[DNA Sequence-Specific Ligands. 19. Synthesis, Spectral Properties, Virological and Biochemical Studies of DB3(n) Fluorescent Dimeric Trisbenzimidazoles].

In this work, we synthesized and characterized the properties of a series of new fluorescent DB3(n) narrow-groove ligands. DB3(n) compounds based on dimeric trisbenzimidazoles have the ability to bind to the AT regions of DNA. The synthesis of DB3(n), whose trisbenzimidazole fragments are linked by oligomethylene linkers of different lengths (n = 1, 5, 9), is based on the condensation of the MB3 monomeric trisbenzimidazole with α,ω-alkyldicarboxylic acids. DB3 (n) proved to be effective inhibitors of the catalytic activity of HIV-1 integrase at submicromolar concentrations (0.20-0.30 µM). DB3(n) was found to inhibit the catalytic activity of DNA topoisomerase I at low micromolar concentrations.

Use of Additive Technologies in Surgical Treatment of Chronic Posterior Dislocations of the Shoulder.

The aim of the study was to evaluate the efficiency of additive technologies in surgical treatment of patients with osteochondral defects of the humeral head articular surface against the background of chronic posterior dislocation of the shoulder by means of comparing clinical and radiological results with the McLaughlin procedure. Materials and Methods: A prospective randomized comparative group clinical study was conducted, which included 20 patients who in 2019-2021 underwent surgical treatment of chronic posterior dislocation of the shoulder in the Traumatological and Orthopedic Department of the Institute of Traumatology and Orthopedics of the Privolzhsky Research Medical University (Nizhny Novgorod, Russia). Depending on the type of surgery, all patients were divided into 2 groups: group 1 (n=10) was subject to McLaughlin procedure, whereas group 2 (n=10) - to reconstruction of the humeral head using a customized implant based on additive technologies (3D printing). To assess postoperative results, 6 months after the surgery all patients underwent the following procedures: X-ray imaging of the shoulder joint in two projections, CT scanning, and angulometry as well as provided their responses in line with the following questionnaires: Visual Analog Scale (VAS), Disabilities of the Arm, Shoulder and Hand (DASH), American Shoulder and Elbow Surgeons Shoulder Score (ASES), Constant Shoulder Score (CSS), Shoulder Rating Questionnaire (SRQ), and the Hospital for Special Surgery Shoulder Surgery Expectations Survey (Survey of patient, SP). Results: Both the McLaughlin procedure and the reconstruction of the humeral head using a customized implant made using additive 3D printing technologies increased the range of motion in the shoulder joint, mitigated the pain syndrome and improved the patients' quality of life. During the postoperative period, there were no infectious complications in both groups. The total bed-day in group 1 was 7 [5; 9] days; in group 2, it was 8 [6; 9] days. There was no recurrence of dislocation or progression of osteoarthritis of the shoulder joint in patients in both groups during 6 months after the surgery. The ASES, SP, SRQ, CSS, DASH, and VAS questionnaires assessment for both groups showed a statistically significant improvement for all indicators in the postoperative period. There were no statistically significant differences found between the groups as to the results of angulometry and answering the questionnaires. Conclusion: Customized implants made using additive technologies can shorten the surgery duration by 1.3 times, whereas the volume of intraoperative blood loss - by at least 1.5 times compared to the McLaughlin procedure.

[Main Approaches to Controlled Protein Degradation in the Cell].

One of the most informative methods to study the roles of individual proteins in cell functions is based on changing their intracellular concentrations. Genetic knockouts or knockdowns are most commonly used for the purpose. However, acting directly at the level of an expressed protein is more informative or convenient to perform in some cases. This action should ideally be controlled in time and reversible. The review analyzes the current data on systems developed to achieve controlled degradation of proteins via their ubiquitination with subsequent proteasome-mediated degradation or other mechanisms.

Consensus Integrase of a New HIV-1 Genetic Variant CRF63_02A1.

The high genetic variability of the human immunodeficiency virus (HIV-1) leads to a constant emergence of new genetic variants, including the recombinant virus CRF63_02A1, which is widespread in the Siberian Federal District of Russia. We studied HIV-1 CRF63_02A1 integrase (IN_CRF) catalyzing the incorporation of viral DNA into the genome of an infected cell. The consensus sequence was designed, recombinant integrase was obtained, and its DNA-binding and catalytic activities were characterized. The stability of the IN_CRF complex with the DNA substrate did not differ from the complex stability for subtype A and B integrases; however, the rate of complex formation was significantly higher. The rates and efficiencies of 3'-processing and strand transfer reactions catalyzed by IN_CRF were found to be higher, too. Apparently, all these distinctive features of IN_CRF may result from specific amino acid substitutions in its N-terminal domain, which plays an important role in enzyme multimerization and binding to the DNA substrate. It was also found that the drug resistance mutations Q148K/G140S and G118R/E138K significantly reduce the catalytic activity of IN_CRF and its sensitivity to the strand transfer inhibitor raltegravir. Reduction in sensitivity to raltegravir was found to be much stronger in the case of double-mutation Q148K/G140S.

