Measuring the variability of local characteristics in complex networks: Empirical and analytical analysis.

We examine the dynamics for the average degree of a node's neighbors in complex networks. It is a Markov stochastic process, and at each moment of time, this quantity takes on its values in accordance with some probability distribution. We are interested in some characteristics of this distribution: its expectation and its variance, as well as its coefficient of variation. First, we look at several real communities to understand how these values change over time in social networks. The empirical analysis of the behavior of these quantities for real networks shows that the coefficient of variation remains at high level as the network grows. This means that the standard deviation and the mean degree of the neighbors are comparable. Then, we examine the evolution of these three quantities over time for networks obtained as simulations of one of the well-known varieties of the Barabási-Albert model, the growth model with nonlinear preferential attachment (NPA) and a fixed number of attached links at each iteration. We analytically show that the coefficient of variation for the average degree of a node's neighbors tends to zero in such networks (albeit very slowly). Thus, we establish that the behavior of the average degree of neighbors in Barabási-Albert networks differs from its behavior in real networks. In this regard, we propose a model based on the NPA mechanism with the rule of random number of edges added at each iteration in which the dynamics of the average degree of neighbors is comparable to its dynamics in real networks.

Effects of endogenous hypercortisolism on bone mRNA and microRNA expression in humans.

Hypercortisolism in humans suppresses osteoblastogenesis and osteoblast function through the upregulation of Wnt-signaling antagonists (sclerostin, Dkk1) and changes in microRNAs levels (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) which are associated with mesenchymal stem-cell commitment to adipocytes or cartilage cells over the osteoblasts. INTRODUCTION: The purpose of this study was to evaluate the responses of bone to chronic glucocorticoid (GC) excess by measuring the levels of selected mRNA and microRNA (miR) in bone samples of patients with Cushing's disease (CD). METHODS: Bone samples were obtained during transsphenoidal adenomectomy from the sphenoid bone (sella turcica) from 16 patients with clinically and biochemically evident CD and 10 patients with clinically non-functioning pituitary adenomas (NFPA) matched by sex, age, and body mass index. Quantitative polymerase chain reactions (qPCR) were used to examine the expression of genes (mRNA and miRs) known to be involved in bone remodeling regulation based on studies in animals and cell culture. RESULTS: Hypercortisolism was associated with the downregulation of genes involved in osteoblast function and maturation (ACP5, ALPL, BGLAP, COL1A1, COL1A2, BMP2, RUNX2, TWIST1). An excess of GC caused increased expression of Wnt-signaling antagonists (Dkk1, SOST) and changes in the levels of miRs that are known to suppress osteoblastogenesis (miR-125b-5p, miR-218-5p, miR-34a-5p, miR-188-3p, miR-199a-5p) p < 0.05, q < 0.1. Interestingly, compensatory mechanisms were found in long-term hypercortisolism: upregulation of Wnt10b, LRP5, and LRP6; downregulation of SFRP4; changes in miRs involved in osteoblastogenesis (miR-210-5p, miR-135a-5p, miR-211, miR-23a-3p, miR-204-5p); and downregulation of genes associated with osteoclastogenesis. None of these changes prevented the suppression of bone formation. CONCLUSIONS: An excess of endogenous GC in humans suppresses bone formation through the upregulation of Wnt-signaling antagonists and dysregulation of miRs involved in mesenchymal stem-cell commitment. Both Wnt-signaling antagonists and miRs seem to be promising targets for further research in therapeutic intervention in glucocorticoid-induced osteoporosis.

Radiation situation dynamics at the Andreeva Bay site for temporary storage of spent nuclear fuel and radioactive waste over the period 2002-2016.

