Selective bypass of a lagging strand roadblock by the eukaryotic replicative DNA helicase.

The eukaryotic replicative DNA helicase, CMG, unwinds DNA by an unknown mechanism. In some models, CMG encircles and translocates along one strand of DNA while excluding the other strand. In others, CMG encircles and translocates along duplex DNA. To distinguish between these models, replisomes were confronted with strand-specific DNA roadblocks in Xenopus egg extracts. An ssDNA translocase should stall at an obstruction on the translocation strand but not the excluded strand, whereas a dsDNA translocase should stall at obstructions on either strand. We found that replisomes bypass large roadblocks on the lagging strand template much more readily than on the leading strand template. Our results indicate that CMG is a 3' to 5' ssDNA translocase, consistent with unwinding via "steric exclusion." Given that MCM2-7 encircles dsDNA in G1, the data imply that formation of CMG in S phase involves remodeling of MCM2-7 from a dsDNA to a ssDNA binding mode.

5†µm CW Ce3+-doped chalcogenide glass fiber laser with 17% slope efficiency.

Efficient room temperature mid-infrared laser action in a Ce3+-doped chalcogenide fiber was demonstrated. The fiber had a doped selenide glass core in an undoped sulfide glass cladding. The pump source was a CW Fe2+:ZnSe laser emitting at 4.14 µm. The optimized fiber length allowed obtaining up to 7 mW of 5.06 µm output with 17% slope efficiency at room temperature.

Charge carrier transport in PbS films doped with iodine.

The results of the measurements of electrical and Hall resistivities on polycrystalline PbS films doped with iodine obtained through hydrochemical deposition are presented. The analysis of the temperature dependence of resistivity points out the crossover from the hopping mechanism due to thermal delocalization in the impurity band to the variable range hopping mechanism. The increase in the iodine content in the films leads to an increase in the impurity ionization energy. It has been established that the temperature dependence of resistivity over a wide temperature range obeys the inverse Arrhenius law, which is characteristic of disordered polycrystalline films with different sizes and orientations of crystallites relative to the substrate, as confirmed by AFM topography, Raman spectra and X-ray diffraction measurements. We found that the type of charge carrier changes from electrons to holes with an increase in the iodine content. Additionally, for a wide range of iodine doping, the concentration of charge carriers is low, indicating the possible occurrence of a self-compensation mechanism due to the formation of impurity defects.

The Study of the Effectiveness of Ethylmethylhydroxypyridine Succinate in Acute Alcohol Intoxication.

The effectiveness of ethylmethylhydroxypyridine succinate (EMHPS) in acute alcohol intoxication was tested in a study on SPF male outbred ICR mice. Ethanol (concentration 40%) was administered to animals once intraperitoneally at a dose of 4 g/kg. Control animals were injected with saline in an equivalent volume. In 15 min after the administration of alcohol, the animals were injected intravenously or intramuscularly with EMHPS at a dose of 50 or 100 mg/kg or with saline via the same route in an equivalent volume. Animal behavior was tested 3 and 24 h later after administration of the substances. After 3 and 24 h, mice in the pathological control groups developed semiptosis, the gait and the turning over reflex were impaired, the strength of the hind limbs decreased and the distance between the hind limbs increased when landing; in the open-field test, the latency of the first movement increased, and the number of rearing postures decreased. Intravenous and intramuscular administration of EMHPS in doses of 50 and 100 mg/kg had a pronounced antitoxic and neuroprotective effect in acute alcohol intoxication: all studied parameters did not differ significantly from the control.

Suprastin (Chloropyramine) Causes Proarrhythmic Deterioration of Excitation Conduction, Depolarization and Potentiates Adrenergic Automaticity in the Pulmonary Veins Myocardium.

A number of pharmacological drugs have side effects that contribute to the occurrence of atrial fibrillation, the most common type of cardiac rhythm disorders. The clinical use of antihistamines is widespread; however, information regarding their anti- and/or proarrhythmic effects is contradictory. In this work, we studied the effects and mechanisms of the potential proarrhythmic action of the first-generation antihistamine chloropyramine (Suprastin) in the atrial myocardium and pulmonary vein (PV) myocardial tissue. In PV, chloropyramine caused depolarization of the resting potential and led to reduction of excitation wave conduction. These effects are likely due to suppression of the inward rectifier potassium current (IK1). In presence of epinephrine, chloropyramine induced spontaneous automaticity in the PV and could not be suppressed by atrial pacing. Chloropyramine change functional characteristics of PV and contribute to occurrence of atrial fibrillation. It should be noted that chloropyramine does not provoke atrial tachyarrhythmias, but create conditions for their occurrence during physical exercise and sympathetic stimulation.

