Isoniazid urine spectrophotometry for prediction of serum pharmacokinetics in adults with TB.

BACKGROUND: Isoniazid (INH) is an important drug in many TB regimens, and unfavorable treatment outcomes can be caused by suboptimal pharmacokinetics. Dose adjustment can be personalized by measuring peak serum concentrations; however, the process involves cold-chain preservation and laboratory techniques such as liquid chromatography (LC)/mass spectrometry (MS), which are unavailable in many high-burden settings. Urine spectrophotometry could provide a low-cost alternative with simple sampling and quantification methods. METHODS: We enrolled 56 adult patients on treatment for active TB. Serum was collected at 0, 1, 2, 4, 6, and 8 h for measurement of INH concentrations using validated LC-MS/MS methods. Urine was collected at 0-4, 4-8, and 8-24 h intervals, with INH concentrations measured using colorimetric methods. RESULTS: The median peak serum concentration and total serum exposure over 24 h were 4.8 mg/L and 16.4 mg*hour/L, respectively. Area under the receiver operator characteristic curves for urine values predicting a subtherapeutic serum concentration (peak <3.0 mg/L) were as follows: 0-4 h interval (AUC 0.85, 95% CI 0.7-0.96), 0-8 h interval (AUC 0.85, 95% CI 0.71-0.96), and 0-24 h urine collection interval (AUC 0.84, 95% CI 0.68-0.96). CONCLUSION: Urine spectrophotometry may improve feasibility of personalized dosing in high TB burden regions but requires further study of target attainment following dose adjustment based on a urine threshold.

CONTEXTE: L'isoniazide (INH) est un médicament important dans de nombreux schémas thérapeutiques contre la TB, et des résultats thérapeutiques défavorables peuvent être dus à une pharmacocinétique sous-optimale. L'ajustement de la dose peut être personnalisé en mesurant les concentrations sériques maximales ; cependant, le processus implique la conservation de la chaîne du froid et des techniques de laboratoire telles que la chromatographie liquide (LC)/spectrométrie de masse (MS), qui ne sont pas disponibles dans de nombreuses régions à forte charge de morbidité. La spec-trophotométrie urinaire pourrait constituer une alternative peu coûteuse avec des méthodes d'échantillonnage et de quantification simples. MÉTHODES: Nous avons recruté 56 patients adultes sous traitement pour une TB active. Le sérum a été prélevé à 0, 1, 2, 4, 6 et 8 h pour mesurer les concentrations d'INH à l'aide de méthodes LC-MS/MS validées. L'urine a été prélevée à des intervalles de 0­4, 4­8 et 8­24 h, et les concentrations d'INH ont été mesurées à l'aide de méthodes colorimétriques. RÉSULTATS: La concentration sérique maximale médiane et l'exposition sérique totale sur 24 h étaient respectivement de 4,8 mg/L et de 16,4 mg*heure/L. L'aire sous les courbes caractéristiques de l'opérateur récepteur a été mesurée à l'aide de méthodes color-imétriques. Les aires sous les courbes caractéristiques des récepteurs pour les valeurs urinaires prédisant une concentration sérique sous-thérapeutique (pic <3,0 mg/L) étaient les suivantes : intervalle 0­4 h (AUC 0,85 ; IC 95% 0,7­0,96), intervalle 0­8 h (AUC 0,85 ; IC 95% 0,71­0,96), et intervalle de collecte d'urine 0­24 h (AUC 0,84 ; IC 95% 0,68­0,96). CONCLUSION: La spectrophotométrie urinaire peut améliorer la faisabilité d'un dosage personnalisé dans les régions à forte charge de TB, mais nécessite une étude plus approfondie de l'atteinte de la cible après l'ajustement de la dose sur la base d'un seuil urinaire.

[Metformin ameliorates PM2.5-induced functional impairment of placental trophoblasts by inhibiting ferroptosis].

