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Biomedical subjects

H Arai

Publications and source records attributed to H Arai.

At least 109 records · Page 6Linked to original sources
PubMed2001

Coordinate regulation of endothelin and adrenomedullin secretion by oxidative stress in endothelial cells.

To elucidate the significance of oxidative stress in the modulation of endothelial functions, we examined the effects of H(2)O(2) on the expression of two endothelium-derived vasoactive peptides, endothelin (ET) and adrenomedullin (Am), and their interaction. H(2)O(2) dose dependently suppressed ET secretion and ET-1 mRNA expression in bovine carotid endothelial cells (ECs). Menadion sodium bisulfate, a redox cycling drug, also decreased ET secretion in a dose-dependent manner. Catalase, a H(2)O(2) reductase, and dl-alpha-tocopherol (vitamin E) significantly inhibited H(2)O(2)-induced suppression of ET secretion. Downregulation of ET-1 mRNA under oxidative stress was regulated at the transcriptional level. In contrast, H(2)O(2) increased Am secretion (and its mRNA expression) accompanied by the augmentation of cAMP production. Am, as well as 8-bromo-cAMP and forskolin decreased ET secretion in a dose-dependent fashion. Furthermore, an anti-Am monoclonal antibody that we developed abolished H(2)O(2)-induced suppression of ET secretion at 6-24 h after the addition of H(2)O(2). H(2)O(2) increased the intracellular Ca(2+) concentration ([Ca(2+)](i)). Moreover, treatment with ionomycin, a Ca(2+) ionophore, and thapsigargin, an inhibitor of endoplasmic reticulum ATPase, decreased ET secretion dose dependently for 3 h. These results suggest that the production of ET was decreased via activation of the Am-cAMP pathway and by the elevation of [Ca(2+)](i) under oxidative stress. These findings elucidate the coordinate expression of two local vascular hormones, ET and Am, under oxidative stress, which may protect against vascular diseases.

Adrenomedullin↗
PubMed2001

Elevated plasma homocysteine levels and risk of silent brain infarction in elderly people.

BACKGROUND AND PURPOSE: Silent brain infarction (SBI) on MRI is common in elderly people, and recent studies have demonstrated that SBI increases the risk of progression to clinically apparent stroke and cognitive decline. Therefore, an early and accurate detection of SBI and a search for potential treatable risk factors may have a significant impact on public health. METHODS: Community-dwelling elderly people aged >/=66 years who participated in the present study (n=153) underwent brain MRI and standardized physical and neuropsychological examinations as well as blood biochemistry determinations, including total plasma homocysteine (pHcy), renal function, vitamin status, and polymorphisms of the methylenetetrahydrofolate reductase gene. RESULTS: SBI was found in 24.8% of the participants. In the univariate analysis, the pHcy levels in subjects with SBI (13.6+/-4.1 micromol/L) were significantly higher (P=0.0004) than those in subjects without SBI (11.0+/-3.3 micromol/L). When pHcy levels were stratified into high (>/=15.1 mmol/L), moderate (11.6 to 15.0 mmol/L), and low (</=11.5 mmol/L) groups, age (P<0.0001), male sex (P<0.0001), the habits of cigarette smoking (P<0.0001) and of alcohol consumption (P=0.0002), and folate levels (P=0.01) were significantly associated with an elevation of pHcy levels. The elevated pHcy levels were significantly associated with SBI after individual adjustment for age, sex, hypertension, renal function, and the habits of smoking and alcohol consumption. CONCLUSIONS: pHcy level is associated with age and nutritional and other lifestyle factors, and it contributes to a risk for SBI.

Age Distribution↗
PubMed2001

Impairment of gingival fibroblast adherence by IL-6/sIL-6R.

Interleukin-6 (IL-6) binds to human gingival fibroblasts (HGF) in the presence of a soluble form of IL-6 receptor (sIL-6R). We investigated the effects of IL-6 on the functions of HGF in the presence of sIL-6R. HGF changed their morphology from spindle-shaped to round, and detached from the culture dish by stimulation with IL-6/sIL-6R. In this condition, a signal transducer gp130 and a transcription factor Stat3 were phosphorylated, resulting in activation of transcription factors Stat3 and C/EBPbeta. Cytoskeletal beta-actin and adhesion molecule integrin-alpha5, a subunit of alpha5beta1 integrin (VLA-5), were found to possess potential binding domains for these transcription factors in their promoters. Accumulation of beta-actin and integrin-alpha5 mRNA decreased, contrary to the expectation of the induction of gene transcription. Furthermore, the decrease in their mRNAs was associated with reduced expression of both actin and VLA-5 proteins. These results suggest that the expression of VLA-5 and actin was down-regulated in HGF through an IL-6 signaling pathway, resulting in impairment of HGF adherence.

