Luciana Neves Torres

Retrospective – systematic study and quantitative analysis of cellular proliferation and apoptosis in normal, hyperplastic and neoplastic perianal glands in dogs

Neoplasms in the perianal region are frequently diagnosed in dogs. The aetiology is unknown, and most of them are benign. In this study, 240 neoplasms of the perianal glands of dogs were retrieved from the Department of Pathology archives of the Faculty of Veterinary Medicine and Zootechny of University of São Paulo (FMVZ/USP), from 1984 to 2004. All 240 cases were re-examined by two pathologists. Nine cases (4%) were diagnosed as hyperplasia, 49 (20%) as group I adenoma, 81 (34%) were classified as moderately differentiated adenomas of the group II, 46 (19%) were poorly differentiated adenomas of group II, 48 (20%) were carcinoma of the group III according to the classification proposed by Berrocal, and 7 (13%) were other kind of tumours. Males over 8 years of age were predominantly affected. Cell proliferation was quantified by counting proliferating cell nuclear antigen (PCNA) positive nuclei, and apoptosis was quantified by counting fluorescent eosin-stained apoptotic corpuscles (AC) in normal tissue, hyperplasia and in different histologic types of neoplasia of these glands. A parallel pattern of increase in both parameters (cell proliferation and apoptosis) was obtained. The net growth index (NGI), represents how much a cell population is proliferating or dying and was achieved by dividing the mean PCNA count in 1000 cells by the mean AC stain count in 1000 cells. NGI was different between hyperplasia and neoplasia; group I adenomas have a much higher potential of growth, and NGI decreases from benign towards malignant lesions. These results show up the importance of studying cell proliferation and apoptosis to understand the carcinogenesis of dog perianal gland.

Chronic exposure of lung alveolar epithelial type II cells to tobacco‐specific carcinogen NNK results in malignant transformation: A new in vitro lung carcinogenesis model

Lung cancer is the leading cause of cancer‐related mortality in both men and women throughout the world. This disease is strongly associated with tobacco smoking. The aim of this manuscript was to establish an in vitro model that mimics the chronic exposures of alveolar epithelial type II cells to the tobacco‐specific nitrosamine carcinogen, NNK. Immortalized non‐neoplastic alveolar epithelial cells type II, (E10 cells), from BALB/c mice were exposed to low concentration of NNK (100 pM) during 5, 10, 15, and 20 cycles of 48 h. NNK‐transformed cells showed an increase of proliferation rate and motility. Moreover, these cells underwent epithelial‐to‐mesenchymal transition (EMT). Increased migratory capacity and EMT were correlated to the time of exposure to NNK. NNK‐transformed cells were tested for their growth and metastatic capacity in vivo. Subcutaneous injection of cells exposed to NNK for 20 cycles (E10‐NNK20 clone) into BALB/c mice led to the formation of subcutaneous tumors that arose after 40 ± 17 d in all animals, which died 95 ± 18 d after cell inoculation, with lymph nodes and lung metastasis. The morphological characteristics of tumors were compatible with metastatic undifferentiated carcinoma. Cells exposed to NNK for 5–10 cycles did not display metastatic capacity, while those exposed for 15 cycles displayed low capacity. Our results show that prolonged exposures to NNK led the cells to increasingly acquire malignant properties. The cellular model presented in this study is suitable for studying the molecular events involved in the different stages of malignant transformation.

Pneumonia and bacteremia in a golden-headed lion tamarin (Leontopithecus chrysomelas) caused by Klebsiella pneumoniae subsp. pneumoniae during a translocation program of free-ranging animals in Brazil

Klebsiella pneumoniae is an important emerging pathogen in humans, particularly the invasive hypermucoviscosity (HMV) phenotype. In addition, the organism is an important public health concern because of nosocomial infections and antimicrobial resistance. Nonhuman primates in captivity are susceptible to Klebsiella, particularly when a stress factor is involved. Infections vary depending on the species but can cause significant morbidity and mortality in these animals. The objective of this study was to describe a case of bronchopneumonia and bacteremia caused by Klebsiella pneumoniae in a free-ranging golden-headed lion tamarin (Leontopithecus chrysomelas) caught and maintained in quarantine during a translocation program for conservation purposes. An adult male, that had showed emaciation and apathy, was clinically examined and, despite being provided supportive therapy, died 2 days after onset of clinical signs. At postmortem examination, generalized bilateral pneumonia and pericarditis were observed. Tissue samples were fixed in 10% formalin for histology, and pulmonary tissues and cardiac blood were collected for microbiologic diagnostic procedures. Bacteria that were shown to be HMV K. pneumoniae subsp. pneumoniae strains were isolated from the pulmonary fluids and cardiac blood in pure cultures. Severe bronchopneumonia was the main pathological finding. The consequences of the confirmed presence of the HMV phenotype of K. pneumoniae subsp. pneumoniae in this wildlife species for human, animal, and ecosystem health should be determined. These results demonstrate the importance of quarantine and potential pathogen screening during wildlife translocation procedures.

