Biomedical subjects
Publications and source records attributed to K Kurachi.
Explore the source record for details and available documents.
Recombinant plasmids containing human and baboon cDNA have been screened for alpha 1-antitrypsin, a major serine protease inhibitor present in blood. One plasmid, designated pBa alpha 1a2, was found to contain a cDNA insert of 1352 base pairs coding for the baboon inhibitor. It included 45 nucleotides that code for 15 amino acids present in the amino-terminal signal sequence of the protein, 1182 nucleotides that code for 394 amino acids in the mature protein, a stop codon, and a noncoding region of 76 nucleotides. Comparison of the amino acid sequences of baboon alpha 1-antitrypsin, human antithrombin III, and chicken ovalbumin indicated that these three proteins are about 230% homologous. A second plasmid, designated pH alpha 1a1, was found to contain a human cDNA insert of 306 base pairs. This plasmid coded for 69 amino acids present in the carboxyl-terminal region of human alpha 1-antitrypsin. The human and baboon cDNAs and their amino acid sequences are greater than 96% homologous.
Carboxypeptidase A gamma from porcine pancreas was purified to homogeneity by ammonium sulfate fractionation, autolysis, batch absorption and elution from DEAF-Sephadex, and crystallization. The overall purification was about 32-fold with a yield of 31% and the specific activity of the purified protein was 108 units/mg protein. The apparent relative molecular mass determined by gel filtration on a Sephadex G-200 column was 38 900. The amino-terminal sequence of the porcine carboxypeptidase A gamma was Asn-Tyr-Ala-Thr-Tyr-His-Thr-Leu-Glu-Glu-Ile-Tyr-Asp-Phe-Met-Asp-Ile-Leu-Val-Ala -Glu-His-Pro-Gln-Leu- which was highly homologous to that of bovine carboxypeptidase A gamma. The purified enzyme was characterized with respect to isoelectric point (4.3). Km for N alpha-carbobenzoxyglycyl-L-phenylalanine (Cbz-Gly-LPhe) (20 mM), amino acid composition, pH optimum, pH stability, stability at different temperatures and effect of drying. The enzyme contained 1.01 mol zinc/mol and was inhibited by chelating agents such as EDTA and o-phenanthroline. Among substrates such as Cbz-Gly-LPhe, N alpha-benzoylglycyl-L-arginine, various kinds of amino acid esters, casein and elastin, porcine carboxypeptidase A gamma showed an enzymatic activity only towards Cbz-Gly-LPhe and casein. These data are in good agreement with the substrate specificity of bovine carboxypeptidase A.
Maternal thyroid regulation in pregnancy was examined by measuring the concentrations of TRH, T4, T3, free T4 (by RIA), T4-binding globulin, TSH, PRL, and hCG in the sera of 30 normal pregnant women, 10 puerperally lactating women, and 10 normal pregnant women, 10 puerperally lactating women, and 10 normal nonpregnant female controls. Results showed that serum T4, T3, T4-binding globulin, PRL, and hCG, but not free T4 (by RIA), increased significantly during pregnancy. The plasma level of TRH was significantly higher (P less than 0.01) in the second trimester and significantly lower (P less than 0.05 1 month post partum than those values in nonpregnant controls. No significant correlations, however, were observed between the serum level of TRH and those of the thyroid hormones TSH, PRL, and hCG in pregnancy. The TRH-degrading activity of the plasma in the second trimester was normal. These results indicate that TRH secretion may be increased in the second trimester of pregnancy.
The recovery of the ovarian response to gonadotropin stimulation after molar abortion was investigated in relation to the serum human chorionic gonadotropin (hCG) level. Thirteen women with an aborted mole were given 225 IU of human menopausal gonadotropin (hMG) per day for 3 consecutive days, and their serum levels of estradiol (E2) were determined by radioimmunoassay on days 1, 3, 5, and 7 after hMG administration. Women with serum hCG levels of less than 200 mIU/ml exhibited a normal increase in serum E2 levels in response to hMG, whereas women with serum hCG levels of 2000 mIU/ml or more did not show any change after hMG administration. These findings suggest that a serum level of hCG in excess of 2000 mIU/ml prevents normal ovarian E2 responsiveness to exogenous gonadotropin stimulation.
Immunoperoxidase reactions with the use of anti-HCG antibody was applied to formalin-fixed and paraffin-embedded sections of 52 squamous cell carcinomas of human uterine cervix. These include 19 cases of carcinoma in situ, 5 microinvasive and 28 invasive squamous cell carcinomas. We found that the HCG-like antigen was present in a few cells of cancer cell nests and didn't distribute as found on the syncytiotrophoblastic cells. We couldn't correlate the presence or absence of HCG-like antigen to histological degrees of cancer cell differentiation and lymphocyte infiltrations. This antigen seemed to occur in lymphatic type more than in cirrhotic type, although no statistical significant correlation could be found. These results were discussed in the association of immunological meaning of HCG.
