Adenocarcinoma em glândula lacrimal de equino / Equine lacrimal gland adenocarcinoma

Background: Lacrimal gland adenocarcinoma is an extremely rare malignant neoplasm, with few descriptions in the literature. Therefore, its etiology and treatment are not well understood. The present study aims to report the case of an equine histologically diagnosed with lacrimal gland adenocarcinoma in the lower eyelid region and third eyelid treated by surgical excision and intralesional chemotherapy. Case: A 17-year-old male mixed-breed equine weighing 300 kg was treated in the large animal clinic and surgery sector of the Federal University of Santa Catarina in the city of Curitibanos, Santa Catarina, Brazil. The equine revealed an alert and docile temperament without considerable physiological changes in the physical examination. In the evaluation of the right eye, a tumor mass was observed in the region of the lacrimal gland adhered to the third eyelid and lower eyelid, with a light red ulcerated appearance approximately 7 cm in diameter. Therefore, the surgical excision of the adhered tumor mass was performed, with the subsequent intralesional application of 2 mL of Vincristine Sulfate. In the histopathological evaluation following the surgical excision of the tumor mass, yellowish-white fragments of irregular nodules were observed measuring from 3.5×2.0×1.7 cm to 2.0×0.5×0.3 cm, in addition to microscopy focus clusters of weakly basophilic neoplastic glandular cells, some with a randomly arranged lacy aspect, forming disorganized acinar structures and others showed marking islands of the cells organized in a palisade shape by vascular delicate stroma. The neoplastic cells presented anisocytosis, anisokaryosis, prominent nucleoli sometimes binucleated and with basophilic intracytoplasmic secretory material, delimited by scarce connective tissue. In some areas, there were small foci of infiltrated lymphocytes and plasmocytes and areas of necrosis. The mass was surrounded by connective tissue, where red blood vessels were found outside the vessels (hemorrhage), and mitoses were observed 2 per field at high magnification (40x). After the surgical procedure, it was not possible to follow up and reassess of the patient, so there is no clarification on the possibility of tumor recurrence. Discussion: The case reported is uncommon, being only the second report of adenocarcinoma in the equine lacrimal gland. Therefore, there are few descriptions in the literature about its defined etiology and the best treatment method, although, surgical excision is the method of choice because it is a tumor of high recurrence and invasiveness. In this case, we opted for the exeresis of the tumor mass and later application of chemotherapy, a treatment that was relatively effective, to avoid recurrence and the failure of the technique. In these cases, monitoring the animal after the procedure is recommended, evaluating whether there was tumor recurrence, although this was not possible in the present possible. The third eyelid, lacrimal, and zygomatic salivary glands may be sources of intraorbital neoplasms. These neoplastic processes may have similar histological and behavioral characteristics, and their differentiation is, therefore, problematic. These structures may be differentiated based on the anatomical location, however, clinical appearance and symptoms are identical in most cases. Adenocarcinoma in the equine lacrimal gland is a neoplasm considered rare, so it is important to emphasize an accurate diagnosis through histopathological analyses to differentiate it from other frequent orbital neoplasms in horses, allowing more information about this tumor and establishing different treatment methods.

Progressive histiocytosis of non-epitheliotropic dendritic cells in a feline

Background: Histiocytic tumors in felines are nodules that commonly develop on limbs and head extremities. They can be divided into many subtypes including cutaneous histiocytoma, histiocytic sarcoma, reactive fibrohistiocytic nodule, Langerhans cell histiocytosis, and progressive feline dendritic cell. Despite the same origin, they have behaviors that differ from each other, thus it is important to confirm diagnosis with histopathological and immunohistochemical tests, because early identification can facilitate prognosis and treatment. In this study, we describe the pathological and immunohistochemical characteristics, enabling differentiation feline neoplasms derived from histiocytes. Case: A 5-year-old, crossbreed, male, feline presented with a nodulation at the base of the left ear. The mass was slow growing, partially alopecic, with no other changes associated with tumor development. The nodule was round and circumscribed, movable, with an elevated surface. He was referred for surgery and an elliptical sample around the tumor was carefully dissected. Routine histopathological evaluation was performed with hematoxylin and eosin (HE), as well as immunohistochemistry. Histopathology showed circumscribed proliferation of histiocytic cells, with abundant and eosinophilic cytoplasm. The proliferative cells were large and rounded, extending from the superficial dermis and basement membrane to the deep dermis. At the extremities, some cells had visible vacuoles. Mitotic activity ranged from 3 to 4 mitoses per field in 40x magnification. Immunohistochemistry showed positive staining for histocompatibility complex MCII and lysozyme antibodies, marking histiocytic cells. Labeling was positive for CD20 in cells of lymphoid lineage B and negative for E-cadherin. Histiocytic cells did not invade the epidermis; hence, proliferation was classified as nonepitheliotropic. These methods contribute to the literature regarding the...

Progressive histiocytosis of non-epitheliotropic dendritic cells in a feline

Background: Histiocytic tumors in felines are nodules that commonly develop on limbs and head extremities. They can be divided into many subtypes including cutaneous histiocytoma, histiocytic sarcoma, reactive fibrohistiocytic nodule, Langerhans cell histiocytosis, and progressive feline dendritic cell. Despite the same origin, they have behaviors that differ from each other, thus it is important to confirm diagnosis with histopathological and immunohistochemical tests, because early identification can facilitate prognosis and treatment. In this study, we describe the pathological and immunohistochemical characteristics, enabling differentiation feline neoplasms derived from histiocytes. Case: A 5-year-old, crossbreed, male, feline presented with a nodulation at the base of the left ear. The mass was slow growing, partially alopecic, with no other changes associated with tumor development. The nodule was round and circumscribed, movable, with an elevated surface. He was referred for surgery and an elliptical sample around the tumor was carefully dissected. Routine histopathological evaluation was performed with hematoxylin and eosin (HE), as well as immunohistochemistry. Histopathology showed circumscribed proliferation of histiocytic cells, with abundant and eosinophilic cytoplasm. The proliferative cells were large and rounded, extending from the superficial dermis and basement membrane to the deep dermis. At the extremities, some cells had visible vacuoles. Mitotic activity ranged from 3 to 4 mitoses per field in 40x magnification. Immunohistochemistry showed positive staining for histocompatibility complex MCII and lysozyme antibodies, marking histiocytic cells. Labeling was positive for CD20 in cells of lymphoid lineage B and negative for E-cadherin. Histiocytic cells did not invade the epidermis; hence, proliferation was classified as nonepitheliotropic. These methods contribute to the literature regarding the...(AU)

