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1.
Diabet Med ; 37(12): 2009-2018, 2020 12.
Article in English | MEDLINE | ID: mdl-32124488

ABSTRACT

AIMS: To select a core list of standard outcomes for diabetes to be routinely applied internationally, including patient-reported outcomes. METHODS: We conducted a structured systematic review of outcome measures, focusing on adults with either type 1 or type 2 diabetes. This process was followed by a consensus-driven modified Delphi panel, including a multidisciplinary group of academics, health professionals and people with diabetes. External feedback to validate the set of outcome measures was sought from people with diabetes and health professionals. RESULTS: The panel identified an essential set of clinical outcomes related to diabetes control, acute events, chronic complications, health service utilisation, and survival that can be measured using routine administrative data and/or clinical records. Three instruments were recommended for annual measurement of patient-reported outcome measures: the WHO Well-Being Index for psychological well-being; the depression module of the Patient Health Questionnaire for depression; and the Problem Areas in Diabetes scale for diabetes distress. A range of factors related to demographic, diagnostic profile, lifestyle, social support and treatment of diabetes were also identified for case-mix adjustment. CONCLUSIONS: We recommend the standard set identified in this study for use in routine practice to monitor, benchmark and improve diabetes care. The inclusion of patient-reported outcomes enables people living with diabetes to report directly on their condition in a structured way.


Subject(s)
Diabetes Complications/epidemiology , Diabetes Mellitus/therapy , Amputation, Surgical/statistics & numerical data , Autonomic Nervous System Diseases/epidemiology , Cardiovascular Diseases/epidemiology , Cerebrovascular Disorders/epidemiology , Diabetes Mellitus/metabolism , Diabetic Foot/epidemiology , Diabetic Ketoacidosis/epidemiology , Diabetic Nephropathies/epidemiology , Diabetic Nephropathies/therapy , Diabetic Neuropathies/epidemiology , Glycated Hemoglobin/metabolism , Glycemic Control , Heart Failure/epidemiology , Humans , Hyperglycemic Hyperosmolar Nonketotic Coma/epidemiology , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Lipodystrophy/epidemiology , Myocardial Infarction/epidemiology , Myocardial Ischemia/epidemiology , Patient Outcome Assessment , Periodontitis/epidemiology , Peripheral Arterial Disease/epidemiology , Peripheral Nervous System Diseases/epidemiology , Renal Dialysis , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/therapy , Stroke/epidemiology , Vision Disorders/epidemiology
2.
Nutr Metab Cardiovasc Dis ; 26(7): 553-566, 2016 07.
Article in English | MEDLINE | ID: mdl-27146363

ABSTRACT

BACKGROUND: New evidence suggests the potential involvement of epigenetic mechanisms in type 2 diabetes (T2D) as a crucial interface between the effects of genetic predisposition and environmental influences. AIM: To systematically review studies investigating the association between epigenetic marks (DNA methylation and histone modifications) with T2D and glycemic traits (glucose and insulin levels, insulin resistance measured by HOMA-IR). METHOD AND RESULTS: Six bibliographic databases (Embase.com, Medline (Ovid), Web-of-Science, PubMed, Cochrane Central and Google Scholar) were screened until 28th August 2015. We included randomized controlled trials, cohort, case-control and cross-sectional studies in humans that examined the association between epigenetic marks (global, candidate or genome-wide methylation of DNA and histone modifications) with T2D, glucose and insulin levels and insulin metabolism. Of the initially identified 3879 references, 53 articles, based on 47 unique studies met our inclusion criteria. Overall, data were available on 10,823 participants, with a total of 3358 T2D cases. There was no consistent evidence for an association between global DNA-methylation with T2D, glucose, insulin and insulin resistance. The studies reported epigenetic regulation of several candidate genes for diabetes susceptibility in blood cells, muscle, adipose tissue and placenta to be related with T2D without any general overlap between them. Histone modifications in relation to T2D were reported only in 3 observational studies. CONCLUSIONS AND RELEVANCE: Current evidence supports an association between epigenetic marks and T2D. However, overall evidence is limited, highlighting the need for further larger-scale and prospective investigations to establish whether epigenetic marks may influence the risk of developing T2D.


