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1.
Diabet Med ; 37(12): 2009-2018, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32124488

RESUMO

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.


Assuntos
Complicações do Diabetes/epidemiologia , Diabetes Mellitus/terapia , Amputação Cirúrgica/estatística & dados numéricos , Doenças do Sistema Nervoso Autônomo/epidemiologia , Doenças Cardiovasculares/epidemiologia , Transtornos Cerebrovasculares/epidemiologia , Diabetes Mellitus/metabolismo , Pé Diabético/epidemiologia , Cetoacidose Diabética/epidemiologia , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/terapia , Neuropatias Diabéticas/epidemiologia , Hemoglobinas Glicadas/metabolismo , Controle Glicêmico , Insuficiência Cardíaca/epidemiologia , Humanos , Coma Hiperglicêmico Hiperosmolar não Cetótico/epidemiologia , Hipoglicemia/induzido quimicamente , Hipoglicemia/epidemiologia , Lipodistrofia/epidemiologia , Infarto do Miocárdio/epidemiologia , Isquemia Miocárdica/epidemiologia , Avaliação de Resultados da Assistência ao Paciente , Periodontite/epidemiologia , Doença Arterial Periférica/epidemiologia , Doenças do Sistema Nervoso Periférico/epidemiologia , Diálise Renal , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/terapia , Acidente Vascular Cerebral/epidemiologia , Transtornos da Visão/epidemiologia
2.
Nutr Metab Cardiovasc Dis ; 26(7): 553-566, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27146363

RESUMO

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.


Assuntos
Glicemia/genética , Montagem e Desmontagem da Cromatina , Metilação de DNA , Diabetes Mellitus Tipo 2/genética , Epigênese Genética , Histonas/metabolismo , Acetilação , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Regulação da Expressão Gênica , Interação Gene-Ambiente , Estudos de Associação Genética , Predisposição Genética para Doença , Histonas/genética , Humanos , Insulina/sangue , Resistência à Insulina/genética , Masculino , Fenótipo , Fatores de Risco
3.
Am J Gastroenterol ; 107(1): 75-81, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21931380

RESUMO

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.


Assuntos
Permeabilidade da Membrana Celular , Diarreia/imunologia , Hipersensibilidade/complicações , Síndrome do Intestino Irritável/complicações , Síndrome do Intestino Irritável/imunologia , Mastócitos/imunologia , Adulto , Colo/metabolismo , Feminino , Humanos , Mucosa Intestinal/citologia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
4.
Gut ; 58(2): 196-201, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18824556

RESUMO

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.


Assuntos
Colo , Mucosa Intestinal/metabolismo , Síndrome do Intestino Irritável/metabolismo , Adulto , Idoso , Análise de Variância , Biópsia , Células CACO-2 , Estudos de Casos e Controles , Membrana Celular/fisiologia , Permeabilidade da Membrana Celular , Impedância Elétrica , Feminino , Humanos , Mucosa Intestinal/patologia , Síndrome do Intestino Irritável/patologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Ocludina , Fosfoproteínas/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não Paramétricas , Adulto Jovem , Proteína da Zônula de Oclusão-1
5.
Diabetes Metab ; 42(6): 389-397, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27396752

RESUMO

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.


Assuntos
Bilirrubina/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Síndrome Metabólica/sangue , Síndrome Metabólica/epidemiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Adulto Jovem
6.
Biochim Biophys Acta ; 876(1): 72-9, 1986 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-3633199

RESUMO

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.


Assuntos
Colesterol/biossíntese , Intestinos/citologia , Lipoproteínas/metabolismo , Acetatos/metabolismo , Ácido Acético , Animais , Células Cultivadas , Colesterol/metabolismo , Relação Dose-Resposta a Droga , Células Epiteliais , Hidroximetilglutaril-CoA Redutases/metabolismo , Hidroximetilglutaril-CoA-Redutases NADP-Dependentes , Cinética , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/metabolismo , Lovastatina , Naftalenos/farmacologia , Ratos
7.
Biochim Biophys Acta ; 1051(3): 259-65, 1990 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-2310777

RESUMO

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.