Hemangiossarcoma metastático em uma vaca / Metastatic hemangiosarcoma in a cow

Background: Hemangiosarcoma is a malignant mesenchymal neoplasm of endothelial cells that mainly affects dogs and is less common in horses, cattle, goats, pigs, and sheep. In ruminants, however, few cases of hemangiosarcoma have been reported. Although this neoplasm may primarily occur in any tissue, it most often originates in the spleen, liver, heart, and skin. This study reports the clinical and pathological findings of a bovine hemangiosarcoma.Case: A 10-year-old lactating Girolando cow from the municipality of Vassouras/RJ was examinated because of uncontrolled cough and bilateral hemoptysis, loss of appetite, fever, weight loss, severe decline in milk production (a decrease of 28 L), and respiratory wheezing during chest auscultation. We performed a necropsy and collected fragments of various organs which were fixed using 10% buffered formalin and sent to the Pathology Anatomy Sector (SAP) of the Federal Rural University of Rio de Janeiro (UFRRJ) for routine histological assessment. Macroscopically, large hemorrhagic areas were observed in the lungs, mainly in the cranioventral portion of the pulmonary lobes, multifocal areas of hemorrhages in the liver, and a 10x8x5 cm soft red mass was observed in the spleen. Microscopically, was observed lung proliferation of endothelial cells arranged in tapes, supported by a collagenous stroma associated with severe multifocal lobular hemorrhage with a large number of siderophages and diffuse and marked edema, and congestion. In the mediastinal lymph node, liver, and spleen, the proliferation of neoplastic endothelial cells equivalent to those described in the lungs was observed. The histological sections of liver and tumor spleen were subjected to immunohistochemical analysis for von Willebrand factor, in which marking was observed in neoplastic endothelial cells.[...]

Hemangiossarcoma metastático em uma vaca / Metastatic hemangiosarcoma in a cow

Background: Hemangiosarcoma is a malignant mesenchymal neoplasm of endothelial cells that mainly affects dogs and is less common in horses, cattle, goats, pigs, and sheep. In ruminants, however, few cases of hemangiosarcoma have been reported. Although this neoplasm may primarily occur in any tissue, it most often originates in the spleen, liver, heart, and skin. This study reports the clinical and pathological findings of a bovine hemangiosarcoma.Case: A 10-year-old lactating Girolando cow from the municipality of Vassouras/RJ was examinated because of uncontrolled cough and bilateral hemoptysis, loss of appetite, fever, weight loss, severe decline in milk production (a decrease of 28 L), and respiratory wheezing during chest auscultation. We performed a necropsy and collected fragments of various organs which were fixed using 10% buffered formalin and sent to the Pathology Anatomy Sector (SAP) of the Federal Rural University of Rio de Janeiro (UFRRJ) for routine histological assessment. Macroscopically, large hemorrhagic areas were observed in the lungs, mainly in the cranioventral portion of the pulmonary lobes, multifocal areas of hemorrhages in the liver, and a 10x8x5 cm soft red mass was observed in the spleen. Microscopically, was observed lung proliferation of endothelial cells arranged in tapes, supported by a collagenous stroma associated with severe multifocal lobular hemorrhage with a large number of siderophages and diffuse and marked edema, and congestion. In the mediastinal lymph node, liver, and spleen, the proliferation of neoplastic endothelial cells equivalent to those described in the lungs was observed. The histological sections of liver and tumor spleen were subjected to immunohistochemical analysis for von Willebrand factor, in which marking was observed in neoplastic endothelial cells.[...](AU)

Influência da via de sinalização HIPPO na segregação entre a massa interna celular e o trofectoderma em embriões bovinos

Resumo: O primeiro evento de diferenciação celular em mamíferos consiste na separação entre a massa celular interna (MCI) e o trofectoderma (TE). Em camundongos, a via de sinalização HIPPO atua no controle da expressão de genes que definem essa diferenciação. Em bovinos, há indícios que os mesmos genes não participam da mesma maneira, porém a via HIPPO pode estar implicada nesse evento biológico. No presente estudo buscou-se testar a hipótese de que a atividade da proteína quinase LATS2 é necessária para a diferenciação da MCI em embriões bovinos. Para isso, realizou-se edição gênica via sistema CRISPR/Cas9 com intuito de inibir a função quinase de LATS2. Zigotos bovinos produzidos in vitro foram microinjetados com RNAs guia para o gene LATS2 acrescidos da enzima de restrição Cas9. Os zigotos foram separados em 3 grupos experimentais, sendo: grupo controle (não microinjetado), grupo Cas9 (microinjetado apenas com a proteína Cas9) e grupo gRNA (microinjetado com dois RNAs guias para o gene LATS2 e proteína Cas9). Os embriões foram cultivados para avaliação da taxa de formação de blastocistos, distribuição celular e fixados em paraformol 3,8% para posterior realização da imunofluorescência para YAP, seguido de avaliação de genótipo. Os resultados obtidos sugeriram que a clivagem não foi afetada no grupo editado, sendo as taxas 58%, 36% e 50% para grupo controle, Cas9 e gRNA respectivamente; porém, as taxas de formação de blastocisto sugeriram uma interferência direta no grupo editado, sendo 30%, 10% e 6% respectivamente, para os grupos controle, Cas9 e gRNA. Observou-se no âmbito morfológico que os embriões do grupo gRNA aparentavam estruturas assemelhadas a mórulas, sugestivo de morte embrionária ou bloqueio da diferenciação nessa fase do desenvolvimento. Houve redução numérica no número de células nas estruturas do grupo gRNA. As imagens obtidas via microscopia confocal, após a realização de imunofluorescência para YAP, demonstram a marcação de células do TE nos embriões microinjetados apenas com Cas9 e controle, porém, essa marcação não ocorreu nas no grupo gRNA em embriões que não formaram blastocele. Após a extração individual de DNA dos embriões testados na imunofluorescência, a PCR da região alvo de LATS2 resultou em uma banda de 478pb, além da banda original de 650pb, em uma amostra do grupo gRNA. Após sequenciamento dos produtos de PCR pelo método Sanger, constatou-se a alteração genética oriunda da deleção de trecho do gene LATS2 em 2 embriões, demonstrando o sucesso da edição gênica e corroborando com os demais achados. Isso sugere que a via HIPPO possui papel significativo na diferenciação de MCI e TE em embriões bovinos e de que o gene LATS2 está ligado à formação de blastocistos na espécie bovina.