OBJECTIVE: To investigate the protective effect of metformin against PM2.5-induced functional impairment of placental trophoblasts and explore the underlying mechanism. METHODS: Sixteen pregnant Kunming mice were randomly assigned into two groups (n=8) for intratracheal instillation of PBS or PM2.5 suspension at 1.5, 7.5, and 12.5 days of gestation. The pregnancy outcome of the mice was observed, and placental zonal structure and vascular density of the labyrinth area were examined with HE staining, followed by detection of ferroptosis-related indexes in the placenta. In cultured human trophoblasts (HTR8/SVneo cells), the effects of PM2.5 exposure and treatment with metformin on cell viability, proliferation, migration, invasion, and tube formation ability were evaluated using CCK8 assay, EDU staining, wound healing assay, Transwell experiment, and tube formation experiment; the cellular expressions of ferroptosis-related proteins were analyzed using ELISA and Western blotting. RESULTS: M2.5 exposure of the mice during pregnancy resulted in significantly decreased weight and number of the fetuses and increased fetal mortality with a reduced placental weight (all P<0.001). PM2.5 exposure also caused obvious impairment of the placental structure and trophoblast ferroptosis. In cultured HTR8/SVneo cells, PM2.5 significantly inhibited proliferation, migration, invasion, and angiogenesis of the cells by causing ferroptosis. Metformin treatment obviously attenuated PM2.5-induced inhibition of proliferation, migration, invasion, and angiogenesis of the cells, and effectively reversed PM2.5-induced ferroptosis in the trophoblasts as shown by significantly increased intracellular GSH level and SOD activity, reduced MDA and Fe2+ levels, and upregulated GPX4 and SLC7A11 protein expression (P<0.05 or 0.01). CONCLUSION: PM2.5 exposure during pregnancy causes adverse pregnancy outcomes and ferroptosis and functional impairment of placental trophoblasts in mice, and metformin can effectively alleviate PM2.5-induced trophoblast impairment.

[Modern approaches to studying the molecular mechanisms of lung functioning in normal and pathological conditions]. / Sovremennye podkhody k izucheniyu molekulyarnykh mekhanizmov funktsionirovaniya legkikh v norme i pri patologii.

Problems with breathing and lung function are caused by the development of various lung diseases associated with lifestyle, harmful environmental factors and genetic predisposition. Knowledge of the molecular mechanisms of the development of the pathological process will allow on time identification of the disease or the development of targeted therapy. The article provides an overview of modern methods that make it possible to most accurately reproduce the structural, functional and mechanical properties of the lung (organ-on-a-chip), to perform non-invasive molecular studies of biomarkers of bronchopulmonary pathology using saliva diagnostics, as well as using DNA and RNA aptamers, verify tumor markers in biological samples of human tissue. Analysis of alterations in the pattern of protein glycosylation using glycodiagnostic methods makes it possible to detect lung cancer in the early stages.

[Short-term outcomes of mechanical and hand-sewn laparoscopic one-anastomosis mini-gastric bypass]. / Sravnitel'naya otsenka blizhaishikh rezul'tatov laparoskopicheskogo minigastroshuntirovaniya s apparatnym i manual'nym sposobami formirovaniya gastroeyunoanastomoza.

OBJECTIVE: To evaluate the short-term outcomes of mechanical and hand-sewn laparoscopic one-anastomosis mini-gastric bypass. MATERIAL AND METHODS: There were 233 patients who underwent laparoscopic one-anastomosis mini-gastric bypass. Short-term results were analyzed in groups of mechanical (the first group, n=108) and hand-sewn (the second group, n=125) gastrojejunostomy. No significant between-group differences in baseline data were detected (demographic characteristics, body mass index, comorbidity and previous abdominal surgeries). RESULTS: Surgery time and blood loss were similar in both groups. Intraoperative morbidity was 7.2-10.2% (p=0.485). All complications required no surgical conversion (Satava-Kazaryan grade I). Overall postoperative morbidity was 16.0-21.3% (p=0.314). Most events corresponded to Accordion grade I and had no significant effect on hospital-stay. CONCLUSION: This study revealed no significant differences in short-term outcomes after laparoscopic one-anastomosis gastric bypass with mechanical and hand-sewn gastrojejunostomy. Further study of long-term clinical outcomes is necessary.

