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Biomedical subjects

T Okabe

Publications and source records attributed to T Okabe.

At least 289 records · Page 16Linked to original sources
PubMed1990

[An investigation of X-ray examinations classified according to cases of dental diseases at Fukuoka Dental College Hospital].

This paper reports the results of an investigation on the types and frequencies of X-ray examinations given to patients with various types of their dental diseases from their first visit to the hospital to the end of treatment. The subjects were 337 patients (not including orthodontic patients and in-patients) randomly sampled out of all those who visited the Fukuoka Dental College Hospital in 1986. Out of these 337, the number of those who were given X-ray examinations was 284. 1. The Cases of dental diseases for which X-ray examinations were given were classified into the following seven: diseases caused by dental caries, trauma, inflammation, diseases of temporomandibular joint, diseases of salivary gland and other diseases, and other examinations. Out of these X-ray examinations, those given to the patients of diseases caused by dental caries and marginal periodontitis amounted to the 60% of the total X-ray examinations. 2. On the average, 3.3 radiographs were taken per patient. 3. In the examination of luxation, a case of trauma, 7.8 radiographs were taken per patient, the largest number of all diseases on this report. In the examination of marginal periodontitis, a case of inflammation, 5.4 dental radiographs and 0.5 panoramic radiograph were taken per patient. It is necessary to make the most of panoramic examination effective for this disease to decrease radiation exposure. 4. The diseases that have more difficulty of diagnosis and more necessity of observing the prognosis had a greater tendency to depend on X-ray examinations. 5. The percentage of the patients who did not receive X-ray examination was 15.7%. Out of these patients, the patients in pedodontics accounted for 34.5%.

Adolescent↗
PubMed1990

[Quantitative evaluation by measuring affected area for cytotoxicity of dental materials].

The agar overlay method was modified and employed in this study to quantitatively evaluate the cytotoxicity of dental materials. The area of fibroblasts affected by the release of toxic substances from tested materials was determined with an image analysis system in order to compare the relative cytotoxicity of amalgams and composite resins. The cytotoxicity of amalgams decreased by 50% or more with aging time. Zinc appeared to be the major contributor to the cytotoxicity of amalgams. The cytotoxicity of chemically cured composite resins was also reduced with hardening time. However, even after 24 hours, the cytotoxicity of all chemically cured composite resins was still apparent. The cytotoxicity of light cured composite resins was dramatically reduced after illumination with the light source. The cytotoxicity of both amalgams and composite resins was strongly dependent upon their hardening process, since aging and curing produced a more stable material which was less likely to release toxic substances into the culture medium. The technique developed in the present study for measuring the area of affected cells to quantitatively evaluate the cytotoxicity of dental materials is simple and reproducible.

Composite Resins↗
PubMed1990

[Clinical trial of KRN 8601 in patients with neutropenia induced by chemotherapy for lung cancer].

The clinical trial of KRN 8601 was conducted in patients with neutropenia induced by chemotherapy for lung cancer. Thirty-six patients were treated with KRN 8601 subcutaneously for 14 days once daily at the dose of 50 or 100 micrograms/m2, and the effects were compared with the control phase without KRN 8601 treatment. Both the elevation of neutrophil count and shortened period of neutropenia were observed by the administration of KRN 8601. The efficacy rate was 75% (18/24) at 50 micrograms/m2 and 100% (10/10) at 100 micrograms/m2. A side effect observed was fever in one patients, and in 2 patients, abnormal GOT, GPT and LDH elevation were observed in each. We concluded that KRN 8601 was clinically effective and safe at the dose of 50 micrograms/m2 or 100 micrograms/m2 for neutropenia induced by chemotherapy for lung cancer.

Adult↗
PubMed1990

[Growth inhibition of human myeloid leukemia cells in vitro by harringtonine].

