Effect of 5-HT4 receptor agonist mosapride citrate on rectosigmoid sensorimotor function in patients with irritable bowel syndrome

BACKGROUND

The 5-HT(4) receptor agonist, mosapride citrate, accelerates gastric emptying. However, the effect of mosapride on colonic function has not been well investigated. We examined whether mosapride changes rectosigmoid motility and perception in patients with irritable bowel syndrome (IBS).

METHODS

Thirty-seven patients with IBS and 18 healthy subjects were studied. All subjects underwent a rectosigmoid barostat test to measure pain perception to intraluminal distention and resting smooth muscle motility for 20 min in the fasting state. Irritable bowel syndrome patients were then randomly assigned to receive either mosapride 15 mg (n=19) or placebo (n=18) orally with 200 mL water. Rectosigmoid motility and perception were measured again for 60 min following dosing. Rectosigmoid tone and contractility were evaluated in each 10-min period.

KEY RESULTS

The pain threshold in the patients was significantly lower than that in controls (P<0.01). There were no differences between mosapride and placebo groups in pain threshold, barostat bag volume, or number of contractions at baseline. Mosapride significantly decreased the mean bag volume (P<0.01; group × period interaction by two-way anova) and increased the mean number of contractions (P<0.05) compared with placebo, but did not affect the perception. In IBS patients with constipation (i.e., excluding diarrhea-predominant subjects), mosapride (n=13) increased rectosigmoid tone (P<0.01) and contractions (P<0.05) more than placebo (n=14).

CONCLUSIONS & INFERENCES

Mosapride stimulates colonic motility without any adverse effect. These findings suggest that mosapride may have the potential to treat IBS patients with constipation and/or functional constipation. Further clinical trials are warranted to confirm the efficacy of this agent.

Effect of rikkunshito on gastric sensorimotor function under distention

BACKGROUND

The herbal medicine rikkunshito is effective for the treatment of gastrointestinal symptoms in patients with functional dyspepsia. Although some basic studies on the effects of rikkunshito have been reported in rats, its effects on human gastric function have not yet been clarified. Psychosocial stress induces visceral hypersensitivity and elements of rikkunshito may reasonably affect or suppress this process. We conducted a study to verify the hypothesis that rikkunshito improves stress-induced gastric hypersensitivity and/or changes in gastric wall tone.

METHODS

Nine healthy volunteers (five males, four females) participated in the study. The counterbalanced regimen consisted of a 2-week period of oral administration of 7.5 g day(-1) rikkunshito, then a 2-week period without treatment. Fundic sensorimotor function was examined using a gastric barostat twice on the day after each period. Virtual reality stress was imposed during the measurements of gastric tone and electrocardiogram.

KEY RESULTS

Stress induced a significant increase in heart rate (P = 0.041), gastric volume (P = 0.008), and phasic volume events (P = 0.049) and a decrease in sensory (P = 0.038), discomfort (P = 0.011), and pain (P = 0.041) thresholds of the stomach. Rikkunshito significantly reduced epigastric fullness (P = 0.037) and perceived stress (P = 0.034) following stimulation of the pain threshold, regardless of stress without the drug. Stress reduced gastric volume at the sensory threshold and increased anxiety at the discomfort threshold, and these responses were significantly inhibited by rikkunshito (P = 0.026, P = 0.022, respectively).

CONCLUSIONS & INFERENCES

These findings suggest that rikkunshito may improve symptoms and impaired gastric accommodation under distention stimuli of the proximal stomach superimposed by stress.

Association between masticatory performance using a colour-changeable chewing gum and jaw movement

The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (ΔE) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (ΔE60) for each subject was obtained using ΔE for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ΔE60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum.