Mutagenic Effect during Combined Exposure to Ionizing and Non-Ionizing Electromagnetic Radiation.

Using the method of dominant lethal mutations, we assessed the frequency of the death of Drosophila melanogaster embryos under combined exposure to ionizing γ-radiation and non-ionizing pulsed magnetic field at various doses and modes of exposure. Mutagenic effect of combined exposure is antagonistic in nature. The antagonism is more pronounced when the following mode of exposure was used: exposure to non-ionizing pulsed magnetic field for 5 h followed by exposure to γ-radiation at doses of 3, 10, and 60 Gy. In case of reverse sequence of exposures, the antagonistic effect was statistically significant after exposure to γ-radiation at doses of 3 and 10 Gy, whereas at a dose of 20 Gy, a synergistic interaction was noted.

Automated Determination of Morphometric Parameters of the Human Radius Based on the Results of Its Computed Tomography.

A fundamentally new software method for automated measurement of morphometric parameters of computed tomographic image of the human radius has been designed. The parameters obtained by manual morphometry of computed tomograms using the RadiAnt DICOM Viewer software were compared with the results of the software product developed by us. The relative error in the measurement of morphometric parameters was about 10%. In the future, the presented software method of automated determination of morphometric parameters of the bone will enable modeling of individual prosthesis of the head of the radius based on the results of computed tomograms with consideration of the structural features of the human radius.

Assessment of the Sensitivity of Foodborne Cronobacter spp. Strains and Other Enterobacteria to Temperature Stresses and Chlorine-Containing Biocides.

We examined the effects of elevated temperatures and biocides on survivability of food isolates of Cronobacter spp. (C. sakazakii) and concomitant enterobacteriaceae obtained in microbiological control of infant nutrition products. Increased resistance of certain strains of Cronobacter, Enterobacter cloacae, and Pantoea spp. to thermal processing was revealed. Salmonella, Pantoea, and Cronobacter bacteria were least sensitive to antimicrobial action of chlorine-containing agents. The above properties varied in the strains of the same species. Specifically, only two of three examined isolates of Cronobacter spp. demonstrated lower sensitivity to heat in comparison with the enterobacterial test-cultures of other species.

Complete Mitochondrial Genome of Clupeonella abrau (Maliatsky, 1930) (Clupeiformes), an Endemic Freshwater Fish from the Lake Abrau (Russia).

The Abrau sprat (tyulka or sardelka) Clupeonella abrau (Maliatsky, 1930) is an endemic fish of the Lake Abrau (Krasnodar Krai, Russia). The full C. abrau mitochondrial genome (16 650 bp) showed a gene arrangement conserved in Clupeidae and 98.8% similarity with the mitochondrial genome of the related species Black and Caspian Sea sprat C. cultriventris from the Black Sea. The COX1 gene sequence was additionally studied in a museum specimen collected in the Lake Abrau in 1938. Variability in modern Abrau sprat COX1 gene locus was estimated at approximately 0.15%, the difference between C. abrau and C. cultriventris was 1.2%, and the difference between the museum and modern C. abrau specimens from the Lake Abrau was 0.92%. The study confirmed that the Abrau sprat is present in the fish community and is capable of reproducing in the lake. Various scenarios were proposed to explain colonization of the Lake Abrau by C. abrau.

[Amplifiation of the c-MYC gene in acinar prostate adenocarcinoma. Morphogenic comparisons]. / Amplifikatsiya gena c-MYC pri atsinarnoi adenokartsinome prostaty. Morfogeneticheskie sopostavleniya.

