Removal of sulfacid brilliant pink from an aqueous stream by adsorption onto surfactant-modified Ti-pillared montmorillonite.

A modified hydrophobic and organophilic pillared clay (CTAC-TiH-montm) was prepared by exchanging some Ti polymeric cations into the interlamellar space of one Algerian montmorillonite (montm) and then by co-adsorption of some surfactant molecules such as cetyltrimethylammonium chloride (CTAC). These new materials were used in adsorption of an anionic textile dye: Sulfacid brilliant pink (SAP). According to adsorption isotherms, the organic modification of Ti-montmorillonite clay by CTAC surfactant increases the amount of textile dye fixed to more than 1000 mg g(-1). The adsorption experiments showed that a ratio of 3 mmol of CTAC per g of clay and an acidic medium (pH = 4) were the optimal parameters necessary to obtain good adsorption uptake and colourless treated solutions. A comparative study proved the high adsorption capacity of the synthesised adsorbents; they can thus be considered as powerful competitors to activated carbon in the treatment of aqueous textile plants and industry effluents.

Physiological correlates of colonic motility in patients with irritable bowel syndrome.

Irritable bowel syndrome is frequently encountered in clinical practice, and it has been repeatedly suggested that abnormal colonic motor activity is one of the major pathophysiological mechanisms responsible for the origin of symptoms in such disorder. If this statement is true, then high-amplitude propagated colonic contractions (HAPCs), i.e. the mass movements, may play an important role. To test this hypothesis, we conducted an investigation by recording colonic motility for a prolonged (24 h) period in 25 patients with irritable bowel syndrome and in 18 healthy volunteers, to compare the number of mass movements over 24 h in patients (constipation-predominant, alternating bowel habits) and controls. The overall amount of motility was also assessed in twelve patients and 13 controls. We also looked for the possible changes in mass movements and motility which may occur with defecation and after a meal. The results showed that 1) with respect to HAPCs and motility index, neither group was significantly different from controls; 2) HAPCs and the motility index were significantly reduced during sleep in all groups tested; 3) HAPCs were significantly more common before as compared to after defecation and after as compared to before meals; 4) HAPCs are not independent from the segmental contractile activity; 5) the motility index/24 h was lower in the constipation-predominant group of patients with respect to controls. We conclude that in patients with irritable bowel syndrome colonic motility per se may play a pathophysiological role in the genesis of the symptoms, although other mechanisms are likely to concur, or to be responsible for the complaints of these patients. However, colonic prolonged recordings are very useful for studying physiological and pathophysiological correlates of sleep, eating, and defecation.

Assessment of nalmefene glucuronide as a selective gut opioid antagonist.

Opioid use often causes troublesome constipation as a side-effect. Selective antagonism of the intestinal actions of opioids might be useful in the treatment of opioid-induced constipation. We tested the inactive metabolite of nalmefene, nalmefene glucuronide, which showed promise of gut selectivity in rodent models, by administering ascending doses in single-blind, placebo-controlled fashion to five methadone-maintained, opioid-dependent male volunteers. Assessment of whether systemic or gut-selective opioid antagonist effects occurred was measured by vital signs, pupillary diameter, opioid withdrawal symptom scales, and bowel function. Oral nalmefene glucuronide precipitated symptoms and signs consistent with the opioid abstinence syndrome in all five subjects a mean of 9.0 h after dosing. We conclude that nalmefene glucuronide does not appear to exert sufficient gut selectivity to be useful in antagonizing constipation due to exogenous opioid administration without antagonizing systemic opioid effects.

Gastrointestinal symptoms in bulimia nervosa: effects of treatment.

