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Biomedical subjects

N Amino

Publications and source records attributed to N Amino.

At least 307 records · Page 17Linked to original sources
PubMed1982

A microcytotoxicity assay for thyroid-specific cytotoxic antibody, antibody-dependent cell-mediated cytotoxicity and direct lymphocyte cytotoxicity using human thyroid cells.

A microcytotoxicity assay for detection of thyroid-specific complement-dependent cytotoxic antibody (cytotoxic antibody), antibody-dependent cell-mediated cytotoxicity (ADCC) and direct lymphocyte cytotoxicity was developed using human, thyroid epithelial cells as targets. Thyroid tissue was obtained from patient with Graves' disease and was treated with collagenase and then trypsin. The red blood cells, interfollicular fibroblasts and infiltrating lymphoid cells in thyroid tissue from patients with Graves' disease could be removed by this procedure. To obtain entirely single cells as target cells, the suspension of dispersed thyroid epithelial cells was allowed to stand for 1 h at 4 degree C in culture medium to allow cell clumps to settle. For assay of cytotoxic antibody, a mixture of the single target cells, patient's serum and human complement was incubated in microwells for 18 h. After removing the detached cells, remaining target cells in the wells were fixed, stained and counted to assess cytotoxicity. For assay of ADCC and of direct lymphocyte cytotoxicity, target thyroid cells were precultured in the microwells for 18 h. Then effector cells with or without patient's serum were added and cultured further for 24-72 h. Cytotoxicity was assessed as described above. Adherence of effector cells to target thyroid cells sometimes disturbed the enumeration of target cells when the effector/target cell ratio was high. With this microassay system 3 different cytotoxic immune reactions against human thyroid cells could be measured quantitatively at the same time on 2-3 ml blood samples.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1982

Aggravation of thyrotoxicosis in early pregnancy and after delivery in Graves' disease.

The effect of pregnancy on the clinical course of Graves' disease was examined by studies on 41 pregnancies in 35 patients with Graves' disease, who were considered to be in a state of remission or near remission and were not receiving antithyroid drugs, during and after delivery. Eighteen of the 41 cases (44%) showed transient increases in the serum free T4 index (FT4 index) during weeks 10--15 of pregnancy, but normal thyroid function in the second and third trimesters. Similar transient increases in the serum free T3 index (FT3 index) were observed in early pregnancy in these patients. These early increases in the FT4 and FT3 indexes were specific to Graves' disease and were not observed in Hashimoto's disease. Two to 4 months postpartum, 32 cases (78%) developed various degrees of thyrotoxicosis, which was divided into 3 types: 1) persistent thyrotoxicosis with high radioactive iodine (RAIU) (10 cases), 2) transient thyrotoxicosis with normal or high RAIU) (10 cases), and 3) destruction-induced thyrotoxicosis with low RAIU (12 cases). An increase in the FT4 index in early pregnancy was significantly (P less than 0.001) associated with relapse of stimulation-induced thyrotoxicosis of either the persistent or transient type. Patients who developed destruction-induced thyrotoxicosis after delivery had significantly higher titers of antithyroid microsomal antibodies (P less than 0.001) and a longer euthyroid period before pregnancy (P less than 0.01) than patients who had recurrent persistent thyrotoxicosis. These data indicate that Graves' disease is aggravated in early pregnancy and after delivery and ameliorates in the latter half of pregnancy. Postpartum relapse of persistent hyperthyroidism could be predicted from an early increase in the FT4 index during pregnancy.

Adult↗
PubMed1982

Decrease of immunoglobulin G-Fc receptor-bearing T lymphocytes in Graves' disease.

