Transcriptional stimulation of the eNOS gene by the stable prostacyclin analogue beraprost is mediated through cAMP-responsive element in vascular endothelial cells: close link between PGI2 signal and NO pathways.

Beraprost sodium (BPS), an orally active prostacyclin analogue, has been reported to be beneficial in the treatment of primary pulmonary hypertension and obstructive peripheral arterial disease. Although BPS was originally described for its effects on platelet aggregation and vasodilatory response, the effect on endothelial cells has been poorly understood. In this study, we examined the effects of BPS on the eNOS gene expression in mouse aorta and cultured human and bovine aortic endothelial cells.

Preparation and enzymatic recognition of guanine lesions induced by nitrogen oxides.

Xanthine (Xan) and oxanine (Oxa) are the major deamination products of guanine formed by the treatment with nitrogen oxides (e.g., NO and HNO2).

Enzymatic properties of Escherichia coli and human 7,8-dihydro-8-oxoguanine DNA glycosylases.

Oxidative damage to DNA generates aberrant guanine bases such as 2,6-diamino-4-hydroxy-formamido-pyrimidine (Fapy) and 7,8-dihydro-8-oxoguanine (8-oxoG). Although synthetic oligonucleotides containing a single 8-oxoG have been widely used to study enzymatic processing of this lesion, the synthesis of oligonucleotides containing Fapy as a unique lesion has not been achieved to date. In this study, an oligonucleotide containing a single 2,6-diamino-4-hydroxy-5-(N-methyl)formamido-pyrimidine (me-Fapy, a methylated derivative of Fapy) was prepared by a DNA polymerase reaction and the subsequent alkali treatment.

Extensive methylation of CpG island of CYP24 gene in osteoblastic ROS17/2.8 cells.

CYP24 is a target gene of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and is induced in the cells expressing vitamin D receptor (VDR) in response to 1,25-(OH)2D3. The osteoblastic ROS17/2.8 cells abundantly express VDR and have been used for the promoter analysis of many of vitamin D3 target genes.

Detection of NO-induced DNA lesions by the modified aldehyde reactive probe (ARP) assay.

When DNA is exposed to NO or HNO2, oxanine (Oxa) is formed as a major guanine lesion. For highly sensitive detection of Oxa using ARP, a probe molecule for DNA damage detection, the reactivity of ARP to Oxa was examined. Oxa site-specifically embedded in an oligonucleotide reacted with ARP but it took relatively long time (ca.

Adduct formation between oxanine and amine derivatives.

Oxanine (Oxa) is a major guanine lesion produced by nitric oxide (NO) under aerobic conditions. To elucidate the genotoxic mechanism of Oxa, this lesion was site-specifically incorporated into an oligonucleotide and allowed to react with cellular amines. Analysis of the reaction product revealed that Oxa formed adducts with spermidine and lysine, suggesting a novel genotoxic mechanism associated with NO-induced DNA damage.

Quantitation of DNA damage by an aldehyde reactive probe (ARP).

DNA is constantly damaged by endogenous and environmental agents. Abasic sites representing a major class of DNA damage can be quantitated by an ELISA-like assay using an aldehyde reactive probe (ARP). It is shown that oxidative pyrimidine lesions can be also quantitated by the ARP assay in combination with the treatment with endonuclease III.

DNA-protein cross-link formation mediated by oxanine. A novel genotoxic mechanism of nitric oxide-induced DNA damage.

Chronic inflammation is a risk factor for many human cancers, and nitric oxide (NO) produced in inflamed tissues has been proposed to cause DNA damage via nitrosation or oxidation of base moieties. Thus, NO-induced DNA damage could be relevant to carcinogenesis associated with chronic inflammation. In this report, we report a novel genotoxic mechanism of NO that involves DNA-protein cross-links (DPCs) induced by oxanine (Oxa), a major NO-induced guanine lesion.

Mammalian 5-formyluracil-DNA glycosylase. 2. Role of SMUG1 uracil-DNA glycosylase in repair of 5-formyluracil and other oxidized and deaminated base lesions.

In the accompanying paper [Matsubara, M., et al. (2003) Biochemistry 42, 4993-5002], we have partially purified and characterized rat 5-formyluracil (fU)-DNA glycosylase (FDG).

Mammalian 5-formyluracil-DNA glycosylase. 1. Identification and characterization of a novel activity that releases 5-formyluracil from DNA.

5-Formyluracil (fU) is a major oxidative thymine lesion produced by reactive oxygen species and exhibits genotoxic and cytotoxic effects via several mechanisms. In the present study, we have searched for and characterized mammalian fU-DNA glycosylase (FDG) using two approaches. In the first approach, the FDG activity was examined using purified base excision repair enzymes.

Accumulation of oligoclonal T cells in the infiltrating lymphocytes in oral lichen planus.

Background: Identification of a disease-specific and possibly pathogenic T-cell receptor (TCR) in oral lichen planus (OLP) is one of the most important steps to reveal the pathogenic antigen recognized by the T cells and thereby elucidate the pathogenesis and etiology of OLP.

Methods: In buccal mucosa biopsy specimens and peripheral blood mononuclear cells (PBMC) from seven patients with OLP, the TCR V beta gene usage was examined by polymerase chain reaction-based and single-strand conformation polymorphism analyses.

Results: The V beta families expressed in the biopsy specimens were markedly heterogeneous, but they were restricted in comparison to those observed in the PBMC.

Core structure in roselipins essential for eliciting inhibitory activity against diacylglycerol acyltransferase.

