Search PubMed⌕ Search

Biomedical subjects

K Kurachi

Publications and source records attributed to K Kurachi.

At least 235 records · Page 13Linked to original sources
PubMed1976

[Estrogen receptor in human endometrium--energy requirement, stability and subunit structure-- (author's transl)].

1) In our previous paper, it was reported that in human endometrium the step of formation of nuclear receptor -estradiol complex was not temperature dependent but in rat uteri temperature dependent. In order to clarify whether this temperature dependency in rat uteri means an energy requirement for this step or not, experiments with 2,4 dinitrophenol as an energy uncoupler were done. Even when rat uteri or endometrium of women were incubated with 10 muc of 3H-estradiol and 10(-4)M of 2,4-dinitrophenol, 8S estrogen receptor-E2 complex in cytosol and 5S estrogen receptor-E2 complex in nuclear extract were recognized in both rat and woman. Namely, no evidence was recognized for this step to require activation energy in rat uterus as well as in human endometrium. 2) The cytosol fraction was prepared after human endometrium had been incubated with 3HE2 at 2 degrees C. Cytosol was analysed on sucross density gradient after heat treatment (at 10 degrees C, 31 degrees C or 37 degrees C). At 31 degrees C and 37 degrees C treatment, the 8S receptor peak was difficultly recognized. Namely, the 8S receptor-E2 complex was heat labile in cell free condition. This appears to be one of the reasons why 8S cytosol receptor was not visible in human endometrium incubated with 3HE2 at 37 degrees C. 3) When the cytosol fraction from the human endometrium was analysed on 3--20% linear sucrose gradient containing 0.4M KCl, the 8S peak diminished and about 4S peak appeared. This was considered to mean that 8S receptor in human endometrium was also split to a 4S binding unit at high salt condition and the 8S receptor in humans had also a subunit structure. 4) 8S receptor in cytosol and 5S receptor in nuclear fraction were recognized in one case of human endometrial carcinoma, but in another case both receptors were not recognized. 5) Estrogen binding protein in human serum was sedimented at 6S fraction by sucrose gradient.

Animals↗
PubMed1976

Characterization of human, bovine, and horse antithrombin III.

A comparison of the physical-chemical properties of human, bovine, and horse antithrombin III has been made. These three plasma proteins are strong inhibitors of bovine factor Xa and form a 1:1 molar complex with this coagulation enzyme. Human, bovine, and horse antithrombin III are glycoproteins containing hexose, hexosamine, and neuraminic acid. The total carbohydrate was 9, 12, and 16% for human, bovine, and horse antithrombin III, respectively. These proteins have a similar amino acid composition, although some monor variations were noted. Each antithrombin III is composed of a single polypeptide chain with an amino-terminal histidine residue. Of the first 17 amino-terminal residues, only three differences were noted between the three proteins. These occur in position 2 which is occupied by Gly, Arg, and Trp in human, bovine, and horse, respectively; position 6 which has a deletion in human antithrombin III; and position 8 where Ile in human and horse antithrombin III has been replaced by Val in the bovine preparation. The remainder of the first 17 residues is the same in all three proteins. The molecular weights for the bovine and horse preparation were 56 600 and 52 500, respectively, as determined by sedimentation equilibrium in the presence of guanidine hydrochloride. Some immunological cross-reactivity was also observed between the three different proteins.

Amino Acids↗
PubMed1976

Inhibition of bovine factor IXa and factor Xabeta by antithrombin III.

Factor IXa and factor Xabeta are serine proteases which participate in the middle phase of blood coagulation. These two enzymes are inhibited by antithrombin III by the formation of an enzyme-inhibitor complex containing 1 mol of enzyme and 1 mol of antithrombin III. The complex was readily demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and loss of coagulant or esterase activity at increasing concentrations of inhibitor. The inactivation of factor IXa by antithrombin III was relatively slow, but the reaction was greatly accelerated by the addition of heparin.

Animals↗
PubMed1976

[Studies on the measurements of LH-releasing hormone (LH-RH) by radioimmunoassay (RIA) (author's transl)].

