Concentration-Dependent Viscoelasticity of Poloxamer-Shelled Microbubbles

The oscillation of shelled microbubbles during exposure to ultrasound is influenced by the mechanical properties of the shell components. The oscillation behavior of bubbles coated with various phospholipids and other amphiphiles has been studied. However, there have been few investigations of how the adsorption conditions of the shell molecules relate to the viscoelastic properties of the shell and influence the oscillation behavior of the bubbles. In the present study, we investigated the oscillation characteristics of microbubbles coated with a poloxamer surfactant, that is, Pluronic F-68, at several concentrations after the adsorption kinetics of the surfactant at the gas-water interface had reached equilibrium. The dilatational viscoelasticity of the shell during exposure to ultrasound was analyzed in the frequency domain from the attenuation characteristics of the acoustic pulses propagated in the bubble suspension. At Pluronic F-68 concentrations lower than 2.0 × 10^-2 mol L^-1, the attenuation characteristics typically exhibited a sharp peak. At concentrations higher than 2.0 × 10^-2 mol L^-1, the peak flattened. The dilatational elasticity and viscosity of the shell were estimated by fitting the theoretical model to the experimental values, which revealed that both the elasticity and viscosity increased markedly at approximately 2.0 × 10^-2 mol L^-1. This suggests that the adsorption properties of Pluronic F-68 strongly affect the oscillation characteristics of microbubbles of a size suitable for medical ultrasound diagnostics.

Effects of Arterial Stiffness on Cerebral WM Integrity in Older Adults: A Neurite Orientation Dispersion and Density Imaging and Magnetization Transfer Saturation Imaging Study

BACKGROUND AND PURPOSE

Arterial stiffness is reported to be able to cause axonal demyelination or degeneration. The present study aimed to use advanced MR imaging techniques to examine the effect of arterial stiffness on the WM microstructure among older adults.

MATERIALS AND METHODS

Arterial stiffness was measured using the cardio-ankle vascular elasticity index (CAVI). The high-CAVI (mean CAVI ≥ 9 points) and the low-CAVI groups (mean CAVI < 9 points) were created. The neuronal fiber integrity of the WM was evaluated by neurite orientation dispersion and density imaging and magnetization transfer saturation imaging. Tract-Based Spatial Statistics and the tracts-of-interest analysis were performed. Specific WM regions (corpus callosum, internal capsule, anterior thalamic radiation, corona radiata, superior longitudinal fasciculus, forceps minor, and inferior fronto-occipital fasciculus) were selected in the tracts-of-interest analysis.

RESULTS

In Tract-Based Spatial Statistics, the high-CAVI group showed a significantly lower myelin volume fraction value in the broad WM and significantly higher radial diffusivity and isotropic volume fraction values in the corpus callosum, forceps minor, inferior fronto-occipital fasciculus, internal capsule, corona radiata, and anterior thalamic radiation than the low-CAVI group. In tracts-of-interest analysis using multivariate linear regression, significant associations were found between the mean CAVI and radial diffusivity in the anterior thalamic radiation and the corona radiata; isotropic volume fraction in the anterior thalamic radiation and the corona radiata; and myelin volume fraction in the superior longitudinal fasciculus (P < .05). Additionally, partial correlation coefficients were observed for the significant associations of executive function with radial diffusivity and myelin volume fraction (P < .05).

CONCLUSIONS

Arterial stiffness could be associated with demyelination rather than axonal degeneration.

Cribriform carcinoma in the lymph nodes is associated with distant metastasis, recurrence, and survival among patients with node-positive colorectal cancer

Cribriform lymph node pattern is an independent risk factor for metachronous or synchronous distant metastasis in patients with stage III and IV node-positive colorectal cancer. Multivariable analysis in patients with stage III disease indicated that the cribriform pattern of carcinoma in the lymph nodes was an independent risk factor for recurrence and survival. Kaplan–Meier analysis demonstrated that the group with stage III cribriform-type lymph node carcinoma had shorter recurrence-free and overall survival times than the stage III group with the tubular type (P &lt; 0.001).

P1496Impact of electrical reverse remodeling by cardiac resynchronization therapy on adverse cardiac events in patients of heart failure with reduced ejection fraction

Background

Recently, structural reverse remodeling (SRR) and electrical reverse remodeling (ERR) after cardiac resynchronization therapy (CRT) have been reported in patients of heart failure with reduced ejection fraction (HFrEF). However the relationship between ERR and subsequent adverse cardiac events is still unknown. We aimed to elucidate the impact of ERR after CRT on the occurrence of heart failure events and ventricular arrhythmias.

Methods

A total of 36 HFrEF patients who underwent newly CRT implantation were investigated retrospectively. The intrinsic QRS duration (iQRSd) had been recorded before and more than 6 months after CRT implantation. Biventricular pacing was temporarily turned off during measurement of iQRSd. ERR was defined as positive shortening of iQRSd and SRR was defined as reduction of left ventricular end systolic volume by more than 15% after CRT implantation. The primary endpoint was a composite of all cause death, heart failure hospitalizations and ventricular tachyarrhythmia events.

Results

ERR was observed in 17 patients (47.2%) and SRR in 22 patients (61.1%). The group with ERR included more patients with lower NYHA class prior to CRT and patients with SRR. The primary endpoint was observed in 15 patients (51.4 %) for a median of 181 [63, 367] days during follow-up. Kaplan-Meier analysis revealed that the group without ERR was poor prognosis compared with the group with ERR (p = 0.022, Log-rank test).

Conclusion

Patients of HFrEF with ERR after CRT may have fewer adverse cardiac events such as worsening heart failure or ventricular arrhythmia events from this short-term study.

Abstract Figure. Adverse cardiac events and ERR

P1353Echocardiographic predictor of sick sinus syndrome following catheter ablation of persistent atrial fibrillation

Funding Acknowledgements

Abbott Medical Japan, Medtronic Japan, Boston Scientific Japan, Biotronic Japan, Japan Life Line

Background / Introduction

Although sick sinus syndrome(SSS) can be associated with atrial fibrillation(AF), predictive factors of SSS following catheter ablation(CA) of persistent atrial fibrillation(perAF) are not well known.

