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Biomedical subjects

J Frexinos

Publications and source records attributed to J Frexinos.

At least 91 records · Page 5Linked to original sources
PubMed1987

Influence of acoustic stress by noise on gastrointestinal motility in dogs.

The effects of acoustic stress (AS) on gastrointestinal motility and their prevention by previous treatment with naloxone, phentolamine, propranolol, muscimol, and diazepam were investigated in intact and vagotomized fasted dogs fitted with chronically implanted strain gauges on the antrum at 10 cm from pylorus and on the jejunum at 70 and 140 cm from the pylorus. These effects were compared to those produced by intracerebroventricular administration of ovine corticotropin releasing factor (oCRF). Beginning 40-50 min after the occurrence of a gastric migrating motor complex (MMC), a 1-hr hearing of prerecorded intense music through earpieces (less than 100 dB) delayed the occurrence of the next gastric MMC observed after 2.8 +/- 1.2 hr, while jejunal MMC were still present at a normal frequency. During AS, heart rate and plasma cortisol were significantly increased by 32.7 and 215%, respectively, 10-15 min after the beginning of hearing. The AS-induced lengthening of the gastric MMC cycle as well as cortisol increase were abolished after previous administration of diazepam (0.5 mg/kg intramuscular) or muscimol (10 micrograms/kg intravenous), while they were still present after naloxone (0.1 mg/kg intravenous), phentolamine (0.2 mg/kg intravenous), or propranolol (0.1 mg/kg intravenous). CRF administered intracerebroventricularly (100 ng/kg) also delayed the occurrence of gastric MMC without affecting jejunal motility, and this effect was not antagonized by previous treatment with diazepam or muscimol. Both the effects of AS and CRF were abolished after bilateral thoracic vagotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Colonic myoelectrical activity in IBS painless diarrhoea.

Colonic myoelectrical activity was recorded during 24 hours in 23 patients with painless diarrhoea and compared with a control group of 10 healthy subjects without digestive functional disorders. Diurnal fasting activity showed no significant difference in the total long spike bursts activity (LSB lasting greater than 7 seconds), but short spike bursts activity (SSB, lasting less than 7 seconds) was significantly lower (p less than 0.05) in diarrhoeal patients. A striking difference was observed in colonic response to eating, with an increased number of migrating long spike bursts (MLSB: mass movements) during the first postprandial hour in diarrhoeal patients (p less than 0.001), while short spike bursts (segmental activity) were almost absent in the rectosigmoid area. A marked decrease in the retrograde LSB activity was also observed in eight patients. During the night (from 2200 h to 0600 h) the number of migrating long spike bursts was increased in the diarrhoea group, but almost absent in controls (p less than 0.001). This study shows that colonic motor activity was altered in painless diarrhoea. These disturbances were not limited to the decreased SSB activity in the sigmoid, but involved the whole colon, with lower SSB activity and abnormal increase of migrating long spike bursts activity (MLSB) in postprandial and nocturnal periods.

Action Potentials↗
PubMed1986

[Treatment of rectal cancer with the neodymium-YAG laser].

Fifty-two non-surgical patients presenting rectal carcinoma were treated initially with palliative laser Nd-YAG. Their mean age was 79 years (49-92). Thirty patients had a severe diarrheic syndrome, associated with tenesmus in 27 cases; 20 patients had repeated hematochezia (5 presenting diarrhea as well); 6 had obstructive signs and one was symptom-free. Thirty lesions were less than 6 cm in size, 12 were between 7 and 10 cm and 10 were greater than 10 cm. Twenty-two lesions were circumferential. During the study period, 444 laser sessions were performed (mean 8.5/patient). Bleeding was stopped in all cases during the first session. Improvement of the diarrheic syndrome, obtained in 24 of the 30 patients, was correlated with the reduction of tumor volume. Tenesmus disappeared after 1 or 2 sessions, regardless of whether the tumor was destroyed or not. Failure was observed in 6 patients with lesions larger than 10 cm. Colostomy was avoided in 4 of the 6 obstructed patients. Negative biopsies were repeatedly obtained after mucosal repair in 9 patients with small lesions (less than 6 cm). Mean follow-up is now 8.2 months for the patients still alive. Complications were: 2 cicatricial stenosis and 3 hemorrhages (one required blood transfusion). Laser Nd-YAG allows palliative but conservative and effective treatment for rectal cancers. Although complete destruction is possible for small lesions, indications with curative intent are currently limited to patients with major contraindications to surgery.

