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Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 325 records · Page 18Linked to original sources
PubMed1993

[A case of intrathoracic dumb-bell ganglioneuroma and a surgical approach using spinal evoked potentials (SEP)].

A successfully treated case of a seven-year-old girl with a left intrathoracic Dumb-bell ganglioneuroma is reported. The tumor was 10 cm in diameter. Preoperative angiography revealed that the location of tumor was very close to the Adamkiewicz artery. In order to prevent the artery from damaging, spinal evoked potentials (SEP) was used during the surgery and was very useful for monitoring the spinal cord. Although SEP has often been employed in spine surgery, the literature on the use of it for posterior mediastinal tumor is scarce. It is considered that SEP is very useful for not damaging the feeding artery to the spinal cord, and for preventing the postoperative neurologic complications.

Child↗
PubMed1993

[A case report of redo Fontan operation].

A 21-year-old man, who had undergone Fontan operation for tricuspid atresia type 1b using 21 mm Hancock valved conduit 15 years ago, had right sided heart failure when his heart rhythm turned to atrial fibrillation. On cardiac catheterization, pressure data revealed that trans valved conduit pressure gradient reached to 5.2 mmHg. Chest CT and right atrial angiography showed right atrial wall thrombus. Right upper lobe perfusion defect was detected by lung perfusion scintigraphy. Then he was recommended redo Fontan operation. He underwent resection of stenosed valved conduit, right atrial thrombectomy and reconstruction of new route between right atrium and pulmonary artery with bovine pericardium. He tolerated well that operation and now 3 months passed, he resumed fairly vigorous physical activity.

Adult↗
PubMed1993

[Effect of substrate and diluent for factor VIII activity in highly purified factor VIII concentrate and patient plasma infused factor VIII concentrate].

We studied the difference between congenital factor VIII deficient plasma and factor VIII immuno-depleted plasma on the effect of pre-dilution for factor VIII activity determined by the one-stage assay. When standard curves of one-stage assay for factor VIII: C by GEORGE KING factor VIII deficient plasma (frozen at -80 degrees C), BEHRING factor VIII deficient plasma (lyophilized), DADE factor VIII depleted plasma (lyophilized, von Willebrand factor antigen 0.2 U/ml) and DADE factor VIII depleted plasma (lyophilized, von Willebrand factor antigen 1.0 U/ml) were compared, the difference between the clotting times for 100% and 6.25% of activity in each reagent were 39.5, 29.5, 25.0, 23.0 seconds respectively. Potency values in concentrates without albumin or von Willebrand factor showed a discrepancy between pre-dilution in Owren-Koller buffer and pre-dilution in factor VIII deficient plasma. Potencies of those products pre-diluted in Owren-Koller buffer were 40-60% lower than potencies pre-diluted in factor VIII deficient plasma. These results showed substrate and pre-diluent must be chosen carefully for the accurate assay of factor VIII activity in vitro for the highly purified factor VIII concentrates.

Adult↗
PubMed1993

[Endoscopic sphincterotomy for lithotripsy (EST-L) of bile duct stones].

We performed EST-L for 555 patients with choledocholithiasis between 1981 and 1992. With the aid of conventional occlusion balloons and dormia-type baskets, calculi < or = 1.5 cm was extracted with relative ease. In patients with larger stone (> 1.5 cm), the mechanical lithotripter, extracorporeal shock wave lithotripsy (ESWL) and electrohydrolic lithotripsy were used for the lithotripsy. The overall success rate was 95%. Important early and late complications from these procedures occurred in 6.9% and 9.1% of all cases respectively. This result reveal that EST-L is safe and effective therapeutic procedures for choledocholithiasis. We would recommend EST-L is adopted as an initial measure to remove common bile duct stones.

Bile Duct Diseases↗
PubMed1993

Study of the titers of anti-Epstein-Barr virus antibodies in the sera of atomic bomb survivors.

Antibody titers to Epstein-Barr virus antigens were determined in the sera of 372 atomic bomb survivors to evaluate the effect of the previous radiation exposure on immune competence against the latent infection of the virus. The proportion of persons with high titers (> or = 1:40) of IgG antibodies to the early antigen was significantly elevated in the exposed survivors. Furthermore, the distribution of IgM titers against the viral capsid antigen was significantly affected by radiation dose with an increased occurrence of titers of 1:5 and 1:10 in the exposed persons, although the dose effect was only marginally suggestive when persons with rheumatoid factor were eliminated from the analysis. These results suggest that reactivation of Epstein-Barr virus in the latent stage occurs more frequently in the survivors, even though this might not be affected by the radiation dose. Otherwise, there was neither an increased trend in the prevalence of high titers (> or = 1:640) of IgG antibodies to the viral capsid antigen among the exposed people nor a correlation between the radiation exposure and distributions of titers of IgA antibodies to the viral capsid antigen or antibodies to the anti-Epstein-Barr virus-associated nuclear antigen.

