The effect of hydroxyethyl starch 6% 130/0.4 compared with gelatin on microvascular reactivity.

We compared the effects on microvascular reactivity of hydroxyethylstarch (Volulyte(®) ) and gelatin (Geloplasma(®) ) during acute haemodilution. The hypothesis was that Volulyte would provide better microvascular reactivity than Geloplasma. Forty patients undergoing elective cardiac surgery were randomly assigned to receive either Volulyte or Geloplasma as the exclusive priming solution of the cardiopulmonary bypass. To evaluate microvascular reactivity, postocclusive reactive hyperaemia was examined before and after cardiopulmonary bypass. Microvascular reactivity assessments included the rate of the occlusion and reperfusion slopes and reperfusion times. After cardiopulmonary bypass, increases in reperfusion time were significantly smaller in the Volulyte group (3 (-27 to 9 [-35 to 33]%) vs 29 (-17 to 76 [-34 to 137]%) in the Geloplasma group, p = 0.02 between groups). Rate of reperfusion increased in the Volulyte group (26 (-17 to 43 [-59 to 357])%), whereas it decreased in the Geloplasma group (-22 (-47 to 16 [-84 to 113])%), p = 0.02 between groups. The shorter reperfusion times and increased reperfusion rate suggest that Volulyte maintains better microvascular reactivity than Geloplasma.

Cilansetron acts at its site of absorption to antagonize the sensitivity of mesenteric afferent fibres to 5-hydroxytryptamine in the rat jejunum.

The present study compares the efficacy of cilansetron, a 5-hydroxytryptamine (5-HT3)-receptor antagonist, delivered via intravenous and intraluminal routes, on the sensitivity of mesenteric afferent fibres supplying the proximal jejunum. Waveform analysis was performed to extract 5-HT sensitive single units from electrophysiological recordings of whole afferent nerve discharge. Dose effects of intravenous cilansetron (0.2-20 microg/kg) on the afferent response to 5-HT (10 microg) were examined to determine the threshold dose of cilansetron (2 microg/kg). This dose applied intraluminally to the region of jejunum innervated by the afferents, resulted in a greater degree of antagonism of the 5-HT response than intravenous administration (47.8+/-7.9 vs. 76.9+/-4.7%, P = 0.008). We concluded that cilansetron is active at its site of absorption to antagonize 5-HT3 receptors on vagal mucosal afferent terminals.

Intracolonic glycerol induces abdominal contractions in rats: role of 5-HT3 receptors.

Serotonin and 5-HT3 receptors may be involved in the activation of nociceptive afferent pathways by rectal distension. In rats, intracolonic infusion of glycerol is able to trigger nociceptive inputs as evidenced by the occurrence of abdominal constrictions. This work was designed to evaluate the influence of 5-HT3 receptor antagonists on this reflex and to approach the site of action by comparing their relative efficacies according to the route of administration. Male Wistar rats (250-350 g) were surgically prepared for abdominal electromyography and a catheter was placed in the colonic lumen. Five days after surgery, electrical activity of abdominal muscles was recorded before and during (20 min) intracolonic infusion of glycerol (60% glycerol + 40% saline, rate 0.75 mL/h). Cilansetron was administered intraperitoneally, 15 min before glycerol infusion, at doses of 5 to 500 micrograms/kg. Granisetron, ondansetron and cilansetron were administered at the dose of 20 micrograms/kg by intraperitoneal (i.p.), intravenous (i.v.) or intracolonic (i.c.) routes. The number of abdominal spike bursts was used as an index of visceral nociception. Intracolonic infusion of glycerol increased significantly (P < 0.05) the number of abdominal spike bursts during the time of infusion compared with saline (30.6 +/- 6.6 vs 4.5 +/- 3.4 bursts). When administered i.p., cilansetron dose-dependently reduced the frequency of abdominal spike bursts from the dose of 20 micrograms/kg i.p. Administration i.p. of granisetron and ondansetron at this dose also significantly reduced the number of abdominal spikes (19.0 +/- 6.0 and 18.3 +/- 6.9 respectively). Cilansetron, ondansetron and granisetron were also effective by i.v. and i.c. routes, cilansetron was more active by the i.c. route. Serotonin, via 5-HT3 receptors, is involved in the mediation of abdominal contractions induced by intracolonic infusion of glycerol. 5-HT3 receptor antagonists are also active by i.c. route suggesting a local site of action.

Influence of 5-HT3 receptor antagonists in visceromotor and nociceptive responses to rectal distension before and during experimental colitis in rats.