Subject(s)
Blood Glucose/genetics , Chromatin Assembly and Disassembly , DNA Methylation , Diabetes Mellitus, Type 2/genetics , Epigenesis, Genetic , Histones/metabolism , Acetylation , Biomarkers/blood , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Female , Gene Expression Regulation , Gene-Environment Interaction , Genetic Association Studies , Genetic Predisposition to Disease , Histones/genetics , Humans , Insulin/blood , Insulin Resistance/genetics , Male , Phenotype , Risk Factors
3.
Am J Gastroenterol ; 107(1): 75-81, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21931380

ABSTRACT

OBJECTIVES: Recent evidence suggests a role for increased colonic permeability and mucosal mast cell (MC) mediators on symptoms related to the irritable bowel syndrome (IBS). Whether allergic factors (AFs) are involved in the pathophysiology of IBS is unclear. We addressed the question of the possible influence of an allergic background on IBS symptoms. METHODS: We assessed paracellular permeability, mucosal MCs counts, and spontaneous release of tryptase of colonic biopsy specimens in 34 IBS patients and 15 healthy subjects. The severity of IBS was assessed through self-reported questionnaires. All individuals were tested for the presence of AF, including self-perception of adverse reaction to food, personal and familial history of atopic disease, elevated total or specific immunoglobulin E against food/inhalant antigens, blood eosinophilia, and skin tests. RESULTS: IBS patients had significant enhanced colonic permeability, higher number of MCs, and spontaneous release of tryptase than healthy subjects. The severity of IBS was significantly correlated with colonic permeability (r=0.48, P=0.004), MCs counts (r=0.36, P=0.03), and tryptase (r=0.48, P=0.01). In 13 IBS patients (38.2%) having at least three AFs, symptoms scores, colonic permeability, MCs counts, and tryptase release by colonic biopsies were significantly higher than in those with less than three AFs. IBS patients with at least three AFs were more prone to diarrhea or alternating symptoms. None AF was found to be predictive of IBS severity. CONCLUSIONS: In IBS patients, the presence of an allergic background correlates with a more severe disease and diarrhea predominance, possibly by enhancing mucosal MC activation and paracellular permeability.


Subject(s)
Cell Membrane Permeability , Diarrhea/immunology , Hypersensitivity/complications , Irritable Bowel Syndrome/complications , Irritable Bowel Syndrome/immunology , Mast Cells/immunology , Adult , Colon/metabolism , Female , Humans , Intestinal Mucosa/cytology , Male , Middle Aged , Severity of Illness Index
4.
Gut ; 58(2): 196-201, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18824556

ABSTRACT

BACKGROUND: Growing evidence suggests that patients with irritable bowel syndrome (IBS) have increased intestinal permeability. In addition, mucosal soluble mediators are involved in the pathophysiology of pain in IBS. We aimed to investigate (1) paracellular permeability in colonic biopsies of patients with IBS; and (2) the ability of soluble factors from colonic biopsies to reproduce these alterations in vitro. METHODS: Paracellular permeability in colonic biopsies of healthy subjects and patients with IBS was measured by mounting the biopsies in Ussing chambers. Cleared supernatant (SUP) of the culture from colonic biopsies was collected and applied to Caco-2 cells for 48 h. Paracellular permeability and transepithelial resistance (TER) were evaluated. mRNA expression of the tight junction proteins, zonula occludens (ZO)-1 and occludin, was assessed in colonic biopsies. Abdominal pain was assessed using a validated questionnaire. RESULTS: Permeability of colonic biopsies was significantly higher in patients with IBS compared to healthy subjects. These changes were associated with significantly lower expression of ZO-1 mRNA in biopsies of IBS as compared to healthy subjects. Compared to healthy subjects, SUP of IBS markedly reduced TER and significantly increased permeability in Caco-2 cells. SUP of IBS patients induced a significant decrease of ZO-1 mRNA in Caco-2 as compared to healthy subjects. SUP-induced increased paracellular permeability correlated with the severity of abdominal pain. CONCLUSIONS: Our study shows that colonic soluble mediators are able to reproduce functional (permeability) and molecular (ZO-1 mRNA expression) alterations observed in IBS patients. These findings might pave the way both to identify novel biomarkers as well as new therapeutic targets in IBS.


