Canine Mammary Neoplasms - Evaluation of Tumor Microenvironment

Background: The tumor microenvironment is an important target of studies in different types of neoplasms. Understanding the role of general components such as immune, vascular and fibroblastic cells has the objective of contributing to prognosis and treatment. The aim of this study was to evaluate the relationship between mast cells and angiogenesis in benign and malignant mammary neoplasms by investigating the role of degranulation and microlocation of mast cells and neoformed vessels in canine mammary neoplasms.Materials, Methods & Results: Mammary glands (n = 122) from 50 female dogs submitted to mastectomy without chemotherapy were evaluated and categorized into 3 groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. To evaluate the MCD (mast cell density) and angiogenesis, Toluidine Blue (0.1%) and Gomori’s Trichrome techniques were performed and adapted from previous studies. Photomicrographs of 10 hotspot areas on a 40x objective lens of the mammary glands and lymph nodes were captured to assess MCD and angiogenesis. In the absence of these areas, random fields were captured. For the mammary glands of the malignant and benign groups, 20 fields were analyzed, as the analysis considered the microlocation (peritumoral and intratumoral). Counting was performed manually using ImageJ software version 1.42q by 2 observers. The statistical analysis were performed using SPSS software version 19.0. The most frequent histological type in the malignant group was carcinoma in mixed tumor (68.42%; 39/57) and in the benign group was benign mixed tumor (57.89%; 11/19). Female dogs without breed pattern were more frequently affected represented 70% of the animals and the mean age was 9 years and 8 months ± 3 years and 1 month. The granulated density of mast cells and peritumor vessels was higher in the malignant group (P = 0.03; P = 0.02). There was also a positive correlation between intratumor and total vessel density and mast cell density. There was no significance between the malignant and benign groups in regard with fibrosis density.Discussion: In this study were observed a greater density of blood vessels in malignant group, suggesting the participation of blood vessels for neoplastic proliferation. Furthermore, these vessels were located in the peritumoral region as in previous studies. The positive correlation between MCD and blood vessels was similar to a previous study performed in canine breast carcinomas and breast cancer in women. Regarding microlocation, another study also found higher MCD in the peritumoral region than in the intratumoral region of canine carcinomas. Although there are already studies for this purpose in cases of oral squamous cell carcinoma in humans, we believe this is the first study to investigate the role of mast cell degranulation in mammary neoplasm of bitches. The MCD was not significant among the malignant and benign groups and in the mammary glands of the control group the MCD was higher, as observed by other studies. Future studies should be associated the survival time and the presence of metastases in order to confirm the findings. In view of these findings, we may conclude that a higher density of mast cells is related to a higher density of blood vessels and that these are more abundant in malignant neoplasms, which reinforces the crucial role of angiogenesis in the neoplastic development.Keywords: tumor microenvironment, mammary tumor, mast cells, angiogenesis, bitches

Intoxicação espontânea por monensina em bovinos

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Intoxicação experimental por Brachiaria decumbens em coelhos

