Alterações vasculares na coróide de ratos diabéticos tratados e não tratados

OBJETIVO: Conhecer os efeitos do diabetes e o impacto de seu tratamento medicamentoso em curto e longo prazo sobre os vasos da coróide e membrana de Bruch. MÉTODOS: Foram estudados 30 ratos Wistar, divididos em 3 grupos experimentais: grupo controle (GC), grupo diabético (GD) e grupo diabético tratado (GT), estudados 1 mês (momento M1) e 12 meses (momento M2) após o início do experimento. O diabetes foi induzido por aloxana endovenosa, na dose de 42 mg/kg. O GT foi tratado com hipoglicemiante oral (acarbose) e insulina subcutânea. Após o sacrifício, os olhos foram preparados para exame ao microscópio eletrônico de transmissão, interessando a ultra-estrutura da membrana de Bruch e os vasos da coróide. RESULTADOS: O exame ultra-estrutural da coróide dos ratos diabéticos mostrou depósitos na membrana de Bruch, acúmulo de vesículas, glicogênio e corpos densos no citoplasma das células endoteliais. O grupo mais afetado foi de ratos diabéticos de 12 meses (GDM2). Os animais com menor intensidade de alterações foram os ratos tratados por 12 meses (GTM2). CONCLUSÃO: Os ratos diabéticos desenvolveram alterações degenerativas na membrana de Bruch e vasos da coróide. Estas alterações foram mais evidentes nos animais submetidos à doença crônica, mas também ocorreram agudamente. O tratamento a curto prazo não foi capaz de evitar os processos degenerativos. A longo prazo, o tratamento inibiu a progressão destes processos.

Uso de viscoelásticos na facoemulsificação em cães portadores de catarata: efeitos sobre a pressão intraocular, a morfologia das células endoteliais e a espessura corneana

Avaliaram-se as células endoteliais, a espessura corneana e a pressão intraocular (PIO) de cães portadores de catarata madura, empregando-se viscoelástico à base de hialuronato de sódio 3% e sulfato de condroitina 4% e hidroxipropilmetilcelulose 2%, utilizando-se 20 cães, distribuídos entre os dois grupos dos viscoelásticos. A técnica cirúrgica adotada foi a da facoemulsificação bimanual. As avaliações tonométricas foram efetuadas antes e após o ato cirúrgico, aos 1, 7, 14, 21, 28 e 60 dias de pós-operatório, e a microscopia especular, antes e após 7, 28 e 60 dias. Não houve diferença estatística entre os grupos quanto à PIO, com exceção aos 14 dias, em que se observou maior PIO com o uso de hialuronato de sódio 3% e sulfato de condroitina 4%. Não houve diferença entre os grupos quanto aos parâmetros relacionados ao endotélio, com diminuição discreta da densidade celular endotelial e aumento da área celular com a utilização de hidroxipropilmetilcelulose 2%. A utilização de ambos os dispositivos viscoelásticos analisados é recomendada para o procedimento de facoemulsificação em cães.

Suppression of TNBS-induced colitis in rats by 4-methylesculetin, a natural coumarin: Comparison with prednisolone and sulphasalazine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reduced allergic lung inflammation in rats following formaldehyde exposure: Long-term effects on multiple effector systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Scanning electron microscopy of the corneal endothelium of ostrich

Objetivou-se examinar a superfície posterior do endotélio corneano e realizar análise morfométrica das células endoteliais da córnea de avestruz (Struthio camelus) valendo-se da microscopia eletrônica de varredura. Avaliaram-se o número de lados, a área celular média, a densidade celular e o coeficiente de variação da área celular. O endotélio corneano de avestruz constitui-se de células poligonais uniformes em tamanho e forma, e com poucas interdigitações das bordas celulares. Visibilizaram-se microvilosidades na superfície celular. A área celular média foi de 269±18µm² e a densidade celular foi de 3717±240 células mm-2. O coeficiente de variação foi de 0,06 e o percentual de células hexagonais de 75%. Não foram observadas diferenças significativas entre os parâmetros avaliados entre os olhos esquerdo e direito. Este estudo demonstrou que o endotélio corneano de avestruz é semelhante ao descrito em outros vertebrados.

Morphometric analysis of the corneal endothelium of Yacare caiman (Caiman yacare) using scanning electron microscopy

The objective of this study was to examine the endothelial surface morphology and to perform morphometric analysis of the corneal endothelial cells of Yacare caiman (Caiman yacare) using scanning electron microscopy. Morphometric analysis with regard to polygonality, mean cell area, cell density and coefficient of variation of mean cell area was performed. Cell areas were measured using image analysis software. The normal corneal endothelium of Yacare caiman consisted of polygonal cells of uniform size and shape with interdigitations of the cell borders. Microvilli appeared as protrusions on the cellular surface. The average cell area was 270 +/- 24 mum(2) and the endothelial cell density was 3704 +/- 324 cells/mm(2). The coefficient of variation of cell area was 0.22. This study demonstrates that the Yacare caiman corneal endothelium is similar to those described in other vertebrates.

