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Biomedical subjects

T Sakurai

Publications and source records attributed to T Sakurai.

At least 703 records · Page 39Linked to original sources
PubMed1986

[Histological findings determining disease-free survival rate].

Histological findings of malignant tumors were reviewed in relation to the prognosis following surgery, radiotherapy and/or chemotherapy. To say the histological grading of malignancy by differentiation (maturation), estimation of it seemed to be subjective and it did not always correlate with the disease free survival rate. Histological findings which indicated a high degree of tumor-host interaction were a good predictor of the prognosis as well as the cell type, and the disease free survival rate of the cases with these findings was relatively higher following not only surgery, radiotherapy but also chemotherapy.

Brachytherapy↗
PubMed1985

Oxidation of reduced cucumber ascorbate oxidase.

Reoxidation process of reduced cucumber ascorbate oxidase (1.10.3.3) with dioxygen was investigated in detail through absorption, circular dichroic (CD) and electron paramagnetic resonance (EPR) spectra. One of the three type I coppers and the type II copper were reoxidized more rapidly than other type I coppers. The principal active site of ascorbate oxidase was considered to be comprised of one type I, one type II and a pair of type III coppers similarly to the active sites in laccase and ceruloplasmin. Remaining two type I and a pair of type III coppers were also disclosed to contribute to the oxidation of L-ascorbate.

Ascorbate Oxidase↗
PubMed1985

Characterization of cucumber ascorbate oxidase and its reaction with hexacyanoferrate (II).

The spectroscopic features of cucumber ascorbate oxidase (AOase) and its type-2 copper-depleted (T2D) derivative, and the electron pathway among the copper sites in the enzyme have been investigated. The electronic and CD spectra of native and T2D AOase in the visible region bear a striking resemblance to those of plastocyanin or azurin, which contain type-1 copper alone. The electronic absorption shoulder of the native enzyme at around 330 nm for the native enzyme which has been assigned to type-3 copper disappears with the depletion of the type-2 copper. The reduction of AOase with a large excess of hexacyanoferrate(II) results in a selective reduction of the type-2 Cu, giving rise to an additional EPR-detectable species which is considered to be originated from partly reduced type-3 copper. The type-1 copper is, however, not reduced even in the presence of excess hexacyanoferrate(II). The redox potential of type-1 Cu was determined to be +350 mV, which is distinctly lower than that of hexacyanoferrate(II-III). Type-2 copper was supposed to be a mediator of the electron transfer between type-1 and type-3 coppers in consideration of the extremely low activity of the T2D enzyme under the same condition. A comparison of the electron pathway in AOase with that in laccase is also argued.

Aerobiosis↗
PubMed1985

Molecular and functional organization of yeast plasmid pSR1.

The nucleotide sequence of a 6251 base-pair plasmid, pSR1, harbored in an osmophilic haploid yeast, Zygosaccharomyces rouxii (formerly Saccharomyces rouxii), was determined. No homology was detected between the sequences of pSR1 and 2-micron DNA of Saccharomyces cerevisiae. pSR1 has a pair of inverted repeats consisting of completely homologous 959 base-pair sequences, which separate two unique sequences 2654 base-pairs and 1679 base-pairs long. Each inverted repeat has an ARS sequence functional in both Z. rouxii and S. cerevisiae hosts. Short direct repeats or dyad symmetries were observed in the inverted repeats similar to those found close to the replication origin of 2-micron DNA. Three open reading frames, P, S and R, each able to encode a protein of molecular weight larger than 10,000, were found. Insertional inactivation of R gave rise to a defect in the intramolecular recombination at the inverted repeats, and that of S reduced the copy number of pSR1 in the S. cerevisiae host. The maintenance stability of the plasmid was also tested in the heterogeneous S. cerevisiae host, but the results of the insertional inactivation of P, S and R were ambiguous. pSR1 and 2-micron DNA were compatible in S. cerevisiae cells, but the protein factors encoded by these plasmids did not complement each other.

