Biomedical subjects

Y Nakashima

Publications and source records attributed to Y Nakashima.

At least 37 records · Page 2Linked to original sources

PubMed2002

Sex-role orientation, marital status and mental health in working women.

The objectives of this study were to make a men-women comparison as to the effects of job stress and sex-role orientation on mental health and to determine if marital status modifies effects of job stress and sex-role orientation on mental health in women. Subjects were 644 men and 301 women who were working at two private companies and one national agency. Job contents, sex-role orientation and mental health were measured by the Job Content Questionnaire, the Bem Sex-Role Inventory and the 30-item General Health Questionnaire, respectively. High job demands and femininity in men, masculinity in women predicted poor mental health. The best predictor of poor mental health was consciousness of being a woman in unmarried women, and stress outside the job in married women.

Adolescent↗

PubMed2002

The mature form of adrenomedullin correlates with brain natriuretic peptide in plasma of chronic hemodialysis patients.

AIM: Adrenomedullin (AM), a hypotensive and natriuretic peptide, consists of an amidated mature form (mAM) and an intermediate form in human plasma, of which only mAM exerts biological activity. Like atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), plasma levels of mAM are reported to be significantly elevated in hemodialysis (HD) patients, suggesting that mAM may be stimulated partly by increased body fluid volume in a manner similar to the natriuretic peptides. Here, we examined the relationship between mAM levels and ANP or BNP levels and the effect of HD on plasma mAM in HD patients. PATIENTS AND METHODS: We measured plasma levels of mAM, total AM (tAM), ANP and BNP before and after HD in patients on long-term HD (n = 22, mean age 56.3 +/- 3.2 years) using radioimmunoassay. RESULTS: Baseline mAM (2.7 +/- 0.3 fmol/ml) and tAM (23.6 +/- 2.0 fmol/ml) were significantly higher in HD patients than in healthy subjects (1.1 +/- 0.2 fmol/ml, 9.0 +/- 2.1 fmol/ml, respectively). HD significantly reduced the levels to 1.2 +/- 0.2 fmol/ml and 13.8 +/- 1.4 fmol/ml, respectively, although tAM levels were still elevated compared to healthy subjects. Similar plasma ANP and BNP levels were obtained in HD patients. There were significant correlations between mAM and tAM levels before and after HD and between HD-induced changes in mAM and tAM levels. In the pre-HD state, levels of both mAM and tAM correlated significantly with BNP levels, but the correlation of BNP with mAM was closer than that with tAM. In contrast, no correlations were observed between the 2 forms of AM and ANP. Changes in mAM levels during HD also correlated significantly with BNP but not ANP levels, although the changes in tAM did not correlate with those of the 2 natriuretic peptides. CONCLUSION: Our results suggest that the secretion/metabolism of mAM may be regulated in a manner similar to that of BNP in HD patients.

Adrenomedullin↗

PubMed2001

Expression of the MTA1 mRNA in thymoma patients.

The MTA1 gene is a recently identified metastasis-associated gene which has been implicated in the signal transduction or regulation of gene expression. We examined the mRNA expression levels of the MTA1, the human homologue of the rat mta1 gene in thymoma. Expression of MTA1 mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR) in 30 thymoma samples using LightCycler. The data was analyzed in reference to clinicopathological data. There was no relationship between MTA1 gene expression and age and gender. MTA1/GAPDH mRNA level in stage IV thymoma (6.431+/-3.404) was significantly higher than the level in stage I thymoma (2.592+/-1.902, P=0.0081). There was a tendency towards higher MTA1/GAPDH mRNA level in stage IV thymoma when compared to stage II thymoma (3.746+/-3.292, P=0.072). Thus our results show that the expression of the MTA1 gene is closely related to invasiveness in thymoma. The gene MTA1 could potentially provide information on the mechanism of tumor invasion and metastasis.

Adult↗

PubMed2001

Simultaneous electrophoretic determination of vanadium(V) and vanadium(IV) based on the complex formation with a Mo(VI)-P(V) reagent.

A capillary electrophoretic (CE) method was developed for the sensitive determination of V(V) and V(IV). A Mo(VI)-P(V) reagent reacted with a mixture of trace amounts of V(V) and V(IV) to form the [P(V(V)Mo(11))O40]4- and [P(V(IV)Mo11)O40]5- complexes in 0.1 M monochloroacetate buffer (pH 2.2). Since the V-substituted Keggin anions possessed high molar absorptivities in the UV region and the peaks due to their migrations were well separated in the electropherogram, the pre-column complex formation reaction was applied to the simultaneous CE determination of V(V) and V(IV) with direct UV detection at 220 nm. The calibration curves were linear over two orders of magnitude with detection limits of 5 x 10(-7) M for V(V) and 2 x 10(-7) M for V(IV).

