Jutta Keller

Effects of 5-Hydroxytryptamine (Serotonin) Type 3 Antagonists on Symptom Relief and Constipation in Nonconstipated Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND & AIMS We performed a systematic review and meta-analyses to estimate treatment efficacy and constipation rate of 5-hydroxytryptamine (serotonin) (5-HT(3)) antagonists in patients with nonconstipated (NC) or diarrhea-predominant (D)-irritable bowel syndrome (IBS). METHODS Two reviewers independently searched MEDLINE, EMBASE, and Web of Science (January 1, 1966 to December 15, 2006) for randomized controlled trials of 5-HT(3) antagonists in IBS reporting clinical end points of the IBS symptom complex and safety parameters. Study characteristics, markers of methodologic quality, and outcomes for the intention-to-treat population for each randomized controlled trial were extracted independently. RESULTS We found 14 eligible randomized controlled trials of alosetron (n = 3024) or cilansetron (n = 1116) versus placebo (n = 3043) or mebeverine (n = 304). Random-effects meta-analyses found 5-HT(3) antagonists more effective than the comparators in achieving global improvement in IBS symptoms (pooled relative risk, 1.60; 95% confidence interval [CI], 1.49-1.72; I(2) = 0%) and relief of abdominal pain and discomfort (pooled relative risk, 1.30; 95% CI, 1.22-1.39; I(2) = 22%). Benefit was apparent for both agents, in patients of either sex. These agents were more likely to cause constipation (pooled relative risk, 4.28; 95% CI, 3.28-5.60, I(2) = 65%); there was less constipation with 5-HT(3) antagonists in D-IBS patients than in mixed populations (NC-IBS and D-IBS; relative risk ratio, 0.65; 95% CI, 0.41-0.99). Nine patients (0.2%) using 5-HT(3) antagonists had possible ischemic colitis versus none in control groups. CONCLUSIONS 5-HT(3) antagonists significantly improve symptoms of NC-IBS or D-IBS in men and women. There is an increased risk of constipation with 5-HT(3) antagonists, although the risk is lower in those with D-IBS.

Inspection of the human stomach using remote-controlled capsule endoscopy: a feasibility study in healthy volunteers (with videos)

BACKGROUND Remote control of capsule endoscopes might allow reliable inspection of the human stomach. OBJECTIVE To assess the safety and efficacy of manipulation of a modified capsule endoscope with magnetic material (magnetic maneuverable capsule [MMC]) in the human stomach by using a handheld external magnet. DESIGN Open clinical trial. SETTING Academic hospital. PATIENTS Ten healthy volunteers. INTERVENTIONS Subjects swallowed the MMC and sherbet powder for gastric distention. An external magnetic paddle (EMP-2) was used to manipulate the MMC within the stomach. MMC responsiveness was evaluated on a screen showing the MMC film in real time. MAIN OUTCOME MEASUREMENTS Safety and tolerability (questionnaire), gastric residence time of the MMC, its responsiveness to the EMP-2, area of gastric mucosa visualized. RESULTS There were no adverse events. The MMC was always clearly attracted by the EMP-2 and responded to its movements. It remained in the stomach for 39 ± 24 minutes. In 7 subjects, both the cardia and the pylorus were inspected and 75% or more of the gastric mucosa was visualized (≥50% in all of the remaining subjects). A learning curve was clearly recognizable (identification of MMC localization, intended movements). LIMITATIONS Small amounts of fluid blocked the view of apical parts of the fundus; gastric distention was not sufficient to flatten all gastric folds. CONCLUSIONS Remote control of the MMC in the stomach of healthy volunteers using a handheld magnet is safe and feasible. Responsiveness of the MMC was excellent, and visualization of the gastric mucosa was good, although not yet complete, in the majority of subjects. The system appeared to be clinically valuable and should be developed further. ( CLINICAL TRIAL REGISTRATION NUMBER DE/CA05/2009031008.).

Pancreatic enzymes : Secretion and luminal nutrient digestion in health and disease

Severe pancreatic exocrine insufficiency leading to malabsorption of nutrients is one of the most important late features of chronic pancreatitis. In contrast to other key enzymes, pancreatic synthesis and secretion of lipase is impaired more rapidly, its intraluminal survival is shorter due to its higher susceptibility against acidic and proteolytic denaturation, and its luminal digestive action is hardly compensated by nonpancreatic mechanisms. As a consequence, steatorrhea is in general more severe and occurs several years before clinical malabsorption of protein or starch. Apart from the detrimental effects of nutrient deficiency, profound alterations of upper gastrointestinal secretory and motor functions may be an additional and hitherto underestimated consequence of increased nutrient delivery to distal intestinal sites. Effective reduction of nutrient malabsorption in pancreatic insufficiency requires delivery of sufficient enzymatic activity into the duodenal lumen simultaneously with meal nutrients. Modern enteric-coated pancreatin microsphere preparations attempt to achieve this by optimizing the size of individual microspheres and chemical properties of the coating. However, lipid digestion cannot be completely normalized in most patients by current standard therapy. In the future, acid and protease stable bacterial and fungal lipases with additional pH optima in the acidic milieu or animal or bioengineered human gastric lipase preparations may offer superior therapeutic alternatives. This review first summarizes current knowledge about secretion and luminal fate of pancreatic enzymes and their effects on nutrient digestion in health and chronic pancreatitis. Second, rationale, current standards, options, and future aspects of enzyme replacement therapy are discussed.