The Coastal Technical Base (CTB) №569 at Andreeva Bay was established in the early 1960s and intended for the refueling of nuclear submarine reactors and temporary storage of spent nuclear fuel (SNF) and radioactive waste (RW). In 2001, the base was transferred to the Russian Ministry for Atomic Energy and the site remediation began. The paper describes in detail the radiation situation change at the technical site in Andreeva Bay from 2002-2016, the period of preparation for the most critical phase of remedial work: removal of spent fuel assemblies. The analysis of aggregated indicators and data mining were used. The article suggests the best number and location of checkpoints needed to ensure sufficient accuracy of the radiation situation description. The fractal properties of the radiation field are studied using the Hurst index. The relationship between checkpoints was assessed using the method of searching for checkpoint communities. The decrease in the integral of the ambient dose equivalent rate (ADER) at the technical site was evaluated by the method of time series decomposition. Three components of time series were identified: trend, seasonal and residual. The trend of the ADER integral over the technical site is a monotonic decreasing function, where the initial and final values differ tenfold. Taking into account that 137Cs dominates the radiation situation on-site, it is clear that the ADER due to the radionuclide decay will have decreased by 1.4 times. It is estimated that only a small proportion of 137Cs has migrated off-site. Therefore, approximately a sevenfold decrease in dose rate is mainly due to remediation activities of personnel. During the year, the seasonal component varies the ADER integral by a factor of two, due to snowfall. The residual component reflects the uncertainty of the ADER integral calculation and phases of active SNF and RW management. The methods developed are used to support the optimization of remediation work as well as regulatory supervision of occupational radiation protection.

The Differential Expression of Adhesion Molecule and Extracellular Matrix Genes in Mesenchymal Stromal Cells after Interaction with Cord Blood Hematopoietic Progenitors.

The dynamics of the expression of genes encoding adhesion molecules, molecules of the connective tissue matrix, and its remodeling enzymes was studied in multipotent mesenchymal stromal cells (MSCs) from human adipose tissue after interaction with cord blood hematopoietic progenitors (HSPCs). An upregulation of ICAM1 and VCAM1, directly proportional to the coculture time (24-72 h), was found. After 72 h of culturing, a downregulation of the genes encoding the majority of matrix molecules (SPP1; COL6A2,7A1; MMP1,3; TIMP1,3; and HAS1) and cell-matrix adhesion molecules (ITGs) was revealed. The detected changes may ensure the realization of the stromal MSC function due to improvement of adhesion and transmigration of HSPCs into the subcellular space.

Quantitative target proteomics of chromosome 13 human blood plasma proteins.

Quantitative proteomic analysis of 50 blood plasma samples of healthy volunteers who underwent a comprehensive medical examination and were found eligible for space flights was performed. As a result of directed mass spectrometric analysis, signals for 128 proteins, which accounted for nearly 40% of the total number of chromosome 13 gene products, were detected. The analysis of interindividual variation of concentrations of chromosome 13 proteins showed the presence of a pool comprising 41 proteins with a low variation (CV < 30%), which can potentially be used as biomarkers.

[Increase of reparative potential of fabrics in sugar diabetes]. / Povyshenie reparativnogo potentsiala tkanei pri sakharnom diabete.

AIM: The purpose of the study was to study the effectiveness of the domestic drug Remaxol in reparative processes of laparotomic wound tissues in acute surgical abdominal pathology in patients with diabetes mellitus. MATERIAL AND METHODS: Clinical and laboratory studies were performed in 86 patients with acute surgical pathology of the abdominal cavity, 56 patients with type 1 diabetes mellitus, including 26 patients who received Remaxol in the early postoperative period (daily intravenous infusions of 400.0 ml for 5 days). RESULTS: It was established that diabetes mellitus is an important aggravating factor in the reparative process of tissue structures of a laparotomic wound. Undoubtedly, a significant factor in reducing the reparative potential of tissues is a significant activation of factors leading to membrane-destabilizing phenomena - oxidative stress, activation of phospholipases, hypoxia. The inclusion of Remaxol, which has antioxidant and antihypoxic effects, allows to significantly correct these pathogenetic components, which is the basis for optimization of the reparative process against the background of diabetes mellitus. There was a significant decrease in wound complications in the early postoperative period, a significant reduction in the stay of patients in the hospital.

Circulating microRNAs.

The detection of miRNAs in plasma and other body fluids opened up a fascinating possibility that animal noncoding RNAs can act as extracellular signaling molecules. In this review, we discuss recent progress in the field including the ability of miRNAs to participate in intercellular communication in vitro and in vivo, and the application of circulating miRNAs as diagnostic markers of a wide range of diseases. Special attention is paid to the relevance of the development and unification of current techniques for isolation of circulating miRNAs.