Subject(s)
Colon , Intestinal Mucosa/metabolism , Irritable Bowel Syndrome/metabolism , Adult , Aged , Analysis of Variance , Biopsy , Caco-2 Cells , Case-Control Studies , Cell Membrane/physiology , Cell Membrane Permeability , Electric Impedance , Female , Humans , Intestinal Mucosa/pathology , Irritable Bowel Syndrome/pathology , Male , Membrane Proteins/genetics , Middle Aged , Occludin , Phosphoproteins/genetics , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Statistics, Nonparametric , Young Adult , Zonula Occludens-1 Protein
5.
Diabetes Metab ; 42(6): 389-397, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27396752

ABSTRACT

OBJECTIVE: Emerging evidence suggests that bilirubin levels might be associated with the metabolic syndrome (MetS) and type 2 diabetes (T2D), although the nature of the association remains unclear. DESIGN: This systematic review and meta-analysis investigated the relationship between total plasma bilirubin and the risk of MetS and T2D. DATA SOURCES: Relevant studies were identified using five databases (Embase, Medline [Ovid], Web of Science, PubMed, Cochrane Central and Google Scholar), with the last search done on 21 October 2015. Study references were checked and authors contacted to identify additional studies. STUDY SELECTION: Randomized controlled trials, and cohort, case-control and cross-sectional studies of adults examining the association between blood bilirubin levels and MetS and T2D were included, irrespective of language and date of publication. Abstract and full-text selection was done by two independent reviewers, with a third reviewer available in case of disagreement. DATA EXTRACTION: Data were extracted by two independent reviewers using a predesigned data collection form. MAIN OUTCOMES AND MEASURES: MetS and T2D. METHODS: Summary estimates were obtained by random-effects meta-analysis. RESULTS: Of the 2313 searched references, 16 observational studies (11 cross-sectional, two prospective, one that was both cross-sectional and prospective, two retrospective and one national survey) met our inclusion criteria. Overall, data were available for 175,911 non-overlapping participants, including 7414 MetS cases and 9406 T2D cases. In the meta-analysis of seven cross-sectional studies, the pooled odds ratio (95% confidence interval) for MetS in a comparison of extreme tertiles of serum bilirubin levels was 0.70 (95% CI: 0.62, 0.78), whereas no significant association was found for the pooled estimated relative risk between two prospective studies (0.57, 95% CI: 0.11, 2.94). The corresponding estimate was 0.77 (95% CI: 0.67, 0.87) for T2D from four cross-sectional studies. CONCLUSION: The available evidence, mainly from cross-sectional studies, supports an inverse association of bilirubin levels with adverse metabolic outcomes. Large-scale prospective studies are now needed to establish whether bilirubin levels may be useful in the prevention of MetS and T2D.


Subject(s)
Bilirubin/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/epidemiology , Metabolic Syndrome/blood , Metabolic Syndrome/epidemiology , Adult , Female , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic , Young Adult
6.
Biochim Biophys Acta ; 1051(3): 259-65, 1990 Mar 09.
Article in English | MEDLINE | ID: mdl-2310777

ABSTRACT

Endogenous mitotic inhibitors act as control-mechanisms in intestinal epithelium proliferation. The presence of an inhibitor of cultured intestinal epithelial cell from a villous extract of rat jejunum has been reported in one of our papers. The object of the study now reported was to find the presence of a growth inhibitor in the villous extract from man's small intestine and to purify and characterize this factor when found. Our results reveal that: (1) Such an inhibitor was found in a supernatant preparation obtained from human intestinal epithelial cells. The inhibition of the proliferation of epithelial cells (IRD-98) it induced was seem to be dose-dependent and non-cytotoxic. (2) After chromatography on hydroxylapatite, on DEAE and then on ACA 54 (gel permeation), a low-molecular-weight protein (15 kDa) called purified intestinal inhibitor (PII) was isolated (purification factor of approx. 50,000 with respect to the supernatant fraction). This fraction proved to inhibit the IRD-98 cells in a reversible manner. When cells are incubated with this protein, cells prove to be arrested in phase G1 of the cell cycle as is revealed by the flow cytometry studies. The results obtained support the hypothesis that regulation of cell proliferation is mediated by endogenous inhibitors at the epithelial level.


