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T Hachet

Publications and source records attributed to T Hachet.

8 recordsLinked to original sources
PubMed1994

Experimental colitis alters visceromotor response to colorectal distension in awake rats.

The influence of intermittent colorectal distension (CRD) on proximal colonic motility and abdominal pain perception was investigated in awake rats equipped with intraparietal electrodes on the cecum, proximal colon, and abdomen, before and three days after rectocolitis induction by trinitrobenzene sulfonic acid (TNB)/ethanol. The normal myoelectrical activities of cecum and proximal colon [5.2 +/- 0.5 and 9.7 +/- 0.7 long spike bursts (LSB) per 5 min, respectively] were significantly (P < 0.05) and gradually decreased by control CRD, at diameters above 9 mm. At the maximum CRD diameter (13.7 mm), 1.6 +/- 0.6 cecal and 3.9 +/- 0.8 colonic spike bursts occurred per 5 min (respectively, 69 and 60% decreases). This upstream inhibition was accompanied by a significant (P < 0.05) and gradual increase in abdominal contractions (0.4 +/- 0.4 per 5 min in control vs 23.4 +/- 1.9 in response to 13.7 mm in diameter). Three days after TNB/ethanol, visceromotor and abdominal responses were significantly (P < 0.05) enhanced at the least CRD diameter of 9 mm (cecum: 3.1 +/- 0.4 after TNB vs 5.0 +/- 0.7 in control; proximal colon: 5.1 +/- 0.9 vs 9.3 +/- 2.2; abdomen: 7.7 +/- 1.5 vs 0.5 +/- 0.4). We conclude that in awake rats, CRD evokes both abdominal contractions in response to pain and inhibition of cecal and proximal colonic motility, which thresholds are both lowered by TNB-induced rectocolitis.

Abdominal Muscles↗
PubMed1993

A multifunction and programmable computerized barostat.

A new computerized barostat allowing digestive tone measurement but also programmed distensions is described. The apparatus consists of a pump, driven by a computer, which injects or aspirates air in a flacid bag placed in a part of the gastrointestinal tract when relaxation or contraction occurs. Several parameters can be programmed for tone measurement: mean pressure, window pressure and air flow rate. Isovolumic or isobaric distensions can be performed using three modes: linear, stepwise or step by step with intermediate deflation. The height (mL or mmHg) of the steps and the duration of the distensions and the deflations can also be programmed. Three automatic and one manual safety systems are included. In comparison with previously described barostats the main feature of this apparatus is that it is entirely computerized and can be used for programmed distensions.

Atropine↗
PubMed1991

Absorptive and motor components of the antidiarrhoeal action of loperamide: an in vivo study in pigs.

The effects of loperamide (0.1 mg/kg orally) on net colonic water absorption, orocolonic transit time, and intestinal motility were investigated in pigs chronically fitted either with two cannulas in the proximal colon and a catheter in the duodenum and the ileum or with intraparietal electrodes on the duodenum, jejunum, caecum, and proximal colon and a duodenal catheter. Loperamide, given 20 minutes before a meal reduced significantly colonic net water absorption for 10 hours after eating. It also reduced colonic flow rate, increased orocolonic transit time, modified the postprandial intestinal motility by inducing supplementary phase 3 motor complexes and did not affect caecocolonic motility. Intraduodenal infusion of a hypertonic solution of mannitol (900 mOsm/l; 0.6 ml/minute) for the first postprandial hour strongly reduced or reversed net colonic water absorption, increased the colonic flow rate, accelerated the orocolonic transit, and induced profuse diarrhoea. After loperamide administration, all these effects were blocked and the relative colonic water absorption, expressed as the fraction of flow entering the colon, was strongly increased. Mannitol did not modify motility of the small and large intestine, and supplementary phase 3 motor complexes were observed when mannitol infusion was preceded by loperamide administration. It is concluded that in experimental osmotic diarrhoea loperamide causes a reduction in digesta flow entering into the colon, mediated by its action on small intestinal motility, and an increase in colonic water absorption.

Animals↗
PubMed1986

The use of a compact protable microcomputer system (EPSON HX 20) to measure on-line the contractile activity of the digestive tract from eight channels. Application to pharmacological tests.

The chronically prepared gut with strain-gauge transducers is a useful model to evaluate the effects of drugs affecting the digestive motility in fed and fasted animals. This paper describes a rapid and reproducible on-line microcomputerized technique to evaluate continuously, 23 hr per day, the level of gut motility using a portable compact microcomputer (EPSON HX 20). The gastric, intestinal, and colonic motility indexes were automatically determined from the surface of the contractile waves from eight different sites over periods of time varying from 1 to 120 min. This system has been successfully used to investigate the motor effects of spasmolytic or antidiarrheal drugs inravenously (N-butyl-hyoscine, trospium, secoverine, and prifinium) or orally (trimebutine, loperamide) administered in conscious, fed dogs.

Animals↗
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↗