Laser-based angle-resolved photoemission spectroscopy with micrometer spatial resolution and detection of three-dimensional spin vector.

We have developed a state-of-the-art apparatus for laser-based spin- and angle-resolved photoemission spectroscopy with micrometer spatial resolution (µ-SARPES). This equipment is realized by the combination of a high-resolution photoelectron spectrometer, a 6 eV laser with high photon flux that is focused down to a few micrometers, a high-precision sample stage control system, and a double very-low-energy-electron-diffraction spin detector. The setup achieves an energy resolution of 1.5 (5.5) meV without (with) the spin detection mode, compatible with a spatial resolution better than 10 µm. This enables us to probe both spatially-resolved electronic structures and vector information of spin polarization in three dimensions. The performance of µ-SARPES apparatus is demonstrated by presenting ARPES and SARPES results from topological insulators and Au photolithography patterns on a Si (001) substrate.

X-ray magnetic circular dichroism of a valence fluctuating state in eu at high magnetic fields.

X-ray magnetic circular dichroism (XMCD) at the Eu L edge in two compounds exhibiting valence fluctuation, namely EuNi_{2}(Si_{0.18}Ge_{0.82})_{2} and EuNi_{2}P_{2}, has been investigated at high magnetic fields of up to 40 T. A distinct XMCD peak corresponding to the trivalent state (Eu(3+)), whose ground state is nonmagnetic (J = 0), was observed in addition to the main XMCD peak corresponding to the magnetic (J = 7/2) divalent state (Eu(2+)). This result indicates that the 5d electrons belonging to both valence states are magnetically polarized. It was also found that the ratio P_{5d}(3+)/P_{5d}(2+) between the polarization of 5d electrons (P_{5d}) in the Eu(3+) state and that of Eu(2+) depends on the material. The possible origin of the XMCD and an explanation of the material dependence of P_{5d}(3+)/P_{5d}(2+) are discussed in terms of hybridization between the conduction electrons and the f electrons.

Kinetic analysis of apolipoproteins in postprandial hypertriglyceridaemia rabbits.

The postprandial hypertriglyceridaemia (PHT) rabbit, developed as a new animal model of metabolic syndrome, is characterized by PHT, central obesity and glucose intolerance. For detailed investigation of lipid metabolism characteristics in PHT rabbit, the plasma levels of apolipoproteins A-I, B, C-II, C-III and E were measured. Movements of apolipoproteins B100 and B48 were investigated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis to determine whether postprandially increased triglyceride is exogenous or endogenous. The level of apolipoproteins A-I, B, C-II and E were increased in PHT rabbit after feeding. Apolipoproteins B100 and B48 were detected in the plasma fraction of d < 1.006 g/mL of the PHT rabbit. The postprandial increase in apolipoprotein B in the PHT rabbit reflects a numerical increase in lipoprotein particles in the blood; the increase in apolipoproteins C-II and E suggests some disturbance in lipoprotein catabolism. Apolipoprotein B48 was detected postprandially in PHT rabbits. These results suggest that delayed catabolism of exogenous lipids caused the retention of chylomicron remnants in the blood. Results also suggest that activities of the lipolytic enzyme lipoprotein lipase and hepatic triglyceride lipase were deficient and that the hepatic uptake of exogenous lipoproteins was delayed in the PHT rabbit. Especially, for examining remnant hyperlipoproteinaemia in humans, PHT rabbit is an excellent animal model for hypertriglyceridaemia research.

Linkage mapping of the locus responsible for forelimb-girdle muscular anomaly of Japanese black cattle on bovine chromosome 26.

Forelimb-girdle muscular anomaly is an autosomal recessive disorder of Japanese black cattle characterized by tremor, astasia and abnormal shape of the shoulders. Pathological examination of affected animals reveals hypoplasia of forelimb-girdle muscles with reduced diameter of muscle fibres. To identify the gene responsible for this disorder, we performed linkage mapping of the disorder locus using an inbred pedigree including a great-grand sire, a grand sire, a sire and 26 affected calves obtained from a herd of Japanese black cattle. Two hundred and fifty-eight microsatellite markers distributed across the genome were genotyped across the pedigree. Four markers on the middle region of bovine chromosome 26 showed significant linkage with the disorder locus. Haplotype analysis using additional markers in this region refined the critical region of the disorder locus to a 3.5-Mb interval on BTA26 between BM4505 and MOK2602. Comparative mapping data revealed several potential candidate genes for the disorder, including NRAP, PDZD8 and HSPA12A, which are associated with muscular function.

