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Biomedical subjects

J Hostein

Publications and source records attributed to J Hostein.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Chronologic relationship between gastroesophageal reflux and asthma. Simultaneous study of the measured pH and respiratory function].

UNLABELLED: The aim of the study was: 1) to define the frequency of gastroesophageal reflux (GER) in asthmatics; 2) to study a possible relationship between episodes of GER and changes in airflow obstruction while maintaining as far as possible physiological conditions. Nineteen consecutive patients (aged 40.3 +/- 19 years) presenting with severe asthma requiring continuous treatment, were studied in a stable period. All treatments were stopped for 12 hours before the examination, except corticosteroids and sustained theophylline. Esophageal pH was measured continuously one hour before and three hours after a standardized meal. Respiratory function was measured every 30 minutes using a miniaturized spirometer which enabled the measurement of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1-VC ratio: 1) the frequency of pathological GER was defined by a Kaye's score greater than 90 and was 32%; 2) there was no significant correlation between the individual changes in FEV1 and different variables for the pH measured in the 30 mn before the measurement of bronchial obstruction (number of GER episodes, duration of GER, duration of the last GER episode, time of the last GER); 3) we have found no significant difference between the variation of FEV1 above or below 10% of the best FEV1 of each patient in relation to the quality (intensity, duration, delay) of GER episodes recorded 10 minutes before the spirometry. IN CONCLUSION: in severe asthmatics these results: 1) confirm the high frequency of pathological GER; 2) do not allow the establishment of a direct causal relationship between GER episodes and occurrence of a bronchial obstruction.

Adult↗
PubMed1988

[Reduction of postprandial gastroesophageal reflux with sodium alginate in suspension. Multicenter pH study in 21 patients].

The purpose of this study was to ascertain the pharmacological effectiveness of sodium alginate liquid in the treatment of gastroesophageal acid reflux. The pharmacological test selected was 3 hours postprandial oesophageal pH, because of the physico-chemical properties of this drug. Twenty-one patients of both sexes were included in this study. The initial pH measurement served both as inclusion criteria, by confirming the presence of gastric acid reflux, and as reference for the evaluation of the effect of sodium alginate liquid by a second pH determination after treatment. After treatment with sodium alginate liquid, the number and mean duration of episodes of reflux, as well as the time spent at each pH level, had significantly decreased as compared to the initial value. The gastroesophageal reflux score was significantly reduced during the second hour in recumbent posture, but none of the different parameters studied separately (number and mean duration of episodes of reflux and time spent at each pH level) was significantly decreased. This study demonstrates the pharmacological effectiveness of the drug during the post prandial period and indicates that it is more effective in upright than in supine position.

Adult↗
PubMed1988

Local nerve blockade by tetrodotoxin induces ectopic phase 3 of the migrating myoelectric complex in dogs.

The effect on the migrating myoelectric complex (MMC) of local nerve blockade in the jejunum was studied in five unanesthetized dogs. A silastic catheter was implanted in a terminal branch of a jejunal artery, perfusing a 5- to 10-cm segment, 45 cm below the ligament of Treitz. Small-bowel motor activity was studied electromyographically with implanted electrodes. Three different doses of tetrodotoxin (166, 333, 500 ng/kg/h) were administered intra-arterially for 5 h. During the 333- and 500-ng but not during the 166-ng/kg/h perfusions ectopic activity fronts started just below the perfused segment. At this time no phase-3 activity was observed in the proximal bowel. In addition to ectopic fronts normal MMCs were observed during the perfusions. These observations show that local nerve blockade induces phase-3 activity, probably by inhibiting an inhibitory nerve action.

Animals↗
PubMed1988

Scintigraphic study of duodenogastric reflux. Value of a computerized image-subtraction method.

Duodenogastric reflux (DGR) could be implicated in several esophageal and gastric diseases. Establishing its pathophysiological role however is difficult because of the problems in the demonstration and quantification of DGR episodes. The aim of this study was to improve a scintigraphic method of detection and quantification of DGR episodes during the postprandial period in man. The study was carried out in 14 control subjects (7 males and 7 females, median age = 25 years, range: 22-35 years). As scintigraphic recording was continuous during 150 min, all DGR episodes were revealed. In order to improve visual detection of DGR episodes, images were treated by a computerized image subtraction method. The visual detection limit of DGR episodes determined by comparison to test images was 0.6 p. 100 of the dose injected intravenously or 17 microCi. A DGR episode was demonstrated in one of the 14 control subjects. The quantity of refluxed liquid was estimated, in this case, at 30 microCi, and the duration of the reflux greater than 2 min. Continuous scintigraphic recording in association with a computer based technique of image subtraction seems to improve scintigraphic performance in the study of DGR episodes under pathological conditions.

