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Biomedical subjects

K Miyai

Publications and source records attributed to K Miyai.

At least 19 recordsLinked to original sources
PubMed1992

Nucleotide sequence of the complementary DNA for human Pit-1/GHF-1.

Human cDNA clones encoding Pit-1/GHF-1, a pituitary-specific DNA binding factor, were obtained by PCR following reverse transcription of human pituitary RNA. It is approx. 1.3 kb in size with 0.1 kb 5' non-coding region, 0.9 kb protein-coding region and 0.3 kb 3' non-coding region. The predicted human Pit-1/GHF-1 peptide structure has 291 amino acids and is highly conserved among mouse, rat and bovine. In addition, the 5' non-coding region is highly conserved with rat pit-1/GHF-1 sequence to the transcription start site.

Amino Acid Sequence↗
PubMed1992

Regenerative stimulus increases hepatocyte tight junctional permeability.

Experience with young animals, animals administered certain hepatotoxins and animals with two-thirds hepatectomy suggests that tight junctional permeability is increased in states characterized by architectural remodeling in the liver. In this work we correlate changes in tight junctional morphometry induced by two-thirds hepatectomy with changes in biliary permeability assessed by sucrose and horseradish peroxidase permeation and by alterations in biliary outputs of anionic and cationic cholephilic probes. By freeze-fracture examination tight junctional strand counts, density and orientation parallel to canaliculi were all reduced 24 hr after two-thirds hepatectomy. Occasionally, strands were perpendicular to the canaliculi, creating an unobstructed communication between bile and intercellular spaces. These morphological changes correlated with increased sucrose and paracellular horseradish peroxidase access into bile, with reduced biliary outputs of low molecular weight and especially with cationic cholephilic probes. The data support an increased but still charge-selective permeability of the biliary tree, which was induced by two-thirds hepatectomy 24 hr before. Presumably, fixed intercellular connections (tight junctions and gap junctions) must be loosened or lysed to allow the architectural reorganization required by the hepatocellular regenerative process.

Animals↗
PubMed1992

Chinese medicine, Coix seeds increase peripheral cytotoxic T and NK cells.

Coix seeds, a Chinese medicine have been used in Japan and reported to be effective in patients with verruca vulgaris and verrucae planae juveniles. We investigated the in vivo effects on lymphocyte subsets in seven healthy volunteers who took six tablets of Coix seeds three times a day (a typical dose) for four weeks. Leukocyte counts and the percentage of total lymphocytes did not change but the percentages of CD3+CD56+ cells and CD16+CD57- cells increased significantly. These results indicate that Coix seeds increase peripheral cytotoxic lymphocytes and may be effective to viral infection through the enhancement of cytotoxic activity.

Adult↗
PubMed1992

Enzyme immunoassay for serum dexamethasone using 4-(carboxymethylthio)dexamethasone as a new hapten.

A sensitive and simple enzyme immunoassay for direct quantitation of serum dexamethasone was established. An antiserum with high specificity was produced by the immunization of rabbits with a newly synthesized 4-(carboxymethylthio)dexamethasone-bovine serum albumin conjugate. Alkaline phosphatase was used as a labeling enzyme. The minimum amount of dexamethasone detected was 2 pg per tube on the basis of B/Bo 100 - 2 SD (%) of standard curve. However, taking into account the cross-reaction with steroids such as cortisol in dexamethasone-free serum, the measurable range was from approximately 0.13 to 10 micrograms/dl. Intra- and interassay coefficients of variation were 1.5 - 5.4% and 0.6 - 6.5%, respectively. Serum levels of dexamethasone and cortisol in four normal subjects after an oral administration of 1 mg of dexamethasone are also reported.

Animals↗
PubMed1992

Cretinism with combined hormone deficiency caused by a mutation in the PIT1 gene.

Cretinism is marked by irreversible mental and growth retardation. We describe here an entirely new case of cretinism showing combined pituitary hormone deficiencies of thyrotropin, growth hormone and prolactin that appears to be caused by homozygosity for a nonsense mutation in the gene for the pituitary specific transcription activator, Pit-1/GHF-1 (designated PIT1 in humans for pituitary specific factor 1). This is the first report in humans of a defect in a transcription activator causing deficiency of multiple target genes.