Actins↗
PubMed2001

Localization of calcineurin in the mature and developing retina.

We studied the localization of calcineurin by immunoblotting analysis and immunohistochemistry as a first step in clarifying the role of calcineurin in the retina. Rat, bovine, and human retinal tissues were examined with subtype-nonspecific and subtype-specific antibodies for the A alpha and A beta isoforms of its catalytic subunit. In mature retinas of the three species, calcineurin was localized mainly in the cell bodies of ganglion cells and the cells in the inner nuclear layer, in which amacrine cells were distinctively positive. The calcineurin A alpha and A beta isoforms were differentially localized in the nucleus and the cytoplasm of the ganglion cell, respectively. Calcineurin was also present in developing rat retinas, in which the ganglion cells were consistently positive for it. The presence of calcineurin across mammalian species and regardless of age shown in the present study may reflect its importance in visual function and retinal development, although its function in the retina has not yet been clarified. (J Histochem Cytochem 49:187-195, 2001)

Aged↗
PubMed2001

The participation of pharmacists in a team to introduce a clinical pathway to laparoscopic cystectomy in obstetrics and gynecology.

In the Department of Obstetrics and Gynecology at our hospital, a team of doctors, pharmacists, nurses, and other medical staff was established to prepare a clinical pathway for laparoscopic cystectomy. Various data on clinical charts including the use of drugs were collected from 57 patients by pharmacists and nurses. Based on the analysis of these data, hospitalization period, method of preoperative bowel preparation, time to initiation of food intake, duration of antibiotic administration, and time and content of pharmaceutical instructions to patients of dosage and administration were determined. Criteria for variances requiring the doctor's directions were determined for fever, wound pain, and vomiting. The clinical pathway established here allows of not only the efficient and uniform care of patients, but also the active exchange of opinions among members of the medical team. Moreover, most patients who replied to a questionnaire said that they were at ease during hospitalization because they had received detailed information about the clinical pathway including the use of drugs before surgery. Thus, the participation of pharmacists on a medical team that is introducing a clinical pathway is particularly important because the use of drugs and pharmaceutical care are an important part of good patient care.

Adult↗
PubMed2001

Role of hypertension, dyslipidemia and diabetes mellitus in the development of coronary atherosclerosis in Japan.

The present study evaluated the effect of hypertension (HT), dyslipidemia and diabetes mellitus (DM) on the development of coronary atherosclerosis in the Japanese population, using a cross-sectional study of 433 patients (254 men and 179 women) aged 30 years or older who underwent coronary angiography for suspected or known coronary heart disease angina at 5 cardiology departments in the Fukuoka area between September 1996 and August 1997. Patients with a disease duration of 6 months or more were excluded. The main outcome measure was angiographically defined coronary artery stenosis and was found to a significant degree in 146 patients (33.7%). HT, DM, low levels of high-density lipoprotein cholesterol (HDL-C) and hypertriglyceridemia remained as significant coronary artery disease (CAD) risk factors even after controlling for age, sex, hospital, smoking, alcohol use, body mass index and leisure time physical activity. However, hypercholesterolemia was not a significant risk factor after adjusting for these variables. After controlling for these variables, DM, low HDL-C and hypertriglyceridemia were significant CAD risk factors for men, but only DM was a significant CAD risk factor in women. These results indicate that in Japan DM, low HDL-C and hypertriglyceridemia may be more important CAD risk factors than hypercholesterolemia.

Adult↗
PubMed2001

Total occlusion of inferior vena cava in a patient with antiphospholipid antibody syndrome associated with behçet's disease.

