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Biomedical subjects

M Boivin

Publications and source records attributed to M Boivin.

At least 37 records · Page 2Linked to original sources
PubMed1997

Management of complicated gastroesophageal reflux disease: atypical chest pain.

Although most patients with gastroesophageal reflux disease (GERD) present with the classic symptoms of heartburn and acid regurgitation, many complain of atypical chest pain suggestive of cardiac disease. Once cardiac ischemia has been excluded, it is important to consider GERD because this may be established as the cause of pain in 10% to 50% of such patients. If GERD is suspected or documented, vigorous antireflux treatment, preferably with proton pump inhibitory therapy, is indicated.

Chest Pain↗
PubMed1995

Eimeria magna: pathogenicity, immunogenicity and selection of a precocious line.

A precocious line (PrEmag) of Eimeria magna in rabbits was obtained by selecting for early development of oocysts. The prepatent period was shortened by 46 h. The pathogenicity of PrEmag was substantially reduced and its reproductive potential was much lower (500 times) than that of the parent strain. Rabbits given 2500 oocysts of PrEmag were almost totally protected against a challenge with the parent strain. As in other precocious lines of coccidia from the rabbit, PrEmag showed morphological anomalies of the sporulated oocysts. Each sporocyst harboured one large refractile body instead of the two smaller ones in the parent strain.

Animals↗
PubMed1995

Individual-group behavioral similarity and peer status in experimental play groups of boys: the social misfit revisited.

This study evaluated individual-group similarity and dissimilarity hypotheses generally stipulating that the behavioral correlates of status are moderated by the peer group context in which they are displayed. Thirty play groups of 5 or 6 unacquainted same-age boys participated in five 45-min sessions. Five behaviors described group and individual characteristics: reactive aggression, proactive aggression, solitary play, rough-and-tumble play, and positive interactive behavior. Individual social preference scores were computed following a variant of the J. D. Coie and K. A. Dodge (1983) procedure. The behavioral correlates of emerging peer status were examined as a function of the group's behavioral norms. Evidence of a dissimilarity effect was found for solitary play and reactive aggression whereas positive interactive behavior followed a rule of similarity.

Child↗
PubMed1995

Gastric emptying of solid food in edentulous patients.

Whether mastication of food by teeth is a physiological contributor in the process of nutrient digestion remains a debatable issue. In this study we sought to determine whether mastication could influence the gastric emptying of solid food. In 8 edentulous patients, we measured the gastric emptying of a test meal ingested with or without their dental prostheses. Clinical dental evaluation and Helkimo chewing test were first performed to verify that the mastication deficiency was adequately corrected by the dental prostheses. A mixed meal containing ten cubes (1.5 cm) of beef liver labeled with 99mTc and mixed in a chicken stew was ingested by the subjects and followed by gamma camera external scintigraphy. The gastric emptying rate of the 99mTc-labeled liver was similar whether the meal was ingested with the denture properly inserted, allowing normal mastication of the liver cubes, or whether the food was swallowed unmasticated in the absence of functional prostheses (Tlag = 60 +/- 5 vs. 58 +/- 11 min, p = NS; T1/2 = 73 +/- 21 vs. 55 +/- 10 min, p = NS; Tlag+T1/2 = 133 +/- 19 vs. 114 +/- 17 min, p = NS). These results show that gastric trituration and emptying of solid food was not facilitated by prior mastication.

Dentures↗
PubMed1995

Prosthetic relining and dietary counselling in elderly women.

A reduced consumption of hard-textured fibrous foods may promote the development of digestive disturbances in more susceptible elderly people who wear prostheses having deficient masticatory function. The purpose of this study was to evaluate the effects of a program combining denture relining and dietary counselling on the masticatory performance, fibre intake, and prevalence of digestive symptoms in elderly women with low chewing efficiency. This program was provided to 55 women between 55 and 74 years of age. Chewing ability was assessed quantitatively with the Swallowing Threshold Test Index (STTI), and qualitatively according to the participants' experience in chewing five specific foods. Nutritional data were collected using a food frequency questionnaire. The mean value of the STTI was significantly increased at three weeks and at six to nine months after completion of relining by 37 and 31 per cent, respectively. Subjects included one more food in their diet at the end of the six- to nine-month period only. Fibre intake from vegetables was significantly increased by 18 per cent, while colonic and gastrointestinal symptoms were both reduced. Prosthetic relining increased the masticatory performance of elderly women, but not to a functional level. In addition, dietary counselling stimulated subjects to eat foods that had previously been avoided. These observations suggest that the improvement of chewing efficiency, combined with dietary counselling, could reduce the presence of digestive symptoms.

