E.G. Melo

Hidroxiapatita sintética como substituto ósseo em defeito experimental provocado no terço proximal da tíbia em cão: aspectos à microscopia eletrônica de transmissão

With the objective of studying the synthetic hydroxyapatite (HAP-91) as a bone substitute, eight healthy mongrel adult dogs were used. Following the habitual anesthetic and surgical protocol, a bone defect was provoked in the proximal diafisis of the left and right tibias, being implanted the graft of HAP-91 just in the right tibia. The animals, two at each time, were sacrificed at the 8th, 30th, 60th and 120th days after the surgery, when lesion samples were obtained for histopathology, submitted to the double coloration in 1% uranil acetate solution and in lead citrate solution. These sections were examined and photographed in an electronic transmission microscope. The bone tissue components were identified both in the control and treated tibia. The absorption of HAP-91 was characterized by the presence of multinuclear cells in the interface between the hydroxyapatite and the bone, morphologically considered as osteoclasts. In addition, the concomitant presence of HAP-91, with the adjacent formation of new bone was found, which suggests that the osteointegration of HAP-91 is similar to the bone reabsorption apposition normal process.

Effects of dantrolene on apoptosis and immunohistochemical expression of NeuN in the spinal cord after traumatic injury in rats

Dantrolene has been shown to be neuroprotective by reducing neuronal apoptosis after brain injury in several animal models of neurological disorders. In this study, we investigated the effects of dantrolene on experimental spinal cord injury (SCI). Forty‐six male Wistar rats were laminectomized at T13 and divided in six groups: GI (n = 7) underwent SCI with placebo and was euthanized after 32 h; GII (n = 7) underwent laminectomy alone with placebo and was euthanized after 32 h; GIII (n = 8) underwent SCI with dantrolene and was euthanized after 32 h; GIV (n = 8) underwent SCI with placebo and was euthanized after 8 days; GV (n = 8) underwent laminectomy alone with placebo and was euthanized after 8 days; and GVI (n = 8) underwent SCI with dantrolene and was euthanized after 8 days. A compressive trauma was performed to induce SCI. After euthanasia, the spinal cord was evaluated using light microscopy, TUNEL staining and immunochemistry with anti‐Caspase‐3 and anti‐NeuN. Animals treated with dantrolene showed a smaller number of TUNEL‐positive and caspase‐3‐positive cells and a larger number of NeuN‐positive neurons, both at 32 h and 8 days (P ≤ 0.05). These results showed that dantrolene protects spinal cord tissue after traumatic SCI by decreasing apoptotic cell death.

Site of Intrauterine Artificial Insemination in the Bitch does not Affect Sperm Distribution within the Uterus

The aim of this study was to evaluate the distribution of frozen-thawed spermatozoa within the uterine lumen and oviducts following intrauterine laparoscopic deposition at two sites. Twelve bitches of unknown reproductive history were randomly distributed into two groups. Semen (3 ml containing 300 × 10(6) frozen-thawed spermatozoa) was infused at the uterine body (UB group) or at the cranial tip of the left uterine horn. A 22-G catheter was used to access the uterine lumen. Sperm cell distribution was evaluated after ovariohysterectomy performed 3 h after artificial insemination (AI). There was no difference between groups in mean time to perform AI. Spermatozoa were detected in all uterine segments, including the tip of both horns, but none was detected in the oviduct. The 22-G catheter facilitated deposition of semen in the uterine lumen, particularly at the UB site. Sperm cell distribution occurred evenly along both horns, independent of the site of semen deposition.

Effects of chondroitin sulfate and sodium hyaluronate on chondrocytes and extracellular matrix of articular cartilage in dogs with degenerative joint disease

Foram utilizadas amostras de cartilagem articular do femur, tibia e patela de 15 caes com doenca articular degenerativa (DAD), induzida experimentalmente. Foram constituidos tres grupos de cinco animais: grupo 1 - controle, nao medicado; grupo 2 - tratado com sulfato de condroitina e grupo 3 - tratado com hialuronato de sodio. As amostras foram processadas e coradas pelas tecnicas de HE e de azul de toluidina para avaliacao das alteracoes morfologicas, e impregnadas pelo nitrato de prata para analise da atividade metabolica e/ou proliferativa dos condrocitos, por meio da visualizacao e quantificacao de regioes organizadoras do nucleolo (NORs). Nao foram notadas diferencas significativas (P 0,05) na contagem de NORs, celulas e NORs/celula entre os grupos. As maiores contagens de NORs e de celulas no grupo tratado com hialuronato de sodio sugeriram aumento da taxa de proliferacao dos condrocitos. A maior relacao de NORs/celula obtida no grupo tratado com sulfato de condroitina sugere que essa droga estimula a atividade metabolica do condrocito, minimizando as lesoes ocorridas durante a DAD.

