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Biomedical subjects

M Nakabayashi

Publications and source records attributed to M Nakabayashi.

At least 19 recordsLinked to original sources
PubMed1992

Cell growth on immobilized cell-growth factor. II. Adhesion and growth of fibroblast cells on poly(methyl methacrylate) membrane immobilized with proteins of various kinds.

The surface of poly(methyl methacrylate) membrane was partially hydrolysed and the carboxyl groups produced were coupled with various protein molecules with water-soluble carbodiimide. The immobilized proteins were a cell-growth factor insulin, cell adhesion factors fibrinogen and fibronectin, and serum proteins albumin and gamma-globulin. The insulin-immobilized poly(methyl methacrylate) membrane strongly accelerated the growth and slightly accelerated the adhesion of fibroblast cells. The immobilized fibronectin and fibrinogen enhanced the cell adhesion, and the former also accelerated the cell growth. The immobilized albumin and gamma-globulin influenced the adhesion and growth of cells very little. It was found that various proteins specifically influence the adhesion and growth of cells in an immobilized state.

Animals↗
PubMed1992

Quantitative investigations of placental terminal villi in maternal diabetes mellitus by scanning and transmission electron microscopy.

The structure of the terminal villi was observed in placentae from non-diabetic mothers and mothers with diabetes mellitus using scanning and transmission electron microscopy. The metabolic condition of maternal diabetes was tightly controlled. In the diabetic group, the diameter of the terminal villi was significantly smaller than in the control group. The ramification pattern of villi, classified into hypo-, moderate- and hyper-ramifications, was shown to be mostly moderate in the non-diabetics whereas most of the diabetic placentae had either hypo- or hyper-ramifications. Mothers with a longer duration of diabetes and complicated with retinopathy tended to have hypo-ramification; in these mothers, the weight of the neonates was significantly less than normal. Moreover, in the diabetic placentae, syncytial knots were found more frequently, the percentage of vasculo-syncytial membranes tended to be lower, and the trophoblastic basement membrane was significantly thicker than in the control. These abnormalities in the diabetic placentae were independent of the methods of delivery; they seem to be related with fetal growth retardation and poor neonatal outcome, which are commonly seen in diabetic pregnancy.

Adult↗
PubMed1992

[Assessment of fetal lung maturity using newly developed immunological measurement of fetal pulmonary surfactant apoprotein-A in amniotic fluid].

The level of immunoreactive lung surfactant apoprotein A (SP-A) was determined with a newly developed one-step ELISA kit (TDR-20) in 217 samples obtained by transabdominal or transvaginal amniocentesis from 217 pregnant women with high risk pregnancy. The lecithin/sphingomyelin ratio (L/S ratio) by two-dimensional thin layer chromatography, disaturated phosphatidylcholine (DSPC) values, shake test and the stable microbubble method were done simultaneously to compare diagnostic reliability in estimating fetal lung maturity. Amniotic fluid SP-A levels increased with advancing gestational age and correlated well with the values obtained by the other methods. When the cut-off SP-A value for the assessment of lung maturity was set at 1,700ng/ml in the amniotic fluid obtained within 24h before delivery, the true-negative rate for RDS was 71% and the true-positive rate for non-RDS was 83%. The sensitivity, specificity and accuracy were 100%, 83% and 88%, respectively. These results are comparable with those for the L/S ratio, DSPC determination and the stable microbubble method, and were slightly better than those for the shake test. In conclusion, this newly developed ELISA kit for the measurement of amniotic fluid SP-A is more effective than other methods currently available for the evaluation of fetal lung maturity, when it is considered that it requires only 0.2ml of amniotic fluid and provides results in only 2h without technical difficulties.

Amniotic Fluid↗
PubMed1992

[Efficacy of individual smoking cessation instructions for general smokers among clients of a health center].

Smoking cessation instruction for individuals using a standardized smoking cessation manual and a handout developed by the authors was studied in a controlled trial among employees who visited a health center for Industrial Safety and Health Law mandated annual health examinations. Smokers in the study group were given 5-10 minutes smoking cessation instruction mainly by public health nurses and nutritionists following the above-mentioned manual and using the handouts. Subjects in both groups were interviewed by telephone to assess changes in smoking habits one month after the first contact. Smoking clients who came on Friday (132) and on Monday (93) were assigned to study and control groups, respectively. One hundred and nineteen members (90.2%) of the study group and 88 (94.6%) of the control group were successfully followed until one month after the initial contact. Seven subjects in the study group were not smoking one month after the instruction, while no one gave up smoking in the control group (p less than 0.05). It was confirmed by telephone survey that 6 of the 7 subjects who were not smoking at one month were still maintaining abstinence from smoking one year after the instruction. Smokers who did not stop smoking reported a reduction in their smoking dose in the study group. Lighter smokers reacted more readily to instruction than did heavier smokers and the knowledge level of subjects was positively associated with the success rate.

