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Biomedical subjects

Y Naruse

Publications and source records attributed to Y Naruse.

At least 19 recordsLinked to original sources
PubMed2005

Electric-field-temperature phase diagram of an antiferroelectric liquid crystal.

We present a precise electric-field-temperature phase diagram of an antiferroelectric liquid crystal with a short pitch Sm-Calpha* phase. This was obtained by using a photoelastic modulator. A unique field-induced phase was found inside the Sm-Calpha* phase, which displayed low birefringence. Two tricritical points related to the phase were also observed. In addition, numerical calculations were made based on the discrete phenomenological model. The numerical results reproduced the experimental ones and it was clarified that the phase has a three-layer structure without spatial modulation.

Journal Article↗
PubMed2005

[Indication and strategy of on-pump coronary artery bypass grafting in elderly patients].

As elderly people are increasing nowadays, so is coronary artery bypass grafting (CABG) for these older patients. The risk of on-pump CABG for elderly patients is thought to be higher than that for younger patients. We assessed 12 patients, 80 years of age or older, who underwent on-pump CABG, and compared them with 1,988 patients younger than 80 years old. In the elderly patient group, there were no in-hospital mortality and no postoperative complications. There was no statistical difference in the pre- and postoperative factors between the 2 groups except for the cardiopulmonary bypass time. We also compared the pre- and postoperative factors of 341 patients, 70 years of age or older, who underwent on-pump CABG with those of 1,659 patients under 70 years of age. The preoperative factors of elderly patients indicated that they were more severely ill than younger patients. In the analysis of postoperative factors, the rate of postoperative complications were similar between the 2 groups, despite the significantly higher rate of in-hospital mortality in the elderly group. The risk of on-pump CABG for elderly patients is higher than that for younger patients, but with careful management of the pre-, intra-, and postoperative procedures, we can perform on-pump CABG safely even in the elderly patients.

Age Factors↗
PubMed2005

[Fungal endocarditis found at onset of lower limb acute aortic occlusion; report of a case].

Fungal endocarditis caused by Candida species is associated with high morbidity and mortality. A combination of surgical resection and antifungal drug therapy is the golden standard for treatment. We reported a case of fungal endocarditis due to Candida lusitaniae found at onset of lower limb acute aortic occlusion cured by emergency operation. This case suggests that Candida endocariditis can be managed medically with antifungal drug therapy in life time.

Acute Disease↗
PubMed2003

Mitral stenosis due to fibrous tissue overgrowth after mitral valve repair.

We report an extremely rare case of fibrous tissue overgrowth 3 years after mitral valve repair using a mitral annuloplasty ring in a 53-year-old woman who underwent mitral valve replacement for mitral stenosis. Whitish fibrous tissue had overgrown from the ring on the atrial side of the annulus, and had severely reduced the valvular area. However, the motion of the mitral leaflets was not restricted. Considering the presence of concomitant aortitis syndrome, it is strongly suggested that the overgrowth of fibrous tissue was promoted as a reaction to chronic inflammation.

Cardiac Catheterization↗
PubMed2002

A cross-sectional study on association of calcium intake with blood pressure in Japanese population.

To investigate the association of calcium intake independently of other nutrients already known as predictors of hypertension, a cross-sectional study was carried out on the same population in Japan as used for the INTERSALT study. Dietary calcium intake was estimated from a 1-day 24-h recall. Sodium and potassium intakes were evaluated by 24-h urinary excretion. Data from 476 subjects aged 20-59 years, 230 men and 246 women, were analysed. The mean dietary calcium intake ranged from 557 to 608 mg/day among men, and from 528 to 639 mg/day among women. Among men, the pooled estimate of the regression coefficients of blood pressure (mm Hg) per 100 mg increase of calcium intake, adjusted for age and body mass index (BMI), were -0.42 mm Hg for systolic blood pressure (SBP) and -0.35 mm Hg for diastolic blood pressure (DBP), but there was no statistical significance. Among women, the pooled estimates of regression coefficients adjusted for age and BMI were -0.92 mm Hg for SBP and -0.83 mm Hg for DBP with statistical significance. After adjustment for age, BMI, alcohol intake and urinary excretion of sodium and potassium, the pooled estimate of calcium intake was -0.66 mm Hg for DBP with statistical significance and -0.70 mm Hg for SBP. A significant negative association of calcium intake with blood pressure was observed among the subjects in Osaka. Our study suggests that increased calcium intake may provide a benefit of lowering blood pressure independently of other minerals such as sodium and potassium.

