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Biomedical subjects

J R Poley

Publications and source records attributed to J R Poley.

At least 19 recordsLinked to original sources

The scanning electron microscope: how valuable in the evaluation of small bowel mucosal pathology in chronic childhood diarrhea?

Data are presented on scanning electron microscopy (SEM) on small intestinal biopsies of children with chronic diarrhea. In particular, there were 230 patients aged 3 months to 13 years with the following diagnoses: chronic nonspecific diarrhea, cow's milk protein intolerance, soy protein intolerance, giardiasis, cystic fibrosis, gluten-sensitive enteropathy, isolated lactase deficiency, isolated sucrase-isomaltase lactase deficiency, microvillus inclusion disease, rotavirus enteritis, protracted diarrhea of infancy, chylomicron retention disease, visceral myopathy and villous asthenia. Examination of biopsied intestinal mucosa by SEM has yielded important new information and insights on structural pathology and ultrastructural topography. Many of the observed changes helped to better understand the pathophysiology of some of the diarrheal disorders. SEM was also able to detect new features such as mycoplasma-like microorganisms and the absence of the glycocalyx. To adequately assess small bowel mucosal pathology at the ultrastructural level, scanning electron microscopy is an indispensable tool.

Adolescent

Intestinal alkaline phosphatase activity in relation to age in humans.

Early studies of a few subjects suggested that intestinal alkaline phosphatase (IAP) activities in children 5 years of age or less were higher than in older individuals. To further investigate this finding, the IAP and disaccharidase activities of 298 subjects (133 were 5 years of age or less) with normal intestinal histology were assayed. Ninety-five of the children had serum alkaline phosphatase determined. The youngest individual with a low lactase activity was 5 years of age, which supported the earlier findings. When the whole population was tested, there was no correlation between the intestinal and serum alkaline phosphatase values. The mean IAP activity of subjects 1 year old and less was greater than in older individuals, but there was greater statistical dispersion and the data were not normally distributed. When studying the natural logarithm of the data, a wide dispersion of values about the mean in the 0 to 3 year-old age group was observed. This qualitative behavior is characteristic of functions involving the base of the natural logarithm and of processes that "age" in a simple way.

Adolescent

Congenital pancreatic lipase deficiency.

A 5 1/2-year-old boy is reported with congenital lipase deficiency and the presence of colipase. He presented with greasy-oily stools since infancy, but growth and development have been normal. No other cause for exocrine pancreatic insufficiency could be found. Intraluminal (jejunal) fat digestion was defective, but some hydrolytic products of dietary long-chain triglyceride were present. The di- and monoglycerides were probably generated by pregastric lipases, although this was not measured directly. Amylase activity was depressed to some extent, a finding which could not be explained. Our studies do not clarify the issue of whether or not the absence of pancreatic lipase is explained as an inherited defect of lipase synthesis, or if it was acquired in utero or in the early postnatal period.

Amylases

[Diagnostic value of laboratory and scintigraphic investigations in young infants with cholestatic jaundice (author's transl)].

The diagnostic value of laboratory and scintigraphic examination techniques in young infants with cholestatic jaundice will be discussed. The correct diagnosis of neonatal hepatitis or extrahepatic biliary atresia cannot be derived from such investigations as determination of bilirubin, enzyme activities, immunologic or serologic parameters or scintigraphy of the liver. Only quantitative changes of serum LP-X before and after administration of cholestyramin and the modified rose-bengal test may help to establish a correct diagnosis in cholestatic jaundice during the first 6 weeks of life.

Cholestasis

Quantitative changes of serum lipoprotein-X after cholestyramine administration in infants with cholestatic biliary tract and liver disease.

Lipoprotein-X (LP-X) was determined before and after the administration of cholestyramine in fifty-five infants with persistent cholestatic jaundice to differentiate between intra- and extrahepatic disease. In twenty-seven infants with biliary atresia, serum LP-X prior to cholestyramine ranged from 0.87 to 11.42 g/l (mean: 3.43 g/l; the average concentration was significantly lower (P less than 0.001) in males. After cholestyramine, LP-X rose in twenty-three, remained the same in two, and decreased slightly in two infants. Serum LP-X was present in twenty of the twenty-eight infants with intrahepatic cholestasis prior to cholestyramine in concentrations from 0.84 to 14.19 g/l (mean: 3.13 g/l). After cholestyramine, LP-X decreased in all by an average of 78% (P less than 0.005). The other eight infants did not have LP-X before or after cholestyramine. This study shows that LP-X in the serum of infants with cholestatic jaundice indicates severe cholestasis, but is not itself diagnostic of biliary atresia. The differentiation of biliary atresia from other diseases is readily achieved, as the administration of cholestyramine for 2-3 weeks causes a marked decrease of serum LP-X in patients with patent extrahepatic bile ducts. The absence of serum LP-X excludes biliary atresia.

Bile Ducts, Intrahepatic

Disaccharidase deficiency in infants with cow's milk protein intolerance. Response to treatment.

7 infants, aged 5 weeks to 11 months, with clinically documented intolerance to cow's milk protein, chronic diarrhea, and failure to thrive, underwent small intestinal (peroal, suction) biopsy before and after withdrawal of milk proteins. Mucosal specimens were examined by light microscopy and assayed for disaccharidase activities. In all patients, moderate to severe mucosal changes were presented, associated with marked inflammation of lamina propria and damages to the brushborder. Disaccharidase activities (lactase, sucrase, maltase and palatinase) were markedly depressed in all. Follow-up biopsies were obtained in 6 infants, after 3-5 months on a milk-protein-free diet. At the time of the second biopsy, the disaccharidase activities had risen significantly and histologic improvement had occurred in each instance. In infancy, intestinal mucosal lesions due to intolerance to cow's milk protein are histologically indistinguishable from those seen in gluten-sensitive enteropathy and are associated with marked secondary disaccharidase deficiencies. Following therapy, the activity of the disaccharidases become normal or near normal prior to the complete morphologic recovery of the small intestinal mucosa.

Animals

Intestinal disaccharidase activities in relation to age, race, and mucosal damage.

Studies were undertaken to determine the relationship of intestinal disaccharidase activity to age and race, and the relationship of mucosal damage to a primary low lactase activity. The first study consisted of data on 399 persons (339 whites, 53 blacks, and 7 American Indians) ages 1 month to 93 years, with normal intestinal histology. Among whites, all 117 children 5 years old or under had high lactase levels, whereas low levels were found only in subjects over 5 years of age. No low lactase levels were identified among the 11 black children 3 years old or under, but in comparison to coetaneous white children, their mean lactase activity was signficantly less. The majority of older blacks had low lactases. In whites and blacks alpha-disaccharidases did not participate in the age-related changes demonstrated with lactase. Of the 7 American Indians, none under 26 months old had low lactase levels, whereas the 4 over 10 years old had low activities. Heterozygotes for sucrase-isomaltase deficiency were identified only among whites. Low lactase levels developed during childhood in all races studied, however, many for unknown reasons maintained their lactose tolerance until adulthood. In the second study of 13 additional children with secondary disaccharidase deficiencies, emergence of a primary low lactase was related to age and race, rather than to mucosal damage. It appears that primary low intestinal lactase levels are absent or rare in whites under 5 and blacks under 3 years of age, and the deficiency is not related to mucosal damage.

Adolescent