Adult↗
PubMed1993

Normal age-related alterations on chest radiography. A longitudinal investigation.

To ascertain serial changes on chest radiography attributable to aging, 16 parameters and 4 pulmonary parenchymal manifestations were assessed at 2 intervals; namely, 18.5 and 10 years after initial radiography in healthy men (n = 51) and women (n = 149) (age range 41-82 years). The transverse cardiac diameter, cardiothoracic ratio, and aortic arch transverse diameter increased significantly in both sexes from the initial to the final examinations. Although several other factors changed significantly, these changes were relatively small and the individual variations large. Initially, 13% and finally, 27% of the subjects exhibited at least one of the selected pulmonary manifestations.

Adult↗
PubMed1993

Method of identifying inhibitors of oncogenic transformation: selective inhibition of cell growth in serum-free medium.

We developed a new method for evaluating inhibitors of oncogenic signal transduction pathways based on different growth abilities between normal and transformed cells in a defined serum-free medium. The growth rates of src, abl or ras oncogene-transformed cells, activated raf proto-oncogene transformed cells, and normal NIH-3T3 cells were 60-90%, 20-30% and 10% in a serum-free medium, respectively, compared to the growth rates in a serum-containing medium. An addition of a growth factor (PDGF, FGF or TGF-beta) stimulated the growth of normal NIH3T3 cells by 40-80% in a serum-free medium. Herbimycin A, a specific cytoplasmic protein tyrosine kinase inhibitor, selectively inhibited the growth of src or abl transformed cells in the serum-free medium resulting in about 10-fold or fivefold lower IC50 than those in the serum-containing medium. The antibiotic did not show such an effect on ras transformed cells, and the treatment of src transformed cells with other protein kinase inhibitors or cytotoxic drugs showed little IC50 shifts between the two media. Thus, this method of comparing growth inhibition in the serum-free and the serum-containing media may be useful in evaluating specific inhibitors of signaling pathways mediated by growth factors and certain oncogene products.

3T3 Cells↗
PubMed1992

Secondary aminoglycoside resistance in aminoglycoside-producing strains of Streptomyces.

The role of aminoglycoside (AG) acetyltransferases (AACs) and of the corresponding genes in resistance to foreign AGs in AG-producing strains of Streptomyces were studied. The research focussed on (i) the activation mechanism of the cryptic kanamycin(Km)-resistance-encoding gene that encodes an AAC(3) in streptomycin-producing S. griseus SS-1198, and (ii) an AAC(2') with novel activity and substrate specificity in kasugamycin-producing S. kasugaensis MB273. Activation of the cryptic kan gene in S. griseus SS-1198 is probably due to a single base substitution at the putative -10 promoter region, leading to the enhancement of transcription, resulting in resistance to AG. The coding region of the kan gene was highly homologous to that of the aacC7 gene of paromomycin-producing S. rimosus forma paromomycinus. On the other hand, resistance in S. kasugaensis MB273 was found to be due to an AAC(2') capable of acetylating astromicin group AGs at two different sites (1-NH2 with istamycin B, and 2'-NH2 with astromicin and istamycin A). These additional antibiotic resistances that are independent of a self-resistance basis may be regarded as 'secondary' resistances, so as to distinguish them from 'primary' resistances arising from a self-resistance basis.

Aminoglycosides↗
PubMed1992

Structure of the Bombyx mori fibroin light-chain-encoding gene: upstream sequence elements common to the light and heavy chain.

Two overlapping genomic clones containing the fibroin light-chain (Fib-L)-encoding gene (Fib-L) were obtained from the cosmid library of the silkworm, Bombyx mori J-139, by hybridization with the Fib-L cDNA clone. Sequencing of the 14.6-kb region revealed that Fib-L was 13,472 bp long containing seven exons, and that the gene contained a large first intron which occupied about 60% of the gene. Comparison of restriction patterns of the J-139 Fib-L with those of eight other B. mori breeds producing normal-level fibroin demonstrated that considerable restriction-fragment length polymorphisms were present in regions containing the first intron and the 3'-flanking sequence. However, sizes of the Fib-L mRNA and the Fib-L polypeptide were very similar among the nine breeds tested, suggesting that the exon sequences and the splice signals were all well conserved. 5'-Flanking regions of Fib-L and the fibroin heavy-chain (Fib-H)-encoding gene (Fib-H) compared in this study contained three 18-30-bp sequences of high similarity and many 8-10-bp common elements, six of which coincided with the binding sites of homeodomain proteins. Gel retardation assays with the nuclear extracts of the posterior and middle silk glands suggested that protein factors present in the posterior silk-gland nuclei could bind to a set of those common upstream elements.

