Novel G423S mutation of human alpha7 nicotinic receptor promotes agonist-induced desensitization by a protein kinase C-dependent mechanism.

The alpha7 nicotinic acetylcholine receptor subunit (CHRNA7) gene harbors a high degree of polymorphism. In this study, we found a novel variant (1267 G to A) in exon 10 of the CHRNA7 gene in a Japanese population. This variant results in glycine-to-serine substitution at position 423 (G423S) located in the large cytoplasmic loop of the protein.

Cerebral perfusion MR imaging using FAIR-HASTE in chronic carotid occlusive disease: comparison with dynamic susceptibility contrast-perfusion MR imaging.

To determine the efficacy of flow-sensitive alternating inversion recovery using half-Fourier single-shot turbo spin-echo (FAIR-HASTE) in detecting cerebral hypoperfusion in chronic carotid occlusive disease, we subjected 12 patients with various degrees of cervical internal carotid artery stenoses and/or occlusion (Stenosis group) and 24 volunteers (Normal group) to FAIR-HASTE. In addition, 10 out of 12 patients in the Stenosis group underwent dynamic susceptibility contrast-perfusion magnetic resonance imaging (DSC-pMRI) before and after revascularization in the dominantly affected side. The absolute asymmetry indexes (AIs) of both cerebral hemispheres in the Normal and Stenosis groups were compared in FAIR-HASTE.

Recent advances in methods for the analysis of catecholamines and their metabolites.

Catecholamines, for example epinephrine, norepinephrine, and dopamine, are widely distributed and are important neurotransmitters and hormones in mammalian species. Several methods have been developed for analysis of catecholamines and related compounds. Determination of catecholamines in biological fluids has enabled us to clarify the physiological role played by these amines.

Associations of health behaviors on depressive symptoms among employed men in Japan.

The associations between health behaviors and depressive symptoms have been demonstrated in many studies. However, job strain has also been associated with health behaviors. The aim of this study was to analyze whether health behaviors such as physical activity, sleeping, smoking and alcohol intake are associated with depressive symptoms after adjusting for job strain.

Overexpression of monocyte chemoattractant protein-1 in adipose tissues causes macrophage recruitment and insulin resistance.

Adipose tissue expression and circulating concentrations of monocyte chemoattractant protein-1 (MCP-1) correlate positively with adiposity. To ascertain the roles of MCP-1 overexpression in adipose, we generated transgenic mice by utilizing the adipocyte P2 (aP2) promoter (aP2-MCP-1 mice). These mice had higher plasma MCP-1 concentrations and increased macrophage accumulation in adipose tissues, as confirmed by immunochemical, flow cytometric, and gene expression analyses.

Determination of NG,NG-dimethyl-L-arginine in rat plasma and dimethylarginine dimethylaminohydrolase activity in rat kidney using a monolithic silica column.

A fast, simple and sensitive column-switching high-performance liquid chromatography (HPLC)-fluorescence detection method was developed on a monolithic silica column for the determination of N(G),N(G)-dimethyl-L-arginine (ADMA), which is an endogenous nitric oxide synthase inhibitor. After fluorescence derivatization of plasma samples or homogenized tissues with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), the samples were injected into the HPLC system. The NBD-derivatized ADMA was trapped on a cation-exchange column and separated within 15 min on a monolithic silica column.

A surgical approach for an avulsion fracture of the ischial tuberosity: a case report.

We report a case of an avulsion fracture of the ischial tuberosity treated with a new surgical approach early after injury. Although surgical treatment of this fracture is usually avoided because of the difficulty of the procedure and the risk of sciatic nerve complication, we believe our subgluteal approach is simple and safe. We therefore recommend it for treating avulsion fractures of the ischial tuberosity, especially when the fragment is displaced by >2 cm and the sciatic nerve is not involved.

Crystallization and preliminary X-ray crystallographic analysis of yeast tyrosyl-tRNA synthetase complexed with its cognate tRNA.

Yeast tyrosyl-tRNA synthetase (yTyrRS) has been crystallized by the vapor diffusion method in the presence of its cognate tRNA(Tyr). The crystals belong to a tetragonal space group P4(1)2(1)2 with cell dimensions of a = b = 63.85 Angstrom, and c = 330.

Depletion of serotonin selectively impairs short-term memory without affecting long-term memory in odor learning in the terrestrial slug Limax valentianus.

The terrestrial slug Limax is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory.