Adenocarcinoma↗
PubMed1985

Effect of trimebutine on colonic myoelectrical activity in IBS patients.

The effect of trimebutine 100 mg i.v. and placebo on colonic myoelectrical activity was investigated in 10 patients with the irritable bowel syndrome (IBS) (5 constipated and 5 diarrhoeic), using an intraluminal probe supporting 8 groups of electrodes. At each site examined from transverse to sigmoid colon, the electromyograms exhibited two kinds of spike bursts: short spike bursts (SSB) localized at one electrode site and appearing rhythmically at 10.3/min, and long spike bursts (LSB), isolated or propagated orally or aborally. Computerized analysis of the duration of each kind of spike burst showed that, as compared to the control, trimebutine 100 mg, selectively inhibited by 43 to 73% the mean duration of LSB activity in the transverse, descending and sigmoid colon, from 0 to 30 min after administration. The inhibitory effect was similar in constipated and diarrhoeic patients. Placebo injection did not significantly affect (p greater than 0.05) the duration of LSB and SSB activity. Variance analysis indicated that the inhibitory effect of trimebutine was significantly greater (p less than 0.05) on LSB activity in the transverse than the descending colon, and that it was absent from the sigmoid colon. The results suggest that trimebutine selectively inhibits the propulsive activity of the proximal two thirds of the colon in IBS patients, and that this effect cannot entirely explain its therapeutic efficacy in IBS.

Adult↗
PubMed1985

On-line four channel measurements of colonic myoelectrical activity in humans using a compact portable microcomputer (EPSON HX20).

This paper describes a rapid, inexpensive method for a quantitative analysis of colonic myoelectrical analysis using a simple low-cost portable, battery-powered microcomputer EPSON HX20, including a printer and microcassette units. The EMG signals from the right to the left colon were obtained using an intraluminal probe supporting 8 groups of electrodes, placed by endoscopy and connected to an 8-channel amplifiers. The EMG signals were continuously and successively amplified, filtered, rectified, integrated for the computerized analysis consisting of the recognition of the different kinds of spike bursts and their separate measurement during successive 30 min intervals over the entire (24-36 h) period of EMG recordings. For each channel, the printing program shows each 30 min interval, total duration and number of each kind of spike bursts. An histogram of the total values for 4 channels was printed at 12-h intervals and stored in the microcassette unit. This microcomputerized system was successfully used in 4 healthy volunteers during 36 h recording sessions performed to analyze the influence of feeding and sleep of colonic myoelectrical activity.

Biomedical Engineering↗
PubMed1985

Diurnal changes in myoelectric spiking activity of the human colon.

Using an intraluminal probe supporting eight groups of electrodes, the myoelectrical activity of the proximal, transverse, and distal colon was recorded during 24-h sessions in 10 healthy subjects receiving evening and noon meals (greater than 800 kcal) and breakfast (less than 300 kcal). At each colonic site considered, the electromyograms exhibited two kinds of spike bursts: (a) short spike bursts localized at one electrode site and appearing rhythmically at a frequency of 10.6 +/- 0.3/min and (b) long spike bursts isolated or propagated orally or aborally. A peculiar pattern consisting of nearly permanent short spike bursts at a rate of 6.7 +/- 0.4/min was observed at the rectosigmoid junction. Computerized analysis of the duration of each kind of spike burst showed that the long spike burst activity increased by 63%-129% (p less than 0.05) during 2 h after each meal (but not after breakfast) at each colonic site. Furthermore, a significant (p less than 0.05) decrease in the long spike burst but not short spike burst activity was observed during sleep. These results provide evidence for circadian variations of colonic motility associated with eating and sleeping in the healthy human.

