Fate of charge order in overdoped La-based cuprates

In high-temperature cuprate superconductors, stripe order refers broadly to a coupled spin and charge modulation with a commensuration of eight and four lattice units, respectively. How this stripe order evolves across optimal doping remains a controversial question. Here we present a systematic resonant inelastic x-ray scattering study of weak charge correlations in La2-xSrxCuO4 and La1.8-xEu0.2SrxCuO4. Ultra high energy resolution experiments demonstrate the importance of the separation of inelastic and elastic scattering processes. Long-range temperature-dependent stripe order is only found below optimal doping. At higher doping, short-range temperature-independent correlations are present up to the highest doping measured. This transformation is distinct from and preempts the pseudogap critical doping. We argue that the doping and temperature-independent short-range correlations originate from unresolved electron-phonon coupling that broadly peaks at the stripe ordering vector. In La2-xSrxCuO4, long-range static stripe order vanishes around optimal doping and we discuss both quantum critical and crossover scenarios.

Evidence for a Square-Square Vortex Lattice Transition in a High-T_{c} Cuprate Superconductor

Using sound velocity and attenuation measurements in high magnetic fields, we identify a new transition in the vortex lattice state of La_{2-x}Sr_{x}CuO_{4}. The transition, observed in magnetic fields exceeding 35 T and temperatures far below zero field T_{c}, is detected in the compression modulus of the vortex lattice, at a doping level of x=p=0.17. Our theoretical analysis based on Eilenberger's theory of the vortex lattice shows that the transition corresponds to the long-sought 45° rotation of the square vortex lattice, predicted to occur in d-wave superconductors near a van Hove singularity.

Unveiling Unequivocal Charge Stripe Order in a Prototypical Cuprate Superconductor

In the cuprates, high-temperature superconductivity, spin-density-wave order, and charge-density-wave (CDW) order are intertwined, and symmetry determination is challenging due to domain formation. We investigated the CDW in the prototypical cuprate La_{1.88}Sr_{0.12}CuO_{4} via x-ray diffraction employing uniaxial pressure as a domain-selective stimulus to establish the unidirectional nature of the CDW unambiguously. A fivefold enhancement of the CDW amplitude is found when homogeneous superconductivity is partially suppressed by magnetic field. This field-induced state provides an ideal search environment for a putative pair-density-wave state.

Evaluation of apocynin in vitro on high glucose-induced oxidative stress on tenocytes

Aims

The purpose of this study was to evaluate the in vitro effects of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase (NOX) and a downregulator of intracellular reactive oxygen species (ROS), on high glucose-induced oxidative stress on tenocytes.

Methods

Tenocytes from normal Sprague-Dawley rats were cultured in both control and high-glucose conditions. Apocynin was added at cell seeding, dividing the tenocytes into four groups: the control group; regular glucose with apocynin (RG apo+); high glucose with apocynin (HG apo+); and high glucose without apocynin (HG apo–). Reactive oxygen species production, cell proliferation, apoptosis and messenger RNA (mRNA) expression of NOX1 and 4, and interleukin-6 (IL-6) were determined in vitro.

Results

Expression of NOX1, NOX4, and IL-6 mRNA in the HG groups was significantly higher compared with that in the RG groups, and NOX1, NOX4, and IL-6 mRNA expression in the HG apo+ group was significantly lower compared with that in the HG apo– group. Cell proliferation in the RG apo+ group was significantly higher than in the control group and was also significantly higher in the HG apo+ group than in the HG apo– group. Both the ROS accumulation and the amounts of apoptotic cells in the HG groups were greater than those in the RG groups and were significantly less in the HG apo+ group than in the HG apo– group.

Conclusion

Apocynin reduced ROS production and cell death via NOX inhibition in high-glucose conditions. Apocynin is therefore a potential prodrug in the treatment of diabetic tendinopathy.

Cite this article:Bone Joint Res 2020;9(1):23–28.

High-Temperature Charge-Stripe Correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}

We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

Coexistence of the Kondo effect and spin glass physics in Fe-doped NbS2

We report the coexistence of the Kondo effect and spin glass behavior in Fe-doped NbS₂ single crystals. The Fe _x NbS₂ shows the resistance minimum and negative magnetoresistance due to the Kondo effect, and exhibits no superconducting behavior at low temperatures. The resistance curve follows a numerical renormalization-group theory using the Kondo temperature [Formula: see text] K for x  =  0.01 as evidence of Kondo effect. Scanning tunneling microscope/spectroscopy (STM/STS) revealed the presence of Fe atoms near sulfur atoms and asymmetric spectra. The magnetic susceptibility exhibits a feature of spin glass. The static critical exponents determined by the universal scaling of the nonlinear part of the susceptibility suggest a three-dimensional Heisenberg spin glass. The doped-Fe atoms in the intra- and inter-layers revealed by the x-ray result can realize the coexistence of the Kondo effect and spin glass.

