Search PubMed⌕ Search

Biomedical subjects

Y Shibuya

Publications and source records attributed to Y Shibuya.

At least 109 records · Page 6Linked to original sources
PubMed1991

Mechanized assay of plasma prekallikrein by activation with Pseudomonas aeruginosa elastase and amidolysis of chromogenic substrate.

An automated assay of plasma prekallikrein is described. Prekallikrein was converted to kallikrein with Pseudomonas aeruginosa elastase, and the hydrolytic activity of kallikrein to H-D-Pro-Phe-Arg-paranitroanilide subsequently measured. The conversion was complete within 8 minutes and the amidolytic activity remained stable at least another 10 min at 37 degrees C. This method worked in plasma deficient in Hageman factor (blood coagulation factor XII). Using anti-prekallikrein antibody and plasma deficient in prekallikrein, the amidolytic activity generated in normal plasma was identified as due to kallikrein. With plasma samples, the coefficients of variation (CV) for multiple measurements within run (n = 10) and between run (n = 10) were as low as 5.0% and 6.6%, respectively, and the minimum measurable concentration of prekallikrein in plasma was 10% of the normal level.

Adult↗
PubMed1991

Activation of human plasma prekallikrein by Pseudomonas aeruginosa elastase in vitro.

Human plasma prekallikrein, precursor of the bradykinin-generating enzyme, was activated in a purified system under a near physiological condition (pH 7.8, ionic strength I = 0.14, 37 degrees C) by Pseudomonas aeruginosa elastase which is a tissue-destructive metalloproteinase. Compared with that, Pseudomonas aeruginosa alkaline proteinase poorly activated it with a rate as low as less than one-twentieth of that of elastase. The activation by elastase was blocked with a specific inhibitor of elastase, HONHCOCH(CH2C6H5)CO-Ala-Gly-NH2 (10 microM). Generation of kallikrein-like amidolytic activity was also observed in plasma deficient in Hageman factor by treatment with elastase, but was not in plasma deficient in prekallikrein. The kallikrein-like activity generated in Hageman factor deficient plasma as well as the generation process itself was indeed inhibited by anti-human prekallikrein goat antibody. These results suggest that the pathological activation of the kallikrein-kinin system might occur under certain clinical conditions in pseudomonal infections.

Amino Acid Sequence↗
PubMed1991

Pseudomonas aeruginosa alkaline proteinase might share a biological function with plasmin.

Pseudomonas aeruginosa alkaline proteinase, which is a zinc-dependent bacterial endopeptidase, preferentially hydrolyzed Boc-Val-Leu-Lys-methylcoumarylamide (MCA) which was originally designed as a specific substrate of plasmin, a plasma serine proteinase. The hydrolytic capacity was resistant to tosyl-lysine chloromethylketone at a concentration as high as 1 mM, but was blocked by a treatment with metal chelator such as o-phenanthroline at the concentration of 5 mM. Kinetic parameters of the amidolytic reaction were Km = 21 microM, kcat = 0.067 s-1 and kcat/Km = 3190 M-1 s-1. A synthetic peptide inhibitor which bore a possible ligand for zinc atom at the carboxy terminal was designed. This inhibitor, Ac-Val-Leu-Lys-4-mercaptoanilide, blocked the amidolytic activity of the pseudomonal alkaline proteinase in a competitive manner with the dissociation constant (Ki) value of 24 microM. The results imply that P. aeruginosa alkaline proteinase must be an unusual zinc-dependent 'C (COOH)-type' endopeptidase, which hydrolyzes the peptide bond of certain amino acid residues at the carboxyl group side by specific recognition, like serine- and cysteine-proteinases. In comparison, P. aeruginosa elastase which is a typical 'N (NH2)-type' metalloproteinase did not hydrolyze all of the commercially available peptide-MCA substrates tested at the present study. P. aeruginosa alkaline proteinase also hydrolyzed natural substrates of plasmin, such as fibrin and fibrinogen, with similar specific activities to plasmin. The susceptible subunits of fibrinogen were the A-alpha and B-beta ones, in this order. P. aeruginosa alkaline proteinase also exhibited an anti-coagulant activity in human plasma attributed to the direct fibrinogenolytic function. Such potential anti-coagulant capacity of the P. aeruginosa alkaline proteinase might explain, at least partly, the most characteristic pathologic feature of the P. aeruginosa septicemia, hemorrhagic lesions with lacking thrombi (Fetzer, A.E. et al. (1967) Am. Rev. Respirat. Dis. 96, 1121-1130).