Purpose

We investigated echocardiographic parameters to predict occurrence of SSS after restoration of sinus rhythm by CA for perAF patients.

Methods

Ninety-eight consecutive perAF patients from June 2014 to May 2018 treated with CA were retrospectively reviewed. Twelve patients(12%, SSS group) developed SSS after successful CA and 86 patients(88%, non-SSS group) did not. Baseline characteristics, blood exam, and echocardiographic findings(RA area size, LA area size, EF, etc) before AF CA were analyzed using Student’s t test, Mann-Whitney test, Chi-square test and Univariate analysis. Multivariate logistic analysis was then performed using those parameters. The atrial area size was calculated from 4 chamber view at the atrial end- systole.

Results

The multivariate analysis for predictive factors of SSS is shown in the table. Right atrium(RA) area could predict SSS(17.3 ± 4.8cm2 vs. 14.7 ± 3.6cm2, odds ratio 1.468; 95% confidence interval 1.088 to 1.981, p = 0.012). Gender (female) was also an independent predictor(4/12 (33%) vs. 8/86 (9%), odds ratio 39.832; 95% confidence interval 2.589 to 612.938, p = 0.008). The other echocardiographical findings(LA area size, EF, etc), baseline characteristics and blood exam results were not related to SSS after successful CA of perAF patients.

Conclusions

The large RA area size and gender (female) could predict SSS in perAF patients after restoration of sinus rhythm by successful CA. We may need to inform possible SSS after CA to female patients with a large RA before CA.

Multivariate Logistic analysis Total(N = 98) SSS group (N = 12) Non SSS group (N = 86) Odds ratio 95% CI P-value Age 64(58-69) 68(60-72) 63(57-69) 1.032 0.929-1.145 0.560 Gender/Female 12(12%) 4(33%) 8(9%) 39.832 2.589-612.938 0.008 CKD 27(28%) 6(50%) 21(24%) 1.264 0.179-8.945 0.814 BNP 91(53-180) 206(167-304) 82(48-169) 1.003 0.993-1.012 0.609 RDW 45.1 ± 3.9 46.4 ± 4.8 44.9 ± 3.8 1.242 0.971-1.588 0.085 RA area 15.1 ± 3.8 17.3 ± 4.8 14.7 ± 3.6 1.468 1.088-1.981 0.012 LA area 24.2(17.0-24.9) 24.4(17.7-26.3) 24.1(16.8-24.4) 0.967 0.803-1.165 0.726 Right atrium area and gender were the independent predictor of SSS in persistent atrial fibrillation patients after restoration of sinus rhythm

Vibration Characteristics and Persistence of Poloxamer- or Phospholipid-Coated Single Microbubbles under Ultrasound Irradiation

Microbubbles shelled with soft materials are expected to find applications as ultrasound-sensitive drug delivery systems, including through sonoporation. Microbubbles with specific vibrational characteristics and long intravascular persistence are required for clinical uses. To achieve this aim, the kinetics of the microbubble shell components at the gas/liquid interface while being subjected to ultrasound need to be better understood. This paper investigates the vibration characteristics and lifetime of single microbubbles coated with a poloxamer surfactant, Pluronic F-68, and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) under ultrasound irradiation. Air- and perfluorohexane (PFH)-filled microbubbles coated with Pluronic F-68 and DMPC at several concentrations (0 to 10^-2 mol L^-1) were produced. An optical measurement system using a laser Doppler vibrometer and microscope was used to observe the radial vibration mode of single microbubbles. The vibrational displacement amplitude and resonance radius of Pluronic- or DMPC-coated microbubbles were found to depend very little on the concentrations. The resonance radius was around 65 μm at 38.8 kHz under all the experimental conditions investigated. The lifetime of the microbubbles was investigated simultaneously by measuring their temporal change in volume, and it was increased with Pluronic concentration. Remarkably, the oscillation amplitude of the bubble has an effect on the bubble lifetime. In other words, larger oscillation under the resonance condition accelerates the diffusion of the inner gas.

Randomized clinical trial of landiolol hydrochloride for the prevention of atrial fibrillation and postoperative complications after oesophagectomy for cancer

Background

Atrial fibrillation is common after oesophageal surgery. The aim of this study was to evaluate whether landiolol hydrochloride was effective and safe in the prevention of atrial fibrillation after oesophagectomy, and to see whether a reduction in incidence of atrial fibrillation would reduce other postoperative complications.

Methods

This single-centre study enrolled patients scheduled for transthoracic oesophagectomy in a randomized, double-blind, placebo-controlled trial between March 2013 and January 2016. Enrolled patients were randomized with a 1 : 1 parallel allocation ratio to either landiolol prophylaxis or placebo. The primary endpoint was the occurrence of atrial fibrillation after oesophagectomy. Secondary endpoints were incidence of postoperative complications, and effects on haemodynamic and inflammatory indices.

Results

One hundred patients were enrolled, 50 in each group. Postoperative atrial fibrillation occurred in 15 patients (30 per cent) receiving placebo versus five (10 per cent) receiving landiolol (P = 0·012). The overall incidence of postoperative complications was significantly lower in the landiolol group (P = 0·046). In the landiolol group, postoperative heart rate was suppressed effectively, but the decrease in BP was not harmful. The interleukin 6 level was significantly lower on days 3 and 5 after surgery in the landiolol group (P = 0·001 and P = 0·002 respectively).

Conclusion

Landiolol was effective and safe in preventing atrial fibrillation after oesophagectomy. Registration number: UMIN000010648 (http://www.umin.ac.jp/ctr/).