Direct observation of orbital hybridisation in a cuprate superconductor

The minimal ingredients to explain the essential physics of layered copper-oxide (cuprates) materials remains heavily debated. Effective low-energy single-band models of the copper–oxygen orbitals are widely used because there exists no strong experimental evidence supporting multi-band structures. Here, we report angle-resolved photoelectron spectroscopy experiments on La-based cuprates that provide direct observation of a two-band structure. This electronic structure, qualitatively consistent with density functional theory, is parametrised by a two-orbital (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d_{x^2 - y^2}$$\end{document}dx2-y2 and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d_{z^2}$$\end{document}dz2) tight-binding model. We quantify the orbital hybridisation which provides an explanation for the Fermi surface topology and the proximity of the van-Hove singularity to the Fermi level. Our analysis leads to a unification of electronic hopping parameters for single-layer cuprates and we conclude that hybridisation, restraining d-wave pairing, is an important optimisation element for superconductivity.

The essential physics of cuprate superconductors is often described by single-band models. Here, Matt et al. report direct observation of a two-band electronic structure in La-based cuprates.

Evidence for carrier localization in the pseudogap state of cuprate superconductors from coherent quench experiments

A 'pseudogap' was introduced by Mott to describe a state of matter that has a minimum in the density of states at the Fermi level, deep enough for states to become localized. It can arise either from Coulomb repulsion between electrons, and/or incipient charge or spin order. Here we employ ultrafast spectroscopy to study dynamical properties of the normal to pseudogap state transition in the prototype high-temperature superconductor Bi2Sr2CaCu2O8+δ. We perform a systematic temperature and doping dependence study of the pseudogap photodestruction and recovery in coherent quench experiments, revealing marked absence of critical behaviour of the elementary excitations, which implies an absence of collective electronic ordering beyond a few coherence lengths on short timescales. The data imply ultrafast carrier localization into a textured polaronic state arising from a competing Coulomb interaction and lattice strain, enhanced by a Fermi surface instability.

Comparison of the NMIJ and the ARPANSA standards for absorbed dose to water in high-energy photon beams

The authors report the results of an indirect comparison of the standards of absorbed dose to water in high-energy photon beams from a clinical linac and (60)Co radiation beam performed between the National Metrology Institute of Japan (NMIJ) and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Three ionisation chambers were calibrated by the NMIJ in April and June 2013 and by the ARPANSA in May 2013. The average ratios of the calibration coefficients for the three ionisation chambers obtained by the NMIJ to those obtained by the ARPANSA were 0.9994, 1.0040 and 1.0045 for 6-, 10- and 15-MV (18 MV at the ARPANSA) high-energy photon beams, respectively. The relative standard uncertainty of the value was 7.2 × 10(-3). The ratio for (60)Co radiation was 0.9986(66), which is consistent with the results published in the key comparison of BIPM.RI(I)-K4.

Pitfalls in mouse norovirus (MNV) detection in fecal samples using RT-PCR, and construction of new MNV-specific primers

The murine norovirus (MNV), which belongs to the Caliciviridae family, is prevalent in laboratory mice. Since this virus affects macrophages and dendritic cells, infected mice are not suitable for immunological investigations, making it important to detect MNV infections accurately. When we tested RNA extracts derived from mouse feces for MNV detection using nested RT-PCR with a set of MNV-specific primers reported by Goto et al. (Exp. Anim. 58: 135-140, 2009), we found that these primers amplified not only an MNV-specific signal but also amplified a relatively weak signal with a size almost identical to that of the specific signal. Analysis of the nucleotide sequence of this amplified signal revealed that it was at least 98% identical to the exophosphatase gene of a commensal bacterium, Bacteroides vulgatus. Subsequent analysis showed that the signal amplified with a pair of nested primers was from DNA derived from B. vulgatus, which is sometimes present in SPF laboratory mouse feces, and the nested primers used were both partly homologous with the B. vulgatus nucleotide sequence. We thus designed a new set of nested RT-PCR primers that was not cross-reactive with the B. vulgatus genome. PCR products amplified by the newly designed primers were at least 89.3% identical to the MNV RNA polymerase gene in all cases. Our findings demonstrated that the primer set we designed was suitable for detecting an MNV-specific signal without cross-reacting with B. vulgatus DNA in mouse feces.

