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Biomedical subjects

J Tsukada

Publications and source records attributed to J Tsukada.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Clinical significance of determination of serum RNase activities in patients with eosinophilia--II. Measurements using polyuridylic acid and polycytidylic acid as substrates].

The activities of RNase (RNase-U and RNase-C) were determined in the serum and leukocytes of 277 patients with 14 cases of various kinds of eosinophilia (not less than 10(3)/microliters), 28 cases of chronic myelocytic leukemia (CML), using polyuridylic acid and polycytidylic acid as synthetic substrates according to the method of Raddi et al. Serum RNase-U activity, serum RNase-C activity and the activity ratio (U/C x 10(-3)) were 55 +/- 14 U, 1,280 +/- 235 U and 44 +/- 11 (mean +/- SD), 196 +/- 137, 1,992 +/- 1,134 U and 97 +/- 38, and 110 +/- 50 U, 1,854 +/- 625 U and 65 +/- 13 for normal subjects, eosinophilia and CML (untreated), respectively. U/C ratio in eosinophilia and CML (untreated) showed a highly significant positive correlation (p less than 0.001) with peripheral eosinophil count; the activity of serum RNase-U per cells in the supernatant of eosinophil homogenate rose significantly (p less than 0.001) compared with that of lymphocytes or granulocytes. Besides, serum and eosinophil RNase-U had a similar optimal pH. These results suggested that serum RNase-U in eosinophilia originated mostly from eosinophils and its rise was correlated strongly with the increase in eosinophils.

Clinical Enzyme Tests↗
PubMed1989

Effect of recombinant human interleukin 3, granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor on human BFU-e in serum-free cultures.

The effects of recombinant human hemopoietic growth factors on early and late human erythroid progenitors (BFU-e and CFU-e) were investigated in serum-free cultures. Recombinant human erythropoietin (rhEpo) induced the formation of not only human CFU-e-derived colonies but also human BFU-e-derived bursts. Recombinant human interleukin 3 (rhIL-3) alone did not induce the formation of human BFU-e-derived bursts and human CFU-e-derived colonies. In the presence of rhEpo, rhIL-3 dose dependently increased the number of bursts stimulated by rhEpo, although rhIL-3 did not have the augmentative effect on human CFU-e growth. On the other hand, rhIL-3 did not stimulate the formation of murine BFU-e-derived bursts, and murine IL-3 did not stimulate the formation of human BFU-e-derived bursts. The results indicated that the burst-promoting activity of IL-3 was species-specific between human and murine cells. Recombinant human GM-CSF (rhGM-CSF) or recombinant human G-CSF (rhG-CSF) failed to induce human burst formation and did not augment the effect of rhEpo on human burst formation. The results of the present study suggest that in vitro, IL-3 can stimulate BFU-e in collaboration with Epo, but GM-CSF and G-CSF do not stimulate BFU-e growth in the presence or absence of Epo.

Animals↗
PubMed1989

[Successful treatment with a small dose of N4-behenoyl-1-beta-D-arabinofuranosylcytosine in a case of chronic myelomonocytic leukemia in blastic crisis].

A 56-year-old female was admitted for the examination of leukocytosis in May, 1982. The hematological examination showed hemoglobin 12.0g/dl, platelets 14.5 X 10(4)/microliters and leukocytes 18,000/microliters with 28% of monocytes. A bone marrow aspiration revealed granulocytic hyperplasia. Granulocytes showed nuclear abnormalities, such as folding or lobulation. From these data, a diagnosis of chronic myelomonocytic leukemia (CMMoL) was made and followed with no treatment for 2 years. However, fever, bone pain, anemia, thrombocytopenia and the increase of monoblasts in the peripheral blood and bone marrow were observed in May, 1984. These findings indicated that she was in the blastic phase. She was treated by intensive combination chemotherapy (BHAC-AMP), but did not attain any remission. Therefore, a small dose of N4-behenoyl-1-beta-D-arabinofuranosylcytosine (BH-AC; 1 mg/kg/day) was administered for 70 days. As a result, complete remission was obtained and continued for 37 months with the same therapy. The experience of this case suggests that small dose of BH-AC could be applied to a case of CMMoL in blastic crisis.