Microbubbles with a Self-Assembled Poloxamer Shell and a Fluorocarbon Inner Gas

The numerous applications of microbubbles in food science and medicine call for a better understanding and control of the effects of the properties of their shells on their stability and ability to resonate at chosen frequencies when submitted to an ultrasound field. We have investigated both millimetric and micrometric bubbles stabilized by an amphiphilic block copolymer, Poloxamer 188 (e.g., Pluronic F-68). Although Pluronic F-68 is routinely being used as a dispersing and foaming agent to facilitate phospholipid-based microbubble preparation, it has never been studied as a shell component per se. First, we investigated the adsorption kinetics of Pluronic F-68 at the interface between water and air, or air saturated with vapors of perfluorohexane (F-hexane), using bubble profile tensiometry analysis. F-Hexane was found to strongly accelerate the adsorption of Pluronic F-68 (at low concentrations) and decrease the interfacial tension values at equilibrium (at all concentrations). We also found that relatively stable microbubbles could unexpectedly be prepared from Pluronic F-68 in the absence of any other surfactant, but only when F-hexane was present. These bubbles showed an only limited volume increase over ∼3 h, while a 10-fold increase in size occurred within 200 s in the absence of a fluorocarbon. Remarkably, their deflation rate decreased when the Pluronic F-68 concentration decreased, suggesting that bubbles with semidilute copolymer coverage are more stable than those more densely covered by copolymer brushes. Single-bubble experiments using laser Doppler vibratometry showed that, by contrast with other surfactant-coated microbubbles, the resonance radius of the Pluronic F-68-coated microbubbles was lower than that of naked microbubbles, meaning that they are less elastic. It was also found that the bubble's vibrational displacement amplitude decreased substantially when the microbubbles were covered with Pluronic F-68, an effect that was further amplified by F-hexane.

Visualizing septin and cell dynamics in mammalian brain slices

Correct neuronal migration is crucial for the brain architecture and function. During brain development, excitatory and inhibitory neurons generated in the ventricular zone (VZ) of the dorsal telencephalon and ganglionic medial eminence, respectively, move to their final destinations in tightly regulated spatiotemporal manners. While a variety of morphological methods have been applied to neurobiology, in utero electroporation (IUE) technique is one of the most powerful tools for rapid gain- and loss-of-function studies of brain development. This method enables us to introduce genes of interest into VZ progenitor and stem cells of rodent embryos, and to observe resulting phenotypes such as proliferation, migration, and cell morphology at later stages. In this chapter, we first summarize basic immunohistochemistry methods that are foundations for any advanced methods and showed data on the distribution of Sept6, Sept9, and Sept14 as examples. Then, IUE method is described where functional analyses of Sept14 during brain development are used as examples. We subsequently refer to the in vivo electroporation (IVE)-mediated gene transfer, which is conceptually the same method as IUE, into granule cells of hippocampal dentate gyrus in neonatal mice. Finally, an IUE-based time-lapse imaging method is explained as an advanced technique for the analyses of cortical neuron migration. IUE and IVE methods and the application would contribute greatly to the morphological analyses of septins as well as other molecules to elucidate their neuronal functions and pathophysiological roles in various neurological and psychiatric disorders.

Indication of reactor ν(e) disappearance in the Double Chooz experiment

The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944±0.016(stat)±0.040(syst) was obtained in 101 days of running at the Chooz nuclear power plant in France, with two 4.25 GW(th) reactors. The results were obtained from a single 10 m(3) fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a nonzero value of the still unmeasured neutrino mixing parameter sin(2)2θ(13). Analyzing both the rate of the prompt positrons and their energy spectrum, we find sin(2)2θ(13)=0.086±0.041(stat)±0.030(syst), or, at 90% C.L., 0.017<sin(2)2θ(13)<0.16.

Optical dynamics of energy-transfer from a CdZnO quantum well to a proximal Ag nanostructure

We studied photoluminescence (PL) and energy-transfer dynamics in a hybrid structure comprising a Cd(0.08)Zn(0.92)O quantum well (QW) and an Ag nanostructure. The observed PL quenching was dependent on the electronic states in the QW. Quenching occurred at low temperature where excited carriers recombined radiatively because of excitonic localization, which disappeared with increasing temperature due to delocalization of excitons. Furthermore, nanostructured Ag surfaces produced local surface plasmon (LSP) absorption that was resonant with the PL peak energy of the QW emission. These results indicate that the recombination energy of excitons transfers nonradiatively to induce LSP excitation, which was revealed using time-resolved PL measurements.

Hydrogen sensing properties of protective-layer-coated single-walled carbon nanotubes with palladium nanoparticle decoration

Protective-layer-coated single-walled carbon nanotubes (SWNTs) with palladium nanoparticle decoration (Pd-SiO(2)-SWNTs) were fabricated and their sensing properties for hydrogen (H(2)) were investigated. SWNTs were coated with a 3-4 nm thick SiO(2) layer by pulsed laser deposition and subsequently decorated with Pd nanoparticles by electron beam evaporation. Even though the SWNTs were completely surrounded by a protective layer, Pd-SiO(2)-SWNTs responded to H(2) down to a concentration of 1 part per million. Compared with the Pd nanoparticle-decorated SWNTs without a protective layer (Pd-SWNTs), Pd-SiO(2)-SWNTs exhibited highly stable sensor responses with variations of less than 20%; Pd-SWNTs showed a variation of 80%. The density of the Pd-SWNTs significantly decreased after the sensing test, while that of the Pd-SiO(2)-SWNTs with the netlike structure remained unchanged. The hydrogen sensing mechanism of the Pd-SiO(2)-SWNTs was attributed to the chemical gating effect on the SWNTs due to dipole layer formation by hydrogen atoms trapped at the Pd-SiO(2) interface. Moreover, the relationship between H(2) concentration and sensor response can be described by the Langmuir isotherm for dissociative adsorption.

Kimura’s Disease with Marked Proliferation of HLA-DR+CD4+ T Cells in the Skin, Lymph Node and Peripheral Blood

A 41-year-old female had atopic dermatitis-like skin lesions since the age of 21, and for the past 6 years many skin tumors developed on the body, lower extremities and other areas. The histological picture of the tumor, eosinophilia and high IgE in the peripheral blood were consistent with a diagnosis of Kimura's disease. Although the tumors were markedly reduced by oral prednisolone administration, thereafter papules appeared disseminated over the body with swelling of superficial lymph nodes. Immunohistochemical examination indicated marked proliferation of HLA-DR+CD4+ T cells in the skin and lymph nodes, and two-color flow cytometry confirmed it in the lymph nodes and peripheral blood.

