How patient-selected colors for removable appliances are reflected in electronically tracked compliance (wear times and wear behavior).

OBJECTIVES: A broad spectrum of colors for removable appliances, intended to optimize acceptance of treatment and patient cooperation, have been available on the dental market for years. This is the first study to analyze how patient-selected colors are reflected in wear times and wear behavior of removable appliances. MATERIALS AND METHODS: The study included 117 children (55 girls and 62 boys) who were treated with active removable plate or functional appliances. All patients were offered to choose from 11 different colors, which were pooled into six groups (black, blue, green, yellow, pink, red) for analysis, or to combine any two to four colors ("multicolored" group) for their appliances. All appliances featured a built-in microsensor (TheraMon; MC Technology, Hargelsberg, Austria) for objective wear-time tracking. Differences between wear times were analyzed using pairwise t tests and Tukey correction. RESULTS: The longest median wear times were recorded in the blue and green groups (≈11 h/d) and the shortest ones in the red and pink groups (≈9 h/d), but they were not significantly influenced by the patient-selected colors. The median wear times involved an age-related decrease by 0.56 h/y that was statistically significant ( P = .00005). No gender-specific patterns of wear behavior were observed. CONCLUSIONS: Patient-selected colors for removable appliances can presumably improve acceptance of treatment, but they are not associated with statistically significant improvements in wear time or wear behavior.

The Dynamics of Gastric Emptying and Self-Reported Feelings of Satiation Are Better Predictors Than Gastrointestinal Hormones of the Effects of Lipid Emulsion Structure on Fat Digestion in Healthy Adults-A Bayesian Inference Approach.

Background: Limited information exists on the relation between fat emulsion structure and its effect on the release of gastrointestinal hormones and feelings of satiation.Objective: We investigated the impact of fat emulsion droplet size, gravitational and acid stability, and redispersibility on gastrointestinal responses and sought to deduce the relative importance of the hormones ghrelin, cholecystokinin, glucagon-like peptide-1, and peptide YY (PYY) in controlling fat emptying and related satiation.Methods: Within a randomized, double-blind, 4-armed crossover study, an extensive data set was generated by MRI of gastric function, analysis of hormone profiles, and ratings of satiation in healthy participants [10 women and 7 men with a mean ± SD age of 25 ± 7 y and body mass index (in kg/m2) of 22 ± 1] after intake of 4 different fat emulsions. Iterative Bayesian model averaging variable selection was used to investigate the influence of hormone profiles in controlling fat emulsion emptying and satiation.Results: The emulsion structure had a distinct effect on the gastric emptying (primary outcome), gastrointestinal hormone profiles, and ratings of satiation (secondary outcomes). Gravitational and acid stability were stronger modulators of fat emptying and hormone profiles than were emulsion droplet size or redispersibility. Cholecystokinin and PYY were most strongly affected by fat emulsion instability and droplet size. Although both hormones were relevant predictors of gastric emptying, only PYY was identified as a relevant predictor of satiation.Conclusions: This work indicates that evenly dispersed, stable, small-emulsion droplets within the stomach lead to prolonged gastric distension, longer ghrelin suppression, and accelerated fat sensing (cholecystokinin and PPY), triggering prolonged feelings of satiation. It suggests that the effects of emulsion instability and droplet size on energy consumption are best studied by assessing changes in gastric emptying and ratings of satiation rather than changes in venous hormone profiles. This trial was registered at clinicaltrials.gov as NCT01253005.

Relationship of body weight with gastrointestinal motor and sensory function: studies in anorexia nervosa and obesity.