Base Sequence↗
PubMed1985

Improved evaluation of hypertrophic cardiomyopathy by biventriculography with axial projection.

To delineate the precise anatomic abnormalities of the interventricular septum (IVS), mitral valve (MV), and left ventricular posterior wall (LVPW) in patients with hypertrophic cardiomyopathy (HCM), we used axial biventriculography (BVG) (hepato-clavicular projection: angled BVG) to examine 17 patients with HCM and four with concentric hypertrophy due to systemic hypertension. We also examined 9 of these 21 patients with conventional left anterior oblique (LAO) BVG (non-angled BVG). The IVS and along axis of the LV cavity when measured by angled BVG were significantly longer than when measured by non-angled BVG. The IVS, MV, and LVPW were better seen in profile in angled than in non-angled BVG. In two patients with HCM with obstruction (HOCM), systolic anterior motion of the anterior leaflet of the MV was readily identifiable with angled BVG, which is usually not the case with non-angled BVG. Thus, angled BVG is superior to conventional LAO BVG in the angiographic assessment of patients with HCM.

Adult↗
PubMed1985

Mutagenic activation of biliary metabolites of 1-nitropyrene by intestinal microflora.

To investigate the modifying role of intestinal microflora in the metabolism of chemical carcinogens in vivo, we subjected bile from Fischer rats treated per os with chemical carcinogens and related compounds to a mutagenicity assay in the presence and absence of a cell-free extract from human feces. A mixture of the bile sample and potassium phosphate buffer was incubated in the presence or absence of human cell-free fecal extract and then further incubated with a bacterial suspension of Salmonella typhimurium tester strains TA98 or TA100. Bile from rats treated with 1-nitropyrene (1-NP) produced about 2700 and 400 revertants per plate in strain TA98 in the presence and absence of the fecal extract, respectively. There was a drug dose- and bile volume-related response. Treatment of 1-NP-bile with beta-glucuronidase, but not aryl sulfatase, enhanced its mutagenicity. Cell-free extracts of some strains of intestinal bacteria (Bacteroides fragilis ATCC 12044, B. vulgatus ATCC 8482, B. thetaiotaomicron ATCC 12290, Bacteroides sp. strain 524, Eubacterium eligens VPI C15-48, Peptostreptococcus sp. strain 204 and Escherichia coli A-5-18) also enhanced the mutagenicity of 1-NP-bile. These bacterial cell-free extracts hydrolyzed the synthetic beta-D-glucuronides of phenolphthalein and/or p-nitrophenol. These data indicate that the glucuronide(s) of 1-NP-metabolite(s) secreted into bile can be hydrolyzed in the intestine by bacterial beta-glucuronidases to potent mutagenic aglycone(s).

Animals↗
PubMed1985

Hepatic disorder in burn patients.

Changes in liver function were studied in 33 patients with burns. In 21 of these patients hepatic disorder developed relatively early after the injury (early hepatic disorder), with a relapse of hepatic disorder occurring later in 8 patients (late hepatic disorder). Our study demonstrated that these hepatic dysfunctions may largely be attributable to post-transfusion acute hepatitis (non-A, non-B or B types).

Biopsy↗
PubMed1985

Sclerosing lipogranuloma of the penis: chemical analysis of lipid from the lesional tissue.

The origin of paraffin from penile granuloma tissue was determined first by field desorption mass spectrometry. A case of penile granuloma with histopathological findings of sclerosing lipogranuloma is presented. Chemical composition of the lesional lipid by elemental analysis and infrared absorption spectroscopy revealed paraffin hydrocarbon. Field desorption mass spectrometric analysis showed the paraffin to be a mixture of saturated hydrocarbons containing substantially 24 to 40 carbon atoms. On the basis of the chemical structure of naturally occurring lipids we concluded that this paraffin was exogenous and not endogenous material that was produced in the tissue following lipid degeneration.

Granuloma↗
PubMed1985

Pathophysiology of otitis media with effusion: clinical evaluation through some qualitative methods.

