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Biomedical subjects

M Yasui

Publications and source records attributed to M Yasui.

At least 163 records · Page 9Linked to original sources
PubMed1989

[The correlation of serum parathyroid hormones among patients with dementia of vascular type, hemodialysis, and bone-joint disorders].

PTH levels were analysed in sera of patients receiving maintenance hemodialysis, with the vascular type of dementia and orthopedic patients with bone-joint disorders, using PTH assay kits. There were significant interrelationship among all kinds of PTH levels in the hemodialysis patients, but not in patients with the vascular type of dementia and the bone-joint disorders. Renal functions might be responsible for fragmentation of PTH in blood stream. These results suggested that the measurement of PTH levels is needed to examine various kinds of amino-sequence of PTH levels in keeping normal function of kidney.

Aged↗
PubMed1989

[2-color analysis of lymphocyte subpopulation of bronchoalveolar lavage fluid and peripheral blood in patients with sarcoidosis].

By means of 2-color analysis, we investigated the lymphocyte subpopulation of bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) of 13 patients with pulmonary sarcoidosis. The BALF-CD4+ T cells of normal subjects and patients with sarcoidosis consisted almost completely of CD4+4B4+ cells (helper inducer T cells) and BALF-CD8+ T cells were almost completely composed of CD8+CD11- cells (cytotoxic T cells). The BALF findings of sarcoidosis were characterized by increased percentages of CD4+4B4+ cells (54.9 +/- 15.7%), decreased percentage of CD8+CD11- cells (12.0 +/- 8.4%) and increased percentage of CD4+HLA-DR+ cells (27.8 +/- 13.1%). These findings suggest that activated CD4+4B4+ cells (helper inducer T cells) may primarily contribute to the pathogenesis of pulmonary sarcoidosis. The in vivo or in vitro functions of CD4+4B4+ cells in sarcoidosis need further investigation.

Adult↗
PubMed1989

Free energy change in the elementary steps of actomyosin ATPase reaction.

We determined the rate constants of the elementary steps of actomyosin ATPase reaction, and calculated the effective free energy change in the elementary steps of ATPase reaction. It was shown that most of the free energy obtained by ATP hydrolysis is liberated in the step from the actomyosin-phosphate-ADP complex to actomyosin-ADP complex.

Actins↗
PubMed1989

[The inhibitory effect of elastase on calcium increase in brain and spinal cord of rabbits with atherosclerosis induced by cholesterol-rich diet].

The aim of present experiment was to investigate the decalcified effects of exogenous elastase in liver, kidney and central nervous system (CNS) of rabbits with atherosclerosis experimentally induced by the modified procedure of Kritchevsky et al. Twenty five male rabbits, weighing approximately 2 kg, were divided into 6 groups. Animals were fed for 3 months with standard diet (group A), standard diet containing 1.5% cholesterol (group B) and 1.5% cholesterol-rich diet plus intraperitoneal (ip) daily administration of elastase 450 EL. U/kg (group C). Another groups were kept for 6 months with standard diet (group D), standard diet containing 0.67% cholesterol (group E) and 0.67% cholesterol-rich diet plus same dose of elastase (group F). The rabbits treated with cholesterol-rich diet were confirmed to be induced atherosclerosis biochemically as well as histologically. All groups were maintained under these conditions for experimental periods and allowed tap water. After 3 and 6 months, blood collected by cardiocentesis using ether anesthesia and then sacrificed to remove CNS and internal organs. Blood had stood for 1 hour at room temperature. Serum was separated by centrifugation at 3,000 rpm for 10 min to determine total cholesterol, triglyceride, phospholipids, HDL-cholesterol, and so on. Calcium contents in the cerebral frontal lobe, cerebellum, pons, spinal cord, liver and kidney were measured by neutron activation analysis method. In this experiment the amelioration of atherosclerosis by ip administration of elastase was ascertained. In rabbits given cholesterol-rich diet, calcium content in CNS tissues was higher than that of another tissues and paralleled to a rise of serum cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Elementary steps of the actin-activated ATPase reaction of cardiac muscle myosin subfragment-1.