[Treatment of primary malignant melanoma of the esophagus]. / Lechenie pervichnoi melanomy pishchevoda.

OBJECTIVE: To present treatment of primary esophageal melanoma in a young patient, as well as review of modern data on this issue. MATERIAL AND METHODS: We describe the results of treatment of a patient with primary melanoma of the esophagus. PubMed, SCOPUS, and elibrary databases were used for the review. RESULTS: We present a rare case of primary esophageal melanoma and variant of radical surgical treatment. The review is devoted to historical information about this nosology, statistical data, options for diagnosis and treatment. CONCLUSION: Such a rare clinical case is of great scientific interest due to the rarity of this disease. In our opinion, a certain register of orphan malignant tumors is necessary for diagnosis and treatment of various rare malignancies.

Identification of protein components of the transformation system in the cell line of immortalized human keratinocytes HaCaT exposed to surfactants.

Using the method of shotgun mass spectrometry, we have evaluated changes in the proteomic profile of HaCat cells in response to the treatment with sodium dodecyl sulfate (anionic surfactant) and Triton-X100 (non-ionic surfactant) in two concentrations (12.5 µg/ml and 25.0 µg/ml). The study revealed induction of orphan CYP2S1 (biotransformation phase I) in response to Triton-X100. We have identified proteins of II (glutathione-S-transferases, GSTs) and III (solute carrier proteins, SLCs) biotransformation phases, as well as antioxidant proteins (peroxiredoxins, PRDXs; catalase, CAT; thioredoxin, TXN). Thus, proteins of all three xenobiotic detoxification phases were detected. The presented results suggest a new prospect of using HaCaT keratinocytes as a model of human epidermis for studying the metabolism of drugs/toxicants in human skin in vitro.

[Physiological and biochemical in vivo study of polyphenols and 20-hydroxyecdisone from quinoa grains effect on resistance to physical exercise in Wistar rats].

Increasing the ability of the human body to adapt to physical stress is relevant from the standpoint of using foods for special uses containing functional food ingredients (FFI) with effectiveness proven in vivo. The purpose of this study was to evaluate the effect of FFI from Chenopodium quinoa grains with a high content of polyphenols and phytoecdysteroids on the physical endurance of male Wistar rats. Material and methods. The experiment was carried out during 36 days using 50 weaned male Wistar rats. The animals were randomly divided into 3 groups (n=12): Control, Run and Run-FFI. Rats of the Control and Run groups received a standard semisynthetic diet during the experiment. Rats of the Run-FFI group received a semi-synthetic diet with the addition of FFI in an amount of 0.055±0.003%, containing phytoecdysteroids (50.4±0.6 mg/g) and polyphenols (212.0±2.0 mg/g). During the experiment, the rats were assessed for their neuromotor function (grip strength of front paws), memory, and behavioral reactions in the "Elevated Plus Maze" (EPM), "Conditioned Passive Avoidance Reflex" (CPAR) and "Open Field" (OF) tests. Once a week, animals from the Run and Run-FFI groups were subjected to moderate physical load on a "Treadmill". On the 36th day of the experiment, the animals of these groups were subjected to exhausting physical load. Immediately after running, the animals were placed in metabolic cages to collect daily urine. At the end of the experiment, the content of corticosterone, the activity of catalase, indicators of protein, lipid and mineral metabolism, indexes of the liver functional state and antioxidant defense system parameters were analyzed in the blood serum; the level of prostaglandin E2 and dopamine were determined in daily urine. Results. Physiological tests (CRAR, OF) showed that weekly exercise increased anxiety in laboratory animals. The FFI introduction into the diet led to normalization of the assessed parameters (EPM). As a result of 36-day consumption of FFI against the background of physical loads, a significant decrease by 22% in the main stress marker, corticosterone, was revealed in the blood of rats, as well as significant increase by 23% in the stress inhibitor - prostaglandin E2 urinary excretion, compared with animals of the Run group to the level not differed from the indicators of the control animals. There were no differences in endurance performance between the Run and Run-FFI groups on the results of the exhaustive exercise. Consumption of FFI prevented the formation of excess ammonia, significantly reducing the level of urea in the blood and normalizing its excretion to control levels in the urine, which was increased in the Run group by 19%. Conclusion. The results obtained demonstrated the adaptogenic properties of the developed FFI in response to stress caused by weekly moderate and acute exhaustive physical activity. The obtained data on the biological effect of the developed FPI on the adaptive potential of laboratory animals will serve as an experimental basis for its inclusion in the composition of specialized foods.

