Interaction of checkpoint kinase 1 and the X-linked inhibitor of apoptosis during mitosis.

We report here that the checkpoint kinase Chk1 and the inhibitor of apoptosis protein (IAP) family member XIAP can be found in a complex in association with condensed chromosomes aligned at the metaphase plate during mitosis. The interaction between Chk1 and XIAP was transient and followed the breakdown of the nuclear envelope. Chk1 and XIAP also formed a complex in vitro and in coimmunoprecipitation experiments. The interaction between Chk1 and the BIR3 domain of XIAP in vitro required an N-terminal sequence in Chk1 that is identical to the BIR-binding motif at the N-terminus of HID. An interaction of Chk1 and XIAP may imply a mechanism of coupling between the regulatory networks that control cell cycle progression and apoptosis during mitosis.

[Relationship between nonspecific, immunologic reactivity of the body and the type of course of an acute inflammatory process]. / Sviaz' mezhdu nespetsificheskoi, immunologicheskoi reaktivnost'iu organizma i tipom techeniia ostrogo vospalitel'nogo protsessa.

By using the results of clinical, laboratory, and immunological studies, the authors show that the type (normoergic, hypoergic, hyperergic) of an inflammatory response is related to the parameters of nonspecific and immunological responsiveness of patients with pyo-inflammation in the maxillofacial region. The hypoergic inflammatory response is characterized by the least responsiveness mainly to its cellular link. The hyperergic inflammatory reaction is chiefly caused by considerably enhanced phagocytosis.

Electron microscopy mapping of oligopurine tracts in duplex DNA by peptide nucleic acid targeting.

Biotinylated homopyrimidine decamer peptide nucleic acids (PNAs) are shown to form sequence-specific and stable complexes with complementary oligopurine targets in linear double-stranded DNA. The noncovalent complexes are visualized by electron microscopy (EM) without chemical fixation using streptavidin as an EM marker. The triplex stoichiometry of the PNA-DNA complexes (two PNA molecules presumably binding by Watson-Crick and Hoogsteen pairing with one of the strands of the duplex DNA) is indicated by the appearance of two streptavidin 'beads' per target site in some micrographs, and is also supported by the formation of two retardation bands in a gel shift assay. Quantitative analysis of the positions of the streptavidin 'beads' revealed that under optimized conditions PNA-DNA complexes are preferably formed with the fully complementary target. An increase in either the PNA concentration or the incubation time leads to binding at sites containing one or two mismatches. Our results demonstrate that biotinylated PNAs can be used for EM mapping of short targets in duplex DNA.

Electron microscopic studies of sequence-specific recognition of duplex DNA by different ligands.

The following ligands were used to study sequence specific recognition of duplex DNA by electron microscopic techniques: methyltransferases BspR1 and EcoR124 (recognition sequences GGCC and GAAN7RTCG, respectively), a biotinylated deoxyoligonucleotide 5'-CTCTCTCTCTCTCT-3' capable of forming triplex DNA, and PNA oligomer H-T10-LysNH2. For each ligand the best conditions for electron microscopic (EM) detection of stable specific complex formation were determined. It was demonstrated that EM allowed us to determine the position of the individual target site with an error of 15-20 bp, the relative affinities for individual target sites and kinetic parameters of the binding. These results open new possibilities for EM investigations of sequence-specific interactions with a wide range of other ligands of a similar nature. They also imply that a wide range of different sequences can be unambiguously and precisely mapped by EM and greatly extend the scope of EM applications for physical mapping of genomic DNA.

Testing the quality of electron microscope mapping data for DNA molecules with sequence-specific ligands.

A procedure for the testing of Electron Microscope (EM) mapping data for DNA molecules with site-specific bound ligands is suggested. The difficulty of distinguishing DNA molecule ends on electron micrographs indicates that their true orientations are not known. This in turn presents problems in obtaining correct maps relating to their alignment, and complicates checking the maps' validity. For these reasons a computer simulation of the EM study of double-stranded DNA molecules with site-specific bound ligands was carried out. The knowledge of the true orientations of the simulated DNA molecules allowed us to examine their final orientations after alignment. We used the number of improper-oriented molecules as the quantitative measure of the map quality. Detailed investigation based on this parameter permitted us to invent the criterion for the map validity, and to suggest the procedure for the testing of alignment of real DNA molecules. This procedure implies multiple randomization of initial orientations of the DNA molecules and minute analysis of the final maps. Most of the molecular, statistical and experimental parameters inherent to EM investigation of site-specific binding, such as the number of specific binding sites (N), the mean number of bound ligands (A), the length of the DNA molecules (L), the specific/non-specific ratio of binding (K), together with the standard deviation of DNA molecule lengths (HL) were tested for their influence upon the quality of EM mapping data. An empirical equation for the ultimate values of these parameters has been found, allowing us to predict the success of EM mapping.

[Etiology of inflammatory maxillofacial diseases and estimation of the effectiveness of antibacterial drugs in vitro]. / Etiologiia vospalitel'nykh zabolevanii cheliustno-litsevoi oblasti i otsenka éffektivnosti antibakterial'nykh preparatov in vitro.

The results of identification of 710 clinical strains of anaerobic microorganisms isolated from the pathological foci of patients with maxillofacial diseases are presented. The species composition of the microflora associations in the cases with abscesses, phlegmon, lymphadenitis, osteomyelitis and parodontitis is described. Along with a high frequency of nonsporulating anaerobes, staphylococci, microaerophilic streptococci and in the cases with parodontitis actinomycetes, Bacillus licheniformis and Bacillus coagulans strains (1.6-15% of the isolated strains) were first detected in cases with various forms of the disease. Two groups of the drugs effective against the anaerobes were identified by the data on the antibiotic sensitivity. The lowest MICs along with the activity broad spectrum were defined for gramicidin, levomycetin and nitazol.

[The possibilities of using clinical blood analysis for the prognosis of the course of acute suppurative inflammatory processes in the soft tissues of the maxillofacial area]. / Vozmozhnosti ispol'zovaniia klinicheskogo analiza krovi dlia prognozirovaniia techeniia ostrykh gnoinykh vospalitel'nykh protsessov miagkikh tkanei cheliustno-litsevoi oblasti.

The authors have attempted to mathematically predict the length of inpatient treatment of patients with maxillofacial acute pyoinflammatory processes basing on the regression analysis of the peripheral blood parameters. A number of mathematical formulae fit for wide clinical application were derived.