Raman scattering study of multiferroic Ho(3)Fe(5)O(12) thin films

Ho(3)Fe(5)O(12) crystallizes in a body-centered cubic lattice and shows no ferroelectricity because of its highly symmetric (centrosymmetric) crystal structure. However, in heteroepitaxially grown thin films, Ho(3)Fe(5)O(12) may exhibit ferroelectricity because of lattice strains induced by the substrate. In this work, heteroepitaxial films of Ho(3)Fe(5)O(12) were grown with different thicknesses of 50-160 nm and studied by x-ray diffraction and Raman scattering. The results were compared with those of bulk polycrystals to characterize residual strains. At room temperature, Raman spectra of films revealed a phonon frequency shift from those of bulk samples, showing lattice distortion. There was a difference in the lattice distortion scheme between the thinner and thicker films. Results of x-ray diffraction were well correlated with the Raman data. Raman measurements at 300-800 K showed the existence of lattice strain up to ∼650 K. This suggests a remanent-polarization character of Ho(3)Fe(5)O(12) films up to this temperature. Closeness between the magnetic ordering temperature T(N) = 567 K and T(C)∼650 K may bring us the ideal multiferroic material with an enhanced magnetoelectric effect at room temperature.

Centripetal bias on preparation for smooth pursuit eye movements based on the anticipation

It has been reported that a brief perturbation of a stationary target during fixation induces larger eye movement when monkeys anticipate future smooth pursuit than when they do not. Here, we recorded eye movements in human subjects after briefly perturbing a target and the eccentricity of its initial position was changed under three conditions: (1) subjects anticipated saccades for a target that appeared before; (2) they anticipated smooth pursuit for a target that appeared before; and (3) they anticipated smooth pursuit but did not know beforehand where the target started from. We found that in condition 2 substantial eye movements were induced by the perturbation started moving toward the center. However, weak responses were observed in conditions 1 and 3. These results indicate that ocular responses to brief perturbations of the target at eccentric positions are increased with centripetal bias when human subjects prepare for future smooth pursuit.

Combinatorial peptide library for the analysis of antigen recognition by T cells

Peptides that consist of 19 residues with random sequences (X19) were considered to deliver antigenic stimuli to CD4T cells. When IL-4, IL-7, IL-9, IL-15 and agonistic Ab to CD29 were co-cultured with single peripheral CD4T cells in the presence of X19 and feeder cells, T cells exhibited clonal expansion. These T cell clones showed heterogeneous proliferation patterns against KGXXXXXXXXXGK-based and KGXXXXXXXXXGKGKK-based combinatorial peptide libraries. Pattern-match search on one of the T cell clones resulted in peptide ligand candidates, one of which induced proliferation, as did protein molecules carrying the corresponding sequence. Combinatorial chemistry was useful in determining not only peptide ligands but also peptide superagonists. For this purpose, use of reverse-phase hydrophobic interaction chromatography and mass spectrometry analysis was efficient. Detailed methods are described in the paper.

Helicobacter pylori infection in rheumatoid arthritis: effect of drugs on prevalence and correlation with gastroduodenal lesions

OBJECTIVE

The aim of this study was to investigate the impact of Helicobacter pylori infection on clinical features in patients with rheumatoid arthritis (RA) under medication with non-steroidal anti-inflammatory drugs.

METHODS

One hundred and eighty-four patients with RA were tested for the presence of H. pylori infection. Clinical features and gastroduodenal lesions were compared between H. pylori-positive and -negative patients.

RESULTS

One hundred and thirteen patients were positive and 71 patients were negative for H. pylori. The age, severity of RA, prevalence of gastrointestinal symptoms and gastroduodenal lesions and the class of gastroprotective drugs were not different between the two groups. Reflux oesophagitis was less frequent and sulphasalazine was less frequently administered in the H. pylori-positive group.

CONCLUSIONS

The severity of RA, prevalence of gastroduodenal lesions other than reflux oesophagitis and the application of gastroprotective drugs do not seem to depend upon H. pylori infection in RA patients. Sulphasalazine may be protective against H. pylori infection.

Goadsporin, a chemical substance which promotes secondary metabolism and morphogenesis in streptomycetes. I. Purification and characterization

Streptomycetes, which belong to the Gram-positive bacteria, produce secondary metabolites and sporulate. The timing of starting the secondary metabolite production and the sporulation depends on environmental conditions such as nitrogen and carbon sources. In order to obtain a tool for understanding the regulation mechanism, we carried out screening for chemical substances that induce secondary metabolism and sporulation in streptomycetes and found an active substance from the culture broth of Streptomyces sp. TP-A0584. This substance designated goadsporin promoted the formation of red pigment and sporulation at a concentration of 1 microM in Streptomyces lividans TK23 which does not produce the pigment under normal growth conditions. Goadsporin is an oligopeptide consisting of 19 amino acids with the molecular formula C72H97N19020S2. Sporulation and/or secondary metabolite production was induced in 36 streptomycetes strains among 42 strains tested. These results suggest that goadsporin acts on a common regulation pathway for sporulation and secondary metabolism in streptomycetes and can be a powerful tool to analyze the regulation mechanism.

Goadsporin, a chemical substance which promotes secondary metabolism and Morphogenesis in streptomycetes. II. Structure determination

The structure of goadsporin was determined by using spectroscopic techniques. NMR analysis revealed that goadsporin consists of 19 amino acids, two of which are dehydroalanines (Deala), and six of which are cyclized to oxazoles (Oxz) and thiazoles (Thz) by dehydrative cyclization and dehydrogenation from serine, threonine and cysteine. NMR analysis established seven partial structures, and their sequence was determined by CID-MS/MS. Negative mode FAB-MS/MS gave product ions arising from charge-remote fragmentation that allowed determination of the sequence of the amino acid components as AcNH-Ala-MeOxz-Val-Deala-MeOxz-Ile-Leu-Thz-Ser-Gly-Gly-MeOxz-Leu-Deala-Oxz-Ala-Gly-Thz-Val-OH. The chiral amino acids were determined by the advanced Marfey's method to have L-configurations.

