Evaluation and comparison of commercially available Aloe vera L. products using size exclusion chromatography with refractive index and multi-angle laser light scattering detection

Raw materials supplied as Aloe vera L. (sometimes referred to as Aloe barbadensis) samples often contain different composition of low and high molecular weight components when analyzed by size exclusion chromatography. One major reason for variable compositions of commercial A. vera L. materials is that they are produced by different manufacturing techniques. Consistent composition of matter based upon a given standard has been difficult to define. In addition, the method of quantifying and characterization of these commercially available materials has not been agreed upon within the industry. The end user, whether a researcher, a manufacturer, a marketing arm of industry or the consumer, should know that they are receiving a consistent product. A blind study of 32 various A. vera L. samples from different manufacturers, and a prepared sample of fresh A. vera L. gel with the commercial, biologic drug Acemannan Immunostimulanttrade mark, were analyzed for content of high molecular weight (polysaccharides) material by size exclusion chromatography with refractive index detection (SEC/RI) and SEC/RI coupled with multi-angle laser light scattering (MALLS) detection. Results from the SEC/RI analysis showed significant variation in the high molecular weight content, and the MALLS analysis also showed significant variation versus SEC/RI. In addition, HPLC analysis of the anthraquinone content showed that all samples contained significantly less than that of the raw, unwashed aloe gel. The variation of results from all analysis is attributed to differing methods in which the samples were processed by the different manufacturers.     

Functional dyspepsia: drugs for new (and old) therapeutic targets

The therapeutic management of functional dyspepsia remains a major challenge for the gastroenterologist. Current therapies available are based on putative underlying pathophysiologic mechanisms, including gastric acid sensitivity, slow gastric emptying and Helicobacter pylori infection, but only a small proportion of patients achieve symptomatic benefit from these therapeutic approaches. Relatively novel mechanistic concepts under testing include impaired gastric accomodation, visceral hypersensitivity, and central nervous system dysfunction. Serotonergic modulators (e.g. the 5-HT4 agonist tegaserod, the 5-HT3 antagonist alosetron and the 5-HT1P agonist sumatriptan), CCK-1 antagonists (e.g. dexloxiglumide), opioid agonists (e.g. asimadoline), N-methyl-D-aspartate (NMDA) receptor antagonists (e.g dextromethorphan), neurokinin antagonists (e.g. talnetant), capsaicin-like agents and antidepressants are among the agents currently under investigation. It seems unlikely, however, that targeting a single mechanism with an individual drug will result in complete symptom remission in most cases.     

Management of chronic constipation

Constipation is a common problem in the United States. Although most individuals do not seek health care for its symptoms, there are still more than 2 million visits to physicians annually for treatment. In this article, the author presents an overview of current diagnostic tools and treatment options for chronic constipation.     

Empirically derived symptom sub-groups correspond poorly with diagnostic criteria for functional dyspepsia and irritable bowel syndrome. A factor and cluster analysis of a patient sample

AIM: To determine how clusters (groups) of patients with respect to symptoms compare with a clinical diagnosis in patients with irritable bowel syndrome and non-ulcer dyspepsia. METHODS: All patients who attended a gastroenterology practice at Nepean Hospital were included in the study. All patients received the previously validated Bowel Disease Questionnaire, and were independently assessed by the gastroenterologist. Factor analysis and a k-means cluster analysis were completed. RESULTS: The study population comprised 897 patients [320 males (36%) and 577 females (64%)]. Factor analysis identified nine symptom factors: (1) diarrhoea; (2) constipation; (3) dysmotility; (4) dyspepsia/reflux; (5) nausea/vomiting; (6) bowel; (7) meal-related pain; (8) weight loss; and (9) abdominal pain. A k-means cluster analysis identified seven distinct subject groups, which included an undifferentiated group: (1) diarrhoea; (2) meal-related pain; (3) abdominal pain; (4) faecal indicators; (5) nausea/vomiting/weight loss; and (6) constipation. The majority of irritable bowel syndrome patients fitted into two cluster groups [diarrhoea (25%) and constipation (20%)], whereas those with non-ulcer dyspepsia predominantly fitted into the undifferentiated cluster (34%) and the nausea/vomiting cluster (18%). CONCLUSION: This study supports the concept of symptom subgroups, including the subdivision of patients into diarrhoea- and constipation-predominant irritable bowel syndrome.     

