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H Nakao

Publications and source records attributed to H Nakao.

At least 37 records · Page 2Linked to original sources
PubMed2001

The relationship of brain catecholamine levels to enflurane requirements among three strains of mice with different anesthetic sensitivities.

PURPOSE: . It has been reported that brain catecholamines alter the minimum alveolar concentration (MAC) of anesthetics. The extent of the relation between the levels of brain catecholamine and anesthetic sensitivity should be evaluated by excluding several factors. METHODS: Anesthetic sensitivity was measured by using loss of the righting reflex in three strains of mice with different sensitivities. The mice were decapitated without any anesthesia, adding on ddN and C57BL/6J mice in 2% enflurane, their brains were divided into three parts, and dopamine and norepinephrine levels were analyzed by high-performance liquid chromatography (HPLC). Results. The values of enflurane requirement (%) were 1.30 +/- 0.05 in ddN, 1.10 +/- 0.02 in C57BL/6J, and 1.05 +/- 0.02 in MSM mice. The values of dopamine (microg.g(-1)) in the mesencephalon were 0.23 +/- 0.02 in ddN, 0.15 +/- 0.02 in C57BL/6J, and 0.12 +/- 0.02 in MSM (mean +/- SE). No statistical significance in the values in 2% enflurane could be obtained between ddN and C57BL/6J. The stepwise regression line showed a significant correlation: enflurane requirement (%) = -0.89 + 1.60 x (dopamine levels of mesencephalon) (r(2) = 0.571, P < 0.0001). CONCLUSION: Dopamine in the mesencephalon seems to play an important role in the production of different anesthetic sensitivities, and the anesthetic mechanism might be related to the regulation of dopamine levels that promote arousal.

Journal Article↗
PubMed2001

A prospective clinical study on inhaled nitric oxide therapy for neonates in Japan.

BACKGROUND: This is the first report about a prospective clinical investigation to study the efficacy and safety of nitric oxide (NO) inhalation in infants with persistent pulmonary hypertension of the newborn (PPHN) in Japan. METHODS: Patients in the present study had to meet the following entry criteria: (i) they had to be younger than 7 days of age; (ii) they had to have evidence of PPHN as defined by echocardiograph; (iii) they had to have severe systemic hypoxemia under mechanical ventilation at 100% oxygen supplementation; and (iv) they had to have a failure to respond to conventional therapies. Patients were excluded from this trial if they had any of the following: hypoplastic lung, structural cardiac lesions or severe multiple anomalies. RESULTS: Nitric oxide inhalation therapy was performed in 68 infants who had severe PPHN at 18 hospitals between May 1995 and May 1997. At birth, 21 of 68 infants (31%) weighed less than 1,500 g and 39 infants weighed more than 2,500 g. The diagnoses associated with PPHN were as follows: 27 infants had meconium aspiration syndrome, 15 infants had dry lung syndrome, nine infants had congenital diaphragmatic hernia, six infants had respiratory distress syndrome, three infants had pneumonia and eight infants had other diagnoses. The mean oxygenation index (OI) before NO inhalation therapy in 68 infants was 43.2; 55 infants (81%) had good responses. CONCLUSIONS: These results may be valuable for further randomized controlled and double-blind trials in Japan to evaluate whether NO inhalation therapy is more effective than conventional therapy in infants with severe PPHN.

Administration, Inhalation↗
PubMed2001

Effect of dexamethasone therapy on pulmonary function in chronic lung disease: a comparison of disease types.

