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Biomedical subjects

M Yasunaga

Publications and source records attributed to M Yasunaga.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Detection of mRNA in megakaryocytes using in situ hybridization].

The usefulness of in situ hybridization for detecting mRNA encoding various kinds of proteins in megakaryocytic cell lines (K562, HEL and CMK) was examined. Using in situ hybridization, glycoprotein (GP) IIIa mRNA was found to be present in K562, HEL and CMK cells. Both GPIb and GPIIb mRNA were also present in HEL and CMK cells, while only HEL cells expressed platelet factor 4 mRNA. These findings were identical to those obtained with Northern blotting. It should be emphasized that in situ hybridization was useful to clearly define each cell expressing platelet specific protein mRNA. The expression of interleukin-6 (IL-6) and IL-6 receptor mRNA in mononuclear cells prepared from bone marrow aspirates was examined. In situ hybridization study demonstrated the presence of IL-6 receptor mRNA in the recognized megakaryocytes only, while IL-6 mRNA was found to be present in the megakaryocytes and a few mononuclear cells. These findings suggest that differentiation and proliferation of normal megakaryocytes might be controlled by an IL-6 autocrine loop, and detection of IL-6 receptor mRNA might be useful to identify megakaryocytes.

Blotting, Northern↗
PubMed1992

Induction of smg p21/rap1A p21/krev-1 p21 gene expression during phorbol ester-induced differentiation of a human megakaryocytic leukemia cell line.

smg p21A and -B (smg p21s) are ras p21-like small GTP-binding proteins (G proteins) with the same putative effector domain as ras p21s. Both smg p21A mRNA and smg p21B mRNA were detected in CMK, a human megakaryocytic leukemia cell line, and their levels were markedly elevated by treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which caused the differentiation of this cell line into more mature megakaryocytes. The smg p21 protein molecules also increased during the TPA-induced differentiation of CMK cells. The mRNA level of glycoprotein IIb (GPIIb), a typical marker of the megakaryocytes, was increased by this treatment, but the time course of the increase in the smg p21 mRNA levels as more rapid than that of the increase in the GPIIb mRNA level. Ha-ras p21 mRNA was undetectable, but both Ki- and N-ras p21 mRNAs were detected in CMK cells and their levels were also increased during TPA-induced differentiation of CMK cells, although to a lesser extent than those of smg p21 mRNAs. Protein kinase C inhibitors inhibited the basal and TPA-induced smg p21A mRNA level, but cyclic AMP-elevating prostaglandin E1 or Ca(2+)-mobilizing ionomycin did not inhibit them. Cycloheximide enhanced the basal and TPA-induced smg p21A mRNA levels. Actinomycin D blocked the TPA-induced smg p21A mRNA levels, but showed no detectable effect on the elevated smg p21A mRNA level which was induced by pretreatment with TPA. A dramatic increase in the smg p21 mRNA levels was also observed in other leukemia cell lines during TPA-induced differentiation. These results suggest that TPA stimulated expression of the smg p21A gene, presumably through the action of protein kinase C at the transcriptional level rather than at the post-transcriptional level, in hematopoietic leukemia cells.

Alprostadil↗
PubMed1992

[Mean platelet volume in diabetics].

Platelet size is a determinant of platelet function. As platelet size in diabetics has been reported to be larger than normals, we have measured mean platelet volume (MPV) in diabetics simultaneously with fasting plasma glucose, fructosamine, and hemoglobin A1. MPV was positively correlated with fasting plasma glucose and fructosamine. In a sequential observations for a few months of 22 patients, all of whom showed decreasing fasting plasma glucose, MPV decreased in 10 patients, however, increased in only 2 patients. These findings suggest that MPV would be affected with diabetic control.

Blood Glucose↗
PubMed1992

[Analysis of the GPIIb and GPIIIa genes in patients with Glanzmann's thrombasthenia].

Glanzmann's thrombasthenia (GT) is an autosomal recessive bleeding disorder due to a deficiency or abnormality of glycoproteins (GPs) IIb and IIIa, but its genetic basis remains to be determined. We analyzed the genes for GPIIb and 3'GPIIIa in 3 patients with GT and in 7 control subjects by Southern blot. No large deletions or insertions were detected in these genes in any patient with GT. Furthermore, the GPIIb and GPIIIa mRNAs derived from the platelets of patients with GT could be amplified using the reverse transcriptase-polymerase chain reaction (RT-PCR). This finding indicates that the mRNAs of the patients with GT are considered to be normally transcribed. The molecular defects of the GPIIb.