[Influence of chronic immobilization stress on vitamin status in rats fed different diets].

The influence of a stress factor, widespread in modern conditions, on the vitamin status has not been studied enough. At the same time, the negative stress impact can be aggravated against the background of unhealthy nutrition, which in turn affects the vitamin status of the organism. In this regard, the goal of the research was to evaluate the effect of chronic restrict stress on the vitamin supply in rats fed a diet with adequate and increased content of fat, sugar and cholesterol. Material and methods. The experiment was carried out on 37 growing male Wistar rats (initial body weight of 45±5 g) divided into 4 groups. Animals of the 1st (control) and the 2nd groups received a complete semi-synthetic diet (CSSD) (20% protein, 10% fat, 58% carbohydrates in the form of starch, 384 kcal/100 g) for 92 days. The levels of all vitamins and mineral elements in the rats' diets were adequate for growing rats. Rats of the 3rd and the 4th groups were fed a high-calorie, high-fat high-carbohydrate diet (HFHCD) (20% protein, 28% fat, 2% cholesterol, 18% carbohydrates in the form of starch, 20% sucrose, 511 kcal/100 g). Animals of groups 2 and 4 were subjected to daily 90-minute immobilization. The concentration of vitamins A (retinol and retinol palmitate) and E (α-tocopherol) in the blood serum and liver were determined by high-performance liquid chromatography, vitamins B1 and B2 in the liver and urine, as well as riboflavin in the blood serum and 4-pyridoxic acid (4-PA) in urine were determined by fluorimetric methods. Biochemical parameters of blood serum were determined on a biochemical analyzer; the total content of fat, triglycerides (TG) and cholesterol (CH) was determined in the liver. Results. Replacing CSSD with HFHCD, both under restraint stress and without, was accompanied by an increase in liver weight by 1.8-2.0 fold, in its fat content by 2.6-3.3 fold, cholesterol by 32.6-35.3 fold and TG - by 33.0-57.6 fold (p=<0.001). An increase in alanine aminotransferase (ALT) activity by 1.7-2.0 fold (p=<0.01), in low-density lipoprotein (LDL) cholesterol level by 5.4 fold (p=<0.05) and the atherogenic coefficient by 2.5 fold (p<0.01) as well as a decrease in creatinine and urea level (p=<0.05) in blood serum were revealed. Immobilization was accompanied by a decrease in body weight, liver and liver fat in rats fed both CSSD and HFHCD (p<0.05), but didn't affect the blood serum biochemical parameters, with the exception of an increase in ALT activity. If the activity of alkaline phosphatase (ALP) did not change during immobilization of rats fed the CSSD, then in animals fed the high-calorie diet it decreased by 37.5% (p=<0.05 from the control) under its increase against the background of restrict stress by 78.7% (p=<0.01) compared to the indicator of rats of the 3rd group. Immobilization of rats treated with CSSD was accompanied by an increase in both absolute serum α-tocopherol level and concentration correlated with the level of cholesterol and triglycerides by 26.0-57.5% (p<0.05), with a simultaneous decrease in its content in the liver per 1 g of wet tissue by 22.1% (p=0.041) relative to the indicators of intact animals. Immobilization reduced the level of retinol palmitate in the liver by 2.3 times (p<0.01), but did not affect retinol level in the blood serum. At the same time, indicators of B vitamin status (the content of vitamins B1 and B2 in the liver per 1 g of wet tissue and per organ, blood serum riboflavin level, urinary excretion of riboflavin and 4-PA) did not change, with the exception of thiamine urinary excretion, which reduced compared to the control by 38.8%. In rats fed HFHCD, immobilization had no additional effect on the supply with vitamins A and E. The content of vitamins B1 and B2 in the liver in terms of the whole organ was reduced by 14.0-26.7% relative to the indicator in animals of the 3rd group, not subjected to chronic stress, only due to differences in liver weight in animals of these groups. Conclusion. The data obtained indicate that chronic stress has a negative effect on the vitamin status of the body, worsening the supply with vitamins A, E and B1, and substantiate the feasibility of studying the mechanisms of this effect in order to develop effective vitamin complexes for the treatment and prevention of diseases caused by long-term stress.