Antineoplastic Agents↗
PubMed1989

[Changes in serum RNase activities in chronic phase and acute crisis of chronic myelocytic leukemia].

We investigated serum acid and alkaline RNase activities in 16 cases of acute crisis of chronic myelocytic leukemia (CML), 21 cases of untreated CML, and 13 cases of treated CML, to clarify clinical significance of the determination of RNase activities in acute crisis of CML. We obtained results as follows; the ratio of acid to alkaline Rnase activities (Ac/Al ratio) of chronic phase of CML was 1.64 +/- 0.47 (mean +/- SD) in the untreated cases, and was 1.32 +/- 0.16 in the treated cases. The Ac/Al ratio always indicated over 1.0 in the chronic phase of CML without any relationship to treatments. On the other hand, in the cases of acute crisis, the Ac/Al ratio was significantly lowered (0.94 +/- 0.22) as compared to the chronic phase of CML (p less than 0.001), and was similar to that of acute leukemia. The acid and alkaline RNase activities of the blast from the patients with acute crisis of CML showed remarkably lower value than those of leukemic cells from patients with chronic phase of CML. Therefore, it was Suggested that the return to normal range of Ac/Al ratio in acute crisis of CML depended on marked decrease of RNase activities of blasts. Thus, serial determinations of the enzyme activities are considered to be one of useful tools for prediction of acute crisis of CML.

Adult↗
PubMed1988

[The effect of purified mouse GM-CSF on CFU-C colony growth in serum-free cultures].

We investigated the effect of the ingredients in serum-free cultures, in which serum was completely replaced by albumin, cholesterol and transferrin, on the growth of murine granulocyte/macrophage progenitor cells (colony forming unit in culture: CFU-C) stimulated by serum-free PWM-SCM and the influences of purified granulocyte-macrophage colony stimulating factor (GM-CSF) in serum-free cultures. The results were as follows: 1) The number of CFU-C colonies reached a peak after 4 days of incubation. 2) A linear relationship was observed between the number of CFU-C colonies and the number of inoculated bone marrow cells. 3) Serum-free cultures could support CFU-C colony growth to the same degree as that in serum-containing cultures. Also, no significant differences were found in the types of colonies grown in both cultures. 4) Bovine serum albumin (BSA) and cholesterol were considered to play the most important roles among the ingredients in serum-free cultures. 5) Purified GM-CSF supported CFU-C colony growth in serum-free cultures and more than a half of the colonies formed were GM-colonies. These results showed the usefulness of our serum-free cultures for studying the granulopoiesis in vitro without the influences of various substances in the serum.

Animals↗
PubMed1987

The effect of recombinant erythropoietin on murine megakaryocyte colony formation.

We investigated the effect of a recombinant human erythropoietin preparation (recombinant Epo) on murine megakaryocyte (MK) colony formation in serum-free and serum-containing culture systems, in order to study the relationship between Epo and megakaryopoiesis. Pokeweed mitogen spleen-conditioned medium (PWM-SCM), a standard source of MK colony stimulator, dose-dependently stimulated MK colony formation in the two culture systems. The plating efficiency of serum-free cultures was almost equal to that of cultures containing serum. Recombinant Epo also dose dependently stimulated MK colony formation in serum-containing cultures. However, in serum-free cultures recombinant Epo alone did not stimulate the growth of MK colonies; with the addition of fetal calf serum (FCS) to the serum-free cultures, recombinant Epo induced the growth of MK colonies. Furthermore, recombinant Epo enhanced MK colony formation through the stimulation of PWM-SCM or murine interleukin 3 (IL-3) in serum-free cultures. Our data show that Epo can act as a stimulator of megakaryopoiesis in collaboration with a factor in serum, or with an MK colony stimulator such as IL-3.

Animals↗
PubMed1987

Optimal preprocessing Butterworth-Wiener filter for Tl-201 myocardial SPECT.