Amino Acid Sequence↗
PubMed1992

Breakdown of hepatic tight junctions during reoxygenation injury.

We investigated whether reoxygenation following anoxia increased biliary permeability and whether or not allopurinol had a protective effect. Isolated rat livers were perfused for 30 min in a one-pass system with buffer equilibrated with 100% nitrogen after stabilization, and then for 60 min with the oxygenated buffer. Hepatic tight junction permeability was assessed by quantifying the early appearance in the bile of horseradish peroxidase (HRP) injected with the perfusate. This early peak represents paracellular passage of HRP, whereas a later second peak results from transcellular passage. In the control livers, 7% of the total HRP passage (93 +/- 50 pg/g liver) was paracellular and 93% was transcellular. After 30 min of reoxygenation following anoxia, however, 516 +/- 20 pg/g liver of HRP passed paracellularly. Addition of allopurinol (5 micrograms/ml) to the perfusate from the start of perfusion reduced paracellular passage of HRP to 219 +/- 49 pg/g liver after anoxia and reperfusion (P less than 0.01). Allopurinol also reduced the cumulative lactate dehydrogenase (LDH) release during the first 30 min of reoxygenation from 2.1 +/- 0.3 x 10(4) to 1.4 +/- 0.4 x 10(4) units/g liver (P less than 0.01). Reduction of the anoxic period from 30 min to 25 min significantly reduced the change in tight junction permeability and the extent of cellular injury: Paracellular passage of HRP was 336 +/- 20 pg/g and LDH release was 0.7 +/- 0.1 x 10(4) units/g liver, both significantly lower than those at 30 min (P less than 0.01). No significant difference in hepatic ATP levels after 60 min of reoxygenation was noted among the experimental groups, but all had lower levels than the control group. The protective effect of allopurinol suggests that the mechanism of biliary reoxygenation injury involves free radical generation. Susceptibility of tight junctions suggests a pattern of injury similar to that involved in anoxic damage of the vascular endothelium.

Adenosine Triphosphate↗
PubMed1992

Decreases in alpha beta T cell receptor negative T cells and CD8 cells, and an increase in CD4+ CD8+ cells in active Hashimoto's disease and subacute thyroiditis.

We examined peripheral lymphocyte subsets in patients with autoimmune thyroid disease, or subacute thyroiditis, in the active stage when possible. During destructive thyrotoxicosis arising from alpha beta T cell receptor (TCR) negative T (WT31-CD3+) cells and CD8 (CD4-CD8+) cells decreased and those of CD4+CD8+ cells increased slightly, resulting in proportional increases in CD4 (CD4+CD8-) cells, non-T, non-B (CD5-CD19-) cells, and the CD4/CD8 cell ratio. Changes were similar in active subacute thyroiditis. During stimulative thyrotoxicosis in active Graves' disease, the numbers of such T lymphocyte subsets were not changed, but only the number of CD5+ B (CD5+CD19+) cells increased markedly, resulting in proportional decreases in total T (CD3+) cells, alpha beta+ TCR T (WT31+CD3+) cells, CD8 cells, and non-T, non-B cells. A serial study of some of the patients showed opposite changes in alpha beta TCR- T cells, the CD4/CD8 cell ratio, and CD5+ B cells between the active stages of Graves' and Hashimoto's diseases. alpha beta TCR- T cells were mostly gamma delta TCR+ T (IIF2+ CD3+) cells in these patients. These data suggest that alpha beta TCR-T (gamma delta TCR+ T), CD8, and CD4+ CD8+ cells are important in thyroid destruction in Hashimoto's disease and subacute thyroiditis, and that CD5+ B cells are important in thyroid stimulation in Graves' disease.

Adult↗
PubMed1992

Usefulness of thyroglobulin antibody detected by ultrasensitive enzyme immunoassay: a good parameter for immune surveillance in healthy subjects and for prediction of post-partum thyroid dysfunction.