BACKGROUND: Whether gastrointestinal motor and sensory function is primary cause or secondary effect of abnormal body weight is uncertain. Moreover, studies relating continuous postprandial sensations of satiation to measurable pathology are scarce. This work assessed postprandial gastrointestinal function and concurrent sensations of satiation across a wide range of body weight and after weight change. METHODS: Patients with anorexia nervosa (AN) and obesity (OB) were investigated in reference to normal weight controls (HC). AN were additionally investigated longitudinally. Gastric emptying, antral contractions and oro-cecal transit after ingestion of a solid meal were investigated by MRI and 13C-lactose-ureide breath test. The dependency of self-reported sensations of satiation on the varying degree of stomach filling during gastric emptying was compared between groups. RESULTS: 24 AN (BMI 14.4 (11.9-16.0) kg/m2), 16 OB (34.9 (29.6-41.5) kg/m2) and 20 HC (21.9 (18.9-24.9) kg/m2) were studied. Gastric half-emptying time (t50) was slower in AN than HC (p = 0.016) and OB (p = 0.007), and a negative association between t50 and BMI was observed between BMI 12 and 25 kg/m2 (p = 0.007). Antral contractions and oro-cecal transit were not different. For any given gastric content volume, self-reported postprandial fullness was greater in AN than in HC or OB (p < 0.001). After weight rehabilitation, t50 in AN tended to become shorter (p = 0.09) and postprandial fullness was less marked (p < 0.01). CONCLUSIONS: A relationship between body weight and gastric emptying as well as self-reported feelings of satiation is present. AN have slower gastric emptying and heightened visceral perception compared to HC and OB. Longitudinal follow-up after weight rehabilitation in AN suggests these abnormalities are not a primary feature, but secondary to other factors that determine abnormal body weight. TRIAL REGISTRATION: Registered July 20, 2009 at ClinicalTrials.gov ( NCT00946816 ).

Volume, distribution and acidity of gastric secretion on and off proton pump inhibitor treatment: a randomized double-blind controlled study in patients with gastro-esophageal reflux disease (GERD) and healthy subjects.

BACKGROUND: Postprandial accumulation of gastric secretions in the proximal stomach above the meal adjacent to the esophagogastric junction (EGJ), referred to as the 'acid pocket', has been proposed as a pathophysiological factor in gastro-esophageal reflux disease (GERD) and as a target for GERD treatment. This study assessed the effect of proton pump inhibitor (PPI) therapy on the volume, distribution and acidity of gastric secretions in GERD and healthy subjects (HS). METHODS: A randomized, double blind, cross-over study in 12 HS and 12 GERD patients pre-treated with 40 mg pantoprazole (PPI) or placebo b.i.d. was performed. Postprandial secretion volume (SV), formation of a secretion layer and contact between the layer and the EGJ were quantified by Magnetic Resonance Imaging (MRI). Multi-channel pH-monitoring assessed intragastric pH. RESULTS: A distinct layer of undiluted acid secretion was present on top of gastric contents in almost all participants on and off high-dose acid suppression. PPI reduced SV (193 ml to 100 ml, in HS, 227 ml to 94 ml in GERD; p < 0.01) and thickness of the acid layer (26 mm to 7 mm, 36 mm to 9 mm respectively, p < 0.01). No differences in secretion volume or layer thickness were observed between groups; however, off treatment, contact time between the secretion layer and EGJ was 2.6 times longer in GERD compared to HS (p = 0.012). This was not the case on PPI. CONCLUSIONS: MRI can visualize and quantify the volume and distribution dynamics of gastric secretions that form a layer in the proximal stomach after ingestion of a liquid meal. The secretion volume and the secretion layer on top of gastric contents is similar in GERD patients and HS; however contact between the layer of undiluted secretion and the EGJ is prolonged in patients. High dose PPI reduced secretion volume by about 50% and reduced contact time between secretion and EGJ towards normal levels. TRIAL REGISTRATION: NCT01212614.

Imaging gastric structuring of lipid emulsions and its effect on gastrointestinal function: a randomized trial in healthy subjects.

