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H Chiba

Publications and source records attributed to H Chiba.

At least 19 recordsLinked to original sources
PubMed1992

Convenient synthesis of 18-hydroxylated cortisol and prednisolone.

18,20-Epoxy-11 beta,17 alpha,20 beta,21-tetrahydroxypregn-4-en-3-one was synthesized by the application of hypoiodite reaction to the cortisol acetonide. The intermediary 18-iodo derivative was converted to the 11-oxo steroid by chromic acid prior to silver ion-assisted solvolysis. Removal of the protective group with hydrochloric acid was finally carried out to give the desired 11 beta,17 alpha,18,21-tetrahydroxypregn-4-ene-3,20-dione as the hemiacetal form. 18,20-Epoxy-11 beta-17 alpha,20 beta,21- tetrahydroxypregna-1,4-dien-3-one was also prepared from prednisolone through a similar reaction sequence.

Hydrocortisone↗
PubMed1992

A rapid and simple quantification of human apolipoprotein E-rich high-density lipoproteins in serum.

A rapid and simple method for the quantitative determination of human serum apo E-rich high-density lipoproteins is described. A sample was divided into two parts; one part was mixed with an equal volume of 13% polyethylene glycol 6000, and the other part was mixed with a solution containing dextran sulfate, sodium phosphotungstate, and Mg2+, respectively. The mixed solutions were centrifuged (2000 g; 15 min). The supernate obtained by the former procedure contained both apo E-rich HDL and apo E-poor HDL, but that obtained by the latter procedure contained solely apo E-poor HDL. The serum apo E-rich HDL concentration in terms of apo E (E) and cholesterol (C), was given by the following equations: E = EP x 2, and C = (CP - CD) x 2, where EP and CP were the concentrations of apo E and cholesterol, respectively, in the supernate obtained with 13% polyethylene glycol, and CD was the concentration of cholesterol in the supernate obtained with the mixture solution of dextran sulfate, sodium phosphotungstate, and Mg2+. Normal serum apo E-rich HDL concentrations were 2.6 +/- 1.5 and 6.7 +/- 2.3 mg/dl (means +/- SD, n = 38) in terms of apo E and cholesterol, respectively. Apo E-rich HDL was increased strikingly in the sera from three patients with hepatobiliary diseases.

Adult↗
PubMed1992

Peptide inhibitors for angiotensin I-converting enzyme from thermolysin digest of dried bonito.

Dried bonito (Katsuobusi), a Japanese traditional seasoning made of bonito muscle was hydrolyzed by various proteases and the inhibitory activity of the hydrolyzates for angiotensin I-converting enzyme (ACE) [EC 3.4.15.1] was measured. Among the digests, thermolysin digest showed the most potent inhibitory activity. Eight inhibitory peptides were isolated from the digest using HPLC. The amino acid sequences of inhibitory peptides were Ile-Lys-Pro-Leu-Asn-Tyr, Ile-Val-Gly-Arg-Pro-Arg-His-Gln-Gly, Ile-Trp-His-His-Thr, Ala-Leu-Pro-His-Ala, Phe-Gln-Pro, Leu-Lys-Pro-Asn-Met, Ile-Tyr, and Asp-Tyr-Gly-Leu-Tyr-Pro. By searching for the sequence homology in many proteins, four of them were found in the primary structure of actin. Asp-Met-Ile-Pro-Ala-Gln-Lys was obtained from the boiling water extract of dried bonito and this peptide was found in the primary structure of creatine kinase. Fragments of these peptides were prepared by further enzymatic digestion or chemical synthesis and their ACE-inhibitory activities were measured. Among them, Ile-Lys-Pro, Ile-Trp, Leu-Lys-Pro, and Leu-Tyr-Pro had higher inhibitory activity than their parental peptides. Ile-Lys-Pro suppressed the hypertensive activity of angiotensin I.

Amino Acid Sequence↗
PubMed1992

Menopause related changes of adrenocortical steroid production.