Anesthetic effects of a mixture of medetomidine, midazolam and butorphanol in two strains of mice

The combination of ketamine and xylazine is a widely used anesthetic for laboratory animals. However, due to an abuse problem in Japan, ketamine has been specified as a narcotic since 2007. Instead of using ketamine, Kawai et al. reported an injectable formula with an equivalent effect to the mixture of ketamine and xylazine [11]. The mixture of 0.3 mg/kg body weight (b.w.) medetomidine (Med.), 4.0 mg/kg b.w. midazoram (Mid.), and 5.0 mg/kg b.w. butorphanol (But.) produced an anesthetic duration of around 40 min in outbred ICR mice. However, the anesthetic effect of the mixture for inbred mice strains remains unknown. Therefore, we examined anesthetic effects of the mixture of Med., Mid., and But. in the BALB/c and C57BL/6J strains. After intraperitoneal injection into mice, right front paw, left hind paw, and tail pinch reflexes as well as corneal and righting reflexes were observed. Every 5 min, we scored each reflex category as 0 for reaction or 1 for no reaction. As long as the total score was at least 4 out of 5, we considered the mixture as putting a mouse in a surgical anesthetic state. The mixture produced an anesthetic duration of more than 45 min in both strains of mice. These results indicate that the mixture of Med., Mid., and But. can be a useful and effective anesthesia for the BALB/c and C57BL/6J strains of inbred mice as well as outbred ICR mice.

A standard for absorbed dose rate to water in a 60Co field using a graphite calorimeter at the National Metrology Institute of Japan

A primary standard for the absorbed dose rate to water in a ⁶⁰Co radiation field has been newly established at the National Metrology Institute of Japan. This primary standard combines the calorimetric measurements using a graphite calorimeter with the ionometric measurements using a thick-walled graphite cavity ionisation chamber. The calorimeter is operated in the constant temperature mode using AC Wheatstone bridges. The absorbed dose rate to water was determined to be 12 mGy s⁻¹ at a point of 1 m from the radiation source and at a water depth of 5 g cm⁻². The uncertainty on the calibration coefficient in terms of the absorbed dose to water of an ionisation chamber using this standard was estimated to be 0.39 % (k=1).

Effect of three types of mixed anesthetic agents alternate to ketamine in mice

Ketamine is usually used for murine anesthesia in animal experiments with other anesthetics for its sedation and analgesic effects. However, ketamine was categorized as a narcotic drug in Japan on January 1, 2007. After this act came into effect, a narcotic handling license became necessary for using and possessing ketamine. Pentobarbital sodium, which is also used for laboratory animal experiments as Nembutal, is no longer being manufactured. For these reasons, other anesthetic agents that can be used without a license are needed. In this paper, we examined the use of anesthetics other than ketamine and pentobarbital sodium. A combination anesthetic (M/M/B: 0.3/4/5) was prepared with 0.3 mg/kg of medetomidine, 4.0 mg/kg of midazolam, and 5.0 mg/kg of butorphanol. The anesthetics were administered to male ICR mice by intraperitoneal injection. In order to assess anesthetic depth and duration, we stimulated the mice directly after loss of righting reflexes to recovery of these same reflexes and then recorded four parameters--a tail pinch reflex, a pedal withdrawal reflex in the forelimbs, a pedal withdrawal reflex in the hindlimbs, and corneal reflex. Each parameter was scored, and the anesthetic depth, expressed by the total score, was summed. The surgical anesthesia duration of M/M/B: 0.3/4/5 mg/kg was almost identical to the surgical anesthetic duration with a ketamine and xylazine mixture (80-8 mg/kg). These data suggested that mice can be anesthetized by M/M/B: 0.3/4/5 as an alternate to ketamine. We thus can recommend M/M/B: 0.3/4/5 for murine surgical anesthesia.

A randomized, controlled trial of fingolimod (FTY720) in Japanese patients with multiple sclerosis

BACKGROUND

Fingolimod (FTY720) has previously shown clinical efficacy in phase II/III studies of predominantly Caucasian populations with multiple sclerosis (MS).

OBJECTIVES

To report six-month efficacy and safety outcomes in Japanese patients with relapsing MS treated with fingolimod.

METHODS

In this double-blind, parallel-group, phase II study, 171 Japanese patients with relapsing MS were randomized to receive once-daily fingolimod 0.5 mg or 1.25 mg, or matching placebo for six months. The primary and secondary endpoints were the percentages of patients free from gadolinium (Gd)-enhanced lesions at months 3 and 6, and relapses over six months, respectively; safety outcomes were also assessed.