BACKGROUND: Efficient fat digestion requires fat processing within the stomach and fat sensing in the intestine. Both processes also control gastric emptying and gastrointestinal secretions. OBJECTIVE: We aimed to visualize the influence of the intragastric stability of fat emulsions on their dynamics of gastric processing and structuring and to assess the effect this has on gastrointestinal motor and secretory functions. DESIGN: Eighteen healthy subjects with normal body mass index (BMI) were studied on 4 separate occasions in a double-blind, randomized, crossover design. Magnetic resonance imaging (MRI) data of the gastrointestinal tract and blood triglycerides were recorded before and for 240 min after the consumption of the following 4 different fat emulsions: lipid emulsion 1 (LE1; acid stable, 0.33 µm), lipid emulsion 2 (LE2; acid stable, 52 µm), lipid emulsion 3 (LE3; acid unstable, solid fat, 0.32 µm), and lipid emulsion 4 (LE4; acid unstable, liquid fat, 0.38 µm). RESULTS: Intragastric emulsion instability was associated with a change in gastric emptying. Acid-unstable emulsions exhibited biphasic and faster emptying profiles than did the 2 acid-stable emulsions (P ≤ 0.0001). When combined with solid fat (LE3), different dynamics of postprandial gallbladder volume were induced (P ≤ 0.001). For acid-stable emulsions, a reduction of droplet size by 2 orders of magnitude [LE1 (0.33 µm) compared with LE2 (52 µm)] delayed gastric emptying by 38 min. Although acid-stable (LE1 and LE2) and redispersible (LE4) emulsions caused a constant increase in blood triglycerides, no increase was detectable for LE3 (P < 0.0001). For LE3, MRI confirmed the generation of large fat particles during gastric processing, which emptied into and progressed through the small intestine. CONCLUSIONS: MRI allows the detailed characterization of the in vivo fate of lipid emulsions. The acute effects of lipid emulsions on gastric emptying, gallbladder volume, and triglyceride absorption are dependent on microstructural changes undergone during consumption. Gastric peristalsis and secretion were effective at redispersing pools of liquid fat in the stomach. This trial was registered at clinicaltrials.gov as NCT01253005.

Noncoagulating Enteral Formula Can Empty Faster From the Stomach: A Double-Blind, Randomized Crossover Trial Using Magnetic Resonance Imaging.

BACKGROUND: The gastric accumulation of enteral formulas in tube-fed patients leads to an increased risk of vomiting and regurgitation. Gastric secretion-induced coagulation of proteins in enteral formulas might lead to gastric accumulation of solid protein particles that further increase the risk of upper digestive intolerance. This study used magnetic resonance imaging to noninvasively assess the half-emptying time (t50) of enteral formulas differing in protein composition. METHODS: Three isocaloric (450 kcal) and isovolumetric (300 mL) enteral formulas, 1 with a noncoagulating P4 protein blend and 2 with coagulating casein-dominant protein blends, were compared in a double-blind, randomized, 3-way crossover study in 21 healthy volunteers. Gastric content emptying curves were fitted with the LinExp model to compute t50 and the parameter κ with κ > 1 reflecting the accumulation of gastric secretion. t50 and κ were compared between all 3 enteral formulas. The formula that emptied fastest was identified by an ordinal mixed model using the ranks of t50. RESULTS: As indicated by values for κ > 1, all enteral formulas induced gastric secretion. No differences were detected for t50. However, the noncoagulating formula emptied fastest in 74% of all participants (P = .004). CONCLUSION: This study demonstrates that a noncoagulating enteral formula can empty faster from the stomach compared with coagulating formulas in a large cohort of healthy volunteers. Investigations on the efficiency of the noncoagulating P4 protein blend in patients requiring tube feeding will further elucidate its potential for reducing upper digestive intolerance during enteral nutrition. Trial NTR2979.

Abnormal structure and function of the esophagogastric junction and proximal stomach in gastroesophageal reflux disease.

OBJECTIVES: This study applies concurrent magnetic resonance imaging (MRI) and high-resolution manometry (HRM) to test the hypothesis that structural factors involved in reflux protection, in particular, the acute insertion angle of the esophagus into the stomach, are impaired in gastroesophageal reflux disease (GERD) patients. METHODS: A total of 24 healthy volunteers and 24 patients with mild-moderate GERD ingested a test meal. Three-dimensional models of the esophagogastric junction (EGJ) were reconstructed from MRI images. Measurements of the esophagogastric insertion angle, gastric orientation, and volume change were obtained. Esophageal function was assessed by HRM. Number of reflux events and EGJ opening during reflux events were assessed by HRM and cine-MRI. Statistical analysis applied mixed-effects modeling. RESULTS: The esophagogastric insertion angle was wider in GERD patients than in healthy subjects (+7° ± 3°; P=0.03). EGJ opening during reflux events was greater in GERD patients than in healthy subjects (19.3 mm vs. 16.8 mm; P=0.04). The position of insertion and gastric orientation within the abdomen were also altered (both P<0.05). Median number of reflux events was 3 (95% CI: 2.5-4.6) in GERD and 2 (95% CI: 1.8-3.3) in healthy subjects (P=0.09). Lower esophageal sphincter (LES) pressure was lower (-11 ± 2 mm Hg; P<0.0001) and intra-abdominal LES length was shorter (-1.0 ± 0.3 cm, P<0.0006) in GERD patients. CONCLUSIONS: GERD patients have a wider esophagogastric insertion angle and have altered gastric morphology; structural changes that could compromise reflux protection by the "flap valve" mechanism. In addition, the EGJ opens wider during reflux in GERD patients than in healthy volunteers: an effect that facilitates volume reflux of gastric contents.

