Mammary botryomycosis: two concomitant cases in mares: case report / Botriomicose mamária: dois casos concomitantes em éguas: relato de caso

Mammary disorders in mares are rare and usually only one animal per paddock is affected. In this report, two mares with 7 and 9 years old, were concomitantly diagnosis of chronic pyogranulomatous mastitis, associated with the Splendore-Hoeppli reaction, indicative of botryomycosis a rare, chronic suppurative disease with microabscess formation, characterized by in vivo formation of eosinophilic materials around microorganisms or biologically inert material. Various bacteria can cause botryomycosis in horses, and the most frequently isolated one is Staphylococcussp., particularly S. aureus. This report confirms the role of Staphylococcus sp.; however, specifically S. hyicus and S. cohnii that prior to the current report, had not been associated with cases of botryomycosis.(AU)

Enfermidades mamárias em éguas são raras e, normalmente, apenas um animal é afetado. Neste relato, duas éguas, de sete e nove anos, foram diagnosticadas concomitantemente com mastite crônica piogranulomatosa, associada com reação de Splendore - Hoeppli, indicativa de botriomicose, uma doença crônica supurativa rara, com formação de microabscessos caracterizados pela presença de material eosinofílico em torno dos microrganismos ou de material biologicamente inerte. Várias bactérias podem causar botriomicose em cavalos, sendo Staphylococcus sp., particularmente S. aureus, as mais frequentemente isoladas. Este relato confirma o papel do Staphylococcus sp, no entanto este é o primeiro relato em que S. hyicus e S. cohnii foram identificados em lesões relacionadas à botriomicose.(AU)

Refrigerated platelets stored in whole blood up to 5 days adhere to thrombi formed during hemorrhagic hypotension in rats.

Essentials In vivo function of platelets stored at various conditions was studied in normo- and hypotension. Refrigerated platelets stored up to 5 days performed as well as those stored at room temperature. Platelet adhesion and thrombus formation were higher in ruptured vessels of hemorrhaged animals. In vivo data suggest that refrigerated platelets are hemostatically effective during hypotension. SUMMARY: Background There is renewed interest in the therapeutic use of cold-stored platelets for bleeding patients. However, critical information is absent or partially available in vitro. Therefore, thrombus formation and platelet adhesion were studied in vivo, in situ, using bleeding and thrombosis models in instrumented rats, and confocal intravital videomicroscopy. Objectives We tested the hypothesis that refrigerated (4 °C) platelets (stored for 24 h or 5 days) participated in thrombus formation as well as platelets stored at room temperature (RT, 22 °C). This hypothesis was tested in normovolemia and hemorrhagic hypotension. Methods & Results After fluorescently-labeled platelet infusion, endothelial injury and vessel rupture were laser-induced in cremaster microvessels and platelet adhesion in > 230 developing thrombi was evaluated. Blood samples were collected for biochemistry and coagulation assays while multiple systemic physiologic parameters were recorded. Hemorrhagic hypotension study animals were subjected to 40% hemorrhage, leading to hypotension and hemodilution, during in vivo platelet adhesion assessments. The fluorescence intensity associated with labeled platelet adherence provided a quantitative index of adhesion. Cold-stored platelets performed as well as those stored at RT in normovolemic animals. During hypotension, cold-stored platelets still performed as well as RT-stored platelets, whereas platelet adhesion and thrombus formation were increased relative to normovolemic animals, in bleeding model experiments. Conclusions We found the methodology suitable for evaluating platelet function in vivo after different storage conditions in fully monitored animals. Refrigerated platelets (stored up to 5 days) participated as well as RT-stored platelets in thrombi formed after hemorrhage, suggesting that refrigerated platelets are effective during hypotensive situations.