Brachiaria spp. are important sources of forage for ruminants in Brazil, due to the easy cultivation, good resistance to drought, good adaptation to different soils and low maintenance cost. However, the ingestion of this grass has been related to photosensitization outbreaks in cattle and sheep with significant economic losses. The hepatotoxic effects related to the ingestion of grass are the formation of crystals and foamy macrophages due to the accumulation of toxic metabolites. The use of cattle and sheep in experiments involving the plant presents several obstacles in the ethical, economic and animal management. The objective of this study was to evaluate the sensitivity of rabbits as an experimental model for B. decumbens poisoning. Two experiments were carried out. In Experiment 1 four rabbits received the fresh plant in daily doses of 10, 20, 40 and 80g/kg body weight for 120 days. In Experiment 2 three rabbits received the fresh plant in amounts of 500g daily with duration of 210 days. The animals of Experiment 1 showed no clinical signs and no macroscopic and microscopic changes characteristic of B. decumbens poisoning. In Experiment 2 the animals also showed no clinical signs or significant macroscopic alterations. Histological analysis showed isolated foamy macrophages or present in random groups of cells in the liver and mesenteric lymph nodes. Samples of liver and mesenteric lymph nodes of the rabbits of Experiment 2 were submitted to the lectin-histochemistry technique. The WGA, sWGA and RCA lectins showed reactivity in foamy macrophages in both organs. This is the first study of our knowledge that demonstrates histopathological lesions caused expetimentally by Brachiaria spp. in rabbits, demonstrating its potential as an animal model.Brachiaria ssp. são importantes fontes de forragem para ruminantes no Brasil, devido ao fácil cultivo, boa resistência a seca, boa adaptação a diferentes solos e baixo custo de manutenção. Entretanto, a ingestão desta gramínea está relacionada a surtos de fotossensibilização, em bovinos e ovinos, principalmente, ocasionando prejuízos econômicos significativos. Os efeitos hepatotóxicos relacionados à ingestão da gramínea são a formação de cristais e macrófagos espumosos causados pelo acúmulo de metabólitos tóxicos. A utilização de bovinos e ovinos em experimentos envolvendo a planta apresenta vários empecilhos, tanto no âmbito ético, econômico e no manejo dos animais. O objetivo do presente trabalho foi avaliar a sensibilidade de coelhos como modelo experimental para intoxicação por B. decumbens. No presente estudo foram realizados dois experimentos. O Experimento 1 utilizou quatro coelhos que receberam a planta fresca em doses diárias de 10, 20, 40 e 80 g/Kg de peso vivo durante 120 dias. O Experimento 2 utilizou três coelhos recebendo a planta fresca em quantidades de 500g diárias por animal com duração de 210 dias. No Experimento 1, os animais não apresentaram sinais clínicos e nem alterações macroscópicas e microscópicas características de intoxicação por B. decumbens No Experimento 2 os animais também não apresentaram sinais clínicos e alterações macroscópicas significativas. Na análise histológica observou-se presença de macrófagos espumosos isolados ou em grupos aleatórios de células no fígado e nos linfonodos mesentéricos. Amostras de fígado e linfonodos mesentéricos dos animais do Experimento 2 foram submetidos à técnica de lectino-histoquímica. As lectinas WGA, sWGA e RCA apresentaram reatividade em macrófagos espumosos nos dois órgãos. Este é o primeiro trabalho de nosso conhecimento que demonstra lesões histopatológicas por Brachiaria spp conduzido de forma experimental em coelhos, demonstrando seu potencial como modelo animal nesse campo de estudo

Mielite granulomatosa associada à síndrome hemorrágica devido ao consumo de Vicia villosa em um bovino

An unusual case of spontaneous Vicia villosa poisoning affected a 6-year-old Holstein cow. Although the most striking findings included a generalized hemorrhagic condition associated with granulomatous myelitis, histological lesions typically seen with the vetch-associated systemic granulomatous syndrome were also present. Prominent gross findings were bloody nasal and oral discharges, disseminated hemorrhages, and bloody feces. Generalized hemorrhages associated with infiltration of numerous organs by lymphocytes, plasma cells, macrophages, multinucleated giants cells, and eosinophils were the main microscopic findings. Anti-CD68 immunostaining confirmed the presence of moderate histiocytic infiltrate and multinucleated giant cells in the bone marrow. These changes in the bone marrow probably caused the generalized hemorrhagic changes described here. __________________________________________________________________________________________ ABSTRACTUm bovino Holandês de seis anos naturalmente intoxicado pela Vicia villosa apresentou lesões não comumente encontradas nessa intoxicação. Embora a lesão mais evidente fosse hemorragia generalizada associada à mielite granulomatosa, as lesões granulomatosas típicas da intoxicação pela ervilhaca também estavam presentes histologicamente. Os principais achados macroscópicos foram hemorragias nasal e oral, hemorragias generalizadas e fezes com sangue. Lesões hemorrágicas generalizadas associadas com infiltrado inflamatório de linfócitos, plasmócitos, macrófagos, células gigantes multinucleadas e eosinófilos foram os principais achados microscópicos encontrados. O teste imuno-histoquímico anti-CD68 confirmou a presença de infiltrado moderado de macrófagos e de células gigantes multinucleadas na medula óssea. As alterações na medula óssea provavelmente constituem a causa da hemorragia generalizada descrita nesse caso

Equine Sarcoids - Treatment with a Combination of Acyclovir and Surgical Excision

