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Biomedical subjects

A Ono

Publications and source records attributed to A Ono.

At least 145 records · Page 8Linked to original sources
PubMed1995

Structural analysis of 11C, 15N labeled adenosine by solid-state NMR.

Two-dimensional solid-state 13C homonuclear and 13C-15N heteronuclear NMR experiments for dipolar correlations between isotropic chemical shifts were performed for adenosine uniformly labeled with 13C and 15N. All the 13C and 15N signals were assigned from the dipolar couplings. In the mixing periods of the experiments, 13C-13C and 13C-15N dipolar interactions under magic angle spinning conditions were recovered by USEME and TEDOR pulses respectively, which are rf multipulse sequences applied synchronously with sample spinning. Dipolar mixing periods were set to times at which only spin pairs connected with direct covalent bonds give rise to cross peaks in the 2-D spectra. Thus, these high resolution spectra unveil a network of 13C and 15N spins connected with covalent bonds in solids. Structural information obtained for adenosine by the 2-D solid-state NMR will be discussed.

Adenosine↗
PubMed1994

A new variant of muscle phosphofructokinase deficiency in a Japanese case with abnormal RNA splicing.

A genetic defect was investigated in a newly diagnosed Japanese case with muscle type phosphofructokinase (PFK-M) deficiency. Polymerase chain reaction (PCR) amplification of patient cDNA revealed an in-frame truncation of 165 bases. This was compatible to the complete deletion of exon 19. The rest of the sequence was identical to that of the normal PFK-M cDNA. Sequencing of PCR amplified genomic DNA of the patient revealed a point mutation from G to A at the 5' donor site of intron 19. This mutation resulted in the skipping of exon 19 in the patient mRNA. Homozygosity of this patient was confirmed by allele specific amplification of the genomic DNA. Donor mutations in intron 15 and intron 5 associated with different splicing errors were previously reported to cause this disease. Thus, the human PFK-M gene mutations are heterogeneous, however, the donor mutations and splicing errors would represent one of the frequent causes of this disease.

Adult↗
PubMed1994

Mutagenicity of 5-bromouracil and N6-hydroxyadenine studied by yeast oligonucleotide transformation assay.

The mutagenicity of 5-bromouracil (BrU) and N6-hydroxyadenine (HA) was tested by means of the yeast oligonucleotide transformation procedure. BrU-containing oligonucleotide was not mutagenic; although two mutants (per 200 micrograms oligonucleotide) were obtained, they were attributed to base insertion or base substitution at positions different from BrU. This result supports the view that BrU mutagenesis is dependent on intracellular nucleotide pool imbalance. In contrast, HA-containing oligonucleotide was highly mutagenic; 56 mutants (per 140 micrograms oligonucleotide) were obtained. Of 21 induced mutants examined, 20 had G and one had C at the HA position, a result indicating that HA-->G changes took place. To provide back-up evidence, we carried out a general reversion assay for base HA using a set of yeast tester strains, and the results showed that HA induces exclusively AT-to-GC and GC-to-AT transitions. We conclude that in S. cerevisiae HA is a classic base analog mutagen, causing AT-to-GC and GC-to-AT transitions by ambiguous base pairing. The present work has clearly demonstrated the usefulness of the oligonucleotide transformation procedure for elucidating mutagenicity of modified bases.

Adenine↗
PubMed1994

Activation energy for permeation of phosphonium cations through phospholipid bilayer membrane.

The conductance caused by translocation of various phosphonium cations across phospholipid (from soybean) bilayer membrane was measured. Phosphonium cations used were tetraphenylphosphonium (TPP+) and triphenylalkylphosphonium cations formulated as (Phe)3-P(+)-(CH2)nCH3 (n = 0-5). The conductance was dependent on voltage applied externally to the membrane in accordance with a theory developed by previous authors. Using the theory, values of beta K(i) were determined, where beta and k(i) are a linear partition coefficient and a rate constant of transmembrane ion transport, respectively. Since beta k(i) depended on the phosphonium ion concentration, values extrapolated to infinite dilution, (beta k(i))0, were determined. Temperature dependence of (beta k(i))0 allowed us to estimate the activation energy of transport, Ea. For TPP+ thermodynamic values obtained were consistent with values calculated by Flewelling and Hubbell [(1986) Biophys. J. 49, 541-552]. When (Phe)3-P(+)-(CH2)nCH3 (n = 0-5) were used, E(a) depended on the odd or even of n. This "odd and even" pattern was observed in a variety of phenomena such as solubility in water, equivalent ionic conductivity in water, and 31P NMR chemical shift.

