[Topoisomerase I from human placenta. Functional activity of products of expression of cloned cDNA fragments]. / Topoizomeraza I iz platsenty cheloveka. Funktsional'naia aktivnost' produktov ékspressii klinirovannykh fragmentov kDNK.

Immunoscreening of the human placenta cDNA-library in the expression vector lambda gt11 using non-isotope detection based on the avidin-biotin system allowed to identify a number of clones encoding human topoisomerase I. The fusion protein from an extract of Escherichia coli cells infected with the recombinant phage lambda gt11 interacts with the monoclonal antibody raised against topoisomerase I from calf thymus; the dissociation constant being 5.7.10(-8) M. The restricted DNA fragments coding for the topoisomerase polypeptide in the composition of the fusion protein were recloned, and expression in the pEX vector was obtained. The functional analysis of the expression products has enabled localization of the epitope of binding the monoclonal antibody. It was demonstrated that the identified fusion protein can be applied for diagnosis of autoimmune diseases.

[Diagnostic and prognostic value of antioxidant enzyme assay in erythrocytes of patients with end stage renal disease treated with hemodialysis].

Anemia is one of the main complications seen in patients with end stage renal disease (ESRD) treated with hemodialysis. We hypothesized that oxidative stress and decrease of antioxidant defense enzyme activity may be major causes underlying functional insufficiency of erythrocytes. Blood samples of 16 patients with ESRD undergoing hemodialysis were investigated. All patients received Recormon for treatment of anemia. In spite of effective hemodialysis procedures cleared patient blood the erythrocyte activities of superoxide dismutase (SOD), glutathione peroxidase (GP) were lower than in healthy controls and hemodialysis procedure insignificantly influenced enzyme activities. After 6 months repeated study of the erythrocyte enzymes revealed further decrease of SOD and GP activities.

[Interactions of sera from patients with autoimmune diseases with cDNA expressed fragment of topoisomerase I and monoclonal antibodies against enzyme]. / Vzaimodeistvie syvorotok krovi bol'nykh autoimmunnymi zabolevaniiami s ékspressirovannym fragmentom kDNK topoizomerazy I i monoklonal'nymi antitelami k fermentu.

The interaction of sera from 34 patients with different autoimmune diseases with the expressed fusion protein cloned in lambda gt11 vector (topoisomerase I--beta galactosidase) and monoclonal antibodies against enzyme was studied. It was demonstrated that 100% of Scl cases possessed positive activity against fusion protein. It was shown that this test is not absolutely specific for Scl, i. e. 57.1% of Sle and 84.6% of RA demonstrated positive activity against "topoisomerase test". Autoimmune sera had the positive activity against monoclonal antibodies for topoisomerase I. This activity was shown to be due to the presence of antiidiotypic antibodies against topoisomerase in the autoimmune sera.