In an attempt to elucidate the pathophysiology of otitis media with effusion (OME), systematic clinical investigations were undertaken. The high resolution computed tomography, tympanogram, tubal inflation and our qualitative tubal functioning test were routinely applied to cases of OME, both in children and adults. Through these studies, following was concluded: 1. The primary pathology involved may be obstructive lesion somewhere in the tubotympanic cleft including the epitympanum and the mastoid, which in turn results in negative pressure in the middle ear. 2. This negative middle ear pressure may mainly constitute the Eustachian tube dysfunction, which is considered to play an important role in the pathogenesis of OME. Discussed in detail further will be the importance of correcting the negative middle ear pressure substantially for the treatment of OME, and also the essence of our qualitative tubal functioning test.

Adult↗
PubMed1985

Atelectatic ear and pathologic nasopharynx.

Pathologic relation between atelectatic ears and their nasopharynx were investigated in 50 patients with various degrees of atelectatic ears by transnasal fibrescope and C.T. And their morbid adenoids were compared with the adenoids of 20 patients with mouth breathing but free from ear problems. The process of drum bulging after catheterization, retraction after inflation, and inward movement during swallowing, proved that intratympanic pressure was influenced by nasopharyngeal pressure produced by swallowing, and that Eustachian tube itself was functioning to the pressure. Intratympanic negative pressure was proved by the movement of blue solution after the puncture of 5 atelectatic ear with effusion. And more dynamic negative pressure produced by swallowing was demonstrated in 5 other cases. The morbid adenoid with atelectatic eardrum was differentiated from the large posterior type of adenoid of the healthy eardrum, by the pendulous projection over the choana especially in swallowing. A dynamic vacuum caused by "Toynbee phenomenon" is discussed.

Adenoids↗
PubMed1985

Changes in diastolic properties of the regional myocardium during pacing-induced ischemia in human subjects.

Mechanisms related to alterations in the diastolic properties of the left ventricle during angina were studied in seven patients with coronary artery disease. Single plane left ventriculograms were obtained using a high fidelity micromanometer-tipped catheter in both the resting state and immediately after rapid cardiac pacing. In all patients, typical anginal pain developed with pacing stress. After atrial pacing, the left ventricular end-diastolic pressure increased from 10 +/- 3 to 21 +/- 7 mm Hg (+/- standard deviation) (p less than 0.005) regardless of the changes in the end-diastolic volume. The ejection fraction was reduced from 59 +/- 10 to 48 +/- 13% (p less than 0.05). The diastolic pressure-volume curves shifted upward in post-pacing beats in four patients, while in three the curves shifted more to the right. The regional myocardial function was expressed in quantitative terms by a radial coordinate system with the origin at the center of gravity of the end-diastolic silhouette. Two representative radial grids for normal and ischemic segments were selected. In the normal segment, the end-diastolic length was augmented by 15% (p less than 0.005) and was associated with a 24% increase in stroke excursion with pacing stress (p less than 0.05). The increase in diastolic pressure was accompanied by comparable increases in end-diastolic length, and the diastolic pressure-length relation moved up to the higher portion of the single curve. In the ischemic segment, the end-diastolic length remained unchanged in the post-pacing beat, but segment shortening was significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

Effects of freezing on purified nitrite reductase from a denitrifier, Alcaligenes sp. NCIB 11015.

The effects of freezing on Alcaligenes sp. nitrite reductase [nitric-oxide: ferricytochrome c oxidoreductase, EC 1.7.2.1] dissolved in sodium phosphate (pH 7.2) were investigated. The nitrite reductase was gradually activated with time in the frozen state, resulting in an increase in its activity of 2.5-4.5 times. The final freezing temperature influenced the enzyme activation, maximal activation being observed at around -20 degrees C. All the enzymatic activities that the nitrite reductase is known to catalyze were enhanced by freeze-thawing. The activation was followed by neither association-dissociation nor any gross conformational change of the enzyme molecule, but was accompanied by an increase in the fluorescence intensity of 2-p-toluidinonaphthalene-6-sulfonate used as a hydrophobic probe. The results are consistent with the hypothesis that the activation of the NiR is due to a limited conformational change of the enzyme molecule, particularly in the hydrophobic region. The mechanism of the activation of NiR by freeze-thawing is discussed, in comparison with the mechanisms of inactivation by freeze-thawing of many enzymes reported by previous workers.

