Search PubMed⌕ Search

Biomedical subjects

N Amino

Publications and source records attributed to N Amino.

At least 91 records · Page 5Linked to original sources
PubMed1998

[Association between antiphospholipid antibodies and arterial or venous thrombosis/thrombocytopenia].

The relationship between thrombotic or thrombocytopenic complications and the existence of anticardiolipin antibodies (aCL) and/or lupus anticoagulant (LA) was studied in 146 patients with systemic lupus erythematosus (SLE). The prevalence of arterial thrombosis was obviously higher in patients who had both aCL and LA than in patients with either aCL or LA alone or in those with neither. Since a substantial fraction of the former group of patients with arterial thrombosis also had thrombocytopenia, there is a possibility that aCL and LA might enhance platelet activation and aggregation. To test this hypothesis, we studied the in vitro effects of aCL and LA on the enhancement of platelet activation by flow cytometric analysis using anti-CD62P and anti-CD41 monoclonal antibodies directed against platelet activation-dependent granule-external membrane (PADGEM) protein and platelet glycoprotein IIb (GPIIb). The IgG fraction purified from aCL+.LA+ plasma apparently enhanced platelet activation induced by adenosine diphosphate (ADP) at a low concentration, but IgG fractions from aCL+.LA- or aCL-.LA+ plasma did not cause enhancement of platelet activation. These results suggest that aCL and LA may cooperate to promote platelet activation, and may be involved, at least partially, in the pathogenesis of arterial thrombosis in patients with SLE.

Adolescent↗
PubMed1997

Rapid detection of specific messenger RNAs in thyroid carcinomas by reverse transcription-PCR with degenerate primers: specific expression of oncofetal fibronectin messenger RNA in papillary carcinoma.

The search for mRNAs that are specifically expressed in cancer tissues is important for gene diagnosis and therapy. However, finding such mRNAs in human cancers is usually very difficult, both because of the limited volume of RNA obtainable from the tissues and the many technical difficulties of RNA analysis. To address these problems, the present study compared mRNA from thyroid cancer tissues with those from normal and benign tissues by reverse transcription-PCR using two degenerate primers. Amplified cDNAs were separated by electrophoresis with nondenaturing acrylamide gel, then three bands that are increased in cancer tissues were selected, reamplified by PCR, and cloned into T-vector. One of the bands was determined by sequencing analysis to be oncofetal fibronectin. The expression of oncofetal fibronectin mRNA in benign and malignant tissues was examined by Northern blot and reverse transcription-PCR using specific primers of its cDNA sequence, and its increased expression was observed only in papillary and anaplastic carcinomas. Thus, the present method rapidly detected specific mRNAs in cancer tissues, and one of these, oncofetal fibronectin mRNA, is a good target for gene diagnosis of papillary carcinoma.

Adenoma↗
PubMed1997

Effects of autoantibodies on the course of pregnancy and fetal growth.

OBJECTIVE: To assess the effects of autoantibodies on the course of pregnancy and fetal growth. METHODS: One thousand one hundred seventy-nine healthy women with singleton gestations were screened in early pregnancy for seven kinds of autoantibodies: antithyroid microsomal antibody, antithyroglobulin antibody, two kinds of rheumatoid factor, antinuclear antibody, anti-DNA antibody, and antimitochondrial antibody. RESULTS: In 228 cases (19.3%), at least one autoantibody was found; however, overlap of autoantibodies in the same individual was unexpectedly rare, and only two cases were positive for as many as four autoantibodies. A significantly higher rate of spontaneous abortion was observed in antibody-positive subjects, especially those with antithyroid microsomal (10.4%) or antinuclear antibodies (16.0%), compared with all antibody-negative subjects (5.5%). There were no significant differences in any outcome assessed among subjects positive for antithyroglobulin antibody, anti-DNA antibody, or antimitochondrial antibody compared with all antibody-negative subjects. None of the seven autoantibodies affected the rates of preterm delivery, stillbirth, pregnancy-induced hypertension, malformation, or gender ratio. CONCLUSION: Antithyroid microsomal antibody and antinuclear antibody are the only autoantibodies that increase the abortion rate.

