Renato Silva de Sousa

Systemic leukopenia, evaluation of laminar leukocyte infiltration and laminar lesions in horses with naturally occurring colic syndrome.

The present study was aimed at identifying laminar lesions and leukocyte infiltration in hoof laminar tissue of horses with colic syndrome and its correlation with the total leukocyte count before death. Six healthy horses were used as control group (CG), and eighteen horses with lethal gastrointestinal disease were divided into two groups: leukopenic group (LG) with seven leukopenic horses, and non-leukopenic group (NLG) with 11 horses with total leukocyte count within reference range for the species. Leukocyte infiltration was examined by immunohistochemistry. Laminar lesions were observed in both LG and NLG, with no differences in severity between them. LG showed increase of the leukocyte infiltration in the hoof laminar tissue, when compared to CG and NLG. Horses with severe colic syndrome (LG and NLG) developed intense laminar lesions without clinical signs of laminitis, with increased leukocyte infiltration. However, the LG demonstrated an even higher increase of leukocyte infiltration compared to both CG and NLG.

Intraocular signet-ring cell melanoma in a hamster (Cricetulus griseus).

A two-and-a-half year-old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet-ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters.

Adesivo cirúrgico de etil-2-cianoacrilato em lobectomia parcial em ratos

OBJECTIVE To determine the efficacy of ethyl 2-cyanoacrylate adhesive in repairing the lung parenchyma after partial lobectomy in rats, in terms of hemostasis/aerostasis, scarring, and surgical time. METHODS The study involved 30 Wistar rats, randomly divided into five groups (one control group and four study groups). In the study groups, the lung parenchyma was repaired with either cyanoacrylate adhesive or surgical suture following resection of a small or large fragment (25% or 50%, respectively) of the left caudal lung lobe. RESULTS Surgical time and hemostasis time were shorter in the two groups treated with the adhesive than in the two submitted to suture. There were no significant differences among the groups regarding specific lung compliance. Adherences and inflammatory reactions were more severe in the groups submitted to suture. CONCLUSIONS In this study, the use of cyanoacrylate adhesive helped reduce the surgical time and the intensity of inflammatory reactions, as well as preserving lung compliance. Cyanoacrylate adhesives should be considered an option for lung parenchyma repair, decreasing the risk of complications after partial lobectomy in humans.OBJECTIVE: To determine the efficacy of ethyl 2-cyanoacrylate adhesive in repairing the lung parenchyma after partial lobectomy in rats, in terms of hemostasis/aerostasis, scarring, and surgical time. METHODS:The study involved 30 Wistar rats, randomly divided into five groups (one control group and four study groups). In the study groups, the lung parenchyma was repaired with either cyanoacrylate adhesive or surgical suture following resection of a small or large fragment (25% or 50%, respectively) of the left caudal lung lobe. RESULTS: Surgical time and hemostasis time were shorter in the two groups treated with the adhesive than in the two submitted to suture. There were no significant differences among the groups regarding specific lung compliance. Adherences and inflammatory reactions were more severe in the groups submitted to suture. CONCLUSIONS: In this study, the use of cyanoacrylate adhesive helped reduce the surgical time and the intensity of inflammatory reactions, as well as preserving lung compliance. Cyanoacrylate adhesives should be considered an option for lung parenchyma repair, decreasing the risk of complications after partial lobectomy in humans.

Oxidative stress in hoof laminar tissue of horses with lethal gastrointestinal diseases.

Tissue damage caused by oxidative stress is involved in the pathogenesis of several diseases in animals and man, and is believed to play a role in the development of laminitis in horses. The aim of this study was to investigate the oxidative stress associated with laminar lesions in horses with lethal gastrointestinal disorders. Laminar tissue samples of the hoof of 30 horses were used. Tissue samples were divided as follows: six healthy horses (control group-CG), and 24 horses that died after complications of gastrointestinal diseases (group suffering from gastrointestinal disorders-GDG). Superoxide dismutase (SOD2) and nitrotyrosine immunostaining and the severity of laminar lesions were evaluated. Presence of laminar lesions and immunostaining for nitrotyrosine and SOD2 were only evident in horses from the GDG group. Thus, oxidative stress may play a role in the pathogenesis of laminar lesions secondary to gastrointestinal disorders.

Chronic welfare restrictions and adrenal gland morphology in broiler chickens

Gait problems constitute an important and chronic welfare restriction for broiler chickens. The objective of the present study was to determine if adrenal gland morphology indicates chronic welfare restrictions in broiler chickens, using gait problems as the stressor. Sixty-six birds raised on a commercial unit were selected at 40 d of age and separated into groups according to gait score. One group was apparently healthy birds (AH) with gait scores of 0 to 2, and the other group had birds with gait problems (GP) that showed gait scores of 4 to 5. Birds were slaughtered and weighed, and their adrenal glands were measured and weighed; proportions of medullary and adrenocortical tissues, and lymphatic tissue and blood vessels were studied. GP birds had lower BW when compared to AH birds, and when adrenal gland weight values were adjusted to BW, a greater relative adrenal weight was observed for the GP group. Adrenals from GP birds also presented a higher proportion of blood vessels when compared to AH birds. These results might indicate increased adrenal activity and evidence of the inflammatory process as a consequence of chronic stress. Results showed that gait problems caused significant adrenal gland changes, suggesting a possible role for the study of adrenal gland morphology as an indicator of chronic welfare problems in broiler chickens.

