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Biomedical subjects

M Wienbeck

Publications and source records attributed to M Wienbeck.

At least 145 records · Page 8Linked to original sources
PubMed1985

Esophageal disorders in the etiology and pathophysiology of dyspepsia.

Dyspepsia may be caused by reflux esophagitis. We evaluated the symptoms of 45 patients aged 52 +/- 14 years who had a follow-up of 1 to 5 years. Endoscopy and histology demonstrated microscopic inflammation in 14, isolated mucosal defects in 12 and severe inflammation in 19 of the 45 patients. Belching was the leading symptom in patients with microscopic and severe esophagitis, heartburn in mild esophagitis. Upper abdominal pain, nausea and vomiting were present in 31%, 24% and 22% of the patients, respectively. Thus, reflux esophagitis is frequently accompanied by symptoms of dyspepsia which resemble those of other causes of dyspepsia. In contrast, disorders of gastric and intestinal motility may be associated with esophageal motor disturbances, particularly in gastric dysrhythmia, diabetic gastroenteropathy, irritable bowel syndrome, and idiopathic intestinal pseudo-obstruction. How much the esophagus contributes to the clinical symptomatology of dyspepsia awaits further elucidation.

Adult↗
PubMed1985

Different actions of 2 antidiarrheal agents, lidamidine and loperamide, on motility of the isolated cat colon muscle.

Besides their action on intestinal absorption and secretion antidiarrheal agents may affect gastrointestinal motility. Little is known about motor actions in the large intestine. Therefore, the effects of loperamide and lidamidine on contractile and myoelectrical activity were studied in strips of the circular muscle of the cat colon in vitro. Both drugs caused a concentration dependent increase in spontaneous contractions, but the potency of loperamide was greater than that of lidamidine and the efficacy of lidamidine greater than that of loperamide. The corresponding EC50 were 2.9 X 10(-9) M and 1.4 X 10(-5) M, respectively, and the EC100 2.7 X 10(-7) M and 10(-4) M, respectively. In the myoelectrical tracings loperamide stimulated predominantly spike activity, lidamidine oscillatory potentials. The effect of loperamide was antagonized by naloxone, thus indicating an action on opiate receptors. The effect of lidamidine was not inhibited by a variety of drugs. Tetrodotoxin and alpha-adrenergic inhibitors even exaggerated the lidamidine effect, probably by a suppression of tonic nervous inhibition. The receptor for the lidamidine action has yet to be determined. In conclusion, the motor effects may play an important role in the antidiarrheal action of loperamide, but probably not in that of lidamidine, at least not within the range of clinically used doses.

Animals↗
PubMed1984

Local inhibition of myoelectrical activity of human colon by loperamide.

In order to study whether the antidiarrheal effects of loperamide are largely brought about by a local inhibition of the drug, we applied doses of 0.2 mg directly on the mucosa of the descending and sigmoid colon of 33 healthy volunteers. Loperamide decreased BER frequencies and reduced spike activity to 6.6 +/- 0.3% of time vs 11.3 +/- 0.7% in the control recorded from 3 cm aside and to 5.8 +/- 0.4% vs 12.7 +/- 0.9% in the descending and sigmoid colon, respectively. The same effects became apparent when spike activity was stimulated by neostigmine. Loperamide also reduced the occurrence of groups of spikes to 3.8 +/- 0.4/hr vs 10.3 +/- 0.6 and to 3.6 +/- 0.4/hr vs 14.6 +/- 0.7 in the descending and sigmoid colon, respectively. Groups of spikes are thought to be the equivalent of propulsive movements. Thus, loperamide is active locally and exhibits inhibitory effects on the motor activity of the colon. Clinical studies seem warranted to examine the effectiveness of loperamide enemas in motility disturbances of the anorectum.

Adult↗
PubMed1984

Pentagastrin induced motility pattern in the human upper gastrointestinal tract is reversed by proglumide.

The effects of pentagastrin and the putative gastrin antagonist proglumide on interdigestive motility of the upper small bowel were studied in a randomised double blind study in 10 healthy human volunteers. Intraluminal pressures were recorded manometrically in the duodenum and jejunum for five hours. Sixty minutes after starting a pentagastrin infusion (0.15 micrograms/kg/h) either placebo or proglumide was infused intravenously. Pentagastrin converted the normal interdigestive motility to irregular motor activity, while proglumide restored the periodic fasted pattern. We conclude that gastrin is a likely candidate involved in the conversion of the fasted to the fed motility pattern in the human upper gut.

Duodenum↗
PubMed1984

Therapeutic possibilities in colonic motility disorders.