Subject(s)
Growth Inhibitors/isolation & purification , Intestinal Mucosa/metabolism , Intestine, Small/metabolism , Animals , Cell Cycle/drug effects , Cell Division/drug effects , Cell Line , Epithelium/metabolism , Feedback , Growth Inhibitors/pharmacology , Humans , Rats , Thymidine/metabolism
7.
Biochim Biophys Acta ; 876(1): 72-9, 1986 Mar 21.
Article in English | MEDLINE | ID: mdl-3633199

ABSTRACT

The regulation of cholesterol synthesis has been studied using a rat epithelial intestinal cell line (IRD 98) as a cellular model. As observed in other cell types, mevinolin increases the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.34) and concomitantly reduces the incorporation of [14C]acetate into cholesterol. Free cholesterol is able to suppress reductase activity. In contrast, when cells are shifted from standard culture medium to lipoprotein-deficient medium, an increase in hydroxymethylglutaryl-CoA reductase specific activity (2-5-fold) is observed. The possible regulatory roles of the different classes of human lipoproteins were thus compared. The effects of a long-term exposure to LDL and HDL vary according to cell density. In actively growing cells, VLDL and LDL cause a decrease in the level of hydroxymethylglutaryl-CoA reductase, whereas HDL do not have a significant effect. In contrast, in subconfluent preresting cells, HDL provoke large decreases in hydroxymethylglutaryl-CoA reductase activity as compared to VLDL and LDL. While LDL binding is constant, the maximal binding capacity of HDL in subconfluent cells is seven times that of actively growing cells. Altogether, these results suggest an important role for HDL in the regulation of intestinal cholesterol synthesis.


Subject(s)
Cholesterol/biosynthesis , Intestines/cytology , Lipoproteins/metabolism , Acetates/metabolism , Acetic Acid , Animals , Cells, Cultured , Cholesterol/metabolism , Dose-Response Relationship, Drug , Epithelial Cells , Hydroxymethylglutaryl CoA Reductases/metabolism , Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent , Kinetics , Lipoproteins, HDL/metabolism , Lipoproteins, LDL/metabolism , Lipoproteins, VLDL/metabolism , Lovastatin , Naphthalenes/pharmacology , Rats
8.
Biochim Biophys Acta ; 1210(2): 181-6, 1994 Jan 03.
Article in English | MEDLINE | ID: mdl-8280768

ABSTRACT

A new model to study cholesterol absorption in the rat intestinal cells is described. Rat intestine epithelial cells IRD98 were incubated with mixed micelles containing bile acid, phospholipid, cholesterol or its nonabsorbable analogue, sitosterol, and trace amounts of [3H]cholesterol or [14C]sitosterol. Cholesterol and sitosterol uptake was then determined following lipid extraction; specific cholesterol uptake was determined as the difference between cholesterol and sitosterol uptake. Cholesterol, but not sitosterol, uptake was time- and dose-dependent and saturable. Loading of cells with non-lipoprotein cholesterol reduced cholesterol, but not sitosterol, uptake in a dose-dependent manner. In contrast, treatment of cells with an inhibitor of cholesterol synthesis, lovastatin, stimulated cholesterol, but not sitosterol, uptake in a dose-dependent manner. Treatment of cells with palmitic, caproic and oleic acids up-regulated specific cholesterol uptake, while linoleic and stearic acids had an opposite effect. None of the fatty acids affected sitosterol uptake.


