Clinicopathological study of experimentally induced canine monocytic ehrlichiosis

The aims of this study are to investigate the hematology, blood chemistry, pathological study, including macroscopic and microscopic lesions, of experimentally induced canine monocytic erhlichiosis in Thailand and to demonstrate the distribution of Ehrlichia canis in target organs by nested polymerase chain reaction (PCR). Five experimental healthy dogs were inoculated with 5 ml of whole blood (estimated number of E. canis morulae 15 × 10^–5% per monocytes) from the splenectomized dog via the saphenous vein. Two healthy dogs served as a negative control. Hematology revealed nonregenerative normocytic normochromic anemia, thrombocytopenia and mild leukopenia. Blood chemistry revealed an increase in aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (AP), hypoproteinemia, hypoalbuminemia, and hyperglobulinemia by day 66 post-inoculation. Pathology revealed anemia, ascites, jaundice, interstitial pneumonia, splenomegaly, generalized lymphadenopathy, and severe fatty liver. The detection of E. canis was performed using tissue embedded in paraffin wax by nested PCR showing positive in all target organs. This study concluded that acute induced experimental canine monocytic ehrlichiosis can cause significant clinical and pathological lesions.     

Lipoid pneumonia associated with diabetes mellitus type II in a cat

Our purpose is to report a rare case of lipoid pneumonia found in a cat with diabetes mellitus (DM) type II. The cat is an aged, mixed-breed male with a 3-year history of having DM. During the last 16?weeks of its life, the cat presented signs of dyspnea and weakness and was continuously treated by nebulization. Thoracic radiography showed an increased radiopacity of the alveoli. The histopathological findings showed typical lipoid pneumonia, proliferative bronchitis, and diffuse suppurative pneumonia. Chronic pancreatitis with islet amyloidosis and arteriosclerosis was also detected. Immunohistochemistry with anti-Amylin antibody showed a strong positive result in the islet of Langerhans, confirming type II DM in this case. A diagnosis of death from respiratory failure associated with idiopathic lipoid pneumonia was achieved.     

Hepatoprotective activity of Thunbergia laurifolia Linn extract in rats treated with ethanol: in vitro and in vivo studies

Primary cultures of rat hepatocyte and rats were used as the in vitro and in vivo models to evaluate the hepatoprotective activity of aqueous extract from Thunbergia laurifolia (TLE). Ethanol was selected as hepatotoxin. Silymarin (SL) was the reference hepatoprotective agent. In the in vitro study, MTT reduction assay and release of transaminases (ALT and AST) were the criteria for cell viability. Primary cultures of rat hepatocyte (24 h culturing) were treated with ethanol (96 microl/ml) and various concentrations of TLE (2.5, 5.0, 7.5 and 10.0 mg/ml) or SL (1, 2 and 3 mg/ml) for 2 h. Ethanol decreased MTT (%) nearly by half. Both TLE and SL increased MTT reduction and brought MTT (%) back to normal. Ethanol induced release of ALT and AST was also reduced by TLE (2.5 and 5.0 mg/ml) and SL (1 mg/ml). In the in vivo study, serum transaminases, serum triglyceride (STg) together with hepatic triglyceride (HTg) and histopathological examination were the criteria for evidences of liver injury. Ethanol (4 g/(kg day), po for 14 days) caused the increase in ALT, AST, HTg and centrilobular hydropic degeneration of hepatocytes. TLE at 25 mg/(kg day), po, or SL at 5 mg/(kg day), po, for 7 days after ethanol enhanced liver cell recovery by bringing HTg, ALT and/or AST back to normal. These results suggest that TLE and SL possess the hepatoprotective activity against ethanol induced liver injury in both primary cultures of rat hepatocyte and rats.     

C-<Emphasis Type="Italic">erb</Emphasis>B-2 oncogene and <Emphasis Type="Italic">P21</Emphasis><Superscript><Emphasis Type="Italic">WAF/CIP1</Emphasis></Superscript> tumor suppressor gene expression as prognostic factors in canine mammary adenocarcinomas

To evaluate the use of c-erbB-2 oncogene and p21 ^WAF1/CIP1 suppressor gene products as the prognosis markers for canine mammary tumors, expression of these gene products were examined immunohistochemically using tumor tissues and clinical data from 96 dogs with malignant mammary tumors. Semiquantitative data was compared with histopathological grades, proliferating cell nuclear antigen (PCNA)-positive index, and clinicopathological matters. The expression c-erbB-2 protein was found in the cellular membrane and cytoplasm of neoplastic epithelial cells, and the positive index had no significant relation to the histopathological features and PCNA-positive index, except for the individual age of affected dogs (P < 0.05). The product of p21 ^WAF1/CIP1 was mostly found in cytoplasm and occasionally in the nucleus of neoplastic cells. The quantitative data had significant association to the malignancy grade and size of tumors (P < 0.05). However, that had no significant relationship to the PCNA-positive index. The present study concluded that both gene products could not apply as the direct markers to evaluate the prognosis of canine mammary tumors. The detection of c-erbB-2 product may be partly beneficial to the differential diagnosis of epithelial type of mammary cancer. The use of p21 ^WAF1/CIP1 product in prognosis of canine mammary cancer needs further investigation.     