Colonic motility disorders can be treated by changing the diet, modifying the patient's daily behaviour, giving drugs to enhance or inhibit colonic contraction, or by performing surgery. Therapy in constipation mainly relies on the use of bulk-forming agents, in addition to a change in behaviour. Dietary fibre, particularly bran, appears to be effective in diverticular disease. Bowel atony is largely caused by increased sympathetic activity, and thus frequently responds to sympatholysis. In the irritable bowel syndrome, amelioration is achieved by taking bran and omitting badly tolerated food; antispasmodics and psychotherapy are also probably beneficial. Diarrhoea and incontinence may be treated by opioids, such as loperamide. Recent progress has been mainly in the understanding of the pathophysiology of these disorders, but rapid therapeutic advances are now taking place.

Colonic Diseases, Functional↗
PubMed1984

[2 or 4 daily doses of cimetidine in the treatment of gastric ulcer?].

In a randomized multicentre study of 149 patients with gastric ulcer the effect of 1000 mg cimetidine daily applied in four separate doses was compared to that of 400 mg cimetidine twice a day. In both patient groups similar healing rates were observed. 80.3% and 74.0%, respectively, of the ulcers healed within 6 weeks, and 93.8% and 90.3%, respectively, within 10 weeks. Abdominal pain and antacid consumption decreased under both regimens to a similar degree. Drug safety was good. Lower cost and simplicity in the administration make the b. i. d. regimen of cimetidine preferable to the q. i. d. regimen in the acute treatment of gastric ulcer.

Alcohol Drinking↗
PubMed1984

Modulation of the adrenergic system in the treatment of postoperative bowel atonia.

Sympathetic hyperactivity is considered to be the most important factor in the development of postoperative bowel atonia. In a double-blind study we evaluated the gut motor effects of dihydroergotamine, which predominantly acts as a sympatholytic agent in the gastrointestinal tract. Forty-six patients undergoing cholecystectomy received either 0.5 mg dihydroergotamine + 5000 U heparin or 5000 U heparin alone (controls) twice daily in a randomized order starting on the morning of the operation. The first postoperative bowel movement occurred 57 +/- 4 h (means +/- SEM) after operation in the patients receiving dihydroergotamine, compared with 102 +/- 4 h in the control patients (p less than 0.001). Electromyography performed in the stomach and upper small bowel on the 3rd postoperative day showed an increase in the number of activity fronts of the interdigestive migrating motor complex and in the duration of spike activity under the influence of dihydroergotamine compared with the controls (p less than 0.001). It is concluded that dihydroergotamine stimulates depressed gut motility after abdominal surgery and that sympatholysis is the likely mechanism of action.

Adrenergic Fibers↗
PubMed1984

Motility of the terminal ileum and ileocecal sphincter in healthy humans.

Factors controlling the transit of contents between the ileum and cecum should be important determinants of intestinal function; however, the dynamics of the ileocecal region remain largely unexplored in healthy humans. Accordingly, prolonged recordings of intraluminal pressure were obtained from the distal ileum, across the ileocecal sphincter, and from the proximal colon of healthy adults. In one set of studies, 16 subjects each contributed 6 h of basal, fasting recordings; in 2 of the 16, postprandial patterns were also recorded. In a second set, 6 fasting subjects were studied for a total of 120 h. Less than 10% of interdigestive cycles (migrating motor complexes) reached the ileocecal sphincter. The remainder faded out and merged into an active, apparently random pattern of pressure waves that became more intense closer to the sphincter. Discrete, short bursts of phasic pressures migrated rapidly for long distances in the distal ileum and a unique peristaltic wave also migrated rapidly, though infrequently, through the region. Tonic pressures were recorded across the ileocecal sphincter but were present only during the passage of phasic pressure waves; basal tone was minimal. We believe these are the first prolonged observations of motility from the ileocecal sphincter of healthy humans. These descriptions provide insights into and a basis for further studies of a largely unexplored area of the human bowel.

Action Potentials↗
PubMed1984

Breath hydrogen as a test for gastrointestinal transit.

Intestinal transit is an important indicator of small-bowel function. This study served to investigate oro-cecal and duodeno-cecal transit times of different carbohydrate test meals and to evaluate intra- and interindividual variability of the breath hydrogen test. Breath hydrogen was analysed by an electrochemical cell in 25 healthy volunteers. Oro-cecal transit time of lactulose was much shorter than that of a standardized normal test meal. Duodeno-cecal transit was approximately one hour shorter than oro-cecal transit. Considerable intra- and interindividual differences were observed. It is concluded that results of lactulose test meals do not permit conclusions as to the physiological situation. Large intra- and interindividual variability of transit times must be taken into account in any study using the breath hydrogen test.

Adult↗
PubMed1984

The effects of prostaglandins F2 alpha and E2 on the motility of the cat colon in vitro.

