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Biomedical subjects

N Inoue

Publications and source records attributed to N Inoue.

At least 73 records · Page 4Linked to original sources

Role of the vascular NADH/NADPH oxidase system in atherosclerosis.

It is apparent that vascular tissues can produce reactive oxygen species, including the superoxide anion, and that their increased production can contribute to altered control of vasomotor tone and atherosclerosis. The NADH/NADPH oxidase system, which includes a 22 kD subunit (p22 phox), is the major source of superoxide production in vascular tissues. The superoxide radical oxidizes LDL and oxidized LDL is shown to be a key component in atherogenesis. Superoxide anion inactivates the NO radical, an anti-atherogenic molecule. Lysophosphatidylcholine, which accumulates during oxidative modification of LDL, has multiple effects on vascular cells, including cell proliferation, migration, apoptosis, and gene expression. Lysophosphatidylcholine stimulates superoxide production in endothelial cells through the NADH/NADPH oxidase-dependent mechanism. To investigate the expression of p22 phox in normal and atherosclerotic coronary arteries, samples were obtained from autopsy and examined using immunohistochemistry. In normal vessels, weak positive staining of p22 phox was detectable only in the adventitial layer. In contrast, strong immunoreactivity for p22 phox was present in atherosclerotic lesions around lipid core and shoulder regions. P22 phox was localized in the macrophages, fibroblasts, endothelial cells, and some smooth muscle cells which was identified by immunofluorescence double staining. The genetic analysis of the p22 phox gene by restriction fragment length polymorphism (RFLP) for control subject and patients with coronary artery disease revealed that the prevalence of the TC + TT genotype of the C242T polymorphism of the p22 phox gene in control subjects was significantly more frequent than in coronary artery disease patients, indicating that the mutation of the p22 phox gene might reduce the susceptibility for coronary artery disease, which is independent of other coronary risk factors. These observations suggest that oxidative stress, mainly via the NADH/NADPH oxidase system in the vasculature, may play an important role in the pathogenesis of atherosclerosis.

Animals↗

New immunofluorescence assays for detection of Human herpesvirus 8-specific antibodies.

Several assays have been developed for detection of immunoglobulin G antibodies to Human herpesvirus 8 (HHV-8), including immunofluorescence assays (IFAs) and enzyme-linked immunosorbent assays (ELISAs). However, the specificity and sensitivity of these assays are not completely defined due to the lack of a "gold standard." Although IFAs based on primary effusion lymphoma (PEL) cell lines are used widely, the assays can be confounded by nonspecific reactions against cellular components and potential cross-reaction with antibodies against other herpesviruses. To provide more reliable IFAs, we established recombinant Semliki Forest viruses (rSFVs) expressing the HHV-8-specific proteins ORF73 and K8.1 and used BHK-21 cells infected with these rSFVs for IFA (ORF73-IFA and K8.1-IFA). Expression of the HHV-8-specific proteins at very high levels by the rSFV system allowed easy scoring for IFA and thereby increased specificity. The rSFV system also allowed detection of antibodies against glycosylation-dependent epitopes of K8.1. Titers measured by rSFV-based IFAs and PEL-based IFAs correlated well (correlation coefficients of >0.9), and concordances of seroreactivities between rSFV-based and PEL-based IFAs were >97% (kappa > 0.93). K8.1-IFA was more sensitive than either ORF73-IFA or peptide ELISAs. Using PEL-based lytic IFA as a reference assay, the sensitivity and specificity of K8.1-IFA were estimated to be 94 and 100%, respectively. HHV-8 prevalences determined by K8.1-IFA among the human immunodeficiency virus (HIV)-positive (HIV(+)) Kaposi's sarcoma (KS) patients, HIV(+) KS(-) patients, and healthy controls were 100, 65, and 6.7%, respectively, which were consistent with prior reports. Therefore, our rSFV-based IFAs may provide a specific and sensitive method for use in epidemiology studies. In addition, they will provide a basis for further development of diagnostic tests for HHV-8 infection.

Animals↗

Mechanisms of reduced nitric oxide/cGMP-mediated vasorelaxation in transgenic mice overexpressing endothelial nitric oxide synthase.

