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Biomedical subjects

S Ide

Publications and source records attributed to S Ide.

At least 19 recordsLinked to original sources

Current clamp at zero level in JT-60U current hole plasmas.

It is found that no current is driven in a central region of a tokamak plasma once the central current density becomes nearly zero ("current hole"), in spite of high electric conductivity, at the current drive by a toroidal electric field and a radio-frequency wave in experiments on the JT-60U tokamak. This is a new, stiff, self-organized structure of a magnetic field in an axisymmetric toroidal plasma.

Journal Article↗

Measurement of turbulence decorrelation during transport barrier evolution in a high-temperature fusion plasma.

A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast with the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation.

Journal Article↗

Formation of advanced tokamak plasmas without the use of an ohmic-heating solenoid.

A new operational scenario of advanced tokamak formation was demonstrated in the JT-60U tokamak. This was accomplished by electron cyclotron and lower hybrid waves, neutral beam injection, and the loop voltage supplied by the vertical field and shaping coils. The Ohmic heating (OH) solenoid was not used but a small inboard coil (part of the shaping coil), providing less than 20% of total poloidal flux, was used. The plasma thus obtained had both internal and edge transport barriers, with an energy confinement time of 1.6 times H-mode scaling, a poloidal beta of 3.6, and a normalized beta of 1.6, and a large bootstrap current fraction (>90%). This result opens up a possibility to reduce, and eventually eliminate, the OH solenoid from a tokamak reactor, which will greatly improve its economic competitiveness.

Journal Article↗

Changes in expression of the mouse homologues of KIAA genes after subchronic methamphetamine treatment.

Amphetamine abuse may be associated with adaptive changes in gene expression in the brain. In the present study, a newly developed cDNA array system comprising mouse KIAA (mKIAA) cDNA clones was used to examine the gene expression affected by chronic methamphetamine treatment. Approximately 800 mKIAA clones were blotted onto a nylon membrane and hybridized with 33P-labeled cDNA derived from mRNAs isolated from the whole brains of mice that had been treated daily with saline or methamphetamine (2 mg/kg, i.p.) for 2 weeks. The arrays displayed robust hybridization for almost all transcripts. The results obtained from five experiments were averaged, each performed with triplicate samples. Several clones were chosen as positive candidates for methamphetamine-induced changes; however, only Per2 and mKIAA0099 genes showed a significantly increased expression (P < .05). Subsequently, with the focus on the period-related proteins, the expression of these proteins in various parts of the rat brain were assessed by immunoblot analysis. Chronic administration of methamphetamine (8 mg/kg, i.p., for 10 days) caused increased Per2 protein expression in the hippocampus. Interestingly, chronic methamphetamine treatment at a lower dose (4 mg/kg, i.p., for 10 days) induced an increase in SCN circadian oscillatory protein (SCOP) expression, also in the hippocampus. These data suggest that long-lasting alterations of the period-related gene expressions in the hippocampus might play an important role in methamphetamine addiction.

Animals↗

Fourier transform infrared spectra and molecular structure of 5-methoxytryptamine, N-acetyl-5-methoxytryptamine and N-phenylsulfonamide-5-methoxytryptamine.

5-Methoxytryptamine (5-MT) is a potent antioxidant and has radioprotective action. N-acetyl-5-methoxytryptamine (melatonin, NA-5-MT) is a free radical scavenger and antioxidant, which protects against oxidative damage due to a variety of toxicants. The infrared spectra of 5-MT, NA-5-MT and new synthesized N-phenylsulfonamide-5-methoxytryptamine (PS-5-MT) were investigated in the region between 4000 and 400 cm(-1). Vibrational assignments of the molecules have been made for fundamental modes on the basis of the group vibrational concept, infrared intensity and comparison with the assignments for related molecules. X-ray powder diffraction patterns of molecules were also recorded. In order to optimize the geometries of the molecules, molecular mechanic calculations (MM3) were performed. Conformational analysis of 5-MT, NA-5-MT and PS-5-MT was also established by the using PM3 method.

5-Methoxytryptamine↗

Evolution of lower-hybrid-driven current during the formation of an internal transport barrier.

Evolution of the lower-hybrid(LH)-driven current profile was measured during the formation of an internal transport barrier (ITB) in a reversed magnetic shear discharge. As the ITB developed, the initially centrally peaked LH-driven current profile gradually turned hollow and was sometimes accompanied by an off-axis peak in the electron temperature profile. These observations indicate the concentration of LH power deposition to the ITB for this case as a result of nonlinear coupling between the LH waves and the target plasma.

Journal Article↗

Plasma equilibrium and confinement in a tokamak with nearly zero central current density in JT-60U.

A high confinement equilibrium with nearly zero toroidal current in the central region (a "current hole") has been observed for the first time to persist stably for several seconds in the JT-60U tokamak. This observation indicates the possibility of stable tokamak operation without central toroidal current; the central current has previously been believed to be necessary in tokamaks. The radius of the current hole extended up to 40% of the plasma minor radius. It was observed that the current hole was formed by the increase of the off-axis noninductive current.