To elucidate changes of adrenocortical steroid production with age, reproductive age (n = 14), peri-menopausal (n = 12) and post-menopausal (n = 13) women were studied using basal hormone levels and the results of a rapid ACTH stimulation test. Peripheral serum levels of pregnenolone, 17 alpha-hydroxypregnenolone, 17 alpha-hydroxyprogesterone, dehydroepiandrosterone and androstenedione were measured by RIA. The basal levels of all steroids except pregnenolone decreased with age. A significant increase in the levels of all steroids after ACTH stimulation was observed in all subjects. Although, there was an age related decrease in the response of C19-steroids to ACTH, the response of pregnenolone and 17 alpha-hydroxyprogesterone to ACTH did not alter with age. The preserved response of 17 alpha-hydroxyprogesterone to ACTH in post-menopausal women suggests that 17 alpha-hydroxyprogesterone production plays a role in the age independency of cortisol. In the present paper, the changes in the capacity of the post-menopausal adrenal cortex to produce androgens and C21-steroids were demonstrated.

17-alpha-Hydroxypregnenolone↗
PubMed1992

[A case of hyperalphalipoproteinemia with complete deficiency of cholesteryl ester transfer activity].

A 68-year-old male patient with benign hypertension shows high levels of high density lipoprotein cholesterol (HDL-C) of 171 mg/dl. The serum total cholesterol was 240 mg/dl. An abnormal slow alpha band and polydisperse low density lipoprotein (LDL) bands were detected by agarose gel and polyacrylamide gel electrophoresis. The slow alpha band was considered as an apo E-rich HDL. A peak of large HDL particle and a peak of abnormal high-molecular-LDL particle were observed in the patient's serum by gel permeation high performance liquid chromatography. Cholesteryl ester transfer activity (CETA) of the patient's serum was completely deficient (0.0%/10 microliters/18 hr). From these results, it is strongly suggested that patient's hyper-HDL-cholesterolemia caused by a complete deficiency of CETA.

Aged↗
PubMed1992

[Recovery of ovarian function during postpartum period].

To determine the effect of serum prolactin (PRL) on the recovery of ovarian function in the postpartum period, FSH, PRL, estradiol (E2), and 17 alpha-OH-progesterone (17-P) levels were measured in postpartum women and the levels were compared with those in patients treated with bromocriptine. In addition, hMG was given for two days on the 10th and 30th postpartum days to the mothers treated with/without bromocriptine. On the 10th day, FSH levels tended to increase and the E2 and 17-P levels were significantly increased by bromocriptine treatment and these levels are compatible to those on the 30th day in the control group. Although no apparent change in E2 and 17-P levels was observed before and after hMG administration in the control, a significant increase in E2 on the 30th day and in 17-P on the 10th and 30th day was observed when the patients were treated with bromocriptine. These results suggest that high concentrations of PRL in the postpartum period suppressed the ovarian function not only due to the low gonadotropin secretion but also to the poor ovarian response to gonadotropin. 17-P seems to be preceded by estradiol secretion in the recovery of ovarian function during the postpartum period.

17-alpha-Hydroxyprogesterone↗
PubMed1991

Apolipoproteins in rat cerebrospinal fluid: a comparison with plasma lipoprotein metabolism and effect of aging.

Cerebrospinal fluid (CSF) apo E concentrations, determined by a sensitive sandwich ELISA, were 411.3 +/- 76.0 and 454.3 +/- 51.8 micrograms/dl (mean +/- S.D.) for young rats (8-12 weeks old, n = 7) and old rats (36-40 weeks old, n = 10), respectively. Age-related increase, which was conspicuous in serum apo E (21.2 +/- 2.4 vs 60.9 +/- 14.1 mg/dl for young and old rats, respectively), was not observed in CSF apo E. CSF apo A-I concentrations, determined by ELISA, were extremely low in the both groups (less than 10 micrograms/dl). Neither CSF apo A-I nor CSF apo E correlated to any of the plasma lipoprotein components, indicating the presence of largely independent lipoprotein metabolism in the rat central nervous system. Apo E is present in CSF in the form of apo E-rich HDL1 with particle sizes similar to those of plasma E-rich HDL1.

Aging↗
PubMed1991

[Prolactin, ovarian and adrenal steroid hormone in relation to the vaginal opening in immature female rats].