BACKGROUND: In the present study, we investigated the effect of dexamethasone (DEX) therapy on extubation and pulmonary function in patients with chronic lung disease (CLD) who required long-term mechanical ventilation. In addition, we compared the effects of DEX therapy among CLD types. METHODS: Twenty-two CLD patients who were ventilator dependent for 28 days or longer received DEX therapy for the purposes of extubation. A tapering dose of DEX, starting from 0.5 mg/kg per day, was administered for 7 days. Pulmonary function was measured at initiation of administration and 4 days after initiation. We evaluated static respiratory system compliance (Crs) and static respiratory system resistance (Rrs) adjusted by bodyweight. Chronic lung disease types were categorized according to the classification of the Ministry of Health and Welfare Research Project. We compared the effect of DEX therapy among CLD types. RESULTS: Dexamethasone therapy was started at a mean (+/-SD) 45 =/- 11 days after birth and 32.1 +/- 1.3 weeks of postconceptional age in infants with a mean bodyweight of 939 +/- 153 g. After DEX therapy, extubation was successful in all 22 patients. Following DEX administration, Crs was significantly increased from 0.69 +/- 0.13 to 1.17 +/- 0.21 mL/cm H2O per kg. In contrast, Rrs did not show any clear changes. Comparing CLD types, no difference was observed for Crs and Rrs in each disease type. CONCLUSIONS: Dexamethasone was administered to CLD patients requiring long-term mechanical ventilation for the purposes of extubation and extubation was successful in all patients. It was found that Crs was increased in all patients following DEX, regardless of CLD type. The increase in Crs following DEX administration may have been related to successful extubation.

Anti-Inflammatory Agents↗
PubMed2001

Spectroelectrochemical characterization of Si-bridged diphenylamines: influence of Si-bridging upon electronic structures of diphenylamines.

Spectroelectrochemical properties of monosilane bridged diphenylamine (5,10-dihydro-2,8-diphenyl-5, 10,10-trimethylphenazasiline, Phenaz) and disilane bridged diphenylamine (2,8-diphenyl-10,11-dihydro-10,11-disila-5,10,10,11,11-pentamethyldibenzo[b,f]azepine, DSiAzep) were investigated. The electrochemical oxidation of Phenaz was reversible and its cyclic voltammogram was almost the same shape as that of diphenylamine (DPA). The electrochemical oxidation of DSiAzep was followed by irreversible reactions leading to the cleavage of the Si-Si bond. On electrochemical oxidations of Phenaz and DPA, the formation of a stable radical cation was observed with UV-Vis spectroscopy. In comparison with the absorption characteristics of oxidized radical cations, it was seen that the oxidized radical cation of Phenaz was more delocalized than that of DPA. In the same way, absorption characteristics of oxidized DSiAzep were observed to be different from those observed in Phenaz and DPA.

Journal Article↗
PubMed2001

Nitrobenzylthioinosine (NBT), a nucleoside transport inhibitor, protects against Shiga toxin cytotoxicity in human microvascular endothelial cells.

Infections with Shiga toxin (Stx)-producing Escherichia coli (STEC) cause microvascular endothelial cell damage, resulting in hemorrhagic colitis and hemolytic uremic syndrome. The prevention of endothelial cell damage is therefore a crucial step in overcoming this disorder. Here, we report that nitrobenzylthioinosine (NBT), a nucleoside transport inhibitor, has a protective effect against the cytotoxicity of Stxs in human microvascular endothelial cells (HMVECs). The relative viability of cells treated with 1.5-15 pM of Stx1 was reduced to 10-20% of that without Stx1. However, the viability of cells treated with NBT (10-100 microM) remained higher than 80%, even in the presence of Stx1. NBT also protected against Stx1 cytotoxicity in sodium butyrate-treated hypersensitive HMVECs. The protective effect of NBT against Stx cytotoxicity may be due to the depletion of ATP in the cells, thereby inhibiting the entry of Stx1.

Adenosine Triphosphate↗
PubMed2001

[Diphtheria].

Explore the source record for details and available documents.

Age Factors↗
PubMed2000

Genetic analysis of the gene cluster for the synthesis of serotype a-specific polysaccharide antigen in Aactinobacillus actinomycetemcomitans.

