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Biomedical subjects

A Shirahata

Publications and source records attributed to A Shirahata.

At least 37 records · Page 2Linked to original sources
PubMed2000

Self-assembly of an oligodeoxyribonucleotide harboring the estrogen response element in the presence of polyamines: ionic, structural, and DNA sequence specificity effects.

Estrogenic regulation of gene expression is mediated by the binding of the hormone to its specific receptor, estrogen receptor (ER), which undergoes structural and conformational alterations to recognize specific DNA sequences, estrogen response elements (ERE), in responsive genes to trigger a series of events culminating in the transcription of these genes. Polyamines are ubiquitous cellular cations that are important for cell growth and differentiation, and have been shown to participate in estrogenic regulation of gene expression. Polyamine-mediated DNA condensation/aggregation has been studied to understand the ionic and structural requirements for the compaction of DNA. DNA condensation/decondensation may also play a role in transcription and replication. We studied the aggregation of a 38-mer oligonucleotide duplex (ODN) in the presence of natural and synthetic polyamines under different ionic conditions (NaCl, KCl, and K glutamate). Our results showed that an ODN harboring the consensus ERE (ODN1) was 2-fold more susceptible to precipitation by spermine compared to ODN2 containing scrambled sequences, or a mutant ODN (ODN3). The nature of the monovalent cations (Na+ vs K+), and anions (Cl- vs glutamate) also played an important role in the efficacy of a polyamine to precipitate ODNs: potassium glutamate being the least effective in suppressing the ability of spermine to precipitate ODNs. The concentration of polyamines required for precipitating the ODNs increased with monovalent ion concentration in the buffer. With ODN1, a plot of log[spermine4+] at the 50% precipitation concentrations against log[Na+/K+] yielded a straight line, with a slope of 1.8 +/- 0.18, a value comparable to that predicted by the counterion condensation theory (1.85). We also observed significant structural specificity effects of spermine and its analogues [NH2(CH2)3NH(CH2)nNH(CH2)3NH2, where n = 2-9; n = 4 for spermine] on aggregating the ODN1. These results demonstrate DNA sequence and polyamine structural specificity effects on the aggregation of ODNs, and suggest that the gene regulatory function of ERE may be linked to its ability to undergo facile condensation/decondensation in the presence of biological cations, such as polyamines.

Base Sequence↗
PubMed2000

Differences in reactivity to vitamin K administration of the vitamin K-dependent procoagulant factors, protein C and S, and osteocalcin.

Vitamin K is a trace nutrient necessary not only for the synthesis of four plasma clotting factors but also the production of two important anticlotting factors, protein C and protein S, and the synthesis of two bone proteins. If protein C and protein S are produced more quickly and/or in higher quantities than four plasma coagulation factors after vitamin K administration, then the result is unfavorable for stopping of hemorrhage. We therefore studied the difference of time dependence of prothrombin procoagulant factors, protein C and S and bone Gla protein after the administration of vitamin K in normal and vitamin K-deficient neonates. Results of our study showed that, on the whole, coagulation factors increased markedly more than anticlotting factors after vitamin K administration. Furthermore, the increase in bone Gla protein was also higher compared with protein C activity, although the detailed mechanism of the difference in reactivity of prothrombin procoagulant factors, protein C and S and bone Gla protein to vitamin K administration is not clear.

Female↗
PubMed2000

Vitamin K contents in liver tissue of hepatocellular carcinoma patients.

Serum protein induced in vitamin K absence-II (PIVKA-II) is used as a tumor marker because it increases at a notably higher rate in patients with hepatocellular carcinoma. To clarify the mechanism causing the elevation of serum PIVKA-II, we measured the contents of vitamins K1 (phylloquinone, PK) and K2 (menaquinone, MK) (MK-4, MK-5, MK-6, MK-7, MK-8, MK-9, MK-10) in liver tissue resected from 21 hepatic cancer patients (12 patients with hepatocellular carcinoma and 9 patients with metastatic hepatic cancer), using HPLC combined with coulometric reduction and fluorometric detection. In the cancerous tissue of hepatocellular carcinoma patients, PK, MK-7, MK-8, and MK-10 were significantly lower than that found in the noncancerous tissue. Furthermore, MK-6, MK-7, MK-8, and MK-10 in the cancerous tissue of hepatocellular carcinoma patients were significantly lower than that in the cancerous tissue of metastatic hepatic cancer patients. These data suggested that one of the mechanisms of the elevation of serum PIVKA-II levels in hepatocellular carcinoma patients is a vitamin K deficiency in the local cancerous tissue.

