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Biomedical subjects

J Hellemans

Publications and source records attributed to J Hellemans.

At least 37 records · Page 2Linked to original sources
PubMed1979

Motilin and the interdigestive migrating motor complex in man.

In order to assess the possible role of the new candidate gut hormone, motilin, in controlling the interdigestive migrating motor complex (MMC) in man, 14 normal subjects were studied after an overnight fast by means of three pressure-recording catheters with orifices 25 cm apart in the upper small intestine. The typical aboral progressing bursts of pressure waves occurred at a mean interval of 137 minutes and were preceded by a peak motilin level 25 pmol/liter higher than the lowest level in the postactivity-front quiescent period. To study the effect of exogenous motilin, an infusion of pure porcine motilin at various dose levels was given to 16 normal volunteers shortly after the onset of the phase I quiescent period. Motilin infusion induced an activity front in 12 of the 16 subjects. The mean activity front interval was reduced to 46 min (P less than 0.001). This effect could be obtained even at the low dose level of 0.4 pmol/kg/min, which produced an increase in plasma motilin level of only 57 pmol/liter. These data suggest that a cyclic rise in plasma motilin levels is one of the factors involved in the production of the activity front of the migrating motor complex in man.

Adolescent↗
PubMed1979

Achalasia, diffuse esophageal spasm, and related motility disorders.

From 1972 to 1977, the authors observed 156 patients with primary esophageal motility disorders which caused such a severe degree of dysphagia that treatment by pneumatic dilatation was deemed necessary. Before dilatation, 24% of the patients presented with motility disorders that did not fit well into the two classical disease entities, diffuse esophageal spasm and achalasia (absence of peristalsis with presence of lower esophageal sphincter (LES) relaxations or presence of peristalsis with absence of LES relaxations). After treatment with pneumatic dilatation, these "intermediate" forms constituted 45% of the motor disorders. This was due mainly to the reappearance, on manometric tracings, of peristaltic contractions and of LES relaxations. Radiologic and manometric observations suggest that in many patients, this "return of peristalsis" may be an apparent change in pressure pattern rather than a real change in motility. In 6 of the 156 patients, a deterioration of the esophageal motility disorder was observed, which was characterized by the loss of peristalsis and of LES relaxations over a period of a few months or years. The frequent occurrence of intermediate types of motility disorders and the transition from diffuse spasm to achalasia suggest that achalasia and diffuse esophageal spasm are part of a spectrum of related motor disorders.

Adolescent↗
PubMed1978

Glucose intolerance during diuretic therapy. Results of trial by the European Working Party on Hypertension in the Elderly.

119 elderly, hypertensive patients were followed-up for 1 year and 48 for 2 years in a double-blind, randomised, controlled trial in which they received either placebo or 25-50 mg hydrochlorothiazide and 50-100 mg of triamterene daily. Half of the active treatment group also received 250 mg to 2 g methyldopa daily. After 2 years the active treatment group had an average increase in fasting blood-sugar of 9.6 mg/dl compared with an average fall of 3.1 mg in the placebo group (p less than 0.001). Blood-glucose rose by an average of 26.6 mg/dl in the active group when determined 1 hour after 50 g oral glucose and decreased by an average of 5.3 mg/dl in patients who had been on placebo for two years (p less than 0.05). The hyperglycaemic effect of diuretics appeared to be related to potassium loss since, in both groups, impairment of glucose tolerance was most marked in those in whom the serum-potassium decreased over the 2 years.

Aged↗
PubMed1978

Disruptive effect of test meals on interdigestive motor complex in dogs.

The disruptive effect of food and food components on the migrating myoelectric complex (MMC) was studied in conscious dogs. Three types of test meals were fed, and the interval between feeding and the reappearance of the first phase III of the MMC was determined. When commercial dog food was used a linear relation was observed btween the quantity of food (expressed as kcal/kg body wt) and the duration of the disruption of the MMC. Equicaloric amounts of the three major food components disrupted the MMC pattern for periods of time that were related to the nature of the food: the effect of arachis oil lasted longer than that of sucrose and much longer than that of milk protein. Medium chain triglycerides had a potent disruptive effect. Mixtures of these food components produced a disruptive effect that could not be calculated from the individual effect of each component. Phase III of the first and second MMC after feeding started at a lower level of the intestine than after a long fast. The duration of disruption of the MMC after a meal depends much more on the physicochemical composition of the food than on its volume or amount of calories.

Action Potentials↗
PubMed1978

Role of gastrin and insulin in postprandial disruption of migrating complex in dogs.

The duration of the disruption of the interdigestive migrating myoelectric complex (MMC) by various test meals in dogs was correlated with changes in serum gastrin and insulin levels. The test meals consisted of milk protein, sucrose, arachis oil and medium chain triglycerides (MCT). Intravenous infusions of glucose 20% were also used. Electrical activity of the small intestine was registered by means of electrodes implanted over the entire length of the gut. Hormones were assayed by radioimmunoassay techniques. The insulin level rose significantly after both the glucose infusion and the sucrose meal. The rise was small after the milk protein meal and nothing after arachis oil and MCT. Gastrin level was not changed by arachis oil or MCT and rose slightly after sucrose and milk protein. The MMC was not disrupted by glucose infusions, but was disrupted for 5--7 h by archis oil and for 6--12 h by MCT. We conclude that in dogs neither gastrin nor insulin have an important role in the mechanism of disruption of the MMC after feeding.