The radioimmunoassay for LH-RH would aid greatly in the assessment of hypothalamic function. The anti-LH-RH was prepared by immunizing rabbits with LH-RH conjugate of BSA. 125I-LH-RH was prepared by the lactoperoxidase method and Sephadex G-10 column chromatography. The double antibody RIA technique was employed. On the assay of biological materials, LH-RH was extracted by methanol because LH-RH was rapidly destroyed in the serum, and this breakdown could not be prevented by benzamidine or 2,3-dimercaptopropranol. Sensitivity of this RIA system ranged from 10 tp 104 pg/ml, and the coefficient of variations of intra- and interassay were 12.9% and 9.% respectively. The serum LH-RH levels of men in a normal gonad state were below 10 pg/ml, and those of women in a normal gonad state in the early follicular or luteal phase were below 50 pg/ml. Whereas those of postmenopausal or castrated women were increased, and were highest in women with several gonadal disturbed states. The disappearance curve of LH-RH in women was characterized by two exponentials, t(1/2) of the initial component was 4.9 min, and that of the second component 24.6 min. Urinary excretion of exogenously administered LH-RH was also studied.

Amenorrhea↗
PubMed1976

Pregnancy following 2-bromo-alpha-ergocryptine (CB-154)-induced ovulation in an acromegalic patient with galactorrhea and amenorrhea.

An acromegalic patient with galactorrhea-amenorrhea who conceived following long-term 2-bromo-alpha-ergocryptine (CB-154) therapy is described. During CB-154 therapy, determinations of serum prolactin (PRL), luteinizing hormone (LH)-human chorionic gonadotropin, follicle-stimulating hormone a reduction in PRL level followed by an LH peak, a rise in basal body temperature and menstruation. The patient became pregnant during the next cycle, but therapeutic abortion was performed because of the active acromegaly. These results demonstrate that CB-154 can restore ovulatory function not only to the patient with a hypothalamic disorder but also to the acromegalic patient with an enlarged sella turcica.

Acromegaly↗
PubMed1976

Formation of 5alpha-reduced C19-steroids from progesterone in vitro by a pathway through 5alpha-reduced C21-steroids in ovaries of late prepubertal rats.

Ovarian homogenates from 10-150-day-old rats were incubated with [3H]progesterone and NADPH. Also, ovarian homogenates from 28-day-old rats were incubated for 5-180 min with either [14C]progesterone, [3H]5alpha-pregnane-3,20-dione or [14C]progesterone plus [3H]5alpha-pregnane-3,20-dione. Following incubation, radioactive metabolites were isolated, identified, and measured by column and paper chromatography, with derivative formation and recrystallizations to constant specific activity. Prepubertal ovaries (10, 20, and 28 days of age) converted 15-60% of progesterone to C21-17-hydroxysteroids and C19-steroids. At 40 and 150 days of age (postpubertal), the formation of these steroids decreased to less than 2%. At 10 and 150 days of age, the major C19-steroids formed from progesterone were androstenedione and testosterone. At 20 and 28 days of age, however, no accumulation of these C19-delta4-3ketosteroids was found (less than 0.1% of each), at which time the conversion of progesterone to 5alpha-reduced C19-steriods, such as androsterone and 5alpha-androstane-3alpha,17beta-diol, reached 30%. In ovaries of 28-day-old rats, the results from incubation studies for the detection of metabolic pathways indicated two biosynthetic pathways leading to 5alpha-reduced C19-steroids, one from progesterone via 5alpha-reduced C21 steroids, such as 3alpha-hydroxy-5alpha-pregnan-20-one and 3alpha,17alpha-dihydroxy-5alpha-pregnan-20-one, and a second via 17-hydroxyprogesterone, androstenedione, and testosterone. It seems that the active 5alpha-reduction of C19-delta4-3-ketosteroids and the formation of 5alpha-reduced C19-steroids by the pathway through 5alpha-reduced C21-steroids, are present in the ovaries of older prepubertal rats and may be the biological significance.

Androgens↗
PubMed1976

Influence of surgical stress under general anesthesia on serum gonadotropin levels in male and female patients.