Behçet's disease frequently involves the venous system, usually affecting small vessels, but sometimes large vessels such as the vena cava. Antiphospholipid antibody syndrome is associated with an increased incidence of arterial and venous thrombosis. A 29-year-old male with Behçet's disease developed bilateral leg edema secondary to thrombotic occlusion of the inferior vena cava. Laboratory tests revealed positive antiphospholipid antibodies and lupus anticoagulant. Treatment with steroid and warfarin subsequent to intravenous administration of uro-kinase resulted in improvement of symptoms. The association of antiphospholipid antibody syndrome and Behçet's disease may have caused the total thrombotic occlusion of the vena cava in this case.

Adult↗
PubMed2001

The polymorphism in the caudal-related homeodomain protein Cdx-2 binding element in the human vitamin D receptor gene.

The major physiological activity of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] is the regulation of calcium absorption in the small intestine, and the level of vitamin D receptor (VDR) is an important factor in this regulation. In a previous study, we indicated-that the caudal-related homeodomain Cdx-2 played an important role in the intestine-specific transcription of the human VDR gene. In this study, the polymorphism was identified in the core sequence 5'-ATAAAAACTTAT-3' in the Cdx-2 binding site in the VDR gene promoter. In 261 Japanese women with genotyped VDR polymorphisms, 48 were genotype Cdx-A (adenine at -3731 nucleotides [nt] relative to the transcription start site of human VDR gene 5-ATAAAAACTTAT), 82 were genotype Cdx-G (guanine at -3731 nt, 5'-GTAAAAACTTAT-3'), and 131 were genotype Cdx-A/G (heterozygote). In postmenopausal Japanese women, the bone mineral density (BMD) in the lumbar spine (L2-L4) with the Cdx-G homozygote was 12% lower than that with the Cdx-A homozygote (p < 0.05). In electrophoretic gel mobility shift assay (EMSA), the oligonucleotide with Cdx-G allele markedly decreased the binding to Cdx-2 compared with that in the Cdx-A allele. The transcriptional activity of the VDR promoter with Cdx-G allele was decreased to 70% of the Cdx-A allele. In addition, in the herpes simplex virus thymidine kinase promoter, the Cdx-2 binding element with the G allele showed significantly lower transcriptional activity than that of the A allele. Thus, the polymorphism in the Cdx-2 binding site of the VDR gene (Cdx-polymorphism) would affect the expression of VDR in the small intestine. In addition, this polymorphism may modulate BMD in postmenopausal Japanese women.

Adult↗
PubMed2001

Heterogeneity of host immunological risk factors in patients with aggressive periodontitis.

BACKGROUND: The pathogenesis of early-onset periodontitis (EOP) can be explained by various host risk factors. Previous studies have focused on a single (among many possible) immunological risk factor and the association among the factors has not been assessed. We comprehensively investigated the associations among multiple host immunological risk factors in EOP patients to further elucidate their role in the pathogenesis of EOP. METHODS: Sixty-eight EOP patients (50 generalized EOP, 18 localized EOP), 51 EOP-suspected patients (S-EOP), 43 adult periodontitis (AP) patients, and 36 periodontally healthy subjects (HS) participated in this cross-sectional study. We examined peripheral neutrophil functions, phenotypic and functional characterization of peripheral lymphocytes (lymphocyte subsets, T-cell proliferative activity), cytokine productivity (interleukin [IL]-1, IL-2, tumor necrosis factor [TNF]-alpha, interferon [IFN]-gamma, IL-4 and IL-6), serum immunoglobulin G (IgG) antibody titers against 12 periodontal bacteria, and HLA class II genotypes. RESULTS: G-EOP, S-EOP, and AP patient groups showed significantly lower percentages of pan T cells and CD8-positive cells (P < 0.02) compared with the HS group. L-EOP patients showed depressed IL-4 and TNF-alpha productivity compared with the HS group (P < 0.02). The EOP group showed significantly elevated antibody levels against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Fusobacterium nucleatum compared with the HS group (P < 0.05). The frequency with DQB1*0503 was significantly higher in the EOP patient group than the HS group (P = 0.045) due to the higher frequency in L-EOP patients than the HS group (P = 0.035). There were wide interindividual variations in each of the tests among patient and HS groups; however, EOP patients showed wider intradiagnostic group variations in certain host defensive cell functions than the other groups. There were some EOP patients who showed extremely low or high values in some tests; the EOP patients could be further divided into subgroups according to their host defensive and immunological profiles. However, there was heterogeneity in some of the other host immunological tests even in the subgroups. CONCLUSIONS: The association of host immunological risk factors in EOP patients is widely varied and more complex than previously thought. These results indicate the difficulty of explaining the pathogenesis of EOP based on a single host risk factor and also emphasize the importance of critical assessment of not only EOP patient groups, but also individual patients.

