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Biomedical subjects

M Irie

Publications and source records attributed to M Irie.

At least 253 records · Page 14Linked to original sources
PubMed1983

Radioimmunoassays for two types of human urinary ribonucleases: differential determination of ribonucleases in human serum.

We developed radioimmunoassays for two types of human urinary ribonucleases. The assays are sensitive, reproducible and specific. One human urinary ribonuclease (RNase UL) showed strong immunological identity with human pancreatic ribonuclease, and the other ribonuclease (RNase Us) showed strong immuno cross-reactivity with human liver ribonuclease. There was no immuno cross-reactivity between these two urinary ribonucleases. Serum immunoreactive RNase UL was eluted as four peaks on phosphocellulose chromatography, whereas immunoreactive RNase US was eluted as a single peak. Serum content of immunoreactive RNase UL was 354 +/- 105 ng/ml (mean +/- SD) in normal individuals, and that of immunoreactive RNase Us was 15.9 +/- 5.7 ng/ml (mean +/- SD). No correlation was demonstrated between these two ribonuclease contents in serum.

Adult↗
PubMed1983

Studies on salivary gland ribonucleases. III. Purification and properties of three ribonucleases from bovine parotid gland.

Three alkaline ribonucleases [EC 3.1.4.22] were purified 4,500- to 7,850-fold from bovine parotid gland by repeated CM-Sephadex C-25 chromatography and Sephadex G-50 gel filtration, with a total recovery of about 33%. They were designated as RNase BP1, BP2, and BP3, based on their order of elution from a CM-Sephadex C-25 column. The molecular weights of these enzymes were estimated by gel electrophoresis to be 18,500, 18,000, and 14,000, respectively. These enzymes are very similar to RNase A in that they are inhibited by heparin, show preferential hydrolysis of C5'-O-P linkages adjacent to a cytosine nucleotide rather than a uracil nucleotide, and in their antigenic properties. Spermine was found to stimulate the activities of these enzymes; the degree of stimulation was in the order of RNase BP3 greater than BP2 greater than BP1. The stimulation by spermine is mainly due to the increased cleavage of C5'-O-P linkages adjacent to cytosine nucleotides. From the results of amino acid analysis, glycosidase digestion and amino-terminal sequencing, it was suggested that the differences in molecular weights of RNase BP1, BP2, and BP3 are due to the differences in carbohydrate contents. In addition, it was suggested that RNase BP3 is identical with RNase A.

Animals↗
PubMed1983

Modification of a major ribonuclease from Aspergillus saitoi with 1-cyclohexyl-3-(2-morpholinyl-(4)-ethyl)carbodiimide.

In order to investigate the role of carboxyl groups of a base non-specific ribonuclease from Aspergillus saitoi [EC 3.1.27.1] (RNase M, molecular weight 36,000), the modification of RNase M with a water-soluble carbodiimide, 1-cyclohexyl-3-(2-morpholinyl-(4)-ethyl)carbodiimide(CMC), was studied. The inactivation of RNase M proceeded almost linearly with the incorporation of about 9.5 CMC moieties. The peptide backbone structure of the modified RNase M was practically the same as that of the native RNase M, as assessed from the CD spectra in the region of 200-250 nm. In the presence of competitive inhibitors, adenosine, and cytidine, inactivation of RNase M by CMC was partially inhibited. In the presence of cytidine (1 M), the modification of about 4 carboxyl groups of RNase M proceeded with a slight loss of enzymatic activity (ca. 20%). Further modification inactivated RNase M with the incorporation of ca. 4-5 CMC without any detectable intramolecular peptide bond formation. Therefore, it was concluded that carboxyl groups responsible for enzymatic activity were included among these carboxyl groups protected by cytidine. The logarithm of the half-live of the inactivation of RNase M by CMC was a linear function of log[CMC] with a slope of minus one, indicating that at least one carboxyl group among the modified ones may be essential for catalysis. The digestion of CMC-modified RNase M with carboxypeptidase A eliminated the carboxyl terminal group from the site of CMC modification.

Amides↗
PubMed1983

Characterization of two forms of base non-specific and adenylic acid preferential ribonuclease from Aspergillus saitoi.

Two forms of RNases (RNase ML and RNase MM) from Aspergillus saitoi which are base non-specific and adenylic acid preferential were separated from each other by DEAE-cellulose column chromatography. They are indistinguishable with respect to enzymatic properties such as base preferability, pH optimum, kinetic constants measured with 2',3'-cUMP and 2',3'-cCMP as substrates, and effects of ionic strength, physical properties such as heat stability, isoelectric point and circular dichroism spectra, amino acid composition and immunological property. They only differ in carbohydrate content. The apparent molecular weight determined by SDS-disc electrophoresis was 36,000 for RNase ML and 32,000 for RNase MM. Both RNases were reduced and carboxymethylated, and then digested with trypsin, separately. Glycopeptides were isolated from the both digests by gelfiltration and paper chromatography. The amino acid compositions of glycopeptides obtained from RNase ML (ML TS-IIC) and that obtained from RNase MM (MM TS-IIIC) were the same. The amino acid sequences of both glycopeptides determined by Edman degradation and carboxypeptidase digestion were also the same. The results indicated that RNase ML and RNase MM were the same protein having different sizes of carbohydrate chains at one site on the molecule.