Incidence of a clinical diagnosis of the irritable bowel syndrome in a United States population

BACKGROUND: The incidence of irritable bowel syndrome is uncertain. We aimed to determine the incidence of clinically diagnosed irritable bowel syndrome in the community. METHODS: Using the Rochester Epidemiology Project, all diagnoses of irritable bowel syndrome made among adult residents of Olmsted County, Minnesota, over a 3-year period were identified. The complete medical records of a random sample of the potential subjects were reviewed for the 10 years prior to the irritable bowel syndrome diagnosis and any patient who had received a previous diagnosis of irritable bowel syndrome was excluded (prevalent cases). RESULTS: The diagnostic index listed 1245 possible irritable bowel syndrome patients; 416 patient charts were reviewed and, of these, 149 were physician diagnosed incident cases of irritable bowel syndrome. The age- and sex-adjusted incidence rate was 196 per 100,000 person-years and increased with age (P = 0.006). The age-adjusted annual incidence per 100,000 in women was higher than in men: 238 vs. 141 (ratio 3:2; P = 0.005). The overall symptom frequency at the time of diagnosis was abdominal pain (73%), diarrhoea (41%) and constipation (16%). CONCLUSIONS: The incidence of a clinical diagnosis of irritable bowel syndrome in adults was estimated to be two per 1000 per year, increased with age and was higher in women than men. As many people with irritable bowel syndrome do not seek care, the true incidence of irritable bowel syndrome is likely to be higher.     

Management of dyspepsia

Proper management of uninvestigated dyspepsia is a challenging task for any clinician. Efficient and cost-effective management of such patients requires careful history taking and awareness of the available options. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Comparison of one-year outcomes following coronary artery stenting in diabetic versus nondiabetic patients (from the Enhanced Suppression of the Platelet IIb/IIIa Receptor With Integrilin Therapy [ESPRIT] Trial)

For patients undergoing nonurgent coronary stent implantation, blockade of the glycoprotein IIb/IIIa receptor with eptifibatide reduces the incidence of ischemic complications. We evaluated the interaction of eptifibatide with diabetes in patients who underwent this procedure by analyzing the 1-year outcomes of those enrolled in the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial (466 diabetic and 1,595 nondiabetic patients). At 1 year, the composite end point of death, myocardial infarction (MI), or target vessel revascuarlization (TVR) was higher in diabetic patients (24.5% vs 18.4%; p = 0.008). At 1 year, eptifibatide had a similar effect on the composite end point of death, MI, or TVR in diabetic (hazards ratio [HR] 0.71, 95% confidence interval [CI] 0.49 to 1.04) and nondiabetic patients (HR 0.80, 95% CI 0.63 to 0.99). A similar treatment effect was also seen on death or MI in both groups. The 1-year mortality rate for diabetic patients assigned to placebo was 3.5% versus 1.3% for patients receiving eptifibatide (HR 0.37, 95% CI 0.10 to 1.41); the latter rate was similar to the mortality rate of 1.4% for nondiabetic patients in the eptifibatide group. However, eptifibatide did not have a significant effect on TVR in diabetic patients (HR 0.90, 95% CI 0.57 to 1.41). Our data suggest that treatment with eptifibatide is associated with a similar relative reduction in adverse ischemic complications in diabetic and nondiabetic patients undergoing coronary stent implantation. There is no evidence of a statistical interaction in the treatment effect of eptifibatide between patients with and without diabetes.     

Is irritable bowel syndrome more likely to be persistent in those with relatives who suffer from gastrointestinal symptoms? A population‐based study at three time points

BACKGROUND: We tested the hypothesis that subjects with relatives who suffered from abdominal pain or bowel dysfunction would be at an increased risk of more persistent irritable bowel syndrome. METHODS: A valid, self-report questionnaire was mailed to an age- and gender-stratified random sample of residents, aged 30-64 years, in Olmsted County, MN, USA, on three occasions over a 4-year period. Persistent irritable bowel syndrome was defined as the presence of irritable bowel syndrome on at least two of the three surveys, and fluctuating irritable bowel syndrome was defined as the presence of irritable bowel syndrome on only one of the surveys. RESULTS: Subjects were less likely to have persistent irritable bowel syndrome over the age of 50 years [odds ratio (OR), 0.20; 95% confidence interval (CI), 0.09, 0.47]. A positive family history was reported by 23%. A family history of gastrointestinal symptoms was independently associated with persistent irritable bowel syndrome (vs. no irritable bowel syndrome: OR, 2.5; 95% CI, 1.3, 4.9) and fluctuating irritable bowel syndrome (vs. no irritable bowel syndrome: OR, 2.4; 95% CI, 1.3, 4.4). However, subjects reporting a positive family history were not more likely to report persistent vs. fluctuating irritable bowel syndrome (OR, 1.2; 95% CI, 0.5, 2.9). The use of non-steroidal anti-inflammatory drugs (OR, 2.3; 95% CI, 1.2, 4.3) and a history of food sensitivity (OR, 3.6; 95% CI, 1.9, 6.9) were the only other predictors of persistent irritable bowel syndrome. CONCLUSIONS: A history of abdominal pain or bowel troubles in first-degree relatives appears to be independently associated with both persistent and fluctuating irritable bowel syndrome.