The optimal frequency characteristic of Butterworth-Wiener filters (BWF) for improving the image quality of 201Tl myocardial SPECT was determined by a phantom experiment. Thirty two projection images of the phantom containing 11.1 MBq of 201Tl with 4 different cold lesions were collected during a 180 degree arc of a gamma camera. A set of the projection images were processed with each of 27 different BWFs, and SPECT images were reconstructed by Shepp-Logan filtered backprojection. The SPECT images were evaluated for their diagnostic ability to visibly detect the cold lesions by four nuclear medicine physicians. The lesion contrasts were used as an adjunctive tool to determine the optimum filter. The optimal combination of the parameters determining BWF characteristics (for the data of about 100 count/pixel at the myocardium) is: 1) cutoff of 0.25/pixel, 2) FWHM of 3 pixels, 3) noise/signal ratio of 0.02. FWHM and noise/signal ratio affected lesion contrast much less than cutoff frequency. Clinical myocardial SPECT images processed with the optimal BWF showed less noise and sharper delineation of the myocardium.

Filtration↗
PubMed1986

[Basic studies on colony formation of erythroid progenitor cells].

Fundamental studies on CFU-E colony formation were done using bone marrow cells of mice by the methylcellulose culture method. The number of CFU-E colonies reached a peak after 48 hours of incubation. A linear relationship was observed between the number of CFU-E colonies and the number of inoculated bone marrow cells. The number of CFU-E colonies increased dependently on the concentration of erythropoietin (Epo) and reached almost a plateau above 0.25 U/ml. There was little difference in the CFU-E colony forming activity of the two sources of Epo (one partially purified from human urine at our laboratory and the other obtained from Connaught Laboratories Ltd. as Step III derived from plasma of anemic sheep). There was little difference in the number of marrow CFU-E of two strains of mice (ddY and BDF1). The best conditions in the concentration of culture medium were 10-30% in FCS, 0.5-1.0% in BSA, 10(-4) M in 2-mercaptoethanol, respectively. These observations are thought to be useful for the development of studies on CFU-E.

Animals↗
PubMed1986

Effect of absolute and relative changes of hematocrit on erythropoiesis in mice.

The serial changes of peripheral reticulocytes and marrow erythroid progenitor cells (CFU-e) in mice were monitored under the conditions of absolute or relative changes in red cell mass to study the regulatory mechanism of erythropoiesis. A decreased number of marrow CFU-e and peripheral reticulocytes was observed in the mice with relative polycythemia induced by dehydration as well as in the mice with absolute polycythemia induced by hypertransfusion. On the other hand, a transient increase in the number of marrow CFU-e followed by a gradual increase in the number of peripheral reticulocytes was seen after a considerable amount of exsanguination. Similar stimulatory effects on marrow CFU-e were also observed either by rehydrating the dehydrated mice or by overhydrating the untreated mice to relatively decrease the level of hematocrit. The results suggested that in addition to factors relating to the balance between oxygen supply and requirement, which has been well known, erythropoiesis is greatly affected by hematocrit.

Animals↗
PubMed1986

[The study of a two-dimensional polar representation of the cardiac SPECT image--a new method of displaying left ventricular wall motion].

A new method was developed to display left ventricular wall motion using two dimensional polar representation of cardiac SPECT image. After intravenous administration of 740 MBq (20 mCi) 99mTc (in vivo labeling of red blood cell), ECG-gated SPECT image of cardiac pool was recorded (32 directions, 180 degrees). The short axis images of left ventricle were constructed at end-diastole (ED) and end-systole (ES). Then the functional images of (ED-ES)/ED were calculated at each compatible slices and displayed in color according the degree of wall motion. In 8 cases with cardiac diseases this method was applied and clinically useful functional images could be obtained. The area of akinesia or hypokinesia are successfully demonstrated clearly separated from the area of normokinesia. We conclude that this method is useful to show left ventricular wall motion and to evaluate the segment and grade of abnormal wall motion of left ventricle.

Adult↗