Difference in degree of mucosal atrophy between elevated and depressed types of gastric epithelial tumors

BACKGROUND

The significance of atrophy in the background mucosa and Helicobacter pylori infection in the morphogenesis of gastric epithelial tumors has not yet been investigated.

METHODS

The degree of mucosal atrophy, as determined by a histological analysis and the serum pepsinogen (PG) levels, and H. pylori status were investigated in patients with elevated adenoma (EA group; n = 40), elevated early cancer of intestinal type (ECI group; n = 30), depressed early cancer of intestinal type (DCI group; n = 37) and depressed early cancer of diffuse type (DCD group; n = 33), and the findings were then compared to those in 91 controls.

RESULTS

At all sites of the stomach, the histologic score of atrophy was higher in the EA group and in the ECI group than in the controls. In the DCI group, the histologic score of atrophy in the antrum was higher than in the controls, but no such difference in the score was found in the DCD group. The PG I/II ratios in the EA, ECI and DCI groups were significantly lower than in the controls, and the value was also different between the ECI and DCI groups. While H. pylori prevalence was higher in all groups than in the controls, a logistic regression analysis which included the grade of atrophy as a determinant revealed the infection to be an independent associated factor for the DCD group.

CONCLUSIONS

The difference in the background mucosal atrophy seems to contribute to different macroscopic types in gastric epithelial tumors. This seems to be the case especially for cancer of intestinal type.

Sarcoidosis with giant parotomegaly

We report the case of a 63-year-old man with bilateral parotid gland sarcoidosis. Giant, elastic, hard, subcutaneous tumors had been present on the right parotic and submaxillary regions for 11 years and on the left for 1 year. The patient had had diabetes mellitus for 8 years. Noncaseating epithelioid cell granulomata were revealed histopathologically in the periductal area of the parotid gland. Bilateral hilar lymphadenopathy was noted on chest x-ray studies. Serum levels of lysozyme were increased. Levels of serum angiotensin-converting enzyme were within normal limits. Tuberculin skin reaction was positive. The tumors gradually improved after treatment with oral minocycline. Giant parotomegaly, as it occurred in this case, is very rare.

Efficient in utero gene transfer system to the developing mouse brain using electroporation: visualization of neuronal migration in the developing cortex

We report a novel gene transfer system using electroporation. We used this technique to introduce a marker gene plasmid containing enhanced green fluorescent protein into mouse brains at embryonic day 12-17 without removing the embryos from the uterus. The embryos were allowed to continue to develop in utero, and more than 80% were born normally expressing the exogenous gene. Enhanced green fluorescent protein driven by the cytomegalovirus promoter was strongly expressed in the ventricular zone, radial fibers and migrating neuroblasts, but not in mature neurons, suggesting that the cytomegalovirus promoter is silenced after the cells differentiate into mature neurons. Since there is still no convenient way of visualizing the migrating neuroblasts, especially of distinguishing them from the surrounding mature neurons in the cortical plate, this system should provide a good tool for analysing neuronal migration. In the postnatal lateral cortex, neuroblasts migrated almost "tangentially" along the obliquely running "radial" fibers beneath the cortical plate, and after entering the cortical plate, turned towards the marginal zone and migrated radially. Neurons with primitive dendrites were observed only along the border between the marginal zone and the cortical plate, and never at other sites, such as in the middle of the cortical plate. These results imply that the neuroblasts do terminate migration and start differentiation to mature neurons when they encounter the marginal zone, as has long been suggested. By contrast, when elongation factor 1alpha promoter was used, prominent fluorescence allowed visualization of the entire mature neurons as well. The labeled neurons were observed to send axons to the contralateral cortex where they arborized extensively.Thus, this system is much easier and more efficient than virus-mediated gene transfer, and is useful for gain-of-function analysis of neural cell fate determination, migration, positioning and axon path-finding in mouse embryos.

[A case report of mirror writing with low perfusion of bilateral anterior cerebral arteries]

A 20-year-old female experienced temporary unintentional mirror writing associated with low perfusion of the bilateral anterior cerebral arteries. When she was 17 years old, she had developed multiple idiopathic intracerebral hemorrhages and right hemiparesis. At the age of 20, she had a generalized convulsion for which she was transferred to our department. Computed tomography (CT) and magnetic resonance images of the brain were obtained, but no fresh abnormal lesion could be detected. The following day, after she had recovered from postictal symptoms, she wrote mirror image words, and her mirror writing then gradually improved within one week. Single photon emission CT showed low perfusion of both anterior cerebral arteries. We concluded that bilateral vascular insufficiency to the supplementary motor areas and corpus callosum caused mirror writing in this case.

Molecular and cellular analyses of HLA class II-associated susceptibility to autoimmune diseases in the Japanese population

Abstract It is well known that individuals who are positive for particular HLA class II alleles show a high risk of developing autoimmune diseases. HLA class II molecules expressed on antigen-presenting cells present antigenic peptides to CD4(+) T cells. Their extensive polymorphism affects the structures of peptides bound to HLA class II molecules to create individual differences in immune responses to antigenic peptides. In order to gain a better understanding of mechanisms of the association between HLA class II alleles and susceptibility to autoimmune diseases, it is important to identify self-peptides presented by disease-susceptible HLA class II molecules and triggering disease-causative T cells. Many of the autoimmune diseases are observed in all ethnic groups, whereas the incidence of diseases, clinical manifestations and disease-susceptible HLA class II alleles are different among various ethnic groups for some autoimmune diseases. These phenomena suggest that differences in autoimmune self-peptide(s) in the context of disease-susceptible HLA class II molecules may cause these differences. Therefore, comparisons among disease-susceptible HLA class II alleles, autoantigenic peptides, and clinical manifestations of autoimmune diseases in different ethnic groups would be helpful in elucidating the pathogenesis of the diseases. In this review, we describe our recent findings on (1) the uniqueness of both clinical manifestations and the HLA-linked genetic background of Asian-type (opticospinal form) multiple sclerosis, (2) the characteristics of glutamic acid decarboxylase 65 (GAD65) or β2-glycoprotein I (β2-GPI) autoreactive T cells in Japanese patients with insulin-dependent diabetes mellitus (IDDM) or anti-β2-GPI antibody-associated autoimmunity, respectively, and (3) the generation of an efficient delivery system of peptides to the HLA class II-restricted antigen presentation path-way by utilizing a class II-associated invariant chain peptide (CLIP)-substituted invariant chain, which may be applicable to an evaluation of the "molecular mimicry hypothesis" for the activation of autoreactive T cells.