Aged↗
PubMed2000

Covalent linkage of polyamines to peptidoglycan in Anaerovibrio lipolytica.

Spermidine and cadaverine were found to be constituents of the cell wall peptidoglycan of Anaerovibrio lipolytica, a strictly anaerobic bacterium. The peptidoglycan was degraded with the N-acetylmuramyl-L-alanine amidase and endopeptidase into two peptide fragments, peptide I and peptide II, at a molar ratio of 4:1. Peptides I and II were identified as L-alanine-D-glutamic acid(alphacadaverine)gammameso-diaminopimelic acid (DAP)-D-alanine and L-alanine-D-glutamic acid(alphaspermidine)gammameso-DAP-D-alanine, respectively. The N(1)-amino group of spermidine was linked to the alpha-carboxyl group of the D-glutamic acid residue of peptide II.

Cadaverine↗
PubMed2000

Measurements of macromolecule-bound and ultra-filtrable polyamines in rat liver homogenized without buffer.

Ultra-filtrable and macromolecule-bound polyamines in rat liver homogenates, made without buffer, were determined, using Potter-Elvehjem homogenizer and commercially available, pressure-aided ultrafiltration device with a membrane pore size that allows passage of particles of molecular weight no larger than 5000. About 90% of polyamines in the liver were shown to be equilibrated with externally added 15N-labeled polyamines, based on the difference in the ratio of the natural to 15N-labeled polyamine in the liver homogenate and the ultrafiltrate. The entire amount of ultrafiltrate in the homogenized liver, required for calculation of the amounts of ultra-filtrable and macromolecule-bound polyamines, was estimated to be about 0.25 g in one gram of the homogenate, using a limited dilution curve of spermine in the ultrafiltrate with phosphate buffered saline and distilled water. With this value, ultra-filtrable polyamines in normal rat liver homogenate were calculated as about 25%, 8%, and 2% of the total amount of putrescine, spermidine, and spermine, respectively. The method was then used to measure ultra-filtrable and macromolecule-bound polyamines in regenerating rat liver homogenates, to examine possible changes of polyamines during cell growth. The method was also applied to measure other ultra-filtrable compounds such as amino acids and inorganic ions in rat liver homogenate.

Amino Acids↗
PubMed2000

Pharmacokinetics, prophylactic effects, and safety of a new recombinant FVIII formulated with sucrose (BAY 14-2222) in Japanese patients with hemophilia A.

A clinical trial of BAY 14-2222, a recombinant factor VIII preparation (rFVIII) manufactured by new purification and formulation processes using sucrose as a stabilizer instead of human serum albumin, was performed in 5 previously treated Japanese patients with severe hemophilia A. In stage I, a single dose of BAY 14-2222 and Kogenate (a currently licensed rFVIII preparation) was administered alternately in the same patients to compare the pharmacokinetics of the 2 compounds using FVIII:C (FVIII clotting activity) as the measure of plasma drug levels. The normalized area under the curve (AUCnorm) and normalized maximal concentration (Cmax,norm) were slightly lower following the administration of BAY 14-2222 than those after the administration of Kogenate (ratio of BAY 14-2222/Kogenate:AUCnorm = 0.88, P = .050; and Cmax,norm = 0.87, P = .041). However, the biological half-life (t1/2) did not differ significantly between the 2 preparations (13.96 +/- 4.18 vs. 13.48 +/- 2.40 hours). The in vivo recovery of FVIII was 67.9 +/- 11.3% after the administration of BAY 14-2222 and 74.4 +/- 5.3% after the administration of Kogenate. In stage II, BAY 14-2222 was administered regularly to the 5 patients with hemophilia at single doses of 20 to 40 IU/kg 3 times weekly for 4 weeks, and its prophylactic effect on bleeding was evaluated. Results indicated that BAY 14-2222 has a good preventive effect on bleeding. Sixty-six infusions were performed in stages I and II of this trial, and no adverse reactions related to BAY 14-2222 were observed. In addition, there were no FVIII inhibitors or antibodies to foreign proteins detected. The trial confirmed that BAY 14-2222 is similar to Kogenate with respect to t1/2 and the in vivo recovery of FVIII:C and that periodic infusions for 4 weeks can be well tolerated. In addition, it was shown that BAY 14-2222 is effective in preventing bleeding. Thus it is expected that BAY 14-2222 will exhibit a hemostatic effect comparable to that of Kogenate in patients with hemophilia A.

