Development, Histological, and Ultrastructural Evaluation of Sheep Hyperimmune Serum Therapy for COVID-19 / Desarrollo, Evaluación Histológica y Ultraestructural de la Terapia con Suero Hiperinmune de Oveja para COVID-19

SUMMARY: In response to the threat posed by new variants of SARS-CoV-2 and the urgent need for effective treatments in the absence of vaccines, the aim of this study was to develop a rapid and cost-effective hyperimmune serum (HS) derived from sheep and assess its efficacy. The utilization of a halal-certified, easily maintained in certain geographic regions, easy-to-handle animal such as sheep could provide a viable alternative to the expensive option of horses. Sheep were immunized with a whole inactivated SARS-CoV- 2 antigen to produce HS, which was evaluated for neutralizing potency using the PRNT50 assay. K18-hACE2 transgenic mice (n=35) were divided into three groups: control, SARS-CoV-2 exposure through inhalation, and SARS-CoV-2 exposed mice treated with HS. HS efficacy was assessed through serum proinflammatory cytokine levels, qRT-PCR analysis, histopathological examination of lungs and hearts, and transmission electron microscopy. Purified HS exhibited significant neutralizing activity (1/24,576). The SARS-CoV-2+HS group showed lower levels of TNF-α, IL-10, and IL-6 (P<0.01) and relatively lower levels of MCP-1 compared to the SARS-CoV-2 group. HS prevented death, reduced viral RNA levels in the lungs and hearts, protected against severe interstitial pneumonia, preserved lung tissue integrity, and prevented myocyte damage, while the SARS-CoV-2 group exhibited viral presence in the lungs. This study successfully developed a sheep-derived HS against the entire SARS-CoV-2 virus, resulting in a significant reduction in infection severity, inflammation, and systemic cytokine production. The findings hold promise for treating severe COVID-19 cases, including emerging viral variants, and immunocompromised patients.

En respuesta a la amenaza que suponen las nuevas variantes del SARS-CoV-2 y la urgente necesidad de tratamientos eficaces en ausencia de vacunas, el objetivo de este estudio fue desarrollar un suero hiperinmune (HS) rápido y rentable derivado de ovejas. y evaluar su eficacia. La utilización de un animal con certificación halal, de fácil mantenimiento en determinadas regiones geográficas y de fácil manejo, como las ovejas, podría proporcionar una alternativa viable a la costosa opción de los caballos. Las ovejas fueron inmunizadas con un antígeno de SARS-CoV-2 completamente inactivado para producir HS, cuya potencia neutralizante se evaluó mediante el ensayo PRNT50. Los ratones transgénicos K18-hACE2 (n = 35) se dividieron en tres grupos: control, exposición al SARS-CoV-2 mediante inhalación y ratones expuestos al SARS-CoV-2 tratados con HS. La eficacia de HS se evaluó mediante niveles de citoquinas proinflamatorias en suero, análisis qRT-PCR, examen histopatológico de pulmones y corazones y microscopía electrónica de transmisión. El HS purificado exhibió una actividad neutralizante significativa (1/24,576). El grupo SARS-CoV-2+HS mostró niveles más bajos de TNF-α, IL-10 e IL-6 (P<0,01) y niveles relativamente más bajos de MCP-1 en comparación con el grupo SARS-CoV-2. HS evitó la muerte, redujo los niveles de ARN viral en los pulmones y el corazón, protegió contra la neumonía intersticial grave, preservó la integridad del tejido pulmonar y evitó el daño de los miocitos, mientras que el grupo SARS-CoV-2 exhibió presencia viral en los pulmones. Este estudio desarrolló con éxito un HS derivado de ovejas contra todo el virus SARS-CoV-2, lo que resultó en una reducción significativa de la gravedad de la infección, la inflamación y la producción sistémica de citocinas. Los hallazgos son prometedores para el tratamiento de casos graves de COVID- 19, incluidas las variantes virales emergentes y los pacientes inmunocomprometidos.

Ultrastructural lesions in the myocardium and kidneys of rabbits in experimental acute Amorimia exotropica poisoning / Lesões ultra-estruturais no miocárdio e rins de coelhos na intoxicação experimental aguda por Amorimia exotropica

Amorimia exotropica is an important plant associated with sudden death in cattle in Southern Brazil. In order to understand the mechanisms by which A. exotropica causes acute lesions in the heart and kidney of intoxicated animals, an experiment was conducted to determine the histopathology and ultrastructure of myocardial and renal lesions of intoxicated rabbits. After receiving 18g/kg of dried plant, six rabbits died suddenly. At necropsy, the liver was swollen and no other macroscopic lesions were observed. Histologically, centrolobular and midzonal hepatocytes were vacuolated. These vacuoles were strong PAS stained positive, suggesting that they corresponded to glycogen accumulations. In some regions of the ventricular septum and ventricles were found vacuoles of different sizes and the kidneys of two rabbits showed vacuolar degeneration on distal convoluted tubules. Ultrastructurally, the myocardium had cardiomyocytes swelling with separation of myofibrils bundles and rupture and disorganization of the sarcomeres. The mitochondria displayed swelling, disorganization, disruption of the mitochondrial cristae, and electron-dense matrix. Some mitochondria exhibited eccentric projections of their membranes with disruption of both outer and inner membranes. The sarcoplasmic reticulum had no alterations, whereas the T-tubule system was occasionally dilated and ruptured. The kidneys had mitochondrial swelling with disorganization and disruption of the mitochondrial cristae. The vacuoles result from the swelling of the endoplasmatic reticulum and usually were located between two basolateral infoldings and mitochondria, occurring preferentially around the nucleus. The myocytes and T system damages induced by A. exotropica result in acute heart failure and death. Furthermore, this mechanism of cardiotoxicity may be common to all plant containing monofluoroacetate.