[Mid-term efficacy evaluation of ABO incompatible living relative kidney transplantation based on protocol biopsy].

Objective: To evaluate the mid-term efficacy of ABO incompatible living donor kidney transplantation (ABOi-KT) based on the results of routine renal biopsy for transplantation. Methods: Retrospective collection of clinical data from 23 pairs of ABOi-KT donors and recipients at the First Affiliated Hospital of Sun Yat-sen University from July 2015 to November 2021. ABOi-KT was performed on recipients after desensitization treatment, and the results of routine kidney transplant biopsy at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were analyzed. Combined with blood type antibody levels and renal function recovery, the mid-term efficacy of ABOi-KT was evaluated. Results: Among the 23 recipients, there were 19 males and 4 females; age range from 19 to 47 years old [(29.6±6.7) years old], all underwent ABOi-KT successfully after receiving desensitization treatment. The follow-up time was (44.6±22.4) months, of which 22 cases were followed up for more than 1 year. The incidence rates of rejection reactions at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were 15.0% (3/20), 11.1% (1/9), 7.7% (1/13), 25.0% (3/12), and 12.5% (1/8), respectively. For receptors with rejection reactions, targeted anti-rejection therapy was performed based on clinical symptoms and various indicators. Borderline T cell mediated rejection (TCMR) can be converted to mild tubular inflammation after anti-rejection treatment. The positive rate of complement C4d in peritubular capillaries was 95.0% (19/20) one week after surgery, and the positive rate of complement C4d was 100% at 3 and 12 months after surgery. The cumulative survival rates at 1, 3, 5, and 7 years after surgery were all 100%. The cumulative survival rates at 1, 3, 5, and 7 years after kidney transplantation were 100%, 93.3%, 84.0%, and 84.0%, respectively. Except for 2 recipients who underwent transplantation in 2017 and experienced kidney failure at 30 and 49 months after surgery, all other transplanted kidneys survived. Conclusions: The results of routine renal transplant biopsy show that ABOi-KT has a good mid-term therapeutic effect. The pathological changes of ABOi-KT can be dynamically observed through routine renal transplant biopsy and targeted treatment for rejection reactions can be provided accordingly.

Multi-omics Integration Identifies Genes Influencing Traits Associated with Cardiovascular Risks: The Long Life Family Study.