Adult↗
PubMed1997

Risk of arterial thrombosis in patients with anticardiolipin antibodies and lupus anticoagulant.

The relationship between arterial or venous thrombosis and the levels of anticardiolipin antibodies (aCL) and/or existence of lupus anticoagulant (LA) was studied. The 141 patients with systemic lupus erythematosus (SLE) were divided into four groups: aCL single positive (25 cases), LA single positive (11 cases), aCL and LA double positive (25 cases), aCL and LA double negative (80 cases). The prevalence of thrombosis was higher in aCL and LA double positive patients (21/25 cases, 84.0%, P <0.01) than that in aCL single positive patients (4/25 cases, 16.0%), LA single positive patients (1/11 cases, 9.1%) and double negative patients (3/80 cases, 3.8%). Furthermore, in these double positive patients, all patients (10/10 cases) with a high positive level of aCL (> 10 units/ml) had arterial thrombosis, whereas only 2/15 patients (13.3%) with a low positive level of aCL (3-10 units/ml) were affected. Venous thrombosis was frequently found in the low positive group (9/15 cases, 60.0%). On the contrary, none of 105 LA negative patients had arterial thrombosis and only seven (6.7%) had venous thrombosis. These findings indicate that a high aCL activity combined with a LA positive result might be a risk factor for arterial thrombosis.

Adolescent↗
PubMed1997

Subtypes of anti-TSH receptor antibodies classified by various assays using CHO cells expressing wild-type or chimeric human TSH receptor.

To analyze the heterogeneity of anti-TSH receptor antibodies (TSHRAb), we measured serum TSH-binding inhibitory immunoglobulin (TBII), thyroid-stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) activities in 31 patients with positive TSHRAb, using CHO cells expressing wild-type TSHR (WT) or TSHR chimera (Mc2) wherein residues 90-165 were substituted by the LH/CG receptor. Using membranes from WT cells, we detected TBII activity in all 31 patients; 10 (32%), all with TSAb activity only, completely lost TBII activity using Mc2 membranes. TSAb activity was found in 26 sera using WT cells; 20 (77%) completely lost TSAb activity in Mc2 cells. Comparisons of TBII and TSAb activity in WT cells did not exhibit a strong positive correlation (r = 0.52). Of the 20 sera that completely lost TSAb activity in Mc2 cells, 10 retained some TBII activity in Mc2 cells. In each of the sera with retained TBII activity, TSAb activity was recovered in Mc2 cells using the conversion assay, which measures the conversion of a nonstimulating TSHRAb to a TSAb by the action of an anti-human IgG. Additionally, the TBII and conversion assay values in Mc2 cells exhibited a strong positive correlation (r = 0.86). Of the 31 sera, TSBAb was found in 7 samples, with no difference in WT and Mc2 cells. TBII activity was detected in all 7 sera with WT cells; TSAb activity in only 2. In the 5 sera with TSBAb but no TSAb activity, and with only a minimal or no decrease in TBII activity in Mc2 cell membranes, the in vitro conversion assay uncovered TSAb activity. Analyzing these data, we classify the sera into 5 groups containing multiple, different TSHR autoantibodies, including two different TSAbs, three different TBIIs, and one nonfunctional antibody. The heterogeneity of TBIIs as well as TSAbs provides a basis to explain the lack of correlation between TBII and TSAb activities in some past studies of Graves' sera.

Animals↗
PubMed1997

Opposite changes in serum soluble CD8 in patients at the active stages of Graves' and Hashimoto's diseases.