Amorimia exotropica é uma importante planta associada à morte súbita em bovinos no Sul do Brasil. Visando compreender os mecanismos pelos quais a A. exotropica provoca lesões agudas no coração e rins de animais intoxicados, foi conduzido uma intoxicação experimental em coelhos para determinar a histopatologia e ultraestrutura da lesão miocárdica e renal. Depois de receber 18g/kg de planta seca, seis coelhos morreram subitamente. Na necropsia, o fígado apresentava acentuação do padrão lobular. Os demais órgãos não apresentaram alterações macroscópicas. Histologicamente, os hepatócitos centrolobulares e mediozonais estavam vacuolizados e coraram-se fortemente com PAS. Em algumas regiões foram observados vacúolos de diferentes tamanhos no septo ventricular e ventrículos e os rins de dois coelhos mostraram degeneração vacuolar nos túbulos contorcidos distais. Ultraestruturalmente, o miocárdio apresentou cardiomiócitos tumefeitos com separação das bandas de miofibrilas e ruptura e desorganização dos sarcômeros. As mitocôndrias estavam tumefeitas exibindo desorganização das cristas mitocondriais, e a matriz estava eletrodensa. Algumas mitocôndrias exibiam projecções excêntricas das suas membranas com ruptura das membranas externas e internas. O retículo sarcoplasmático não tinha alterações, e os túbulos T estavam ocasionalmente dilatados e rompidos. Os rins apresentavam tumefação mitocondrial com desorganização e ruptura das cristas mitocondriais. Os vacúolos resultam da expansão do retículo endoplasmático e foram localizados geralmente entre duas invaginações basolaterais e as mitocôndrias, ocorrendo preferencialmente ao redor do núcleo. A lesão nos miócitos e o dano no sistema T induzido pela A. exotropica resultam na insuficiência cardíaca aguda e morte. Este mecanismo de cardiotoxicidade pode ser comum a todas as plantas contendo monofluoroacetato.

Risk factors associated with the transmissionof Brazilian spotted fever in the Piracicaba river basin, State of São Paulo, Brazil

INTRODUCTION : Brazilian spotted fever (BSF) is a disease transmitted by ticks for which the etiological agent is Rickettsia rickettsii. The present essay evaluates the risk factors associated with the transmission of cases of BSF in the time period between 2003 and 2013 in the Piracicaba river basin, state of São Paulo. METHODS : This essay presents a retrospective study to identify the factors associated with the transmission of cases of BSF among all suspected cases identified by the System for Epidemiological Surveillance of São Paulo (CVE). After the description of temporal distribution (onset of symptoms) and the environmental and demographic variations of the confirmed and discarded cases, a multiple logistic regression model was applied. RESULTS : We searched 569 probable locations of infection (PLI) with 210 (37%) confirmed cases of BSF and 359 (63%) discarded cases. The associated variables for the confirmation of BSF in the multiple logistic model using a confidence interval (CI) of 95% were age (OR = 1.025 CI: 1.015-1.035), the presence of Amblyomma sculptum in the environment (OR = 1.629 CI: 1.097-2.439), the collection of ticks from horses (OR = 1.939 CI: 0.999-3.764), the presence of capybaras (OR = 1.467 CI: 1.009-2.138), an urban environment (OR = 1.515 CI: 1.036-2.231), and the existence of a dirty pasture (OR = 1.759 CI: 1.028-3.003). CONCLUSIONS : The factors associated with the confirmation of BSF cases included an urban environment, age, presence of the A. sculptum vector, the collection of ticks from horses, the presence of a capybara population, and a dirty pasture environment. .

Alteraciones morfo-cardiovasculares producidas por bacterias periodontopatógenas en modelo murino / Morphological and cardiovascular alterations produced by periodontopathic bacteria in a murine model

Diferentes autores han descrito a la enfermedad periodontal como un factor de riesgo de ateroesclerosis. Este estudio tuvo como objetivo determinar la posible relación entre las bacterias periodontopatógenas y alteraciones cardiovasculares en modelos murinos con ingesta hiperlipídica. Se utilizaron 30 ratas Wistar divididas en un grupo control (n=5) y tres grupos experimentales (n=15): Grupo I (n=5): dieta normal e infectados; Grupo II (n=5): dieta hiperlipídica y sin infectar y Grupo III (n=5): dieta hiperlipídica e infectados. La infección del surco gingival se logró previa sedación a través de hilos de sutura contaminados, colocados durante 6 días consecutivos, con Pophyromonas gingivalis (P. gingivalis) (5x10a-4 UFC) y Agregatibacter actinomycetemcomitans (A. actinomycetemcomitans) (5x10-4 UFC) obtnidas de muestras de pacientes con periodontitis crónica. A los 30 días posinfección se fijaron muestras de corazón y arteria aorta para su procesamiento. En el grupo control no se encontraron alteraciones. En el grupo I se observó en el endocardio valvular abundante exudado fibrinoleucocitario y focos hemorrágicos. En el miocardio, neovascularización y sufusiones hemorrágicos y en la pared de vasos arteriales, engrosamiento intimal. En el grupo II se observaron depósitos lipídicos en el interior de las células endoteliales, estrías grasas y pequeños ateromas. El grupo III mostró en un 100 por ciento de los casos, placas ateromatosas bien detalladas con abundante depósito de colesterol, calcificaciones, hemorragias y neovascularización. La suma de estos factores de riesgo: dieta hiperlipídica e infección con bacterias periodontopatógenas, potenciarían la expresión de alteraciones cardíacas y coronarias, incrementando la formación de ateromas

Light and electron microscopic study on the effect of diazepam on the cardiac muscle of adult albino rat and the possible role of garlic