The Long Life Family Study (LLFS) enrolled 4,953 participants in 539 pedigrees displaying exceptional longevity. To identify genetic mechanisms that affect cardiovascular risks in the LLFS population, we developed a multi-omics integration pipeline and applied it to 11 traits associated with cardiovascular risks. Using our pipeline, we aggregated gene-level statistics from rare-variant analysis, GWAS, and gene expression-trait association by Correlated Meta-Analysis (CMA). Across all traits, CMA identified 64 significant genes after Bonferroni correction (p ≤ 2.8×10-7), 29 of which replicated in the Framingham Heart Study (FHS) cohort. Notably, 20 of the 29 replicated genes do not have a previously known trait-associated variant in the GWAS Catalog within 50 kb. Thirteen modules in Protein-Protein Interaction (PPI) networks are significantly enriched in genes with low meta-analysis p-values for at least one trait, three of which are replicated in the FHS cohort. The functional annotation of genes in these modules showed a significant over-representation of trait-related biological processes including sterol transport, protein-lipid complex remodeling, and immune response regulation. Among major findings, our results suggest a role of triglyceride-associated and mast-cell functional genes FCER1A, MS4A2, GATA2, HDC, and HRH4 in atherosclerosis risks. Our findings also suggest that lower expression of ATG2A, a gene we found to be associated with BMI, may be both a cause and consequence of obesity. Finally, our results suggest that ENPP3 may play an intermediary role in triglyceride-induced inflammation. Our pipeline is freely available and implemented in the Nextflow workflow language, making it easily runnable on any compute platform (https://nf-co.re/omicsgenetraitassociation).

[Endocrine and psychosomatic disorders in patients with amenorrhea].

The article presents data on the relationship of pathogenetic mechanisms for the development of menstrual disorders of functional and organic origin in connection with mental disturbances from the point of view of the psychosomatic concept. According to the latter, functional disorders of the menstrual cycle are considered as psychosomatic, in which gynecological pathology develops as a result of psychopathological illness. A striking example of such a disorder is functional hypothalamic amenorrhea. At the same time, endocrinopathies, such as polycystic ovary syndrome and premature ovarian insufficiency, can also be considered in the paradigm of psychosomatic illnesses of ovarian function due to the high prevalence of anxiety and depressive disorders in this cohort of patients. This review highlights the importance of interdisciplinary collaboration between a gynecologist and a psychiatrist for the most effective reproductive rehabilitation of patients with amenorrhea. Literature search was carried out in national (eLibrary, CyberLeninka.ru) and international (PubMed, Cochrane Library) databases in Russian and English. The priority was free access to the full text of articles. The choice of sources was prioritized for the period from 2018 to 2023.However, taking into account the insufficient knowledge of the chosen topic, the choice of sources dates back to 1985.

[Bilateral stenting for malignant tracheal and bronchial stenosis]. / Bilateral'noe stentirovanie opukholevogo stenoza trakhei i glavnykh bronkhov: pervyi opyt (klinicheskoe nablyudenie).

Malignant lesions of tracheal bifurcation usually lead to respiratory failure and risk of mortality. Airway stenting is the only minimally invasive method for these patients. The authors present a patient with T4N3M0 left-sided lung cancer (inoperable stage IIIc) complicated by respiratory failure due to tracheal bifurcation obstruction. Bilateral stenting by self-expanding stents with perforated coatings was effective for airway recanalization and provided subsequent chemotherapy.

Cardiac MRI feature-tracking-derived torsion mechanics in systolic and diastolic dysfunction in systemic light-chain cardiac amyloidosis.