Monocytes are differentially activated through HLA-DR, -DQ, and -DP molecules via mitogen-activated protein kinases

When HLA-DR, -DQ, and -DP were cross-linked by solid-phase mAbs, monocytes produced monokines and only anti-DR markedly activated mitogen-activated protein (MAP) kinase extracellular signal-related kinase, whereas anti-DR, anti-DQ, and anti-DP all activated MAP kinase p38. Activation of extracellular signal-related kinase was not inhibited by neutralizing Ab to TNF-alpha. Anti-DR and DR-restricted T cells stimulated monocytes to produce relatively higher levels of proinflammatory monokines, such as IL-1beta, whereas anti-DQ/DP and DQ-/DP-restricted T cells stimulated higher levels of anti-inflammatory monokine IL-10. IL-10 production was abrogated by the p38 inhibitor SB203580, but rather enhanced by the MAP/extracellular signal-related kinase kinase-I-specific inhibitor PD98059, whereas IL-1beta was only partially abrogated by SB203580 and PD98059. Furthermore, DR-restricted T cells established from PBMC, which are reactive with mite Ags, purified protein derivative, and random 19-mer peptides, exhibited a higher IFN-gamma:IL-4 ratio than did DQ- or DP-restricted T cells. These results indicate that HLA-DR, -DQ, and -DP molecules transmit distinct signals to monocytes via MAP kinases and lead to distinct monokine activation patterns, which may affect T cell responses in vivo. Thus, the need for generation of a multigene family of class II MHC seems apparent.

Correlation between diffuse pigmentation and keratinocyte-derived endothelin-1 in systemic sclerosis

BACKGROUND

The precise mechanism of diffuse pigmentation in systemic sclerosis (SSc) is still unknown. We suspected the participation of endothelin-1 (ET-1), which is produced by keratinocytes, in the hyperpigmentation in SSc. The aims of this study are to demonstrate the hyperproductivity of ET-1 from epidermal cells in SSc by in situ hybridization histochemistry, and to show a correlation between the hyperproductivity of ET-1 in keratinocytes and skin hyperpigmentation.

METHODS

In situ hybridization histochemistry was performed on nine SSc specimens (five cases of diffuse scleroderma (dSSc), four cases of acrosclerosis (lSSc)), and compared with four normal control specimens. We counted the grains on 10 x 10 microm(2) of epidermis and microvessels in each histology and examined the degree of skin pigmentation using the skin reflectance factor (Y).

RESULTS

In the specimens of the SSc patients, the number of grains on the epidermis was remarkably higher than those of the control specimens (P < 0.01). We found a close correlation between the number of grains and the skin reflectance factor in dSSc patients (P = 0.02). Correlations were not identified between serum ET-1 and skin pigmentation and between serum ET-1 and the frequency of grains on the epidermis. As for grains on microvessels, lSSc patients showed a greater frequency than dSSc patients.

CONCLUSIONS

The findings of this study suggest that an increase in the ET-1 productivity of keratinocytes is experienced in SSc patients, especially in dSSc patients. The results suggest a strong correlation between the ET-1 productivity of keratinocytes and skin pigmentation in severe cases of SSc. We conclude from these results that keratinocyte-derived ET-1 plays an important role in the pathogenesis of the hyperpigmentation of the skin in SSc patients.

Ligation of HLA-DR molecules on B cells induces enhanced expression of IgM heavy chain genes in association with Syk activation

Signals transmitted by class II major histocompatibility complex are important regarding cell function related to antigen presentation. We examined effects of DR-mediated signaling on Ig production from B cells. Cross-linking HLA-DR molecules on B cells by solid-phase anti-HLA-DR monoclonal antibodies, led to an increased production of IgM, without proliferation or apoptosis. This event was accompanied by an enhanced expression of both membrane- and secretory-type IgM heavy chain mRNA. When peptide-pulsed B cells were co-incubated with an HLA-DR-restricted T cell clone treated by the protein synthesis inhibitor emetine, peptide-induced de novo expression of lymphokines and cell-surface molecules on T cells can be neglected. CD40-CD154 interaction was not involved in IgM enhancement, in such a system. The protein-tyrosine kinase inhibitors and the Syk inhibitor piceatannol, but not the Src inhibitor PP2 had a marked inhibitory effect on IgM secretion. Furthermore, ligation of HLA-DR on B cells using the F(ab')2 fragment of anti-DR monoclonal antibody, enhanced Syk activity. Our data suggest that HLA-DR on B cells not only present antigenic peptides to T cells, but also up-regulate IgM production, in association with Syk activation and without the involvement of Src kinases, hence the possible physiological relevance of Src-independent Syk activation.

A parallel comparison of age-related peripheral nerve changes in three different strains of mice

Strain-specific differences contributing to spontaneous age-related peripheral nerve changes were examined in three different strains of 100-week-old female mice housed under the same conditions over the same period: inbred C57BL and C3H strains, and the hybrid B6C3F1 strain. A lower incidence of obesity and significantly lower body weight, grasping power of fore- and hind-limbs, blood lipid level, tail-flick latency and motor nerve conduction velocity were observed in C57BL mice; significantly lower body temperature, blood glucose and HbA1c levels were observed in C3H mice. Histological examination conducted on isolated sciatic nerves and brachial plexuses revealed peripheral nerve lesions, characterized by axonal degeneration and remyelination, in all strains. Although the extent of histopathologic change in nerve fibers was similar in quality to those observed in all three mouse strains, the incidence and severity of nerve lesions in B6C3F1 and C3H mice were significantly greater than those observed in C57BL mice.

