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Biomedical subjects

H Furuya

Publications and source records attributed to H Furuya.

At least 253 records · Page 14Linked to original sources
PubMed1986

Effects of linoleic acid and cations on the activity of a novel high-molecular weight protease, ingensin, from human placenta.

A linoleic acid-sensitive protease, ingensin, was purified to homogeneity from human placenta. The physical properties of the placental ingensin were found to be very similar to those of skeletal muscle ingensin [Ishiura et al. (1985) FEBS Lett. 189, 119-123]. The purified ingensin was activated by linoleic acid and SDS. The linoleic acid-activated form was inhibited preferentially by divalent cations, whereas the SDS-activated form was inhibited by monovalent cations instead.

Cations↗
PubMed1986

Purification and characterization of a high-molecular-weight protease, ingensin, from human placenta.

We purified a high-molecular-weight protease, ingensin, from extract of human placenta by successive DEAE-cellulose, hydroxyapatite, and high performance liquid chromatographies. The activity of ingensin was determined by using a synthetic substrate, succinyl-leucyl-leucyl-valyl-tyrosine-methylcoumarinamide (MCA). The purified ingensin, which gave a single band in 6.5% nondenaturing polyacrylamide gel electrophoresis, was activated by linoleic acid and sodium dodecyl sulfate (SDS). Maximum activity was observed at pH 9.5 in the presence of 0.06% SDS, but at pH 8.0 in the presence of linoleic acid. A subcellular fractionation study showed that a large amount of ingensin activity was present in the cytosol or microsome fraction rather than in the precipitate of low-speed centrifugation. The effect of protease inhibitors on the activated ingensin was also investigated.

Chromatography, DEAE-Cellulose↗
PubMed1986

Natural killer cell activity against a variety of target cell lines in normal persons: NK-target sensitivity and effect of age and sex on NK levels.

Natural killer (NK) cells have been implicated as first line of defence mechanism for carcinogenesis in humans. A lot of studies of depressed NK activity in patients with malignancies have supported this. Two major problems, however, in these studies are the choice of normal controls and target cells. To study this problem, peripheral mononuclear cells (PBMC) of sixty-six normal subjects from young and elderly, males and females were tested for NK function against twenty target cell lines with a microcytotoxicity assay. The result was shown that no sex or age difference existed with respect to NK function, except for a slight but significant decreased in NK activity of young female to K562 target cells. Target cells were divided into four groups by their NK sensitivity, namely, high, moderate, low and refractory sensitive. In general, NK activity of healthy persons is considered to remain stable and polyspecific in our results.

Adolescent↗
PubMed1986

Growth and function of the placenta--with special reference to various enzymes involved in the biosynthesis of steroids in the human placenta.

To study the function of the placenta from the viewpoint of placental aging, we measured the activity of various enzymes, sulfatase, 3 beta-hydroxysteroid dehydrogenase + isomerase (3 beta-HSD) and aromatizing enzyme, which are involved in the synthesis of estrogen in the placenta, as well as placental RNA and DNA levels during gestation. Our results are as follow; Enzymes involved in estrogen synthesis in human placental villi. Sulfatase activity (n mole/flask/10 min) in each trimester was not significantly different (4.10 +/- 0.10 in the first, 3.40 +/- 0.49 in the second and 4.33 +/- 0.67 in the third). 3 beta-HSD activity (n mole/flask/10 min) in each trimester was not significantly different (2.57 +/- 0.55 in the first, 2.70 +/- 0.30 in the second and 2.90 +/- 0.53 in the third). Aromatizing enzyme activity (n mole/flask/30 min) in cytosome fraction in each trimester was not significantly different (1.80 +/- 0.28 in the first, 1.60 +/- 0.28 in the second and 2.40 +/- 0.28 in the third). However, in the total homogenate, it was significantly higher in the third trimester (6.27 +/- 0.25) than in the first (3.83 +/- 0.85) or second (3.40 +/- 0.14). RNA and DNA concentrations in human placental villi. The RNA concentration (mg/g tissue) in each trimester was insignificantly different (2.48 +/- 0.20 in the first, 2.57 +/- 0.58 in the second and 2.63 +/- 0.42 in the third). However, the DNA concentration was significantly higher in the second (2.49 +/- 0.34) and third (2.42 +/- 0.45) trimesters than in the first (1.62 +/- 0.32).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxysteroid Dehydrogenases↗
PubMed1986

Structure of the mutant prealbumin gene responsible for familial amyloidotic polyneuropathy.

Familial amyloidotic polyneuropathy (FAP) is a genetic disorder showing autosomal dominant inheritance. Amyloid fibrils of FAP patients from various origins have been shown to contain a prealbumin variant with Val30----Met30 substitution as a major component. However, the structure of the prealbumin gene responsible for the variation has not been characterized. We determined the complete nucleotide sequence of the prealbumin gene from a patient with the Japanese type of FAP. In comparison with a normal prealbumin gene sequence, the patient's gene was found to be carrying seven base substitutions. The substitution responsible for the Val----Met change was found in exon 2, as expected, and the others were in introns. Hybridization analyses of normal and FAP patient DNAs showed that the base substitution in exon 2 was specific for FAP but the others were polymorphic changes. It was concluded that the mutation responsible for the Val----Met change is the only base change specific for FAP in the prealbumin gene.