Background: Sarcoids are the most frequent skin tumors among horses, causing serious lesions due to their different shapes, sizes, degree of invasiveness and distribution on the body. The pathogenesis of sarcoids is multifactorial, with genetic, viral and environmental involvement, making their treatment complex. The aggressiveness and high rate of recurrence of sarcoids makes it difficult to use an effective treatment, which is why there are several therapeutic routes described in the literature. Aiming to describe and expand sarcoid treatments, this paper reports on the use of acyclovir in the treatment of this type of tumor. Cases: Four horses sent to the Large Animal Veterinary Hospital of the Federal University of Lavras - UFLA were diagnosed and treated for sarcoids. Case 1. Lesions on the right ear, region of the masseter muscle of the right side of the face, neck, vulva and medial aspect of the left pelvic limb. Case 2. Lesion in the left groin region. Case 3. Lesions on the face, masseter muscle region on the left side, mandibular region and right ear pinna. Case 4. Lesion in the lateral region of the left pelvic limb, close to the tarsometatarsal joint. All horses had a diagnosis of sarcoid, which was confirmed by histopathological examination of material collected after surgical excision. Macroscopically, the neoplastic lesions were classified as fibroblastic, verrucous and nodular. The tumors exhibited irregular surfaces, keratinization, and a firm consistency. Their surfaces were alopecic, slightly rough, some of them were ulcerated, and their color ranged from greyish to rosy and reddish. All the tumor masses were surgically excised from the 4 horses, and one sarcoid was treated by thermal cauterization with liquid nitrogen due to the lesion’s depth and size.  In most cases, the sarcoid removal sites were closed with sutures. Only 2 lesions were not sutured due to the impossibility of bringing the edges of tissue close together, or due to proximity to the tarsometatarsal joint. The surgical wounds were cleaned twice a day with sterile saline solution followed by the topical application of Acyclovir. One of the animals received complementary therapy with Cimetidine. Discussion: The equines recovered completely from their sarcoid treatment, and no recurrences were reported a year later. Thus, the combination of treatments employed for the extirpation of sarcoids proved to have greater chances of success. First, all the tumors were surgically removed with the largest possible margins of safety in order to ensure the elimination of neoplastic cells. In the postoperative period, all the animals received topical treatment of the lesions with acyclovir after surgical resection of the tumors. The drug aided the complete healing of post-surgical wounds, and healing time varied according to the size and depth of the lesion. One tumor was treated with liquid nitrogen after surgical excision of the sarcoid. Another horse was treated with cimetidine over a 3-month period after surgical excision of the neoplasm in order to reduce the sarcoid and prevent its evolution. Surgical excision of the sarcoid associated with topical application of acyclovir ointment showed satisfactory results. Moreover, the combination of surgical excision and administration of liquid nitrogen on the lesion and topical application of acyclovir ointment in the postoperative period also provided good results. Given the complexity of sarcoid treatment and the high recurrence rate of these tumors, the use of combined treatments should be taken into account. Keywords: horses, skin tumor, cutaneous neoplasm, therapy. Título: Sarcoide em equinos - tratamento com associação de Aciclovir e excição cirúrgica Descritores: equinos, tumor de pele, neoplasia cutânea, terapia

Esophageal Squamous Cell Carcinoma in Cats

Background: Esophageal neoplasms are rarely reported in cats. The frequency rate is less than 0.5% and those neoplasms are usually malignant. Esophageal squamous cell carcinoma (SCC) is an idiopathic epithelial neoplasm, invasive and metastatic that can induce partial or complete obstruction of the esophageal lumen. There is no breed or sex predisposition, and it is more common in cats over 8-years-old. Esophageal SCC is more frequent in the middle third of the esophagus. The prognosis is poor, as the cats are usually diagnosed at an advanced stage. This report aims to describe clinical, endoscopic, radiographic, and pathological features of two cases of esophageal squamous cell carcinoma in cats.Cases: A 11-year-old neutered male cat presenting regurgitation, weight loss, anorexia and dyspnea was referred to veterinary internal medicine care. Simple and contrast-enhanced radiographic images of the cervical and thoracic regions showed an alveolar pattern in the cranial lung lobes and signs of esophageal lumen irregularity and dilatation in the mediastinum topography. The upper digestive endoscopy showed a dilated esophageal lumen, and an irregular mass was observed in the thoracic esophagus involving the entire esophageal circumference. Biopsy fragments were collected, and the histopathological result was compatible with squamous cell carcinoma. The second case was a 10-year-old neutered male cat presenting hyporexia, regurgitation, dyspnea, tachypnea, and abnormal breath sounds. The ultrasound of the chest showed 3 amorphous hypoechogenic and heterogeneous areas in the right and left hemithorax between parietal and visceral pleura. The cytological examination was compatible with a malignant epithelial tumor. The patient died 3 months after the onset of clinical signs. At gross exam, it was observed a friable, irregular, and ulcerated mass of 5.0 x 3.0 cm in the middle third of the esophagus. Metastatic foci in the lungs and liver were also observed. The histopathological diagnosis was esophageal squamous cell carcinoma, with metastases to liver and lungs. Microscopically, in both cases, were seen aproliferation of polyhedral epithelial cells in the mucosa, arranged in nests or trabeculae with central keratinization. These cells presented oval to rounded nuclei, loose chromatin, prominent nucleolus, and abundant eosinophilic cytoplasm, with marked anisocytosis and anisokaryosis, supported by a thin fibrovascular stroma. In the second cat the neoplastic cells infiltrated the esophageal submucosa, including lymphatic vessels and muscle layer. Lung and liver metastases from theSCC had a cellular pattern similar to the primary neoplasm.Discussion: Esophageal squamous cell carcinoma is extremely rare in cats. The SCC begins in the squamous layer of the mucosa and can infiltrate the muscular layer or protrude into the esophageal lumen, leading to clinical signs, as seen in these 2 cats. The differential diagnoses for esophageal SCC include foreign bodies, esophageal strictures, and infiltrative or compressive non-esophageal tumors. Although uncommon, esophageal tumors should be considered when evaluatingelderly cats with regurgitation and weight loss. The diagnosis of esophageal SCC was confirmed by histopathological findings collected endoscopically or during necropsy. As noted in both cases, the prognosis of SCC is generally unfavorable, usually due to the difficulty in treatment and diagnosis in a late stage of the disease.Keywords: feline, esophagus, neoplasms, metastasis, cancer