Advances in structural studies of recombination mediator proteins.

Recombination mediator proteins (RMPs) are critical for genome integrity in all organisms. They include phage UvsY, prokaryotic RecF, -O, -R (RecFOR) and eukaryotic Rad52, Breast Cancer susceptibility 2 (BRCA2) and Partner and localizer of BRCA2 (PALB2) proteins. BRCA2 and PALB2 are tumor suppressors implicated in cancer. RMPs regulate binding of RecA-like recombinases to sites of DNA damage to initiate the most efficient non-mutagenic repair of broken chromosome and other deleterious DNA lesions. Mechanistically, RMPs stimulate a single-stranded DNA (ssDNA) hand-off from ssDNA binding proteins (ssbs) such as gp32, SSB and RPA, to recombinases, activating DNA repair only at the time and site of the damage event. This review summarizes structural studies of RMPs and their implications for understanding mechanism and function. Comparative analysis of RMPs is complicated due to their convergent evolution. In contrast to the evolutionary conserved ssbs and recombinases, RMPs are extremely diverse in sequence and structure. Structural studies are particularly important in such cases to reveal common features of the entire family and specific features of regulatory mechanisms for each member. All RMPs are characterized by specific DNA-binding domains and include variable protein interaction motifs. The complexity of such RMPs corresponds to the ever-growing number of DNA metabolism events they participate in under normal and pathological conditions and requires additional comprehensive structure-functional studies.

[Nitrobenzofuroxane derivatives as dual action hiv-1 inhibitors]. / Proizvodnye nitrobenzofuroksanov v kachestve ingibitorov VICh-1 dvoinogo deistviia.

Human immunodeficiency virus first type (HIV-1) is a main cause of one of the most dangerous diseases, AIDS. The search for new inhibitors of the virus still remains an urgent task. One approach to suppress the HIV infection is to use a double-acting inhibitors, i.e. inhibitors directed to two stages of the viral life cycle. The catalytic domain of HIV-1 integrase has a similar spatial organization with ribonuclease (RNase H) domain of HIV-1 reverse transcriptase, and approach aimed to create HIV-1 integrase and RNase H double-acting is very promising. In this work we synthesized a series of 6-nitrobenzofuroxane derivatives and studied their ability to inhibit two viral enzymes - integrase and RNase H HIV-1.

Host Proteins Ku and HMGA1 As Participants of HIV-1 Transcription.

Human immunodeficiency virus type 1 is known to use the transcriptional machinery of the host cell for viral gene transcription, and the only viral protein that partakes in this process is Tat, the viral trans-activator of transcription. During acute infection, the binding of Tat to the hairpin at the beginning of the transcribed viral RNA recruits the PTEFb complex, which in turn hyperphosphorylates RNA-polymerase II and stimulates transcription elongation. Along with acute infection, HIV-1 can also lead to latent infection that is characterized by a low level of viral transcription. During the maintenance and reversal of latency, there are no detectable amounts of Tat protein in the cell and the mechanism of transcription activation in the absence of Tat protein remains unclear. The latency maintenance is also a problematic question. It seems evident that cellular proteins with a yet unknown nature or role regulate both transcriptional repression in the latent phase and its activation during transition into the lytic phase. The present review discusses the role of cellular proteins Ku and HMGA1 in the initiation of transcription elongation of the HIV-1 provirus. The review presents data regarding Ku-mediated HIV-1 transcription and its dependence on the promoter structure and the shape of viral DNA. We also describe the differential influence of the HMGA1 protein on the induced and basal transcription of HIV-1. Finally, we offer possible mechanisms for Ku and HMGA1 proteins in the proviral transcription regulation.

Structural-Functional Analysis of 2,1,3-Benzoxadiazoles and Their N-oxides As HIV-1 Integrase Inhibitors.