Adolescent↗
PubMed2000

Molecular correlates of the action of bis(ethyl)polyamines in breast cancer cell growth inhibition and apoptosis.

Polyamines are known to be involved in cell growth regulation in breast cancer. To evaluate the efficacy of bis(ethyl)polyamine analogs for breast cancer therapy and to understand their mechanism of action we measured the effects of a series of polyamine analogs on cell growth, activities of enzymes involved in polyamine metabolism, intracellular polyamine levels, and the uptake of putrescine and spermidine using MCF-7 breast cancer cells. The IC50 values for cell growth inhibition of three of the compounds, N1,N12-bis(ethyl)spermine, N1,N11-bis(ethyl)norspermine, and N1,N14-bis(ethyl)homospermine, were in the range of 1-2 microM. Another group of three compounds showed antiproliferative activity at about 5 microM level. These compounds are also capable of suppressing colony formation in soft agar assay and inducing apoptosis of MCF-7 cells. The highly effective growth inhibitory agents altered the activity of polyamine biosynthetic and catabolic enzymes and down-regulated the transport of natural polyamines, although each compound produced a unique pattern of alterations in these parameters. HPLC analysis showed that cellular uptake of bis(ethyl)polyamines was highest for bis(ethyl)spermine. We also analyzed polyamine analog conformations and their binding to DNA minor or major grooves by molecular modelling and molecular dynamics simulations. Results of these analyses indicate that tetramine analogs fit well in the minor groove of DNA whereas, larger compounds extend out of the minor groove. Although major groove binding was also possible for the short tetramine analogs, this interaction led to a predominantly bent conformation. Our studies show growth inhibitory activities of several potentially important analogs on breast cancer cells and indicate that multiple sites are involved in the mechanism of action of these analogs. While the activity of an analog may depend on the sum of these different effects, molecular modelling studies indicate a correlation between antiproliferative activity and stable interactions of the analogs with major or minor grooves of DNA.

Acetyltransferases↗
PubMed2000

A prospective, randomized trial of conventional, dose-accelerated corticosteroids and intravenous immunoglobulin in children with newly diagnosed idiopathic thrombocytopenic purpura.

