Biomedical subjects

Y Okuno

Publications and source records attributed to Y Okuno.

At least 181 records · Page 10Linked to original sources

PubMed1991

In vitro growth pattern of myeloma cells in liquid suspension or semi-solid culture containing interleukin-6.

We examined in vitro growth pattern of myeloma cells from 21 patients with multiple myeloma either in liquid suspension or methylcellulose semi-solid culture, both in the presence of interleukin-6 (IL-6). The survival or growth of myeloma cells in liquid culture was classified into four categories. Type 1: myeloma cells survived for only 2-3 weeks in eight patients; Type 2: survival for 1-2 months in seven patients; Type 3: survival for more than 3 months without an obvious increase in cell number in three patients; and Type 4: continuous proliferation (cell line) in three patients. As the clinical stage advanced, the survival of myeloma cells became longer. All three myeloma cell lines were obtained from patients in an advanced clinical stage. Human plasma added to the liquid culture induced the survival or growth of myeloma cells better than fetal calf serum in any survival or growth type. Myeloma colonies or clusters were generated in seven of 21 patients, though myeloma colony formation was restricted to Type 4 patients. IL-6 neither prolonged the survival of myeloma cells nor promoted their growth in vitro except for Type 4 cells. Moreover, IL-6 did not increase the success rate of generating myeloma colonies in vitro. However, IL-6 did elevate the number of myeloma clusters in Types 1, 2 and 3 patients examined. These results suggest that IL-6 has a minor proliferative effect on myeloma cells in semi-solid culture but not in liquid suspension culture except for cells from patients with aggressive myeloma.

Cell Division↗

PubMed1991

Effect of 1,25(OH)2D3 on normal human CFU-GM: target cells of the agent in the suppression of colony formation and induction of macrophage colonies.

1,25-Dihydroxyvitamin D-3 (1,25(OH)2D3) suppresses colony formation of normal human granulocyte macrophage progenitors (CFU-GM) and induces differentiation of colonies into monocyte macrophages in vitro. We examined whether or not the target cell of 1,25(OH)2D3 is only CFU-GM in the suppression and differentiation of colonies by the agent. Reduction of colony counts was observed only when 1,25(OH)2D3 was added to CFU-GM cultures at days 0 or 3, and after day 5 the agent did not affect the colony count. However, the delayed addition of 1,25(OH)2D3 elevated the proportion of granulocyte macrophage (GM) or macrophage (M) colonies even after 5 days of culture. We confirmed transformation of day 11 colony cells into macrophages by 1,25(OH)2D3 during the following 3 days' culture period based on serial observations of single colonies. Day 11 colonies contained very few CFU-GM and their most immature cells were promyelocytes. Short-term exposure to 1,25(OH)2D3 (4 h) of bone marrow cells, which had been precultured for 24 to 72 h with a purified granulocyte-colony stimulating factor caused a reduction of colony counts but did not elevate the proportions of GM or M colonies. These results indicate that 1,25(OH)2D3 inhibits the growth of CFU-GM itself and induces differentiation into macrophages at the progeny level (probably promyelocytes) and not at the level of CFU-GM.

Calcitriol↗

PubMed1991

Effects of contrast media on the RR and QT interval during coronary arteriography.

During coronary arteriography, transient prolongation of the RR and QT intervals can be observed to occur. Animal experiments have suggested that low-osmolality contrast media have less effect, but there have been few clinical studies of this phenomenon. We analyzed 95 electrocardiographic records from patients who had undergone coronary arteriography and assessed the maximal prolongation of the RR and QT intervals. The contrast media used for arteriography included meglumine sodium diatrizoate, iopamidol, iohexol, and meglumine sodium ioxaglate. Diatrizoate caused the greatest electrocardiographic changes. Among the low osmolality contrast media, ioxaglate caused the smallest bradycardial effect and iohexol the smallest prolongation of the QT interval. It appears necessary to consider some additional factors for osmolality or ionicity, such as the chemotoxicity of the chemical structure of the iodinated contrast medium moiety, when assessing their potential adverse effect on the cardiac conduction system.

Contrast Media↗

PubMed1991

Establishment and characterization of four myeloma cell lines which are responsive to interleukin-6 for their growth.

