[Machine learning methods in differential diagnosis of ACTH-dependent hypercortisolism].

AIM: To develop a noninvasive method of differential diagnosis of ACTH-dependent hypercortisolism, as well as to evaluate the effectiveness of an optimal algorithm for predicting the probability of ectopic ACTH syndrome (EAS) obtained using machine learning methods based on the analysis of clinical data. MATERIALS AND METHODS: As part of a single-center, one-stage, cohort study, a retrospective prediction of the probability of EAS among patients with ACTH-dependent hypercortisolism was carried out. Patients were randomly stratified into 2 samples: training (80%) and test (20%). Eleven machine learning algorithms were used to develop predictive models: Linear Discriminant Analysis, Logistic Regression, elastic network (GLMNET), Support Vector machine (SVM Radial), k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM). RESULTS: The study included 223 patients (163 women, 60 men) with ACTH-dependent hypercortisolism, of which 175 patients with Cushing's disease (CD), 48 - with EAS. As a result of preliminary data processing and selection of the most informative signs, the final variables for the classification and prediction of EAS were selected: ACTH level at 08:00 hours, potassium level (the minimum value of potassium in the active stage of the disease), 24-h urinary free cortisol, late-night serum cortisol, late-night salivary cortisol, the largest size of pituitary adenoma according to MRI of the brain. The best predictive ability in a training sample of all trained machine learning models for all three final metrics (ROC-AUC (0.867), sensitivity (90%), specificity (56.4%)) demonstrated a model of gradient boosting (Generalized Boosted Modeling, GBM). In the test sample, the AUC, sensitivity and specificity of the model in predicting EAS were 0.920; 77.8% and 97.1%, respectively. CONCLUSION: The prognostic model based on machine learning methods makes it possible to differentiate patients with EAS and CD based on basic clinical results and can be used as a primary screening of patients with ACTH-dependent hypercortisolism.

Effects of Chromatin Structure Modifiers on the trans-Acting Heterochromatin Position Effect in Drosophila melanogaster.

The heterochromatin position effect is manifested in the inactivation of euchromatin genes transferred to heterochromatin. In chromosomal rearrangements, genes located near the new eu-heterochromatin boundary in the rearrangement (cis-inactivation) and, in rare cases, genes of a region of the normal chromosome homologous to the region of the eu-heterochromatin boundary of the chromosome with the rearrangement (trans-inactivation) are subject to inactivation. The In(2)A4 inversion is able to trans-inactivate the UAS-eGFP reporter gene located on the normal chromosome. We knockdown a number of chromatin proteins using temperature-controlled RNA interference and investigated the effect of knockdown on trans-inactivation of the reporter. We found suppression of trans-inactivation by knockdowns of Su(var)2-HP2, a protein that binds to the key heterochromatin protein HP1a, SAYP, a subunit of the chromatin remodelling complex, and Eggless histone methyltransferase (SETDB1), which introduces a H3K9me3 histone mark, recognized by the HP1a protein. The method of studying the effects of gene knockdown on heterochromatin position effects presented in this work is of independent methodological interest.

Temporal and spatial dynamics of arthropod groups in terrestrial subsurface habitats in central Portugal.

The mesovoid shallow substratum (MSS) can act as a climatic refuge for invertebrates, as a biogeographic corridor to deeper substrates or as a permanent habitat for some species. This study characterizes the seasonal invertebrate diversity and abundance of MSS ecosystems in central Portugal focusing on Diplopoda, Diplura, Orthoptera and Coleoptera during one year. Sampling was performed with standard MSS pitfalls in scree slopes (colluvial MSS) of karst areas and environmental parameters (temperature, pH, conductivity, water content, organic carbon, nitrate, phosphate and ammonium) were quantified. Our results show that winter was the season with the highest arthropod abundance and that the MSS acts as a permanent habitat for chordeumatidan millipedes and as a climatic refuge for orthopterans and most beetles. All Diplura collected belong to a single species known previously from surface habitats in the Iberian Peninsula, which does not seem to use the Portuguese MSS as a refuge. MSS habitats in central Portugal, classified as western Mediterranean and thermophile deposits protected by the Natura 2000 network based on plant communities and geology, revealed an abundant and diverse invertebrate community that urges characterization and protection.