AIM: To describe the myocardial torsion mechanics in cardiac amyloidosis (CA), and evaluate the correlations between left ventricle (LV) torsion mechanics and conventional parameters using cardiac magnetic resonance imaging feature tracking (CMR-FT). MATERIALS AND METHODS: One hundred and thirty-nine patients with light-chain CA (AL-CA) were divided into three groups: group 1 with preserved systolic function (LV ejection fraction [LVEF] ≥50%, n=55), group 2 with mildly reduced systolic function (40% ≤ LVEF <50%, n=51), and group 3 with reduced systolic function (LVEF <40%, n=33), and compared with age- and gender-matched healthy controls (n=26). All patients underwent cine imaging and late gadolinium-enhancement (LGE). Cine images were analysed offline using CMR-FT to estimate torsion parameters. RESULTS: Global torsion, base-mid torsion, and peak diastolic torsion rate (diasTR) were significantly impaired in patients with preserved systolic function (p<0.05 for all), whereas mid-apex torsion and peak systolic torsion rate (sysTR) were preserved (p>0.05 for both) compared with healthy controls. In patients with mildly reduced systolic function, global torsion and base-mid torsion were lower compared to those with preserved systolic function (p<0.05 for both), while mid-apex torsion, sysTR, and diasTR were preserved (p>0.05 for all). In patients with reduced systolic function, only sysTR was significantly worse compared with mildly reduced systolic function (p<0.05). At multivariable analysis, right ventricle (RV) end-systolic volume RVESV index and NYHA class were independently related to global torsion, whereas LVEF was independently related to sysTR. RV ejection fraction (RVEF) was independently related to diasTR. LV global torsion performed well (AUC 0.71; 95% confidence interval [CI]: 0.61, 0.77) in discriminating transmural from non-transmural LGE in AL-CA patients. CONCLUSION: LV torsion mechanics derived by CMR-FT could help to monitor LV systolic and diastolic function in AL-CA patients and function as a new imaging marker for LV dysfunction and LGE transmurality.

Assessment of Autophagy in Tumor Cells of Human Skin Melanoma of Different Stages.

High levels of autophagy can increase the viability of tumor cells as well as their resistance to chemotherapy. Evaluation of the dynamics of autophagy processes at different stages of carcinogenesis can extend our understanding of melanoma pathogenesis to develop new therapeutic approaches. We performed a comparative study of tumor cell autophagy in stages II and III human skin melanoma. Tumor cells were characterized by high content of structures associated with autophagy (autophagosomes and autolysosomes). In stage III melanoma characterized by the presence of regional metastases in the lymph nodes, tumor cells showed higher expression of the autophagy marker protein LC3beta in comparison with stage II melanoma cells, which can indicate the involvement of autophagy processes in tumor progression and the formation of metastases in the lymph nodes.

The content and composition of organic compounds in the bottom sediments of the Norilsk-Pyasina water system one year after the accidental spill of diesel fuel.

One year after the emergency diesel fuel spill in Norilsk, hydrocarbon concentrations in bottom sediments of the Norilsk-Pyasina water system decreased. However the average concentrations of hydrocarbons in surface sediments decreased in the same sequence (µg/g) as in 2020: the mouth of the Ambarnaya R. (835, σ = 1788) > Bezymyanny Cr.-the Daldykan R.-the Ambarnaya R. (306, σ = 273) > the Pyasina R. (23, σ = 20) > the Pyasino Lake (12, σ = 8). Concentrations decreased due to degradation of low molecular weight hydrocarbons. The content of polycyclic aromatic hydrocarbons in 2021 also changed in a smaller range (0-1027 ng/g) than in 2020 (0-3865 ng/g). Petroleum origin of polycyclic aromatic hydrocarbons in the sediments of the Ambarnaya R. (including the mouth), Bezymyanny Cr. and the Daldykan R. is confirmed by the dominance of alkylated naphthalene homologues in their composition. Hydrocarbons accumulation in some layers of the sedimentary column is caused not only by the spill of diesel fuel, but also by the organic matter from the surrounding swamps, from wetlands and floodplain lakes, as well as by the burial of the surface layer by the 2021 flood.

[Endoscopic stenting for malignant pancreatobiliary strictures]. / Endoskopicheskoe stentirovanie pri opukholevykh strikturakh pankreatobiliarnoi zony.

OBJECTIVE: To improve the outcomes in patients with malignant obstructive jaundice using intraluminal stenting. MATERIAL AND METHODS: The present study included 62 patients with clinical symptoms of malignant obstructive jaundice. In the main group, we performed biliary stenting with self-expanding multi-perforated stents (Hanarostent Multi-hole Biliary). Microscopic perforations of these stents prevent migration and reduce the risk of blocking the cystic and main pancreatic ducts. In the control group, stenting was performed with fully and partially covered self-expanding stents. RESULTS: Lower incidence of obstructive cholecystitis and acute pancreatitis in the main group was associated with multiperforated stents reducing the risk of blocking the main pancreatic and cystic ducts. CONCLUSION: In our study, multiperforated stents excluded migration and reduced the incidence of complications (acute cholecystitis from 11.5 to 3.8%, acute pancreatitis from 15.3 to 7.7%).

