Maternal uniparental disomy of chromosome 21 as a cause of pseudo-exclusion from paternity.

Uniparental disomy (UPD) is a rare chromosomal condition, which apart from its importance in medical genetics can affect an outcome of parentage DNA testing, often causing pseudo exclusions. We describe a case of trio paternity test using 24 informative STR loci with potential exclusion at 2 systems located on chromosome 21. Consequent genotyping of an additional 25 autosomal and 27 Y-specific STRs revealed one other inconsistency, also located on this chromosome. All three inconsistent markers had the same heteroallelic state between the child and the biological mother providing evidence for maternal heterodisomy of chromosome 21. The case highlights the importance of considering UPD as a cause of genetic inconsistencies, especially when the inconsistent marker systems are located on the same chromosome.

Paternity pseudo-exclusion caused by tetragametic chimerism in a gestational surrogacy case.

Chimerism is a condition when an organism is composed of two or more populations of genetically distinct cells. Chimerism often produces curious results of medical and genetic investigations and could be a major cause of false negative conclusions in parentage testing. Here we describe a paternity pseudo-exclusion due to tetragametic chimerism in a gestational surrogacy case originated in a fertility clinic. Initial analysis using a buccal swab from the child and a peripheral blood sample from the father showed paternity exclusion at 6 STR loci. To find out the reason for observed paternal discrepancy father's semen sample used for IVF and samples from other tissues were genotyped. Buccal swabs, semen, hair follicles, nail clippings and cerumen showed identical mixed autosomal STR profiles originated from two genetically different cell lines and for all the 24 informative loci contain paternal obligate alleles. Results of Y-STR profiling of all paternal sample types showed a DNA profile originated from a single man. The mixed profiles obtained for different tissue types suggest that two genetically different cell lines contributed to formation of both the endoderm and the ectoderm of the father. The mesoderm seems to be monoclonal having originated from a genetically homogenous cell line as evidenced by the STR profile of peripheral blood. Such allelic pattern for various tissues suggests that the clonal origin happened at the very early stage of embryonic development. Approaches to minimise the rate of false exclusions in DNA parentage tests due to chimerism are discussed.

Genetic diversity and forensic parameters of autosomal STR markers included PowerPlex® CS7 panel in the general population of the Russian Federation.

PowerPlex® CS7 multiplex is commonly used as a source of supplementary markers in parentage and kinship studies. We analysed a total of 687 unrelated individuals from 94 geographically different localities across all Federal Districts of the Russian Federation and provide forensically important parameters and allele frequencies. The paper also presents results of an intra-population genetic diversity study between the populations of the Federal Districts and comparison with populations from various regions of the world.

Molecular Dynamics Study of Cured ED-20 Epoxy Resin for Predicting the Glass Transition Temperature and Relationship with Structure Features.

A structural model of ED-20 epoxy resin cured by triethylenetetramine was constructed using a molecular dynamics (MD) simulation method. In order to model the epoxy resin hardening, we modified a typical stepwise protocol introducing cross-links between the amino groups and epoxide carbon atoms that allowed us to reproduce experimentally observed glass transition temperature at the value of 360-364 K. The set of MD trajectories of the final molecular-mechanical model can be useful for analysis of alterations in structural and physical properties of the epoxy resin depending on scaleable parameters. The relationships among qualitative alterations in macromolecular structure, the glass transition temperature, and the number of imposed cross-links were elucidated. Analysis of intermolecular interactions between the largest macromolecules and other molecules of a system made it possible to observe the features of the transition from glassy to the viscoelastic state of the studied polymer during the temperature rise.

Genetic diversity and forensic parameters of 12 X-STR included in Argus X-12® marker panel in the population of the Russian Federation.

BACKGROUND: X-chromosome specific short tandem repeats (X-STR) are indispensable for parentage analysis, kinship determination and forensic casework. AIM: To determine allelic frequencies and forensic parameters of the 12 X-STR markers from the Investigator® Argus X-12® kit panel for the population of the Russian Federation. SUBJECTS AND METHODS: We analysed 803 unrelated individuals from 58 localities across the Russian Federation. Intra-population genetic diversity was evaluated and comparison of the Russian population with 19 geographically distant populations performed. RESULTS: Heterozygosity values across all the loci ranged from 0.685 for DXS7423 to 0.939 for DXS10135. Deviations from the Hardy-Weinberg equilibrium were observed for DXS10074 (p < 0.05) and DXS10146 (p < 0.01). The value for power of discrimination across all the loci in males was 0.9999999996, while in females it equalled 0.9999999999. Combined mean exclusion chances MECKruger, MECKishida, MECD-trio, and MECD-duo were 0.9999988168, 0.9999999983, 0.9999999983, and 0.9999995797, respectively. Phylogenetic analysis indicated small genetic differences between the Russian population and the populations of neighbouring Lithuania, Belarus and the Slavic-speaking countries (Czech Republic, Serbia and Croatia). CONCLUSIONS: This paper is the first report of forensically important parameters and allele frequencies for the 12 X-STR loci included in Argus X-12® marker system in the population of the Russian Federation.