The rates of the elementary steps of the actomyosin ATPase reaction were measured using the myosin subfragment-1 of porcine left ventricular muscle. The results could be explained only by the two-route mechanism for actomyosin ATPase (Inoue, Shigekawa, & Tonomura (1973) J. Biochem. 74, 923-934), in which ATP is hydrolyzed via routes with or without accompanying dissociation of actomyosin. The dependence on the F-actin concentration of the rate of the acto-S-1 ATPase reaction in the steady state was measured in 5 mM KCl at 20 degrees C. The maximal rate, Vmax, and the dissociation constant for F-actin of the ATPase, Kd, were 3.0 s-1 and 2.2 mg/ml, respectively. The Kd value was almost the same as that determined from the extent of binding of S-1 with F-actin during the ATPase reaction. The rate of recombination of the S-1-phosphate-ADP complex, S-1ADPP, with F-actin, vr, was lower than that of the ATPase reaction in the steady state. Thus, ATP is mainly hydrolyzed without accompanying dissociation of acto-S-1 into S-1ADPP and F-actin. In the cardiac acto-S-1 ATPase reaction, the rate of the ATPase reaction in the steady state and that of recombination of S-1ADPP with F-actin were about 1/5 those of the skeletal acto-S-1 ATPase reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Oxygen exchange during the acto-subfragment-1 ATPase reaction: evidence for the two-route mechanism of the actomyosin ATPase reaction.

The oxygen exchange occurring during the acto-S-1 ATPase reaction was analyzed based on the distribution of 18O-labeled species of P1 using [gamma-18O]ATP as a substrate. Evidence was found for the two-route mechanism in which ATP is hydrolyzed via the dissociation of acto-S-1 into F-actin and the S-1-phosphate-ADP complex, S-1PADP, and their recombination, and also hydrolyzed without the dissociation of acto-S-1 (Inoue, A., Shigekawa, M., & Tonomura, Y. (1973) J. Biochem. 74, 923-934; Inoue, A., Ikebe, M., & Tonomura, Y. (1980) J. Biochem. 88, 1663-1677). When ATP was mainly hydrolyzed without the dissociation of acto-S-1, the extent of oxygen exchange was low. When ATP was hydrolyzed by both routes, the distribution of product P1 with 3, 2, 1, and 0 18O atoms showed a mixture resulting from low and high oxygen exchange. The rate of ATPase without the dissociation of acto-S-1 can be estimated from the rate of the overall reaction (v), the rate of recombination of S-1PADP with F-actin (vr), and the extent of dissociation of acto-S-1 (a). The distribution of the P1 species measured was almost equal to that calculated from the ratio of ATP hydrolysis via the two pathways as avr and v-avr, respectively. This result indicates that the rates of the dissociation of acto-S-1PADP into S-1PADP and F-actin and their recombination are much lower than the rate of decomposition of the acto-S-1PADP complex into acto-S-1 + ADP + Pi.

Adenosine Triphosphatases↗
PubMed1988

[Markers of bone pain in hemodialysis patients with renal insufficiency].

The patients receiving maintenance hemodialysis were divided into two groups in the absence and the presence of bone pain and investigated the markers of bone pain in these patients. These results suggested that the duration of receiving hemodialysis, serum concentrations of alkaline phosphatase, osteocalcin and parathyroid hormone became to be the markers of bone pain.

Adolescent↗
PubMed1988

[Effect of age on markers of bone metabolism in renal hemodialysis patients].

Bone metabolic markers were investigated in the male hemodialysis patients within and over 60 years old and the female hemodialysis patients within and over 50 years old. Our results indicated that bone metabolic markers were more increased in the lower values of serum estradiol in the male patients, but inversely were more enhanced in higher values of serum estradiol in the female patients.

Adult↗
PubMed1988

[Relationship between parathyroid hormone and magnesium in sera of the dementia patients].

The dementia patients with central nervous or neuro-cerebro vascular disorders seemed to be decreased serum Mg due to abnormal Mg uptake in diet. An increment of PTH level was paralleled with a rise of serum Mg and hypomagnesemic group was shown to have a lower PTH level in these patients. Our results suggested that secondary hypoparathyroidism was likely to be induced by normo-calcemic hypomagnesemia.

Adult↗
PubMed1988

[Influences of serum magnesium on measurements of serum parathyroid hormone].

The amino sequence recognizable parathyroid hormones (PTH) in lower and non-lower magnesemic groups in randomized samples were measured by using various kinds of the well established PTH kits. The levels of carboxy terminal, mid-region and intact PTH in lower magnesemic group were more decreased than these in non-lower magnesemic group. It is likely that the shortage of magnesium in serum makes a suppression of PTH secretion.

Humans↗
PubMed1988

[Clinical evaluation of osteocalcin in sera of the patients with neoplasms of bone].

The clinical significance of osteocalcin in sera of bone tumors were measured in sera of various kinds of bone tumors. The levels of osteocalcin were higher in bone tumors than those in normal subjects. Serum osteocalcin levels in hypercalcemic groups of bone metastasis and myeloma showed a remarkable increase in a parallelism with serum ALP and LDH levels. These results suggested to be directly or indirectly activated on osteoblast by bone tumors and to be synthesized osteocalcin in osteoblast.