Amino Acid Sequence↗
PubMed1992

Distribution of XhoI and EcoRI family repetitive DNA sequences into separate domains in the chicken W chromosome.

Fluorescence in situ hybridization using as probes three biotinylated or digoxigenin-labeled chicken W chromosome-specific repeating DNA units (0.7 and 1.1 kb XhoI family and 1.2 kb EcoRI family units) suggested that a large fraction of one arm of the W chromosome was occupied by the EcoRI family sequences and that pericentromeric regions were widely occupied by the XhoI family sequences. A minor fraction of the EcoRI family was also present in a narrow region in the proximal half of the other arm. There was a region in the distal half of the latter arm where sequences from neither family hybridized. Evolutionary aspects of the presence of different domains occupied by different repetitive families and the significance of the unhybridized distal region are discussed.

Animals↗
PubMed1992

Late results of operation for ventricular tachycardia.

We have analyzed results in 54 consecutive patients with recurrent ventricular tachycardia and coronary artery disease in whom we used an aggressive surgical approach involving map-directed ventricular tachycardia ablation, scar excision and left ventricular remodeling, and coronary artery bypass grafting, as well as staged mitral valve replacement when necessary. We have previously shown age greater than 65 years to be an independent predictor of mortality and have excluded such patients from this series. Average age was 56 +/- 7 years. All patients had a previous myocardial infarction; 24% of the infarctions (13/54) were posterior in location. Symptoms included syncope or presyncope in 83% of the patients (45/54), angina in 54% (29/54), and congestive heart failure in 52% (28/54). Extensive coronary artery disease was found in 78% (42/54), and 89% (48/54) had serious compromise of left ventricular function (ejection fraction < 0.40; average ejection fraction, 0.28 +/- 0.12). Only 63% (34/54) appeared to have a resectable left ventricular aneurysm on the preoperative angiogram. Ablation techniques included endocardial excision in 82% (44/54), with the addition of cryoablation in 60% (32/54), and balloon electric shock ablation in 22% (12/54); coronary artery bypass grafting was performed in 85% (46/54). There were four hospital deaths (7%). The surgical cure rate (no inducible VT at postoperative electrophysiologic study was 72% (39/54). During follow-up (mean, 50 +/- 31 months) there have been six late deaths (1 sudden death, 1 stroke, 4 congestive heart failures with or without mitral regurgitation). Four patients with progressive congestive heart failure and serious mitral regurgitation have undergone repeat operation for mitral valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Identification of a 64-kDa protein phosphorylated with glucose in human polymorphonuclear leukocytes in a cell-free system.

We previously reported that a 64-kDa protein (p64) in human polymorphonuclear leukocytes (PMN) was phosphorylated with [gamma-32P]ATP under a micromolar concentration of glucose in a cell-free system. The present paper presents the results of analysis of phosphorylation reaction and the identification of phosphoprotein. The findings that p64 was also phosphorylated with glucose-6-[32P]phosphate and that phosphorylation was inhibited with mannoheptulose suggested that the reaction was mediated by hexokinase. In fact, it was found that [32P]phosphate in glucose-6-[32P]phosphate was incorporated into either p64 or rabbit muscle phosphoglucomutase and that glucose-6-phosphate formation from glucose and ATP was detected in over 100-kDa fraction of PMN cytosol. These results showed that p64 was phosphoglucomutase in PMN and that phosphate incorporation into p64 was a conversion of a phosphate group in glucose-6-phosphate produced by hexokinase. It was further demonstrated by analysis of two-dimensional electrophoresis that p64 phosphorylated with glucose induction was different from another 64-kDa protein phosphorylated by stimulation with formyl-methionyl-leucyl-phenylalanine in vivo.

Cell-Free System↗
PubMed1992

A 50-year projection of lung cancer deaths among Japanese males and potential impact evaluation of anti-smoking measures and screening using a computerized simulation model.

The lung cancer death rate among Japanese males was projected for 50 years to the year 2041 by a computerized simulation model. Long-term effects of anti-smoking measures and mass screening on lung cancer deaths were also evaluated. The simulation showed that the age-adjusted lung cancer death rate would increase and reach a peak of 166 per 100,000 in 1989 and then decrease to 148 per 100,000 in 2003. It then shows an increasing tendency again, up to 255 per 100,000 in 2028. The smoking initiation rates estimated from the observed lung cancer death rates showed that the changes in death rates may be attributed to a lower smoking initiation rate among those born in the 1930's. Promotion of mass screening programs is effective more quickly than anti-smoking measures but the reduction in annual cancer deaths is expected to be only 11%, even if 100% participation is achieved by the year 2000. A reduction in smoking initiation rate, on the other hand, affects lung cancer deaths very slowly. It was predicted that a 1% annual reduction in smoking initiation rate would result in a 20% decrease in the number of lung cancer deaths in 2041. A smoking cessation program is intermediate with regard to promptness. The predicted reductions in lung cancer deaths in 2041 were 13%, 47%, and 66%, respectively, when the annual smoking cessation rate was increased from 0.46% (present status) to 1%, 3%, and 5%. In conclusion, the combined application of all three preventive measures seems essential to realize the most effective reduction in lung cancer deaths.