The involvement of type 1a angiotensin II receptors in the regulation of airway inflammation in a murine model of allergic asthma.

BACKGROUND: There has been increasing evidence suggesting the involvement of angiotensin II (Ang II) and type 1 Ang II receptors (AT1) in the pathogenesis of bronchial asthma. However, whether such an involvement would promote or suppress the pathophysiology of asthma is controversial. OBJECTIVE: The aim of this study was to investigate the role of AT1 in the development of allergic airway inflammation. METHODS: Agtr1a+/+ [wild-type C57BL/6 mice (WT)] and Agtr1a-/- mice [AT1a knockout mice (AT1aKO)] with a genetic background of C57BL/6 were systemically sensitized to ovalbumin (OVA), followed by OVA inhalation. OVA-specific IgE in serum obtained just before the inhalation was measured. Bronchoalveolar lavage (BAL) fluid and lung tissues were obtained at various time-points. Cell numbers and differentiation, and cytokine contents in BAL fluids were determined. Peribronchial accumulation of eosinophils and mucus inclusions in the bronchial epithelium were evaluated in lung tissues stained histochemically. Cell numbers and differentiation in BAL fluids of the mice were also determined after lipopolysaccharide (LPS) inhalation. RESULTS: The levels of OVA-specific IgE in AT1aKO were significantly higher than those in WT. The numbers of total cell, eosinophils and lymphocytes in BAL fluids 7 days after OVA inhalation in AT1aKO were significantly higher than those in WT. Airway inflammation in bronchial tissues in terms of eosinophil accumulation and mucus hypersecretion in AT1aKO was also stronger than in WT. The contents of IL-4, IL-5 and IL-13, but not IFN-gamma, in BAL fluids of AT1aKO were significantly higher than those of WT. In contrast, neutrophil accumulation in BAL fluids after LPS inhalation was significantly higher in WT than in AT1aKO. CONCLUSION: AT1a might be involved in the negative regulation of the development of allergic airway inflammation through polarizing the T-helper (Th) balance towards Th1 predominance. Therefore, it would be of clinical importance to investigate the effects of long-term administration of AT1 blockers on the Th1/Th2 balance in hypertensive patients with bronchial asthma.

Mott gap excitations in twin-free YBa2Cu3O7-delta (Tc=93 K) studied by resonant inelastic x-ray scattering.

Mott gap excitations in the optimally doped high-T(c) superconductor YBa(2)Cu(3)O(7-delta) (T(c)=93 K) have been studied by the resonant inelastic x-ray scattering method. Anisotropic spectra in the ab plane are observed in a twin-free crystal. The excitation from the one-dimensional CuO chain is enhanced at 2 eV near the zone boundary of the b* direction, while the excitation from the CuO2 plane is broad at 1.5-4 eV and almost independent of the momentum transfer. Theoretical calculations based on the one-dimensional and two-dimensional Hubbard model reproduces the observed spectra when different values of the on-site Coulomb energy are assumed. The Mott gap of the CuO chain site is found to be much smaller than that of the CuO2 plane site.

"Devil's staircase"-type phase transition in NaV2O5 under high pressure.

The "devil's staircase"-type phase transition in the quarter-filled spin-ladder compound NaV2O5 has been discovered at low temperature and high pressure by synchrotron radiation x-ray diffraction. A large number of transitions are found to successively take place among higher-order commensurate phases with 2a x 2b x zc type superstructures. The observed temperature and pressure dependence of modulation wave number q(c), defined by 1/z, is well reproduced by the axial next nearest neighbor Ising model. The q(c) is suggested to reflect atomic displacements presumably coupled with charge ordering in this system.

Characterization of psychrotrophic bacteria in the surface and deep-sea waters from the northwestern Pacific Ocean based on 16S ribosomal DNA analysis.

Seventy-eight 4 degrees C-culturable bacteria were isolated using ZoBell 2216E medium from surface (0-200 m) and deep-sea (1000-9671 m) waters in the northwestern Pacific Ocean. Growth studies indicated that all 4 degrees C-culturable bacteria were psychrotrophs. Six phylotypes were observed in the surface water samples and 8 phylotypes in the deep-sea waters. Phylogenetic characterization based on 16S ribosomal DNA sequence analysis of the representative phylotypes revealed that some bacterial genera, Pseudoalteromonas, Photobacterium, and Vibrio, were common to surface and deep-sea waters, and others, Pseudomonas and Halomonas, specifically occurred in surface water. Overall, the members of Vibrionaceae appear to be dominant in both habitats.

X-Ray anomalous scattering study of a charge-ordered state in NaV2O5

Charge ordering of V4+ and V5+ in NaV2O5 has been studied by an x-ray diffraction technique using anomalous scattering near a vanadium K-absorption edge to critically enhance a contrast between the two ions. A dramatic energy dependence of the superlattice intensities is observed below T(C) = 35 K. The charge ordering pattern is the fully charged zigzag-type ladder with the unit cell 2ax2bx4c, but not the chain-type originally proposed for the spin-Peierls state. Charge disproportionation suggested in our model as the average valence V(4.5+/-delta(c)/2) is observed below T(C), showing continuous variation of delta(c) as a function of temperature.

Clonotypes of Staphylococcus aureus isolated from continuous ambulatory peritoneal dialysis patients: what is the vector between nares and infection site?

Staphylococcus aureus is frequently isolated from patients with infections related to continuous ambulatory peritoneal dialysis (CAPD). In many cases, the organism is also isolated simultaneously from the anterior nares. To clarify the transmission trail of S. aureus, we used DNA analysis to identify clonotypes of clinical strains. The nares and exit sites of 32 CAPD patients were swabbed, and PD fluid samples were taken for pathogen culture. Genome DNA of S. aureus was digested with restriction enzyme Sma I for pulsed-field gel electrophoresis. We also asked the patients how they usually performed the PD procedure. S. aureus was isolated from 4 patients, including 3 who hosted two strains isolated separately from different sites. The DNA patterns of the strains isolated from these latter 3 patients were identical. However, the clonotypes from all 4 patients were different. Most of the patients did not wash their hands and wear masks while exchanging PD bags and caring for their exit sites. After the patients were disinfected and re-educated in proper procedures, S. aureus was not detected in any of them. These data suggest that no outbreak occurred in our hospital and that the vectors of endogenous infection were the patients themselves, probably their hands. A bacteriological study presents an efficient opportunity to re-educate patients in PD procedure.

Effects of "isolating hemodialysis" on prevention of methicillin-resistant Staphylococcus aureus cross-infection in a hemodialysis unit.

AIM: To evaluate the effects of a contact isolation program against methicillin-resistant Staphylococcus aureus (MRSA) cross-infection among patients in a hemodialysis unit. CLINICAL SETTING AND METHODS: In all patients maintaining hemodialysis therapy were tested for MRSA infection and who had MRSA infection, not only inpatients but also outpatients were separated into a designated area (isolating hemodialysis). Clinically isolated MRSA strains were clonotyped with coagulase typing, staphylococcal enterotoxin typing and restriction enzyme analysis of plasmid DNA. RESULTS: The frequency of patients with MRSA infection was 4.5% before starting this protocol and was reduced to 2.9% two and a half years later. At this time, MRSA was isolated from the 8 patients. These 8 clinical strains were differentiated into 6 clonotypes and 3 strains showed the same patterns. Two of 3 were isolated from inpatients and the other was from a patient with community onset MRSA colitis. In this case, most MRSA infections were independent under prophylaxis control and cross-infection was observed only once between hospitalized patients who stayed in a same ward. CONCLUSION: This "isolating hemodialysis" should be useful to prevent cross-infection among patients in end-stage renal disease in a dialysis unit.

Heteronuclear diatomic force constants clarified through perturbation theory II.

A simple relationship between the heteronuclear diatomic force constant (K(AB)) and the homonuclear diatomic force constants (K(AA), K(BB)), which was proposed in a previous report, has been improved through the second-order perturbation theory as K(AB) = zeta3(K(AA) x K(BB))(1/2); zeta = (R(AA) x R(BB))(1/2)/R(AB) where zeta denotes the correction factor in which R(AB), R(AA), and R(BB) are the equilibrium internuclear distances of diatomic molecules AB, AA, and BB, respectively. To test the above expression, a large number of heteronuclear diatomic force constants have been calculated and compared with those obtained from normal coordinate analyses as well as ab initio quantum mechanical methods (Gaussian 98W). We have found that the above modified expression better reproduces the force constants of most heteronuclear diatomic molecules than the previous expression. It is therefore expected that the expression may also be applied to the prediction of stretching force constants between heteronuclear diatomics in various polyatomic molecules.