Inflammation-induced modulation of cellular galectin-1 and-3 expression in a model of rat peritonitis

Objective and design: To investigate the effect of galectin-1 (Gal-1) and -3 (Gal-3) on leukocyte migration and analyze the expression of both galectins in inflammatory cells using a model of rat peritonitis.Material or Subjects: Sprague-Dawley rats (n = 4 per group).Treatment: Peritonitis was induced in animals through intraperitoneal injection of carrageenin (1.5 mg/kg) and rat mesenteries were analyzed at different time points (0, 4, 24 and 48h). For pharmacological treatment, rats received intravenous injection of Gal-1 or -3 (3 mu g/kg) followed by carrageenin.Methods: Western blotting and immunoelectron microscopy analysis. Statistical analysis was performed using ANOVA followed by Bonferroni test.Results: Pharmacological treatment with Gal-1, but not Gal-3, inhibited (similar to 50%) leukocyte recruitment into the peritoneal cavity at 4h time-point. In this early phase, immunogold staining of mesenteries showed a diminished Gal-3 expression in degranulated mast cells and Gal-1 in transmigrated neutrophils (similar to 20% reduction compared to intravascular cells). In the later phases (24 and 48 h), leukocyte turnover was associated with augmented Gal-1 expression in neutrophils and macrophages and Gal-3 in mast cells and macrophages.Conclusions: These results point to a balanced expression of cell-associated-Gal-1/Gal-3 and might impact on the development of new therapeutic strategies for inflammatory diseases.

Agents that inhibit histamine release: A review

It is well known that histamine is found in high concentration in mast cell granules(1). The histamine content of these granules may be released to the extracellular space if an appropriate stimulus is provided(2). Besides histamine, other preformed active substances like enzymes, chemotatic factors and proteoglycans, as well as newly generated mediators like eicosanoids, platelet activating factor and adenosine are released during the secretion process of mast cells(3). The activation of mast cell degranulation has been associated with a number of pathologic disorders, most frequently, diseases derived from the atopic state(4). It is now evident that mast cells are the primary effector cells in the early reaction in both allergic and non-allergic asthma(5,6), although some authors doubt that the late reaction of asthma is a mast cell dependent event(6). Other studies point towards basophils as cellular elements involved in the secondary phase of inflammation in allergic diseases(7). Secretion would depend on a histamine releasing factor, and on the presence of IgE on the basophil's surface(8). There is also evidence suggesting involvement of mast cells in some non-allergic inflammatory processes like arthritis(9). The pharmacological management of these diseases basically consists in the use of methylxantines, beta 2-adrenergic agonists, glucocorticoids, sodium cromoglycate-like drugs, anticholinergic and antihistaminic H 1 antagonists(10). Their therapeutic effects include bronchodilatation, receptor and physiological antagonism, prevention of inflammatory responses induced by secondary cells, and finally, inhibition of mast cell activation(11). This review is concerned with compounds having inhibitory action on mast cell activation, and their possible importance on the pathophysiology of mast cell-related diseases.

The hemolytic uremic syndrome as a complication of adriamycin nephropathy

Rats treated with two injections of adriamycin (week 0 and week 12) developed glomerusclerosis and severe tubulointerstitial lesions as described in the literature. In addition, a number of glomerular alterations were present. These included capillary loop dilation, insudation of eosinophilic material, necrosis, duplication of the glomerular basement membrane, severe mesangiolysis with disruption of the mesangial matrix and segmental double- contours. The renal arterioles and interlobular arteries showed endothelial cell swelling. The subendothelial space was infiltrated by fibrinoid material and there was intensive fibrinoid necrosis of the wall of both arteries and arterioles extending into the glomerular tuft. These alterations were very similar to those observed in the hemolytic uremic syndrome. This observation suggests that the two injections of adriamycin, with a long interval in between them, might induce renal lesions similar to those observed in the hemolytic uremic syndrome.

New bioactive metabolites produced by Phomopsis cassiae, an endophytic fungus in Cassia spectabilis

Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays. ©2005 Sociedade Brasileira de Química.

