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Y Nakashima

Publications and source records attributed to Y Nakashima.

At least 163 records · Page 9Linked to original sources
PubMed1998

Chromosomal localization of a human deoxyribonuclease II gene (DNASE2) to 19p13.2-p13.1 using both the polymerase chain reaction and fluorescence in situ hybridization analysis.

Recently obtained information on the cDNA encoding human deoxyribonuclease II (DNase II) (T. Yasuda et al., 1998, J. Biol. Chem. 273, 2610-2616) has made it possible to demonstrate the precise position of the the human DNase II gene (DNASE2) on human chromosomes. Two different sets of oligonucleotide primers specific for human DNase II cDNA sequences were used to amplify unique DNA fragments in the human DNase II gene from a panel of human x rodent hybrid cell lines carrying different human chromosomes. Based on this analysis, DNASE2 was assigned to human chromosome 19. Furthermore, regional localization of the gene to 19p13.2-p13.1 was achieved by fluorescence in situ hybridization analysis using a full-length cDNA probe corresponding to the entire open reading frame.

Chromosome Mapping↗
PubMed1998

Transfer of wild-type p53 gene effectively inhibits vascular smooth muscle cell proliferation in vitro and in vivo.

Wild-type p53 (wt-p53), a key protein in cell cycle regulation, inactivates the G1 cyclins through direct activation of p21Waf-1/Cip-1/Sdi-1. Persistent vascular smooth muscle cell (VSMC) proliferation following vascular interventions hinders the benefits of these therapeutics. Using the hemagglutinating virus of Japan/liposome-mediated gene transfer method, we examined the inhibitory effect of overexpression of exogenous wt-p53 on VSMC proliferation in vitro and in vivo. We assessed the proliferative activity of human p53 cDNA-transduced bovine VSMCs by DNA synthesis assay, flow cytometry, and cell proliferation assay. p53 gene transfer reduced thymidine incorporation of VSMCs stimulated by platelet-derived growth factor-BB (P<.001). The p53-transduced VSMCs underwent synthetic phase depletion (mean, 8.02% versus 33.7% of control; P<.001) and transient G2/M accumulation 2 days after gene transfection, and in almost all cells, G1 arrest occurred (mean, 92.6% versus 79.3% of control; P<.001) 5 days later. The wt-p53 gene transfection also inhibited the VSMC proliferation (P<.001) with no detectable induction of apoptosis. Cell death of p53-transduced VSMCs was induced only by additional treatment with an apoptosis-stimulating reagent, doxorubicin. The verification of apoptosis was made by DNA ladder, flow cytometry, and electron microscopy. In vivo transfection of p53 cDNA inhibited neointimal formation after balloon injury in rabbit carotid arteries, without apoptotic stimuli (P<.01). Thus, overexpression of the p53 gene in the injured arterial wall inhibits the proliferation of VSMCs in vitro and in vivo. This novel concept, including not only exogenous but also endogenous p53 overexpression in the vessel wall, may be one approach worth exploring in the treatment of patients with restenosis occurring after vascular interventions.

Animals↗
PubMed1998

Molecular cloning of the cDNA encoding human deoxyribonuclease II.

A rapid amplification of cDNA ends method, using degenerate oligonucleotides based upon the N-terminal amino acid sequence of human hepatic deoxyribonuclease II (DNase II), allowed a novel cDNA encoding DNase II to be constructed from thyroid gland RNA. The composite nucleotide sequence (1593 bases) included an open reading frame of 1080 bases, which encoded a single polypeptide of 360 amino acids (signal peptide, 16; propeptide, 91; mature protein, 253). Although the sequence of DNase II showed no significant homology to other mammalian proteins, its cDNA structural organization resembled those of the lysosomal cathepsin families. The two parts of the cDNA corresponding to the propeptide and the mature protein were expressed in Escherichia coli, and the recombinant polypeptides thus obtained were strongly stained with an anti-DNase II antibody on Western blotting. DNase II is ubiquitously expressed in human tissues, and the DNase II gene (DNASE2) was assigned to chromosome 19.

Amino Acid Sequence↗
PubMed1998

Detection of isozymes of deoxyribonucleases I and II on electrophoresed gels with picogram sensitivity using SYBR Green I.