Long-term survival of dental implants placed in the grafted maxillary sinus: systematic review and meta-analysis of treatment modalities.

BACKGROUND: A prevalent modality to increase the amount of available bone prior to implantation is grafting of the maxillary sinus. Multiple factors such as the surgical technique, moment of implant placement as well as grafting materials and membranes are known to affect implant survival. However, the role of different factor combinations and associated reciprocal effects remain unclear. Conventional statistical methods do not consider inconsistency of study designs and do not take covariables into account. Hence, a systematic research and meta-analysis was conducted to investigate the influence of various treatment modalities on implant survival in the grafted maxillary sinus. MATERIALS AND METHODS: A meta-analysis was conducted according to the PRISMA guidelines. Articles published from 1980 through January 2013 were electronically and manually searched in MEDLINE (Ovid), the Cochrane Register of Controlled Trials, the Database of Abstracts of Effects, and the Cochrane Database of Systematic Reviews. Clinical reports on single intervention sinus augmentation with root-form implants, a minimum of 10 patients and 6 months of loading were eligible for inclusion if implant survival was stated or calculable. Results were calculated by non-parametric univariate Kaplan-Meier analysis and Bayesian multivariate interval-censored Cox regression. RESULTS: A total of 122 publications on 16268 endosseous implants placed in grafted maxillary sinus were included. The treatment parameters surgical approach, grafting material and implant type showed no selective preference. However, application of membranes showed a significantly reduced hazard-ratio, independent of other co-factors. CONCLUSIONS: The use of membranes is the most significant factor to achieve long-term implant survival in sinus augmentation procedures. More data exceeding 3 years follow-up are needed to address prospective confounding and improve clinical evidence.

The effect of Helicobacter pylori infection and eradication in patients with gastro-oesophageal reflux disease: A parallel-group, double-blind, placebo-controlled multicentre study.

OBJECTIVES: This study aimed to resolve controversy regarding the effects of Helicobacter pylori eradication therapy and H. pylori infection in gastro-oesophageal reflux disease. DESIGN: A randomized, double-blind, multicentre trial was performed in patients presenting with reflux symptoms. H. pylori-positive patients were randomized to receive either antibiotics or placebo for 7 days. H. pylori-negative patient controls received placebo. All received esomeprazole 20 mg b.d. for 7 days, followed by 40 mg o.d. to complete an 8-week course, and were followed up for 32 weeks by telephone. RESULTS: In this study, 198/589 (34%) patients were H. pylori-positive and 113 H. pylori-negative patients served as controls. Baseline endoscopy revealed 63% Los Angeles grade 0A and 37% Los Angeles grade BCD oesophagitis with no difference between patient groups. Symptom improvement on esomeprazole was seen in 89%. H. pylori eradication was successful in 82%. H. pylori eradication had no effect on symptomatic relapse (hazard ratio 1.15, 95% CI 0.74-1.8; p = 0.5). Overall, H. pylori-positive patients had a lower probability of relapse compared to H. pylori-negative controls (hazard ratio 0.6, 95% CI 0.43-0.85; p = 0.004). Relapse hazard was modulated also by oesophagitis grade (BCD vs. 0A, hazard ratio 2.1, 95% CI 1.5-3.0). CONCLUSION: Relapse of gastro-oesophageal reflux disease symptoms after a course of high dose acid suppression took longer for H. pylori-positive patients than H. pylori-negative controls; however eradication therapy had no effect on the risk of relapse; ClincialTrials.gov number, NCT00574925.

Assessing antiangiogenic therapy response by DCE-MRI: development of a physiology driven multi-compartment model using population pharmacometrics.