Amyloidosis↗
PubMed1985

The role of transferrin and ferritin in the fetal-maternal-placental unit.

The rapidly growing human fetus requires a large supply of iron, which is obtained from the iron stores of the mother. Iron is transported from mother to fetus against a concentration gradient. The placenta plays a key role in regulating the supply of iron in the fetus. In both anemic and nonanemic patients serum ferritin levels decreased and total iron-binding capacity increased as gestation progressed. The total iron-binding capacity is higher in maternal than in umbilical cord blood at delivery; this suggests that little or no ferritin or transferrin is transferred from mother to fetus. Mother and fetus appear to have independent systems controlling iron metabolism. Transferrin was localized on the site facing the intervillous space, on the surface of the microvilli of the syncytiotrophoblasts. The removal of transferrin from the surface of the trophoblast by thiocyanate and its rebinding were demonstrated. Ferritin was shown to be present in all layers of the trophoblast and especially in the syncytiotrophoblast.

Anemia↗
PubMed1985

Preoperative estimation of cerebral blood flow autoregulation curve for control of cerebral circulation after cerebral revascularization.

In this report, the anesthetic management for cerebral revascularization in 3 patients with ischemic cerebral vascular disease was presented. Arterial pressure was maintained above their ordinary level before revascularization. To prevent cerebral hemorrhage or edema due to the breakthrough phenomenon, the arterial pressure was reduced to the lower limit pressure of cerebral blood flow (CBF) autoregulation which was measured preoperatively. The patients did not show any new neurological deficit after the operations.

Adult↗
PubMed1985

Evaluation of antiarrhythmic drug efficacy using holter electrocardiographic technique.

This study was performed to investigate spontaneous variability in VPC frequency, to determine standards for distinguishing antiarrhythmic efficacy from the spontaneous variability, and to compare the effectiveness of disopyramide, mexiletine, aprindine, propranolol, and diltiazem. Holter ECG techniques were used for this study and the population studied consisted of 182 patients having more than 1000 VPCs/day. Forty patients had ischemic heart disease, 52 had miscellaneous heart disease and 90 were free of heart disease (idiopathic VPCs). Circadian variability of VPCs can be divided into 4 types; Type D (VPCs increasing during waking hours), Type DN (small VPC changes between waking and sleeping hours), Type N (VPCs increasing during sleeping hours) and Type Ir (irregularly occurring VPCs). The incidence of Type D, DN, N and Ir was 45%, 29%, 12% and 14%, respectively. VPC frequency in the first and second recordings at a 7 up to 21 day interval was highly reproducible (r = 0.951). The percent reduction in VPC frequency necessary to distinguish true drug response from spontaneous VPC variability, corresponded to 57% with 95% confidence level, and 67% with 99% confidence level. VPCs were reduced by at least 57% in 19 out of 33 patients (58%) with disopyramide, 9 of 15 (60%) with mexiletine, 11 of 18 (61%) with aprindine, 9 of 24 (38%) with propranolol and 8 of 22 (36%) with diltiazem. Concerning Prop., it is exclusively effective to the Type D VPCs (70%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Studies on the placental transport mechanism for iron.

Transferrin (Tf) and ferritin (Fr), the proteins which participate in iron transport, were examined to determine their fluctuation during pregnancy and their localization in human placental tissue, and the iron transport mechanism between mother and fetus was discussed. The main results are as follows: Maternal serum ferritin (SFr) decreased remarkably and the maternal total iron binding capacity (TIBC) increased gradually as pregnancy progressed. Maternal serum iron (SI), SFr and TIBC at delivery were 59.8 +/- 26.2 micrograms/dl, 9.6 +/- 7.2 ng/ml and 495.2 +/- 100.3 micrograms/dl, and cord blood SI, SFr and TIBC were 161.5 +/- 42.1 micrograms/dl, 160.5 +/- 67.2 ng/ml and 177.7 +/- 33.9 micrograms/dl, respectively. Peroxidase conjugating antibody method revealed the localization of Tf on the microvillous surface of syncytiotrophoblasts, and the localization of Fr in all layers of trophoblasts, especially in the neighborhood of the surface. Ferritin content of the placenta in the 1st, 2nd and 3rd trimesters was 0.07 +/- 0.03, 0.18 +/- 0.03 and 0.25 +/- 0.09 (micrograms/mg protein), respectively. These results indicate that iron is transferred from the mother to the fetus by the placental active function, and Tf receptor and Fr on trophoblasts participate in the adequate placental iron transport.

Biological Transport↗