Action Potentials↗
PubMed1978

Antihypertensive therapy in patients above age 60. Third interim report of the European Working Party on High blood pressure in Elderly (EWPHE).

Three hundred forty nine hypertensive patients above the age of 60 have entered the double-blind multicentre trial of the European Working Party on High blood pressure in the Elderly (EWPHE). After stratification and randomisation half were treated with one or two capsules containing 25 mg hydrochlorothiazide and 50 mg triamterene and if blood pressure control was insufficient methyldopa was added up to 2 g daily; the other half received matching placebo. No significant differences between the groups were present prior to randomisation. A significant blood pressure difference of 25/10 mm Hg was obtained between the groups and maintained during two years of follow-up. No major disturbances in serum potassium or serum sodium were noted with the present drug combination. However, during the initial phase an increase in serum creatinine and serum uric acid was noted in the actively treated group, which was maintained for two years. Also glucose tolerance was impaired after 2 years in the actively treated group. A favourable influence on prognosis by active treatment can be expected on the basis of the blood pressure reduction and in the absence of major electrolytes disturbances. But this benefit must be proven by observed statistical differences in terminating events between the groups. Therefore the patients are being followed for a longer period of time and more patients are admitted into the trial.

Aged↗
PubMed1977

Antihypertensive therapy in elderly patients. Pilot trial of the European Working Party on High Blood Pressure in the Elderly.

A study protocol for a double-blind randomised control trial of hypotensive treatment in elderly hypertensive patients has been tested in a number of pilot centres throughout Europe. It was shown that this study is possible from the logistic point of view. In these elderly patients, hydrochlorothiazide + triamterene treatment with or without methyldopa, maintained a significant hypotensive effect in the absence of major electrolyte disturbances. The initiation of hypotensive therapy did not provoke an excess of cardiovascular complications. The influence of hypotensive therapy on the general well-being and on the morbidity and the mortality of elderly patients with high blood pressure, is thereby being assessed. The study will continue for 5 years and other centres are invited to join.

Aged↗
PubMed1977

The interdigestive motor complex of normal subjects and patients with bacterial overgrowth of the small intestine.

Intraluminal pressures were measured in the gastric antrum and at different levels of the upper small intestine in 18 normal subjects to investigate whether or not the interdigestive motor complex, identified in several animal species, occurs in man and, if so, to determine its characteristics. In all normal subjects, the activity front of the interdigestive motor complex was readily identified as an uninterrupted burst of rhythmic contraction waves that progressed down the intestine and that was followed by a period of quiescence. Quantitative analysis of various parameters of the complex and simultaneous radiological and manometrical observations revealed that it resembled closely the canine interdigestive motor complex. To test the hypothesis that disorders of this motor complex may lead to bacterial overgrowth in the small intestine, similar studies were performed in 18 patients with a positive (14)CO(2) bile acid breath test and in an additional control group of 9 patients with a normal (14)CO(2) breath test. All but five patients had normal interdigestive motor complexes. The five patients in whom the motor complex was absent or greatly disordered had bacterial overgrowth as evidenced by (14)CO(2) bile acid breath tests before and after antibiotics. These studies establish the presence and define the characteristics of the normal interdigestive motor complex in man. They also suggest that bacterial overgrowth may be due to a specific motility disorder i.e., complete or almost complete absence of the interdigestive motor complex.

Adolescent↗
PubMed1976

Endogenous motilin and the LES pressure.

The changes in LES pressure were measured after alkalinization and subsequent acidification of the antrum or duodenum. For the alkalinization of the antrum, a strong (sodium-hydroxide) and a weaker alkaline stimulus were used in different subjects. At the end of the experiments, glycine 5% was infused into antrum and glycine 5% or phenylalanine 0.1 N into the duodenum. Plasma samples were drawn for determination of the motilin levels. Although in some experimental situations, motilin levels and LES pressure were significantly correlated, any correlation was lacking in other test situations. It may be concluded that the role of endogenous motilin for the regulation of the LES pressure is either non-existent or frequently overwhelmed by other influences.

Duodenum↗
PubMed1976

Peristalsis in smooth muscle esophagus after transection and bolus deviation.

The importance of the continuity of the muscle coat and of the presence of an intraluminal bolus for the peristaltic performance of the Rhesus monkey esophagus was studied. Transection and reanastomosis with muscle-to-muscle contact in the striated muscle part of the esophagus did not interfere with the progression of primary peristaltic contractions. However, when the transection with reanastomosis was performed in the smooth muscle part of the gullet the peristaltic progression of the deglutitive contraction waves in the segment below the transection was affected. After deviation of the swallowed bolus either in the cervical striated esophagus or in the smooth muscle part of the thoracic esophagus, primary peristaltic contractions were seen to progress over the entire length of the gullet; however, in the thoracic esophagus the presence of a bolus facilitated the peristaltic progression of primary waves. These studies also indicate that the extramural vagal innervation is involved in secondary peristaltic contractions of the smooth muscle esophagus.

Animals↗