Veterinary pathology. Supplement最新文献

Light and electron microscopy showed gastric spirilla in the gastric mucosa of 45 clinically normal rhesus monkeys (Macaca mulatta). In paraffin sections, gastric spirilla were best shown by silver impregnation stains. When stained by hematoxylin and eosin (HE), gastric spirilla may be mistaken for strands of mucus. In thick sections of epon-embedded tissue, gastric spirilla looked like "corkscrews" with up to 12 coils. They were 8 microns long and 0.7 micron wide, and had characteristic bipolar flagella. They were concentrated in the gastric glands at the isthmus, were less common at the neck and base, and were absent in the gastric lumen. Gastric spirilla were associated closely with parietal cells and could penetrate their cytoplasm. Gastric spirilla elicit neither changes of host cytocomponents nor an inflammatory response in the gastric mucosa.

Light and electron microscopy showed gastric spirilla in the gastric mucosa of 45 clinically normal rhesus monkeys (Macaca mulatta). In paraffin sections, gastric spirilla were best shown by silver impregnation stains. When stained by hematoxylin and eosin (HE), gastric spirilla may be mistaken for strands of mucus. In thick sections of epon-embedded tissue, gastric spirilla looked like "corkscrews" with up to 12 coils. They were 8 microns long and 0.7 microns wide, and had characteristic bipolar flagella. They were concentrated in the gastric glands at the isthmus, were less common at the neck and base, and were absent in the gastric lumen. Gastric spirilla were associated closely with parietal cells and could penetrate their cytoplasm. Gastric spirilla elicit neither changes of host cytocomponents nor an inflammatory response in the gastric mucosa.

In a colony of rhesus monkeys (Macaca mulatta), 42 cases of nontuberculous mycobacterial-related disease were identified from 1970 to 1978. The disease affected young and old colony-born and wild-caught monkeys of both sexes. Serotypes 1, 2, 4, 8, and 18 of the Mycobacterium avium-intracellulare group were isolated from different monkeys. The lesions were primarily intestinal in 36 monkeys. Lesions of the large intestine, small intestine, and mesenteric lymph nodes were characterized by diffuse accumulations of large macrophages containing many acid-fast bacteria. Acid-fast bacteria could not be identified histologically in four monkeys with typical histories of diarrhea and weight loss, positive skin reactions to the tuberculin test with M. avium tuberculin, and isolation of the organism from tissues on one or more occasions. Two monkeys had histologically positive lesions limited to the lungs, although chronic colitis of undetermined cause was present.

Features and pathogenesis of adenoviral pancreatitis in rhesus monkeys were studied with an immunofluorescence staining procedure on tissues from two previously documented cases. Fluorescing adenovirus antigen in epithelial cells of the pancreatic ducts, duodenum, and jejunum suggests that under as yet undefined conditions, a primary adenovirus infection of the gastrointestinal tract ascends to the pancreatic parenchyma via pancreatic ducts. In a retrospective survey, over 3,000 microslides of pancreas taken at necropsy from several species of nonhuman primates (1,002 animals) were studied to determine the incidence of and species susceptibility to adenoviral pancreatitis. Other than the two documented cases from our files, we found comparable lesions in only one rhesus monkey. Adenoviral pancreatitis seems to be a distinct entity in rhesus monkeys, and it should be considered when pancreatitis is found in this species. Our findings also suggest a possible viral cause for some cases of pancreatitis in man.

Intestinal spirochetosis, an infection of the mucosa by spiral-shaped organisms, was studied in clinically normal rhesus monkeys (Macaca mulatta) by histology, transmission and scanning electron microscopy. The incidence of intestinal spirochetosis was 42% in 221 monkeys. Spiral organisms stained with hematoxylin and eosin (HE) appeared as a broad basophilic haze on the colonic surface and were strongly positive by the Warthin-Starry stain. Spiral-shaped bacteria include two structurally different organisms: spirochetes and flagellated microbes. They intimately populated the brush border of the surface of the epithelium of the large intestine. They were absent in the crypts and in the small intestine. Infection by spirochetes produced no alteration of cytocomponents of the underlying host structures. Spirochetes and flagellates infrequently penetrated beyond the brush border into the epithelial cytoplasm and also into the lamina propria. Even in cases where invasion was documented, no inflammatory response was found.