Abstract: The first cellular differentiation event in mammals consists of the separation between the internal cellular mass (ICM) and the trophectoderm (TE). In mice, the HIPPO signaling pathway acts to control the expression of genes that define this differentiation. In cattle, there are indications that the same genes do not participate in the same way, but the HIPPO pathway may be involved in this biological event. In the present study we aimed to test the hypothesis that the activity of LATS2 kinase is necessary for the differentiation of ICM in bovine embryos. In order to achieve this, we employed CRISPR/Cas9 gene editing system to inhibit the kinase function of LATS2. In vitro produced bovine zygotes were microinjected with RNAs guide aiming the LATS2 gene plus Cas9 restriction enzyme. The zygotes were sorted in 3 experimental groups: control group (not microinjected), Cas9 group (microinjected only with Cas9 protein) and gRNA group (microinjected with guide RNAs aiming the LATS2 gene and Cas9 protein). The embryos were cultured to evaluate the rate of blastocysts formation, cellular distribution, then fixed in 3.8% paraformol for subsequent immunofluorescence for YAP, followed by genotyping. The results suggested that the cleavage was not affected in the edited group, as rates were 58%, 36% and 50% for control , Cas9 and gRNA groups respectively; however, the blastocyst formation rates suggested a direct interference in the edited group, being 30%, 10% and 6% respectively, for the control groups, Cas9 and gRNA. Morphologically, it was observed that the embryos of the gRNA group appeared as morulas, suggestive of embryonic death or inhibition of differentation in this phase of development. There was a numeric reduction in total cell count in the structures of the gRNA group.. The images obtained via confocal microscopy, after performing immunofluorescence for YAP demonstrate the marking of cells of the TE and MCI in the microinjected embryos only with Cas9 and control, however, this marking did not occur in the microinjected structures that did not form a blastocoel. After individual DNA extraction from the embryos tested in immunofluorescence, PCR of the LATS2 target region resulted in a band of 478pb, in addition to the original 650pb band, in one sample of the gRNA group. After Sanger sequencing of PCR products, genetic alteration derived from deletion of part of the LATS2 gene was observed in 2 embryos, demonstrating gene editing success and corroborating the findings. This suggests that HIPPO pathway has a significant role in the differentiation of MCI and TE in bovine embryos and that the LATS2 gene is linked to the formation of blastocysts in bovine species.

Oxitetraciclina para marcação química de juvenis de piava Leporinus obtusidens: determinação de doses e duração do tratamento / Oxytetracycline for chemical marking of piava juveniles Leporinus obtusidens: determining concentration and time of treatment

The aim of this study was to define the concentrations and immersion periods for the chemical marking of piava juveniles Leporinus obtusidens, using oxytetracycline (OTC). Twenty piava juveniles were used per treatment and submitted to six concentrations of OTC (50, 100, 150, 300, 500, 800 mg OTC L-1) and three immersion periods (6, 12, 24 h), and one treatment as control. Scales of three fishes per treatment were evaluated under a confocal microscope with UV light. The mean values of temperature, pH and dissolved oxygen were kept at 27.4ºC, 7.2, and 7.4 mg L-1, respectively. No mortality was observed in the treatments. The presence of a chemical mark was only observed from the treatment 100 mg L-1 24 h-1, however it was of low intensity and discontinuous. Treatments with immersion periods of 12 and 24 h produced visible marks in 300 mg L-1, and clear bright and continuous marks in 500 mg L-1. Treatments of 800 mg L-1, for all immersion periods, produced clear bright and continuous marks.(AU)

O objetivo deste estudo foi definir concentrações e tempos de imersão para a marcação química de juvenis de Leporinus obtusidens, utilizando oxitetraciclina (OTC). Foram utilizados 20 juvenis por tratamento submetidos a banhos com seis concentrações de OTC (50, 100, 150, 300, 500, 800 mg L-1) e três tempos de imersão (6, 12, 24 h), mais um tratamento controle. Foram avaliadas escamas de três indivíduos por tratamento em microscópio confocal com luz UV. Os valores médios de temperatura, pH e OD se mantiveram em 27,4C; 7,2 e 7,4 mg L-1, respectivamente. Em nenhum dos tratamentos foi observada mortalidade. A presença da marca só foi observada a partir do tratamento 100 mg L-1 24 h-1, sendo de fraca intensidade. Os tratamentos com 12 e 24 h produziram marcas visíveis para 300 mg L-1 e fortemente visíveis e contínuas para 500 mg L-1. Nos tratamentos com 800 mg L-1, todos os tempos de exposição produziram marcas fortemente visíveis e contínuas.(AU)

Oxitetraciclina para marcação química de juvenis de piava Leporinus obtusidens: determinação de doses e duração do tratamento / Oxytetracycline for chemical marking of piava juveniles Leporinus obtusidens: determining concentration and time of treatment

The aim of this study was to define the concentrations and immersion periods for the chemical marking of piava juveniles Leporinus obtusidens, using oxytetracycline (OTC). Twenty piava juveniles were used per treatment and submitted to six concentrations of OTC (50, 100, 150, 300, 500, 800 mg OTC L-1) and three immersion periods (6, 12, 24 h), and one treatment as control. Scales of three fishes per treatment were evaluated under a confocal microscope with UV light. The mean values of temperature, pH and dissolved oxygen were kept at 27.4ºC, 7.2, and 7.4 mg L-1, respectively. No mortality was observed in the treatments. The presence of a chemical mark was only observed from the treatment 100 mg L-1 24 h-1, however it was of low intensity and discontinuous. Treatments with immersion periods of 12 and 24 h produced visible marks in 300 mg L-1, and clear bright and continuous marks in 500 mg L-1. Treatments of 800 mg L-1, for all immersion periods, produced clear bright and continuous marks.

O objetivo deste estudo foi definir concentrações e tempos de imersão para a marcação química de juvenis de Leporinus obtusidens, utilizando oxitetraciclina (OTC). Foram utilizados 20 juvenis por tratamento submetidos a banhos com seis concentrações de OTC (50, 100, 150, 300, 500, 800 mg L-1) e três tempos de imersão (6, 12, 24 h), mais um tratamento controle. Foram avaliadas escamas de três indivíduos por tratamento em microscópio confocal com luz UV. Os valores médios de temperatura, pH e OD se mantiveram em 27,4C; 7,2 e 7,4 mg L-1, respectivamente. Em nenhum dos tratamentos foi observada mortalidade. A presença da marca só foi observada a partir do tratamento 100 mg L-1 24 h-1, sendo de fraca intensidade. Os tratamentos com 12 e 24 h produziram marcas visíveis para 300 mg L-1 e fortemente visíveis e contínuas para 500 mg L-1. Nos tratamentos com 800 mg L-1, todos os tempos de exposição produziram marcas fortemente visíveis e contínuas.