Systemic infection by Yersinia enterocolitica in chinchillas (Chinchilla laniger)

Yersinia enterocolitica é uma bactéria Gram-negativa que causa infecções em diversas espécies de mamíferos. O agente, geralmente, provoca infecções restritas ao intestino e linfonodos mesentéricos, porém a infecção pode se tornar sistêmica ocasionando lesões em outros órgãos como fígado e baço. Neste trabalho descrevem-se dois surtos de infecções sistêmicas causadas pela Yersinia enterocolitica em criatórios comerciais de chinchilas no Rio Grande do Sul (Brasil). Os proprietários relatavam que os animais acometidos apresentavam apatia, anorexia e morte. Foram encaminhados 13 animais para a realização de necropsia. No exame post mortem dos animais observou-se esplenomegalia, hepatomegalia e áreas multifocais esbranquiçadas no fígado, baço, pulmões, rins e intestino. No exame microscópico visualizou-se infiltrado inflamatório de neutrófilos e macrófagos, necrose, deposição de fibrina e ocasionalmente pode ser observado coco-bacilos no centro das áreas de necrose. No cultivo bacteriológico obteve-se o crescimento de Yersinia enterocolitica nos animais provenientes dos dois criatórios. O agente foi isolado de amostras no fígado, baço, intestino e pulmões dos animais necropsiados, além do cultivo de fezes de animais de uma das propriedades acometidas. A yersiniose, portanto, é uma patologia que deve ser investigada em casos de mortalidade de chinchilas.Yersinia enterocolitica is a Gram-negative bacterium, which causes infections in several mammalian species. It is often recognized as an agent causing intestinal and mesenteric lymph nodes lesions. However, Yersinia enterocolitica infection may also become systemic, with lesions in others organs such as liver and spleen. This paper describes outbreaks of systemic infection due to Yersinia enterocolitica in two commercial chinchilla breeders in Rio Grande do Sul (Brazil). Owners reported that affected animals showed apathy, anorexia prior to death. Macroscopic examination performed in 13 animals revealed splenomegaly, hepatomegaly and multifocal whitish pinpoint foci in liver, spleen, lung, kidney and intestine. Microscopically, the affected tissues had infiltration of neutrophils and macrophages, as well as fibrin and necrosis with central areas containing cocobacilli bacteria. Yersinia enterocolitica was isolated from liver, spleen, lung and intestine samples from animals of both breeders, and from feces of chinchillas of one of the breeders. Therefore, yersiniosis is a disease to be investigated in cases of mortality of chinchillas

Surto de aborto, mumificação fetal e morte perinatal em um rebanho caprino infectado por toxoplasma gondii no Rio Grande do Sul

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Spontaneous poisoning by larvae of Perreyia flavipes in cattle from the State of Santa Catarina, Brazil