Dynamic contrast enhanced (DCE-) MRI is commonly applied for the monitoring of antiangiogenic therapy in oncology. Established pharmacokinetic (PK) analysis methods of DCE-MRI data do not sufficiently reflect the complex anatomical and physiological constituents of the analyzed tissue. Hence, accepted endpoints such as Ktrans reflect an unknown multitude of local and global physiological effects often rendering an understanding of specific local drug effects impossible. In this work a novel multi-compartment PK model is presented, which for the first time allows the separation of local and systemic physiological effects. DCE-MRI data sets from multiple, simultaneously acquired tissues, i.e. spinal muscle, liver and tumor tissue, of hepatocellular carcinoma (HCC) bearing rats were applied for model development. The full Markov chain Monte Carlo (MCMC) Bayesian analysis method was applied for model parameter estimation and model selection was based on histological and anatomical considerations and numerical criteria. A population PK model (MTL3 model) consisting of 3 measured and 6 latent (unobserved) compartments was selected based on Bayesian chain plots, conditional weighted residuals, objective function values, standard errors of model parameters and the deviance information criterion. Covariate model building, which was based on the histology of tumor tissue, demonstrated that the MTL3 model was able to identify and separate tumor specific, i.e. local, and systemic, i.e. global, effects in the DCE-MRI data. The findings confirm the feasibility to develop physiology driven multi-compartment PK models from DCE-MRI data. The presented MTL3 model allowed the separation of a local, tumor specific therapy effect and thus has the potential for identification and specification of effectors of vascular and tissue physiology in antiangiogenic therapy monitoring.

In vivo knot scoring model for a multifilament suture.

BACKGROUND: A surgical knot is the key feature to assure appropriate wound support while combining tissue edges. Little evidence is available on the in vivo behavior of knots and the evaluation of knots in the living tissue. This study introduces a knot score model, which is defined by microscopic evaluation and the loop-holding capacity. MATERIALS: In a double-blinded and comparative study, 3 surgeons placed 10 intramuscular single-loop sutures in the longissimus muscle group of the dorsolumbar region at each side parallel to the vertrebral column. For accomplishing the study, 72 rabbits and 3 calibers of a test and control suture were used. On the fourth day, the knot safety was assessed by microscopical and mechanical analyses for scoring and classifying the knots of the different suture materials into the defined categories for loop-holding capacity. The statistical evaluation was performed using Hodges-Lehmann rank score. A Wilcoxon test was used to estabilish a significant difference between the suture types. RESULTS: When comparing Novosyn (Aesculap AG) with Vicryl (Johnson & Johnson Medical GmbH) a comparable knot safety was assessed based on a 95% confidence interval. CONCLUSIONS: The new method compares the knot safety between 2 braided multifilament sutures in the living tissue. Results were discussed and examined for statistical significance.

Bone marrow concentrate and bovine bone mineral for sinus floor augmentation: a controlled, randomized, single-blinded clinical and histological trial--per-protocol analysis.

PURPOSE: The purpose of this work was to evaluate the potential of substituting autogenous bone (AB) by bone marrow aspirate concentrate (BMAC). Both AB and BMAC were tested in combination with a bovine bone mineral (BBM) for their ability of new bone formation (NBF) in a multicentric, randomized, controlled, clinical and histological noninferiority trial. MATERIALS AND METHODS: Forty-five severely atrophied maxillary sinus from 26 patients were evaluated in a partial cross-over design. As test arm, 34 sinus of 25 patients were augmented with BBM and BMAC containing mesenchymal stem cells. Eleven control sinus from 11 patients were augmented with a mixture of 70% BBM and 30% AB. Biopsies were obtained after a 3-4-month healing period at time of implant placement and histomorphometrically analyzed for NBF. RESULTS: NBF was 14.3%±1.8% for the control and nonsignificantly lower (12.6%±1.7%) for the test (90% confidence interval: -4.6 to 1.2). Values for BBM (31.3%±2.7%) were significantly higher for the test compared with control (19.3%±2.5%) (p<0.0001). Nonmineralized tissue was lower by 3.3% in the test compared with control (57.6%; p=0.137). CONCLUSIONS: NBF after 3-4 months is equivalent in sinus, augmented with BMAC and BBM or a mixture of AB and BBM. This technique could be an alternative for using autografts to stimulate bone formation.

Effect on gastric function and symptoms of drinking wine, black tea, or schnapps with a Swiss cheese fondue: randomised controlled crossover trial.