NO, constitutively produced by endothelial NO synthase (eNOS), plays a key regulatory role in vascular wall homeostasis. We generated transgenic (Tg) mice overexpressing eNOS in the endothelium and reported the presence of reduced NO-elicited relaxation. The purpose of this study was to clarify mechanisms of the reduced response to NO-mediated vasodilators in eNOS-Tg mice. Thoracic aortas of Tg and control mice were surgically isolated for vasomotor studies. Relaxations to acetylcholine and sodium nitroprusside were significantly reduced in Tg vessels compared with control vessels. Relaxations to atrial natriuretic peptide and 8-bromo-cGMP were also significantly reduced in Tg vessels. Reduced relaxations to these agents were restored by chronic N(G)-nitro-L-arginine methyl ester treatment. Basal cGMP levels of aortas were higher in Tg mice than in control mice, whereas soluble guanylate cyclase (sGC) activity in Tg vessels was approximately 50% of the activity in control vessels. Moreover, cGMP-dependent protein kinase (PKG) protein levels and PKG enzyme activity were decreased in Tg vessels. These observations indicate that chronic overexpression of eNOS in the endothelium resulted in resistance to the NO/cGMP-mediated vasodilators and that at least 2 distinct mechanisms might be involved: one is reduced sGC activity, and the other is a decrease in PKG protein levels. We reported for the first time that increased NO release from the endothelium reduces sGC and PKG activity in mice. These data may provide a new insight into the mechanisms of nitrate tolerance and cross tolerance to nitrovasodilators.

Animals↗

Regional differences of metabolism in human masseter muscle by two-dimensional 31P-chemical shift imaging.

Many reports have demonstrated significant region-dependent differences in the fiber-type composition of the human masseter muscle. Therefore, it is considered that there is intramuscular heterogeneity of metabolic activity in the muscle. The present study was carried out, with two-dimensional Chemical Shift Imaging, to detect differences between the deep and superficial parts of the human masseter muscle at rest. Masseter muscle from 11 volunteers, from 20 to 27 years old, was examined, and characteristic spectra of the inorganic phosphate (Pi), phosphocreatine (PCr), and alpha-, beta-, and gamma-adenosine triphosphate (ATP) from each part of the muscles were obtained. In this study, the deep and superficial parts of the masseter muscle were distinguished by the existence of aponeurosis. The Pi/PCr, PCr/beta-ATP, and Pi/beta-ATP ratios as well as the pH in the deep and superficial parts were calculated from the peak spectra. Compared with the deep part, the Pi/PCr of the superficial part was lower (p < 0.05) and the PCr/beta-ATP was higher (p < 0.01). The Pi/beta-ATP and pH showed no significant differences between the two parts. The results indicate that the superficial part of the masseter muscle contains more PCr than the deep part, and this may be related to functional differences between these two parts. In future examinations of the metabolic activity of the human masseter muscle, the deep and superficial parts must be measured separately.

Adenosine Triphosphate↗

Effects of ZNC-2381, a new oral compound, on several hepatic injury models and on hepatocellular apoptosis in mice and rats.

The hepatoprotective effect of ZNC-2381 (1-(4-aminophenyl) methyl-3-(3-nitrophenyl)-1,3-dihydroimidazo[4,5-b]pyridine-2-one), a novel 2-one dihydroimidazopyridine derivative, has been evaluated in several experimental models of hepatic injury. In mice, oral ZNC-2381, administered at doses of 3, 10 or 30 mgkg(-1), 1 h before induction of hepatic injury with concanavalin A, dose-dependently inhibited increases in serum alanine aminotransferase (ALT) activity. Apoptosis of liver cells, as indicated by DNA fragmentation (nucleosome assay) and DNA-ladder formation (electrophoresis), was also inhibited dose-dependently. ZNC-2381 dose-dependently inhibited concanavalin A-induced increases in serum tumour necrosis factor (TNF)-alpha levels, and TNF-alpha mRNA expression in the liver. Oral ZNC-2381 also dose-dependently inhibited increases in serum ALT activity in mice with hepatic injury induced by Propionibacterium acnes and a bacterial lipopolysaccharide (LPS) or D-galactosamine-LPS, and in rats with D-galactosamine-induced hepatic injury. These results indicate that oral ZNC-2381 inhibits cytokine (TNF-alpha) production and cytokine-related hepatocellular apoptosis, and might thus prevent different types of hepatic injury.

Alanine Transaminase↗

Synergistic effects of iontophoresis and jet injector pretreatment on the in-vitro skin permeation of diclofenac and angiotensin II.

