Error analysis of classic colonic transit time estimates.
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Estimates of colonic transit times (CTT) through the three colonic segments, right colon, left colon, and rectosigmoid, are commonly based on radiopaque markers. For a given segment, CTT is usually calculated from just the number of markers visible in that segment on abdominal X-rays. This procedure is only strictly valid for the theoretical, but unrealistic, case of continuous marker ingestion (i. e., not for a single or once-daily ingestion). CTT was analyzed using the usual estimate of the mean CTT of one marker and also using a new, more realistic estimate based on the kinetic coefficients of a three-compartment colonic model. We directly compared our compartmental approach to classic CTT estimates by double-marker studies in six patients. We also retrospectively studied CTT in 148 healthy control subjects (83 males, 65 females) and 1,309 subjects with functional bowel disorders (irritable bowel syndrome or constipation). Compared with the compartmental estimates, the classic approach systematically underestimates CTT in both populations, i.e., in patients and in healthy control subjects. The relative error could easily reach 100% independent of the site of colonic transit delay. The normal values of total CTT are then 44.3+/-29.3 instead of 30.1+/-23.6 h for males and 68.2+/-54.4 instead of 47.1+/-28.2 h for females. (+info)
Evidence for a schedule-dependent deleterious interaction between paclitaxel, vinblastine and cisplatin (PVC) in the treatment of advanced transitional cell carcinoma.
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A phase II study to evaluate the efficacy and toxicity of the combination of vinblastine, paclitaxel and cisplatin (PVC) in previously untreated patients with advanced transitional cell carcinoma. Chemotherapy naive patients with locally advanced or metastatic transitional cell carcinoma received the intravenous combination of paclitaxel 175 mg/m(2)over three hours followed by cisplatin 70 mg/m(2)over 3 hours on day 1 and vinblastine 3 mg/m(2)as a bolus on days 1 and 8 on a 21-day cycle, to a maximum of 6 cycles. The day 8 vinblastine was omitted if the total neutrophil count was <1.0. 15 patients (13 M, 2 F) of median age 66 (54-75) received a median of 5 cycles of treatment. There were two complete responses (13%; 95% CI 2-40%) and five partial responses (33%; 95% CI 12-62%), for an overall response rate of 46% (95% CI 21-73%). Responses occurred only in those with locally recurrent tumours and/or lymph nodes involved. Neutropenia at Grade 3-4 occurred in 14 of 67 cycles (21%) resulting in 7 episodes of neutropenic sepsis. Grade 3-4 thrombocytopenia was not observed. Other Grade 3 toxicity included alopecia (10 pts), diarrhoea (2 pts), constipation resulting in bowel obstruction (2 pts), nephrotoxicity (1 pt), myalgic pain (1 pt) and peripheral neuropathy (1 pt). Six patients developed Grade 2 paraesthesia. The median time to progression was 6 months and the median survival was 11 months. The regimen PVC was both less effective against transitional cell carcinoma and less toxic than expected. This may reflect an inhibitory interaction between vinblastine and paclitaxel and this schedule cannot be recommended for further investigation. (+info)
An exaggerated sensory component of the gastrocolonic response in patients with irritable bowel syndrome.
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BACKGROUND/AIMS: Visceral hypersensitivity is a feature of the irritable bowel syndrome (IBS). Postprandial symptoms are common in these patients. The effects of nutrients on colonic perception in IBS are incompletely understood. SUBJECTS: We studied 13 healthy subjects and 16 patients with IBS-eight had diarrhoea predominant (IBS-D) and eight constipation predominant (IBS-C) IBS. METHODS: Colonic perception thresholds to balloon distension and viscerosomatic referral pattern were assessed before and after duodenal infusion of lipid or saline, respectively. At the end of the infusions, plasma levels of gastrointestinal peptides were determined. RESULTS: Lipids lowered the thresholds for first sensation, gas, discomfort, and pain in the IBS group but only for gas in the control group. The percent reduction in thresholds for gas and pain after lipids was greater in the IBS and IBS-D groups but not in the IBS-C group compared with controls. IBS patients had an increased area of referred discomfort and pain after lipids compared with before infusion whereas the referral area remained unchanged in controls. No group differences in colonic tone or compliance were observed. In both groups higher levels of cholecystokinin, pancreatic polypeptide, peptide YY, vasoactive intestinal polypeptide, and neuropeptide Y were seen after lipids. Motilin levels were higher in patients and differences in the subgroups were observed. Levels of corticotrophin releasing factor were lower in the constipated group than in the diarrhoea group. CONCLUSIONS: Postprandial symptoms in IBS patients may be explained in part by a nutrient dependent exaggerated sensory component of the gastrocolonic response. (+info)
Docetaxel-carboplatin as first line chemotherapy for epithelial ovarian cancer.