OBJECTIVE: To compare the effects of drinking white wine or black tea with Swiss cheese fondue followed by a shot of cherry schnapps on gastric emptying, appetite, and abdominal symptoms. DESIGN: Randomised controlled crossover study. PARTICIPANTS: 20 healthy adults (14 men) aged 23-58. INTERVENTIONS: Cheese fondue (3260 kJ, 32% fat) labelled with 150 mg sodium (13)Carbon-octanoate was consumed with 300 ml of white wine (13%, 40 g alcohol) or black tea in randomised order, followed by 20 ml schnapps (40%, 8 g alcohol) or water in randomised order. MAIN OUTCOME MEASURES: Cumulative percentage dose of (13)C substrate recovered over four hours (higher values indicate faster gastric emptying) and appetite and dyspeptic symptoms (visual analogue scales). RESULTS: Gastric emptying was significantly faster when fondue was consumed with tea or water than with wine or schnapps (cumulative percentage dose of (13)C recovered 18.1%, 95% confidence interval 15.2% to 20.9% v 7.4%, 4.6% to 10.3%; P<0.001). An inverse dose-response relation between alcohol intake and gastric emptying was evident. Appetite was similar with consumption of wine or tea (difference 0.11, -0.12 to 0.34; P=0.35), but reduced if both wine and schnapps were consumed (difference -0.40, -0.01 to -0.79; P<0.046). No difference in dyspeptic symptoms was present. CONCLUSIONS: Gastric emptying after a Swiss cheese fondue is noticeably slower and appetite suppressed if consumed with higher doses of alcohol. This effect was not associated with dyspeptic symptoms. TRIAL REGISTRATION: ClinicalTrials.gov NCT00943696.

Effect of meal volume and calorie load on postprandial gastric function and emptying: studies under physiological conditions by combined fiber-optic pressure measurement and MRI.

This study assessed the effects of meal volume (MV) and calorie load (CL) on gastric function. MRI and a minimally invasive fiber-optic recording system (FORS) provided simultaneous measurement of gastric volume and pressure changes during gastric filling and emptying of a liquid nutrient meal in physiological conditions. The gastric response to 12 iso-osmolar MV-CL combinations of a multinutrient drink (MV: 200, 400, 600, 800 ml; CL: 200, 300, 400 kcal) was tested in 16 healthy subjects according to a factorial design. Total gastric volume (TGV) and gastric content volume (GCV = MV + secretion) were measured by MRI during nasogastric meal infusion and gastric emptying over 60 min. Intragastric pressure was assessed at 1 Hz by FORS. The dynamic change in postprandial gastric volumes was described by a validated three-component linear exponential model. The stomach expanded with MV, but the ratio of GCV:MV at t(0) diminished with increasing MV (P < 0.01). Postprandial changes in TGV followed those of GCV. Intragastric pressure increased with MV, and this effect was augmented further by CL (P = 0.02); however, the absolute pressure rise was <4 mmHg. A further postprandial increase of gastric volumes was observed early on before any subsequent volume decrease. This "early" increase in GCV was greater for smaller than larger MV (P < 0.01), indicating faster initial gastric emptying of larger MV. In contrast, volume change during filling and in the early postprandial period were unaffected by CL. In the later postprandial period, gastric emptying rate continued to be more rapid with high MVs (P < 0.001); however, at any given volume, gastric emptying was slowed by higher CL (P < 0.001). GCV half-emptying time decreased with CL at 18 +/- 6 min for each additional 100-kcal load (P < 0.001). These findings indicate that gastric wall stress (passive strain and active tone) provides the driving force for gastric emptying, but distal resistance to gastric outflow regulates further passage of nutrients. The distinct early phase of gastric emptying with relatively rapid, uncontrolled passage of nutrients into the small bowel, modulated by meal volume but not nutrient composition, ensures that the delivery of nutrients in the later postprandial period is related to the overall calorie load of the meal.

Effect of a prebiotic mixture on intestinal comfort and general wellbeing in health.

