v.3, n.1, 01
Download full article – 01: V.3,-N.1,-01-20881_2010_4_29_32_23
v.3, n.1, 02
Intestinal pathogens are exposed to various stress conditions during their infectious cycle. Anaerobiosis, one of such hostile condition, is offered by the host within gut and intestinal lumen, where survival, multiplication and entry into intestinal epithelial cells are priority for the invasion of the pathogen. The fumarate reductase (frdABCD),dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. Vitamin B12 (cobalamin) is synthesized by SalmonellaTyphimurium only under anaerobic growth conditions used as a cofactor in four known reactions. The deletion of cobS and cbiA genes prevent any form of cobalamin production. In the present study we evaluate the infection of birds by mutants of STM, with the anaerobic respiratory system committed by mutations in the genes: narG, napA, cobS, cbiA, frdA, dmsA, and torC. Virulence was assessed by oral inoculation of groups of one-day-old broilers with 0.1 mL of culture contained 108 colony forming units (CFU)/mLdiluted at 10-3 and 10-2 of strains mutants of Salmonella Typhimurium. Clinical signs and mortality were recorded over a period of 21 days. In general, the symptoms of chickens infected with the mutant strains were similar to those presenting by control birds. Except for STMNalr &916;cbiA, all showed reduced capacity to cause mortality in comparison with the original strain. The mortality of group of chickens infected with STMNalr &916;narG, STMNalr &916;frdA, STMNalr &916;dmsA and STMNalr&916;cobS&916;cbiA showed significant decrease in mortality compared to control group (p<0.05).
Key Words: Salmonella Typhimurium, respiration, anaerobic, gene.
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v.3, n.1, 03
Experimental models for hepatic lesions are necessary so the effectiveness of new drugs in reversing cirrhosisfibrosis can be tested. This is the case of liver cirrhosis, which requires animal models. Three drugs widely used to induce cirrhosis in animal models are carbon tetrachloride (CCI4), Dimethylnitrosamine (DMN), and Thioacetamide (TAA). TAA has been largely used, but a model that confirms the occurrence of chronic cirrhosis in rats has not yet been well defined. In this study we developed a model of chronic cirrhosis induced by TAA in rats. Our cirrhotic protocol used 200 mg of TAA in 4% aqueous solution per kg of body weight applied intraperitoneally three times per week for 14 weeks in Wistar rats. On the seventh week the dose was increased by 20%. Our protocol caused low mortality rate and represents an alternative and valid model for chronic cirrhosis.
Key Words: animal model, fibrosis, chronic cirrhosis, rat, thioacetamide.
Download full article – 03: V.3,-N.1,-03-20881_2010_4_29_33_51
v.3, n.1, 04
Astroglial cells are the most abundant cells in the mammalian central nervous system, yet our knowledge about their function in bovine Herpesvirus type 5 (BoHV-5) has been limited. The aim of this study was to detect by immunohistochemistry assay the reactive astrocytes for glial fibrilary acidic protein (GFAP) and vimentin (VIM), considered intermediate filaments of the cytoskeleton, localized in olfactory bulb from natural acute cases of BoHV-5 infection. All samples were submitted to virus isolation, real-time polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) technique to confirm the virus transcription and respective genome. Samples were classified into four groups according to the severity of histological lesions. Groups III and IV, which histological lesions were classified as alacia, gliosis, satellitosis, neuronophagia and neuronal necrosis, 35% (± 1.8-2.1) of the inflammatory mononuclear cells, corresponded to CD3 positive lymphocytes. In the same group, 35% (± 1.8) of astrocytes were described as reactive to GFAP and VIM proteins. An agreement of r = 1.0 (P<0.0001) was found between histological lesions, intermediate filaments expression, viral DNA and transcription and CD3 lymphocytes. However, samples with mild histological lesions, 10.8 to 14.2% of astrocytes were classified as reactive to GFAP and VIM filaments. Our findings suggest that GFAP and VIM reactive astrocytes, in primary site of virus replication, seems to play an important role in neurovirulence, in spite of many questions concerning the virus immunopathology remains unclear.
Key Words: Bovine Hespesvirus, BoHV-5, Neuropathology, GFAP, VIM.
Download full article – 04: V.3,-N.1,-04-20881_2010_4_29_34_20
v.3, n.1, 05
Angiogenesis is involved in several physiological and pathological processes, and the proliferation of endothelial cells is a central event in the generation of new blood vessels. Gap junctions (GJ) are membrane structures that communicate adjacent cells, contribute to tissue homeostasis, and are important to the control of cell proliferation. Connexins (Cxs) are the proteins that form gap junctions. Endothelial cells may express Cx43, Cx37 and Cx40. In this study, we analyzed the effect of the heterologous deletion of the Gja1 (Cx43 gene) on the development of newly formed blood vessels (NFBV) in the mouse cornea. Heterozygous (Cx43+/-) and wild-type (Cx43+/+) mice were submitted to the silver crystal corneal cauterization model. Two parameters were quantified by image analysis 26 days after cauterization: NFBV density and length. At days 2 and 6 after corneal cauterization, Cx43+/- mice showed smaller density of NFBV as compared to Cx43+/+ mice. Therefore, deletion of one Gja1 allele (connexin-43 gene) may lead to impaired cell-cell communication in endothelial cells, diminishing angiogenesis after cauterization of the mouse cornea.