Sulfato de condroitina e hialuronato de sódio no tratamento da doença articular degenerativa em cães: estudo histológico da cartilagem articular e membrana sinovial

Fifteen mongrel dogs, both genders, weighting from 18 to 25kg were used and Degenerative Joint Disease (DJD) was induced through cranial cruciate ligament (CCrL) artroscopical section. After three weeks, CCrL was reconstructed by Schawalders (1989) technique. Then, dogs were distributed in three groups and the following protocols were used: group I, control, no other treatment but the CCrL reconstruction; group II received chondroitin sulfate 24mg per animal every five days, intramuscularly, in a total of six injections; and group III received sodium hyaluronate 20mg per animal every five days, intravenously, in a total of three injections. Clinical observation was done until 90 days after treatments. By that time, the articular cartilage and synovium were collected and their morphology was evaluated. In group I, the degenerative alterations of the DJD were the most intense. Thus, decrease of chondrocytes number, pannus, fibrillations, grooves, erosion, and irregular articular surface were observed on the cartilage. In group II, raise of chondrocytes number was observed, with increase of synthesis activity of matrix and decrease of lesions on the articular surface. There was an increase of chondrocytes in group III, but the cells were morphologically unviable. All the groups showed proliferation of the synovial membrane, with limpho-plasma cells infiltrated in subintim and perivascular. In groups I and III, the proliferation of synovium was abundant, with formation of pannus, flattened synoviocytes or synovium absent with granulation tissue. Those results suggest that the chondroitin sulfate stimulated the articular cartilage; decreasing or delaying the alterations of DJD, as well as, the sodium hyaluronate did not interfere on degenerative process in articular cartilage. No favorable action of these drugs in the synovial membrane was verified.

Sulfato de condroitina e hialuronato de sódio no tratamento da doença articular degenerativa experimental em cäes. Aspectos clínicos e radiológicos

The aim of this study was the evaluation of the effects of chondroitin sulfate and sodium hyaluronate in the knee joint of dogs with experimentally induced degenerative joint disease (DJD). Fifteen mongrel dogs, weighing 18 to 25kg were used. DJD was induced by cranial cruciate ligament (CCL) arthroscopical transection. After three weeks, CCL was repaired by an intrarticular technique, which uses fascia lata. The dogs were then divided into three groups as follows: group I received no other treatment, but the CCL reconstitution, group II received 24mg/animal of chondroitin sulfate/IM every five days, totaling six injections, and group III received 20mg/animal of sodium hyaluronate /IV every five days, totaling three injections. All dogs were examined clinically and radiographically for 90 days after the repairment surgery. The clinical evaluation was performed by assessment of lameness, weight-bearing, limb muscle atrophy and range of motion. The results demonstrated that the group treated with sodium hyaluronate had lower degree of lameness in comparison with other groups. The radiographic evaluation showed marginal osteophytes and subchondral bone sclerosis. These changes were more severe in the group treated with sodium hyaluronate. The better clinical results observed in this group, compared with the others, was probably due to the greater action of the drug in the synovium, decreasing the pain and lameness. Radiographic findings correlated poorly with the clinical signs in the group treated with sodium hyaluronate.

Utilização de hidrocortisona em eqüinos submetidos a isquemia e reperfusão no jejuno e suas conseqüências sobre o cório laminar

To evaluate whether hydrocortisone sodium succinate (HSS) aggravates lesions in the laminar tissue secondary to intestinal ischemia and reperfusion (IR), two segments of the jejunum were isolated in 12 halothane-anesthetized horses, and total ischemia was induced on them. Three other horses were used as controls. One hour after the onset of the ischemia, HSS (4.0mg/kg) was administered intravenously to six animals (T group) and saline to the others (NT group). After two hours of ischemia and two hours of reperfusion the abdomen was closed and the horses were allowed to recover from anesthesia. After 12 hours of reperfusion the horses were euthanatized and biopsy specimens were taken from the laminar tissue and the lesions were evaluated and scored. No significant differences between T (0.41) and NT (0.54) groups for laminar lesion scores were observed. The results indicate that HSS did not produce harmful effects in the laminar tissue, suggesting that the occurrence of undesirable effects in the digit are not a limiting factor for using this drug to treat equine patients with acute abdomen.