Blood Coagulation↗
PubMed1991

Automated immunoturbidimetric analysis of six plasma apolipoproteins: correlation with radial immunodiffusion assays.

We measured six apolipoproteins (apo AI, AII, B, CII, CIII, and E) by turbidimetric method using an automatic discrete biochemical analyzer and commercially available antisera. The turbidimetric method was compared with the single radial immunodiffusion method. Linearity for serum apolipoprotein assay by the automated turbidimetric method was better than by the single immuno-diffusion method. The linearity by the turbidimetric method was 2.5 G/L for AI, 1.0 G/L for AII, 4.5 G/L for B, 0.12 G/L for CII, 0.3 G/L for CIII, and 0.12 G/L for E. The presence of high concentrations of bilirubin (up to 0.15 G/L) and hemoglobin (up to 50 G/L) interfered with apolipoprotein measurement. Comparison of the immunoturbidimetric and the single radial immunodiffusion (SRID) methods showed excellent coefficients of correlation, r = 0.963, 0.896, 0.846, 0.936, 0.972, and 0.937 for apo AI, AII, B, CII, CIII, and E, respectively. Reference ranges for the six apolipoproteins were determined by using sera from 450 healthy subjects and were 1.4 +/- 0.3 G/L for AI and 0.3 +/- 0.01 for E. The observed levels of AII (P less than 0.001), B (P less than 0.01), and CIII (P less than 0.01) were significantly higher in males. The serum levels of apo B, CII, and E showed a gradual increase with age which was more prominent in females than in males. The levels of apo AI, AII decreased significantly over an 11 day period in 22 patients with myocardial infarction.

Adolescent↗
PubMed1991

Identification of a marker chromosome as inv dup(15) by molecular analysis.

The origin of an extra marker chromosome in a patient with mental retardation and intractable epilepsy was ascertained by DNA analysis. Gene dose and restriction fragment length polymorphism (RFLP) studies of D15S9 proved that the patient was tetrasomic for the gene and that the extra chromosome was of maternal origin. On the basis of the molecular findings, further detailed GTG-banded chromosome analysis interpreted the marker chromosome as inv dup(15)(pter----q14::q14----pter). The clinical manifestations of the patient are consistent with those of the patients previously described.

Adolescent↗
PubMed1991

Quantification of cell nuclei isolated from hepatocytes by cell lysis with nonionic detergent in citric acid.

A method was developed for determining the number of nuclei of hepatocytes cultured on collagen gel using a nonionic detergent, Nikkol BO-10TX. The cells were recovered in a test tube after solubilizing the gel by incubating it with the detergent in 0.1 M citric acid and then centrifuging the mixture. Nuclei were isolated from the cells with the same detergent solution and collected by centrifugation. The numbers of nuclei in cultures, scored with a hemocytometer or an electronic particle counter, were proportional to the lactate dehydrogenase activities of the cells. This method was also applicable for scoring the number of nuclei of hepatocytes cultured on collagen-coated plastic.

Animals↗
PubMed1991

[A case of diffuse aspiration bronchiolitis secondary to achalasia of the esophagus].

A 12-year-old male was admitted to our hospital because of cough, sputum and increasing fever. Chest CT revealed ill-defined small round opacities located around the end of the bronchovascular branchings in almost all of the lung fields. These findings were compatible with diffuse panbronchiolities (DPB). On the other hand, the boy was diagnosed as having achalasia of the esophagus and fragments of food were observed in the bronchi by bronchoscopy. Repeated aspiration and infection due to achalasia are factors which brought about diffuse aspiration bronchiolitis (DAB).

Bronchiolitis↗
PubMed1990

Activation of human Hageman factor by Pseudomonas aeruginosa elastase in the presence or absence of negatively charged substance in vitro.