RESULTS

147 patients completed the study. Higher proportions of patients were free from Gd-enhanced lesions at months 3 and 6 with fingolimod (0.5 mg: 70%, p = 0.004; 1.25 mg: 86%, p < 0.001) than with placebo (40%). Odds ratios for the proportions of relapse-free patients over six months favoured fingolimod versus placebo but were not significant. Adverse events related to fingolimod included transient bradycardia and atrioventricular block at treatment initiation, and elevated liver enzyme levels.

CONCLUSIONS

This study demonstrated the clinical efficacy of fingolimod for the first time in Japanese patients with MS, consistent with the established effects of fingolimod in Caucasian patients.

Chiral charge-density waves

We discovered the chirality of charge-density waves (CDW) in 1T-TiSe₂ by using STM and time-domain optical polarimetry. We found that the CDW intensity becomes Ia₁∶Ia₂∶Ia₃ = 1∶0.7 ± 0.1∶0.5 ± 0.1, where Ia(i) (i=1,2,3) is the amplitude of the tunneling current contributed by the CDWs. There were two states, in which the three intensity peaks of the CDW decrease clockwise and anticlockwise. The chirality in CDW results in the threefold symmetry breaking. Macroscopically, twofold symmetry was indeed observed in optical measurement. We propose the new generalized CDW chirality H(CDW) ≡ q₁·(q₂×q₃), where q(i) are the CDW q vectors, which is independent of the symmetry of components. The nonzero H(CDW)-the triple-q vectors do not exist in an identical plane in the reciprocal space-should induce a real-space chirality in CDW system.

Ectopic ossification with haematopoietic bone marrow in the heart valves of a crossbred heavy horse

Ectopic bone formation in the left atrioventricular valves and cardiac fibroskeleton, with systemic circulatory disturbance, is reported in a 4-year-old crossbred heavy horse. Microscopically, there was fibrosis, chondral metaplasia and mature bone, with bone marrow within the left atrioventricular cusps and in the annuli of the aortic and right atrioventricular valves.

Development of improved free-air ionisation chamber as absolute dosimetry standard for low-energy X rays in INER

The National Radiation Standard Laboratory of the Institute of Nuclear Energy Research (INER) designed and constructed an improved Attix style free-air ionisation chamber (FAC) for low-energy X-ray measurements. Clinically, X rays in this energy range are used in mammography radiology. This chamber is also used to perform air-kerma measurements. The original Attix two-sectional design was redesigned by INER using the piston design. The correction factors were determined experimentally for volume estimation, ion recombination and air attenuation. The aperture transmission, wall transmission, electron loss and photon scatter correction factors were determined using Monte Carlo calculations. INER established the Bureau International des Poids et Mesures (BIPM) X-ray beam code and performed a comparison of secondary standard air-kerma calibration factors for 10-50 kV low- energy X rays to verify the experimental accuracy and measurement consistency of the improved chamber. The INER-NMIJ/National Institute of Advanced Industrial Science and Technology (AIST) experimental results comparison using a transfer chamber yielded a difference <1.0% at the 95% confidence level in calibration factors. The overall uncertainty for the X-ray measurement in terms of air kerma was <0.6% at the 95% confidence level. These results indicated that the improved FAC is capable of serving as a primary standard as well as a trace standard in low-energy X-ray calibration services in Taiwan and even forming a basis for the future mammography X-ray air-kerma primary standard.

Implementation of the Three Rs in Biomedical Research —Has the Turn of the Century Turned the Tide?

There has been increasing pressure from the public against animal experimentation for testing and research purposes. The Three Rs ( replacement, reduction, and refinement) principle is thought to be a key foundation concept in optimising the welfare of animals used in experiments. This retrospective study attempts to investigate the transition of the Three Rs in biomedical research through a review of articles published in Nature Medicine. We categorised all of the articles published in Nature Medicine from 1998 to 2003, on the basis of the pain and distress of the animals used in the experiments featured in the analysed article. We found there were no large fluctuations in the distribution of these categories over this time period. We also examined each article for the presence of a statement relating to the humane use of laboratory animals, and found that the number of articles which included such a statement dramatically increased in 2002. Over the years studied, there was a decreasing trend in the total number of animal types used for the experiments in the articles. Our results suggest that: a) more encouragement by journal editors might improve the attitude of scientists in terms of animal welfare; and b) the progress of replacement appears to be a more long-term effort in the field of biomedical research.