Choroid plexus papilloma in a Rottweiler: computed tomographic, gross morfological and histological features / Papiloma do plexo coroide em um cão da raça Rottweiler: aspectos tomográficos, macroscópicos e histológicos

Among the tumors affecting the choroid plexus in dogs, the papilloma ranks second place in incidence after cell carcinoma tumors. Presumptive diagnosis can be made through imaging methods, such as computed tomography and magnetic resonance images. Definitive diagnosis of plexus choroid tumor is based on histopathological findings. This report presented the tomographic features of the brain in a 6-year-old intact female Rottweiler with choroid plexus papilloma. The computed tomography showed right lateral ventricle enlargement, midline deviation and an enhanced mass into the postcontrast phase. At necropsy, a mass on the floor of the right lateral ventricle was observed, associated with important ventricle dilatation. The histopathological analysis demonstrated the presence of neoplastic cell forms with papillary projections. The computed tomography proved to be an effective tool in the presumptive diagnosis of this kind of cerebral disorder.

Dentre os tumores que afetam o plexo coroide em cães, o papiloma figura como o segundo tipo de maior incidência, antecedido apenas pelo carcinoma. O diagnóstico presuntivo pode ser elaborado por meio de métodos de imagem, como a tomografia computadorizada e a ressonância magnética. O diagnóstico definitivo de tumor do plexo coroide é estabelecido com base nos achados histopatológicos. Relatamos os aspectos tomográficos do crânio em uma fêmea de 6 anos, inteira, da raça Rottweiler, com papiloma do plexo coroide. A tomografia computadorizada revelou dilatação do ventrículo lateral direito, desvio da linha média e a presença de uma massa, que sofreu realce na fase pós-contraste. À necropsia, foi observada uma massa sobre o assoalho do ventrículo lateral direito, associada à importante dilatação ventricular. A análise histopatológica demonstrou a presença de células poligonais neoplásicas, arranjadas em papilas longas. A tomografia computadorizada apresentou-se como uma ferramenta eficaz no diagnóstico presuntivo desse tipo de alteração cerebral.

Expression of connexins in normal and neoplastic canine bone tissue.

Previous studies showed that intercellular communication by gap junctions has a role in bone formation. The main connexin involved in the development, differentiation, and regulation of bone tissue is connexin (Cx) 43. In addition, Cx46 is also expressed, mostly localized within the trans-Golgi region. Alterations in the expression pattern and aberrant location of these connexins are associated with oncogenesis, demonstrating a deficient gap junctional intercellular communication (GJIC) capacity in neoplastic tissues. In this study, we evaluated normal and neoplastic bone tissues regarding the expression of Cx43 and Cx46 by immunofluorescence, gene expression of these connexins by real-time PCR, and their correlation with cell proliferation index and deposition of collagen. Fourteen neoplastic bone lesions, including 13 osteosarcomas and 1 multilobular tumor of bone, were studied. The mRNA levels of Cx43 were similar between normal and neoplastic bone tissue. In normal bone tissue, the Cx43 protein was found mainly in the intercellular membranes. However, in all bone tumors studied here, the Cx43 was present in both cell membranes and also aberrantly in the cytoplasm. Regarding only tumor samples, we determined a possible inverse correlation between Cx43 expression and cellular proliferation, although a positive correlation between Cx43 expression and collagen deposition was also noted. In contrast, Cx46 had lower levels of expression in neoplastic bone tissues when compared with normal bone and was found retained in the perinuclear region. Even though there are differences between these two connexins regarding expression in neoplastic versus normal tissues, we concluded that there are differences regarding the subcellular location of these connexins in normal and neoplastic dog bone tissues and suggest a possible correlation between these findings and some aspects of cellular proliferation and possibly differentiation.

In vitro chemosensitivity of canine mast cell tumors grades II and III to all-trans-retinoic acid (ATRA).

Mast cell tumor (MCT) is one of the most prevalent neoplasms that affect the skin and soft tissue of dogs. Because mast cell tumors present a great variety of clinical appearance and behavior, their treatment becomes a challenge. While retinoids are well recognized as promising antitumor agents, there have been only a few reports about retinoids' effect on canine cancers. The aim of this study was to investigate the chemosensitivity of MCT grades II and III to all-trans retinoic acid (ATRA). Immediately after surgical resection, MCT were prepared for primary culture. Samples of MCTs were also fixed in formalin for histopathology and grading according to the classification of Patnaik et al. (Veterinary Pathology 21(5):469-474, 1984). The best results were obtained when neoplastic mast cells were co-cultivated with fibroblasts. Cultured mast cells were, then, treated with concentrations of 10(-4) to 10(-7) M of ATRA, in order to evaluate their chemosensitivity to this retinoid. MTT assay was performed to estimate cell growth and death. The highest level of mast cell chemosensivity was obtained at the dose of 10(-4) M (p < 0,002). MCT of grades II or III were equally susceptible to the treatment with ATRA. Cell death was observed on the first 24 h until 48 h. According to these results, ATRA may be a potential chemotherapeutic agent for the treatment of canine MCT.