Adult↗
PubMed1987

[Ambulatory recording of esophageal pH over a 24-hour period in a population of 27 control subjects: analysis of technical and methodological factors influencing results].

Twenty-four hour pH monitoring is used increasingly as a technique for diagnosis of gastro-esophageal reflux (GER). The Synectics recording apparatus (Stockholm, Sweden) was used in 27 ambulatory control subjects in order to: identify the variations of the data-dependent factors (electrodes, buffer solutions, calibration, placement of esophageal electrode). The consequences of these variations were evaluated by studying the measurement deflection after 24 h, baseline variations, and a comparative double pH esophageal recording with reference equipment for 3 h postprandial; to provide normal values for several parameters of GER measurement under the conditions of this study (total number of reflux, number of reflux episodes longer than 5 min, duration of the longest reflux, percentage of time during which pH was less than 4.0). Important interindividual variations were observed. When interpreting the results provided by this type of apparatus, one should take into account these large variations due, first, to the technique used and second, to the conditions of ambulatory recording.

Adult↗
PubMed1987

[Diagnostic value of gastric pHmetry in duodenogastric reflux].

Several studies have been performed to examine the problem of diagnosing gastroduodenal reflux (GDR). No single method is widely accepted. The aim of this work was to evaluate the diagnostic value of gastric pHmetry in this regard. A gastric aspiration probe attached to a combined glass electrode was placed in the stomach of 24 patients, with its distal tip located between 9 and 12 cm below the cardia. One ml samples of gastric juice were taken from 8 of the patients every 30 min for 15 h and as well as, every time a spontaneous alkalinization (SA) (defined by a pH greater than or equal to 4 for at least 1 min) was observed. The pH of each sample was measured by colorimetry whereas the concentration of total biliary acids (CTBA) was evaluated by the fluorimetric method (Kit Sterognost 3 alpha Flu); pH value measured via the intragastric electrode during aspiration was also recorded (protocol A). Continuous gastric aspiration was carried out in the remaining 16 patients for the entire duration of the test (6 h) which was divided into periods of 20 min. Apart from the parameters evaluated during protocol A, the percentage of time during which the stomach had a pH greater than or equal to 4 was recorded, as well as the quantity of total biliary acids collected over the 20 min periods (protocol B). Correlation studies were carried out using the Kendall tau and Spearman tests. Percentages were compared using the chi 2 test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Gastric emptying of a solid-liquid meal in gastroesophageal reflux in adults].

Several studies concerning the relationships between gastroesophageal reflux (GOR), gastric emptying and esophageal motility are available. So far, results have been contradictory. The purpose of this work was to study gastric emptying in patients with GOR; to search for simultaneous esophageal motility disorders and to specify their type and frequency; to establish a potential relationship between motor disorders of the esophagus and the stomach in these patients. Thirty-two consecutive patients were selected according to clinical criteria, i.e. presence of at least two of the three characteristic symptoms of GOR, and the data of a three-hour post-prandial pH-metry. Gastric stasis related clinical manifestations (nausea, post-prandial vomiting, sensation of abdominal distension or of post-prandial epigastric fullness) were also searched for in all patients. A gastroscopy allowed to score esophagitis in each case. All patients, including adult controls underwent an esophageal manometry as well as a radionuclide determination of gastric emptying, after isotopic labelling of the solid (S) and liquid (L) phases of a test meal. The results showed that there was no significant modification of gastric emptying of the S and L phases of the meal in the group of patients with GOR whatever the intensity of the reflux, judged on the pH-metry results and the endoscopic data. Thus the average time of gastric half-emptying of S and L was respectively 115 and 52 min for the patients vs 111 and 51 min for the control group. As well, no correlation was found between the gastric emptying parameters and the presence or absence of clinical signs of gastric stasis or the amplitude of esophageal contraction waves. On an individual basis, two patients showed a significant decrease in gastric emptying of either the S or L phases without any attendant modification in the kinetics of the other. These results suggest that, in the adult, gastric emptying cannot be considered to be a determining factor of GOR and there are no diffuse motility disorders of the upper digestive tract during this illness.

Adult↗
PubMed1985

[Esophageal motility in Raynaud's disease, systemic scleroderma and presclerodermal Raynaud's syndrome].