OBJECTIVE: The purpose of this work was to evaluate c-MYC gene amplification in the substrate of prostate acinar adenocarcinoma at various Gleason scores and various stages of the disease, taking into account the morphological characteristics of the tumor. MATERIAL AND METHODS: The number of cases in the study was 82, including the control group - 12 cases. Morphological assessment included: determination of the total Gleason score, grading group, assessment of lymphovascular/perineural invasion, and architectural characteristics of the tumor. Gene amplification was assessed by FISH using the c-MYC (8q24)/SE8 probe. RESULTS: In all cases of the study group, amplification of the c-MYC gene was detected in the tumor, with a significant difference from the control group (p<0.05). When assessing cases with 4-6 fold copies of the gene, significant differences were established between patients with stages II and III of the disease and stage IV (10.0 and 13.5 versus 30.0) (p<0.05). Cluster amplification of the c-MYC gene was detected with equal frequency in groups of patients with stages III and IV of the disease, while in stage II of the disease, the event almost did not occur (p<0.05). A significant increase in the level of c-MYC gene amplification was found in groups with advanced stages of the disease (p<0.02). Non-cluster amplification significantly distinguishes T4M0 and T4M1 stage patients from the rest with a significant increase in the score (p<0.05). In the metastatic stage of the disease, there was an increase c-MYC gene amplification compared to the non-metastatic stage (p<0.02). The copy number of the c-MYC gene was significantly higher in cases with perineural and lymphovascular invasion, as well as in cases of cribriform tumor organization (p<0.05). CONCLUSION: Amplification of the c-MYC gene in prostate tumor cells is associated with advanced stages of the disease (T4M0 and T4M1) with an increase in the copy number of the gene during the metastatic stage of the process. It was found that increased amplification of the c-MYC gene distinguishes groups of patients whose tumors exhibit perineural and lymphovascular invasion, as well as a cribriform pattern of tumor organization.

Chronic Heart Failure in Patients Hospitalized in 2002 and 2021: Comparative Analysis of Prevalence, Clinical Course and Drug Therapy.

AIM: Comparative analysis of the prevalence of chronic heart failure (CHF), clinical and medical history data, and drug therapy of patients admitted to a cardiology hospital in 2002 and 2021. MATERIAL AND METHODS: The study analyzed the medical records of patients with a confirmed diagnosis of CHF who were admitted in 2002 (n=210) and 2021 (n=381) to a specialized cardiology hospital. RESULTS: According to medical records of 2021, the proportion of patients with a confirmed diagnosis of CHF (87.6%) in the cohort of patients admitted to a cardiology hospital was twice as high as in 2002 (46.4%; p<0.001). The majority of patients with CHF in the study sample were patients with preserved left ventricular ejection fraction (HFpEF). The proportion of such patients significantly increased to reach 75.9% in 2021 compared to 58.6% in 2002 (p<0.001). At the same time, the number of severe forms of CHF (NYHA functional class (FC) IV) decreased by 10% and was 13.2% in 2002 and 1.3% in 2021 (p<0.001). In the majority of patients, ischemic heart disease (98.1 and 91.1% in 2002 and 2021, respectively, p<0.001) and hypertension (80.5 and 98.2%, respectively, p<0.001) were diagnosed as the cause for CHF. Furthermore, the incidence of comorbidity increased significantly: atrial fibrillation was detected in 12.3% of patients in 2002 and 26.4% in 2021 (p < 0.001); type 2 diabetes mellitus, in 14.3 and 32% of patients (p <0.001); and obesity, in 33.3 and 43.7% of patients, respectively (p=0.018). The frequency of using the major groups of drugs increased during the analyzed period: renin-angiotensin-aldosterone system blockers were administered to 71.9% of patients in 2002 and to 87.7% in 2021 (p<0.001); beta-blockers were administered to 53.3 and 82.4% of patients (p<0.001); and mineralocorticoid receptor antagonists, to 1.9 and 18.6% of patients, respectively (p=0.004). CONCLUSION: In 2021, the proportion of patients with a confirmed diagnosis of CHF in the patient cohort admitted to a cardiology hospital was twice as high as in 2002; the phenotype with preserved left ventricular ejection fraction predominated in the CHF structure. During the analyzed twenty-year period, the prevalence of comorbidities increased among CHF patients. The prescription frequency of pathogenetic evidence-based therapy has significantly increased by 2021, however, it remains insufficient even in patients with CHF with reduced left ventricular ejection fraction.