Peripheral neuropathy in B6C3F1 mice and SD rats induced by chronic intermittent insulin hypoglycemia

The effects of sustained insulin-induced hypoglycemia on peripheral nerves were examined in 9-10-week old female B6C3F1 mice and 9-10-week old female SD rats. Insulin was administered via osmotic minipumps at a dose of 81 IU/kg/day for 2 consecutive weeks. Mice and rats treated with this high insulin dose showed marked hypoglycemia, resulting in half the normal blood glucose level, hypothermia, impaired motor nerve conduction velocity, and an increased incidence of peripheral nerve lesions, consisting of nerve fiber degeneration characterized by irregular myelin sheaths and axonal atrophy.

The exacerbating effect of insulin-induced hypoglycemia on spontaneous peripheral neuropathy in aged B6C3F1 mice

The effect of insulin-induced hypoglycemia on spontaneous peripheral neuropathy in aged mice was examined. Ninety-five-week-old female B6C3F1 mice were infused subcutaneously for 2 weeks with 40 or 80 IU/kg/day of insulin with a micro osmotic pump. Blood glucose level was decreased during the infusion (4.3-6.8 mmol/L in mice receiving 40 IU/kg/day of insulin or 2.4-5.4 mmol/L in mice receiving 80 IU/kg/day of insulin versus 6.5-7.6 mmol/L in control mice). In histopathological examination, axonal degeneration and/or remyelination were observed in a small number of nerve fibers of control mice. Similar nerve fiber lesions were observed in mice receiving 40 IU/kg/day of insulin, whereas severer lesions with an increase in segmental axonal degeneration of nerve fibers were observed in 4/7 mice receiving 80 IU/kg/day of insulin. These findings suggest that spontaneous peripheral neuropathy in aged mice is exacerbated by sustained hypoglycemia induced by insulin treatment.

Spontaneous age-related peripheral neuropathy in B6C3F1 mice

Peripheral neuropathy, which accompanies aging, occurs during the long-term rearing of laboratory animals. The present study set out to delineate the clinical and functional features of this neuropathy. A total of 200 B6C3F1 female mice, in groups of 5 to 20 mice, were sacrificed and autopsied each week beginning at 5 weeks and continuing to 130 weeks of age. Examination for histopathologic changes was conducted on the dorsal nerve roots, sciatic nerves, peroneal nerves, tibial nerves, plantar nerves and brachial nerve plexuses. At 90 weeks of age or later, peripheral neuropathy, characterized by axonal degeneration and Schwann cell proliferation, were observed mainly in the sciatic nerves, brachial nerve plexus and peroneal nerves. These spontaneous age-related nerve lesions appeared in all animals by 100 weeks of age in all nerves, and increased with increasing age. The nerve lesions were most prominent in the distal sciatic nerve. The rectal and hind-limb surface temperatures, motor nerve conduction velocity, blood glucose and HbA1C decreased with increasing age. Elevation of sorbitol contents in sciatic nerves and reduction of myo-inositol levels were also detected in 120-week-old mice. However, except for blood glycemic parameters, no correlation with peripheral nerve lesions could be demonstrated. Spontaneous hypoglycemia (< 40 mg/dL) persisted throughout the day in a small percentage (< 5%) of animals aged 80 weeks or more; these animals had extensive lesions in the peripheral nerves and showed decreased plasma levels of HbA1C and frucutosamines and increased plasma levels of ketones. These results suggest that spontaneous peripheral nerve disorders which accompany aging might worsen if spontaneous age-related hypoglycemia is also present. Such age-related changes must be taken into consideration in experimental studies performed on mice of this age.

Comparison of age-related peripheral nerve changes in mice housed in either plastic cages with sawdust-covered solid flooring or wire-mesh-floor cages

A comparative histologic survey was conducted on the dorsal root, sciatic, tibial and medial plantar nerves of 90- and 110-week-old B6C3F1 female mice reared in either solid-floor cages covered in sawdust or wire-mesh-floor cages. Age-related peripheral nerve lesions, characterized by axonal degeneration and remyelination, were present in all nerves surveyed, and were especially prominent in the sciatic and medial plantar nerves at 110 weeks of age but, there were no differences associated with the type of cage floor in clinical signs, grasping power of the fore- and hind-limbs, motor nerve conduction velocity or histopathologic findings at these ages.

Acute parietal and chief cell changes induced by a lethal dose of lipopolysaccharide in mouse stomach before thrombus formation

The common lipopolysaccharide (LPS)-induced gastric lesions, such as erosions or ulcers, have been investigated in depth. Little is known, however, about the acute gastric lesions following a high dose of LPS. In a time-course study, ICR female mice were given a high subcutaneous dose of LPS (50 mg/kg). Mice were sacrificed at 4, 6, 12, and 24 hours after dosing and were assessed histopathologically for acute gastric lesions. The major gastric changes were seen in the fundic region and included vacuolar degeneration of parietal cells and apoptosis of chief cells. The vacuole in parietal cells was apparent as early as 4 hours postinjection (PI), and apoptosis of chief cells was apparent at 12 hours PI. Thrombus formation, in contrast, was not seen until 24 hours PI. No erosion, ulcer, or hemorrhage was seen in any gastric region in any of the treated animals at 24 hours PI. These results indicate that a subcutaneous high dose of LPS in mice causes vacuolar degeneration of parietal cells and apoptosis of chief cells before thrombus formation or subsequent ulcerative lesions.