Harringtonine was discovered as an anticancer agent in China. It has been shown to be effective against myeloid leukemia. In this report, we have demonstrated that harringtonine inhibited the growth of human myeloid leukemia cells in vitro at low concentrations. Together with the clinical data in which 28% of the patients could be induced into complete remission only by harringtonine, this agent may be used as a first choice of antileukemia agents in the treatment of myeloid leukemia. The mechanism of the antitumor action of harringtonine is considered to be an effect on protein synthesis and is characterized by breakdown of polysomes to monosomes. The mechanism of action appears to be different from those of the other antileukemia agents, such as cyclophosphamide, daunorubicin, vincristine, or cytosine arabinoside. Harringtonine could be added to the other anti-leukemia agents used routinely in treatment of leukemia, and the combination of harringtonine with the other agents is expected to improve the therapy of myeloid leukemia.

Alkaloids↗
PubMed1990

[The use of the panel D-15 test in estimating the convergence points for deuteranopia].

In order to study the deuteranopic convergence points we compared the patterns of the simulated panel D-15 test with the actual data from 73 cases of deuteranopia. It was found that 39 of the 73 cases matched one of the four simulation patterns perfectly while another 25 cases showed similar patterns. Of the 64 cases, 9 cases matched the simulated pattern obtained when the x chromaticity coordinates were between 1.1810 and 1.4319, 42 cases when they were between 1.4320 and 2.2588, 7 cases when they were between 2.2589 and 3.6255 and 6 cases when they were between 3.6256 and 4.6572. These results confirm that there are significant individual differences in the convergence points of deuteranopes and support the theory that the confusion lines meet at a specific point rather than running parallel.

Adolescent↗
PubMed1989

Recombinant human granulocyte colony-stimulating factor as an activator of human granulocytes: potentiation of responses triggered by receptor-mediated agonists and stimulation of C3bi receptor expression and adherence.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) enhanced superoxide release and membrane depolarization in parallel in human granulocytes stimulated by the receptor-mediated agonists, N-formyl-methionyl-leucyl-phenylalanine and wheat germ agglutinin, but not by the Ca2+ ionophore ionomycin and phorbol myristate acetate, which bypass the receptors to stimulate the cells. The optimal effect was obtained by pretreatment of cells with 25 to 50 ng/mL (1.3 to 2.6 nmol/L) rhG-CSF for 10 minutes at 37 degrees C. rhG-CSF produced by bacteria and mammalian cells had identical biological effects on a molar basis. rhG-CSF neither affected stimulus-induced increase in cytoplasmic free Ca2+ nor changed the number and affinity of N-formyl-methionyl-leucyl-phenylalanine receptors. The priming effect of rhG-CSF was temperature dependent and did not require new protein synthesis. rhG-CSF increased the expression of C3bi receptors on human granulocytes and enhanced granulocyte adherence to nylon fiber. The optimal effect was obtained by pretreatment of cells with 25 to 50 ng/mL rhG-CSF for 30 minutes at 37 degrees C. rhG-CSF had no effect on human monocytes. These findings demonstrate that rhG-CSF can selectively stimulate mature granulocyte functions.

Calcium↗
PubMed1989

Paraneoplastic syndrome of hypercalcemia and leukocytosis caused by squamous carcinoma cells (T3M-1) producing parathyroid hormone-related protein, interleukin 1 alpha, and granulocyte colony-stimulating factor.

Previously we reported that a clonal squamous cell carcinoma cell line (T3M-1) derived from a lower jaw cancer of a patient with marked leukocytosis and hypercalcemia produced factors containing a potent bone-resorbing activity (BRA) (Mr 15,000-20,000) and a colony-stimulating activity. To elucidate the pathogenesis of this humoral hypercalcemia, BRA and colony-stimulating activity in both the conditioned medium and cells were characterized. The conditioned medium, when eluted at neutral pH, contained colony-stimulating activity and thymocyte proliferation-stimulating activity, the latter of which comigrated with BRA. Upon elution with acetic acid (pH 2.0), the conditioned medium contained no interleukin 1-like activity but potent parathyroid hormone-like activity, which comigrated with BRA. Northern blot hydridization analysis revealed that T3M-1 cells produced constitutively mRNA for parathyroid hormone-related protein and granulocyte colony-stimulating factor. Furthermore, primer extension analysis revealed that the cells also produced mRNA for interleukin 1 alpha (IL-1 alpha). Since parathyroid hormone-related protein and IL-1 alpha (osteoclast-activating factor) synergistically increase the concentration of serum calcium, and since IL-1 alpha (hemopoietin 1) potentiates granulocyte colony-stimulating factor-induced granulocytopoiesis, we speculate that parathyroid hormone-related protein, granulocyte colony-stimulating factor, and IL-1 alpha are synergistically involved in a paraneoplastic syndrome of hypercalcemia and leukocytosis, at least in some patients with solid tumors.

