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Biomedical subjects

C Betti

Publications and source records attributed to C Betti.

13 recordsLinked to original sources
PubMed1992

Genotoxic activity of methyl mercury chloride and dimethyl mercury in human lymphocytes.

The genotoxicity of methyl mercury chloride (MMC, 0-25 x 10(-6) M) and dimethyl mercury (DMM, 0-434 x 10(-6) M) was evaluated by chromosome metaphase analysis in human lymphocytes treated in vitro for 24 h. Structural (CA) and numerical (AN) chromosomal aberrations were scored for the assessment of induced genotoxic effects, while the variation in mitotic index (MI) was considered a monitor for induced cellular toxicity. MMC induced CA and AN in a dose-related manner at doses exceeding 0.6 x 10(-6) M, and the proportion of cells with CA was constantly and significantly higher than that of cells with AN. DMM was able to induce both effects as well, although to a lesser extent than MMC, CA and AN being induced at doses exceeding 43.4 x 10(-6) M and 1.73 x 10(-6) M, respectively. MMC was 6-fold more effective in inducing CA than DMM at equivalent toxic doses. On the other hand, no significant difference was observed between the two compounds in inducing AN. Therefore MMC was much more clastogenic than DMM, whereas mitotic spindle disturbances appeared to be almost equally induced by both compounds.

Adult↗
PubMed1992

Impaired colonic motor response to eating in patients with slow-transit constipation.

Because little is known about the pathophysiological mechanisms responsible for chronic idiopathic constipation, we studied colon motor response to eating, one of the most physiological and reproducible stimuli, in a clinically homogeneous group of severely constipated subjects. Fifteen patients (14 women, one man) with slow transit constipation (average duration of symptoms 18 +/- 2 yr) entered the study. After colonoscopic positioning of a manometric probe, 2-h basal and 3-h postprandial (1000 kcal standard mixed meal) recordings were obtained. Comparison of tracings with those of 29 healthy volunteers showed that motor response to eating was decreased in constipated subjects. Patients' response was characterized by a shorter duration of contractile activity in all three colon segments studied, after ingestion of the meal, and significantly less high-amplitude propagated contractions (7% vs. 45%). We conclude that several mechanisms are involved in the pathophysiology of colon contractile motor function of patients with chronic idiopathic constipation.

Adult↗
PubMed1992

Extensive investigation on colonic motility with pharmacological testing is useful for selecting surgical options in patients with inertia colica.

Three women with idiopathic severe chronic constipation and inertia colica, who failed to respond to medical treatment, were extensively investigated for gut motor function, especially that of the colon. Twenty-four-hour manometric recordings disclosed that motility was severely reduced throughout the entire colon and response to eating was minimal. One of the patients also was tested for esophageal, gastric, and small bowel motor activity, which gave normal results. Edrophonium chloride stimulation (10 mg iv) provoked no increase in colonic contractile activity in any patient. On these grounds, the patients were submitted to surgical intervention (total colectomy with ileorectal anastomosis two, and left hemicolectomy the other) with fairly good results at follow-up. These results indicate the wisdom of carrying out extensive functional investigations in severely constipated patients before surgery is contemplated.

Colon↗
PubMed1991

Effects of parenteral diclofenac sodium on upper gastrointestinal motility after food in man.

In experimental animal models nonsteroidal anti-inflammatory drugs may influence gastrointestinal motility, but as evidence is lacking in man. The effect of diclofenac sodium 75 mg i.m. on the motor response of the upper gastrointestinal tract to food has been studied by manometry in 9 healthy volunteers. Diclofenac had no effect on the motor activity of the stomach, duodenum, or jejunum after a 605 kcal meal.

Adult↗
PubMed1991

Edrophonium chloride for testing colonic contractile activity in man.

The effects of cholinergic stimulation on the entire human colon are at present relatively unknown. For this reason, we evaluated the influence of a short-lived anticholinesterase agent, edrophonium chloride, on proximal and distal colonic contractile activity in man. Eight healthy volunteers of both sexes were studied with a multi-lumen manometric probe positioned with the aid of a colonoscope. Recordings were then obtained 30 minutes pre- and post-drug administration. Edrophonium chloride (10 mg intravenous) significantly stimulated both proximal and distal colonic contractile activity, and the maximum increase was observed within 10 minutes following injection, although some differences were observed between colonic segments in response to the drug. No important side effects were complained of after edrophonium. Due to the potent stimulatory property on colonic smooth muscle, to its short duration of action, and to the paucity of side effects, it is concluded that edrophonium chloride may be useful as a stimulating substance during manometric investigations of the human colon.

Adult↗
PubMed1991

Prolonged (24-hour) manometric recording of rectal contractile activity in patients with slow transient constipation.

A periodic motor activity, named the rectal motor complex, has been recently described in the healthy human rectum. We studied the rectal contractile activity for 24 h by a low compliance manometric system in a group of 10 women with slow transit constipation. Analysis of the 24-hour manometric recordings showed that these subjects: (1) had overall scarce rectal motility; (2) display few rectal motor complexes (average, 3.3 +/- 1.3/subject/24 h) which are irregularly distributed over time, and (3) respond weakly to ingestion of a standard meal (average duration of the motor response 19 +/- 6 min). The observations suggest that an underlying neuropathic process may be involved in the pathogenesis of the impaired rectal motility in patients with slow transit constipation.