OBJECTIVE: Using newly developed ultrasensitive enzyme immunoassay (EIA) for thyroglobulin antibody (TgAb), we have evaluated physiological and pathological implications of the antibody in healthy subjects as well as in autoimmune thyroid diseases. MEASUREMENTS: This EIA was based on the immune complex transfer method, and was 10(4)-fold more sensitive compared with the conventional haemagglutination assay (HA); the detection limit was 0.1 micrograms IgG/I, and the specificity of the assay was confirmed from the unequivocal decrease in the fluorescence intensity by the preincubation of test serum with Tg and/or inactive beta-D-galactosidase which blocks antibodies to the enzyme. RESULTS: TgAb was detectable in 159 (91%) of 175 healthy subjects aged 3rd to 7th decade (96 men and 79 women), and did not exhibit age or sex-associated change. In nine healthy women, the TgAb level significantly decreased as pregnancy progressed but increased transiently after delivery. TgAb was detectable in 52 (98%) of 53 patients with Graves' disease and all (100%) of 107 patients with chronic thyroiditis. Abnormal high TgAb values (> 40 micrograms/I), determined from the 95th percentile in healthy subjects, were shown in 40 (75%) with the former disease and 94 (88%) with the latter disease. Moreover, in 14 goitrous patients with biopsy-proved chronic thyroiditis with negative HA results, 12 (86%) showed abnormal high TgAb levels. In 69 patients with post-partum thyrotoxicosis in Graves' disease, 15 (79%) of 19 patients with the TgAb level of more than 2 x 10(3) micrograms/I in early pregnancy showed destructive thyrotoxicosis and 46 (92%) of 50 with less than this level showed stimulative thyrotoxicosis. This TgAb test could discriminate the two types of thyrotoxicosis more clearly than could the conventional TGHA test. In chronic thyroiditis, the mean TgAb value in early pregnancy was significantly higher in patients with postpartum hypothyroidism than in those without thyroid dysfunction. Hypothyroidism developed in 80% of the patients with a TgAb value of more than 10(3) micrograms/I. CONCLUSIONS: The ultrasensitive TgAb EIA was useful for detecting the physiological changes in autoantibody formation in healthy subjects and the TgAb value was useful for predicting post-partum thyroid dysfunction in autoimmune thyroid diseases. This EIA is useful for the evaluation of the immune surveillance in patients with autoimmune thyroid diseases as well as in healthy subjects.

Adult↗
PubMed1992

New screening system for simultaneous determination of two marker proteins by homogeneous enzyme immunoassay.

AIMS: To save time and labour in mass screening, by detecting two marker proteins on one specimen using only one test. METHODS: alpha Fetoprotein and ferritin were chosen to demonstrate the principal of this system. The assay reagents were horseradish peroxidase (HRP)-labelled anti-alpha fetoprotein and HRP-labelled anti-ferritin antibodies. After the serum sample had been incubated with these reagents the substrate for HRP was added and the absorbance measured. An absorbance value below the cutoff point indicated that both parameters were within normal limits; a value above the cutoff point indicated that at least one of the two parameters was abnormally high. RESULTS: Fifty sera from healthy Japanese subjects were assayed by the simultaneous assay method. All samples gave absorbancy values below the cutoff point. Fifty serum samples from patients with high alpha fetoprotein concentrations (over 20 ng/ml) and 50 samples with high ferritin concentrations (over 200 ng/ml) were also assayed. The absorbancy values of all samples with high alpha fetoprotein concentrations, and all but one sample with high ferritin concentrations gave values above the cutoff point. CONCLUSIONS: Although this homogeneous enzyme assay method was applied to the combination of alpha fetoprotein and ferritin, it could be used in mass screening for any other combination of two markers.

Biomarkers↗
PubMed1992

Increase in peripheral natural killer cell activity in patients with autoimmune thyroid disease.