The serotype a-specific polysaccharide antigen (SPA) of Actinobacillus actinomycetemcomitans consists of 6-deoxy-D-talose. A gene cluster associated with the biosynthesis of SPA was cloned and sequenced from the chromosomal DNA of A. actinomycetemcomitans SUNYaB 75 (serotype a). This cluster consisted of 14 open reading frames. Insertional inactivation of eight genes in this cluster resulted in loss of the ability of A. actinomycetemcomitans SUNYaB 75 cells to produce the polysaccharide. A protein database search revealed that the 11 sequential genes containing these eight genes were not found in SPA-associated gene clusters of the other serotypes of A. actinomycetemcomitans. These results suggest that the gene cluster is unique to serotype a and is essential to the synthesis of the SPA.

Aggregatibacter actinomycetemcomitans↗
PubMed2000

X-Ray anomalous scattering study of a charge-ordered state in NaV2O5

Charge ordering of V4+ and V5+ in NaV2O5 has been studied by an x-ray diffraction technique using anomalous scattering near a vanadium K-absorption edge to critically enhance a contrast between the two ions. A dramatic energy dependence of the superlattice intensities is observed below T(C) = 35 K. The charge ordering pattern is the fully charged zigzag-type ladder with the unit cell 2ax2bx4c, but not the chain-type originally proposed for the spin-Peierls state. Charge disproportionation suggested in our model as the average valence V(4.5+/-delta(c)/2) is observed below T(C), showing continuous variation of delta(c) as a function of temperature.

Journal Article↗
PubMed2000

A novel cell adhesion inhibitor, K-7174, reduces the endothelial VCAM-1 induction by inflammatory cytokines, acting through the regulation of GATA.

A novel inhibitor for the adhesion of monocytes to cytokine-stimulated endothelial cells, K-7174, was selected by an assay system using the cultured human monocytic cells and human endothelial cells. K-7174 inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1) induced by either tumor necrosis factor alpha or interleukin-1beta, without affecting the induction of intercellular adhesion molecule-1 or E-selectin. K-7174 had no effect on the stability of VCAM-1 mRNA. Electrophoretic mobility shift assay revealed that its inhibitory effect on VCAM-1 induction was mediated by an effect on the binding to the GATA motifs in the VCAM-1 gene promoter region. K-7174 did not influence the binding to any of the following binding motifs: octamer binding protein, AP-1, SP-1, ets, NFkappaB, or interferon regulatory factor. These results suggest that the regulation of GATA binding may become a new target for anti-inflammatory drug development, acting through a mechanism independent from NFkappaB activity.

Anisoles↗
PubMed2000

Direct observation of antiferroquadrupolar ordering: resonant X-Ray scattering study of DyB2C2

Antiferroquadrupolar (AFQ) ordering has been conjectured in several rare-earth compounds to explain their anomalous magnetic properties. No direct evidence for AFQ ordering, however, has been reported. Using the resonant x-ray scattering technique near the Dy L(III) absorption edge, we have succeeded in observing the AFQ order parameter in DyB2C2 and analyzing the energy and polarization dependence. The much weaker coupling between the orbital degrees of freedom and the lattice in 4f electron systems than in 3d compounds makes them an ideal platform to study orbital interactions originating from electronic mechanisms.

Journal Article↗
PubMed2000

Aliphatic Hydroxylation by a Bis(µ-oxo)dicopper(III) Complex.

By using molecular oxygen bis(µ-oxo)dicopper(III) complexes can be produced from Cu(I) complexes with ligand L(X) (L(X)=p-substituted N-ethyl-N-[2-(2-pyridyl)ethyl]-2-phenylethylamine; X=OMe, Me, H, Cl, NO(2)) in which the benzylic position of the ligand is activated and hydroxylated by the Cu(2)O(2) core (see reaction scheme). Detailed characterization of this new C-H bond activation reaction by the bis(µ-oxo)dicopper(III) core reveals important information on the fundamental chemistry underlying copper monooxygenase reactivity.

Journal Article↗
PubMed2000

Activity of rheumatoid arthritis and urinary pyridinoline and deoxypyridinoline.