To determine the minimal essential treatment for childhood acute idiopathic thrombocytopenic purpura (ITP), a prospective, randomized trial was conducted focusing on hemorrhagic manifestation as well as platelet count. Subjects with a platelet count of <10 x 10(3)/microL or 10 to 29 x 10(3)/microL and mucosal bleeding (group 1) were randomly assigned to receive intravenous immunoglobulin (IVIg) at 1 to 2 g/kg, conventional oral prednisolone (o-PSL) (2 mg/kg for 2 weeks). parenteral methylprednisolone (mPSL) (5 mg/kg for 5 days), or pulsed parenteral methylprednisolone (PmPSL) (30 mg/kg for 3 days). Subjects with a platelet count of 10 to 29 x 10(3)/microL without mucosal bleeding (group 2) were randomized to receive either o-PSL or no treatment. In subjects with a platelet count of 30 x 10(3)/microL or higher (group 3), patients undergoing no specific treatment were monitored. In group 1, IVIg offered faster platelet enhancement compared with o-PSL and mPSL, although neither mPSL no PmPSL showed any advantage, even over o-PSL. Platelet response was uniformly excellent when pretreatment platelet coun was > or = 10 x 10(3)/microL. Furthermore, the presence or absence of mucosal bleeding in subjects with a platelet count <10 x 10(3)/microL had no effect on the response to treatment. In group 2, platelet increase was indifferently attained with or without o-PSL. These data suggest that childhood acute ITP with a platelet count > or = 10 x 10(3)/microL may be left untreated or may be treated with o-PSL when mucosal bleeding is evident, whereas for those with a platelet count <10 x 10(3)/microL, IVIg is the most predictable platelet enhancer. Thus, a platelet count of 10 x 10(3)/microL seems to be informative enough to decide whether to treat childhood acute ITP.

Adolescent↗
PubMed1999

Activation of nuclear factor kappaB by polyamines in breast cancer cells.

Polyamines-putrescine, spermidine, and spermine-are involved in the growth of breast cancer cells. A possible target of polyamine action is at the site of interaction of transcription factors with their response elements. NF-kappaB is a member of the rel family of transcription factors that regulate transcription of genes in the proliferative/anti-apoptotic pathways. We performed electrophoretic mobility shift assays to study the role of polyamines in NF-kappaB binding to NF-kappaB response elements (NREs), the consensus sequence of which is GGGGAATTCCCC. Using cellular extract from MCF-7 breast cancer cells, we found very little binding of NF-kappaB to NRE in the absence of polyamines. Addition of 1 mM spermidine or spermine caused a 4- and 6-fold increase in NF-kappaB-NRE binding, respectively. Putrescine induced a 2-fold increase in the binding at 2 mM concentration. Using antibody supershift assays, we identified the p50 subunit of NF-kappaB to be a major component in NF-kappaB-NRE complex formation in the presence of polyamines. However, the decreased intensity of the band corresponding to NF-kappaB-NRE complex in the presence of anti-p65, c-rel, relB and p52 antibodies suggested the participation of these subunits also. Spermine also stimulated NF-kappaB-NRE binding using cellular extracts from other breast cancer cell lines and a normal breast epithelial cell line. A differential effect of spermine analogues on NF-kappaB-NRE binding was observed, with spermine exerting the maximal effect. CD spectra of NRE containing oligonucleotides was asymmetric and distinct from that of a typical B-DNA CD spectrum. A concentration-dependent increase in T(m) of the duplex NRE was seen in the presence of polyamines. In transient transfection experiments using an NF-kappaB driven secreted alkaline phosphatase (SEAP) reporter, spermine induced NF-kappaB activity by approximately 2-fold as compared to controls. Spermine induced activation of NF-kappaB was also confirmed using an NF-kappaB-EGFP (enhanced green fluorescent protein) vector in transient transfections in which expression of the green fluorescent protein was visualized by fluorescence microscopy. These data show a gene regulatory function of polyamines involving enhanced binding of NF-kappaB to NRE and a possible mechanism for the action of polyamines in breast cancer cell proliferation.

Breast Neoplasms↗
PubMed1999

Antitumor effects of bis(ethyl)polyamine analogs on mammary tumor development in FVB/NTgN (MMTVneu) transgenic mice.

We studied the therapeutic potential of two polyamine analogs on breast cancer using FVB/NTgN (MMTVneu), a transgenic mouse model with neu/erb-B2 oncogene overexpression. Treatment was initiated at 31 weeks of age with bis(ethyl)norspermine (BE333) and its higher homolog, BE3333 as i.p. injections once weekly. There was a 40% reduction in the average number of tumors per mouse in both treatment groups, by 10 weeks of treatment. BE3333-treated mice had 70-75% lower tumor volume than controls. Spermidine/spermine acetyl transferase activity was significantly higher in tumor tissues and kidneys of treated animals, whereas polyamine levels were lower than controls. Beneficial effects were also evident from the mortality rates in control and treatment groups. Our results suggest a potential use of selected bis(ethyl) polyamine analogs as antitumor agents in breast cancer.