Alkaline Phosphatase↗
PubMed1988

[Magnesium, parathyroid hormone and osteocalcin in the sera of hospitalized patients with chronic alcoholism].

Levels of parathyroid hormone (PTH) and osteocalcin in hypomagnesemic sera of chronic alcoholism patients were carried out to evaluate the roles of chronic alcohol poisoning on bone metabolism. Serum gamma-GTP activity showed inverse relationships among serum Mg and osteocalcin in these patients and PTH levels were also more decreased in these patients than in healthy subjects. These results indicated that the direct actions of alcohol might be brought about by the deterioration of bone metabolism, due to the decrease of serum PTH and osteocalcin levels by chronic alcohol poisoning.

Alcoholism↗
PubMed1988

[Parathyroid hormone and bone mineral content in male and female patients receiving hemodialysis].

Relative bone mineral content in the lumbar spine was measured by phantom B-MAs with the apparatus of computerized tomography in order to study the relationships between bone mineral content with age and parathyroid hormone in sera of randomized out- and in-patients and the hemodialysis patients. There exists a significant difference between male and female in the loss of bone mineral content of three groups.

Adult↗
PubMed1987

Activity of blood coagulation factor XIII as a prognostic indicator in patients with Henoch-Schönlein purpura. Efficacy of factor XIII substitution.

UNLABELLED: Determination of coagulation Factor XIII (F XIII)-related parameters in 21 patients with Henoch-Schönlein purpura documented a significant decrease of F XIII activity as well as of the F XIII-related antigenic determinants. Subgroup analysis with regard to the clinical symptoms showed an even further decrease of these parameters in patients with gastrointestinal complications. Stimulated by these findings a substitution therapy with a F XIII concentrate was initiated in those patients whose F XIII activity in plasma remained low and who developed severe abdominal pain accompanied by persisting gastrointestinal bleeding. This therapeutic approach not only corrected the laboratory data, but more important led to a cessation of pain and bleeding. A rapid decrease of F XIII levels after transfusion below 40 U/ml was indicative of relapse of abdominal symptoms, while increasing values were associated with the recovery of the patients. IN CONCLUSION: F XIII activity determinations appear to have a predictive value in patients with Henoch-Schönlein purpura, and the administration of F XIII concentrates may contribute to the improvement of gastrointestinal complications.

Child↗
PubMed1987

[Whole-body transmission scintigraphy using a line source].

Transmission scanning was proposed to be a useful adjunct to conventional emission scanning for accurately keying radionuclide deposition to radiographic anatomy. After introduction of a scintillation camera, transmission whole-body scintigraphy using a flood source has been performed in a patient with differentiated thyroid carcinoma. Recently immunoscintigraphy with radiolabeled monoclonal anti-tumor antibodies has become popular and transmission whole-body scintigraphy has been re-evaluated to make diagnosis for laterality of metastases. However, there are several problems to handle a flood source for preparation and shielding. We developed a special line source for transmission whole-body scintigraphy. The line source is composed of a plastic tube (inner diameter: 3 mm) with three-way stop in a U-shaped metal. There are several advantages to use this line source as compared to a flood one; (1) a small volume of radioactive solution (less than 5 ml), (2) easy preparation and setting, and (3) less radiation. Moreover good quality of transmission image is obtained using this line source.

Humans↗
PubMed1987

[Attenuation correction of SPECT imaging by dual energy method--quantification of 111In-labeled monoclonal anti-tumor antibody localization].

Application of radiolabeled monoclonal anti-tumor antibodies for diagnosis and therapy has made remarkable progress in the past few years. Quantification of radiopharmaceutical localization is required adequate attenuation correction in SPECT imaging. Attenuation correction by transmission CT (TCT) data is one of the best method at present time. However, if a patient is moved between TCT and SPECT, this method is no more applicable. We developed a new attenuation correction algorithm by dual energy method, using 99mTc and 111In because of similarity of these linear attenuation coefficients. The new algorithm uses data of TCT with an external source of 99mTc, and requires another data from SPECT of 111In labeled monoclonal anti-tumor antibody, which are simultaneously obtained. TCT results in an attenuation map, which then serves as input into the final intrinsic correction algorithm to uncorrected SPECT data. In chest phantom experiment, the attenuation corrected SPECT images revealed nearly same distribution of actual radioactivity of 111In as compared to that of uncorrected one.

Antibodies, Monoclonal↗