Butyrate enemas upregulate Muc genes expression but decrease adherent mucus thickness in mice colon.

Colonic mucosal protection is provided by the mucus gel, mainly composed of mucins. Several factors can modulate the formation and the secretion of mucins, and among them butyrate, an end-product of carbohydrate fermentation. However, the specific effect of butyrate on the various colonic mucins, and the consequences in terms of the mucus layer thickness are not known. Our aim was to determine whether butyrate modulates colonic MUC genes expression in vivo and whether this results in changes in mucus synthesis and mucus layer thickness. Mice received daily for 7 days rectal enemas of butyrate (100 mM) versus saline. We demonstrated that butyrate stimulated the gene expression of both secreted (Muc2) and membrane-linked (Muc1, Muc3, Muc4) mucins. Butyrate especially induced a 6-fold increase in Muc2 gene expression in proximal colon. However, butyrate enemas did not modify the number of epithelial cells containing the protein Muc2, and caused a 2-fold decrease in the thickness of adherent mucus layer. Further studies should help understanding whether this last phenomenon, i.e. the decrease in adherent mucus gel thickness, results in a diminished protective function or not.

MUC genes are differently expressed during onset and maintenance of inflammation in dextran sodium sulfate-treated mice.

Colonic mucosal protection is provided by mucous gel, mainly composed of secreted (Muc2) and membrane-bound (Muc1, Muc3, Muc4) mucins. Our aim was to determine the expression profile of secreted and membrane-bound mucins in experimental dextran sulfate sodium (DSS)-induced colitis. Acute colitis was induced in Balb/C mice by oral administration of 1.0% DSS (5 days) and chronic colitis was maintained by subsequent 0.15% DSS treatment (28 days). Clinical symptoms (mortality, weight gain), stool scores, and MPO activity confirmed the inflammatory state in the two phases of colitis. Muc2 gene expression was not modified by colitis, whereas Muc3 gene expression was increased (x2) only in the cecum and the distal colon of mice after acute colitis. Muc1 and Muc4 mRNA levels were more significantly increased in the cecum (x8-10) than in colonic segments (x4) after acute colitis. TFF3 involved in mucosal repair was up-regulated during colitis induction. These results indicate that Muc and TFF3 genes are regulated early in inflammation and suggest that their mRNA levels could be used as early markers of inflammation.

Involvement of small intestinal motility in blood glucose response to dietary fibre in man.

Three dietary fibres with different physicochemical properties were studied in healthy humans for their effects on small intestinal motility and postprandial hyperglycaemia. Duodeno-jejunal motor activity was evaluated electromyographically for 180 min in six subjects who had ingested a test meal composed of glucose alone or glucose with 15 g of wheat bran (WB), sugar beet (SB) or ispaghula (I) fibres. Glucose and insulin concentrations were determined during the same period. Each subject received each of the four test meals randomly during a 4 d period. Addition of SB or I to the glucose meal altered duodeno-jejunal motility. Both of these fibres inhibited stationary contractile activity and increased the propagation length and velocity of propagated activity, whereas addition of WB had no effect. These results could reflect the high water-holding capacity of SB and I. Blood glycaemic response to the glucose meal was reduced by SB and I but remained unchanged with WB. Postprandial blood glucose levels were significantly correlated with the total motility index (r 0.82) and stationary activity (r 0.79). Taken together, these observations suggest that the contractile activity induced by dietary fibre in the small intestine probably plays a major role in delayed glucose absorption.

[Myxoma of the left ventricle. Apropos of a successfully operated case]. / Les myxomes du ventricule gauche. A propos d'un cas opéré avec succès

Left ventricular myxomata are exceptional (12 published cases). In the case reported, the clinical picture included emboli (cerebral and coronary) and syncope. Auscultation, the electrocardiogram and the phonomechanocardiographic tracings suggested an impaired left ventricular ejection, while the left ventriculography demonstrated the tumour and the coronary arteriography its vascular relationship with the right coronary artery. Cure was obtained by surgical removal. In that respect, an attempt was made to describe the clinical and paraclinical bases for the diagnosis of the myxomata of the left ventricle.

[Coronary emboli in mitral stenosis]. / Les embolies coronariennes du rétrécissement mitral

Study of four personal cases and of twelve cases reported in the literature makes it possible to describe the characteristics of coronary embolism in mitral stenosis, a rare complication but indicating the presence of a left intra-atrial thrombosis: -- variable clinical picture, dominated by a syndrome combining simultaneously a picture of myocardial infarction and of peripheral arterial emboli of other localizations; -- diagnosis to be discussed within the framework of coronary syndromes in mitral heart disease: embolism requiring to be distinguished from coronary atherosclerosis combined with mitral stenosis, more rarely a functional coronary insufficiency; -- severe course and prognosis: besides the possibility of rapidly lethal cases, coronary embolism seems liable to result in weakening and diminishing of the adaptation possibilities of the left ventricle, responsible for attacks of heart failure after mitral valvulotomy.