[Multiple endocrine neoplasia type 1 syndrome with three classical components and chiasm glioma: specific features of target organ lesions and a clinical observation].

The article briefly reviews the specific features of target-organ lesions in multiple endocrine neoplasia type 1 (MEN1) syndrome and a clinical case of genetically confirmed MEN1 syndrome in a young female patient. Despite the relative rarity of this disease, timely diagnosis, treatment and screening for its main components are very important for the overall prognosis of patients with MEN1 and their first-degree relatives who are MEN1 gene mutation carriers. The described case is noteworthy for a number of specific features. The authors could find no account of optic chiasm glioma within the framework of MEN1 in the literature. Moreover, therapy-resistant somatoprolactinoma engages attention, which points to its aggressive nature with pituitary adenoma that is not been clearly visualized on magnetic resonance imaging. Of interest is the order of detection of neoplasms, in particular the manifestation of hypoglycemic episodes as a sign of organic hyperinsulinism. which have been initially regarded as epileptic seizures, after the use of sustained-release somatostatin analogues for the treatment of acromegaly.

Nonthermal plasma affects viability and morphology of Mycoplasma hominis and Acholeplasma laidlawii.

AIM: To study the effects exerted by argon microwave nonthermal plasma (NTP) on cell wall-lacking Mollicutes bacteria. METHODS AND RESULTS: 10(8) CFU ml(-1) agar plated Mycoplasma hominis and Acholeplasma laidlawii were treated with the nonthermal microwave argon plasma for 30-300 s. The maximal 10- and 100-fold drop was observed for A. laidlawii and Myc. hominis, respectively. Similarly treated Escherichia coli and Staphylococcus aureus demonstrated the 10(5) and 10(3) drop, respectively. Removal of cholesterol affected resistance of A. laidlawii. 10 mmol l(-1) antioxidant butylated hydroxytoluene decreased mortality by a factor of 25-200. UV radiation alone caused 25-85% mortality in comparison with the whole NTP. Exogenously added hydrogen peroxide H2O2 did not cause mortality. NTP treatment of Myc. hominis triggered growth of microcolonies, which were several tenfold smaller than a typical colony. CONCLUSIONS: Despite the lack of cell wall, A. laidlawii and Myc. hominis were more resistant to argon microwave NTP than other tested bacteria. Mycoplasma hominis formed microcolonies upon NTP treatment. A role of UV and active species was demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: The first study of NTP effects on Mollicutes revealed importance of a membrane composition for bacterial resistance to NTP. New specific Myc. hominis morphological forms were observed. The study confirmed importance of the concerted action of reactive oxygen species (ROS) with UV and other plasma bioactive agents for NTP bactericidal action.

[The BION-M1 project: overview and first results].

Biosatellite BION-M1 was launched on April 19 and landed on May 19, 2013. The mission program was largely a continuation of the earlier flown 11 BION projects, FOTON-M2 and FOTON-M3. The biosatellite was inhabited by a great variety of living organisms used for experiments and studies in gravitational physiology, gravitational biology, biotechnology, astrobiology and radiation biology, dosimetry and spectrometry. This was the first time in the history of national biology and physiology when male mice C57bl/6 were chosen for a long-term space experiment focused upon molecular biology investigations. Unfortunately, because of technical failures during the flight a part of the animals were lost. However, the major objectives were attained through reconsideration of biomaterial division among investigators and completion of virtually the total scope of investigations.

The loss of ions from Venus through the plasma wake.

Venus, unlike Earth, is an extremely dry planet although both began with similar masses, distances from the Sun, and presumably water inventories. The high deuterium-to-hydrogen ratio in the venusian atmosphere relative to Earth's also indicates that the atmosphere has undergone significantly different evolution over the age of the Solar System. Present-day thermal escape is low for all atmospheric species. However, hydrogen can escape by means of collisions with hot atoms from ionospheric photochemistry, and although the bulk of O and O2 are gravitationally bound, heavy ions have been observed to escape through interaction with the solar wind. Nevertheless, their relative rates of escape, spatial distribution, and composition could not be determined from these previous measurements. Here we report Venus Express measurements showing that the dominant escaping ions are O+, He+ and H+. The escaping ions leave Venus through the plasma sheet (a central portion of the plasma wake) and in a boundary layer of the induced magnetosphere. The escape rate ratios are Q(H+)/Q(O+) = 1.9; Q(He+)/Q(O+) = 0.07. The first of these implies that the escape of H+ and O+, together with the estimated escape of neutral hydrogen and oxygen, currently takes place near the stoichometric ratio corresponding to water.