Subacute administration of tributyltin chloride modulates neurotransmitters and their metabolites in discrete brain regions of maternal mice and their F1 offspring.

Tributyltin (TBT) compounds have been used as anti-fouling agents and the central nervous system is one of its target organs. TBT-induced modulations of neurotransmitters in the brains of adult mice have been reported. However, little is known about the developmental neurotoxicity of TBT.

Low catechol-O-methyltransferase activity in the brain and blood pressure regulation.

Catecholamines (CAs) are important hormones in regulating blood pressure both in centrally and peripheral sympathetic nerve endings. Production of CAs, release and inactivation are three components to regulate CAs level. We have reported that the inactivation of CAs by catechol-O-methyltransferase (COMT) in the liver is important in high blood pressure in spontaneously hypertensive rats (SHR).

Enhancement of lactate metabolism in the basolateral amygdala by physical and psychological stress: role of benzodiazepine receptors.

Lactate is considered to play a significant role in energy metabolism and reflect neural activity in the brain. Using in vivo microdialysis technique, we measured extracellular lactate concentrations in the basolateral amygdaloid nucleus (BLA) of rats under electric footshock or psychological stress. We also attempted to determine whether the stress-induced changes of extracellular lactate concentrations in the BLA are attenuated by diazepam, an agonist at benzodiazepine receptors, and whether FG7142, an inverse agonist at benzodiazepine receptors, have a facilitative effect on energy metabolism in the BLA.

Catecholamine analysis with microcolumn LC-peroxyoxalate chemiluminescence reaction detection.

Background: Plasma catecholamines (CAs) are widely used as an index of sympathetic nervous system activity. In addition, CAs are known to be metabolized by catechol-O-methyltransferase (COMT) to produce their 3-O-methyl metabolites. We previously established a sensitive determination method of CAs and their 3-O-methyl metabolites using HPLC-peroxyoxalate chemiluminescence (POCL) reaction detection system.

Familial Parkinson mutant alpha-synuclein causes dopamine neuron dysfunction in transgenic Caenorhabditis elegans.

Mutations in alpha-synuclein gene cause familial form of Parkinson disease, and deposition of wild-type alpha-synuclein as Lewy bodies occurs as a hallmark lesion of sporadic Parkinson disease and dementia with Lewy bodies, implicating alpha-synuclein in the pathogenesis of Parkinson disease and related neurodegenerative diseases. Dopamine neurons in substantia nigra are the major site of neurodegeneration associated with alpha-synuclein deposition in Parkinson disease. Here we establish transgenic Caenorhabditis elegans (TG worms) that overexpresses wild-type or familial Parkinson mutant human alpha-synuclein in dopamine neurons.

Effect of tributyltin compound onN-methyl-D-aspartate (NMDA) receptors in brain of preweanling mice.

Objective: The aim of this study was to investigate the effect of tributyltin (TBT) compound onN-methyl-D: -aspartate (NMDA) receptors in the brains of preweanling mice.

Methods: Pregnant ICR mice were exposed to TBT chloride at concentrations of 0, 15, and 50 ppm in water. Male offspring were sacrificed at 1, 2 and 3 weeks after birth.

Determination of methylated arginines by column-switching high-performance liquid chromatography-fluorescence detection.

A column-switching high-performance liquid chromatography (HPLC)-fluorescence detection method for the determination of three methylated arginines, N(G)-monomethyl-L-arginine (L-NMMA), N(G),N(G)-dimethyl-L-arginine (asymmetric dimethyl-L-arginine, ADMA), and N(G),N(G)'-dimethyl-L-arginine (symmetric dimethyl-L-arginine, SDMA), which are endogenous nitric oxide synthase inhibitors, was developed. After fluorescence derivatization of plasma samples with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), the samples were injected into the HPLC system. The NBD-derivatized methylated arginines were trapped on a cation exchange column with filter to remove proteins, separated within 42 min on a reversed-phase column, and detected at an emission wavelength of 530 nm with excitation at 470 nm.

Increased proportion of high-affinity dopamine D2 receptors in rats with excitotoxic damage of the entorhinal cortex, an animal model of schizophrenia.

Excitotoxic lesions of the left entorhinal cortex (EC) cause dopamine supersensitivity. In order to determine if these lesions selectively alter the high-affinity state of dopamine D2 receptors (D2(High)), these high-affinity states were measured by competition between dopamine and [3H]domperidone in striata from lesioned rats and sham-operated animals. The proportion of D2(High) sites was significantly elevated by 200% in the EC-lesioned rats while that of the D1(High) sites, measured by dopamine/[3H]SCH23390 competition, was unaltered.

