Alterações no líquido sinovial do joelho de cães com osteoartrite induzida pelo modelo Pond e Nuki

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

Linfoma primário de células T no líquido cefalorraquidiano de cão: relato de caso

Relata-se o diagnóstico de linfoma primário no sistema nervoso central em um cão Labrador Retrievier, de 10 anos de idade, que apresentava episódios convulsivos, incoordenação nos membros posteriores, head tilt, ataxia e sensibilidade diminuída no lado esquerdo. Constataram-se alterações laterais esquerdas, como ausências de propriocepção e de posicionamento tátil, alterações posteriores nas provas de carrinho de mão e de reação ao pulo e diminuição da extensão da postura e hemilocomoção. No líquido cefalorraquidiano (LCR), houve predomínio de linfócitos atípicos, caracterizados pela presença de anisocitose e anisocariose, nucléolos evidentes e anisonucleose, basofilia e microvacuolização citoplasmáticas, mitoses atípicas e corpúsculos linfoglandulares, compatíveis com linfoma, confirmado pelo exame histológico e imunocitoquímico, o qual revelou origem T, com expressão CD3+ e CD79-. A tomografia computadorizada não foi conclusiva e evidenciou diversas áreas hipodensas e intensificação de contraste na região de sulcos e giros do parênquima encefálico. A coleta do LCR foi essencial na rapidez do diagnóstico definitivo, indicando a natureza rara desta lesão primária.

Contribuição do contraste negativo na artrografia tomográfica do joelho normal de cães

A ruptura do ligamento cruzado cranial é uma das causas mais comuns de claudicação do membro pélvico de cães. A radiografia e a ultrassonografia são métodos de diagnóstico frequentemente utilizados na rotina clínica de pequenos animais, porém a tomografia computadorizada é uma modalidade de imagem ainda pouco estudada para avaliar a articulação do joelho de cães. O presente trabalho teve por objetivo avaliar a contribuição do contraste negativo na artrografia tomográfica do joelho normal de cães, para visibilizar as estruturas intra-articulares e padronizar o uso desse contraste na articulação. Foram utilizados 24 membros pélvicos de cães de raças variadas, selecionados pela ausência de histórico de doença articular prévia do joelho e por apresentarem exames radiográficos, ultrassonográficos e macroscópicos normais. O experimento foi delineado em dois grupos, sendo o grupo I constituído de animais com peso até 20 kg e grupo II acima de 20 kg. Foram feitos cortes tomográficos com o membro flexionado e estendido. A quantidade média de ar empregada para a distensão da cápsula articular foi de 49 ml para o Grupo I e de 81 ml para o Grupo II. Utilizou-se um tubo de látex na porção distal à articulação do joelho para reduzir o escape de ar pelo tendão extensor digital profundo, que possui comunicação intra-articular. Foi possível visibilizar pela imagem tomográfica, em todas as articulações, as seguintes estruturas: ligamento cruzado cranial e caudal, meniscos medial e lateral, ligamento patelar, ligamentos colaterais e cápsula articular. Desta forma, o contraste negativo se mostrou uma alternativa eficaz para auxiliar a identificação das estruturas anatômicas do joelho na artrografia tomográfica.

Radiography, computed tomography and magnetic resonance imaging at 0.5 Tesla of mechanically inducedosteoarthritis in rabbit knees