A highly sensitive method for detecting deoxyribonucleases (DNases) I and II on an electrophoresed gel is described. A dried agarose film sheet containing DNA as a substrate and a buffer reagent was placed in contact with the gel surface after electrophoresis (DAFO method, Yasuda et al., Anal. Biochem. 1989, 183, 84-88). After an appropriate incubation period, the film sheet was peeled off and stained with SYBR-Green I (SG), and then the DNase isozyme bands were detected using a fluorescence image analyzer. We could detect pg levels of the DNases (DNase I, 2 pg; DNase II, 2pg), which represents a 32- to 128-fold increase in sensitivity compared with the original DAFO method using ethidium bromide (EB) as the fluorescent dye. A combination of this new detection method and isoelectric focusing electrophoresis in polyacrylamide gel allowed accurate DNase I typing from 1 microL human serum. This new technique has been named SG-DAFO, after its original dried agarose film overlay method using EB (EB-DAFO).

Benzothiazoles↗
PubMed1998

Modulation of endothelin and nitric oxide: a rational approach to improve canine hepatic microcirculation.

ET receptor blocker (TAK-044) and NO donor (FK409) were used to improve the hepatic microcirculation following ischemia-reperfusion injury. In the first experiment (60 minutes of ischemia), 15 dogs were divided into three groups: group A (control), saline; group B, TAK 5 mg/kg; and group C, FK 0.4 mg/kg. In the second experiment (90 minutes of ischemia), 38 dogs were divided into six groups that underwent 90 minutes of hepatic ischemia followed by reperfusion: group I (control), saline only; group II, TAK 5 mg/kg and FK 3.2 mg/kg; group III, TAK 5 mg/kg and FK 0.4 mg/kg; group IV, TAK 5 mg/kg; group V, FK 0.4 mg/kg; and group VI, FK3.2 mg/kg. All drugs were administered through the portal vein. Following 60 minutes of ischemia, both FK and TAK produced significant improvement in hepatic microcirculation and enzymatic status when compared with the control group. After 90 minutes of ischemia, low doses of FK and TAK significantly improved hepatic microcirculation and reduced portal pressure following reperfusion in group III compared with group I. Leakage of hepatic enzymes was prevented and tissue injury score was significantly lower in group III. In group VI, early protection was obtained to some extent; however, blood pressure was reduced significantly following reperfusion compared with group I. In contrast, hepatocellular function deteriorated and the tissue injury score was higher in group II animals. TAK pretreatment with low doses of FK provided the best protection for the hepatic microcirculation in ischemia-reperfusion injury of the liver.

Animals↗
PubMed1998

C-type natriuretic peptide inhibits rat mesangial cell proliferation by a phosphorylation-dependent mechanism.

We studied the effects of C-type natriuretic peptide (CNP) on rat cultured mesangial cell proliferation. (1) Exposure to CNP (10 nM-1 microM for 72 h) inhibited [3H]thymidine incorporation into mesangial cells in a concentration-dependent manner. Atrial natriuretic peptide (1 nM-1 microM), a peptide related to CNP, also decreased [3H]thymidine incorporation into these cells in a concentration-dependent manner. (2) Both CNP (10 nM- microM) and atrial natriuretic peptide (10 nM-1 microM) also decreased mesangial cell number. (3) The cyclic GMP analog, 8-bromo-cyclic GMP (100 microM and 1 microM), mimicked the inhibitory effects of CNP and atrial natriuretic peptide on [3H]thymidine incorporation into mesangial cells, whereas inhibitors of protein kinase C, protein kinase A, and protein kinase G reduced the effect of both natriuretic peptides. Moreover, the phosphatase inhibitor, calyculin A, increased [3H]thymidine incorporation into mesangial cells. (4) CNP and atrial natriuretic peptide decreased interleukin-1-, interleukin-6-, platelet derived growth factor-, angiotensin II-induced [3H]thymidine incorporation into mesangial cells. These results suggest that CNP exerts inhibitory effects on mesangial cell proliferation and that this effects depend on protein phosphorylation pathways.

Angiotensin II↗
PubMed1998

Atherogenic lipoproteins inhibit catecholamine secretion in cultured bovine adrenal medullary cells.