Amino Acid Sequence↗
PubMed1983

Effects of synthetic ovine corticotropin-releasing factor (CRF) on plasma ACTH and cortisol in 31 normal human males.

Responses of plasma ACTH and cortisol to corticotropin-releasing factor (CRF) were evaluated in 31 normal human males. 1.0 micrograms/ks of sterilized synthetic ovine CRF was administered to the subjects, aged 19 to 53 yr and weighing 50 to 78 kg, at between 9:30 a.m. and 10:30 a.m. as an intravenous bolus injection after an overnight fast. Blood specimens were drawn before and 15, 30, 60, 90 and 120 min after injection for later determination of plasma ACTH and cortisol concentrations by radioimmunoassays. Plasma ACTH and cortisol levels for all subjects rose significantly (p less than 0.001) from the basal level (mean +/- SEM, 26.8 +/- 4.5 pg/ml and 12.6 +/- 0.9 micrograms/dl) to peak levels (58.4 +/- 5.5 pg/ml and 22.9 +/- 1.0 micrograms/dl) at 30 min and at 60 min, respectively. Although the plasma concentrations of ACTH and cortisol thereafter declined gradually, the levels at 120 min (43.4 +/- 5.2 pg/ml and 18.9 +/- 0.9 micrograms/ml, respectively) were still significantly higher than the basal levels (p less than 0.001). Significant inverse correlations were observed between the basal levels of each hormone and the ratio of the peak level to the basal level (p less than 0.01), and the increases in plasma ACTH and cortisol concentrations were either not significant or much smaller for the individuals in whom the basal levels were higher than 65 pg/ml and 17.0 micrograms/dl, respectively. No serious subjective symptom was observed during the experimental period in any of the subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1983

Incidence of hyperlipemia in diabetics in Okinawa and its relation to ischemic heart disease.

The average value for total cholesterol in the healthy population of Okinawa was significantly higher than that of Kyushu, but there were no differences in triglyceride levels. It is presumed that the difference in cholesterol levels was due to a 10 g difference in fat intake. The average values for total cholesterol and triglycerides in diabetics before treatment in both Kyushu and Okinawa were higher than in the healthy populations of Kyushu and Okinawa. The average values for total cholesterol and triglycerides in the diabetics in Okinawa were higher than those in the diabetics of Kyushu. The incidence of ischemic heart disease in diabetics in Okinawa classified by the Minnesota Code was higher than in the healthy population. It can be concluded that the development of ischemic heart disease in diabetics is influenced by both hypercholesterolemia and other metabolic disorders due to insufficiency of insulin action.

Adult↗
PubMed1983

An inter- and intralaboratory quality-control survey of radioimmunoassay of insulin, thyroxin, thyrotropin, cortisol, digoxin, gastrin, beta 2-microglobulin, and IgE in Japan with commercially available kits.

We report results of a quality-control survey of radioimmunoassay (RIA) of eight analytes, participated in by 249 laboratories of various types throughout Japan. For the purpose of the external control survey, lyophilized specimens containing two different concentrations of each analyte were sent to the participating laboratories, which supplied both their assay values and their raw data for the standard curves and for the samples. The individual data for the standard curve were analyzed by the RIA data-processing program described by Faden and Rodbard. The precision profile obtained for the individual assay was used as the estimate of the quality of each assay. Although there was a wide scatter in assay values, the quality of the assay by the individual laboratories was not the major contributor to this scattering, because the values they reported for the assays and precision profiles of the standard curves were almost identical with those obtained from the kit manufacturers. When the reported assay values were analyzed according to the brand of kits, by analysis of variance, the treatment mean square due to difference in the make of the kits significantly exceeded the error mean square due to "within-kit" variation in the assay of insulin, thyroxin, thyrotropin, cortisol, gastrin, and digoxin. The CVs for "between-kit," "within-kit," "between-assay" and "within-assay" variations (the latter two aspects were studied in a representative laboratory, for convenience of comparison) were about 20, 15, 13, and 7%, respectively. Because the observed within-kit variation is of almost the same magnitude as that expected from the combination of within-assay and between-assay variation, the skill of the users probably was equal and the accuracy and precision of the kits probably had the greatest impact on assay variation. This survey also emphasizes the criteria for commercially available RIA kits.

Analysis of Variance↗