Effects of Orthosiphon stamineus aqueous extract on plasma glucose concentration and lipid profile in normal and streptozotocin-induced diabetic rats

The objective of this study was to investigate the effects of Orthosiphon stamineus Benth. aqueous extract on plasma glucose concentration and lipid profile in normal and streptozotocin-induced diabetic rats. The chemical screening of the extract showed phenolic compound and flavonoid content were 13.24+/-0.33 mg/g and 1.73+/-0.14 microg/g, respectively. In oral glucose tolerance test, the extract (0.2-1.0 g/kg) significantly decreased plasma glucose concentration in a dose-dependent manner in both normal and diabetic rats. The extract at 1.0 g/kg was most effective in decreasing plasma glucose concentrations and the response was closed to the result of glibenclamide (5 mg/kg). After repeated daily oral administrations of the extract (0.5 g/kg) for 14 days, the extract significantly reduced plasma glucose concentration in diabetic rats at days 7 and 14. By the end of the study, plasma triglyceride concentration was lower in the extract-treated diabetic rats than untreated ones. Furthermore, plasma HDL-cholesterol concentration was significantly increased in diabetic rats treated with the extract. In perfused rat pancreas, the extract did not increase insulin secretion in the presence of 5.5 mM glucose, but 100 microg/ml extract potentiated glucose-induced insulin secretion. Our findings suggested that Orthosiphon stamineus aqueous extract is effective for alleviating hyperglycemia and improving lipid profile in diabetic rats.     

Histopathological classification and immunophenotyping of spontaneous canine lymphoma in Bangkok metropolitan

The purpose of this study was to examine the immunophenotype of canine lymphomas according to the updated Kiel classification adapted for canine species and to relate the immunophenotype to the anatomical classification, clinical stage, and the malignancy. Forty formalin-fixed embedded tissue sections from dogs affected with lymphoma during 2002–2008 at the Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University were retrospectively studied. Results indicated that the prevalence of canine lymphoma occurred at the average age of 7.6 years old. Of the total 40 samples, 67.5 % (27/40) and 32.5 % (13/40) were found among pure breeds and mixed breeds, respectively. The tumors were classified by anatomical locations: multicentric (25/40, 62.5 %), mediastinal (2/40, 5.0 %), alimentary (2/40, 5.0 %), extranodal (7/40, 17.5 %), and cutaneous (4/40, 10.0 %). The clinical stages are divided as 7.5 % (3/40), 17.5 % (7/40), 17.5 % (7/40), 45.0 % (18/40), and 12.5 % (5/40) in stages I–V, respectively. Histopathology categorization of the lymphomas into low and high grade was accounted for 34 % (17/40) and 46 % (23/40) cases, in that order. Both immunophenotyping cases were 50 % (20/40) of T-cell (CD3 expression) and B-cell (IgM expression) lymphomas. T-cell phenotype showed higher malignancy than B-cell phenotype.     

Clinical evaluation of canine mast cell tumor treatment between combined vinblastine and prednisolone and single prednisolone

Thirty three dogs having cutaneous mast cell tumors (MCT) were divided into two groups; group 1 had 23 dogs that were treated with vinblastine and prednisolone and group 2 had 10 dogs that were treated with prednisolone. Evaluation of the 33 pre- and post-treated tissue samples was performed on their clinical stages, histopathological features, expression of proliferative markers such as argyrophilic nucleolar organizer regions (AgNORs), proliferative cell nuclear antigen (PCNA) and Ki-67 and clinical response. All cases were diagnosed as MCT grade II without post-treatment changes in histopathological grade. An increase of uniform nucleus, stroma but a decrease of cytoplasm, the number of visible nucleolus, intralesional vascularization, eosinophilic aggregation, and the mean of mitotic index (pretreatment = 1.6 cells/HPF, post-treatment = 1.1 cells/HPF) was observed in the post-treated samples of both groups. With regard to the clinical evaluation, 18 dogs (78.2%) were partially responsive and the rest (21.8%) were stable in group 1 while five dogs (50%) were partially responsive, three dogs (30%) were stable, and the remaining two dogs (20%) were progressive in group 2. The median survival time of the group 1 cases was 101 days and for the group 2 cases was 175 days. In addition, mean ± standard deviations of AgNORs (dots/cell), PCNA (%), and Ki-67 (%) were 1.83 ± 0.4, 18.67 ± 9.25, and 6.86 ± 7.23 in the pretreatment group 1 and 1.59 ± 0.3, 12.4 ± 7.15, and 1.9 ± 1.35 in the post-treatment group 1, respectively. Mean ± standard deviations of AgNORs, PCNA and Ki-67 were 1.83 ± 0.42, 18 ± 20.01 and 6.74 ± 5.42 in the pretreatment group 2 and 1.67 ± 0.28, 6.28 ± 5.59 and 2.3 ± 1.55 in the post-treatment group 2, respectively. All proliferative markers decreased differently statistically after treatment (P < 0.05). In conclusion, the MCT dogs treated with vinblastine and oral prednisolone and single oral prednisolone were shown to have a decrease in histopathological malignancy characteristics which included AgNORs, PCNA, Ki-67 indices.     