High Level of Gene Transcription at the Embryonic Stage Leads to the Suppression of Heterochromatic Trans-Inactivation in Drosophila melanogaster Adults.

In some cases, gene transfer from euchromatin to constitutive heterochromatin as a result of chromosomal rearrangement is accompanied by epigenetic inactivation of this gene (cis-inactivation). In the case of trans-inactivation, transgenes in the normal chromosome are repressed by the cis-inactivation-causing rearranged homologous chromosome. Trans-inactivation is a result of the somatic pairing of homologs and the transfer of the normal chromosomal segment to the heterochromatic compartment of the nucleus. Previously, we have shown that the degree of trans-inactivation of the UAS-eGFP reporter gene in adult flies depends on its transcription level that can be regulated by temperature using the GAL4 transcription activator and its temperature-sensitive inhibitor GAL80ts. In this paper, we investigated the epigenetic inheritance of the active/repressed state of the trans-inactivated reporter gene at different expression levels by measuring eGFP fluorescence in the individual cells of Malpighian tubules in adult flies. High expression levels at the embryonic stage protected the eGFP gene from trans-inactivation in adult flies. The activated state was inherited over the entire period of development and differentiation, while the activating effect of GAL4 was turned off.

Characteristics of miniature pulsed penning ion source: Experiment and PIC simulation.

In the present work, the results of the experimental and particle in cell (PIC) simulation studies of the discharge combustion modes in a miniature Penning ion source (PIS) under the pulse-periodic power supply conditions are presented. Dynamics of discharge ignition and discharge operation mode at a pulsed anode voltage supply are investigated for different values of anode voltage and gas pressure in various magnetic field configurations. Typical examples of current pulse waveforms are shown. Also, numerical simulations of the PIS were performed using 3D PIC combined with Monte Carlo collisions in the code VSim. Temporal dependencies of electron, ion, and potential distributions in the Penning cell are simulated. Differences between the numerical and experimental results are discussed.

Regulated Gene Expression as a Tool for Analysis of Heterochromatin Position Effect in Drosophila.

Position effect variegation (PEV) is a perturbation of genes expression resulting from the changes in their chromatin organization due to the abnormal juxtaposition with heterochromatin. The exact molecular mechanisms of PEV remain enigmatic in spite of the long history of PEV studies. Here, we developed a genetic model consisting of PEV-inducing chromosome rearrangement and a reporter gene under control of the UAS regulatory element. Expression of the reporter gene could be regulated by adjustment of the GAL4 transactivator activity. Two UAS-based systems of expression control were tested - with thermosensitive GAL4 repressor GAL80ts and GAL4-based artificial transactivator GeneSwitch. Both systems were able to regulate the expression of the UAS-controlled reporter gene over a wide range, but GAL80ts repressed the reporter gene more efficiently. Measurements of the heterochromatin-mediated repression of the reporter gene in the GAL4+GAL80ts system point to the existence of a threshold level of expression, above which no PEV is observed.

Quality of life for up to 18 months after low-energy hip, vertebral, and distal forearm fractures-results from the ICUROS.

