First Measurement of the Total Neutron Cross Section on Argon between 100 and 800 MeV.

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

[The state of the vascular endothelium and histological changes of the muscular tissue in patients with chronic ischemia of the extremities].

One of perspective trends of treatment in patients, suffering chronic ischemia of extremities, is application of a cellular technologies. This trend needs scientific confirmation, basing on investigations, which discover primary signs, characterizing chronic ischemic impact on the muscular tissue structure and ultrastructure of vascular endothelium in capillaries of the muscle. The results of investigations conducted witness the muscular tissue reconstruction occurrence under impact of chronic ischemia: restoration of muscular fascicles by connective tissue, spoiling young myons regeneration, the capillaries lumen obturation. In addition, in ischemic state the destruction of energetic organelles and endotheliocytes occurs.

[Endocrine function of the thymus and ionizing radiation]. / Endokrinnaia funktsiia timusa i ioniziruiushchaia radiatsiia.

It is shown that external as well as incorporated radiation inhibit the endocrine function of the thymus in the result of the direct and indirect effects. Postradiation deficiency of thymic hormones plays a significant role in pathogenesis of functional disorders in the immunity system. Immunocorrection with thymic agents is the most effective method when the mechanism of inhibition of thymic hormonal function are taken into account.

[The lymphokine-mediated activation of effector cells in the natural resistance system induced by gamma-interferon]. / Limfokin-oposredovannaia aktivatsiia kletok-éffektorov sistemy estestvennoi rezistentnosti, indutsirovannaia gamma-interferonom.

Some mechanisms of biologic action of gamma-interferon (INF) agents have been studied in mice systems in vivo. The obtained results testify to the possibility of existence of inductor mechanisms for activation of the effector cells of immunobiologic surveillance. It is supposed that gamma-INF is a binding chain of the natural host resistance.

[Effectiveness of correcting radiation injuries of the thymic endocrine function by T-activin in conditions of reduced postradiation hypercorticism reaction]. / Effektivnost' korrektsii luchevykh narushenii éndokrinnoi funktsii timusa taktivinom v usloviiakh oslableniia reaktsii postradiatsionnogo giperkortitsizma.

T-activin administered to rats after exposure to whole-body 1.5 Gy neutron- and 6 Gy X-radiation increases considerably the thymosin-like serum activity, accelerates cellularity restoration in the thymus and spleen, but does not influence the survival rate. Ionol administered prior to X-irradiation reduces the postirradiation hypercorticism reaction and the indirect effect of radiation on lymphoid organs which it is responsible for. The combined injection of ionol and T-activin increases the thymosin-like serum activity and spleen cellularity to the highest possible level and increases the survival rate of rats from 24 to 64 per cent and the lifespan up to 6 days.

[Thymus endocrine function and the immune system indices of cancer patients after neutron and gamma therapy]. / Endokrinnaia funktsiia timusa i nekotorye pokazateli sostoiannia immunnoi systemy onkologicheskikh bol'nykh posle neitronnoi i gamma-terapii.

Patients with head and neck and locomotor system tumors received neutron therapy in the total doses of 4-8 and 12-14 Gy which was followed by a pronounced dose-dependent decrease in the serum thymus factor and total blood-lymphocyte levels. The latter changes were predominantly due to a decrease in the non-T-non-B cell concentration. Following the treatment, a rise in the level of circulating immune complexes and those of IgA and IgG was observed. Changes in the immune system proved less apparent in patients with locomotor system cancer who had been given 20 Gy of gamma-ray radiation.

[The status of the endocrine function of the thymus in acute radiation sickness resulting from the accident at the Chernobyl Nuclear Power Station]. / Sostoianie éndokrinnoi funktsii timusa pri ostroi luchevoi bolezni, voznikshei vsledstvie avarii na ChAES.

Data are presented on the role of inhibition of endocrine function of the thymus in the pathogenesis of acute radiation sickness resulted from the direct and indirect (via the increased glucocorticoid production) effects of ionizing radiation. The complex treatment, including nonspecific active immunotherapy, permitted to normalize the thymic hormone level and certain parameters of the immune system.