Suppressive effects of Moringa oleifera Lam pod against mouse colon carcinogenesis induced by azoxymethane and dextran sodium sulfate

Moringa oleifera Lam (horseradish tree; tender pod or fruits) is a major ingredient in Thai cuisine and has some medicinal properties. Previous studies have shown potentially antioxidant, antitumor promoter, anticlastogen and anticarcinogen activities both in vitro and in vivo. The present study was conducted to investigate chemopreventive effects on azoxymethane (AOM)-initiated and dextran sodium sulfate (DSS)-promoted colon carcinogenesis in mice. Male ICR mice were divided into 8 groups: Group 1 served as a negative control; Group 2 received AOM/DSS as a positive control; Groups 3-5 were fed boiled freeze-dried M. oleifera (bMO) at 1.5%, 3.0% and 6.0%, respectively supplemented in basal diets for 5 weeks; Groups 6-8 were fed with bMO diets at the designed doses above for 2 weeks prior to AOM, during and 1 week after DSS administration. At the end of the study, colon samples were processed for histopathological examination. PCNA indices, and iNOS and COX-2 expression were assessed by immunohistochemistry. The results demonstrated the incidences and multiplicities of tumors in Groups 6-8 to be decreased when compared to Group 2 in a dose dependent manner, but this was significant only in Group 8. The PCNA index was also significantly decreased in Group 8 whereas iNOS and COX-2 protein expression were significantly decreased in Groups 7 and 8. The findings suggest that M. oleifera Lam pod exerts suppressive effects in a colitis-related colon carcinogenesis model induced by AOM/DSS and could serve as a chemopreventive agent.     

Histopathological changes and apoptosis detection in canine myxomatous mitral valve disease using tissue microarray technique

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs. The etiology of MMVD is currently unclear. The cell density has been found increasingly in myxomatous mitral valves. The proliferation is unlikely a major mechanism of increased cell density in diseased valves. Other mechanisms such as anti-apoptosis or cell migration may be involved. The objective of this study was to determine the apoptotic cells within MMVD valves by assessing the immunoreactivity of cleaved caspase-3 and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay using tissue microarray technique. Fifteen normal and 40 MMVD valves were included in the study. TUNEL marker and cleaved caspase-3 expressions were significantly decreased in myxomatous valves compared to normal valves (p?Apoptotic bodies were hardly seen in normal and diseased valves. These findings suggest a relationship between the anti-apoptotic mechanism and increased cellularity in canine MMVD.     

Chemopreventive Effects of Eryngium foetidum L. Leaves on COX-2 Reduction in Mice Induced Colorectal Carcinogenesis

To investigate the potential effects of Eryngium foetidum Linn. leaves (EF) in colitis-induced colorectal carcinogenesis in mice by azoxymethane (AOM) and dextran sulfate sodium (DSS), 39 ICR male mice were studied and divided into 6 groups. The mice were received a modified AIN-76 diet in Group 1, whereas Group 2 was given an AOM, DSS, and AIN-76 diet. Groups 3 and 4 were fed with 0.8% and 3.2% freeze-dried EF with AIN-76 diets, for 5 wk. Groups 5 and 6 were fed with 0.8% and 3.2% EF diets for 5 wk during AOM/DSS administration. The mice were necropsied at Week 20 and their colons were collected. The results indicated that the incidences of tumors in Groups 2, 5, and 6 was 100%, 75%, and 88%, with multiplicities (mean ±SE) of 3.75 ±0.92, 2.38 ± 0.96 and 4.25 ± 0.79, respectively. Interestingly, there was a significant difference in COX-2 expression in mice received 3.2% EF in their diet, but the proliferative cell nuclear antigen index and iNOS protein expression were not significantly different. We concluded that EF at a dose level of 3.2% in their diet had a preventive effect on colorectal carcinogenesis via the proinflammatory cytokine, COX-2.