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Biomedical subjects

Naoki Hayashi

Publications and source records attributed to Naoki Hayashi.

At least 19 recordsLinked to original sources
PubMed2007

Synaptotagmin XI as a candidate gene for susceptibility to schizophrenia.

Synaptotagmin XI (Syt11) is a member of the synaptotagmin family, which is localized in cells either in synaptic vesicles or the cellular membrane, and is known to act as a calcium sensor. The Syt11 gene is located on chromosome locus 1q21-q22, which was previously reported as a major susceptibility locus of familial schizophrenia. Here, we present evidence for an association between the number of 33-bp repeats in the promoter region of the Syt11 gene and schizophrenia. We found that the transcriptional activity of the gene is affected by the number of 33-bp repeats, which include an Sp1 binding site, suggesting that the excessive expression of Syt11 can be associated with schizophrenia. Another (single nucleotide) polymorphism in the Syt11 5'UTR region, where the potent transcription factor YY1 can bind, also affects the transcriptional activity of Syt11.

Base Sequence↗
PubMed2006

Stereotactic imaging for radiosurgery: localization accuracy of magnetic resonance imaging and positron emission tomography compared with computed tomography.

Computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) provide complementary information for treatment planning in stereotactic radiosurgery. We evaluated the localization accuracy of MRI and PET compared with CT. Two kinds of phantoms applicable to the Leksell G stereotactic skull frame (Elekta, Tokyo) were developed. Deviations of measured coordinates at target points (x = 50, 100, 150; y = 50, 100, 150) were determined on different axial planes (z = 30-140 for MRI and CT study and Z = 50-120 for PET and CT study). For MRI, the deviations were no more than 0.8 mm in each direction. For PET, the deviations were no more than 2.7 mm. For both imaging modalities studied, accuracy was at or below the imaging resolution (pixel size) and should be considered useful for clinical stereotactic planning purposes.

Fluorodeoxyglucose F18↗
PubMed2005

Evidence for a wide distribution of negative motor areas in the perirolandic cortex.

OBJECTIVE: The perirolandic regions were studied by extensive electrical stimulation to clarify the topography and somatotopic distribution of negative motor areas (NMAs) and examine the clinical significance of these areas. METHODS: We evaluated the cortical function elicited by electrical stimulation in 30 patients with tumors or intractable epilepsy. The somatotopic distribution of NMAs was examined by localizing these regions using Talairach's bicommissural reference system. NMAs within the lesions of two patients were removed under local anesthesia. RESULTS: We obtained negative motor responses following the stimulation of 30 electrodes in 15 patients. On the lateral brain surface, the majority of NMAs for the upper extremities were distributed broadly throughout the premotor cortex, while NMAs for the tongue were only found in the inferior frontal gyrus of the dominant hemisphere. During removal of the NMAs within the lesions of two patients, we documented transient hand clumsiness in one patient. CONCLUSIONS: NMAs were widely distributed throughout the perirolandic area, as well as the previously reported regions in the inferior frontal gyrus. These areas likely function in the control of skilled movements; dysfunction of such movements transiently follows resection of these regions, but is subsequently well compensated for after surgery. SIGNIFICANCE: The localization and consequences of resection of NMAs suggests their clinical significance in motor control.

Adolescent↗
PubMed2005

Inter- and intramolecular radical couplings of ene-ynes or halo-alkenes promoted by an InCl3/MeONa/Ph2SiH2 system.

[reaction: see text] An effective generation of indium hydride (HInCl(2)) under nonacidic conditions is achieved by transmetalation between Ph(2)SiH(2) and InCl(2)OMe. The presented system achieves the titled coupling reactions in a radical manner. In particular, the nonacidic character enables the applications to acid-sensitive inter- and intramolecular ene-yne couplings.

Journal Article↗
PubMed2005

Evidence for de Vries structure in a smectic-A liquid crystal observed by polarized Raman scattering.