A non-needle syringe (jet injector) was utilized to increase skin permeation of drugs by iontophoresis. Briefly, physiological saline was initially flushed by the injector to make a pore in the stratum corneum of excised hairless rat skin, and the iontophoretic skin permeation of two model compounds, sodium diclofenac and angiotensin II, was followed using a 2-chamber diffusion cell. Constant voltage and constant current iontophoresis treatments were evaluated. Pretreatment using the jet injector alone resulted in about 13- and 22-fold increases in the steady-state flux of diclofenac and angiotensin II, respectively, through the skin, compared with non-treated controls. Jet injector pretreatment with constant voltage iontophoresis further enhanced skin permeation of diclofenac and angiotensin II, and the enhancement was also greater than that by constant voltage iontophoresis alone. Thus, a synergistic effect was observed. The ratio of enhancement was greater compared with the control. Jet injector pretreatment with constant current iontophoresis, however, did not always yield higher skin permeation of the drugs than injector pretreatment alone, although the lag time was shortened. The difference in the enhancement between the constant voltage- and constant current iontophoresis can be explained by the electric current through the excised skin. Constant current iontophoresis after a short period of constant voltage iontophoresis with multiple jet injector pretreatments may be the best way to increase drug permeability while preventing severe skin damage.

Administration, Cutaneous↗

Labeling conditions using a 2-aminobenzamide reagent for quantitative analysis of sialo-oligosaccharides.

During 2-aminobenzamide (2-AB)-labeling of sialo-oligosaccharides the authors encountered a significant loss of sialic acids under the reported conditions, at 65 degrees C for 2 h. By examination of the relationship between labeling temperature and recovery of tetra-sialylated oligosaccharides, 2-AB-labeling at 37 degrees C for 16 h resulted in a maximum yield with practically no loss of sialic acid. Under the newly optimized conditions, the reproducibility of 2-AB-labeling was examined in triplicate with three lots of recombinant human erythropoietin (r-HuEPO). The present conditions gave analytical data comparable to those obtained by the established NaB[3H]4 labeling procedure. The modified method has been applied to oligosaccharide structural analysis of sialoglycoprotein therapeutics.

Animals↗

Retinoidal pyrimidinecarboxylic acids. Unexpected diaza-substituent effects in retinobenzoic acids.

Several pyridine- and pyrimidine-carboxylic acids were synthesized as ligand candidates for retinoid nuclear receptors, retinoic acid receptors (RARs) and retinoic X receptors (RXRs). Although the pyridine derivatives, 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]pyri dine-3-carboxylic acid (2b) and 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carboxamido]py ridine-3-carboxylic acid (5b) are more potent than the corresponding benzoic acid-type retinoids, Am80 (2a) and Am580 (5a), the replacement of the benzene ring of Am580 (5a), Am555 (6a), or Am55 (7a) with a pyrimidine ring caused loss of the retinoidal activity both in HL-60 cell differentiation assay and in RAR transactivation assay using COS-1 cells. On the other hand, pyrimidine analogs (PA series, 10 and 11) of potent RXR agonists (retinoid synergists) with a diphenylamine skeleton (DA series, 8 and 9) exhibited potent retinoid synergistic activity in HL-60 cell differentiation assay and activated RXRs. Among the synthesized compounds, 2-[N-n-propyl-N-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)a mino]pyrimidine-5-carboxylic acid (PA013, 10e) is most active retinoid synergist in HL-60 assay.

Animals↗

Infective endocarditis with extensive calcified granulation of the mitral annulus and valve--a case report.

Mitral annular calcification, a degenerative process usually seen in the elderly or in chronic renal failure, is rarely seen in an extensive form. A 69-year-old man with no history of renal failure, rheumatic fever, or heart disease had mitral valve vegetation and regurgitation, together with extensive mitral annuls and valve calcification, which may or may not have been secondary to the infective endocarditis.

Aged↗

Onset of spermatogenesis is accelerated by gestational administration of 1,2,3,4,6,7-hexachlorinated naphthalene in male rat offspring.