Subject(s)
Cholesterol/metabolism , Intestine, Small/metabolism , Animals , Carbon Radioisotopes , Cell Line/drug effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Lovastatin/pharmacology , Models, Biological , Oleic Acid , Oleic Acids/pharmacology , Palmitic Acid , Palmitic Acids/pharmacology , Rats , Sitosterols/metabolism , Stearic Acids/pharmacology , Time Factors , Tritium
9.
Biochim Biophys Acta ; 1166(2-3): 313-6, 1993 Feb 24.
Article in English | MEDLINE | ID: mdl-8443250

ABSTRACT

Cholesterol uptake was studied at the small intestine biopsies taken from patients without intestinal malfunction. Three distinct groups of patients were described: those with low (146 +/- 19) nmol/mm2 per 2 h), medium (455 +/- 18 nmol/mm2 per 2 h) and high (833 +/- 24 nmol/mm2 per 2 h) rates of cholesterol uptake. Positive correlation between cholesterol uptake and intestinal cholesterol synthesis was observed in the last two groups.


Subject(s)
Cholesterol/biosynthesis , Cholesterol/metabolism , Intestine, Small/metabolism , Acetates/metabolism , Carbon Radioisotopes , Culture Techniques , Humans , Kinetics
10.
Biochimie ; 58(8): 917-26, 1976.
Article in English | MEDLINE | ID: mdl-990334

ABSTRACT

The accumulation of four bile salts at the interface between water and n-hexyl laurate is studied. Gibb's interfacial excesses of these salts are calculated, starting from interfacial tension measurements. At the same time, emulsions of the ester are treated by lipase and reactions rates are plotted against the bile salt concentrations present in the water phase of the emulsions. Inhibition by conjugated bile salts appear before the critical micellar concentration is approached. There is no defined relationship between this inhibition and the fraction of interfacial area covered by detergent molecules. In accordance with recent publication, the discussion suggests that the energy level of interfaces is important for lipase action and that, when interfacial tension becomes too small, lipase does not attach to interfaces and appears as inactive.


Subject(s)
Bile Acids and Salts/metabolism , Laurates/metabolism , Lauric Acids/metabolism , Lipase/metabolism , Pancreas/enzymology , Animals , Emulsions , Isoenzymes/metabolism , Kinetics , Lipid Mobilization/drug effects , Protein Binding , Swine
11.
Int J Parasitol ; 29(5): 697-702, 1999 May.
Article in English | MEDLINE | ID: mdl-10404263

ABSTRACT

The effects of the excretory/secretory (ES) products of the parasitic nematode Trichostrongylus colubriformis were examined on the proliferation of seven cell lines derived from a digestive or non-digestive origin. The excretory/secretory products of T. colubriformis were incorporated in the culture medium of the different cell lines and cell proliferation was measured by means of the 5-bromo-2'-deoxy-uridine (Brdu) assay. An increase in cell numbers was found with the three epithelial intestinal cells (RIC, IEC-6, IRD-98) and with epithelial kidney cells (MDCK). In contrast, an inhibition in the proliferation of epithelial ovarian cells (CHO) and fibroblasts (3T3) was observed with the addition of the excretory/secretory products and no effect was detected on the cell growth of hepatocytes (HepG2). These data are discussed with respect to the tissue specificity of the existing mitogenic effect of the worms on the intestinal crypt cells during parasitism.


Subject(s)
Cell Line/drug effects , Helminth Proteins/pharmacology , Trichostrongylus/metabolism , 3T3 Cells/cytology , 3T3 Cells/drug effects , Animals , CHO Cells/cytology , CHO Cells/drug effects , Cell Count/drug effects , Cell Division/drug effects , Cell Line/cytology , Cricetinae , Dogs , Female , Mice , Rabbits
12.
Article in English | MEDLINE | ID: mdl-1337209

ABSTRACT

Several studies have demonstrated that certain essential fatty acids present a specific cytotoxicity for tumor cells. However, no investigation of this type has been performed on human colon cancer cells to date. This study investigated the effect of gamma-linolenic acid (GLA), eicosapentaenoic acid (EPA) and prostaglandin (PG) E1 on the proliferation and metabolism of three human colon cancer cell lines: HT 29, HRT 18, and CACO 2. GLA, EPA and PGE1 all inhibited the proliferation of the three cell lines, but with a decreasing gradient of sensitivity: HRT 18 > HT 29 > CACO 2, and with different IC50 values. PGE1 was markedly less effective than the other two. GLA and EPA increased lipid peroxidation and membrane fluidity in a dose-dependent manner. The presence of indomethacin did not modify the effects of GLA and EPA. In addition, PGE1 had little effect on membrane fluidity and lipid peroxidation. The antitumoral effect thus does not appear to be mediated by PGE1. Addition of vitamin E decreased the effects of GLA and EPA, which supports the hypothesis of direct action by these fatty acids. In conclusion, while EPA and GLA have an antitumoral effect in vitro, their effect on primary cultures of normal human colon cells must be investigated to determine whether this effect is specific to tumoral cells, as has been observed for other cell types.