Serum concentrations of soluble CD8 (sCD8) were examined by enzyme immunoassay in 154 patients with autoimmune thyroid diseases and 46 healthy controls. The numbers of peripheral CD8+ cells were also examined in the same subjects by flow cytometry. The serum concentrations of sCD8 were increased in patients with stimulative thyrotoxicosis caused by active Graves' disease, and decreased in patients with transient destructive thyrotoxicosis caused by the aggravation of Hashimoto's disease, and normal in euthyroid and hypothyroid patients with Graves' or Hashimoto's disease. The ratios of serum sCD8 levels to the numbers of CD8+ cells were increased in thyrotoxic patients with active Graves' disease, but not with active Hashimoto's disease, suggesting an increase in sCD8 production by CD8+ cells in active Graves' disease. The serum concentrations of sCD8 were correlated with the serum levels of thyrotropin receptor antibody (TRAb) and thyroid hormones in Graves' disease. These data indicate that serum sCD8 proteins change in opposite directions in the active stages of Graves' and Hashimoto's diseases, and may represent the disease activities.

Acute Disease↗
PubMed1997

Changes in T, B, and NK lymphocyte subsets during and after normal pregnancy.

PROBLEM: Pregnancy affects the maternal immune system and the clinical course of maternal diseases. Here we report the changes in the detailed lymphocyte subsets of helper T cells, suppressor T cells, CD5+ B cells, T cell receptor (TCR) alpha beta-positive T cells (T alpha beta cells), TCR alpha beta-negative T cell (T gamma delta cells), and other during and after pregnancy through to one year postpartum, and discuss the significance of the changes. METHOD: The absolute numbers of helper T cells, suppressor T cells, cytotoxic T cells, TCR alpha beta-negative T cells (T gamma delta cells), CD5- B cells, CD5+ B cells, and NK cell subsets were examined by two-color flow cytometry in peripheral blood from 51 healthy non-pregnant women, 106 healthy pregnant women, and 148 healthy postpartum women. RESULTS: In early pregnancy, the numbers of suppressor T cells and NK cells with strong cytotoxicity (NK+3 cells) increased, and the number of cytotoxic T cells decreased. In late pregnancy, the helper T cell and NK+3 cell numbers decreased. T alpha beta, CD5- B and CD5+ B cells decreased during pregnancy. After delivery, helper T cells and cytotoxic T cells increased from 1 to 4 months postpartum, and suppressor T cells increased at 7 months postpartum. TCR alpha beta-negative T cells increased at 4 to 10 months postpartum. Both CD5- and CD5+ B cells decreased further at 1 month postpartum, but CD5+ B cells increased markedly at 7 to 10 months postpartum. CONCLUSIONS: These data indicate that 1) early increases of suppressor T cells and NK+3 cells during pregnancy may be related to the mechanism to accept or reject the fetus in early pregnancy, respectively; 2) late decreases of helper T cells and NK+3 cells may be related to the maintenance of pregnancy: 3) postpartum increases of helper T cells, cytotoxic T cells, TCR alpha beta-negative T cells (T gamma delta cells), and CD5+ B cells may be related to the postpartum aggravation of autoimmune diseases; and 4) the immunological effects of pregnancy remains until about 1 year after delivery.

Adult↗
PubMed1997

New enzymatic assay with urea amidolyase for determining potassium in serum.

We developed a new simple assay for potassium ion in serum using urea amidolyase (UAL) from yeast sp. The method is based on activation of the enzyme by potassium ion. We eliminated endogenous ammonium ion by use of glutamate dehydrogenase (GLDH), and then monitored the production of ammonium ion by UAL, urea, ATP, bicarbonate and magnesium ions. Ammonium ion was produced proportional to the potassium ion concentration and was determined by adding GLDH to produce NADP+ in the presence of 2-oxoglutarate and NADPH. We monitored the change of absorbance at 340 nm. The inhibitory effect of calcium ion to this assay was eliminated by adding glycoletherdiamine-N, N, N', N'-tetraacetic acid to the reaction. The within-assay coefficients of variation (CV) of this method were 0.9-1.55% (n = 10) at 3.32-6.18 mmol/L. Day-to-day CVs ranged from 1.49% to 2.46%. The analytical recovery was 96-108%. The correlation coefficient between the values obtained by our method (y) and those by the ion-selective electrode (ISE) method (x) was 0.994 (y = 1.032x-0.166 mmol/L, Syx = 0.110, n = 100). The presence of bilirubin, haemoglobin or other ions did not affect this assay, confirming the usefulness of this assay for clinical purposes.