This study used data from the International Costs and Utilities Related to Osteoporotic fractures Study (ICUROS) to estimate the quality of life (QoL) impact of fracture. Hip, vertebral, and distal forearm fractures incur substantial QoL losses. Hip and vertebral fracture results in markedly impaired QoL for at least 18 months. INTRODUCTION: The International Costs and Utilities Related to Osteoporotic fractures Study (ICUROS) is a multinational observational study that aims to describe costs and quality of life (QoL) consequences of osteoporotic fractures. To date, 11 countries have participated in the study: Australia, Austria, Estonia, France, Italy, Lithuania, Mexico, Russia, Spain, the UK, and the USA. The objective of this paper is to describe the QoL impact of hip, vertebral, and distal forearm fracture. METHODS: Data were collected at four time-points for five QoL point estimates: within 2 weeks after fracture (including pre-fracture recall) and at 4, 12, and 18 months after fracture. Quality of life was measured as health state utility values (HSUVs) derived from the EQ-5D-3L. Complete case analysis was conducted as the base case with available case and multiple imputation performed as sensitivity analyses. Multivariate analysis was performed to explore predictors of QoL impact of fracture. RESULTS: Among 5456 patients enrolled using convenience sampling, 3021 patients were eligible for the base case analysis (1415 hip, 1047 distal forearm, and 559 vertebral fractures). The mean (SD) difference between HSUV before and after fracture for hip, vertebral, and distal forearm fracture was estimated at 0.89 (0.40), 0.67 (0.45), and 0.48 (0.34), respectively (p < 0.001 for all fracture types). Eighteen months after fracture, mean HSUVs were lower than before the fracture in patients with hip fracture (0.66 vs. 0.77 p < 0.001) and vertebral fracture (0.70 vs. 0.83 p < 0.001). Hospitalization and higher recalled pre-fracture QoL were associated with increased QoL impact for all fracture types. CONCLUSIONS: Hip, vertebral, and distal forearm fractures incur substantial loss in QoL and for patients with hip or vertebral fracture, QoL is markedly impaired for at least 18 months.

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.

[THE COMPARISON OF RESULTS OF DETECTION OF MINIMAL RESIDUAL DISEASE IN PERIPHERAL BLOOD AND MARROW IN CHILDREN OF THE FIRST YEAR OF LIFE WITH ACUTE LYMPHOBLASTIC LEUCOSIS].

The occurrence of minimal residual disease is an important prognostic factor under acute lymphoblastic leucosis in children and adults. In overwhelming majority of research studies bone marrow is used to detect minimal residual disease. The comparative characteristic of detection of minimal residual disease in peripheral blood and bone marrow was carried out. The prognostic role of occurrence of minimal residual disease in peripheral blood and bone marrow under therapy according protocol MLL-Baby was evaluated. The analysis embraced 142 pair samples from 53 patients with acute lymphoblastic leucosis and various displacements of gene MLL younger than 365 days. The minimal residual disease was detected by force of identification of chimeric transcripts using polymerase chain reaction in real-time mode in 7 sequential points of observation established by protocol of therapy. The comparability of results of qualitative detection of minimal residual disease in bone marrow and peripheral blood amounted to 84.5%. At that, in all 22 (15.5%) discordant samples minimal residual disease was detected only in bone marrow. Despite of high level of comparability of results of detection of minimal residual disease in peripheral blood and bone marrow the occurrence of minimal residual disease in peripheral blood at various stages of therapy demonstrated no independent prognostic significance. The established differences had no relationship with sensitivity of method determined by value of absolute expression of gene ABL. Most likely, these differences reflected real distribution of tumor cells. The results of study demonstrated that application of peripheral blood instead of bone marrow for monitoring of minimal residual disease under acute lymphoblastic leucosis in children of first year of life is inappropriate. At the same time, retention of minimal residual disease in TH4 in bone marrow was an independent and prognostic unfavorable factor under therapy of acute lymphoblastic leucosis of children of first year of life according protocol MLL-Baby (OO=7.326, confidence interval 2.378-22.565).

[Prognostic value of bone marrow lesions in children with neuroblastoma detected by flow cytometry].

The purpose of the study was to evaluate the prognostic value of the detection of tumor cells in the bone marrow (BM) in children with neuroblastoma (NB) by flow cytometry. The detection of tumor cells was performed in BM of 51 patients with NB (24 boys and 27 girls) aged from 6 days to 15 years (median--1 year 3 months). Flow cytometry allowed determining NB cells in BM in a much larger number of cases than cytomorphology (49.0% and 29.4% of patients, respectively). Patients, in whom NB cells were not detected in BM by flow cytometry, had significantly better event-free and overall survival rates as well as progression free survival (83.5%, 87.7% and 86,8%, respectively) compared with those in whom immunophenotyping revealed the tumor cells (28.0%, 35.87% and 34,3%, respectively). The prognostic value of the detection of BM lesion by flow cytometry was also confirmed in selected groups of patients with other criteria of stratification. Therefore the detection of tumor cells in BM by flow cytometry could potentially be considered in conjunction with other factors in choosing treatment strategy in patients with NB.