Effects of surgical stress under the same general anesthesia (nitrous oxide, oxygen and halothane following induction with thiopental and succinylcholine chloride) on serum LH levels were studied in 18 postmenopausal females, 15 menstruating females and 17 males. In addition, serum FSH levels in female patients and testosterone levels in male patients were estimated. As controls without surgery and anesthesia, serum levels of LH, FSH and testosterone were estimated at identical time intervals to the experimental group in 15 normal postmenopausal females, 15 normal menstruating females and 10 normal males. In male patients, serum LH levels at 30 min and 1 hr after onset of anesthesia increased significantly over those of pre-anesthesia, while no significant intra-operative increase in LH levels was found in female patients. In male and female patients, the LH levels decreased slightly 5-6h and 2 days after onset of anesthesia, though the decreases were not statistically significant except in postmenopausal females. On the 7th postoperative day, the LH levels returned toward the baseline. In female patients, no significant intra-operative changes in FSH levels were found. In male patients, there were significant intra- and post-operative decreases in testosterone levels. In control subjects, no significant changes in serum levels of LH, FSH and testosterone were demonstrated. These observations suggest that significant intraoperative increases in serum LH levels occur in males but not in females.

Adult↗
PubMed1976

Suppression of luteinizing hormone in castrated women by the administration of human chorionic gonadotropin.

The suppressive effect of human chorionic gonadotropin (hCG) on luteinizing hormone (LH) and/or LH-beta was studied by specific LH-beta radioimmunoassay following hCG administration. Eight castrated women were each administered 10,000 IU of hCG in a single intramuscular injection and five women in the control group were injected with saline. The serum level of hCG increased after the injection, reaching 217.6 mIU/ml after 8 h. There was a significant suppression of LH levels as compared to those of the control group and the pre-injection levels: 68.2% 1 h after injection, 64.7% after 2h, 65.5% after 4 h, 77.0% after 8 h, 78.6% after 12 h, and 78.2% after 24 h. There was no significant suppression of the follicle-stimulating hormone (FSH) as compared to the preinjection and control values. Serum concentration of estradiol1 was not detectable either before or after the hCG injection. We conclude that hCG has a suppressive effect on LH and/or LH-beta secretion not mediated by estradiol.

Adult↗
PubMed1975

[Pathophysiology of gonadotropin secretion in patients with idiopathic precocious puberty and follow up studies during and after therapy with medroxyprogesterone acetate (author's transl)].

In order to assess the pathophysiology of gonadotropin secretion in patients with idiopathic precocious puberty, responses of LH and FSH to LH-releasing hormone (LH-RH), clomiphene citrate (Clomid) and medroxyprogesterone acetate (Deop-provera) in 6 female patients were tested. The basal levels of serum LH and FSH were elevated in 4 of 6 patients and enhanced LH response to 100 mug of intravenous LH-RH was observed in 5 patients, while FSH response was comparable to that of prepubertal subjects. Administration of Clomid (50 mg) for 7 days provoked LH increase in 3 out of 6 patients in contrast to no LH change found in normal prepubertal girls. while FSH levels decreased in 3 out of 6 patients. Intramuscular injection of Depo-Provera (100 mg) reduced LH and FSH levels in 4 patients. The Depo-Provera therapy in a dose of 75 approximately 225 mg every two weeks, caused suppression of breast development and menstrual bleeding but the prevention of growth spurt and bone age maturation were insufficient. Basal body temperature charts in 2 patients showed an ovulatary pattern immediately following cessation of Provera therapy of more than 8 years' duration. In conclusion, it is suggested that 1) function of hypothalamo-pituitary-ovarian system in patients with idiopathic precocious puberty is similar to that of normal pubertal subjects, 2) therapeutic doses of Depo-Provera, enough to suppress the patients' secondary sex characterics, was not sufficient to control bone age maturation 3) it is necessary to follow up patients more closely by measuring serum levels of gonadotropin and estrogen during the course of therapy.

Child↗
PubMed1975

Metal ion binding in triclinic lysozyme.

