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Biomedical subjects

M Eguchi

Publications and source records attributed to M Eguchi.

At least 199 records · Page 11Linked to original sources
PubMed1987

Cinemicrography of human erythroblasts--direct measurement of generation time and delineation of their pedigrees.

To clarify the mode of erythropoiesis, the in vitro proliferation of single human erythroblasts was recorded continuously for 80 hours by time-lapse, phase-contrast cinemicrography. Progenies from single erythroblasts were followed, their pedigrees were delineated, and their generation times were measured by counting the frames of the film. In one erythroblast pedigree, a daughter cell continued to divide three times to yield eight smaller erythroblasts; another daughter cell yielded four progenies, three of which abruptly lost most of their cytoplasm and became immobile. The generation time ranged from 15.8-30.0 hours (mean +/- SD: 23.3 +/- 4.8 hours), which corresponded to generation times calculated from in vivo data, such as the mitotic index, isotope labeling, or red cell turnover. Paired daughter cells showed very similar generation times. During succeeding mitoses, erythroblast size and nucleus/cytoplasma ratio decreased, cytoplasm darkened, and cell movement became more prominent. These studies on clonal cell proliferation using cinemicrography provide considerable information on the mechanism of hemopoiesis.

Cells, Cultured↗
PubMed1986

Quantitative evaluation of leukemic mitochondria with a computer-controlled image analyzer.

Mitochondria from 25 patients with acute lymphoblastic leukemia (ALL) and 25 patients with acute myelogenous leukemia (AML) were compared in terms of their number, area, and shape index using a computer-controlled image analyzer. The number of mitochondria was greater in the AML than in the ALL patients. However, their size, as measured in electron micrographic profiles was similar in the two groups, in disagreement with conventional reports that mitochondria are small in granulocytes but large in lymphocytes. Two ALL patients had giant mitochondria. The mitochondria of the ALL cells were more irregular than those of the AML cells, and furthermore, within the ALL group, the degree of the irregularity was greater in those with a poor prognosis than in those in longstanding remission. The number of mitochondria was significantly greater in B-cell ALL than in null cell and T-cell ALL.

Bone Marrow↗
PubMed1986

Myeloid and erythroid lineage expression of haemopoietic progenitors derived from an abnormal clone in erythroleukaemia.

To clarify the lineage involvement of haemopoietic progenitor cells in erythroleukaemia, the morphology and chromosomes of single colonies from a patient with erythroleukaemia were analysed simultaneously. The cytogenetic analysis of bone marrow cells revealed two clones; 44,XY,-7,-12,-17, del (5)(q31), +Mar and 43,XY,-7,-12,-17,-19,del(5)(q31),+Mar. Of 40 metaphases examined, there were 34 and six of these clones, respectively. Bone marrow mononuclear cells were plated at 5 X 10(4)/ml in methylcellulose medium containing phytohaemagglutinin-stimulated leucocyte conditioned medium and erythropoietin. Seventeen colonies, i.e. nine blast cell colonies, four myeloid (Sudan black B-positive) colonies, and four erythroid (benzidine-positive) colonies contained analysable metaphases, yielding 102 metaphases in total. Except for chromosome random loss, the karyotype within a colony remained constant. All three types of colonies showed an abnormal clone; 44,XY,-7,-12,-17,del(5)(q31),+Mar. From these findings, it is concluded that myeloid and erythroid lineages in erythroleukaemia were derived from the same abnormal clone.

Aged↗
PubMed1986

Megakaryocytopoiesis in vitro of patients with essential thrombocythaemia: effect of plasma and serum on megakaryocytic colony formation.

To clarify the mechanism of increased numbers of megakaryocytes in patients with essential thrombocythaemia (ET), we studied in vitro megakaryocytopoiesis in ET and other myeloproliferative disorders, using a megakaryocytic colony assay in methylcellulose containing plasma or serum and medium conditioned by phytohaemagglutinin (PHA) stimulated leucocytes (PHA-LCM). Megakaryocytic colony formation was supported well by heparinized or citrated plasma and citrated serum which was harvested after clot formation of citrated plasma. Whole serum was inhibitory for megakaryocytic colony growth. The addition of platelet releasates and partially purified platelet derived growth factor (PDGF) resulted in a decrease in the number of megakaryocytic colonies. These findings suggested that platelet-derived factor(s) in serum was inhibitory to megakaryocytic colony formation. ET plasma supported the megakaryocytic colony formation by normal or ET bone marrow cells better than normal plasma. Moreover, in ET bone marrow cells, spontaneous megakaryocytic colonies were formed in the absence of PHA-LCM. Increased megakaryocytopoiesis in ET may be ascribed to (i) increased megakaryocyte-colony stimulating activity (Meg-CSA) in plasma and (ii) increased sensitivity to Meg-CSA or autonomous proliferation of megakaryocytic progenitor cells.

Adult↗
PubMed1986

Ultrastructural evaluation of periodate-reactive glycoconjugates in human leukaemia cells.

