Evaluation of chitosan-GP hydrogel biocompatibility in osteochondral defects: an experimental approach

Background: Articular cartilage, because of its avascular nature, has little capacity for spontaneous healing, and tissue engineering approaches, employing different biomaterials and cells, are under development. Among the investigated biomaterials are the chitosan-based hydrogels. Although thoroughly studied in other mammalian species, studies are scarce in equines. So, the aim of the present study was to investigate the biocompatibility of chitosan-GP in horse joints submitted to high mechanical loads.Results: An osteochondral defect was created by arthroscopy in the medial surface of lateral trochlea of talus of left or right leg, randomly selected, from six healthy geldings. the defect was filled up with chitosan-GP. the contralateral joint received an identical defect with no implant. the chondral fragment removed to produce the defect was collected, processed and used as the Initial sample (normal cartilage) for histology, immunohistochemistry, and metabolic labelling of PGs. After 180 days, the repair tissues were collected, and also analyzed. At the end of the experiment (180 days after lesion), the total number of cells per field in repair tissues was equal to control, and macrophages and polymorphonuclear cells were not detected, suggesting that no significant inflammation was present. These cells were able to synthesize type II collagen and proteoglycans (PGs). Nevertheless, the cell population in these tissues, both in presence of chitosan-GP and in untreated controls, were heterogeneous, with a lower proportion of type II collagen-positives cells and some with a fibroblastic aspect. Moreover, the PGs synthesized in repair tissues formed in presence or absence of chitosan-GP were similar to those of normal cartilage. However, the chitosan-GP treated tissue had an disorganized appearance, and blood vessels were present.Conclusions: Implanted chitosan-GP did not evoke an important inflammatory reaction, and permitted cell growth. These cells were able to synthesize type II collagen and PGs similar to those synthesized in normal cartilage and in healing tissue without implant, indicating its chondrocyte nature.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Fac Med Vet & Zootecnia, Dept Cirurgia, BR-09500900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Bioquim, BR-04044020 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecnia, Dept Clin Med, BR-09500900 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecnia, Dept Patol, BR-09500900 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Bioquim, BR-04044020 São Paulo, BrazilWeb of Scienc

Sialolipoma na glândula salivar sublingual em cão – primeiro relato

This report describes a 14-year-old Pit Bull dog presenting with a soft tissue swelling of 3-month progression in the right sublingual region. Histopathological analysis of the surgically resected specimen revealed large numbers of mature adipocytes and islets consisting of mucin-containing atrophic acini and dilated ducts surrounded by a thin fibrous capsule. Findings were consistent with sialolipoma of the sublingual salivary gland. To the authors’ knowledge, this is the first case of sialolipoma affecting the sublingual salivary gland in dogs.O presente relato descreve um cão Pit Bull, de 14 anos, com aumento de volume de consistência macia em região sublingual direita com evolução de 3 meses. Após excisão cirúrgica, a análise histopatológica revelou grande número de adipócitos maduros, tecido glandular composto por ductos dilatados e ácinos atróficos contendo mucina, circundados por fina cápsula fibrosa, achados compatíveis com sialolipoma da glândula salivar sublingual. Pelo conhecimento dos autores, este é o primeiro relato de sialolipoma acometendo glândula salivar sublingual em cão

Morphometric aspects of the thymus in domestic cats (Felis domesticus)

O timo é um órgão linfático primário que desenvolve sua atividade em organismos jovens. Apesar de sua função ser responsável por mecanismos fundamentais na aquisição das defesas e conseqüentes respostas orgânicas, ela ainda não está totalmente esclarecida, nem tampouco as bases morfológicas que respondem por tais funções, como o processo de desenvolvimento e involução do órgão. Objetivou-se analisar e caracterizar os aspectos morfológicos do timo, tais como seu tamanho e volume, e aspectos histológicos do timo em gatos, correlacionando o sexo e o desenvolvimento etário. Doze timos provenientes de fetos de gatos domésticos (Felis domesticus) sem raça definida (SRD), machos e fêmeas, separados em três grupos etários. O timo apresentou-se com uma coloração rosa-pálida e com duas porções, a torácica e a cervical, sendo que cada uma delas possuía um lobo direito e um lobo esquerdo em sua maioria. A porção torácica localizava-se em região de mediastino cranial, entre os pulmões e à base do coração. E a porção cervical estendia-se além das costelas em sentido cranial, estando localizada ventralmente à traqueia. A estrutura celular do timo demonstrou-se organizada com a presença de agregados concêntricos, os chamados corpúsculos tímicos, formados por células epiteliais, sustentada por uma cápsula de tecido conjuntivo de onde partiam septos que ao penetrar no órgão dividia-o em lóbulos. Ocorreram variações significativas quanto à lobação e as dimensões do timo entre indivíduos da mesma faixa etária, e entre sexos diferentes. Os valores relativos ao comprimento, espessura e largura, de maneira geral, apresentaram aumento, em conformidade ao desenvolvimento dos animais, mas com diferenças entre os sexos

