Biomedical subjects

L C Kelley

Publications and source records attributed to L C Kelley.

23 records · Page 2Linked to original sources

PubMed1991

Comparative study of colonizing and noncolonizing Campylobacter jejuni.

Campylobacter jejuni A74/O and A74/C are congenic strains. An oral dose of 10(5) organisms of strain A74/C colonizes chicken intestines. Strain A74/O, from which A74/C is derived, does not colonize the chicken intestines with an oral dose of 10(5) organisms. In this study, the congenic bacteria were compared to identify possible colonization mechanisms. Differences were not observed in plasmid content or by HindIII, Pst I, Acc I, HincII, Ava I, Ava II, Xba I, and BamHI restriction enzyme digestion of total DNA. Transmission electron microscopy of negatively stained samples revealed no differences between the strains. Sections of cecal tissue from nonfed day-of-hatch chicks were cultured with each strain for 2 hours and then examined by light and electron microscopy. Both strains caused necrosis of villus epithelial cells. Immunofluorescent or silver staining revealed strain A74/C located deep in numerous epithelial crypts, but strain A74/O only was present in one sample mixed with sloughed necrotic cells. Similarly, organisms were detected by transmission electron microscopy deep in crypts in tissues cultured with A74/C, but not A74/O. Cells of A74/C detected in crypts did not appear to associate with epithelial cells. The strains did not differ in chemotactic behavior to mucin or fucose.

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PubMedDate not supplied

Visceral granulomas in chickens infected with a filamentous bacteria.

Visceral granulomas containing gram-positive filamentous bacteria were diagnosed in eight chickens collected from processing plants over a period of 4 years. Formalin-fixed tissues were submitted from the chickens after slaughter, but no specimens suitable for bacterial culture were received. The bacteria lacked similar tinctorial, morphologic, and ultrastructural features of other gram-positive bacteria that have been identified in chickens. The bacteria were visible with hematoxylin and eosin and faintly visible with Gomori methenamine-silver, but negative with periodic acid-Schiff and Fite-Faraco acid-fast stains. Granulomas were found in the liver, spleen, and peritoneum.

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PubMedDate not supplied

Hepatic protoporphyrin accumulation in a broiler chicken.

Hepatocellular accumulation and biliary excretion of protoporphyrin in a 6-week-old chicken are described. The affected liver was grossly dark gray to black. Histologically, hepatocytes, bile canaliculi, and bile-duct lumina contained dark-brown granules. These protoporphyrin pigment accumulations were brightly birefringent under polarized light. The ultrastructural appearance of granules revealed hair-like crystals in a radial arrangement. Extracted levels of protoporphyrin in the affected liver were determined to be 630 micrograms per gram of wet (frozen) liver. Spectrofluorometric scans of liver extracts and sedimented crystals were characteristic of protoporphyrin.

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PubMedDate not supplied

Multicentric histiocytosis in young chickens. Gross and light microscopic pathology.

During 1991-94, tissue specimens from 262 young chicken carcasses condemned at slaughter contained novel multicentric proliferations of histiocytelike cells. These tissues had been submitted to the USDA FSIS Eastern Laboratory because of grossly enlarged spleens, livers, or kidneys. The spleens were two to three times normal diameter and contained miliary white or yellow 1-3-mm foci. Similar miliary foci were present throughout the enlarged livers and kidneys. Microscopic examination of these tissues revealed discrete circular nodules expanding splenic periarteriolar lymphoid sheaths, hepatic periportal nodules, and discrete perivascular and more diffuse interstitial nodules replacing renal tubules. Nodules also were present in the pancreas, bone marrow, proventriculus, and lung, with more diffuse infiltrates in intestinal lamina propria. The cells composing these nodules contained irregularly oval, folded, or pleomorphic nuclei and relatively abundant eosinophilic cytoplasm. Mitotic figures and pyknotic nuclei were common. These cells were interpreted to be histiocytes (tissue macrophages or dendritic cells) and did not resemble lymphocytes. These proliferating cells also did not resemble the cell population of commonly diagnosed lymphoid neoplasms of young chickens. No intralesional organisms were detected and polymerase chain reaction analysis failed to detect Marek's herpesvirus DNA or leukosis/sarcoma and reticuloendotheliosis proviral DNA.

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PubMedDate not supplied

Pulmonary sarcomas in a young chicken.

Both lungs of a 5-wk-old broiler chicken contained miliary, round, white tumors. Microscopically, these masses were composed of compactly arranged cells with round to oval nuclei and indistinct cytoplasmic borders. Immunohistochemically, tumor cells were positive for vimentin but negative for cytokeratin, S-100 protein, neuron-specific enolase, smooth muscle actin, and muscle-specific actin. Ultrastructurally, tumor cells were separated by collagen bands and some contained collagen fibrils. These results suggest that the primitive mesenchymal cells composing these sarcomas may have originated from precursors of interstitial cells or fibroblasts of the interparabronchial or interatrial septa. DNA was extracted from paraffin-embedded tissues and probed for sequences specific for Marek's disease virus, reticuloendotheliosis viruses, exogenous avian leukosis viruses, and subgroup J avian leukosis viruses. Only sequences specific for subgroup J avian leukosis viruses were identified in the DNA extracted from tumors and surrounding lung.

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