The effects of lipoproteins on ion channel-mediated catecholamine secretion were investigated in cultured bovine adrenal medullary cells. Low density lipoprotein (LDL: 20-80 mg/dl) and lipoprotein(a) [Lp(a); 10-80 mg/dl] inhibited catecholamine secretion induced by carbachol, an activator of nicotinic acetylcholine receptor-ion channels. LDL and Lp(a) suppressed carbachol-induced 22Na+ influx as well as 45Ca2+ influx in a concentration-dependent manner similar to that of catecholamine secretion. The inhibition of catecholamine secretion by Lp(a) was not overcome by increasing the concentration of carbachol. On the other hand, high density lipoprotein (HDL; < 150 mg/dl) had no effect on 22Na+ influx, 45Ca2+ influx, and catecholamine secretion. Like LDL and Lp(a), a synthetic peptide homologous to human plasma apolipoprotein B (apoB), apoB fragment(3358-3372)-amide (3-60 microM), attenuated 22Na+ influx, 45Ca2+ influx, and catecholamine secretion caused by carbachol. The apoB fragment also suppressed 22Na+ influx induced by veratridine (an activator of voltage-dependent Na+ channels) and 45Ca2+ influx induced by 56 mM K+ (an indirect activator of voltage-dependent Ca2+ channels). These findings suggest that atherogenic lipoproteins such as LDL and Lp(a) suppress catecholamine secretion by interfering with Na+ influx through nicotinic acetylcholine receptor-ion channels, in which apoB, a structural component common to both LDL and Lp(a), plays an important role. The inhibition by atherogenic lipoproteins of catecholamine secretion may influence the progression of atherosclerosis induced by these lipoproteins.

Adrenal Medulla↗
PubMed1998

A temperate phage with cohesive ends induced by mitomycin C treatment of Lactobacillus casei.

A temperate phage, named PL-2, was induced from Lactobacillus casei ATCC 27092 by mitomycin C treatment of the cells at exponential growth phase. The phage had an isometric head of 45 nm in diameter and a flexible, non-contractile tail, 150 nm long and 10 nm wide, with a sharp tip. Along the tail axis, about 40 regularly spaced striae were seen. The phage DNA had complementary cohesive ends. The restriction enzyme map of the DNA was constructed by using 13 different restriction endonucleases. The size of the DNA was 35.2 kb, 83% in size of that of phage PL-1 lytic for the same Lb. casei strain.

Bacteriophages↗
PubMed1998

Enhanced macrophage uptake of lipoprotein(a) after Ca2+-induced aggregate-formation.

We tested the hypothesis that aggregated lipoprotein(a) [Lp(a)] is avidly taken up by macrophages. Lp(a) was isolated by sequential centrifugations and gel chromatography from a patient with high plasma levels of Lp(a) who was being treated with low density lipoprotein (LDL)-apheresis. Aggregated Lp(a) was prepared by mixing native Lp(a) with 2.5 mmol/L CaCl2, and 54% of the 125I-Lp(a) aggregated after interacting with CaCl2. The binding and degradation of aggregated Lp(a) in macrophages were 4.6- and 4.7-fold higher than those of native Lp(a), respectively. An excess amount of LDL did not inhibit either increase. Cholesterol esterification in macrophages was markedly stimulated by aggregated Lp(a), and macrophages were transformed into foam cells. Cytochalasin B, a phagocytosis inhibitor, strongly inhibited the degradation and cholesterol esterification (78 and 83%, respectively). These findings suggested that aggregation may be partially involved in Lp(a) accumulation, thereby contributing to the acceleration of atherosclerosis.

Aged↗
PubMed1998

Safety and optimal dose of intracoronary adenosine 5'-triphosphate for the measurement of coronary flow reserve.

BACKGROUND: Adenosine 5'-triphosphate (ATP) has been demonstrated to have similar vasodilator potency and fewer hemodynamic or electrocardiographic derangements compared with papaverine in the measurement of coronary flow reserve. However, there is little data about its optimal dose and the effect on myocardial lactate metabolism. METHODS: Under continuous monitoring of the left anterior descending coronary flow velocity with a Doppler guide wire, we investigated the changes of hemodynamics, electrocardiogram, and myocardial lactate metabolism before and after the administration of 50 microg ATP and 10 mg papaverine into the left coronary artery in 18 patients with normal coronary arteries. To determine the optimal dose of ATP for the coronary flow reserve in the left coronary artery, we measured coronary flow velocity with five incremental doses of intracoronary ATP (0.5, 5, 15, 30, and 50 microg) and 10 mg of papaverine in another seven patients. RESULTS: In contrast to papaverine, ATP did not produce any significant changes in hemodynamics or the electrocardiogram. The increase in the coronary flow velocity of the two agents was similar. Although all patients showed lactate production after the administration of papaverine, only three patients showed lactate production after ATP (p < 0.001). The coronary flow reserve derived from > or = 215 microg of ATP was similar to that derived from papaverine. There was a significant correlation between the coronary flow reserve obtained with > or = 5 microg of ATP and that obtained with papaverine. CONCLUSIONS: These results suggest that maximal coronary vasodilation in the left coronary artery can be safely obtained with doses > or = 15 microg of intracoronary ATP in patients with normal coronary arteries.