The aims of this study were to examine levels of the crosslinking components of collagen, pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) which are bone resorption markers, in patients with rheumatoid arthritis (RA), and to determine their association with disease activity and bone mineral density (BMD). These bone resorption markers were measured in 35 postmenopausal women with RA, 30 age-matched female patients with osteoarthritis of the knee (controls), and 47 patients with bone fracture. The mean BMD in the RA patients was lower than that in the control group, and the Z-score (number of standard deviations above and below the normal mean after comparison with age and sex matched normal control values) was significantly lower. Mean levels of Pyr and D-Pyr were significantly higher in the RA patients than in the control group, and the Pyr/D-Pyr ratio was also higher in the RA patients than in the other groups. Regarding the relationship between the bone resorption markers and RA activity, Pyr increased as the Lansbury's joint score (number of swollen joints corrected for joint size according Lansbury) rose, showing a normal correlation; D-Pyr also showed a normal correlation. Pyr and D-Pyr were high in patients with a high erythrocyte sedimentation rate, showing a normal correlation. Only Pyr increased with increases in C-reactive protein (CRP), showing a normal correlation. These findings suggested that a high value for Pyr (which includes a large amount of collagen type II) indicated that RA activity was affected more by synovitis, rather than by systemic osteoporosis.

Absorptiometry, Photon↗
PubMed2000

Direct polymerase chain reaction for detection of toxigenic Corynebacterium diphtheriae strains from the Republic of Georgia after prolonged storage.

A total of 226 paired nose and throat swab specimens from 113 clinical diphtheria cases from the republic of Georgia were analyzed by direct polymerase chain reaction targeting both A and B subunits of the diphtheria toxin gene, tox. Even after prolonged transport and extensive storage (7-14 months) of the clinical specimens in silica gel packages, direct polymerase chain reaction detected the diphtheria tox gene in 54% of the specimens. Specimens obtained by throat swab were three times more likely than those obtained by nose swab to be positive for Corynebacterium diphtheriae.

Case-Control Studies↗
PubMed2000

Cloning and characterization of the ddc homolog encoding L-2,4-diaminobutyrate decarboxylase in Enterobacter aerogenes.

L-2,4-diaminobutyrate decarboxylase (DABA DC) catalyzes the formation of 1,3-diaminopropane (DAP) from DABA. In the present study, the ddc gene encoding DABA DC from Enterobacter aerogenes ATCC 13048 was cloned and characterized. Determination of the nucleotide sequence revealed an open reading frame of 1470 bp encoding a 53659-Da protein of 490 amino acids, whose deduced NH2-terminal sequence was identical to that of purified DABA DC from E. aerogenes. The deduced amino acid sequence was highly similar to those of Acinetobacter baumannii and Haemophilus influenzae DABA DCs encoded by the ddc genes. The lysine-307 of the E. aerogenes DABA DC was identified as the pyridoxal 5'-phosphate binding residue by site-directed mutagenesis. Furthermore, PCR analysis revealed the distribution of E. aerogenes ddc homologs in some other species of Enterobacteriaceae. Such a relatively wide occurrence of the ddc homologs implies biological significance of DABA DC and its product DAP.

Amino Acid Sequence↗
PubMed2000

Prediction of diabetes in Biobreeding/Aburahi rats by the measurement of soluble L-selectin.

L-selectin was initially identified as a homing receptor, recently soluble L-selectin has been used as a marker of the inflammation. Therefore, we investigated the relation between the development of diabetes and serum L-selectin levels in the Biobreeding (BB) rats. Serum L-selectin were measured from 30 days old to the onset of diabetes or to 90 days old in Biobreeding (BB) rats and Wistar Furth (WF) rats. Significant elevation of L-selectin was found in diabetes prone (DP) rats from 45 days old to the onset of diabetes or through 90 days old. No elevation was found in other strain of rats. In histological study, all of DP rats had insulitis and no other strain of rats had it. Therefore, we conclude that the measurement of serum L-selectin could be useful tool to predict the onset of diabetes or presence of insulitis in BB rats.

Age Factors↗