Aged↗
PubMed1994

Studies on the structure-activity of motilin in vivo. Effect of motilin synthetic analogues in conscious dog.

Synthetic analogues of motilin were tested for their capacity to stimulate the intestinal motor activity of the conscious dog. Physiological doses (75 pmol/kg) of motilin 1-22 and of motilin fragments 1-21, 1-20 and 1-19 induced premature periods of phase III activity in all tested animals. Motilin fragments 1-15, 1-12, 1-11 and 1-10 failed to influence the intestinal myoelectrical activity even when given at doses 10-times superior (750 pmol/kg). Motilin-like-immunoreactivity was measured in plasma during the analogues infusion. During the infusion of the bioactive analogues (1-22, 1-21, 1-20, 1-19), plasma motilin increased by 174 +/- 25 fmol/ml while a small rise (22 +/- 7.6 fmol) was noted with the inactive fragments (P < 0.001). Our data are in agreement with the in vitro findings that the N-terminal portion of the motilin molecule is responsible for its biological activity and suggests that the middle portion of the molecule is important to prevent degradation and maintain biological activity in vivo.

Animals↗
PubMed1994

Eimeria media: selection and characterization of a precocious line.

A precocious line of Eimeria media was obtained by selection for early development of oocysts in rabbits. The prepatent period was reduced from 108 to 72 h. The precocious line was less pathogenic than the original strain, and its multiplication rate was lower. Rabbits given oocytes of the precocious line were totally immune to challenge with the original strain as assessed by change in weight gain but were partially protected as assessed by oocyst output. Selection for precocious development was accompanied by morphological changes in the sporulated oocytes; each sporocyst contained only one large refractile body instead of the two smaller bodies seen in the original strain.

Animals↗
PubMed1992

Mechanisms for postprandial release of motilin in humans.

Plasma concentrations of motilin rise in the first 30 min following the ingestion of a meal in man. To elucidate the mechanisms of this postprandial motilin release, we verified the effect of cerebral stimulation and of gastric distension, both events normally occurring in the early postprandial period, on plasma motilin concentrations. Cerebral stimulation was induced by modified sham feeding (MSF) and gastric distension was done by inflating (with 0, 60, 240, or 480 cc of air) a latex balloon positioned in the gastric fundus. The experiments were performed in healthy volunteers where antroduodenal contractile activity was continuously recorded and where plasma motilin was measured each 10 min. The stimuli were administered 30 min after a phase III of the migrating motor complex (MMC) was seen migrating from the antrum to the duodenum. The interval period between two successive spontaneous peak increases in plasma motilin was estimated at 113.7 +/- 8.5 min in 24 historical control subjects, and it lasted 97 +/- 13 min in the five control volunteers here distended with 0 cc of air (P = NS). This interval was significantly (P < 0.05) shortened with MSF (70 +/- 6.3 min) or following distension with 60 cc (60 +/- 11.4 min), 240 cc (54 +/- 1.9 min) or 480 cc of air (45 +/- 3.2 min). During the 60-min period following the administration of the stimuli, phase IIIs were not seen in the subjects distended with 0 cc of air or in those submitted to MSF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Motilin and the postprandial motility of the antrum.

This study was designed to establish whether the rise in plasma motilin observed after a meal in humans can influence the postprandial motor activity of the antrum. Antroduodenal postprandial motility profiles and indices obtained from 5 controls and 5 subjects infused with exogenous synthetic motilin (0.1 microgram.kg-1) or with the motilin receptor agonist erythromycin lactobionate (200 mg) were compared. Motilin infusion increased plasma motilin concentrations about 5 times above the physiological range but failed to modify the normal postprandial contractile response. On the other hand, in 4 of the 5 subjects, erythromycin induced an intense motor response that mimicked phase III of the migrating motor complex. Our study demonstrates that, during the postprandial period, motilin antral receptors can be stimulated only with doses of motilin exceeding the physiological plasma concentrations, and that the motor effect obtained did not mimic the usual postprandial motility pattern. Our results, therefore, do not support the proposal that the postprandial motility of the antrum is regulated by the plasma levels of motilin.

Adolescent↗