Subject(s)
Alprostadil/pharmacology , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Eicosapentaenoic Acid/pharmacology , Linolenic Acids/pharmacology , Cell Division/drug effects , Cell Line , Cyclic AMP/biosynthesis , Humans , Lipid Peroxidation/drug effects , Membrane Fluidity/drug effects , Tumor Cells, Cultured , Vitamin E/pharmacology , gamma-Linolenic Acid
13.
Clin Nutr ; 12(3): 174-81, 1993 Jun.
Article in English | MEDLINE | ID: mdl-16843308

ABSTRACT

UNLABELLED: Chronic malnutrition results in severe metabolic imbalance in man as the body modifies its modes of regulation of different nutrients, and in particular lipids. This study of the modifications in lipid metabolism induced by 15 days of enteral renutrition include: 12 malnourished patients (global nutritional deficit (GND) <20%) were given a cyclical enteral diet for 15 days under two conditions: ternary diet (Sondalis) or a similar diet whose lipid concentration was enriched by 5.3 g omega3 fatty acid per day. On Day 0 and Day 15, the serum lipid values were assayed and duodenal biopsies were taken to measure HMG-CoA reductase and (14)C acetate incorporation in the various classes of lipids. After 15 days of refeeding, the GND had been corrected by an average of 27% and HMG-CoA reductase activity had increased by 37% (60.2 +/- 7.46 vs 82.88 +/- 14.8 pmol/min/mg protein; p < 0.05). In 7 12 patients, the serum cholesterol values had increased (p < 0.01). No difference was observed in synthesis of FA, DG or cholesterol. Synthesis of phosphatidylcholines (PC) and phosphatidylglycerols (PG) was reduced by 12% and 23% respectively. Triglyceride synthesis (TG) increased by 20% (p < 0.05). The only difference between the two diets was in TG synthesis in organ-specific culture, which was increased only by the standard diet. IN CONCLUSION: (i) refeeding is accompanied by an increase in intestinal HMG-CoA reductase activity, a decrease in PC and PG synthesis, and an increase in TG synthesis; (ii) a diet enriched in omega3 FA increases TG synthesis less than the standard diet.

14.
Biol Trace Elem Res ; 20(1-2): 31-43, 1989.
Article in English | MEDLINE | ID: mdl-2484400

ABSTRACT

The effects of selenium were investigated on three human colon cancer cell lines: Caco 2, HRT 18, and HT 29. At low concentrations (10-100 nM), selenium stimulated cell growth in serum-free medium. Thus, selenium is an essential trace element for cell proliferation. At higher concentrations, selenium inhibited cell growth. The rate of 75Se uptake was the same in all of the cell lines studied, but the quantity incorporated differed. GSH-Px activity was dependent on the selenium content of the medium. DNA and protein synthesis paralleled the growth curve. Comparison with the curve of viability revealed that selenium inhibited cell growth in two ways: by inhibiting DNA synthesis, without affecting cell viability, and, at higher doses, by cytotoxicity.


Subject(s)
Colonic Neoplasms/pathology , Selenium/pharmacology , Tumor Cells, Cultured/drug effects , Cell Division/drug effects , Chromium Radioisotopes , Colonic Neoplasms/metabolism , DNA, Neoplasm/biosynthesis , Glutathione Peroxidase/analysis , Glutathione Peroxidase/metabolism , Humans , Leucine/metabolism , Neoplasm Proteins/biosynthesis , Selenium Radioisotopes , Subcellular Fractions/metabolism , Thymidine/metabolism , Tumor Cells, Cultured/metabolism , Tumor Cells, Cultured/pathology
15.
Gastroenterol Clin Biol ; 13(4): 383-7, 1989 Apr.
Article in French | MEDLINE | ID: mdl-2544474

