Reconstruction of band structure induced by electronic nematicity in an FeSe superconductor.

We have performed high-resolution angle-resolved photoemission spectroscopy on an FeSe superconductor (T_{c}∼8 K), which exhibits a tetragonal-to-orthorhombic structural transition at T_{s}∼90 K. At low temperature, we found splitting of the energy bands as large as 50 meV at the M point in the Brillouin zone, likely caused by the formation of electronically driven nematic states. This band splitting persists up to T∼110 K, slightly above T_{s}, suggesting that the structural transition is triggered by the electronic nematicity. We have also revealed that at low temperature the band splitting gives rise to a van Hove singularity within 5 meV of the Fermi energy. The present result strongly suggests that this unusual electronic state is responsible for the unconventional superconductivity in FeSe.

Diversity and pattern in the developing spinal cord.

The generation of distinct neuronal cell types in appropriate numbers and at precise positions underlies the assembly of neural circuits that encode animal behavior. Despite the complexity of the vertebrate central nervous system, advances have been made in defining the principles that control the diversification and patterning of its component cells. A combination of molecular genetic, biochemical, and embryological assays has begun to reveal the identity and mechanism of action of molecules that induce and pattern neural tissue and the role of transcription factors in establishing generic and specific neuronal fates. Some of these advances are discussed here, focusing on the spinal cord as a model system for analyzing the molecular control of central nervous system development in vertebrates.

A family of metabotropic glutamate receptors.

Three cDNA clones, mGluR2, mGluR3, and mGluR4, were isolated from a rat brain cDNA library by cross-hybridization with the cDNA for a metabotropic glutamate receptor (mGluR1). The cloned receptors show considerable sequence similarity with mGluR1 and possess a large extracellular domain preceding the seven putative membrane-spanning segments. mGluR2 is expressed in some particular neuronal cells different from those expressing mGluR1 and mediates an efficient inhibition of forskolin-stimulated cAMP formation in cDNA-transfected cells. The mGluRs thus form a novel family of G protein-coupled receptors that differ in their signal transduction and expression patterns.

Patterning of muscle acetylcholine receptor gene expression in the absence of motor innervation.

The patterning of skeletal muscle is thought to depend upon signals provided by motor neurons. We show that AChR gene expression and AChR clusters are concentrated in the central region of embryonic skeletal muscle in the absence of innervation. Neurally derived Agrin is dispensable for this early phase of AChR expression, but MuSK, a receptor tyrosine kinase activated by Agrin, is required to establish this AChR prepattern. The zone of AChR expression in muscle lacking motor axons is wider than normal, indicating that neural signals refine this muscle-autonomous prepattern. Neuronal Neuregulin-1, however, is not involved in this refinement process, nor indeed in synapse-specific AChR gene expression. Our results demonstrate that AChR expression is patterned in the absence of innervation, raising the possibility that similarly prepatterned muscle-derived cues restrict axon growth and initiate synapse formation.

Bacillus cereus nosocomial infection from reused towels in Japan.

It was noticed that there was an increase in Bacillus cereus nosocomial infections in the summer from 2000 to 2005. In 2005, five bloodstream infections occurred in five patients related to catheter use. The causative strains were distinct from each other and belonged to novel multilocus sequence types (ST): ST365, ST366, ST367 and ST368. Two ST365 strains from two patients were further distinguished by pulsed-field gel electrophoresis. B. cereus contamination was observed with reused (dried and steamed) towels (>10(6)cfu/towel) and washing machines in hospital linen rooms. B. cereus strains from towels belonged to ST167, ST365, ST380 and ST382, and a proportion of these were the same, or similar, to strains from patients. All the hospital strains of B. cereus were distinct from those from food-poisoning strains (ST26, ST142, ST381). Ciprofloxacin resistance was observed only in hospital strains. Neither emetic toxin nor cytotoxin K gene, usually present in food poisoning strains, were found in the hospital strains, except for one patient isolate. The data suggest that specific B. cereus strains are circulating within a hospital, with genotypes, antibiotic susceptibilities and virulence gene patterns generally distinct from those of food poisoning, and that in Japan, towels are an important source of contamination, especially in summer.