Human immunodeficiency virus type 1 integrase is one of the most attractive targets for the development of anti-HIV-1 inhibitors. The capacity of a series of 2,1,3-benzoxadiazoles (benzofurazans) and their N-oxides (benzofuroxans) selected using the PASS software to inhibit the catalytic activity of HIV-1 integrase was studied in the present work. Only the nitro-derivatives of these compounds were found to display inhibitory activity. The study of the mechanism of inhibition by nitro-benzofurazans/benzofuroxans showed that they impede the substrate DNA binding at the integrase active site. These inhibitors were also active against integrase mutants resistant to raltegravir, which is the first HIV-1 integrase inhibitor approved for clinical use. The comparison of computer-aided estimations of the pharmacodynamic and pharmacokinetic properties of the compounds studied and raltegravir led us to conclude that these compounds show promise and need to be further studied as potential HIV-1 integrase inhibitors.

[The mitral valve dysplasia in adults: the choice of surgical tactics].

Early and long-term results of hereditary mitral valve dysplasia surgical treatment were obtained in 203 patients. All patients were divided in 2 groups: 73 (36%) patients after valve-preserving operations and 130 patients after universal chorda-preserving valve prosthetics. The choice of treatment modality depended on the type of anatomical changes and overall surgical volume. Hospital lethality rate was 2.46%. Surgery led to satisfactory functional results, thus, 83.3% of the operated patients have I-II NYHA functional class. Analysis of the own experience allowed to mark out factors, contraindicating the durable plastic mitral valve.

[Diagnostic and treatment patterns in management of male patients with nongonococcal urethritis: results of Russian multicentral cross-sectional study].

The aim of the study was to estimate the diagnostic and treatment patterns in the management of acute nongonococcal urethritis (NGU) in males in some cities of Russia. Retrospective cross-sectional study was conducted in 2009 in 5 centers of 4 cities in the Central Part of Russia (Kaluga, Pskov, Smolensk - 2 centres and Tula). The data on the diagnostic and treatment approaches to the management of NGU in male subjects >16 years old were collected and analyzed with the use of specially designed case report forms. 556 cases of acute urethritis were analyzed during the study. The diagnosis of NGU was confirmed in 401 cases. The average age of the patients was 29.8 years (16-68 years). The following diagnostic methods were used in 95% of the cases: urethral smear microscopy (314/82.4%), C. trachomatis - PCR (113/29.7%), ELISA (155/40.7%); T. vaginalis - PCR (106/27.8%); U. urealyricum and M. hominis, respectively - bacteriology (140/36.7% and 126/33.1%), PCR (110/28.9% and 108/28.3%); M. genitalium - PCR (110/28.9%). The treatment patterns included antimicrobials AMs alone in 60.3, and AMs + non-AMs in 37.8% of the cases. The most frequently prescribed AMs were azithromycin (27.5%), fluconazole (16.4%), doxycycline (13.6%), metronidazole (11.2%), ofloxacine (7.3%), ceftriaxone (4.4%), josamycin (4.2). According to the results use of the standard methods for NGU diagnosis was rather rare. The use of PCR for atypical pathogens was the following: C. trachomatis 29.7%, U. urealyticum 36.7%, M. hominis 28.9%, M. genitalium 28.3%. Doubtful culture methods were used for detection of U. urealyticum and M. hominis (36.7% and 33.1%). The AMs treatment in some cases was not in compliance with the up-to-date practical guidelines for STD and NGU.

[The postoperative pancreatitis after the pancreatic surgery].

The results of 302 operations on the pancreas were analyzed: of them 107 were pancreatoduodenal resections; 67 were distal resections of the pancreas; 74 were various resections of the head of the pancreas and middle resections and 54 other operations. The postoperative pancreatitis was registered in 178 patients. The preventive use of the octreotide intraoperatively and in early postoperative period showed no influence on the frequency and severity of the postoperative pancreatitis. The ultrasound was the optimal screening diagnostig method, whereas the computed tomography was the best in pancreonecrosis diagnostics and the volume of the pancreatic tissue damaged. Of 178 patients with the postoperative pancreatitis 17 died, the lethality rate was 9.5%.

[The resection of the head of the pancreas with longitudinal pancreatojejunostomy (Frey procedure)].

The indications to Frey operation are severe pain syndrome and pancreatic hypertension, caused by concrements and strictures of the main pancreatic duct and/or postnecrotic pancreatic cysts. The pancreaticojejunoanastomosis is performed on the isolated by Roux intestinal loop. The average operating time was 4.62±1.39 hours. 28,3% of the operated patients developed various postoperative complications. 2 (6.7%) patients had the anastomosis insufficiency; the 2 patients had intraanastomotic bleeding and 1 patient had the arrosive bleeding caused by pancreonecrosis. 2 patients had external pancreatic fistulae. 1 patient died. The average hospital stay after the operation was 12±4 days.