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A prospective, non-randomized, multicentre, open, dose-finding study of a carboplatin-docetaxel (C-D) combination as first-line chemotherapy in FIGO stage Ic-IV epithelial ovarian cancer. C-D was given 3-weekly for 6 planned cycles, with a 3-day prophylactic dexamethasone regimen (8 mg b.i.d.). 139 eligible patients (Pts) (median age 56 years, range 28-85) were given a total of 750 cycles of chemotherapy in 5 cohorts: Co1, 32 pts, 169 cycles (C at AUC 5 + D 60 mg/m(2)); Co2, 22 pts, 122 cycles (5 + 75), Co3, 29 pts, 156 cycles (6 + 75), Co4, 27 pts, 146 cycles (7 + 75), Co5, 30 pts, 157 cycles (6 + 85). 110 patients (79%) completed 6 cycles; 17 (12%) stopped due to toxicity. 104 patients (75%) had CTC grade IV neutropenia, and 5 patients (4%) had this associated with fever. There were 2 probable treatment-related deaths. Only 8 patients (6%) experienced grade II-III neurotoxicity (all sensory; no motor > grade I). The maximum tolerated dose was reached in cohorts 4 and 5, and the dose limiting toxicities were myelosuppression and diarrhoea. The overall response rate for the study was 66% (49/74); CA125 response was 75% (70/93). Median progression-free survival was 16.6 months (95% CI 13.3-19.1). Recommended doses are carboplatin AUC 5 (via(51)Cr EDTA) or AUC 6 (if calculated) plus docetaxel 75 mg/m(2). A randomized trial comparing this regimen with carboplatin-paclitaxel has just completed recruitment. (+info)
Effect of an enteric-release formulation of naloxone on intestinal transit in volunteers taking codeine.
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INTRODUCTION: Constipation is a common side-effect of opioid therapy; in addition to their analgesic effect, opioids reduce intestinal secretion and motility with an increase in whole-gut transit time. Naloxone, a specific opioid antagonist, reverses these effects but may also cause symptoms of opioid withdrawal in patients on long-term therapy. AIM: To use an enteric-release formulation, designed to produce a topical effect in the gut, with minimum systemic effects. METHODS: Naloxone 10 mg b.d. and codeine 30 mg b.d. were used with identical placebo capsules in four sets of studies; 12 male volunteers were given the drugs alone and in combination, with a control study involving double placebo, during each of four study periods. Whole-gut transit time was calculated and compared for each treatment period. RESULTS: Naloxone, both alone and with codeine, significantly shortened the mean whole-gut transit time compared with the control period, respectively, from 53.1 to 42.1 h (P=0.005) and to 40.7 h (P=0.024). Urgency to defecate was reported by two volunteers on naloxone alone and by three on combination therapy. CONCLUSIONS: The results show that the naloxone formulation counteracts the effect of codeine on intestinal transit, suggesting that it may have useful clinical applications. (+info)
Strategies to manage the adverse effects of oral morphine: an evidence-based report.
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Successful pain management with opioids requires that adequate analgesia be achieved without excessive adverse effects. By these criteria, a substantial minority of patients treated with oral morphine (10% to 30%) do not have a successful outcome because of (1) excessive adverse effects, (2) inadequate analgesia, or (3) a combination of both excessive adverse effects along with inadequate analgesia. The management of excessive adverse effects remains a major clinical challenge. Multiple approaches have been described to address this problem. The clinical challenge of selecting the best option is enhanced by the lack of definitive, evidence-based comparative data. Indeed, this aspect of opioid therapeutics has become a focus of substantial controversy. This study presents evidence-based recommendations for clinical-practice formulated by an Expert Working Group of the European Association of Palliative Care (EAPC) Research NETWORK: These recommendations highlight the need for careful evaluation to distinguish between morphine adverse effects from comorbidity, dehydration, or drug interactions, and initial consideration of dose reduction (possibly by the addition of a co analgesic). If side effects persist, the clinician should consider options of symptomatic management of the adverse effect, opioid rotation, or switching route of systemic administration. The approaches are described and guidelines are provided to aid in selecting between therapeutic options. (+info)
Review article: the therapy of constipation.
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Constipation is a common symptom that may be idiopathic or due to various identifiable disease processes. Laxatives are agents that add bulk to intestinal contents, that retain water within the bowel lumen by virtue of osmotic effects, or that stimulate intestinal secretion or motility, thereby increasing the frequency and ease of defecation. Drugs which improve constipation by stimulating gastrointestinal motility by direct actions on the enteric nervous system are under development. Other modalities used to treat constipation include biofeedback and surgery. Laxatives and lavage solutions are also used for colon preparation and evacuation of the bowels after toxic ingestions. (+info)
Effects of brewer's yeast cell wall on constipation and defecation in experimentally constipated rats.
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Brewer's yeast cell wall (BYC) was tested on constipated male Sprague-Dawley rats that had been induced by loperamide (2 mg/kg of body weight). The preventive effect of BYC on constipation was examined and compared with that of a non-fiber diet (NF) as the control. The dose-response of BYC and the effect on defecation by constipated experimental rats were also compared with the characteristics of cellulose diet (CE) group which served as a control. Defecation was observed to be greater by the rats fed with BYC than by those fed with NF or CE. The fecal water content and level of volatile fatty acids (VFA) in the cecal contents were likewise higher in the rats fed with BYC. These results indicate that the administration of BYC was effective for improving defecation and other parameters related to defecation. These favorable effects of BYC supplemented to the diet are attributed to the fermentation ability, water holding capacity and swelling force in the large intestine. (+info)