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Abstract: Background and aims: Endoscopic injection of filler agents into the esophagogastric junction has been developed to augment the antireflux barrier and decrease gastroesophageal reflux (GER). However, evidence of efficacy is lacking and serious complications have been reported in humans. The aim of this study was to assess whether endoscopic implantation of polymethylmethacrylate augments the antireflux barrier in a porcine model for GER. Methods: Large White pigs underwent esophageal manometry, gastric yield pressure (GYP), and gastric yield volume (GYV) measurements and implantation of PMMA in the distal esophagus under general anesthesia. After follow-up of 28 days, esophageal manometry and gastric yield measurements were repeated and animals sacrificed. Results: Implantation of PMMA was performed in 18 animals, and 14 animals survived 28 days. There was a significant increase in GYP (10.7 mmHg versus 8.1 mmHg; p = 0.017) and GYV (997 ml versus 393 ml; p < 0.001) after PMMA implantation, whereas resting LES pressure did not change significantly. Acute inflammatory changes and fibrous tissue deposits were found surrounding the PMMA implants during histology. One animal died after esophageal perforation and three others due to pneumonia (two) and colon perforation (one) in the postoperative period. Conclusions: Endoscopic implantation of PMMA in the distal esophagus augments the antireflux barrier 28 days after the procedure. However, esophageal perforation points to the need for technical refinements to make the procedure safer.

Ten out of 47 calves that were born in a small Brahman herd from southern Brazil developed progressive muscular weakness and tremors, lethargy and poor body condition. Necropsy was performed on three affected animals. The only gross lesion detected was paleness of the muscles of the trunk and limbs. Multiple cytoplasm vacuoles located in different tissues were the principal microscopic lesions. Vacuoles were particularly evident in skeletal muscles and myocardium. PAS-positive granules were numerous in skeletal muscle fibres and Purkinje fibres of the myocardium, but were also observed in the neurons of the brain and spinal cord, and in the vascular smooth muscle fibres from all the examined tissues. Pretreatment with diastase completely abolished the PAS reactivity. The vacuoles reacted strongly to Griffonia simplicifolia II and Concanavalia ensiformes lectins, whose biding pattern has been reported as useful for demonstration of glycogen. Examination of the electron micrographs revealed that glycogen was free within the cytoplasm or accumulated in membrane-bound granules of several tissues, especially in striated muscle, liver and neurons of the CNS. These findings were consistent with generalized glycogenosis.

The clinical, epidemiological and pathological aspects of protothecal mastitis in a Brazilian dairy herd are described. Prototheca zopfiiinfection was diagnosed in 11 of 121 milking cows. Clinical mastitis refractory to usual therapy was observed in 7 cows. Several environmental conditions conducive to the growth of Protothecaspp., such as wetness, muddiness and the presence of organic material, were present in the dairy. Improper milking practices and insanitary infusion of the intramammary antibiotics were also observed. Six cows with protothecal mastitis were slaughtered and the affected quarters of each cow were examined by histology and immunohistochemical staining for bovine keratin and P. zopfii. The histological lesions were characterized by interstitial infiltrates of macrophages, plasma cells and lymphocytes; algae were seen in the alveolar lumen and interstitium. The lack of a positive reaction with an antiserum against bovine keratin in the mammary alveolar epithelial layer in some affected areas suggests destruction of milk-producing tissues, which may be related to the low milk production observed. The algal organisms stained positively with a polyclonal antibody against P. zopfii.

Immunohistochemistry (IHC) of bovine cytokeratin combined with periodic acid-Schiff (PAS) was applied to study the pathogenesis, localization and distribution of Prototheca zopfii in bovine mammary protothecosis. The standard immunohistochemical procedure using anti-bovine cytokeratin was employed before and after PAS staining to optimize this combined method. The best results were obtained when IHC procedures were performed first. Most of the epithelial cells reacted strongly with the pancytokeratin antibody. Protothecal cell walls stained well with PAS. Algal organisms were present within the lumen and between the epithelial lining and basement membrane of the affected alveoli, but not inside the positive mammary epithelial cells. This combined staining method resulted in clear alveolar epithelial detail and good contrast between the epithelial cells and algae, and contributed to studying the pathogenesis of P. zopfii in mammary protothecosis.

A neurologic disease characterized by ataxia, hypermetria, hyperesthesia, and muscle tremors of the head and neck was observed for 2 years in a flock of 28 Anglo-Nubian and Saanen goats on a farm with 5 ha of pasture. Six newborns died during the first week of life, and five abortions were recorded. The predominant plant in the pasture was Sida carpinifolia. The disease was reproduced experimentally in two goats by administration of this plant. Three goats with spontaneous disease and the two experimental animals were euthanatized and necropsied. No significant gross lesions were observed. Fragments of several organs, including the central nervous system, were processed for histopathology. Small fragments of the cerebellar cortex, liver, and pancreas of two spontaneously poisoned goats and two experimentally poisoned goats were processed for electron microscopy. Multiple cytoplasm vacuoles in hepatocytes, acinar pancreatic cells, and neurons, especially Purkinje cells, were the most striking microscopic lesions in the five animals. Ultrastructural changes included membrane-bound vacuoles in hepatocytes, Kupffer cells, acinar pancreatic cells, Purkinje cells, and the small neurons of the granular cell layer of the cerebellum. Paraffin-embedded sections of the cerebellum and pancreas were submitted for lectin histochemical analysis. The vacuoles in different cerebellar and acinar pancreatic cells reacted strongly to the following lectins: Concanavalia ensiformis, Triticum vulgaris, and succinylated Triticum vulgaris. The pattern of staining, analyzed in Purkinje cells and acinar pancreatic cells coincides with results reported for both swainsonine toxicosis and inherited mannosidosis.

Market reports of white striping in broiler breast fillets have been increasing, which has generated concerns in the broiler meat industry regarding negative effects on consumer acceptance. This study was conducted to macro- and microscopically characterize the condition of white striping at varying degrees of severity on Cobb 500 broiler breast fillets slaughtered at 42 d of age. Carcasses of 2,512 broilers presenting white striping were slaughtered and macroscopically classified according to the degree of severity of the striations as moderate or severe; further histological microscopic evaluation demonstrated degenerative myopathy in both moderate and severe cases, but 75% of those breast fillets were classified as moderate. Typically, the samples classified macroscopically as moderate showed microscopic necrosis only (65.17%) or moderate multifocal necrosis (9.83%), whereas those classified as severe showed diffuse and strong necrosis (25.00%). The proliferation of connective tissue was not observed for either of the degrees of white striping investigated, characterizing this profile as an acute occurrence.