Neste trabalho, é descrito um surto de intoxicação por Perreyia flavipes ocorrido em agosto de 2006, em um rebanho bovino de 280 animais, no município de Sombrio, em Santa Catarina. Ocorreram 17 mortes em um lote de 77 bovinos de raça mista com idades entre um e dois anos mantidos em um piquete (P1) de aproximadamente 90 hectares por cerca de 30 dias. Após as primeiras duas mortes, os animais foram movidos para um segundo piquete (P2), onde ainda ocorreram 15 mortes nos cinco dias após a transferência. Seis bovinos foram necropsiados, e amostras de tecidos foram avaliadas para exame histológico. Os achados de necropsia incluíam hemorragias subcutâneas na mucosa do abomaso e superfície subepicárdica. Ascite e edema do abomaso, duodeno, pâncreas e vesícula biliar foram observados. O fígado apresentava-se amarelado com petéquias subcapsulares e acentuação do padrão lobular. No rúmen de três bovinos, foram encontrados fragmentos de corpos e cabeças de larvas de P. flavipes em meio ao conteúdo ruminal. Histologicamente o fígado apresentava tumefação hepatocelular e necrose centrolobular e mediozonal, difusa e acentuada, com hemorragia e congestão centrolobular. Havia depleção e necrose linfóide no baço, placas de Peyer e linfonodos mesentéricos. O diagnóstico de intoxicação pelas larvas da P. flavipes foi baseado nos dados epidemiológicos, nos achados de necropsia e nas alterações histopatológicas. As lesões hepáticas e em tecidos linfóides, além da grande quantidade de larvas de P. flavipes no primeiro piquete (P1) e no rúmen de animais necropsiados, foram dados importantes para o diagnóstico. ____________________________________________________________________________ ABSTRACTThis article describes an outbreak of Perreyia flavipes poisoning in August of 2006 in a cattle herd of 280 animals in Sombrio, Santa Catarina, southern Brazil. Seventeen bovines between 1 and 2 years old from one herd of 77 mixed breed cattle died. The herd was kept in a paddock of 90 hectares (P1) for 30 days. After de first two deaths occurred, the herd was transferred to a second paddock (P2), and 15 more animals died in the next 5 days. Samples from 6 of these animals were analyzed. During the necropsy, hemorrhage was seen in the subcutaneous tissue, abomasal mucosa, and subepicardial area. The animals presented ascites and edema of the abomasal folds, duodenum, pancreas, and gallbladder. The liver was yellowish, had subcapsular petechial hemorrhages, and accentuated lobular pattern. P. flavipes larval body fragments and heads were found in the rumen content of three of the animals. In the histological examination the liver showed hepatocellular tumefaction, diffuse coagulative necrosis of centrilobular and midzone hepatocytes, hemorrhage and centrilobular congestion. Lymphoid depletion and diffuse necrosis of germinative centers of lymphoid follicles in mesenteric lymph nodes, Peyer’s patches and spleen were also observed. The diagnosis of intoxication by P. flavipes larvae in this outbreak was based on the epidemiological data, necropsy, and histological findings. The confirmation of P. flavipes larvae as cause of the outbreak was done by the observation of intact larvae and remnants in the ruminal content of the necropsied bovines and by the presence of a great number of larvae clusters in the paddock 1 (P1)

Intoxicações naturais por plantas em ruminantes diagnosticadas no Setor de Patologia Veterinária da UFRGS no período de 1996-2005

As intoxicações por plantas em animais pecuários têm particular importância em áreas onde o manejo do pastoreio é feito de forma extensiva. Entre os herbívoros, os ruminantes são os mais suscetíveis. Esse estudo retrospectivo incluiu as intoxicações por plantas em ruminantes diagnosticadas no Setor de Patologia Veterinária (SPV) da Universidade Federal do Rio Grande do Sul (UFRGS) no período de 1996-2005. Essas intoxicações causaram 7,58% (43/567) das mortes de bovinos, 11,46% (25/218) de ovinos e 7,69 % (16/208) de caprinos necropsiados pelo SPV-UFRGS. Destaca-se que das perdas associadas com intoxicações: 62,79% das mortes em bovinos foram atribuídas à lesão hepática crônica causada por Senecio spp.; 28% das mortes em ovinos, às lesões no trato gastrintestinal por Baccharis coridifolia e 75% das mortes em caprinos, à doença de depósito lisossomal por Sida carpinifolia. Os achados indicam que a intoxicação por plantas é importante causa de perda econômica em ruminantes na área de atuação do SPV/UFRGS no Rio Grande do Sul