We investigated the possible involvement of 5-HT3 receptors in the colonic motor alterations and abdominal pain evoked by rectal distension (RD) in rats, under normal and inflammatory conditions. Responses to RD were evaluated by electromyography in rats treated with 5-HT3 antagonists (ondansetron and cilansetron, 0.1 and 1 mg/kg, intraperitoneally), before and 3 days after intrarectal administration of TNB/ethanol. RD evoked a significant (P < 0.05) and gradual inhibition of the occurrence of colonic spike bursts (SB) and a gradual increase in abdominal SB from 11 mm in diameter on wards. Ondansetron and cilansetron (0.1 mg/kg) significantly reduced both the colonic (62 and 66%, respectively) and the abdominal response (28 and 61%, respectively) for an 11 mm diameter of RD. After TNB/ethanol, both colonic and abdominal responses to RD were significantly (P < 0.05) enhanced and appeared for a lower diameter (9 mm) (colon: 4.8 +/- 0.9 vs 8.4 +/- 1.1, abdomen: 7.7 +/- 1.5 vs 0.5 +/- 0.4). Cilansetron (0.1, 1 mg/kg) significantly (P < 0.05) attenuated the TNB-induced colonic motor inhibition, while ondansetron and cilansetron (0.1, 1 mg/kg) reduced the TNB-induced increase in abdominal response. We conclude that 5-HT and 5-HT3 receptors mediate RD-induced viscerosensitive alterations in rats, both in normal conditions and during TNB-induced rectocolitis. However, the relative efficacy of the 5-HT3 receptor antagonists depends on the experimental conditions (intact or inflamed bowel) and does not appear to increase with the dose.

Intrapleural quinacrine instillation for recurrent pneumothorax or persistent air leak.

From 1982 to 1990, 27 patients with recurrent pneumothorax or persistent air leak (28 episodes) underwent pleurodesis with intrapleural administration of quinacrine, according to a standardized scheme. A first evaluation was done about 1 month after the intervention. In August 1990, all patients were invited for a second check-up. In 4 patients quinacrine plasma concentrations were determined. There was one early failure. No late recurrences were observed. Neither serious nor late complications were seen with our low-dose regimen. Transient fever was the only constant side effect. In contrast to other chemicals proposed for pleurodesis, quinacrine did not cause major pain. Only very low quinacrine plasma concentrations (peak, < 10 ng/mL) were found. In conclusion, chemical pleurodesis with quinacrine can be considered a safe and effective treatment. The number of administrations as well as the dosage are important to prevent morbidity and recurrence.

Peritoneal lavage after abdominal trauma: indications, technique, results.

This study represents our experience with 1461 patients who were seen in the Emergency Room of the University Hospital in Ghent with multiple traumatic lesions, between 1978 and 1982. In 43% of these polytraumata, we did an explorative peritoneal lavage in order to obtain a quick evaluation of intrabdominal haemorrhage. In 65% of the patients, the lavage was negative; 221 positive lavages (35%) underwent abdominal exploration; in 85% of these there were evident positive findings. The remaining 15% showed either no lesions, or minor lesions not involving risk of life. The overall accuracy-rate of the technique described above is at least 93%.

Actomyosin, collagen, and cell hypertrophy in intestinal muscle after jejunoileal bypass.

Previous observations indicate that bypass of 70% of the small bowel of rats induces increases in the seromuscular mass of both the in-continuity and the bypassed segment. The purpose of this study was to quantify the amount of actomyosin and collagen in the muscle layer and to determine the number of cells per cross-sectional area of the circular muscle layer at various locations of the small intestine after jejunoileal bypass. The amount of actomyosin relative to total tissue protein remained the same in the hypertrophied tissues compared with controls, and the actin-to-myosin ratios were similar. The collagen content per wet weight of the tissue from the sham- and bypass-operated animals tended to be less than in tissue from unoperated controls and was significantly less at the distal in-continuity location. The number of cells per cross-sectional area was decreased in tissues from all locations of the bypassed animals. These findings support the hypothesis that the increase in seromuscular mass after intestinal bypass is due to an increase in functioning smooth muscle tissue and that at least part of the increase is due to cell hypertrophy.

Lymphocytapheresis therapy in multiple sclerosis, a preliminary study.

10 patients with definite multiple sclerosis (MS), most of them with the chronic progressive type, were treated with lymphocytapheresis during one year. The DSS (Disability Status Scale) improved in 4 patients during the intensive phase of treatment, remained stable in 5 patients and deteriorated in one. The NSS (Neurological Status Scale) showed a stabilisation for the majority of the neurologic functions. Using the ISS (Incapacity Status Scale), an improvement was measured in 6 patients, a stabilisation in one and a deterioration in 3. Exacerbations could not be prevented by lymphocytapheresis.

Different meals produce different digestive motility patterns.