Assuntos
Inibidores do Crescimento/isolamento & purificação , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Animais , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Epitélio/metabolismo , Retroalimentação , Inibidores do Crescimento/farmacologia , Humanos , Ratos , Timidina/metabolismo
8.
Biochim Biophys Acta ; 1210(2): 181-6, 1994 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-8280768

RESUMO

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.


Assuntos
Colesterol/metabolismo , Intestino Delgado/metabolismo , Animais , Radioisótopos de Carbono , Linhagem Celular/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases , Lovastatina/farmacologia , Modelos Biológicos , Ácido Oleico , Ácidos Oleicos/farmacologia , Ácido Palmítico , Ácidos Palmíticos/farmacologia , Ratos , Sitosteroides/metabolismo , Ácidos Esteáricos/farmacologia , Fatores de Tempo , Trítio
9.
Biochim Biophys Acta ; 1166(2-3): 313-6, 1993 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-8443250

RESUMO

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.


Assuntos
Colesterol/biossíntese , Colesterol/metabolismo , Intestino Delgado/metabolismo , Acetatos/metabolismo , Radioisótopos de Carbono , Técnicas de Cultura , Humanos , Cinética
10.
Biochimie ; 58(8): 917-26, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-990334

RESUMO

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.


Assuntos
Ácidos e Sais Biliares/metabolismo , Lauratos/metabolismo , Ácidos Láuricos/metabolismo , Lipase/metabolismo , Pâncreas/enzimologia , Animais , Emulsões , Isoenzimas/metabolismo , Cinética , Mobilização Lipídica/efeitos dos fármacos , Ligação Proteica , Suínos
11.
Int J Parasitol ; 29(5): 697-702, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10404263

RESUMO

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.


Assuntos
Linhagem Celular/efeitos dos fármacos , Proteínas de Helminto/farmacologia , Trichostrongylus/metabolismo , Células 3T3/citologia , Células 3T3/efeitos dos fármacos , Animais , Células CHO/citologia , Células CHO/efeitos dos fármacos , Contagem de Células/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular/citologia , Cricetinae , Cães , Feminino , Camundongos , Coelhos
12.
Artigo em Inglês | MEDLINE | ID: mdl-1337209

RESUMO

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.


Assuntos
Alprostadil/farmacologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ácido Eicosapentaenoico/farmacologia , Ácidos Linolênicos/farmacologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , AMP Cíclico/biossíntese , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Células Tumorais Cultivadas , Vitamina E/farmacologia , Ácido gama-Linolênico
13.
Clin Nutr ; 12(3): 174-81, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16843308

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-2484400

RESUMO

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.


Assuntos
Neoplasias do Colo/patologia , Selênio/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Radioisótopos de Cromo , Neoplasias do Colo/metabolismo , DNA de Neoplasias/biossíntese , Glutationa Peroxidase/análise , Glutationa Peroxidase/metabolismo , Humanos , Leucina/metabolismo , Proteínas de Neoplasias/biossíntese , Radioisótopos de Selênio , Frações Subcelulares/metabolismo , Timidina/metabolismo , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia
15.
Gastroenterol Clin Biol ; 15(1): 22-7, 1991.
Artigo em Francês | MEDLINE | ID: mdl-1849105

RESUMO

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.


Assuntos
Clostridioides difficile/patogenicidade , Citotoxinas/farmacologia , Enterotoxinas/farmacologia , Íleo/efeitos dos fármacos , Saccharomyces , Animais , Linhagem Celular , AMP Cíclico/metabolismo , Replicação do DNA/efeitos dos fármacos , Íleo/microbiologia , Proteínas dos Microfilamentos/metabolismo , Proteínas/metabolismo , Ratos
16.
Gastroenterol Clin Biol ; 13(4): 383-7, 1989 Apr.
Artigo em Francês | MEDLINE | ID: mdl-2544474

RESUMO

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.