In the present experimental study we assessed induced osteoarthritis data in rabbits, compared three diagnostic methods, i.e., radiography (XR), computed tomography (CT) and magnetic resonance imaging (MRI), and correlated the imaging findings with those obtained by macroscopic evaluation. Ten young female rabbits of the Norfolk breed were used. Seven rabbits had the right knee immobilized in extension for a period of 12 weeks (immobilized group), and three others did not have a limb immobilized and were maintained under the same conditions (control group). Alterations observed by XR, CT and MRI after the period of immobilization were osteophytes, osteochondral lesions, increase and decrease of joint space, all of them present both in the immobilized and non-immobilized contralateral limbs. However, a significantly higher score was obtained for the immobilized limbs (XT: P = 0.016, CT: P = 0.031, MRI: P = 0.0156). All imaging methods were able to detect osteoarthritis changes after the 12 weeks of immobilization. Macroscopic evaluation identified increased thickening of joint capsule, proliferative and connective tissue in the femoropatellar joint, and irregularities of articular cartilage, especially in immobilized knees. The differences among XR, CT and MRI were not statistically significant for the immobilized knees. However, MRI using a 0.5 Tesla scanner was statistically different from CT and XR for the non-immobilized contralateral knees. We conclude that the three methods detected osteoarthritis lesions in rabbit knees, but MRI was less sensitive than XR and CT in detecting lesions compatible with initial osteoarthritis. Since none of the techniques revealed all the lesions, it is important to use all methods to establish an accurate diagnosis.

Avaliação dos reflexos espinhais em bezerros

Este trabalho objetivou avaliar, quantificar e padronizar a ocorrência dos reflexos espinhais em bezerros da raça holandesa de 15 a 90 dias de idade, os quais foram submetidos a avaliação nos membros torácicos (reflexo carpo radial, reflexo bicipital, reflexo tricipital e reflexo flexor) e nos membros pélvicos (reflexo patelar, reflexo tibial cranial, reflexo gastrocnêmio, reflexo ciático e reflexo flexor). Para quantificação da resposta involuntária frente ao reflexo realizado, padronizou-se a ausência do reflexo como sendo o algarismo 0; resposta discreta do reflexo como sendo l e a presença evidente da resposta como sendo 2. Os reflexos mais evidentes e constantes foram os reflexos flexor, carpo radial, patelar e tricipital. Os reflexos menos evidentes e menos freqüentes foram os reflexos tibial cranial, bicipital, gastrocnêmio e ciático.

Avaliação dos reflexos espinhais em cordeiros da raça Suffolk

Fez-se a avaliação qualitativa e semiquantitativa dos reflexos espinhais em ovinos, utilizando-se 51 animais da raça Suffolk, machos e fêmeas, entre quatro e cinco meses de idade. Usaram-se os reflexos bilaterais dos membros torácicos, extensor carpo-radial, bicipital, tricipital e flexor, e pélvicos, isquiático, gastrocnêmio, patelar, tibial cranial e flexor, sendo zero indicativo de ausência de reflexo, 1= reflexo discreto e 2= reflexo evidente. Nos membros torácicos, as melhores respostas foram obtidas no flexor (99,0%) e no extensor carpo-radial (87,3%), seguidos de valores menos expressivos no bicipital (11,8%) e no tricipital (2,0%), com grau 2 de avaliação. Nos membros pélvicos, todos os ovinos produziram respostas em grau 2 para o reflexo flexor. Verificam-se também respostas evidentes nos reflexos patelar (98,0%) e isquiático (81,4%). Apenas 20,6% dos animais apresentaram resposta evidente ao reflexo tibial cranial, e nenhum ovino respondeu ao reflexo gastrocnêmio de forma satisfatória.

Rehabilitation of Atrophic Maxilla Using the Combination of Autogenous and Allogeneic Bone Grafts Followed by Protocol-Type Prosthesis

Currently, there are several techniques for the rehabilitation of atrophic maxillary ridges in literature. The grafting procedure using autogenous bone is considered ideal by many researchers, as it shows osteogenic capability and causes no antigenic reaction. However, this type of bone graft has some shortcomings, mainly the restricted availability of donor sites. In recent years, several alternatives have been investigated to supply the disadvantages of autogenous bone grafts. In such studies, allogeneic bone grafts, which are obtained from individuals with different genetic load, but from the same species, have been extensively used. They can be indicated in cases of arthroplasty, surgical knee reconstruction, large bone defects, and in oral and maxillofacial reconstruction. Besides showing great applicability and biocompatibility, this type of bone is available in unlimited quantities. on the other hand, allogeneic bone may have the disadvantage of transmitting infectious diseases. Atrophic maxillae can be treated with bone grafts followed by osseointegrated implants to obtain aesthetic and functional oral rehabilitation. This study aimed to show the viability of allogeneic bone grafting in an atrophic maxilla, followed by oral rehabilitation with dental implant and protocol-type prosthesis within a 3-year follow-up period by means of a clinical case report.