Histologia do fígado de avestruz (Struthio camelus, Linnaeus 1758)

At present the ostrich (Struthio camelus) breeding has been showing a great economical potential, although yet there are not distinct patterns about the histology of its liver, which is an organ of key importance in terms of metabolism. The knowledge of its histology can help the detection of diseases and nutritional deficiencies of this bird. Twenty four ostriches with an average age of 12-18 months and average weight of 80-100 Kg, proceeding from Don Pig Abatteur, located at Botucatu, São Paulo, were used. The birds were slaughtered with and to bleeding. Liver samples were processed for light and electron transmission microscopic studies. Hematoxilin and eosin (HE), picrosirius, Gordon and Sweets, Sudan black and Schiff periodic acid (PAS) were respectively used to observe the liver morphology, collagen, reticular fibers, lipids and glycogen. The liver portal spaces were determined. An average of 5.68% of glycogen was observed. The lipidic content with an average of 9.83%. Collagen fibers at an average of 14.71%. Reticular fibers with an average of 5.96%. Through transmission electron microscopy we noticed in the hepaticyte cytoplasm the presence of numerous mithocondria, glycogen, several lipidic droplets, some lysosomes, granular endoplasmatic reticulum around the mithocondria, some stellate cells, erythrocytes, nucleus and degenerating cells, besides the central biliary canaliculus. The suggestive steatotic results might result from the animals nutritional status Our results demonstrated that ostrich and other birds hepatocytes are very similar.A criação de avestruz (Struthio camelus, Linnaeus 1758) é uma atividade de grande potencial, porém não existem padrões definidos sobre a histologia do seu fígado, que é um órgão de grande importância no metabolismo. O conhecimento de sua histologia pode contribuir para a detecção de doenças e deficiências nutricionais no animal. Para este estudo foram utilizados 24 avestruzes com idades entre 12 e 18 meses (com peso médio em torno de 80 a 100 kg), provenientes do abatedouro Don Pig, em Botucatu no estado de São Paulo. Os animais foram abatidos com pistola pneumática e, após a sangria, as amostras do fígado foram processadas e observadas em microscopia de luz e microscopia eletrônica de transmissão (MET). A hematoxilina e eosina (H.E), picrossírius, Gordon e Sweets, Sudan black e o ácido peródico de Schiff (PAS) são colorações usadas respectivamente para observar a morfologia do fígado, colágeno, fibras reticulares, gordura e glicogênio. Foram encontrados os espaços portahepáticos.O glicogênio mostrou média de 5,68%, o conteúdo lipídico, média de 9,83%, o colágeno média de 14,71% e as fibras reticulares média de 5,96%. Quanto à MET notou-se no citoplasma dos hepatócitos, numerosas mitocôndrias, glicogênio, muitas gotas de gordura, alguns lisossomos, retículo endoplasmático granular ao redor das mitocôndrias, algumas células estreladas, célula em degeneração e o canalículo biliar ao centro. Provavelmente o quadro sugestivo de esteatose é resultante do estado nutricional dos animais. Estes resultados demonstraram que os hepatócitos dos avestruzes são muito similares às outras aves, como também muito semelhantes à estrutura e ultraestrutura das células do fígado de mamíferos

Inhibition of connexin hemichannels alleviates non-alcoholic steatohepatitis in mice