Diazepam is a drug that belongs to a group of pharmacological agents called benzodiazepines. Several studies have indicated that diazepam exerts a myocardial depressant effect. Garlic preparations have been used widely for the prevention and treatment of cardiovascular conditions. This work aimed to study the effect of diazepam on the cardiac muscle of adult albino rat and the possible role of garlic as a protective agent. Forty adult male albino rats were divided into four equal groups: control group, garlic-treated group [250mg/kg body weight], diazepam-treated group [1mg/kg body weight], and both garlic and diazepam-treated group. The animals were treated orally daily for 4 weeks. Specimens from the cardiac muscle were processed for light and electron microscopy. Immunohistochemical study was carried out using an antibody against vimentin. Specimens from diazepam-treated animals showed focal disruption of cardiac myocytes, peripheral deeply stained nuclei, and vacuolated sarcoplasm. Focal aggregation of mononuclear cells and dilated congested blood vessels were also observed in between the myocytes. Ultrastructurally, irregular indented nuclei, focal lysis of the myofibrils, loss of normal cross striations, swelling of mitochondria, and distortion of intercalated disks were also observed. Immunohistochemical study showed a highly significant increase in vimentin immunoreaction in the endomysial and perimysial sheaths, in the walls of blood vessels, and in some interstitial cells. In contrast, minimal changes were observed in rats treated concomitantly with both garlic and diazepam, with a non significant increase in the immunoreaction. Diazepam induced structural changes in rat cardiac muscle that could be ameliorated by concomitant treatment with garlic

Clinical and ultramicroscopic myocardial randomized study of beating versus arrested heart for mitral surgery / Estudo randomizado clínico e ultramicroscópico na cirurgia valvar mitral com o coração com atividade elétrica versus sem atividade elétrica

INTRODUCTION: Beating heart surgery on normothermic bypass simulates physiologic cardiac status. OBJECTIVES: This study compared clinical and transmission electron microscopic aspects of myocardial protection during mitral valve replacement using warm retrograde perfusion in empty beating versus arrested heart with cold blood anterograde cardioplegia. METHODS: Randomized study to evaluate myocardial cellular ischemia-reperfusion of both techniques to replace the mitral valve. Thirty-four patients were randomly assigned into group A (beating heart) and group B (arrested heart). The following parameters were assessed: echocardiography, blood chemistry, hemoglobin, lactate. During the surgical procedure a total of 102 myocardial biopsies were performed for ultrastructural analysis from anterior left ventricular wall: before cardiopulmonary bypass, before aortic desclamping and 10 minutes after reperfusion. RESULTS: Elevation of lactate at 3 hours during the procedure was higher in group A, but similar at the end of surgery (P=0.06). Cardioversion was necessary in 5/17 (A) vs. 13/17 (B) P=0.07. Median intraoperative systemic temperature was significantly lower in the group B compared to A (32oC vs. 36oC), P<0.001. There was no significant difference of the ultramicroscopic aspects of the heart biopsies before, during and after surgery in both groups. Cellular and mitochondrial transient abnormalities such as mitochondrial swelling, glycogen loss and cytosol swelling were detected independently of the moment of the biopsies. CONCLUSION: Myocardial protection and ultrastructural abnormalities were similar for both types of mitral valve replacement beating or arrested heart techniques.

INTRODUÇÃO: A cirurgia valvar mitral pode ser realizada com o coração com atividade elétrica, vazio e normotérmico com pinçamento aórtico, perfusão sanguínea no seio coronário, simulando um estado fisiológico. OBJETIVOS: Comparar as manifestações clínicas e ultramicroscópicas do miocárdio, na cirurgia valvar mitral, com o coração com atividade elétrica versus sem atividade elétrica. MÉTODOS: Estudo randomizado constituído de 34 pacientes: grupo A (batendo) e grupo B (parado). Os parâmetros foram: hematológico, bioquímico, ecocardiográfico, lactato. Foram realizadas 102 biopsias da parede anterior do ventrículo esquerdo preparadas para análise ultraestrutural: antes da circulação extracorpórea, antes do despinçamento aórtico e 10 minutos após a interrupção da circulação extracorpórea. RESULTADOS: Verificou-se elevação do lactato 3 horas após o início do procedimento, que foi maior no grupo A (P=0,06), todavia semelhantes no final da cirurgia. A cardioversão foi necessária em (A) 5/17 vs. (B) 13/17, P=0,07. A temperatura intraoperatória média foi significativamente menor no grupo B em relação ao grupo A (32oC vs. 36oC), P<0,001. A análise ultramicroscópica das amostras das biopsias do coração antes da circulação extracorpórea, ao término do pinçamento aórtico e após a saída da circulação extracorpórea, revelou anormalidades transitórias semelhantes no citoplasma, núcleos e mitocôndrias em ambos os grupos, independentemente do momento das biopsias. CONCLUSÃO: A proteção miocárdica na cirurgia valvar mitral apresentou aspectos semelhantes na preservação da integridade ultraestrutural dos cardiomiócitos quando realizada com o coração com ou sem atividade elétrica.

Estudo dos efeitos da radioterapia no tecido cardíaco e sua associação com o metabolismo energético / Study of the effects of radiation therapy in cardiac tissue and its association with energy metabolism

Durante o tratamento radioterápico para tumores localizados na região torácica, parte do coração frequentemente é incluída no campo de tratamento e pode receber doses de radiação ionizante, significativas em relação à terapêutica. A irradiação do coração é capaz de causar importantes complicações cardíacas ao paciente, caracterizadas por alterações funcionais progressivas cerca de 10 a 20 anos após a exposição do órgão. Devido ao seu alto grau de contração e grande consumo energético, o tecido cardíaco é altamente dependente do metabolismo oxidativo que ocorre nas mitocôndrias. Danos as estas organelas podem levar ao decréscimo da produção de energia, tendo um impacto direto sobre a performance cardíaca. Ainda, ao interagir com as células, a radiação ionizante pode gerar uma série de eventos bioquímicos que conduzem a uma resposta celular complexa, em que muitas proteínas parecem estar envolvidas. Tendo em vista tais conhecimentos, o objetivo do estudo foi avaliar o aspecto ultraestrutural do tecido cardíaco, a bioenergética mitocondrial e a expressão diferencial de proteínas após irradiação. Os ensaios foram realizados em amostras de tecido cardíaco de ratos Wistar irradiados com dose única de 20 Gy direcionada ao coração. As análise tiveram início 4 e 32 semanas após irradiação. A análise ultraestrutural foi realizada através de microscopia eletrônica de transmissão. A respiração mitocondrial foi mensurada em oxígrafo, a partir das taxas de consumo de oxigênio pelas fibras cardíacas. A identificação de proteínas diferencialmente expressas foi investigada através de duas técnicas proteômicas: 2D-DIGE (2-D Fluorescence Difference Gel Electrophoresis) e uma abordagem label-free seguida de espectrometria de massas. Os resultados mostraram que os efeitos tardios da radiação incluem a degeneração das mitocôndrias e das unidades contráteis do tecido cardíaco, disfunções na cadeia respiratória mitocondrial e expressão diferencial de proteínas...