Epithelioid cells in mediastinal lymph nodes of cattle without cancer

Epithelioid cells are found in lymph nodes in cases of metastatic carcinoma; however, epithelioid cells with benign features have also been discovered incidentally in lymph nodes. Epithelioid cells were observed in mediastinal lymph nodes of cattle without cancer during routine diagnostic necropsy. To explain this finding, the authors evaluated the prevalence and histopathologic, immunohistochemical, and ultrastructural features retrospectively using mediastinal lymph nodes from 110 cattle and found that 66 of the lymph nodes contained epithelioid cells. In all 66 nodes, most of the epithelioid cells were individual or aggregated in nodal sinuses; in 21 nodes, some epithelioid cells formed tubular structures. The individual and aggregated epithelioid cells were mostly considered to be mesothelial in origin by immunohistochemical and ultrastructural examination; presumably, they entered the lymph nodes via lymphatic vessels, because they were found in afferent lymphatic vessels and nodal sinuses. Although the presence of epithelioid cells in lymph nodes prompts suspicion of metastatic carcinoma, the epithelioid cells in these bovine lymph nodes did not disrupt nodal architecture, lacked atypia or mitotic figures, and did not invade nodal parenchyma.

Serological evidence for hepatitis e virus infection in laboratory monkeys and pigs in animal facilities in Japan

In laboratory animal facilities, monkeys and pigs are used for animal experiments, but the details of hepatitis E virus (HEV) infection in these animals are unknown. The risk of infection from laboratory animals to humans has become a concern; therefore, much attention should be paid to the handling of these animals during their care and use, including surgical procedures performed on infected animals. In this connection, serum samples collected from 916 monkeys and 77 pigs kept in 23 animal facilities belonging to the Japanese Association of Laboratory Animal Facilities of National University Corporations (JALAN) and the Japanese Association of Laboratory Animal Facilities of Public and Private Universities (JALAP) in Japan were examined for the purpose of detecting antibodies to HEV and HEV RNA by using ELISA and RT-PCR, respectively. One hundred and seven serum samples of 916 (11.7%) monkeys were positive for anti-HEV IgG, and 7 and 17 serum samples of 916 (0.8% and 5.3%) monkeys were positive for anti-HEV IgM and IgA, respectively. Thirty-six samples from 62 (58.1%) farm pigs were positive for anti-HEV IgG, whereas all samples tested from miniature pigs were negative (0/15, 0%). Seven samples from 62 (9.1%) farm pigs and 7 samples from 916 (0.8%) monkeys were positive for IgM antibody, but these HEV-IgM antibody positive serum samples were HEV-RNA negative by RT-PCR. The IgM antibody positive rate (9.1%) of farm pigs was much higher than that of monkeys (0.8%). These results suggest the relative levels of risk of HEV infection from these animals to animal handlers and researchers who work with them in laboratory animal facilities.

A reliable method for the counting and control of single ions for single-dopant controlled devices

By 2016, transistor device size will be just 10 nm. However, a transistor that is doped at a typical concentration of 10(18) atoms cm(-3) has only one dopant atom in the active channel region. Therefore, it can be predicted that conventional doping methods such as ion implantation and thermal diffusion will not be available ten years from now. We have been developing a single-ion implantation (SII) method that enables us to implant dopant ions one-by-one into semiconductors until the desired number is reached. Here we report a simple but reliable method to control the number of single-dopant atoms by detecting the change in drain current induced by single-ion implantation. The drain current decreases in a stepwise fashion as a result of the clusters of displaced Si atoms created by every single-ion incidence. This result indicates that the single-ion detection method we have developed is capable of detecting single-ion incidence with 100% efficiency. Our method potentially could pave the way to future single-atom devices, including a solid-state quantum computer.

Hepatocyte growth factor (HGF) promotes oligodendrocyte progenitor cell proliferation and inhibits its differentiation during postnatal development in the rat

Hepatocyte growth factor (HGF) was initially cloned as a mitogen for hepatocytes and has been identified as a neurotrophic factor for a variety of neurons. However, few attempts have assessed the role of HGF in cells of oligodendrocyte lineage. The purpose of this study was to elucidate the role of HGF in such cells during development. Double immunostaining for either c-Met/HGF receptor or phospho-c-Met with either NG2 or RIP in rat striatum at postnatal day 3 (P3), P7, and P14 revealed that c-Met was phosphorylated on tyrosine residues and thereby activated in NG2(+) oligodendrocyte progenitor cells (OPCs) at P3-P14 and in RIP(+) oligodendrocytes at P14. Intrastriatal injections of recombinant human HGF at both P7 and P10 revealed that the relative ratio of BrdU(+)/NG2(+) cells per total number of NG2(+) cells increased, while BrdU(+)/MBP(+) oligodendrocyte numbers decreased. Western blot analysis showed a down-regulation of myelin basic protein (MBP) after HGF injection. Electron microscopy revealed that the numbers of myelinated nerve fibers decreased after HGF treatment. Furthermore, administration of anti-HGF IgG into the striatum increased the number of BrdU(+)/MBP(+) oligodendrocytes. These findings demonstrated that HGF increases proliferation of OPCs and attenuates their differentiation into myelinating oligodendrocytes, presumably by favoring neurite outgrowth that may be inhibited by the myelin inhibitory molecules on oligodendrocytes. Down-regulation of HGF mRNA in the striatum from P7 to P14, as revealed by quantitative real-time RT-PCR, may be favorable for OPC differentiation into myelinating oligodendrocytes. Our findings suggest that c-Met signaling, together with HGF regulation, plays an important role in developmental oligodendrogenesis.