The second- and fourth-order apparent orientational order parameters of the core part of the molecule P2 (app) and P4 (app) , have been measured by polarized vibrational Raman spectroscopy for a homogeneously aligned ferroelectric smectic liquid crystal with three dimethyl siloxane groups in the achiral terminal chain, which shows de Vries-type phenomena, i.e., very large electroclinic effect in the smectic- A (Sm-A) phase and a negligible layer contraction at the phase transition between the Sm-A and Sm- C(*) phases. The apparent orientational order parameters of the rigid core part of the molecule are extremely small both with and without the external electric field in Sm-A . These results provide evidence for the existence of the de Vries Sm-A phase, where the local molecular director is tilted at a large angle.

Journal Article↗
PubMed2005

Occupation and social experience: Factors influencing attitude towards people with schizophrenia.

The purpose of the present study was to examine the role of occupation and social experience as factors determining the attitude of psychiatric care workers and other workers from various backgrounds toward people with schizophrenia. To measure the attitude of 786 subjects from six occupational groups toward people with schizophrenia, the evaluation scale applying semantic differential technique and the modified Social Rejection Scale were used, which assess two aspects of the attitude: affective acceptance and social distancing, respectively. The results of the two scales from the six groups were similar on the whole. Public health nurses showed the most accepting attitude in both scales. Psychiatric nurses and local welfare commissioners were the second and the third groups in affective acceptance, and the third and the second in socially accepting behavior, respectively. There was no significant difference in attitude among the rest of the groups (non-psychiatric care workers, professional probation officers and non-care workers). These results can be understood in terms of the workers' experience of contact with people with schizophrenia, and education and other support opportunities. The importance of positive contact experiences and the means for facilitation of an accepting attitude in psychiatric care workers and other workers need to be stressed.

Adult↗
PubMed2005

Predicting features of later development of schizophrenia among patients with acute and transient psychotic disorder.

It is acknowledged that a considerable proportion of patients who have an episode of acute and transient psychotic disorder (ATPD), will develop schizophrenia after the episode is remitted. If features discriminating the patients who later developed schizophrenia from those who underwent a monomorphous ATPD-only course are discerned, they may be useful for predicting the prognosis. The authors performed a chart review study of those who were hospitalized with the diagnosis of ATPD and followed up thereafter for >5 years and compared two subject groups: 10 later-schizophrenia-developing (SD) patients and 15 non-schizophrenia-developing (non-SD) patients. Assessment of the subjects, conducted by two psychiatrist raters blind to the subject groups, included frequency of ATPD episodes, adaptation levels and life events before admission, and psychiatric symptoms before and after admission. The interrater reliability of the assessment proved to be favorable. As a result, early recurrence of psychotic episodes in the follow-up period, lack of acute upsurge of insomnia in an early phase of the episode and poor premorbid heterosexual relations characterized the SD patients. The result indicated heterogeneity of ATPD episodes.

Acute Disease↗
PubMed2004

Triethylsilane-indium(III) chloride system as a radical reagent.

[reaction: see text] A novel generation method of indium hydride (Cl2InH) was found by the transmetalation of InCl3 with Et3SiH. In the intramolecular cyclization of enynes, the previously reported system (NaBH4-InCl3) has a problem of side reactions with the coexistent borane. In contrast, the problem was solved by the presented system, which affords effective hydroindation of alkynes.

Journal Article↗
PubMed2004

Phenomenological features of auditory hallucinations and their symptomatological relevance.

Auditory hallucinations include particularly diverse phenomena that reflect various mental functions and pathologies. Their assessment may provide valuable clinical information. This article describes the development of the Matsuzawa Assessment Schedule for Auditory Hallucination (MASAH), which was designed to obtain a broadened view of the phenomena by investigating a wide range of their characteristics. The aim was to identify the basic phenomenological features of auditory hallucinations by performing a factor analytic study of the MASAH ratings of 214 patients with schizophrenia or schizoaffective disorder. Four identified factors were intractability, delusion, influence, and externality, on the basis of which we constructed composite scales that were assumed to represent the features. The correlation analysis of the scales with symptom dimensions derived from the positive and negative syndrome scale verified their clinical relevance. They were also interpretable in terms of human responses to the abnormal experience and some symptom constructs such as delusion and influence experience. It is concluded that the MASAH is an efficient means for evaluating the features, and that this study elicited new understandings of the phenomena such as their multifarious composition and contiguities with other psychotic symptoms.