During radiotherapy for tumors located at toracic region, part of the heart is often included in the treatment field and may receive a significant ionizing radiation dose comparing to the therapeutics. Heart irradiation is able to cause substantial cardiac complications to patient, characterized by functional progressive changes from 10 to 20 years after the exposure of the organ. Because of its high level of contraction and large energetic consumption, cardiac tissue is highly depending on oxidative metabolism which happens at mitochondrias. Damage to these organelles can lead to decreased energy production, having a direct impact on cardiac performance. Even when interacting with cells, ionizing radiation can generate a series of biochemical events that lead to a complex cellular response, in many proteins seem to be involved. Given this knowledge, the aim of the study was to evaluate the ultrastructural appearance of cardiac tissue, mitochondrial bioenergetics and differential expression of proteins after irradiation. The tests were performed on samples of cardiac tissue of rats irradiated with single dose of 20 Gy directed to the heart. The analysis started 4 to 32 weeks after irradiation. The ultrastructural analysis was performed by transmission electron microscopy. Mitochondrial respiration was measured in oxigraph from rates of oxygen consumption by cardiac fibers. The identification of differentially expressed proteins was investigated using two proteomic techniques: 2D-DIGE (2-D Fluorescence Difference Gel Electrophoresis) and a label-free approach followed by mass spectrometry. The results showed that the late effects of radiation include degeneration of mitochondria and contractile units of cardiac tissue, dysfunction in the mitochondrial respiratory chain and differential expression of proteins involved in energy metabolism of carbohydrates, lipids and phosphocreatine. In general, the study showed that the cardiac irradiation damages...

Sanguineous normothermic, intermittent cardioplegia, effects on hypertrophic myocardium: morphometric, metabolic and ultrastructural studies in rabbits hearts / Efeitos da cardioplegia sanguínea normotérmica intermitente, em miocárdio hipertrófico: estudos morfométricos, metabólicos e ultraestruturais em corações coelhos

OBJECTIVES: The present investigation aimed to study the protective effect of intermittent normothermic cardioplegia in rabbit's hypertrophic hearts. METHODS: The parameters chosen were 1) the ratio heart weight / body weight, 2) the myocardial glycogen levels, 3) ultrastructural changes of light and electron microscopy, and 4) mitochondrial respiration. RESULTS: 1) The experimental model, coarctation of the aorta induced left ventricular hypertrophy; 2) the temporal evolution of the glycogen levels in hypertrophic myocardium demonstrates that there is a significant decrease; 3) It was observed a time-dependent trend of higher oxygen consumption values in the hypertrophic group; 4) there was a significant time-dependent decrease in the respiratory coefficient rate in the hypertrophic group; 5) the stoichiometries values of the ADP: O2 revealed the downward trend of the values of the hypertrophic group; 6) It was possible to observe damaged mitochondria from hypertrophic myocardium emphasizing the large heterogeneity of data. CONCLUSION: The acquisition of biochemical data, especially the increase in speed of glycogen breakdown, when anatomical changes are not detected, represents an important result even when considering all the difficulties inherent in the process of translating experimental results into clinical practice. With regard to the adopted methods, it is clear that morphometric methods are less specific. Otherwise, the biochemical data allow detecting alterations of glycogen concentrations and mitochondria respiration before the morphometric alterations should be detected.

OBJETIVOS: O presente estudo teve como objetivo estudar o efeito protetor da cardioplegia normotérmica intermitente em corações hipertróficos de coelhos. MÉTODOS: Os parâmetros escolhidos foram: 1) relação peso cardíaco/peso corporal; 2) níveis de glicogênio nos músculos cardíacos; 3) alterações ultraestruturais por microscopia óptica e eletrônica; e 4) respiração mitocondrial. RESULTADOS: 1) O modelo experimental de coarctação da aorta induziu hipertrofia ventricular esquerda; 2) a evolução temporal dos níveis de glicogênio no miocárdio hipertrófico demonstra que há diminuição significativa; 3) observou-se tendência dependente do tempo para maiores valores do consumo de oxigênio para o grupo hipertrófico; 4) houve diminuição dependente do tempo da taxa de coeficiente respiratório no grupo hipertrófico; 5) os valores estequiométricos da ADP: O2 revelou a tendência decrescente no grupo hipertrófico; 6) observaram-se lesões mitocondriais do miocárdio hipertrófico, enfatizando a grande heterogeneidade dos dados. CONCLUSÃO: A aquisição de dados bioquímicos, principalmente o aumento na velocidade de quebra do glicogênio, quando mudanças anatômicas não são detectadas, representa um resultado importante, mesmo quando se consideram todas as dificuldades inerentes ao processo translacional de resultados experimentais para a prática clínica. No que diz respeito aos métodos adotados, é evidente que os métodos morfométricos são menos específicos. Os dados bioquímicos permitem a detecção de alterações das concentrações de glicogênio e respiração mitocondrial antes das alterações morfométricas serem detectadas.