Specific carbohydrates, i.e. prebiotics such as fructo-oligosaccharide (FOS), are not digested in the small intestine but fermented in the colon. Besides beneficial health effects of an enhanced bifidobacteria population, intestinal gas production resulting from fermentation can induce abdominal symptoms. Partial replacement with slowly fermented acacia gum may attenuate side effects. The aim was to compare the effects of FOS with those of a prebiotic mixture (50 % FOS and 50 % acacia gum; BLEND) and a rapidly absorbed carbohydrate (maltodextrin) on general intestinal wellbeing, abdominal comfort and anorectal sensory function. Twenty volunteers (eight male and twelve female; age 20-37 years) completed this double-blind, randomised study with two cycles of a 2-week run-in phase (10 g maltodextrin) followed by 5 weeks of 10 g FOS or BLEND once daily, separated by a 4-week wash-out interval. Abdominal symptoms and general wellbeing were documented by telephone interview or Internet twice weekly. Rectal sensations were assessed by a visual analogue scale during a rectal barostat test after FOS and BLEND treatment. Both FOS and BLEND induced more side effects than maltodextrin. Belching was more pronounced under FOS compared with BLEND (P = 0.09 for females; P = 0.01 for males), and for self-reported general wellbeing strong sex differences were reported (P = 0.002). Urgency scores during rectal barostat were higher with FOS than BLEND (P = 0.01). Faced with a growing range of supplemented food products, consumers may benefit from prebiotic mixtures which cause fewer abdominal side effects. Sex differences must be taken in consideration when food supplements are used.

The effect of macronutrients on gastric volume responses and gastric emptying in humans: A magnetic resonance imaging study.

The effects of macronutrients on gastric volume changes, emptying, and gastrointestinal symptoms are incompletely understood. Three liquid meals of 500 ml (fat emulsion, 375 kcal; protein solution, 375 kcal; glucose solution, 400 kcal) were infused into the stomach of 12 healthy volunteers on three occasions. Studies were performed in seated body position using an open-configuration magnetic resonance imaging (MRI) system. MRI imaging sequences, assessing stomach and meal volumes, were performed prior to and at times t = 0, 3, 6, 9, 12, 15, 25, 35, 45, 60, 75, and 90 min after meal administration. Areas under the curve for the early emptying phase (0-15 and 0-45 min) were calculated, and characteristics of the volume curves were analyzed by a gastric emptying model. Gastrointestinal symptoms were assessed by a self-report scale. Initial (t = 0 min) and early postprandial gastric volumes were highest for glucose because of lower initial emptying. However, in the early emptying phase the characteristics of the volume curves for stomach and meal were uniform for all macronutrients. Perceptions of fullness and satiety were linearly associated with postprandial gastric volumes, but not with macronutrient composition. Isovolumic macronutrient meals modulate gastric volume response by initial meal emptying patterns. Macronutrient specific accommodation responses, as shown in barostat studies, are not reflected as gastric volume responses under noninvasive conditions.

Quantification of distal antral contractile motility in healthy human stomach with magnetic resonance imaging.

PURPOSE: To quantify healthy postprandial: 1) propagation, periodicity, geometry, and percentage occlusion by distal antral contraction waves (ACWs); and 2) changes in ACW activity in relationship to gastric emptying (GE). MATERIALS AND METHODS: Using 1.5-T MR scanner, nine healthy fasted volunteers were examined in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) with 500 microM Gd-DOTA. Total gastric (TGV) and meal volumes (MV) were assessed every five minutes for 90 minutes, in and interspersed with dynamic scan sequences (duration: 2.78 minutes) providing detailed images of distal ACWs. RESULTS: TGV increased by 738+/-38 mL after ingestion (t0), subsequently decreasing in parallel to GE. The mean GE rate and half-emptying time were 24+/-3 mL/5 minutes and 71+/-6 minutes, respectively. Accompanying ACWs reached a periodicity of 23+/-2 seconds at t35 and propagated at an unvarying speed of 0.27+/-0.01 cm/second. Their amplitude of 0.70+/-0.08 cm was constant, but the width decreased along the antral wall by 6+/-2%/cm (P=0.003). ACWs were nonocclusive (percentage occlusion 58.1+/-5.9%, t0 at the pylorus) with a reduction in occlusion away from the pylorus (P<0.001). No propagation and geometry characteristics of ACWs correlated with the changes of MV (mL/5 minutes; R2<0.05). CONCLUSION: Our results indicate that ACWs are not imperative for emptying of liquids. This study provides a detailed quantitative reference for MRI inquiries into pharmacologically- and pathologically-altered gastric motility.

The effects of loperamide on continence problems and anorectal function in obese subjects taking orlistat.