Four human myeloma cell lines (MM-S1, MM-A1, MM-Y1 and MM-C1) were established from patients in the terminal stage of multiple myeloma. All the cell lines were PCA-1 positive and three were CD38 (OKT10) positive. The class of cytoplasmic immunoglobulin in each of these cell lines was identical to that of the monoclonal protein detected in each patient. Epstein-Barr virus nuclear antigen was negative in all cell lines. An examination of the tritiated thymidine uptake showed that all four cell lines proliferated in response to interleukin-6 (IL-6), while MM-S1 also responded to IL-5. Immunological staining with an anti-IL-6 receptor monoclonal antibody revealed the presence of receptors for IL-6 on the cells from each cell line. Three of them formed colonies dependent on IL-6 in methylcellulose semi-solid culture. All four cell lines grew better when human plasma was added as a supplement to the culture in comparison to fetal calf serum. Northern blot analysis showed that the three cell lines tested did not express IL-6 messenger RNA. These results indicate that these four cell lines are responsive to IL-6, but not by an autocrine mechanism, at least in the three lines examined.

Adult↗

PubMed1990

Establishment of an erythroid cell line (JK-1) that spontaneously differentiates to red cells.

The authors established a new hemopoietic cell line (JK-1) from a patient with chronic myelogenous leukemia in erythroid crisis. This JK-1 line predominantly consists of immature cells, but a small number of mature erythroblasts and red cells can be consistently seen without any specific differentiation inducer. The JK-1 cells grow in suspension culture supplemented with human plasma and carry double Philadelphia chromosomes. Hemoglobin staining with benzidine was positive for about 20% of cells and the type of the hemoglobin was for the most part HbF. Surface-marker analysis revealed JK-1 cells positive for glycophorin A, EP-1, and HAE9. The proportion of mature cells was elevated by the addition of delta-aminolevulinic acid. Erythropoietin (EPO) enhanced the growth of JK-1 cells either in the suspension or in methylcellulose semisolid culture. The total number of EPO receptors was 940 per cell, of which 220 sites had an affinity higher than the other 720 sites. This is the first report of an established human erythroid cell line which spontaneously undergoes terminal differentiation.

Antigens, Surface↗

PubMed1990

Expression of the erythropoietin receptor on a human myeloma cell line.

We demonstrated the expression of the erythropoietin (EPO) receptor by a human myeloma cell line (MM-S1) which was established in our laboratory. EPO dose-dependently stimulated the proliferation of MM-S1 cells. Binding of radioiodinated EPO (125I-Epo) to MM-S1 cells was competitively inhibited by unlabeled EPO, but not by other recombinant cytokines. Specific binding of 125I-Epo to MM-S1 cells was saturable, and the Scatchard analysis revealed 330 EPO binding sites per cell with a Kd of 0.56 nmol/L. Bound EPO was internalized by MM-S1 cells during incubation at 37 degrees C. This is the first report describing the expression of the EPO receptor by human cells other than those of the erythroid lineage.

Cell Division↗

PubMed1990

[Fever of unknown origin: re-evaluation of 67Ga scintigraphy in detecting causes of fever].

Radioactive gallium citrate has been known to accumulate not only in neoplasms but also in inflammatory foci, and thus widely used to find out pyrogenic lesions in cases of unexplainable prolonged fever. However, with developments and improvements of other imaging modalities, its diagnostic significance may have changed. To probe that issue, recent 65 scans for the patients with fever of unknown origin were reviewed retrospectively. Of these, 56 had sufficient clinical assessment and laboratory examinations to evaluate causative illnesses. Gallium images of 33 patients were interpreted as positive. Local inflammatory lesions were detected in 23 cases, with lung tuberculosis, urinary tract infection, and inflammatory joint diseases as prevalent final diagnoses. Pyogenic abscesses, though popular in the literatures on fever of unknown origin, were found in only 2 cases in our present series. This seemed to be due to earlier detection of affected sites by other imaging technics. Osteomyelitis, other major cause of fever in the past, was not found this time, probably owing to wide use of antibiotics. Besides localized diseases, seven cases of generalized disorders were found. There were 3 patients with hematological malignancies, 3 with systemic autoimmune diseases, and 1 with severe infectious mononucleosis. There were three false positive cases; intestinal gallium radioactivity in 2 cases and physiological pulmonary hilar accumulation in 1 were erroneously read as abnormal. Of 23 cases with negative gallium scan, no definite cause of fever were found in 19; twelve patients had spontaneous reduction of fever, 2 did so with antibiotics, and 5 with corticosteroids. False negative cases were; two with urinary tract infection on antibiotics, one with bacterial meningitis, and one with polyarteritis nodosa. Our results reconfirmed the excellent sensitivity and accuracy of gallium scan in the diagnosis of fever of unknown origin. In addition to the detection of focal inflammations, it may sometimes contribute to an early diagnosis of unexpected systemic diseases. From the results obtained, it is advisable that, in patients with fever of unknown origin, this test should be done early in diagnostic schedule and before administration of drugs that may mask potential sites of abnormal accumulation.

