[The application of the computer technologies for the mathematical simulation of the ethmoidal labyrinth]. / Komp'iuternye tekhnologii dlia matematicheskogo modelirovaniia reshetchatogo labirinta.

The objective of the present work was to study the relationship between the dimensions of the ethmoidal labyrinth and the skull in the subjects differing in the nose shape by means of the factorial and correlation analysis with the application of the modern computer-assisted methods for the three-dimensional reconstruction of the skull. We developed an original method for computed craniometry with the use the original program that made it possible to determine the standard intravital craniometrics characteristics of the human skull with a high degree of accuracy based on the results of analysis of 200 computed tomograms of the head. It was shown that the length of the inferior turbinated bones and the posterior edge of the orbital plate is of special relevance for practically all parameters of the ethmoidal labyrinth. Also, the width of the choanae positively relates to the height of the ethmoidal labyrinth.

[Objective roentgenologic diagnostics of anterior cruciform ligamentous disruption in servicemen].

The article is dedicated to the method of roentgenological diagnostics, developed at military traumatology and orthopaedics department of the S.M. Kirov Military medical academy, which allows objectively assessing degree of knee joint instability in consequence of anterior cruciform ligamentous disruption.

Revision anterior cruciate ligament of knee reconstruction in case of anterolateral rotation knee instability in servicemen.

To identify the reasons for the high rate of revision operations after primary reconstruction of the anterior cruciate ligament analyzed the causes of recurrent anterolateral rotary instability of the knee in the military personnel. From 208 operations (2006-2011) performed according to transtibial method in 21 cases (10, 1%) recurrence of instability, requiring revision joint stabilization . From 484 reconstructions of the anterior cruciate ligament (2011-2015) according to transportal anatomical reconstruction technique revision performed in 11 cases (2.3%). It was established that the main cause of recurrent anterolateral rotary instability were non-anatomical bone channels conduction and violation of the physical exertion during the recovery period.

[An importance of early diagnosis in the course of knee joint instability treatment in military personnel].

The aim of the study was to determine the cause of the high frequency of meniscal tear coexisting rupture of the anterior cruciate ligament of the knee joint and to establish an optimal timing of surgical stabilization of the knee joint. Medical records of 476 patients who had surgery at the clinic of the Kirov Military Traumatology and Orthopedics of Military Medical Academy were studied. In 82 patients operation on the reconstruction of the anterior cruciate ligament was perormed in the early period after injury (up to 6 weeks), 347 patients were operated within a period exceeding 6 weeks. It was revealed that the soldiers who had the operation in the period after 6 weeks from the date of injury, secondary damage of meniscus and articular cartilage occured twice as much as in surgery performed during the acute phase. Thus, the reconstruction of the anterior cruciate ligament should be carried out in a specialized epartment in the early stages after injury, when not yet any secondary damage to the meniscus and articular cartilage.

Investigation of the regulatory function of archaeal ribosomal protein L4.

Ribosomal protein L4 is a regulator of protein synthesis in the Escherichia coli S10 operon, which contains genes of 11 ribosomal proteins. In this work, we have investigated regulatory functions of ribosomal protein L4 of the thermophilic archaea Methanococcus jannaschii. The S10-like operon from M. jannaschii encodes not 11, but only five ribosomal proteins (L3, L4, L23, L2, S19), and the first protein is L3 instead of S10. We have shown that MjaL4 and its mutant form lacking an elongated loop specifically inhibit expression of the first gene of the S10-like operon from the same organism in a coupled transcription-translation system in vitro. By deletion analysis, an L4-binding regulatory site has been found on MjaL3 mRNA, and a fragment of mRNA with length of 40 nucleotides has been prepared that is necessary and sufficient for the specific interaction with the MjaL4 protein.

Molecular mechanism of actomyosin-based motility.

Sophisticated molecular genetic, biochemical and biophysical studies have been used to probe the molecular mechanism of actomyosin-based motility. Recent solution measurements, high-resolution structures of recombinant myosin motor domains, and lower resolution structures of the complex formed by filamentous actin and the myosin motor domain provide detailed insights into the mechanism of chemomechanical coupling in the actomyosin system. They show how small conformational changes are amplified by a lever-arm mechanism to a working stroke of several nanometres, explain the mechanism that governs the directionality of actin-based movement, and reveal a communication pathway between the nucleotide binding pocket and the actin-binding region that explains the reciprocal relationship between actin and nucleotide affinity. Here we focus on the interacting elements in the actomyosin system and the communication pathways in the myosin motor domain that respond to actin binding.

[The Thermus thermophilus 5S rRNA-protein complex: Identifications of specific binding sites for proteins L5 and L18 in 5S rRNA]. / 5S rRNK-belkovyi kompleks Thermus thermophilus. Opredelenie spetsificheskikh uchastkov sviazyvaniia belkov L5 i L18 na 5S rRNK.