Adult↗
PubMed2001

Cell-type non-selective transcription of mouse and human genes encoding neural-restrictive silencer factor.

Neural-restrictive silencer (NRS) has been identified in at least twenty neuron-specific genes, and its nuclear DNA-binding factor, NRSF (also known as RE1-silencing transcription factor (REST)), has been cloned from human and rat, and was shown to repress transcription by recruiting corepressors mSin3 and/or CoREST via its N- and C-terminal domains, leading to chromatin reorganization by mSin3-associated histone deacetylase, HDAC. However, it is largely unknown how NRSF gene expression is regulated. To elucidate the mechanisms for gene expression of NRSF, we isolated the transcriptional unit of the NRSF gene from mouse and human, identified three 5'-non-coding exons in addition to three coding exons, determined transcription start sites, and identified two basal promoter activities in the upstream of the first two non-coding exons. Both promoters functioned equally in neuronal and non-neuronal cells, suggesting that levels of initial transcripts of NRSF gene are similar in neuronal and non-neuronal cells. These results suggest that the level of NRSF gene expression is not determined by transcription per se, and rather is modulated at the post-transcriptional level, e.g. splicing, mRNA stability, and/or post-translational modifications, in a cell-specific manner. Consistent with this idea, NRSF protein was apparently present even in neuronal cells and tissues, but was unable to bind to the NRS element, suggesting that NRSF is regulated at least in part post-translationally.

3T3 Cells↗
PubMed2001

Localization of neuronal growth-associated, microtubule-destabilizing factor SCG10 in brain-derived raft membrane microdomains.

Raft is a mobile membrane subdomain enriched in sphingolipid and cholesterol and also various signaling molecules. Previous observation suggested that brain-derived rafts contain tubulin but that rafts of non-neural origin do not. We hypothesized that SCG10, one of the neuronal growth-associated proteins (nGAPs), might be a neuron-specific molecule that anchors tubulin to neuronal rafts, and we explored biochemically its subcellular localization, interaction with tubulin, and effects on microtubule dynamics. In postnatal rat brain extracts, SCG10 was recovered mostly in membrane-associated fractions, and at least half was included in the raft fraction that was also enriched in GAP-43 and NAP-22. SCG10-enriched brain rafts also contained tubulin, and chemical cross-linking experiments revealed that SCG10 was closely associated with tubulin. In addition, SCG10 was able to inhibit polymerization of tubulin. These results indicate that SCG10 is a component of neuronal rafts as are other nGAPs, and suggest that SCG10 may be involved in signaling events in membranes for cytoskeletal reorganization around neuronal rafts.

Animals↗
PubMed2001

The neuron-restrictive silencer element-neuron-restrictive silencer factor system regulates basal and endothelin 1-inducible atrial natriuretic peptide gene expression in ventricular myocytes.

Induction of the atrial natriuretic peptide (ANP) gene is a common feature of ventricular hypertrophy. A number of cis-acting enhancer elements for several transcriptional activators have been shown to play central roles in the regulation of ANP gene expression, but much less is known about contributions made by transcriptional repressors. The neuron-restrictive silencer element (NRSE), also known as repressor element 1, mediates repression of neuronal gene expression in nonneuronal cells. We found that NRSE, which is located in the 3' untranslated region of the ANP gene, mediated repression of ANP promoter activity in ventricular myocytes and was also involved in the endothelin 1-induced increase in ANP gene transcription. The repression was conferred by a repressor protein, neuron-restrictive silencer factor (NRSF). NRSF associated with the transcriptional corepressor mSin3 and formed a complex with histone deacetylase (HDAC) in ventricular myocytes. Trichostatin A (TSA), a specific HDAC inhibitor, relieved NRSE-mediated repression of ANP promoter activity, and chromatin immunoprecipitation assays revealed the involvement of histone deacetylation in NRSE-mediated repression of ANP gene expression. Furthermore, in myocytes infected with recombinant adenovirus expressing a dominant-negative form of NRSF, the basal level of endogenous ANP gene expression was increased and a TSA-induced increase in ANP gene expression was apparently attenuated, compared with those in myocytes infected with control adenovirus. Our findings show that an NRSE-NRSF system plays a key role in the regulation of ANP gene expression by HDAC in ventricular myocytes and provide a new insight into the role of the NRSE-NRSF system outside the nervous system.