Ponte miocárdica associada a lesões cardiovasculares em bovinos adultos da raça Canchim / Myocardial bridge associated with cardiovascular injuries in bovines adult of Canchim race / Puente miocárdico asociado a lesiones cardiovasculares en bovinos adultos de la raza canchim

FUNDAMENTO: A influência que a ponte miocárdica exerce sobre a corrente sanguínea no curso do segmento arterial sob a ponte tem sido objeto de discussão pela comunidade científica. OBJETIVO: Comparar o tecido muscular ultraestrutural da ponte miocárdica e a parede ventricular; analisar o grau de lesão da camada íntima dos segmentos arteriais e investigar possíveis mudanças que podem preceder ou iniciar o processo de lesões ateroscleróticas. MÉTODOS: Quarenta corações bovinos da raça Canchim foram estudados em relação às alterações da camada íntima das artérias coronarianas nos diferentes segmentos de ponte miocárdica. Para o exame microscópico, foram feitas colorações por hematoxilina-eosina e fucsina-resorcina seguindo técnicas microscópicas convencionais. Para o exame de microscopia eletrônica, os segmentos da ponte miocárdica de doze corações bovinos Canchim foram coletados a partir da parede ventricular e da artéria coronariana e foram processados de acordo com técnicas convencionais. RESULTADOS: Na microscopia de luz, foi observada maior frequência de lesões em segmentos pré-ponte e pós-ponte da camada íntima, em comparação ao segmento ponte. Espessamentos da camada íntima foram seguidos por um desarranjo na lâmina limitante elástica interna. Essas células frequentemente apresentaram seus citoplasmas ingurgitados por gotas lipídicas, compondo as chamadas células de espuma. A microscopia eletrônica revelou que as fibras musculares da ponte miocárdica geralmente se unem de forma reta e lisa apresentando ramos laterais com um número maior de mitocôndrias no músculo ventricular do que na ponte. CONCLUSÃO: Há poucas diferenças entre os tecidos musculares estudados; lesões da camada íntima são menos frequentes em regiões da ponte em comparação com as regiões pré e pós-ponte.

BACKGROUND: The influence that myocardial bridge exercises over blood stream in the course of arterial segment under the bridge has been discussed by the scientific community. OBJECTIVE: To compare ultrastructural muscle tissue of myocardial bridge and the ventricular wall; to analyze the degree of injury to the tunica intima of the arterial segments, and look for possible changes that may precede or initiate the process of atherosclerotic lesions. METHODS: Forty Canchim bovine hearts were studied regarding alterations of the tunica intima from coronary arteries on the different myocardial bridge segments. For the microscopic examination, hematoxylin-eosin and fuchsin-resorcin staining following conventional microscope techniques were made. For the electronic microscopic examination, myocardial Bridge segments from twelve Canchim bovine hearts were collected from the ventricle wall and coronary artery and were processed according to conventional techniques. RESULTS: In the light microscopy, a higher frequency of lesions on prepontine and postpontine segments of the tunica intima was observed, compared to the pontine segment. Tunica intima thickenings were followed by a disarrangement on the internal elastic limitant lamina. These cells often presented their cytoplasmas engorged by lipidic drops, making up the so-called foam cells. Electronic microscopy revealed that the muscular fibers of the myocardial bridge are usually joined in a straight and smooth way presenting lateral branches with a greater number of mitochondria in the ventricular muscle than in the bridge. CONCLUSION: There are few differences between the muscle tissues studied; intimae lesions are less frequent in pontine regions compared to pre and post-pontine regions.

FUNDAMENTO: La influencia que el puente miocárdico ejerce sobre la corriente sanguínea en el transcurso del segmento arterial bajo el puente, ha sido objeto de discusión por parte de la comunidad científica. OBJECTIVO: Comparar el tejido muscular ultra estructural del puente miocárdico y la pared ventricular; analizar el grado de lesión de la capa íntima de los segmentos arteriales e investigar posibles cambios que pueden preceder o iniciar el proceso de lesiones ateroscleróticas. MÉTODO: Cuarenta corazones bovinos de la raza Canchim fueron estudiados con respecto a las alteraciones de la capa íntima de las arterias coronarias en los diferentes segmentos del puente miocárdico. Para el examen microscópico, se hicieron coloraciones por hematoxilina-eosina y fucsina-resorcina secundando las técnicas microscópicas convencionales. Para el examen de microscopía electrónica, los segmentos del puente miocárdico de doce corazones de bovinos de la raza Canchim, fueron recolectados así como de la pared ventricular y de la arteria coronaria y fueron procesados de acuerdo con las técnicas convencionales. RESULTADOS: En la microscopía de luz, observamos una mayor frecuencia de lesiones en segmentos de pre puente y pos-puente de la capa íntima, en comparación con el segmento puente. Los espesamientos de la capa íntima vinieron acompañados por un desarreglo en la lámina limitante elástica interna. Esas células a menudo presentan sus citoplasmas ingurgitados por gotas lipídicas, lo que compone las llamadas células de espuma. La microscopía electrónica reveló que las fibras musculares del puente miocárdico generalmente se unen de forma recta y lisa, presentando ramas laterales con un número mayor de mitocondrias en el músculo ventricular que en el puente. CONCLUSIONES: Existen pocas diferencias entre los tejidos musculares estudiados. Las lesiones de la capa íntima son menos frecuentes en las regiones del puente en comparación con las regiones pre y pos puente.