Adenosine Triphosphate↗
PubMed1998

Nitroglycerin-induced aortic relaxation mediated by calcium-activated potassium channel is markedly diminished in hypertensive rats.

Nitroglycerin (NTG), a nitric oxide (NO) donor, is considered to relax vascular smooth muscle by stimulating soluble guanylate cyclase, which in turn increases cyclic GMP (cGMP) level. Recently it became evident that NO-induced vasodilatation is also mediated by stimulating Ca-activated K (K(Ca)) channels directly and/or indirectly through cGMP. We, therefore, tried to investigate the possible involvement or the alteration of K(Ca) channels in the mechanism of vasodilation induced by NTG in physiological and pathological conditions. Using rings prepared from thoracic aortas of spontaneously hypertensive rats (SHR) and those of age-matched Wistar-Kyoto rats (WKY), we studied changes in isometric tension of the rings in response to NTG to evaluate effects of a soluble guanylate cyclase inhibitor methylene blue (MB), and a specific blocker of K(Ca) channel charybdotoxin (CTX). Rings from WKY and SHR precontracted with norepinephrine showed similar aortic relaxation to NTG. MB markedly suppressed the NTG-induced relaxation in both strains, leaving about 30% of MB-resistant relaxation. CTX nearly completely eliminated this MB-resistant relaxation in WHY but did not affect this relaxation in SHR. These results suggest that NTG-induced vasorelaxation is mediated through i) cGMP-dependent and ii) cGM P-independent K(Ca) channel involving mechanisms, the latter may be diminished or virtually eliminated in hypertensive state.

Animals↗
PubMed1998

Serum carcinoembryonic antigen as a prognostic factor in resectable gastric cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) has been widely accepted as a tumor marker useful in the diagnosis and management of colorectal cancer. When CEA levels are positive in gastric cancer patients, they could be useful prognostic indicators. However, the value of CEA as a tumor marker for gastric cancer remains a matter of controversy. STUDY DESIGN: We measured preoperative serum CEA levels in 196 patients with resectable gastric cancer between May 1986 and April 1996 and then evaluated the correlation between serum CEA levels, clinicopathologic features, and prognostic information. RESULTS: Serum levels of CEA were above the normal range in 29 of 196 (14.8%) surgically resected patients (range, 5.2-570 ng/mL). Among 100 early gastric cancers confined to the submucosal layer, only 7 patients (7.0%) had positive CEA levels, but among 96 advanced cancers, 22 patients (22.9%) had high CEA levels. The CEA positive patients had more macroscopically infiltrative tumors, a more prominent serosal invasion, more frequent lymph nodes involvement, and a more advanced stage than did the CEA negative patients. The 3- and 5-year cumulative disease-specific survival rates of patients positive for serum CEA were 39.6% and 31.7%, respectively; these rates for patients negative for CEA were 83.0% and 77.3%, respectively (p < 0.0001 for comparison of survival curves). In various clinicopathologic parameters, nine parameters (tumor size, macroscopic type, type and time of operation, Laurén classification, depth of invasion, lymph node involvement, CEA, alpha-fetoprotein [AFP], and carbohydrate antigen [CA] 19-9) showed statistically significant differences in the cumulative survival rates. Of these nine parameters, independent prognostic factors by multivariate analysis were depth of invasion (T1, 2 versus T3, 4, p < 0.0001), serum CEA levels (negative versus positive, p = 0.0003), and lymph node metastasis (negative versus positive, p = 0.0005). CONCLUSIONS: Preoperative serum CEA levels provide a predictive value in determining tumor stage and prognostic information for patients with potentially resectable gastric cancer during the preoperative period.

Adenocarcinoma↗
PubMed1998

Structure and organization of the human deoxyribonuclease II (DNase II) gene.

The structure of the human gene for deoxyribonuclease II (DNase II; EC 3.1.22.1) was determined using several specific primers based on the human DNase II cDNA sequence [Yasuda et al. (1998). J. Biol. Chem. 273, 2610-2616] in a polymerase chain reaction-based strategy. The gene spanned about 6 kb and consisted of 6 exons. No canonical TATA or CAAT boxes could be identified within the 1341 nucleotides upstream of the putative transcription start site, although the 5'-flanking region contained a CpG island and several putative binding motifs for transcription factors Sp1 and ETF. These properties indicate that the DNase II gene is a housekeeping gene and this is compatible with its ubiquitous expression in human tissues. Three different cleavage/polyadenylation sites were identified in the 3'-flanking region, leading to the production of multiple DNase II mRNA species. However, a comparison of the entire translated sequences of the gene from a pair of subjects with homozygous DNase II phenotypes H and L revealed no differences in the nucleotide sequences.