Adolescent↗

PubMed1990

Mechanism in 1,25(OH)2D3-induced suppression of helper/suppressor function of CD4/CD8 cells to immunoglobulin production in B cells.

On the basis of previous data that 1,25(OH)2D3 suppressed both helper and suppressor activities of CD4 and CD8 cells in the pokeweek mitogen-stimulated culture, we examined the further effect of 1,25(OH)2D3 on both cells to define how 1,25(OH)2D3 is involved in the deterioration of their functions. 1,25(OH)2D3 suppressed the pokeweed mitogen and phytohemagglutinin-induced DNA synthesis of CD4 and CD8 cells. The suppression by 1,25(OH)2D3 of DNA synthesis was caused by a time lag in reaching maximal response. 1,25(OH)2D3 also suppressed interleukin-2 production of CD4 and CD8 cells. 1,25(OH)2D3 did not, however, affect their interleukin-2 receptor expression detected within 24 hr after phytohemagglutinin stimulation. In addition, 1,25(OH)2D3 failed to suppress DNA synthesis of CD4 and CD8 cells when cultured with a large amount of interleukin-2. Suppression by 1,25(OH)2D3 of proliferation and interleukin-2 production in CD4 and CD8 cells would bring about the decrease of their helper or suppressor functions by inhibiting their expansion or maturation.

Antibody-Producing Cells↗

PubMed1990

Insulin sensitivity in patients with anorexia nervosa and bulimia.

Insulin sensitivity was studied using the euglycemic insulin clamp technique in 5 female patients with anorexia nervosa and 4 females with bulimia. The results were compared with those of 15 male patients with non-insulin-dependent diabetes mellitus. Euglycemic insulin clamp is performed for 2 h using the Biostator, during which time insulin was infused at a rate of 0.77 mU kg-1 min-1. Fasting plasma glucose and immunoreactive insulin tended to be lower in patients with anorexia nervosa than in those with bulimia (69.8 +/- 6.7 vs 75.9 +/- 7.7 mg/dl, and 5.9 +/- 2.0 vs 9.8 +/- 3.4 U/ml). The mean metabolic clearance rate (MCR) was 9.2 +/- 3.9 ml kg-1 min-1 for patients with anorexia nervosa, 5.1 +/- 2.2 ml kg-1 min-1 for patients with bulimia, and 3.8 +/- 0.3 ml kg-1 min-1 for patients with diabetes mellitus. However, one anorectic had a significantly high MCR. One anorectic and 3 bulimics had a significantly low MCR. These results suggest that insulin sensitivity varied in patients with anorexia nervosa, whereas it tended to decrease in some patients with bulimia but not to the same degree as in patients with diabetes mellitus.

Adult↗

PubMed1990

Rapid focus reduction neutralization test of influenza A and B viruses in microtiter system.

A rapid neutralization test for influenza A and B viruses was developed. In this method, a 96-well tissue culture plate was used for the preparation of cell monolayers and the peroxidase-antiperoxidase staining technique was used for the visualization of foci infected with these viruses. In the presence of trypsin and tragacanth gum, clear foci developed 1 day after infection. A linear relationship between virus dilutions and numbers of foci was observed. When neutralizing antibodies in some test sera were assayed, a good correlation was observed between the titers obtained by the focus method and those obtained by the ordinary plaque method. In addition, many serum specimens were investigated by the neutralization test, and it was demonstrated that the test is useful for serological studies of influenza.

Animals↗

PubMed1990

[Diaphragmatic electromyography (DEMG) in achalasia patients].