Journal Article↗

[Bis(diphenylphosphino)methane][1,3-bis(diphenylphosphino)propane]platinum(II) dibromide.

The asymmetric unit of the title compound, [Pt(C(25)H(22)P(2))(C(27)H(26)P(2))]Br(2) or [Pt(dppm)(dppp)]Br(2), where dppm is bis(diphenylphosphino)methane and dppp is 1,3-bis(diphenylphosphino)propane, consists of a discrete [Pt(dppm)(dppp)](2+) cation and two Br(-) anions at van der Waals distances. This is the first reported platinum(II) complex containing both dppm and dppp ligands. Noticeable features are that the coordination of platinum by the differing dppm and dppp ligands produces a distorted coordination geometry with differing ligand bite angles (and to a lesser extent bond distances), and that the strain induced by the formation of the four-membered dppm chelate ring has a marked effect upon the bond angles at the P atoms of this ligand.

Journal Article↗

Quasisteady high-confinement reversed shear plasma with large bootstrap current fraction under full noninductive current drive condition in JT-60U.

A quasisteady reversed shear plasma with a large bootstrap current fraction ( approximately 80%) has been obtained for the first time in the JT-60U tokamak. The shrinkage of reversed shear region was suppressed by the bootstrap current peaked at the internal transport barrier (ITB) layer and the ITBs at a large radius were sustained, which, by combination with an H-mode edge pedestal, resulted in a high confinement or 2.2 times the H-mode scaling for 6 times energy confinement time or 2.7 s. Furthermore, a full noninductive current drive was obtained by the bootstrap current and the beam driven current.

Journal Article↗

A simple contrast enhancement by potassium permanganate oxidation for Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution.

A simple contrast enhancement method is presented for Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution. The sections were treated with an acidified potassium permanganate oxidizing solution followed by uranyl acetate and lead citrate staining. The method, designated KMnO4-UA/Pb staining, provided a much greater contrast in electron microscopy than conventional UA/Pb staining. In detail, the visibility of plasma membrane was especially improved and the nuclear heterochromatin, mitochondria and cytoplasmic ribosomes showed an adequate increase in electron density. In the mucous cells of rat Brunner's glands, the Golgi cisternae were well defined with the KMnO4-UA/Pb staining. Interestingly, the membranes of the intermediate compartments were moderately reactive to the KMnO4-UA/Pb staining, whereas the cis and the trans compartments were only faintly stained. It should be emphasized that the KMnO4 oxidation following colloidal gold labelling did not cause a remarkable reduction of immunogold labelling and the enhanced contrast helped us to examine the gold particles with high accuracy. This contrast enhancement method is highly promising, with the potential to become a useful tool for histochemical investigation, including immunocytochemistry with the Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution techniques.

Acrylic Resins↗

Fever and survival with drug-treated non-small cell lung cancer.

Patients with non-small cell lung cancer who develop fever during anti-neoplastic chemotherapy are treated empirically, before the cause of fever has been determined. Little study has been made of episodes of infection during chemotherapy with respect to antineoplastic response, other adverse reactions, or survival time. In particular, the relationship between fever and long-term survival is not clear. The prognostic significance of febrile episodes was investigated in patients with non-small cell lung cancer receiving full-dose chemotherapy. Most were treated only with chemotherapy during the period of investigation, although some had concurrent or subsequent radiotherapy, and a few had surgery following chemotherapy. No significant difference was seen between febrile and afebrile patients regarding therapeutic modality. Patients with poor performance status (PS) had a higher incidence of febrile episodes (P < .001). Multivariate analysis, however, showed febrile episodes to be a major prognostic factor independent of PS on clinical stage. PS and stage affected short-term survival, while febrile episodes were related to decreased long-term survival (203 vs. 366 days; with deaths in the first 3 months excluded, 241 vs. 377 days). Although existing evidence is inconclusive, our study suggests that prevention of infection during antineoplastic treatment by administration of granulocyte stimulating factors and early initiation of antimicrobials might improve long-term survival.

Adult↗

Treatment of ulcerative endobronchial tuberculosis and bronchial stenosis with aerosolized streptomycin and steroids.

OBJECTIVES: Endobronchial tuberculosis (EBTB) is defined as a tuberculous infection of the tracheobronchial tree. It has been reported that aerosolized therapy with streptomycin and steroids is useful for EBTB; however, the effectiveness of this therapy for bronchial stenosis has yet to be clarified. This study was undertaken to determine the effectiveness of aerosol therapy in the treatment of bronchial stenosis due to EBTB. DESIGN: An observational, historical, controlled comparative study. Retrospective analysis of 27 patients treated with conventional therapy, and prospective analysis of 30 patients treated with aerosol therapy. METHOD AND PATIENTS: Flexible bronchoscopy was performed at least twice in 57 patients with ulcerative EBTB, in whom the degree of bronchial stenosis between the first and last bronchoscopic examinations was estimated. Bronchial stenosis was graded as minimal, mild, moderate, severe or obstructive, and the follow-up of bronchial stenosis assessed as aggravation, no change or improvement. RESULTS: Conventional therapies led to aggravation in 13 patients, no change in 13 patients, and improvement in one patient. Aerosol therapy led to no change in 27 patients, and improvement in three patients. No patients developed aggravation. The differences between the therapeutic groups were significant. CONCLUSION: Aerosol therapy helps to prevent progressively severe bronchial stenosis due to EBTB.