EXPRESSÃO DE ALFA-B CRISTALINA EM TUMORES MAMÁRIOS CANINOS E SUA RELAÇÃO COM ANGIOGÊNES

Tumores mamários são as neoplasias mais frequentes em cadelas, sendo que em até 90% dos casos correspondem a processos malignos. A retirada cirúrgica com margens é o tratamento mais eficaz para tal enfermidade, porém na maior parte dos casos podem ocorrer recidivas e metástases. Mesmo com indicações clínicas, como tamanho da massa e velocidade de evolução, a histopatologia ainda é o método determinante para classificação de malignidade. A alfa-b cristalina (CRYAB) é membro da família de proteínas de choque térmico e sua relação com a oncogênese vem sendo estudada recentemente, vinculada principalmente com a evolução da doença. O objetivo deste trabalho é avaliar a expressão de CRYAB em tumores mamários caninos e correlacionar os achados com a angiogênese. Para isso, foram coletados dados de 31 animais atendidos no Hospital Veterinário da Universidade Federal de Viçosa, realizados exames ultrassonográficos em modo B e Doppler para avaliação das massas, remoção cirúrgica e avaliação microscópica das neoplasias, classificando-as. Cortes histológicos também foram utilizados para reação de imuno-histoquímica (IHQ) com anticorpos anti-VEGF e anti-CRYAB, analisados de acordo com a quantidade de células marcadas e a intensidade da marcação. As variáveis qualitativas foram analisadas por teste de qui-quadrado ou o teste exato de Fisher, conforme o caso. A comparação das variáveis ultrassonográficas, do tumor e da avaliação microscópica foi realizada por análise de variância (ANOVA) seguida pelo teste de Tukey, teste t de Student, Kruskal-Wallis ou Mann-Whitney. Valores de p < 0,05 foram considerados significativos. Houve correlação entre dados clínicos dos animais (faixa etária, porte, uso de anticoncepcionais, castração, gestações prévias, estadiamento clínico), dados do tumor (malignidade, pleomorfismo, formação tubular, número de mitoses, graduação histológica), dados ultrassonográficos (ecotextura, índice de resistividade, velocidades média, máxima e mínima) e da IHQ (quantidade e intensidade de VEGF e CRYAB, além da marcação de macrófagos). A expressão de CRYAB está relacionada com dados clínicos e ultrassonográficos, além da expressão de VEGF e angiogênese

Mammary tumors are the most frequent neoplasias in bitches, and in up to 90% of cases they correspond to malignant processes. Surgical removal with margins is the most effective treatment for such disease, but in most cases relapses and metastases may occur. Even with clinical indications, such as mass size and rate of evolution, histopathology is still the determining method for malignancy classification. The alpha-b crystalline (CRYAB) is a member of the family of thermal shock proteins and its relation with oncogenesis has been studied recently, mainly linked to the evolution of the disease. The aim of this work is to evaluate the expression of CRYAB in canine mammary tumors and to correlate the findings with angiogenesis. For this purpose, data were collected from 31 animals treated at the Veterinary Hospital of the Federal University of Viçosa, performing ultrasound examinations in B and Doppler mode for evaluation of masses, surgical removal and microscopic evaluation of the neoplasms, classifying them. Histological sections were also used for immunohistochemistry (IHC) reaction with anti-VEGF and anti-CRYAB antibodies, analyzed according to the number of labeled cells and the intensity of labeling. Qualitative variables were analyzed by the chi-square test or Fisher's exact test, as the case may be. The comparison of ultrasound, tumor and microscopic evaluation was performed by analysis of variance (ANOVA) followed by Tukey's test, Student's t-test, KruskalWallis or Mann-Whitney test. Values of p <0.05 were considered significant. There was a correlation between the clinical data of the animals (age range, size, contraceptive use, castration, previous pregnancies, clinical staging), tumor data (malignancy, pleomorphism, tubular formation, number of mitoses, histological grade), ultrasonographic data, index of resistivity, mean, maximum and minimum velocities) and of IHC (quantity and intensity of VEGF and CRYAB, in addition to macrophage marking). The expression of CRYAB is related to clinical and ultrasonographic data, as well as the expression of VEGF and angiogenesis.

T-cell lymphoma in the tongue of a dog with cutaneous and striated forelimb muscle involvement / Linfoma de células T em língua de cão com envolvimento cutâneo e de musculatura estriada de membro torácico

Background: Primary tongue tumors rarely affect dogs and correspond to 4% of tumors involving the oropharynx. Until now, primary tongue lymphoma had not been reported. However, lymphoma involvement in the skeletal muscle, although quite unusual, was described in the literature in four cases. Cutaneous lymphoma is another rare extranodal manifestation. The objective of this report is to describe a case of T immunophenotype lymphoma occurrence, whose manifestation is atypical, not only because it is situated in the tongue muscle but also because of the subsequent involvement of the striated musculature of the left forelimb and the skin, which showed unfavorable evolution. Case: A female seven-year-old mongrel was seen showing a regular lump in the base of the tongue, 3 cm in diameter, not ulcerated and of firm consistency, with halitosis as the only clinical sign of the disease. Incisional biopsy of the lump was performed and histopathology verified that it was large cell lymphoma. The material was sent for immunohistochemical evaluation and was characterized as T immunophenotype lymphoma by positive CD3 and negative CD79a marking. The CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy protocol was established as treatment and after the first chemotherapy session there was partial remission of the mass, measuring 2 cm in diameter. The lump, however...(AU)

T-cell lymphoma in the tongue of a dog with cutaneous and striated forelimb muscle involvement / Linfoma de células T em língua de cão com envolvimento cutâneo e de musculatura estriada de membro torácico

Background: Primary tongue tumors rarely affect dogs and correspond to 4% of tumors involving the oropharynx. Until now, primary tongue lymphoma had not been reported. However, lymphoma involvement in the skeletal muscle, although quite unusual, was described in the literature in four cases. Cutaneous lymphoma is another rare extranodal manifestation. The objective of this report is to describe a case of T immunophenotype lymphoma occurrence, whose manifestation is atypical, not only because it is situated in the tongue muscle but also because of the subsequent involvement of the striated musculature of the left forelimb and the skin, which showed unfavorable evolution. Case: A female seven-year-old mongrel was seen showing a regular lump in the base of the tongue, 3 cm in diameter, not ulcerated and of firm consistency, with halitosis as the only clinical sign of the disease. Incisional biopsy of the lump was performed and histopathology verified that it was large cell lymphoma. The material was sent for immunohistochemical evaluation and was characterized as T immunophenotype lymphoma by positive CD3 and negative CD79a marking. The CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy protocol was established as treatment and after the first chemotherapy session there was partial remission of the mass, measuring 2 cm in diameter. The lump, however...