Lipase supplementation therapy: standards, alternatives, and perspectives.

Treatment of steatorrhea by lipase supplementation therapy has become more successful in the last decade due to better understanding of the physiology and pathophysiology of the digestive process. Porcine lipase has been the therapeutic standard for several decades and will continue to be the treatment of choice in pancreatic exocrine insufficiency. Modern therapeutic concepts recommend administration of 25,000–40,000 units of porcine lipase per meal using pH-sensitive pancreatin microspheres. In case of treatment failure, the dose should be increased, compliance should be checked, and other reasons for malabsorption should be excluded. Still, in most patients, lipid digestion cannot be completely normalized by current standard therapy, and future developments are needed for optimizing treatment. In this article, pathophysiologic characteristics of pancreatic exocrine insufficiency, prerequisites for use of alternative lipase sources as well as currently available lipases of nonporcine origin, and new developments are discussed. Current literature suggests that bovine lipase products present a theoretical alternative but play no major role in the western world. Fungal lipase has inferior properties compared with conventional products. Bacterial lipase products show promising potential and offer future therapeutic alternatives. Moreover, human pancreatic lipase gene transfer and application of bioengineered human gastric lipase appear on the horizon.

Delivery and fate of oral mesalamine microgranules within the human small intestine

BACKGROUND/AIMS Oral use of mesalamine in inflammatory bowel disease requires slow-release preparations to prevent premature absorption and inactivation. Resulting luminal concentrations within the human small intestine are unknown. The aim of this study was to determine human intestinal delivery patterns of mesalamine from a microgranule preparation (Pentasa; Ferring Arzeimittel, Kiel, Germany) effective in Crohns disease with small bowel involvement. METHODS A multilumen tube for duodenal, jejunal, and ileal aspiration and marker perfusion was placed in 6 normal subjects. Levels of luminal, plasma, and urinary mesalamine and its main metabolite, acetyl mesalamine, were measured for 7 hours after ingestion of mesalamine (500 mg) with a labeled meal. RESULTS Gastric emptying of mesalamine paralleled the meal, and its release occurred throughout the small intestine (cumulative, 20% of dose). For 4 hours, mean luminal mesalamine and acetyl mesalamine concentrations were 52 and 38 micrograms/mL (duodenum), 59 and 82 micrograms/mL (jejunum), and 64 and 104 micrograms/mL (ileum). Cumulative colonic delivery was 82% (7% dissolved, 75% in microgranules), and urinary excretion was 3.5%. CONCLUSIONS Although the major part of continuous-release mesalamine is delivered to the colon, large proportions are liberated and available at high concentrations within the small intestinal lumen, thus explaining its therapeutic efficacy in small intestinal Crohns disease.

Tests of pancreatic exocrine function - Clinical significance in pancreatic and non-pancreatic disorders

The pancreas functions as the main factory for digestive enzymes and therefore enables food utilisation. Pancreatic exocrine insufficiency, partial or complete loss of digestive enzyme synthesis, occurs primarily in disorders directly affecting pancreatic tissue integrity. However, other disorders of the gastrointestinal tract, such as coeliac disease, inflammatory bowel disease, Zollinger-Ellison syndrome or gastric resection can either mimic or cause pancreatic exocrine insufficiency. The overt clinical symptoms of pancreatic exocrine insufficiency are steatorrhoea and maldigestion, which frequently become apparent in advanced stages. Several direct and indirect function tests are available for assessment of pancreatic function but until today diagnosis of excretory insufficiency is difficult as in mild impairment clinically available function tests show limitations of diagnostic accuracy. This review focuses on diagnosis of pancreatic exocrine insufficiency in pancreatic and non-pancreatic disorders.

Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group

An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro‐esophageal reflux disease (GERD).

