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Biomedical subjects

Y Homma

Publications and source records attributed to Y Homma.

At least 19 recordsLinked to original sources
PubMed2005

NMR evidence for triple-q multipole structure in NpO2.

In order to elucidate the nature of the exotic ordered phase of NpO2 below T(0)=26 K, we have initiated the first 17O-NMR measurements on this system. From the 17O-NMR spectrum, the occurrence of two inequivalent oxygen sites has been confirmed below T0. It has also been shown that the characteristic features of the hyperfine interaction at the oxygen sites are well explained by invoking a hyperfine interaction with field-induced antiferromagnetic moments which appear as a result of the triple-q antiferroquadrupolar order. The NMR findings strongly support the occurrence of the longitudinal triple-q multipole structure in NpO2.

Journal Article↗
PubMed2004

Health-related quality of life of Japanese patients with overactive bladder treated with extended-release tolterodine or immediate-release oxybutynin: a randomized, placebo-controlled trial.

Overactive bladder (OAB) has a significant impact on a patient's health-related quality of life (HRQoL). This study assessed the HRQoL of Japanese OAB patients following 12 weeks' treatment with tolterodine extended release (ER) or oxybutynin. A total of 293 patients with symptoms of OAB were randomized for treatment with tolterodine ER 4 mg once daily (n=114), oxybutynin 3 mg three times daily (n=122) or a placebo (n=57). Treatment efficacy and safety assessments were made over the 12-week period. HRQoL was assessed using the King's Health Questionnaire (KHQ). Patients receiving tolterodine ER or oxybutynin showed a significant (P<0.05) improvement in the Incontinence Impact, Role Limitations and most other KHQ domains compared with the placebo. These changes in HRQoL corresponded with significant (P<0.05) improvements in micturition diary variables for patients receiving tolterodine ER and oxybutynin compared with placebo. Our findings demonstrate that Japanese OAB patients receiving tolterodine ER or oxybutynin experienced overall improvement in their quality of life.

Adult↗
PubMed2004

A PLCdelta1-binding protein, p122RhoGAP, is localized in focal adhesions.

We have investigated the cellular distribution of p122RhoGAP, a GTPase-activating protein of Rho small GTPase and an activator of phospholipase C-delta(1). Immunofluorescence studies demonstrated that endogenous p122 is localized at the tips of actin stress fibres and co-localizes with vinculin in normal rat kidney cells. In immunoprecipitation studies, p122 co-precipitated with vinculin, indicating that p122 is localized at the sites of focal adhesion. We have also shown that the N-terminal half of p122 is responsible for this localization. It is conceivable, therefore, that p122 is involved in the reorganization of the actin cytoskeleton and focal adhesions that regulate cell-substratum adhesion and cell migration.

Animals↗
PubMed2004

Use of the short form of King's Health Questionnaire to measure quality of life in patients with an overactive bladder.

OBJECTIVE: To develop a short version of the King's Health Questionnaire (KHQ), as there is a practical need to have a shorter version to summarize the eight domain scores into fewer domains. PATIENTS AND METHODS: Data from 293 patients were obtained from a randomized, double-blind, placebo-controlled clinical trial in Japan of oxybutynin and tolterodine in patients with symptoms of an overactive bladder. The KHQ has two single-item and six multiple-item domains. To construct the short form of the KHQ one item was selected from the each of multiple-item domains, based on standardized structural coefficients estimated by confirmatory factor analysis (CFA) in a previous study. These six items include the domains: 'daily activities from role limitation', 'travel from physical limitation', 'social life from social limitation', 'family life from personal relationship', 'depressed from emotion' and 'tired from sleep and energy'. Based on the six selected items a series of psychometric analyses were conducted. RESULTS: Exploratory factor analysis (EFA) with promax rotation identified two factors 'limitation of daily life' (LDL) and mental health. LDL consisted of 'daily activities', 'travel' and 'social life', and mental health included 'family life', 'depressed' and 'tired'. Based on the results from the EFA, the second-order factor structure was tested by CFA. The model fitted the data well for both the male and female model. The KHQ short form showed excellent reliability with Cronbach's alpha coefficients for LDL and mental health for both genders. The domains in the short form were responsive to clinical efficacy variables, and had statistically significant sensitivity to change in the patients' perception of bladder condition in all domains. CONCLUSION: These analyses confirm the psychometric properties and clinical validity of the short-form KHQ, which appears to offer a practical, valid and reliable health-related quality-of-life instrument.