Electrophoresis, Capillary↗

PubMed2001

Successful treatment with an implantable cardioverter defibrillator for spontaneous ventricular fibrillation in dilated cardiomyopathy with very high defibrillation thresholds.

A 72-year-old male patient with idiopathic dilated cardiomyopathy who had shown recurrent episodes of drug refractory ventricular fibrillation underwent implantation of a transvenous implantable cardioverter defibrillator (ICD). Ventricular fibrillation (VF) was induced by a T wave shock at the implantation. However, the ICD device with a maximum energy of 30 J failed to terminate the VF. Reversing defibrillation polarity and/or adding a defibrillation electrode lead at the site of a high superior vena cava were also ineffective. The ICD was programmed to a maximum energy of 30 J when the device sensed spontaneous VF. During the follow-up period of 5 months, two episodes of spontaneous VF were recorded from ICD telemetry, and the ICD device terminated VF successfully with the first therapy shock in both episodes. No previous reports have shown failure to terminate induced VF at implantation of the ICD with successful termination of spontaneous VF during follow-up. Careful follow-up is needed in ICD patients, especially those with very high defibrillation thresholds.

Aged↗

PubMed2001

Expression of the cdc25B gene as a prognosis marker in non-small cell lung cancer.

There is an evidence to suggest that cdc25B phosphatase is an oncogenic. We hypothesized that cdc25B gene may be expressed in tumors of patients with non-small cell lung cancer (NSCLC) and affect their clinical outcome. Expression of cdc25B messenger RNA was evaluated by reverse transcription polymerase chain reaction in 55 non-small cell lung carcinomas and adjacent histological normal lung samples using LightCycler. The data was analyzed in reference to clinicopathological data and survival data. There was no difference of cdc25B expression level between the NSCLC tissue and normal lung tissue. There was no relationship between cdc25B gene expression and age, gender, N or T-status and clinical stage. However, the NSCLC patients with high cdc25B expression had significantly poor survival than the patients with low cdc25B expression (P=0.0173). Thus we suggest that cdc25B may predict poor survival.

Adenocarcinoma↗

PubMed2001

Expression of the sensitive to apoptosis gene, SAG, as a prognostic marker in nonsmall cell lung cancer.

Inhibition of programmed cell death (apoptosis) is associated with increased tumor aggressiveness. We hypothesized that a novel sensitive to apoptosis gene, SAG, may be expressed in tumors of patients with nonsmall cell lung cancer (NSCLC) and may affect their clinical outcome. Expression of SAG messenger RNA was evaluated by reverse transcription polymerase chain reaction in 80 nonsmall cell lung carcinomas and 65 adjacent histologic nonmalignant lung samples using a LightCycler. The data were analyzed in reference to clinicopathologic data and survival. The SAG/GAPDH mRNA level in 80 NSCLC was 2.337 +/- 1.972. Of 65 paired NSCLC and nonmalignant lung samples, SAG/GAPDH mRNA levels were 2.313 +/- 2.064 and 1.696 +/- 1.910, respectively. The SAG mRNA level was significantly higher in NSCLC compared with nonmalignant lung tissue (p = 0.0169). There was no relationship between SAG gene expression and age, gender, T- or N-status or clinical stages. The NSCLC patients with high SAG/GAPDH expression (>1.8) had significantly poorer survival than the patients with low SAG/GAPDH expression (<1.8, p = 0.0227). Thus we suggest that SAG gene expression in NSCLC may be a useful prognostic marker.

Adenocarcinoma↗

PubMed2001

Overexpression of EC-SOD suppresses endothelial-cell-mediated LDL oxidation.

Reactive oxygen species have been proposed to play important roles in atherosclerosis. To investigate the protective role of extracellular superoxide dismutase (EC-SOD), its inhibition of endothelial-cell-mediated LDL oxidation was examined. We constructed the recombinant adenovirus AxCAEC-SOD expressing human EC-SOD by CAG promoter. Infection of endothelial cells with AxCAEC-SOD resulted in EC-SOD protein secretion in a dose-dependent manner and a decrease of endothelial-cell-derived superoxide production. Moreover, it was proven to coexist with heparan sulfate by immunohistochemical staining. Endothelial-cell-mediated LDL oxidation enhanced by ferric-sodium EDTA was inhibited by 47% in TBARS formation by AxCAEC-SOD infection. In agarose gel electrophoresis, AxCAEC-SOD decreased the negative charge of oxidized LDL by 50% and suppressed fragmentation of apolipoprotein B. These results suggested that human EC-SOD localized in the extracellular space and reduced endothelial-cell-mediated LDL oxidation. In subendothelial space, EC-SOD bound on heparan sulfate might suppress LDL oxidation through reduction of superoxide anion.

