Natural hidden autoantibodies react with negatively charged carbohydrates and xenoantigen Bdi.

Immunoglobulin preparations from sera of healthy donors contain polyspecific autoantibodies interacting with DNA and other charged antigens. These antibodies belong to the IgG class and can exist in the free or hidden state. The hidden antibody activity can be revealed after ion-exchange chromatography on QAE-Sephadex A-50.

Destabilase from the medicinal leech is a representative of a novel family of lysozymes.

Intrinsic lysozyme-like activity was demonstrated for destabilase from the medicinal leech supported by (1) high specific lysozyme activity of the highly purified destabilase, (2) specific inhibition of the lysozyme-like activity by anti-destabilase antibodies, and (3) appreciable lysozyme-like activity in insect cells infected with recombinant baculoviruses carrying cDNAs encoding different isoforms of destabilase. Several isoforms of destabilase constitute a protein family at least two members of which are characterized by lysozyme activity. The corresponding gene family implies an ancient evolutionary history of the genes although the function(s) of various lysozymes in the leech remains unclear.

Histones evoke thymocyte death in vitro; histone-binding immunoglobulins decrease their cytotoxicity.

Effects of various histones, poly-L-lysine, spermine, and the synthetic peptide Arg-Lys-Asn-Val-Tyr-Arg (thymohexine) on intact rat thymocytes were studied. Histones and poly-L-lysine displayed cytotoxicity, causing disorders in the membrane permeability of thymocytes and their death. The dose and time dependences of the effects of histones on thymocytes were determined.

Reciprocal effect of optical isomerism of EW-dipeptides on immune response.

Dipeptides of the EW-sequence, consisting of D-amino acids, were shown to inhibit spleen colony formation both after in vitro treatment of bone marrow and after the peptide injection to the donor 2-48 h prior to bone marrow taking. The inhibiting effect of D-(EW) peptides can be eliminated by injection of thymic cells to the recipient. L-(EW) peptides have no influence on colony forming activity of intact bone marrow cells but stimulate regeneration of colony formation by irradiated (1 Gy) bone marrow.

Effects of low level radiation from the Chernobyl accident in a population with iodine deficiency.

Unlabelled: To determine the effects of low dose radiation from 131I and 137Cs resulting from the Chernobyl disaster on the expression of endemic goiter in children, we studied children in regions with and without evidence of radiocontamination but comparable iodine insufficiency. We included 89 children in the study (radiocontaminated) region (SR) and 116 in the control region (CR) because they were either fetuses, infants, or pre-adolescents at the time of exposure. We evaluated thyroid dimensions by clinical examination and ultrasound; thyroid function by hormonal levels, and thyroglobulin measurement; histology of the thyroid by fine needle aspiration; and thyroid autoimmunity.