Administration, Inhalation↗

Efficacy of the novel selective platelet-derived growth factor receptor antagonist CT52923 on cellular proliferation, migration, and suppression of neointima following vascular injury.

Exaggerated or inappropriate signaling by the platelet-derived growth factor receptor (PDGFR) tyrosine kinase has been implicated in a wide variety of diseases. Thus, a series of piperazinyl quinazoline compounds were identified as potent antagonists of the PDGFR by screening chemical libraries. An optimized analog, CT52923, was shown to be an ATP-competitive inhibitor that exhibited remarkable specificity when tested against other kinases, including all members of the closely related PDGFR family. The PDGFRs and stem cell factor receptor were inhibited with an IC(50) of 100 to 200 nM, while 45- to >200-fold higher concentrations of CT52923 were required to inhibit fms-like tyrosine kinase-3 and colony-stimulating factor-1 receptor, respectively. Other receptor tyrosine kinases, cytoplasmic tyrosine kinases, serine/threonine kinases, or members of the mitogen-activated protein kinase pathway were not significantly inhibited at 100- to 1000-fold higher concentrations. In addition, this compound also demonstrated specificity for inhibition of cellular responses. Platelet-derived growth factor-induced smooth muscle cell migration or fibroblast proliferation was found to be blocked by CT52923 with an IC(50) of 64 and 280 nM, respectively, whereas 50- to 100-fold higher concentrations were required to inhibit these responses when induced with fibroblast growth factor. To investigate the effect of CT52923 on PDGFR signaling, in vivo studies demonstrated that CT52923 could significantly inhibit neointima formation following carotid artery injury by oral administration in the rat. Therefore, PDGFR antagonism by CT52923 could be a viable strategy for the prevention of clinical restenosis or the treatment of other human diseases involving PDGFR signaling.

Angioplasty, Balloon↗

Depression among caregivers of elderly patients on chronic hemodialysis.

The present study was conducted to investigate depression in caregivers of elderly hemodialysis patients. Caregivers answered a self-administered questionnaire about various factors that may affect their depression, and also completed a Center for Epidemiologic Studies Depression Scale evaluation (CESD). The frail elderly who received regular nurse visits were used as controls. Compared with the caregivers of controls, those of hemodialysis patients spent less time on caregiving and had more time to go out unaccompanied by their patients. Males were numerous among hemodialysis patients than in the controls. Compared with the controls, hemodialysis patients were less likely to be older old (80 years old and more), diagnosed as demented or severely limited in activities of daily living (ADL). On the other hand, we did not find any significant difference between the two groups with regard to either the prevalence of depression, the rate of those who experienced any life event such as to cause depression within 6 months (e.g., death of family member), duration of caregiving or time looking after patients. Caregivers of hemodialyis patients may feel a heavy burden because they are obliged to play an important role in supporting patients on dialysis. They seem to need more social support regardless of whether or not their patients suffer from dementia.

Aged↗

Depression among caregivers of the frail elderly in urban Japan.

A cross-sectional study was conducted in order to investigate the various factors related to the depression in caregivers of the elderly in need of care in urban Japan. The caregivers answered a self-administered questionnaire about various factors that may affect their depression, and also completed a Center for Epidemiologic Studies Depression Scale evaluation (CES-D). Compared with non-depressed caregivers, depressed caregivers attended the elderly longer, while time spent for physical caregiving did not differ between the two groups. Even after controlling confounding factors, time of attending the elderly was an independent factor related to caregiver's depression.

Aged↗

Tuft cells in the main excretory duct of the rat submandibular gland.

The fine structure of tuft cells in the main excretory duct of rat submandibular gland was investigated using the high pressure freezing and freeze substitution (HPF-FS) method and compared with that seen with both conventional chemical fixation (CF) method and en bloc treatment with ruthenium red. Some MEDs also were subjected to histochemistry for lectins. The apical vesicles and tubules of tuft cells observed by TEM after the HPF-FS method were different in shape from those treated by CF. With the first method, these vesicles and tubules, which may represent sections of a tubular system, appeared more slender and filled with a material of moderate density. A prominent glycocalyx covering the microvillar plasma membrane was observed in tuft cells processed both with the HPF-FS method and with ruthenium red. The surface of microvilli and the tubulo-vesicular structures of these cells exhibited the same soybean agglutinin (SBA) reactivity, suggesting a relationship between them.

Animals↗