Animals↗

PubMed2001

Distribution of serum C-reactive protein and its association with atherosclerotic risk factors in a Japanese population : Jichi Medical School Cohort Study.

The distribution of serum C-reactive protein (CRP) levels and their association with age, sex, and atherosclerotic risk factors were studied in a large Japanese population between 1992 and 1995. The subjects consisted of 2,275 males and 3,832 females aged 30 years and over. CRP was measured by nephelometry. The distribution of CRP was highly skewed toward a lower level than that of previous studies and seemed to be a combination of two separate distribution curves. The increase in CRP with age was statistically significant, and males had higher CRP levels than did females. Males who were current smokers had higher CRP levels than did nonsmokers. Age, systolic blood pressure, diastolic blood pressure, triglycerides, fibrinogen, and body mass index were all positively associated with CRP in both sexes, while total cholesterol and blood glucose were positively related in females only. High density lipoprotein cholesterol was inversely related in both sexes. Multiple logistic regression analysis showed that sex, age, systolic pressure, high density lipoprotein cholesterol, triglycerides, fibrinogen, and body mass index were significant independent variables. In conclusion, the distribution of CRP among the Japanese was quite different from that among Westerners, although CRP levels correlated with other atherosclerotic risk factors, similar to those in Westerners.

Adult↗

PubMed2001

Nitric oxide regulates actin reorganization through cGMP and Ca(2+)/calmodulin in RAW 264.7 cells.

Nitric oxide (NO) has been reported to be involved in the regulation of pseudopodia formation, phagocytosis and adhesion in macrophages through the reorganization of actin. In the present study, we directly separated the globular (G) and filamentous (F) actin from quiescent or NO-stimulated macrophage-like cell line RAW 264.7 cells in order to investigate the dynamic redistribution of actin pools. We also focused on the regulatory mechanisms of actin assembly, induced by NO and its possible subsequent signaling pathway. We showed that predominant G-actin coexisted with Triton X-100-insoluble filamentous (TIF) and Triton X-100-soluble filamentous actin in resting RAW 264.7 cells. The exogenous NO produced by (+/-)-(E)-2-[(E)-hydroxyimino]-6-methoxy-4-methyl-5-nitro-3-hexenamide (NOR1), the endogenous NO induced by lipopolysaccharide (LPS) plus interferon-gamma (IFNgamma), and dibutyryl-cGMP increased the contents of TIF-actin in dose- and time-dependent manners and altered its morphology. The increase in the TIF-actin contents induced by NOR1 or LPS plus IFNgamma was efficiently blocked by the radical scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide and the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or the arginine analogue N(G)-monomethyl-L-arginine acetate, respectively. Preincubation with the calmodulin antagonist W-7 almost completely blocked the NO-induced TIF-actin increase and morphological change. On the other hand, preincubation with C3 transferase, an inhibitor of Rho protein, efficiently prevented the change in cell morphology, but had no effect on the TIF-actin increase. We postulate that cGMP and subsequent Ca(2+)/calmodulin may be key regulators of actin reorganization in NO-stimulated RAW 264.7 cells.

Actins↗

PubMed2001

Generalized scaling laws of the formation and effects of plasma-confining potentials for tandem-mirror operations in GAMMA 10.

The main operations from 1979 to 2000 in the GAMMA 10 tandem-mirror, characterized in terms of the high-potential mode having kV-order plasma-confining potentials and the hot-ion mode yielding fusion neutrons with 10-20 keV bulk-ion temperatures, are summarized and generalized as a result of scalings of the formation and the effects of the potentials. The wide validity of potential-formation physics from Cohen's theory and the validity of the generalized Pastukhov's theory for the effects of thermal-barrier potentials on electron confinement are verified and consolidated through electron-energy balance.

Journal Article↗

PubMed2001

Increased levels of hypothalamic neuronal nitric oxide synthase and vasopressin in salt-loaded Dahl rat.

