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Biomedical subjects

K Miyai

Publications and source records attributed to K Miyai.

At least 199 records · Page 11Linked to original sources
PubMed1986

Automatic analysis of serum lactate dehydrogenase isoenzymes by high-performance ion-exchange chromatography.

The repetitive analysis of serum lactate dehydrogenase (LDH) isoenzymes has been performed on a weak anion exchanger (TSKgel DEAE-5PW), which was developed by introducing diethylaminoethyl groups into TSKgel G5000PW (10 microns particle diameter)--a hydrophilic polymer-based material of large pore size--for high-performance gel chromatography. By use of this anion exchanger, a high-pH (greater than 8.0) solvent could be used and the albumin peak was completely separate from the LDH isoenzyme peaks. After 10 successive analyses with an autosampler, the coefficient of variation of the LDH isoenzyme elution times was less than or equal to 0.90%, and the coefficient of variation for peak areas was less than or equal to 3.85%. After 40 successive analyses, resolution between isoenzymes was generally greater than 1.25. This column can be used for more than 300 intermittent injections of human serum.

Autoanalysis↗
PubMed1986

Structural and functional integrity of rat liver perfused in backward and forward directions.

The purpose of this study was to assess if reversal of the direction of isolated rat liver perfusion would cause significant alterations in hepatic functions and structure. Five isolated rat livers were perfused forward and another five backward with oxygenated Ringer's solution for up to 90 min (hydrostatic pressure: less than or equal to 13 cm H2O; flow rate: forward 3.88 +/- 0.34 ml/min per gram and backward 3.76 +/- 0.34 ml/min per gram). At the end of the experiment, livers were perfusion-fixed for morphological examination. The following results were obtained: No significant differences were noted between the forward and backward perfusions with respect to oxygen uptake, mean bile flow (forward 0.57 +/- 0.12; backward 0.60 +/- 0.14 ml/min per gram), average bile acid excretion (forward 2.39 +/- 1.11; backward 2.83 +/- 0.94 nmol/min per gram), hydroxylation pattern of bile acids, urea synthesis, release of lactic dehydrogenase, glucose secretion, and redox ratios. Light and electron microscopy, including morphometry of parenchymal and sinusoidal areas, revealed that the backward perfusion caused a greater degree of sinusoidal distension, but no other noteworthy differences. Hepatic ultrastructure was well preserved. We conclude that reversing the direction of perfusion does not alter structure and major hepatic functions significantly.

Animals↗
PubMed1986

Effects of corticotropin releasing factor and growth hormone releasing factor on pituitary hormone secretion in patients with congenital thyrotropin deficiency. Abnormal response of growth hormone to corticotropin releasing factor.

Blood concentrations of anterior pituitary hormones, ACTH, GH, TSH, PRL, LH, and FSH were determined in corticotropin releasing factor (CRF) test (synthetic ovine CRF 1.0 microgram per kg body weight) and growth hormone releasing factor (GRF) test (synthetic human pancreatic GRF-44 100 micrograms) in 2 female sibling patients with congenital isolated TSH deficiency, in their mother, in 2 patients with congenital primary hypothyroidism and in 8 normal controls. The patients with isolated TSH deficiency showed normally increased plasma ACTH and serum GH after CRF and GRF, respectively, and also showed an abnormal GH response to CRF. The serum GH showed a rapid increase to maximum levels (12.9 ng/ml) within 30 to 60 min followed by decrease. The possibility of secretion of abnormal GH could be excluded by the fact that on serum dilution, GH value gave a linear plot passing through zero. In addition, serum PRL, LH and FSH levels after CRF administration in case 1 and PRL after GRF in case 2 were also slightly increased but these responses were marginal. The mother of the patients, patients with congenital primary hypothyroidism, and normal healthy controls showed normal responses of pituitary hormones throughout the experiment. Data from the present study and a previous report show that abnormal GH response to the hypothalamic hormones (CRF, TRH and LHRH) may be observed in patients with congenital isolated TSH deficiency.

