Pamela Colony Moxey

Chronic Intestinal Coccidiosis in Man: Intestinal Morphology and Response to Treatment

A patient is described who had intermittent diarrhea for more than 20 years, documented eosinophilia and probable malabsorption for more than 7 years, and intestinal coccidial infestation documented for 10 months by biopsy. A severe mucosal lesion of the small intestine characterized by shortened villi, hypertrophied crypts, and infiltration of the lamina propria with eosinophils, polymorphonuclear leukocytes, and round cells was associated with the intestinal coccidial infestation. Various stages of both the asexual and sexual cycles of Isospora belli were identified in the epithelium of the small intestine with light and electron microscopy. Clinical symptoms and coccidial infestation persisted during administration of quinacrine HCl, nitrofurantoin, tetracycline, and metronidazole. Administration of primaquine phosphate and chloroquine phosphate in combination was associated with a transient (1 month) improvement in symptoms and transient disappearance of coccidia from the gut. Treatment with pyrimethamine and sulfadiazine in combination was associated with prompt disappearance of symptoms and intestinal coccidia and gradual reversion of mucosal histology to normal. The patient has remained asymptomatic without evidence of intestinal coccidial reinfestation for 3 years.

Endocrine cells in the human fetal small intestine.

SummaryIn this report we describe the time of appearance and ultrastructural features of enteroendocrine cells (EECs) in the human fetal small intestine (SB) between 9 and 22 weeks gestation. Thirteen distinctive EECs were identified in fetal SB. Two of these, not found in normal adult SB, appeared within the stratified epithelium of the proximal SB at 9–10 weeks. They were arbitrarily termed “primitive” and “precursor” cells. As in all fetal EECs, the pale cytoplasm of the “primitive” cell contains a distinctive population of secretory granules (SGs). Primitive cell SGs average 200–330 nm; some have dense cores with lucent halos while others are filled with a homogeneous dense or flocculent material. The SGs of the “precursor” cells are larger, averaging up to 1 μm in diameter and their contents vary in electron density. A third group of cells not described in normal adult SB was arbitrarily termed “transitional” cells. These have two populations of SGs; one resembles the SGs of the “precursor” cells, and the other resembles the SGs of some of the specific adult type EECs. Transitional EC, S, I and G cells are seen. In addition, mature appearing EC, S, G, I, L, D, and D1 cells were identified by 12 weeks of gestation. The “primitive”, “precursor”, and “transitional” cells may represent sequential developmental precursors of adult type EECs.

Maturation and Differentiation of Cultured Fetal Stomach: Effects of Corticosteroids, Pentagastrin, and Cytochalasin B

Gastric mucosa of fetal rats undergoes striking developmental changes during the last few days of gestation in utero. To investigate some aspects of this process, gastric explants from 18-day fetuses (4 days before birth) were maintained in organ culture for 3 days, then assessed by light and electron microscopy. The epithelia from base line uncultured stomachs were stratified and morphologically undifferentiated. During culture in basic medium (Leibovitz L 15), modest maturation of antral and fundic architecture occurred, characterized by epithelial invagination to produce small pit-glands. Secretory granules appeared in occasional epithelial cells, and cytochemistry indicated that most were mucous granules. Addition of pentagastrin (10(-9) to 2 X 10(-7) M) did not induce further morphological maturation in this system. However, addition of cortisol (10(-6) to 10(-5) M) resulted in a marked, dose-related increase of pit-gland formation and of cytological differentiation (appearance of secretory granules). This cortisol-induced architectural maturation was completely inhibited by the mold metabolite cytochalasin B (10(-5) M). The results indicate that fetal gastric maturation can be partially reproduced by culture in chemically defined media, and also suggest that corticosteroids may plan an important role in gastric organogenesis.

Epithelial cell proliferation in the intestine of the winter flounder, Pseudopleuronectes americanus

SummaryTo study epithelial cell proliferation in the North American flounder (Pseudopleuronectes americanus), fed and fasted fish received intravenous injections of 3H-thymidine and were killed 11/2 to 2 h later. Radioautographs of proximal, middle, and distal intestinal segments revealed proliferating epithelial cells at all levels of intestinal folds including the crest although labelled nuclei were most abundant in the epithelial cells on the lower half of folds and between folds. Mature appearing goblet cells with labelled nuclei were observed at all levels of the folds. The mean labelling index was greater in the epithelium of fed than fasted flounder. In fed flounder the mean labelling index was greatest in the proximal segment and least in the distal segment; no substantive differences in mean labelling indices were observed in the various segments of intestine from fasted fish. Electron microscopy revealed no major structural differences among epithelial cells along the base of folds compared to cells near the crest of folds. These findings indicate that 1) epithelial cell proliferation occurs at all levels of the folds of flounder intestine and is not compartmentalized to the base of the folds and interfold epithelium as reported in other teleosts, and 2) epithelial cell proliferation in the flounder intestine varies with feeding status.

Identification of cell types in semithin epoxy sections of gastric fundic mucosa.

J Med Chem 12:818, 1969 11. Tsou KC, Yip KF: A comparative study of Deoxyribonuclease I and Deoxyribonuclease II on Adriamycin-polynucleotide complexes. Cancer Res, in press 12. Van Dilla M, Steinmetz L, Davis D, Calvert R, Gray J: High speed cell analysis and sorting with flow systems: Biological applications and new approaches. IEEE Trans Nucl Sci 21:714, 1974 13. Weisblum B, de Haseth PL: Qumnacrine, a chromosome stain specific for deoxyadenylate-deoxythymidylate-rich regions in DNA. Proc NatI Acad

Distribution of Glucocorticoid Receptors in Rat Intestinal Epithelium

Corticosteroids influence intestinal function.Glucocorticoid receptors are present in cytosol of small intestinal mucosa of normal and steroid depleted adult rats.We examined the distribution of cytoplasm ic glucocorticoid receptor proteins in small intesti nal villous and crypt cells using the technique of Weiser to separate cells into 6 fractions.Fraction 1 was highly enriched in villous tip cells and fraction 6 in crypt cells. Alkaline phosphatase,sucrase and 3H-Thymidine incorporation were used to monitor the composition of each fraction.Steroid cytosol receptor activity was measured in each fraction using 3H-dexamethasone and a standard charcoal adsorption technique In normal rats receptor activity was detected in all fractions but was significantly greater in fraction 6 than in fraction 1(p<0.005).These data suggest that cytoplasmic corticosteroid receptors in normal rats have higher binding activity in crypt cells than in villous tip cells. Corticosteroid hormones may influen ce immature crypt cells more than mature villous tip cells in normal rats since glucocorticoid receptor activity is substantially higher in crypt dells.