Risk factors for the progression of endoscopic Barrett's epithelium in Japan: a multivariate analysis based on the Prague C & M Criteria

PURPOSE

To determine the prevalence and progression of Barrett's epithelium and associated risk factors in Japan.

METHODS

The study population comprised 869 cases. Endoscopic Barrett's epithelium was diagnosed based on the Prague C & M Criteria. The correlations of clinical factors with the prevalence and progression of endoscopic Barrett's epithelium were examined.

RESULTS

Endoscopic Barrett's epithelium was diagnosed in 374 cases (43%), in the majority of which the diagnosis was short-segment Barrett's esophagus. The progression of Barrett's epithelium was identified in 47 cases. In univariate and multiple logistic regression analyses, aging, smoking habit, and erosive esophagitis were significantly associated with the prevalence of Barrett's epithelium, whereas aging and erosive esophagitis, especially severe erosive esophagitis, were significant contributing factors to the progression of Barrett's epithelium.

CONCLUSIONS

Forty-three percent of the total study population was diagnosed as having endoscopic Barrett's epithelium. During the follow-up period, 12.6% of the cases with Barrett's epithelium exhibited progression which was associated with aging and severe erosive esophagitis.

Aperitif effects on gastric emptying: a crossover study using continuous real-time 13C breath test (BreathID System)

The aim of this study was to determine whether there is a correlation between aperitif and gastric emptying. Ten healthy male volunteers participated in this randomized, two-way crossover study. Under two conditions (after drinking an aperitif versus not), the (13)C breath test was performed for 4 h with a liquid meal (200 kcal/200 ml) containing 100 mg (13)C acetate. We used 50 ml of umeshu as the aperitif. This is a traditional Japanese plum liqueur, and contains 7 ml alcohol (14%). In the aperitif group, T(1/2), T(lag), and T(peak) were significantly delayed [T(1/2) (132: 113-174) versus (112: 92-134) (P = 0.0069); T(lag) (80: 63-94) versus (55: 47-85) (P = 0.0069); and T(peak) (81: 62-96) versus (54: 34-84) (P = 0.0069), (median: range, aperitif versus control, min)]. Gastric emptying was significantly delayed in the aperitif group as compared with the control group. This study revealed that even a small amount of alcohol such as an aperitif may contribute to delayed gastric emptying.

Implantable cardioverter defibrillator discharge rates in patients with unexplained syncope, structural heart disease, and inducible ventricular tachycardia at electrophysiologic study

BACKGROUND AND HYPOTHESIS

The implantable cardioverter defibrillator (ICD) is the best available strategy to protect patients from life-threatening ventricular arrhythmia. Although unproven, it is commonly utilized to treat subjects with syncope, a negative clinical workup, structural heart disease, and inducible sustained monomorphic ventricular tachycardia (VT) on programmed electrophysiologic stimulation (EPS). The purpose of this paper was to validate this approach.

METHODS

We retrospectively identified 36 subjects who received primary ICD therapy for syncope in the setting of structural heart disease with inducible sustained monomorphic VT on EPS. The cohort was predominantly male (32/36) with underlying coronary artery disease (29/36). The mean left ventricular ejection fraction was 31 +/- 12%, and a third of the patients (12/36) had undergone bypass surgery.

RESULTS

The study group was followed for a mean of 23 +/- 15 months (range 3-81 months) and experienced an ICD event rate of 22% at 3 months, which increased to 55% at 36 months. This event rate was comparable with the 66% event rate seen in a group of patients with primary ICD therapy for spontaneous life-threatening VT treated during the same time period. No future predictors of ICD events in the study group could be identified.

CONCLUSION

Syncope patients with negative workup, structural heart disease, and sustained monomorphic VT at EPS are at high risk for future tachyarrhythmic events. Based on present evidence, primary ICD therapy in this group appears warranted and justified.

