(J Clin Pathol 1998;51:512-514)

No abstract

No abstract

Studies on this immunological component in critically ill patients are limited by ethical and therapeutic constraints; however, suitable tissues may be obtained from patients whose condition necessitates surgical removal of part of the small bowel. A series of such specimens was retrieved for the present study. Tissues from near the excision margins considered viable by the surgeons and judged to be relatively remote from the primary intraabdominal damage by the pathologists-were selected for immunohistochemical studies. Methods PATIENTS AND TISSUESBlocks from the small intestines of 17 patients were taken from the files of the Department of Pathology, Aberdeen Royal Infirmary, Scotland (12 patients: six males, aged 54-78; six females, aged 34-79), and the Department of Surgery, Universidade Federal de Pernambuco, Recife, Brazil (five patients: one male, aged 39; four females, aged 57-79). All of the Aberdeen cases had presented with an acute abdomen; 11 had infarction of the small bowel attributed to a variety of thrombotic or mechanical causes. The Recife cases met the same criteria for selection. One Aberdeen case had a perforated ulcer. Controls were normal small intestine from two transplant donors. Tissues had been fixed in 10% neutral buffered formalin and processed to paraffin wax. Sections of 4 ztm were cut onto 3-aminopropyltriethoxysilane-subbed slides and dried at 60°C for 30 minutes. IMMUNOHISTOLOGYSections were first dewaxed in xylene and endogenous peroxidase blocked using 1.5% hydrogen peroxide in methanol. Optimal unmasking of antigens other than IgM was obtained by placing sections in 10 mM citrate buffer, pH 6.0, in an 800 W microwave oven operated on full power for 20 minutes, maintaining the level of buffer at 600 ml. Sections were left in hot buffer on the bench for a further 20 minutes prior to transferring to Tris buffered saline (TBS). IgM was exposed by digestion in 0.1% trypsin in 0.1% calcium chloride at 37°C, pH 7.8, for 30 minutes, followed by five-minute washes in running water (once) and TBS (twice).Murine monoclonal antibodies against IgM

A group of youngsters (4-18 years old) in northeast Brazil

No abstract

The fine structure of the pancreas of the South American three toed sloth, Bradypus trídactylus, is described. In exocrine cells two types of granules are found. The first variety of granules is circular, of about 0.9 µm mean diameter, and probably represents zymogen granules. The second type of granule is larger (up to 1.4 µm in diameter) and contains a granular electron-dense material which is separated from the limiting membrane by a wide space. Only one type of islet cell was found. It contains spherical membrane-bound granules of uniform size.

Differing from the studied Eutheria the white belly opossum Peyer's patches do not present a conspicuous dome. M cells are located in the inner layer of bilaminal formed at the bottom of the villi. A great variation in the morphology of M cells was observed. The enterocytes located at the epithelial inner layer may present endocytic vesicles, and the microvilli are shorter than the microvilli of enterocytes lining the small intestine. As these morphological aspects have been described to exist in the enterocytes of the lactent opossum small intestine it was surmised that the opossum Peyer's patches special epithelium could represent the persistence in adult animals of a cellular pattern established before the intestinal maturation had occurred.