A new method for identifying rigid link models of lower limbs

A new method for identifying rigid link models of human lower limbs has been proposed in this paper. The method was motivated by necessity of simulating human body movements for rehabilitation or for design of assistive devices. The method is based on combination of random search and least squares estimation techniques. Simulation and experimental results are given to illustrate the effectiveness of the proposed method.

Genetic Uniformity of Echinococcus multilocularis Collected from Different Intermediate Host Species in Hokkaido, Japan

DNA from several isolates of Taenia taeniaeformis and Echinococcus multilocularis were digested with restriction enzymes and hybridized with digoxigenated oligonucleotide probe (CAC)5. Within the six wild isolates of Taenia taeniaeformis from Norway rats in Hokkaido, although several bands were common among isolates, fingerprinting patterns were specific to each isolate. In the case of E. multilocularis, regardless of hosts from which each isolate has been isolated, the five isolates collected from Hokkaido, showed the same fingerprinting pattern. These results indicate that there was very little genetic difference among these isolates. Although the fingerprinting pattern of E. multilocularis from St. Lawrence Is. was similar to that of the Hokkaido isolates, some bands were different from those in the Hokkaido isolates. Echinococcus multilocularis in Hokkaido seems to be closely-related genetically to that from St. Lawrence Is.

Deficiency of the tensin2 gene in the ICGN mouse: an animal model for congenital nephrotic syndrome

The ICGN mouse is a model for nephrotic syndrome (NS) which presents with proteinuria, hyperlipidemia, and edema. In this study we attempted to identify the gene(s) responsible for NS. By analyzing albuminuria in 160 (ICGN x MSM)F(1) x ICGN backcross progenies, we found that NS in the ICGN mouse is caused by more than one gene. We then performed a quantitative trait locus (QTL) analysis and detected a QTL with a very high LOD score peak in the telomeric region of Chr 15. By analyzing the nucleotide sequence of 22 genes located close to the QTL, we found that the tensin2 gene of the ICGN mouse possessed an 8-nucleotide deletion mutation in exon 18, leading to a frameshift and giving rise to a terminal codon at a premature position. Analyses of in situ hybridization and immunohistochemistry revealed that tensin2 was expressed in podocytes and tubular epithelial cells in normal mice but not in the ICGN mouse. These data raise the possibility that a mutation of the tensin2 gene is responsible for NS of the ICGN mouse and tensin2 is a prerequisite for the normal kidney function.

The effect of angiotensin receptor blockade ARB on the regression of left ventricular hypertrophy in hemodialysis patients: comparison between patients with D allele and non-D allele ACE gene polymorphism

OBJECTIVE

It is revealed that LVH is one of risk factors for the development of cardiac complications in long-term HD patients. Therefore, maneuvers to reduce hypertrophy of cardium are very important for improving life prognosis. Angiotensin II receptor blockade (ARB) could reduce LVH in general populations without renal failure. However, no conclusive data has been available regarding the clinical consequences of ARB administration on the regression of LVH in HD patients. Furthermore, it has not clearly determined if ACE gene polymorphism has a possible influential effect on it. This study is conducted to clarify these issues.

SUBJECTS AND METHOD

32 hypertensive patients on regular HD (male/female: 21/11, mean age: 60.5 years, mean duration of HD: 52.8 months) were studied. Patients were classified into two groups according to the different type of ACE gene polymorphism: cases with D allele (DD/ID; D group: n = 13) and those without (II; non-D group: n = 19). All patients were administered ARB (losartan 50 - 100 mg/day) and echocardiography (UCG) was performed at 6-month-interval regularly until the end of observation (24 months).

