Juliana da Silva Leite

Immunohistochemical identification of Toxoplasma gondii in tissues from Modified Agglutination Test positive sheep

Toxoplasma gondii is a zoonotic agent of great importance in veterinary and public health. The aim of this study was to identify T. gondii by IHC (immunohistochemistry) in different sheep tissues and to determine if an association exists between the results obtained by this method and those obtained by the Modified Agglutination Test (MAT). Tissue specimens of twenty-six sheep seroreactive for T. gondii were selected for histopathological evaluation. The presence of T. gondii was investigated in brain, liver and heart samples by IHC and a possible anti-T. gondii antibody cross reactions with other parasites. McNemars, Chi-square and Fishers Exact Tests were applied for the statistical analysis of the results. The analysed tissues showed at least one of the following histopathological changes: mild-to-moderate congestion, focal polymorphonuclear inflammatory infiltrate and multifocal or focal mononuclear inflammatory infiltrate. Sarcocystis spp. were identified in the histological sections from both the heart and diaphragm tissues of 88.5% (23/26) of the animals. A total of 46.2% (12/26) of the T. gondii seroreactive sheep was also positive for T. gondii by IHC in at least one organ (brain, liver or heart). The liver IHC-positivity for T. gondii was statistically equivalent to the global individual IHC-positivity, according to McNemars test. In addition, IHC allowed the detection of T. gondii in infected animals regardless of the titration observed in the MAT. The statistical difference observed between the three organs when comparing the low titration group, suggested that the heart might be the most suitable organ to detect T. gondii infection by IHC. The IHC results in this study revealed that almost half of MAT positive animals could serve as potential sources of infection for humans because bradyzoites were identified in different tissues, regardless of the MAT titration.

Assessing the histopathology to depict the different stages of bovine tuberculosis infection in a naturally infected herd

The standard method for detection of bovine tuberculosis (TB) is the single intradermal tuberculin test (SITT). Nevertheless, current studies suggest that a single test is not enough to detect all cattle infected by TB, particularly when animals present different stages of infection. A dairy herd comprised of 270 cows was studied and 15 were reactive to SITT plus nine inconclusive animals. Blood samples (for IFN and ELISA) were collected from these 24 cows. At 30 days after injection of PPD, all the cows that were reactive to any of the employed tests were slaughtered, and tissues were processed by Bacteriology, Histopathology (HP) and PCR. According to HP 33.4% of the animals were positive, 45.8% inconclusive and 20.8% were negative. The inconclusive samples came from IFN positive animals, signalizing recent infection. Regarding the animals that were negative to HP, all of them were identified by IFN while ELISA was negative. Immune responses are different in recent and advanced infections, what supports the identification between chronically or recently infected animals. This multidisciplinary approach is mandatory for the interpretation of the various tools that are frequently employed for the diagnosis of TB and mainly to identify all infected animals.

The intake of Yam (Dioscorea bulbifera Linn) attenuated the hyperglycemia and the bone fragility in female diabetic rats

INTRODUCTION Diabetic patients have a higher risk to osteoporotic fractures. Foods, such as yam, to oppose hyperglycemia, has been used to treatment of diabetes. OBJECTIVE The goal was assess the role of Brazilian yam (Dioscorea bulbifera) on glycemia and bone parameters of female diabetic rats. METHODS Female Wistar rats with 3 months age were allocated in three groups. Control group (C, n = 6), treated with normal fat diet. Diabetic rats treated with high-fat diet without (DM, n = 8) and with (DMY, n = 8) liofilized yam flour. After 5 weeks of the experiment, serum glucose and insulin, pancreas mass, number and area of pancreas islets were quantified. And femur parameters were analyzed by dual-energy X-ray absorptiometry (DXA) and computed tomography (CT). RESULTS Differences were considered significant if P<0.05. Diabetic groups showed lower (P < 0.05): femur and pancreas mass, area of the pancreatic islets and insulin. However, DMY showed lower (-10%, P < 0.05) concentrations of glucose to DM group. Femur, by DXA, showed lower bone mineral density, content and area in the DM group. While the DMY group showed greater (+27%, P < 0.05) radiodensity of femoral head when compared to DM group. DISCUSSION Brazilian yam flour supplement did not fix a defect, but alleviated the consequences of the experimental diabetic disease. It showed results to control the rise in blood glucose levels in diabetic rats, suggesting protection in oxidative agents and postpone harm in the bone. CONCLUSION Considering all the findings of the present study, our results suggest that yam flour does act producing benefits in the experimental diabetes.