Biological Transport↗
PubMed1994

Preparation and heteronuclear 2D NMR spectroscopy of a DNA dodecamer containing a thymidine residue with a uniformly 13C-labeled deoxyribose ring.

[13C5]-2-Deoxy-D-ribose, synthesized from [13C6]-D-glucose (98% 13C), was coupled with thymine to give [1',2',3',4',5'-13C5]-thymidine (T) in an 18% overall yield. The thymidine was converted to the 3'-phosphoramidite derivative and was then incorporated into a dodecamer 5'-d(CGCGAATTCGCG)-3' by solid-phase DNA synthesis. Preparation of 0.24 mumole of the labeled dodecamer, which is sufficient for a single NMR sample, consumed only 25 mg of glucose. By virtue of the 13C labels, all of the 1H-1H vicinal coupling constants in the sugar moieties were accurately determined by HCCH-E.COSY.

Base Sequence↗
PubMed1994

Ulcerative colitis associated with Weber-Christian panniculitis and musculitis: a case report.

A case of 22-year-old man suffering from ulcerative colitis, in whom Weber-Christian panniculitis and musculitis occurred simultaneously, is reported. He had suffered from ulcerative colitis for 7 years and he again had bloody stools 1 month before being admitted. Two weeks before admission, large (2-4 cm) subcutaneous tumors appeared. Weber-Christian panniculitis, musculitis, and active stage ulcerative colitis were diagnosed. All the symptoms went into remission after steroid therapy. The possibility of the existence of a common antigen in enterobacterial wall, colonic epithelium, and adipose tissue was suggested.

Adult↗
PubMed1994

Influence of daily drinking habits on ethanol-induced hyperuricemia.

We examined the influence of alcohol drinking habits on the serum uric acid level after the ingestion of a small amount of ethanol. Subjects were divided into two groups according to their alcohol drinking habits--regular drinkers, who consume more than 60 g ethanol every day, and nondrinkers/occasional drinkers, who consume less than 20 g ethanol occasionally. Drinking 0.5 g ethanol/kg increased serum uric acid levels in regular drinkers by 52.6 +/- 26.3 mumol/L (0.8 +/- 0.4 mg/dL), whereas it did not in nondrinkers/occasional drinkers. Urinary excretion of uric acid was unaltered in both groups. Hypoxanthine and xanthine in both plasma and urine and serum acetate were increased more in regular drinkers than in nondrinkers/occasional drinkers. Accelerated adenine nucleotide degradation secondary to enhanced ethanol oxidation likely explains the ethanol-induced hyperuricemia in regular drinkers.

Acetates↗
PubMed1994

Involvement of the sympathetic nervous system in antihypertensive effect of cicletanine in salt-loaded young spontaneously hypertensive rats.

We examined the role of the sympathetic nervous system in the antihypertensive effect of long-term (4-week) administration of cicletanine (50 mg/100 g in diet) in young (6 week-old) spontaneously hypertensive rats (SHR) fed an 8.0% salt-containing diet. Salt loading accelerated the development of hypertension in young SHR (mean blood pressure [BP]: 158 +/- 3 v 196 +/- 5 mm Hg, P < .01). Although cicletanine did not affect mean BP in non-salt-loaded SHR, it reversed salt-induced hypertension (155 +/- 3 mm Hg, P < .01). Salt loading elevated plasma norepinephrine (NE) (246 +/- 16 v 451 +/- 87 pg/mL, P < .05) but simultaneous administration of cicletanine inhibited the increase in plasma NE with salt loading (234 +/- 12 pg/mL, P < .01). Hexamethonium, a ganglionic blocking agent, produced a greater hypotensive effect in salt-loaded than in non-salt-loaded SHR (-40 +/- 4 v -78 +/- 4 mm Hg, P < .01). In salt-loaded SHR with cicletanine, however, the hypotensive effect of hexamethonium was suppressed compared with salt-loaded SHR without cicletanine (-52 +/- 4 mm Hg, P < .01). Both plasma NE (r = 0.608, P < .01) and decrease in mean BP with hexamethonium (r = -0.798, P < .01) correlated with baseline mean BP. Thus, cicletanine inhibited the salt-induced rise in mean BP of young SHR, possibly through the suppression of enhanced sympathetic nerve activity.

Animals↗
PubMed1994

Transport of envelope proteins of Sendai virus, HN and F0, is blocked at different steps by thapsigargin and other perturbants to intracellular Ca2+.