The plasma concentration of arginine vasopression (AVP) and the expression level of the neuronal nitric oxide synthase (nNOS) gene in the paraventricular nucleus (PVN) and the Supraoptic nucleus (SON) of Sprague-Dawley (SD). Dahl salt-sensitive (S) and Dahl salt-resistant (R) rats on a high salt diet were examined by radioimmunoassay for AVP and in situ hybridization histochemistry for nNOS. The high salt diet containing 8.0% NaCl was given for 4 weeks. The concentrations of AVP in hypertensive Dahl S rats were significantly increased in comparison with those in SD rats and Dahl R rats on a high salt diet. The levels of nNOS mRNA and NADPH-diaphorase activity in the PVN and SON of hypertensive Dahl S rats were greater than those in Dahl R rats on a high salt diet. The antihypertensive drugs, either nicardipine or captopril were administered to the Dahl S rats for 2 weeks beginning 2 weeks after the start of the high salt diet The nNOS mRNA in the PVN and SON of Dahl S rats given a high salt diet was not upregulated by treatment with nicardipine, while the nNOS mRNA in salt loaded Dahl S rats was greater upregulated by treatment with captopril to that greater than without the antihypertensive drug. Our results suggest that the increased NO production in the PVN and SON of hypertensive Dahl S rats may be ineffective in decreasing blood pressure or inhibiting AVP secretion.

Animals↗

PubMed2001

Homocysteine inhibits angiogenesis in vitro and in vivo.

Homocysteine has been reported to inhibit endothelial cell proliferation, which is closely related to angiogenesis. However, the relationship between homocysteine and angiogenesis is unknown. To clarify whether homocysteine would inhibit angiogenesis in vitro and in vivo, we examined the effect of homocysteine on tube formation by bovine aortic endothelial cells (BAECs) and by human microvessel endothelial cell-1 (HMEC-1) in vitro, and on angiogenesis in vivo using the chorioallantoic membrane (CAM) assay, as well as on BAEC proliferation and migration. Homocysteine, but not cysteine, inhibited BAEC proliferation, migration, and tube formation in a dose-dependent manner at concentrations from 0 to 10 mM. Homocysteine also inhibited tube formation by HMEC-1s. In these assay, 50% inhibition was induced by about 1 mM homocysteine. In the in vivo CAM assay, 0, 10, 100, 500, and 1000 microgram homocysteine induced an avascular zone by 0, 0, 16.7, 53.3 and 76.5%, respectively, also showing a dose-dependent effect. It was suggested that homocysteine inhibited angiogenesis by preventing proliferation and migration of endothelial cells.

Animals↗

PubMed2001

Isolation and expression of a gene (CGR1) regulated during the yeast-hyphal transition in Candida albicans.

We used RNA fingerprinting of arbitrarily primed PCR to isolate genes upregulated during the yeast-hyphal transition in Candida albicans. The sequence and expression of one of these genes (CGR1, Candida growth regulation) are presented. Our results suggest that CGR1 expression is associated with a growth cessation of yeast cells, a prerequisite for germination in this organism.

Amino Acid Sequence↗

PubMed2001

Capillary electrophoretic determination of phosphate based on the formation of a Keggin-type [PMo12O40]3- complex.

Based on the formation of a Keggin-type [PMo12O40]3- complex, a sensitive capillary electrophoresis (CE) method was developed for the determination of P(V) with direct UV detection at 220 nm. A mixture of alpha- and beta-Keggin-type [PMo12O40]3- complexes was readily formed in a sample solution consisting of a trace amount of P(V), 2.5 mM Mo(VI), 0.050 M p-C6H3(CH3)-2-SO3H (XSA), and 60% v/v CH3CN. When a 0.05 M HCl and 60% v/v CH3CN solution was used as a migration electrolyte, the Keggin complexes exhibited a sharp and well-defined peak in the electropherogram. The peak area was linearly dependent on the P(V) concentration in the range of 5 x 10(-7)-5 x 10(-5) M; a detection limit of 1 x 10(-7) M was achieved. In comparison with indirect UV detection, the direct UV detection is about ten times more sensitive, because the Keggin complexes possess high molar absorptivities. The developed CE method was applied to the determination of P(V) in river water, and the results were in good agreement with those obtained by ion chromatography (IC) and colorimetry (COL) based on the formation of mixed-valence heteropoly blue species.

Acetonitriles↗

PubMed2001

Clinical significance of matrix metalloproteinase-7 and Ets-1 gene expression in patients with lung cancer.