Tuberculosis screening programme using the QuantiFERON-TB Gold test and chest computed tomography for healthcare workers accidentally exposed to patients with tuberculosis

Healthcare workers (HCWs) have an increased incidence of tuberculosis (TB). Periodic and as-needed screenings of HCWs exposed to patients with TB are important. We integrated chest computed tomography (CT) and the QuantiFERON-TB Gold (QFT-G) test into our TB screening programme for HCWs. First, contacts were tested using the QFT-G test. Those positive for the QFT-G test were investigated by CT and classified as having active, latent (LTBI), or old TB. Between April 2005 and April 2010, 11 patients who had not been diagnosed with active TB on admission were found to have the disease. A total of 512 close or high risk contacts were identified, and underwent screening. Out of those, 34 (6.64%) were QFT-G positive, whereas 478 (93.36%) were negative. Of the 34 QFT-G-positive HCWs, four had CT findings compatible with active TB and received multidrug treatment; 24 showed no findings of active TB and received isoniazid for six months. All completed their regimens without any adverse effects. The TB screening programme integrating CT and the QFT-G test was safe and feasible. The efficacy of the programme needs to be confirmed by large scale clinical trials.

Differential responding of autonomic function to histamine H₁ antagonism in irritable bowel syndrome

BACKGROUND

The role of histamine in the pathophysiology of irritable bowel syndrome (IBS) is largely unknown. Dysfunction of the autonomic nervous system (ANS) in IBS patients is also not fully confirmed. We hypothesized that blockade of histamine H₁ receptors affects ANS responses differently between IBS subjects and controls.

METHODS

Subjects were 12 IBS subjects and 12 age- and sex-matched controls. Either 100 μg kg⁻¹ chlorphenamine or the same amount of saline was administered on different days. The rectum was stimulated with electrical currents of 0 mA (sham) or 30 mA. Autonomic nervous system function was measured using mean arterial pressure (MAP), heart rate (HR), high frequency (HF) component of HR variability, low frequency/high frequency ratio (LF/HF ratio) and plasma catecholamines and histamine. Subjective perceived stress during the examination was evaluated on an ordinate scale.

KEY RESULTS

Mean arterial pressure showed significant effects of diagnosis (P < 0.05) and drug × diagnosis interaction (P < 0.05). The MAP significantly increased after chlorphenamine administration in IBS subjects, but not in controls. Heart rate revealed a significant drug effect (P < 0.001), which decreased after chlorphenamine administration in controls, but not in IBS subjects. Perceived stress significantly increased by rectal stimulation (P < 0.001) and a significant stimulus × diagnosis interaction (P < 0.05) was revealed, indicating greater reduction in IBS subjects by chlorphenamine.

CONCLUSION & INFERENCES

Sympathetic vasomotor tone in IBS subjects differentially responded on administration of a histamine H₁ antagonist to that of controls. These findings suggest an increased histaminergic activity in IBS subjects.

Altered profiles of intestinal microbiota and organic acids may be the origin of symptoms in irritable bowel syndrome

BACKGROUND

The profile of intestinal organic acids in irritable bowel syndrome (IBS) and its correlation with gastrointestinal (GI) symptoms are not clear. We hypothesized in this study that altered GI microbiota contribute to IBS symptoms through increased levels of organic acids.

METHODS

Subjects were 26 IBS patients and 26 age- and sex-matched controls. Fecal samples were collected for microbiota analysis using quantitative real-time polymerase chain reaction and culture methods, and the determination of organic acid levels using high-performance liquid chromatography. Abdominal gas was quantified by image analyses of abdominal X-ray films. Subjects completed a questionnaire for GI symptoms, quality of life (QOL) and negative emotion.

KEY RESULTS

Irritable bowel syndrome patients showed significantly higher counts of Veillonella (P = 0.046) and Lactobacillus (P = 0.031) than controls. They also expressed significantly higher levels of acetic acid (P = 0.049), propionic acid (P = 0.025) and total organic acids (P = 0.014) than controls. The quantity of bowel gas was not significantly different between controls and IBS patients. Finally, IBS patients with high acetic acid or propionic acid levels presented with significantly worse GI symptoms, QOL and negative emotions than those with low acetic acid or propionic acid levels or controls.