We treated pregnant rats with 1 microg/kg body weight/day 1,2,3,4,6,7-hexachlorinated naphthalene (1,2,3,4,6,7-HxCN) on days 14-16 of gestation and examined the effects on the reproductive systems of their male offspring at various phases of sexual maturation. Sperm count in the cauda epididymidis did not change in 1,2,3,4,6, 7-HxCN-treated rats on postnatal day 89, the age of sexual maturity, but the sperm count in the cauda epididymidis did increase to approximately 180% of the control value on postnatal day 62. In addition, homogenization-resistant testicular spermatids increased to approximately 160% of the control value on postnatal day 48, and the percent of postmeiotic tubules increased to approximately 190% of the control value on postnatal day 31 in this group. These results indicate that the onset of spermatogenesis was accelerated in the 1,2,3,4,6,7-HxCN rats. Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) had already reached the maximum level on postnatal day 31 in the 1,2,3,4,6, 7-HxCN group, suggesting that the onset of LH and FSH secretions from the pituitary gland was also accelerated and that this endocrine disruption was the cause of early onset of spermatogenesis in this group. In the fat of 1,2,3,4,6,7-HxCN-treated dams, 5.75+/-2.81 ppb 1,2,3,4,6,7-HxCN was detected when offspring were weaned. This concentration was 5-10 times higher than that found in human adipose tissue.

Adipose Tissue↗

Novel species specific antigens of trypanosoma congolense and their different localization among life-cycle stages.

Seven monoclonal antibodies (mAbs) were raised against Trypanosoma congolense procyclic form (PCF). Localization of the antigens recognized by the mAbs was determined in bloodstream form (BSF), PCF, epimastigote form (EMF) and metacyclic form (MCF) by confocal laser scanning microscopy (CLSM). Two mAbs (10F9 and 20H12) showed different fluorescent patterns among different life-cycle stages of the parasite. The 10F9 recognized a 76 kDa antigen of all life-cycle stages of the parasite and the antigen localization corresponded with that of a mitochondrion. While the 20H12 recognized 119 and 122 kDa antigens of all the life-cycle stages and the antigen localization corresponded with a flagellum in BSF and MCF, tip of a flagellum in PCF, and part of cytoplasm in EMF. Moreover, the 20H12 did not react to T. brucei gambiense, T. b. rhodesiense and T. evansi antigens in both CLSM and immunoblotting. Therefore, the antigens recognized by the 20H12 seem to be T. congolense specific. Although, further studies will be required for a full characterization of the T. congolense specific 119 and 122 kDa antigens, the mAb 20H12 and the specific antigens may be useful in not only establishment of T. congolense specific diagnosis methods but also studies on molecular mechanisms regulating differentiation of the parasite during life-cycle.

Animals↗

Antigens expressed in feline enteroepithelial-stages parasites of Toxoplasma gondii.

In an investigation aimed to identify Toxoplasma gondii antigens expressed in feline enteroepithelial-stages parasites, a cDNA library was constructed and fourteen positive clones were isolated by immunoscreening using sera from cats immunized with feline enteroepithelial-stages parasites. By DNA sequence homology analysis, these fourteen isolated clones were classified into four groups: hypoxanthine-guanine phosphoribosyl transferase (HGPRT) cDNA, heat shock protein 70 (HSP70) cDNA, 14-3-3 protein homologue cDNA, and cDNA encoding an unknown product. In an indirect immunofluorescence antibody test, sera from mice immunized with the recombinant protein encoded by the cDNA for HGPRT, HSP70, 14-3-3 protein, or the unknown product each showed a relatively high level of immunoreactivity with feline enteroepithelial-stages parasites.

Animals↗

Distraction osteogenesis after acute limb-shortening for segmental tibial defects. Comparison of a monofocal and a bifocal technique in rabbits.