The effects of thapsigargin (Tg), a specific inhibitor of Ca(2+)-ATPase of the endoplasmic reticulum (ER), on replication of Sendai virus (HVJ) in BALB3T3 cells were examined. In the presence of Tg, the cells infected with HVJ did not release viral particles to the culture medium. Tg inhibited almost completely the expression of viral envelope proteins, HN and F0, on the cell surface, although it did not affect the synthesis of viral proteins. Two other inhibitors of Ca(2+)-ATPase of the ER, 2,5-di(tert-butyl)-1,4-benzohydroquinone (BHQ) and cyclopiazonic acid (CPA), as well as Ca(2+)-ionophores such as A23187 and ionomycin, also inhibited the expression of HN protein on the cell surface. Tg seemed to inhibit the intracellular transport or maturation of the viral membrane proteins by perturbing intracellular distribution of Ca2+ ions. In the presence of Tg, HN protein remained sensitive to endoglycosidaseH (endoH) for 3 h after its synthesis. On the other hand, F0 protein became resistant to endoH and sensitive to neuraminidase even in the presence of Tg. These results indicate that the transport of HN protein is blocked at the ER or the cis-Golgi region, while that of F0 protein is blocked at the post-Golgi stage in the presence of Tg.

3T3 Cells↗
PubMed1994

High-calcium diet prevents salt-induced hypertension and impairment of renal hemodynamics in young spontaneously hypertensive rats.

We studied the effects of a high Ca (4.07%) diet on mean arterial pressure (MAP) and renal hemodynamics in young (6 weeks) spontaneously hypertensive rats (SHR) fed a normal (0.66%) or a high-salt (8.00%) diet for 4 weeks. The high-salt diet accelerated development of hypertension (213 +/- 5 vs. 159 +/- 2 mm Hg, p < 0.01) and increased renal vascular resistance (RVR) (26.4 +/- 2.3 vs. 18.2 +/- 1.2 U, p < 0.01) in young SHR. Simultaneous Ca supplementation prevented the salt-induced increase in MAP (158 +/- 3 mm Hg, p < 0.01) and in RVR (17.3 +/- 1.1 U, p < 0.01). The high-Ca diet did not affect MAP (151 +/- 3 mm Hg, NS) and RVR (17.4 +/- 1.3 U, NS) in young SHR fed a normal salt diet. RVR and MAP were positively correlated in all rats (r = 0.634, n = 38, p < 0.001). The high-Ca diet also prevented salt-induced left ventricular (LV) hypertrophy. Dietary Ca supplementation attenuated the increased salt sensitivity of arterial pressure, possibly by normalizing renal hemodynamics, in salt-loaded young SHR.

Animals↗
PubMed1994

Subtype analysis of HTLV-1 in patients with HTLV-1 uveitis.

The hypothesis that HTLV-1 uveitis, a recently identified disease entity associated with human T-cell leukemia virus type I (HTLV-1), is caused by a specific subtype of the virus was tested. The nucleotide sequences of the long terminal repeat of HTLV-1 from five patients with HTLV-1 uveitis (HU) and four with adult T-cell leukemia were phylogenetically analyzed. Our results showed that both subtypes which had been identified in Japan were associated with HU, indicating that there was no difference in pathogenicity between these phylogenetic subtypes. One of the subtypes was more frequently isolated in Okinawa than in Kyushu, suggesting a bias in the prevalence of each subtype among the inhabitants of these two areas of Japan.

Adult↗
PubMed1994

Residual neurobehavioural effects associated with chronic exposure to mercury vapour.

To find the residual effects of long term exposure to mercury vapour, neurobehavioural tests were given to ex-mercury miners about 18 years after the end of mercury exposure. Seventy six male ex-mercury miners who had been exposed to high concentrations of mercury vapour (over 1.0 mg/m3) and with a history of mercury intoxication were compared with controls matched for age (within 3 years), sex, and education. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, decreased considerably after the end of exposure, matched paired comparison showed that performances of motor coordination, simple reaction time, and short term memory had deteriorated significantly in the exposed group. Multiple linear regression analysis of exposure variables with neurological examination measures showed positive correlations between poorer neurological performance and variables related to mercury exposure. Thus the duration of exposure correlated with poorer performance of hand-eye coordination, tapping, and a colour card reading test. Job categories classified by exposure to mercury also had a significant negative correlation with these performances. The period of years after the end of exposure had a significant correlation with better performance of reaction time and digit span. On the other hand, the history of intoxication itself had no significant correlation with any of the current neurobehavioural performances. These results suggest that there are slight but persistent effects on neurobehavioural function, especially on motor coordination, among mercury miners even more than 10 years after the end of exposure.