CONCLUSIONS & INFERENCES

These results support the hypothesis that both fecal microbiota and organic acids are altered in IBS patients. A combination of Veillonella and Lactobacillus is known to produce acetic and propionic acid. High levels of acetic and propionic acid may associate with abdominal symptoms, impaired QOL and negative emotions in IBS.

Site-specific differences in central processing of visceral stimuli from the rectum and the descending colon in men

BACKGROUND

It has been reported that different brain activation areas are demonstrated during somatosensory and visceral stimulation. However, no study thus far has investigated how activated patterns in the human brain differ during visceral stimulation of different sites of the digestive tracts. The aim of this study was to determine possible site-specific differences in brain responses and perceptions during visceral stimulation of two different sites, the intraluminal distentions of the rectum and descending colon.

METHODS

Regional cerebral blood flow was assessed in 32 healthy right-handed male subjects using H(2)(15)O positron emission tomography during distention of the rectum (R group, n = 16) or descending colon (DC group, n = 16) at 40 or 20 mmHg.

KEY RESULTS

R group reported significantly higher scores of abdominal pain (P < 0.05) and urge to defecate (P < 0.001) during the application of stimulus at 40 mmHg compared with DC group but not of abdominal bloating or anxiety. In comparisons of response to the 40-mmHg stimulus, R group showed significantly greater activation in posterior midcingulate cortex (MCC) and right anterior and posterior insula, whereas DC group showed greater activation in subgenual anterior cingulate cortex (ACC), perigenual ACC and left orbitofrontal and superior temporal cortices.

CONCLUSIONS & INFERENCES

These findings suggest that central projections of painful visceral stimulation from the rectum and descending colon differ in affective, cognitive and nociceptive processing in the brain, which may result in different perceptions of visceral stimulation from different sites.

Multi-center intervention study on glycohemoglobin (HbA1c) and serum, high-sensitivity CRP (hs-CRP) after local anti-infectious periodontal treatment in type 2 diabetic patients with periodontal disease

The purpose of this study was to examine whether periodontal treatment incorporating topical antibiotic therapy affects on levels of glycohemoglobin (HbA1c) and serum high-sensitivity C-reactive protein (hs-CRP) in type 2 diabetic patients with periodontal disease, and to explore the relationship between CRP and glycemic control. The whole intervention group (n=32), which underwent anti-infectious periodontal treatment, showed only transient reduction in HbA1c levels without any change in hs-CRP, while the control group (n=17) did not show any changes in HbA1c or hs-CRP. Multiple regression analysis of all subjects revealed that BMI and change in hs-CRP correlated significantly with the reduction of HbA1c at 6 months after the periodontal treatment. Based on the results of multiple regression analysis, the intervention group was subdivided into two groups: those in which hs-CRP levels decreased (CRP-D group), and those in which hs-CRP levels unchanged or increased (CRP-N group) (n=16, respectively), and re-analysis was conducted based upon these subgroups. In the CRP-D subgroup, HbA1c was significantly reduced at the end of the study, but it did not decrease in the CRP-N subgroup. The decrease of HbA1c in the CRP-D subgroup following periodontal treatment was significantly greater than that in the CRP-N subgroup. BMI of each group remained unchanged in this study at the end of the study. Thus, the results suggested that periodontal treatment with topical antibiotics improves HbA1c through reduction of CRP, which may relate to amelioration of insulin resistance, in type 2 diabetic patients with periodontal disease.