Histopathological hoof laminar changes in horses with Pituitary Pars Intermedia Adenoma: cases report

Laminitis in horses is often associated with endocrine disorders, especially the pituitary pars intermedia dysfunction (PPID) in older animals. Morphologic exams of the laminar tissue of the hoof were performed in two horses with suspected PPID, with no clinical signs of laminitis. Changes compatible with laminitis of endocrine origin were observed, such as rounding of the nuclei of the basal cells, thinning and stretching of the secondary epidermal laminae and tissue proliferation. PPID horses with no clinical signs of laminitis may be affected by lesions of the laminar tissue of the hoof that compromise the integrity of the dermal-epidermal junction and may develop clinical symptoms of the disease. It has been suggested that the development stage of endocrine laminitis is longer, but further studies should be conducted to confirm it.

DNA Methylation Status of the Estrogen Receptor α Gene in Canine Mammary Tumors

Estrogen receptor α (ERα) has an important role in mammary carcinogenesis, prognosis, and treatment. In human and canine mammary cancer, the most aggressive tumors show loss of ERα expression, which in human breast cancer has been attributed to methylation of the cytosine followed by guanine (CpG) island within the estrogen receptor α gene (ESR1) promoter. This study aimed to investigate the role of ESR1 CpG island (CGI) methylation in ERα expression in canine mammary tumors. Twenty-one canine mammary samples were sorted into three groups: malignant tumor (n = 9), benign tumor (n = 8), and normal gland (n = 4). Immunohistochemical analysis and reverse-transcription quantitative real-time PCR were performed to assess ERα expression and ESR1 mRNA levels. The methylation status was determined using sodium-bisulfite-treated DNA sequencing. All normal mammary glands and benign tumors showed high ERα expression (score range, 5–8). Six of the nine malignant tumors did not show ERα expression (score 0), two had score 2, and one had score 4. Lower ERα (P < .005) and ESR1 mRNA levels (P < .005) were found in malignant mammary tumors than in the other two groups. Canine ESR1 has an intragenic and non-promoter-associated CGI, different from humans. No significant variation in methylation percentage was observed among the groups, suggesting that ESR1 is not regulated by DNA methylation, unlike that in humans. This difference should be considered in further research using ERα as a biomarker for mammary tumors in canine studies on ERα-targeting therapy.

Spinal cord compression caused by melanoma in brown coat horse

This paper describes a case of malignant melanoma in brown coat horse, which had ataxia and proprioceptive deficits in hind limbs, progressing to permanent decubitus. The animal was euthanized and the final diagnosis was based on necropsy and histopathology. At necropsy different masses and / or nodules in skeletal muscle, bone, abdominal cavity, lungs, heart, spleen, liver, adrenal gland, lymph nodes, brain and cerebellum were found. Neurological clinical signs presented by the animal were justified by spinal cord compression caused by melanocytic mass invading the medullary canal of the flow segment of the thoracic spine (between 15th and 18th thoracic vertebrae). This is the first case report of melanoma leading to spinal cord compression in a non-gray horse. Thus, it is important to include this neoplasm in the differential diagnosis list of cutaneous and subcutaneous masses and / or nodules, and in suspected cases of spinal cord compression in horses of any coat.

Laminar lesions in horses with systemic oxidative stress, committed by experimentally induced or naturally occurring gastrointestinal disorders

Laminitis in horses can be associated with lesions in multiple organs secondary to sepsis. Twenty-one horses suffering from gastrointestinal disorders were used in the experiment; 7 horses with experimentally induced endotoxemia and intestinal ischaemia, and 14 horses suffering from naturally occurring colic syndrome. Tissue samples of lungs, liver, heart, brain, cerebellum and hoof laminar tissue were collected for histopathological and oxidative stress evaluation using nitrotyrosine and superoxide dismutase (SOD2) immunostaining. The horses were divided into two groups: the non-oxidative lesions group (NOLG), with 7 horses showing weak immunostaining in lungs, liver and kidney, and the oxidative lesions group (OLG), with 14 horses showing immunostaining indicating systemic oxidative stress in multiple organs. The horses from OLG showed increase of laminar lesions and SOD2 immunostaining in multiple organs when compared to the horses from the NOLG. No differences were found ln regard to laminar immunostaining by nitrotyrosine and SOD2 between experimental groups. It was concluded that systemic oxidative stress can be associated with the development of laminar lesions, and that the laminar tissue does not respond to oxidative stress with increase of SOD as occurs in other organs.

Teste rápido para detecção da Proteína C-Reativa (FASTest® CRP canino) como auxílio diagnóstico de piometra em cadelas

A piometra e uma enfermidade comum em cadelas, caracterizada pela inflamacao do utero com acumulo de exsudato purulento. A avaliacao ultrassonografica abdominal e um dos principais exames utilizados para o diagnostico da doenca e o tratamento de eleicao e a ovario-histerectomia (OSH). A proteina C reativa (PCR) e uma proteina de fase aguda que apresenta concentracao serica aumentada na ocorrencia de processos inflamatorios. O objetivo deste trabalho foi avaliar a eficacia do teste rapido para deteccao da PCR serica (FASTest® CRP canino), como auxiliar no diagnostico de piometra em cadelas com suspeita da doenca ao exame ultrassonografico. Das 25 cadelas com imagem ultrassonografica sugestiva de piometra incluidas no estudo, apenas 12 (48,0%) tiveram o diagnostico confirmado por exame histopatologico uterino realizado apos a OSH. Em todas as pacientes com o diagnostico de piometra confirmado pelo exame histologico a PCR foi positiva. O FASTest® CRP apresentou valor preditivo positivo de 92,3%, valor preditivo negativo e sensibilidade de 100,0% e 92,3% de especificidade. Logo, a acuracia do FASTest® CRP canino para diagnostico de piometra em cadelas com suspeita ao exame ultrassonografico foi de 96,0%. Conclui-se que o teste rapido para deteccao da PCR serica pode ser utilizado como exame auxiliar para o diagnostico de piometra em cadelas.