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Biomedical subjects

J Janssens

Publications and source records attributed to J Janssens.

At least 127 records · Page 7Linked to original sources

A wave of inhibition precedes primary peristaltic contractions in the human esophagus.

Animal studies have shown that primary esophageal peristalsis is preceded by a wave of inhibition spreading rapidly down the esophagus and lasting longer in more distal segments. In humans, its presence in the esophageal body cannot be demonstrated manometrically because of the absence of tone. To study deglutitive inhibition in humans, an artificial high-pressure zone was created by inflating an intraesophageal balloon to a critical level. The pressure changes at the interface between the balloon and the esophageal wall at various levels along the esophagus were measured. In this artificial high-pressure zone, deglutition induced a relaxation beginning simultaneously at various levels of the esophagus but lasting progressively longer in progressively more distal segments. Latency from onset of deglutition to onset of relaxation at 13 cm and 8 cm above the lower esophageal sphincter and at the lower esophageal sphincter was 0.06 +/- 0.19 seconds, 0.10 +/- 0.31 seconds, and 0.89 +/- 0.53 seconds, respectively; latency to contraction was 4.45 +/- 0.54 seconds, 6.04 +/- 0.79 seconds, and 9.14 +/- 1.04 seconds, respectively. This is the first direct evidence that deglutition produces in the human esophagus a wave of inhibition that precedes the primary peristaltic contraction.

Adult↗

Erythromycin accelerates gastric emptying by inducing antral contractions and improved gastroduodenal coordination.

Erythromycin has been shown to act as a motilin agonist by binding to motilin receptors on gastrointestinal smooth muscle and to improve the severely impaired gastric emptying in patients with diabetic gastroparesis. To elucidate the motor pattern that accounts for this accelerated emptying, the effect of 200 mg erythromycin vs. placebo on postprandial motility of the stomach and the upper small intestine was examined in 13 normal subjects. Erythromycin significantly increased the amplitude of the antral contractions during the 2-hour postprandial study period (maximal difference in mean amplitude of distal antral contractions between erythromycin and placebo recorded from 80 to 90 minutes after meal: 123 +/- 17 vs. 44 +/- 12 mm Hg; P less than 0.005). The total number of antral contractions was not affected, but the contractions could be recorded manometrically higher up in the stomach after erythromycin than after placebo (9-12 vs. 3-6 cm above the pylorus). Antroduodenal coordination was significantly improved during the first postprandial hour, and the first normal phase 3 of the migrating motor complex, indicating the reappearance of fasting motility, occurred earlier after erythromycin than after placebo (128.3 +/- 14.3 vs. 173.4 +/- 16.1 minutes; P less than 0.05). These changes in postprandial motility induced by erythromycin may well account for its accelerating effect on gastric emptying.

Adult↗

Effect of erythromycin on gastric motility in controls and in diabetic gastroparesis.

The effect of three doses of erythromycin on interdigestive gastrointestinal motility and on plasma motilin levels was studied in healthy volunteers and patients with diabetic gastroparesis. Abnormalities of interdigestive motility were observed in 40% of the patients. In healthy volunteers, 40 mg erythromycin elicited a premature phase 3 that started in the stomach. In contrast to the spontaneous gastric phase 3, this erythromycin-induced phase 3 was not accompanied by a motilin peak. In patients with diabetic gastroparesis, 40 mg erythromycin induced a premature phase 3 in three patients, no response in one patient, and a burst of antral contractions in another patient. Doses of 200 and 350 mg erythromycin elicited a burst of antral phase-3-like contractions in both volunteers and patients, which was not accompanied by a motilin peak. This phase-3-like activity did not migrate to the small intestine and was not followed by a phase 1, but by a prolonged period of antral contractile activity. The number and amplitude of antral contractions after 200 or 350 mg erythromycin were significantly higher than after 40 mg. The motor patterns induced by different doses of erythromycin offer potential therapeutic applications.

Adult↗

Effect of motilin on gastric emptying in patients with diabetic gastroparesis.