Blotting, Southern↗
PubMed1991

Platelet factor 4 mRNA expression in cells from a patient with megakaryoblastic crisis of chronic myelogenous leukemia.

A 61-year-old man with Philadelphia chromosome-positive chronic myelogenous leukemia developed megakaryoblastic leukemia. In the blast phase, his blast cells showed undifferentiated megakaryoblastic characteristics with no alpha-granules or demarcation membranes but with detectable platelet peroxidase (PPO) activity and surface glycoprotein (GP) IIb/IIIa. The patient has remained reasonably well for at least 12 months after blastic crisis, and 6-mercaptopurine alone has been effective in controlling leukocytosis and megakaryoblast proliferation. The expression of mRNA for platelet-specific proteins, such as GPIIb and platelet factor 4 (PF4), was studied in the patient's blast cells by the Northern blot analysis. Both GPIIb and PF4 mRNA were detected in the blast cells. Cytoplasmic maturation occurs later than the synthesis of the surface GP during megakaryocyte maturation. Therefore, PF4 mRNA expression should be a marker of mature megakaryoblasts. The PF4 mRNA expression in megakaryoblastic leukemia may indicate that a patient will have long survival and a good response to chemotherapy.

Antibodies, Monoclonal↗
PubMed1991

[Expression and detection of platelet specific genes in human megakaryocytic cells].

The expression and biological function of interleukin-6(IL-6), and its receptor mRNA, were studied in a human megakaryocytic cell line (CMK). IL-6 possessed stimulatory effects on the DNA synthesis as well as colony formation of CMK cells. The IL-6 receptor mRNA could be detected by the method of reverse transcriptase polymerase chain reaction (RT-PCR) but not Northern blotting. On the contrary, IL-6 mRNA was detected by the method of RT-PCR, and its expression induced by the addition of 12-O-tetradecanoylphorbol-13-acetate (TPA) could be clearly shown by Northern blotting. These findings indicate that IL-6 and its receptor mRNA should be analyzed by both methods, and the growth and differentiation of CMK cells may be controlled by an IL-6 autocrine loop. Next, the expression and biological role of low molecular GTP-binding proteins (smg p21A and -B) mRNAs were examined in CMK cells. Both the smg p21A and -B mRNAs were detected in CMK cells using Northern blotting, and their levels were markedly elevated by TPA treatment. The mRNA level of glycoprotein IIb, a typical marker of the megakaryocytes, was increased by TPA, but the time course of the increase in the smg p21 mRNA levels was more rapid that that in the GPIIb mRNA level. These findings suggest that smg p21s play an important role during the TPA-induced differentiation of CMK cells.

Blood Platelets↗
PubMed1990

Cytosolic calcium mobilization and thromboxane synthesis in a human megakaryocytic leukemia cell.

The functional and biochemical characteristics of human megakaryocytic leukemia cells remain unclear. In this study, we examined cytosolic Ca2+ ([Ca2+]i) mobilization and thromboxane (TX) formation in a megakaryocytic leukemia cell line, designated CMK. Stimulation of CMK cells with thrombin resulted in an increase of [Ca2+]i as measured with the fluorescent marker Fura 2-AM. The rise in [Ca2+]i was mostly dependent on extracellular Ca2+. Prostaglandin E1 (PGE1) further increased [Ca2+]i after thrombin addition, thus indicating that PGE1 had a different action on [Ca2+]i in cells of the platelet-megakaryocyte lineage. The addition of thrombin and the calcium ionophore A23178 to CMK cells caused similar rapid formations of TXB2 as measured by RIA. Thrombin plus A23178 had a synergistic effect on TXB2 synthesis in CMK cells. Thrombin had no effect of TX metabolism in the cells with myeloid, erythroid, B-lymphoid, and T-lymphoid lineages. These results indicate that thrombin-induced TX synthesis may serve as a marker of immature megakaryocytes.

Alprostadil↗
PubMed1989

A new therapeutic trial of secretin in the treatment of intrahepatic cholestasis.