Age Factors↗
PubMed1992

Flow cytometric analyses of the characteristics of tumor cells treated with two platinum compounds: 1,1-cyclobutanedicarboxylato(2-aminomethylpyrrolidine)- platinum(II) and cisplatin.

In order to reduce the toxicities of cisplatin (DDP) and/or to improve antitumor efficacy, a large number of new platinum analogues have been synthesized. 1,1-Cyclobutanedicarboxylato(2-aminomethylpyrrolidine)platin um(II) (DWA2114R) is one of them. In this study, we characterized the action mechanism of DWA2114R flow-cytometrically in 3 human lung cancer cell lines by using bromodeoxyuridine (BrdUrd), rhodamine 123 (Rho) and Ki-67 antibody (Ab), and compared the results with those for DDP. We found that the actions of these 2 platinum analogues were characteristically different at the subcellular level. Our observations may be summarized as follows. a) Simultaneous exposure of cells to DDP and BrdUrd resulted in decreases in fluorescence intensity, i.e. in the amount of BrdUrd incorporated into single-stranded DNA. b) DDP appears to be approximately 20-fold more active than DWA2114R in producing cell cycle perturbation. c) In PC-6 small cell carcinoma cells, DDP induced decreases in S phase cells and accumulation of cells in the G2M phase, whereas in PC-10 squamous carcinoma and PC-3 adenocarcinoma cells DDP produced S phase cell accumulation. Weak but similar changes occurred with DWA2114R. d) The high Ki-67 antigen cell population was decreased by treatment with either DDP or DWA2114R, but DDP reduced the low Ki-67 antigen population more than DWA2114R. e) In PC-10 and PC-6 cells, DDP suppressed Rho incorporation into live mitochondria, whereas DWA2114R produced no change in Rho incorporation. PC-3 cells were not affected by either DDP or DWA2114R. It is likely that these differences reflect the biological activities of DDP and DWA2114R.

Antineoplastic Agents↗
PubMed1992

Inhibitory effects of pravastatin, a competitive inhibitor of hydroxymethylglutaryl coenzyme A reductase, on cholesterol gallstone formation in prairie dogs.

The effects of pravastatin on cholesterol gallstone formation were determined in prairie dogs. We fed 10 prairie dogs 1% cholesterol with or without 0.05% (w/w) pravastatin (n = 5, each) for 4 weeks. In addition, another 5 prairie dogs were fed a standard rodent chow as a control. Only the animals fed 1% cholesterol without pravastatin treatment formed cholesterol gallstones. Gallbladder bile from cholesterol-fed animals contained cholesterol monohydrate crystals, whereas those treated with pravastatin contained no crystal. Furthermore, marked increases in tissue cholesterol levels (serum, liver and bile), and in biliary mucous glycoprotein levels were evident in cholesterol-fed animals, whereas pravastatin treatment normalized these levels. These findings raise the possibility that such inhibitors might have a future role to play in the prevention of cholesterol gallstone formation and/or recurrence.

Animals↗
PubMed1992

Platelet-activating factor acetylhydrolase in plasma lipoproteins from patients with ischemic stroke.

BACKGROUND AND PURPOSE: Platelet-activating factor is a potent bioactive phospholipid and may play an important role in occlusive vascular diseases. To assess the inactivation of this autacoid in plasma, we measured platelet-activating factor acetylhydrolase activity in plasma low density and high density lipoproteins from patients with ischemic stroke. METHODS: Low density and high density lipoproteins were separated by ultracentrifugation from plasma of 33 patients with cerebral thrombosis and 31 age-matched healthy control subjects, and platelet-activating factor acetylhydrolase activity in each fraction was assayed. RESULTS: The average values of platelet-activating factor acetylhydrolase activity in low density lipoprotein from patients and control subjects were 41 +/- 18 and 29 +/- 17 nmol/ml per minute, respectively, and the difference was statistically significant (p less than 0.01 U test). There was no difference in activity in high density lipoprotein between the two groups (16 +/- 11 versus 14 +/- 9 nmol/ml per minute, respectively). CONCLUSIONS: The increased plasma platelet-activating factor acetylhydrolase activity in stroke patients is primarily attributable to the increased binding to low density lipoprotein, and this increase may be an adaptation to the augmented generation of platelet-activating factor in ischemic stroke.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