Avaliação ultrassonográfica de linfonodos na pesquisa de metástases de neoplasia mamária em cadelas

Evaluation of lymph nodes is part of the staging of the mammary tumors and helps to establish a prognosis and therapy. B-mode ultrasonography was used to evaluate size, edge, nodal borders, shape, architecture, echotexture and echogenicity of lymph nodes and Doppler ultrasonography to evaluate the quantity and distribution of the vessels. The aims of this work were to identify which ultrasound features can be used to classify a lymph node as metastatic or non-metastatic; to establish its accuracy as a useful tool to this differentiation, and to establish procedures that permit the reproducibility of the results. Sixty seven lymph nodes of 30 female dogs with mammary tumors were examined by ultrasound and classified as metastatic or non-metastatic. The ultrasonographic diagnostic impression was confronted with the histopathologic results. The ultrasonographic classification of the lymph nodes was correct in 92.5% of the cases, with sensibility of 94.1%, specificity of 92%, positive predictive value of 0.8, and negative predictive value of 0.9787.The characteristics of the nodes to classify them as metastatic or non metastatic were registered. Ultrasound imaging of regional lymph nodes is important to detect metastases and it is suggested that it becomes a regular procedure in the staging of canine mammary tumors.

Heartworm (Dirofilaria immitis) disease in a Brazilian oncilla (Leopardus tigrinus)

Heartworm disease is caused by the intravascular nematode Dirofilaria immitis, a pathogen of public health importance usually associated to domestic dogs and cats, and to a lesser extend to other mammal species. The oncilla (Leopardus tigrinus) is a threatened neotropic felid species that naturally occurs in Brazil. Here, we report the encounter of adult and larval stages of heartworms in a female specimen of L. tigrinus, probable of free-ranging origin, from Ubatuba, Sao Paulo, Brazil, which died showing clinical signals compatible with heartworm disease. This was the first reported case of D. immitis infection and associated disease in L. tigrinus, also suggesting that the oncilla acted as a definitive host for this parasite. The present findings confirmed D. immitis as a pathogenic agent for this felid species, thus supporting the recommendation for the inclusion of diagnostic testing for this pathogen in routine health screening procedures for captive and free-ranging oncillas in Brazil, especially in those localities where climate conditions support the occurrence of the parasite. Potential reservoirs as oncillas are established beyond the reach of veterinary care, thus representing a continuing risk for domestic animals and humans acquiring heartworm infection. We encourage further serologic and molecular studies aiming to establish D. immitis prevalences in L. tigrinus and other wild carnivores in the region of Ubatuba, as well as ecological and veterinary studies to access the role of this pathogen for the survival of this threatened felid species.

Clostridium perfringens Type A Enteritis in Blue and Yellow Macaw (Ara ararauna)

SUMMARY This study describes an outbreak of necrotic enteritis caused by Clostridium perfringens type A in captive macaws (Ara ararauna). Two psittacine birds presented a history of prostration and died 18 hr after manifestation of clinical signs. The necropsy findings and histopathologic lesions were indicative of necrotic enteritis. Microbiologic assays resulted in the growth of large gram-positive bacilli that were identified as C. perfringens. PCR was used to identify clostridium toxinotypes and confirmed the identification of isolated strains as C. perfringens type A, positive to gene codifying beta 2 toxin. The infection source and predisposing factors could not be ascertained. RESUMEN Reporte de Caso—Enteritis por Clostridium perfringens tipo A en guacamayos azul y amarillo (Ara ararauna). Este estudio describe un brote de enteritis necrótica causada por Clostridium perfringens tipo A en guacamayos azul y amarillo (Ara ararauna). Dos aves psitácidas presentaron una historia de postración y murieron 18 horas después de la manifestación de los signos clínicos. Los resultados de la necropsia y las lesiones histopatológicas fueron indicativos de la enteritis necrótica. Los ensayos microbiológicos dieron como resultado el crecimiento de bacilos gram-positivos grandes que fueron identificados como C. perfringens. Se utilizó PCR para identificar los tipos de toxinas clostridiales y este método confirmó la identificación de las cepas aisladas como C. perfringens tipo A, positivas para el gene que codifica para la toxina beta 2. La fuente de la infección y los factores predisponentes no se pudieron determinar.

Avaliação ultra-sonográfica e pelo Doppler colorido do carcinoma de células transicionais da bexiga em cães

The aims of this study were to evaluate the ultrasonographic findings in dogs with suggestive transitional cell carcinoma (TCC) lesion, to investigate the use of the color Doppler for the diagnosis of that condition and to establish the efficacy of the ultrasound catheter biopsy by suction via urethral probing for collecting material to confirm bladder TCC. A total of nine dogs were selected, seven with TCC confirmed. The ultrasonographic finding in TCC patients detected sessile masses in the bladder of five dogs and infiltrative mural lesion extent to the urethra in two dogs. The color Doppler and the power Doppler showed the internal vascular flow in four animals indicating tumor neoangiogenesis. It was concluded that the ultrasonography may identify abnormalities in the majority of cases with suggestive lesions of TCC and the ultrasonographic evaluation should be considered as the first diagnostic imaging modality in patients presented with hematuria and dysuria.

