Myotoxic effects of mastoparan from Polybia paulista (Hymenoptera, Epiponini) wasp venom in mice skeletal muscle

In a previous study, we showed that the Polybia paulista wasp venom causes strong myonecrosis. This study was undertaken to characterize the myotoxic potency of mastoparan (Polybia-MPII) isolated from venom (0.25 mu g/mu l) and injected in the tibial anterior (TA) muscle (i.m.) of Balb/c mice. The time course of the changes was followed at muscle degenerative (3 and 24 h) and regenerative (3, 7, and 21 days) periods (n = 6) after injection and compared to matched controls by calculation of the percentage of cross-sectional area affected and determination of creatine kinase (CK) activity (n = 10). The results showed that although NIP was strongly myotoxic, its capacity for regeneration was maintained high. Since the extent of tissue damage was not correlated with the CK serum levels, which remained very low, we raised the hypothesis that the enzyme underwent denaturation by the peptide. Evidence suggested that MP induced the death of TA fibers by necrosis and apoptosis and had the sarcolemma as its primordial target. Given its amphiphilic polycationic nature and based on the vast spectrum of functions attributed to the peptide, we suggest that MP interaction with cell membrane impaired the phosphorylation of dystrophin essential for sarcolemma mechanical stability, and disturbed Ca2+ mobilization with obvious implications on sarcoplasmic reticulum and mitochondrial functioning. (c) 2007 Elsevier Ltd. All rights reserved.

Histological study of the dynamics in epidermis regeneration of the carp tail fin (Cyprinus carpio, Linnaeus, 1758)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The midgut of Cephalotes ants (Formicidae: Myrmicinae): Ultrastructure of the epithelium and symbiotic bacteria

The ultrastructural analysis of the midgut of Cephalotes atratus. C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined. (C) 2010 Elsevier Ltd. All rights reserved.

Histology and Histochemistry of the Stomach Epithelium of Pachycondyla (= Neoponera) villosa (Formicidae: Ponerinae)

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

Diplopods as Bioindicators of Soils: Analysis of Midgut of Individuals Maintained in Substract Containing Sewage Sludge

Diplopods feed organic matter in decomposition; however, some environmental factors can promote changes in tissues of these animals. Sewage sludge has been applied for recuperation of physical structure of degraded soil. This work analyzed the influence of the sludge from a city of So Paulo in the midgut of the diplopod Rhinocricus padbergi. After the exposition to sludge, the midgut was prepared for histological and ultra-structural analyses. After 1 week of exposition, there were various glycoprotein globules in the fat body, which appeared, ultrastructurally, little electron dense. In the animals exposed for 2 weeks, there was an intensive renovation of the epithelium with the invasion of regenerative cells, which was observed in the histological and ultra-structural analyses. These data showed that the sludge present various substances that were very hazardous for these animals; more studies were necessary before the application of this in agriculture.

Influence of ultrasound and physical activity on bone healing

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

Desenvolvimento pós-embrionário do intestino anterior de Dermatobia hominis (Linnaeus Jr.) (Diptera, Cuterebridae)

Foregut in D. hominis (Linnaeus Jr., 1781) as the majority of the larval Diptera somatic tissue, is made up of polytenic cells, and grows at the expenses of the polytenization of its nuclei followed by the increase in size of each cell. The oesophagus, of ectodermic origem, is interiorly covered by a chitinous squamous epithelium that rests upon a very thin basal lamina. This sheet is surrounded by thick muscle bundles. The oesophagus intussuscepts the midgut forming the cardia. The cardia, with three epithelial layers: two internal ones, of ectodermal origin and one external of endodermic origin. At the anterior portion of the cardia, between these two types of epithelium, there is a cluster of small, non polytenic cells, forming the imaginal disk of the foregut. Metamoiphosis begins at the end of the larval period with signs of nuclear degeneration of all the polytenic cells, as well as the increase in number of the imaginal disk ones. The oesophagic portion intussuscepted into the cardia, everts; its cells suffer apoptosis and are replaced by the new cells growing from the imaginal disk. The external layer cells also degenerate and are pinched off into the lumen of the very anterior portion of the midgut. The newly formed oesophagus intussuscepts de novo to form the two internal layers of the adult cardia. At the same time the midgut regenerative cells grow anteriorly to form the new external layer of the adult cardia.