Ombitasvir-Paritaprevir-Ritonavir Therapy in a Kidney Transplant Recipient With Chronic Hepatitis C Virus Genotype 1 Infection: A Case Report on the Importance of Considering Drug-Drug Interactions and Monitoring Cyclosporine Levels.

A 74-year-old Japanese man with a history of chronic hepatitis C and kidney transplant (KT) was administered pegylated-interferon plus ribavirin therapy. However, this therapy was ineffective. The patient was then hospitalized to receive ombitasvir (OBV) plus paritaprevir (PTV) plus ritonavir (r) antiviral combination therapy. He tested negative for the virus after 4 weeks, and completed 12 weeks of treatment. The patient ultimately achieved a sustained virological response after the 12 weeks of treatment. Cyclosporine (CyA) trough levels, during the OBV-PTV-r therapy, reached a peak within 5 days of initiating therapy, and increases in serum creatinine and total bilirubin were also observed. However, onset of irreversible nephropathy and hepatopathy were avoided by reducing the CyA dosage. The OBV-PTV-r therapy demonstrated a sufficient antiviral effect and could be safely administered postoperatively to patients having undergone KT. When a combination therapy with interferon-free, direct-acting antivirals is used in patients post-transplantation, consideration of drug-drug interactions with and monitoring CyA are of vital importance.

Induction of motor neurons by Sonic hedgehog is independent of floor plate differentiation.

BACKGROUND: The differentiation of floor plate cells and motor neurons in the vertebrate neural tube appears to be induced by signals from the notochord. The secreted protein encoded by the Sonic hedgehog (Shh) gene is expressed by axial midline cells and can induce floor plate cells in vivo and in vitro. Motor neurons can also be induced in vitro by cells that synthesize Sonic hedgehog protein (Shh). It remains unclear, however, if the motor-neuron-inducing activity of Shh depends on the synthesis of a distinct signaling molecule by floor plate cells. To resolve this issue, we have developed an in vitro assay which uncouples the notochord-mediated induction of motor neurons from floor plate differentiation, and have used this assay to examine whether Shh induces motor neurons in the absence of floor plate differentiation. RESULTS: Floor plate cells and motor neurons were induced in neural plate explants grown in contact with the notochord, but only motor neurons were induced when explants were separated from the notochord. COS cells transfected with Shh induced both floor plate cells and motor neurons when grown in contact with neural plate explants, whereas only motor neurons were induced when the explants were grown at a distance from Shh-transfected COS cells. Direct transfection of neural plate cells with an Shh-expression construct induced both floor plate cells and motor neurons, with motor neuron differentiation occurring prior to, or coincidentally with, floor plate differentiation. The induction of motor neurons appears, therefore, not to depend on floor plate differentiation. CONCLUSIONS: The induction of motor neurons by Shh does not depend on distinct floor-plate-derived signaling molecules. Shh can, therefore, initiate the differentiation of two cell types that are generated in the ventral region of the neural tube. These results show that the early development of motor neurons involves the inductive action of Shh, whereas the survival of motor neurons at later stages of embryonic development requires neurotrophic factors.

Renal dysplasia unrelated to claudin-16 deficiency in Japanese Black cattle.

Renal lesions of the type usually found in claudin-16 (CL-16) defective Japanese Black cattle (homozygous for CL-16 deficiency) were identified in six animals of this breed, aged 28-59 months, which were either heterozygous for CL-16 deficiency (type 1) or normal, as judged by a DNA-based test associated with the CL-16 gene. Histopathologically, all six cases showed elongated focal lesions which ran through the cortex to terminate in the outer zone of the medulla. The lesions contained components that included: (1) immature tubules, (2) small irregularly shaped tubules with thickening of the basement membrane, (3) mesenchymal cells in an increased interstitium, (4) small atrophic glomeruli, and (5) immature glomeruli. The glomeruli were noticeably reduced in number, and large glomeruli with an increased number of mesangial cells were observed throughout the entire cortical area. Cystic dilation of tubules and flattening of the epithelium were noted in all areas of the kidney. Histopathologically, the renal lesions in the six cases were indistinguishable from those reported previously in cattle homozygous for CL-16 deficiency. These findings demonstrate that such renal lesions in Japanese Black cattle are not necessarily associated with homozygous deletion of the CL-16 gene.