Human Hageman factor, a plasma proteinase zymogen, was activated in vitro under a near physiological condition (pH 7.8, ionic strength I = 0.14, 37 degrees C) by Pseudomonas aeruginosa elastase, which is a zinc-dependent tissue destructive neutral proteinase. This activation was completely inhibited by a specific inhibitor of the elastase, HONHCOCH(CH2C6H5)CO-Ala-Gly-NH2, at a concentration as low as 10 microM. In this activation Hagemen factor was cleaved, in a limited fashion, liberating two fragments with apparent molecular masses of 40 and 30 kDa, respectively. The appearance of the latter seemed to correspond chronologically to the generation of activated Hageman factor. Kinetic parameters of the enzymatic activation were kcat = 5.8 x 10(-3) s-1, Km = 4.3 x 10(-7) M and kcat/Km = 1.4 x 10(4) M-1 x s-1. This Km value is close to the plasma concentration of Hageman factor. Another zinc-dependent proteinase, P. aeruginosa alkaline proteinase, showed a negligible Hageman factor activation. In the presence of a negatively charged soluble substance, dextran sulfate (0.3-3 micrograms/ml), the activation rate by the elastase increased several fold, with the kinetic parameters of kcat = 13.9 x 10(-3) s-1, Km = 1.6 x 10(-7) M and kcat/Km = 8.5 x 10(4) M-1 x s-1. These results suggested a participation of the Hageman factor-dependent system in the inflammatory response to pseudomonal infections, due to the initiation of the system by the bacterial elastase.

Amino Acid Sequence↗
PubMed1990

A long-term surveillance of occupational health hazards faced by cadmium workers.

The decrease or damage of renal tubular functions by cadmium (Cd) exposure is designated as the critical effect on human body. When the Cd workers suffer from tubular damage, it is matter of concern whether the damage is reversible or irreversible. In this study, chronic influences of long-term exposure to Cd dust or fumes in the working environment were clarified. Besides the survey on Cd contents in work environment and production amounts of Cd pigments in the factory, the changes of Cd concentration in blood and urine, beta 2-microglobulin (beta 2MG) in serum and urine, C beta 2-MG/Ccr, the rate of tubular reabsorption of phosphorus (% TRP) and other laboratory examinations in 7 Cd pigment workers were observed for the past 15 years. In almost workers, the changes of Cd concentrations in blood and urine, beta 2MG in urine, and C beta 2MG/Ccr basically paralleled those of Cd concentrations in working environment. In some workers the fluctuations of beta 2MG in urine, C beta 2MG/Ccr and %TRP did not paralleled those of environmental Cd concentration and they were very variable. From the results obtained, it is stressed that the long-term follow-up studies on environmental Cd concentrations and analysis of biological indicators are necessary to determine the degree of the renal tubular dysfunction by Cd.

Adult↗
PubMed1989

Two erbA homologs encoding proteins with different T3 binding capacities are transcribed from opposite DNA strands of the same genetic locus.

Two erbA homologs, termed ear-1 and ear-7, are present in the human genome on chromosome 17. The two genes reside in the same genetic locus with overlapping exons and are transcribed from opposite DNA strands. In addition, the ear-7 mRNA is alternatively spliced to generate two protein isoforms, namely the ear71 and ear72 proteins. Nucleotide sequence analysis predicts that the ear71 protein is a human counterpart of the chicken c-erbA protein, a molecule closely related or identical to thyroid hormone receptor. Indeed, Scatchard analysis of proteins synthesized in vitro indicated very high affinity binding of T3 to the ear71 protein but not to the ear72 protein. Interestingly, the ear-1 gene product showed low, but appreciable, binding to T3, although its authentic ligand remains to be clarified.

Amino Acid Sequence↗
PubMed1989

Waardenburg syndrome type I in a child with de novo inversion (2)(q35q37.3).

We report on a child with Waardenburg syndrome type I and a paracentric inversion of chromosome 2. This 20 month-old boy has dystopia canthorum, sensorineural deafness, heterochromia iridis, partially albinotic ocular fundi, and partial leukodermia. He does not have mental retardation or any skeletal abnormalities. Family history was unremarkable. Cytogenetic studies demonstrated that the patient has a paracentric inversion (2)(q35q37.3); his parents have normal chromosomes. These findings suggest that the locus of the gene for Waardenburg syndrome type I may be at 2q35 or 2q37.3.

Abnormalities, Multiple↗
PubMed1989

[Clinical analysis on the temporomandibular joints of the fifteen patients of rheumatoid arthritis].

