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Biomedical subjects

H Aramaki

Publications and source records attributed to H Aramaki.

At least 19 recordsLinked to original sources
PubMed2001

Effect of dosing schedule on pharmacokinetics of alpha interferon and anti-alpha interferon neutralizing antibody in mice.

The influences of dosing time and dosing schedule on the plasma alpha interferon (IFN-alpha) concentration and the production of anti-IFN-alpha neutralizing antibodies were investigated in ICR male mice adapted to cycles of 12 h of light and 12 h of dark. In mice pretreated with IFN-alpha for 21 days, the plasma IFN-alpha concentrations were significantly lower than those in control mice (P < 0.01). The clearance of IFN-alpha and its volume of distribution obtained at steady state were significantly higher in the animals with IFN-alpha pretreatment than in the mice without IFN-alpha pretreatment. The area under the concentration-time curve and the mean residence time of IFN-alpha were significantly smaller in IFN-alpha-pretreated animals than in control animals. The plasma IFN-alpha levels (measured 2 h after dosing) were significantly lower in mice treated daily with IFN-alpha, while the anti-IFN-alpha neutralizing antibody levels (measured 24 h after dosing) were significantly increased on days 15 and 21 of treatment. Plasma IFN-alpha levels were significantly decreased in association with the production of anti-IFN-alpha neutralizing antibodies in mice treated with IFN-alpha daily at either 0900 or 2100 h. By contrast, the plasma IFN-alpha levels (measured 2 h after dosing) remained stable in mice treated with IFN-alpha at 0900 h on alternate days, while they were significantly lower after 21 days of treatment in mice treated with IFN-alpha at 2100 h on alternate days. These changes were associated with a significant increase in the levels of anti-IFN-alpha neutralizing antibodies in the latter group. The present findings suggest that an appropriate dosing schedule and/or dosing time for IFN-alpha may reduce the level of production of anti-IFN-alpha neutralizing antibodies in experimental and clinical situations.

Animals↗
PubMed2000

Archaeal adaptation to higher temperatures revealed by genomic sequence of Thermoplasma volcanium.

The complete genomic sequence of the archaeon Thermoplasma volcanium, possessing optimum growth temperature (OGT) of 60 degrees C, is reported. By systematically comparing this genomic sequence with the other known genomic sequences of archaea, all possessing higher OGT, a number of strong correlations have been identified between characteristics of genomic organization and the OGT. With increasing OGT, in the genomic DNA, frequency of clustering purines and pyrimidines into separate dinucleotides rises (e.g., by often forming AA and TT, whereas avoiding TA and AT). Proteins coded in a genome are divided into two distinct subpopulations possessing isoelectric points in different ranges (i.e., acidic and basic), and with increasing OGT the size of the basic subpopulation becomes larger. At the metabolic level, genes coding for enzymes mediating pathways for synthesizing some coenzymes, such as heme, start missing. These findings provide insights into the design of individual genomic components, as well as principles for coordinating changes in these designs for the adaptation to new environments.

Adaptation, Physiological↗
PubMed2000

In vitro transcription system using reconstituted RNA polymerase (Esigma(70), Esigma(H), Esigma(E) and Esigma(S)) of Pseudomonas aeruginosa.

We have developed an in vitro transcription system for Pseudomonas aeruginosa genes, using RNA polymerase (RNAP) holoenzyme reconstituted with purified sigma protein and RNAP core enzyme. The RNAP core enzyme was directly purified from P. aeruginosa PAO1 cells. The sigma factors of P. aeruginosa (sigma(70), sigma(H), sigma(E) and sigma(S)) were prepared in a hexa-histidine tagged form, which were expressed in Escherichia coli and purified using a HisTrap Chelating column. The RNAP holoenzyme reconstituted from core enzyme with each sigma factor recognized correctly each of the cognate promoters. This system will be useful for the promoter analysis of many genes in P. aeruginosa.

Promoter Regions, Genetic↗
PubMed2000

Oropharyngotonsillitis associated with nonprimary Epstein-Barr virus infection.