Short wavelength far infrared laser polarimeter with silicon photoelastic modulators

A short wavelength far infrared laser whose wavelength lambda is about 50 microm is preferable for a polarimeter and an interferometer for high density operations in the Large Helical Device (LHD) and on future large fusion devices such as ITER. This is because the beam bending effect (proportional to lambda(2)) in a plasma, which causes fringe jump errors, is small and the Faraday and the Cotton-Mouton effects are moderate. We have developed a polarimeter with highly resistive silicon photoelastic modulators (PEMs) for the CH(3)OD laser (lambda=57.2 and 47.7 microm). We performed bench tests of the polarimeter with a dual PEM and demonstrated the feasibility for the polarimeter. Good linearity between actual and evaluated polarization angles is achieved with an angular resolution of 0.05 degrees and a temporal resolution of 1 ms. The baseline drift of the polarization angle is about 0.1 degrees for 1000 s.

Detection of high k turbulence using two dimensional phase contrast imaging on LHD

High k turbulence, up to 30 cm(-1), can be measured using the two dimensional CO2 laser phase contrast imaging system on LHD. Recent hardware improvements and experimental results are presented. Precise control over the lens positions in the detection system is necessary because of the short depth of focus for high k modes. Remote controllable motors to move optical elements were installed, which, combined with measurements of the response to ultrasound injection, allowed experimental verification and shot-to-shot adjustment of the object plane. Strong high k signals are observed within the first 100-200 ms after the initial electron cyclotron heating (ECH) breakdown, in agreement with gyrotron scattering. During later times in the discharge, the entire k spectrum shifts to lower values (although the total amplitude does not change significantly), and the weaker high k signals are obscured by leakage of low k components at low frequency, and detector noise, at high frequency.

Two-dimensional phase contrast imaging for local turbulence measurements in large helical device (invited)

Two-dimensional phase contrast imaging (2D) installed on the large helical device (LHD) is a unique diagnostic for local turbulence measurements. A 10.6 microm infrared CO(2) laser and 6x8 channel HgCdTe 2D detector are used. The length of the scattering volume is larger than plasma size. However, the asymmetry of turbulence structure with respect to the magnetic field and magnetic shear make local turbulence measurements possible. From a 2D image of the integrated fluctuations, the spatial cross-correlation function was estimated using time domain correlation analysis, then, the integrated 2D k-spectrum is obtained using maximum entropy method. The 2D k-spectrum is converted from Cartesian coordinates to cylindrical coordinates. Finally, the angle in cylindrical coordinate is converted to flux surface labels. The fluctuation profile over almost the entire plasma diameter can be obtained at a single moment. The measurable k-region can be varied by adjusting the detection optics. Presently, k=0.1-1.0 mm(-1) can be measured which is expected region of ion temperature gradient modes and trapped electron mode in LHD. The spatial resolution is 10%-50% of the minor radius.

Development of a phase contrast imaging system based on a yttrium aluminum garnet laser with folded beam for observations of density fluctuations in compact helical system

A near-infrared laser phase contrast optical system incorporating a folded beam was developed in order to measure the distribution of density fluctuations in a high-temperature plasma. The coherent light source used was an yttrium aluminum garnet laser stabilized by a ring oscillator. The probe beam system separates and reflects the incident and exiting beams with a polarizer and a fully reflective mirror with a waveplate. This system was employed with a compact helical system to detect fluctuations at the plasma edge.

Development of terahertz laser diagnostics for electron density measurements

A two color laser interferometer using terahertz laser sources is under development for high performance operation on the large helical device and for future burning plasma experiments such as ITER. Through investigation of terahertz laser sources, we have achieved high power simultaneous oscillations at 57.2 and 47.6 microm of a CH(3)OD laser pumped by a cw 9R(8) CO(2) laser line. The laser wavelength around 50 microm is the optimum value for future fusion devices from the consideration of the beam refraction effect and signal-to-noise ratio for an expected phase shift due to plasma. In this article, recent progress of the terahertz laser diagnostics, especially in mechanical vibration compensation by using a two color laser operation and terahertz laser beam transmission through a dielectric waveguide, will be presented.

Chronic expanding hematoma in combination with a pseudoaneurysm: a case report

After bleeding from trauma or surgery, most of the hematomas undergo spontaneous reabsorption. But, in some rare cases, hematomas persist for long periods as slowly expanding masses for months or years. These hematomas were termed as chronic expanding hematomas. In this report, we describe a case of chronic expanding hematoma with a pseudoaneurysm that underwent surgical biopsy, which led to an increase in its expansion speed.