Adult↗
PubMed1986

New indices for thyroid functional status, hormone binding, and peripheral hormone metabolism. Principal component analysis of 24,000 clinical data.

Principal component analysis of three thyroid function tests, thyroxine (T4), 3,5,3'-triiodothyronine (T3), and T3 uptake (T3U), was done using 24,000 data obtained from patients with a wide range of pathophysiologic conditions related to the thyroid. The three component scores were obtained as follows: Z1 = 2.62 square root T4 + 0.63 square root T3 + 3.18 square root T3U - 32.43; Z2 = 0.91 square root T4 + 0.24 square root T3 - 4.68 square root T3U + 20.14; and Z3 = 3.94 square root T4 + 0.95 square root T3 + 0.18 square root T3U - 1.53 (T4 micrograms/dL, T3 ng/dL, T3U%). The first component (Z1) represents an apparent axis to the direction of thyroid functional status. It provides a new metabolic index putting conventional free T4 and free T3 indices together. The second component (Z2) was found to be a sensitive indicator of abnormal hormone binding. It showed a close correlation with serum concentration of thyroxine-binding globulin. The third component (Z3) represents the degree of T3 predominance over T4. Computation of these scores will facilitate the diagnosis of atypical cases in which hyper-or hypothyroidism is complicated by abnormal peripheral hormone binding and/or metabolism.

Humans↗
PubMed1986

Asymptomatic primary biliary cirrhosis in an old man.

We report asymptomatic primary biliary cirrhosis (PBC) in an 83-year-old man. The diagnosis was based on an elevated alkaline phosphatase, a high titer antimitochondrial antibody, normal ERCP, and characteristic histological changes on liver biopsy.

Aged↗
PubMed1986

Asymptomatic hyperprolactinaemia and prolactinoma in the general population--mass screening by paired assays of serum prolactin.

A total of 10,550 'normal' adults (8450 men and 2100 women) in the general population were screened by a paired assay method for serum PRL and 40 subjects with hyperprolactinaemia (greater than 75 micrograms/l) were detected. Of these, five patients (three men and two women) with pituitary prolactinoma, one man with empty sella syndrome, 10 cases of 'big' prolactinaemia, seven pregnant women and 13 subjects with drug-induced hyperprolactinaemia were found. The patients with prolactinoma had few if any complaints (asymptomatic prolactinoma).

Female↗
PubMed1986

Greater taurodeoxycholate biotransformation during backward perfusion of rat liver.

Differing patterns of taurodeoxycholate (TDC) metabolism and biliary excretion were studied with a forward-and-backward perfusion model of the isolated rat liver. Livers were perfused with 8 microM TDC via either the portal vein (forward) or the hepatic vein (backward). Bile was collected, total bile acids measured enzymatically, and bile composition determined by high-pressure liquid chromatography and thin-layer chromatography. During backward perfusion 48% of infused TDC was metabolized to taurocholate (TC) and 22.0% to other minor TDC metabolites. During forward perfusion, however, only 16% of administered TDC was metabolized to TC and 6.5% to minor metabolites. Total bile acid output was similar for both forward and backward perfusions. The kinetics of biliary bile acid excretion also differed between forward and backward perfusion. The time necessary for 50% excretion of labeled TDC and its metabolites was 3.5 +/- 0.45 min during forward and 18 +/- 3.50 min during backward perfusion, a time difference of 14.5 min. The greater biotransformation of TDC during backward perfusion could be explained by its longer intracellular residence. The reason for the delayed excretion of TDC during backward perfusion is unknown.

Animals↗
PubMed1986

Reduced serum carnosinase activity in hypothyroidism.

Carnosinase hydrolyses carnosine in muscle, and its deficiency is associated with extensive neuromuscular abnormalities. We measured serum carnosinase activity in patients with thyroid dysfunction which often involves neuromuscular systems. In hyperthyroidism, the carnosinase activity was not significantly different from that in normal subjects. In hypothyroidism, however, it was significantly lower than that in normal subjects. The activity examined in five patients with hypothyroidism returned to normal after replacement therapy. In hypothyroidism, the carnosinase activity showed significant correlation with concentration of serum thyroxine and negative correlation with serum creatine kinase activity. This finding may be of practical importance in the differential diagnosis of disorders causing carnosinase deficiency.