RESULTS

Before the commencement of ARB, no differences were found between the two groups, neither in mean blood pressure (MBP: D group/non-D group: 120 +/- 13 vs. 115 +/- 14 mmHg) nor in left ventricular mass index (LVMI: D/non-D: 172 +/- 41 vs. 165 +/- 41 g/m2). During the 24r-month follow-up, there were significant and similar reductions in MBP in both groups. In respect to LVMI, a significant reduction of LVMI was found in the D group after six months (p < 0.01 vs. basal) with a final reduction rate (FRR) -26 +/- 13%, whereas in the non-D group it was found at 24 months (p < 0.01 vs. basal) with FRR -11 +/- 16% (p < 0.01 vs. D group). There were significant differences between the two groups at all points (p < 0.05 at 6, 18 and 24 months, p < 0.005 at 12 months, respectively).

CONCLUSION

It is indicated that ARB could insert a regression effect on LVH predominantly in patients with D allele ACE polymorphism, due partly to factor (s) independent of its anti-hypertensive effect.

Loss of ions in cavity ionization chambers

Ion losses due to initial recombination, volume recombination, and back diffusion were each determined by measurements and calculations for different size cylindrical ionization chambers and spherical ionization chambers. By measuring signal currents from these ionization chambers irradiated with (60)Co gamma rays, two groups of ion losses were obtained. (Group 1) Ion loss due to initial recombination and diffusion, which changes proportionally to the inverse of the voltage applied to the ionization chambers; (and group 2) ion loss due to volume recombination, which changes proportionally to the inverse of the square of the applied voltage. The diffusion loss was obtained separately by computing electric field distributions in the ionization chambers. It was found that diffusion loss is larger than initial recombination loss for the cylindrical ionization chambers and vise versa for the spherical ionization chambers.

Overview of secondary neutron production relevant to shielding in space

An overview of experimental secondary neutron measurements relevant to space-related activities is presented. Stopping target yields and cross section measurements conducted at particle accelerators using heavy ions with energies > 100 MeV per nucleon are discussed.

Metabolic profiles and bile acid extraction rate in the liver of cows with fasting-induced hepatic lipidosis

This study was designed to monitor lipid profile in the portal and hepatic blood of cows with fasting-induced hepatic lipidosis, and to compare the results with those in the jugular blood. The work was also carried out to investigate bile acid (BA) in these vessels, and further to investigate BA extraction rate in the liver. Five cows were equipped with catheters in the portal, hepatic and jugular veins (day 0), fasted for 4 days (day 1-day 4) and then refed (day 5-day 11). Before morning feeding, blood was sampled before, during and after fasting from the catheterized vessels. In the portal blood, the concentration of non-esterified fatty acids (NEFA) showed a progressive increase and at day 5 there was an approximate twofold rise. Increased NEFA concentrations were also found similarly in the other two veins. At day 5, beta-hydroxybutyrate (BHBA) in the portal, hepatic and jugular blood rose to 197, 190 and 186% of the pre-fasting value, respectively. However, the concentrations of NEFA and BHBA in the three veins gradually returned to pre-fasting concentration during the refeeding period. Compared with the pre-fasting value at day 0, the content of liver triglyceride (TG) increased significantly at day 5 (P < 0.01). In the liver, the hepatic extraction rate of BA dropped from 3.1 times pre-fasting to 2.2 times during fasting. There were no significant differences in the concentrations of glucose, TG, total cholesterol, cholesterol esters, free cholesterol and phospholipids. The results of the current study show that metabolic alterations occur in the portal, hepatic and jugular veins during induction of hepatic lipidosis in cows, and mostly metabolites, with exception of BA concentration, run parallel. The decreased BA extraction rate in the liver of fasted cows was considered to reflect hepatic cell impairment caused by TG accumulation. Hopefully, the findings, at least in part, contribute to the explanation of the pathophysiology of hepatic lipidosis in dairy cows.

Transcutaneous ultrasound-guided pancreatic biopsy in cattle and its safety: a preliminary report

This study describes a free-hand technique for percutaneous pancreatic biopsy in cattle with ultrasound-guidance using a 14G spinal biopsy needle. Its safety was evaluated based on 36 consecutive procedures. To assess the immediate effects of pancreatic biopsy, 31 cows were necropsied shortly after the procedure and examined. The remaining five cows were examined daily for eight days and then necropsied and examined. No life-threatening complications nor clinically detectable abnormalities were observed. Changes indicative of inflammation were not apparent in total and differential WBC counts or in total protein and fibrinogen concentrations. A small increase of amylase activity was detected in only one cow kept for the eight-day observation period. Serum lipase activity increased significantly on day four after biopsy. Urea nitrogen, creatinine, glucose and the activities of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase remained within reference ranges. Changes in the peritoneum and pancreas observed at necropsy were negligible. We conclude that percutaneous ultrasound-guided pancreatic biopsy did not appear to influence the cow's condition adversely and the procedure provided an excellent method of obtaining a pancreatic specimen for histological examination. The procedure was considered safe, fast, cost-effective, and practical when performed properly. We believe that the technique can be used in cows with suspected pancreatic disease for making an ante mortem diagnosis.

