Effect of aniline and hydrazine derivatives on reversible oxygen addition in model systems of cobalt complexes of etioporphyrin and alpha, beta, gamma, delta-tetraphenylporphine]

The influence of aniline and hydrazine derivatives on the reversible oxygenation of cobaltous complexes of etioporphyrin I and alpha,beta,gamma,delta-tetraphenylporphin has been studied by means of ESR and electronic spectra. The formation of stable six-coordinated complexes with the said reagents prevents the oxygenation. The excess of hydrazines cause the destruction of porphyrin nucleus. The formation of intermediate dihydroporphyrins (chlorins) has been noticed.     

Intensification of cellular immune response by immunization of mice with the cells preincubated in interferon]

Mice F1(CBA X C57BL/6) were immunized intraperitoneally with a single injection of L-1210 cells preincubated in interferon or control "false" preparation. CBA mice were injected with MX-11 cells: similarly treated according to the same scheme. Injection of interferon-treated cells was accompanied by the enhancement of the cellular immune response. The greatest cytotoxic activity was possessed by the lymphocytes of mice to which M-11 cells were administered together with interferon in which the cells were formerly incubated.     

Induced leukemias and their connection with radiation exposure

The cytogenetic study of bone marrow cells was performed in 40 patients with secondary leukemias which have arisen after application of cytostatic and/or radiotherapy for primary tumours (Hodgkin's disease, lymphomas, acute lymphoblastic leukemias, breast cancer and other solid tumours). The comparative analysis of results has shown, that the leukemias after irradiating or application of alkylating agents and irradiation, have the quite particular clinico-morphological and cytogenetic characteristics. In 70% of cases these diseases develops as smouldering leukemias with subsequent transformation in M-4, M-6, and rarely M-2 cytochemical variants. Primary cytogenetic events in 60% of researched karyotypes are the losses of long arms or whole chromosomes 5 and 7. In 20% of the researched cases normal karyotype was found, in the left 20%, the changes of a karyotype not including anomalies 5 and 7 chromosomes were detected. The obtained outcomes allow to consider the discharged complex of tags as reference for leukemias, induced by irradiating or chemical agents with similar mechanism of action (alkylating agents, benzene and its derivates). This complex of tags is typical for induced leukemias, and in a combination with definition of a level of stable aberrations in peripheral blood lymphocytes, can be utilised for abjection of radiation-induced leukemias from common mass of cases detected in regions, polluted by radionuclides. In this study in 60% of cases only specific for secondary leukemias chromosomal aberrations, including monosomy 5 and 7, rearrangements of 11q23 were found. On the base of the obtained data the differences in concepts of "secondary" and "induced" leukemias are considered.     

The insulin-secreting and proliferative activity of established islet cells in the presence of sulfonylurea]

Exponentially growing rat islet cells (RINr) and hamster islet cells (HIT T-15) were incubated in presence of tolbutamide (10-1000 microM), gliclazide (0.1-10 microM) or glibenclamide (0.01-10 microM) for 15 hrs. Accumulation of insulin in culture medium was estimated by RIA. Effects of sulfonylureas (SU) on cell proliferation were assessed by 3H-thymidine (3H-T) incorporation into cellular DNA. All of SUs used stimulated insulin production in RIN and HIT cell cultures (with an exception of tolbutamide, which markedly suppressed insulin secretion in HIT cells at 1000 microM). 3H-T incorporation into RIN cells was elevated only in presence of gliclazide (10 microM), whereas tolbutamide at 1000 M significantly inhibited RIN cell proliferation. Gliclazide (0.1 microM) and glibenclamide (0.01-10 microM) enhanced 3H-T incorporation into HIT cells. Further detailed investigations of mechanisms of SU effects on islet cell reproduction will be of use for designing optimal strategy of hypoglycemizing therapy of diabetes mellitus.