Cardioprotective effect of edaravone against ischaemia-reperfusion injury in the rabbit heart before, during and after reperfusion treatment.

The free radical scavenger edaravone is able to stimulate prostacyclin release and inhibit the lipoxygenase pathway in the arachidonic acid cascade. The effect of edaravone administration on myocardial damage in rabbit hearts subjected to ischaemia-reperfusion was examined at different times relative to reperfusion. All rabbits underwent sustained coronary artery occlusion for 30 min followed by 3 h of reperfusion. Rabbits were divided into the following groups: control; early (3 mg/kg edaravone IV 10 min before reperfusion); immediate (3 mg/kg edaravone IV immediately after the start of reperfusion); and late (3, 6 or 10 mg/kg edaravone IV 5 min after the start of reperfusion). Single bolus administration of edaravone 10 min before reperfusion or immediately upon initiation of reperfusion appears to be associated with reductions in infarction size and the percentage of apoptotic cells, but treatment with edaravone 5 min after initiation of reperfusion does not appear to have this protective effect.

Comparison of chairside microbiological screening systems and conventional selective media in children with and without visible dental caries.

PURPOSE: The purpose of this study was to compare the results of commercial chairside microbial tests (CT) and conventional selective media (GS, gold standards) for mutans streptococci (MS) and lactobacilli (LB) using oral specimens from young children with and without visible dental caries. METHODS: Using cotton swabs to collect oral microbial specimens from children 10 to 36 months old, microbial counts of CT and GS were compared with caries experience of the subjects. Contamination levels by non-MS or non-LB isolates on CT and GS were also determined. The CT employed were: (1) CRT bacteria for MS and LB; (2) CarioCheck Plus for MS and LB; and (3) Dentocult SM and Mucount for MS. RESULTS: All CT and GS for MS represented caries status of the participants (P<.001, Fisher exact test; P<.015 linear regression), whereas only GS for LB showed significant association with caries status (P<.001, Fisher exact test; P<.001, linear regression). Non-MS or non-LB isolates were observed on most media, and CT usually exhibited higher contaminant levels than GS. Dentocult SM and Mucount did not harbor contaminants. CONCLUSIONS: Despite contamination, CT and GS for MS and GS for LB exhibited satisfactory outcomes based on cross-sectional caries experience of infants and toddlers.

Origin of Nicotiana tabacum detected by primary structure of fraction I protein.

Nicotiana tabacum is believed to have arisen after hybridization of Nicotiana sylvestris with a species in the Tomentosae section of the genus Nicotiana. Recent biochemical experiments have confirmed the conclusions from previous cytogenetic studies that N. sylvestris was the maternal parent and have indicated that Nicotiana tomentosiformis was the paternal parent. However, these studies did not take into account the possibility that a new species of Nicotiana, called K-12, discovered in South America in 1968, could also have been one of the parents. Fraction I proteins were purified from N. tabacum and its putative progenitors, and separated into large and small subunits. Chymotryptic peptides of each subunit were analyzed by ion exchange column chromatography with a gradient elution system. Among 38 resolved peaks of the large subunits, 2 peaks were found to be different among the putative species. Since only N. sylvestris showed an identical chromatogram with N. tabacum, N. sylvestris was concluded to be the maternal progenitor, as the genetic information for the large subunit of Fraction I protein was known to be inherited by the cytoplasmic mode. On the other hand, the small subunit of Fraction I protein is inherited by the Mendelian mode and therefore N. tabacum, an allopolyploid, could be expected to contain two types of small subunits, one derived from N. sylvestris and the other from a paternal progenitor. N. sylvestris lacks two of the 25 chymotryptic peptides of the small subunit of N. tabacum. Among 3 putative paternal progenitors, these two peaks appeared only in N. tomentosiformis, but not in Nicotiana otophora or K-12. Thus, N. tomentosiformis was concluded to be a paternal progenitor of N. tabacum. The conclusion was verified by comparing chymotryptic peptides of small subunits from three amphidiploids of N. sylvestris crossed with N. tomentosiformis, N. sylvestris crossed with N. otophora snd N. sylvestris crossed with K-12. The analytical results showed that only the progeny of N. sylvestris crossed with N. tomentosiformis contained the same small subunits as N. tabacium.