Key Words: gap junctions, connexin, Gja1, angiogenesis, endothelial cell, cornea
Abbreviations: GJ: gap junctions, Connexin 43: Cx43; Connexin 37: Cx37, Connexin 40: Cx40; Cx43+/+ wild type mice; Cx43+/- heterozygous mice; NFBV: newly formed blood vessels, Gja1: gap junction alpha 1
Download full article – 05: V.3,-N.1,-05-20881_2010_4_29_34_44
v.3, n.1, 06
COX-2 and TGF-&946; expression was determined in order to correlate non-neoplastic lesions, preneoplastic lesions and carcinoma in the prostate of dogs. The results show that neoplastic and preneoplastic lesions express more COX-2 and TGF-&946; when compared to carcinomas, which suggests these proteins may cooperate in the process of prostate tumorigenesis.
Key Words: carcinoma prostate, COX-2, dog, preneoplastic lesions, TGF-&946.
Download full article – 06: V.3,-N.1,-06-20881_2010_4_29_35_14
v.3, n.1, 07
Rabbits were experimentally infected with sporulated Eimeria stiedai oocysts. A total of 50 white adult rabbits, New Zealand race, were distributed into two groups: group A was infected with 1×104 sporulated Eimeria stiedai oocysts, while group B was inoculated with distilled water as a control. The animals generally displayed increased levels of total protein, globulin, total cholesterol, LDL-c and triacylglycerols; however, total levels of liver lipids and HDL-c decreased, and plasma glucose levels varied during the experimental period. In sum, Eimeria stiedai infection of rabbits caused a considerable number of changes in the metabolism of lipids, proteins and glucose, which is likely due to direct effects of liver cirrhosis on normal body function.
Key Words: Eimeria stiedai, Apicomplexa, metabolism, rabbits.
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v.3, n.1, 08
The present study was designed to investigate the significance of mitotic index and AgNOR count in canine mammary tumours. Samples from 74 grossly suspected cases of bitches for mammary tumour were collected from different veterinary hospitals in 10% buffered formalin, of which 65 were confirmed as tumours on histopathological examination. Among them, 11 (16.92%) were benign and 54 (83.08%) were malignant tumours. Benign tumours included benign mixed mammary tumour (36.36%), fibroadenoma (27.27%), duct papilloma (18.18%) and simple adenoma (18.18%). The malignant mammary tumours comprised of papillary adenocarcinoma (27.78%), malignant mixed mammary tumour (25.92%), solid carcinoma (18.52%), squamous cell carcinoma (5.56%), fibrosarcoma (5.56%), infiltrative adenocarcinoma (3.7%), mucinous carcinoma (3.7%) and each (1.54%) of osteochondrosarcoma, carcinosarcoma, myxosarcoma, intraductal carcinoma and spindle cell carcinoma (malignant myoepithelioma). Mitotic index and AgNOR counts were significantly (P<0.05) differ for benign and malignant mammary tumours. Among malignant mammary tumours mitotic index ranged from 1.08 to 4.19 with solid carcinoma showing the highest index (4.197±1.570) and osteochondrosarcoma the lowest (1.08±0.0) while in benign mammary tumours, it ranged from 0.63 t0 0.9. AgNOR counts were significantly lower (2.57± 0.68) in benign mammary tumours than malignant (3.38±1.01). From this study it was concluded that mitotic index and AgNOR count was a good indicator of transformation of tumours towards the malignancy.
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v.3, n.1, 09
Connexin (Cx) expression is reportedly altered in neoplasms. This study aimed to investigate the expression of Cx43, 26 and 32 in normal and pathological canine perianal glands. Thirty perianal glands bearing pathological processes and ten normal canine perianal glands were submitted to immunohistochemistry to search for presence of Cx43, Cx26 and Cx32. Both Cx43 and Cx26 expressions were observed in normal, hyperplastic glands, and in well and moderately differentiated adenomas. However, in poorly differentiated adenomas, expressions were reduced, and they were absent in carcinomas. Cx26 was located in the cytoplasm of normal, hyperplastic perianal gland cells, and in well and moderately differentiated adenomas. Cx32 was not observed in any neoplasm neither in normalhyperplastic glands. Our results show that Cx43 and Cx26 expressions are altered in more aggressive canine perianal gland neoplasms, and we conclude that they may be related to the perianal gland carcinogenesis process.