Remote magnetic control of a wireless capsule endoscope in the esophagus is safe and feasible: results of a randomized, clinical trial in healthy volunteers

BACKGROUND Remote control of esophageal capsule endoscopes could enhance diagnostic accuracy. OBJECTIVE To assess the safety and efficacy of remote magnetic manipulation of a modified capsule endoscope (magnetic maneuverable capsule [MMC]; Given Imaging Ltd, Yoqneam, Israel) in the esophagus of healthy humans. DESIGN Randomized, controlled trial. SETTING Academic hospital. PATIENTS This study involved 10 healthy volunteers. INTERVENTION All participants swallowed a conventional capsule (ESO2; Given Imaging) and a capsule endoscope with magnetic material, the MMC, which is activated by a thermal switch, in random order (1 week apart). An external magnetic paddle (EMP; Given Imaging) was used to manipulate the MMC within the esophageal lumen. MMC responsiveness was evaluated on a screen showing the MMC film in real time. MAIN OUTCOME MEASUREMENTS Safety and tolerability of the procedure (questionnaire), responsiveness of the MMC to the EMP, esophageal transit time, and visualization of the Z-line. RESULTS No adverse events occurred apart from mild retrosternal pressure (n = 5). The ability to rotate the MMC around its longitudinal axis and to tilt it by defined movements of the EMP was clearly demonstrated in 9 volunteers. Esophageal transit time was highly variable for both capsules (MMC, 111-1514 seconds; ESO2, 47-1474 seconds), but the MMC stayed longer in the esophagus in 8 participants (P < .01). Visualization of the Z-line was more efficient with the ESO2 (inspection of 73% ± 18% of the circumference vs 33% ± 27%, P = .01). LIMITATIONS Magnetic forces were not strong enough to hold the MMC against peristalsis when the capsule approached the gastroesophageal junction. CONCLUSION Remote control of the MMC in the esophagus of healthy volunteers is safe and feasible, but higher magnetic forces may be needed.

The spectrum and treatment of gastrointestinal disorders during pregnancy

Gastrointestinal symptoms are extremely common during pregnancy. Increased levels of female sex hormones cause or contribute to symptoms such as heartburn, nausea, vomiting and constipation. If these symptoms do not respond adequately to lifestyle and dietary changes, drug therapy is often warranted to improve quality of life and to prevent complications. Physicians, therefore, need to be familiar with the low-risk treatment options available. Treatment of chronic conditions such as IBD or chronic liver disease during pregnancy can be demanding. In women with IBD, maintenance of adequate disease control during pregnancy is crucial. Most IBD drugs can be used during pregnancy, but the benefits and risks of specific drugs should be discussed with the patient. Liver diseases can be coincidental or pregnancy-specific. Pregnancy-specific liver diseases include not only benign disorders such as intrahepatic cholestasis of pregnancy, but also pre-eclampsia, eclampsia and HELLP syndrome (hemolytic anemia, elevated liver enzymes and low platelet count). Accordingly, the spectrum of therapeutic measures ranges from expectant management to urgent induction of delivery. During pregnancy, lamuvidine therapy for chronic hepatitis B can be continued; however, interferon and ribavirin therapy for chronic hepatitis C is contraindicated. This Review provides an overview of the spectrum and therapy of motility disturbances that occur during pregnancy, and discusses pregnancy-specific aspects of IBD and liver diseases.

Influence of clinical parameters on the results of 13C-octanoic acid breath tests: Examination of different mathematical models in a large patient cohort

Abstract  It is assumed, although not proven, that 13CO2‐excretion following ingestion of 13C‐octanoic acid (13C‐OA) does not only depend on gastric emptying (GE) but also on absorption and metabolism of 13C‐OA and endogenous CO2‐production. Our aims were (i) to test the effects of patient characteristics and of diseases that may impair 13C‐OA‐metabolism on GE parameters. (ii) To compare different GE endpoints. Therefore, we investigated effects of age, gender, BMI and diseases with potential impact on 13C‐OA‐metabolism (including pancreatic, liver and lung disease, diabetes, IBD) on cumulative 4h‐13CO2‐excretion (4h‐CUM) and T½ calculated by non‐linear regression model (NL, determined by shape of breath test curve) and generalized linear regression model (GLR, reflects absolute 13CO2‐excretion) in 1279 patients and 19 healthy controls who underwent a standardized 13C‐OA‐breath test. Digestive and metabolic disturbances hardly influenced 4h‐CUM or T½ calculated by NL or GLR models. In the multivariate linear regression models, 4h‐CUM was significantly predicted by diabetes adjusted for age, gender and IBD but influence of these parameters was small (R2 = 0.028, P < 0.0001). T½NL and 4h‐CUM were weakly correlated, even after exclusion of tests with unrealistically high estimates for T½NL (n = 1095, R2 = 0.029, P < 0.0001). Conversely, 4h‐CUM was closely associated with T½GLR (exponential correlation, R2 = 0.774, P < 0.00001, n = 1279). We conclude that influences of digestive and metabolic disturbances on 13CO2‐excretion following 13C‐OA‐application are generally low. Thus, our findings resolve an important criticism of methods using absolute 13CO2‐excretion for evaluation of 13C‐OA‐breath tests and suggest that such models may correctly identify T½ in a mixed patient population.