Adult↗
PubMed1991

Prolonged manometric investigation of the colon in research on chronic constipation.

We studied the whole colonic motility for 24 hours in controls and in constipated patients. In the patient group we found a significant reduction in the colonic mass movements (6.1 +/- 0.9 vs 2.6 +/- 0.7 controls vs patients, respectively). The constipated patients showed a reduction of the colonic motor activity after the ingestion of a standard meal. Moreover, they showed, compared with controls, a significant reduction of postprandial mass movements. On the other hand we were not able to find the so-called rectal motor complex described by others. In conclusion, we believe that prolonged colonic manometry would become an important step when evaluating the pathophysiology of constipated patients, particularly of those not responding to standard treatment.

Colon↗
PubMed1990

Manometric evaluation of jejunal limb after total gastrectomy and Roux-Orr anastomosis for gastric cancer.

Total gastrectomy with Roux-Orr anastomosis is frequently performed for gastric cancer. Since intestinal motility of the Roux limb has never been evaluated after this operation, pressure activity was investigated in the Roux limb of ten patients (aged 51-77 years) who had undergone total gastrectomy and Roux-Orr reconstruction. Investigations were carried out during a 6-h fast and 3 h after a 605 kcal mixed meal. During fasting only two patients had activity fronts and these were abnormal. All ten patients displayed non-propagating bursts of contractions and three had discrete clustered contractions and high amplitude jejunal contractions. The fed state was characterized by a severely reduced motor activity pattern and other abnormalities. Total gastrectomy with Roux-Orr anastomoses provokes a relatively severe disturbance in intestinal activity.

Aged↗
PubMed1990

Genotoxicity of two metabolites of benzene: phenol and hydroquinone show strong synergistic effects in vivo.

Possible interactions between hydroquinone (HQ) and phenol (PHE), 2 known benzene metabolites, in inducing micronuclei in mouse bone marrow cells were investigated. HQ and PHE administered alone gave weak and negative results, respectively, at the doses tested. However, simultaneous administration of both compounds caused a considerable increase in the induction of micronuclei as well as an increase in bone marrow toxicity. Using 3 different statistical methods, it was shown that the observed joint effect was significantly higher than additive interaction, and was close to multiplicative interaction. These findings bring further support to the hypothesis that the toxic and genotoxic effects of benzene are produced by several metabolites acting synergistically.

Animals↗
PubMed1989

Colonic motor response to eating: a manometric investigation in proximal and distal portions of the viscus in man.

The motor response of the human colon to a meal is still poorly characterized. Such data as are available were obtained chiefly for the distal colonic portions with myoelectrical techniques. For these reasons, we investigated proximal and distal colonic motor responses to food ingestion in a rather large group of healthy subjects. Twenty-nine healthy volunteers were studied with a colonoscopically positioned multilumen manometric probe and low-compliance infusion system. Recordings were obtained for 2 h during fasting and for 3 h after the subjects had eaten a 1000-kcal standard mixed meal. During fasting, motility was quite low, and no significant differences between proximal and distal portions were seen. After eating, each portion significantly increased its motor activity throughout the subsequent recording period, but there were differences in the time course in the response to eating for different colonic segments. Proximal portions (especially the transverse colon) had first a sudden maximal increase and then a decrease, whereas the distal ones had a slower and more sustained increase in activity. These findings are of interest, especially for comparison with those of patients with suspected motor dysfunction of the large bowel.

Adult↗
PubMed1988

Manometric evaluation of cimetropium bromide activity in patients with the nutcracker oesophagus.

There are at present few therapeutic alternatives to calcium channel blockers for the medical treatment of patients with nutcracker oesophagus. For this reason, we evaluated by means of a low-compliance manometric system the effect of a new anticholinergic compound, cimetropium bromide (10 mg intravenously), on oesophageal variables of eight patients with nutcracker oesophagus, in a single-blind study. Eight age-matched healthy volunteers served as controls. In both patients and controls, cimetropium bromide significantly decreased lower oesophageal sphincter pressure and the distal and proximal mean contraction amplitude of the oesophageal body. Apart from an increase in pulse rate, no noteworthy side effects were observed. It is concluded that cimetropium bromide may be an effective therapeutic option in patients with nutcracker oesophagus.

Adult↗
PubMedDate not supplied

[Changes in upper gastrointestinal motility during scleroderma].

Scleroderma (progressive systemic sclerosis) is a systemic collagen disease in which the upper gut is frequently involved. In particular, most patient show altered esophageal motility, which frequently result in severe esophagitis, often resistant to therapeutic measures. The small bowel is also frequently involved by the disease, especially in the late stage of scleroderma. Small bowel alterations are sometimes clinically silent, but can also be the origin of malabsorption syndrome, small intestine perforation, pneumatosis cystoides or chronic intestinal pseudo-obstruction. The occurrence of an altered gastrointestinal motility in scleroderma can be detected by means of manometric techniques; their use in the wide area of collagenopathies may help understanding the pathophysiology of the altered gastrointestinal function frequently existing in these diseases.

Esophagus↗