[Immunomodulating mechanism of the antitumor effect of asterin]. / Immunomoduliruiushchii mekhanizm protivoopukholevogo deistviia asterina.

It was shown that asterin therapy performed on a model of spontaneous metastasis markedly changed the content of the thymus serum factor in mice and normalized its level. The inducing mechanism of the drug's antitumor action was realized both at the stage of the metastatic postinvasion phase and during its terminal period which was probably due to an increase in the influence of the thymus on the immune system and evident from an increase in the therapeutic action of the drug.

[Blood thymus hormone content in different types of neoplastic process and its changes as a result of chemotherapy and surgical removal of tumors]. / Soderzhanie gormonov timusa v krovi pri razlichnykh tipakh opukholevogo protsessa i ego izmenenie v rezul'tate khimioterapii i khirurgicheskogo udaleniia opukholi.

Levels of thymic hormones in blood serum were found to decrease during the development of Guerin's carcinoma, methylcholanthrene- and DMBA-induced carcinogenesis, soft tissue sarcomas, mammary cancer, in children with tumors of the urinary-genital tract, that evidences for the suppression of the thymic endocrine function in neoplastic processes. A decrease in the level of substances, active in the test under study is not revealed in patients with different forms of leukemias. The tumour elimination normalizes the thymic endocrine function, while multiagent chemotherapy increases the insufficiency. The data obtained suggest the immunotherapy for malignant neoplasms with thymic hormones.

Production of substances with thymosin-like activity by B- and T-lymphocytes.

The authors investigated the ability of various lymphocyte subpopulations to synthesize substances with thymosin-like activity under the influence of thymostimulin, a preparation of active thymic factors. Experiments carried out on T- and B-mice revealed that only T-lymphocytes synthesized thymosin-like substances in response to thymostimulin administration. Thus induced substances differed significantly from those which ensure the serum activity of normal animals in that their thermostability is by far greater. The feasibility was also explored of inducing by thymosin the in vitro synthesis of substances with thymosin-like activity in cells derived from a variety of lymphoid formations of thymectomized mice. The serum of thymectomized lethally irradiated recipients of lymph node and spleen cells pretreated with thymostimulin was found to contain, 4 h after the transfer, relatively high levels of substances with thymosin-like activity. Contrariwise, the pretreatment of bone marrow cells with thymostimulin resulted in declined levels of substances with thymosin-like activity in recipient sera as compared to those in B-mice which were given untreated bone marrow cells. The incubation of bone marrow cells in a medium containing substances with thymosin-like activity caused a decrease in that activity. Thus, the biologically active thymic factors were shown to induce the synthesis by T-cells of substances with thymosin-like activity.

[Comparative action of X-rays and fast neutrons on thymus endocrine function]. / Sravnitel'noe vozdeistvie rentgenovskikh luchei i bystrykh neitronov na éndokrinnuiu funktsiiu vilochkovoi zhelezy.

Whole-body exposure of rats to X-rays (4, 6 and 8 Gy) and neutron radiation (1, 1.5 and 2 Gy) causes a dose-dependent inhibition of endocrine function of thymus and death of its lymphoid cells. Shielding of thymus somewhat reduces the degree and duration of inhibition of thymus hormone secretion.

[Inhibition of the endocrine function of the rat thymus by x-irradiation]. / Ugnetenie éndokrinnoi funktsii vilochkovoi zhelezy u krys rentgenovskim oblucheniem.

Whole-body X-irradiation of rats caused inhibition of endocrine function of thymus. The effect was a function of radiation dose and time after irradiation. 72 h following irradiation with doses of 6 and 8 Gy the thymus hormone content of blood serum fell down the level registered in the thymectomized animals. Cellularity of the thymus and spleen concurrently decreased. The kinetics of spontaneous chemiluminescence of blood serum, thymus and spleen cells characterized the hypersecretion of glucocorticoids in response to radiation activation of lipid peroxidation in radiosensitive rat organs.