Low frequency of genetic change in p53 immunopositive clones in human epidermis

Sun-exposed skin of Caucasians harbors thousands of p53-mutated clones, which are clinically invisible. Using whole mount immunostaining for p53 or Ki67 antigens, p53 sequencing, and loss of heterozygosity analysis, we have further characterised these clones. Loss of heterozygosity for the alleles examined is uncommon with the exception of 9q, which occurred in 28.3% of the samples. P53 clones are more common and larger in individuals with basal cell carcinoma than in control subjects (p < 0.03). Loss of heterozygosity is also more common in clones from individuals with basal cell carcinoma than in clones from subjects without a history of basal cell carcinoma, as would be expected if both relate to ultraviolet radiation exposure. p53 sequencing of clones is in keeping with the mutagenic role of ultraviolet radiation. Surprisingly, skin found to harbor p53 clones showed no clusters of Ki67 positive cells, unlike the situation for actinic keratoses or basal cell carcinomas. These results show that in human skin p53 mutation is not directly associated with genomic instability or abnormal cell cycling; that the p53 immunopositive clones are either genetically distinct or precursors to other squamous cell lesions of skin; and that p53 immunopositive clones are early lesions, in that gross disturbance of proliferation has not already occurred.

Helicobacter pylori and mucosal atrophy in patients with gastric cancer: a special study regarding the methods for detecting Helicobacter pylori

We assessed the sensitivities of several methods for detecting Helicobacter pylori (culture, histology, rapid urease test, and serology), and evaluated the H. pylori positivity considering the degree of atrophy in the background mucosa in 202 gastric cancer patients and 101 controls. The positivity of H. pylori determined by culture (81%) was significantly higher than that determined by serology (62%) in gastric cancer patients (P < 0.001). The positivities of H. pylori determined by biopsy and/or serology in intestinal (84%) and diffuse (95%) types of gastric cancer were higher than that observed in controls (54%) (P < 0.001). Intestinal-type gastric cancer tended to occur in the atrophic mucosa, in which H. pylori positivity was not different from that in controls after adjusting for the degree of atrophy, whereas diffuse-type gastric cancer was observed more often in the nonatrophic mucosa, in which H. pylori positivity was higher than that in controls even after adjusting for the degree of atrophy.

Effects of glutathione depletion on selenite- and selenate-induced embryotoxicity in cultured rat embryos

Effects of depletion of reduced glutathione (GSH) on selenium (Se) embryotoxicity in cultured rat embryos were examined. Rat embryos at day 9.5 of gestation were cultured for 48 h in the presence of Se as either sodium selenite at 10 and 20 microM or sodium selenate at 30 and 100 microM. Embryonic GSH was depleted by the addition of 0.1 mM of L-buthionine-[S,R]-sulfoximine (BSO) without embryotoxicity, i.e., significant growth retardation and malformation of the embryos. Selenite at 10 microM or selenate at 100 microM significantly increased the incidence of malformation of the embryos. The incidence of selenite-induced malformation of the embryos at 20 microM was significantly decreased with BSO. On the contrary, the incidence of selenate-induced malformation at 30 microM was significantly increased with BSO. It was noted that the major malformed regions of the embryos by the embryotoxic concentration of BSO alone were the same to those affected by selenite or selenate. It was considered from these results that embryonic GSH was involved in the embryotoxicity of selenite and selenate. The embryotoxicity of selenate may not be mediated through the reduction to selenite. It was suggested that the formation of selenodiglutathione and the oxidative stress were involved in the embryotoxicity of selenite and selenate, respectively.

Evaluation of ready-to-use liquid reagents for clinical chemistry in laboratory animals

We evaluated the ready-to-use liquid reagents for clinical chemistry (6 tests), to assess their suitability for use in the toxicology laboratory setting. Hitachi 736 automated analyzer was used for the analyses. The evaluation included the following studies: Precision, Linearity, Effects of interference substances such as hemolytic hemoglobin, bilirubin, turbidity to the analytical values and correlation to the solid reagents, which are prepared each time they are needed. The precision and linearity data were within the reagents' specifications. Results of comparison of the liquid reagents and the solid reagents in analyzing plasma samples of rats, dogs and monkeys were generally good except for a bias in results for GOT and GPT, regardless of the animal species tested. It is concluded that these types of liquid reagents can be used in clinical pathology examinations in animal studies.

Effects of ascorbic acid on selenium teratogenicity in cultured rat embryos

The effects of ascorbic acid, as an exogenous antioxidant, on selenium (Se) teratogenicity were examined using rat embryo culture. Rat embryos at day 9.5 of gestation were cultured for 48 h in the presence of sodium selenite at 10 and 20 microM or sodium selenate at 30 and 100 microM with or without the addition of 1 mM of L-ascorbic acid (AsA). Selenite or selenate alone increased the incidence of embryonic malformation. With AsA, the incidence of selenite-induced embryonic malformation was increased. On the contrary, the incidence of selenate-induced embryonic malformation was decreased with AsA. It was considered from these results that the redox states in the embryonic environment and of Se are critical in Se teratogenicity.

Tissue interaction regulates expression of a spasmolytic polypeptide gene in chicken stomach epithelium

The primitive epithelium of embryonic chicken proventriculus (glandular stomach) differentiates, after day 6 of incubation, into luminal epithelium, which faces the lumen and abundantly secretes mucus, and glandular epithelium, which invaginates into mesenchyme and later expresses embryonic chicken pepsinogen (ECPg). So far it is not well understood how undifferentiated epithelial cells differentiate into these two distinct cell populations. Spasmolytic polypeptide (SP) is known to be expressed in surface mucous cells of mammalian stomach. In order to obtain the differentiation marker for proventricular luminal epithelial cells, we cloned a cDNA encoding chicken SP (cSP). Sequence analysis indicated that cSP has the duplicated cysteine-rich domain characteristic of SP. Examination of the spatial and temporal expression pattern of cSP gene revealed that, during embryogenesis, cSP was expressed in lumina epithelial cells of the proventriculus, gizzard, small intestine, and lung, but not the esophagus. In the proventriculus, cSP mRNA was first detected on day 8 of incubation and was localized to differentiated luminal epithelial cells. By using cSP as a molecular marker, the effects of mesenchyme on the differentiation of epithelium were analyzed in vitro. On the basis of these data, a model is presented concerning the differentiation of proventricular epithelium.