Erythromycin markedly accelerates gastric emptying, possibly because it acts as a motilin agonist. In the present study, the effect of an equipotent dose of motilin was tested. In six patients with severe diabetic gastroparesis, gastric emptying of liquids and solids was examined scintigraphically after motilin or placebo in a double-blind crossover study. Motilin (10 pmol.kg-1.min-1) or saline was infused over a 90-minute period starting 5 minutes before breakfast. Motilin markedly accelerated emptying. For liquids, the half-emptying time was reduced from 51 +/- 6 to 22 +/- 11 minutes (P less than 0.01) and for solids from 111 +/- 4 to 51 +/- 12 minutes (P less than 0.01). The mean increase in plasma motilin levels was 1315 +/- 342 pg/mL, corresponding to an effective infusion rate of about 4 pmol.kg-1.min-1. In the control experiments, basal motilin levels (173 +/- 17 pg/mL) were within the normal range but increased steadily postprandially, reaching 321 +/- 25 pg/mL at the end of the study period, probably reflecting gastric distension. The postprandial increase in pancreatic polypeptide level was blunted compared with accepted normal values but was more pronounced during motilin infusion, i.e., 650 +/- 217 vs. 279 +/- 66 pg/mL (P less than 0.01), probably because of the improved emptying. Our data show that motilin accelerates gastric emptying in diabetic gastroparesis and support the hypothesis that erythromycin's effect is mediated through motilin receptors.

Diabetic Neuropathies↗

Urinary and faecal incontinence in community-residing elderly women.

The prevalence of urinary and faecal incontinence was investigated in a sample of 1049 women aged 60 years and over in the municipality of Amstelveen, the Netherlands; 719 postal histories were completed. The overall prevalence of urinary incontinence was 23.5%. Daily urine loss was reported by 14.0% of all women. In women aged 60 to 84 years and 85 years and over 4.2% and 16.9% were faecally incontinent, respectively. In all age groups poor mobility and frequency were associated with urinary incontinence. Urgency was independently associated in women aged 60-85 years as was nocturia in women aged 85 years and over.

Age Factors↗

Actions of 5-hydroxytryptamine on myenteric neurons in guinea pig gastric antrum.

Intracellular recording methods were used to study the actions of 5-hydroxytryptamine (5-HT) on 257 myenteric neurons in the guinea pig gastric antrum. Application of 5-HT caused three types of postsynaptic responses. A fast-activating depolarizing response was accompanied by a decreased input resistance and desensitized quickly to repeated applications. It was mediated by a 5-HT3 receptor. A slowly activating depolarization, accompanied by an increase in the input resistance and enhancement of the excitability, was mainly observed in after hyperpolarizing/type 2 neurons. It was suppressed by the prokinetic benzamide compound renzapride, while classical 5-HT1-4 receptor antagonists had no effect, suggesting the involvement of a 5-HT1p receptor as described in small intestinal neurons. A long-lasting hyperpolarizing response, accompanied by a decreased input resistance, was observed in a small subset of neurons. This response seemed to be mediated by a 5-HT1a receptor. Superfusion of 5-HT caused a dose-dependent inhibition of the stimulus-evoked nicotinic cholinergic fast excitatory postsynaptic potential (EPSP), which was mediated by a presynaptic 5-HT1a receptor. 5-HT also presynaptically inhibited the slow EPSP.

Animals↗

Comparison of the effects of midecamycin acetate and clarithromycin on gastrointestinal motility in man.

The gastrointestinal motor effects of the macrolide antibiotic, clarithromycin, were compared with those of midecamycin acetate. The method of investigation consisted of intraluminal pressure measurements in the gastric antrum and upper small intestine by means of a low compliance perfused catheter system. Six healthy volunteers participated in the single-blind, placebo-controlled study of both interdigestive and postprandial gastrointestinal motility. Clarithromycin was administered by mouth in a dose of 250 mg b.i.d.; midecamycin acetate was given in a dose of 600 mg b.i.d. The effect of midecamycin acetate on gastric antral and jejunal motility was not significantly different from that of placebo. This was true for both the interdigestive and the postprandial phases of gastrointestinal motility. Oral treatment with clarithromycin (250 mg, b.i.d.) resulted in a statistically significant increase in the postprandial number of antral contractions per hour as well as in the postprandial antral motility index, as compared to placebo.

Adult↗

The three-group metaphase as a morphologic indicator of high-ploidy cells in cervical intraepithelial neoplasia.