Animals↗
PubMed1989

Production of salivary type alpha-amylase in human lung cancer.

alpha-Amylase, which is produced by lung cancer tissue, was studied by cloning cDNAs from a cell line originating from lung cancer that produces amylase. Sequencing studies with this cDNA showed that the expressing gene is of the salivary type. The specific location of the start point of transcription, as revealed by S1 mapping, supported this conclusion.

Base Sequence↗
PubMed1989

Tumor necrosis factor as an activator of human granulocytes. Potentiation of the metabolisms triggered by the Ca2+-mobilizing agonists.

TNF stimulated superoxide (O2-) release directly in human granulocytes in a dose-dependent manner (1 to 1000 U/ml), although its potency was weak. TNF-induced O2- release was inhibited by cAMP agonists or ionomycin, and was not accompanied with an increase in cytoplasmic free Ca2+ [( Ca2+]i) and membrane potential changes (depolarization). These findings indicate that neither Ca2+ mobilization nor membrane depolarization is required for TNF-receptor-mediated cell activation. The pretreatment of human granulocytes with TNF enhanced O2- release and membrane depolarization in parallel stimulated by the receptor-mediated Ca2+-mobilizing agonists (FMLP, Con A, and wheat germ agglutinin) or the Ca2+ ionophore ionomycin, but not by PMA, a direct activator of protein kinase C. The optimal effect was obtained by pretreatment of cells with 100 U/ml TNF for 5 to 10 min at 37 degrees C, although the magnitude of enhancement varied according to the agonists used as subsequent stimuli. TNF did not affect an increase in [Ca2+]i stimulated by the Ca2+-mobilizing agonists, except Con A. Con A-induced increase in [Ca2+]i was enhanced by TNF in a dose-dependent manner. These diverse effects of TNF could be partly explained by the exclusive potentiation by TNF of the metabolic events triggered by an increase in [Ca2+]i.

Adjuvants, Immunologic↗
PubMed1989

Treatment of myelodysplastic syndromes with recombinant human granulocyte colony-stimulating factor: a preliminary report.

PURPOSE: The expansion of an abnormal hemopoietic stem cell line is responsible for the myelodysplastic syndromes, which are characterized by pancytopenias, often resulting in lethal infections. Cloned granulocyte colony-stimulating factor (G-CSF) was recently shown to enhance the growth and differentiation of normal granulocyte progenitor cells in vitro. The aim of our study was to examine the effects of recombinant human G-CSF in patients with myelodysplastic syndromes. PATIENTS AND METHODS: Four patients with myelodysplastic syndromes and one patient with smoldering acute myelogenous leukemia following the occurrence of a myelodysplastic syndrome received recombinant human G-CSF by intravenous infusion for six days. Patients received different dosage levels (50 to 1,600 micrograms/m2). RESULTS: A response was seen in all patients, with an increase in both immature myeloid cells in the bone marrow and mature granulocytes in the peripheral blood. The dose levels that could stimulate granulocytopoiesis differed among patients. CONCLUSION: These results suggest that, at least in some cases of myelodysplastic syndromes, granulocytopenia can be improved by G-CSF, although it still remains to be determined whether the increase in the number of granulocytes is due to the differentiation and maturation of the myelodysplastic clone or restoration of a residual normal clone.

Adult↗
PubMed1989

The effect of trituration time on the mechanical properties of four high-copper amalgam alloys.

Several manipulative variables have been shown to influence the physical properties of dental amalgam. Variation in trituration time has been reported to affect creep, compressive strength, and diametral tensile strength in various amalgams. Recent classification of amalgam alloys by particle microstructure reveals four categories: single-composition lathe-cut; single-composition spherical; lathe-cut and eutectic admixture; and lathe-cut and single-composition spherical admixture. The effect of variation of trituration times has not been studied for these newer high-copper alloys. A representative from each classification was selected and physical properties tested, with varied times for trituration utilized. Results showed little compromise in laboratory values for the properties tested. Additional laboratory and clinical trials are warranted, but this study supports the premise that clinicians may vary trituration time to improve handling characteristics without significantly affecting mechanical properties.