Interferon-beta augments eosinophil adhesion-inducing activity of endothelial cells

Viral infections induce exacerbations of asthma. One of the earliest host responses to viral infections is the production of innate cytokines including type I interferons (IFNs), such as IFN-beta, which may act to modify airway inflammation. The objective of the present study was to investigate whether IFN-beta modifies the eosinophil adhesion-inducing activity of endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with IFN-beta for 24 h in the presence or absence of tumour necrosis factor (TNF)-alpha. Eosinophils were isolated from the peripheral blood of healthy volunteers. The ability of the IFN-beta-stimulated HUVEC monolayers to induce eosinophil adhesion was assessed according to the eosinophil peroxidase assay. Eosinophil adhesion to HUVECs was significantly augmented by IFN-beta in the presence of TNF-alpha but not in its absence. The augmented adhesion was inhibited by anti-alpha(4) integrin monoclonal antibody (mAb) or anti-beta(2) integrin mAb. IFN-beta significantly enhanced the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 on HUVECs in the presence of TNF-alpha. Interferon-beta can augment the adhesiveness of endothelial cells to eosinophils, mainly through the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. This action of interferon-beta may contribute to the intensification of airway inflammation in asthma that is associated with exacerbations induced by viral infections.

Clinical features of patients with myasthenia gravis associated with autoimmune diseases

We investigated the incidence and clinical features of patients with myasthenia gravis (MG) associated with autoimmune diseases. Associated autoimmune diseases were found in 28 of 142 consecutive Japanese MG patients (19.7%), amongst which Graves' disease (7.7%) and Hashimoto's thyroiditis (4.2%) were predominant. The clinical features of MG patients with Graves' disease were different from those of MG patients without autoimmune diseases in terms of age at onset of MG symptoms (35.5 +/- 4.0 years and 49.0 +/- 1.7 years; P < 0.05), positivity for the anti-acetylcholine receptor antibody (44.4% and 89.8%; P < 0.05), and association with thymic hyperplasia (72.7 and 17.9%; P < 0.05). The therapeutic outcome of MG patients with Graves' disease and that of those without autoimmune diseases were not significantly different. Further studies should be performed to investigate whether MG associated with Graves' disease is a distinct subtype of MG.

Role of histaminergic neurons in hypnotic modulation of brain processing of visceral perception

Modulating visceral sensation of the body is important to the understanding of emotion formation. Molecules that act during hypnosis and modify visceral pain perception are not known. We tested our hypothesis that hypnotic suggestion changes electrophysiological processing of visceroafferent signals in the human brain and that these conditions are in part dependent on histaminergic neurons. Twelve healthy male subjects were studied on two separate days: a day of treatment with histamine H1 receptor antagonist (d-chlorpheniramine 100 microg kg(-1), intravenously) and another day of that with placebo (saline, the same amount) in a randomized order. We recorded cortical evoked potentials to 100 rectal electrical stimuli after neutral, hyperalgesic or analgesic hypnotic suggestions as given to modulate the visceral perception. Analgesic suggestion reduced the amplitude of the deepest positive peak of viscerosensory evoked potential. Administration of histamine H1 antagonist diminished the attenuation of viscerosensory evoked potential by analgesic suggestion. Our results suggest that central pain modulatory system in the brain is activated by hypnotic suggestion and that brain histamine is a mediator in the hypnotic modulation of visceral sensory pathway as well as in the control of consciousness level. These findings lead us to possible new treatment for control of visceral perception.

Chronic myositis with cardiomyopathy and respiratory failure associated with mild form of organ-specific autoimmune diseases

We report the four patients with chronic myositis characterized by a very slow progression with cardiomyopathy and frequently with marked respiratory muscle weakness associated with other organ-specific autoimmune diseases such as primary biliary cirrhosis. The histopathology of the muscle showed many degenerative and regenerative fibers, but inflammatory-cell infiltration were minimal. The patients showed favorable response to high-dose corticosteroid treatment. Because of these clinical features, these patients are sometimes misdiagnosed as muscular dystrophy and not treated properly. It is important to distinguish this type of treatable myositis.