Base Sequence↗
PubMed1998

Association of human papillomavirus type 16 with malignant melanoma.

We report a case of malignant melanoma associated with human papillomavirus (HPV) in a 37-year-old woman. The patient has had numerous brown papular and nodular tumors, 5 to 30 mm in diameter, on her left leg for > 15 years, some of them coalescing rapidly in the last 12 months to a multilobulated black nodule diagnosed as malignant melanoma by histology and immunohistochemistry. HPV type 16 DNA was detected in the melanoma specimen by reverse transcriptase polymerase chain reaction (rt-PCR) and in situ hybridization (ISH) of the tumor tissues. This is the first report of melanoma associated with HPV 16.

Adult↗
PubMed1998

Comparative studies of the detection rates of Leishmania parasites from formalin, ethanol-fixed, frozen human skin specimens by polymerase chain reaction and Southern blotting.

In this study, detection rates of Leishmania parasites from human skin were compared among three different types of specimens, formalin-fixed, ethanol-fixed, and frozen, by polymerase chain reaction (PCR) and Southern blotting. For this purpose, we used biopsy specimens collected from 19 leishmaniasis patients and performed PCR and Southern hybridization with the probe specific for Leishmania (Viannia) braziliensis complex. Among these 19, 16 specimens were from cutaneous leishmaniasis (CL), one, diffuse cutaneous leishmaniasis (DCL) and 2, mucocutaneous leishmaniasis (MCL) and were formalin-fixed and paraffin-embedded. The causative agents for one case of CL and one case of DCL were already identified as L. (Leishmania) complex. Six specimens of CL were preserved in 100% ethanol. Two specimens of MCL were frozen tissues. PCR using the formalin-fixed and paraffin-embedded specimens revealed positive bands at 70 bp in 9 (47.4%) out of 19 specimens of CL, MCL and DCL. Southern blotting detected the signals in 12 (63.2%) out of the 19. PCR using the 100% ethanol-fixed specimens revealed positive bands in 4 (66.7%) out of 6, and Southern blotting also detected the signals in 4 (66.7%) out of the 6. PCR and Southern blotting using 2 frozen specimens of MCL were always positive (100%). Although we failed to detect significant differences by Chi-square test between the results from the formalin-fixed, paraffin-embedded specimens and those from 100% ethanol-fixed ones, we concluded that ethanol-fixed specimens, convenient for transportation and storage, would be more useful for diagnosis of leishmaniasis by PCR in a developing country.

Adolescent↗
PubMed1998

Treatment of malignant neurocardiogenic vasovagal syncope with a rate drop algorithm in dual chamber cardiac pacing.

A 29-year-old man with malignant vasovagal syncope presented with episodes of abrupt loss of consciousness associated with an aura, totaling more than 10 episodes over 3 months. Holter monitoring showed cardiac arrest with a duration of 15 seconds. Oral propranolol and disopyramide therapy failed to prevent the syncope. A dual chamber pacemaker with a rate drop response algorithm successfully prevented the syncope but not the aura. There may be multifactors involved in the mechanism of this syndrome. The patient has returned to a normal active life. This rate drop algorithm is an effective therapy for the prevention of syncope in malignant vasovagal syncope.

Adult↗
PubMed1998

Can aggressive lipid lowering using low-density lipoprotein apheresis prevent restenosis after percutaneous transluminal coronary angioplasty in patients with normocholesterolemia?

We examined whether aggressive lipid lowering using low-density lipoprotein (LDL) apheresis could prevent restenosis after percutaneous transluminal coronary angioplasty (PTCA). Fifteen patients with 17 lesions underwent LDL apheresis once within a week before and after PTCA and thereafter every 2 or 3 weeks (apheresis group) for about 4 months. The control group consisted of 17 patients with 17 lesions. No patients received additional lipid lowering drugs after PTCA. In the apheresis group, the time interval means of the total and LDL cholesterol levels were significantly lower than those in the control group whereas no significant differences were found between the 2 groups regarding the mean percent diameter stenosis or minimal lumen diameter before and after PTCA and at follow-up. The restenosis rate was 29.4% in the apheresis group and 47.1% in the control group. The restenosis rate tended to be slightly lower in the apheresis group. The overall results, however, indicated that aggressive lipid lowering does not prevent restenosis.

Aged↗