Characteristics of nighttime reflux assessed using multichannel intraluminal impedance pH monitoring and a portable electroencephalograph

Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances. Although the mechanisms of this association have not been fully elucidated, nighttime reflux plays a central role. However, the detailed characteristics of nighttime reflux occurring during sleep are unknown. The aim of the present study was to examine the characteristics and prevalence of nighttime reflux in the natural sleep environment of GERD patients. Seventeen patients experiencing daily moderate-to-severe heartburn and/or regurgitation were studied using multichannel intraluminal impedance pH monitoring and electroencephalography off-proton pump inhibitor treatment. Nighttime reflux was divided based on reflux type (liquid or gas), acidity (acidic, weakly acidic, or alkaline) and extent (distal only or proximal migration) according to the standard criteria. Nighttime phases were divided as follows: recumbent-awake before falling asleep, nonrapid eye movement, rapid eye movement, awakening from sleep, and post-awakening in the morning. Among 184 nighttime refluxes, 43 (23%) occurred during recumbent-awake before falling asleep, 28 (15%) during nonrapid eye movement, 14 (8%) during rapid eye movement, 86 (46%) during awakening from sleep, and 13 (7%) during post-awakening in the morning. Liquid reflux was more common in awakening during sleep (92%), nonrapid eye movement (100%), and rapid eye movement (100%) compared with awakening before falling asleep (68%). The prevalence of proximal migration was significantly lower in nonrapid eye movement and rapid eye movement than in the other phases. There were no differences in acidity and bolus clearance time among the phases. Thirteen (65%) of 20 events with GERD symptoms had nighttime reflux, suggesting that only 7.1% (13 of 184) of nighttime refluxes were symptomatic. Nighttime reflux was observed in 48 (11%) of 425 awakening episodes during sleep. Different reflux patterns at each phase during nighttime might explain the pathogenesis of GERD and its related sleep disturbances.

Differences between risk factors among irritable bowel syndrome subtypes in Japanese adults

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. Detailed clinical characteristics of patients with different IBS subtypes have not been well established. Our aim was to examine the prevalence and risk factors of IBS and its subtypes in Japanese adults.

METHODS

We performed a cross-sectional study of Japanese workers who visited a clinic for a routine health check-up and asked them to fill out a self-report questionnaire. Irritable bowel syndrome and its subtypes were defined by ROME III criteria. A logistic regression model was used to identify risk factors.

KEY RESULTS

Irritable bowel syndrome was present in 367 (13.5%) of 2717 eligible subjects; 79 had IBS with constipation (IBS-C); 102 had IBS with diarrhea (IBS-D); 89 had mixed IBS (IBS-M); and 97 had unsubtyped IBS (IBS-U). Irritable bowel syndrome was significantly associated with young age [odds ratio (OR) = 0.87, 95% confidence interval (CI) 0.80-0.95], female gender (OR = 1.78, 95% CI 1.38-2.29), low body mass index (BMI) (OR = 0.95, 95% CI 0.92-0.99), and the presence of allergic disease (OR = 2.19, 95% CI 1.40-3.54). Analysis of IBS subtypes revealed that IBS-C was associated with young age and female gender; IBS-D with young age, low BMI, and drinking habit; IBS-M with female gender, smoking habits, and allergic diseases; and IBS-U with age, female gender, and allergic diseases.

CONCLUSIONS & INFERENCES

Irritable bowel syndrome was common and associated with young age, female gender, low BMI, and presence of allergic diseases in Japanese adults. Several differences were noted between the risk factors among different IBS subtypes.

[Detection of K-ras point mutations in the stool of patients with colorectal tumors]

Using mutant-allele-specific amplification procedure, patients with colorectal tumors were analyzed for K-ras point mutations in the stool and the tumor tissue. K-ras mutation of DNA purified from the stool was detected in 10 of 40 (25.0%) cancer patients, and in 3 of 10 (30.0%) adenoma patients. Otherwise, in the cases whose tumors contained the mutations, it was detected with the frequency of 71.4% in cancers, and 100% in adenomas. This frequency tended to decrease in the cancers of distal colon or small size, but there was no significant. This study suggested that stool analysis of genetic alterations would develop diagnostic method for colorectal cancer.

External control of drug release and penetration. VI. Enhancing effect of ultrasound on the transdermal absorption of indomethacin from an ointment in rats

The effect of an ultrasound (1 MHz) on transdermal absorption of indomethacin from an ointment was studied in rats. Ultrasound energy was supplied for between 5 and 20 min at a range of intensities (0.25, 0.5, 0.75, and 1 W cm-2), energy levels commonly used for therapeutic purposes. For evaluating skin penetration of indomethacin, the change of plasma concentration was measured. The pronounced effect of ultrasound on the transdermal absorption of indomethacin was observed at all ultrasound energy levels studied. The intensity and the time of application were found to play an important role in the transdermal phonophoretic delivery system of indomethacin; 0.75 W cm-2 appeared to be the most effective intensity in improving the transdermal absorption of indomethacin, while the 10 min ultrasound treatment was the most effective. Although the highest penetration was observed at an intensity of 0.75 W cm-2, 0.5 W cm-2 was preferred because intensities of less than 0.5 W cm-2 of ultrasound for 10 min did not result in any significant skin temperature rise nor did it have any destructive effect on rat skin. Progressively more skin damage was noted as the intensity and the time of application of ultrasound increased. When used at a proper intensity and time of application, ultrasound appears to be a safe technique for enhancing the passage of various drug molecules through human skin.

Morphological and functional reconsideration of the cytoplasmic bridges which connect male germ cells in snails

Cytoplasmic bridges (CB) between male germ cells of three fresh-water snails have been examined by electron microscopy, using ultrathin sections and freeze-fracture replicas prepared by ordinary methods and after use of filipin for indicating the presence of membrane cholesterol. The bridge plasma membrane, which was formerly considered to be smooth, was found in these snails to be corrugated. The corrugations were periodically parallel and oriented parallel to the axis of the bridge. The mature bridges showed very low densities of intramembranous particles. No filipin-sterol complexes formed on either the P face or the E face of the bridge plasma membrane, in contrast to plasma membranes elsewhere. The numbers of corrugations in each CB varied with the species. The membrane corrugations overlie bundles of electron dense fibers measuring approximately 30 nm in diameter and 60 nm in center-to-center distance, fitting into convexities of the plasma membrane. The present observations lead us to the necessity of reconsidering the morphological and functional aspects of cytoplasmic bridges in vertebrate as well as in invertebrate germ cells.