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.

Avaliação ultra-sonográfica e pelo Doppler colorido do carcinoma de células transicionais da bexiga em cães / Ultrasonography and color Doppler investigation of transicional cell carcinoma of the bladder in dogs

Estudaram-se os aspectos ultra-sonográficos das lesões sugestivas de carcinoma de células transicionais (CCT), investigou-se a contribuição do mapeamento Doppler colorido e de amplitude no diagnóstico das lesões sugestivas de CCT e verificou-se a acurácia do método de biópsia ecodirigida por sucção traumática via sondagem uretral na coleta de material para confirmação diagnóstica CCT da bexiga. Para tal, foram selecionados nove cães que atendiam aos critérios de inclusão determinados. Destes, sete apresentavam CCT. A ultra-sonografia permitiu a detecção de massas exofílicas com características vegetantes em cinco cães, e de lesões infiltrativas na parede vesical estendendo-se para a uretra em dois. Pelo exame com Doppler colorido e de amplitude, constatou-se a vascularização interna da massa, indicativa de neoangiogênese tumoral, em quatro animais. A técnica de sucção traumática por aspiração permitiu a elucidação diagnóstica em cinco dos sete animais com CCT. Concluiu-se que, na maioria dos casos, a ultra-sonografia propicia a identificação de lesões sugestivas de CCT, constituindo a primeira técnica de diagnóstico por imagem indicada para pacientes que apresentem hematúria e disúria

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

Expression of connexins 26 and 43 in canine hyperplastic and neoplastic mammary glands.

Gap junctions are the only communicating junctions found in animal tissues and are composed of proteins known as connexins. Alterations in connexin expression have been associated with oncogenesis; reported studies in rodent and human mammary glands, which normally express connexins 26 and 43, confirm these alterations in malignancies. Mammary neoplasms represent the second most frequent neoplasm in dogs, and since there are no reports on the study of connexins in canine mammary glands, the present study investigated the expression of connexins 26 and 43 in normal, hyperplastic, and neoplastic mammary glands of this species, to verify if altered patterns of connexin staining are related to higher cell proliferation and malignant phenotypes. A total of 4 normal, 8 hyperplastic mammary glands, 9 benign, and 51 malignant mammary gland neoplasms were submitted for the immunostaining of connexins 26 and 43, E-cadherin, and proliferating cell nuclear antigen (PCNA). Normal, hyperplastic, and benign neoplastic mammary glands showed a punctate pattern for connexin 26 and 43 staining and an intercellular E-cadherin staining. Malignant neoplasms, especially the most aggressive cases with high cell proliferation rates, presented either fewer gap junction spots on the cell membranes or increased cytoplasmic immunostaining. Malignant tumors also expressed a less intense immunostaining of E-cadherin; the expression of this adhesion molecule is important for the transportation of connexins to cell membranes and in forming communicating gap junctions. Deficient expression of E-cadherin could be related to the aberrant connexin localization and may contribute to the malignant phenotype. In conclusion, the expression and distribution of connexins and E-cadherin are inversely correlated to cell proliferation in malignant mammary neoplasms of dogs and may well be related to their more aggressive histologic type and biologic behavior.

Effects of hypertonic saline solution on mesenteric microcirculation.