Truncation mutations abolish chromatin-associated activities of adenomatous polyposis coli

The adenomatous polyposis coli (APC) is a tumor suppressor whose loss of function leads to colon cancer. APC shuttles between the nucleus and cytoplasm, however its role in the nucleus remains elusive. We have found that nuclear APC specifically associates with transcriptionally active chromatin through structural elements located downstream to the region of frequent truncation mutations found in colorectal tumors. We show that a recombinant APC fragment comprising such elements associates in vivo with euchromatin and preferentially binds in vitro to acetylated histone H3. Induction of DNA double-strand breaks (DSB) stimulates accumulation of APC at the damaged DNA chromatin marked by histone H2AX and S139-phosphorylated histone H2AX. A nuclear complex containing the DNA-dependent protein kinase catalytic subunit (DNAPKcs) and APC associates with chromatin in response to DNA DSB. APC knockdown with siRNA decreased the rate of DNA DSB-induced S139 histone H2AX phosphorylation in cells expressing endogenous full-length APC, but not in colon cancer cells with its truncation mutants, whereas ectopic APC expression stimulated the H2AX phosphorylation regardless of the type of endogenous APC. Our data suggest that APC involves in the DSB DNA repair and that truncation mutations impair chromatin-associated functions of APC.

Isoflurane attenuates myoglobin release during ischemic and/or reperfusion periods

BACKGROUND

Recently, we have developed cardiac microdialysis for detection of protein leakage from the injured myocardium. We examined whether the exposures to isoflurane would exert a beneficial effect on myocardial injury caused by ischemia or reperfusion.

METHODS

A dialysis probe was implanted into the left ventricle free wall in the rabbits. The dialysate myoglobin level served as an index of myocardial interstitial myoglobin levels. Rabbits were randomly assigned to one of three groups: (1) without exposure to isoflurane (vehicle, n=6), (2) inhale 1 MAC isoflurane once for 30 min (ISO30-1, n=6), and (3) twice for 30 min (ISO30-2, n=6). All rabbits underwent 30 min of coronary occlusion and 60 min of reperfusion. To determine whether the isoflurane induced myocardial protection against chemical hypoxia, sodium cyanide (30 mM) was administered and dialysate myoglobin levels were measured with (n=6) and without pre-exposure to isoflurane twice for 30 min (n=6).

RESULTS

In all three groups dialysate myoglobin levels were increased by coronary occlusion and furthermore augmented by reperfusion. In comparison with the vehicle group, the ISO30-1 group suppressed only the increase in the dialysate myoglobin level during reperfusion. The ISO30-2 group suppressed during both the ischemic and reperfusion periods. Cyanide induced increases in dialysate myoglobin levels. These increments in dialysate myoglobin levels were suppressed by repeated exposure to isoflurane.

CONCLUSION

Repeated exposure to isoflurane suppressed myocardial myoglobin release caused by both ischemia and reperfusion injury. Isoflurane may provide protection against myocardial ischemia/reperfusion and hypoxic injuries.

Emission- and fluorescence-spectroscopic investigation of a glow discharge plasma: absolute number density of radiative and nonradiative atoms in the negative glow

The excited-state atom densities in the negative glow of a direct-current glow discharge are derived from the spectral-line intensity of radiative atoms and the resonance-fluorescence photon flux of nonradiative atoms. The discharge is operated in a helium-argon gas mixture (molar fraction ratio 91:9; total gas pressure 5 Torr) at a dc current of 0.7-1.2 mA. The observations are made in the region of the maximum luminance in the cathode region, where high-energy electrons accelerated in the cathode fall are injected into the negative glow. The emission intensities of the He I, He II, Ar I, and Ar II spectral lines are measured with a calibrated tungsten ribbon lamp as an absolute spectral-radiance standard. Fluorescence photons scattered by helium and argon atoms in the metastable state and argon atoms in the resonance state are detected by the laser-induced fluorescence (LIF) method with the Rayleigh scattering of nitrogen molecules as an absolute standard of scattering cross section. The laser absorption method is incorporated to confirm the result of the LIF measurement. Excitation energies of the measured spectral lines range from 11.6 (Ar I) to 75.6 eV (He II), where the excitation energy is measured from the ground state of the neutral atom on the assumption that, in the plasma of this study, both the neutral and the ionic lines are excited by electron impact in a single-step process from the ground state of the corresponding neutral atoms. Experimental evidence is shown for the validity of this assumption.