Population genetic data and forensic parameters of the 27 Y-STR panel Yfiler® Plus in Russian population.

This is the first report of a nation-wide study of the 27-STR Yfiler® Plus panel in the population of the Russian Federation. A total of 691 unrelated males from 89 locations split into seven subpopulations were analysed. Forensic parameters, haplotype and allele frequencies and presented. Inter-population comparison indicated the biggest genetic differences with the population of Italy and the smallest with that of Hungary. Haplogroup R1a was the most common and haplogroup J2a4h was the rarest in the Russian population.

Fungal literature records database of the Northern West Siberia (Russia).

BACKGROUND: Mycological research in the Northern part of West Siberia has now become sufficient for review and digitisation as over 460 scientific works have been completed mainly since the beginning of the 20th century. The history of research in the region started from isolated studies at the beginning of the 20th century, but regular and systematic research started from the 1970s. Over the following decades, several dozens of researchers have worked in the area, but the reported occurrences were scattered amongst a broad variety of publications, mainly hardly available. The great need in digitisation and accumulation of fungal records reported in published literature in a standardised regional database has now become evident. The «Fungal records database of the Northern West Siberia¼ (FuNWS) was initiated in 2016 according to contemporary biodiversity data standards (Darwin Core), to be compatible and accessible by the broad research community. The database has been supplemented ever since by the collective effort of specialists working in the area. According to the database summary report, there are 3358 fungal and fungus-like species revealed in the Northern West Siberia at present. The richest in species number classes are Agaricomycetes (60%) and Lecanoromycetes (33%) with a total of 25 classes represented. The FuNWS database was uploaded to Global Biodiversity Information Facility (GBIF) (Ygra State University Biological Collection publisher) on 11 November 2017 (earlier titled «Fungal Records Database of Yugra, FReDY¼) to provide open access to the data and its reusability (Filippova et al. 2020). NEW INFORMATION: This publication summarises the results of the digitisation of literature-based occurrence records of fungi and fungus-like organisms initiated in the Northern part of West Siberia for the first time in the history of mycological research. The bibliography of regional mycological publications was created to include about 460 published works (Suppl. material 2). In total, about 140 literature sources were digitised and about 22000 occurrence records were integrated into the FuNWS database (Filippova et al. 2020).

Immunosuppressive Treatment for Lupus Nephritis: Long-Term Results in 178 Patients.

Lupus nephritis is one of the most severe Systemic Lupus Erythematosus features, defining treatment modality and prognosis. Our retrospective study, including 178 patients treated for lupus nephritis during 23 years with mostly cyclophosphamide-based initial regimens followed by azathioprine or mycophenolic acid, demonstrates 84.8% of renal response with 19.2% of flares, 15-year patient survival 78.7% and kidney survival 76.3%, and low damage accrual. Both patient and kidney survival significantly differ for subgroups that achieved complete or partial renal response and nonresponders: patient 15-year survival 95% versus 65% versus 35%; kidney 15-year survival 100% versus 58% versus 0%, respectively. 51% (24 out of 47) of patients evaluated at the end of the study period sustained complete renal response; however, only 9 of them had 0 disease activity according to SELENA SLEDAI scale, while 13 patients had scores 2-4 due to the serological abnormalities only. We conclude that (1) initial treatment with cyclophosphamide followed by azathioprine is effective and can be used in agreement with International Guidelines until the evidence for biological treatments benefits becomes available; (2) complete and even partial renal response have positive prognostic value, and failure to achieve renal response negatively influences kidney and patient survival; (3) the validity of complete renal response in SLE is questioned by the absence of conventional definition of SLE remission.

Induced ferromagnetism in helium bombarded graphite.

Irradiation with helium ions is an effective method for triggering ferromagnetism in graphite. Chemical inertness of helium suggests that local magnetic moment formation is determined solely by the intrinsic carbon defects created during the target damage. Interacting moments are located in two places: in the vicinity of the sample surface and near the point of maximum defect generation.