ABSTRACT

Cholera toxin acts in vivo by activating intestinal adenylate cyclase. This study was designed to determine (1) whether normal rat epithelial intestinal cell lines (IRD 98 and IEC 17) respond to cholera toxin (CT) by an increased concentration of cyclic AMP and (2) whether the yeast Saccharomyces boulardii, which reduced CT-induced secretion of water and electrolytes using the isolated jejunal loop technique, has an effect on these models. The cAMP concentration evaluated in cells exposed to Saccharomyces boulardii and to cholera toxin (1 microgram/ml for 90 min) was compared to the concentration of cAMP obtained in control cells without yeast. Prior exposure of IRD 98 and IEC 17 cells to Saccharomyces boulardii, reduced CT-induced cAMP by 50 p. 100. This effect disappeared after destruction of the yeast by heating. Results show that the IRD 98 and IEC 17 cells are good models for in vitro investigation of the effects of cholera toxin. Our results suggests that Saccharomyces boulardii prevents the water and electrolyte secretion induced by cholera toxin.


Subject(s)
Cholera Toxin/physiology , Cyclic AMP/biosynthesis , Intestines/enzymology , Saccharomyces/physiology , Adenylyl Cyclases/biosynthesis , Animals , Cell Line , Rats , Time Factors
16.
Gastroenterol Clin Biol ; 15(1): 22-7, 1991.
Article in French | MEDLINE | ID: mdl-1849105

ABSTRACT

In vivo, Clostridium difficile acts by releasing 2 toxins: toxin A, an enterotoxin, and toxin B, a cytotoxin. This study was performed to determine: a) whether the rat epithelial intestinal cell line IRD 98 responds to Clostridium difficile toxin A and B; b) whether the yeast Saccharomyces boulardii has an effect on this model. Evaluation of 3H-thymidine incorporation into IRD 98 cells exposed to toxin B revealed that DNA synthesis was inhibited for low concentrations (10 ng/ml). For higher concentrations, DNA synthesis was not modified. Evaluation of 14C-leucine incorporation into IRD 98 cells exposed to toxin B revealed that this toxin affected protein synthesis. Whereas cholera toxin stimulates adenylate cyclase in IRD 98 cells, cAMP levels in cells exposed to various quantities of toxin A was similar to that in control cells. As opposed to cholera toxin, which does not affect the cytoskeletal structure of IRD 98 cells, 7 micrograms/ml of toxin A and even smaller amounts of toxin B (1 ng/ml) were found to cause structural alterations by immunofluorescence studies. Prior exposition of cells to Saccharomyces boulardii reduced or prevented the rounding of cells in the presence of these toxins. IRD 98 cells can thus be considered a good model for in vitro investigation of the effects of Clostridium difficile toxins A and B, and findings suggest that Saccharomyces boulardii has a protective effect against the action of these toxins.


Subject(s)
Clostridioides difficile/pathogenicity , Cytotoxins/pharmacology , Enterotoxins/pharmacology , Ileum/drug effects , Saccharomyces , Animals , Cell Line , Cyclic AMP/metabolism , DNA Replication/drug effects , Ileum/microbiology , Microfilament Proteins/metabolism , Proteins/metabolism , Rats
18.
Pflugers Arch ; 439(5): 547-54, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10764213

ABSTRACT

Using 3H-Tyr-D-Ala-Gly-Phe-D-Leu-OH (3H-DADLE) as a radioligand, delta-opioid binding sites on the IRD 98 rat epithelial cell line were identified. These sites were found to be reversible, saturable, specific and displayed high affinity for DADLE. Scatchard analysis revealed a dissociation constant (Kd) of 4.9+/-0.5 nmol/l, a maximum binding capacity (Bmax) of 1.7 pmol/mg protein, and 5x10(5) binding sites per cell. The presence of opioid receptors suggests the possibility that enkephalins directly control ion transport in enterocytes. In order to verify this hypothesis, investigations were designed to determine whether these receptors are functional and whether enkephalins can inhibit the stimulation of adenosine 3',5' cyclic monophosphate (cAMP) synthesis induced by cholera toxin. The increase in cAMP synthesis induced by cholera toxin was inhibited in a dose-dependent manner by H-Tyr-D-Ser-Gly-Phe-Leu-Thr-OH (DSLET), a delta-agonist. The enkephalinase inhibitor thiorphan potentiated this effect on IRD 98 cells, which contain enkephalinase. The action of DSLET was increased by 40% in the presence of this inhibitor. This effect was reversed by naltrindole, a potent delta-antagonist. Enkephalins can regulate intestinal secretion by acting directly on enterocytes: they thus have an antidiarrheal role, especially in the presence of an enkephalinase inhibitor.