EXPRESSÃO DE LEPTINA E RECEPTOR DE LEPTINA (ObR) COMO FATOR DE RISCO PARA NEOPLASIAS DE MAMA EM CADELAS E CORRELAÇÃO COM OBESIDADE

Na espécie humana e em cadelas a obesidade é considerada fator de risco no desenvolvimento de neoplasias mamárias e a leptina é um hormônio liberado por adipócitos que estimula a proliferação de células cancerosas. Objetivou-se verificar a expressão da leptina e seu receptor em carcinomas mamários de cadelas, por meio da técnica de imunohistoquímica e correlacionar esta expressão com a obesidade, tamanho do tumor, idade e graduação histológica. Relacionou-se ainda tamanho do tumor, idade e graduação histológica com obesidade e marcação de leptina e seu receptor (Obr) no tecido neoplásico. Foram utilizadas 84 cadelas, submetidas à exérese cirúrgica de carcinomas mamários, totalizando 95 amostras de carcinomas simples e complexo ssubmetidas à avaliação imunohistoquímica para a expressão de leptina e seu receptor. Carcinomas complexos corresponderam a 41% das amostras e (39/95) e 59% carcinomas simples (56/95). Quanto ao índice de massa corporal dos cães (IMCC) 9,52% estavam abaixo do peso (8/84), 29,76% estavam dentro do peso ideal (25/84), 33,33% se encontravam acima do peso (28/84) e 27,39% estavam obesas (23/84) no momento da mastectomia. Observou-se que a idade dos animais obesos com carcinomas mamários era menor e que animais obesos eram portadores de tumores com maiores tamanhos quando comparados à aqueles com outras condições corporais. A expressão de leptina não está diretamente relacionada ao IMCC, porém a expressão de ObR foi maior (p<0.05) em cadelas com maiores valores de IMCC. Houve correlação entre idade e expressão de leptina indicando que animais mais velhos são portadores de tumores que expressam leptina com maior frequência. A obesidade pode ser considerada fator de risco para carcinomas mamários em cadelas uma vez que cadelas obesas apresentam carcinomas mamários mais precocemente e massas tumorais de maior tamanho. Ainda, a expressão de Obr é maior em carcinomas de cadelas obesas.

In humans and female dogs obesity is considered a risk factor in the development of mammary tumor and leptin is a hormone released by adipocytes that stimulates the proliferation of cancer cells. The objective of this study was to verify the expression of leptin and its receptor in mammary carcinomas of bitches using immunohistochemistry and to correlate this expression with obesity, tumor size, age and histological grade. Tumor size, age and histological grade with obesity and marking of leptin and its receptor (Obr) in the neoplastic tissue were also related. We used 84 female dogs, submitted to surgical excision of mammary carcinomas, totaling 95 samples of simple and complex carcinomas submitted to the immunohistochemical evaluation for the expression of leptin and its receptor. Complex carcinomas corresponded to 41% of the samples and (39/95) and 59% simple carcinomas (56/95). Regarding the body mass index of dogs (BMI), 9.52% were underweight (8/84), 29.76% were within ideal weight (25/84), 33.33% were overweight ( 28/84) and 27.39% were obese (23/84) at the time of mastectomy. It was observed that the age of the obese animals with mammary carcinomas was smaller and that obese animals were carriers of tumors with larger sizes when compared to those with other body conditions. The expression of leptin was not directly related to the BMI, but the expression of ObR was higher (p <0.05) in bitches with higher BMI values. There was a correlation between age and leptin expression indicating that older animals are carriers of tumors that express leptin more frequently. Obesity may be considered a risk factor for breast carcinomas in bitches since obese dogs have breast carcinomas earlier and larger tumor masses. Moreover, the expression of Obr is greater in carcinomas of obese bitches.

Spatial distribution of weeds and forage production in areas of continuous grazing / Distribuição espacial de plantas daninhas e produção de forragem em áreas de pastejo contínuo

The objective of this work was to map the incidence of weed flora and forage dry matter using tools of precision agriculture, seeking to ascertain the degree of correlation between them. The experiment was conducted at the Experimental Station for Research, owned by the University of Tocantins - Campus Universitario de Araguaina. The area of the experiment was composed of seven continuous grazing paddocks, with 2ha each and within each paddock were scored six points. After the marking, a radius of 5m was limited where the count of weeds was made and in a representative point the quantification of the dry mass of forage. The sampling points were chosen at random, at irregular intervals in a total of 42 points. Statistical analysis of weed infestation and the amount of dry matter were generated by the technique of interpolation by kriging. The management system in continuous grazing significantly influenced the incidence of weeds and yield of dry forage in the studied areas. The incidence of weeds and the production of herbage dry matter also showed a degree of spatial dependence of 99%, which classifies these variables as having a high degree of spatial dependence.

Objetivou-se mapear a incidência de flora daninha e a massa seca de forragem com utilização de ferramentas da agricultura de precisão para verificar o grau de correlação entre estes. O experimento foi conduzido na Estação Experimental de Pesquisa, pertencente à Universidade Federal do Tocantins - Campus Universitário de Araguaína. A área do experimento foi composta por sete piquetes com pastejo continuo, de 2ha cada e foram marcados seis pontos dentro de cada piquete. Após essa marcação delimitou-se um raio de 5m onde foi realizada a contagem das plantas daninhas e em um ponto representativo a quantificação da massa seca de forragem. Os pontos amostrados foram escolhidos de forma aleatória, com intervalos irregulares, em uma totalidade de 42 pontos. As análises estatísticas de infestação de plantas daninhas e quantidade de massa seca foram geradas pela técnica de interpolação por krigagem. O manejo do sistema em pastejo contínuo influenciou significativamente a incidência de plantas daninhas e a produção de massa seca de forragem nas áreas estudadas. A incidência de plantas daninhas e a produção de massa seca de forragem também apresentaram um grau de dependência espacial de 99%, o que classifica estas variáveis como de forte grau de dependência espacial.