Copper↗
PubMed1989

Identification and characterization of receptors for granulocyte colony-stimulating factor on human placenta and trophoblastic cells.

Since radioiodination of human granulocyte colony-stimulating factor (G-CSF) is difficult, we synthesized a mutein of human G-CSF that retains full biological activity and receptor-binding capacity for at least 2 weeks after radioiodination. Receptors for human G-CSF were characterized in the plasma membrane fraction from the human term placenta (human placental membranes) and trophoblastic cells by using the 125I-labeled mutein of human G-CSF (KW-2228). The specific binding of 125I-labeled KW-2228 to placental membranes was pH-dependent, with maximal specific binding at pH 7.8; it increased linearly with protein to 3.7 mg of protein per ml and was both time- and temperature-dependent, with maximal binding at 4 degrees C after a 24-hr incubation. When we examined the ability of hematopoietic growth factors to inhibit 125I-labeled KW-2228 binding, we found that KW-2228 and intact human G-CSF inhibited 125I-labeled KW-2228 binding, whereas erythropoietin or granulocyte-macrophage colony-stimulating factor did not. Scatchard analysis revealed a single receptor type with a Bmax of 210 fmol/mg of protein and a Kd of 480 pM. The human G-CSF receptors on human placental membranes were shown to consist of two molecular species of 150 kDa and 120 kDa that could be specifically cross-linked to 125I-labeled KW-2228. Human trophoblastic cells, T3M-3, also possessed a single receptor for G-CSF with a Bmax of 533 receptors per cell and a Kd of 390 pM. Thus we have identified the receptor for human G-CSF on human placental membranes and trophoblastic cells, and the presence of this receptor in these membranes suggests that human G-CSF plays some role in the feto-placental unit during human development.

Binding, Competitive↗
PubMed1989

Combined effects of differentiation-inducing factor and other cytokines on induction of differentiation of mouse myeloid leukemic cells.

Mouse myeloid leukemic M1 cells are induced to differentiate into macrophage-like cells by differentiation-inducing factors (D-factors) and granulocyte colony-stimulating factor. We examined the effects of recombinant human tumor necrosis factor (rTNF), lymphotoxin (rLT) and interleukin 1 (rIL-1) on the induction of differentiation of M1 cells, compared with the effects of D-factor purified from the conditioned medium of mouse Ehrlich ascites tumor cells and recombinant human granulocyte colony-stimulating factor (rG-CSF). rIL-1 induced phagocytic activity, a typical marker of cell differentiation, in at most 30% of M1 cells at concentrations ranging from 10(-10) M to 10(-7) M. The differentiation-inducing activity of rIL-1 was similar to that of rG-CSF and less than that of D-factor. rTNF induced phagocytic activity in 14% of M1 cells only at a high concentration (10(-7) M). rLT did not induce differentiation of the cells even at 10(-7) M. rTNF stimulated induction of differentiation of M1 cells by D-factor, rG-CSF or rIL-1 by two or three fold. The combination of any two of the cytokines D-factor, rG-CSF and rIL-1 induced differentiation of M1 cells more efficiently than any of these cytokines alone. Moreover, the combination of three cytokines rG-CSF, rIL-1 and rTNF, all of which are known to be produced by macrophages, was more effective than the combination of any two of these cytokines in induction of differentiation of M1 cells.

Animals↗
PubMed1989

Dopaminergic instability in children with orthostatic dysregulation.

Effects of postural change on plasma catecholamine levels were examined in 53 children with orthostatic dysregulation (OD). Special interest was focused on plasma dopamine and dopamine-beta-hydroxylase (DBH) activity, since one patient showed a prominent rise in plasma dopamine from 822 pmol/L to 126 nmol/L in postural change. She had a wide fluctuation of plasma dopamine from 209 pmol/L to 305 nmol/L during 12 hours of observation period, but plasma norepinephrine and epinephrine remained within the normal range as well as urinary excretion of catecholamines. Of 52 children with OD, 11 had a marked increase in plasma dopamine, whereas 11 showed a reduction of it by postural change. Plasma DBH activity was significantly decreased in the former (81 +/- 14 nmol/h/ml), while it was elevated in the latter (320 +/- 48 nmol/h/ml, P less than 0.001 vs the former), although DBH activity in individuals was not affected by postural change. These results indicate the involvement of dopaminergic instability as a cause of OD in childhood.