Three 5S rRNA-binding ribosomal proteins (L5, L18, TL5) of extremely thermophilic bacterium Thermus thermophilus have earlier been isolated. Structural analysis of their complexes with rRNA requires identification of their binding sites in the 5S rRNA. Previously, a TL5-binding site has been identified, a TL5-RNA complex crystallized, and its structure determined to 2.3 A. The sites for L5 and L18 were characterized, and two corresponding 5S rRNA fragments constructed. Of these, a 34-nt fragment specifically interacted with L5, and a 55-nt fragment interacted with L5, L18, and with both proteins. The 34-nt fragment-L5 complex was crystallized; the crystals are suitable for high-resolution X-ray analysis.

Crystals of a mutant form of ribosomal protein L22 rendering bacterial ribosomes resistant to erythromycin.

A mutant form of Thermus thermophilus ribosomal protein L22 responsible for erythromycin resistance has been overexpressed in Escherichia coli, purified to homogeneity and crystallized using the hanging-drop vapour-diffusion technique. While several different crystallization conditions were found, only one set of conditions yielded crystals suitable for X-ray diffraction analysis. These crystals grow as thick plates, with unit-cell parameters a = 31.8, b = 86.59, c = 38.96 A, beta = 104.47 degrees. The crystals belong to the space group P2(1) and diffract to 1.8 A resolution. On the basis of density calculations, two monomers are predicted per asymmetric unit (V(M) = 2.06 A(3) Da(-1)), with a solvent content of 40%.

Structure of ribosomal protein TL5 complexed with RNA provides new insights into the CTC family of stress proteins.

The crystal structure of Thermus thermophilus ribosomal protein TL5 in complex with a fragment of Escherichia coli 5S rRNA has been determined at 2.3 A resolution. The protein consists of two domains. The structure of the N-terminal domain is close to the structure of E. coli ribosomal protein L25, but the C-terminal domain represents a new fold composed of seven beta-strands connected by long loops. TL5 binds to the RNA through its N-terminal domain, whereas the C-terminal domain is not included in this interaction. Cd(2+) ions, the presence of which improved the crystal quality significantly, bind only to the protein component of the complex and stabilize the protein molecule itself and the interactions between the two molecules in the asymmetric unit of the crystal. The TL5 sequence reveals homology to the so-called general stress protein CTC. The hydrophobic cores which stabilize both TL5 domains are highly conserved in CTC proteins. Thus, all CTC proteins may fold with a topology close to that of TL5.

Crystal structure of the GAP domain of Gyp1p: first insights into interaction with Ypt/Rab proteins.

We present the 1.9 A resolution crystal structure of the catalytic domain of Gyp1p, a specific GTPase activating protein (GAP) for Ypt proteins, the yeast homologues of Rab proteins, which are involved in vesicular transport. Gyp1p is a member of a large family of eukaryotic proteins with shared sequence motifs. Previously, no structural information was available for any member of this class of proteins. The GAP domain of Gyp1p was found to be fully alpha-helical. However, the observed fold does not superimpose with other alpha-helical GAPs (e.g. Ras- and Cdc42/Rho-GAP). The conserved and catalytically crucial arginine residue, identified by mutational analysis, is in a comparable position to the arginine finger in the Ras- and Cdc42-GAPs, suggesting that Gyp1p utilizes an arginine finger in the GAP reaction, in analogy to Ras- and Cdc42-GAPs. A model for the interaction between Gyp1p and the Ypt protein satisfying biochemical data is given.

Archaeal ribosomal protein L1: the structure provides new insights into RNA binding of the L1 protein family.

BACKGROUND: L1 is an important primary rRNA-binding protein, as well as a translational repressor that binds mRNA. It was shown that L1 proteins from some bacteria and archaea are functionally interchangeable within the ribosome and in the repression of translation. The crystal structure of bacterial L1 from Thermus thermophilus (TthL1) has previously been determined. RESULTS: We report here the first structure of a ribosomal protein from archaea, L1 from Methanococcus jannaschii (MjaL1). The overall shape of the two-domain molecule differs dramatically from that of its bacterial counterpart (TthL1) because of the different relative orientations of the domains. Two strictly conserved regions of the amino acid sequence, each belonging to one of the domains and positioned close to each other in the interdomain cavity of TthL1, are separated by about 25 A in MjaL1 owing to a significant opening of the structure. These regions are structurally highly conserved and are proposed to be the specific RNA-binding sites. CONCLUSIONS: The unusually high RNA-binding affinity of MjaL1 might be explained by the exposure of its highly conserved regions. The open conformation of MjaL1 is strongly stabilized by nonconserved interdomain interactions and suggests that the closed conformations of L1 (as in TthL1) open upon RNA binding. Comparison of the two L1 protein structures reveals a high conformational variability of this ribosomal protein. Determination of the MjaL1 structure offers an additional variant for fitting the L1 protein into electron-density maps of the 50S ribosomal subunit.

