Polymerization of lactams, 88. Copolymers poly(ϵ-caprolactam)-block-polybutadiene prepared by anionic polymerization,part III. Model polymerizations initiated with potassium salt of ϵ-caprolactam and accelerated with isocyanates and their derivatives

Anionic polymerization of ?-caprolactam was initiated with the potassium salt of ?-caprolactam and accelerated with phenyl isocyanate, toluylene diisocyanate, 4,4′-diphenylmethane diisocyanate, some derivatives of these isocyanates (urethanes, ureas, and allophanates), or combinations of phenyl isocyanate with its derivatives at 150°C. The effect of individual structures on the polymerization kinetics and their contribution to the preparation of block copolymers of ?-caprolactam with hydroxy-terminated prepolymers, in-situ functionalized with diisocyanates, are discussed on the basis of a detailed analysis of time functions of polymer yield and degree of polymerization.     

Knowledge, attitudes and practices about blood donation. A sociological study among the population of Lomé in Togo]

GOALS: 1) analyse the knowledge, attitudes and practices of Lome population about blood donation; 2) identify obstacles to blood donation among the population of Lome; 3) suggest some solutions to improve the performance of the National Blood Transfusion Centre (CNTS). METHODOLOGY: We have conducted a sample survey among the population of Lome from the 6th to 21st October 2003. Three hundred persons filled a questionnaire. RESULTS: In the sample, 183 (61%) were males. Their age ranged from 18 to 67 years with 2/3 of young peoples between 18 and 37 years. Pupils/students were 24,33%, wage-earners, 55% and the unemployed, 17,67%. More than the half of the investigated persons (54,67%) were unmarried and 96, 33% persons were literate. Nearly all the people (96,33%) knew about blood donation in Lome and they have received information mainly from friends, media and sensitization by the CNTS. Sixty-one percent of the investigated knew where blood is donated. All the investigated were unanimous about the vital role of blood. Whatever their religion, they recognized its sacred nature. The majority of the investigated (85%) were willing to donate blood. Only 95 people were donors. The reasons for non-donation were mainly related to the fear of catching diseases (31,71%) especially the HIV (9,76%), the lack of information (25,37%), the religious beliefs (19,51%) and the fear of knowing the result of one's HIV test. 277 people (92,33%) said that blood should be donated without remuneration. CONCLUSION: There is a growing interest in the blood donation among the population of Lome but new strategies must be elaborated to inform the population and motivate blood donors.     

Activation of peripheral 5-HT4 receptors attenuates colonic sensitivity to intraluminal distension

Tegaserod is a 5-HT(4) receptor partial agonist approved for the treatment of irritable bowel syndrome in women with constipation and in both men and women with chronic constipation. The efficacy of tegaserod is based on the importance of 5-HT(4) receptors regulating intestinal peristalsis and secretion, and possibly visceral sensory pathways. Our aim was to investigate the effect of tegaserod on colorectal sensitivity using models of normal and exaggerated responsiveness to colorectal distension (CRD). The visceromotor responses (VMR) to CRD at graded pressures (0-60 mmHg) were measured by the number of reflex abdominal contractions. Acute colorectal hypersensitivity was induced by intracolonic infusion of dilute acetic acid. Chronic hypersensitivity was observed in rats following spontaneous resolution of trinitrobenzenesulfonic acid-induced colitis. Rats with normosensitive colons served as controls. Tegaserod (0.1-10 mg kg(-1)) caused dose-dependent reduction of the VMR to CRD in control rats and in those with colonic hypersensitivity. 5-HT(4) antagonists reversed the effects of tegaserod in rats with normosensitive colons, and partially inhibited effects in rats with colonic hypersensitivity. Central administration of tegaserod had no inhibitory effect. These results support the assumption that colonic hypersensitivity could be normalized by tegaserod acting, at least in part, through peripheral 5-HT(4) receptors.     

Effect of female sex hormone supplementation and withdrawal on gastrointestinal and colonic transit in postmenopausal women

Females are disproportionately affected by constipation, which is often aggravated during pregnancy. Bowel function also changes during the luteal phase of the menstrual cycle. The aim was to compare the effects of acute administration of female sex steroids on gastric emptying, small bowel transit and colonic transit in healthy postmenopausal subjects. A second aim was to determine whether withdrawal of the hormones was associated with a change in transit. Forty-nine postmenopausal females were randomized to receive for 7 days 400 mg day(-1) micronized progesterone, 0.2 mg day(-1) oestradiol, combination of the two, or placebo. Treatment groups were balanced on age. Participants underwent whole gut transit measurement by scintigraphy using a 99m-labeled technetium-egg meal and 111-labeled indium-charcoal via a delayed-release capsule. Transit measurement was repeated after withdrawal of the study medications. The primary endpoints were ascending colon (AC) emptying half-life time (t1/2) and colonic geometric centre (GC) at 24 h. Secondary analysis variables were GC at 4 and 48 h, gastric emptying t1/2 and colonic filling at 6 h. There was a significant overall effect of progesterone on colonic transit with shorter AC emptying t1/2 and significantly greater colonic GC at 48 h. No transit endpoints were altered by oestradiol or combined hormonal treatment relative to placebo. Oestradiol and progesterone resulted in looser stool consistency. Withdrawal of the hormone supplement was not associated with significant alteration in transit. Micronized progesterone does not retard colonic transit in postmenopausal females.     

Antigen capture assay for detection of bovine leukemia virus proteins by monoclonal antibodies.

A capture monoclonal antibody-based assay has been established for detecting the p24 core protein and the gp51 envelope glycoprotein of bovine leukemia virus (BLV). This assay is rapid, highly sensitive and specific. Viral antigens in test samples were identified using mouse monoclonal antibody-coated or microtiter plates by adding labeled monoclonal antibodies with different epitope specificities. The choice of an appropriate epitope specificity for the specificity of monoclonal antibodies was important for optimal performance of the assay. Results of this assay were in agreement with the syncytia induction assay routinely used for detecting BLV production by cells in vitro. The sensitivity of monoclonal antibody assay was 0.5 ng/ml for p24 and 1.25 ng/ml for gp51, respectively. The specificity was demonstrated by immunoblotting. The assay can be performed in a few hours, is simple, and is comparable with more time-consuming assays with regard to sensitivity and specificity.     

Renal involvement in the Laurence-Moon-Bardet-Biedl syndrome: report of five cases

.We report five patients with Laurence-Moon-Bardet-Biedl syndrome (LMBBS) who had renal involvement. Intravenous pyelography showed bilateral or unilateral calyceal clubbing and blunting in all patients. In addition, one patient had a parapelvic cyst in the left kidney and another had bilateral lobulated renal outlines of the fetal type. One patient had a urinary concentrating defect and two patients showed increased fractional sodium excretion. Estimated tubular phosphate reabsorption values were in normal limits in all of five patients. No patient had a urine acidification defect, proteinuria, glycosuria, or hyperaminoaciduria. One patient died from end-stage renal failure. The remaining four patients had normal serum creatinine values and estimated creatinine clearances. ^99mTechnetium-diethylenetriamine pentaacetate renal scanning showed prolonged and delayed concentration and delayed excretion in three of the four patients who survived. A focal scar was determined on the left kidney of one of four patients by ^99mtechnetium-dimercaptosuccinic acid renal scanning. All LMBBS cases with or without renal symptoms should be routinely evaluated for renal abnormalities. Renal scanning is a valuable method, especially for determining the renal involvement in the early stage of disease. Received November 14, 1995; received in revised form and accepted May 23, 1996