BACKGROUND: Matrix metalloproteinase-7 (MMP-7) is a member of the MMP family and has a wide variety of substrate spectra. Ets domain transcription factors are reported to play an important role in carcinoma invasion and metastasis. The regulatory role of Ets-1 has been shown in several MMPs. We have hypothesized that MMP-7 and Ets-1 mRNA levels could be predictors of the development and invasion of lung cancer. METHODS: The study included 73 lung cancer cases. The mRNA levels were quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR) using a LightCycler. RESULTS: No significant difference in MMP-7 and Ets-1 mRNA levels was found among gender, age, and pathological subtype. The MMP-7 mRNA levels were elevated in tumor tissues from stage II-IV lung cancer (1.629 +/- 2.267) compared to those from stage I lung cancer (0.762 +/- 1.463) (P = 0.0290). There was a tendency toward higher MMP-7 mRNA expression levels in tumors with lymph node metastasis (1.728 +/- 2.432) compared to those without lymph node metastasis (1.141 +/- 1.838) (P = 0.1076). Thus, MMP-7 mRNA levels may serve as a marker of higher stages in lung cancer. No significant difference in Ets-1 mRNA levels was found among clinical stages and T-status. The Ets-1 mRNA levels were elevated in tumors from N2 patients (7.512 +/- 13.306) compared to those from N0 patients (2.525 +/- 4.719) (P = 0.0209). Ets-1 mRNA levels showed a positive correlation with MMP-7 expression (P = 0.0042). CONCLUSIONS: Using the LightCycler RT-PCR assay, the determination of MMP-7 and Ets-1 mRNA levels might provide a potential marker for advanced lung cancer. However, further studies and a longer follow-up are needed to confirm the impact of MMP-7 in the biological behavior of the tumor.

Adult↗

PubMed2001

Chronic rejection in H-2 matched cardiac allografts: early emergence of vasculopathy, alloantibody, and accumulation of IFN-gamma and IL-10 mRNA.

Cardiac allograft vasculopathy (CAV) is one of the crucial problems of clinical heart transplantation. We have developed a novel model of murine cardiac allograft rejection, in which chronic rejection associated with CAV occurs in its natural course. In this study we analyzed the pathogenesis of chronic cardiac allograft rejection using an H-2 matched multiple minor histocompatibility antigen-mismatched combination, AKR (H-2k) to C3H (H-2k) recipient mice. All the cardiac allografts survived for more than 100 days but were rejected within 260 days post-transplant (n = 13; mean survival times +/- standard deviation = 189.0+/-72.0; median = 210). The heartbeats of the graft became gradually weaker throughout the duration of the rejection process. Serial histological analyses with hematoxylin and eosin, elastica van Gieson or Masson trichrome staining revealed mononuclear cell infiltration and intimal thickening (i.e. CAV) which started in most grafts at 2 weeks post-transplant. These pathological changes eventually developed to severe graft fibrosis, and the severity of these changes correlated with the deterioration of the heartbeats. Production of anti-donor antibodies in most recipients was detectable by 2 weeks post-transplant, it peaked before day 100, and subsided before rejection was complete in most grafts. Intragraft expression of IFN-gamma and IL-10 mRNA was demonstrated by reverse transcriptase-polymerase chain reaction during early periods post-transplant. In this study, we demonstrate a novel model feasible for analysis of chronic cardiac allograft rejection, in which the vascular rejection processes, including fibrosis and alloantibody production, can be tested from an early stage on, after transplantation.

Animals↗

PubMed2001

Subchondral changes in transient osteoporosis of the hip.

OBJECTIVE: To review the subchondral changes on MR imaging in transient osteoporosis of the hip (TOH) and to consider the pathophysiology. DESIGN AND PATIENTS: MR images of 12 hips of 11 consecutive patients with TOH were retrospectively studied. The diagnoses of TOH were confirmed on the basis of previously published criteria, including decreased bone density of the femoral head and/or neck on radiographs, bone marrow edema (BME) pattern on MR images, spontaneous resolution of the symptoms and a return to normal radiodensity. RESULTS: All 12 hips showed a BME pattern in the femoral head and/or neck. Linear patterns of very low signal intensity were identified on T1-weighted images in the subchondral area within the diffuse low signal intensity area in all 12 hips. On T2-weighted images, a low signal intensity line was observed in the corresponding area in eight hips only. These linear patterns were thought to represent subchondral fracture lines. CONCLUSIONS: The presence of a subchondral fracture may be important when considering the pathophysiology of TOH.

Adult↗