NC-1900, an arginine-vasopressin analogue, ameliorates social behavior deficits and hyperlocomotion in MK-801-treated rats: therapeutic implications for schizophrenia.

We previously reported that chronic administration of N-methyl-D-aspartate (NMDA) antagonists reduced the density of vasopressin V1a receptors in several brain regions in rats that demonstrated social interaction deficits and increased locomotor activity. These observations indicate the ability of arginine-vasopressin (AVP), or its analogues, to modulate behavioral abnormalities associated with blockade of NMDA receptors. The present study was performed to investigate the effect of NC-1900, an AVP analogue, on social behavior and locomotor activity in rats treated with MK-801, a non-competitive NMDA receptor antagonist.

Improved assay for catechol-O-methyltransferase activity utilizing norepinephrine as an enzymatic substrate and reversed-phase high-performance liquid chromatography with fluorescence detection.

We have previously established a rapid catechol-O-methyltransferase (COMT) assay using norepinephrine (NE) as a natural substrate and flow-injection analysis. In this study, the method is improved for screening of COMT inhibitors or activators using reversed-phase high-performance liquid chromatographic separation with fluorescence detection. The excess substrate, NE, was removed by the addition of borate in the eluent for HPLC to make an ionic complex with NE, which was eluted faster than the enzymatic product, normetanephrine.

Relationship between exploratory eye movements and brain morphology in schizophrenia spectrum patients: voxel-based morphometry of three-dimensional magnetic resonance imaging.

The exploratory eye movements of schizophrenia patients and their relatives have been shown to differ from those of patients without schizophrenia and healthy controls. However the mechanism of exploratory eye movement disturbances in schizophrenia patients remains elusive. We investigated the relationship between the exploratory eye movements and brain morphology in 39 schizophrenia spectrum patients.

Rapid assay for catechol-O-methyltransferase activity by high-performance liquid chromatography-fluorescence detection.

A rapid assay for measuring the activities of catechol-O-methyltransferase (COMT) is described. The method is based on high-performance liquid chromatography (HPLC)-fluorescence detection, and includes on-line extraction of catecholamines with a precolumn, separation of norepinephrine (NE) and normetanephrine (NMN) on an ODS column, electrochemical oxidation, and post-column fluorogenic derivatization using ethylenediamine. The method took less than 25 min for one sample, which is half that of the previous method and the sensitivity was similar.

Traumatic dislocation of the hamate and pisiform: a case report and review of the literature.

Isolated dislocation of the hamate bone and pisiform bone is rare. We describe the simultaneous complete dislocation of both the hamate and pisiform bones in a 27-year-old man who crushed his right hand in a rolling press. An open reduction and internal fixation with Kirschner wires was performed.

High-performance liquid chromatographic assay of N(G)-monomethyl-L-arginine, N(G),N(G)-dimethyl-L-arginine, and N(G),N(G)'-dimethyl-L-arginine using 4-fluoro-7-nitro-2, 1,3-benzoxadiazole as a fluorescent reagent.

N(G)-Monomethyl-L-arginine (L-NMMA), N(G),N(G)-dimethyl-L-arginine (ADMA), and N(G),N(G)'-dimethyl-L-arginine (SDMA) are emerging cardiovascular risk factors. A high-performance liquid chromatographic method with fluorescence detection for the simultaneous determination of L-NMMA, ADMA and SDMA is described. The assay employed 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) as a fluorescent derivatization reagent.

[Treatment of non-union and delayed-union by low intennsity pulsed ultrasound].

Low intensity pulsed ultrasound (LIPUS) has been used for non-union and delayed-union since 1998 in Japan. The LIPUS signal is 200 microsecond sine wave of 1.5 MHz repeating at a frequency of 1 KHz.

[Healing process of fracture].

Fracture healing consists of a sequence of events beginning with inflammation, followed by repair of the damaged tissue and then remodeling of the newly formed tissue, ultimately restoring the injured bone to its original state. Bone induction is also a sequential cascade of cellular and molecular events that includes chemotaxis, mitosis and differentiation. Several signaling molecules, such as inflammatory cytokines, morphogens and growth factors, are produced during fracture healing and initiate the cascade of critical cellular events of fracture healing.