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Biomedical subjects

M P Van Craynest

Publications and source records attributed to M P Van Craynest.

14 recordsLinked to original sources
PubMed1986

Response of human and rat small intestinal mucosa to oral administration of Saccharomyces boulardii.

To evaluate the response of the small intestinal mucosa to Saccharomyces boulardii (S.b.), a yeast widely used in some countries as an adjuvant drug with oral antimicrobial therapy, seven healthy adult volunteers were treated with high doses of lyophilized S.b. (250 mg four times per day) for 2 wk. A peroral jejunal suction biopsy was performed on days 0 and 15 of the study. Compared to the initial biopsy, histological examination of the posttrial biopsy revealed no morphological alteration nor change in villus height or crypt depth. After treatment, the specific activity (per U protein) of sucrase, lactase, and maltase was, respectively, increased by 82% (p less than 0.05) 77% (p less than 0.05), and 75% (p less than 0.05) over the basal activity of the enzymes measured on day 0, whereas mucosal protein content remained unchanged. Similar findings were found in the jejunum of adult rats treated for 5 days with either viable or killed S.b. cells. The changes in total enzyme activity (per jejunal segment) paralleled the changes in specific enzyme activity. In vitro assays on freshly prepared suspensions of S.b. (6.0 X 10(8) viable cells/ml) evidenced a high activity for sucrase (mean +/- SE: 8 364 +/- 1280 U X g X protein-1) but no maltase, neutral lactase, acid beta-galactosidase, or aminopeptidase activity. To determine whether treatment with S.b. could influence the incorporation rate of neutral lactase into the brush border membrane, 14-day-old sucklings treated either with saline or with S.b. were given intraperitoneally a dose of 20 microCi D-[1(14)C] glucosamine 3 hours before sacrifice.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1984

Role of dietary iron in maturation of rat small intestine at weaning.

The weanling process is characterized by the transition from a liquid diet poor in iron (rat milk) to a solid diet high in iron (chow pellets). To examine the effects of iron content of the weanling diet on terminal maturation of rat small intestine, suckling pups, nursed by iron-sufficient mothers, were weaned by day 16 onto a solid basal diet that was either deficient [low-iron diet (LID): 0.5 mg iron/100 g solid] or high [high-iron diet (HID) controls: 30 mg iron/100 g solid] in iron. The animals were studied during or at the end of the 4th postnatal wk. By day 17 rats weaned onto the LID exhibited an initial rise in jejunal sucrase activity as did their controls, but the activity plateau of the enzyme was reduced to a level 60% of the controls. On day 28 iron-deprived rats were anemic and showed significant decreases (P less than 0.01 compared with HID rats) in the activity of jejunal sucrase (-57%), neutral lactase (-83%), and maltase (-46%), whereas villus height, crypt depth, mucosal mass parameters, ileal acid beta-galactosidase activity, mucosal protein, and DNA synthesis rates were equivalent in LID and HID groups. The concentration of the secretory component, a glycoprotein synthesized by the intestinal crypt cell, was markedly depressed (P less than 0.01 vs. controls) in the jejunum (-54%) and ileum (-79%) of iron-deprived rats. When D-[1-14C]glucosamine was injected intraperitoneally, incorporation of the label into jejunal and ileal brush-border proteins was two to three times lower for iron-deficient rats than for controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Adaptive response of growing rat small intestine to acute Adriamycin injury.

The response of the intestinal mucosa to Adriamycin (ADR) was studied in the duodenum, jejunum, and ileum of 25-day-old rats. A single injection of ADR resulted in decreases in mucosal DNA per centimeter of length and in sucrase activity, which were proportional to the doses given (2, 5, and 8 mg/kg). ADR at 2 mg/kg had no significant effect on body weight, gut length, epithelial structure, or mucosal protein content per unit length. The morphological modifications occurred mostly in the proximal intestine and consisted of villous atrophy and degenerative changes of villus and crypt cells. A single dose of 5 mg ADR/kg acutely affected the gut. At 48 and 96 h the changes were characterized by marked decreases in mucosal weight, DNA per centimeter, sucrase activity, and villous shortening. At 144 h, the ADR-treated intestine entered a highly proliferative state and showed increased villous height, mucosal weight, and DNA per centimeter. Although villous hyperplasia was observed at 144 and 192 h, the mucosal weight and DNA concentrations did not exceed the corresponding levels in the control. During the period of active epithelial proliferation, sucrase activity remained depressed. We conclude that in the growing rat: (a) the acute intestinal injury of ADR is short-lived, dose dependent, and predominates in the proximal small intestine; (b) the enteric mucosa reacts to cytotoxic injury by excessive proliferation of immature enterocytes; and (c) the hyperplastic response to ADR is confined to the mucosal epithelium.

Animals↗
PubMed1980

[Choledochus cyst: a case with dilatation of the intrahepatic bile ducts and congenital liver fibrosis].

The authors report the case of a 2-year-old girl with hepatomegaly and failure to thrive in whom the diagnosis of congenital hepatic fibrosis was first considered on the basis of the histological examination of a percutaneous liver biopsy. Further radiographic and ultrasonic investigations of the biliary tree showed a choledocal cyst and dilatation of the intrahepatic ducts. Surgical operation consisted in complete removal of the cyst with hepaticojejunostomy. The congenital intrahepatic abnormalities associated with the choledochal cyst are commented.

Bile Ducts, Intrahepatic↗