Adolescent↗
PubMed1991

Relationship between fetal hypoxia and endothelin-1 in fetal circulation.

The role of endothelin-1 (ET-1), a potent vasoconstrictor peptide secreted by endothelial cells, in fetal circulation was investigated in relation to fetal hypoxia. Umbilical venous blood was obtained from 23 subjects who delivered between 36 and 41 weeks of gestation. In all cases, pH of umbilical venous blood was measured immediately after the delivery of placenta. ET-1 was extracted from the umbilical venous plasma by an Amprep C2 column and determined by a specific radioimmunoassay. Immunoreactive ET levels in the umbilical cord plasma (pg/ml, mean +/- SEM) from subjects with umbilical venous blood pH levels below 7.30 (n = 9) were 12.53 +/- 2.03, significantly higher than those with pH levels above 7.30 (6.44 +/- 1.11, n = 14). These results indicate that ET-1 in the fetal circulation may be involved in the regulation of the circulation in response to changes in acid-base balance related to fetal hypoxia.

Adult↗
PubMed1991

Effect of experimental ocular hypertension on macrovacuolation in Schlemm's canal endothelial cells of monkey eyes.

The severance of all the extraocular muscles (tenotomy) caused temporary ocular hypertension, lasting a few days, in Japanese monkey (Macaca fuscata) eyes. We studied the morphology of Schlemm's canal endothelium of the eyes under a light microscope after quick fixation through continuous irrigation of the anterior chamber with a 10% acrolein solution, with precise control of the hydrostatic pressure on the eyes during fixation. A statistically significant increase in macrovacuolation in endothelial cells of Schlemm's canal of normal eyes was observed when additional hydrostatic pressure was applied. However, such an increase was not observed in the case of tenotomized temporary hypertensive eyes.

Animals↗
PubMed1991

The relationship between clinical signs and hypercoagulable state in toxemia of pregnancy.

The hypercoagulable state in patients with toxemia of pregnancy was investigated in comparison with normal pregnant women using new coagulation parameters, mainly thrombin-antithrombin III (TAT) complexes, alpha 2-antiplasmin-plasmin complexes (PIP), and D-dimer FDP. When the patients were categorized by the classification of the WHO Study Group (1985), significant increases of TAT complexes and alpha 2-PIP complexes with decreases of the ATIII level were observed in the groups with preeclampsia and severe gestational hypertensive disease as compared to normal pregnant women. A significant increase of D-dimer FDP was observed in a group with severe gestational hypertensive disease. Additionally, the relationship between clinical signs and the hypercoagulable state in the patients was analyzed using canonical correlation analysis as a multivariate analysis. The clinical signs and coagulation parameters had a significantly high correlation of lambda 1 = 0.7219, p less than 0.01. The results showed that clinical signs were associated with simultaneous coagulation abnormalities. The indices obtained from the results of canonical correlation analysis, which were called the clinical index and the coagulation index, should be useful in evaluating the efficacy of anticoagulation therapy.

Adult↗
PubMed1991

[Deformation of brain and stress distribution caused by putaminal hemorrhage--numerical computer simulation by finite element method].

Deformation and stress distribution caused by putaminal hemorrhage in two-dimensional model brain were analyzed by computer simulation using finite element method. The model brain was composed of cerebral cortex, white matter, caudate nucleus, lenticular nucleus, thalamus and lateral ventricle. Young's modulus of gray and white matter was assumed to be 0.08 and 0.04 kgf/cm2, respectively, and Poisson's ratio was 0.47 for both of them. Bleeding of 100 mmHg pressure was represented by 4 vectors of force directing anterior, lateral, posterior and medial direction from the middle portion of putamen. Calculation of finite element method was carried out by a 16-bit personal computer. The calculated deformation of brain presented a hematoma cavity elongated from anterior to posterior direction at the lenticular nucleus. Mass effect of hematoma was noted from displacement of the anterior horn of the lateral ventricle and the internal capsule. Distribution of stress vector revealed the stress concentration at the lenticular nucleus while small stress was noted all over the model brain. Strength of principal stress was presented by contour-line and took the shape of concentric circles with a center at the putamen. This study suggested that the computer simulation by finite element method would be a useful technique to analyze the physical phenomenon of brain suffered from intracerebral hemorrhage.