OBJECTIVE: To identify distinct clinical features of pharyngotonsillitis or oropharyngitis associated with Epstein-Barr virus (EBV) infection from herpes simplex virus infection. DESIGN: Clinical studies by case exploration. SETTING: Institutional practice at a university hospital. PATIENTS: Thirty-three patients with pharyngotonsillitis and 4 patients with oropharyngitis of nonbacterial infection underwent biopsy of pharyngotonsillar lesions. MAIN OUTCOME MEASURE: The specimens were examined by histopathology, immunohistochemistry, in situ hybridization, and polymerase chain reaction. In addition to serological testing and routine laboratory data, photographic oropharyngeal findings were collected for clinical evaluation. RESULTS: In situ hybridization to detect EBV-encoded small nuclear RNA-1 and -2 disclosed 8 cases of pharyngotonsillitis and 4 cases of oropharyngitis associated with EBV infection. Immunohistochemical analysis identified 5 cases of pharyngotonsillitis associated with herpes simplex virus infection. Serological examination showed that, among 12 cases positive by in situ hybridization, 3 cases were primary infection with infectious mononucleosis and 9 were nonprimary infection. The staining pattern of in situ hybridization was different, ie, a linear pattern in cases of nonprimary infection and a scattered pattern in cases of primary infection. The clinical manifestations of EBV pharyngotonsillitis were distinct from those of herpes simplex virus pharyngotonsillitis and were characteristic irrespective of infectious status, while those of EBV oropharyngitis were more variable. CONCLUSIONS: Epstein-Barr virus-associated pharyngotonsillitis was demonstrated in patients with nonprimary infection unaccompanied by infectious mononucleosis. Epstein-Barr virus should be considered a potential causative agent of oropharyngotonsillitis even in absence of infectious mononucleosis, especially in a young adult.

Acute Disease↗
PubMed2000

Syntheses of stereochemically restricted lactone-type analogues of jasmonic acids.

5-Oxa-7-epi-jasmonic acid and 5-oxa-jasmonic acid, which are stereochemically restricted lactone-type analogues of jasmonic acids, were synthesized via three-component coupling of 2(5H)-furanone, tert-butyl acetate and 1-bromo-2-pentyne. After acidic deprotection of the tert-butyl esters, the (Z)-olefin was introduced by catalytic partial reduction with the Lindlar catalyst to give the desired analogues.

Acetates↗
PubMed2000

Basis for dosing time-dependent changes in the antiviral activity of interferon-alpha in mice.

The influence of dosing time on the pharmacological effect (antiviral activity) of interferon-alpha (IFN-alpha), and the pharmacological and pharmacokinetic mechanisms, were investigated in ICR male mice under a 12-h light/dark cycle (lights on from 7:00 AM to 7:00 PM). 2'-5'Oligoadenylate synthetase activity in plasma at 24 h after IFN-alpha (10 MI.U./kg, i.v.) injection, as an index of antiviral activity, was significantly higher for injections given at 9:00 AM than for injections given at 9:00 PM (P <.05). The uptake of [(3)H]thymidine by lymphocytes after 24-h incubation with IFN-alpha, as an index of lymphocyte-stimulating effect, was significantly higher in cells obtained at 9:00 AM than in the cells obtained at 9:00 PM (P <.01). The number of receptors per cell and the expression of interferon-stimulated gene factor in lymphocytes after 24-h incubation with IFN-alpha were significantly higher in the cells obtained at 9:00 AM than at 9:00 PM (P <.05). A significant dosing time-dependent difference was demonstrated for the pharmacokinetic parameters of IFN-alpha, which showed higher clearance for injections given at 9:00 PM than for those at 9:00 AM (P <.05). The metabolism of IFN-alpha was significantly higher in kidney obtained at 9:00 PM than at 9:00 AM (P <.05). These findings support that choosing the most appropriate time of day for administration of IFN-alpha, associated with the rhythmicity of IFN-alpha receptor function and IFN-alpha pharmacokinetics, may increase the antiviral activity in experimental and clinical situations.