The serum prolactin levels in human girls are thought to be increased gradually throughout puberty, but some authors have reported that prolactin decreases transitorily before menarche. Prolactin has not been shown to play a significant role on the initiation of human pubertal development. However, in immature female rats, it is thought that prolactin is one of the most important hormones during sexual maturation. In experiment I, the serum concentrations of prolactin, estradiol (E2) and dehydroepiandrosterone-sulfate (DHA-S) in immature female rats were measured. Prolactin increases gradually before vaginal opening and tends to decrease after vaginal opening, while E2 increases throughout sexual maturation. No significant changes were noticed in DHA-S levels. In experiment II, sulpiride, which raises serum prolactin level, was injected daily in to 4 groups of immature female rats starting from 14, 21, 28, and 35 days of age till the day before vaginal opening. Physiological saline solution was injected daily in to age-matched controls. On the day of vaginal opening, serum levels of prolactin, E2 and DHA-S were studied, weights of bodies and internal genital organs were measured, and corpora lutea of the ovaries were inspected. Vaginal opening was accelerated in the group of rats injected with sulpiride 5mg every morning from 14 days of age (p less than 0.05). The weights of their bodies and internal organs were less than those of the control rats (p less than 0.05). Percent of ovaries which contained corpora lutea were lower than the controls. Although their serum levels of prolactin tended to be suppressed, three hormone levels were not different from those of control rats on the day of vaginal opening. However, when mean prolactin levels were depicted on the day of vaginal opening in both groups, a peak was noticed at 37 days of life, indicating that the secretion pattern of this hormone has been programmed according to the day of life. There was a close relation between prolactin and DHA-S levels (p less than 0.05). No significant relation between prolactin and E2 levels was noticed. The possible role of prolactin and DHA-S on the regulation of sexual development is suggested. To our knowledge, this is the first demonstration of a significant relation between prolactin and DHA-S in immature female rats.

Age Factors↗
PubMed1991

Spurious elevation of serum high-density lipoprotein cholesterol in patients with cholestatic liver diseases.

Strikingly discrepant values were obtained by two commercial precipitating reagents for serum HDL cholesterol determination in three patients with cholestatic liver diseases (two patients with primary biliary cirrhosis and one patient with chronic hepatitis). An abnormal alpha 2-migrating lipoprotein (slow alpha-lipoprotein) was observed in agarose gel electrophoresis for each serum. The slow alpha-lipoprotein was partly recovered in the supernatant by precipitation with polyethylene glycol, and was completely precipitated with a polyanion-containing reagent, which well explains the discrepancy. The slow alpha-lipoprotein isolated from one of the cases is notable for (1) having an intermediate particle size between normal LDL and normal HDL, (2) containing apo E as the major apolipoprotein, and (3) being enriched with cholesterol (esterified and free) and phospholipid. Cholesterol accumulation was also found in another HDL subclass, alpha 1-migrating HDL. A severe impediment in the clearance of cholesterol-loaded HDL particles from plasma was implied. Electrophoresis of serum lipoproteins and/or the measurement of serum apo E concentrations are necessary to avoid an erroneous estimation of HDL cholesterol in patients with hepatobiliary diseases.

Adult↗
PubMed1991

A sensitive sandwich enzyme-linked immunosorbent assay of rat apolipoprotein A-I: effect of various sample treatments on apolipoprotein A-I immunoreactivity and an application to young and aged rat sera.

A highly sensitive sandwich enzyme-linked immunosorbent assay for rat apo A-I was developed. Samples and standards were added to each well of microtiter plates precoated with immunoaffinity-purified IgG. Bound apo A-I was detected with immunoaffinity-purified Fab'-horseradish peroxidase conjugate by a colorimetric method. The sensitivity reached 2.5 pg/well, and the working range for the measurement of serum apo A-I concentration was 0.1 to 1.0 ng/well. The mean intra- and interassay coefficients of variation were 2.8 and 4.1%, respectively. The epitopes of apo A-I in serum were effectively exposed by the use of 6 mol/liter guanidine.HCl. Serum apo A-I concentrations in 36- to 40-week-old rats (62.3 +/- 8.6 mg/dl, mean +/- SD, n = 16) were significantly higher (P less than 0.05) than those in 8- to 12-week-old rats (55.1 +/- 4.3 mg/dl, n = 9). But the age-related change of serum apo A-I was much smaller than that of serum apo E. Apo A-I was contained in smaller HDL particles (or HDL2) in normal rat serum.

Aging↗
PubMed1991

[Changes in the values of estrogen stimulated neurophysin, oxytocin and prostaglandin in the maternal blood after the administration of dehydroepiandrosterone-sulfate to the pregnant women near term].