Basal Ganglia Diseases↗
PubMed1990

Quantitative analysis of serum alpha 1-acid glycoprotein levels in normal and diabetic pregnancy.

In an attempt to clarify the mechanism of lipid metabolism during pregnancy, alpha 1-acid glycoprotein (alpha 1-AG) was analyzed in normal and diabetic pregnant women. Seventy-two determinations of serum alpha 1-AG levels were performed in 18 diabetic pregnant women and 82 determinations in 82 normal pregnant women in all three trimesters and within 14 days postpartum. Serum alpha 1-AG levels in both normal and diabetic pregnant women decreased throughout pregnancy and rapidly increased postpartum. In all gestational stages, the serum alpha 1-AG levels were lower in diabetic women than in normal women, but the differences were not significant. No significant correlation was obtained between serum alpha 1-AG and hemoglobin A1 (HbA1) in diabetic patients. On the contrary, the serum triglyceride levels increased during pregnancy and decreased postpartum in both groups of subjects. These findings suggest that serum alpha 1-AG plays an important role in the activation of lipoprotein lipase during pregnancy.

Adult↗
PubMed1990

[A study of growth prediction of low-birth-weight infants].

To predict the time required for low-birth-weight (LBW) infants to catch-up with standard weight, the growth curves for weight in 156 LBW infants with no medical abnormalities were examined. The proportion of infants who caught-up with standard weight by 1.5 years of age was significantly higher in appropriate-for-dates (AFD) infants than in small-for-dates (SFD) infants (93% vs. 70%). The age of catch-up with standard weight had a significant inverse correlation with birth weight in AFD infants, and not in SFD infants. The age of catch-up standard weight of AFD infants, as predicted by the regression analysis was 4-8 months for 2,000 g of birth weight, 8-12 months for 1,500 g, and 12-15 months for 1,000 g, with about 80% accuracy. This prediction may be valuable in providing health advice to mothers with LBW infants.

Age Factors↗
PubMed1990

[Fifteen-year experience with 24 pregnancies associated with prosthetic valve replacements].

During the past 15 years, we followed 21 patients with prosthetic heart valves who experienced a total of 24 pregnancies at mean age of 31.3 +/- 3.6 years. The course of these patients and their pregnancies were reviewed to evaluate the problems associated with prosthetic heart valves and anticoagulation. Among the 21 patients, the aortic valve (AV) had been replaced in 10 (12 pregnancies), the mitral valve (MV) in nine (10 pregnancies), AV + MV in one (one pregnancy), and the tricuspid valve (TV) in one (one pregnancy). The implanted prosthetic valves were mechanical type in 16 cases (Björk-Shiley 15, Starr-Edwards 1) and bioprosthetic type in six (Hancock 5, Ionescu-Shiley 1). With the exception of one case of intra-uterine fetal death probably related with warfarin therapy, all the patients with bioprosthetic valves underwent successful deliveries. Anticoagulant therapy was employed for 11 pregnancies; warfarin for 10 and subcutaneous heparin for one. No anticoagulant therapy was performed for 13 pregnancies. Ten of the 21 mothers had atrial fibrillation. Eighteen pregnancies (67%) culminated in uneventful deliveries for both mothers and infants. Three mothers (13%) died of thromboembolic complications; two of cerebrovascular accidents and one of acute heart failure caused by thrombus on the replaced valve. All of them had Björk-Shiley valves. Oral warfarin was administered in one of the three, heparin in one and no anticoagulant in the remaining one. Massive maternal bleeding occurred in two cases (8%). There were three cases (12%) of intra-uterine fetal death which were caused by intracranial hemorrhages.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗
PubMed1990

Elevation of immunoreactive platelet prostaglandin E and plasma prostaglandin F2 alpha in diabetic pregnancy.

Platelet prostaglandin (PG) E and plasma PGF2 alpha concentrations were measured by radioimmunoassay methods and compared in non-pregnant and pregnant, normal and diabetic subjects. The blood samples were obtained in the follicular phase in the non-pregnant women and in the third trimester and after delivery in the pregnant women. The immunoreactive platelet PGE (IRPGE) levels were significantly higher in the pregnant diabetic women than in the normal non-pregnant and pregnant women and diabetic non-pregnant women. The immunoreactive plasma PGF2 alpha (IRPGF2 alpha) concentrations were significantly higher in the non-pregnant diabetic women than in the normal non-pregnant and pregnant women. During pregnancy, the plasma IRPGF2 alpha were further increased significantly in the diabetic subjects compared to the non-pregnant diabetics. Both the platelet IRPGE and plasma IRPGF2 alpha concentrations were higher in the pregnant diabetic subjects with retinopathy than in those without retinopathy. These findings suggest that pregnancy and diabetes influence the synthesis of PGE and PGF2 alpha in the platelets and plasma, respectively. The increased production of these prostaglandins are possible exacerbating factors of diabetic retinopathy during pregnancy.