OBJECTIVES: The aim of this study was to characterize the frequency and severity of gastrointestinal symptoms in bulimic patients and to determine their response to treatment of the eating disorder. METHODS: Forty-three consecutive bulimic patients admitted to the inpatient Eating Disorders Unit of the Psychiatry Service were asked to fill out a gastrointestinal symptoms questionnaire, an Eating Disorders Inventory, and a Zung Depression Inventory on admission and discharge. Thirty-two age- and sex-matched healthy volunteers completed the same questionnaire. RESULTS: In bulimic patients, the most commonly reported gastrointestinal symptoms were bloating (74.4%), flatulence (74.4%), constipation (62.8%), decreased appetite (51.2%), abdominal pain (48.8%), borborygmi (48.8%), and nausea (46.5%). The average symptom score (sum of severity ratings) on the gastrointestinal symptoms questionnaire decreased from 20.6 +/- 10.8 (mean +/- SD) on admission to 13.46 +/- 10.5 (t(27) = 3.31, p < 0.01) on discharge but remained significantly higher than that of the control group (4.4 +/- 6.2, t(43) = 4.02, p < 0.001). However, the severity of reported gastrointestinal symptoms was correlated with the severity of depression (r = 0.43, p < 0.05), and when the possible mediating effects of depression on gastrointestinal symptoms were controlled statistically (analysis of covariance), the effects of treatment on gastrointestinal symptoms were not statistically significant. CONCLUSION: Gastrointestinal symptoms in bulimics are common, multiple, and often severe and they improve with treatment. However, the most important determinant of gastrointestinal symptoms appears to be depression.

Angiosarcoma of the small intestine: a case report and literature review.

A case of primary intestinal angiosarcoma in a 59-yr-old man is reported. The patient had recurrent gastrointestinal bleeding with normal upper and lower gastrointestinal endoscopies, technetium-99m-labeled erythrocyte scan, and angiography. Barium small bowel series and abdominal computerized tomography showed an ileal mass. Pathological examination was consistent with hemangiosarcoma with both solid and vasoformative patterns. Metastatic disease was also identified in the small bowel mesentery, liver, spleen, lungs, and brain. No identifiable underlying or epidemiologic factors have previously been reported to be associated with this rare type of tumor of the gastrointestinal tract. The pertinent literature on gastrointestinal angiosarcoma also is reviewed.

Delayed gastrointestinal transit times in anorexia nervosa and bulimia nervosa.

Anorectic and bulimic patients frequently report symptoms of constipation, bloating, and abdominal pain suggestive of abnormal gastrointestinal motility or transit. However, except for studies of gastric emptying, gastrointestinal motility and transit in these eating disorders have not been investigated. Ten anorectic and 18 bulimic inpatients were compared with 10 healthy controls. Whole-gut transit was tested by the radiopaque marker technique, and mouth-to-cecum transit time was assessed by the lactulose breath test. All anorectics and 67% of bulimics complained of constipation. Whole-gut transit time was significantly delayed in both anorectics (66.6 +/- 29.6 hours) and bulimics (70.2 +/- 32.4 hours) compared with controls (38.0 +/- 19.6 hours). Mouth-to-cecum transit time also tended to be longer in anorectics (109.0 +/- 33.5 minutes) and bulimics (106.2 +/- 24.5 minutes) than in controls (84.0 +/- 27.7 minutes), but these differences were not statistically significant. Delayed transit could contribute to or perpetuate the eating disorders by (a) causing the patient to feel bloated, thereby exacerbating fear of fatness, or (b) causing rectal distention, which may reflexly inhibit gastric emptying.

A simple radiologic method to estimate the quantity of bowel gas.

Patients with functional bowel disorders frequently complain of bloating and abdominal pain, but no practical method is available to measure intestinal gas objectively. To evaluate a new technique, we evaluated 54 abdominal radiographs from 19 patients. A gastroenterologist and a radiologist independently outlined the intestinal gas bubbles in these films. Areas of gas bubbles were measured with a computer digitizing board. Bowel gas was also measured in 24 healthy controls, and in five emergency room patients, supine and erect radiographs were compared to evaluate the effects of position on bowel gas patterns. The two evaluators agreed well on the measured areas of bowel gas (r = 0.96), showing that this is a reliable method. Bowel gas was significantly greater in patients than in controls but did not correlate with symptoms. Bowel gas was significantly greater in supine than upright films, showing that the position of the patient must be standardized.