Peripheral immunoglobulin G (IgG)-Fc receptor-bearing T lymphocytes (T gamma cells) in patients with autoimmune thyroid diseases and destruction-induced thyrotoxicosis were assayed by measuring erythrocyte antibody-rosette formation using a microplate technique. In untreated patients with Graves' disease, the percentage of T gamma lymphocytes (mean +/- SD, 8.9 +/- 3.9%; n = 15) was significantly lower (P less than 0.001) than that in normal controls (21.7 +/- 9.1%; n = 35). A similar decrease was found in thyrotoxic patients with Graves' disease under antithyroid drug therapy (12.1 +/- 5.6%; n = 11; P less than 0.01). Normal percentages were observed in euthyroid patients with Graves' disease under antithyroid drug therapy or in remission. In patients with Hashimoto's disease and destruction-induced thyrotoxicosis, the percentage of T gamma lymphocytes was similar to that in normal controls. The percentage of T gamma lymphocytes was significantly correlated inversely with the serum T4 level, the free T4 index, the T3 level, and the free T3 index in patients with autoimmune thyroid diseases, excluding those with Hashimoto's disease with destructive thyrotoxicosis. There were no correlations between T gamma lymphocytes and other variables, such as goiter size, the titer of antithyroid antibodies, or proptosis, in a group of untreated cases of autoimmune thyroid disease. The decreased proportion of T gamma lymphocytes in thyrotoxic patients with Graves' disease may be related to the perpetuation of thyrotoxicosis in patients with Graves' disease.

Adolescent↗
PubMed1982

Radioimmunoassay of "free thyroxin" in dried blood spots on filter paper - preliminary observations on the effective differentiation of subjects with congenital hypothyroidism from those with subnormal thyroxin-binding globulin and normal subjects.

In this sensitive, simple method for measuring "free thyroxin" (FT4) in eluates of dried blood spots on filter paper by use of a radioimmunoassay kit (Amerlex Free T4 RIA), the measurable range of FT4 is 1.8 to 57 ng/L (equivalent to the concentration in serum), or 7 to 237 fg/tube. The mean coefficients of variation for within assay-within spots, within assay-between spots, and between assays were 5.3%, 5.0%, and 6.2%, respectively. FT4 in blood spotted on filter paper is stable for at least a month when dried and kept at either -20 degrees C, 4 degrees C, room temperature (about 25 degrees C), or 37 degrees C. The results for FT4 in dried blood spots correlated closely with the free-T4 concentration in serum (r = 0.99). The method can be used to differentiate cases of primary and secondary hypothyroidism from normal subjects and those with subnormal thyroxin-binding globulin. This method may be useful in screening for congenital hypothyroidism, because sample-retesting is not necessary.

Adolescent↗
PubMed1981

Elevated levels of circulating carcinoembryonic antigen in hypothyroidism.

The level of circulating carcinoembryonic antigen (CEA) was measured in 148 patients with various thyroid diseases. A significantly high frequency of positive CEA was observed in hypothyroid patients with Hashimoto's disease, but the serum CEA levels were not correlated with the serum calcitonin concentrations in Hashimoto's disease. The CEA levels were inversely correlated with the serum T4 concentrations (P less than 0.001) and were positively correlated with the serum TSH concentrations (P less than 0.001), but not with the titers of serum antithyroid antibodies or the size of goiter in autoimmune thyroid disease. Moreover, the increase in CEA was significantly related to the duration of hypothyroidism (P less than 0.001). The high CEA levels in all hypothyroid patients decreased when the patients attained a euthyroid state after thyroid hormone therapy for 4-9 months. The gradual decrease in the serum CEA levels during treatment was roughly correlated with the decreases in serum cholesterol concentration and serum lactic dehydrogenase and glutamic oxalacetic transaminase activities. On Sephadex G-200 column chromatography of serum from hypothyroid patients, the CEA immunoreactivity, like purified standard CEA, was recovered in the large molecular weight fraction. These findings indicate that elevated CEA levels in hypothyroid patients do not necessarily indicate malignancy. CEA elevation in hypothyroidism may be caused by decreased degradation of CEA.

Adolescent↗
PubMed1981

Serum ratio of triiodothyronine to thyroxine, and thyroxine-binding globulin and calcitonin concentrations in Graves' disease and destruction-induced thyrotoxicosis.