There is a need for additional morphologic criteria to improve the value of histologic classification for the prediction of the biologic behavior of cervical intraepithelial neoplasia (CIN). Representative slides from 72 cone specimens containing CIN were examined to study the correlation between the presence of three group metaphases (TGMs), a morphologically well defined and light microscopically readily recognizable atypical mitotic figure, and the incidence of aneuploid cells with a nuclear DNA content greater than 5C. The numbers of cells greater than 5C (minus the polyploid cells 8C +/- 1C) were counted, using LEYTAS image cytometry on Cytospin preparations from the 72 blocks corresponding to the slides searched for TGMs and used for histologic classification of the lesions in classes CIN 1-3. It appeared that large numbers of aneuploid cells greater than 5C were more closely related to the presence of TGM than to a higher CIN class per se, particularly in women older than 35. Since aneuploid CIN has a higher progression rate than euploid CIN, the presence of TGMs will indicate a biologically unfavorable lesion. Thus, TGM deserves further investigation as an additional morphologic parameter for predicting the biologic behavior of CIN.

Adult↗

Effect of midecamycin acetate on gastrointestinal motility in humans.

The effect was studied on gastrointestinal motor activity of three different macrolides (erythromycin, roxithromycin and midecamycin acetate), administered by mouth in therapeutic doses. This placebo-controlled study was performed in 12 normal human subjects by means of intraluminal pressure measurements in the gastric antrum, duodenum and upper jejunum. In each subject, three manometries were done for 5 h in the interdigestive period and for 3 h postprandially. In the interdigestive period, midecamycin acetate did not affect the characteristics of the gastric migrating motor complex (MMC) and did not increase the number of antral contractions or the gastric motility index as compared to the placebo. Erythromycin and roxithromycin increased the number of antral contractions (24.5 +/- 11 versus 15.2 +/- 7 and 28.4 +/- 12 versus 14.9 +/- 5.9 respectively) and the motility index (4.05 +/- 0.5 versus 3.17 +/- 0.6 and 4.38 +/- 0.2. versus 3.64 +/- 0.7 respectively) as compared to the placebo. In the postprandial period, the number of antral contractions was not significantly increased by any of the three antibiotics. The postprandial antral motility index was not significantly increased by midecamycin acetate. In contrast, the postprandial antral motility indexes after erythromycin (4.4 +/- 0.5) and after roxithromycin (4.3 +/- 0.2) were significantly greater than after the placebo. In the upper small intestine, erythromycin elicited an increased number of phase-III-like activity events and roxithromycin shortened the MMC cycle length. Midecamycin acetate had no effect on interdigestive upper jejunal motility. The postprandial jejunal motor activity was not altered by any of the three antibiotics neither during the interdigestive nor the postprandial periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Apraxia of eyelid opening secondary to right frontal infarction.

Apraxia of eyelid opening is the incapacity of voluntarily eyelid opening in the absence of motor dysfunction or blepharospasm. It has mostly been described in extrapyramidal diseases and only very rarely in cortical lesions. We report a right-handed patient with a right frontal infarction exhibiting eyelid opening apraxia.

Aged↗

[The prevalence of urinary incontinence in elderly women].

On the basis of a survey in March 1989 among non institutionalized women aged 60 years and older living in Amstelveen, the prevalence of urinary incontinence was estimated. Also investigated were factors potentially associated with urinary incontinence, as well as the psychosocial impact on daily living activities. The sample comprised 1049 women; 719 postal histories were completed. Statistical analyses involved chi 2 and chi 2 trend tests, and the influence of determinants was assessed with multivariate logistic regression. The prevalence of urinary incontinence was 23.5%, with a slight increase with increasing age. Daily urine loss was reported in 14.0% of all women. Significantly associated with urinary incontinence were an increased diurnal as well as nocturnal voiding frequency, immobility and use of diuretics. Urinary incontinence actually interfered with daily living activities in 65.3% of the women.

Activities of Daily Living↗

Prospective study on prevalence of esophageal chest pain in patients referred on an elective basis to a cardiac unit for suspected myocardial ischemia.