Changes in the activity and number of natural killer (NK) cells in peripheral blood in patients with autoimmune thyroid disease were examined. NK activity was measured in a 4-hr 51Cr-release assay and the number of NK cells was analyzed with FITC-conjugated monoclonal antibodies by use of an automated flow cytometer. NK activity in patients with untreated Graves' disease (n = 25, 39.7 +/- 13.5%, P less than 0.05) and Hashimoto's thyroiditis (n = 18, 41.0 +/- 14.2%, P less than 0.05) was high compared to the activity in non-pregnant controls (n = 61, 32.6 +/- 15.0%). NK activity in patients with postpartum Graves' thyrotoxicosis (n = 11, 48.6 +/- 18.9%) was markedly increased compared to the activity in non-pregnant controls (P less than 0.01) and in postpartum controls (n = 29, 33.8 +/- 15.2%, P less than 0.05), although the mean ages of each group did not differ significantly. Moreover, NK activities in the thyrotoxic state were significantly higher than those in the euthyroid state in the same patients with postpartum Graves' thyrotoxicosis or with postpartum destructive thyrotoxicosis. The number of CD16 positive cells increased in patients with postpartum Graves' thyrotoxicosis. However the number of CD16 and CD57 positive cells were normal in all other groups of patients. These results indicate that an increase of NK activity is associated with exacerbation of autoimmune thyroid disease both in Hashimoto's thyroiditis and in Graves' disease and suggest that NK cells might have an important role for the control of disease activity in autoimmune thyroid disease.

Adult↗
PubMed1992

[Symposium: the role of laboratory medicine in modern medical care--chairman's remarks].

Recent developments in laboratory techniques have brought dramatic changes in medical diagnosis, that is, a change from physical diagnosis to laboratory diagnosis. It is imperative that laboratory medicine develop further to meet the continuously growing needs of medical care. Major progress in medical care is classified into two categories, (A) treatment of severe disorders by modern technology and (B) health maintenance to prevent disease and achieve a higher quality of life. In this symposium, category (A) is subdivided in to (A-1) development of new drugs and (A-2) organ transplantation. In (A-1) the field of new drugs, "Recent Trends in Granulocyte Colony Stimulating Factor Therapy and its Relation to Clinical Laboratory Tests" is reviewed as an example of applying recombinant peptides to treatment. In (A-2) transplantation, two papers (A-2a) "Effect of HLA Matching in Renal Transplantation" and (A-2b) "Liver Transplantation and Function of the Graft Liver" are reported. In category (B), health maintenance, (B-1) exercise and (B-2) nutrition are important subjects. (B-1a) "The Role of Clinical Laboratory Examinations During Physical Exercise Therapy for Diabetes Mellitus" and (B-1b) "Exercise Loading Test for Evaluating Cardio-Pulmonary Functions" are given attention. In (B-2) nutrition, artificial feeding, such as intravenous hyperalimentation (IVH) is a current issue. The role of laboratory medicine in modern medical care will be discussed under each of these subjects.

Clinical Laboratory Techniques↗
PubMed1992

[Changes of differential leukocyte counts during pregnancy and in the postpartum period].

We examined differential leukocyte counts in peripheral blood from 177 pregnant and postpartum women with an automated leukocyte differential system, and compared them with those of 52 nonpregnant and non-postpartum women. The proportions and numbers of neutrophils and monocytes increased throughout pregnancy, returned to the non-pregnant levels within one month after delivery, and decreased transiently at 4 or 7 to 10 months postpartum. The proportions and numbers of lymphocytes and eosinophils decreased throughout pregnancy, and increased transiently at 4 to 10 months postpartum and one month postpartum, respectively. The proportion and number of basophils decreased during pregnancy and one month postpartum, and those of large unstained cells (LUC) decreased in the third trimester of pregnancy, and both returned to the non-pregnant levels at 4 months postpartum and within one month postpartum, respectively. These data indicate that differential leukocyte counts change dynamically during pregnancy and after delivery until 1 year postpartum.

Adult↗
PubMed1992

Immunoglobulin-complexed aspartate aminotransferase with a possible association with ulcerative colitis and its activity.

We demonstrate immunoglobulin-complexed aspartate aminotransferase (macro-AST) in a 14-year-old boy with rectitis-type ulcerative colitis by using both gel filtration and electrophoresis methods. The immunoglobulin complexed with AST in this case was identified as an IgG kappa both by electrosyneresis and immunoprecipitation reactions. The present case was noted to have a concomitant elevation of macro-AST associated with deterioration of ulcerative colitis. However, macro-AST has continued to exist when the activity of ulcerative colitis subsided, and the serum level of AST became normal. Thus, macro-AST might be related to an immunological component of ulcerative colitis as well as to the activity of the disease.

Adolescent↗
PubMed1992

Risk factors for developmental disorders in infants born to women with Graves disease.