LES pressure increase following diaphragmatic contraction as a pinch-cock action acts as one of the barrier mechanism for gastroesophageal reflux. In achalasia patients, incomplete LES relaxation following wet swallow is one of the characteristic manometric findings, along with loss of peristalsis. On the other hand, it has been reported that swallowing effort or esophageal distention have no effect on the increase of LES pressure induced by diaphragmatic contraction, which condition is similar to achalasia. Therefore, to evaluate that whether diaphragmatic contraction is involved in the cause of achalasia, we recorded diaphragmatic electromyography (DEMG) using bipolar electrodes in 12 achalasia patients and 4 normal subjects. The phasic DEMG amplitude was 80-90 microV in normal subjects and achalasia patients. LES pressure and DEMG amplitude increased during both straight leg raising (SLR) and abdominal distention (AD), both of the maneuver induce diaphragmatic contraction, in normal subjects and achalasia patients similarly. From the data obtained with this equipment, we conclude that diaphragmatic involvement is not likely as a pathogenesis of LES dysfunction in achalasia patients.

Adult↗

PubMed1990

[Effect of feeding on recording characteristics of electrogastrography (EGG) in normal subjects].

Cutaneous recording of electrogastrography reflects gastric mechanical activity. Epigastric leads are superior in recording characteristics than meso-gastric leads, in fasting state, 3.0 cpm waves dominate EGG recording in fasting state. In this study, we analyzed the EGG recording characteristic after feeding in 10 normal subjects. Though the physical changes of gastric shape and volume after feeding, EGG recording was dominated by 3.0 cpm waves. Epigastric leads are still superior in recording characteristics, amplitude of EGG waves and read-abilities, than meso-gastric leads, after feeding. Amplitude of EGG waves increased after feeding when compared to fasting state, suggesting increased mechanical activity of the stomach. We conclude that epigastric leads are suitable in recording of EGG in fasting and in fed state in normal subjects. This position could be most standard recording leads for EGG in clinical settings.

Action Potentials↗

PubMed1990

[Teeth arrangement of anterior artificial teeth. 1. Age and teeth exposure].

In selecting and arranging anterior artificial teeth for edentulous patients, it is necessary to consider their sex, personality, age and other factors. The relation of upper and lower lip lines to incisal edge has been one of the standards for the selection and the arrangement of anterior artificial teeth. The purpose of this report was to establish and to evaluate decision bases for the selection and arrangement. We recorded and measured the exposure rate of anterior natural teeth (48 men, 46 women) during function, such as smile, pronunciation, by means of the image analysis. Following results were obtained. 1. As the age of patients increased, upper anterior teeth appeared less than lower's. 2. Differences in exposure ratio between upper and lower teeth were found more remarkable in smiling rather than in pronunciation.

Adult↗

PubMed1990

[Clinical studies on crevicular fluid of abutment tooth. 3. Effect of tannin-fluoride preparation on gingival health].

It was examined, in this study, whether the tannin-fluoride preparation (HY preparation), which might have a caries reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth for removable partial dentures. Zinc oxide eugenol cement mixed with HY preparation filled in the cavity prepared in the resin base facing the abutment tooth. Crevicular fluid (Periotron unit: GCF), gingival index (GI), plaque index (PII), probing depth and caries activity around the abutment tooth were measured during 12 months. The following results were obtained: 1. GCF decreased at 1 month later and showed low values at 2, 3, 6 and 12 months. 2. The percentage of low GI value showed an increasing tendency during the experimental period. 3. There was slight variation in PII and probing depth during the experimental period. 4. Caries activity showed a decreasing tendency. These results indicate that the tannin-fluoride preparation reduces not only caries activity but also gingival inflammation around abutment tooth.

Dental Abutments↗

PubMed1990

Bacillus stearothermophilus glyceraldehyde-3-phosphate dehydrogenase as a source of angiotensin-converting enzyme inhibitors.

