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Biomedical subjects

K Miyai

Publications and source records attributed to K Miyai.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Effect of coix seed on the changes in peripheral lymphocyte subsets].

Coix seed has been used in patients with verruca vulgaris and verruca planae juveniles, which have been considered to be induced by viral infection. Moreover, coixenolide, component in the seeds of coix, was reported to show anti-tumor activity. Possibly coix seed may have some influence on the cytotoxic activity of peripheral lymphocytes but there has been no data on this. Then we investigated the changes in number of cytotoxic lymphoid cells in seven volunteers before, during (four weeks) and after taking six coix seed tablets. Lymphocyte subsets were analyzed with monoclonal antibodies using a flow cytometer. The level of CD3+CD56+ (MHC-non restricted cytotoxic T cells) markedly increased at four weeks (before 1.9 +/- 0.5% vs four weeks 4.2 +/- 0.7%, p less than 0.01). The level of CD16+CD57- (the mature, most active natural killer cells) increased at three weeks (before 4.5 +/- 0.8% vs three weeks 5.2 +/- 0.8%, p less than 0.05). The level of CD3-CD56+ (natural killer cells) and the level of CD16+CD57+ (the variable active natural killer cells) decreased at one week and returned to normal level thereafter (before 13.7 +/- 2.1% vs one week 11.2 +/- 1.5%, p less than 0.05; before 8.8 +/- 1.5% vs one week 6.9 +/- 1.3%, p less than 0.05, respectively). These results indicate that coix seed modulate the peripheral blood lymphocyte subsets and may be effective to virus disease through the enhancement of cytotoxic activity.

Drugs, Chinese Herbal↗
PubMed1992

[Effect of various sampling condition on the measurement of circulating TSH and free thyroxine].

We report here the effect of various sampling and storage condition on the measurement of circulating TSH and free thyroxine (FT4). Blood samples were obtained from five normal subjects using four kinds of sampling tubes; plane glass tube, glass tube containing serum separator, and glass tube containing EDTA-2Na or heparin-sodium. We stored whole blood, serum or plasma at low temperature (4-8 degrees C) or at room temperature (20-25 degrees C) from one hour to thirteen days. Both values of EDTA-plasma TSH and FT4 were significantly lower than those of serum samples, EDTA-plasma TSH value was increased gradually during storage at room temperature but not at low temperature. Serum or plasma FT4 values were decreased during storage at room temperature but not at low temperature. In conclusion, circulating TSH and FT4 values are influenced by different sampling tubes and, serum or plasma TSH and FT4 are not always stable under the storage condition at room temperature. Serum samples obtained by using plane glass tube and kept at low temperature give us more reliable values of TSH and FT4.

Adult↗
PubMed1992

New enzymatic method with tryptophanase for determining potassium in serum.

We established a simple and rapid enzymatic method for measuring potassium ion in serum by using tryptophanase (EC 4.1.99.1) purified from Escherichia coli K12 strain (E. coli K12 IFO 3301). The presence of pyridoxal 5-phosphate promotes this enzymatic reaction, and potassium and (or) ammonium ions further accelerate it, with ammonium and potassium ions providing equivalent acceleration. We eliminated endogenous ammonium ion by using glutamate dehydrogenase (GLDH; EC 1.4.1.4), then produced ammonium ion in the presence of tryptophanase, tryptophan, and pyridoxal 5-phosphate. The concentration of formed ammonium ion, which was proportional to that of potassium ion in sample, was determined by adding GLDH to produce NADP+ in the presence of 2-oxoglutarate and NADPH; we then read the change of absorbance at 340 nm. The standard curve was linear for potassium ion concentrations up to 7.00 mmol/L. The within-assay variation (CV) was 0.89% at 5.51 mmol/L and 1.32% at 3.37 mmol/L. The day-to-day CVs were 0.99% at 6.85 mmol/L and 1.71% at 3.52 mmol/L. Analytical recoveries ranged from 98.7% to 108.9%. The correlation coefficient between values obtained with this enzymatic assay (y) and by flame photometry (x) was 0.995: y = 0.984x + 0.091 mmol/L (Sy.x = 0.105, n = 100). The presence of hemoglobin, bilirubin, or other cations little affects this system.

Ammonia↗
PubMed1991

Immunological and biological characteristics of recombinant human thyrotropin.

Analyses of epitopes and biological activity were made on two preparations of recombinant human thyrotropin produced in Chinese hamster ovary cells. Seven monoclonal antibodies recognizing four epitopes on alpha subunit of hTSH (hTSH alpha) and three on beta subunit (hTSH beta) were used for the analysis. Binding activities of the two rhTSH with each antibody were almost identical with that of a pituitary-derived reference hTSH, except at one epitope on hTSH alpha. Their immunoreactivity measured by four commercial immunoassay kits and their bioactivity by thyrotropin dependent FRTL-5 cell system, however, agreed closely with those of the reference hTSH. From these results and its constant availability, rhTSH will be a good candidate for a future standard material in assays for hTSH.