Fifty-five consecutive subjects with Raynaud's phenomenon were submitted to esophageal manometry. According to the results of clinical examination and periungual capillaroscopy, they were divided into three groups: sixteen patients presented presclerodermal Raynaud's phenomenon, and nineteen, systemic sclerosis; twenty others had Raynaud's disease. Twenty volunteers formed the control group. Esophageal motor disorders were observed in the group with presclerodermal Raynaud's phenomenon, affecting the esophageal lower sphincter and the peristalsis of the body of the esophagus. In the group with systemic sclerosis, these motor disorders were associated with alterations in the amplitude and the duration of contractions. Esophageal motility was normal in subjects with Raynaud's disease. We can conclude that: 1) esophageal motor disorders can be seen in presclerodermal Raynaud's phenomenon. The kind of abnormalities observed at this stage of the disease are in favor of an early alteration of the neurogenic component of esophageal motility; 2) there is no relationship between esophageal motor disorders and Raynaud's phenomenon in scleroderma.

Adult↗
PubMed1985

[Gastric emptying of a solid-liquid meal in normal subjects: validity of the labeling (99mTc) of chicken liver by a multipuncture technic].

For gastric emptying studies of a solid-liquid meal by the scintigraphic method, a valid isotope labeling method for each phase of the meal must be obtained. The aim of this study was to validate a simple chicken liver labeling method in normal subjects by multipuncture technic with 99mtechnetium. Labeling according to Meyer's method was chosen as a reference. Simultaneously, a study of the quality of liquid phase labeling by 111indium was done. The labeling process quality for each phase of the meal was assessed: a) in vitro, after incubation of the meal with human gastric juice (n = 12); b) in vivo, after meal ingestion and sequential collection of gastric contents by aspiration (n = 4). Furthermore, in 8 healthy volunteers, gastric emptying curves of the solid and liquid phases of the meal were determined scintigraphically and compared. Our results showed: a) for the solid phase: a good specificity of the marker, which was assessed in vitro and in vivo, after liver labeling with multipuncture technique (89 p. 100 and 92 p. 100 after 180 min, respectively); b) for the liquid phase: a good specificity of the marker in vitro and a poor specificity in vivo (82 p. 100 and 27 p. 100 after 180 min, respectively); c) similar half-gastric emptying times and cumulative percentages for the solid and liquid phases with both liver labeling methods. In conclusion, the multipuncture technique for chicken liver labeling may be used for gastric emptying studies in humans.

Adult↗
PubMed1984

Somatostatin induces ectopic activity fronts of the migrating motor complex via a local intestinal mechanism.

To study the peripheral effect of somatostatin in dogs a tiny Silastic catheter was implanted in an almost terminal branch of the mesenteric artery, providing blood supply to a jejunal segment of 5-10 cm. In 4 dogs one catheter was implanted, perfusing a small bowel segment about 60 cm below the angle of Treitz; in 3 dogs two catheters were implanted, perfusing two small bowel segments about 30 and 60 cm below the angle of Treitz. The catheter was kept open by continuous perfusion with a diluted heparin solution by means of a portable insulin infusion pump fixed to the animal's protection jacket. Small bowel motility was recorded electromyographically. Experiments were started 2 wk after surgery and were performed in conscious fasted animals. Control experiments using intraarterial saline perfusion showed normal migrating motor complexes in the perfused segment. Intraarterial perfusion of somatostatin (50-200 ng/kg X h) induced ectopic activity fronts, which always started just distal to the perfused segment and progressed down the small bowel at a normal propagation velocity. During the occurrence of ectopic fronts no activity fronts were observed in the small bowel proximal to the perfusion site. Apart from ectopic fronts, normal activity fronts, starting in the duodenum and passing the perfused segment, were also observed. The most proximal part of the jejunum was more sensitive to intraarterial somatostatin than the more distal jejunum. Intravenous infusion of the same doses of somatostatin had no effect. Somatostatin, therefore, seems to induce ectopic fronts via a local mechanism. We propose that somatostatin is able to relieve the intestine locally from an inhibitory mechanism that prevents the development of activity fronts.

Action Potentials↗
PubMed1983

[Effects of propantheline on the motor activity of the normal human esophagus].

The aim of this study was to examine the action of orally administrated propantheline bromide, an anticholinergic agent, on esophageal motor function. To evaluate these effects a double blind randomized study was carried out in ten normal volunteers. An optimal effective dose for each subject was determined according to the Sun and Shay method. Esophageal motor activity following dry and wet swallow was markedly altered by propantheline. This drug: a) dramatically lowered the peristaltic wave amplitude in the smooth muscle part of the esophagus (P less than 0.001); b) decreased the wave velocity in the proximal part of the smooth muscle (P less than 0.05), and c) increased the frequency of both the non peristaltic and repetitive waves (P less than 0.001). On the other hand propantheline weakly but significantly diminished the lower esophageal sphincter resting pressure (P less than 0.05). These results suggest that: a) the peristaltic function of the human esophageal smooth muscle is greatly dependent on muscarinic neurotransmission, and b) in patients with gastroesophageal reflux, orally as well as parenterally administrated anticholinergic agents are contraindicated.

Administration, Oral↗