The more potent inhibitory activity against angiotensin-converting enzyme (ACE) was excised from a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) preparation of Bacillus stearothermophilus by heating at 120 degrees C in 1 M AcOH-20 mM HCl, as compared with GAPDH preparations of yeast and pig. Sufficient excision of B. stearothermophilus ACE inhibitors required a longer proteolysis time of 60 min. Two inhibitors were then purified by gel-permeation and reverse-phase chromatographies. One of the B. stearothermophilus ACE inhibitors BG-1, was the GAPDH peptide 68-77 (Gly-Lys-Glu-Ile-Ile-Val-Lys-Ala-Glu-Arg, IC50: 32 microM). Another inhibitor, BG-2 (Gly-Lys-Met-Val-Lys-Val-Val-Ser-Trp-Tyr, IC50: 6 microM), correspond to GAPDH peptide 304-313. These sequences were quite different from those of vertebrate GAPDH peptides and the venom peptide family with ACE inhibitory activity. BG-2 was found to be a non-competitive type inhibitor, differing from many natural peptide inhibitors. Thus, B. stearothermophilus GAPDH seemed to be a good source of new type ACE inhibitors, in addition to the advantages due to its thermophilic property.

Amino Acid Sequence↗

PubMed1990

Clinical application of electric resistance welding and soldering methods to removable partial dentures.

The joining procedure for uniting metal structures is very important in the construction of removable partial dentures. However, it has several restricted problems in joining wrought wire clasps to rests or major connectors. For example, the base metal wires made of chromium-cobalt alloy are subject to changes in their mechanical properties caused by heating, and damage to acrylic resin materials (denture base and artificial teeth) occurs in the repair of removable partial dentures by using the torch soldering method. In this paper, in order to resolve these problems, an electric resistance welding machine was applied to attach wrought wire components to a removable partial denture framework. This welding machine was used to attach metal structures temporarily to each other, and to solder the welded joint with hard solder. Consequently, some problems of the conventional torch soldering method were improved by using the electric resistance welding and soldering methods. It was suggested that the clinical application of the electric welding and soldering methods was very useful in the construction of removable partial dentures.

Aged↗

PubMed1990

[Removable partial dentures applied by electric welding and soldering methods].

The joining procedure for uniting metal structures is very important in the dental clinic, and various kinds of metal joining methods have been performed for clinical application. The conventional torch soldering method using a blow torch has been generally adopted. However, it has several clinical problems, especially in the construction of removable partial dentures. The base metal wires made of a chromium-cobalt alloy are subject to changes in their mechanical properties caused by heating, when wrought wire clasps are joined to rests or frameworks. In addition to the flexibility of wrought wire clasps, damage to acrylic resin denture bases and acrylic resin teeth occurs in the repair of removable partial dentures. In this paper, the electric resistance welding and soldering methods were applied to attach wrought wire components to a removable partial denture framework to resolve the problems of the torch soldering method. As a result, it is suggested that these electric resistance welding and soldering methods have the following advantages, as compared with the conventional torch soldering method. 1. When using this electric resistance welding method, it is possible to fix metals temporarily to each other more securely and strongly than the conventional temporary fixation methods using sticky wax or acrylic resin. 2. The electric resistance soldering method does not require any heat insulation or a partition as the torch soldering method does, because the soldered area is only heated partially. 3. In the case of soldering electrically wrought wire clasps to metal structures such as rests and connectors, there is no fear of of overheating a wide area of wires.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromium Alloys↗

PubMed1990

Clasping system with rotational path of insertion. 2. Relation between mesio-distal distance of edentulous space and retentive force.

The rotational path of insertion differs substantially from the conventional path or perpendicular path of insertion. With a rotational path, one segment of the partial denture is seated first, then the remainder of it is rotated into position. One segment of this system is the rigid retentive component with a long occlusal rest and the other is the conventional clasp. This study examined the influence of mesio-distal distance of the edentulous space, the point of the displacing force, the undercut of rigid retentive component and the inclination of the abutment tooth on the retention of this system. The following results were obtained: 1) Retention of the denture was the lowest when a displacing force was applied at the conventional clasp part under the conditions of mesio-distal distances with edentulous spaces of 10, 20 and 30 mm, respectively. 3) Retention showed a tendency to decrease progressively as the proximal undercut on the rigid retentive component was changed to 2.0, 1.5, 1.0 and 0.5 mm, respectively. The values of the decreasing ratio of retentive forces were almost the same regardless of the mesio-distal distance of the edentulous space. 4) Retention of the denture was improved when a tilted tooth was used as an abutment tooth on the rigid retentive component side.

Dental Clasps↗