New functions of small nucleolar RNAs.

Small nucleolar RNAs (snoRNAs) are one of the most abundant and well-studied groups of non-coding RNAs. snoRNAs are mostly engaged in processing of rRNA. However, recent data indicate that snoRNAs are also involved in other processes including regulation of alternative splicing, translation and oxidative stress. snoRNAs are also involved in pathogenesis of some hereditary diseases and cancer. Therefore, the range of snoRNAs' functions is significantly wider than it has been assumed earlier.

Complete coverage of the Schizosaccharomyces pombe genome in yeast artificial chromosomes.

The genome of the fission yeast, Schizosaccharomyces pombe, consists of some 14 million base pairs of DNA contained in three chromosomes. On account of its excellent genetics we used it as a test system for a strategy designed to map mammalian chromosomes and genomes. Data obtained from hybridization fingerprinting established an ordered library of 1,248 yeast artificial chromosome clones with an average size of 535 kilobases. The clones fall into three contigs completely representing the three chromosomes of the organism. This work provides a high resolution physical and clone map of the genome, which has been related to available genetic and physical map information.

[Diagnosis and new treatment options for pituitary adenomas].

Currently, the treatment of pituitary adenomas is inextricably linked with transsphenoidal neurosurgical intervention. Modern technologies used in surgery for this pituitary pathology, such as endoscopy using angled optics, as well as the use of specialized instruments, sealing and hemostatic materials, increase the effectiveness of surgical treatment of pituitary adenomas and reduce the incidence of intraand postoperative complications. The development of radiation methods of diagnostics, such as MRI, makes it possible to more accurately identify the formation of the pituitary gland, assess its size, direction of growth, and the degree of invasion of surrounding tissues. The authors of the article described in detail the modern technique of transsphenoidal removal of pituitary adenoma using an endoscope. Each stage of the operation is described step by step, taking into account various anatomical features and illustrated. This article discusses the MRI characteristics of pituitary adenomas: size of the tumor, the direction of its growth, the degree of invasion of the cavernous sinuses, the compression effect on the structures of the chiasmal-sellar region. The use of treatment methods, knowledge of the features of MRI diagnostics described in this article greatly increase the effectiveness of the treatment of patients with pituitary adenomas and reduce the risk of complications after neurosurgical intervention in such patients.

[Cyclic Cushing's syndrome: difficulties of diagnostic search and choice of treatment tactics. A clinical case].

Cyclic Cushing's syndrome is a pathological condition characterized by alternating periods of excessive cortisol secretion with corresponding clinical manifestations and periods of spontaneous remission of the disease.To diagnose Cyclic Cushing's syndrome it is necessary to record at least three episodes of excessive cortisol secretion alternating with periods of normalization of its production.In most cases, this pathology is diagnosed in patients with ACTH-secreting pituitary tumor, however, there are rare cases of cyclic hypercorticism with ectopic ACTH secretion by tumors of different localization and without verification of pathological hormonal secretion focus. In addition, cyclic hyperproduction of cortisol can be also observed in ACTH-independent Cushing's syndrome associated with the presence of corticosteroma or adrenal hyperplasia. The exact causes and mechanisms of the cyclic hypercorticism are currently insufficiently studied.Due to the atypical course of the disease, the unpredictability of the occurrence of a new «cycle¼, the variability of its duration and manifestations (not only in different patients, but also in the same patient), verification of the diagnosis and determination of treatment tactics may be difficult in the daily practice of specialists, and the prevalence of this condition can be undervalued.

[Thyrotropin-secreting pituitary adenomas: clinical features and results of treatment in 45 patients].