Pós-operatório tardio da substituição do ligamento cruzado cranial no cão

After the replacement of the cranial cruciate ligament (CrCL) with an autogenous fascia lata graft, radiographic and clinic post-surgical evaluation were performed. Fourteen male and female dogs averaging 68 month-old and 28.6kg body weight with unilateral rupture of CrCL were selected. Twenty-eight joints were studied. The treated joints consisted of the treated and non-treated animals. The mean time from the initial onset of the symptoms to the surgery was five months and 15 days and the mean interval between the surgery and the follow-up examination was 14 months. No lameness was observed in 57.1% of the treated dogs and mild lameness in 42.9% of them. In this group, articular crepitus, pain, reduced articular motion amplitude and muscular atrophy were observed. No lameness was observed in 98.2% of the non-treated dogs. These joints showed mild arthrosis. Degenerative joint disease was observed in both groups. The surgical technique was efficient, the dogs showed clinical improvement after surgery, regardless of radiographic signs. The results were better in the dogs submitted to surgery soon after the onset of the symptoms. The interval between the injury and the treatment was the most important factor involved in the recovering after surgery.

Cortisol sérico e glicemia em cadelas tratadas com tramadol e submetidas à ovário-histerectomia

Tramadol is an opiate analgesic used in veterinary medicine, although few studies exist on this drug. The objective of this work was to evaluate the analgesic effect promoted by the administration of tramadol, determined the serum cortisol and blood glucose concentrations of female dogs. For that, 15 animals were used, submitted to the ovaryhysterectomy under general anesthesia with isofluorane. The animals were assigned into three groups. Group 1 (Tep): received epidural tramadol (1.0mg kg-1 diluted in bi-distilled water at 3.0mL final volume), followed by 3.0mL of bi-distilled water applied intravenously fifteen minutes later. Group 2: (Tiv) 3.0mL of bi-distilled water applied via epidural, following intravenous tramadol (1.0mg kg-1 diluted in bi-distilled water at 3.0mL final volume) applied fifteen minutes later. Group 3 (CT): 3.0mL of bi-distilled water applied via epidural, followed by 3.0mL of bi-distilled water applied intravenously fifteen minutes later. The efficacy of each analgesia regimen was evaluated for 12 hours after epidural. There were no significant differences among the experimental groups to the studied variables (P(0.05). Significant differences were observed in each treatment. In the Tep group, there was a serum cortisol increase in the 25 minutes of the transoperatory (M3), in relation to the obtained value right after the anesthesia induction (M2) (P<0.05). In the Tiv and CT groups, we could check an elevation of the variables two (M4) and four (M5) hours of the epidural injection, when compared to the pretreatment (M1) (P<0.05). In these periods, the variables that were studied in the Tep treatment were statistically similar to the pretreatment (M1). According to the results it can be concluded that 1) used methods were sensitive to determine the most stressful surgical moments as well as and, 2) epidural tramadol seems to produce longer analgesia when compared to the intravenous administration.

Modelo experimental de trauma medular agudo produzido por aparelho estereotáxico modificado

Foram utilizados 55 ratos machos da especie Rattus novergicus, variedade Wistar, com o objetivo de propor um modelo experimental de trauma medular produzido por aparelho estereotaxico modificado, capaz de reproduzir clinicamente lesoes medulares padronizadas. Apos realizacao de laminectomia dorsal de T13, utilizou-se peso compressivo de 50,5g (25 animais - grupo I) ou 70,5g (30 animais - grupo II), durante cinco minutos, comprimindo a medula espinhal. Os animais foram assistidos durante oito dias, por meio de testes comportamentais para avaliar a sensibilidade dolorosa, a capacidade motora, o posicionamento tatil e proprioceptivo e a capacidade de manter-se em plano inclinado. No grupo I, observaram-se deficits neurologicos moderados e transitorios, que variaram entre os animais. No grupo II, foi possivel obter um trauma padronizado, caracterizado por paraplegia bilateral e simetrica dos membros posteriores, perda de propriocepcao e da sensibilidade dolorosa de todos os animais. A utilizacao do aparelho estereotaxico desenvolvido permite reproduzir clinicamente trauma medular padronizado em ratos, de maneira simples, economica e satisfatoria, o que podera proporcionar avancos nas investigacoes terapeuticas, abrangendo doencas neurodegenerativas, como e o caso do trauma medular agudo.