A clinicopathologic study of primary cholesterol hepatolithiasis

BACKGROUND/AIMS: We conducted the present study in order to clarify the clinicopathologic features of primary cholesterol hepatolithiasis and compare them with those in primary calcium bilirubinate hepatolithiasis. MATERIALS AND METHODS: We reviewed the clinicopathologic features of 24 patients with primary cholesterol hepatolithiasis. The clinical symptoms were mild, and the median duration of symptoms was 5 years. RESULTS: In 22 patients complete stone clearance was obtained using percutaneous cholangioscopic lithotomy, partial hepatectomy, or their combination. The patients showed excellent clinical outcome (median follow-up period, 6 years) despite the absence of bilioenteric drainage. Stones have recurred in 4 patients, who remain asymptomatic. The histopathologic findings in 7 hepatectomized patients were compared with those in 7 patents with calcium bilirubinate hepatolithiasis. The inflammatory changes around the stone-containing duct, i.e., wall thickening, fibrosis, sludge formation, and glandular hyperplasia, were significantly milder in the cholesterol hepatolithiasis patients (p < 0.01 or p < 0.05). CONCLUSIONS: These clinical and histopathologic findings indicate that primary cholesterol hepatolithiasis should be regarded as a different clinical entity from calcium bilirubinate hepatolithiasis which has a close relationship with bile stasis and bacterial infection as etiological factors.     

Kinematics,dynamics and stability of the tubular film extrusion of various polyethylenes

A basic study of the kinematics, dynamics, and heat transfer occuring during tubular film extrusion of polyethylene is outlined. Three rheologically characterized polyethylenes, a low-density polyethylene (LDPE), a linear-low-density polyethylene (L-LDPE), and a high-density polyethylene (HDPE) were used in this study. The kinematics and stability of the tubular film process were investigated over a wide range of blow-up ratios, drawdown ratios, and frost-line heights. Local deformation rates along the bubble have been determined. Regions of stability and instability are described. Tensions and inflation pressures have been measured and expressed in terms of locol elongational viscosities. Temperature profiles along the bubble were determined and interpreted in terms of local heat transfer coefficients. Positions of crystallization and temperature profiles have been noted and used to estimate rates of crystallization. The characteristics of the LDPE, LLDPE, and HDPE are contrasted.     

Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 degrees C, 50% RH; heat stress: 35 degrees C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.     

Identifying sources and mass balance of dioxin pollution in Lake Shinji Basin, Japan

On the basis of congener-specific analysis of dioxins in a dated sediment core, the sources and behavior of dioxins in Lake Shinji Basin, Japan, were estimated. The dioxins in the core showed that their deposition in the lake increased rapidly during the 1960s, peaked in the early 1970s, and then decreased gradually. Principal component analysis of the congener-specific data showed that three major sources existed: pentachlorophenol (PCP), chloronitrophen (CNP), and combustion. PCP and CNP are paddy field herbicides used extensively in the basin. The time trends of source contributions were estimated by multiple regression analysis using the source profiles. The results revealed that dioxin emission from PCP and CNP herbicides was high in the 1960s and the early 1970s, respectively. The contributions from PCP, CNP, and combustion in recent surface sediment were about 68, 16, and 16% in terms of total amount of dioxins. From the decreasing trend of dioxin deposition in the lake after extensive herbicide use, the amount of dioxins that accumulated in the agricultural soil in the basin was estimated to have decreased by about 2%/yr or a half-life of about 35 yr, indicating that dioxin runoff from agricultural fields would continue for a long time.     

Identification of the glucosamine kinase in the chitinolytic pathway of Thermococcus kodakarensis

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Speciation of sulfate in size-fractionated aerosol particles using sulfur K-edge X-ray absorption near-edge structure

X-ray absorption near-edge structure (XANES) at sulfur K-edge was used to determine the sulfate species present in size-fractionated aerosol particles based on the postedge structure after the main absorption peak in the XANES region. A comparison of the XANES spectra of reference sulfate materials and aerosol samples collected in Tsukuba in Japan clearly showed that (NH4)2SO4 was the main sulfur species in particles with a smaller diameter and CaSO4 x 2H2O (gypsum) was the main sulfur species in particles with a larger diameter. A simulation of the XANES spectra by reference materials allows us to obtain the quantitative mixing ratios of the different sulfate species present in the aerosol samples. The presence of minor sulfur species other than (NH4)2SO4 and gypsum at the surface of mineral aerosols is suggested in our simulations and by a surface-sensitive conversion electron/He-ion yield XANES. In the absence of a contribution from a large dust event, the mole concentration of gypsum in the mineral aerosol fraction (particle diameter > 1 microm) determined by XANES is similar to that of Ca which is determined independently using ion chromatography. This shows that the Ca and sulfate in the mineral aerosols are present only as gypsum. Considering that calcite is the main Ca mineral in the original material arising from an arid and semiarid area in China, it is strongly suggested that gypsum is formed in aerosol during its long-range transportation by a reaction between calcite and sulfate ions.     