Temporal response pattern of biochemical analytes in experimental diabetes

The activities of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LD), creatine kinase (CK), amylase (AMS) and angiotensin converting enzyme (ACE) have been used to assess the toxic effects of xenobiotics that have hypoglycaemic action in hepatic, pancreatic, renal and muscle tissue. Using a validated experimental model of diabetes mellitus in rats, we ascertained whether this syndrome itself affected the serum activities of these enzymes over a 53-day period. Levels of hepatic enzymes AST, ALT and ALP were higher in the streptozotocin (STZ)diabetic rats (group D), but were controlled by insulin therapy (group DI). AMS was reduced in group D and unchanged in group DI rats. Proteinuria was detected 1 day after STZ administation and partially controlled by insulin (group DI); its early presence in group D rats, and the lack of any change in serum ACE in this group, indicates that proteinuria is the better marker for microangiopathy. Microscopic examination of liver, kidney, heart and skeletal muscles (soleus and extensor digitorum longus) revealed various alterations in group D rat tissues, which were less pronounced in group DI. The liver, pancreas and kidney tissue-damage was consistent with the altered serum levels of AST, ALT, ALP and AMS and proteinuria. We conclude that: (i) rigorous control is required when these serum-enzyme levels are used as indicators of tissue toxicity in experimental diabetes, and (ii) LD, CK and bilirubin serum levels, which are unaffected by diabetes, can be used when testing effects of xenobiotics on tissues.

Cyclic-loading of the human gracilis and semitendinosus muscle tendons: Study of young adult cadavers

During knee ligament reconstruction, the tendon graft is tensioned to prevent the occurrence of excessive graft elongation during the postoperative period. Tensioning may be achieved by applying a cyclic or static load to the graft during fixation. Although this procedure is part of the surgery, there is no consensus in international literature regarding ideal tension levels to be used in this procedure. This study was conducted on 10 tendons of the human gracilis muscle and 10 tendons of semitendinosus muscle removed from five male cadavers whose mean age was 20.8 years. These tendons underwent 10 in vitro strain cycles at three levels of deformation (2.5, 3, and 4%) and the value of the deforming load used for each cycle was recorded. The statistical analysis demonstrated that in order to attain the same level of deformation during the 10 cycles there was a reduction in the value of strain applied to the graft, observed at the three levels of deformation. It was concluded that the semitendinosus tendon presents a more uniform mechanical behavior and that there is a need for new graft tensioning protocols that consider the force associated with deformation.

Differential morphofunctional characteristics and gene expression in fast and slow muscle of rats with monocrotaline-induced heart failure

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

Investigation of Risk Factors and Characteristics of Dance Injuries

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

Paralyzing and myotoxic effects of a recombinant bothropstoxin-1 (BthTX-I) on mouse neuromuscular preparations

As a first step to investigate the structure-function relationship of bothropstoxin-1 (BthTX-1), a myotoxin from Bothrops jararacussu snake venom, Our group previously cloned a recombinant toxin (rBthTX-1) in Escherichia coli. The aim or this work was to characterize the biological activities of this rBthTX-1 (1.0 mu M) in both phrenic-diaphragm and extensor digitorum longus preparations in vitro, by means of myographic and morphologic techniques. Native BthTX-1 (1.0 mu M) was used as a standard. The influence of heparin (27.5 mu g/ml) upon the biological activities of both toxins was also investigated. rBthTX-1 had similar effects to the native toxin inducing blockage of both directly and indirectly evoked contractions in phrenic-diaphragm preparations, and muscle damage characterized by edema, round fibers, and cell areas devoid of myofibrils. Interestingly the paralyzing activity of rBthTX-1 was slightly more potent than the native toxin. Heparin prevented paralyzing and myotoxic effects of both the native and recombinant toxins. This work shows that rBthTX-1 was expressed in a fully active form, and presents a biological profile similar to the native toxin. (c) 2005 Elsevier GmbH All rights reserved.