Action Potentials↗
PubMed1985

[Yag laser photocoagulation and monopolar electrohydrocoagulation: randomized study of the hemostatic effect on experimental hemorrhagic ulcer in dogs].

The purpose of this randomized study was to compare the effects of two methods of hemostasis--photocoagulation using YAG Neodyme laser and liquid monopolar electrocoagulation--on acute experimental bleeding ulcers created in the dog stomach with an ulcer-maker. One hundred and fifty-three lesions were made and randomized into 3 groups; 51 lesions were treated with photocoagulation and complete hemostasis was achieved in all cases. Hemostasis was obtained in 80 p. 100 of 51 ulcers treated with liquid electrocoagulation. Control untreated ulcers remained hemorrhagic after 45 min of observation. The mean external muscle injury on day 7 was 55 p. 100 after photocoagulation and 65 p. 100 after liquid electrocoagulation. On day 14, mean external injury was 60 p. 100 after photocoagulation and 75 p. 100 after liquid electrocoagulation (non-significant difference). On day 7, the mean re-epithelization index, expressed as the percentage of the original ulcer diameter, ranged from 8 to 10 p. 100 in each trial group. On day 14, reepithelization covered 78 p. 100 of control ulcers and 72 p. 100 of photocoagulated ulcers (NS). This percentage falls to 47 p. 100 in ulcers treated with liquid electrocoagulation (p less than 0.01 when compared with ulcers treated with photocoagulation). Photocoagulation seemed to be more efficient in ensuring hemostasis and external muscle injury was correlated with the energy delivered. External muscle injury could not be controlled by liquid electrocoagulation. However the difference in the percentages of mean external muscle injury between the two methods was not significant. Therefore, in man, the risk of perforation is certainly slight and not very different whatever the method of hemostasis considered.

Animals↗
PubMed1984

Early and late complications after endoscopic sphincterotomy for biliary lithiasis with and without the gall bladder 'in situ'.

Endoscopic sphincterotomy has gained wide acceptance in the treatment of biliary lithiasis. We attempted endoscopic sphincterotomy in 443 patients and were successful in 407 (92%). Sphincterotomy was carried out with the gall bladder in situ in 234 cases (57%) of advanced age or high surgical risk. Immediate complications occurred in 7%, of which haemorrhage was the most frequent. The mortality rate was 1.5%. Three hundred and sixteen endoscopic sphincterotomies were performed more than six months before writing and follow up was available for 226 (72%) from six to 78 months. Late complications were observed in 16 patients with gall bladder 'in situ' (12%); the most frequent was cholecystitis in 6%. In five patients of the group without gall bladder, four had cholangitis related to retained or recurrent stones, and one restenosed . No episodes of cholangitis were observed in patients without stones despite reflux of barium up the biliary tree as observed during a barium meal examination.

Aged↗
PubMed1983

[Physiopathology of the irritable colon. Searching for Ariane's thread].

For more than thirty years the pathophysiology of the so-called "irritable bowel syndrome" has given rise to numerous theories. These can be summarized in a series of questions to which this review paper does not pretend to provide definite answers. Is there a basic myoelectric anomaly specific to the irritable bowel syndrome? Are there disorders of colon motility that characterize the symptoms experienced by the patient? Are specific tests available that would stimulate colonic contractions in a reproducible and comparative manner? What place should be given to disturbances in bowel sensitivity? Is the colon the only target-organ in functional intestinal disorders? Is the role of digestive hormones underrated or at least insufficiently known? Do patients with the syndrome have a special psychological profile? Has intolerance to various foodstuffs been excluded too hastily? The secrets of the irritable colon syndrome are far from being entirely unravelled. This heterogeneous group of symptoms seems to be due to many different causes associated to varying degrees in each patient.

Colon↗