ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The digestive tract and the gut as a paradigm represents an attractive system for the study of mechanisms involved in the differentiation of two types of progenitor cells: the endodermal cells during embryonic life and the undifferentiated crypt cells during epithelial renewal of the adult intestine. The morphological and functional events that accompany the differentiation processes of progenitor cells into the polarized epithelial cell types characteristic of the intestine appear comparable in both situations (1,2). During organogenesis of the gut, histological observations underlined a close relationship between epithelial cells and their underlying mesenchymal cells (3,4). Developmental biologists have emphasized experimentally the importance of interactions between the endoderm and mesenchyme during organogenesis of the digestive tract. In the adult intestine, gastroenterologists have focused their attention on a specialized mesenchymal cell type (the pericryptal fibroblasts) that displays, like epithelial cells, proliferative activities and migrating properties. The aim of this review is to provide current knowledge on epithelial-mesenchymal interactions during ontogenesis of the digestive tract and also to relate some experiments supporting the view of the perpetuation of epithelial-mesenchymal interactions beyond embryonic life.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

One hundred two pediatric patients received all or part of their nutritional needs parenterally at home during the past decade. All received total parenteral nutrition (TPN) at night during an 8-to 12-h infusion. Patients with short bowel syndrome (33%), inflammatory bowel disease (23%), chronic intractable diarrhea (15%), chronic idiopathic intestinal pseudo-obstruction syndrome (10%), and malignancy (10%) made up the largest groups. The mean duration of parenteral support was 735 days (range, 90–3650 days); the mean number of catheters per patient was 2.1 (range, 1–8). Twenty-one patients continue to receive full or partial home TPN: four for more than 10 years and seven for more than 5 years. Fifty-one no longer require it and have had healing of mucosa or bowel adaptation. Complications related to administration of fluid and electrolytes were quite rare. Biotin deficiency was recognized once. Thirty-one have died, but only 13 deaths were related to TPN. Sepsis in nine and liver failure in two were the most common causes of death in the TPN-related group. Three of 21 still on home TPN have graduated either from high school or college. All but one of the school age children attend regular school; one attends a school for the medically disabled, another attends a school for the mentally gifted.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A male born to first cousins presented at 12 months with hypocalcemic convulsions, rickets, epistaxis due to vitamin K deficiency, and extremely low serum levels of beta-carotene and vitamin A. Liver function was altered moderately (glutamic-oxaloacetic transaminase, 55 U/L; glutamic-pyruvic transaminase, 37 U/L; lactate dehydrogenase, 255 U/L; alkaline phosphatase, 437 U/L). To correct the deficiencies, 8000 IU vitamin D/day, 10,000 IU vitamin A/day, and intramuscular administration of vitamin K1 were required. At 9 years, he presented signs of neuromuscular affection, and the serum vitamin E level (measured for the first time) was extremely low. Classic lipid malabsorption syndromes (abetalipoproteinemia, chronic cholestasis, mucoviscidosis, coeliac disease, Whipple's disease) were excluded by appropriate examinations. Composition of duodenal bile acids was characterized by undetectable levels of cholic acid metabolites, and only chenodeoxycholic acid metabolites were present. Serum total bile acid concentration was normal, with an atypical low cholic acid/chenodeoxycholic acid ratio and abnormal presence of 3β-OH-δ5-cholenic acid and 6-OH-bile acids. Urinary bile acid composition was also characterized by elevated 6-OH-bile acids. Known enzymopathies of the bile acid synthetic pathway were excluded (cerebrotendinous xanthomatosis, cerebro-hepato-renal syndrome of Zellweger, coprostanic acidemia). Bile acid pool sizes were determined by using stable isotopes: cholic acid pool size [2.90 (N, 32 ± 16) μM/kg] and chenodeoxycholic acid pool size [10.8 (N, 32.6 ± 9.9) μM/kg] were extremely low; fractional turnover rates of both bile acids were in a normal range. Treatment with chenodeoxycholic acid markedly improved the absorption of fat soluble substances and normalized hepatic function. A partial enzyme defect in the metabolism of the steroid nucleus is proposed.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

We evaluated plasma PIVKA-II (protein induced by vitamin K absence or antagonist-II, acarboxy prothrombin) levels in three infants with hepatoblastoma as a tumor marker. PIVKA-II levels were highly elevated in all three patients. Vitamin K administration, performed in two patients, resulted in only moderate reduction of PIVKA-II levels. Chemotherapy against tumor cells reduced the PIVKA-II levels without exception. Immunohistochemical study of the liver tissue indicated the presence of PIVKA-II in the hepatoblastoma cell. These findings suggest that elevated PIVKA-II in these patients was not due to nutritional vitamin K deficiency, but to excess production of tumor cells. A measurement of plasma PIVKA-II may be useful as a new marker of hepatoblastoma.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

In the present study, the clinical application of a new functional test for vitamin E deficiency was evaluated. Erythrocytes from cholestatic children at risk for vitamin E deficiency and appropriate controls were incubated in vitro with hydrogen peroxide and the malondialdehyde generated and released into the supernatant quantitated. The results of these incubations were compared with fasting plasma vitamin E levels, the ratio of plasma vitamin E to plasma lipid levels, and, in some instances, hydrogen peroxide hemolysis tests. Malondialdehyde formation was less than 6% in controls and vitamin E-sufficient cholestatic children. However, cholestatic vitamin E-deficient children had a mean malondialdehyde formation of 41%. The results also suggest that for children less than 4 months of age, a ratio of plasma vitamin E to total plasma lipids less than 0.6 mg/g may be sufficient to provide protection from in vitro peroxidation. The authors suggest that this functional assay of vitamin E status be included in the evaluation of individuals with the potential for vitamin E deficiency.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Thin frozen sections of 11 jejunal biopsies from 10 children at different stages of coeliac disease were stained by immunofluorescence technique using a panel of anti-HLA class I (A, B, C) and anti-HLA class II (DR and DQ) monoclonal antibodies. On the epithelium of flattened mucosa, in contrast with control sections, the intensity of the labeling on the basolateral membranes with both anti-class I and class II DR antibodies decreased strongly from the bottom to the upper part of the crypts, and no bright patchy staining was observed on the apical part of enterocytes with anti-HLA DR antibodies. Numerous cells with large granules expressing class I and class II DR antigens were found in the epithelium of the small intestine. Children with a fully recovered mucosa expressed MHC antigens identical to those previously observed in normal epithelium. On the other hand, children with intermediate mucosal lesions showed the presence of MHC antigens in varying degrees. The results of this report indicate that immunological mechanisms may play a prominent role in coeliac disease.

ISSN:0277-2116    

出版商:OVID    

年代:1987

数据来源: OVID