3' Untranslated Regions↗
PubMed2001

The relationship between new stroke onset and serum thiocyanate as an indicator to cigarette smoking.

The case subjects were 67 stroke patients (27 males and 40 females, mean age 65.7+/-7.1), who suffered from stroke attack and had participated in annual medical check-up between 1987 and 1988 at Oyabe Public Health Center. The controls, which were adjusted for sex, age and blood pressure level with the case subjects, were selected from participants attending their annual medical check-up in 1987-1988. The serum thiocyanate level of case subjects were significantly higher than that of controls (p<0.05). The usefulness of measurement of serum thiocyanate level as an indicator of smoking status was assessed by using multiple logistic regression analysis adjusting for body mass index, mean blood pressure, and serum cholesterol was found. An odds ratio of 3.00 (95% confidence interval: 1.06-8.48, p<0.05) in cerebral infarction. It is considered that serum thiocyanate may be useful as an indicator of smoking status to assess the relationship with stroke onset, especially for cerebral infarction.

Age Distribution↗
PubMed2001

Coronary artery bypass grafting in patients with dialysis-dependent renal failure.

This study identified preoperative characteristics of dialysis patients undergoing coronary artery bypass grafting (CABG) and determined the early and long-term results. We retrospectively analyzed the data of 60 patients (mean age 60.8 +/- 7.6 years) with end-stage renal disease who underwent CABG between 1982 and 1999. Seventeen (28%) patients underwent CABG for unstable angina, and 9 (15%) patients required preoperative intraaortic balloon pumping. The incidence of congestive heart failure (18%) and diseased aorta (42%) was higher in the dialysis group. In-hospital mortality in the dialysis group was 13% (8/60). The estimated survival rate at 5 and 10 years in the dialysis patients was 55.6 +/- 8.8% and 31.8 +/- 11.6%, respectively. The cardiac event-free rate, excluding the in-hospital mortality, was 62.5 +/- 9.9% at 5 years. Although the early and long-term results of CABG in dialysis patients were inferior to those of nondialysis patients, CABG in dialysis-dependent patients allows the patients to continue their dialysis therapy and to improve their functional status.

Coronary Artery Bypass↗
PubMed2001

Sickness absence and shift work among Japanese factory workers.

To investigate the effect of shift work on long-term sickness absence (more than 7 calendar days), an 8-year follow-up study was carried out in a factory in Japan. The participants were male employees aged 18-54 years who were engaged in manufacturing sites. Shift patterns were classified by the number of non-daytime working days during the previous one-year. The causes of sickness absence were classified into three groups, 1) causes except injury, diseases of the musculoskeletal system and connective tissue, 2) injury, 3) diseases of the musculoskeletal system and connective tissue. The analysis of long-term sickness absences was based on the first occurrence. The age-adjusted incidence of sickness absence among shift workers who were on non-daytime shifts more than two-thirds of working days during the previous one year was significantly higher than that among other workers. After adjusting for confounding factors, a significant high risk still existed for this group of workers taking sickness absence for all causes and causes except for injury and the musculoskletal disorders. These findings suggest that shift workers who are engaged on a particular shift schedule are more likely to take leave due to sickness.

Accidents, Occupational↗
PubMed2000

Translocation of aortic valve for calcific aortic stenosis.

A 56-year-old man underwent surgery for treatment of severe calcific aortic stenosis. Because it was found after excision of the aortic valve that calcification of the annulus was too extensive for the placement of sutures, translocation of the aortic valve was performed. The results were satisfactory and indicate that translocation is a useful alternative in cases of severe calcification of the aortic valve which cannot be treated by ordinary valve replacement.