Clinical Enzyme Tests↗
PubMed1986

Measurement of iodide in urine using the iodide-selective ion electrode.

A simple and rapid way to measure the concentration of iodide in urine with an iodide-selective ion electrode was described. Potentiometric equilibrium was attained in less than 5 min, and a linear calibration curve was obtained over the potassium iodide (KI) concentration range of 10(-2) to 10(-6) M. The coefficients of variation ranged from 6.2 to 10.0% within assay, and 5.4 to 14.4% between assays. The serial dilution of 3 urine samples with different concentration of iodide showed good linear correlations passing through zero. In practice, the chloride ions in urine did not cause serious errors in the measurement of iodide at molar ratios of chloride ion to iodide up to 2 X 10(4). A good linear correlation was obtained between iodide concentrations in urine determined by the electrode method and by the conventional chemical method (r = 0.92). A linear correlation was also observed between the iodide concentrations of 24 h collected urine and those of single morning urine (r = 0.91). The normal iodide content in single morning urine specimens from 127 Japanese people was 5.3 to 62.0 X 10(-6) moles/g creatinine.

Adult↗
PubMed1986

Studies on beta-lactam antibiotics. X. Synthesis and structure-activity relationships of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(carboxymethoxyimino)acetamido] cephalosporin derivatives.

The synthesis of 7 beta-([Z) -2-(2-amino-4-thiazolyl)-2-(carboxymethoxyimino) acetamido]-cephalosporins (2a-h) modified at the C-3 position of a cephem nucleus and the effect of the C-3 substituents on the antibacterial activity, oral absorptivity and therapeutic activity are discussed. The cephems (2a and 2b) having a C-3 substituent such as hydrogen or vinyl were more potent than other cephalosporins against Gram-negative bacteria. However, the cephalosporin (2f) having methylthio group at the 3-position showed the highest absorption rate in rats. These three cephalosporins (2a, b and f) exhibited equally good protective activities in mice infected. Furthermore, the serum levels of these cephalosporins (2a, b and f) were examined in dogs, and 2b and 2f showed outstanding high and prolonged serum levels.

Administration, Oral↗
PubMed1986

Radioreceptor assay of anti-TSH receptor antibody activity: comparison of assays using unextracted serum and immunoglobulin fractions, and standardization of expression of activities.

A radioreceptor assay for TSH receptor antibodies developed by Shewring and Smith is described in which unextracted serum is used. The assay is simple and reproducible. TSH-binding inhibitor immunoglobulin (TBII) activity determined using unextracted serum correlated well with that determined using the immunoglobulin fraction purified with polyethylene glycol. The assay detected TSH receptor antibodies in 81 of 85 patients (95%) with untreated Graves' disease, no patients with Graves' disease in remission, and 7 of 57 patients (12%) with Hashimoto's disease. TSH-binding inhibitor activity of a human TSH preparation (Kabi Diagnostica) was not detectable at 100 mU/L, but detectable at 1,000 mU/L. Consistent with this, TBII activity was not detectable in hypothyroid patients with goitrous Hashimoto's disease, whose serum TSH concentrations were 11-520 mU/L. Of 57 patients with Hashimoto's disease positive TBII activity was detected in only 7 of 15 patients (46%) with primary atrophic hypothyroidism. Five of these had very high TBII activities (greater than 90% inhibition of labelled TSH binding), and no linear dose-response relationship was observed in dilution experiments. For exact determination of TBII activity in specimens with high activities, serum samples were diluted with normal pooled serum and activities were expressed in U/ml by comparison with values for standard serum, prepared from bovine TSH diluted with normal pooled serum. In this way, samples with TBII activities of 1-50 U/ml (20-90% inhibition of binding of labelled TSH) showed linear dose-response relations in dilution experiments, and the dilution curves of all samples examined were parallel to the standard curve. This standardization procedure was used in determining the half life of TBII.

Autoantibodies↗