Desenvolvimento pós-embrionário do intestino médio de Dermatobia hominis (Linnaeus Jr.) (Diptera, Cuterebridae)

Dermatobia hominis (Linnaeus, 1781) midgut is internally lined by an epithelium of polytenic cells, some low others prismatic with well developed brush border. Their apical portion are enlarged by secretory vesicles, forming button-like structures that are pinched off to the lumen, some accompained by the nucleus characterizing apocrine and holocrine secretions. This epithelium is gradually renewed by small, non polytenic regenerative cells, found scattered at its basal portion. At the end of the third instar the metamorphosis begins. The epithelial cells present signs of degeneration and at the first day of pupation the regenerative cells increase in number. By the 5th day of pupation these regenerative cells, besides being increased in number, differentiate themselves into two layers: one similar to the dense conective tissue that sustainning the larval epithelium is pinched off to the midgut lumen forming the yellow bodies; the other, develops right under it as the imaginal epitelium. The disorganized muscles bundles of the midgut wall, are invaded by phagocytes. At the end of pupation the midgut has a low prismatic epithelium with brush-border. In the adult, the torax portion of the midgut has prismatic homogeneously basophilic epithelium while in the abdominal portion the epithelium is made of high prismatic cells full of small vacuoles. The larval midgut epithelium suffers programmed cell death non compatible with apoptose. During the metamorphosis the midgut lenght diminishes from 31mm in the larva to 14mm in the adult.

Assessment of bovine biomaterials containing bone morphogenetic proteins bound to absorbable hydroxyapatite in rabbit segmental bone defects

OBJETIVO: Avaliar a capacidade osteo-regenerativa de dois biomateriais utilizando um modelo de defeito segmentar efetuado nas diáfises do rádio de coelhos. MÉTODOS: O defeito direito foi preenchido com pool de proteínas morfogenéticas ósseas (pBMPs) e hidroxiapatita em pó ultrafina absorvível (HA) combinada com matriz óssea inorgânica desmineralizada e colágeno, derivados do osso bovino (Grupo A). O defeito esquerdo foi preenchido com matriz óssea desmineralizada bovina com pBMPs e hidroxiapatita em pó ultrafina absorvível (Grupo B). em ambos os defeitos utilizou-se membrana reabsorvível de cortical bovina desmineralizada para reter os biomateriais no defeito ósseo e guiar a regeneração tecidual. Os coelhos foram submetidos à eutanásia aos 30, 90 e 150 dias após a cirurgia. Foram efetuados exames radiográficos, tomográficos e histológicos em todos os espécimes. RESULTADOS: Aos 30 dias de pós-cirúrgico, o osso cortical desmineralizado foi totalmente reabsorvido em ambos os grupos. A HA tinha reabsorvido nos defeitos do Grupo A, mas persistiu nos do Grupo B. Uma reação de corpo estranho foi evidente com ambos os produtos, porém mais pronunciada no Grupo B. Aos 90 dias os defeitos do grupo B tinham mais formação óssea que os do Grupo A. Entretanto, aos 150 dias após a cirurgia, nenhum tratamento havia promovido o completo reparo do defeito. CONCLUSÃO: Os biomateriais testados contribuíram pouco ou quase nada para a reconstituição do defeito segmentar.

Quadro seroproteico como auxílio diagnóstico na anemia hemolítica imunomediada em cães

No presente protocolo experimental, determinaram-se os proteinogramas séricos, por intermédio da eletroforese em gel de poliacrilamida contendo duodecil sulfato de sódio (SDS-PAGE), de 120 cães com raças e idades variadas e atendidos junto ao Hospital Veterinário Governador Laudo Natel da FCAV/Unesp, com o objetivo principal de comparar diferentes frações seroproteicas em estados anêmicos regenerativos, arregenerativos, imunomediados primários e secundários. Os referidos animais foram distribuídos em cinco grupos experimentais: grupo 1: 20 cães de controle; grupo 2: 28 cães com anemia regenerativa não imune; grupo 3: 27 cães com anemia arregenerativa não imune; grupo 4: 10 cães com anemia hemolítica imunomediada primária; grupo 5: 35 cães com anemia hemolítica imunomediada secundária. A técnica SDS-PAGE permitiu o fracionamento de 24 proteínas, cujos pesos moleculares (PM) variaram de 18.000 a 165.000 daltons (Da). Os cães com AHIM primária e secundária apresentaram 24 frações proteicas em seus traçados eletroforéticos, enquanto que cães de controle (1) e portadores de anemia regenerativa (2) e arregenerativa (3) de natureza não imune apresentaram 23 frações de proteínas, cuja proteína de peso molecular 68.000Da não foi encontrada. Dessa forma, 23 frações proteicas foram detectadas e revelaram-se comuns aos proteinogramas dos cães de controle e daqueles dos quatro grupos experimentais. Destas, identificaram-se nominalmente 11 frações proteicas, e as demais foram estudadas com base nos seus respectivos pesos moleculares. em relação aos cães de controle, os anêmicos (grupos 2, 3, 4 e 5) apresentaram maiores concentrações de transferrina sérica e entre estes os animais portadores da AHIM primária. Todos os cães anêmicos apresentaram teores séricos de haptoglobina e fosforilase significativamente maiores que os controles, enquanto que a concentração sérica de ceruloplasmina foi significativamente maior nestes. Tais achados analisados em conjunto agregam informações adicionais úteis à elucidação das AHIMs em cães.