The binding sites of Mn2+, Co2+, and Gd3+ have been determined in triclinic lysozyme at pH 4.5 to 4.6. Mn2+ and Co2+ bind a site approximately 2.5 A from 1 of the oxygen atoms of the Glu-35 chain. The occupancy of the Mn2+ site is 0.22, corresponding to 1 bound ion for each 4.6 protein molecules. The occupancy of the Co2+ site is much lower, about 0.048. Gd3+ appears to be bound at two sites, the main one 2.5 A from an oxygen atom of the Glu-35 side chain, the other 3.1 A from an oxygen atom of the Asp-52 chain. The occupancy of both Gd3+ sites is low, 0.036 and 0.016, the latter being so low that the presence of the ion at this site is in doubt. The binding site of Mn2+ in the di(N-acetylglucosamine)-lysozyme complex has also been determined. It does not differ significantly from the Mn2+ binding site in the native protein, but the occupancy is lower, 0.16.

Acetylglucosamine↗
PubMed1975

[Studies on the RNA synthesized in the ovary of immature rats after HCG administration (author's transl)].

Although many researchers have reported that RNA synthesis in the ovary is enhanced by gonadotropin treatment, there are only a few papers concerning the character of newly synthesized RNA after gonadotropin treatment. In this paper, the RNA synthesized in the ovary of immature rats after HCG treatment was qualitatively studied. Immature female Sprague-Dawley rats were administered with 0.3 mc per rat of 3H-uridine at a certain time interval after injection of HCG (10 iu/rat) and the ovaries were subsequently isolated after 15, 30 or 60 minutes. RNA was extracted from the homogenate of the ovaries according to the hot phenol method after Scherrer and Darnell. The 3H-RNA thus extracted was treated with electrophoretically purified DNase to break down and remove DNA that mingled with it. The RNA solution ultimately obtained was analysed on a 3-20% sucrose gradient. The different fractions thus separated were then subjected to measurement of radioactivity and optical density at 260 mmug. The RNA extracted from the ovary of immature untreated rat labeled with 3H-uridine for 15 minutes showed a flat pattern of radioactivity from the top to the bottom fractions with low radioactivity. Otherwise, when labeled for one hour, the RNA showed a pattern of radioactivity like those of optical density at 260 mumu with peaks of r-RNAs and t-RNA. When the ovary was pulse-labeled with 3H-uridine for 15 minutes starting 2 hours after injection of HCG, the RNA with a large S value was synthesized and the pattern of variation in radioactivity was that of rising near the bottom fraction and declining with access to the top fraction. The results obtained by labeling for 15 minutes starting 40 hours after PMS administration were similar to those obtained in immature untreated rats. The patterns of radioactivity in RNA obtained by the labeling for 15 minutes starting 2 hours after HCG and 42 hours after PMS were similar to those starting 2 hours after only HCG injection. The patterns of radioactivity became similar to those of optical density at 260 mmu, when the ovaries were labeled for 30 or 60 minutes. From these results, it was suggested that the newly synthesized RNA 2 hours after HCG was constructed from m-RMA with rapid turn over and precursors of r-RNAs and t-RNA. This RNA synthesis was blocked by pretreatment with actinomycin but not by cycloheximide. From these results, it was suggested that enhancement in RNA polymerase activity or change in template capacity of DNA which would have an effect on RNA synthesis was not based on newly synthesized protein.

Animals↗
PubMed1975

Assessment of gonadotrophin secretion in women with anorexia nervosa.

The LH and FSH secretions in 21 patients with anorexia nervosa were assessed by radioimmunoassay. On a single iv injection of 100 mug LH-releasing hormone (LH-RH), 8 patients showed LH response comparable to that of normal cyclic women in the follicular phase, and 5 patients showed excessive response. Although the remaining 8 patients showed almost no LH response, infusion of 400 mug LH-RH or daily im injections of LH-RH restored gonadotrophin responsiveness to LH-RH in all patients tested. The initial rise in LH during clomiphene citrate treatment was observed in 3 out of 5 patients, but the second peak of LH was found in only one patient. The initial suppression of LH following iv injection of conjugated oestrogen (Premarin) was observed in 9 out of 10 patients but a rebound increase comparable to that in normal cyclic women in the mid-follicular phase was found in only 3 patients. These results seem to suggest that impaired hypothalamic function is the cause of gonadotrophin deficiency and the resultant anovulation in most patients with anorexia nervosa.

Adolescent↗