Structure of ribosomal protein L30 from Thermus thermophilus at 1.9 A resolution: conformational flexibility of the molecule.

The crystal structure of ribosomal protein L30 from the extreme thermophilic bacterium Thermus thermophilus has been determined at 1. 9 A resolution. The crystals are trigonal and belong to space group P3(2)21, with unit-cell parameters a = b = 63.5, c = 77.8 A, alpha = beta = 90, gamma = 120 degrees and two molecules per asymmetric unit. The structure was solved by the molecular-replacement method with AMoRe and refined with X-PLOR to an R value of 20.3% and an R(free) of 25.3% in the resolution range 8-1.9 A. Detailed analyses of the structures of the two molecules in the asymmetric unit and comparison of T. thermophilus L30 structure with the structure of homologous L30 from Bacillus stearothermophilus reveal two flexible regions at opposite ends of the rather elongated molecule. Such flexibility could be important for the protein fitting in the ribosome. A comparison with B. stearothermophilus L30 shows a higher number of salt bridges and unbound positively charged residues and an increased accessible hydrophobic area on the surface of T. thermophilus L30. This could contribute to the stability of both the extreme thermophile protein and the ribosome as a whole.

Structural studies of ribosomal proteins.

Crystal and solution structures of fourteen ribosomal proteins from thermophilic bacteria have been determined during the last decade. This paper reviews structural studies of ribosomal proteins from Thermus thermophilus carried out at the Institute of Protein Research (Pushchino, Russia) in collaboration with the University of Lund (Lund, Sweden) and the Center of Structural Biochemistry (Karolinska Institute, Huddinge, Sweden). New experimental data on the crystal structure of the ribosomal protein L30 from T. thermophilus are also included.

[Determination of antimicrobial activity of wound discharge for assessing wound healing]. / Opredelenie antimikrobnoi aktivnosti ranevogo otdeliaemogo dlia otsenki zazhivleniia rany.

The authors studied the dynamics of changes of antimicrobial activity of the wound discharge in 70 patients, aged from 18 to 83 years, who underwent operations for emergency diseases of the abdominal organs with postoperative suppuration of the wound. The study was conducted at the peak of suppuration, in the regeneration phase, and before closure of the wound with sutures. The antimicrobial activity of the wound discharge was found to be low at the peak of wound suppuration with marked necrotic changes of the tissues, as well as in poor granulations, and good in uncomplicated course of the wound process. Changes of antimicrobial activity of the wound discharge, both in uncomplicated and complicated course of the wound process, correlated with the clinical signs of healing. The obtained data make in possible to determine antimicrobial activity of the wound discharge for evaluation of healing, prognostication of bacterial complications in the wound, and control over the efficacy of the treatment.

[Persistence of opportunistic Staphylococcus and disorders of immune homeostasis in frequently sick children]. / Persistentsiia uslovno-patogennogo stafilokokka i narushenie immunnogo gomeostaza u chasto i dlitel'no boleiushchikh detei.

Clinical, microbiological and immunological examinations were made of ailing children with localized (fauces) and spread (fauces, skin, intestine) staphylococcal lesions. The clinicogenealogical analysis revealed considerable hereditary aggravation as regards immune pathology, the presence of immunopathological diatheses, and a high level of dysembryogenesis stigmas in the given children's group. S. aureus and S. epidermidis were identified. In ailing children, the authors proved the persistence of ubiquitary staphylococcus, giving rise to the deficiency of immune factors consumption as related to the characteristics of antigenic adaptation of such children. Immunologic tolerance was found to fail at one of the crucial periods of immunity, with the opsonocytophagic component appearing to be the site of application of the suppressant action of Staphylococcus.

[Deoxyribonuclease from Corynebacterium diphtheriae: dynamics of synthesis and properties]. / Dezoksiribonukleaza difteriinykh bakterii: dinamika obrazovaniia i nekotorye svoistva.

Diphtheritic bacteria of PW-8 Massachusetts strain produced into cultural medium only one nucleotidase--endoDNAase. The enzyme was synthesized by the cells during the exponential phase of growth. The DNAase was purified 500-fold and exhibited properties specific to neutral-alkaline DNAases (pH optimum about 7.5, absolute requirements for Me2+, single-step mechanism of substrate hydrolysis). The following properties were typical for the enzyme: absence of distinct specificity to structure of bases surrounding the hydrolyzed bond, formation of 5'-end phosphate groups and slightly higher preference to denatured DNA.