[The enteral tube feeding and selective intestinal decontamination for the treatment of the acute pancreatitis].

The treatment results of 174 patients with the acute pancreatitis were analyzed. 51 (29.5%) patients were on total parenteral feeding (the 1st group); 93 (53%) patients received the early enteral feeding through the nasoenteral tube (the 2nd group); 30 (17.5%) patients received the enteral feeding together with the selective intestinal decontamination ( the 3rd group). The combination of enteral feeding together with the selective intestinal decontamination proved to have the positive influence and prevent the infectious complications of the acute pancreatits. Therefore, they should be used in the treatment of such patients.

[Surgical treatment of the unformed intestinal fistulae].

Treatment results of 5 patients with unformed intestinal fistulae are represented. High unformed intestinal fistulae are acknowledged to be completely unsuitable for conservative treatment and should be operated on. Complex treatment should include complete parenteral feeding, adequate fecal diversion with the use of aspirational drainage. Surgical treatment must be y the increase of fistula discharge or absence of fistula formation. Low intestinal fistulae should better be surgically dissected after their organization, otherwise urgent surgery is to be performed by complications development, such as purulent leakage into the abdominal cavity or severe wound infection.

Clinical Use of Inhibitors of HIV-1 Integration: Problems and Prospects.

The HIV-1 integrase enzyme is responsible for one of the key stages of retroviral replication; it acts as a catalyst for the integration of viral cDNA into the cell's genome. Inhibitors of HIV-1 integration have been under development for over 10 years; yet, only one integration inhibitor, raltegravir, has been approved for clinical use so far. Raltegravir binds two metal ions in the enzyme's active centre and blocks one of the integration stages: the strand transfer. Unfortunately, the clinical use of raltegravir results in the development of viral resistance among some patients. Several more HIV-1 integration inhibitors are undergoing clinical trials at the moment. However, the structure and mechanism of action of those are similar to raltegravir, which results in the emergence of cross resistance with raltegravir. The present review is focused on the history of the development and clinical trials of raltegravir and its analogues, the problems connected with the emergence of viral resistance to integration inhibitors, and the prospect of their future clinical use.

[HIV-1 integrase inhibition by dimeric bisbenzimidazoles having different spacers].

HIV-1 integrase is responsible for one of the key steps of the viral replication, integration of the viral cDNA into the host cell genome. Integration inhibition leads to complete block of the virus replication. In this study inhibition of integration by dimeric bisbenzimidazoles DBBI(7) with heptamethylene and DBBI(8) with tri(ethylene glycol) spacers was examined, and it was learned out that IC50 for DBBI(7) was about 0.03 microM, and IC50 for DBBI(8) was about 10 microM. By using cross-linking assays, it was shown that both compounds impeded a proper disposition of DNA-substrate at the active centre of integrase. Dissociation constants for complexes between either DBBI and DNA-substrate of integrase were determined. Calculated Kd values were 270 nM and 140 nM for complexes formed by DBBI(7) and DBBI(8), respectively. Therefore, inhibition of integration does not directly result from the binding of DBBIs with DNA. The dependence of initial rates of enzymatic reaction on the DNA-substrate concentration in presence of different concentrations of inhibitors was found, and inhibition constants were determined. All the data obtained allow us to suppose that the different inhibition activity of DBBI(7) and DBBI(8) results from the different mechanism of their binding: DBBI(7) is a competitive inhibitor of integrase whereas DBBI(8) is assumed to show a more complex mechanism of inhibition.

[Treatment of patients with chronic pancreatitis complicated by pseudoaneurysms of the celiac trunk basin arteries].

The authors have analyzed results of treatment of 26 patients with chronic pancreatitis complicated by pseudoaneurysms. Hospitalization and treatment of such patients should be performed in specialized hospitals which can fulfill special examination in detail and carry out roentgen-endovascular operations. Intraintestinal bleeding is an absolute indication for emergent surgery for performing hemostasis. Conservative treatment is indicated for intestinal bleedings and after arrest of bleeding the patients should be transported to specialized institutions. Two types of the appearance of pseudoaneurysms were established depending on the pathological mechanism: when there was a relationship of the pseudocyst with the main pancreatic duct (I type) and when there was not (II type). For the I type roentgen-endovascular treatment (RET) followed by operation is indicated, for the II type RET is thought to be enough.