Gastric stimulation: influence of electrical parameters on gastric emptying in control and diabetic rats

BACKGROUND: The aim of this study was to test the effect of different pulse frequencies and amplitudes during gastric stimulation (GS) on gastric emptying in the rat. METHODS: GS was performed in 2 groups of laparotomized rats: healthy control animals, and rats with acute diabetes. The effects of four pulse frequencies (0.5, 1, 10, 20 Hz) and three pulse amplitudes (5, 20, 40 mA) were tested. The volumes emptied from the stomach after the oro-gastric instillation of a nutrient solution were compared to those obtained in animals without GS. Intragastric pH values were assessed under basal conditions and after GS. RESULTS: In both groups, GS increased emptied volumes compared to conditions without stimulation (p < 0.05) for pulse frequencies above 0.5 Hz. Increases in pulse frequencies accelerated gastric emptying (p < 0.01) with a plateau at around 10 Hz. The increase in pulse amplitudes resulted in larger emptied volumes only when the pulse frequency was 1 Hz (p < 0.04) while the opposite effect was observed at 20 Hz (p < 0.04). The most effective combinations to enhance gastric emptying compared to baseline conditions were 10 Hz with 5 or 20 mA. The overall effect of GS on gastric emptying compared to baseline conditions without stimulation, was greater in diabetic than in controls rats (p < 0.05). During stimulation, intragastric pH values were not different from basal conditions during fasting or after a meal in control and diabetic rats. CONCLUSIONS: Although both pulse frequency and amplitude should be considered during GS, frequency appears to be the most critical point. The possibility of increasing gastric emptying by electrical stimulation in diabetic rats suggests potential clinical applications for this method

ROLE DES PROTEINES GAG DU RETROVIRUS HTLV-1 DANS LA FORMATION D'UN VIRUS INFECTUEUX

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

False positive aortic dissection on postmortem computed tomography

International audiencePost-mortem CT-scan (PMCT) has become increasingly useful as a diagnostic tool. However, certain normal postmortem changes may mimic the appearance of pathologic findings. We report two cases of false positive aortic dissection.METHODS:Non-contrast PMCT was performed on a sixty-four-detector row scanner. Each PMCT examination was assessed and reported by two independent radiologists. Autopsies were performed according European recommendations.CASES:In two corpses, a false positive DeBakey type I aortic dissection was detected. Autopsies confirmed that CT findings were artifactual. For each case the cause of the mistake was individually discussed and mainly based on the abnormalities observed during the autopsy. In fact, in our series (750 PMCT) a true aortic dissection was detected in two corpses during the same period.CONCLUSION:When a PMCT is performed, false positive aortic dissection can occur, which confirms the interest in combining opacification

Does mechanical massage of the abdominal wall after colectomy reduce postoperative pain and shorten the duration of ileus? Results of a randomized study

The aim of this study was to determine the effectiveness of mechanical abdominal massage on postoperative pain and ileus after colectomy. We hypothesized that parietal abdominal stimulation could counteract induced pain and postoperative ileus, through common spinal-sensitive pathways, with nociceptive visceral messages. After preoperative randomization, 25 patients (age 52 ± 5 years) underwent active mechanical massage by intermittent negative pressure on the abdominal wall resulting in aspiration (Cellu M50 device, LPG, Valence, France), and 25 patients (age 60 ± 6 years) did not receive active mechanical massage (placebo group). Massage sessions began the first day after colectomy and were performed daily until the seventh postoperative day. In the active-massage group, amplitude and frequency were used, which have been shown to be effective in reducing muscular pain, whereas in the placebo group, ineffective parameters were used. Visual analogue scale (VAS) pain scores, doses of analgesics (propacetamol), and delay between surgery and the time to first passage of flatus were assessed. Types and dosages of the anesthetic drugs and the duration of the surgical procedure did not differ between groups. From the second and third postoperative days, respectively, VAS pain scores (P \u3c 0.001) and doses of analgesics (P \u3c 0.05) were significantly lower in patients receiving active massage compared to the placebo group. Time to first passage of flatus was also significantly shorter in the active-massage group (1.8 ± 0.3 days vs. 3.6 ± 0.4 days, P \u3c 0.01). No adverse effects were observed. These results suggest that mechanical massage of the abdominal wall may decrease postoperative pain and ileus after colectomy. © 2002 The Society for Surgery of the Alimentary Tract, Inc