Periodate-reactive glycoconjugates in human leukaemic cells were examined electron microscopically by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method. Granules in ALL cells were classified into 4 types based on PA-TCH-SP staining features. Abnormal granules containing glycogen were observed only in children with treatment-resistant ALL. Cytoplasmic granules in leukaemic cells of patients with AML and acute monocytic leukaemia exhibited moderate reactivity. The distribution pattern of glycogen in the cytoplasm of leukaemic cells was classified into 3 types, one lacking glycogen, one containing small glycogen particles scattered throughout cytoplasm, and one showing clusters of glycogen particles. Cells with glycogen clusters were observed in ALL cells and in erythroblasts from patients with erythroleukaemia. PA-TCH-SP reactivity was detected in the rough endoplasmic reticulum in acute promyelocytic leukaemia but not in ALL or other types of AML. Megakaryoblasts in megakaryocytic crisis of chronic myelogenous leukaemia exhibited characteristic PA-TCH-SP reactivity similar to that of normal megakaryocytes.

Bone Marrow↗
PubMed1986

The calcium antagonist diltiazem inhibits calcification enhanced by calcitonin in growth cartilage of rats in ethane-1-hydroxy-1,1-diphosphonate (EHDP)-induced rickets.

In an animal model of human rickets developed by giving a short-term administration of large doses of EHDP to young rats, concomitant administration of [Asu1,7]eel calcitonin (CT) with EHDP resulted in the promotion of calcification in growth cartilage. In an attempt to clarify the mechanisms related to the accelerated calcification due to CT, the effects of diltiazem, a calcium antagonist, were studied. Diltiazem suppressed, in a dose-dependent manner, the accelerated calcification due to CT in the growth cartilage, as determined by findings on the soft X-ray photos, contact microradiograph and light microscopic histology of the proximal region of the tibia. This suppression was only evident when diltiazem and CT were given concomitantly. If it is assumed that diltiazem inhibits the entry of calcium ion into the cells of growth cartilage, in the same manner as seen in case of smooth muscle and myocardial cells, then our results indicate that intracellular concentrations of calcium might play an important role in the occurrence of accelerated calcification due to CT.

Animals↗
PubMed1986

Infantile hypertrophic cardiomyopathy with QT prolongation.

An infant who died at 5 months with hypertrophic cardiomyopathy accompanied by QT prolongation was examined at autopsy. At the age of 16 days, serum IgM level was elevated (226 mg/dl). Microscopic examination revealed characteristics of hypertrophic cardiomyopathy with myocardial cell hypertrophy with disarray and healed myocarditis with patchy fibrosis and mononuclear cell infiltration. The histological findings were compatible with those of postmyocarditic cardiomegaly developing during the fetal period.

Arrhythmias, Cardiac↗
PubMed1986

[Studies on antimicrobial concentration of clindamycin phosphate in serum, pelvic dead space exudate, and pelvic organs/tissues].

In women undergoing radical and total abdominal hysterectomy, clindamycin phosphate (CLDM-P) in a dose of 1,200 mg was administered by intravenous drip infusion over 1 hour and the drug concentrations in serum and pelvic dead space exudate, as well as pelvic organs/tissues, were determined over time. The following results were obtained: The serum concentration of clindamycin (CLDM) after intravenous infusion showed the peak value of 24.54 +/- 7.02 micrograms/ml at the end of infusion and then gradually decreased to 3.87 +/- 0.70 micrograms/ml in 6 hours. Concentration in pelvic dead space exudate, which was 2.82 +/- 3.90 micrograms/ml at the end of intravenous infusion, gradually increased to the peak value of 13.49 +/- 6.62 micrograms/ml in 1 hour. Two hours after infusion, the level of 12.43 +/- 5.56 micrograms/ml outstripped serum concentration. Continuously in excess of serum concentration, the exudate concentration gradually decreased to 6.65 +/- 2.27 micrograms/ml at 6 hours after infusion. Cubital venous serum concentration (16.36 +/- 3.68 micrograms/ml) was almost equal to uterine arterial serum concentration (16.36 +/- 4.05 micrograms/ml) of CLDM at uterine removal. In the pelvic organ/tissue concentrations, 15.71 +/- 3.86 micrograms/g in endometrium was highest, followed by 15.19 +/- 3.80 micrograms/g in oviduct, 14.80 +/- 3.52 micrograms/g in myometrium, 14.74 +/- 4.02 micrograms/g in ovary, 14.09 +/- 2.90 micrograms/g in portio vaginalis. The concentration was lowest (11.49 +/- 1.44 micrograms/g) in cervix uteri. Clinically, combined treatment with CLDM-P and ceftizoxime was excellently effective for endometritis induced by P. asaccharolyticus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Ultrastructural and ultracytochemical identification of the small granules in basophils from human and animals.