Antibodies, Monoclonal↗
PubMed1991

Pravastatin, a HMG-CoA reductase inhibitor, blocks the cell cycle progression but not Ca2+ influx induced by IGF-I in FRTL-5 cells.

IGF-I, when added to the TSH-primed FRTL-5 cells, induces a long lasting Ca2+ influx, and then, DNA synthesis. Moreover, Ca2+ channel agonist, B AY K8644 can mimic these effects on cell proliferation. We studied the effect of HMG-CoA reductase inhibitor, Pravastatin on IGF-I-induced cell cycle progression in FRTL-5 cells. Pravastatin inhibited DNA synthesis induced both by IGF-I and by BAY K8644. In contrast, Ca2+ influx stimulated by IGF-I was unaffected. These data demonstrate that the signal transduction pathway evoked by IGF-I may possibly involve pravastatin-sensitive process at the downstream step of Ca2+ entry. HMG-CoA reductase inhibitors are known to modulate some cellular signal transduction systems by blocking the membrane attachment of low molecular weight GTP binding proteins such as p21ras. Therefore, pravastatin-sensitive process that we have shown here might possibly involve some of such small G protein.

Animals↗
PubMed1991

Human gallbladder morphology after gallstone dissolution with methyl tert-butyl ether.

The effects of methyl tert-butyl ether exposure on the human gallbladder in five patients who were treated for gallstones by contact dissolution is described. Two patients underwent cholecystectomy within 1 week of methyl tert-butyl ether treatment, one patient 2 weeks after, another 10 weeks after, and one 12 weeks after. Indications for cholecystectomy were bilirubinate stones (resistant to methyl tert-butyl ether), catheter dislodgement, bile leakage, and gallstone recurrence (2 patients). Gallstones were dissolved completely in three patients, there was approximately 50% stone reduction in one patient, and no dissolution occurred in the fifth patient. Each gallbladder was examined grossly and histologically. Electron microscopic evaluation was performed in one cases. Typical inflammatory findings of chronic cholecystitis were observed in each gallbladder and were most conspicuous in the submucosa; the mucosal and serosal surfaces were intact. Mild acute inflammatory changes were noted in the submucosa in the two patients with the shortest interval between methyl tert-butyl ether administration and cholecystectomy. There were no ulcerations in the mucosa and no unusual wall thickening or fibrosis in any patient. These observations support the safety of methyl tert-butyl ether perfusion in the human gallbladder; the mild acute changes may be a transient and reversible phenomenon.

Cholecystectomy↗
PubMed1991

Changes in natural killer cell activity in normal pregnant and postpartum women: increases in the first trimester and postpartum period and decrease in late pregnancy.

Changes in the activity and number of natural killer (NK) cells in peripheral blood in normal pregnant and postpartum women were examined. NK activity was measured in a 4-h 51Cr-release assay and evaluated by conventional relative lytic units and absolute lytic units which represent the total NK activity within a fixed volume of circulating blood. The number of NK cells was analyzed with FITC-conjugated monoclonal antibodies and by use of an automated flow cytometer. Unexpectedly, the relative NK activity increased in the first trimester and also for 1 month postpartum compared to the activity in normal non-pregnant controls. On the other hand, absolute NK activity decreased in the third trimester compared to the activity in normal non-pregnant controls. The percentage of CD57+ cells decreased in the second trimester, but the percentage of CD16+ cells did not change during pregnancy or the postpartum period. The absolute counts of CD57+ cells and CD16+ cells decreased in the second and third trimesters and increased transiently in the postpartum period. These findings indicate that the increased NK activity in the first trimester and at 1 month postpartum is induced by increased cytotoxic activity of individual NK cells, and that the decreased NK activity in late pregnancy is induced by a decrease in the numbers of NK cells. These physiological changes may play an important role in implantation in early pregnancy, protection of the fetal allograft in late pregnancy and in the natural defense against infection during the puerperal period.

Adult↗
PubMed1991

A placenta-specific 5' non-coding exon of human prolactin.

Expression of human prolactin (hPRL) is restricted to the anterior pituitary and the placenta, strictly, the decidualized endometrium of the uterus. We have cloned and sequenced placental hPRL cDNAs and also the 5' part of the hPRL gene, and found that the placental mRNA consisted of six exons including a 5' non-coding exon which was not present in the pituitary mRNA known to consist of five exons. The placenta-specific exon, designated exon 0, was located 5.3 kb upstream of the first exon of the pituitary mRNA. We have also located the transcriptional start site of the hPRL gene in the placenta to be 21 bp upstream from the 5' end of the longest cDNA clone we obtained using mRNA from human placenta of 22 weeks of gestation. These results suggest that the hPRL gene contains a placenta-specific promoter other than the pituitary-specific promoter.