We evaluated systemic and microvascular effects of hypertonic NaCl solution on normovolemic and hemorrhaged animals. Forty-three Wistar rats (186 +/- 4 g, mean +/- SEM) were anesthetized with pentobarbital and cannulated for mean arterial pressure (MAP), heart rate (HR), and mean pulse pressure (MPP) monitoring and blood withdrawal. Diameters of 126 arterioles and 88 venules of the exteriorized mesentery were studied by using intravital microscopy. Microvascular blood flow was calculated from diameter and red blood cell velocity measurements. The protocol consisted of 15 min control, 30 min hypotension (MAP = 52.9 +/- 0.9 mmHg, hemorrhaged vol. = 17.1 +/- 0.7 mL/kg) and 60 min post-infusion of either normal (0.9%) or hypertonic saline (7.5%, 4 mL/kg). Normovolemic animals showed no systemic or microvascular effects of hypertonic saline. Hemorrhagic hypotension resulted in HR fall that was not changed after infusions. Hypertonic infusion reversed MPP decrease during hypotension but only partially restored MAP and microvascular blood flow. Venules did not change diameter during protocols. During hypotension, 24% of arterioles displayed vasomotion (38% of the rats) with low- and high-frequency components present in 74% and 87% of arterioles, respectively. Arterioles with vasomotion during hypotension had larger control diameters (28.9 +/- 2.0 microm) and contracted more (30.8 +/- 4.1%) than arterioles without vasomotion (18.7 +/- 1.2 microm and 8.1 +/- 1.5%, respectively). Mean arteriolar diameter did not change after infusions. After hypertonic solution, the number of vessels showing vasomotion increased 80%, frequency of vasomotion was unchanged, and amplitude increased. These findings may help to explain some of the mechanisms underlying resuscitation effects of hypertonic infusions during hemorrhagic hypotension.

Determination of macromolecular exchange and PO2 in the microcirculation: a simple system for in vivo fluorescence and phosphorescence videomicroscopy.

We have developed a system with two epi-illumination sources, a DC-regulated lamp for transillumination and mechanical switches for rapid shift of illumination and detection of defined areas (250-750 microm(2)) by fluorescence and phosphorescence videomicroscopy. The system permits investigation of standard microvascular parameters, vascular permeability as well as intra- and extravascular PO2 by phosphorescence quenching of Pd-meso-tetra (4-carboxyphenyl) porphine (PORPH). A Pechan prism was used to position a defined region over the photomultiplier and TV camera. In order to validate the system for in vivo use, in vitro tests were performed with probes at concentrations that can be found in microvascular studies. Extensive in vitro evaluations were performed by filling glass capillaries with solutions of various concentrations of FITC-dextran (diluted in blood and in saline) mixed with different amounts of PORPH. Fluorescence intensity and phosphorescence decay were determined for each mixture. FITC-dextran solutions without PORPH and PORPH solutions without FITC-dextran were used as references. Phosphorescence decay curves were relatively unaffected by the presence of FITC-dextran at all concentrations tested (0.1 microg/ml to 5 mg/ml). Likewise, fluorescence determinations were performed in the presence of PORPH (0.05 to 0.5 mg/ml). The system was successfully used to study macromolecular extravasation and PO2 in the rat mesentery circulation under controlled conditions and during ischemia-reperfusion.

Determination of macromolecular exchange and PO2 in the microcirculation: a simple system for in vivo fluorescence and phosphorescence videomicroscopy

We have developed a system with two epi-illumination sources, a DC-regulated lamp for transillumination and mechanical switches for rapid shift of illumination and detection of defined areas (250-750 æm²) by fluorescence and phosphorescence videomicroscopy. The system permits investigation of standard microvascular parameters, vascular permeability as well as intra- and extravascular PO2 by phosphorescence quenching of Pd-meso-tetra (4-carboxyphenyl) porphine (PORPH). A Pechan prism was used to position a defined region over the photomultiplier and TV camera. In order to validate the system for in vivo use, in vitro tests were performed with probes at concentrations that can be found in microvascular studies. Extensive in vitro evaluations were performed by filling glass capillaries with solutions of various concentrations of FITC-dextran (diluted in blood and in saline) mixed with different amounts of PORPH. Fluorescence intensity and phosphorescence decay were determined for each mixture. FITC-dextran solutions without PORPH and PORPH solutions without FITC-dextran were used as references. Phosphorescence decay curves were relatively unaffected by the presence of FITC-dextran at all concentrations tested (0.1 æg/ml to 5 mg/ml). Likewise, fluorescence determinations were performed in the presence of PORPH (0.05 to 0.5 mg/ml). The system was successfully used to study macromolecular extravasation and PO2 in the rat mesentery circulation under controlled conditions and during ischemia-reperfusion