Thermographic assessment of skin and soft tissue tumors in cats.

OBJECTIVES: This study set out to determine the average temperature of skin and soft tissue tumors in cats using infrared thermography and to investigate correlations between thermographic findings and tumor type. Correlations between thermographic findings, histologic subtype and tumor grade were also investigated in cases of feline injection site sarcoma (FISS). METHODS: Thermographic images of normal skin and skin overlying neoplastic lesions were prospectively obtained. Following thermographic assessment, tumors were resected and submitted to histopathologic and immunohistochemical analysis. Mean temperatures detected in tumoral areas were compared between different tumor types and between FISSs of different histologic subtypes and grades. RESULTS: Thermograms obtained from 11 healthy cats and 31 cats presenting with skin and soft tissue tumors (eight benign and 23 malignant tumors, including 21 FISSs) were evaluated in this study. Thermal behavior varied widely in normal skin, as well as in skin overlying neoplastic lesions. Mean temperatures were significantly higher in malignant compared with benign tumors (35.4 ± 1.8ºC and 34.5 ± 1.7ºC respectively; P = 0.01), with a temperature above 34.7ºC being associated with malignancy (sensitivity 76%, specificity 80%; P = 0.01). Temperatures detected in FISS did not differ significantly according to histologic subtype (P = 0.91) or tumor grade (P = 0.46), or between primary and recurring tumors (P = 0.25). CONCLUSIONS AND RELEVANCE: Infrared thermography proved to be a sensitive and effective method for detection of temperature differences between malignant and benign skin and soft tissue tumors in cats. Thermographic assessment may contribute to diagnosis and prognostic estimation in feline oncologic patients.

18F-FDG PET/CT AS AN ASSESSMENT TOOL OF HEPATOCELLULAR CARCINOMA SECONDARY TO NON-ALCOHOLIC FATTY LIVER DISEASE DEVELOPMENT IN EXPERIMENTAL MODEL.

BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.

PET/CT com 18F-FDG como ferramenta de avaliação do desenvolvimento de carcinoma hepatocelular secundário a doença hepática gordurosa não alcoólica em modelo experimental / 18f-fdg pet/ct as an assessment tool of hepatocellular carcinoma secondary to non-alcoholic fatty liver disease development in experimental model

ABSTRACT BACKGROUND: Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression. OBJECTIVE: To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD. METHODS: Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed. RESULTS: The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC. CONCLUSION: 18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.

RESUMO BACKGROUND: O carcinoma hepatocelular (CHC) pode ser a última fase da doença hepática gordurosa não alcoólica (DHGNA). Modelos experimentais são cruciais para elucidação da patogênese do CHC secundário a DHGNA. A tomografia por emissão de pósitrons/tomografia computadorizada (PET/TC) com 2-desoxi-2-(18F)fluoro-D-glicose (18F-FDG) desempenha um importante papel na avaliação do desenvolvimento e progressão do CHC. OBJETIVO: Padronizar a metodologia de imagem por PET/TC com 18F-FDG como uma ferramenta de avaliação do modelo experimental de CHC secundário a DHGNA. MÉTODOS: Dez ratos Sprague-Dawley machos foram alimentados com dieta hiperlipídica deficiente em colina associada a dietilnitrosamina (DEN) na água de beber por 16 semanas e depois receberam 1 mL de solução salina (0,9%) por gavagem diariamente por três semanas. Nas 16ª e 19ª semanas, foi realizada a ultrassonografia abdominal. As imagens do PET/TC com 18F-FDG foram obtidas antes do início do experimento (semana 0) e no final (semana 19). Análises histológica e imunohistoquímica também foram realizadas. RESULTADOS: Os resultados da ultrassonografia demonstraram um grupo homogêneo na 16ª semana com uma média de 4,6±2,74 nódulos por animal. Na 19ª semana, os achados do PET/CT demonstraram uma média de 8,5±3,7 nódulos por animal. Os valores médios de SUVmed e SUVmáx foram 2,186±0,1698 e 3,8±1,74, respectivamente. A média do número de nódulos na análise histológica foi de 5,5±1,5. De todos os nódulos, 4,6% foram classificados como bem diferenciados e 81,8% foram classificados como CHC pouco diferenciado. CONCLUSÃO: O PET/TC com 18F-FDG foi capaz de avaliar o desenvolvimento do CHC secundário a DHGNA de forma não invasiva. A partir da padronização do PET/CT neste modelo, faz-se possível a utilização desta ferramenta em futuros estudos para monitorar, in vivo e de forma não invasiva, a progressão do CHC.

Recovery of the Cholangiocytes After Ischemia and Reperfusion Injury: Ultra-Structural, Hystological and Molecular Assessment in Rats.

INTRODUCTION: Ischemia-reperfusion (I/R) injury of the liver is a common area of interest to transplant and hepatic surgery. Nevertheless, most of the current knowledge of I/R of the liver derives from the hepatocyte and little is known of what happens to the cholangiocytes. Herein, we assess the sequence of early events involved in the I/R injury of the cholangiocytes. METHODS: Sixty Wistar rats were randomized in a SHAM group and I/R group. Serum biochemistry, histopathology, immunohistochemistry, transmission electron microscopy (TEM) and laser capture microdissection (LCM) were used for group comparison. RESULTS: There was peak of alkaline phosphatase 24 h after IR injury, and an increase of aspartate aminotransferase and alanine aminotransferase after 6 h of reperfusion, followed by a return to normal levels 24 h after injury. The I/R group presented the liver parenchyma with hepatocellular degeneration up to 6 h, followed by hepatocellular necrosis at 24 h. TEM showed cholangiocyte injury, including a progressive nuclear degeneration and cell membrane rupture, beginning at 6 h and peaking at 24 h after reperfusion. Cytokeratin-18 and caspase-3-positive areas were observed in the I/R group, peaking at 24-h reperfusion. Anti-apoptotic genes Bcl-2 and Bcl-xl activity were expressed from 6 through 24 h after reperfusion. BAX expression showed an increase for 24 h. CONCLUSIONS: I/R injury to the cholangiocyte occurs from 6 through 24 h after reperfusion and a combination of TEM, immunohistochemistry and LCM allows a better isolation of the cholangiocyte and a proper investigation of the events related to the I/R injury. Apoptosis is certainly involved in the I/R process, particularly mediated by BAX.

Immunohisto- and Cytochemistry Analysis of Connexins.

Immunohistochemistry (IHC) is a ubiquitous used technique to identify and analyze protein expression in the context of tissue and cell morphology. In the connexin research field, IHC is applied to identify the subcellular location of connexin proteins, as this can be directly linked to their functionality. The present chapter describes a protocol for fluorescent IHC to detect connexin proteins in tissues slices and cells, with slight modifications depending on the nature of biological sample, histological processing, and/or protein expression level. Basically, fluorescent IHC is a short, simple, and cost-effective technique, which allows the visualization of proteins based on fluorescent-labeled antibody-antigen recognition.