Aged↗
PubMed2003

Bright band gap photoluminescence from unprocessed single-walled carbon nanotubes.

Unprocessed single-walled carbon nanotubes suspended in air at room temperature emit bright, sharply peaked band gap photoluminescence. This is in contrast with measurements taken from nanotubes lying on the flat surface for which no luminescence was detected. Each individual nanotube has a luminescence peak of similar linewidth ( approximately 13 meV), with different species emitting at various different wavelengths spanning at least 1.0 to 1.6 microm. A strong enhancement of photoluminescence intensity is observed when the excitation wavelength is resonant with the second Van Hove singularity, unambiguously confirming the origin of the photoluminescence.

Journal Article↗
PubMed2003

Biochemical markers of vasospastic coronary artery disease.

OBJECTIVE: The risk factors for vasospastic angina pectoris (VSA) have not yet been well defined. We compared the plasma levels of lipids, apo(lipo)proteins, remnants of triglyceride (TG)-rich lipoproteins, oxidized low density lipoprotein (Ox-LDL), cholesteryl ester transfer protein (CETP) [which transfers esterified cholesterol (EC) from HDL to TG-rich lipoproteins and reduces plasma HDL levels], high-sensitivity C-reactive protein (hs-CRP), homocysteine and plasminogen-activator inhibitor (PAI)-1 in background-matched groups of controls, and patients with VSA or coronary atherosclerotic disease (CAD) (n=50 subjects each). METHODS AND RESULTS: The cholesterol levels of remnant-like particles (RLP), which are equivalent to the remnants of TG-rich lipoproteins, were measured using a precipitation method. Ox-LDL, CETP and PAI-1 were measured by means of sandwich ELISA; hs-CRP by means of nephelometry; and homocysteine by means of HPLC. Plasma LDL-C levels were high only in the CAD group, and plasma apo E and PAI-1 levels were high only in the VSA group. The plasma levels of TG, apo CII and RLP-C were highest in the VSA group, followed by the CAD group. The plasma levels of apoB, apo CIII, Ox-LDL, CETP, hs-CRP and homocysteine were equally increased in both the VSA and CAD groups. The increases in plasma RLP-C, CETP, hs-CRP and homocysteine were not significantly different between stable and unstable states of angina pectoris in either the VSA or CAD group. CONCLUSION: The increases in plasma TG-rich lipoproteins and their remnants were more significant markers of VSA than of CAD. The increases in plasma CETP, Ox-LDL, hs-CRP and homocysteine were equally important markers of VAS and CAD.

Analysis of Variance↗
PubMed2003

A prospective and randomized study of primary hormonal therapy for patients with localized or locally advanced prostate cancer unsuitable for radical prostatectomy: results of the 5-year follow-up.

OBJECTIVE: To evaluate the effect of primary hormonal therapy for patients with localized and locally advanced prostate cancer. PATIENTS AND METHODS: Patients with stage T1b-T3 prostate cancer who were not scheduled for radical prostatectomy were allocated into two groups: group 1 (73 men) received luteinizing hormone-releasing hormone (LHRH) agonist monotherapy and group 2 (78 men) received LHRH agonist and chlormadinone acetate. Patients were followed using serum prostate specific antigen levels, prostate size and the detection of distant metastasis for 5 years. RESULTS: The median (range) follow-up was 78 (63-87) months. The 5-year progression-free survival rate was significantly higher in group 2 (68%) than in group 1 (47%). However, the overall and cause-specific survival rate at 5 years were similar in both groups, at 72% and 93% in group 1, and 64% and 89% in group 2, respectively. CONCLUSION: The overall survival rates of the both groups were no different from that of the normal Japanese population of the same age group. Although this study did not include an untreated group, i.e. watchful waiting, these results might indicate the usefulness of primary hormonal therapy in controlling localized and locally advanced prostate cancer. The 5-year observation period is still short and the study is continuing to determine the 10-year survival.