Comparative study on the effects of grape seed extract and telmisartan on doxorubicin-induced cardiotoxicity in adult male rats: light and electron microscopic study

Doxorubicin [DOXO] is a chemotherapeutic agent used effectively for the treatment of several malignancies. The major side effect of DOXO is oxidative injury-related cardiotoxicity, which has markedly hindered its usage. Grape seed extract [GSE] has been reported to exert protective effects on DOXO -induced cardiotoxicity. However, studies have suggested that the angiotensin receptor blocker [telmisartan] may also play a protective role in DOXO -induced cardiotoxicity. The aim of this work was to determine the effect of DOXO on rats' hearts and to compare the effects of GSE and telmisartan against DOXO -induced cardiotoxicity. Thirty adult male albino rats were used. They were divided into six groups of five animals each. Group I served as a control. Group II was administered a single intraperitoneal injection of DOXO [20mg/kg]. Group III received GSE, which was administered daily by a gavage at a dose of 100mg/kg for 12 days and DOXO was administered on the seventh day as in group II. Group IV received telmisartan, which was administered daily by a gavage at a dose of 10mg/kg for 12 days and DOXO was administered on the seventh day as in group II. Group IV received telmisartan, which was administered on the seventh day as in group II. Group V received GSE alone for 12 days. Group VI received telmisartan alone for 12 days. At the end of the experiment, the heart was prepared for histological examination and morphometric studies were carried out. It was found that DOXO exerted deleterious effects on the heart structure. GSE and telmisartan exerted a protective effect against DOXO-induced heart damage. The present study indicated that DOXO affected the structure of the rat's heart, which could be protected by GSE and telmisartan. However, the protective effect of GSE on DOXO-induced cardiac injury needs further researches for a longer duration of time to obtain more definitive results

Postmortem diagnosis of early myocardial infarction in adult albino rats

Postmortem diagnosis of early myocardial infarction is still a puzzling problem in forensic pathology practice, especially in sudden cardiac death. Forensic autopsy data shows that sudden cardiac death victims usually die in less than 6 h after acute myocardial infarction occurs. Postmortem diagnosis of early myocardial infarction within the first 6 hours based on biochemical and morphologic changes. Rats divided into control group and operated group which had a ligation of The left anterior descending coronary artery. The rats were killed at 5, 15, 30, 60, 120, 240 and 360 mines post ligation intervals. Serum and myocardial tissue samples was collected from two groups at the previous postmortem time intervals for measurement of Creatine kinase- MB, Troponin I [CTnl], myoglobin and histopathological examination by light and electron ; microscopy . The same work was repeated after induction early acute myocardial infarction by beta- adrenergic shock and by lethal hemorrhage. Levels of CK-MB and CTnl had statistical significant rise with increasing postmortem intervals whatever method of myocardial infarction induction, but myoglobin level was less sensitive in different methods of induction. Ultrastructural changes were detected after 30 mines post-mortem in different methods of induction. Diagnosis of early myocardial infarction can be performed within the first postmortem six hours Depending on biochemical and morphological changes

Structural adaptations of the heart to physical exercises in the metabolic syndrome

The objective of this investigation was to conduct a literature review on the structural adaptations of the heart to physical exercises in the Metabolic Syndrome. The search was conducted in the following electronic databases: PubMed, Web of Sciences, LILLACS and MEDLINE using keywords in English without time restrictions. The metabolic syndrome (MS) is characterized by a group of metabolic risk factors in a person. In Brazil, more than 300.000 people die every year of cardiovascular diseases. According to the Brazilian Ministry of Health, there are currently over 20 million hypertensive and 15 million have diabetes in the country, and this rate is increasing. Physical inactivity, in most individuals, leads to well characterized structural and functional cardiovascular alterations such as myocyte loss with subsequent hypertrophy of the remaining cells and reduction of the arterial complacency. However, the etiology of the cardiovascular alterations is still under investigation. The most likely mechanisms are related to the cumulative harm and several different aggressive factors. Oxidative stress, inflammations, and changes in cardiovascular gene expression seem to influence this system. The benefits of physical exercises have been studied combined with pharmacotherapy offering the opportunity of intervention in the process by using exercises and drugs that can reduce arterial rigidity, cardiac fibrosis, and ventricular hypertrophy.

Application of confocal laser scanning microscope in forensic pathology / 法医学杂志

Confocal laser scanning microscopy(CLSM) is a new technique for microscopic imaging, which can collect the transverse section image of the samples and produce three-dimensional reconstruction and present higher spatial resolution than the conventional light microscope. As a precision instrument for the microscopic image, it plays an important role in forensic pathology. The article reviews the recent research achievements from sudden cardiac death, bullet wound and nervous system damage, etc, and explores the potential applications of the forensic pathology research and forensic practice.

[Ultra structure study of lead acetate cytotoxic effects on heart tissue in rabbit]

Lead is one of the world wide using metals that have been used since ancient time. It is also a toxin, known to have adverse effects on the body even at low level of exposure and it induces a bread range of physiological, biochemical and behavioral dysfunctions. Studies have shown that this metal has harmful effects on several tissues such as nervous system, blood tissues, cardiovascular system, reproductive and urinary system. In this experimental study white male rabbits of New Zealand race were used and divided into two groups. Experimental group [N=10] 6.5 mg/kg of lead acetate were injected intra peritoneal every other day to each animal for 7 weeks as chronic dose and control group [N=10] were injected only with demonized water. After taking biopsy from left ventricular heart tissues of each group, tissue preparation was performed for LM and EM studies as standard method. Morphologic study was carried out on electron micrographs. Data have been compared with statistical methods. Electron microscopic study revealed the nuclei of left ventricular muscles were heterochromatin appearance and abnormality and vacuolization in mitochondria in experimental group when compared with control group. Morphological findings in experimental group showed that histological tissue changes have been more significant to control group [p<0.05]. These results suggest that lead acetate had severing effects on heart tissue during chronic dose.