UNLABELLED: Continence problems during treatment with orlistat (a lipase inhibitor) are caused when susceptible patients are exposed to increased volumes of loose, fatty stool. AIM: To investigate the dose-response effects of loperamide on continence and anorectal function in subjects susceptible to continence problems on orlistat. METHOD: Ten obese subjects enterred a randomized controlled, double-blind study of loperamide at placebo, 2, 4, and 6 mg/day in a factorial design. Continence problems during orlistat treatment were self-assessed by patient diary. Anorectal function and continence were assessed by barostat, manometry, and retention testing. RESULTS: Loperamide increased stool consistency with dose (p = 0.07) and this effect reduced continence problems during orlistat treatment (p < 0.05). A bell-shaped dose-response relationship was present with anal sphincter function (p < 0.01) and anorectal sensitivity (p < 0.01). CONCLUSION: Loperamide has beneficial effects on stool consistency and continence in obese subjects taking orlistat. The effect on stool consistency appeared more important than effects on anorectal function.

The physical properties of rectal contents have effects on anorectal continence: insights from a study into the cause of fecal spotting on orlistat.

PURPOSE: The intermittent loss of oil or stool ("spotting") is an adverse effect that occurs in patients taking orlistat; the pathophysiology is unknown. This study was designed to investigate the local effects of orlistat, free fatty acids, and the effects of the physical properties of rectal contents on anorectal function and continence. METHODS: Anorectal physiology and continence function were assessed in ten healthy patients after the application of four test enemas: 1) high-viscosity stool substitute, 2) stool substitute with free fatty acid, 3) low-viscosity oil with placebo, 4) oil with orlistat. Rectal function and capacity were assessed by barostat techniques. Anal resting pressure, squeeze pressure, and squeeze duration were assessed by manometry. A retention test was performed using the same enemas as a quantitative assessment of continence. RESULTS: Orlistat and free fatty acid had no adverse effects on anorectal function or continence. For each enema, the maximum volume retained correlated with rectal capacity (r = 0.85; P < 0.01). Continence during rectal filling was better maintained for high-viscosity stool substitute than low-viscosity oil enemas (P < 0.03). Patients able to maintain effective squeeze pressure retained more of the low-viscosity enemas than those with short squeeze duration (P < 0.01); in contrast, the volume retained of high-viscosity enemas was unaffected by anal sphincter function. CONCLUSIONS: The physical properties of rectal contents, rectal capacity, and voluntary anal sphincter function have effects on continence function in healthy patients. The occurrence of spotting may depend on both intrinsic anorectal function and the effects of orlistat on the volume and physical properties of stool.

Propofol and sevoflurane in subanesthetic concentrations act preferentially on the spinal cord: evidence from multimodal electrophysiological assessment.

BACKGROUND: Animal experiments in recent years have shown that attenuation of motor responses by general anesthetics is mediated at least partly by spinal mechanisms. Less is known about the relative potency of anesthetic drugs in suppressing cortical and spinal electrophysiological responses in vivo in humans, particularly those, but not only those, connected with motor responses. Therefore, we studied the effects of sevoflurane and propofol in humans using multimodal electrophysiological assessment. METHODS: We studied nine healthy volunteers in two sessions during steady state sedation with 0.5, 1.0, and 1.5 microg/l (targeted plasma concentration) propofol or 0.2 and 0.4 vol% (end-tidal) sevoflurane. Following a 15-min equilibration period, motor responses to transcranial magnetic stimulation and peripheral (H-reflex, F-wave) stimulation were recorded, while electroencephalography and auditory evoked responses were recorded in parallel. RESULTS: At concentrations corresponding to two thirds of C(50 awake), motor responses to transcranial magnetic stimulation were reduced by approximately 50%, H-reflex amplitude was reduced by 22%, F-wave amplitude was reduced by 40%, and F-wave persistence was reduced by 25%. No significant differences between sevoflurane and propofol were found. At this concentration, the Bispectral Index was reduced by 7%, and the middle-latency auditory evoked responses were attenuated only mildly (N(b) latency increased by 11%, amplitude P(a)N(b) did not change). In contrast, the postauricular reflex was suppressed by 77%. CONCLUSIONS: The large effect of both anesthetics on all spinal motor responses, compared with the small effect on electroencephalography and middle-latency auditory evoked responses, assuming that they represent cortical modulation, may suggest that the suppression of motor responses to transcranial magnetic stimulation is largely due to submesencephalic effects.