Lymphotoxin beta receptor signaling limits mucosal damage through driving IL-23 production by epithelial cells.

The immune mechanisms regulating epithelial cell repair after injury remain poorly defined. We demonstrate here that lymphotoxin beta receptor (LTßR) signaling in intestinal epithelial cells promotes self-repair after mucosal damage. Using a conditional gene-targeted approach, we demonstrate that LTßR signaling in intestinal epithelial cells is essential for epithelial interleukin-23 (IL-23) production and protection against epithelial injury. We further show that epithelial-derived IL-23 promotes mucosal wound healing by inducing the IL-22-mediated proliferation and survival of epithelial cells and mucus production. Additionally, we identified CD4(-)CCR6(+)T-bet(-) RAR-related orphan receptor gamma t (RORγt)(+) lymphoid tissue inducer cells as the main producers of protective IL-22 after epithelial damage. Thus, our results reveal a novel role for LTßR signaling in epithelial cells in the regulation of intestinal epithelial cell homeostasis to limit mucosal damage.

[Evaluating radiation dose load in medical personnel of radiologic diagnostic departments].

The article deals with materials on radiation hygienic evaluation of radiologic diagnostic departments in various medical institutions of Moscow. The studies covered work of medical staffers in X-ray examination and in contact with short-lived isotope generators. The authors outlined the examination types and stages with maximal radiation danger. Disimetric information obtained during the study helped to calculate values of equivalent, effective doses of radiation for medical personnel and maximal potential doses.

[Special industrial medicine as a basis for workers' health preservation].

The article covers results and prospects of research in special industrial medicine on improving methodology of complex evaluation of work conditions in major economy branches including medical sphere workers. On the basis of ecologic epidemiologic research, remote effects of occupational and non-industrial hazards in workers and general population were studied, new technologic processes and equipment were assessed, principles for unifying methods to control chemicals in workplace air were defined, regulation methodical documents concordant with WHO, ILO and EC are specified.

[Evidence-based medicine in evaluating occupational health risk in workers engaged into graphite ware production].

The article deals with results of epidemiologic study on evaluating the health state of workers engaged into graphite ware production, through three various parameters based on data about chronic non-occupational diseases. The authors evaluate carcinogenic risk for the population residing on various distances from the enterprise.

[Serological study of a repertoire of human cancer antigens and autoantigens]. / Serologicheskie issledovaniia reperatura rakovykh antgenov i autoanigenov cheloveka.

The spectrum of human antigens allows a monitoring of various pathological processes such as autoimmune disorders and tumorigenesis. Serological analysis of cDNA expression libraries (SEREX) is now used to search for new cancer-associated antigens, which are potential diagnostic markers or targets for immunotherapy of cancer. The results obtained for several solid tumors are reviewed. Groups of antigens detectable by SEREX, causes of immunogenicity of autoantigens, and prospective implication of antigens in diagnostics and monitoring of cancer are discussed.

[State of nonspecific anti-infection resistance among medical personnel]. / Sostoianie nespetsificheskoi antiinfektsionnoi rezistentnosti meditsinskikh rabotnikov.

The authors compared nonspecific anti-infectious resistance among medical staffers varying in speciality. Skin microflora parameters and salivary lysozyme content appeared to be considerably lower in obstetric staffers and in State sanitary and epidemiologic supervision officers than in general population.

[Intracellular proteolysis: signals of selective protein degradation]. / Vnutrikletochnyi proteoluz. Signaly selektivnoi degradatsii belkov.

Selective proteolysis is one of the mechanisms for the maintenance of cell homeostasis via rapid degradation of defective polypeptides and certain short-lived regulatory proteins. In prokaryotic cells, high-molecular-mass oligomeric ATP-dependent proteases are responsible for selective protein degradation. In eukaryotes, most polypeptides are attacked by the multicatalytic 26S proteasome, and the degradation of the majority of substrates involves their preliminary modification with the protein ubiquitin. The proteins undergoing the selective proteolysis often contain specific degradation signals necessary for their recognition by the corresponding proteases.

Mutations in the proteolytic domain of Escherichia coli protease Lon impair the ATPase activity of the enzyme.

Conserved residues of the proteolytic domain of Escherichia coli protease Lon, putative members of the classic catalytic triad (H665, H667, D676, and D743) were identified by comparison of amino acid sequences of Lon proteases. Mutant enzymes containing substitutions D676N, D743N, H665Y, and H667Y were obtained by site-directed mutagenesis. The mutant D743N retained the adenosine triphosphate (ATP)-dependent proteolytic activity, thereby indicating that D743 does not belong to the catalytic site. Simultaneously, the mutants D676N, H665Y, and H667Y lost the capacity for hydrolysis of protein substrates. The ATPase activity of these three mutants was decreased by more than an order of magnitude, which suggests a close spatial location of the ATPase and proteolytic active sites and their tight interaction in the process of protein degradation.