The effect of prostaglandin E2 (PGE2 on the circular and longitudinal contractions of the canine colon was studied in chronic conditions. A mechanical transducer capable of recording simultaneously the variations of length in two perpendicular directions at 90° to each other was developed and implanted on the canine colon 10 cm distal to the ileocaecal junction. The recording sessions started on the 6th postoperative day. The colonic motility was recorded two hours before (control period) and two hours after the intravenous injection of PGE2 in three different doses (0.1, 1.0 and 10 μg/kg). Two sorts of mechanical activity were identified: contractile phases (mean duration: 8.8 min for longitudinal and 6.7 min for circular contractions) and sporadic contractions (mean duration: 0.37 min for longitudinal and 0.28 min for circular contractions).

The small bowel is difficult to explore because of its location far away from the natural orifices. The aim of this study is to describe a telemetric, autonomous and multifunctional capsule (39 mm in length and 11 mm in diameter) designed according to a modular system to explore the small bowel. It consists of a central cylinder containing a location detector which allows permanent data collection concerning its position in the small bowel, the length of the small bowel and the transit velocity; secondly, several interchangeable tips allow either aspiration of a sample of intestinal juice, or release of a substance previously placed in the capsule, or to perform a mucosal biopsy. After having been swallowed by the patient, the capsule passes through the whole gut and is then recovered in the stools between 24 and 48 hours later. The preliminary study consisted of comparing, in patients undergoing a surgical procedure, the small bowel length measured by telemetry (542.3 +/- 113.8 cm) to that measured intraoperatively by the arithmetical mean of the mesenteric and antimesenteric edges (515 +/- 112.7 cm), p = 0.28. These different interchangeable working tips have already been used to determine the level of absorption of various substances, the discovery of absorption sites and the performance of mucosal biopsies without any material link between patient and the measuring or recording equipment. The main advantages of this intestinal capsule are the possibility to continuously transmit its location, its total autonomy and remote control of the desired action.

This study aimed at testing human skin wound healing improvement by a 21-day supplementation of 1.0 g ascorbic acid (AA) and 0.2 g pantothenic acid (PA). 49 patients undergoing surgery for tattoos, by the successive resections procedure, entered a double-blind, prospective and randomized study. Tests performed on both skin and scars determined: hydroxyproline concentrations, number of fibroblasts, trace element contents and mechanical properties. In the 18 supplemented patients, it was shown that in skin (day 8) Fe increased (p < 0.05) and Mn decreased (p < 0.05); in scars (day 21), Cu (p = 0.07) and Mn (p < 0.01) decreased, and Mg (p < 0.05) increased; the mechanical properties of scars in group A were significantly correlated to their contents in Fe, Cu and Zn, whereas no correlation was shown in group B. In blood, AA increased after surgery with supplementation, whereas it decreased in controls. Although no major improvement of the would healing process could be documented in this study, our results suggest that the benefit of AA and PA supplementation could be due to the variations of the trace elements, as they are correlated to mechanical properties of the scars.

The role of trace elements in the wound-healing process is still controversial. Their variations within a normal colonic wound healing have never been studied. An experimental study on rabbits was designed to study magnesium, iron, copper and zinc variations in blood, normal colonic walls and colonic anastomoses on each of the first 7 postoperative days. No major variations of Mg could be observed. Fe decreased in blood as well as in colonic walls and anastomoses. Cu increased in blood, whereas it decreased in colonic walls and anastomoses. Zn decreased in blood, whereas it increased in colonic walls without significant changes in anastomoses. The role of Fe seemed to be rather difficult to understand. Plasma mobilization seems to explain the local use of Zn, while early tissue release with further return in blood occurred for Cu. The importance of a well-balanced nutritional status is underlined to prevent and correct the variations of trace elements in the postoperative course.

The effect of prostaglandin E2 (PgE2) on the circular and longitudinal contractions of the canine colon was studied in chronic conditions. A mechanical transducer developed in our laboratory and implanted on the canine colon collected simultaneously and separately the variations of length in two perpendicular directions. The recordings started at the 6 postoperative day. The colonic motility was recorded two hours before (as control period) and two hours after the intravenous injection of PgE2 at three different doses: 0.1-1.0 and 10 micrograms/kg. PgE2, at the three doses, induced, progressively over time, a significant decrease in duration and amplitude of the circular contractions, while the amplitude of longitudinal contractions remained unchanged. 10 micrograms/kg of PgE2 immediately induced a significant increase in the duration of longitudinal contractions followed by a decrease in this value during the 2nd hour after PgE2 administration. Each dose of PgE2 shortened the period of recurrence of longitudinal contractions, inducing rapid or immediate bursts of contractions. This effect was moderate or absent for the circular contractions. It is concluded, that PgE2 has different actions on circular and longitudinal contractions of the colon. According to the dose used, it induces hypokinesia (relaxation) in the circular muscle and premature strong contractions in the longitudinal motor activity.