It is seemed to be really important, when making a selection on the treatment for rheumatoid arthritis, to gain an insight into progress and activity of the disease. This analysis was taken in order to look upon the clinical symptoms and the radiographic abnormalities of the temporomandibular joints, obtained from fifteen rheumatoid arthritis patients who has visited on our department, since 1974. Ten patients (66.7%) had clinical evidences of temporomandibular joint. The most frequent symptom was pain on movement, followed by disturbances on mouth opening and crepitation. Patients who had been suffering from the disease for a long period offered more frequent clinical evidences. The acute phase symptoms, such as disturbances on mouth opening, swelling and oppressive pain in the preauricular area, was found in one patients. All of the patients showed some radiographic abnormalities. We've devised a criteria on the degree of condylar absorption on the purpose of comparison to the other abnormalities. The degree 1 was found in 3 joints, the degree 2 in 12 joints, the degree 3 in 14 joints, and the degree 4 in 7 joints. An absorption on the articular fossae and the tubercles were well along with this degrees. The higher degree the more frequent of clinical evidences in each joints was disclosed. And the period of the disease was related on the degrees, too. We can expect the bone scintigraphy by using 99mTc-MDP to be a good way for expression of the activity of the disease.

Arthritis, Rheumatoid↗
PubMed1988

Effects of 2-(4-phenylpiperidino)cyclohexanol (AH5183) and barium ions on frog neuromuscular transmission.

1. By applying electrophysiological techniques such as frequency facilitation, tetanic run-down and depression, recovery from depression and post-tetanic potentiation (PTP) of the end-plate potential (EPP), the effects on frog neuromuscular transmission of 2-(4-phenylpiperidino)cyclohexanol (AH5183), a compound known to inhibit specifically the loading of newly synthesized acetylcholine (ACh) molecules into synaptic vesicles, and Ba2+, a selective activator of the augmentation phase of PTP, were investigated to elucidate whether these were related to ACh turnover. 2. Effects of AH5183 and Ba2+ ions were frequency dependent. At low frequency of stimulation, both agents showed essentially no effects on the EPPs recorded from Mg2+-blocked preparations. 3. AH5183 pivoted the log-linear frequency facilitation relation clockwise without altering the intercept on the ordinate, whereas Ba2+ ions did so counter-clockwise. As is the case with Ca2+ ions, Sr2+ ions shifted the relation upwards leaving its slope unaffected. 4. AH5183 selectively depressed the component of potentiation in PTP while the effect of Ba2+ ions was a specific increase in the augmentation phase of PTP. 5. Ba2+ ions increased the amplitude of EPPs in the late depressed phase during the tetanic run-down and depression experiment, but 4-aminopyridine and Ca2+ ions failed to do so. 6. AH5183 increased, Ba2+ ions reduced but Ca2+ ions did not change the constant of recovery from depression of the EPP measured on curarized preparations. 7. The present results suggested that mobilization of the ACh quanta readily available for release might be a common mechanism underlying both frequency facilitation and two components of PTP (augmentation and potentiation). The term 'frequency facilitation' would be more comprehensive if it were re-termed 'frequency augmentation' or 'frequency potentiation'.

4-Aminopyridine↗
PubMed1987

Lysosomal enzymes in tear fluids from patients with Terrien's marginal corneal degeneration.

We examined biochemically the lysosomal enzyme activities in tear fluids from patients with mild myopia, senile cataract, and Terrien's marginal corneal degeneration. Tear acid phosphatase activities in Terrien's degeneration were almost the same as those in mild myopia and senile cataract, while those of N-acetyl-beta-D-glucosaminidase in Terrien's degeneration were higher. The high activity of tear N-acetyl-beta-D-glucosaminidase may be derived from the lacrimal gland and infiltrate histiocytelike cells in Terrien's marginal corneal degeneration.

Acetylglucosaminidase↗
PubMed1987

Urinary fluoride monitoring of industrial hydrofluoric acid exposure.

Preworkshift and postworkshift urinary fluoride concentrations were measured in 142 hydrofluoric acid (HF) workers and 82 unexposed workers aged 18 to 59. Postshift urinary fluoride concentration in HF workers was significantly higher than that in preshift or control workers. A linear relationship was observed between the mean values in urinary fluoride concentration and the HF concentration in the air. The mean urinary fluoride concentration of 4 ppm and its lower fiducial limit (95%, P = 0.05) of 2 ppm (specific gravity 1.024) were estimated corresponding to the atmospheric HF concentration of 3 ppm, which is the maximal allowable concentration recommended by the Japanese Association of Industrial Health and also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results suggest that exposure to HF can be monitored by determining the urinary fluoride concentration.

Adolescent↗