BACKGROUND: Thyrotropin-secreting pituitary adenomas (TSH-PA) are a rare cause of thyrotoxicosis and account for 0.5-2% of all pituitary adenomas. Taking into account the rarity of the disease, it is extremely important to analyze each case of TSH-PA. AIM: To analyze the clinical characteristics and treatment outcomes of patients with TSH-PA, as well as to determine preoperative and early postoperative factors that predict long-term remission. MATERIALS AND METHODS: In a single-center retrospective study we analyzed clinical signs, laboratory and instrumental studies, as well as the treatment outcomes of patients with TSH-PA from 2010 to 2023. Preoperative factors, as well as TSH level measured on day 3 postoperatively, were evaluated for their ability to predict long-term remission when comparing groups of patients with and without remission. RESULTS: The study included 45 patients with TSH-PA (14 men, 31 women), with a median age of 45 years [30; 57]. The most common clinical manifestations of TSH-PA were: cardiac arrhythmia in 37 (82.2%) patients, thyroid pathology in 27 (60%), neurological disorders in 24 (53.35%). Most PAs were macroadenomas (n=35, 77.8%). Preoperatively, 28 (77.8%) patients received somatostatin analogs, and 20 (71.4%) patients were euthyroid at the time of surgery. Surgical treatment was performed in 36 (80%) patients, postoperative remission was achieved in 31 cases (86.1%). Administration of somatostatin analogues to patients with no remission/relapse after surgery lead to the remission in 100% of cases (4/4). A 1 mm increase in PA size raised the odds of recurrence/no remission by 1.15-fold,and PA invasion during surgery - by  5.129 fold. A TSH level on day 3 postoperatively above 0.391 mIU/L (AUC, 0.952; 95% CI 0.873-1.000; standard error 0.04; p<0.001) identifies patients with relapse/absence of remission after surgical treatment (sensitivity = 100%, specificity = 88.9%). CONCLUSION: The TSH-PA in the structure of PAs is extremely rare, and as a result, most of them are misdiagnosed and detected already at the stage of macroadenoma. The most effective method of treatment is transnasal transsphenoidal adenomectomy. Somatostatin analogues can be used as second-line therapy if surgical treatment is ineffective. We have proposed a possible model for postoperative TSH levels (>0.391 mU/l) to predict recurrence of TSH-PA, which requires validation on an expanded number of cases.

[Clinical features, diagnostics and treatment of FGF23 secreting tumors: series of 40 clinical cases].

INTRODUCTION: Tumor-induced osteomalacia is an acquired rare disease manifested by hypophosphatemic osteomalacia due to excessive secretion of fibroblast growth factor 23 (FGF23). FGF 23 is a non-classical hormone secreted by bone tissue (osteocytes) and regulates phosphorus metabolism.The aim of this work is to present clinical experience in the diagnosis, treatment and rehabilitation of patients with tumor-induced osteomalacia. MATERIALS AND METHODS: 40 patients with clinically-confirmed tumor-induced osteomalacia were included in the study, 34 of whom had the tumor localized, 27 underwent surgical treatment and 21 achieved stable remission. RESULTS: The median age was 48 [41; 63] years, 43% were men, the time left from the the onset of the disease was 8 [4; 10] years. Biochemical findings were hypophosphatemia 0.47 [0.4; 0.53] mmol/l, a decrease in the tubular reabsorption phosphate 62 [52; 67]%, and an increase in alkaline phosphatase of 183 [112; 294] units/l. At the time of diagnosis, 100% had multiple pathological fractures, only 10% could move independently, and 77.5% classified the pain as unbearable (8-10 points according to the 10-point pain syndrome scale ). Among the methods used to detect tumors, the most sensitive were scintigraphy with tectrotide with SPECT/CT 71.4% (20/28) and MRI 90% (18/20). In 35% of cases, the tumor was localized in soft tissues and in 65% in bone tissue; The tumor was most often detected in the lower extremities, followed by the head in frequency of localization. 18 patients currently have no remission and they receive conservative treatment (phosphorus and alfacalcidol n=15 and burosumab n=3). In case of achieving remission (n=21), regression of clinical symptoms and restoration of bone and muscle mass was observed. Extensive excision of the tumor without prior biopsy resulted in the best percentage of remission - 87%. CONCLUSION: Tumor-induced osteomalacia is characterized by severe damage to bone and muscle tissue with the development of multiple fractures, muscle weakness and severe pain syndrome. In laboratory diagnostics, attention should be paid to hypophosphatemia, a decrease in the tubular reabsorption phosphate index and increased alkaline phosphatase. The use of functional diagnostic methods with a labeled somatostatin analogue to the subtype 2 receptor and MRI with contrast enhancement are the most accurate methods of topical diagnostics. In case of localization of the tumor, a wide excision without a preliminary biopsy is recommended.