Amino Acid Sequence↗
PubMed1991

A hamartoma of the colon with unusual features.

An unusual case of colonic hamartoma in a 67-year-old man is reported. Colonoscopy polyp surveillance revealed a polypoid lesion of the sigmoid colon which had the characteristics of a hamartoma on microscopic examination. The lesion, which was classified as a colonic hamartoma, is described. Review of the literature revealed no previous report of such a colonic poylp.

Aged↗
PubMed1991

Reoxygenation injury following anoxic perfusion preferentially impairs bile acid-independent bile flow.

We perfused isolated rat livers with Krebs-Ringer buffer, with no recirculation. Bile flow virtually stopped during 30 min of anoxia and resumed following reoxygenation to reach a plateau of 44% of the control level. When taurodehydrocholic acid (TDHC, 50 nmol/min/g liver) was administered during reoxygenation, bile flow increased three-fold (16.1 +/- 1.3 to 45.3 +/- 6.3 microliters/g liver). The increase in bile output with TDHC was 27.8 microliters/g liver, which was 89% of the control output. Bile acid output during this period was 1.4 mumol/g liver, which was 93% of the control level. Addition of allopurinol (50 nmol/min/g liver) without TDHC increased bile flow significantly (16.1 +/- 1.3 to 21.3 +/- 1.2 microliters/g liver), but the change was not significant when allopurinol and TDHC were given. The addition of allopurinol also reduced the cumulative release of lactate dehydrogenase from the liver during the reoxygenation period, but had no effect on hepatic adenosine triphosphate levels. Our data suggest that the bile acid-independent bile flow is sensitive to reoxygenation injury following anoxia whereas bile acid output and bile acid-dependent bile flow are resistant.

Adenosine Triphosphate↗
PubMed1991

Detection of thyroid microsomal and thyroglobulin antibodies by new sensitive radioimmunoassay in Hashimoto's disease; comparison with conventional hemagglutination assay.

We evaluated clinical usefulness of thyroid microsomal antibody (MCAb) and thyroglobulin antibody (TGAb) measured by new sensitive radioimmunoassays (RIA). These assays are simple and reproducible; the intra- and inter-assay coefficients of variation were 3.6-6.8% and 6.6-13.2% in the MCAb assay, and 3.2-7.7% and 7.6-12.3% in the TGAb assay, respectively. In 126 patients with Hashimoto's disease, the antibody activity determined by this RIA correlated with that determined by the hemagglutination assay (HA) (r = 0.848 for MCAb, r = 0.686 for TGAb, p less than 0.001). MCAb was detected by RIA in all of 115 HA-positive and 4 of 11 HA-negative patients, and TGAb by RIA in all of 84 HA-positive and 29 of 42 HA-negative patients: the prevalence of MCAb was 94% and that of TGAb was 90% in the disease. Moreover, some showed high antibody activity only in RIA. In another group of 14 patients with biopsy-proved Hashimoto's disease with no antibody activity by routine HA tests, serum MCAb was detected in 3 (21%), TGAb in 11 (79%), and both activities in 2 (14%). Our results indicate that (1) the RIA tests are more sensitive than the conventional HA test, and that (2) the present RIA test for TGAb is more sensitive than that for MCAb in detecting autoimmune abnormalities, especially in patients with biopsy-proved Hashimoto's disease who give negative results in the HA test.

Adult↗
PubMed1991

The stability of immunological and biological activity of human thyrotropin in buffer: its temperature-dependent dissociation into subunits during freezing.

The stability of thyroid-stimulating hormone (TSH) in buffer under various storage conditions was studied with regard to its immunoreactivity measured by an immunoradiometric assay and its bioactivity by a sensitive FRTL-5 cell bioassay. The immunoreactivity was well retained at 4 degrees C or 24 degrees C throughout the study period of 90 days. At -20 degrees C, however, it decreased proportionately with the storage time. The mean reduction was 42.1% at 90 days compared with that when stored at -80 degrees C. The bioactivity showed a similar course of change with its reduction of 44.3% at -20 degrees C in 90 days. The loss of both activities was attributed to the dissociation of human (h) TSH molecule into its subunits. The concentration of the alpha subunit of hTSH in those samples stored at -20 degrees C gradually increased from the initial undetectable level to that almost equivalent on a molar basis to the loss of immunoreactivity. The enrichment of albumin in the buffer to a level of more than 1.0% was effective in preventing the occurrence of such a phenomenon. These data indicate that hTSH, when frozen at -20 degrees C in buffer is gradually dissociated into its subunits, despite its outstanding stability for 90 days at both 4 degrees C and 24 degrees C. However, no apparent inconsistency between immunological and biological activities, was observed at any temperature between -20 degrees C and 24 degrees C.

Albumins↗