Interação de Paracoccidioides brasiliensis com células endoteliais

Paracoccidioidomycosis has a variety of clinical manifestations and Paracoccidioides brasiliensis, the causative agent, may infect many tissues, most importantly the lungs. Migration of pathogenic yeasts to the endothelial cell layer is considered a prerequisite for multiple organ invasion and dissemination of the fungus. In this study of the adhesion of P. brasiliensis to endothelial cells in vitro, we investigated whether this adhesion could represent a mechanism of dissemination. To this end, as well as using conventional optical microscopy, an alternative in vivo technique was developed, to detect the presence of fungal cells in umbilical cords embedded in paraffin wax. An experiment on the migration of P. brasiliensis through an endothelial cell monolayer was carried out, and the migration of yeast cells was greater, and took less time, in control wells with no cells. The fungus crossed the monolayer, but, compared to control wells, the migration-rate was about 30% lower. This shows that the monolayer only partially blocked migration of the fungus. In these experiments, we had great difficulty finding P. brasiliensis adhered to the cell monolayer, when it was examined at different times, suggesting that migration of the fungus across the endothelial layer is very fast, and cannot normally be observed in cell culture in vitro. Thus, P. brasiliensis can cross the endothelium rapidly and probably invades deeper tissue.

Cellular and molecular mechanisms of apoptosis in skeletal muscle atrophy

Apoptosis is necessary for maintaining the integrity of proliferative tissues, such as epithelial cells of the gastrointestinal and integumentary systems. The role of apoptosis in post-mitotic tissues, such as skeletal muscle, is less well defined, but several lines of evidence suggest that it occurs in both myofiber and other interstitial muscle cell types. Apoptosis of myonuclei likely contributes to the loss of muscle mass, but the mechanisms underlying this process are largely unknown. Caspase-dependent as well as caspase-independent pathways have been implicated, and the mode by which atrophy is induced likely determines the apoptotic mechanisms that are utilized. It remains to be determined whether a decrease in apoptosis will alleviate atrophy and distinct research strategies may be required to clarify the different causes of skeletal muscle mass loss. In this review, it was also speculated that apoptosis is a normal regulatory process that the myofiber can use to reduce the number of nuclear domains, thus ensuring optimal cell functions according to the mechanical load imposed on the muscle. ©FUNPEC-RP.

High Content Screening of a Kinase-Focused Library Reveals Compounds Broadly-Active against Dengue Viruses

Dengue virus is a mosquito-borne flavivirus that has a large impact in global health. It is considered as one of the medically important arboviruses, and developing a preventive or therapeutic solution remains a top priority in the medical and scientific community. Drug discovery programs for potential dengue antivirals have increased dramatically over the last decade, largely in part to the introduction of high-throughput assays. In this study, we have developed an image-based dengue high-throughput/high-content assay (HT/HCA) using an innovative computer vision approach to screen a kinase-focused library for anti-dengue compounds. Using this dengue HT/HCA, we identified a group of compounds with a 4-(1-aminoethyl)-N-methylthiazol-2-amine as a common core structure that inhibits dengue viral infection in a human liver-derived cell line (Huh-7.5 cells). Compounds CND1201, CND1203 and CND1243 exhibited strong antiviral activities against all four dengue serotypes. Plaque reduction and time-of-addition assays suggests that these compounds interfere with the late stage of viral infection cycle. These findings demonstrate that our image-based dengue HT/HCA is a reliable tool that can be used to screen various chemical libraries for potential dengue antiviral candidates. © 2013 Cruz et al.

Macrophage migration inhibitory factor and oral cancer

Background: Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with pro-inflammatory functions and involved in tumorigenesis. The aim of this study was to evaluate the expression and localization of the macrophage MIF in oral squamous carcinoma (OSC). In addition, the relationship between MIF expression and clinicopathological parameters such as survival data, tobacco use, alcohol habits, TNM stage, tumor graduation, and peritumoral inflammatory infiltrate were evaluated. Methods: Using immunohistochemistry, expression and localization of MIF was detected in 44 specimens of OSC. The absolute number and relative proportions of MIF-positive cells detected were also determined separately for tumor parenchyma vs. stroma. All counts were determined from 10 consecutive high-power fields using an integration graticule. Moreover, some parameters were analyzed separately for lip and intra-oral cancers. Results: Migration inhibitory factor-positive cells were observed in both the tumor parenchyma and in inflammatory cells of all specimens. In contrast, MIF expression was not detected in tumoral nests associated with poorly differentiated tumors. In specimens of lip cancer, a greater number of MIF-positive stromal immune cells were detected than in intra-oral cancer specimens (Mann-Whitney test, P = 0.049). Conclusions: Oral squamous carcinoma cells consistently express MIF independent of their location. Lip tumors presented more MIF-positive peritumoral inflammatory cells, similar to control, suggesting that immunological differences in leukocyte activation exist between in lip and intra-oral cancers. © 2012 John Wiley & Sons A/S.

Anticorpos monoclonais em imunohematologia

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB