First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and β-delayed neutron emission probability, P_{1  n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Swelling of Doubly Magic ^{48}Ca Core in Ca Isotopes beyond N=28

Interaction cross sections for ^{42-51}Ca on a carbon target at 280  MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

Effects of muscarinic acetylcholine receptor stimulation on the differentiation of mouse induced pluripotent stem cells into neural progenitor cells

Muscarinic acetylcholine receptors (mAchRs), which are expressed in various embryonic cells, may regulate neuronal differentiation. In the present study, we examined the effects of mAchR stimulation on the differentiation of mouse induced pluripotent stem (iPS) cells into neural progenitor cells (NPCs). Mouse iPS cells were cultured on ultra-low attachment dishes to induce embryoid body (EB) formation. All-trans retinoic acid (ATRA, 3 μmol/L) and/or pilocarpine (10 or 100 μmol/L), a mAchR agonist, were added to EB cultures for 4 days, following which the EBs were cultured on gelatin-coated plates for 7 days. Subtype-specific antibody staining revealed that mouse iPS cells predominantly express m₂ - and m₄ -AchR. Treatment with pilocarpine alone did not affect the expression of Nestin (a specific marker for neural progenitor cells). However, additional treatment with pilocarpine significantly suppressed ATRA-induced Nestin expression. Pretreating EBs with either AF-DX116 (an antagonist of both m₂ - and m₄ -AchR) or forskolin (an activator of adenylate cyclase) significantly reversed the pilocarpine-induced suppression of Nestin expression. In addition, treatment with pilocarpine significantly suppressed ATRA-induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB). These findings suggest that the stimulation of m₂ - or m₄ -AchR suppresses ATRA-induced differentiation of mouse iPS cells into NPCs by inhibiting the cAMP/protein kinase A pathway and CREB activation.

Evidence for prevalent Z = 6 magic number in neutron-rich carbon isotopes

The nuclear shell structure, which originates in the nearly independent motion of nucleons in an average potential, provides an important guide for our understanding of nuclear structure and the underlying nuclear forces. Its most remarkable fingerprint is the existence of the so-called magic numbers of protons and neutrons associated with extra stability. Although the introduction of a phenomenological spin-orbit (SO) coupling force in 1949 helped in explaining the magic numbers, its origins are still open questions. Here, we present experimental evidence for the smallest SO-originated magic number (subshell closure) at the proton number six in 13-20C obtained from systematic analysis of point-proton distribution radii, electromagnetic transition rates and atomic masses of light nuclei. Performing ab initio calculations on 14,15C, we show that the observed proton distribution radii and subshell closure can be explained by the state-of-the-art nuclear theory with chiral nucleon-nucleon and three-nucleon forces, which are rooted in the quantum chromodynamics.

First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph

The masses of ^{246}Es, ^{251}Fm, and the transfermium nuclei ^{249-252}Md and ^{254}No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N=152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ^{246}Es and ^{249,250,252}Md were measured for the first time. Using the masses of ^{249,250}Md as anchor points for α decay chains, the masses of heavier nuclei, up to ^{261}Bh and ^{266}Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ_{2n} derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr.

High repetition pump-and-probe photoemission spectroscopy based on a compact fiber laser system

The paper describes a time-resolved photoemission (TRPES) apparatus equipped with a Yb-doped fiber laser system delivering 1.2-eV pump and 5.9-eV probe pulses at the repetition rate of 95 MHz. Time and energy resolutions are 11.3 meV and ∼310 fs, respectively, the latter is estimated by performing TRPES on a highly oriented pyrolytic graphite (HOPG). The high repetition rate is suited for achieving high signal-to-noise ratio in TRPES spectra, thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence (p) region. TRPES of polycrystalline bismuth (Bi) at p as low as 30 nJ/mm² is demonstrated. The laser source is compact and is docked to an existing TRPES apparatus based on a 250-kHz Ti:sapphire laser system. The 95-MHz system is less prone to space-charge broadening effects compared to the 250-kHz system, which we explicitly show in a systematic probe-power dependency of the Fermi cutoff of polycrystalline gold. We also describe that the TRPES response of an oriented Bi(111)/HOPG sample is useful for fine-tuning the spatial overlap of the pump and probe beams even when p is as low as 30 nJ/mm².

Histamine Amplifies Immune Response of Gingival Fibroblasts

Histamine is an important mediator in immune responses, but it is unclear whether periodontal tissues express histamine receptors and are able to respond to histamine. We hypothesized that histamine, inflammatory cytokines, and bacterial components released in inflamed periodontal tissues may be synergistically involved in periodontitis. The present study showed that human gingival fibroblasts mainly express histamine receptor H1R, and responded to histamine to produce interleukin (IL)-8. Stimulation of gingival fibroblasts with tumor necrosis factor-α, IL-1α, and lipopolysaccharide markedly induced IL-8 production, and the IL-8 production was synergistically augmented in the presence of or pre-treatment with histamine. Selective inhibitors of mitogen-activated protein kinases (MAPKs), nuclear factor (NF)-κB, and phospholipase C (PLC) significantly inhibited the synergistic effect. These results indicate that histamine induces IL-8 production from gingival fibroblasts through H1R, and synergistically augments the inflammatory stimuli by amplification of the MAPK and NF-κB through H1R-linked PLC. Abbreviations used: HDC, histidine decarboxylase; LPS, lipopolysaccharide; IL, interleukin; TNF, tumor necrosis factor; HR, histamine receptor; PLC, phospholipase C; MAPK, mitogen-activated protein kinase; NF, nuclear factor; ERK, extracellular signal-related kinase; JNK, c-Jun N-terminal kinase; R, receptor; TLR, Toll-like receptor; α-MEM, alpha-minimum essential medium; FCS, fetal calf serum; RT-PCR, reverse-transcriptase polymerase chain-reaction; ELISA, enzyme-linked immunosorbent assay; SD, standard deviation; LDH, lactate dehydrogenase.

Identification of the Lowest T=2, J^{π}=0^{+} Isobaric Analog State in ^{52}Co and Its Impact on the Understanding of β-Decay Properties of ^{52}Ni

Masses of ^{52g,52m}Co were measured for the first time with an accuracy of ∼10  keV, an unprecedented precision reached for short-lived nuclei in the isochronous mass spectrometry. Combining our results with the previous β-γ measurements of ^{52}Ni, the T=2, J^{π}=0^{+} isobaric analog state (IAS) in ^{52}Co was newly assigned, questioning the conventional identification of IASs from the β-delayed proton emissions. Using our energy of the IAS in ^{52}Co, the masses of the T=2 multiplet fit well into the isobaric multiplet mass equation. We find that the IAS in ^{52}Co decays predominantly via γ transitions while the proton emission is negligibly small. According to our large-scale shell model calculations, this phenomenon has been interpreted to be due to very low isospin mixing in the IAS.

Stimulation of 5-HT4 receptor enhances differentiation of mouse induced pluripotent stem cells into neural progenitor cells

Activation of serotonin (5-hydroxytryptamine; 5-HT) receptors plays a role in adult neurogenesis and differentiation of neural progenitor cells (NPC). Herein, we examined the involvement of 5-HT receptors in the differentiation of mouse induced pluripotent stem (iPS) cells into NPC. To induce embryoid body (EB) formation, mouse iPS cells were cultured on ultralow-attachment dishes. All-trans retinoic acid (ATRA; 1 μmol/L) and/or 5-HT (0.03 or 0.1 μmol/L) was added to the EB cultures for 4 days and then EB plated on gelatin-coated plates were cultured for 7 or 14 days. Immunofluorescence staining revealed that mouse iPS cells expressed both 5-HT2A and 5-HT4 receptors and, to a lesser extent, 5-HT1A receptors. Treatment with 5-HT significantly enhanced the ATRA-induced expression of nestin, a specific marker for NPC, and phosphorylation of cAMP response element-binding protein (CREB). Pretreatment of EB cultures with either 1 μmol/L GR113808 (a selective 5-HT4 receptor antagonist) or 1 μmol/L H89 (a protein kinase (PKA) inhibitor) significantly inhibited these effects of 5-HT. These findings suggest that stimulation of 5-HT4 receptors may enhance ATRA-induced neural differentiation of mouse iPS cells through activation of PKA and CREB.

A NovelIn VitroPharmacokinetic/Pharmacodynamic Model Based on Two-Compartment Open Model Used to Simulate Serum Drug Concentration-Time Profiles

An in vitro pharmacokinetic/pharmacodynamic perfusion model that simulates a two-compartment open model of serum drug concentration-time profiles following intravenous bolus injection and infusion was developed and mathematically described. In the present apparatus model, flow was kept in a one-way mode to avoid liquid traffic, and the washout effect seen in dilution models was overcome by embedding the tested bacteria in low melting point agarose gel. The validity of the equations and the reproducibility of the apparatus model were ascertained by simulating the concentration-time profiles of cefazolin and fosfomycin by substitution of their pharmacokinetic parameters obtained from humans for the equations. An empirical regimen 1X(q24h) of 1 g with cefazolin administered by intravenous infusion effectively killed a Staphylococcus aureus strain. The same regimen with fosfomycin produced a marked kill-curve with a fosfomycin-susceptible enterohaemorrhagic Escherichia coli O157:H7, whereas considerable regrowth was observed with a resistant strain. These results indicated that the present model was able to provide a convenient and reliable method for evaluating the efficacy of antimicrobial agents administered by intravenous infusion.

A new objective histological scale for studying human photoaged skin

BACKGROUND

A quantitative understanding of the histological alteration of the skin is important for assessing the severity of photoaging.

METHODS

We performed Elastica-van Gieson staining and immunohistochemistry for decorin on 34 facial skin sections. We evaluated the alteration of collagen fibers and decorin (a modulator for collagen fibrillogenesis), according to the 5 grades of morphological change in elastic fibers that was established by Kligman (1969). The objectivity of a stage (Stages I-VI), which was established in this study, was evaluated using weighted kappa statistical analysis based on the degree of agreement in stage determination by 11 observers using a blind procedure. Correlation between the crow's-feet-area wrinkles grades of another 26 women and stages was also analyzed.

RESULTS

The initial alteration of elastic fibers was observed in the deep dermis. Decorin was not detected in very severely altered skin. Based on the combination of changes in the elastic fibers, collagenic fibers, and decorin, skin tissues were categorized into 6 stages according to severity. The statistical analysis showed almost perfect agreement between observers. Significant positive correlation between stages and wrinkle scores was found.

CONCLUSIONS

We propose a new objective histological scale that is useful for assessing the severity of photoaging.

Effect of nicotine on the proliferation and differentiation of mouse induced pluripotent stem cells

The molecular mechanisms that regulate the proliferation and differentiation of induced pluripotent stem (iPS) cells are of great interest. However, whether stimulation with nicotine enhances the proliferation and differentiation of iPS cells has not been investigated. In the present study, western blot analysis revealed that the α4-nAchR and α7-nAchR are expressed in mouse iPS cells. Mouse iPS cells were treated with nicotine for 24 h under feeder-free conditions. Mouse iPS cells were guided to differentiate into mesodermal progenitor cells on type IV collagen (Col IV)-coated dishes in differentiation medium. Mouse iPS cells were guided to differentiate into neural progenitor cells by embryoid body (EB) formation on ultra-low-attachment dishes. After 4 days of growth, all-trans retinoic acid (ATRA; 1 μM) or nicotine (300 nM) was added to the EB cultures and maintained for additional 4 days and plated onto fibronectincoated plates. A BrdU incorporation assay showed that treatment with 300 nM nicotine significantly increased the DNA synthesis of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells. This effect was significantly inhibited by pretreatment with an α4-nAchR antagonist, an α7-nAchR antagonist, or a CaMKII inhibitor. The differentiation potential of mouse iPS cells into mesodermal progenitor cells or neural progenitor cells was not affected by the nicotine treatment. The present study indicates that stimulation of the α4-nAchR and α7-nAchR may lead to a significant increase in the proliferation of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells through the CaMKII signaling pathway.

β1-adrenoceptor stimulation enhances the differentiation of mouse induced pluripotent stem cells into neural progenitor cells

The cyclic AMP/protein kinase A signaling pathway is thought to be involved in neural differentiation of mesenchymal stem cells. In the present study, we examined the involvement of β-adrenoceptor signaling on the differentiation of mouse induced pluripotent stem (iPS) cells into neural progenitor cells. Mouse iPS cells were cultured on ultra-low-attachment dishes to induce embryoid body (EB) formation. All-trans retinoic acid (ATRA, 1 μM) and/or the β-adrenoceptor agonist l-isoproterenol (0.3 or 1 μM) were added to the EB cultures for 4 days, then EBs were plated on gelatin-coated plates and cultured for 7 or 14 days. Subtype-specific antibody staining revealed that mouse iPS cells express β(1)-adrenoceptors predominantly. Although treatment with l-isoproterenol alone did not affect the expression of Nestin (a specific marker for neural progenitor cells), l-isoproterenol significantly enhanced ATRA-induced Nestin expression. Pretreatment of EBs with either atenolol (a selective β(1)-adrenoceptor antagonist) or H89 (a protein kinase A inhibitor) significantly inhibited the l-isoproterenol-enhancement of ATRA-induced Nestin expression. In addition, the l-isoproterenol treatment significantly enhanced ATRA-induced expression of NeuN (a neuron-specific nuclear protein). These findings suggest that β(1)-adrenoceptor stimulation enhances ATRA-induced neural differentiation of mouse iPS cells.

Interferometric autocorrelation in the ultraviolet utilizing spontaneous parametric down-conversion inside an enhancement cavity

Autocorrelation is a common method to estimate the duration of ultrashort laser pulses. In the ultraviolet (UV) regime it is challenging to employ the process of second-harmonic generation, most prominently due to absorption in nonlinear crystals at very short wavelengths. Here we show how to utilize spontaneous parametric down-conversion (SPDC) to generate an autocorrelation signal in the infrared (IR) for UV pulses. Our method utilizes the nth-order emission of the SPDC process, which occurs for low pumping powers proportional to the nth power of the UV intensity. Thus, counting 2n down-converted photons directly yields the nth-order autocorrelation. The method, now with detection of near-IR photons, is applied to the first direct measurement of ultrashort UV pulses circulating inside a UV enhancement cavity.

Diagnostic usefulness of 3 tesla MRI of the brain for cushing disease in a child

It is sometimes difficult to confirm the location of a microadenoma in Cushing disease. Recently, we experienced an 11-yr-old female case of Cushing disease with hyperprolactinemia. She was referred to our hospital because of decrease of height velocity with body weight gain. On admission, she had typical symptoms of Cushing syndrome. Although no pituitary microadenomas were detected on 1.5 Tesla MRI of the brain, endocrinological examinations including IPS and CS sampling were consistent with Cushing disease with hyperprolactinemia. Oral administration of methyrapone instead of neurosurgery was started after discharge, but subsequent 3 Tesla MRI of the brain clearly demonstrated a 3-mm less-enhanced lesion in the left side of the pituitary gland. Finally, transsphenoidal surgery was performed, and a 3.5-mm left-sided microadenoma was resected. Compared with 1.5 Tesla MRI, 3 Tesla MRI offers the advantage of a higher signal to noise ratio (SNR), which provides higher resolution and proper image quality. Therefore, 3 Tesla MRI is a very useful tool to localize microadenomas in Cushing disease in children as well as in adults. It will be the first choice of radiological examinations in suspected cases of Cushing disease.

Observation of a large reaction cross section in the drip-line nucleus 22C

Reaction cross sections (sigma(R)) for 19C, 20C and the drip-line nucleus 22C on a liquid hydrogen target have been measured at around 40A MeV by a transmission method. A large enhancement of sigma(R) for 22C compared to those for neighboring C isotopes was observed. Using a finite-range Glauber calculation under an optical-limit approximation the rms matter radius of 22C was deduced to be 5.4+/-0.9 fm. It does not follow the systematic behavior of radii in carbon isotopes with N < or = 14, suggesting a neutron halo. It was found by an analysis based on a few-body Glauber calculation that the two-valence neutrons in 22C preferentially occupy the 1s(1/2) orbital.

Identification of proSAAS homologs in lower vertebrates: conservation of hydrophobic helices and convertase-inhibiting sequences

The prohormone convertases (PCs) 1/3 and 2 accomplish the major proteolytic cleavage events in neuroendocrine tissues; each of these convertases has a small associated binding protein that inhibits convertase action in the secretory pathway. The proSAAS protein binds to PC1/3, whereas the 7B2 protein binds to PC2. However, both convertase-binding proteins are more widely expressed than their cognate enzymes, suggesting that they may perform other functions as well. All known mammalian proSAASs are over 85% conserved; thus, identifying functionally important segments has been impossible. Here, we report the first identification of nonmammalian proSAAS molecules, from Xenopus and zebrafish (Danio rerio). Although these two proteins show an overall amino acid sequence identity of only 29 and 30% with mouse proSAAS, two 14-16 residue hydrophobic segments (predicted to form alpha-helices) and two, nine through 11 residue sequences containing basic convertase cleavage sites are highly conserved; therefore, these sequences may be of functional importance. Confidence that these nonmammalian molecules represent authentic proSAAS is supported by the finding that both inhibit mouse PC1/3 with nanomolar inhibition constants; human furin was not inhibited. In vitro, the two proteins were cleaved by PC2 and furin to three or more peptide products. Both zebrafish and Xenopus proSAAS exhibited neural and endocrine distributions, as assessed by in situ and PCR experiments, respectively. In summary, the identification of proSAAS molecules in lower vertebrates provides clues as to functional regions within this widely expressed neuroendocrine protein.

High harmonic frequency combs for high resolution spectroscopy

We generated a series of harmonics in a xenon gas jet inside a cavity seeded by pulses from a Ti:sapphire mode-locked laser with a repetition rate of 10.8 MHz. Harmonics up to 19th order at 43 nm were observed with plateau harmonics at the microW power level. An elaborate dispersion compensation scheme and the use of a moderate repetition rate allowed for this significant improvement in output power of the plateau harmonics of 4 orders of magnitude over previous results. With this power level and repetition rate, high-resolution spectroscopy in the extreme ultraviolet region becomes conceivable. An interesting target would be the 1S-2S transition in hydrogenlike He+ at 60 nm.

Non-collinear high harmonic generation: a promising outcoupling method for cavity-assisted XUV generation

We present first experimental results of our investigation of non-collinear high harmonic generation (NCHHG) with a chirped pulse amplification system. Collimated high harmonic radiation of higher than 9th order is observed along the bisector of two fundamental beams crossing in a xenon gas target. The obtained results show that cavity-assisted non-collinear high harmonic generation is a promising candidate for efficient generation and outcoupling of extreme ultraviolet (XUV) radiation.

EXpression of ErbB proteins in human prostate

ErbB proteins are widely expressed in human and animal tissues, notably in cells of epithelial or neuroendocrine origin. Protein expression and interactions of ErbBs were examined in prostate cancer specimens. Expression of ErbB1-4 proteins was determined with immunohistochemical methods using each monoclonal antibody in 20 prostatic adenocarcinomas. The 4 ErbB proteins were widely expressed in normal, hyperplastic and cancerous tissues of the prostate. ErbBs may contribute to normal development or tumor growth and progression in human prostate.

Vanishing N = 20 shell gap: study of excited states in (27,28)Ne

This Letter reports on the (1)H((28)Ne, (28)Ne) and (1)H((28)Ne, (27)Ne) reactions studied at intermediate energy using a liquid hydrogen target. From the cross section populating the first 2(+) excited state of (28)Ne, and using the previously determined BE(2) value, the neutron quadrupole transition matrix element has been calculated to be M(n)=13.8 +/- 3.7 fm(2). In the neutron knockout reaction, two low-lying excited states were populated in (27)Ne. Only one of them can be interpreted by the sd shell model while the additional state may intrude from the fp shell. These experimental observations are consistent with the presence of fp shell configurations at low excitation energy in (27,28)Ne nuclei caused by a vanishing N=20 shell gap at Z=10.

Assignment of 101 genes localized in HSA10 to a swine RH (IMpRH) map to generate a dense human-swine comparative map

Economically important traits such as growth and backfat in pigs have been shown to be influenced by genes in swine chromosome (SSC) 10q12-->qter corresponding to human chromosome (HSA) 10p. However, since gene information in the swine chromosomal region was limited, we attempted to generate a dense comparative map between SSC10 and HSA10 by mapping the 115 genes of HSA10 to a swine RH map (IMpRH map). In the mapping ten genes were assigned to SSC10, 88 to SSC14, and one to SSC3. One gene was suggested to link to SSC3, and another to SSC9. The correspondences between HSA10 and SSC10 and between HSA10 and SSC14 were essentially consistent with the observations obtained from bi/uni-directional chromosome painting or other results. This study further indicated that a large number of intrachromosomal rearrangements occurred in the synteny-conserved regions following species separation.

Shell structure of the near-dripline nucleus 23O

Breakup reactions were used to study the ground-state configuration of the neutron-rich isotope 23O. The 22O fragments produced in one-nucleon removal from 23O at 938 MeV/nucleon in a carbon target were detected in coincidence with deexciting gamma rays. The widths of the longitudinal momentum distributions of the 22O fragments and the one-neutron removal cross sections were interpreted in the framework of a simple theoretical model which favors the assignment of Ipi = 1/2+ to the 23O ground state.

Probiotic bifidobacteria protect mice from lethal infection with Shiga toxin-producing Escherichia coli O157:H7

The anti-infectious activity of probiotic Bifidobacteria against Shiga toxin-producing Escherichia coli (STEC) O157:H7 was examined in a fatal mouse STEC infection model. Stable colonization of the murine intestines was achieved by the oral administration of Bifidobacterium breve strain Yakult (naturally resistant to streptomycin sulfate) as long as the mice were treated with streptomycin in their drinking water (5 mg/ml). The pathogenicity of STEC infection, characterized by marked body weight loss and subsequent death, observed in the infected controls was dramatically inhibited in the B. breve-colonized group. Moreover, Stx production by STEC cells in the intestine was almost completely inhibited in the B. breve-colonized group. A comparison of anti-STEC activity among several Bifidobacterium strains with natural resistance to streptomycin revealed that strains such as Bifidobacterium bifidum ATCC 15696 and Bifidobacterium catenulatum ATCC 27539(T) did not confer an anti-infectious activity, despite achieving high population levels similar to those of effective strains, such as B. breve strain Yakult and Bifidobacterium pseudocatenulatum DSM 20439. The effective strains produced a high concentration of acetic acid (56 mM) and lowered the pH of the intestine (to pH 6.75) compared to the infected control group (acetic acid concentration, 28 mM; pH, 7.15); these effects were thought to be related to the anti-infectious activity of these strains because the combination of a high concentration of acetic acid and a low pH was found to inhibit Stx production during STEC growth in vitro.

Development of a lethal Shiga toxin-producing Escherichia coli-infection mouse model using multiple mitomycin C treatment

The aim of this study was to develop a lethal Shiga toxin-producing Escherichia coli (STEC) infection model in mice. A small inoculum of 5 x 10(3) CFU of STEC strain 89020087 to mice treated with streptomycin sulfate in drinking water (5 mg/ml) lead to marked increase in the excretion of the bacteria of up to 10(9)CFU/g feces within 18 h after the challenge. Combination of administration of 5 x 10(3) CFU of STEC followed by mitomycin C (MMC) treatment during the late log phase to the early stationary phase of STEC growth in the intestine lead to fatal infection. Periodic analysis showed that there is transient but dramatic increase in the Stxs (Stx1 and Stx2) concentration in the lower intestines after multiple MMC treatment. Histopathological analysis and blood chemistry revealed damages in both kidney and hematopoietic organs but not in the brain. Comparison of the virulence of 11 different STEC strains revealed that only strains which produced high amount of Stx2 responding to MMC treatment and exerted lethal toxicity to mice, suggesting that Stx2 plays a pivotal role in the lethal infection of STEC in the mouse model.

Coulomb dissociation of 8B and the low-energy cross section of the 7Be(p,gamma)8B solar fusion reaction

An exclusive measurement of the Coulomb breakup of 8B into 7Be+p at 254A MeV allowed the study of the angular correlations of the breakup particles. These correlations demonstrate clearly that E1 multipolarity dominates and that E2 multipolarity can be neglected. By using a simple single-particle model for 8B and treating the breakup in first-order perturbation theory, we extract a zero-energy S factor of S17(0)=18.6+/-1.2+/-1.0 eV b, where the first error is experimental and the second one reflects the theoretical uncertainty in the extrapolation.

Therapeutic guidelines for the treatment of generalized pustular psoriasis (GPP) based on a proposed classification of disease severity

Generalized pustular psoriasis (GPP) is a rare but notoriously recalcitrant cutaneous diseases. Therefore, there have been few reports of more than ten patients with GPP who were treated at the same institution. The severity of this disease and its response to each therapeutic modality vary among patients. In some GPP is life-threatening, but in others it may show a benign, chronic course for a long period of time. Before starting treatment, a knowledge of the therapeutic efficacy and side effects of each drug used in the treatment of GPP is necessary. In our multicenter study, we compared the effectiveness of and adverse reactions to several systemically administered drugs. Following the development of a unique classification of the disease severity based on scoring the clinical symptoms and the laboratory findings, we propose here therapeutic guidelines for the treatment of GPP.

Experimental evidence for the existence of 7H and for a specific structure of 8He

Experimental search for the superheavy 7H isotope was performed in the reaction p(8He,pp)7H with the 8He beam at 61.3A MeV. The evidence for existence of the 7H state near the t+4n threshold was obtained. In the same experiment, the p(8He,t) reaction populating the ground and excited 2(+) state of 6He was investigated. The obtained results argue on a specific structure of the 8He ground state containing the 6He subsystem in the excited 2(+) state with a large weight.

Photonic crystal waveguides utilizing a modulated lattice structure

We experimentally demonstrate a new class of optical waveguide consisting of a-Si/SiO(2) autocloned photonic crystals with modulated lattice structure. The waveguide utilizes the macroscopic form birefringence of photonic crystals and confines light by the difference in the effective refractive index. A monopole modal field with spot diameters of 6.9 micromx6.5 microm was observed at a wavelength of 1.55 microm. The propagation loss of the waveguide at the wavelength was found to be ~4.2 dB/mm at most.

Genetic variation in the flanking regions of Shiga toxin 2 gene in Shiga toxin-producing Escherichia coli O157:H7 isolated in Japan

We found frequent IS1 integration nearby the stx(2) gene during in vitro mutagenesis of an stx(2) variant, stx(2vhd). To examine the possibility that such insertions have been contributing to generate new stx(2) variants, we screened 86 strains of Escherichia coli O157:H7 isolated in Japan for variations in the ca. 4-kb region flanking the stx(2) locus using PCR methods. Two major classes were identified based on the PCR amplicon size. DNA sequence analysis revealed that the stx(2) subtype of the two classes were stx(2) (referred to as stx(2-EDL933)) and stx(2vhd). IS1203v insertions were found in three stx(2vhd)-positive strains and two stx(2-EDL933)-positive strains, and no other insertions were found. These results suggest that the DNA sequences surrounding the stx(2) genes are preferably integrated by IS1203v in wild-type Shiga toxin-producing E. coli strains.

Momentum distribution of 15B fragments from the breakup of 17B

The two-neutron removal cross section (sigma(-2n)) and the longitudinal momentum distribution of 15B fragments from the breakup of 17B on 9Be were measured at 70A MeV. The distribution in the projectile rest frame is characterized by a FWHM of 80+/-10 MeV/c for 15B. The sigma(-2n) is found to be 0.22+/-0.05 b. A Glauber-type analysis of the data provides clear evidence of a two-neutron halo structure in 17B.

Corneodesmosin DNA polymorphisms in MHC haplotypes and Japanese patients with psoriasis

In order to examine the relationship between corneodesmosin (CDSN) and psoriasis we have determined the presence of CDSN polymorphisms by DNA sequencing in (a) nine B-LCL cell lines of major histocompatibility complex ancestral haplotypes known to be associated with psoriasis vulgaris including 13.1AH, 46.1AH, 46.2 and 57.1AH, and in (b) a group of 267 unrelated individuals comprising Japanese psoriasis patients (n = 101) and Japanese subjects without the disease (n = 166). Three novel CDSN gene sequences were identified. In addition, we have classified the 18 alleles into seven main groups based on phylogeny of non-synonymous substitutions. However, we have found no statistically significant differences between the patients and the unaffected individuals in any of these groups. These findings indicate that CDSN is not a major psoriasis susceptibility gene.

Tsutsugamushi disease in Kanagawa Prefecture, Japan: clinical report of two cases and survey of other incidences in 1998

Tsutsugamushi disease is characterized by the early appearance of a black crust at the bitten area and the subsequent development of macular or macropapular rush on the whole body with high fever. While treatment with tetracycline derivatives and chloramphenicols is effective, delayed diagnosis or inappropriate treatment will lead to fatality. In this report, we describe two typical cases of tsutsugamushi disease and discuss other incidences in Kanagawa Prefecture, Japan, in 1998. One of the present two patients was diagnosed to be a case of the new type by Kawasaki strain of Rickettsia tsutsugamushi, while responsible strain was not identified for the other case. Since the disease is spreading widely even to suburban areas, we emphasize the need to consider the possible diagnosis of tsutsugamushi disease in patients with generalized eruption and high fever.

Effects of heat exposure on adrenergic modulation of insulin and glucagon secretion in sheep

The effects of heat exposure on the adrenergic modulation of pancreatic secretion were investigated. Five ewes fed at maintenance level (ME base) were housed in thermoneutral (TN; 20 degrees C) and hot (30 degrees C) environments. Heat exposure caused an increase in respiration rate and a slightly higher rectal temperature, and decreases in basal insulin and glucose concentrations. Infusions of saline plus epinephrine caused increases in glucagon and glucose concentrations, and no significant change in insulin secretion. Phentolamine (an adrenergic alpha-antagonist) plus epinephrine augmented insulin secretion; however, this insulin secretory response was inhibited by heat exposure. Propranolol (a beta-antagonist) plus epinephrine produced a slight decrease in insulin secretion in the TN environment, whereas no effect was observed during heat exposure. While glucagon secretion through alpha-adrenergic stimulation was not affected by heat exposure, homeostatic signals controlling insulin release seemed to be affected during heat exposure. We thus hypothesised that insulin concentration is decreased in sheep fed at maintenance level in hot environments, and that this response is mediated in part by a modulation of beta-adrenergic function.

Isolation and characterization of the rat prolactin-releasing peptide gene: multiple TATA boxes in the promoter region

The prolactin-releasing peptide (PrRP) gene is a novel bioactive peptide expressed in very restricted regions in the brain. To explore the molecular mechanism of PrRP gene expression, we cloned and characterized the gene and its promoter region. The gene spans approximately 2.4 kb and contains three exons and two introns. 3'RACE analysis showed that a polyadenylation signal 103 bp downstream from the stop codon was functional. Primer extension analysis indicated three transcriptional start sites (TSSs) 92, 199, and 325 bp upstream from the translational start site. Interestingly, in addition to the putative binding sites for SP1-1, AP-2, and Oct-2A, three characteristic TATA boxes were identified close to these TSSs. Transient transfection study using a series of deletion mutants revealed that the middle TATA box is important for the promoter activity. Furthermore, the cloned 1.6 kb promoter region was active only in neuron- and pituitary-derived cell lines, and the promoter region -1600 approximately -800 bp worked as a negative regulatory element. We demonstrated for the first time, the genomic organization and promoter function of the PrRP gene, and this knowledge will facilitate elucidation of transcriptional control of the PrRP gene.

Congenital giant aneurysm of the left atrial appendage mimicking pericardial absence case report

A 25-year-old man was found to have an abnormal cardiac contour on a chest radiograph, and was referred. Transesophageal echocardiography suggested herniation of the left atrial appendage (LAA) through a gap in the pericardium, and magnetic resonance imaging indicated congenital partial absence of the pericardium. Cardiac dysfunction was caused by compression from the enlarged left atrium and thrombi were thought to be present in the appendage, so surgery was performed. The intraoperative diagnosis was congenital LAA aneurysm. Although distinguishing between congenital LAA aneurysm and congenital absence of the pericardium is reported to be possible with magnetic resonance imaging, we were unable to so in this case.

Labor reduction for mold preparation of a commercial titanium cast denture system using a heat-shock method

The purpose of this study was to investigate the application of a heat-shock method to fabricate titanium cast plates. Duplications of a maxillary model were prepared using DM under different firing schedules. Molds with patterns on the duplications were made by an outer investment (D), followed by heat shock at 850 degrees C. Duplications heat shocked at 850 degrees C after 30 min from mixing exploded within a few minutes. This explosion was successfully avoided by a drying procedure prior to the heat-shock. The molds were available for the heat shock at 850 degrees C when the duplicate models were prepared by firing either using the conventional method and the heat shock above method described. Therefore, we could reduce the preparation time from about 16 hr with the conventional method to about 10 hr at the longest with the heat-shock method. These results suggested that the heat-shock method was labor-saving for fabricating titanium cast denture plates when controlling preliminary conditions prior to use.