Prolonged recovery of cardiac output after maximal exercise in patients with chronic heart failure.

OBJECTIVES: The aim of this study was to characterize the kinetics of cardiac output during recovery from maximal exercise in patients with chronic heart failure (CHF). BACKGROUND: Recent studies have shown that oxygen uptake kinetics during recovery from exercise are delayed in patients with CHF. However, the kinetics of cardiac output during recovery from maximal exercise in CHF has not been examined. METHODS: Thirty patients with CHF performed maximal upright ergometer exercise with respiratory gas analysis. Kinetics of oxygen uptake (VO2) and carbon dioxide output (VCO2) during recovery were characterized by T1/2, the time to reach 50% of the peak values. Cardiac output was measured at 1-min intervals during exercise and recovery. Kinetics of cardiac output during recovery were characterized by the ratios of cardiac output during the first 4 min of recovery to cardiac output at peak exercise. Overshoot of cardiac output was defined as a further increase in cardiac output at 1 min of recovery above the cardiac output at peak exercise. RESULTS: Both T1/2 VO2 and T1/2 VCO2 increased as CHF worsened. The ratios of cardiac output during recovery to cardiac output at peak exercise were significantly correlated with T1/2 VO2 (r = 0.47 to 0.62, p < 0.05) and T1/2 VCO2 (r = 0.40 to 0.70, p < 0.05). There was a negative correlation between cardiac index at peak exercise and both T1/2 VO2 (r = -0.65, p < 0.001) and T1/2 VCO2 (r = -0.60, p < 0.001). Overshoot of cardiac output was recognized in 11 of 30 patients. Cardiac index at peak exercise was significantly lower in patients with overshoot (4.5 +/- 0.9 L/min/m2) than in those without overshoot (6.1 +/- 2.1 L/min/m2, p < 0.05). However, because of a continued increase in cardiac output at 1 min of recovery in patients with overshoot, there were no differences in cardiac index after the first minute of recovery. Heart rate at peak exercise and recovery of heart rate did not differ between these groups. Overshoot of cardiac output was caused by a rebound increase in stroke volume which was due to a reduction in systemic vascular resistance. CONCLUSIONS: Prolonged kinetics of VO2 or VCO2 during recovery from maximal exercise represent impairment of circulatory response to exercise and delayed recovery of cardiac output after exercise. Overshoot of cardiac output at 1 min of recovery was characteristic of severe CHF with poor cardiac output response to exercise.

Sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than LQT2 forms of congenital long QT syndrome.

OBJECTIVES: The study compared the influence of sympathetic stimulation on transmural and spatial dispersion of repolarization between LQT1 and LQT2 forms of congenital long QT sYndrome (LQTS). BACKGROUND: Cardiac events are more associated with sympathetic stimulation in LQT1 than in LQT2 or LQT3 syndrome. Experimental studies have suggested that the interval between Tpeak and Tend (Tp-e) in the electrocardiogram (ECG) reflects transmural dispersion of repolarization across the ventricular wall. METHODS: We recorded 87-lead body-surface ECGs before and after epinephrine infusion (0.1 microg/kg/min) in 13 LQT1, 6 LQT2, and 7 control patients. The Q-Tend (QT-e), Q-Tpeak (QT-p), and Tp-e were measured automatically from 87-lead ECGs, corrected by Bazett's method (QTc-e, QTc-p, Tcp-e), and averaged among all 87-leads and among 24-leads, which reflect the potential from the left ventricular free wall. As an index of spatial dispersion of repolarization, the dispersion of QTc-e (QTc-eD) and QTc-p (QTc-pD) were obtained among 87-leads and among 24-leads, and were defined as the interval between the maximum and the minimum of the QTc-e and the QTc-p, respectively. RESULTS: Epinephrine significantly increased the mean QTc-e but not the mean QTc-p, resulting in a significant increase in the mean Tcp-e in both LQT1 and LQT2, but not in control patients. The epinephrine-induced increases in the mean QTc-e and Tcp-e were larger in LQT1 than in LQT2, and were more pronounced when the averaged data were obtained from 24-leads than from 87-leads. Epinephrine increased the maximum QTc-e but not the minimum QTc-e, producing a significant increase in the QTc-eD in both LQT1 and LQT2 patients, but not in control patients. The increase in the QTc-eD was larger in LQT1 than in LQT2 patients. CONCLUSIONS: Our data suggest that sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than in LQT2 syndrome, and this may explain why LQT1 patients are more sensitive to sympathetic stimulation.