Acetyltransferases↗
PubMed1999

Facilitation of the cellular uptake of a triplex-forming oligonucleotide by novel polyamine analogues: structure-activity relationships.

The inefficient uptake of oligodeoxynucleotides, including that of TFO, through the cell membrane is a limiting factor in developing gene therapy approaches for cancer and other diseases. To develop a new strategy for oligonucleotide delivery into the nucleus, we synthesized a series of novel polyamine analogues and examined their effects on the uptake of a 37-mer [32P]-labeled TFO, targeted to the promoter region of c-myc oncogene. We used MCF-7 breast cancer cells to investigate the efficacy of polyamines on the internalization of the TFO. The uptake of TFO was enhanced by complexing it with several unsubstituted polyamine analogues at 0. 1-5 microM concentrations, with up to 6-fold increase in TFO uptake in the presence of a hexamine, 1,21-diamino-4,9,13, 18-tetraazahenicosane (H2N(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(2) or 3-4-3-4-3). TFO uptake increased with the cationicity of the polyamines; however, bis(ethyl) substitution and structural features of the methylene bridging region had significant effects on TFO uptake. The majority of labeled TFO was recovered from the nuclear fraction containing genomic DNA. Electrophoretic mobility shift assay revealed enhanced binding of TFO to a target duplex containing promoter region sequence of c-myc oncogene. Treatment of MCF-7 cells with the TFO complexed with 0.5 microM 3-4-3-4-3 suppressed c-myc mRNA level by 65%, as determined by Northern blot analysis. These data indicate a novel approach to deliver oligodeoxynucleotides to the cell nucleus, and suppress the expression of target genes, and provide new insights into the mechanism of oligonucleotide transport in living cells.

Breast Neoplasms↗
PubMed1999

Increase in hepatic content of oleic acid induced by dehydroepiandrosterone in the rat.

The effects of dehydroepiandrosterone (DHEA) on the acyl composition of lipids in rat liver were studied. The content of oleic acid (18:1) in hepatic lipids was increased markedly by feeding rats a diet containing 0.5% (w/w) DHEA for 14 days. Treatment of rats with DHEA caused an increase in the activity of the terminal desaturase of the stearoyl-CoA desaturation system, without changing either the activity of NADH-cytochrome b5 reductase or the microsomal content of cytochrome b5. Among the changes observed in hepatic lipids, the increase in 18:1 content in phosphatidylcholine (PtdCho) was the most prominent; an approximately 2.5-fold increase in the proportion of 18:1 was induced at position 2, but not at position 1, by DHEA. This selective elevation of 18:1 at position 2 of PtdCho seems to be produced by the concerted actions of the induced 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase and the induced stearoyl-CoA desaturase. The content of 18:1 in serum lipids was unchanged by DHEA treatment, suggesting that secretion of lipids containing 18:1 into the circulation was not affected by DHEA. These results suggest that the elevation of hepatic content of 18:1 caused by DHEA treatment is mainly due to the induction of stearoyl-CoA desaturase.

Animals↗
PubMed1999

[Progress in research of the blood coagulation system].

Blood coagulation is an amplification system consisting of reactions between enzymes and zymogens. It has been illustrated as a cascade model. However, the exact mechanism by which haemostasis is achieved under physiological conditions remains to be clarified. The solving of structure-function relation of each coagulation factor, analysis of the enzymological characteristics of each reaction, analysis of the regulation mechanism of the reactions and identification of novel factors involved in coagulation reactions contribute to the understanding of this complex system. Based on these findings, some new conceptions of blood coagulation are proposed. In the model introduced in this review, the extrinsic pathway and the intrinsic pathway of the 'classical' cascade model of the blood coagulation system could not be separated, and the suppression of fibrinolysis by TAFI (thrombin activatable fibrinolysis inhibitor) during coagulation reactions is thought to be a critical process for effective haemostasis.