UNLABELLED: In order to examine the effect of dehydroepiandrosterone-sulfate (DHA-S) on the production of uterus-contractive substances in perinatal women, the concentrations of estrogen stimulated neurophysin (ESN), oxytocin, 13, 14-dihydro-15-keto-Prostaglandin F2 alpha(PGF2 alpha) and DHA-S related steroids in the maternal blood of 12 cases of primigravida were serially estimated after intravenous administration of 200mg DHA-S twice a week from 38 weeks of gestation till the onset of labor. RESULTS: 1) The duration of labor was significantly shortened in the DHA-S group (mean; 9.3 +/- 2.8 hours) compared to the 11 control cases (13.5 +/- 5.2 hours). 2) i) The ESN concentration, which correlated well with that of free estradiol-17 beta, increased significantly at 1 week after the Ist administration. ii) The oxytocin concentration, which correlated well with that of ESN, increased significantly at 39 weeks of gestation, the first stage of labor and especially at delivery compared to the control. iii) The PGF2 alpha concentration, which increased in parallel with those of DHA-S, estrone-S and pregnenolone-S, increased significantly at delivery in comparison with the control and correlated well with estrone-S in the DHA-S group. CONCLUSION: These findings suggest that DHA-S administration to perinatal women may enhance the production of ESN, oxytocin and PGF2 alpha in the fetoplacento-maternal compartment, which may result in the shortening of labor.

Dehydroepiandrosterone↗
PubMed1991

[An adult case of the left coronary artery anomalously originating from the pulmonary artery (BWG syndrome), demonstrating remarkable improvement in postoperative thallium-201 myocardial imaging].

Stress thallium-201 myocardial scintigraphy were performed in a 44-year-old female with BWG syndrome before and after aorto-coronary bypass surgery. Preoperative stress thallium-201 studies demonstrated anterior reversible perfusion defect and posterior persistent defect. But postoperative studies demonstrated no defects in both areas. These data suggest that preoperative anterior defect was due to transient myocardial ischemia, but the finding of posterior persistent defect wasn't due to infarction or scarring. Thus, stress thallium-201 myocardial imaging provided useful informations to clarify the myocardial perfusion patterns pre- and postoperatively.

Adult↗
PubMed1991

[201Tl-reverse redistribution in a case with stunned myocardium].

A 58-year-old man was admitted to our hospital because of chest pain. Electrocardiogram showed giant negative T waves in leads I, II, III, aVl, aVf and V2 through V6. Echocardiogram showed anterior wall motion abnormality. Rest-redistribution thallium scan obtained 3 days after admission revealed reverse redistribution in antero-apical area. Coronary angiogram showed no significant stenotic lesions and left ventriculogram in chronic stage showed improvement of wall motion abnormality. Repeat thallium scan in chronic stage showed disappearance of perfusion defect in apical area. It was difficult to diagnose myocardial viability in our case with stunned myocardium because rest-redistribution thallium scan showed reverse redistribution. As the mechanism of this finding, early coronary recanalization in acute stage of the event was suspected.

Coronary Disease↗
PubMed1990

[A study of non-aromatizing androgen C10-19lyase in adrenal tissue].

The conversion of androgen to estrogen is mediated by aromatase activity, and 19-hydroxylase and C10-19lyase are seen to be involved in C19-demethylation. The present study is to demonstrate C10-19lyase activity in adrenal tissue. Fetal bovine and pig adrenal tissue homogenates were incubated with 14C-androstenedione(A) and NADPH under air. The products 14C-19-OHA, 14C-19-norA, with added carrier standard 3H-19-OHA, 3H-19-norA were separated and purified by T.L.C.. The identification of 19-norA was established by recrystallization and that of 19-OHA by C.C.D.. The 3H/14C ratios of the products 19-norA were found to be constant in repeated crystallization. The amount of 19-OHA from A in fetal adrenal tissue was 30.0nmol/h/g protein, and that of 19-norA from A was 12.59pmol/h/g protein. C10-19lyase activity from 19-OHA, calculated by the amounts of 19-norA in fetal, bovine and pig adrenal tissue, was 49.7, 3.50, 10.3pmol/h/g protein, respectively. This is the first report to demonstrate androgen C10-19lyase in human fetal adrenal tissue, and it is assumed that fetal adrenal tissue forms 19-norA via 19-OHA.