The purpose of these experiments was to characterize the pattern of digestive myoelectric activity produced by four different test meals in dogs. A new approach for the analysis of the myoelectric activity of the small intestine was used. In contrast with methods dividing the tracings into present time periods, the present method respected the "motor entities," hence the continuity, of the tracing. Two types of motor entities occurred: "activity units" which are groups of consecutive slow waves with spiking, and "rest units," which are groups of consecutive slow waves without spiking. The frequency of occurrence and frequency of alternation of the various activity and rest units occurring during digestion was calculated. Digestive myoelectrical activity was characterized by the frequent occurrence and alternation of short activity and rest units. Three different patterns of digestive activity could be discriminated, ie, a fat, a protein and carbohydrate, and a canned food pattern.

Intestinal motility after infusion of arachis oil into duodenum and ileum of dogs.

Arachis oil and a mixture of arachis oil with bile and pancreatic enzymes were infused into the duodenum and ileum of dogs via surgically positioned catheters in order to study the mechanism of disruption of the migrating complex by intraluminally infused triglycerides, the importance of cholecystokinin and neurotensin in this event, and the pattern of digestive myoelectrical activity during fat digestion. When infused into the duodenum both arachis oil and the oil-bile-pancreatic enzyme mixture disrupted the migrating myoelectric complex (MMC). When infused into the ileum, only the oil-bile-pancreatic enzyme mixture disrupted the MMC. The duration of the disruption lasted as long as when the same amount of oil was administered orally. Triglyceride-induced digestive activity was characterized by the frequent alternation of short periods of spiking activity and short periods of quiescence. It is concluded that the triglyceride-induced disruption of the MMC-pattern is not caused by the triglyceride itself but by some emulsion or digestion product. We further suggest that the disruption is hormonally mediated and due to fat-stimulated neurotensin, rather than cholecystokinin (CCK), release.

Local disorganization of interdigestive migrating complex by perfusion of a Thiry-Vella loop.

In dogs, a 50-cm Thiry-Vella loop was perfused with different glucose solutions (10-60%) and the effect on the interdigestive migrating myoelectric complex was studied. The perfusions did not disrupt the interdigestive pattern outside the loop, but produced a progressive "fall-out" of phase III, related to the concentration of the glucose solution. Quantitative analysis of the spike activity in the loop showed that the interdigestive pattern was partially disrupted by the 10% glucose solutions and that the 50 and 60% glucose perfusions induced a typical fed pattern characterized by short periods of spike activity alternating with short periods of quiescence. It was concluded that 1) perfusion of a Thiry-Vella loop with glucose solutions changes the myoelectrical activity of the loop from an interdigestive to a digestive pattern without interfering with the migrating myopelectric complex outside the loop; and 2) this local disorganization must be mediated by factors interfering with the effector mechanism in the loop.

Disruptive effect of test meals on interdigestive motor complex in dogs.

The disruptive effect of food and food components on the migrating myoelectric complex (MMC) was studied in conscious dogs. Three types of test meals were fed, and the interval between feeding and the reappearance of the first phase III of the MMC was determined. When commercial dog food was used a linear relation was observed btween the quantity of food (expressed as kcal/kg body wt) and the duration of the disruption of the MMC. Equicaloric amounts of the three major food components disrupted the MMC pattern for periods of time that were related to the nature of the food: the effect of arachis oil lasted longer than that of sucrose and much longer than that of milk protein. Medium chain triglycerides had a potent disruptive effect. Mixtures of these food components produced a disruptive effect that could not be calculated from the individual effect of each component. Phase III of the first and second MMC after feeding started at a lower level of the intestine than after a long fast. The duration of disruption of the MMC after a meal depends much more on the physicochemical composition of the food than on its volume or amount of calories.

Role of gastrin and insulin in postprandial disruption of migrating complex in dogs.

The duration of the disruption of the interdigestive migrating myoelectric complex (MMC) by various test meals in dogs was correlated with changes in serum gastrin and insulin levels. The test meals consisted of milk protein, sucrose, arachis oil and medium chain triglycerides (MCT). Intravenous infusions of glucose 20% were also used. Electrical activity of the small intestine was registered by means of electrodes implanted over the entire length of the gut. Hormones were assayed by radioimmunoassay techniques. The insulin level rose significantly after both the glucose infusion and the sucrose meal. The rise was small after the milk protein meal and nothing after arachis oil and MCT. Gastrin level was not changed by arachis oil or MCT and rose slightly after sucrose and milk protein. The MMC was not disrupted by glucose infusions, but was disrupted for 5--7 h by archis oil and for 6--12 h by MCT. We conclude that in dogs neither gastrin nor insulin have an important role in the mechanism of disruption of the MMC after feeding.