Aortic Valve↗
PubMed2000

Surgical excision of malignant pheochromocytoma in the left atrium.

We present a rare case of malignant pheochromocytoma in the left atrium and its surgical treatment. The patient was a 39-year-old male who presented a low-grade fever with perspiration. A large tumor was first detected in the left atrium by chest CT, and was confirmed by ultrasonic echo cardiogram and chest MRI. A left adrenal tumor was indicated also by abdominal echography. To prevent the risk of its embolization, surgical excision was performed on a subemergency basis. The patient developed near Shock State on the operative day, presumably due to catecholamine depletion. The preoperative urinary levels of norepinephrine and dopamine were abnormally high. Bilateral adrenal tumors also, confirmed postoperatively by abdominal MRI, were developing rapidly. The pathological examination revealed that the tumor was a pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed2000

Ultrasonic aortic valve decalcification.

We report a case of calcific aortic stenosis in a 79-year-old man who had undergone aortocoronary bypass. Since ordinary valve replacement was problematic because of severe annular calcification, a small annular diameter, and three patent vein grafts, we performed ultrasonic aortic valve decalcification. As a result, the pressure gradient across the aortic valve decreased from 100 mmHg to 25 mmHg, and the patient is doing well to date at two years after the operation. Although long-term results of ultrasonic aortic valve decalcification are still undetermined, it appears worth considering in cases in which ordinary valve replacement could be extremely difficult.

Aged↗
PubMed2000

Large pulmonary arteriovenous fistula.

A 55-year-old woman with Rendu-Osler-Weber disease underwent surgical resection of a pulmonary arteriovenous fistula deriving from right middle lobe vessels. The fistula was 10 x 6 x 5 cm, to our knowledge, the largest ever reported. Although the major part of the fistula was well exposed through median sternotomy, extensive bleeding during dissection of feeding and drainage vessels precluded safe dissection. Total cardiopulmonary bypass was therefore used to divert the pulmonary blood flow. Anatomy was clearly delineated and connecting vessels were safely suture-closed from within the fistula without sacrificing the right middle lobe vein, which might have been damaged without cardiopulmonary bypass. The postoperative course was uneventful, and no complications associated with cardiopulmonary bypass occurred.

Arteriovenous Fistula↗
PubMed2000

Descending aortic aneurysm with Takayasu's disease.

A 69-year-old woman with Takayasu's disease was referred to our hospital for surgical treatment of a descending aortic aneurysm. Preoperative angiography and computed tomography revealed abdominal aortic stenosis and severe calcification in the descending aorta. The abdominal aorta was first replaced, since the aortic stenosis would have disturbed blood flow to the abdominal organs during extracorporeal circulation, which would be needed for subsequent thoracic surgery. The descending aortic aneurysm was then resected under femoro-femoral bypass. Since the descending aorta was severely calcified, two occlusion balloon catheters were used to clear the aorta. After aortic walls just proximal and distal to the aneurysm were decalcified, a short prosthetic tube graft was anastomosed. Only 2 pairs of intercostal arteries were sacrificed and paraplegia was prevented. Vascular lesions must thus be accurately evaluated and suitable procedures selected in surgically treating Takayasu's disease.

Aged↗
PubMed2000

Surgical management of ascending aortic graft infection. No-sedation-technique for open mediastinal irrigation.

Two patients with ascending aortic graft infection were successfully treated. The first patient underwent ascending aortic replacement using a Dacron graft for aortic dissection, and developed graft infection. After 25 days' open mediastinal irrigation, allograft replacement and rectus muscle flap transfer were performed. The second patient underwent translocation of the aortic valve with a composite graft for calcific aortic stenosis, and developed graft infection. After 29 days' open irrigation, omental and rectus muscle flap transfer were performed. We were able to perform long-term open mediastinal irrigation using our original no-sedation-technique without any severe complication such as bleeding or secondary infection. We believe this technique is helpful in the management of severe ascending aortic graft infection.

Aortic Dissection↗