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Biomedical subjects

J F Grenier

Publications and source records attributed to J F Grenier.

At least 91 records · Page 5Linked to original sources
PubMed1979

An automated continuous flow procedure for the determination of enterokinase.

A continuous flow method has been developed for the automatic determination of enterokinase in rat small intesstine mucosa and/or luminal content. Trypsinogen was first hydrolysed by enterokinase under conditions which minimize autocatalytic activation. L-benzoyl-arginine paranitroanilide was then added and split to paranitroaniline by the trypsin so formed. Liberated paranitroalinine was diazotized and converted by the Bratton-Marshall reagent (N-naphthyl ethylene diamine) to an azodye, with maximum absorption at 550 nm. This method of determination was found to be six times more sensitive than the direct p-nitroaniline determination method. 36 determinations can be made hourly.

Animals↗
PubMed1979

Intestinal brush border enzymes and chronic alcohol ingestion.

The effect of graded (5, 10, 20, and 50%) chronic ethanol administration on the intestinal brush border enzymic activities has been investigated in the rat at three levels of the intestinal tract (duodenum, jejunum, ileum). Ethanol has been administered for 8, 15, 30, and 90 days. A 30% to 50% decrease of sucrase and alkaline phosphatase results, showing that the effect of alcohol appears in the first 8 days of intoxication is not reversible after 8 days of an alcohol-free diet. The effect of ethanol is not limited to disaccharidases. Impairment of alkaline phosphatase, peptidases and also enterokinases is observed. The decrease is more marked in the duodenum and jujunum than the ileum. The decrease of enzymic activity is generally maximal after 30 days of intoxication. There is then little further deterioration or even significant improvement. At the 30th day of ethanol administration, a clearcut dose-response relationship has been established. The results obtained suggest that ethanol exerts an effect on the intestinal mucosa which is not directly correlated to morphological villus changes.

Alcoholism↗
PubMed1979

[Vasoactive intestinal peptide (VIP) in the Verner-Morrison syndrome (author's transl)].

An early diagnosis of the Verner-Morrison syndrome will greatly enhance the chances of curative resection. There is a striking need for a simple diagnostic test. A number of suggestions have been made for the presumed hormone mediator of this syndrome. Numerous reports have led to a wide acceptance that vasoactive intestinal peptide (VIP) is the responsible mediator for the pharmacologic actions of this peptide are similar to the physiological characteristics noted in the watery diarrhea syndrome. A raised plasma VIP concentration, on the other hand, would suggest the presence of a tumour. These observations argue for the radioimmunoassay measurement of plasma VIP in a patient with the watery diarrhea syndrome.

Adenoma, Islet Cell↗
PubMed1979

[Islet cell transplantation and diabetes (author's transl)].

It is now apparent that transplantation of islet cells is biologically feasible in experimental animals utilizing adult neonatal or fetal islet cells and employing many different sites for implantation of the islet cells. It is reasonable to expect that with successful acquisition of new basic information in immunology, endocrinology, metabolism and developmental biology islet cell transplantation should be used as a therapeutic approach to human diabetes.

Animals↗
PubMed1979

Developmental pattern of rat intestinal brush-border enzymic proteins along the villus--crypt axis.

At various postnatal stages, intestinal epithelial cells were isolated sequentially from villus tip to crypt base by successive EDTA treatments. According to the localization of marker enzymic activities, isolated cells were pooled into three cell compartments: villus (V), lower villus and upper crypt (VC) and crypt (C). Purified brush-border-membrane proteins were separated by 7.5%-polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. Enzymic activities could be assigned to some protein bands: maltase/glucoamylase (protein band 3), sucrase-isomaltase (protein bands 3 and 6), lactase (protein band 5) and alkaline phosphatase (region of protein bands 8 and 9). The findings suggest the following. (1) Sucrase-isomaltase activities appeared in compartment C at 17 days with a simultaneous increase of the pre-existing protein band 3 and appearance of a well-defined protein band in position 6; the enzymic complex remained still present in the crypt cells until adulthood. From the day 21 onwards, sucrase-isomaltase was detected in compartments VC and V. (2) Lactase was only present in the three cell compartments until day 21; at this developmental stage its activity completely disappeared from compartment C, in spite of the persistence of a weak protein band. (3) Alkaline phosphatase activity could be detected as a single peak corresponding to protein band 9 in all three cell compartments until day 21; thereafter it was replaced by two peaks of activity showing a less precise correlation with the well-defined protein bands 8 and 9. In the crypt cells of the adult rat, however, the preweaning situation, which was regularly observed, is an unexpected phenomenon. (4) Maltase and glucoamylase did not display any marked qualitative or quantitative modifications either along the villus-crypt axis or during the period of postnatal development studied. Evidence is given from the present data that each brush-border enzyme investigated has a specific developmental pattern.

Age Factors↗
PubMed1979

Computer program for intestinal spike bursts recognition.

A FORTRAN program has been developed for locating intestinal spike bursts and for estimating their strength. Tested against human scanning, the reliability rate was 92% and the misrecognition rate was 2.5%. This program was applied to the automatisation of the Migrating Myoelectric Complex analysis. A first method computed the percentage of Basic Electrical Rhythm (BER) cycles with superimposed spike bursts. A second one was based on the evaluation of spike bursts strength.

Animals↗
PubMed1979

In vivo exploration of the tensile strength of the abdominal wall after repair with different prosthetic materials. Experimental study in the rat.

The problem of parietal herniation seems to be a simple mechanical one for which there should be a safe method of repair. In the present study, the bursting strength of abdominal wounds was explored by mechanical investigation and the repair process evaluated at a cellular level by quantitative microscopy. Both methods of investigation show that mesh materials have advantages over nonporous cloth materials in the repair of large defects of the abdominal wall.