The prevalence of esophageal chest pain was studied prospectively in patients referred on an elective basis to a cardiac unit for suspected myocardial ischemia. A group of 248 consecutive patients without previously documented heart disease was admitted for elective diagnostic coronary angiography. The clinical history classified 185 patients as having anginal pain and the coronary angiogram was normal in 48 of them. In 37 of these 48 patients full esophageal testing was performed including 24-hr intraesophageal pH and pressure recordings with indication of chest pain episodes as well as a number of esophageal provocation tests, ie, acid perfusion, edrophonium stimulation, balloon distension, and ergonovine stimulation, all performed under continuous esophageal manometric and electrocardiographic monitoring. In 19 of these 37 patients, the familiar chest pain could be reproduced by esophageal provocative testing without ischemic ST-T segment alterations; six of these 19 patients had also a positive 24-hr pH and pressure recording. These data strongly suggest an esophageal origin of chest pain in half the patients with typical angina and a normal coronary angiogram.

Angina Pectoris↗

Inversion of the slow-wave frequency gradient in symptomatic patients with Roux-en-Y anastomoses.

Patients with Roux-en-Y anastomoses may have chronic symptoms of nausea, vomiting, epigastric fullness, and abdominal pain. To investigate the mechanism of these symptoms, the electrical activity of the Roux limb was studied in five symptomatic and four asymptomatic patients with Roux-en-Y anastomoses. Slow-wave and spike activity in the Roux limb were recorded using six bipolar suction electrodes positioned 10 cm apart. Ten healthy volunteers were studied as a control. In the control subjects, the mean slow-wave frequency decreased from 11.27 +/- 0.2 cycles/min at 30 cm below the ligament of Treitz to 10.96 +/- 0.2 cycles/min at 80 cm past Treitz. By contrast, in five patients the slow-wave frequency in the Roux limb increased from 11.12 +/- 0.2 cycles/min 10 cm below the gastrojejunal anastomosis to 11.42 +/- 0.4 cycles/min 50 cm more distally. Four of these five patients had severe symptoms. In the other four patients, of whom three were completely symptom-free, an aborally decreasing slow-wave frequency was observed. In both the controls and the patients with Roux-en-Y anastomoses, the direction of propagation of phase 3 spike bursts of the migrating motor complex was always aboral. During phase 2, most spike bursts were uncoordinated at adjacent recording sites. Propagated spike bursts, single or repetitive, were rare. The propagation direction of these spike bursts was always aboral in healthy controls. In symptomatic patients with inverted slow wave frequency gradients, however, the rare propagated spike bursts always propagated orally. The observed electrical abnormalities may in part be responsible for the symptoms of patients with the Roux-en-Y syndrome.

Abdominal Pain↗

Variation of slow-wave frequency and locking during the migrating myoelectric complex in dogs.

Slow waves determine rhythm and polarity of spike bursts. We measured the variation of slow-wave frequency (swf) and locking (swl) in the canine jejunum during the various phases of the migrating myoelectric complex (MMC) and during induced phase III (erythromycin 125 micrograms/kg iv bolus or somatostatin 2.5 micrograms.kg-1.h-1 iv infusion), blocked phase III (atropine 20 micrograms/kg iv bolus), and so-called stationary phase III activity (cisapride 150 micrograms/kg iv bolus). The EMG of 4 dogs, implanted with 10 bipolar electrodes, was recorded on a polygraph. Our results indicate that swf and swl change during the MMC from a stepwise swf gradient with slow waves locked in plateaus during phase I to a continuous swf gradient without or with significantly reduced phase locking during phase III. The length of the first swf plateau decreases significantly from 42 +/- 12 cm post Treitz during phase I to 11 +/- 4 cm during spontaneous phase III. Atropine block of phase III activity prevents phase unlocking and development of a continuous swf gradient. Our hypothesis is that phase unlocking may be one of the induction mechanisms of spike-burst activity.

Animals↗

Clinical significance of squamous cell carcinoma antigen in cancer of the human uterine cervix. Comparison with CEA and CA-125.

Serum squamous cell carcinoma antigen (SCCa) concentrations were determined by a radioimmunoassay kit before and during the treatment of 50 patients with cervical carcinoma: 44 with squamous cell carcinoma (SCC) and 6 with adenocarcinoma. The positivity rate of SCCa was 50% (52% for SCC and 33% for adenocarcinoma). The sensitivity of SCCa for SCC was twice as high as that of CEA and CA-125. Low serum concentrations were observed in early-stage carcinoma, indicating that SCCa is not useful for diagnosis. In advanced cases, serum levels were directly and significantly correlated with the stage of the disease.

Adenocarcinoma↗