2',5'-Oligoadenylate Synthetase↗
PubMed1999

In vitro transcription analysis of rpoD in Pseudomonas aeruginosa PAO1.

The rpoD gene encoding the principal sigma factor (sigma(70)) of Pseudomonas aeruginosa is transcribed from two promoters, P(C) and P(HS). The sequence of P(C) is similar to the Escherichia coli sigma(70) consensus promoter sequence and that of P(HS) is similar to the E. coli sigma(H) consensus promoter sequence. Synthesis of rpoD mRNA from P(C) is constitutive under both steady-state and heat-shock growth conditions, while that of P(HS) is transiently induced upon heat-shock. To gain a better understanding of the regulation of rpoD expression, we examined in vitro transcription of rpoD using two RNA polymerases (Esigma(70) and Esigma(H), containing sigma(70) and sigma(H), respectively) purified from P. aeruginosa. DNase I footprinting analysis showed specific bindings of Esigma(70) and Esigma(H) to P(C) and P(HS) promoter regions, respectively. In the in vitro runoff transcription assay, Esigma(H) transcribed the template from P(HS) both at 30 degrees C and 42 degrees C but not from P(C). However, Esigma(70) transcribed rpoD not only from P(C) both at 30 degrees C and 42 degrees C but also from P(HS) at 42 degrees C.

Base Sequence↗
PubMed1999

cDNA cloning, overproduction and characterization of rat adrenodoxin reductase.

We isolated a full-length cDNA clone for rat adrenodoxin reductase (AdR). The precursor of rat AdR was predicted to consist of 34 amino-terminal residues of extrapeptide for transport into mitochondria and the following 460 residues of the mature peptide region. The deduced amino acid sequence was 70.8 and 61.8% homologous to those of bovine and human AdRs in the extrapeptide region, respectively, and 88.5% homologous to both the sequences of bovine and human AdRs in the mature peptide region. The predicted mature form of rat AdR was directly expressed in Escherichia coli, using cDNA, and was purified with a yield of 32 mg/l of culture. The purified recombinant rat AdR showed an absorption spectrum characteristic of a flavoprotein with peaks at 270, 378 and 450 nm and shoulders at 280, 425 and 474 nm. The extinction coefficient was estimated to be 10.9 mM(-1) cm(-1) at 450 nm. The absorbance ratio at 270 nm/450 nm was 7.1. From the &theta;(208) value in the circular dichroism spectrum, the alpha-helix content in the rat AdR was calculated to be 30%. In NADPH-cytochrome c reductase activity reconstituted with adrenodoxin (Ad), the apparent K(m) value of rat AdR for NADPH was 0.32 microM, a value significantly lower than that of bovine AdR (1.4 microM). The rat AdR showed a higher affinity to the heterologous redox partner (bovine Ad, K(m)=9.3 nM) than to the native partner (rat Ad, K(m)=16.7 nM), whereas the affinity of bovine AdR was slightly higher to the native partner (bovine Ad, K(m)=37.1 nM) than to the heterologous partner (rat Ad, K(m)=46.8 nM). The K(m) values showed a reverse correlation to the difference of pI values between the redox partners. These results indicate that AdR binds to Ad mainly by ionic interaction.

Amino Acid Sequence↗
PubMed1999

Cloning and sequencing of rpoH and identification of ftsE-ftsX in Pseudomonas putida PpG1.

The rpoH gene encoding the heat-shock sigma factor of Pseudomonas putida was cloned by using its ability to complement the temperature-sensitive growth of the Escherichia coli rpoH mutant. The cloned DNA contained an open reading frame for a 284 amino acid sequence exhibiting high homology to the sigmaH proteins of P. aeruginosa and E. coli. Moreover, homologs to the cell division genes ftsX and ftsE were found immediately upstream of the rpoH gene.

ATP-Binding Cassette Transporters↗
PubMed1999

In vitro transcriptional analysis of the cytochrome P-450cam hydroxylase operon.