Serum extracellular secreted antagonists of the canonical Wnt/ß-catenin signaling pathway in patients with Cushing's syndrome.

UNLABELLED: Patients with endogenous hypercortisolism have higher sclerostin, but do not differ in Dickkopf 1 (Dkk1) or secreted frizzled-related protein 1 (SFRP1) levels as compared to healthy control. INTRODUCTION: Endogenous Cushing's syndrome (CS), usually affecting young and otherwise healthy patients, is a good model to validate the effects of supraphysiological levels of glucocorticoids in humans. This study evaluates circulating levels of extracellular antagonists of the Wnt/ß-catenin signaling pathway (sclerostin, Dkk1, SFRP1) in patients with CS versus healthy individuals. METHODS: Forty patients with clinically and biochemically evident CS and 40 sex-, age-, and body mass index-matched healthy subjects provided fasting serum samples for sclerostin, SFRP1 and Dkk1, along with bone turnover markers. RESULTS: Patients with CS had higher sclerostin levels (34.5 (30.3-37.1) pmol/L) versus healthy individuals (29.9 (24.3-36.8) pmol/L) (p = 0.032). Differences in sclerostin were due to the lack of lower sclerostin values rather than an increase in protein levels above the upper limits of the healthy control. The odds of sclerostin levels being higher than 30 pmol/L were greater in patients with CS as compared with the odds in healthy subjects (odds ratio = 3.81 95 % confidence interval 1.45-10.02) (p = 0.01). It coexisted with suppressed bone formation and unchanged bone resorption markers. Dkk1, SFRP1 did not differ from the control group. CONCLUSIONS: Of all the tested proteins (sclerostin, Dkk1, SFRP1), only sclerostin showed a significant difference when contrasting CS with healthy subjects. Hypercortisolism might prevent the down-regulation of sclerostin. Targeting sclerostin seems to be a promising therapeutic approach to treating osteoporosis in patients with CS.

Revision of the rove beetle genus Antimerus (Coleoptera, Staphylinidae, Staphylininae), a puzzling endemic Australian lineage of the tribe Staphylinini.

The genus Antimerus Fauvel, 1878, endemic to eastern Australia and Tasmania and a phylogenetically enigmatic member of the large rove beetle tribe Staphylinini, is revised. The genus and each of its four previously known species are redescribed, and a lectotype is designated for Antimerus punctipennis Lea, 1906. Five species are described as new: Antimerus metallicussp. n., Antimerus jamesrodmanisp. n., Antimerus gracilissp. n., Antimerus bellussp. n. and Antimerus monteithisp. n., so that the number of known species in this genus now totals nine. For the first time Antimerus larvae are described, tentatively identified as Antimerus smaragdinus Fauvel, 1878, Antimerus punctipennis and Antimerus metallicus. Available distributional and bionomic data are provided for each species and summarized in the discussion. Adult and larval morphology of Antimerus and its distribution patterns are discussed in the broader context of new data on the evolution of the entire tribe Staphylinini, and with respect to the formation of the Australian fauna of this tribe. The phylogenetic position of Antimerus within Staphylinini remains unresolved pending a targeted formal study. However, a majority of currently available data suggests that it could be a basal member of the recently recovered monophyletic clade of Staphylinini tentatively called "Staphylinini propria".

Robustness of a neural network model for differencing.

A neural network, originally proposed as a model for nuclei in the auditory brainstem, uses gradients of cell thresholds to reliably compute the difference of inputs over wide input ranges. The encoding of difference is linear even though the individual components of the network are finite, saturating, nonlinear devices highly dependent on input level. Theorems are proven that explain the linear dependence of network output on difference and that show the robustness of the network to perturbations of the threshold gradients. There is some evidence that the network exists in the neural tissue of the auditory brainstem.