Sections of pancreas from 21 nonhuman primates with diabetes mellitus were examined by light and electron microscopy. All monkeys showed amyloid accumulation in the islets of Langerhans. Amyloid was identified by its dichroism with three different stains: Congo red, changing from red to yellowish-green; standardized toluidine blue, changing from blue to red; and sulfated alcian blue, changing from blue-green to pink. Sulfated alcian blue was a rapid and effective means of detecting amyloid. The characteristic fibrillar structure of amyloid was seen with transmission electron microscopy. Deposition of islet amyloid was independent of the presence or absence of amyloid in other organs. Results indicate that nonhuman primates offer a model for studying the sequential development of insular amyloidotic diabetes mellitus.

A review of the literature concerning the gross and histologic lesions associated with protozoal and metazoal parasitism in the alimentary tract and pancreas of nonhuman primates is presented. In addition, the natural history, morphology, life cycle, methods for diagnosis, and potential for zoonotic disease are reviewed briefly for each parasite discussed. The parasite species reviewed in detail are those most common or most likely to produce lesions in the alimentary tract and pancreas of the nonhuman primate host. All parasites, both pathogenic and nonpathogenic, in each major group (protozoa: flagellates, sarcodines, sporozoans, neosporans, and ciliates; and metazoa: trematodes, cestodes, nematodes, acanthocephalans, and pentastomids) that have been reported in the nonhuman primate alimentary tract and pancreas are presented in tables.

The phylogenetic relationship of nonhuman primates to man implies that many of these animals could serve as surrogates for studies of diseases of man. Many nonhuman primate species are susceptible not only to viruses of human origin but also to nonhuman primate viruses that are counterparts of viruses of man. All monkeys and great apes do not respond similarly to an antigenic stimulus. Some agents are highly pathogenic for one species and completely innocuous for another. For example, poliovirus causes disease and fatalities in great apes, but picornaviruses given orally cause few lesions in most nonhuman primates. Other enteroviruses (coxsackie-, echoviruses) have caused disease in nonhuman primates. It is difficult to separate viruses into distinct categories according to their anatomic affinities. Many viruses not considered to be enteric may be recovered from the intestinal tract. Adenoviruses, both human and nonhuman strains, which are not considered enteric viruses, nonetheless are recovered frequently from the intestinal tract. Adult animals show little evidence of disease, with the possible exception of diarrhea, after adenovirus infection. Newborns, however, may respond with a fatal pneumoenteritis. Adenovirus may be associated with diseases in organs other than the intestines. The reoviruses, which may be recovered from the intestinal tract, also are generally innocuous. Rotaviruses as pathogens in nonhuman primates are presently under study, and it is suspected that rotaviruses of man may produce experimental disease in nonhuman primates. Production of diabetes by several of the enteric viruses has been suggested but not demonstrated conclusively.

Intestinal spirochetosis, an infection of the mucosa by spiral-shaped organisms, was studied in clinically normal rhesus monkeys (Macaca mulatta) by histology, transmission and scanning electron microscopy. The incidence of intestinal spirochetosis was 42% in 221 monkeys. Spiral organisms stained with hematoxylin and eosin (HE) appeared as a broad basophilic haze on the colonic surface and were strongly positive by the Warthin-Starry stain. Spiral-shaped bacteria include two structurally different organisms: spirochetes and flagellated microbes. They intimately populated the brush border of the surface of the epithelium of the large intestine. They were absent in the crypts and in the small intestine. Infection by spirochetes produced no alteration of cytocomponents of the underlying host structures. Spirochetes and flagellates infrequently penetrated beyond the brush border into the epithelial cytoplasm and also into the lamina propria. Even in cases where invasion was documented, no inflammatory response was found.

Reported gastrointestinal neoplasms in nonhuman primates are reviewed, and the clinical and pathologic features of 11 new cases are described. The 11 monkeys had a total of 12 malignant gastrointestinal neoplasms; one had two primary carcinomas, one in the colon and one in the duodenum. Ten of the 12 tumors were adenocarcinomas: two in the duodenum, one in the jejunum, four in the distal ileum or region of the ileocecal valve and three in the large intestine. The remaining two lesions were a histiocytic lymphosarcoma of the stomach and a poorly differentiated sarcoma of the cecum. The 11 animals included nine Macaca mulatta, one Saguinus oedipus oedipus and one Galago crassicaudatus. All were adults and most were aged. There were six females and five males. Clinical signs included progressive weight loss, a palpable abdominal mass and intermittent diarrhea. Grossly, five of the adenocarcinomas were annular, and constricted the intestinal lumen. Microscopically, the carcinomas generally were well differentiated, and two produced mucin in quantities warranting the modifier "mucinous" adenocarcinoma. All tumors were locally invasive and six of nine monkeys with carcinomas had metastases, with the regional lymph nodes the principal site of involvement.