Reduction of crotoxin-induced neuromuscular blockade by gamma radiation

A comparative study between crotoxin and gamma irradiated crotoxin was performed on the indirectly evoked twitches and tetani of sciatic nerve-extensor digitorum longus muscle of rats. Crotoxin (3 to 14 mu g/ml) decreased the amplitude of twitches and induced a slight tetanic fade, and irradiated crotoxin did not significantly affect either twitch amplitude or tetanic tension. Since gamma radiation reduced the neurotoxicity of crotoxin it may be useful for the production of anticrotalic serum. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Antagonism of myotoxic and paralyzing activities of bothropstoxin-I by surarnin

Polyanionic substances are known to inhibit the myotoxic effects of some crotalide snake venoms. Bothropstoxin-I (BthTX-I), a basic Lys49 phospholipase (PLA(2)) homologue from Bothrops jararacussu venom, besides inducing muscle damage, also promotes the blockade of both directly and indirectly evoked contractions in mouse neuromuscular preparation. In this work, we evaluated the ability of suramin, a polysulfonated naphtylurea derivative, to antagonize the myotoxic and the paralyzing activities of BthTX-I on mice neuromuscular junction in vitro. Myotoxicity was assessed by light and electronic microscopic analysis of extensor digitorum longus (EDL) muscles; paralyzing activity was evaluated through the recording of both directly and indirectly evoked contractions of phrenic-diaphragm (PD) preparations. BthTX-I (1 muM) alone, or pre-incubated with suramin (10 muM) at 37degreesC for 15 min was added to the preparations for 120 min. BthTX-I induced histological alterations typical of myonecrosis in 14.6 +/- 1.0% of EDL muscle fibers. In addition, BthTX-I blocked 50% of both directly and indirectly evoked contractions in PD preparations in 72.1 +/- 9.1 and 21.1 +/- 2.0 min, respectively. Pre-incubation with suramin abolished both the muscle-damaging and muscle-paralyzing activities of BthTX-I. Since suramin is a polyanionic substance, we suggested that its effects result from the formation of inactive acid-base complexes with BthTX-I. (C) 2003 Elsevier Ltd. All rights reserved.

Nandrolone Stimulates Myod Expression During Muscle Regeneration in the Condition of Myonecrosis Induced by Bothrops jararacussu Venom Poisoning

Myonecrosis with permanent loss of muscle mass is a relevant local toxic effect following envenomation with Bothrops jararacussu snake venom. Regeneration of adult skeletal muscle involves the activation of satellite cells, a process regulated by myogenic regulatory factors (MRF). MyoD is an MRF involved in both proliferation and differentiation of satellite cells. Androgens are modulators of skeletal muscle, known to increase muscle mass and strength. This study examined the hypothesis that anabolic androgens improve the muscle regeneration process in mice following envenomation by Bothrops jararacussu snake venom. Myonecrosis was induced by venom injection (30 g/50 l in physiological solution) over the extensor digitorum longus (EDL) muscles of mice. Nandrolone (ND) (6 mg/kg, sc) was administered after 12 h, 7 d, and 14 d following venom injection. The histological changes in EDL muscle at 1, 3, 7, and 21 d after muscle injury were analyzed by light microscopy. Cross-sectional areas of fibers were measured. MyoD was evaluated by immunofluorescence technique. Histological examination revealed the presence of a regeneration process in ND-treated animals, characterized by the appearance of some myotubes at 3 d, and numerous myotubes at 7 d from venom injection. Nandrolone treatment reduced the frequency of small fibers at 7 and 21 d after venom administration, and increased the frequency of large fibers at 7 d postinjury. Nandrolone also significantly augmented the expression of MyoD-positive cells at 7 and 21 d after envenomation. These results suggest that ND accelerates muscle regeneration and indicate the involvement of MyoD in this process.