The serum levels of soluble interleukin-2 receptors (s-IL-2R) and soluble CD8 antigens (s-CD8) were measured in 33 patients with Graves' disease (GD), 29 with toxic nodular goiter (TNG), 6 with toxic adenoma (TA), and 12 with hypothyroidism, as well as in 11 patients with infectious mononucleosis (known to have high s-IL-2R and s-CD8 levels) and 34 normal controls. Serum levels of T3 and T4, both total and free, and of TSH were simultaneously determined. s-IL-2R levels were significantly higher in all patients with hyperthyroidism (mean +/- SD, 3276 +/- 1273 U/mL for GD, 4183 +/- 1832 for TNG, and 1671 +/- 648 for TA) compared to normal control values (P less than 0.001 for GD and TNG and P less than 0.01 for TA), while in the euthyroid state they were within the normal range (535 +/- 240 U/mL). Hypothyroid patients had significantly lower s-IL-2R levels compared to normal controls (P less than 0.05). A positive correlation (P less than 0.001) between serum s-IL-2R levels and total/free T3-T4 levels was found in these groups of patients, while no correlation between s-CD8 levels and s-IL-2R/T3/T4 was found. These findings suggest an association between hyperthyroxinaemia and activation of human lymphocytes in vivo.

Plasma from pig, sheep, goat, cattie, horse, rabbit, dog, rat, guinea pig, and chicken was examined for the presence of specific binders for folic acid. It was found that only pig plasma contains unsaturated avid specific binders of folic acid. The maximum binding capacity of pig plasma for folic acid was found to be 14.0–26.5 ng/ml of plasma. These binders have a lower affinity for other folates and folate analogues. They are partly saturated by endogenous folates and they move electrophoretically in veronal buffer, pH 8.6, in an area including β-globulin and most of the γ-globulin fraction. Specific binders of folic acid with high binding capacity were also found in one female sheep out of the 16 tested.

Erythropoietin levels were determined in 50 Greek females: 20 beta-thalas-saemia (beta-thai) heterozygotes, 15 with a diagnosis of iron-deficiency anaemia and 15 normal controls. In beta-thai trait carriers, the erythropoietin levels were slightly higher than in normal controls (16.65 ± 4.43 vs. 12.84 ± 2.47 mU/ml); these levels were significantly lower than those in iron-deficient subjects with the same degree of anaemia (55.24 ± 31.35 mU/ml). In both groups, the erythropoietin levels are statistically correlated with the severity of anaemia (r = -0.537 p < 0.05 for iron deficiency; r = -0.610 p < 0.01 for beta-thai heterozygotes). In beta-thai heterozygotes, a close inverse correlation with red cell number and erythropoietin levels was also noted. It is suggested that microcytosis accompanying beta-thai trait constitutes an additional factor intervening in the regulation of erythropoiesis.

In 42 postmenopausal women with breast cancer aged 48-85 (mean age 62.4) years, the blood sex hormone levels were measured before and after 6 months of tamoxifen administration (20 mg daily). Follicle-stimulating hormone and luteinizing hormone levels decreased after tamoxifen administration (p < 0.001), but remained in the postmenopausal range, oestradiol levels increased (p < 0.05), sex hormone binding globulin levels increased (p < 0.001), testosterone levels remained stable (p > 0.1), free testosterone levels decreased (p < 0.001), Δ₄-androstenedione, 17-hydroxyprogesterone, and dehydroepiandrosterone sulfate levels remained unchanged (p > 0.1), and basal prolactin levels and their response to thyrotrophin-releasing hormone injection decreased significantly (p < 0.001) after tamoxifen therapy. It is concluded that tamoxifen has many and diverse effects on sex hormone levels, and its adverse effects do not affect the biological status of the patient, except perhaps for oestradiol, that increases in some cases, whose possible effect must be studied.

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