Blood Coagulation↗
PubMed1999

Selectivity of polyamines on the stability of RNA-DNA hybrids containing phosphodiester and phosphorothioate oligodeoxyribonucleotides.

RNA-DNA hybrid stabilization is an important factor in the efficacy of oligonucleotide-based antisense gene therapy. We studied the ability of natural polyamines, putrescine, spermidine, and spermine, and a series of their structural analogues to stabilize RNA-DNA hybrids using melting temperature (Tm) measurements, circular dichroism (CD) spectroscopy, and the ethidium bromide (EB) displacement assay. Phosphodiester (PO) and phosphorothioate (PS) oligodeoxyribonucleotides (ODNs) (21-mer) targeted to the initiation codon region of c-myc mRNA and the corresponding complementary RNA oligomer were used for this study. In the absence of polyamines, the Tm values of RNA-PODNA and RNA-PSDNA helices were 41 +/- 1 and 35 +/- 1 degrees C, respectively, in 10 mM sodium cacodylate buffer. In the presence of a hexamine analogue of spermine at a concentration of 25 microM, the hybrids were stabilized with Tm values of 80 and 78 degrees C, for RNA-PODNA and RNA-PSDNA, respectively. The d(Tm)/d(log[polyamine]) values, representing the concentration-dependent stabilization of hybrid helices by polyamines, increased from 10 to 24 for both the RNA-PODNA and RNA-PSDNA helices. Bisethyl substitution of the primary amino groups of the polyamines reduced the hybrid stabilizing potential of the polyamines. Among the homologues of spermidine [H2N(CH2)3NH(CH2)nNH2, where n = 2-8; n = 4 for spermidine] and spermine [H)N(CH2)3NH(CH2)nNH(CH2)3NH2, where n = 2-8; n = 4 for spermine], spermidine and spermine were the most effective agents for stabilizing the hybrid helices. At a physiologically compatible concentration of 150 mM NaCl, the hybrid helix formed from PODNA was more stable than that formed from PSDNA in the presence of polyamines. CD spectroscopic studies showed that the hybrids were stabilized in a conformation close to A-DNA in the presence of polyamines. The relative binding affinity of the polyamine homologues for the hybrid helices, as measured by the EB displacement assay, followed the same order in which they stabilized the hybrids. These results are important in the antisense context and in the general context of polyamine-nucleic acid interactions, and suggest that pentamine and hexamine analogues of spermine might be useful in improving the efficacy of therapeutic ODNs.

Binding, Competitive↗
PubMed1999

Ionic and structural specificity effects of natural and synthetic polyamines on the aggregation and resolubilization of single-, double-, and triple-stranded DNA.

DNA condensation, precipitation, and aggregation are related phenomena involving DNA-DNA interactions in the presence of multivalent cations, and studied for their potential implications in DNA packaging in the cell. Recent studies have shown that the condensation/aggregation is a prerequisite for the cellular uptake of DNA for gene therapy applications. To elucidate the ionic and structural factors involved in DNA aggregation, we studied the precipitation and resolubilization of high molecular weight and sonicated calf thymus DNA, two therapeutic oligonucleotides, and poly(dA).2Poly(dT) triplex DNA in the presence of the tetravalent polyamine spermine using a centrifugation assay, Tm measurements, and CD spectroscopy. The ability of spermine to provoke DNA precipitation was in the following order: triplex DNA > duplex DNA > single-stranded DNA. In contrast, their resolubilization at high polyamine concentrations followed a reverse order. The effective concentration of spermine to precipitate DNA increased with Na+ in the medium. Tm data indicated the DNA stabilizing effect of spermine even in the resolubilized state. CD spectroscopy revealed a series of sequential conformational alterations of duplex and triplex DNA, with the duplex form regaining the B-DNA conformation at high concentrations (approximately 200 mM) of spermine. The triplex DNA, however, remained in a Psi-DNA conformation in the resolubilized state. Chemical structural specificity effects were exerted by spermidine and spermine analogues in precipitating and resolubilizing sonicated calf thymus DNA, with N4-methyl substitution of spermidine and a heptamethylene separation of the imino groups of spermine having the maximal difference in the precipitating ability of the analogues compared to spermidine and spermine, respectively. Therapeutically important bis(ethyl) substitution reduced the precipitating ability of the analogues compared to spermine. The effect of the cationicity of polyamines was evident with the pentamines being much more efficacious than the tetramines and triamines. These results provide new insights into the mechanism of DNA precipitation by polyamines, and suggest the importance of polyamine structure in developing gene delivery vehicles for therapeutic applications.