Adult↗
PubMed2004

Community discharge of patients with schizophrenia: a Japanese experience.

In Japan, admission to a psychiatric facility for people with schizophrenia is usually for life. We developed a rehabilitation program aimed at discharging these patients into the Tokyo community. This paper describes the results for the 224 patients. Using an inpatient ward at the Tokyo Musashino Hospital, patients were enrolled in the program and subsequently discharged into the community with an assigned worker. The results indicate for the majority (79%) re-integration into the community was successful. The success of this program in a metropolitan city like Tokyo argues for the efficacy of such programs.

Adult↗
PubMed2003

Intrinsic aspect of V-shaped switching in ferroelectric liquid crystals: biaxial anchoring arising from peculiar short axis biasing in the molecular rotation around the long axis.

To clarify the intrinsic aspect of practically usable thresholdless V-shaped switching in ferroelectric liquid crystals, we have observed textures and measured polarized Raman scattering as well as optical transmittance in a thin homogeneous cell of a single compound by applying an electric field. The results indicate that the so-called surface stabilized ferroelectric states are destabilized, and that there exist rather stable two domains with broad and narrow molecular orientational distributions, both of which show the almost ideal V-shaped switching with considerably low transmittance at the tip of the V. We have concluded that the main cause of the V-shaped switching is the biaxial anchoring on the substrates coated with polyimide, which makes the most polarizable short axis normal to the substrates. It is in competition with the ordinary anchoring that favors the director parallel to the substrates, when the material has such a bulk intrinsic property that this short axis is parallel to the tilt plane. The competition makes the total anchoring energy almost independent of the azimuthal angle and gives rise to the V-shaped switching.

Journal Article↗
PubMed2003

Serotonin stimulates endotoxin translocation via 5-HT3 receptors in the rat ileum.

Because few previous studies have investigated the mechanisms of endotoxin translocation induced by intestinal obstruction, we aimed to clarify whether or not serotonin [5-hydroxytryptamine (5-HT)], which is released from enterochromaffin (EC) cells, is responsible for alterations of the mucosal permeability to endotoxin and to identify the 5-HT receptor subtypes that mediate this action. FITC-labeled LPS (FITC-LPS) was injected into the ileum of rats, and the FITC-LPS level in the superior mesenteric vein was subsequently measured by using a fluorescence spectrophotometer. To measure the 5-HT release induced by high intraluminal pressure, ex vivo preparation of vascularly and luminally perfused rat ileum was used. Results demonstrated that elevated intraluminal pressure stimulates the translocation of FITC-LPS and the release of 5-HT from the EC cells into the intestinal lumen but not into the portal circulation. This FITC-LPS translocation, which was stimulated by exogenously applied 5-HT in the lumen and the jugular vein, was inhibited by 5-HT(3) receptor antagonist administration both intaluminally and intravenously. The stimulatory effect of elevated intraluminal pressure on the translocation of FITC-LPS was inhibited by the intraluminal and intravenous administration of 5-HT(3) receptor antagonist. These results suggest that 5-HT released from EC cells may be involved in the translocation of FITC-LPS induced by elevated intraluminal pressure and that this effect is mediated by 5-HT(3) receptors that may be located in the intestinal epithelium.

Animals↗
PubMed2002

Orientational distributions in smectic liquid crystals showing V-shaped switching investigated by polarized Raman scattering.

Molecular orientational order parameters have been obtained by Raman scattering in two types of liquid crystal materials showing the V-shaped switching in thin homogeneous cells. One is the Mitsui mixture and the other is one component of the Inui mixture. The antiferroelectric phase exists in the bulk of both materials but, in thin homogeneous cells, the stability is distinct from each other. The obtained distribution of the local in-plane directors at the tip of the V is considerably broad in the former, while it is narrow in the latter. These differences have been explained by the barrier between the ferroelectric and antiferroelectric orderings, the chiral twisting power, and the interface induced destruction of the antiferroelectric ordering.

Journal Article↗