While gap junctions mediate intercellular communication and support liver homeostasis, connexin hemichannels are preferentially opened by pathological stimuli, including inflammation and oxidative stress. The latter are essential features of non-alcoholic steatohepatitis. In this study, it was investigated whether connexin32 and connexin43 hemichannels play a role in non-alcoholic steatohepatitis. Mice were fed a choline-deficient high-fat diet or normal diet for 8 weeks. Thereafter, TAT-Gap24 or TAT-Gap19, specific inhibitors of hemichannels composed of connexin32 and connexin43, respectively, were administered for 2 weeks. Subsequently, histopathological examination was carried out and various indicators of inflammation, liver damage and oxidative stress were tested. In addition, whole transcriptome microarray analysis of liver tissue was performed. Channel specificity of TAT-Gap24 and TAT-Gap19 was examined in vitro by fluorescence recovery after photobleaching analysis and measurement of extracellular release of adenosine triphosphate. TAT-Gap24 and TAT-Gap19 were shown to be hemichannel-specific in cultured primary hepatocytes. Diet-fed animals treated with TAT-Gap24 or TAT-Gap19 displayed decreased amounts of liver lipids and inflammatory markers, and augmented levels of superoxide dismutase, which was supported by the microarray results. These findings show the involvement of connexin32 and connexin43 hemichannels in non-alcoholic steatohepatitis and, simultaneously, suggest a role as potential drug targets in non-alcoholic steatohepatitis

Histologia do intestino do avestruz (Struthio camelus, Linnaeus 1758)

Regardless of the ostrich (Struthio camelus) share many adaptations to other evolutionary present birds, these animals show some peculiar anatomical features such as their digestive tract than the colon is greater than the cecum. For some time this bird has been economically exploited and especially as an alternative source of animal protein for human consumption. This study examined the histological bowel ostrich produced in good environmental management and nutrition. Thirteen ostriches were used, with 18 to 30 months old, from Brazil Ostrich company, and sent for slaughter in Slaughterhouse School, University of São Paulo Campus Administrative Pirassununga. The animals were killed with pneumatic gun and after bleeding and evisceration were collected, samples of different intestinal segments: duodenum, jejunum, ileum and cecum double. The materials were processed, stained with hematoxylin - eosin (HE) and examined under brightfield microscopy. The results showed that the villi are present in the duodenum but not exist in the cecum. Of the four intestinal segments examined the cecum showed the highest number of goblet cells. Lymph nodes and lymphocytes were observed in all segments examined. In the cecum lymph nodes are added to form the Peyer’s patch. The plan of histological intestinal segments examined followed the pattern observed in other domestic mammals and birds. The knowledge of the histology of the intestines of these animals can provide insight for comparative assessment procedures for environmental management and nutrition that may increase the levels of production and productivity of this livestock activity.A despeito de o avestruz (Struthio camelus) compartilhar muitas adaptações evolucionárias presentes em outras aves, estes animais apresentam algumas características anatômicas peculiares, como é o caso do seu tubo digestivo em que o cólon é maior que o ceco. Há algum tempo, essa ave tem sido explorada econômicamente e principalmente como fonte alternativa de proteína animal na alimentação humana. O presente trabalho analisou os aspectos histológicos do intestino de avestruzes produzidos em boas condições de manejo ambiental e nutricional. Foram utilizados 13 avestruzes, com 18 a 30 meses de idade, provenientes da empresa Brasil Ostrich, e encaminhados para o abate no Abatedouro Escola da Universidade de São Paulo, Campus Administrativo de Pirassununga. Os animais foram abatidos com pistola pneumática e, após a sangria e evisceração, foram colhidas amostras de diferentes segmentos do intestino: duodeno, jejuno, íleo e ceco duplo. Os materiais foram processados, corados pela técnica de hematoxilina-eosina (H-E) e examinados em microscopia de campo claro. Os resultados obtidos revelaram que as vilosidades estão presentes no duodeno, porém, não existem no ceco. Dos quatro segmentos intestinais examinados, o ceco foi o que apresentou maior número de células caliciformes. Os nódulos linfáticos e os linfócitos foram observados em todos os segmentos examinados. No ceco, os nódulos linfáticos se agregam para constituir a placa de Peyer. O plano histológico dos segmentos intestinais examinados seguiu o padrão observado nos mamíferos domésticos e em outras aves. O conhecimento da histologia dos intestinos desses animais pode oferecer subsídios para a avaliação comparativa de procedimentos de manejo ambiental e nutricional que possam aumentar os níveis de produção e produtividade dessa atividade pecuária