Abdominal Muscles↗
PubMed1979

Turnover studies of human intestinal brush border membrane glycoproteins in organ culture.

Turnover in organ culture of human small intestinal membrane glycoproteins was measured by the pulse-chase technique, using 14C-glucosamine, 14C-fucose or 14C-leucine as tracers. Apparently, low degradation rates were found for the major high-molecular-weight proteins which co-migrated on SDS-polyacrylamide gels with maltase-glucoamylase, lactase-phlorizin-hydrolase and sucrase-isomaltase enzymic activities. In contrast, an unidentified glycoprotein appearing on gels next to alkaline phosphatase exhibited a higher degradation rate with an apparent half-life of about 30 h, this being similar to the half-life of total glycoprotein as measured in mucosal homogenates. The results obtained with the pulse-chase technique were confirmed by double isotope experiments using 14C-leucine and 3H-leucine as tracers. These findings indicate that in organ culture there is a low basic turnover of human intestinal membrane glycoproteins which co-migrate on gels with known glycosidase enzymic activities.

Cell Membrane↗
PubMed1979

Chick embryo pancreatic transplants reverse experimental diabetes of rats.

The effectiveness of xenogeneic embryonic tissue in the treatment of experimental diabetes has been investigated in rats. The splenic lobes (80) of 15- to 18-d-old chick embryos, composed almost exclusively of endocrine tissue, were implanted directly into the hepatic parenchyma of the rat recipient. The biochemical and metabolic changes in the recipients suggest that embryonic transplants of 15-d-old chick pancreases were able to significantly improve, for a prolonged period of time (18 mo), the diabetic state of nonimmunosuppressed rats. None of the recipients of 18-d-old embryos splenic lobes exhibited a long-term improvement of the diabetic state after transplantation. The complete destruction of the pancreatic B cells of the recipients was assessed by: (a) immunocytochemical investigations of the recipient's pancreas, (b) measurement of insulin in the liver and pancreas of the recipients and (c) in situ vascular perfusion of their pancreas submitted to high glucose challenge. The results suggest that pancreatic tissue of the 15-d-old embryos is immunologically immature lacking one or several lymphocyte subsets implicated in the afferent lood of "non-self" recognition.

Animals↗
PubMed1979

Effects of oral and parenteral corticosteroids on intestinal villous morphology and brush border enzymes in the rat.

The effects of corticosteroid have been studied in rats submitted to oral administration of prednisone (5 mg. per kg. per day) during 8, 15, 30, and 90 days. The results were compared to those obtained after parenteral administration of hydrocortisone acetate (50 mg. per kg. per day intramuscularly). The morphometric changes of the villus-crypt axis and the brush border enzymic content of the mucosa (sucrase, enterokinase, alkaline phosphatase, and aminopeptidase) were the parameters investigated at the duodenal, jejunal, and ileal levels. Oral administration of prednisone resulted in a significant increase of the duodenal villous height at the 15th (+ 13 per cent, p less than 0.01), 30th (+ 33 per cent, p less than 0.001), and 90th day (+ 56 per cent, p less than 0.001), whereas in the jejunum a constant decrease of the villous height was noted. Parenteral hydrocortisone administration did not affect intestinal morphology. Effects of oral corticosteroids on the microvillous enzymic activities were related to both intestinal level and duration of corticoids administration: (1) in the duodenum increase of sucrase, alkaline phosphatase, and aminopeptidase during 30 days followed by normalization at the 90th day, (2) an initial increase of sucrase, alkaline phosphatase, and aminopeptidase limited to the first 8 days in the jejunum, and (3) a significant rise of alkaline phosphatase (greater than 100 per cent, p less than 0.001) and enterokinase (greater than 100 per cent, p less than 0.001) in the ileum at the 15th day of treatment. Parenteral corticosteroid administration was associated with a significant increase of both sucrase and enterokinase activities. The present study suggests that: (1) Corticosteroids exert a direct effect on the intestinal morphology varying with the intestinal level and duration of treatment. (2) No correlation could be established between anatomic and functional changes. (3) Oral corticosteroids exert an enhancing effect of the brush border enzymic activities, even in the adult mucosa and particularly at the ileal level where they stimulate significantly the enterokinase mucosal activity. (4) Parenteral corticosteroids exert a more specific effect limited to sucrase and enterokinase enhancement.

Administration, Oral↗
PubMed1979

[Relationship between intestinal motility and absorption. Electromyographic study in the dog. (author's transl)].

The effects of different food components on intestinal motility were studied by means of an electromyographic technique. The electrical activity of the small intestine in the fasted state consists of a cyclic recurring phenomenon - the myoelectric complex - which is inhibited by feeding. The duration of inhibition of the myoelectric complex was shown to depend on the nature of the food components (glucose, peptides or lipids) as well as on the caloric load. In the opposite, the intensity of the intestinal motility was seen to depend only on the nature of the food components, and not on the caloric load. Thus, the duration of inhibition of themyoelectric complex can be considered as a consistent and objective parameter, which reflects the duration of the fed state.

Animals↗
PubMed1978

Computer program for intestinal basic electrical rhythm patterns analysis.

A FORTRAN program has been elaborated for computerized intestinal Basic Electrical Rhythm (BER) analysis. It is based on recognition of individual cycles limits. The reliability of the method was assessed by comparison between computer and visual cycle limits identification. The agreement is 98.2% for BER recorded from the frequency plateau. It is 91.4% for fluctuating BER patterns. For BER frequency computing, drawbacks due to misrecognitions were avoided by cancelling sequences in which they occur.

Computers↗