Many animal experiments have been studied on the choleretic effects of secretin. We intended to estimate secretin choleresis in human (15 patients) who had received PTCD or T-tube insertion into the common bile duct. Based upon these data of secretin and choleresis, secretin was administered to 11 patients with prolonged jaundice due to intrahepatic cholestasis in order to evaluate this as a new therapy for intrahepatic jaundice. As controls, eleven patients with intrahepatic cholestasis treated with steroid hormones and/or phenobarbital were used. In all cases with biliary drainage, secretin produced a remarkable choleretic effect with a high concentration of bicarbonate. In 9 out of 11 patients with intrahepatic cholestasis who were treated with secretin, levels of serum bilirubin decreased linearly and other liver function tests returned to the normal range. The mean values of T1/2 (number of days required for reduction by half) of serum bilirubin in 9 effective cases to secretin was 10.8 days. On the other hand, that in 11 effective cases treated with steroid hormones and/or phenobarbital was 23.2 days. These results suggest that secretin therapy may be an effective treatment for intrahepatic cholestasis.

Adult↗
PubMed1989

Preventive effects of pyrroloquinoline quinone on formation of cataract and decline of lenticular and hepatic glutathione of developing chick embryo after glucocorticoid treatment.

When 0.25 mumol of hydrocortisone succinate sodium (HC) was administered to 15-day-old fertile eggs, almost all lenses of chick embryos treated with HC for 48 hr were classified as cataract stage IV-V (95%). A triple application of potassium pyrroloquinoline quinone (PQQ) (1.25 mumol/egg) at 3, 10 and 20 hr after HC treatment showed a preventive effect against the HC-induced cataract formation (I:45%, II:25%, III: 30%). PQQ also prevented the decline of GSH in the lens caused by HC. The decline of GSH in liver 24 hr after HC administration was prevented by PQQ. These data indicate that PQQ can modify HC-induced effects and that the preventive effect of PQQ against HC-induced decline of hepatic GSH seemed to influence HC-induced events in lens.

Animals↗
PubMed1989

[A study of sleep-waking rhythms based on pattern-recognition of continuous fetal heart rate monitoring].

Two different rhythms exist in the fetal heart rate (FHR) pattern of a full-term fetus. These rhythms seem to be related to the rhythms associated with sleep and wakefulness, but the results are not yet conclusive. In this study, at first, the states of sleep and wakefulness in newborn infants (measured simultaneously by EEG, EOG, respiration and body movement) were compared with their heart rate patterns in rest, active, awake and unclassified phases. The results suggest that in newborn infants it is possible to distinguish quiet sleep from other states of sleep and wakefulness by means of the heart rate pattern alone. In the second part of the study, NST for three consecutive hours with 24 to 41 week pregnant women was performed and examined to determine the relationship between maturity and heart rate pattern (measured minute by minute in rest, active and unclassified phases) in their fetus. The findings suggest that the rest phase in a heart rate pattern of a fetus indicates the fetus to be in a state of quiet sleep. Further, the proportional increase and significant increase in the duration of the rest phase after 34 gestational week indicate the maturity of the central nervous system of the fetus.

Central Nervous System↗
PubMed1989

[Antiplasmin drugs and factor XIII concentrates in the treatment of a patient with acute promyelocytic leukemia (M3)].

A female patient what M3 was seen to incur marked hemorrhagic diathesis during therapy. Heparin infusion was performed to inhibit disseminated intravascular coagulation (DIC). However, oozing from the puncture site of the r-subclavian vein was observed. Her data on coagulation were as follows: AT-3 greater than 100%, fibrinogen 69.0 mg, XIII less than 40%, FPA 2.9 ng/ml and FDP-D dimer 256 ng/ml. The alpha-2-plasmin inhibitor (alpha 2-PI) was 44% and FDP 160 microgram/ml. These results suggested DIC with activated fibrinolysis. Thus, epsilon aminocaproic acid in conjunction with heparin, fibrinogen, and concentrated XIII was administered. The abnormal bleeding improved with an increase of alpha 2-PI and XIII. This clinical response indicated that an activated fibrinolysis and a decreased XIII might have been responsible for provoking the bleeding of the patient.

Adult↗
PubMed1987

Clinical evaluation of glucagon and insulin in therapy of fulminant hepatitis.

Forty five patients were examined in order to evaluate the usefulness of glucagon and insulin as a therapy of fulminant hepatitis. Thirty patients were treated with simultaneous infusion of glucagon and insulin, whereas prednisolone was given at a daily dose of 60 to 90 mg in 15 cases. In the former group, 1 mg of glucagon and 10 units of regular insulin were infused over a period of 2 to 6 hours. Two such treatments were given per day in the early critical period of fulminant hepatitis. The therapeutic effect of glucagon and insulin was evaluated in comparison with that of prednisolone, and additionally, with a combination therapy of either blood exchange or plasmapheresis in both groups. The survival rate was superior in the group treated with glucagon and insulin (46%) and in the one with combined infusion of these hormones plus plasmapheresis (33%).

Adult↗