Vimentin, osteocalcin and osteonectin expression in canine primary bone tumors: diagnostic and prognostic implications

Canine primary bone tumors have a plastic radiographic image, demanding histopathological confirmation. Bone tumors are characterized by the type and amount of extracellular matrix produced what cannot be easily recognized, especially in biopsy samples. Identifying cellular markers that could aid diagnosis has supported various studies in oncological pathology. This study aimed to evaluate 22 canine primary bone neoplasms, establishing their histopathological diagnosis and evaluated vimentin, osteonectin and osteocalcin expression and their implication in diagnosis and prognosis. There were 12 productive osteoblastic osteosarcomas, six minimally productive osteoblastic osteosarcoma, two chondrosarcomas, one fibrosarcoma and one hemangiosarcoma. Immunostaining was cytoplasmatic in all cases, with average percentage of 87.9% for vimentin, 98.0% for osteonectin and 99.9% for osteocalcin. In this last case, only osteosarcomas were considered. Intensity was higher in vimentin labeling (+++), followed by osteonectin (++) and osteocalcin (+). One osteosarcoma showed negative immunostaining for vimentin and of samples submitted to anti-osteocalcin immunostaining, three osteosarcomas and one fibrosarcoma had negative staining. Besides identifying mesenchymal origin, vimentin elevated expression in canine bone tumors can be related to epithelial–mesenchymal transition, leading to more aggressive tumoral phenotypes and metastasis development. Similarly, high osteonectin expression is implicated in neoplastic cell invasion and is also related to metastasis spread. Decreased osteocalcin expression was found in some osteosarcoma samples and can be related to poor prognosis, as in human osteosarcomas. Our findings suggest that vimentin, osteonectin and osteocalcin not only aid diagnosis but can be related to prognosis in canine primary bone tumors, especially osteosarcomas and its osteoblastic subtype.

Survival and Disease-free Interval of Cats with Mammary Carcinoma Treated with Chain Mastectomy

Background: Mammary tumors are extremely common in cats and have high metastatic rates with poor prognosis. The main objective of the present study was to evaluate the disease free interval and survival in cats undergoing radical mastectomy as sole therapy. Materials, Methods & Results: Twenty cats with mammary tumors and no evidence of distant metastasis were studied. General health and concomitant diseases were assessed by clinical and hematological examination. Thoracic radiographs and abdominal ultrasonography were performed to evaluate thoracic and abdominal metastases. All cats underwent chain mastectomy, which was unilateral when tumor was present in one mammary chain, and bilateral in steps if tumors were present in both mammary chains. Intact cats were spayed. An elliptical incision was made around the mammary chain with a three centimeter margin around tumor. Regional lymph node was removed. Mean age was ten years, and 14 cats were mixed breed, three were Persian and two were Siamese. Fifteen cats were spayed at tumor diagnosis, but only three had been spayed before one year old. The inguinal mammary glands were the most affected, followed by abdominal and thoracic glands. Histopathology diagnosed well-differentiated adenocarcinoma in eight cases, moderately differentiated adenocarcinoma in nine cases, poorly differentiated adenocarcinoma in two cases and carcinoma in situ in one case. Most tumors were grade II, and regional lymph node metastasis was present in two cases. Disease free interval ranged from 120 to 1800 days, with an average of 678 days. Four cats had tumor local recurrence and six developed lung metastasis. The survival time ranged from seven to 1800 days, with an average of 768 days. Twelve cats are still alive with no tumor recurrence. Discussion: The average age of onset of mammary carcinomas in cats was ten years old, similar to previous studies. Siamese cats have more risk of developing this disease, but mixed breed cats were frequent in this study. Intact or late spayed cats are predisposed to mammary tumors because of hormonal stimulation, the same was observed in this study. Inguinal and abdominal glands were most affected, similar to other reports. The histopathologic diagnosis was adenocarcinoma in most cases of this study, mostly grade II tumors, which was also observed in previous papers. Regional lymph nodes (axillary or inguinal) should always be removed during mastectomy in cats, as regional metastasis at diagnosis is common, even when not clinically palpable, as was observed in two cases. Distant metastasis occurs most often to the lungs, leading to severe dyspnea. In this study, four cats had local tumor recurrence and six developed lung metastasis. Aggressive and early surgical intervention is the treatment of choice for feline mammary tumors. Unlike dogs (where conservative mammary resections are appropriate in some cases), radical chain mastectomy is recommended for feline mammary tumors, as significantly reduces the risk of local recurrence. In this study, all animals underwent radical mastectomy, without previous cytology or biopsy. Survival is variable between studies, ranging from 220 to 1408 days. Several factors may be involved in disease free intervals and survival times, as tumor size, tumor histological grade, presence of metastasis at diagnosis, type of surgery performed, presence of concomitant diseases and adjuvant chemotherapy. In this study, mean survival time was 768 days and 12 cats are still alive and in follow-up, which may increase this number. This study supports that, if treated early and agressively, cats with malignant mammary tumors can have long survival after chain mastectomy.