Dispersal of the egg parasitoid Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) in tobacco crops

A mass marking-recapture experiment was carried out to study the dispersal of Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) in tobacco crops. Parasitoids emerged in the laboratory were marked with dye powder. Six separate field trials were conducted in Jan/Feb 2002 involving the simultaneous release of marked parasitoids. Dispersal was determined by the recapture of individuals in sets of sticky and Moericke traps arranged in three concentric circles arranged at 1.4 m intervals from the central point of release. Traps were checked 4, 8, 24, 28, 32 and 48 h after parasitoid release and weather data were recorded at 2-h intervals from 9 to 17 h at the site. Of the 699 marked parasitoids released, 91 were recaptured (13.02%). Fewer females were recaptured in the late afternoon, suggesting they are less active than males after dusk. G. gallardoi recaptures were not associated with average wind direction in any trials. After eight hours of release, recaptures occurred mostly in the traps farthest from the release point, suggesting that the experimental area was small in relation to the dispersal capacity of the parasitoid. Fitting a 4-h-after-release density-distance curve to a geometric model and considering a daily activity of 12 h, the female dispersal capacity was estimated to be at least 7.6 m/day. The values reported here must be considered as indicative of the potential for active dispersal under the particular experimental conditions of these trials. It is possible that G. gallardoi may disperse downwind much farther than the distance recorded in this study.

Um experimento de marcação e recaptura foi desenvolvido para estudar a dispersão de Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) em cultivo de fumo. Parasitóides emergidos em laboratório foram marcados com pó de corante. Em seis ocasiões distintas, de janeiro a fevereiro de 2002, foram feitos experimentos de campo nos quais parasitóides marcados foram liberados ao mesmo tempo. A dispersão foi determinada pela recaptura de indivíduos em grupos de armadilhas (adesivas e de bandeja com água) dispostas em três círculos concêntricos com intervalos de 1,4 m a partir do ponto central de liberação. As armadilhas foram monitoradas 4, 8, 24, 28, 32 e 48 h após a liberação dos parasitóides e dados climáticos foram obtidos a cada duas horas, das 9 h às 17 h, na área experimental. De 699 parasitóides marcados liberados, 91 foram recapturados (13,02%). Fêmeas foram menos recapturadas ao final da tarde, sugerindo que elas são menos ativas que os machos no período crepuscular. A recaptura de G. gallardoi não foi associada à direção média do vento em todas as ocasiões de liberação. Após oito horas das liberações, a maioria das recapturas ocorreram em armadilhas localizadas mais distantes do ponto de liberação, sugerindo que a área experimental foi pequena em relação à capacidade de dispersão do parasitóide. A partir do ajuste da curva de densidade média de recapturas nas diferentes distâncias aferida 4 h após as liberações ao modelo geométrico e considerando uma atividade diária de 12 h, foi estimada uma capacidade de dispersão para fêmeas de no mínimo 7,62 m/dia. Os valores aqui apresentados devem ser considerados como um indicativo do potencial para a dispersão ativa nas condições particulares do experimento. É possível que G. gallardoi, com a ajuda do vento, possa dispersar distâncias muito maiores do que a registrada neste estudo.

Dispersal of the egg parasitoid Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) in tobacco crops

A mass marking-recapture experiment was carried out to study the dispersal of Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) in tobacco crops. Parasitoids emerged in the laboratory were marked with dye powder. Six separate field trials were conducted in Jan/Feb 2002 involving the simultaneous release of marked parasitoids. Dispersal was determined by the recapture of individuals in sets of sticky and Moericke traps arranged in three concentric circles arranged at 1.4 m intervals from the central point of release. Traps were checked 4, 8, 24, 28, 32 and 48 h after parasitoid release and weather data were recorded at 2-h intervals from 9 to 17 h at the site. Of the 699 marked parasitoids released, 91 were recaptured (13.02%). Fewer females were recaptured in the late afternoon, suggesting they are less active than males after dusk. G. gallardoi recaptures were not associated with average wind direction in any trials. After eight hours of release, recaptures occurred mostly in the traps farthest from the release point, suggesting that the experimental area was small in relation to the dispersal capacity of the parasitoid. Fitting a 4-h-after-release density-distance curve to a geometric model and considering a daily activity of 12 h, the female dispersal capacity was estimated to be at least 7.6 m/day. The values reported here must be considered as indicative of the potential for active dispersal under the particular experimental conditions of these trials. It is possible that G. gallardoi may disperse downwind much farther than the distance recorded in this study.

Um experimento de marcação e recaptura foi desenvolvido para estudar a dispersão de Gryon gallardoi (Brethes) (Hymenoptera: Scelionidae) em cultivo de fumo. Parasitóides emergidos em laboratório foram marcados com pó de corante. Em seis ocasiões distintas, de janeiro a fevereiro de 2002, foram feitos experimentos de campo nos quais parasitóides marcados foram liberados ao mesmo tempo. A dispersão foi determinada pela recaptura de indivíduos em grupos de armadilhas (adesivas e de bandeja com água) dispostas em três círculos concêntricos com intervalos de 1,4 m a partir do ponto central de liberação. As armadilhas foram monitoradas 4, 8, 24, 28, 32 e 48 h após a liberação dos parasitóides e dados climáticos foram obtidos a cada duas horas, das 9 h às 17 h, na área experimental. De 699 parasitóides marcados liberados, 91 foram recapturados (13,02%). Fêmeas foram menos recapturadas ao final da tarde, sugerindo que elas são menos ativas que os machos no período crepuscular. A recaptura de G. gallardoi não foi associada à direção média do vento em todas as ocasiões de liberação. Após oito horas das liberações, a maioria das recapturas ocorreram em armadilhas localizadas mais distantes do ponto de liberação, sugerindo que a área experimental foi pequena em relação à capacidade de dispersão do parasitóide. A partir do ajuste da curva de densidade média de recapturas nas diferentes distâncias aferida 4 h após as liberações ao modelo geométrico e considerando uma atividade diária de 12 h, foi estimada uma capacidade de dispersão para fêmeas de no mínimo 7,62 m/dia. Os valores aqui apresentados devem ser considerados como um indicativo do potencial para a dispersão ativa nas condições particulares do experimento. É possível que G. gallardoi, com a ajuda do vento, possa dispersar distâncias muito maiores do que a registrada neste estudo.