[Diagnosis and management of chronic obstructive pulmonary disease]

Chronic obstructive pulmonary disease (COPD) is defined by the presence of airflow limitation, measured by the forced expiratory volume in 1 second (FEV1) after the administration of bronchodilator. Here the beta2-reversibility is defined by postbronchodilator FEV1-prebronchodilator FEV1 > 12% of pre-bronchodilator FEV1. The simple classification of disease severity into 4 stages is recommended based postbronchodilator FEV1. Bronchodilator medications are central to the symptomatic management of COPD. The principal bronchodilator treatments are beta2-agonists, anticholinergics, theophylline, and a combination of these drugs. Treatments including inhaled glucocorticosteroids are recommended to only severe COPD patients with the FEV1 < 50% predicted and to those who repeat exacerbations. Inhaled bronchodilators and systemic glucocorticosteroids are effective treatments for exacerbations of COPD. Noninvasive intermittent positive pressure ventilation in acute exacerbations reduces mortality, decreases the need for invasive mechanical ventilation and intubation, and decreases the length of hospital stay.

Mutations of carnitine palmitoyltransferase II (CPT II) in Japanese patients with CPT II deficiency

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving beta-oxidation of long-chain fatty acids. CPT II deficiency is a wide-spectrum disorder that includes a lethal neonatal form, an infantile form, and an adult-onset form. However, the ethnic characteristics and the relationship between genotype and clinical manifestation are not well understood. We investigated three non-consanguineous Japanese patients with CPT II deficiency and examined cell lines from 4 unrelated patients and 50 healthy donors. The CPT 2 gene was typed by direct DNA sequencing of polymerase chain reaction-amplified gene products. Case 1 (infantile form) was heterozygous for a phenylalanine to tyrosine substitution at position 383 (p.F383Y) and a novel valine to leucine substitution at 605 (p.V605L). Cases 2, 4, and 5 (infantile form) and case 3 (adult-onset form) were heterozygous for a single mutation at F383Y. Case 6 (adult-onset form) was compound heterozygous at the CPT 2 locus, with deletion of cytosine and thymine at residue 408, resulting in a stop signal at 420 (p.Y408fsX420), and an arginine to cysteine substitution at position 631 (p.R631C). Case 7 (adult-onset form) was homozygous for the p.F383Y mutation. In conclusion, we identified p.F383Y mutations in six of seven patients with CPT II deficiency and two novel variants of the coding gene: p.Y408fsX420 and p.V605L. These mutations differ from those in Caucasian patients, who commonly harbor p.S113L, p.P50H, and p.Q413fsX449 mutations; therefore, our data and those of other Japanese groups suggest that the p.F383Y mutation is significant in Japanese patients with CPT II deficiency.

Gefitinib for non-small-cell lung cancer patients with epidermal growth factor receptor gene mutations screened by peptide nucleic acid-locked nucleic acid PCR clamp

This study was prospectively designed to evaluate a phase II study of gefitinib for non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations. Clinical samples were tested for EGFR mutations by peptide nucleic acid-locked nucleic acid PCR clamp, and patients having EGFR mutations were given gefitinib 250 mg daily as the second treatment after chemotherapy. Poor PS patients omitted chemotherapy. Of 107 consecutive patients enrolled, samples from 100 patients were informative, and EGFR mutations were observed in 38 patients. Gefitinib was given to 27 patients with EGFR mutations, and the response rate was 78% (one complete response and 20 partial responses; 95% confidence interval: 58–93%). Median time to progression and median survival time (MST) from gefitinib treatment were 9.4 and 15.4 months, respectively. Grade 3 hepatic toxicity and skin toxicity were observed in one patient each. There were significant differences between EGFR mutations and wild-type patients in response rates (78 vs 14%, P=0.0017), and MST (15.4 vs 11.1 months, P=0.0135). A Cox proportional hazards model indicated that negative EGFR mutation was a secondary prognostic factor (hazards ratio: 2.259, P=0.036). This research showed the need for screening for EGFR mutations in NSCLC patients.