Adult↗
PubMed2001

[Noninvasive positive-pressure ventilation in an elderly woman with acute respiratory failure caused by influenza a virus pneumonia].

A 79-year-old woman was admitted on January 18, 2000, with a lumbar compression fracture. Two days after admission, a chest X-ray film showed reticular infiltrates in the right lung field. She was diagnosed as having pneumonia and was treated with antibiotics. Despite this therapy, her symptoms did not improve and the infiltrates diffusely extended to involve both lungs on chest X-ray films. She was placed on noninvasive positive pressure ventilation (NIPPV) for progressive respiratory failure at 5 days after admission in order to avoid endotracheal intubation. Her hypoxemia was immediately improved by oronasal bilevel positive airway pressure ventilation (BiPAP) and chest X-ray films revealed improvement of the reticular infiltrates. Measurement of viral antibody titers showed that the cause of acute respiratory failure was influenza A virus pneumonia. In conclusion, NIPPV may reduce the need for intubation of elderly patients with acute respiratory failure, as well as chronic obstructive pulmonary disease (COPD) patients.

Acute Disease↗
PubMed2001

[A case report of aspergillus granuloma in the cavernous sinus].

We encountered a case of aspergillus granuloma in the cavernous sinus originating in the left sphenoid sinus. The patient was a 56-year-old woman who complained of visual loss and cavernous sinus syndrome on the left side. Hematological data were within normal limits. Bone CT showed evidence of bone destruction in the roof of the left sphenoid sinus. MR images with gadolinium demonstrated an enhanced heterogeneous mass extending from the left sphenoid sinus to the cavernous sinus and the orbital apex. Angiography showed occlusion of the left internal carotid artery. Dexamethasone was administered intravenously every day, because the patient was diagnosed as having Tolosa-Hunt syndrome (THS). However, dexamethasone was not effective. We carried out a biopsy of the mass from the sphenoid sinus, and findings showed aspergillosis. On the 19th day after initiation of fluconazole treatment, the patient lapsed into unconsciousness and presented left hemiparesis. T2-weighted MR images showed high intensity areas in the pons and the thalamus. The patient died two days later. An autopsy revealed edema and many infarctions throughout the brain. The cavernous sinus had been replaced completely with aspergillus granuloma. Furthermore, numerous hyphae of aspergillus had adhered to the inside of the basilar artery, and caused occlusions of arteries around the brain. This case indicated the difficulty of diagnosis of THS and the hazard of over-application of steroids. In this paper, we describe the clinical and pathological behavior of aspergillosis in the cavernous sinus.

Aspergillosis↗
PubMed2001

[Comparison of quantitative coronary arteriography using cinefilm and digital images].

OBJECTIVES: Quantitative coronary arteriography using both analog data (cinefilm) and digital data was evaluated with a stenotic vessel phantom and clinical data. METHODS: A stenotic vessel phantom using contrast medium with diameters of 2, 3, 4 and 6 mm was imaged using an X-ray image intensifier. Quantitative coronary arteriography was performed to measure reference and stenosis diameters in the phantom and under clinical conditions to measure coronary artery diameters using cinefilm and digital images. RESULTS: Both cinefilm and digital images were distorted at the peripheral image area, so errors were caused when the reference and stenosis were not in the same area. Measurements of diameters in the horizontal direction were larger than in the vertical and diagonal directions (p < 0.05). Reference diameters measured on digital images were larger than those on analog images (p < 0.0001). The difference in the real and measured reference diameter (2 and 3 mm) was less than 1% on digital images. The mean error in measurement of stenotic diameter measured on cinefilm images was 0.4-6.3% smaller for 0.5-4.5 mm diameter, but on digital images was 13% larger for 1 mm diameter, 18% larger for 0.75 mm diameter and 28% larger for 0.5 mm diameter. Under clinical conditions, the reference vessel diameter measured at the stenosis and the percentage stenosis were well correlated between the analog and digital images. CONCLUSIONS: Reference diameters of stenotic vessels are almost the same on cinefilm and digital images, but stenotic diameters under 1 mm are larger than actual size on digital images and on cinefilm images.

Analog-Digital Conversion↗