Animals↗
PubMed1999

Preparation and usefulness of some fluorogenic substrates for assay of arginyl-tRNA-protein transferase by HPLC.

A series of fluorescent substrates and products was prepared and evaluated for the assay of arginyl-tRNA-protein transferase (arginyltransferase) activity by HPLC. Since N-aspartyl-N'-dansylamido-1,4-butanediamine (Asp(4)DNS) was the most suitable substrate of the compounds tested, which had a three-, four-, or five-methylene-chain interval between Asp or Glu and DNS, the following enzymatic studies were focussed on Asp(4)DNS and its product, N-arginylaspartyl-N'-dansylamido-1,4-butanediamine (ArgAsp(4)DNS). The apparent Km value for Asp(4)DNS was calculated to be 30 microM using a hydroxyapatite-treated arginyltransferase preparation from hog kidney, which was free from any enzyme that might decompose the two compounds. The present HPLC method was shown to be advantageous in reliability and sensitivity compared to the available isotope paper disk method using the hydroxyapatite-treated enzyme preparation and in applicability to crude samples examined using a DEAE-treated arginyltransferase preparation and 105,000g supernatant (105S) from hog kidney. Stepwise elimination of Arg and Asp from ArgAsp(4)DNS was observed with the two crude enzyme solutions, and the elimination of Arg was suppressed by the addition of bestatin, suggesting the participation of certain aminopeptidases. Although Asp(4)DNS was decomposed significantly with 105S, an incubation-time-dependent linear elevation of ArgAsp(4)DNS was maintained for 5 min in the presence of bestatin. Furthermore, an addition-recovery test of the DEAE-treated enzyme preparation for the 105S assured accurate determination of arginyltransferase activity in the 105S under the tentatively established conditions. The present HPLC method, which permits the simultaneous determination of 4-dansylamidobutylamine, Asp(4)DNS, and ArgAsp(4)DNS, was advantageous in measuring arginyltransferase activity and detecting the presence of unfavorable enzyme(s) in samples to ensure accurate determination.

Aminoacyltransferases↗
PubMed1999

Health status and satisfaction of asymptomatic HIV-positive haemophiliacs in Kyushu, Japan.

The purpose of this study was to elucidate the effects of human immunodeficiency virus (HIV) on haemophiliacs with physical functional disabilities induced by haemophilia in Kyushu, Japan. The subjects were 38 adult haemophiliacs who were selected from 129 patients registered with the North Kyushu Haemophilia Centre. They were divided into 21 asymptomatic HIV-positive and 17 HIV-negative adult haemophiliacs. Coagulation factor levels, modified DePalma classification, Arthritis Impact Measurement Scale 2 (AIMS 2), and a satisfaction in daily life (SDL) questionnaire were used to investigate the clinical severity of their haemophilia and arthropathy, physical functional disabilities, and satisfaction. Although there were no significant differences in the objective assessments of health status between the HIV-positive and -negative haemophiliacs, the HIV-positive haemophiliacs were significantly more dissatisfied with their social activities and mood, according to AIMS 2, and with social intercourse, job, self-development, and social security and pension according to SDL assessment. These dissatisfactions were due to the effects of HIV, in addition to the physical functional disabilities that were caused by haemophilia. Dissatisfaction with social security and pension may be a specific feature in HIV-positive haemophiliacs in Japan resulting from the origin of HIV infection.

Adult↗