BACKGROUND: Segmental bone defects can be treated with immediate limb-shortening followed by monofocal or bifocal distraction osteogenesis. In the present study, the efficacy of monofocal distraction osteogenesis was compared with that of bifocal distraction osteogenesis in a rabbit model. METHODS: Twenty-four skeletally mature New Zealand White rabbits were divided into two equal groups: one group had monofocal distraction osteosynthesis, and the other had bifocal distraction osteosynthesis. In both groups, a one-centimeter-long segment of bone was resected from the midpart of the tibial shaft. In the monofocal reconstruction group, the limb was immediately shortened to close the segmental defect and the defect was allowed to heal for ten days. Lengthening was then begun at this site, with use of a specially designed external fixator, at a rate of 0.5 millimeter per twelve hours. In the bifocal reconstruction group, the segmental defect was closed immediately and the fragments were fixed with microplates. A subperiosteal osteotomy was performed proximal to the tibiofibular junction, and lengthening was performed at the site of the osteotomy. The animals in both groups were killed twenty days after the lengthening was completed. New-bone formation then was evaluated with use of radiographs, densitometry, biomechanical testing, and histological and histomorphometric analysis. RESULTS: Osseous consolidation occurred in all but one of the animals. Biomechanical testing demonstrated that the tibiae that had been treated with use of the simple monofocal reconstruction technique tended to have greater torsional stiffness (p = 0.14) and strength (p = 0.09). Follow-up radiographs revealed that both groups had a significant decrease in radiolucent area (p < 0.05), which occurred at essentially the same rate after lengthening. No significant differences were found between the groups with respect to new-bone mineral density, new-bone area, or the amount of callus. Thus, after resection of a diaphyseal bone segment comprising 10 percent of the original length of the tibia and acute shortening, limb reconstruction was completed successfully through distraction osteogenesis with use of either a monofocal or a bifocal technique in rabbits. CONCLUSIONS: In the present study, both monofocal and bifocal techniques of shortening and distraction osteogenesis were effective for the reconstruction of segmental bone defects. Under some conditions, the monofocal method may provide a simpler means of treating such defects. CLINICAL RELEVANCE: Damage to the soft-tissue envelope as well as venous and lymphatic stasis impose limits on the amount of limb-shortening that can be achieved with use of the monofocal method and also influence the indications for this procedure in the clinical setting.

Animals↗

Comparative study of the toxic effects of gallium arsenide, indium arsenide and arsenic trioxide following intratracheal instillations to the lung of Syrian golden hamsters.

Toxic effects of gallium arsenide (GaAs), indium arsenide (InAs) and arsenic trioxide (As2O3) were studied in male Syrian golden hamsters. GaAs (7.7 mg/kg) and As2O3 (1.3 mg/kg) particles were instilled intratracheally twice a week a total of 16 times, while InAs (7.7 mg/kg) was instilled a total of 14 times. As a control, hamsters were treated with the vehicle, phosphate buffer solution. During the instillation period, the cumulative body weight gain of the InAs-, but not the GaAs- or As2O3-treated hamsters was suppressed significantly, when compared with the control group. Slight to severe inflammatory responses were observed in the lung for all treatment groups. The most severe inflammatory change, characterized by an accumulation of neutrophils and macrophages, exudation, thickness of the pleura and fibrotic proliferation was found in the InAs-treated hamsters. Extensive alveolar or bronchiolar cell hyperplasia with or without keratinizing squamous cell metaplasia was observed in almost all the InAs-treated hamsters. Furthermore, squamous cell metaplasia or squamous cell hyperplasia developed in some of the InAs-treated hamsters, but not in the GaAs- or As2O3-treated hamsters. Slight to mild lesions were found in the convoluted tubules of the kidney in both the GaAs and InAs groups. From the present study, the toxic potency of these particles was provisionally estimated to be in the following order: InAs > GaAs > As2O3, at the dosage level used in this study. Furthermore, there was evidence that InAs particles could induce pulmonary, renal or systemic toxicity, and as such, InAs particles may produce pulmonary precancerous change when instilled intratracheally into hamsters.

Animals↗

Cerebral function after aortic surgery using retrograde cerebral perfusion: report of three cases.

INTRODUCTION: The neurological analysis undertaken on three cases of aortic aneurysm treated surgically using retrograde cerebral perfusion (RCP) are reported herein. This is the first detailed analysis of postoperative neurological studies in such cases. METHODS: The oxygenation state of cerebral Hb and cytochrome aa3 levels were monitored by near-infrared spectroscopy (NIR) during RCP. Postoperative neurological scoring, computed tomography (CT), magnetic resonance imaging (MRI), and monitoring of local cerebral blood flow (LCBF) quantatively by N-isopropyl-p-[123I] iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) were performed for an extended follow-up period after surgery. RESULTS: The T2WI of MRI findings which consisted of many spotty high intensity areas in the striatum, cerebellum and hippocampus, may reflect the postoperative severe consciousness and mental disturbances (2-4 weeks). However, in all cases the neurological deficit gradually improved until they returned to their normal preoperative states. The improvement of LCBF correlated well with neurological recovery. CONCLUSION: The conditions of the conventional method of RCP must be improved to prevent transient severe consciousness and mental disturbances which occur after the operation in relationship with the appearance of the high intensity area on the MRI T2WI.

Adult↗