The ability of amine production of argyrophil cell adenocarcinoma of the endometrium was studied by wet-histofluorescence method. The intense green and yellow fluorescence was detected for the first time in the cytoplasm of a few tumor cells by injecting amine precursor (L-Dopa) 3mg intraperitoneally to nude mice, who were transplanted serially with argyrophil cell adenocarcinoma of the endometrium. Similar fluorescence was also located in a few epithelial cells of the small intestine prepared from the same nude mice. These findings strongly suggested that these fluorescent products were amines. In order to specify the sorts of amines, the microspectrophotometric analyses are now in progress.
The measuring methods of fetal rolling movements, which are very important diagnostic informations at the case of Non Stress Test, are analysed. In normal pregnant women (from 29 to 40 gestational weeks), the observation of fetal head and trunk rolling movements by real-time B-scan, and maternal perception of fetal movements are simultaneously recorded in analog data recorder. Analysing these recorded data, we found that 76.7% of fetal rolling movements could be detected by observation of head rolling movements only, and 72.4% with trunk observation only. But maternal perception could find only 28.5% of fetal rolling movements. These results and analysis may suggest us that, if only one machine is available, the observation of fetal head rolling movements by real-time B-scan is the most effective method for the analysis if fetal rolling movements on NST.
Explore the source record for details and available documents.
The activation of plasma prekallikrein by single-chain factor XII has been studied in the presence of high molecular weight kininogen and kaolin. The data indicate that factor XII can initiate blood coagulation, fibrinolysis or kinin generation in the presence of kaolin and does so by converting prekallikrein to kallikrein. An enzyme cascade is then generated leading to the formation of fibrin, plasmin or bradykinin in three closely related physiological events.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Plasma levels of immunoreactive luteinizing hormone-releasing hormone (LH-RH) in 89 women with normal menstrual cycles and 109 patients with amenorrhea of various etiologies were determined by specific radioimmunoassay after methanol extraction. The LH-RH levels in patients with hypergonadotropism and Sheehan's syndrome were more than 10 pg/ml, and were significantly higher than basal levels during normal cycles (4.2 +/- 0.3 pg/ml). The mean levels of LH-RH were low in all hypogonadotropic patients with amenorrhea, with the exception of a few patients who showed high LH-RH levels suggestive of a pituitary lesion. The LH-RH levels in patients with polycystic ovary syndrome were comparable with basal levels during normal cycles. It is concluded that, although there is considerable overlap of the plasma LH-RH levels in each group of amenorrheic patients divided according to gonadotropin level, determination of LH-RH levels may be useful for the differentiation of hypothalamic amenorrhea from pituitary amenorrhea.
The mechanisms by which alpha 1-antitrypsin and antithrombin III inhibit trypsin were investigated by chemical stability studies and amino acid sequence analyses of the enzyme-inhibitor complexes. One-to-one covalently linked complexes were formed between each of the inhibitors and trypsin. The complexes were stable over the course of the experiments at pH 8 or lower, and benzamidine, hydroxylamine, thiols, guanidine, or dodecyl sulfate had no apparent effect on the stability of the complexes. The complexes dissociated slowly at pH 9 or greater. Neither of the inhibitors was active after dissociation from its complex with trypsin. Sequence analysis indicated that no new amino terminus was generated when alpha 1-antitrypsin formed its complex with trypsin, but that two new amino termini were formed in approximately one-to-one ratio when the complex dissociated. This may indicate that alpha 1-antitrypsin contains two inhibitory sites for trypsin in close spatial proximity on the molecule.
The concentration of luteinizing hormone-releasing hormone (LH-RH) in both cerebrospinal fluid (CSF) and plasma in 36 women with various conditions were determined, and the correlation of LH-RH concentrations between plasma and CSF was studied. Paired samples of plasma and CSF were obtained just before operation and were extracted with methanol for LH-RH radioimmunoassay. LH and FSH were also measured by radioimmunoassay. The mean plasma LH-RH levels were 3.79 pg/ml in the follicular phase, 4.15 pg/ml in the luteal phase, 12.73 pg/ml in postmenopausal women and 2.31 pg/ml in pregnant women at term. No immunoreactive LH-RH in the CSF was found in 29 out of 36 subjects, and the remaining 7 subjects showed very low levels (less than 0.95 pg/ml). The LH-RH levels in the CSF of post-menopausal women were not higher their those in the remaining 3 groups, although their plasma levels of LH-RH were significantly (p less than 0.001) elevated. The mean plasma levels of LH and FSH in post-menopausal women were significantly higher than those in normal cyclic women and in pregnant women. The present results suggest that little or no LH-RH is present in the CSF, and it is not clear that there is any correlation between the LH-RH level of plasma and those of CSF.