Aged↗
PubMed2003

Clinical efficacy and tolerability of extended-release tolterodine and immediate-release oxybutynin in Japanese and Korean patients with an overactive bladder: a randomized, placebo-controlled trial.

OBJECTIVE: To compare extended-release (ER) tolterodine and immediate-release (IR) oxybutynin with placebo in Japanese and Korean patients with an overactive bladder (OAB). PATIENTS AND METHODS: Men and women aged >or= 20 years with symptoms of urinary urgency, urinary frequency (>or= 8 micturitions/24 h), urge incontinence (>or= 5 episodes/week) and symptoms of OAB for >or= 6 months were randomized to double-blind treatment with tolterodine ER 4 mg once daily, oxybutynin IR 3 mg three times daily or placebo for 12 weeks. Efficacy assessments included changes from baseline in numbers of incontinence episodes per week, voids/24 h and mean volume voided/void. Patient perceptions of bladder condition, urgency and treatment benefit were also assessed. RESULTS: In all, 608 patients were randomized to treatment with tolterodine (240), oxybutynin (246) or placebo (122). More patients prematurely withdrew on oxybutynin (23%) than with tolterodine (10.4%) or placebo (16.4%). After 12 weeks of treatment, the median number of incontinence episodes/week was reduced significantly more in the tolterodine (79%; P= 0.0027) and oxybutynin groups (76.5%; P= 0.0168) than on placebo (46.4%). There were also significantly greater improvements in the number of voids/24 h and volume voided/void with tolterodine and oxybutynin than with placebo. More patients in the tolterodine and oxybutynin than in the placebo groups reported improvements in perceived bladder condition, ability to hold urine and treatment benefit. Patients treated with oxybutynin reported more adverse events than those treated with tolterodine or placebo. Dry mouth was significantly more common with oxybutynin than with tolterodine (53.7% vs. 33.5%; P < 0.001), and occurred in 9.8% of placebo patients. CONCLUSION: Tolterodine ER has similar efficacy but is better tolerated than oxybutynin IR in Japanese and Korean patients with OAB.

Adult↗
PubMed2002

Dissociation between airway responsiveness to methacholine and responsiveness to antigen.

Repeated aerosolized antigen challenges to brown Norway (BN) rats generate nonspecific airway hyperresponsiveness (AHR). On the other hand, some studies have demonstrated that repeated antigen challenge could attenuate antigen-specific AHR in BN rats. The authors questioned whether such dissociation in airway responses actually occurs when assessed in a single study in the same animals. The authors simultaneously measured AHR to methacholine and antigen-specific AHR in rats that were repeatedly exposed to aerosolized ovalbumin (OA) for 1 or 3 months after sensitization. Four days after the last challenge, airway responses to methacholine and OA, morphometry of the airways, the cell profile in bronchoalveolar lavage fluid, and cytokine messenger ribonucleic acid (mRNA) expression in the lungs were evaluated. The two types of AHR were modulated in opposite directions by repeated antigen challenges. The AHR to methacholine was significantly increased in the rats receiving antigen challenges compared with the control rats receiving saline challenges after sensitization; whereas, the antigen-specific AHR was significantly decreased. The number of alveolar macrophages in lavaged fluid and the expression of transforming growth factor-beta1 mRNA in lung tissue was significantly different between the antigen-challenged rats and the control rats. In conclusion, dissociation between nonspecific airway hyperresponsiveness and antigen-specific airway hyperresponsiveness in brown Norway rats after repeated antigen challenges was demonstrated. Sustained airway inflammation with macrophages and/or upregulation of transforming growth factor-beta1 messenger ribonucleic acid in the lung tissue may be responsible for this dissociation.