Adult↗
PubMed1988

[The role of coagulation and fibrinolysis system in pathogenesis of toxemia of pregnancy].

UNLABELLED: It is well known that many pathophysiological findings in toxemia of pregnancy are explained by imbalance of coagulation and fibrinolysis system. The purpose of this study is to elucidate a precise role of coagulation and fibrinolysis system in pathogenesis of toxemia of pregnancy. SUBJECTS AND METHODS: 1) Classification of toxemia of pregnancy. Three hundred and thirty seven of toxemia of pregnancy are classified based on the onset period, and incidence of severity of disease and IUGR, rate of genetic factor of hypertension are compared in each group. 2) Platelet factor 4 (pf4) and beta-thromboglobulin (beta-TG), Fibrinopeptide A (FPA), thrombin-ATIII complex, ATIII fibrinopeptide B beta 15-42, D dimer FDP and plasmin-alpha 2 PI complex are assayed. The levels of PGI2, tissue plasminogen activator (tPA) and thrombomodulin (TM) are measured after venous occlusion. Immunoreactivity and biological activity of TM in urine are analyzed. 3) Aminoacid sequence of TM from normal and toxemia of pregnancy are determined by analyzing cDNA for TM. Moreover, TM are synthesized from recombined DNA and enzymological properties of TM obtained from normal and toxemia of pregnancy are compared. 4) Release of PGI2, tPA and TM by addition of thrombin are observed using monolayer culture of endothelial cells from cord. Enzymological properties of purified placental TM are analyzed. RESULTS: 1) The incidence of severe type, IUGR and the rate of patients who possess genetic factors for hypertension are higher in early onset type, suggesting that hypertension is the predominant characteristics in early onset type and that genetic factors for hypertension are tightly involved. 2) All parameters such as platelets, coagulation and fibrinolysis system are elevated in toxemia of pregnancy compared to those in normal pregnancy. Coagulation index that consists of above parameters is well correlated with clinical index that consists of clinical findings (r = 0.7006, p less than 0.0001). The net increase of PGI2, tPA and TM by venous occlusion are decreased along with severity of toxemia of pregnancy. The potency of production of PGI2 from endothelial cells in maternal omentum is impaired in the severe toxemia of pregnancy. Purified TM in urine from normal pregnancy and toxemia of pregnancy has 63K dalton of single band on SDS-PAGE. However, bioactivity/immunoreactivity ratio of TM in early onset type is lower than those in late onset type, and affinity of TM for thrombin and protein C is decreased in early onset type.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1987

[A study on the activity of the PGI2 producing enzyme system derived from maternal and fetal vessels of toxemia of pregnancies].

We investigated the conversion rate from arachidonic acid (A.A.) to PGI2 and the activity of PGI2 producing enzyme system in endothelial cells of umbilical veins (U.V.) and maternal omental veins (O.V.) in normal pregnancy (NOR) and toxemia of pregnancy (TOX). The conversion rate from A.A. to PGI2 for U.V. and O.V. in NOR was higher than that in TOX. There was a significant difference between NOR and TOX with the conversion rate for U.V. at a concentration of 172.4 nM/ml A.A. The apparent Vmax value for PGI2 producing enzyme system (nM/mg) in U.V. in NOR (n = 7) was 0.88 +/- 0.21 (mean +/- S.E.) and that for TOX (n = 3) was 1.63 +/- 0.18. The apparent Km value for the enzyme system (microM) in U.V. in NOR (n = 7) was 0.75 +/- 0.25, and that for TOX (n = 3) was 3.26 +/- 0.78. Significant differences (p less than 0.05) between NOR and TOX were observed with Vmax and Km values. The apparent Vmax value for the enzyme system in O.V. in NOR (n = 3) was 0.32 +/- 0.13, and that for TOX (n = 3) was 2.12 +/- 0.38. The apparent Km value for the enzyme system in O.V. of NOR (n = 3) was 0.26 +/- 0.06, and that for TOX (n = 3) was 0.97 +/- 0.09. There was a significant difference between (p less than 0.05) the Vmax and Km values for NOR and TOX. The present study showed that U.V. (fetal vessel) and O.V. (maternal vessel) in TOX had a lower activity PGI2 producing enzyme system than those in NOR due mainly to an imbalance between the substrate supply and cyclooxygenase activity.

Adult↗