To characterize the promoters of cytochrome P-450cam hydroxylase operon (camDCAB) and the repressor gene (camR), in vitro run-off transcription assays were performed using RNA polymerase (RNAP) holoenzyme reconstituted with the core enzyme and the sigma70 protein of Pseudomonas aeruginosa. Both the mRNAs of camDCAB and camR were accurately transcribed from the respective promoter by the reconstituted RNAP holoenzyme. Both the transcriptions were repressed by CamR protein and the repressions were suppressed by D-camphor, consistent with the regulation in P. putida. These results suggest that the RNA polymerase containing sigma70 recognizes the promoter of camDCAB as well as that of camR.

Bacterial Proteins↗
PubMed1998

Transcription of the groESL operon in Pseudomonas aeruginosa PAO1.

Northern hybridization and S1 nuclease mapping demonstrated that the groES and groEL genes in Pseudomonas aeruginosa were transcribed as a bicistronic mRNA of 2.2 kb. Two transcription start sites and a transcription termination site were mapped. Overlapping consensus sequences for sigma 32- and sigma 70-dependent promoters were found in the upstream region of groES. Levels of groESL-specific mRNA were increased about 2-fold upon heat shock. This response differs from the dramatic enhancement (more than 10-fold) of groESL transcription after heat shock observed in other bacterial species.

Bacterial Proteins↗
PubMed1998

Overproduction in Escherichia coli and characterization of the precise mature form of rat adrenodoxin.

The mature form of rat adrenodoxin (Ad) was purified from a heterologous direct expression system in Escherichia coli with a yield of 56 mg/l culture. The purified Ad showed a A414/A280 ratio of 0.91 and the sequence of 10 amino terminal residues was identical with that of authentic rat Ad. By Time of Flight/Mass spectrometry, the molecular mass of purified Ad was identical to that calculated from the cDNA sequence and the carboxy terminal residue was estimated to be Ser, which was also as expected from the cDNA. These results indicate that the purified recombinant Ad is a precise mature form. In measurements of NADPH-cytochrome c reductase activity reconstituted with bovine adrenodoxin reductase (AdR), the apparent Km value for rat Ad was 46.9+/-2.5 nM, indicating a somewhat lower affinity for rat Ad to bovine AdR than for bovine Ad. On the other hand, the spectral Kd value for rat Ad to bovine cytochrome P-450scc was 0.46+/-0.05 microM, a value which was almost identical with that of the bovine counterpart.

Adrenodoxin↗
PubMed1996

Rifampicin resistance and mutation of the rpoB gene in Mycobacterium tuberculosis.

Using 39 clinical isolates of Mycobacterium strains with a broad range of susceptibility to rifampicin, we examined the relationship between the degree of resistance to rifampicin and mutational sites of the rpoB gene. All rifampicin-resistant strains had missense mutations. Twenty strains (95%) had a mutation in the cluster I region, which has also been reported in Escherichia coli [Jin and Gross (1988) J. Mol. Biol. 202, 45-58], and the remaining one strain had a mutation at codon 381 [Ala-->Val] in the N-terminal region, which has not been reported in E. coli. Among 18 rifampicin-susceptible strains, two had a mutation in the cluster I region and the other three strains had a mutation in the cluster III region. The mutations at codons 513 (5%), 526 (33%) or 531 (43%) in the cluster I region led to high level resistance to rifampicin (50 micrograms ml-1 < or = MIC). The mutations at the other sites, in the cluster III region (codons 679 or 687) and even in the cluster I region (codon 514, 521, or 533), showed low level (MIC = 12.5 micrograms ml-1) or no (MIC < 0.39 microgram ml-1) resistance to rifampicin. These results suggest that mutations in the rpoB gene are, mostly, but not necessarily, associated with rifampicin resistance of M. tuberculosis, and the sites of mutations on the rpoB gene will affect the level of resistance to rifampicin.

Amino Acid Sequence↗
PubMed1996

Immediate tonsillectomy for peritonsillar abscess.