The serum ratios of T3 to T4, and T4-binding globulin (TBG) and calcitonin concentrations were studied in cases of thyrotoxic Graves' disease and destruction-induced thyrotoxicosis. In 272 patients with Graves' disease, 209 of 240 (87%) untreated patients without complications had high T3 to T4 ratios (nanograms per micrograms) of more than 20. Six of 32 (19%) patients with Graves' disease who had complications (15 with pregnancy, 14 with increased TBG, and 3 with conditions associated with a low T3 syndrome) had high T3 to T4 ratios. Eleven of 74 (15%) patients with destruction-induced thyrotoxicosis (24 with subacute thyroiditis, 39 with postpartum transient thyrotoxicosis, and 11 with spontaneous transient thyrotoxicosis) had high T3 to T4 ratios. Patients who had serum T4 levels of more than 30 micrograms/dl and/or T3 levels of more than 800 ng/dl had Graves' disease. There was no significant correlation between the T3 to T4 ratio and activities of thyroid-stimulating immunoglobulins in thyrotoxic patients with Graves' disease who had no complications. The average serum levels of TBG in destruction-induced thyrotoxicosis and thyrotoxic Graves' disease were 20.7 +/- 4.3 micrograms/ml (mean +/- SD; n = 22), and 19.9 +/- 4.0 (n = 41), respectively, which were significantly lower than that in healthy subjects (22.7 +/- 4.4 micrograms/ml; n = 165), but there was no difference between the values in the two groups of thyrotoxicosis patients. The average serum level of calcitonin in destruction-induced thyrotoxicosis patients was 96.7 +/- 66.7 pg/ml (n = 21), which was significantly (P less than 0.05) higher than the values in patients with thyrotoxic Graves' disease (62.0 +/- 44.7 pg/ml; n = 26) and in healthy subjects (63.9 +/- 31.2 pg/ml; n = 29), but the difference in values in the two groups of thyrotoxicosis was not clinically useful because of considerable overlap of individual values. The T3 to T4 ratio is a simple and helpful index for the differentiation of the two types of thyrotoxicosis. A T3 to T4 ratio less than 20 in thyrotoxic patients before therapy is a laboratory signal of destruction-induced thyrotoxicosis or Graves' disease with complications, but final differentiation should be confirmed by measuring radioactive iodine uptake.

Adult↗
PubMed1981

Increase in plasma thyrotropin-releasing hormone in normal human pregnancy.

Maternal thyroid regulation in pregnancy was examined by measuring the concentrations of TRH, T4, T3, free T4 (by RIA), T4-binding globulin, TSH, PRL, and hCG in the sera of 30 normal pregnant women, 10 puerperally lactating women, and 10 normal pregnant women, 10 puerperally lactating women, and 10 normal nonpregnant female controls. Results showed that serum T4, T3, T4-binding globulin, PRL, and hCG, but not free T4 (by RIA), increased significantly during pregnancy. The plasma level of TRH was significantly higher (P less than 0.01) in the second trimester and significantly lower (P less than 0.05 1 month post partum than those values in nonpregnant controls. No significant correlations, however, were observed between the serum level of TRH and those of the thyroid hormones TSH, PRL, and hCG in pregnancy. The TRH-degrading activity of the plasma in the second trimester was normal. These results indicate that TRH secretion may be increased in the second trimester of pregnancy.

Adult↗
PubMed1980

Exophthalmos in autoimmune thyroid disease.

Protrusion of the eyes of patients with autoimmune thyroid disease was compared with that of healthy subjects. The mean values for protrusion in patients with thyrotoxic Graves' disease and Hashimoto's disease and in healthy subjects were 16.6 +/- 2.1 mm (mean +/- SD; n = 122), 14.2 +/- 1.8 mm (n = 100), and 13.9 +/- 1.9 mm (n = 558), respectively. The value of Graves' disease was significantly different from that for healthy subjects (P < 0.001). Individual values for protrusion showed a similar normal distribution in these three groups, but were displaced to higher values as a whole in Graves' disease. These results, which suggest that almost all patients with Graves' disease have exophthalmos, do not support the idea that Graves' ophthalmopathy is a distinct single autoimmune disease.

Autoimmune Diseases↗
PubMed1980

Postpartum recurrence of hyperthyroidism and changes of thyroid-stimulating immunoglobulins in Graves' disease.

The changes of circulating thyroid-stimulating antibody (TSAb) in three patients with Graves' disease with relapsed hyperthyroidism after delivery were examined. All three patients were in clinical remission before and during pregnancy, but hyperthyroidism, with high radioactive iodine uptake, recurred 3--5 months post partum. TSAb activity, measured serially, was not detected at the time of the postpartum relapse, although it was detectable during pregnancy and in the euthyroid state after therapy. In two cases, the titer of antithyroid microsomal antibody increased concomitantly with an increase in the free T4 index. These data suggest that TSAb may not be a pathological thyroid stimulator in patients with recurrent hyperthyroidism after delivery in Graves' disease.

Adult↗