Characterization of ouabain-induced noradrenaline and acetylcholine release from in situ cardiac autonomic nerve endings

AIM

Although ouabain modulates autonomic nerve ending function, it is uncertain whether ouabain-induced releasing mechanism differs between in vivo sympathetic and parasympathetic nerve endings. Using cardiac dialysis, we examined how ouabain induces neurotransmitter release from autonomic nerve ending.

METHODS

Dialysis probe was implanted in left ventricle, and dialysate noradrenaline (NA) or acetylcholine (ACh) levels in the anaesthetized cats were measured as indices of neurotransmitter release from post-ganglionic autonomic nerve endings.

RESULTS

Locally applied ouabain (100 microm) increased in dialysate NA or ACh levels. The ouabain-induced increases in NA levels remained unaffected by cardiac sympathetic denervation and tetrodotoxin (Na+ channel blocker, TTX), but the ouabain-induced increases in ACh levels were attenuated by TTX. The ouabain-induced increases in NA levels were suppressed by pretreatment with desipramine (NA transport blocker) and augmented by reserpine (vesicle NA transport blocker). In contrast, the ouabain-induced increases in ACh levels remained unaffected by pretreatment with hemicholinium-3 (choline transport blocker) but suppressed by vesamicol (vesicle ACh transport blocker). The ouabain-induced increases in NA levels were suppressed by pretreatment with omega-conotoxin GVIA (N-type Ca2+ channel blocker), verapamil (L-type Ca2+ channel blocker) and TMB-8 (intracellular Ca2+ antagonist). The ouabain-induced increases in ACh levels were suppressed by pretreatment with omega-conotoxin MVIIC (P/Q-type Ca2+ channel blocker), and TMB-8.

CONCLUSIONS

Ouabain-induced NA release is attributable to the mechanisms of regional exocytosis and/or carrier-mediated outward transport of NA, from stored NA vesicle and/or axoplasma, respectively, while the ouabain-induced ACh release is attributable to the mechanism of exocytosis, which is triggered by regional depolarization. At both sympathetic and parasympathetic nerve endings, the regional exocytosis is because of opening of calcium channels and intracellular calcium mobilization.

Changes of optical properties of retroreflector installed in LHD

This article describes changes of optical properties of retroreflectors installed on the inner wall of the vacuum vessel of the Large Helical Device. They were made of stainless steel and were used for a CO(2) laser polarimeter. The reflectivity for a CO(2) laser beam dropped up to 40% after the start of glow discharge cleanings and main plasma experiments. Then it decreased gradually. The reflectivity in a wavelength range shorter than 10 mum decreased significantly through one experimental campaign (about 4 months). On the other hand the reflectivity in a wavelength range longer than 50 mum was larger than 70%. Decrease in the reflectivity in the central region of mirrors was more significant (the reflectivity for visible beams became almost zero) than that in the edge. The distribution of the reflectivity along the radial direction is expected to be related to the shape of the retroreflector. The parallelism of the reflected beam to an incident one also deteriorated. The changes in the polarization angle and in the ellipticity of reflected light polarization were not observed from the visible to the far infrared range.

Protein tyrosine kinases belonging to the src family

There are nine non-receptor-type protein tyrosine kinases that show a high level of similarity in their primary structures and in the structures of their functional domains. Together, they are called the src family. They seem to have common sites specific for oncogenic activation. Recent findings suggest that the kinases are closely associated with cell surface molecules and that they mediate extracellular signals through the activation of their tyrosine kinase activity. They appear to act more on the differentiated phenotype than in haemopoietic cell proliferation. Possible functions of the products of the lck, fyn, lyn and fgr genes in lymphocytes and monocytes are discussed.