Aerosols↗
PubMed2001

Involvement of a novel zinc finger protein, MIZF, in transcriptional repression by interacting with a methyl-CpG-binding protein, MBD2.

MBD2, a methyl-CpG-binding protein, is a component of the MeCP1 histone deacetylase (HDAC) complex and plays a critical role in DNA methylation-mediated transcriptional repression. To understand the molecular basis of the methylation-associated repression, we attempted to identify MBD2-interacting proteins by a yeast two-hybrid system. Using MBD2 as bait, we isolated a novel zinc finger protein, referred to as MIZF. A direct interaction between MBD2 and MIZF was confirmed by in vitro binding assays and immunoprecipitation experiments. Four of seven zinc fingers present in the C-terminal region of MIZF are required for binding with MBD2. The MIZF mRNA is expressed in all human tissues and cell lines examined. The subcellular localization of MIZF is distinct from that of MBD2, although both proteins co-localize in some areas of the nuclei; MIZF localizes diffusely in the nucleoplasmic region, whereas MBD2 preferentially localizes in major satellites. A reporter assay demonstrated that MIZF significantly abrogates transcriptional activities. This repression is attenuated by an HDAC inhibitor, trichostatin A, and is completely dependent on the interaction with MBD2. These results suggest that MIZF is abundantly present in cells and functions as a negative regulator of transcription by binding to MBD2 and recruiting HDAC-containing complexes.

Amino Acid Sequence↗
PubMed2001

c-Jun N-terminal kinase (JNK)-interacting protein-1b/islet-brain-1 scaffolds Alzheimer's amyloid precursor protein with JNK.

Using a yeast two-hybrid method, we searched for amyloid precursor protein (APP)-interacting molecules by screening mouse and human brain libraries. In addition to known interacting proteins containing a phosphotyrosine-interaction-domain (PID)-Fe65, Fe65L, Fe65L2, X11, and mDab1, we identified, as a novel APP-interacting molecule, a PID-containing isoform of mouse JNK-interacting protein-1 (JIP-1b) and its human homolog IB1, the established scaffold proteins for JNK. The APP amino acids Tyr(682), Asn(684), and Tyr(687) in the G(681)YENPTY(687) region were all essential for APP/JIP-1b interaction, but neither Tyr(653) nor Thr(668) was necessary. APP-interacting ability was specific for this additional isoform containing PID and was shared by both human and mouse homologs. JIP-1b expressed by mammalian cells was efficiently precipitated by the cytoplasmic domain of APP in the extreme Gly(681)-Asn(695) domain-dependent manner. Reciprocally, both full-length wild-type and familial Alzheimer's disease mutant APPs were precipitated by PID-containing JIP constructs. Antibodies raised against the N and C termini of JIP-1b coprecipitated JIP-1b and wild-type or mutant APP in non-neuronal and neuronal cells. Moreover, human JNK1beta1 formed a complex with APP in a JIP-1b-dependent manner. Confocal microscopic examination demonstrated that APP and JIP-1b share similar subcellular localization in transfected cells. These data indicate that JIP-1b/IB1 scaffolds APP with JNK, providing a novel insight into the role of the JNK scaffold protein as an interface of APP with intracellular functional molecules.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Involvement of ErbB-2 in rheumatoid synovial cell growth.