Oviposition behaviour of Gryon gallardoi (Hym.; Scelionidae) on eggs of Spartocera dentiventris (Hem.; Coreidae)

The oviposition behaviour of Gryon gallardoi (Hymenoptera; Scelionidae) on Spartocera dentiventris (Hemiptera; Coreidae) host eggs was investigated in the laboratory. Masses of 12 non-parasitized freshly laid (less than 24 h old) eggs were exposed to 2-5 days old mated females with previous oviposition experience (n = 10). Behaviour was observed for 2 h under the stereomicroscope. The eggs were Then kept individually at 25º ± 1ºC/12 h photophase till hatching. The mean number of parasitized eggs was 7.8 ± 0.81 (IMG01 ± SE). Five distinct kinds of behaviour were observed: drumming with antennae on the eggs, ovipositor insertion, egg marking, walking and resting. On average, ovipositor insertion was not followed by marking 4.3 ± 0.76 times per female. In nearly all of these events, parasitism was unsuccessful. Walking and resting were observed less frequently than the other behaviours (1.6 ± 0.56 and 2.1 ± 0.48 times/female, respectively). Superparasitism occurred on average 3.6 ± 0.88 times per egg mass, with 2.7 ± 0.57 eggs being superparasitized. Among these, on average 87.4 ± 5.37% led to successful development of an adult parasitoid. The average time spent on the each kind of oviposition behaviour was 1.5 ± 0.57 min for drumming, 3.9 ± 0.56 min for ovipositor insertion and 0.4 ± 0.06 min for marking. There was no significant variation on the duration of each behaviour as the parasitoid progressed in parasitizing an egg mass. Ovipositor insertion almost always (87.58%) occurred in the longitudinal extremities of the egg. In average 31.1 ± 7.21% of the individual emerging per egg mass were males, the larger proportion of males originating from the 2nd oviposition. The results show a range of oviposition behaviours common to the Scelionidae family. Egg marking behaviour was a good indicator of the effective oviposition by females. Superparasitism is only partially avoided, but its occurrence does not imply a failure of parasitoid emergence. The sex ratio is skewed towards females, and most males come from the first ovipositions.

O presente estudo teve por objetivo investigar, em laboratório, o comportamento de oviposição de Gryon gallardoi (Hymenoptera; Scelionidae) em grupos de ovos de Spartocera dentiventris (Hemiptera; Coreidae). Dez fêmeas, de 2 a 5 dias de idade, fecundadas e com experiência de oviposição, foram expostas a grupos de 12 ovos, não parasitados, com idade de até 24 horas, e observadas durante 2 horas em estereomicroscópio. Posteriormente, os ovos foram mantidos individualizados em estufa a 25º ± 1ºC, com fotofase de 12 h até o seu destino final. O número médio de ovos parasitados por grupo foi de 7,8 ± 0,81 ovos (IMG01 ± EP). Registraram-se cinco comportamentos distintos: tamborilamento dos ovos com as antenas, inserção do ovipositor, marcação dos ovos, caminhada e descanso. Em média, por fêmea, 4,3 ± 0,76 vezes o comportamento de inserção do ovipositor não foi seguido de marcação. A quase totalidade desses casos resultou no insucesso do parasitoidismo. A caminhada e o descanso foram observados em menor freqüência (1,6 ± 0,56 e 2,1 ± 0,48 vezes/fêmea, respectivamente). O superparasitismo ocorreu em média 3,6 ± 0,88 vezes por grupo de ovos, sendo superparasitados 2,7 ± 0,57 ovos. Destes, em média, 87,5 ± 5,37% lograram sucesso na emergência de um adulto. O tempo médio despendido nos principais comportamentos foi de 1,5 ± 0,57 min para tamborilamento, 3,9 ± 0,56 min para inserção do ovipositor e 0,4 ± 0,06 min para marcação, não havendo alteração significativa na duração desses comportamentos ao longo do parasitoidismo da massa de ovos. A inserção do ovipositor foi feita quase sempre na região próxima às extremidades do ovo (87,58%). Foi obtida porcentagem média de 31,1 ± 7,21% machos/grupo, sendo que na 2ª oviposição originou-se maior proporção de indivíduos machos. Os resultados evidenciam comportamentos de oviposição comuns à família Scelionidae, sendo a marcação dos ovos um bom indicativo de efetiva oviposição da fêmea. O superparasitismo é apenas parcialmente evitado, e sua ocorrência não acarreta o insucesso da emergência de um parasitóide. A razão sexual é desviada para fêmeas, sendo a maioria dos machos gerada nas primeiras oviposições.

Spatial distribution of weeds and forage production in areas of continuous grazing / Distribuição espacial de plantas daninhas e produção de forragem em áreas de pastejo contínuo

The objective of this work was to map the incidence of weed flora and forage dry matter using tools of precision agriculture, seeking to ascertain the degree of correlation between them. The experiment was conducted at the Experimental Station for Research, owned by the University of Tocantins - Campus Universitario de Araguaina. The area of the experiment was composed of seven continuous grazing paddocks, with 2ha each and within each paddock were scored six points. After the marking, a radius of 5m was limited where the count of weeds was made and in a representative point the quantification of the dry mass of forage. The sampling points were chosen at random, at irregular intervals in a total of 42 points. Statistical analysis of weed infestation and the amount of dry matter were generated by the technique of interpolation by kriging. The management system in continuous grazing significantly influenced the incidence of weeds and yield of dry forage in the studied areas. The incidence of weeds and the production of herbage dry matter also showed a degree of spatial dependence of 99%, which classifies these variables as having a high degree of spatial dependence.

Objetivou-se mapear a incidência de flora daninha e a massa seca de forragem com utilização de ferramentas da agricultura de precisão para verificar o grau de correlação entre estes. O experimento foi conduzido na Estação Experimental de Pesquisa, pertencente à Universidade Federal do Tocantins - Campus Universitário de Araguaína. A área do experimento foi composta por sete piquetes com pastejo continuo, de 2ha cada e foram marcados seis pontos dentro de cada piquete. Após essa marcação delimitou-se um raio de 5m onde foi realizada a contagem das plantas daninhas e em um ponto representativo a quantificação da massa seca de forragem. Os pontos amostrados foram escolhidos de forma aleatória, com intervalos irregulares, em uma totalidade de 42 pontos. As análises estatísticas de infestação de plantas daninhas e quantidade de massa seca foram geradas pela técnica de interpolação por krigagem. O manejo do sistema em pastejo contínuo influenciou significativamente a incidência de plantas daninhas e a produção de massa seca de forragem nas áreas estudadas. A incidência de plantas daninhas e a produção de massa seca de forragem também apresentaram um grau de dependência espacial de 99%, o que classifica estas variáveis como de forte grau de dependência espacial.