Hepatitis C virus directly associates with insulin resistance independent of the visceral fat area in nonobese and nondiabetic patients

Insulin resistance (IR) is known to be associated with the visceral adipose tissue area. Elucidation of the relationship between hepatitis C virus (HCV) and IR is of great clinical relevance, because IR promotes liver fibrosis. In this study, we tested the hypothesis that HCV infection by itself may promote IR. We prospectively evaluated 47 patients with chronic HCV infection who underwent liver biopsy. Patients with obesity, type 2 diabetes mellitus (DM), or a history of alcohol consumption were excluded. IR was estimated by calculation of the modified homeostasis model of insulin resistance (HOMA-IR) index. Abdominal fat distribution was determined by computed tomography. Fasting blood glucose levels were within normal range in all the patients. The results of univariate analysis revealed a significant correlation between the quantity of HCV-RNA and the HOMA-IR (r = 0.368, P = 0.0291). While a significant correlation between the visceral adipose tissue area and the HOMA-IR was also observed in the 97 control, nondiabetic, non-HCV-infected patients (r = 0.398, P < 0.0001), no such significant correlation between the visceral adipose tissue area and the HOMA-IR (r = 0.124, P = 0.496) was observed in the patients with HCV infection. Multiple regression analysis with adjustment for age, gender and visceral adipose tissue area revealed a significant correlation between the HCV-RNA and the HOMA-IR (P = 0.0446). HCV is directly associated with IR in a dose-dependent manner, independent of the visceral adipose tissue area. This is the first report to demonstrate the direct involvement of HCV and IR in patients with chronic HCV infection.

Ajuba negatively regulates the Wnt signaling pathway by promoting GSK-3beta-mediated phosphorylation of beta-catenin

The Wnt signaling pathway is essential for embryonic development and carcinogenesis. Upon Wnt stimulation, beta-catenin is stabilized and associates with T-cell factor or lymphoid enhancing factor, thereby activating transcription of target genes. In the absence of Wnt stimulation, the level of beta-catenin is reduced via glycogen synthase kinase (GSK)-3beta-mediated phosphorylation and subsequent proteasome-dependent degradation. Here, we report the identification of Ajuba as a negative regulator of the Wnt signaling pathway. Ajuba is a member of LIM domain-containing proteins that contribute to cell fate determination and regulate cell proliferation and differentiation. We found that enforced expression of Ajuba destabilized beta-catenin and suppressed target gene expression. Ajuba promoted GSK-3beta-mediated phosphorylation of beta-catenin by reinforcing the association between beta-catenin and GSK-3beta. Furthermore, Wnt stimulation induced both accumulation of beta-catenin and destabilization of Ajuba. Our findings suggest that Ajuba is important for regulation of the Wnt signaling pathway.

Identification and characterization of Asef2, a guanine-nucleotide exchange factor specific for Rac1 and Cdc42

The tumor suppressor adenomatous polyposis coli (APC) is mutated in sporadic and familial colorectal tumors. APC interacts with the Rac1-specific guanine-nucleotide exchange factor (GEF) Asef, which contains an APC-binding region (ABR) in addition to Dbl homology (DH), Pleckstrin (PH) and Src homology 3 (SH3) domains. APC stimulates the GEF activity of Asef, and thereby regulates cell adhesion and migration. Here, we have identified a second Asef, termed Asef2, that shows significant structural and functional similarities to Asef. We found that both the N-terminal ABR and SH3 domains of Asef2 are responsible for its interaction with APC. When expressed in HeLa cells, a mutant Asef2 lacking the ABR and SH3 domains, Asef2-DeltaABR/SH3, induced increases in the levels of the active forms of Rac1 and Cdc42. Full-length Asef2 also showed this activity when co-transfected with truncated mutant APC expressed in colorectal tumor cells. Consistent with this, either Asef2-DeltaABR/SH3 or Asef2 plus truncated mutant APC stimulated lamellipodia formation in MDCK cells and filopodia formation in HeLa cells. Furthermore, RNA interference experiments showed that Asef2 is required for migration of colorectal tumor cells expressing truncated APC. These results suggest that similar to Asef, Asef2 plays an important role in cell migration, and that Asef2 activated by truncated mutant APC is required for aberrant migration of colorectal tumor cells.