Análise ultra-estrutural do miocárdio usando solução cardioplégica cristalóide com e sem procaína em pacientes submetidos à troca valvar aórtica / Ultrastructural study of the myocardium using cardioplegic crystalloid solution with and without procaine in patients undergoing aortic valve replacement

OBJETIVO: Avaliar as alterações ultra-estruturais de dois tipos de cardioplegia (com e sem procaína) em corações de pacientes submetidos a troca valvar aórtica eletiva. MÉTODOS: Foram estudados 18 pacientes submetidos a circulação extracorpórea para troca valvular aórtica eletiva, no Hospital de Clínicas de Porto Alegre num período de 10 meses. Cada paciente foi distribuído aleatoriamente em dois grupos: grupo A - oito pacientes que receberam solução cardioplégica sem procaína; grupo B - Dez pacientes que receberam solução cardioplégica com procaína. Em ambos os grupos, o saco pericárdico foi irrigado com solução salina hipotérmica. As biópsias miocárdicas foram realizadas em três momentos: I - antes da parada isquêmica, II- no final do período isquêmico e III-15 minutos após a reperfusão. RESULTADOS: A avaliação ultra-estrutural comparando os grupos nos três momentos não demonstrou diferenças significativas, sendo a média dos escores no grupo A, nos momentos I, II, e III, de 0,1 ± 0,2; 0,4 ± 0,3 e 0,4 ± 0,4. No grupo B, a médio dos escores foi 0,2 ± 0,2; 0,4 ± 0,3 e 0,7 ± 0,2, respectivamente), nos momentos I, II, e III. A curva de CK-MB foi similar entre os dois grupos. O retorno espontâneo do ritmo cardíaco, pós-despinçamento, ocorreu em 70% dos pacientes no grupo B e, em 12,5% no grupo A (p=0,024). CONCLUSÃO: As duas soluções testadas protegeram o miocárdio de forma eficaz e não foi possível demonstrar, em nível ultra-estrutural, a superioridade da solução contendo procaína. Constatou-se que o retorno ao ritmo espontâneo do coração após o despinçamento aórtico foi significativamente maior no grupo que utilizou procaína adicionada à solução.

OBJECTIVE: The aim of this study was to assess whether the presence of procaine in crystalloid cardioplegic solution increases myocardial protection at the ultra structural level. METHODS: Eighteen patients that underwent aortic valve replacement in the Hospital de Clínicas de Porto Alegre over a 10-month period were studied. They were randomly allocated into two groups: group A - eight patients receiving cardioplegia without procaine; group B - ten patients receiving cardioplegia with procaine. Myocardial biopsies were performed in three different periods: 1st - before ischemic arrest, 2nd - at the end of ischemic arrest, and 3rd -15 minutes after reperfusion. RESULTS: The ultra structural analysis comparing the groups in the three moments did not show any statistically significant difference. The mean score in group A at moment I, II and III was 0.1 ± 0.2; 0.4 ± 0.3; 0.4 ± 0.4, and group B 0.2 ± 0.2; 0.4 ± 0.3; 0.7 ± 0.2. Comparative analysis of CK-MB was similar. The spontaneous return to sinus rhythm after aortic declamping in group B occurred in 70% and in group A 12.5% (p=0.024). CONCLUSION: Both cardioplegic solutions tested were equally effective in myocardial preservation, and we could not demonstrate at the ultrastructural level any benefit when procaine was added. The spontaneous return to sinus rhythm after aortic declamping was significantly greater when procaine was added.

Hallazgos histológicoultraestructurales característicos de las células madres (stem cell embriónico fetales): primer reporte internacional / Ultra structural histologic findings characteristic of embryonic fetal stem cells: first international report

Se buscó la evidencia de crecimiento muscular o biogénesis que debería haberse iniciado a partir del transplante de Stem cell embriónico fetales de donantes con el propósito de observar los dos tipos de ADN distintos tanto del receptor como del donante. Materiales y métodos: esta investigación se realizó luego de recibir fragmentos de músculo cardiaco del ventrículo izquierdo en los cuales se implantaron dichas células directamente en el miocardio mediante 80 inyecciones de 1ml cada una en todas las paredes de ambos ventrículos, con especial énfasis en el izquierdo. Las biopsias fueron fijadas con glutaraldehido al 3, post-fijazas con Tetraóxido de Osmio al 1, deshidratadas en diversos gradientes ascendentes de alcohol etílico, preembedidas en Oxido de propileno, embebidas en resina Spurr para realizar los bloques, los cuales fueron cortados por ultramicrotomía, teñidas con acetato de uranilo y citrato de plomo, y finalmente observadas al Microscopio Electrónico de Transmisión JEOL- JEM 1010. Resultados: lo más relevante en esta investigación son los hallazgos encontrados en las mitocondrias que se presentaban hipertróficas, redondeadas con crestas vesiculares, siendo lo distintivo y el más importante hallazgo la presencia de una banda recta trilaminar con una estructura central electrondensa proteica, la misma que atraviesa perpendicularmente en toda la longitud de la mitocondria, formando una “Barra germinativa pluripotencial mitocondrial”, hallazgo propio distintivo de las células Madre. Conclusiones: siendo en la mitocondria esta inusual barra recta transversal electrondensa un importante aporte científico distintivo que identificaría plenamente a las células transplantadas del tipo de Stem cell embriónico fetales, diferentes a las mitocondrias con crestas cortas irregulares onduladas paralelas vacías, dando con esto una diferenciación característica que determinaría su capacidad de ser pluripotencial y de autorenovación.

We looked up an evidence of muscle growth or biogenesis that should have started from the transplant of embryonic fetal stem cells from donors in order to observe the two distinct AND types of both, the receptor and the donor. Materials and methods: this research was made after receiving fragments of the left ventricle cardiac muscle where those cells were implanted directly in the myocardio by means of 80 injections of 1 ml each in all the walls of both ventricles, with special stress in the left one. Biopsies were fixed with 3 glutaraldehido, post fixed with 1 Osmio Tetraoxide, dehydrated in different ascending gradients of ethyl alcohol, pre soaked in propylene oxide, soaked in Spurr resin to make the blocks which were cut by ultramicrotomy, dyed with uramil acetate and lead citrate, and finally observed at the JEOL – JEM 1010 Transmission Electronic Microscope. Results: the most outstanding facts in this research are the findings met in the mitochondrion that were hypertrophic, rounded with vesicular crests, and what makes difference and the most important finding is the presence of a tri-laminar straight strip with a central proteinic electrodense structure which crosses perpendicularly the mitochondrion in its whole length, giving form to a “Mitochondrial pluripotential germinative Bar” distinctive finding of stem cells. Conclusions: this unusual electrodense, transverse, straight bar is an important scientific contribution and a distinctive that would identify completely the transplanted stem cells embryonic fetal type, different from mitochondrion with short irregular wavy, parallel, empty crests, giving this way a characteristic differentiation that would determine their capability of being pluripotential and with self-renovation.