Acetates↗
PubMed1997

Characterization of monoclonal thyroid-stimulating and thyrotropin binding-inhibiting autoantibodies from a Hashimoto's patient whose children had intrauterine and neonatal thyroid disease.

A multiplicity of TSH receptor autoantibodies (TSHRAbs) have been characterized after subcloning heterohybridomas produced from the lymphocytes of a patient who has Hashimoto's thyroiditis and had three children with intrauterine or neonatal hyperthyroidism. Twelve clones produced stimulating TSHRAbs that increased cAMP levels and iodide uptake in rat FRTL-5 thyroid cells and increased cAMP levels in Chinese hamster ovary (CHO) cells transfected with the human TSHR; like 95% of Graves' stimulating TSHRAbs, all 12 have their functional epitope on the N-terminus of the TSHR extracellular domain, requiring residues 90-165 for activity. All 12 bind to human thyroid membranes in the absence, but not the presence, of TSH, but are only weak inhibitors of TSH binding in assays measuring TSH binding-inhibiting Igs (TBIIs). In contrast, 8 different clones produced TSHRAbs that did not increase cAMP levels, but, instead, exhibited significant TBII activity. Four inhibited the ability of TSH or a stimulating TSHRAb to increase cAMP levels and had their functional epitope on the C-terminal portion of the TSHR external domain, residues 261-370, mimicking the properties of blocking TSHRAbs that cause hypothyroidism in patients with idiopathic myxedema. The 4 other TBIIs inhibited the ability of TSH, but not that of a stimulating TSHRAb, to increase cAMP levels, like TBIIs in Graves' patients. The functional epitope for 3 of these Graves'-like TBIIs was residues 90-165; the functional epitope for the fourth was residues 24-89. The fourth also increased arachidonic acid release and inositol phosphate levels in FRTL-5 thyroid cells and exhibited conversion activity, i.e. the ability to increase cAMP levels in the presence of an anti-human IgG. Thus, this TBII exhibited signal transduction activity, unlike the other 3 Graves'-like TBIIs. The patient, therefore, has stimulating TSHRAbs and 3 different types of TBIIs, each with different functional properties and different epitopes on the TSHR.

Adult↗
PubMed1997

Increased serum concentration of soluble CD30 in patients with Graves' disease and Hashimoto's thyroiditis.

This study investigated serum levels of the soluble form of CD30 (sCD30), which is mainly secreted from T helper 2(Th2) cells, in autoimmune thyroid diseases. The possible relationship of sCD30 to autoantibody production was also evaluated. Serum levels of sCD30 were determined by an enzyme-linked immunosorbent assay in 71 patients with Graves' disease, 37 patients with Hashimoto's thyroiditis, and 21 normal donors. Compared with normal subjects (7.1 +/- 4.5 U/mL), sCD30 was increased in patients with Graves' disease (29.2 +/- 25.2 U/mL, P < 0.0001) and in patients with Hashimoto's thyroiditis (29.9 +/- 26.9 U/mL, P < 0.0001). In Graves' disease, sCD30 levels were higher in thyrotoxic patients (41.7 +/- 31.2 U/mL, P < 0.001) than in remission patients (15.8 +/- 11.0 U/mL), and a significant correlation was observed between sCD30 levels and serum activities of TSH receptor antibody (r = 0.444, P < 0.0001). In Hashimoto's thyroiditis, sCD30 levels were higher in patients with transient destructive thyrotoxicosis caused by the aggravation of the disease (48.8 +/- 34.4 U/mL, P < 0.05) than in euthyroid patients (24.2 +/- 19.4 U/mL). These data suggest that serum sCD30 is a valuable marker of disease activity and support an important role of the Th2-type immune response in the pathogenesis in Graves' disease and Hashimoto's thyroiditis.

