No abstract

Black esophagus is the uncommon endoscopic finding of extensive black discoloration of the esophageal mucosa, usually from acute esophageal necrosis. Six cases of black esophagus were seen at Mayo Clinic (Rochester, Minnesota, USA) from 1997 through 2003, and 46 cases were reported in the English-language literature from 1963 through 2003. We studied the demographics, clinical features, and outcomes of these 52 cases of black esophagus. Age and sex were known for 50 patients: the mean (SD) age was 65 years (19), and 42 patients (84%) were men. Symptoms were known for 51 patients: the most common symptom was upper gastrointestinal tract bleeding, occurring in 40 patients (78%). All 52 patients had at least one comorbid condition (with most having two or more), including duodenal ulcer in 17 (33%), cancer in 15 (29%), renal insufficiency in 15 (29%), and diabetes mellitus in 14 (28%). The suspected cause of black esophagus was reported for 40 patients: ischemia in 22 (55%); massive gastroesophageal reflux in seven (18%); and esophageal infection (Lactobacillus acidophilus, herpes simplex, Candida albicans) in four (10%). Most patients received supportive therapy, particularly acid suppression therapy. Of the 47 patients for whom outcomes were known, 17 (36%) died. There were no statistically significant differences between survivors and non-survivors. Black esophagus typically occurs in older men with at least one comorbid condition; a substantial number of patients die. Although the underlying mechanism leading to black esophagus is unknown, clinicians caring for patients with black esophagus should focus on optimizing perfusion, minimizing acid reflux, and treating esophageal infection if present.

Cannabinoid agonist inhibits gastrointestinal motility. The endocannabinoid, anandamide, is inactivated by fatty acid amide hydrolase (FAAH). A single nucleotide polymorphism in the human FAAH gene (C385A) reduces FAAH expression. Our aim was to evaluate associations between FAAH genotype variation and symptom phenotype, gastric emptying and volume, colonic transit, and rectal sensation in patients with functional gastrointestinal disorders (FGID). 482 FGID patients [Rome II positive, 159 constipation disorders, 184 diarrhea disorders (D-IBS), 86 mixed bowel function (M-IBS), 20 chronic abdominal pain (CAP), 33 functional dyspepsia], and 252 healthy volunteers (HV) underwent questionnaires and studies of phenotype and genotype from 2000 to 2007: 250 gastric emptying, 210 fasting and postprandial gastric volume, 152 colonic transit, and 123 rectal sensation. All had FAAH genotype [CC vs. polymorphic (CA/AA)] determined by TaqMan. FAAH genotype distribution of FGID patients and HV did not deviate from Hardy-Weinberg equilibrium. There was a significant association of FAAH genotype with FGID phenotype (overall chi(2), P = 0.011) and with specific individual phenotypes (P = 0.048). Thus FAAH CA/AA increases the odds (relative to HV) for D-IBS (P = 0.008), M-IBS (P = 0.012), and, possibly, CAP (P = 0.055). There was a significant association of FAAH CA/AA genotype with accelerated colonic transit in D-IBS (P = 0.037). There was no association of FAAH genotype with rectal sensation thresholds or ratings. The association of genetic variation in metabolism of endocannabinoids with symptom phenotype in D-IBS and M-IBS and with faster colonic transit in D-IBS supports the hypothesis that cannabinoid mechanisms may play a role in the control of colonic motility in humans and deserve further study.

Background/ Aim-Weight loss in response to sibutramine is highly variable. We assessed the association of specific markers of polymorphisms of candidate a2A adrenoreceptor, 5-HT transporter and GNβ3 genes and weight loss with sibutramine.

Adrenergic and serotonergic mechanisms alter human gut motor functions. Genotype variation influences phenotype. Our aim was to test the hypothesis that variation in genes that control these functions is associated with gastrointestinal (GI) motor functions in humans with functional GI disorders (FGID). A database of 251 people was assembled by combining genotype data with measurements of gut transit and gastric volumes. Genetic variations evaluated were: alpha(2A) adrenergic (C-1291G), alpha(2C) (Del 332-325), 5-HT transporter (SLC6A4) and GNbeta3 (C825T). We sought associations between motor function or disease groups and genotypes, adjusting for age, gender and body mass index. Among 251 participants, 82 were healthy, 20 with irritable bowel syndrome (IBS) with mixed bowel habit, 49 with constipation-predominant IBS, 67 with diarrhoea-predominant IBS and 33 with functional dyspepsia. For all candidate genes, there was no significant association between motor function and wildtype vs non-wildtype gene status. There were significant interactions between genotype and motility phenotype, specifically GNbeta3 and alpha(2A) and gastric emptying at 4 h. Borderline associations were noted for SCL6A4 and alpha(2A) and postprandial gastric volume, and for alpha(2C) and gastric emptying at 2 h. We conclude that genotype variation may affect gastric motor functions in different FGID phenotypes. However, these candidate genes account for only a limited amount of the variance in gastric function of patients with FGID.