, including jaundice, hemorrhage, respiratory alteration, and renal complication (P = 0.0009; chi-square test). The frequency of patients producing serum MBL >1000 ng/mL was higher in the 2001 group than in the 2002 and control groups (P < 0.01), suggesting an association of MBL level with disease severity. The involvement of MBL and genetic variation of the MBL2 gene should be further evaluated to establish the role of this lectin in the pathogenesis of leptospirosis.

El adolescente y sus principales motivos de consulta en una unidad especializada. / The adolescent and its principal reasons for consultation in an specialized unit

En este trabajo se dan a conocer las causas que motivan consulta en la Unidad de Adolescencia del Centro de Crecimiento y Desarrollo dependiente del Hospital Roberto del Rio. El universo de trabajo de la Unidad son los adolescentes pertenecientes al Servicio de Salud Metropolitano Norte, referidos desde su establecimiento educacional y/o consultorio correspondiente a su domicilio. Con el fin de ordenar la exposicion del trabajo se dividieron los motivos de consulta en las siguientes areas: Intelectual, Emocional,Sexual y Social. En el analisis de cada area se hace un bosquejo del desarrollo psicologico normal del adolescente (para aclarar asi las causas que lo llevan a consultar a nuestra Unidad), lo que de por si lo desorientan, y que sumado a estimulos ambientales negativos, alteran su equilibrio bio-psico-social