Subject(s)
Enkephalins/pharmacology , Epithelial Cells/chemistry , Intestinal Secretions/drug effects , Intestines/cytology , Receptors, Opioid, delta/physiology , Analgesics, Opioid/chemistry , Analgesics, Opioid/pharmacology , Animals , Binding, Competitive , Cell Line , Cholera Toxin/pharmacology , Cyclic AMP/metabolism , Dextrorphan/chemistry , Dextrorphan/pharmacology , Enkephalin, Leucine-2-Alanine/metabolism , Enkephalin, Leucine-2-Alanine/pharmacology , Epithelial Cells/cytology , Epithelial Cells/enzymology , Excitatory Amino Acid Antagonists/chemistry , Excitatory Amino Acid Antagonists/pharmacology , Fetus/cytology , Intestines/enzymology , Kinetics , Levorphanol/chemistry , Levorphanol/pharmacology , Naltrexone/analogs & derivatives , Naltrexone/pharmacology , Narcotic Antagonists/pharmacology , Neprilysin/metabolism , Protease Inhibitors/pharmacology , Rats , Stereoisomerism , Thiorphan/pharmacology , Tritium
19.
Alcohol Clin Exp Res ; 14(1): 32-7, 1990 Feb.
Article in English | MEDLINE | ID: mdl-2178469

ABSTRACT

The effect of exposure of an intestinal epithelial cell line to various concentrations of ethanol [217 mM (1%) to 652 mM (3%)] during 24, 48, and 72 hr was investigated in vitro using a rat intestinal epithelial cell line (IRD 98). Incubation of these cells in the presence of ethanol significantly decreased cell growth. This inhibition was accompanied by a strong increase in cellular protein. Stimulation of specific disaccharidases, gamma-glutamyl transferase, and aminopeptidase activities by ethanol was dose- and time-dependent. Ethanol induces a change in the relative proportions of the different lipid classes synthesized; triglycerides, fatty acids, and cholesterol esters were preferentially synthethysed. Our findings show that cell lines are good models for investigation of the effects of ethanol, and that alcohol considerably modifies the functions of intestinal epithelial cells.


Subject(s)
Ethanol/pharmacology , Intestinal Mucosa/metabolism , Animals , Cattle , Cell Line , Chromium Radioisotopes , DNA/biosynthesis , Epithelial Cells , Intestines/drug effects , Leucine/metabolism , Lipids/biosynthesis , Protein Biosynthesis , Thymidine/metabolism
20.
Digestion ; 46 Suppl 2: 170-6, 1990.
Article in English | MEDLINE | ID: mdl-2262051

ABSTRACT

Endogenous mitotic inhibitors have been implicated as controlling mechanisms of intestinal epithelium proliferation. We previously reported the purification of an inhibitor of intestinal epithelial cells in culture isolated from a villous extract of human jejunum. This article describes the biologic effects of this inhibitor on organ cultures of rabbit intestinal mucosa. Our results reveal that (1) this factor is not cytotoxic; (2) it inhibits intestinal epithelial cell proliferation in a dose-dependent and reversible manner; (3) it does not appear to be species-specific; (4) it is specific to the digestive tract, and more particularly to the small intestine.


Subject(s)
Growth Inhibitors/pharmacology , Intestinal Mucosa/growth & development , Animals , Autoradiography , Humans , Intestine, Small/chemistry , Organ Culture Techniques , Organ Specificity , Rabbits , Species Specificity
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