Protection of ischaemic myocardium with coenzyme Q10.

Protection of the ischaemic myocardium with Coenzyme Q10 (COQ10) following constriction of left anterior descending coronary artery was studied in 38 open-chest mongrel dogs. Left anterior descending coronary artery blood flow was independently reduced by tightening a constrictor around the vessel. Aortic pressure and left ventricular pressure were measured, and the Tension Time Index (TTI) was calculated. Myocardial segment shortening in the ischaemic area was measured with an ultrasonic dimension gauge. After obtaining haemodynamic data, the ischaemic myocardium was biopsied and the tissue sample was frozen in liquid nitrogen for adenosine triphosphate (ATP) analysis. Animals premedicated with COQ10 (20 mg . kg-1 iv) had a significantly higher ATP content in ischaemic myocardium (3.25 +/- 0.35 mumol . g-1 wet weight) compared with that in ischaemic myocardium of control animals (2.96 +/- 0.19) (P less than 0.05), when coronary blood flow was reduced by 50 to 74%. There were failure of ATP preservation by COQ10 with a further reduction in coronary blood flow. Changes in the pattern of myocardial segment shortening in the ischemic area induced by a 50 to 74% coronary blood flow reduction were less in COQ10 treated animals than in control animals. Since there were no haemodynamic differences between control and COQ10 treated animals, these effects were considered not to be due to a decrease in myocardial oxygen consumption secondary to haemodynamic changes.

Cre reporter strains produced by targeted insertion of EYFP and ECFP into the ROSA26 locus.

BACKGROUND: Several Cre reporter strains of mice have been described, in which a lacZ gene is turned on in cells expressing Cre recombinase, as well as their daughter cells, following Cre-mediated excision of a loxP-flanked transcriptional "stop" sequence. These mice are useful for cell lineage tracing experiments as well as for monitoring the expression of Cre transgenes. The green fluorescent protein (GFP) and variants such as EYFP and ECFP offer an advantage over lacZ as a reporter, in that they can be easily visualized without recourse to the vital substrates required to visualize beta-gal in living tissue. RESULTS: In view of the general utility of targeting the ubiquitously expressed ROSA26 locus, we constructed a generic ROSA26 targeting vector. We then generated two reporter lines of mice by inserting EYFP or ECFP cDNAs into the ROSA26 locus, preceded by a loxP-flanked stop sequence. These strains were tested by crossing them with transgenic strains expressing Cre in a ubiquitous (beta-actin-Cre) or a cell-specific (Isl1-Cre and En1-Cre) pattern. The resulting EYFP or ECFP expression patterns indicated that the reporter strains function as faithful monitors of Cre activity. CONCLUSIONS: In contrast to existing lacZ reporter lines, where lacZ expression cannot easily be detected in living tissue, the EYFP and ECFP reporter strains are useful for monitoring the expression of Cre and tracing the lineage of these cells and their descendants in cultured embryos or organs. The non-overlapping emission spectra of EYFP and ECFP make them ideal for double labeling studies in living tissues.

Isoform-selective upregulation of mast cell chymase in the development of skin fibrosis in scleroderma model mice.