Characterization of depth-related population variation in microbial communities of a coastal marine sediment using 16S rDNA-based approaches and quinone profiling.

Depth-related changes in whole-community structure were evaluated in a coastal marine sediment using a molecular fingerprinting method, terminal restriction fragment length polymorphism (T-RFLP) analysis, and a chemotaxonomic technique (quinone profiling). Dendrograms derived from both T-RFLP analysis and quinone profiling indicated a significant variation in microbial community structure between the 0-2 cm layer and deeper layers. This corresponded to the dramatic change in the redox potential, acid-volatile sulphide-sulphur and bacterial numbers observed at 0-2 cm and 2-4 cm depths. A significant change in the number of terminal restriction fragments (T-RFs) was also detected at this transition depth. However, the change in major T-RFs with depth was not seen in electropherograms. The population changes were primarily variations in minor ribotypes. Most quinone homologues were detected at all depths, although the quinone composition changed with depth. Therefore, quinone profiling also suggested that the depth-related variation was primarily attributable to minor bacterial groups rather than change in the major population structure. 16S rDNA clone library analysis revealed that clones belonging to the genera Vibrio and Serratia predominated as major bacterial groups at all depths. Our data suggested that the sediment community might result from sedimentation effects of sinking particles. Overall, our results demonstrated that the combined methods of T-RFLP analysis and quinone profiling were effective for assessing depth-related microbial populations.

Biomass Measurement of Methanogens in the Sediments of Tokyo Bay Using Archaeol Lipids.

An archaeal ether-linked lipid, archaeol, was determined to be a biomass indicator for methanogens both in the laboratory enriched culture and in marine sediments. The archaeol measurement method described by Ohtsubo et al. in 1993 was modified and applied to marine sediments. We compared the amount of archaeol with the cell number of methanogens or methane concentration in laboratory enriched culture of methanogens from marine sediment. Good correlations were obtained as follows: (Methane, mmol) = 11.2 x (Archaeol, mg): r =.996 or (Cell number) = 1.13 x 10(11) x (Archaeol, mg): r =.995, respectively. In the sediments of Tokyo Bay, archaeol was measured from approximately 46 to 561 ng/dry g sediment at the entrance to 267 to 4160 ng/dry g sediment at the innermost area. Using the coefficient from the laboratory experiment, these data corresponded to cell numbers of 5.2 x 10(6) to 4.7 x 10(8)/dry g sediment. These values were 1 or 2 orders of magnitude higher than those obtained by culture methods in previous studies. Although dead or decomposed cells might be detected, archaeol measurement is useful for estimating the biomass of methanogens because of the good correlation between methane concentration and archaeol content in marine environments. In this study, we found a correlation of (Methane, mmol) = 0.012 x (Archaeol, mg): r =.932, n = 17 in marine sediments.

Relationship between serum biochemical values and marbling scores in Japanese Black steers.

In order to obtain available biochemical parameters related to the marbling score (MS), by which the meat was graded from 1 to 12 in Japan, serum biochemical values were examined in 13 Japanese Black steers during the fattening stages. The steers were divided into high MS (8-11) and low MS (4-5) groups and the fattening stage was also divided into 4 stages according to their feed contents; Stage I (11-13 month-old; 0-4 months after the fattening (af)), II (5-9 months af), III (10-14 months af), and IV (15-20 months af). High MS group showed significantly higher levels in glucose and urea nitrogen (at Stage I), albumin/globulin ratio (at Stage II), and magnesium (at Stage I and III), and lower level in vitamin A (at Stage III) than low MS group. These biochemical parameters, indicating conditions of steers during the fattening stages, are considered to have a possibility related to MS in fattening steers.

Abundant expression and cytoplasmic aggregations of [alpha]1A voltage-dependent calcium channel protein associated with neurodegeneration in spinocerebellar ataxia type 6.