OBJECTIVE: To identify risk factors for disorders of fetal growth and thyroid function in the presence of maternal Graves disease. METHODS: Two hundred thirty pregnancies in gravidas with Graves disease were analyzed. Maternal thyroid status was evaluated by serum free thyroxine (T4) or free T4 index, TSH, and TSH-receptor antibody; personal history of thyrotoxicosis and total dose of antithyroid drugs during pregnancy were also noted. Neonatal thyroid function was assessed at birth and on the fifth day after birth. RESULTS: Fifteen neonates (6.5%) were small for gestational age (SGA), and this occurrence was significantly associated with thyrotoxicosis lasting for 30 weeks or more of pregnancy, TSH-receptor antibody level of 30% or more at delivery, history of Graves disease of 10 years or longer, and onset of Graves disease before 20 years of age. However, no significant correlation was found between maternal thyroid hormone level and SGA neonates. Thyroid dysfunction developed in 38 infants (16.5%), of whom only four were SGA; development of this dysfunction was significantly related to the mother's total dose of antithyroid drugs, duration of thyrotoxicosis in pregnancy, and/or TSH-receptor antibody level at delivery. CONCLUSIONS: Duration of maternal Graves disease or thyrotoxicosis, either mild chemical or overt, in pregnancy is significantly associated with SGA neonates. Neonatal thyroid dysfunction is associated with the maternal thyroid condition, especially the serum TSH-receptor antibody level.

Adult↗
PubMed1992

[Negative interference with peroxidase-coupled enzymatic serum creatinine assay by a hemostatic drug containing a hydroquinone structure].

We report a discrepancy between serum creatinine levels obtained by the method based on alkaline picric acid (Jaffé reaction) and that by automated analyzer employing enzymatic assay based on peroxidase-coupled reaction in a patient with renal dysfunction taking Ethamsylate, a capillary vessel stabilizer. Serum creatinine level obtained by the Jaffé reaction was 83 mg/l, and that by the enzymatic method was 22 mg/l. Recovery test of creatinine using the patient's serum showed 101 to 102% recovery by the Jaffé reaction and 77 to 89% by the enzymatic method. The same results were observed both in an in vitro test and in serum obtained from a healthy volunteer who had been given Ethamsylate previously. As the chemical structure of Ethamsylate includes a hydroquinone unit, it was thought that the compound may consume hydrogen peroxide produced by the reaction of peroxidase as the hydrogen donor and compete with the substrate used as the hydrogen donor for the color development. Thus evaluation of test results obtained by peroxidase coupled methods should be carefully interpreted in a patient who is consuming drugs which hydrogen peroxide such as hydroquinone.

Creatinine↗
PubMed1992

[Analysis of circulating thyroid-stimulating activities in pregnant women with Graves' disease: differential measurement of activities induced by TSH receptor antibody and hCG].

Thyrotoxicosis in Graves' disease is often aggravated in early pregnancy and this aggravation is associated with postpartum relapse of thyrotoxicosis. To examine whether thyroid-stimulating TSH receptor antibody (TSAb) or human chorionic gonadotropin (hCG), which also has thyroid-stimulating activity (TSA), is responsible for this early aggravation, the respective TSA due to TSAb or hCG were evaluated with a sensitive cAMP accumulation assay using FRTL-5 cells. TSA, which was detectable in all of 11 women in normal early pregnancy, correlated positively with serum hCG level, but was abolished completely by the pretreatment of serum samples with the solid-phase hCG antibody coupled with Sepharose-4B. Total TSA in the model samples of mixture of Graves' and pregnant sera (Gr + Preg), was reduced by the pretreatment with the solid-phase antibody, just corresponding with the reduction in hCG-induced TSA. Total TSA in early pregnant sera in 15 patients with Graves' disease, decreased significantly but was still positive even by the pretreatment with the hCG antibody. Pregnancy-associated changes in TSA was examined serially in a patient with Graves' disease, and hCG-induced TSA increased predominantly along with the serum thyroid hormone in early aggravation period. These data indicate that (1) the respective TSA due to TSAb or hCG can be differentially measured by using the solid-phase hCG antibody and (2) hCG plays an important role for aggravation of Graves' thyrotoxicosis in early pregnancy.

Animals↗