Aged↗
PubMed1994

High calcium diet prevents baroreflex impairment in salt-loaded spontaneously hypertensive rats.

To investigate the role of the sympathetic control mechanism in the antihypertensive effect of dietary calcium supplementation, we examined whether a high calcium diet affected mean arterial pressure, renal sympathetic nerve activity, heart rate, and overall and central properties of the arterial baroreceptor reflex in salt-loaded young spontaneously hypertensive rats (SHR). Six-week-old SHR were fed either a normal (0.66%) or high (8.00%) salt diet with either a normal (1.17%) or high (4.07%) calcium content for 4 weeks. The arterial baroreceptor reflex was elicited with rats under halothane anesthesia by altering mean arterial pressure with nitroprusside or phenylephrine. The overall property of the arterial baroreceptor reflex was assessed by the median mean arterial pressure (MAP50) and maximal gain (Gmax) of the relation between mean arterial pressure and renal sympathetic nerve activity and between mean arterial pressure and heart rate. The central property of the arterial baroreceptor reflex was assessed by reflex inhibition of renal sympathetic nerve activity and heart rate elicited by electrical stimulation of the aortic depressor nerve. Compared with the control group fed a normal salt/normal calcium diet, the high salt/normal calcium group had significantly higher mean arterial pressure and renal sympathetic nerve activity but not heart rate. Moreover, the arterial baroreceptor reflex was impaired in the latter group, as evidenced by an increase in MAP50 and decrease in Gmax of the two relations and an attenuation of reflex inhibition of renal sympathetic nerve activity by aortic depressor nerve stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Calcein release from temperature-sensitive liposome with or without stirring.

Characteristics of the calcein release from temperature-sensitive liposomes with or without stirring were studied. Calcein release from DPPC(dipalmitoylphosphatidylcholine) REV(reverse phase evaporation vesicle) with stirring occurred at a temperature lower by 8 degrees than that without stirring. DPPC-DSPC(distearoylphosphatidylcholine)-mixed REV showed the maximum release(%) for calcein, near 40 degrees C with stirring and 45 degrees C without stirring.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

Nucleosides and nucleotides. 131. Synthesis and properties of oligonucleotides containing 5-formyl-2'-deoxyuridine.

Thymidine was converted into 5-formyl-2'-deoxyuridine (1), which was incorporated into oligonucleotides, 5'd(GGAGA1CTCC)3' (I-1) and 5'd(GCTGC1GCGAAAGCTG)3' (II-1). To avoid side-reactions and degradation, protection of the formyl group of 1 using a newly developed protecting group, N,N-di-(3,5-dichlorophenyl)ethylenediamine, was necessary. Compound 1 was unstable under the conditions employed for enzymatic complete digestion of oligonucleotides, so that a peak corresponding to 1 was not detected clearly by HPLC analysis of a nucleoside mixture obtained by complete hydrolysis of I-1. Therefore, the oligonucleotide I-1 was treated with cyanomethylene-triphenylphosphorane to give an oligonucleotide containing (E) and (Z)-5-(2-cyanovinyl)-2'- deoxyuridine, which was then hydrolyzed, and the newly generated nucleosides were detected by HPLC analysis. The Tm of the self-complementary oligonucleotide I-1 (40 degrees C) was higher than that of the parent oligonucleotide, 5'd(GGAGATCTCC)3', (31 degrees C) in a buffer containing 0.01 M sodium phosphate (pH 7.0) and 0.1 M NaCl. DNA replication study on a template-primer system [primer, 5'd(32P-CAGCTTTCGC)3'; template, 3'd(GTCGAAAGCGXCGTCG)5' (X = 1 or T)] showed that dATP was incorporated into the DNA strand at a site opposite to 1 by Klenow DNA polymerase, but with a reduced rate. The formyl group of 1 in the oligonucleotides reacted with amines to give Schiff base derivatives.

Base Sequence↗
PubMed1994

The first case of polymyositis associated with interferon therapy.

A 54-year-old man with renal cell carcinoma was treated with interferon (IFN)-gamma for 3 weeks soon after nephrectomy. Three months later he received IFN-alpha therapy for 8 weeks due to chronic active hepatitis C. He subsequently contracted polymyositis (PM): proximal muscle weakness, an elevation of muscle enzymes, myogenic patterns on the electromyograph and histologically specific findings in biopsied muscle specimens. After discontinuation of IFN his muscular weakness gradually recovered.

Carcinoma, Renal Cell↗