Histological study on the effect of heat stress on cardiac muscle of adult male albino rats and the possible role of mast cells

Heat stress causes serious physiological dysfunction that may result in heat related diseases. The cardiovascular system has been considered the primary target of heart stress. The mechanism of heat stress- induced myocardial damage remains unclear. Recent findings indicate that mast cells are not only necessary for allergic reaction, but they also involved in a variety of neuro inflammatory diseases especially those worsened by stress. This work was aimed to study the effect of heat stress on the myocardium of rats and to clarify the possible role of mast cells in this process. This study was performed on 30 adult male albino rats, divided into three equal main groups [10 rats/ each]; the first main group was control, divided into two equal subgroups [5 rats/ each], the first subgroup [A] was negative control, the second subgroup [B] received 1 ml sterile saline I.P daily for 15 days. The second main group was heat-stressed group which was exposed to heat stress [39°C for 2 hours daily] and the third main group was mast cell stabilized group that received 10 mg/kg/b.w of doxantrazole followed by exposure to heat stress [the same as the second main group], half an hour after drug intake. All rats were sacrificed after 15 days and heart sections were processed. Paraffin sections were stained with H and E, masson trichrom [M.T] and toluidine blue for histological study. Other sections were processed for immuno histochemical demonstration of actin and caspase- 3. Other very small pieces of heart sections were processed for electron microscopic study [E.M]. The cardiac muscle of stressed second group revealed focal areas of necrosis, areas of vaculations with loss of characteristic striations and mononuclear cell infiltration. Congestion and extravasation of blood with odema fluid between cardiac muscle fibers were evident. Excessive collagen fibers deposition was also seen. Decreased reaction for actin and strong+ve reaction for caspase-3 in the affected fibers were demonstrated. Moreover hyperplasia and activation with degranulation of mast cells were documented in C.T endomesium. On ultrastructural level, the same group showed disorganized and fragmented microfilaments and mitochondrial changes. Moreover, degranulated mast cells were documented in the C.T endomesium. On the other hand, non of these changes were observed in cardiac muscles of mast cell stabilized group with the exception of slight congestion and minimal fibrosis in the interstitium and perivascular areas at light microscopic level. It is concluded that heat stress induced histological and ultra structural changes in myocardium and these changes could be mast cell mediated. Such study provided further support for the role of mast cells in stress induced myocardial damage and therefore it might provide a novel medical strategy and therapeutic target in management of heat stress induced cardiomyopathy. Furthermore, stress exposure should be avoided or minimized as much as possible to seek for good health

Effect of induced iron deficiency and iron supplementation on the myocardium of the left ventricle of post weaned male albino rat. A light and electron microscopic study

Numerous studies have demonstrated the negative impact of iron deficiency on the growth and development. This study was designed to evaluate the effect of iron deficiency on the myocardium of the left ventricle of heart as well as their recovery whether by the therapeutic administration of iron or by balanced diet. Thirty six post weaned male albino rats were divided into three groups. Group I [12 rats] represented the control group receiving balanced diet [containing 36 mg iron/kg diet] and was equally subdivided into subgroup I-A and subgroup I-B according to duration of the experiment. Group II [12 rats] in which iron deficiency state was induced using a deficient diet [5 mg iron/kg diet] for 6 weeks. Group III [12 rats] represented the recovery group. They received iron deficient diet [5 mg/kg] similar to group II and according to the recovery regimen, this group was further subdivided into subgroup III-A [received balanced diet for further 2 weeks] and subgroup III-B [received oral supplementation of iron [9.45 mg/kg. body weight/day] along with the balanced diet for 2 weeks. Blood samples were collected for measuring hemoglobin concentration and chemical analysis for iron. Animals were sacrificed and their hearts were processed for both light and electronmicroscopic examinations. Iron deficiency resulted in vacuolation of left ventricular myocytes, pyknotic nuclei with mitochondrial swelling and disorganization. The sarcomeres were irregularly organized with focal degeneration and discontinuity of myofilaments. There was apparent thickening of the left ventricular muscle fibers. Recovery groups revealed evidence of mild regeneration in subgroup III-A and nearly complete recovery in subgroup III-B. Iron supplementation is essential to recover the changes associating iron deficiency

Histological study of the effect of methamphethamine on the cardiac muscle of albino rats

Abuse of methamphetamine has become a major world-wide health problem. Because of the limited work that had been done looking at the cellular toxicity of methamphetamine and because its cardiotoxicity is not experimentally well documented. The present work was conducted to study the effects of chronic administration of methamphetamine, as well as the effect of withdrawal on the cardiac muscle of albino rats using histological and ultrastructural examination. This study was conducted on 60 adult male albino rats. They were divided into three equal groups. Group I was used as control. Group II received daily subcutaneous injection of 1mg/kg body weight of methamphetamine hydrochloride for 8 weeks. The third group received the same daily dose of methamphetamine hydrochloride for the same duration then, the treatment was discontinued for the next 4 weeks. At the end of the experiment rats were sacrificed and specimens from the heart were taken and were subjected to light and electron microscopic study. Two degrees of myocardial lesions were revealed on examination of the chronic toxicity group ranging from wavy muscle fibers with deeply stained nuclei up to sarcolemmal rupture and extrusion of the organelles. Mitochondrial swelling with focal cristal loss was also revealed. After drug withdrawal, there was reversal of most of myocardial lesions depicted in the chronic toxicity group except for excessive fibrous tissue deposition. Chronic methamphetamine administration brings about various myocardial lesions. However, most of these lesions are reversible after drug withdrawal