Variability among strains of Aspergillus section Nigri with capacity to degrade tannic acid isolated from extreme environments.

Tannins are polyphenolic compounds that cause astringent flavor and turbidity in food. Tannase is an enzyme that catalyzes the hydrolysis of tannins and is used in food industry. This study was conducted to determine the genetic variability and the tannase alleles variation in fungal strains isolated from soil and plants at five extreme areas of Coahuila, México. Two screening assays under 1 and 20 % of tannic acid were performed, with the isolations. In these assays, it was possible to identify 756 and 128 fungal strains, respectively. The major fungal variability was observed in "Cuatro Ciénegas" with 26 strains. The microorganisms were distributed in 11 groups, which correspond to Aspergillus section Nigri. AN7 and AN1 groups showed the major number of isolates from "Paila" and "Cuatro Ciénegas" locations, respectively. In the last location, the major diversity and specific richness were found. But in "Ojo Caliente," tannase allele conservations were observed.

Supporting medical planning by mitigating cognitive load.

OBJECTIVES: Developing a care plan for a patient is a complex task, requiring an understanding of interactions and dependencies between procedures and of their possible outcomes for an individual patient. Decision support for planning has broader requirements than are typically considered in medical informatics applications. We consider the appropriate design of software to assist medical planning. METHODS: The likely cognitive loads imposed by planning tasks were assessed with a view to directly supporting these via software. RESULTS: Five types of cognitive load are likely to be important. A planning support system, REACT, was designed to ameliorate these cognitive loads by providing targeted dynamic feedback during planning. An initial evaluation study in genetic counselling indicates that the approach is successful in that role. CONCLUSIONS: The approach provides the basis of a general aid for visualizing, customizing and evaluating care plans.

Effect of octreotide on small intestinal motility in HIV-infected patients with chronic refractory diarrhea.

Octreotide has been used to treat HIV-associated diarrhea. We aimed to assess the effect of octreotide on small intestinal motility in a group of HIV infected individuals with chronic diarrhea. Small intestinal motility was measured continuously for 48 hr by ambulatory strain gauge manometry in 12 HIV seropositive subjects with chronic diarrhea. During the second 24-hr period, intravenous octreotide was administered (100 microg every 8 hr). Postprandial and nocturnal fasting motility data were compared before and during administration of octreotide. Octreotide was associated with increased numbers of migrating motor complexes (MMCs) (7.25 vs 4.92, P = 0.03), and a relative decrease in the duration of phase II (22% vs 49.8, P = 0.03) during nocturnal fasting activity. Postprandial activity was absent in half of the subjects and the duration significantly reduced in the remainder. In conclusion, octreotide has a significant effect on small intestinal motility in HIV-infected individuals with diarrhea, which may influence intestinal transit.

The measurement of forces exerted during colonoscopy.

BACKGROUND: The widely varying forces used at colonoscopy have not been measured. An electronic device was designed to measure the forces exerted by the clinician on the endoscope during colonoscopy. METHODS: The device featured a handle designed in the shape of a hinged split cylinder that could be locked around the endoscope but readily moved up and down the insertion tube as the colonoscopy proceeded. This cylinder contained strain-gauges arranged so that the forces transmitted could be accurately measured. The device recorded the torque forces in addition to the push and pull forces exerted during diagnostic colonoscopy. RESULTS: In a series of 21 colonoscopies in 20 patients: peak pushing force = 4.4 kg, pulling force = -1.8 kg, anti-clockwise torque = 1.0 Newton meters, clockwise torque = 0.8 Newton meters. Percentage time force greater than 1 kg = 5%. Peak anal insertion force = 1.8 kg. CONCLUSIONS: These measurements represent the first accurate measurements of the forces exerted during colonoscopy. Reducing the force during colonoscopy is likely to diminish pain and reduce the risk of perforation. A knowledge of these forces may also help with the design of new instruments and models for teaching or research.

Human small bowel motor activity in response to liquid meals of different caloric value and different chemical composition.

Previous animal studies have shown that the nature and duration of postprandial motility in the small bowel depend both on the caloric load and the chemical composition of a meal. It is not clear whether this is also true for the human small bowel. Therefore we investigated the motor activity of the human small bowel in response to nutrient liquids of different caloric value and different chemical composition. Ten human volunteers underwent three separate, 24-hr ambulatory manometry studies. They drank water, a pure glucose solution, and Intralipid 10% in volumes of both 300 and 600 ml. The caloric value of the nutrient liquids was 330 and 660 kcal, respectively. Records were analyzed visually for the reappearance of phase III of the MMC after ingestion of a test liquid, and a validated computer program calculated the incidence and amplitude of contractions during the postprandial period. Neither duration of the postprandial interval nor the mean incidence or mean amplitude of contractions were different between the fat and the carbohydrate solutions, but phase III reappeared significantly later after ingestion of the nutrient liquids than after water (P = 0.0002). Duration of the postprandial interval also depended on the volume or the caloric load of a liquid meal (P = 0.0012). Mean incidence of contractions tended to be higher after ingestion of nutrient liquids than after water (P = 0.059). We conclude that in ambulant subjects, small bowel motor activity in response to chemically diverse liquid meals is remarkably uniform. This is true for the duration of the postprandial motor activity, as well as the incidence and amplitude of contractions during that period. The caloric value of a liquid meal, however, regulates the duration of the postprandial interval in the human small bowel.

Small bowel motility following major intra-abdominal surgery: the effects of opiates and rectal cisapride.