The small granules in the basophils obtained from humans and animals were compared ultrastructurally and cytochemically. Cytochemically, there were no qualitative differences among the small granules in the species examined. The small granules in humans, guinea pigs and rabbits were approximately 0.16-0.22 micron, 0.15-0.17 micron, and 0.12-0.16 micron, in diameter, respectively. In all species small granules had a single unit membrane and contained some amorphous material. In immature cells many of the small granules were distributed near the Golgi apparatus, while in the mature cells many of them were found around the periphery of the cell. There were no morphological or cytochemical differences between the small granules of the immature cells and those of the mature cells. The negative reaction in the dialysed iron and high iron diamine methods showed that the small granules did not have acid mucopolysaccharides or sulfated glycoconjugates. The strong reaction of the small granules of all species to the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) test, which was especially prominent in rabbit, showed that the small granules have many periodate-reactive neutral glycoconjugates but no acidic glycoconjugates. Enzyme cytochemistry revealed that the small granules are negative for peroxidase and catalase but positive for acid phosphatase.

Acid Phosphatase↗
PubMed1985

Ultrastructural cytochemistry of glycoconjugates in basophils from humans and animals.

The distribution of glycoconjugates in the basophil granules of humans, guinea pigs, and rabbits was compared. The observation of acid mucopolysaccharides using the dialyzed iron method and of sulfated glycoconjugates using the high iron diamine method revealed three types of reactions in the basophil granules of all three species: granules showing a strong overall reaction, granules showing reaction only at their periphery, and granules showing no reaction. With regard to the relationship between maturation and the types of basophil granules, it appeared that, in general, there were many type-1 granules among immature basophils, but that these granules decreased in mature basophils as type-3 granules increased. The reaction patterns of periodate-reactive neutral glycoconjugates, as shown by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method, were different from those of acid mucopolysaccharides: the reaction of basophil granules was diffusely positive, and localization at the periphery was rarely observed. Therefore, unlike the acid mucopolysaccharides, it was difficult to classify the glycoconjugates into three types. However, as with acid mucopolysaccharides, there was a tendency for periodate-reactive glycoconjugates to decrease as maturation progressed. In terms of different species of animals, the reaction of periodate-reactive glycoconjugates with PA-TCH-SP was stronger in humans and rabbits than in guinea pigs.

Animals↗
PubMed1985

Purification and characterization of membrane-bound alkaline proteases from midgut tissue of the silkworm, Bombyx mori.

Membrane-bound alkaline proteases from the midgut epithelia of the silkworm, Bombyx mori, were solubilized with 1% Lubrol-WX, at pH 11.2. They were purified by gel filtration on Sepharose 6B and Ultrogel AcA-202 columns and a preparative polyacrylamide gel electrophoresis. Two proteases, caseinolytic (6B3-Tc) and benzoyl-arginine-p-nitroanilide-lytic (6B3-Tb) were obtained. Both enzymes were homogeneous as judged by polyacrylamide electrophoresis. These enzymes showed high pH optima, 11.2, and pI values, above 11, and were extremely stable over a wide range of pH. The Km values for 6B3-Tb and Tc were 0.476 mM and 2.5 mg/ml respectively. Hammarsten casein and mulberry leaf protein were rapidly hydrolyzed by Tc, whereas the hydrolytic activity of Tb for Azocoll was higher than that of Tc. The protease Tb was strongly inhibited by diisopropylfluorophosphate, p-chloromercuribenzoate, benzamidine, leupeptin, and soybean trypsin inhibitor; Tc was inhibited by diisopropylfluorophosphate, tosyl phenylalanine chloromethylketone and chymostatin, but not by tosyl lysine chloromethylketone, p-chloromercuribenzoate, or iodoacetamide. The molecular weights of the proteases were estimated to be 12,800 (Tb) and 13,300 (Tc) by Sephacryl S-300 gel filtration. The amino acid analyses showed that both proteases contain a large number of acidic amino acids but a relatively small number of basic amino acids.

Amino Acids↗
PubMed1985

Clonal analysis of basophil differentiation in bone marrow cultures from a Down's syndrome patient with megakaryoblastic leukemia.

We present the in vitro differentiation of marrow cells from a patient with Down's syndrome accompanied by megakaryoblastic leukemia into basophils in the presence of phytohemagglutinin-stimulated leukocyte conditioned medium, using a liquid culture and methylcellulose culture system. Identification of basophils was established by metachromatic staining with toluidine blue, transmission electron microscopy, and the presence of histamine. However, these basophils did not release histamine in response to calcium ionophore or chemotactic peptide. Samples from suspension cultures that contained 90% basophils showed chromosomal markers characteristic of leukemic cells (48, XY, +11, +21, t(1;15)) in all examined mitoses. The cellular composition of leukemic colonies grown in methylcellulose culture from single cells was studied using the micromanipulation technique. High plating efficiency and extreme predominance of basophil colonies were observed. In a total 137 cultures, 79 revealed colony growth. Of 59 colonies that were analyzed by cytologic examination, 46 were pure basophil colonies. These basophil colonies showed disperse morphology, similar to that of a normal basophil colony. The clonality of the basophil colonies and skewing of lineage expression were documented from leukemic single-cell cultures. These data showed that leukemic cells have the capacity for differentiation into some lineages that are not expressed in vivo.

Basophils↗