Controversy exists with respect to the motor effects of prostaglandins (PG) in the colon. We studied the actions of the prostaglandins F2 alpha and E2 on the spontaneous and stimulated contractions of the circular muscle of the cat colon in vitro. Both prostaglandins enhanced contractile activity. PG F2 alpha was more effective than PG E2, the ED50 were 4.2 X 10(-9) M and 2 X 10(-7) M, respectively. The prostaglandin antagonist 8 ethoxycarbonyl-5-methyl-10,11-dihydroxy-PG A1-ethyl-ester (HR 546) in a concentration of 10(-7) M shifted the ED50 of PG F2 alpha to the right by 1 log unit and unmasked motor stimulatory actions of low PG F2 alpha concentrations (10(-11) and 10(-10) M). The latter effect was atropine sensitive. In conclusion, PG F2 alpha and PG E2 stimulate contractions of the circular colon muscle at concentrations naturally occurring in the gut. It is conceivable that they play a role in the control of colonic motility, particularly in diseases like ulcerative colitis and Crohn's disease.

Animals↗
PubMed1983

[Prograde colonic irrigation without disturbance of the water-electrolyte balance].

The effects of four different irrigation solutions for preparation of colonoscopy were assessed in 64 patients. Using saline lavage solutions similar to plasma led to predominant symptoms of volume overload. Body weight transitorily increased by 1.7 +/- 0.2 kg, water and electrolytes were retained. Time until appearance of clear lavage fluid was 145 +/- 5 min. Irrigation by mannitol solution was badly tolerated and frequently led to vomiting. Body weight decreased and loss of water and electrolytes was reflected in changes of blood composition. Lavage with a hypertonic salt and mannitol solution (415 mosmol/l) was tolerated somewhat better. It led to minimal loss of weight, sodium (230 +/- 27 mmol) and chloride (270 +/- 24 mmol) were retained. Colonic cleansing was achieved after only 84 +/- 6 min. Isotonic saline mannitol solution with 105 mmol/l sodium, 93 mmol/l chloride, 10 mmol/l potassium and 22 mmol/l bicarbonate as well as 70 mmol/l mannitol (or 70 mmol/l polyethylene glycol) was tolerated best. There was a minimal weight increase (0.5 +/- 0.2 kg). Sodium metabolism was balanced (-2 +/- 7 mmol), chloride was retained to a slight extent (+ 115 +/- 29 mmol). Colonic cleansing was completed by 110 +/- 8 min.

Adolescent↗
PubMed1983

[Preoperative diagnosis of intra-abdominal diseases. Reliability of sonography and computer tomography].

In a retrospective study the reliability of ultrasound and computed tomography was compared and evaluated using the subsequent intraoperative findings. The analysis comprised ultrasound and computed tomography data of 111 consecutive patients in whom both investigations were performed within one week and whose diagnoses could be ascertained intraoperatively within two weeks. The correct diagnosis was made preoperatively in 80 out of 111 patients by ultrasound (sensitivity 72%) and in 95 out of 111 patients by computed tomography (sensitivity 85%). The results show that computed tomography is superior to ultrasound in preoperative diagnosis of intraabdominal diseases (P less than 0.025). In particular, liver and adrenal tumours and diseases of the air-filled gastrointestinal tract can be diagnosed more reliably preoperatively by computed tomography than by ultrasound.

Adrenal Gland Diseases↗
PubMed1983

The effects of deoxycholic and ricinoleic acid on the isolated circular muscle of the cat colon are modified by leucine-enkephalin.

The mechanism of the diarrheogenic effect of bile acids and fatty acids is incompletely understood. In order to study their effects on motility we tested sodium deoxycholate and sodium ricinoleate in their actions on the spontaneous mechanical and myoelectrical activity of the isolated circular muscle of the cat colon in a perfusion apparatus. Sodium deoxycholate activated the muscle in concentrations from 10(-9) to 10(-5) M. ED50 was 6.3 X 10(-9) M, ED100 10(-6) M. Sodium ricinoleate similarly stimulated muscle contractions. ED50 was 2.3 X 10(-7) M, ED100 5.1 X 10(-6) M. Both agents increased the occurrence of oscillating potentials in the myoelectrical records. Oscillations probably correspond to the migrating electrical complexes in diarrhea. The addition of leucine-enkephalin augmented primarily the number of brief spike potentials which may correspond to segmenting contractions. Thus, bile acids and fatty acids cause profound changes in colonic motility which by themselves may promote diarrhea. The endogenous opiate leucine-enkephalin could possibly counteract these effects.

Animals↗
PubMed1983

[Effect of antacids on intestinal motility].

Disturbances of gut motility occur frequently under a highdose antacid regimen. Typical symptoms are diarrhea and constipation. They are due to the cations of the antacids. Aluminum causes constipation, magnesium induces diarrhea, and calcium has no definite motor effect. The following mechanisms of action have to be taken into consideration: effects of the cations on the smooth muscle of the gut, on the enteric nervous system and on the release of gastrointestinal hormones as well as alterations of the physiochemical properties of the intraluminal contents. Aluminum inhibits the motor activity of the stomach and intestine, magnesium stimulates muscle contractions; however, the simultaneous activation of the intrinsic nerves, which are predominantly inhibitory, by magnesium may conceal the muscular effects of this cation. The diarrhea under a highdose regimen of antacid combinations appears to be due predominantly to the osmotic-secretory effects of the antacids.

Animals↗