[Features of the Reperfusion Therapy for ST-Segment Elevation Myocardial Infarction According to the Russian Registry of Acute Myocardial Infarction - REGION-IM].

AIM: Based on data from the Russian REGION-IM registry, to study the features of reperfusion therapy in patients with ST-segment elevation myocardial infarction (STEMI) in real-life clinical practice. MATERIAL AND METHODS: REGION-IM is a multicenter prospective observational study. The observational period is divided into 3 stages: during the stay in the hospital and at 6 and 12 months after inclusion in the registry. The patient's records contain demographic and history data; information about the present case of MI, including the time of the first symptom onset, first contact with medical personnel, and admission to the hospital; coronary angiography (CAG) data, percutaneous coronary intervention (PCI) data, and information about the thrombolytic therapy (TLT). RESULTS: Reperfusion therapy was performed in 88.9 % of patients with STEMI. Primary PCI (pPCI) was performed in 60.6 % of patients. The median time from the onset of symptoms to pPCI was 315 minutes [195; 720]. The median time from ECG to pPCI was 110 minutes [84;150]. Isolated TLT was performed in 7.4 %, pharmaco-invasive treatment tactics were used only in 20.9 % of cases. The median time from ECG to TLT (prehospital and in-hospital) was 30 minutes [10; 59], whereas the median time from ECG to prehospital TLT was 18 minutes [10; 39], and in 63 % of patients, TLT was performed more than 10 minutes after diagnosis. PCI followed TLT in 73 % of patients. CONCLUSION: The frequency of reperfusion therapy for STEMI in the Russian Federation has increased considerably in recent years. The high frequency of pPCI is noteworthy, but the timing of pPCI does not always comply with clinical guidelines. The results of this registry confirm the high demand for pharmaco-invasive strategies in real-life clinical practice. Taking into account geographical and logistical features, implementing timely myocardial reperfusion requires prehospital TLT. However, the TLT frequency in the Russian Federation is still insufficient despite its proven maximum effectiveness in the shortest possible time from the detection of acute MI.

[Fluorescence lymphoscopy with sentinel lymph node biopsy in research of lymphatic flow in early gastric cancer]. / Vozmozhnosti flyuorestsentnoi limfoskopii s biopsiei signal'nykh limfaticheskikh uzlov v izuchenii kharaktera limfoottoka pri rannem rake zheludka.

OBJECTIVE: To analyze the incidence and risk factors of regional lymph node metastatic lesions, as well as patterns of lymphatic drainage in early gastric cancer using indocyanine green (ICG). MATERIAL AND METHODS: A prospective single-center non-randomized study included 67 patients with early gastric cancer between 2016 and 2019. All patients underwent endoscopic dissection or surgical resection with sentinel lymph node biopsy. RESULTS: Regional lymph node metastatic lesions were detected in 12 (20.2%) out of 59 patients with examined lymph nodes. Of these, 11 out of 12 patients had sentinel lymph node lesion, and only 1 patient had metastasis outside this lymph node. The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). Risk factors for metastasis of early gastric cancer to regional lymph nodes were high grade adenocarcinoma (p=0.038) and tumor of anterior gastric wall (p=0.013). All patients with tumors of the upper third of the stomach had sentinel lymph node in the left gastric artery basin. Lymph flow was multidirectional in patients with tumors of the middle third of the stomach. In tumors of the lower third of the stomach, sentinel lymph node was located in the right gastroepiploic artery (50%) and left gastric artery basins (36.84%) (p=0.002). Sentinel lymph node was located in the left gastric artery basin in 84% of patients with tumors of the lesser curvature (p<0.001). Lymphatic drainage was multidirectional if tumors were localized on anterior and posterior walls, as well as on the greater curvature. CONCLUSION: The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). ICG is valuable to identify the first lymph node in lymphatic drainage pathway in 83.6% of cases that makes it possible to assess the regional lymphatic collector. In addition, sentinel lymph node biopsy with ICG contributes to analysis of lymphatic drainage in early gastric cancer. The last one has both scientific and practical significance.

[Long-term result of aortic root remodeling using the Florida sleeve technique in a patient with connective tissue dysplasia and aortic root aneurysm without aortic insufficiency]. / Otdalennyi rezul'tat ekzoprotezirovaniya kornya aorty po metodike Florida Sleeve u bol'nogo s soedinitel'notkannoi displaziei i anevrizmoi kornya aorty bez aortal'noi nedostatochnosti.

