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Biomedical subjects

M Maki

Publications and source records attributed to M Maki.

At least 271 records · Page 15Linked to original sources
PubMed1981

The thromboplastic activity of lung surfactant in amniotic fluid and its application to prenatal assessment of fetal lung maturity.

Based on the fact that both tissue thromboplastin and lung surfactant show lamellar structures under the electron microscope and belong chemically to lipoprotein, the thromboplastic activity of lung surfactant in amniotic fluid was studied by measuring plasma recalcification time. The results obtained were as follows (1) The surfactant fractions isolated from amniotic fluid and rabbit or pig lung showed the thromboplastic activity with dose response. (2) The thromboplastic activity of amniotic fluid increased with advancing gestational age. (3) It was found that the thromboplastic activity determined by plasma recalcification time was parallel with the surfactant concentration of amniotic fluid. (4) The shortening rate of plasma recalcification time in amniotic fluid could estimate well the risk of RDS, and the critical value for RDS was assumed to be about 33%.

Amniotic Fluid↗
PubMed1981

Effect of conjugated estrogen on disseminated intravascular coagulation induced by endotoxin infusion in rabbits.

Since conjugated estrogen has activities of inhibiting capillary permeability and of blocking alpha-adrenergic action, this study was undertaken to evaluate the effect of conjugated estrogen on experimentally induced disseminated intravascular coagulation (DIC) by endotoxin infusion in rabbits. Endotoxin from E. coli alone was infused into 17 rabbits in a rate of 90 micrograms/kg/hr for 10 hr, the other 17 were given endotoxin with 20 mg of conjugated estrogen, and 6 were infused 20 mg of conjugated estrogen alone. The results obtained were as follows: (1) Decreases in platelet, fibrinogen and plasminogen, prolonged prothrombin time and partial thromboplastin time were noted in animals receiving intravenous drip infusion of endotoxin. All these laboratory findings were typical of consumption coagulopathy. Histologically, fibrin thrombi were demonstrated in the glomeruli, which also indicated the presence of DIC. (2) These changes were almost equally demonstrable in the rabbits given endotoxin alone and in those with endotoxin plus conjugated estrogen. (3) The group of rabbits receiving endotoxin and estrogen, however, showed a significantly low mortality during the study, compared with the group receiving endotoxin alone.

Animals↗
PubMed1981

Effects of conjugated estrogens on ripening of uterine cervix in nonpregnant castrated and pregnant rats.

The stimulating effects of conjugated estrogens (CE, Premarin) on ripening of the uterine cervix were investigated by measuring the wet weight of the cervices, as well as by both light and electron microscopic examinations on non-pregnant castrated (hereinafter called castrated) and pregnant rats. Increase in the wet weight of the cervix was observed, in comparison with lactose control group, 4 and 2 hours after administration of CE in castrated and late pregnant rats, respectively. The maximum increase in the wet weight of the cervix was evident during the period of 4 to 10 hours after administration of CE. Scanning electron microscopic investigation was carried out on the cervices using the previously defined "ripening score". The scores of castrated rats cervices taken 4 hours after administration of different amounts of CE were 24.8 +/- 1.0 (n=5, 100 microgram CE/rat) and 24.8 +/- 2.0 (n=5, 100 microgram CE/rat), showing marked increases in score, as compared with those of control. The light and transmission electron microscopic figures of the cervices of castrated rats treated with CE resembled strikingly to those of pregnant rats, and the resemblance was also striking as compared with those of castrated rats treated with free estrogens. The onset of the action of CE on the cervical capillaries was apparently faster than that on cell components of the connective tissue. There was no essential difference in ultrastructure between the cervices of lactose treated pregnant rats and CE treated pregnant ones. CE exhibited more prompt effects in increasing the wet weight of the cervix than did free estrogens in castrated rats (as observed in earlier experiments). Judging from the close resemblance between the electron microscopic figures of the CE group and those of the free estrogens group, it is postulated that the effect of CE might be due mainly to the action of free type estrogens converted from CE, and additionally, due to some unknown factors involved in the drug.

Animals↗
PubMed1981

In vitro effect of some free estrogens or estrogen precursors on collagenase activity of uterine cervix.

In order to determine whether or not collagenase activity of the uterine cervix can be influenced by estrone (E1), estradiol (E2), estriol (E3), equilin, dehydroepiandrosterone sulfate (DHA-S) or dehydroepiandrosterone (DHA), the collagenase activity of extract of connective tissue of the uterine cervix treated with the drug was measured. A higher collagenase activity was obtained in pregnant cervix than that in nonpregnant ones. There was no difference in collagenase activity of the uterine cervix extract between control and drug (5 X 10(-5) M of E1, E2, E3, equilin, DHA-S or DHA) groups both in nonpregnant and pregnant conditions. After preincubation of tissue with 1 X 10(-5) M of the said drug at 37 degrees C for 60 min, the enzyme activity of the supernatant was also investigated. In nonpregnant conditions, no increase in the enzyme activity was observed. On the contrary, significant increase of the enzyme activity was obtained in pregnant uterine cervix preincubated with equilin, E3, DHA-S or DHA comparing to that of control group. However, this increase was not observed by E1 or E2. Elastase activity was also investigated on cervical connective tissue both in nonpregnant and pregnant conditions. No increase in elastase activity was observed in the pregnant cervix comparing to that of nonpregnant group.

Cervix Uteri↗
PubMed1981

[Human fetal breathing movements: basic analysis and clinical relationship to fetal well-being (author's transl)].