Spinocerebellar ataxia type 6 (SCA6) is one of the eight neurodegenerative diseases caused by a tri-nucleotide (CAG) repeat expansion coding polyglutamine (CAG repeat/polyglutamine diseases) and is characterized by late onset autosomal dominant cerebellar ataxia and predominant loss of cerebellar Purkinje cells. Although the causative, small and stable CAG repeat expansion for this disease has been identified in the [alpha]1A voltage-dependent calcium channel gene (CACNA1A), the mechanism which leads to predominant Purkinje cell degeneration is totally unknown. In this study, we show that the calcium channel mRNA/protein containing the CAG repeat/polyglutamine tract is most intensely expressed in Purkinje cells of human brains. In SCA6 brains, numerous oval or rod-shaped aggregates were seen exclusively in the cytoplasm of Purkinje cells. These cytoplasmic inclusions were not ubiquitinated, which contrasts with the neuronal intra-nuclear inclusions of other CAG repeat/polyglutamine diseases. In cultured cells, formation of perinuclear aggregates of the channel protein and apoptotic cell death were seen when transfected with full-length CACNA1A coding an expanded polyglutamine tract. The present study indicates that the mechanism of neurodegeneration in SCA6 is associated with cytoplasmic aggregations of the [alpha]1A calcium channel protein caused by a small CAG repeat/polyglutamine expansion in CACNA1A.

Reassessment of the taxonomic position of Vibrio iliopiscarius (Onarheim et al. 1994) and proposal for Photobacterium iliopiscarium comb. nov.

The phylogenetic position of Vibrio iliopiscarius was inferred by the maximum-likelihood, maximum-parsimony and neighbour-joining methods on the basis of almost complete 16S rRNA gene sequences. The results showed that this species falls into the same cluster as Photobacterium species and is clearly distinct from other Vibrio species. Its nearest phylogenetic neighbour is Photobacterium phosphoreum. From these results, it is concluded that V. iliopiscarius should be reclassified as Photobacterium iliopiscarium comb. nov., the type strain of which is PS1T (= ATCC 51760T).

16S rDNA restriction fragment length polymorphism analysis of psychrotrophic vibrios from Japanese coastal water.

Restriction fragment length polymorphism (RFLP) analysis was carried out for 136 natural isolates belonging to the family Vibrionaceae. These were collected from inshore areas of Japan, mainly in winter. Twenty-eight 16S rDNA genotypes were obtained by digestion with four restriction endonucleases (HhaI, DdeI, RsaI, and Sau3AI). To estimate the genetic relationships, 53 informative fragments were scored by their presence or absence. A dendrogram was constructed using the unweighted pair group method with the arithmetic averages algorithm. Five RFLP groups (groups I to V) were obtained. Group I corresponded to Vibrio splendidus-like strains. It was confirmed that this group was not only found in Otsuchi Bay, but also in broad coastal areas of Japan. Group II strains were not identified as previously known Vibrio species. Group III strains were regarded as members of the Vibrio main group, which is a major phylogenetic group deduced from 16S rRNA gene analysis in the family Vibrionaceae. The RFLP profile indicated that Group IV strains were closely related to V. hollisae. Group V strains showed RFLP patterns which have not been observed previously. From the clustering analysis, it was concluded that group V strains were not Vibrio species. Most of the isolates studied were not identified as previously described species. It suggests that many psychrotrophic vibrios in cold marine environments remain as unknown species.

Insertion/deletion polymorphism in intron 16 of the ACE gene and left ventricular hypertrophy in patients with end-stage renal disease.

We studied the relationship between polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene and left ventricular (LV) hypertrophy in uremic patients treated with hemodialysis therapy. The LV parameters were not different for age-, hematocrit-, and blood pressure-matched patients in DD, ID, and II genotype groups. The most important factor for LV hypertrophy was systolic blood pressure, which correlated with the posterior wall thickness (r=0.35; P=0.001) and LV mass index (LVMI; r=0.23; P=0.032). Among nonhypertensive patients, the frequency of interventricular septum (IVS) hypertrophy (>12 mm) and hypertrophy in LVMI (>145 g/m2) was significantly greater in patients with the DD genotype than in I allele-positive (+) patients. The odds rate for IVS hypertrophy was 5.04 (95% confidence interval, 1.15 to 24.8). These data suggest that the DD genotype of the ACE gene polymorphism is a contributory factor for the development of LV hypertrophy in patients with end-stage renal disease (ESRD).

Skin sensitization and photosensitization studies of hydrophobically modified hydroxypropyl methylcellulose in guinea pigs.

Skin sensitization and photosensitization tests of hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC), a new cellulose derivative used as a thickener for topical pharmaceuticals, were conducted using guinea pigs. An aqueous dispersion of HM-HPMC (3 w/v %) was applied in the tests. Skin reaction was not observed in any animal in the HM-HPMC-treated group or control group. In the photosensitization test, no skin reaction was found in any animal in the test-preparation group or the control group. It was concluded that HM-HPMC dispersion does not exhibit skin sensitizing or photosensitizing activity under the condition of this test.