Key Words: perianal gland, connexins, neoplasia, hyperplasia, gap junctions
Download full article – 09: DOWNLOAD-FULL-ARTICLE-09-20881_2010_5_10_59_41
v.3, n.1, 10
The aim of this study was to detect the presence of Helicobacter infection inThoroughbred in Venezuela. One hundred and thirty six Thoroughbreds with signs for Equine gastric ulcer syndrome (EGUS) were studied in the National Race Track La Rinconada Caracas Venezuela. Necropsies were performed in all horses and samples of gastric tissue were collected. The tissue samples were fixed in formalin and processed by conventional H&E techniques. Additionally, the special staining procedure of Warthin-Starry, Giemsa and Blue Toluidine were also carried out. Ureasa test: rapid ureasa test (commercial kit) was performing of gastric tissue. The damage of the gastric mucosae in the animals was categorized as 2/136 Grade 0 Epithelium is intact throughout; no hyperemia, no hyperkeratosis. Grade 1 Mucosa is intact but there are areas of hyperemia and/or hyperkeratosis 26/136. Grade 2 small, singlemulti-focal erosionsulcers 38/136.Grade 3 Large, singlemulti-focal ulcers,extensive erosions and sloughing 36/136. Grade 4Extensive ulcers, with areas with deep submucosal damage 34/136. Using the Warthin-Starry special stain, Giemsa and Blue Toluidine with spiral-shaped bacteria were evidenced found in 52, Grade 1: 13/52, Grade 2: 10, Grade 3: 16, Grade 4: 13. There seemed to be no association between Warthin-Starry, Giemsa and Blue Toluidine stain with the grade and location of lesions. Urease activity was then demonstrated in fifty-twoequine. To conclude, we detected the presence of Helicobacter Like Organisms in the gastric mucosa from thoroughbred horses with EGUS.
Key Words: Helicobacter, gastric ulcer, equine gastric ulcer syndrome, horse, Thoroughbred horse
Download full article – 10: V.3,-N.1,-10-20881_2010_4_29_37_24
v.3, n.1, 11
A 10-year-old, female, mixed-breed cat was presented for necropsy with history of inccordination circling and nystagmusfixed gaze. Grossly, slight asymmetry was observed in the right telencephalic hemisphere, mainly in the pyriform lobe. Histologically, sheets of small round neoplastic cells were observed in the pons, midbrain, thalamus and in the subcortical white matter of the parietal, occipital and pyriform lobes. Neoplastic cells were strongly labeled with anti-CD3 antibody by means of immunohistochemistry. Anti-BLA36, CD79a and MAC387 failed to label the neoplastic cells. Based on the histopathological findings and on the immunohistochemical results, a diagnosis of primary brain T-cell lymphoma was made.
Key Words: cat diseases; T-cell lymphoma; CNS neoplasia; neuropathology.
Download full article – 11: V.3,-N.1,-11-20881_2010_4_29_38_23
v.3, n.1, 12
A nine years old, Graded Murrah she buffalo was presented to local Veterinary dispensary with clinical signs of raised elevations of growths on the pinna of right ear near its base and lateral aspects showing ulceration, necrosis, scales, crusts and scabs. Histopathologically, the tissue sections from the growth revealed groups, islandscords of neoplastic squamous epithelium with epithelial pearls at some places. By immunohistochemistry, proliferating epithelial cells were positive for cytokeratin and expressed PCNA. Based on gross, histologic and immunohistochemical findings, the growth was diagnosed as cutaneous squamous cell carcinoma of ear.
Key Words: Indian water buffalo, ear, squamous cell carcinoma, histopathology, immunohistochemistry
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v.3, n.1, 13
A 12 years old ferret was attended with clinical history of prostration and anorexia. The animal died a few hours after consultation. After necropsy, a histopathological exam of a liver tumor was carried out. The morphologic diagnosis was consistent with multicentric lymphoma. Immunohistochemical exam of the neoplastic cells was made additionally, and confirmed the diagnosis of T-cell lymphoma.
Key Words: lymphoma, T-cell lymphoma, ferret, exotic animals, neoplasia
Download full article – 13: V.3,-N.1,-13-20881_2010_4_29_39_44
v.3, n.1, 14
Perineuriomas are slow growing tumors, exclusively compound of well-differentiated perineurial cells. They are rare in human and canine. A dog was submitted to necropsy with a clinical diagnosis of myelin sheath tumor in the brachial plexus area. Slides of the tumor were treated with histochemistry and immunohistochemistry techniches and the diagnostic of perineurioma intraneural was established.
Key Words: peripheral nerve sheath tumors, perineurioma, epithelial membrane antigen
Download full article – 14: V.3,-N.1,-14-20881_2010_4_29_40_56
v.3, n.1, 15
Polioencephalomalacia (PEM) of ruminants is a complex disease. The term indicates a morphological diagnosis where severe cortical neuronal necrosis results in softening of cerebral grey matter. Initially though as a single disease caused by thiamine deficiency, it is currently believed that PEM is caused by different etiological agents through different pathogenic mechanismstrough a single pathogenic mechanism triggered by different agents. In this paper the putative cases and pathogenesis of PEM in ruminants are critically reviewed and discussed. Also reviewed are the epidemiology, clinical signs, gross and histological findings and methods of diagnosis of cases of PEM described in ruminants in Brazil
Key Words: Diseases of cattle, neuropathology, polioencephalomalacia
Download full article – 15: DOWNLOAD-FULL-ARTICLE-15-20881_2010_5_1_20_22