Determination of dimetridazole, metronidazole and ronidazole in salmon and honey by liquid chromatography coupled with tandem mass spectrometry

A liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed to determine the residues of dimetridazole (DMZ), metronidazole (MNZ) and ronidazole (RNZ) in salmon and honey. These compounds were extracted with ethyl acetate from samples and cleaned up using a silica solid phase extraction (SPE) cartridge. These compounds were determined by reversed-phase LC using a C18 column with distilled water-methanol as the mobile phase, and MS detection in the positive mode by applying selected reaction monitoring (SRM). DMZ-d(3), MNZ-(13)C(2),(15)N(2) and RNZ-d(3) were used as internal standards. The method was validated in salmon and honey spiked with these compounds at 0.4-2 μg/kg, and average recoveries were in the range of 91.2-107.0%. Repeatability was 1.7-17.1% and intermediate precision was less than 20%. The detection limits of DMZ, MNZ and RNZ in salmon and honey were 0.05-0.2 μg/kg. The method was applied to 3 salmon and 20 honey samples. The concentrations of these compounds in all samples were lower than the detection limits established by the Ministry of Health, Labour and Welfare in Japan.     

Multi-locus genotyping of bottom fermenting yeasts by single nucleotide polymorphisms indicative of brewing characteristics

Yeast plays a capital role in brewing fermentation and has a direct impact on flavor and aroma. For the evaluation of competent brewing strains during quality control or development of novel strains it is standard practice to perform fermentation tests, which are costly and time-consuming. Here, we have categorized DNA markers which enable to distinguish and to screen brewing strains more efficiently than ever before. Sequence analysis at 289 loci in the genomes of six bottom fermenting Saccharomyces pastorianus strains revealed that 30 loci contained single nucleotide polymorphisms (SNPs). By determining the nucleotide sequences at the SNP-loci in 26 other S. pastorianus strains and 20 strains of the top fermenting yeast Saccharomyces cerevisiae, almost all these strains could be discriminated solely on the basis of the SNPs. By comparing the fermentative phenotypes of these strains we found that some DNA markers showed a strong association with brewing characteristics, such as the production of ethyl acetate and hydrogen sulphide (H2S). Therefore, the DNA markers we identified will facilitate quality control and the efficient development of brewing yeast strains.     

Formation of self-assembled glycolipid nanotubes with bilayer sheets

Rolled-up morphology of bilayer sheets in a self-assembled glycolipid nanotube (LNT) in water was carefully examined by using a cryogenic transmission electron microscope (cryo-TEM) with a rapid-freezing specimen-preparation technique. The LNTs were obtained under a series of self-assembly conditions: boiling of an aqueous dispersion of glycolipid N-(11-cis-octadecenoyl)-beta-D-glucopyranosylamine, subsequent gradual cooling, and incubation at room temperature for several days. Cryo-TEM images revealed that the LNT walls consist of a multilayer structure with interlayer distance of about 4.7 nm. These layers correspond to constituent lipid bilayers. From the result of precise cryo-TEM observations and analyses, we confirmed the rolled-up morphology of the lipid bilayer sheets in a complete self-assembled glycolipid nanotube.     

Individual monitoring for internal contamination with plutonium compounds at JAEA-NCL

This paper provides an outline of an individual monitoring programme for internal contamination with Pu compounds and some of the knowledge obtained from experience of inhalation incidents that occurred over the past few decades at the Japan Atomic Energy Agency, Nuclear Fuel Cycle Engineering Laboratories (JAEA-NCL). Most of the incidents resulted in minor exposure doses, being an average of 0.1 mSv at a mixed oxide plant and 1.5 mSv at a reprocessing plant. Only two incidents involving three workers resulted in exposure over the regulatory dose limits of that time. The maximum exposure dose, an effective dose equivalent of 90 mSv, was assessed for a worker involved in the incident that took place at the reprocessing plant in 1993. Only faecal measurements have been used in final dose assessments because alternative monitoring data have rarely been available. Further investigations on the physicochemical properties specific to Pu compounds in workplaces have therefore been needed to improve not only the accuracy of internal dose assessments but also the nasal swab method useful in deciding medical intervention.