Muscle regeneration through therapy with estromal stem cells in injury of infraespinhosus muscle of sheep

PURPOSE To evaluate the effects of rotator cuff muscle regeneration in sheep and establish an experimental model for the use of autologous stem cells as a treatment option for tendon injuries. METHODS Infrared muscle tenotomies and Penrose drain implantation were performed on 12 shoulders of six clinically healthy adult sheep. After 60 days, the tendons were submitted to tissue repair, drainage removal, and divided into two groups according to the use of autologous stromal stem cells for treatment. Muscle regeneration was performed by biopsy on days 14 and 34 after repair. RESULTS The treatment group with cell therapy showed neovascularization and expressive regeneration. Complete regeneration of the muscle pattern did not occur in any sample although some muscle gain was obtained in the group 1 samples at 34 days after repair and introduction of stem cells. Fatty infiltration of these samples from group 1 at 34 days was less intense than that in samples from group 2 at 34 days after repair without the introduction of autologous precursor cells. CONCLUSION The sheep proved to be a good experimental model to assist in the development of research on muscle regeneration and the autologous manipulation of stem cells as a therapeutic option.

Histologic evaluation of Ki-67 and cleaved caspase-3 expression in feline mammary carcinoma

Objectives The purpose of this study was to evaluate histopathologic aspects of, and the expression of Ki-67 and cleaved caspase-3 in, feline mammary carcinoma (FMC). Methods Feline mammary tumors were surgically obtained by mastectomy from 30 female cats and were fixed with formalin and embedded in paraffin wax. Four-micron sections were stained with hematoxylin and eosin for histopathologic diagnosis. Ki-67 and cleaved caspase-3 were analyzed by immunohistochemistry. Results Samples were histologically confirmed as FMC. Positive immunostaining was observed in all cancer samples for both nuclear Ki-67 and cleaved caspase-3, with a mean positive staining percentage of 27.5% and 21.2%, respectively. No statistically significant correlations between Ki-67 and cleaved caspase-3 were observed within FMC. Conclusions and relevance A high proliferation index was found in feline mammary tumors. This is the first study evaluating cleaved caspase-3 expression in FMC.

Composição miofibrilar do glúteo médio de equinos de concurso completo de equitação na fase inicial do treinamento

The studies of myofibrillar composition in athletic horses make it possible to best direct them according to their specific fitness and certainly saves time and resources in the preparation of these athletic animals. Through the technique of percutaneous muscle biopsy and different enzyme-histochemical techniques have been possible to classify these fibers in three different types, type I, IIA and IIX. This information can be applied in the selection of those horses and to the possibility the proper conduct of training protocols. In order to evaluate the myofibrillar composition of Gluteus Medius to the selected mode of Eventing by Army Riding School -RJ, thirteen horses, crossbred breeds of Hanoverian, Thoroughbred and Brazilian Equestrian, in the age range 6-12 years, were used. All animals were submitted to a percutaneous muscle biopsy procedure and the fragments subjected to enzyme-histochemical techniques for distinguishing the three different types of muscle fibers by assessing the reactivity of the enzyme adenosine triphosphate miosinica ( mATPase ) and succinate dehydrogenase ( SDH). The animals used had an average relative distribution of different types of muscle fibers apparently quite homogeneous, with 25.9 %, 35.7 % and 38.4 % of fibers of type I, IIA and IIX, respectively, but lying statistically significant difference , with a higher proportion of type II fibers compared to type I , suggesting that it was a direct genetic influence of the training squad races of the Brazilian Army .

Infiltração de leucócitos e imunorreatividade antimieloperoxidase em granulócitos da mucosa e submucosa do intestino grosso de equinos submetidos à sobrecarga dietética com amido

This study was carried out to evaluate leukocyte infiltration and anti-myeloperoxidase immunoreactivity in granulocytes of the mucosa and submucosa of the large intestine of horses submitted to dietetic starch overload. Eight adult horses were allocated randomly in three treatments: Treatment I (Control) (n = 2), animals euthanized without starch overload; and Treatments II (n = 3) and III (n = 3), animals undergoing starch overload, with gastric infusion of 17.6 g starch per kg of body weight, euthanized after 24 and 36 hours, respectively. Only afflux of neutrophils in the intestinal mucosa and submucosa blood vessels (leukocyte stasis) was observed. Eosinophils were the predominant cells in the mucosa and submucosa in all horses, independent of dietetic overload, with infiltration grade from mild to moderate. Lymphocyte infiltration was also observed in all horses, but with lower intensity when compared to eosinophils. Congestion, edema and dilatation of lymphatic vessels were the main circulatory alterations observed, with more intensity in the submucosa. Higher immunoreactivity to the anti-myeloperoxidase antibodies was observed in the mucosa and submucosa of horses 36 hours after overload. Horses submitted to dietetic starch overload showed intestinal inflammatory response with prevalence of eosinophils, leukocyte stasis and circulatory alterations, varying from discreet to moderate.