Adult↗
PubMed1997

Detection of thyroid-stimulating antibody using frozen stocks of Chinese hamster ovary cells transfected with cloned human thyrotropin receptor.

To measure thyroid-stimulating antibody (TSAb) in sera from patients with Graves' disease, we developed a new assay system with using frozen stocks of CHO-K1 cells. CHO-K1 cells transfected with cloned thyrotropin (TSH) receptor on a 96 well plate were frozen in Cell Banker and stored at -70 degrees C. Three days before the assay, they were thawed in the culture medium and allowed to grow in a monolayer until use. The medium was replaced with medium containing IgGs from the patients, then after 2 h, it was collected and concentrations of adenosine 3'-5'-cyclicmonophosphate (cAMP) were measured. This method is sensitive enough to detect TSAb and it is simpler and easier than the methods which use FRTL-5 cells.

Animals↗
PubMed1997

[The pituitary specific transcription factor Pit-1/GHF-1 and PIT1 abnormality].

Pit-1/GHF-1 is a pituitary specific POU-domain DNA binding factor, which transactivates the growth hormone (GH), prolactin (PRL), thyrotropin beta subunit (TSH beta) genes, and PIT1 gene itself. It is indispensable for the differentiation and the proliferation of the cells producing GH, and PRL. Loss of the PIT1 gene function (PIT1 abnormality) results in combined deficiency of GH, PRL, and TSH. PIT1 abnormality serves as a model of transcription factor abnormalities.

Animals↗
PubMed1997

[Laboratory diagnosis before onset and prediction of Graves' disease].

Graves' thyrotoxicosis frequently occurs after delivery through immune rebound mechanism. We tried to establish a systematic method of predicting postpartum onset of Graves' thyrotoxicosis. We followed pregnant women with anti-thyroid microsomal antibody (MCAb) from their early pregnancy to the postpartum period, and analyzed the relation between activities of thyroid stimulating antibodies (TSAb) in early pregnancy and the postpartum occurrence of Graves' disease. Among 71 subjects with positive MCAb, 7 showed positive TSAb in their early pregnancy without any thyroid dysfunction. All 7 developed thyroid dysfunction in postpartum period. Five of seven (70% of TSAb positive subjects) developed Graves' disease. None of 64 TSAb-negative subjects developed Graves' thyrotoxicosis, though 44 developed various types of thyroid dysfunction due to postpartum autoimmune thyroiditis. Graves' thyrotoxicosis also occurs after an attack of allergic rhinitis. A patient who developed Graves' thyrotoxicosis after an attack of allergic rhinitis showed positive TSAb before the attack of allergic rhinitis. These findings suggest that high risk of Graves' thyrotoxicosis onset can be predicted by the detection of TSAb.

Female↗
PubMed1997

Detection of CD44 variants in fine needle aspiration biopsies of thyroid tumor by RT-PCR.

Increased expression of CD44 variants is often observed in differentiated thyroid carcinomas. To establish a method for gene diagnosis of thyroid without any additional invasions to the patients, RNA in leftover cells inside the needle used for fine needle aspiration biopsies (FNABs) was extracted to detect the expression of CD44 variants by reverse transcription-polymerase chain reaction (RT-PCR). After FNAB and preparation of sample on a slide glass for cytological examinations, RNA in leftover cells inside the needle was extracted. After reverse transcription, cDNA was amplified by PCR with specific primers for CD44. The results were compared with the cytological diagnosis. CD44 variants were detectable in all seven samples that were diagnosed as positive cytology. However, they were detected in only five of the 29 samples of negative cytology. Therefore, thyroid tumors may be more accurately diagnosed by a combination of cytological examination and detection of CD44 variants in RNA obtained by FNAB.

Adult↗