Sistema porta hepático do bagre africano Clarias gariepinus Burchell, 1822 (Clariidae, Siluriformes, Ostariophysii) / Hepatic portal system of the African catfish Clarias gariepinus Burchell, 1822 (Clariidae, Siluriformes, Ostariophysii)

Estudou-se o sistema porta hepático do bagre africano Clarias gariepinus Burchell, 1822, sob o ponto de vista da anatomia macroscópica e microscópica, utilizando-se várias técnicas anatômicas, que envolveram anestesia, injeção de substâncias recomendadas ao estudo do sistema vascular (látex, nanquim, cloreto de polivinil e substância radiopaca), dissecação, corrosão ou radiografia, conforme a exigência de cada técnica, como meio de compreensão da anatomia vascular do fígado deste peixe. Foram utilizados 16 exemplares do sexo feminino, com comprimento total entre 45 e 53,5 centímetros e massa corpórea entre 575 e 1068 gramas. Para a execução dessas técnicas, os peixes foram devidamente anestesiados com benzocaína, garantindo a narcose profunda e evitando qualquer tipo de sofrimento a eles. Os resultados obtidos com essas técnicas mostram que o fígado de Clarias gariepinus ocupa a cavidade abdominal cranial e apresenta uma lobação bem definida, sendo constituído por dois grandes lobos, denominados direito e esquerdo, conectados cranialmente por uma ponte dorsal à transição entre o esôfago e o estômago. O lobo esquerdo apresenta-se ligeiramente maior que o contralateral. Em suas extremidades caudais, os lobos esquerdo e direito formam um ápice pontiagudo, de formato triangular, que continua tenuemente através de um istmo eminentemente vascular que liga esses ápices a dois outros lobos, chamados acessórios direito e esquerdo, bem menores que os demais, e que ficam seqüestrados em um recesso peritoneal, lateral à cavidade abdominal. Os resultados indicam ainda que o sistema porta hepático de Clarias gariepinus está representado por duas veias portas principais denominadas direita e esquerda, levemente assimétricas em diâmetro, que drenam o sangue das vísceras abdominais (baço, estômago, vesícula biliar, intestino e gônadas) através dos tributários viscerais desse sistema. Ainda, devido a uma situação peculiar dos lobos acessórios, definem-se mais duas veias portas secundárias ligadas às principais e designadas igualmente por acessórias, uma esquerda e outra direita. Ambas as vv. portas principais se ramificam, atingindo o hilo da face visceral, enquanto que as vv. acessórias penetram por uma região restrita do lobo. Através de ramos interlobares, ambas as vv. portas principais se anastomosam no parênquima hepático. A v. porta esquerda, com discreto aumento de diâmetro, forma-se pela terminação da v. intestinal, concomitante à desembocadura da v. gastrointestinal e da v. porta acessória esquerda. A v. porta direita se define pela terminação da v. intestinal cranial, simultaneamente à chegada da v. porta acessória ipsilateral, drenando sangue do intestino médio, estômago e vesícula biliar. Nessa espécie, também estão caracterizados dois sítios de comunicação entre o sistema porta hepático e o sistema porta renal através de anastomoses em cada v. porta. Sob as condições em que o trabalho foi desenvolvido e considerando-se a metodologia proposta e a análise dos resultados, conclui-se que todos os métodos foram adequados ao estudo do aparelho circulatório de Clarias gariepinus, sendo recomendados para experimentos futuros sobre o mesmo assunto em outras espécies piscícolas; porém, dentre as três metodologias utilizadas para análises macroscópicas, a injeção de cloreto de polivinil seguida de corrosão das peças e subseqüente obtenção de moldes vasculares mostrou-se mais eficiente na marcação e identificação dos vasos que compõem o sistema porta hepático deste peixe. Conclui-se também que, devido à presença dos lobos acessórios, a lobação hepática é peculiar nesta espécie, em virtude da posição ocupada por estes lobos, assim como a circulação porta, em função das duas veias porta acessórias, e ainda a anastomose entre as duas veias porta principais, característica que deve ser considerada em trabalhos que envolvam cirurgia hepática no bagre africano

The hepatic portal system of the African catfish Clarias gariepinus Burchell, 1822, was studied considering the macroscopic and microscopic anatomy, by means of several anatomic techniques, including anesthesia, injection of substances recommended to the study of the vascular system (latex, Indian ink, polyvinyl chloride and radiopaque substance), dissection, corrosion or radiography, according to the requirement of each technique, as a way of understanding the hepatic circulatory pathway in the African catfish. Sixteen female specimen were used, being the entire length between 45 and 53.5 centimeters and the corporal mass between 575 and 1068 grams. To perform these techniques, the fishes were adequately anesthetized with benzocaine, assuring the deep narcosis and preventing them from any suffering. The results obtained through such techniques show that the liver of Clarias gariepinus occupies the cranial abdominal cavity and shows a clear lobation, the liver consisting of two large lobes, called right and left, cranially connected by a bridge dorsal to the transition between the esophagus and the stomach. The left lobe is slightly larger than the contralateral lobe. At their caudal ends, the left and the right lobes form a sharp triangle-like apex that tenuously passes through a strip eminently vascular that links these apexes with two other lobes, called right and left accessories, much smaller than the others, these lobes being wrapped in a peritoneal recess, situated at the side of the abdominal cavity. The results still show that the hepatic portal system of Clarias gariepinus is represented by two main portal veins named right and left, slightly asymmetric in diameter, that empty the blood out of the abdominal viscera (spleen, stomach, gall bladder, intestine and gonads) through the visceral tributaries of this system. Furthermore, due to a peculiar situation of the accessory lobes, two other secondary portal veins were defined; they are connected to the main veins and are equally called right and left accessories. Both the main portal veins branch, reaching the hilum of the visceral face, whereas the accessory veins go into a restricted region of the lobe. Through interlobar branches, both the main portal veins anastomose in the hepatic parenchyma. The left portal vein, with a slight increase in diameter, is formed by the terminatio of the intestinal vein, accompanying the discharge of the gastrointestinal vein and the accessory left portal vein. The right portal vein is defined by the terminatio of the cranial intestinal vein, simultaneously with the accessory ipsilateral portal vein, emptying the blood out of the medial intestine, stomach and gall bladder. In this species it is also possible to distinguish two connecting sites between the hepatic portal system and the renal portal system by means of anastomoses in each portal vein. Under the conditions in which the experiment was carried out and considering the methodology suggested and the analysis of the results, it is concluded that all the methods were suitable for the study of the circulatory system of Clarias gariepinus, being recommended for future tests on the same subject in other fish species; however, among the three methodologies used in the macroscopic analyses, the injection of polyvinyl chloride followed by the corrosion of pieces and subsequent getting of vascular moulds was believed to be more efficient at the marking and identification of the vessels that compose the hepatic portal system of this fish. It was also concluded that, due to the presence of the accessory lobes, the hepatic lobation is peculiar in this species because of the position occupied by these lobes, as well as the portal circulation, caused by the two accessory portal veins, in addition to the anastomose between the two main portal veins, a characteristic that must be thought of in studies of hepatic surgery in the African catfish