Assuntos
Toxina da Cólera/fisiologia , AMP Cíclico/biossíntese , Intestinos/enzimologia , Saccharomyces/fisiologia , Adenilil Ciclases/biossíntese , Animais , Linhagem Celular , Ratos , Fatores de Tempo
18.
Digestion ; 56(6): 509-15, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8536822

RESUMO

In addition to their inhibitory action on gastric acid secretion, prostaglandins may exert part of their protective effect on the gastrointestinal mucosa by specifically maintaining the cellular integrity of the intestinal epithelium. This in vitro study investigated the cytoprotective effect conferred on intestinal epithelial cell lines IRD 98 and IEC 17 against ethanol injury by the synthetic prostaglandin enprostil and compared effects with those of the histamine H2-receptor blocker cimetidine. Exposure to 3% ethanol (652 mM) reduced cell viability and increased the cAMP and membrane fluidity of both cell lines. Our results demonstrate that: (i) enprostil exerts a significant cytoprotective effect against damage by ethanol; (ii) cimetidine has no cytoprotective effect; (iii) IRD 98 cells are more sensitive to enprostil than IEC 17 cells.


Assuntos
Antiulcerosos/farmacologia , Cimetidina/farmacologia , Emprostila/farmacologia , Etanol/toxicidade , Intestinos/patologia , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Dimetil Sulfóxido/farmacologia , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/patologia , Intestinos/citologia , Intestinos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Ratos
19.
Gut ; 28 Suppl: 109-15, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3692299

RESUMO

In order to verify the hypothesis that intestinal cell proliferation is controlled by a mitotic inhibitor, extracts of villous epithelial cells from different species were analysed to study their effect on the proliferation of various intestinal cells. Villous extracts from rat and rabbit strongly and reversibly inhibited cell division and DNA synthesis in a rat intestinal epithelial cell line and a primary culture of rabbit intestinal epithelial cells. This non-cytotoxic, tissue specific but not species specific factor is present in both villous cells and crypt cells, with the highest concentrations occurring in the superficial epithelial cells. Assay of a partial purification of this factor showed that it has a molecular weight of approximately 190,000 daltons.


Assuntos
Intestinos/citologia , Microvilosidades/fisiologia , Animais , Divisão Celular/efeitos dos fármacos , Extratos Celulares/isolamento & purificação , Linhagem Celular , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/ultraestrutura , Intestinos/efeitos dos fármacos , Intestinos/ultraestrutura , Masculino , Especificidade de Órgãos , Ratos , Ratos Endogâmicos
20.
Pflugers Arch ; 439(5): 547-54, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10764213

RESUMO

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.


Assuntos
Encefalinas/farmacologia , Células Epiteliais/química , Secreções Intestinais/efeitos dos fármacos , Intestinos/citologia , Receptores Opioides delta/fisiologia , Analgésicos Opioides/química , Analgésicos Opioides/farmacologia , Animais , Ligação Competitiva , Linhagem Celular , Toxina da Cólera/farmacologia , AMP Cíclico/metabolismo , Dextrorfano/química , Dextrorfano/farmacologia , Leucina Encefalina-2-Alanina/metabolismo , Leucina Encefalina-2-Alanina/farmacologia , Células Epiteliais/citologia , Células Epiteliais/enzimologia , Antagonistas de Aminoácidos Excitatórios/química , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feto/citologia , Intestinos/enzimologia , Cinética , Levorfanol/química , Levorfanol/farmacologia , Naltrexona/análogos & derivados , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Neprilisina/metabolismo , Inibidores de Proteases/farmacologia , Ratos , Estereoisomerismo , Tiorfano/farmacologia , Trítio
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