Aortic root remodeling using the Florida sleeve technique was proposed as a simpler alternative to classical reconstructive interventions in patients with aortic root aneurysm without aortic insufficiency. We present a 10-year result of valve-sparing surgical treatment using the Florida sleeve technique in a patient with connective tissue dysplasia and aortic root aneurysm.

[Fluorescence lymphography for sentinal lymph node biopsy in breast cancer]. / Sobstvennyi opyt primeneniya flyuorestsentnoi limfografii dlya biopsii signal'nykh limfouzlov pri rake molochnoi zhelezy.

OBJECTIVE: To study diagnostic value of fluorescence lymphography for sentinel lymph node biopsy in breast cancer. MATERIAL AND METHODS: The study enrolled 25 patients with breast cancer T1-2N0-1M0 between March 2023 and July 2023. Eight ones underwent neoadjuvant chemotherapy. In 3 patients, morphologically verified metastases cN1 in axillary lymph nodes regressed after treatment. After sentinel lymph node biopsy, all patients underwent standard axillary lymphadenectomy. Subareolar injection of indocyanine green 1 ml (5 mg/ml) was performed immediately before surgery. Fluorescence imaging was performed using the MARS system. RESULTS: Detection rate was 100%. Mean number of sentinel lymph nodes was 2. Metastatic lesions of sentinel lymph nodes were observed in 6 patients (24%) with micro-metastases in 2 cases. In 50% of cases, metastatic lesion did not extend beyond sentinel lymph nodes. False negative result was obtained in 1 (4%) patient. Mean number of metastases was 1.8 (max 3 in one patient). CONCLUSION: Sentinel lymph node biopsy with fluorescence lymphography is a sensitive method. The advantages of this technique are visualization of subcutaneous lymphatic vessels and skin incision for access to sentinel lymph nodes, as well as visualization of sentinel lymph nodes after skin incision.

[Minimally invasive surgical treatment of extramedullary tumors at the level of craniovertebral junction: experience of the Burdenko Neurosurgical Center]. / Minimal'no invazivnoe khirurgicheskoe lechenie patsientov s ekstramedullyarnymi opukholyami na urovne kraniovertebral'nogo perekhoda: opyt NMITs neirokhirurgii im. akad. N.N. Burdenko.

OBJECTIVE: To describe own experience of treating patients with extramedullary tumors at the level of craniovertebral junction using minimally invasive surgical approaches. MATERIAL AND METHODS: The study included 29 patients who underwent minimally invasive microsurgical resection of extramedullary tumors at the level of craniovertebral junction. We analyzed the main clinical and surgical parameters. RESULTS: Gross total resection was achieved in most patients with high degree of safety. Two patients required redo surgery due to CSF leakage and soft tissue cyst. Mean length of hospital-stay was 7 days. VAS score of pain syndrome at discharge was 2 points and 0 points after 3 months. No significant differences in neurophysiological monitoring indicators were observed (p=0.76). CONCLUSION: Minimally invasive posterior approaches to extramedullary tumors at the level of craniovertebral junction can significantly reduce surgical trauma with equal extent of resection.

[Comparison of polymethyl methacrylate skull implant fixation by three types of titanium fasteners]. / Sravnenie sposobov fiksatsii implantov cherepa iz polimetilmetakrilata tremya vidami titanovykh krepezhei.

OBJECTIVE: To evaluate mechanical strength of three methods of polymethyl methacrylate skull implant fixation in two experimental models. MATERIAL AND METHODS: The first experiment was performed on a plastic model that was as close as possible to bone in structural characteristics. The second experiment was performed on a biological specimen (a ram's head). We assessed the quality of implant fixation to bone window edges by craniofixes, ties and microscrews and lateral intercortical screws. RESULTS: Craniofixes are feasible for small flat flaps, but not advisable for wide highly curved implants. They are also the most expensive method of fixation. Implant fixation by ties and microscrews is a universal method comparable in price to craniofix. Lateral intercortical fixation is effective both for small flat implants and wide implants with large curvature. However, this method is not always applicable. CONCLUSION: Combined fixation by lateral intercortical screws and ties allows for the most effective fixation while reducing the overall price of consumables.