[Inhibitory effect of Streptococcus mutans antisense vicK RNA regulating the cariogenicity of oral streptococci multi-species biofilm].

Objective: To investigate the regulative effects of Streptococcus mutans (Sm) antisense vicK RNA (ASvicK) on the multi-species biofilm formed by three common oral streptococci (Sm, Streptococcus sanguinis, and Streptococcus gordonii) (Sm+Ss+Sg). Methods: ASvicK over-expression strain was constructed by using a recombinant plasmid, and three-species biofilm UA159+Ss+Sg and ASvicK+Ss+Sg were cultured. The phenotypes of biofilms were detected by scanning electron microscopy (SEM). Crystal violet (CV) assay was used to detect biofilm biomass. Lactate kit and anthrone-sulfuric acid colorimetric assay were used to determine the abilities of lactic acid and exopolysaccharides production, respectively. The proportions of three-species and expression levels of the cariogenic-related genes in biofilms were detected by TaqMan fluorescence quantitative PCR and real-time fluorescence quantitative PCR. A biofilm demineralization model of human enamel slabs was further constructed, and the hardness of enamel surface was detected. Results: Compared to UA159+Ss+Sg, over-expression of ASvicK could inhibit biofilm formation and lactic acid production in ASvicK+Ss+Sg biofilm significantly decreased by 78.93% (P<0.001) and 62.23% (P<0.001), respectively. With ASvicK over-expression, the amounts of water-insoluble and-soluble glucoses in ASvicK+Ss+Sg biofilm were reduced respectively by 39.13% (P<0.001) and 68.00% (P<0.001). Compared to the UA159+Ss+Sg Group, the proportion of Sm, the cariogenic bacteria, showed 33.00% reduction (P<0.01) in Sm+Ss+Sg biofilm, and the gene expressions of cariogenic-relative genes vicK/X, gtfB/C/D, and ftf significantly decreased (P<0.05). The micro-hardness value of enamel slabs after demineralization by ASvicK+Ss+Sg biofilm was significantly increased to 183.84% (P<0.001). Conclusions: ASvicK over-expression could reduce the Sm proportion and weaken the cariogenicity of oral Streptococcus biofilm, thereby possibly slowing down the progression of caries.

Genomic and morphological characterization of a new Thiothrix species from a sulfide hot spring of the Zmeinaya bay (Northern Baikal, Russia).

A survey for bacteria of the genus Thiothrix indicated that they inhabited the area where the water of the Zmeiny geothermal spring (northern basin of Lake Baikal, Russia) mixed with the lake water. In the coastal zone of the lake oxygen (8.25 g/L) and hydrogen sulfide (up to 1 mg/L) were simultaneously present at sites of massive growth of these particular Thiothrix bacteria. Based on the analysis of the morphological characteristics and sequence of individual genes (16S rRNA, rpoB and tilS), we could not attribute the Thiothrix from Lake Baikal to any of the known species of this genus. To determine metabolic capabilities and phylogenetic position of the Thiothrix sp. from Lake Baikal, we analyzed their whole genome. Like all members of this genus, the bacteria from Lake Baikal were capable of organo-heterotrophic, chemolithoheterotrophic, and chemolithoautotrophic growth and differed from its closest relatives in the spectrum of nitrogen and sulfur cycle genes as well as in the indices of average nucleotide identity (ANI < 75-94%), amino acid identity (AAI < 94%) and in silico DNA-DNA hybridization (dDDH < 17-57%), which were below the boundary of interspecies differences, allowing us to identify them as novel candidate species.