Sex-differences in the longitudinal recovery of neuromuscular function in COVID-19 associated acute respiratory distress syndrome survivors

IntroductionPatients admitted to the intensive care unit (ICU) following severe acute respiratory syndrome 2 (SARS-CoV-2) infection may have muscle weakness up to 1 year or more following ICU discharge. However, females show greater muscle weakness than males, indicating greater neuromuscular impairment. The objective of this work was to assess sex differences in longitudinal physical functioning following ICU discharge for SARS-CoV-2 infection.MethodsWe performed longitudinal assessment of physical functioning in two groups: 14 participants (7 males, 7 females) in the 3-to-6 month and 28 participants (14 males, 14 females) in the 6-to-12 month group following ICU discharge and assessed differences between the sexes. We examined self-reported fatigue, physical functioning, compound muscle action potential (CMAP) amplitude, maximal strength, and the neural drive to the tibialis anterior muscle.ResultsWe found no sex differences in the assessed parameters in the 3-to-6-month follow-up, indicating significant weakness in both sexes.Sex differences emerged in the 6-to-12-month follow-up. Specifically, females exhibited greater impairments in physical functioning, including lower strength, walking lower distances, and high neural input even 1 year following ICU-discharge.DiscussionFemales infected by SARS-CoV-2 display significant impairments in functional recovery up to 1 year following ICU discharge. The effects of sex should be considered in post-COVID neurorehabilitation

Low temperatures reduce skin healing in the Jacaré do Pantanal (Caiman yacare, Daudin 1802)

Studies of skin wound healing in crocodilians are necessary given the frequent occurrence of cannibalism in intensive farming systems. Air temperature affects tissue recovery because crocodilians are ectothermic. Therefore, the kinetics of skin wound healing in Caiman yacare were examined at temperatures of 33°C and 23°C. Sixteen caiman were selected and divided into two groups of eight maintained at 23°C or 33°C. The studied individuals' scars were photographed after 1, 2, 3, 7, 15 and 30 days of the experimental conditions, and samples were collected for histological processing after 3, 7, 15 and 30 days. Macroscopically, the blood clot (heterophilic granuloma) noticeably remained in place covering the wound longer for the caiman kept at 23°C. Microscopically, the temperature of 23°C slowed epidermal migration and skin repair. Comparatively, new blood vessels, labeled using von Willebrand factor (vWF) antibody staining, were more frequently found in the scars of the 33°C group. The collagen fibers in the dermis were denser in the 33°C treatment. Considering the delayed healing at 23°C, producers are recommended to keep wounded animals at 33°C, especially when tanks are cold, to enable rapid wound closure and better repair of collagen fibers because such lesions tend to compromise the use of their skin as leather.Fundação de Amparo à Pesquisa do Estado de Mato Grosso (FAPEMAT), 715823/2008São Paulo Research Foundation (FAPESP), 2010/04527-

Connexin and pannexin (hemi) channels in the liver

The liver was among the first organs in which connexin proteins have been identified. Hepatocytes harbor connexin32 and connexin26, while non-parenchymal liver cells typically express connexin43. Connexins give rise to hemichannels, which dock with counterparts on adjacent cells to form gap junctions. Both hemichannels and gap junctions provide pathways for communication, via paracrine signaling or direct intercellular coupling, respectively. Over the years, hepatocellular gap junctions have been shown to regulate a number of liver-specific functions and to drive liver cell growth. In the last few years, it has become clear that connexin hemichannels are involved in liver cell death, particularly in hepatocyte apoptosis. This also holds true for hemichannels composed of pannexin1, a connexin-like protein recently identified in the liver. Moreover, pannexin1 hemichannels are key players in the regulation of hepatic inflammatory processes. The current paper provides a concise overview of the features of connexins, pannexins and their channels in the liver.This work was financially supported by the grants of the Agency for Innovation by Science and Technology in Flanders (IWT), the University Hospital of the Vrije Universiteit Brussel-Belgium (Willy Gepts Fonds UZ-VUB), the Fund for Scientific Research - Flanders (FWO grants G009514N and G010214N), the European Research Council (ERC Starting Grant 335476), the University of Sao Paulo-Brazil (USP) and the Foundation for Research Support of the State of Sao Paulo (FAPESP SPEC grant 2013/50420-6)