BACKGROUND/AIMS: Human small bowel motility is altered after laparotomy. Opiate analgesia is a possible cause of these alterations, and cisapride is a potential therapy. METHODS: Continuous proximal small bowel manometry was performed for up to 92 hours in 23 patients after major intra-abdominal surgery. They were treated with rectal cisapride (30 mg three times daily) or placebo until the clinical resolution of ileus. Small bowel manometry was performed for 30 hours in 5 volunteers receiving 1 mg/kg meperidine over 3 hours. RESULTS: Phase III activity was present within 3 hours of the end of surgery in all patients. Initially, the migrating motor complex (MMC) period was markedly reduced (mean, 22 minutes) but gradually increased. Phase II activity was absent until a median of 40 hours had elapsed. Phase III contractile amplitude was markedly attenuated in the jejunum, in contrast to that in the duodenum, presumably as a result of dilatation and/or altered tone, increasing to normal by 72 hours. In the volunteer group, although the MMC period was reduced by meperidine, it remained significantly greater than that of the placebo patient group for approximately 48 hours and phase II was reduced but not eliminated. Cisapride induced some changes in motor activity but did not accelerate the recovery of normal motility. Clinical outcome, assessed by the return of bowel sounds and passage of flatus, was accelerated by cisapride, but the trend was not significant (P = 0.11). CONCLUSIONS: This is the first published study using prolonged manometry to show the gradual evolution of small bowel motor activity after major intra-abdominal surgery. The findings suggest that surgery decreases the MMC period to the equivalent of the absolute refractory period, thereby eliminating phase II, which returns as the MMC period lengthens. Cisapride, at the dosage given, confers only modest benefit.

Daytime ingestion of alcohol alters nighttime jejunal motility in man.

We studied the effects of acute ingestion of intoxicating doses of alcohol on jejunal motility in six male volunteers ages 24-45 who had two 24-hr ambulatory manometries, one week apart, that each included three standardized meals with either red wine (0.6 g of alcohol/kg) or dealcoholized wine. Breath alcohol was measured at regular intervals for 3 hr following alcohol. The results show that the MMC cycle was significantly (P < 0.01) shorter during the night than during the day in the "nonalcohol" group but not in the "alcohol" group and that the amplitude of contractions was higher during the night than the day in the alcohol group (P < 0.01). All meals interrupted the MMC and induced a fed pattern. After the 300-kcal liquid meal, the duration of the fed pattern was shorter (P < 0.01), with a lower motility index (P < 0.01) and fewer contractions (P < 0.01), than following the two 600-kcal meals. The number of clustered contractions occurring in the postprandial period was lower in the alcohol group than in the nonalcohol group. After the three alcohol doses, a breath alcohol peak was reached in 20-60 min, and in all subjects, breath alcohol fell below 22 micrograms/100 ml after the third hour. This study showed that alcohol had only minor effects on postprandial contractile activity but abolished the circadian variation of the MMC normally seen in healthy subjects. The fact that breath alcohol was low by the time of onset of sleep, suggests that the effects on the MMC may be mediated through central rather than local mechanisms.

The computer as referee in the analysis of human small bowel motility.

The aim of this study was to determine whether visual analysis of graphic records of small bowel motility is a reliable method of discriminating pressure events caused by bowel wall contraction from those of extraenteric origin and to compare this method with computerized analysis. Each of six independent observers was supplied with the same pair of records of 1 h of fasting diurnal duodenojejunal motility, acquired with a 3-channel ambulant data-logging system; one record included many artifacts due to body movement while the other did not. The observers were asked to identify and classify pressure events and to measure the duration and amplitude of "true" contractions. A computer program for on-line analysis is described; the algorithm was designed to overcome the problems of a variable baseline and sudden changes in pressure due to body movements that are unavoidable in prolonged recording from the small bowel of ambulant subjects. For regular contractions (phase III of migrating motor complex) there was good agreement between observers but not for irregular contractions, particularly when movement artifacts were abundant. When the observers were asked to repeat the analysis 6 mo later, there was poor agreement with their original identification of irregular contractions and artifacts. There was, however, good agreement between the computer analysis, which was totally reproducible, and the median decisions of the observer group; this agreement supports the validity of our computer algorithm. We conclude that computer analysis is not merely a valuable ergonomic aid for analysis of large quantity of data acquired in prolonged ambulatory monitoring, but also that, even for brief recordings, it provides a standard of reproducibility unmatched by "expert" inspection. Visual analysis is unreliable and thus susceptible to subjective bias; this may, in part, account for conflicting reports of small bowel motility under similar conditions reported by different workers in our own and other laboratories.

Assessment by prolonged ambulatory manometry of the effect of oral cisapride on proximal small bowel inter-digestive motility.

The effects of cisapride, given orally at standard therapeutic dosage (10 mg tds), on proximal small bowel interdigestive motility in ten healthy volunteers was assessed by prolonged ambulatory manometry. Cisapride did not alter the duration of the MMC cycle, duration of phase II or the propagation rate of phase III in either the daytime or nighttime periods. However, when compared to studies, in which subjects received no drug, both nighttime and daytime phase II mean contractile amplitude, but not contractile incidence, were significantly increased (P < or = 0.001) by cisapride. Cisapride significantly increased the incidence of distally propagated clustered activity. We conclude that the major effects of cisapride on healthy small bowel motor function is to increase the mean contractile amplitude and incidence of distally propagated clustered activity.