Adrenal Glands↗
PubMed1990

Expression of guinea-pig liver transglutaminase cDNA in Escherichia coli. Amino-terminal N alpha-acetyl group is not essential for catalytic function of transglutaminase.

Transglutaminases (EC 2.3.2.13) catalyze the formation of epsilon-(gamma-glutamyl)lysine cross-links and the substitution of a variety of primary amines for the gamma-carboxamide groups of protein-bound glutamine residues. These enzymes are involved in many biological phenomena. Transglutaminase reactions also have been shown to be suitable for applied enzymology. In this study, as a first step of studies to elucidate the structure/function relationship of transglutaminase, we constructed an expression plasmid, pKTG1, containing a cDNA of guinea-pig liver transglutaminase between the NcoI and PstI sites of an expression vector, pKK233-2, and produced the liver transglutaminase as an unfused protein in Escherichia coli. The purified recombinant enzyme was indistinguishable from natural liver transglutaminase in some structural properties such as molecular mass, amino acid composition, and amino- and carboxyl-terminal sequences. However, the alpha-amino group of the amino-terminal alanine residue of the recombinant transglutaminase was not acetylated as was that of the natural enzyme. Comparison of the recombinant enzyme with the natural one did not indicate significant differences in specific activity and apparent Km values for substrates in the histamine incorporation into acetyl alpha s1-casein. The sensitivity to activation by Ca2+ and the rate of catalyzed protein cross-linking were also similar between recombinant and natural transglutaminases. These results indicated that the N alpha-acetyl group in natural liver transglutaminase has not a particular role in the catalytic function of this enzyme.

Acetylation↗
PubMed1990

Sandwich enzyme-linked immunosorbent assay of rat apolipoprotein E.

A sandwich ELISA for rat apo E was developed. Blood was drawn from rats that had been administered with triamcinolone diacetate to increase apo E-rich HDL in serum. Apo E was purified from the d less than 1.225 g/ml lipoproteins, and antiserum was raised in rabbits. Diluted samples and standards were added into the wells of polystyrene microtiter plates precoated with immunoaffinity-purified IgG and incubated for 90 min. After washing, immunoaffinity-purified Fab'-horseradish peroxidase conjugate was added to each well and incubated for 90 min. The bound enzyme was assayed by a colorimetric method. Samples and standards were pretreated with 6 M guanidine. HCl to maximize the antigenic response of apo E. The sensitivity lies around 1 pg apo E, and the working range was 0.1 to 1.0 ng. All assay procedures were completed within 4-5 hr. The mean intra- and interassay coefficients of variation were 1.8 and 4.1%, respectively. Serum apo E concentrations were 21.2 +/- 2.1 and 61.3 +/- 17.0 mg/dl (mean +/- SD) for young (8-12 weeks old, n = 9) and old (36-40 weeks old, n = 16) rats, respectively. As determined by gel filtrations, most of the apo E in fasted rat serum was associated with larger HDL particles (or HDL1) and a small portion of apo E was present in a free form.

Aging↗
PubMed1990

Detection of human papillomavirus DNA in genital condylomata in women and their male partners by using in situ hybridization with digoxygenin labeled probes.

Twelve couples (12 women and their male partners) presenting genital warts were investigated in order to evaluate the sexual transmission of human papillomavirus (HPV) in mutual partners and the localization of HPV DNA. Formalin-fixed, paraffin-embedded biopsy samples of 12 vulvar condylomata, and 12 penile condylomata from male partners were analyzed for the presence of HPV DNA-6, -11, and 16/18 by using in situ hybridization with digoxygenin labeled DNA probes. HPV DNA was identified in 9 women (75%) and in 9 men (75%). HPV-6 was frequently identified, being revealed in 42% of the vulvar specimens, in 67% of the cervical specimens and 58% of the penile specimens. Seven of 9 (77%) positive couples shared the same HPV DNA, and 2 couples harbored different HPV DNA types between the partners. The signal intensity of the HPV DNA was generally strong in superficial cell layers, weak in parabasal or basal cell layers. No malignant lesions resulted from the condyloma acuminatum caused by HPV-6 or -11. There were only mild dysplasia in the both sexes.

Condylomata Acuminata↗