OBJECTIVE: The synovial tissue affected by rheumatoid arthritis (RA) is characterized by hyperproliferation of synovial cells. High amounts of epidermal growth factor (EGF) in the synovial fluid of RA patients contribute to the growth of rheumatoid synovial cells. To characterize the receptor for EGF in rheumatoid synovial cells, the expression and function of ErbB family members were examined. METHODS: Synovial tissues were obtained from surgical excisions. The expression of ErbB products was examined by immunohistochemistry and immunoblotting by using specific antibodies. Primary cultures were established from the surgical materials. Cell growth was measured using MTT. The levels and phosphorylation state of the ErbB-2 protein were analyzed by immunoprecipitation and immunoblotting. RESULTS: The expression of ErbB-2, but not other ErbB-related products, was detected in synovium with RA as compared with that with osteoarthritis (OA) and ligament injury. Growth of primary synovial cells with RA was inhibited by genistein, a tyrosine kinase inhibitor, and herceptin, a specific monoclonal antibody against ErbB-2. Herceptin showed a small effect on growth of primary synovial cells with OA. EGF stimulated the phosphorylation of ErbB-2 in primary synovial cells with RA. This EGF-stimulated phosphorylation was completely abrogated by genistein and herceptin. CONCLUSION: ErbB-2 is expressed in rheumatoid synovial cells and may function as the receptor for EGF. Our data suggest that mitotic signals from EGF family members are transduced by ErbB-2 in these cells. Inhibition of ErbB-2 may provide a new approach to the effective treatment for RA.

Adult↗
PubMed2001

Expression of very low density lipoprotein receptor mRNA in circulating human monocytes: its up-regulation by hypoxia.

Although very low density lipoprotein (VLDL) receptor expression by macrophages has been shown in the vascular wall, it is not clear whether or not circulating monocytes express the VLDL receptor. We investigated the expression of VLDL receptor mRNA in human peripheral blood monocytes and monocyte-derived macrophages by reverse transcriptase polymerase chain reaction (RT-PCR) and nucleotide sequencing after subcloning of PCR product. VLDL receptor mRNA was detected both in peripheral blood monocytes and monocyte-derived macrophages. Expression of VLDL receptor mRNA was upregulated by hypoxia in monocytes, whereas treatment with oxidized LDL, interleukin-1beta or monocyte chemoattractant protein-1 did not affect the levels of VLDL receptor mRNA in monocytes and macrophages. The present study shows a novel response of VLDL receptor mRNA to hypoxia, suggesting a role for VLDL receptor in the metabolism of lipoproteins in the vascular wall and the development of atherosclerosis.

Adult↗
PubMed2001

Noninvasive detection and prediction of bladder cancer by fluorescence in situ hybridization analysis of exfoliated urothelial cells in voided urine.

OBJECTIVES: To investigate the clinical utility of fluorescence in situ hybridization (FISH) of voided urine in the detection of bladder cancer and the prediction of its recurrence. METHODS: FISH with centromere-specific probes for chromosomes 9 and 17 was performed to evaluate the chromosomal alterations of exfoliated urothelial cells in voided urine obtained from 44 patients with bladder cancer and 20 controls. The analysis was also performed in 17 patients with bladder cancer after complete transurethral resection to prospectively determine whether FISH can predict tumor recurrence. RESULTS: The sensitivity to detect bladder cancer by FISH analysis (85%) was significantly higher than that by urine cytologic examination (32%) and by the bladder tumor antigen test (64%) (P <0.0001 and P = 0.026, respectively). The specificity of FISH, cytologic analysis, and the bladder tumor antigen test was 95%, 100%, and 80%, respectively. Among the 17 patients tested after transurethral resection, 7 of 13 FISH-positive patients developed tumor recurrence within the 27-month follow-up period; none of 4 FISH-negative patients developed recurrence during the same period. The recurrence rate in patients with the loss of chromosome 17 was 100%, significantly higher than the 23% for patients without this alteration (P = 0.015). CONCLUSIONS: These findings suggest that FISH analysis of exfoliated urothelial cells in voided urine can efficiently detect bladder cancer and predict its recurrence.