The involvement of connective-tissue-type mast cells and chymase, a protease unique to their secretory granules, has been implicated in fibrotic diseases. To elucidate the role of chymase in fibroproliferative inflammation, in this study we examined the enzymatic activity and mRNA expression of chymase in the sclerotic skin of tight-skin mice; syngeneic Pallid mice served as the control. Dorsal skin specimens from mice aged 5, 10, and 20 wk were evaluated by morphometric and biochemical analyses. At ages 10 and 20 wk, the hydroxyproline concentration in tight-skin dermis was higher than that in Pallid. At any age, the subcutaneous fibrous layer was thicker in tight-skin than in Pallid. In accordance with these fibrous changes, both connective-tissue-type mast cell counts and chymase activity were higher in tight-skin skin than in Pallid skin up to 20 wk of age. Age-matched (10-wk-old) tight-skin and Pallid were quantified for their mRNA of connective-tissue-type mast-cell-specific chymase, mouse mast cell protease-4, by the competitive reverse transcriptase polymerase chain reaction technique, which revealed its higher level in tight-skin than Pallid. In contrast, the mRNA level of mouse mast cell protease-5, the chymase isoform of undifferentiated mast cells, in tight-skin skin was only a tenth that of mouse mast cell protease-4 and no different from the mouse mast cell protease-5 mRNA level of Pallid mice. An in situ hybridization study confirmed the higher expression of mouse mast cell protease-4 by connective-tissue-type mast cells in tight-skin skin than Pallid skin. These results strongly support the contention that the connective-tissue-type mast cell chymase plays a crucial role in fibroproliferative remodeling of the skin.

Antihypertensive and volume-depleting effects of mild exercise on essential hypertension.

After a general clinical observation period of over 4 weeks, 20 essential hypertensive subjects (Japanese) were randomly divided into two groups. One group (n = 10; 4 men and 6 women; 51.4 +/- 2.8 years of age) agreed to physical training using bicycle ergometer exercise with the intensity at blood lactate threshold for 60 minutes three times a week for 10 weeks, while the other group (n = 10; 4 men and 6 women; 51.0 +/- 2.9 years of age) did no particular physical training and was followed once a week as the control. Changes in blood pressure, hemodynamics, and humoral factors of the exercised group were compared with values in the controls. The following significant changes were found only in the exercised group. Blood pressure was significantly (p less than 0.01) reduced. Whole blood and plasma volume indices were significantly reduced (p less than 0.05, p less than 0.01, respectively). The change in ratio of serum sodium to potassium positively correlated with the change in systolic blood pressure (r = 0.76, p less than 0.02). Plasma norepinephrine concentrations both at rest and at the workload of blood lactate threshold during graded exercise tests were significantly reduced (p less than 0.05, p less than 0.02 respectively) after 10 weeks of exercise training. The change in the resting level of plasma norepinephrine positively correlated with that in the mean blood pressure. No such changes were observed in the control group. In both groups, body weight and urinary sodium excretion showed no statistically significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

A family with X-linked dystonia-deafness syndrome with a novel mutation of the DDP gene.

BACKGROUND: X-linked dystonia-deafness syndrome (DDS) is characterized by early-onset deafness followed by progressive dystonia in adulthood. Only 4 families with the syndrome have been reported, and all were white. OBJECTIVE: To describe the first nonwhite family with X-linked DDS, involving 5 affected males in 4 generations. RESULTS: Clinical features of the family members, who were Japanese, were mostly consistent with reports of DDS in whites except for a lack of visual disturbances. Whereas microdeletions in the deafness-dystonia peptide (DDP) gene were found in 2 white DDS families, our patients showed a novel mutation (arg80ter) in exon 2 of the DDP gene. CONCLUSION: The existence of a DDS family of Japanese origin with a new kind of mutation in the DDP gene provides additional evidence that the DDP gene is a causative gene for X-linked DDS.

The use of magnetic resonance imaging in diagnosing infantile neuroaxonal dystrophy.

We used MRI to investigate the brains of four children ranging from 3 to 10 years of age with infantile neuroaxonal dystrophy. T2-weighted imaging revealed characteristic findings of marked cerebellar atrophy and diffuse hyperintensity of the cerebellar cortex. At autopsy, one child had extensive astrogliosis and neuronal loss with shrinkage of the cerebellar cortex, in addition to typical widespread changes of neuroaxonal dystrophy. The characteristic hyperintensity of the cerebellar cortex on T2-weighted imaging probably is secondary to the extensive gliosis and shrinkage of the cerebellar cortex. These cerebellar findings on MRI may permit early diagnosis of infantile neuroaxonal dystrophy.