By means of real time B-scan, human fetal breathing movements (FBM) was basically and clinically investigated on 244 observations in 215 pregnancies. The results obtained were as follows. (1) FBM was frequently observed during active sleep in which FHR variability and fetal movement increased. (2) The incidence of FBM increased rapidly from 12.5% at 23-27 weeks to 77-100% at more than 35 weeks gestation, but reduced to 44% at delivery. (3) FBM became more regular and deeper with advancing weeks of pregnancy, especially after 36 weeks of gestation. The frequency of FBM in normal pregnancy was slightly high at 28-29 weeks, but almost the same rates at 30-41 weeks. (4) Maternal mean blood glucose level of 6 cases (72.3 +/- 5.8 mg/dl) in which FBM absent in repeated observations was significantly lower than those of 10 cases (94.7 +/- 14 mg/dl) in which the percentage time spent breathing were 50% or more. (5) Clinically, a relationship between the presence or absence of FBM and Apgar score was not recognized. However, when the percentage time spent breathing was less than 30% or FBM was continuous and considerably deep, the incidence of neonatal asphyxia or FHR abnormality during labor was significantly increased.

Blood Glucose↗
PubMed1980

Characterization of a progestin-binding component in lactating rat mammary glands.

Experiments were carried out to identify progestin-binding receptors in the mammary gland where casein synthesis is known to be inhibited by this hormone. A progestin-binding component with high affinity, low capacity and a sedimentation coefficient of 8.8 S was isolated from the cytosol of lactating rat mammary glands. This component strongly bound [3H]R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) with a dissociation constant of 3.9 . 10(-9) M under low-salt conditions and with that of 8.2 . 10(-10) M in the presence of 0.3 M KCl. Specificity studies showed a high degree of progestin specificity under high salt conditions. In the absence of KCl, binding of [3H]-R5020 was inhibited by unlabeled glucocorticoid in the same degree as unlabeled progestin, but the inhibition by glucocorticoid was greatly diminished by the presence of 0.3 M KCl. These observations suggest that the [3H]R5020-binding-component is the progestin receptor and that its function may be regulated by the concentration of glucocorticoid and salt.

Animals↗
PubMed1980

Alterations in glucocorticoid receptor conformation by molybdate.

Glucocorticoid receptor activities in cytosol from lactating rat mammary glands were greatly stabilized by molybdate against inactivation during incubation at 25 degrees C. The sedimentation coefficient was 9-10S in the presence of 10 mM Na2MoO4, but 6-7S in the absence of the ion. These data strongly suggest that alterations in receptor conformation induced by direct interaction with molybdate are involved in the stabilization process.

Animals↗
PubMed1980

Occurrence of common binding sites for progestin and glucocorticoid in the lactating mammary gland of the rat.

Previous reports have shown that in the cytosol from rat mammary gland, the high affinity binding of glucocorticoid is strongly inhibited by unlabeled progestin and that of progestin is strongly inhibited by glucocorticoid. Experiments were carried out with [3H]dexamethasone and [3H]R5020 to determine whether the binding sites for glucocorticoid and progestin are the same. Thermal inactivation experiments showed that the molecular properties of the [3H]-dexamethasone-binding sites closely resemble those of the [3H]R5020-binding sites. The dissociation constant of the [3H]R5020-receptor complex was almost exactly the same as the inhibition constant of unlabeled R5020 for [3H]dexamethasone-binding sites. The same correlation was observed between the dissociation constant and the inhibition constant of dexamethasone. In addition, no [3H]R5020-binding was observed after saturating the [3H]-dexamethasone-binding sites. These results led us to conclude that common binding sites for [3H]dexamethasone and [3H]R5020 exist in the cytosol from the rat mammary gland. The results of further experiments, including Scatchard analyses and dEAE-cellulose chromatography, strongly suggest that there are at least two classes of [3H]dexamethasone-binding sites, and that one of them binds both glucocorticoid and progestin stably.

Animals↗
PubMed1980

Fibrinolytic activity during pregnancy.

It has been a general concept that fibrinolytic activity is diminished during pregnancy. However, increase in FDP (fibrin/fibrinogen degradation products by plasmin digestion) which indicates accelerated fibrinolytic activity is also observed during pregnancy. To clarify these conflicting findings, alpha-2-plasmin inhibitor and FDP, sensitive indicators of fibrinolytic activity, were studied during pregnancy. Decrease in plasmin inhibitor and increase in FDP were found during pregnancy suggesting that fibrinolytic activity is accelerated during pregnancy. Since FDP level was higher in blood samples from the uterine vein than those from the artery, the accelerated fibrinolysis characterized by decrease in plasmin inhibitor and increased FDP, might be reflection of local event. On the other hand, systemic blood remains still hypofibrinolytic in normal pregnant condition.

Female↗
PubMed1980

[Surfactant lipoprotein concentration in amniotic fluid of abnormal pregnancies and premature deliveries (author's transl)].

As shown in our previous report surfactant lipoprotein concentration (SLPC) in amniotic fluid measured by sucrose density gradient centrifugation predicts accurately the risk of RDS. In this study SLPC estimations were made on 91 amniotic fluid samples from abnormal pregnancies, spontaneous premature deliveries and anencephalies. The results were as follows. SLPCs increased in placental insufficiency and severe preeclampsia, especially associated with SFD infant, on the other hand, SLPCs decreased in maternal diabetes (Class B), Rh-isoimmunization and anencephaly as compared with normal pregnancy. In most of premature deliveries SLPCs were higher than those of normal pregnancies except for RDS cases. Present evidence suggests that the maturation of fetal lung is accelerated in severe preeclampsia and placental insufficiency and is delayed in maternal diabetes (Class B), Rh-isoimmunization and anencephaly, and it is considered that in spontaneous premature delivery surfactant production in fetal lung is not accelerated but surfactant excretion from fetal lung into amniotic fluid is enhanced by effect of uterine relaxant such as isoxsuprine or terbutaline.

Adult↗