[Venous cerebral complications after microsurgery for complex aneurysms of the middle cerebral arteries]. / Venoznye tserebral'nye oslozhneniya mikrokhirurgicheskikh operatsii po povodu slozhnykh anevrizm srednikh mozgovykh arterii.

Microsurgeries are common for complex aneurysms of the middle cerebral artery (MCA). OBJECTIVE: To evaluate the incidence and types of venous cerebral disorders after microsurgeries for complex MCA aneurysms. MATERIAL AND METHODS: A retrospective study included 285 patients with complex MCA aneurysms between 2009 and 2020. Pterional craniotomy and transsylvian approach were used in all cases. Aneurysm clipping was performed in 230 cases, revascularization - 27, trapping without bypass - 17, reinforcement - in 11 cases. Computed tomography within 1-3 days after surgery recognized venous cerebral disorders as heterogeneous foci of abnormal brain density with unclear boundaries. These foci were crescent-shaped as a rule and located in deep and basal parts of the frontal lobes. RESULTS: Venous abnormalities occurred in 76 (26.7%) patients. Thirty-five (12.3%) patients had mild venous edema of the frontal lobe alone. In 35 (12.3%) patients, we found moderate disorders with focus in the frontal lobe and compression of anterior horn of the left lateral ventricle with or without hemorrhagic imbibition. Severe disorders occurred in 6 (2.1%) patients with lesion extending to the frontal, insular and temporal lobes. These lesions were accompanied by hemorrhagic imbibition, and lateral dislocation exceeded 5 mm. CONCLUSION: Careful dissection of veins in Sylvian fissure with preservation of bridging veins is likely to reduce the risk of this complication. Cauterization of a large vein in Sylvian fissure should be followed by careful hemostasis within frontal or temporal cortex. Bleeding and cortical tension can indicate intracerebral hematoma whose likelihood is higher in patients with venous cerebral disorders.

[Surgical treatment of a patient with syphilitic aortitis]. / Khirurgicheskoe lechenie patsienta s sifiliticheskim aortitom.

Syphilitic aortitis is a rare disease caused by Treponema pallidum affecting the aorta and leading to inflammation. Syphilitic aortitis is one of the causes of aortic aneurysms. This article presents surgical treatment of a patient with syphilitic aortitis and thoracic aortic aneurysm. This clinical case confirms the difficulties of surgical treatment.

[The influence of diet therapy and regular physical trainings on monocyte chemoattractant protein-1 (MCP-1) secretion by monocytes among obese patients with coronary heart disease].

Chronic systemic inflammation is one of the leading pathogenetic pathways for the development of atherosclerosis in obese patients. In this regard, it seems promising to evaluate the effect of the diet and physical exertion on the proinflammatory activity of monocytes. The purpose of this research was to evaluate the effect of the diet and regular physical trainings on the secretion of monocyte chemotactic factor 1 (MCP-1) by monocytes in obese patients with coronary artery disease. Material and methods. 27 obese participants (body mass index >30 kg/m2) with a confirmed diagnosis of coronary heart disease were recruited. All participants were prescribed with 12 weeks of a specialized diet with a restriction of simple carbohydrates and salt, a 500-kcal daily energy deficit, and with inclusion of cruciferous (200 g per day), seasonal dark berries (70 g per day) and green tea (200 ml per day). The regular assisted physical trainings were also administered. The body composition, blood biochemical parameters and MCP-1 secretion rates in the primary culture of monocytes isolated from blood samples via the immunomagnetic separation method were assessed before and after the intervention. Results. As a result, after the 12-weeks intervention the reliable body weight loss (-4.0%), waist circumference (-4.2%), visceral fat (-5.4%), total cholesterol (-9.8%), LDL-cholesterol (-16.6%) and triglycerides (-26.0%), an improvement in the results of the 6-minute walk test (+10.33%) was achieved, as well as an LPS-stimulated monocytes secretion of MCP-1 decreased by 2.8 times (p=0.005). Conclusion. Overall, the results suggest that diet and regular physical activity in patients with obesity and coronary heart disease may decrease the functional "proinflammatory" activity of monocytes.