Functional ultrastructure of the midgut of the fire ant Solenopsis saevissima Forel 1904 (Formicidae : Myrmicinae)

Solenopsis saevissima has a midgut composed of columnar, regenerative, and goblet cells. The midgut epithelium was covered by a basal lamina. Outside the basal lamina, layers of inner oblique, circular, and outer longitudinal muscles were present. Columnar cells showed a basal plasma membrane containing numerous folds, mitochondria, and the nucleus. Rough endoplasmic reticulum, Golgi bodies, membrane bounded vacuoles, and spherocrystals were found in this region. The apical plasma membrane was constituted by microvilli, which were above a region rich in mitochondria. Regenerative cells were found in groups lying by the basal lamina. Goblet cells were associated with an ion-transporting mechanism between the haemolymph and the midgut epithelium. These cells were lying by the midgut lumen and large microvilli were evident, but the cytoplasmic features were similar to the columnar cells.

Low power laser radiation at 685 nm stimulates stem-cell proliferation rate in Dugesia tigrina during regeneration

Today's scientific interest in tissue engineering for organ transplantations and regeneration from stem cells, allied with recent observations on biostimulation of tissues and cells by laser radiation, stands as a strong motivation for the present work, in which we examine the effects of the low power laser radiation onto planarians under regenerative process. To investigate those effects, a number of 60 amputated worms were divided in three study groups: a control group and two other groups submitted to daily 1 and 3 min long laser treatment sections at similar to 910 W/m(2) power density. A 685 nm diode laser with 35 mW optical power was used. Samples were sent to histological analysis at the 4th, the 7th and the 15th (lays after amputation. A remarkable increase in stem cells counts for the fourth day of regeneration was observed when the regenerating worms was stimulated by the laser radiation. Our findings encourage further research works on the influence of optical radiation onto stem cells and tissue regeneration. (c) 2005 Elsevier B.V. All rights reserved.

Histomorphometrical analysis of bone formed after maxillary sinus floor augmentation by grafting with a combination of autogenous bone and demineralized freeze-dried bone allograft or hydroxyapatite

Background: Maxillary sinus floor augmentation procedures are currently the treatment of choice when the alveolar crest of the posterior maxilla is insufficient for dental implant anchorage. This procedure aims to obtain enough bone with biomaterial association with the autogenous bone graft to create volume and allow osteo conduction. The objective of this study was to histologically and histometrically evaluate the bone formed after maxillary sinus floor augmentation by grafting with a combination of autogenous bone, from the symphyseal area mixed with DFDBA or hydroxyapatite.Methods: Ten biopsies were taken from 10 patients 10 months after sinus floor augmentation using a combination of 50% autogenous bone plus 50% dernineralized freeze-dried bone allograft (DFDBA group) or 50% autogenous bone plus 50% hydroxyapatite (HA group). Routine histological processing and staining with hernatoxylin and eosin and Masson's trichrome were performed.Results: the histomorphometrical analysis indicated good regenerative results in both groups for the bone tissue mean in the grafted area (50.46 +/- 16.29% for the DFDBA group and 46.79 +/- 8.56% for the HA group). Histological evaluation revealed the presence of mature bone with compact and cancellous areas in both groups. The inflammatory infiltrate was on average nonsignificant and of mononuclear prevalence. Some biopsies showed blocks of the biomaterial in the medullary spaces close to the bone wall, with absence of osteogenic activity.Conclusions: the results indicated that both DFDBA and HA associated with an autogenous bone graft were biocompatible and promoted osteoconduction, acting as a matrix for bone formation. However, both materials were still present after 10 months.

Corneal endothelial cell morphology of normal dogs in different ages

Endothelial cell function is essential to maintain corneal transparency, but unfortunately the regenerative capacity of the endothelium is limited. There are only a few reports describing the effect of age on morphologic appearance of corneal endothelial cells of dogs. Studies of normal corneal endothelial cells in humans and dogs have shown a decrease in endothelial cell density (ECD) and an increase in pleomorphism and polymegethism with advancing age. The purpose of this study was to investigate the effect of age on ECD and endothelial cell morphology in dogs. A total of 30 dogs were divided into three groups (10 dogs/group) based on age: group 1 (2-12 months old), group 2 (24-72 months old), and group 3 (84 months or older). Corneas were processed for light and scanning electron microscopy. Results showed only difference in cell density between group 1 and groups 2 and 3, showing an initial decrease in cell density as the animal matured. Whereas there was significantly greater variation in cell size within the dogs in group 3 than there was within the other two groups, suggesting that there was increased polymegethism and pleomorphism with advancing age.

Cell-based Therapies for Tendon and Ligament Injuries

Tendon and ligament injuries have proved difficult to treat effectively. Cell-based therapies offer the potential to harness the complex protein synthetic machinery of the cell to induce a regenerative response rather than fibrous scarring. This article reviews the current state of play with respect to the clinically used cell preparations for the treatment of tendon and ligaments overstrain injuries.