Fungal roselipins, discovered as inhibitors of diacylglycerol acyltransferase (DGAT), consist of three parts; highly methylated C20 fatty acid, mannose and arabinitol. Demannosyl and/or dearabinitoyl roselipins were prepared chemically or enzymatically. Demannnosyl roselipins conserved the DGAT inhibitory activity, but the others lost the activity, indicating that the arabinitoyl fatty acid core is essential for eliciting the activity.

Effects of hormone replacement therapy on serum angiotensin-converting enzyme activity and plasma bradykinin in postmenopausal women according to angiotensin-converting enzyme-genotype.

An insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene determines serum ACE levels. The D allele is associated with increased ACE activity and is linked to cardiovascular disease. Hormone replacement therapy (HRT) in postmenopausal women (PMW) decreases serum ACE activity and concomitantly increases plasma bradykinin.

[Radiofrequency ablation of pulmonary malignancies].

Radiofrequency ablation (RFA) with a maximum output of < or = 70 W was used under CT guidance to treat 14 tumors (median diameter 1.5 cm, range 0.8 to 2.

Novel repair activities of AlkA (3-methyladenine DNA glycosylase II) and endonuclease VIII for xanthine and oxanine, guanine lesions induced by nitric oxide and nitrous acid.

Nitrosation of guanine in DNA by nitrogen oxides such as nitric oxide (NO) and nitrous acid leads to formation of xanthine (Xan) and oxanine (Oxa), potentially cytotoxic and mutagenic lesions. In the present study, we have examined the repair capacity of DNA N-glycosylases from Escherichia coli for Xan and Oxa. The nicking assay with the defined substrates containing Xan and Oxa revealed that AlkA [in combination with endonuclease (Endo) IV] and Endo VIII recognized Xan in the tested enzymes.

Calcium channel blockers and myocardial infarction: a case--control study in a Japanese hospital.

Purpose: To examine the relationship of the use of calcium channel blockers (CCBs) in hypertensive patients to myocardial infarction in Japan, where CCBs are prescribed much more frequently than in Europe and America.

Design: We conducted a nested case-control study using a hospital information system in Japan.

Subjects: Cases were hypertensive patients who were repeat visitors to Tokyo University Hospital as of April 1996 and had an incidence of fatal or non-fatal myocardial infarction between 1996 and 1999.

Possible function of salivary gland epithelial cells as nonprofessional antigen-presenting cells in the development of Sjögren's syndrome.

Objective: To explore the potential of salivary gland epithelial cells to act as nonprofessional antigen-presenting cells (APC) in the development of Sjögren's syndrome (SS).

Methods: Expression of HLA-DR antigens, costimulatory molecules, and adhesion molecules on epithelial cells was immunohistochemically examined in labial salivary glands from patients with SS. An association with the expression of T cell derived cytokine messenger RNA (mRNA) was observed.

Reciprocal expression of vascular endothelial growth factor and nitric oxide synthase by coronary arterial wall cells during chronic inhibition of nitric oxide synthesis in rats.

Chronic inhibition of nitric oxide (NO) synthesis by oral administration of N(G)-nitro-L-arginine methyl ester (L-NAME) causes hypertension and produces arteriosclerosis in rats. Balloon injury induces upregulation of vascular endothelial growth factor (VEGF) in medial smooth muscle cells of the rat arterial wall, and NO secreted by a restored endothelium acts as the negative feedback mechanism that downregulates VEGF expression to basal levels. In this study, we tested the hypothesis that a reciprocal relation between VEGF and NO would be established in a rat model of chronic NO blockade.

Expression of Klotho protein in the inner ear.

The Klotho mouse is a recently developed model that exhibits phenotypes resembling human aging. We used this model to investigate sensorineural hearing loss from the point of view that it may be considered an issue of aging. Using reverse transcription-polymerase chain reaction, Western blotting and immunohistochemical staining, we were able to confirm klotho gene transcription and protein synthesis in the kidney and inner ear.

Detection and quantification of oral treponemes in subgingival plaque by real-time PCR.

Oral treponemes have been associated with periodontal diseases. We developed a highly sensitive and specific method to detect and quantify cultivable oral treponemes (Treponema denticola, Treponema vincentii, and Treponema medium) in 50 subgingival plaque samples from 13 healthy subjects as well as 37 patients with periodontal diseases using real-time PCR assays with specific primers and a TaqMan probe for each 16S rRNA sequence. The specificity for each assay was examined by using DNA specimens from various treponemal and other bacterial species.

Production of nitric oxide, but not prostacyclin, is reduced in klotho mice.

A novel murine model of aging (kl/kl mice) has been developed by in vivo mutagenesis. We analyzed endothelial function in this strain. Ring preparations of the thoracic aorta were obtained from 6- to 9-week old wild-type (+/+) and heterozygous (kl/+) klotho mice.

Effects of a guanine-derived formamidopyrimidine lesion on DNA replication: translesion DNA synthesis, nucleotide insertion, and extension kinetics.

2,6-Diamino-4-hydroxy-5-formamidopyrimidine derived from guanine (FapyG) is a major DNA lesion formed by reactive oxygen species. In this study, a defined oligonucleotide template containing a 5-N-methylated analog of FapyG (mFapyG) was prepared, and its effect on DNA replication was quantitatively assessed in vitro. The results were further compared with those obtained for 7,8-dihydro-8-oxoguanine and an apurinic/apyrimidinic site embedded in the same sequence context.

Combined primary aldosteronism and preclinical Cushing's syndrome: an unusual case presentation of adrenal adenoma.

A 55-year-old woman was referred to our institution for evaluation of elevated plasma creatine phosphokinase, hypokalemia and hypertension. Her chief complaints were muscle weakness and polyuria. A left adrenal mass, 4 cm in diameter, was noted on computed tomography.