The usual treatment for peritonsillar abscess (PTAs) in Japan is antibiotic therapy, drainage and incision followed by tonsillectomy several weeks later. This is a retrospective study of cases treated by immediate tonsillectomy (IT) for PTAs between January 1990 and February 1995 in our hospital. There were 119 cases, 94 male and 25 female, ranging in age from 14 to 76 years (average: 36.6). In all cases, we performed CT scan, which is the most reliable diagnostic method for PTAs. Five of the 119 cases were treated by IT under general anesthesia. All five were male and their ages ranged from 50 to 62 years (average: 56.2). Two patients had diabetes mellitus. Bacteriological study revealed alpha-Streptcoccus in 1 case, but the others showed no remarkable findings. Anaerobacteria were not found in any patient. IT under general anesthesia is preferable for advanced PTAs.

Abscess↗
PubMed1995

Purification and characterization of rat adrenodoxin.

Adrenodoxin was purified from the rat adrenal gland. The A414/A280 value of the purified rat adrenodoxin was 0.90 and the oxidized spectrum showed absorption maxima at 320, 414 and 455 nm, similar to those of bovine adrenodoxin. On SDS-PAGE, the rat adrenodoxin showed a single band with a molecular mass of 11.2 kDa, while the apparent molecular mass by gel filtration through Sephadex G-75 equilibrated with 10 mM K-phosphate (pH 7.5) was 27 kDa. In the reconstituted system, Vmax of NADPH-cytochrome c reduction activity and the Km for the rat adrenodoxin were much the same as those for recombinant bovine adrenodoxin. In the case of cholesterol side-chain cleavage activity, however, these values of the rat adrenodoxin were about half of those of the bovine adrenodoxin. The CD spectrum of the rat adrenodoxin was similar to that of the bovine adrenodoxin but showed a significantly lower ellipticity value in the 195-205 nm region than that of the bovine adrenodoxin. The structural differences may possibly explain differences in the enzymic properties between rat and bovine adrenodoxins.

Adrenal Glands↗
PubMed1995

Residues important for the function of a multihelical DNA binding domain in the new transcription factor family of Cam and Tet repressors.

We report that some prokaryotic repressors including CamR and TetR belong to the same family. CamR and TetR bind to DNA using a multihelical DNA binding domain (DBD) at the N-termini of the proteins, while the C-termini are important for regulating the DNA binding in a manner dependent on their co-factors (camphor for CamR, tetracycline for TetR). In all, 11 important amino acid positions have been identified in the CamR DBD by the systematic substitution of residues by Ala. Of the 11 positions, 10 are either buried in the core, and thus important for creating the hydrophobic environment, or exposed on the surface, and thus important for binding to DNA. The eleventh residue, Gly, seems to be important for a loop structure. The DNA binding mode of this type of DBD and a general mechanism of regulating their DNA binding are discussed in reference to the crystal structure of TetR [Hinrichs et al., (1994) Science, 264, 418-420].

Amino Acid Sequence↗
PubMed1995

Purification and characterization of a cam repressor (CamR) for the cytochrome P-450cam hydroxylase operon on the Pseudomonas putida CAM plasmid.

The cytochrome P-450cam hydroxylase operon of Pseudomonas putida PpG1 (ATCC 17543) encodes proteins responsible for early steps of the degradation of D-camphor. Transcription of this operon is negatively controlled by the cam repressor (CamR), and the expression of camR is autoregulated. CamR was purified from Escherichia coli harboring an overproducing plasmid. The repressor forms a homodimer with a molecular mass of 40 kDa, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and gel filtration. CamR protected a specific DNA region from attack by DNase I. This region contains a palindromic operator of the cytochrome P-450cam hydroxylase operon and of the camR gene. Protection was inhibited by the addition of 60 microM D-camphor and also by certain camphor analogs and degradation products, including D-3-bromocamphor, adamantane, 2-adamantanone, 5-exo-hydroxycamphor, and 2,5-diketocamphane. These analogs and degradation products induced cytochrome P-450cam hydroxylase operon expression in vivo.

Base Sequence↗