Alcaligenes↗
PubMed1985

Body reactions during chain saw work.

Body reactions during chain saw work were studied in 14 subjects. The subjects divided into three groups (control, sulpiride, and propranolol) successively cut down logs with a chain saw for seven minutes. The start of the sawing led to a pronounced increase in heart rate which persisted during the sawing. The groups taking sulpiride and propranolol showed a smaller increase in heart rate compared with the controls. Hormonal values (adrenocorticotropic hormone (ACTH), cortisol, adrenaline (Ad), noradrenaline (NA), and dopamine) were increased by the operation. A comparison of these values before and after the operation showed that the increase of cortisol, Ad, and NA values was highest in the controls, intermediate in the propranolol group, and lowest in the sulpiride group. The increase in ACTH, however, was greatest in the sulpiride group, intermediate in the controls and correct in the propranolol group. These findings provide some evidence that chain saw work may have an influence on the whole body, including the hypothalamus and the limbic lobe of the brain.

Adrenocorticotropic Hormone↗
PubMed1985

Comparative study of vibration disease among operators of vibrating tools by factor analysis.

Principal component analysis was carried out to determine the interrelationships between subjective symptoms experienced by workers using various types of vibrating tools (brush saws (41), rock drills (39), chipping hammers (42) and chain saws (49)) and control groups (clerks (44), farmers (42)). The characteristics of the patterns of common factors extracted from these symptoms and the frequency distribution of the factor score of the main principal components were compared among the groups. From a wide variety of symptoms, a principal component related to peripheral nerves, muscles, and joints and a component related to peripheral circulation were extracted specifically and separately. The complaints of rock drillers reflected peripheral circulatory factor and those of chain saw users presented a complex factor of nerve muscle, and joints.

Adult↗
PubMed1985

Follow up study of vibration induced white finger in chain saw operators.

The current status of subjects with vibration induced white finger (VWF) was observed in order to follow up the natural course of VWF after the use of chain saws had ceased. The prevalence rate of VWF after the use of chain saws had ceased in all time periods fell to 50.2% after more than 12 years' observation. There was a pronounced tendency for the percentage prevalence to rise as the vibration exposure periods after VWF occurred increased, and a similar pattern was observed concerning the exposure periods before VWF occurred. Numbness of hands and arms takes longer to recover than VWF.

Adult↗
PubMed1985

Binding of 2-(4'-hydroxyphenylazo) benzoic acid with arginine, lysine, tyrosine and tryptophan modified bovine serum albumin.

The two spectrally distinguishable bound forms of 2-(4'-hydroxyphenylazo) benzoic acid (HABA) on bovine serum albumin (BSA), i.e, the azo and hydrazone forms, were suggested to form ion pairs with basic amino acid residues in our previous study. Arginine (Arg), lysine (Lys), tyrosine (Tyr) and tryptophan (Trp) were modified to estimate the amino acid residues participating in the formation of an ion pair with HABA. Decrease of the binding of only hydrazone form was observed following modification of Arg residues. The modification of Lys, Tyr and Trp residues caused no decrease in binding to either form. However, the induced circular dichroism (CD) spectra of HABA bound to N- and O-acetylated BSA were reversed at 360 and 440 nm, respectively. But two bands of these spectra were capable of taking on the same shape of the spectra of native BSA only by O-deacetylation. The induced CD spectra of bound HABA by Trp modified BSA changed as if the bound amounts of the azo form were increased. The binding sites of the azo form may possibly be situated in the vicinity of Trp 212 on the tertiary structure.

Animals↗