Ultrasonographic imaging of experimentally induced pancreatitis in cattle

This study was conducted to determine the ultrasonographic patterns of pancreatitis evoked in cattle, with reference to laboratory and pathological findings. Using ultrasonographic guidance, acute necrotizing pancreatitis was induced in six cows by injecting chloroform into the pancreatic tissue. Ultrasonographic examination was then performed once daily for nine days. Pancreatic lesions were visible 24h after induction of pancreatitis, as represented by a uniform increase in echogenicity and by intralobular and subcapsular fluid accumulation. As the experiment progressed, patchy hypoechogenic foci appeared within the gland parenchyma. Amylase and lipase activities showed rapid increases. Post mortem examination revealed gross and microscopic necrotic and haemorrhagic lesions in the body and right lobe of the pancreas, accompanied by oedema and fibrosis. Ultrasonography was found to be extremely useful for the detection and characterization of experimentally induced pancreatitis and to monitor its progression in the cow. These findings are of potential value as a reference for the diagnostic workup of bovine pancreatitis, and ultrasonography is seen as a promising non-invasive technique for the diagnosis of suspected pancreatitis in cattle.

Modulatory effect of cAMP on fungal ergosterol level and inhibitory activity of azole drugs

The functions and biosynthesis of sterols have been effective targets for fungal control in different areas, including pharmaceutical and agricultural applications. Fungi are among the organisms that synthesize sterols, principally ergosterol. In this paper, the effect of dibutyryl-cAMP (db-cAMP) on ergosterol level and the interaction of drugs that would change the concentration of cAMP with antifungal drugs have been investigated. Sterols were extracted from Candida albicans, and ergosterol was measured using the gas chromatography method. The interaction of different agents was measured by the broth dilution method. It was found that phosphodiesterase inhibitors reverse the inhibitory activity of azole antifungal drugs. Evaluating the ergosterol level of C. albicans incubated with db-cAMP revealed that it increased ergosterol level. Further experiments provided evidence attributing the observed interaction between azoles and phosphodiesterase inhibitors to the relationship between ergosterol and cAMP. The possible significance of this interaction includes potentiation of antifungal activity of drugs by manipulating the cAMP level.

Evaluation of a forced-air-ventilated micro-isolation system for protection of mice against Pasteurella pneumotropica

Studies to date have established that the physical environment inside cages can be controlled adequately by setting the intra-cage ventilation at 60 air changes per hour in a forced-air-ventilated micro-isolation system (FVMIS). In this study, the capability of FVMIS to prevent inter-cage transmission of microorganisms was evaluated using Pasteurella pneumotropica as a reference microorganism. One FVMIS rack and a conventional rack were used, and cages with mice positive for P. pneumotropica and those with P. pneumotropica-free mice were housed on both racks. The mice were examined for P. pneumotropica contamination every 4 weeks after initiating the experiment for 12 weeks using a polymerase chain reaction method. Some P. pneumotropica-free mice housed in open air cages in the conventional rack became positive for P. pneumotropica (four of 28 animals after 4 weeks; eight of 28 animals after 12 weeks), but all P. pneumotropica-free mice housed in the FVMIS cages remained negative for the bacterium throughout the experiment. The results demonstrate that FVMIS can prevent inter-cage transmission of P. pneumotropica when proper cage handling practice is under taken.

Angle dependence of signal currents from cylindrical ionisation chambers

A signal current from a cylindrical ionisation chamber with an ionisation volume of 62.7 cm3, 40 mm in diameter and 50 mm long, peaked when the chamber was lixed at 0 degrees and at 90 degrees in 137Cs and 60Co gamma ray fields for source-chamber distances of 1 m and 2 m. A smaller ionisation chamber showed a small peak at 0 degrees in both fields but not at 90 degrees. However, calculations indicated that the signal current from the smaller chamber would also show a peak at 90 degrees in a 137Cs point-source gamma ray field. Peaks occur because gamma rays attenuate along the cylindrical side wall or along the end walls when a chamber is tilted slightly from 0 degrees or 90 degrees and the direction of the gamma ray beam agrees with the plane of one of these walls. These facts suggest the need for care in the common practice of measuring and calculating responses for cylindrical ionisation chambers fixed perpendicular to gamma ray beams.