Adult↗
PubMed2001

Effects of intracavernous administration of adrenomedullin on erectile function in rats.

We have reported that adrenomedullin (AM)-induced vasodilation is at least in part nitric oxide (NO)-cGMP-dependent in the rat. Although it is well known that NO is much involved in the erectile function, it is controversial as to whether AM influences the erectile function. Thus, we examined the effects of AM on intracavernous pressure (ICP) during penile erection. The left carotid artery of rats was cannulated to monitor of mean arterial pressure (MAP). Bipolar electrodes were positioned on the cavernous nerve. The right cavernous body was cannulated with a needle connected to a pressure transducer to monitor ICP. Electrical stimulation (ES) increased ICP in a voltage-dependent manner. Elevation of ICP continued during ES. The intracavernous injection of 0.5 nmol AM significantly potentiated ES-induced increases in both maximal developed ICP/MAP and area under the curve (ICP trace; AUC). Since AM slightly lowered MAP, ICP was normalized by MAP. i.v. administration of N(omega)-nitro-L-arginine, a NO synthase inhibitor, markedly decreased AM/ES-induced ICP elevation. However, in the presence of E-4021, a cGMP-specific phosphodiesterase inhibitor, AM further increased both ICP/MAP and AUC. These results suggest that a NO-cGMP pathway is involved in the regulation of AM-induced rat cavernous vasorelaxation.

Adrenomedullin↗
PubMed2001

Pedunculopontine stimulation induces prolonged activation of pontine reticular neurons.

Extracellular and intracellular recordings were carried out from neurons in the region of the pontine reticular formation at the transition between the nucleus reticularis pontis oralis and caudalis, and in the pontis caudalis. Responses were studied after stimulation of the mesopontine cholinergic pedunculopontine nucleus in precollicular-postmammillary transected, paralyzed preparations. Recordings of neurographic activity in hindlimb flexor and extensor nerves served to detect changes in fictive locomotion and muscle tone induced by pedunculopontine nucleus stimulation or occurring spontaneously. Short duration trains of pedunculopontine nucleus stimulation induced long lasting responses, on average over 12s in duration, in one-third of pontine reticular neurons. These prolonged responses were stimulation frequency-dependent such that the longest durations were induced by stimulation at 20-60Hz. In some cells, stimulation at lower (10Hz) or higher (100Hz) frequencies induced responses of shorter duration or were absent, while in others, higher frequencies prolonged the excitatory effects of pedunculopontine nucleus stimulation. We conclude that these stimulation frequency-dependent effects may be related to the modulation of postural muscle tone and locomotion by the pedunculopontine nucleus.

Action Potentials↗
PubMed2001

Age-related changes in cholinergic and purinergic neurotransmission in human isolated bladder smooth muscles.

We evaluated the correlation among age, cholinergic and purinergic neurotransmissions in the electrical field stimulation-induced contractions in human isolated urinary bladder smooth muscles, using the muscle bath technique. Human bladder specimens were divided into three groups (G1, under 50years; G2, 51-70years; G3, over 70years old), and each muscle strip was suspended in a thermostatically controlled organ bath filled with oxygenated Krebs-Henseleit solution, connected to an isometric force displacement transducer, and an isometric tension development was recorded. The contractile responses induced by KCl, carbachol, adenosine triphosphate (ATP) and electrical field stimulation, and the effects of atropine and alpha, beta methylene ATP on electrical field stimulation-induced contractions were observed. The contractile response to KCl and concentration-response curves for carbachol and ATP, and frequency-response curves for electrical field stimulation were not significantly different among the three groups. The atropine sensitive and resistant parts of contraction induced by electrical field stimulation were decreased and increased with age, respectively. There are significant positive and negative correlations between age and the purinergic, and age and the cholinergic neurotransmissions in human isolated bladder smooth muscles, respectively. The age-related changes in neurotransmissions may contribute to the changes in bladder function in the elderly.

Adenosine Triphosphate↗