Adolescent↗
PubMed1989

Occurrence and distribution of Vibrio spp., Listonella spp., and Clostridium botulinum in the Seto Inland Sea of Japan.

The distribution of Vibrio species in samples of surface water, bottom water (water 2 m above the sediment), and sediment from the Seto Inland Sea was studied. A simple technique using a membrane filter and short preenrichment in alkaline peptone water was developed to resuscitate the injured cells, followed by plating them onto TCBS agar. In addition, a survey was conducted to determine the incidence of Clostridium botulinum in sediment samples. Large populations of heterotrophs were found in surface water, whereas large numbers of total vibrios were found in bottom water. In samples from various water sampling regions, high counts of all bacterial populations were found in the inner regions having little exchange of seawater when compared with those of the open region of the inland sea. In the identification of 463 isolates, 23 Vibrio spp. and 2 Listonella spp. were observed. V. harveyi was prevalent among the members of the Vibrio genus. Vibrio species were categorized into six groups; an estimated 20% of these species were in the so-called "pathogenic to humans" group. In addition, a significant proportion of this group was hemolytic and found in the Bisan Seto region. V. vulnificus, V. fluvialis, and V. cholerae non-O1 predominated in the constricted area of the inland sea, which is eutrophic as a result of riverine influence. It was concluded that salinity indirectly governs the distribution of total vibrios and analysis of variance revealed that all bacterial populations were distributed homogeneously and the variance values were found to be significant in some water sampling regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1989

Isolation, purification, and characterization of fragment B, the NH2-terminal half of the heavy chain of tetanus toxin.

Fragment B, the N-terminal half of the heavy chain, an important domain of the tetanus neurotoxin molecule, was isolated for the first time. Tetanus toxin (composed of three domains, A, B, and C) was prepared from culture filtrates. Fragment A-B, derived from the toxin treated mildly with papain, was used for the isolation of fragment B. Fragment A-B obtained was dissociated into fragments A and B by reduction with 100 mM dithiothreitol and treatment with 2 M urea. Fragment B was separated from fragment A by ion-exchange column chromatography on a Mono Q column equilibrated with 20 mM Tris hydrochloride buffer (pH 7.6), containing 1 mM dithiothreitol and 2 M urea, in a fast-protein liquid chromatography system by elution with a linear gradient of 0 to 0.5 M NaCl. Fragment B was obtained in two forms having molecular weights of 48,000 +/- 2,000, which were indistinguishable by sodium dodecyl sulfate-gel electrophoresis or antigenic specificity, but distinguishable on polyacrylamide gel electrophoresis without sodium dodecyl sulfate and on isoelectric focusing (pI 6.7 and 7.3). The recovery of fragment B was 50 to 72% of that of fragment A-B on a molar basis. Purified fragment B was not toxic to mice on intravenous or intramuscular injection at doses of up to 100 micrograms, but was found to form channels (ca. 2.3 pS) in a lipid bilayer membrane by a patch clamp technique. The role of domain B of the tetanus toxin molecule in the mechanism of action of the toxin is discussed.

Amino Acid Sequence↗
PubMed1989

Synthesis of thyrotropin-releasing hormone-related peptides using N alpha-tert-butyloxycarbonyl-omega-(N-tert-butyloxycarbonylcarbamoyl)- alpha-amino acids.

Application of N alpha,Nca-di-tert-butyloxycarbonylhomoglutamine to synthesis of thyrotropin-releasing hormone (TRH) analogs was examined. The delta-lactam formation from homoglutaminylpeptides took place more easily than gamma-lactam formation from glutaminylpeptides in water or dioxane containing acetic acid. [pHgu1,Nva2]-TRH had dose-dependent antagonistic activity against pentobarbital anesthesia in mice, but almost no binding activity to TRH receptor in rat brain.

Amino Acids↗