[Short-term and long-term remission after endoscopic transnasal adenomectomy in patients with acromegaly].

BACKGROUND: Neurosurgery is the most effective treatment for acromegaly. As most of the patients present with macroadenomas, surgical treatment is not always successful, even with the expert level of a neurosurgeon. Assessment of the postoperative remission rates in acromegaly preoperative predictors of treatment efficacy is an urgent task of modern research. AIM: To assess the short-term and long-term remission of acromegaly after endoscopic transnasal adenomectomy in a tertiary medical center and assess preoperative predictors of the treatment effectiveness. MATERIALS AND METHODS: A single-center, prospective, uncontrolled study was conducted. We included patients with active acromegaly who did not receive medical therapy with somatostatin analogues and were referred for endoscopic transsphenoidal adenomectomy. Plasma miRNA expression was assessed by quantitative reverse transcription PCR. Postoperative samples of adenomas were sent for study, with the determination of the immunohistochemical staining for somatostatin receptors 2 and 5 subtypes and morphology was performed on postoperative adenoma samples. RESULTS: The study included 44 patients: 32.8% men, median age 47.0 [34.0; 55.0], IGF-1 744.75 ng/ml [548.83;889.85], growth hormone 9.5 ng/ml [4.94; 17.07]. Tumor volume 832 mm3 [419.25; 2532.38]. Early postoperative remission was achieved in 35 patients (79.5%). Patients who achieved short-term remission had higher IGF-1 and basal growth hormone levels. Median follow-up was 19.0 months [12.5;29.0]. Long-term remission was achieved in 61.4% (27 patients), no remission in 9 (20.5%), recurrency in 2 patients (4.5%), 6 patients were to follow-up (13.6%). In patients with long-term remission, we observed lower growth hormone and IGF-1 levels. No differences in miRNA expression was observesd. The predictive value of basal GH before surgery for long-term remission was assessed: area under the curve 0.811 (95% CI: 0.649; 0.973). A cut-off value of 15.55 ng/mL corresponded to a sensitivity of 70.0% (34.8%; 93.3%), a specificity of 85.7% (67.3%; 96.0%), an accuracy of 81.6% (65 .7%; 92.3%), PPV 63.6% (39.3%; 82.5%), NPV 88.9% (75.4%; 95.4%). CONCLUSION: Rates of short-term and long-term remission after endoscopic transsphenoidal adenomectomy in our cohort is 79,5% и 61,4%, respectively, and is comparable with literature data for expert pituitary centers. Preoperative GH shows potential value in predicting the long-term remission of acromegaly, but further studies in a larger sample are needed to obtain more accurate cut-off values.

Molecular Mechanisms of Muscle Tone Impairment under Conditions of Real and Simulated Space Flight.

Kozlovskaya et al. [1] and Grigoriev et al. [2] showed that enormous loss of muscle stiffness (atonia) develops in humans under true (space flight) and simulated microgravity conditions as early as after the first days of exposure. This phenomenon is attributed to the inactivation of slow motor units and called reflectory atonia. However, a lot of evidence indicating that even isolated muscle or a single fiber possesses substantial stiffness was published at the end of the 20th century. This intrinsic stiffness is determined by the active component, i.e. the ability to form actin-myosin cross-bridges during muscle stretch and contraction, as well as by cytoskeletal and extracellular matrix proteins, capable of resisting muscle stretch. The main facts on intrinsic muscle stiffness under conditions of gravitational unloading are considered in this review. The data obtained in studies of humans under dry immersion and rodent hindlimb suspension is analyzed. The results and hypotheses regarding reduced probability of cross-bridge formation in an atrophying muscle due to increased interfilament spacing are described. The evidence of cytoskeletal protein (titin, nebulin, etc.) degradation during gravitational unloading is also discussed. The possible mechanisms underlying structural changes in skeletal muscle collagen and its role in reducing intrinsic muscle stiffness are presented. The molecular mechanisms of changes in intrinsic stiffness during space flight and simulated microgravity are reviewed.