Hemoperitoneo por linfoma em raiz mesentérica em equino

Hemoperitoneo e o acumulo de sangue na cavidade peritoneal, uma condicao pouco relatada na especie equina. Relata-se aqui o caso de um equino, Quarto de Milha, macho, 6 anos de idade, com queixa de edema recorrente em bolsa escrotal, distensao abdominal e alteracoes em auscultacao pulmonar. O exame fisico revelou baixo escore corporal, taquicardia, mucosas congestas e distensao abdominal. Realizou-se abdominocentese, onde foi observado liquido peritoneal sanguinolento, com 5% de hematocrito, proteina 2 g/dL, 24.900 de celulas nucleadas e lactato 18,6 mmol/L. No ultrassom abdominal, notou-se grande quantidade de liquido com presenca de fibrina e baco com superficie irregular, de tamanho reduzido e afastado da parede abdominal. Indicou-se uma laparotomia exploratoria, onde, alem de grande quantidade de liquido sanguinolento, observou-se a presenca de formacao tumoral em porcao distal do jejuno, estendendo-se desde a raiz mesenterica ate a juncao com a alca intestinal. Devido a impossibilidade de remocao cirurgica, indicou-se a eutanasia. Durante a necropsia, alem da tumoracao, havia tambem aumento de linfonodos mediastinais. O exame histopatologico indicou linfoma na forma multicentrica. O incomum do caso e o acometimento da raiz mesenterica e o desenvolvimento de distensao abdominal e hemoperitoneo. O diagnostico definitivo com o animal vivo e dificil, porem neste caso foi possivel devido a laparotomia exploratoria. Conclui-se que o linfoma deve ser considerado como diagnostico diferencial em cavalos com hemoperitoneo.

Putative progressive and abortive feline leukemia virus infection outcomes in captive jaguarundis ( Puma yagouaroundi )

BackgroundFeline leukemia virus (FeLV) is an exogenous gammaretrovirus of domestic cats (Felis catus) and some wild felids. The outcomes of FeLV infection in domestic cats vary according to host susceptibility, virus strain, and infectious challenge dose. Jaguarundis (Puma yagouaroundi) are small wild felids from South and Central America. We previously reported on FeLV infections in jaguarundis. We hypothesized here that the outcomes of FeLV infection in P. yagouaroundi mimic those observed in domestic cats. The aim of this study was to investigate the population of jaguarundis at Fundação Parque Zoológico de São Paulo for natural FeLV infection and resulting outcomes.MethodsWe investigated the jaguarundis using serological and molecular methods and monitored them for FeLV-related diseases for 5 years. We retrieved relevant biological and clinical information for the entire population of 23 jaguarundis held at zoo. Post-mortem findings from necropsies were recorded and histopathological and immunohistopathological analyses were performed. Sequencing and phylogenetic analyses were performed for FeLV-positive samples. For sample prevalence, 95% confidence intervals (CI) were calculated. Fisher’s exact test was used to compare frequencies between infected and uninfected animals. P-values <0.05 were considered significant.ResultsIn total, we detected evidence of FeLV exposure in four out of 23 animals (17%; 95% CI 5–39%). No endogenous FeLV (enFeLV) sequences were detected. An intestinal B-cell lymphoma in one jaguarundi was not associated with FeLV. Two jaguarundis presented FeLV test results consistent with an abortive FeLV infection with seroconversion, and two other jaguarundis had results consistent with a progressive infection and potentially FeLV-associated clinical disorders and post-mortem changes. Phylogenetic analysis of env revealed the presence of FeLV-A, a common origin of the virus in both animals (100% identity) and the closest similarity to FeLV-FAIDS and FeLV-3281 (98.4% identity), originally isolated from cats in the USA.ConclusionsWe found evidence of progressive and abortive FeLV infection outcomes in jaguarundis, and domestic cats were probably the source of infection in these jaguarundis.

Tomography, Radiography, and Rhinoscopy in Diagnosis of Benign and Malignant Lesions Affecting the Nasal Cavity and Paranasal Sinuses in Dogs: Comparative Study

Canine nasal and paranasal diseases have variable causes. Presumptive diagnosis is based on clinical manifestations; however, high similarity of clinical signs often calls for diagnostic imaging modalities and rhinoscopy before a definitive diagnosis can be reached. This study sets out to determine the value of rhinoscopy, radiography, and computed tomography (CT) of the head for canine nasal and paranasal disease diagnosis using a purposely developed comparative score. In all, 20 dogs presenting with clinical signs consistent with nasal disease were used. Patients were submitted to radiographic, CT, and rhinoscopic assessment; rhinoscopy-guided biopsy collection was performed in cases presenting with tissue proliferation, ulceration, or other nasal mucosal lesions. Rhinoscopy and rhinoscopy combined with CT significantly contributed to nasal disease diagnosis. Rhinoscopy and CT are complementary diagnostic modalities. Rhinoscopy proved helpful for confirmation of presumptive diagnosis and allowed image-assisted biopsy collection whereas CT contributed to effective determination of lesion extension and involvement of adjacent structures. Yet, histologic confirmation remains vital for definitive diagnosis.