Algorithmic Problems in Junior Contests in Latvia

Mathematical contests are of great importance for advanced education in Latvia today. Their content must be well-balanced and must correspond to the inner logic and recent trends of mathematics. A classification of algorithmic problems and characteristic examples are considered

Methicillin Susceptible Panton - Valentine Leukocidin Positive S. Aureus Pneumonia in a Child with Novel Influenza H1N1 Infection

The first case in Latvia of Panton - Valentine leukocidin (PVL) positive methicillin susceptible Staphylococcus aureus (MSSA) pneumonia in an adolescent with novel influenza A H1N1 is described. A 15 year old boy was admitted to intensive care suffering from severe respiratory failure with bilateral necrotic pneumonia. The presence of influenza A H1N1 was confirmed by PCR. Invasive S. aureus was spa type t435 and Panton-Valentine leukocidin gene positive. He received therapy with ceftriaxone, oxacillin, clindamycin and oseltamivir phosphate and underwent two chest operations. He was discharged after 58 days in hospital.publishersversionPeer reviewe

Telomere length in Chernobyl accident recovery workers in the late period after the disaster

Publisher Copyright: © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.The outcome of the Chernobyl nuclear power plant (CNPP) accident was that a huge number of people were exposed to ionizing radiation. Previous studies of CNPP clean-up workers from Latvia revealed a high occurrence of age-associated degenerative diseases and cancer in young adults, as well as a high mortality as a result of cardiovascular disorders at age 45-54 years. DNA tandem repeats that cap chromosome ends, known as telomeres, are sensitive to oxidative damage and exposure to ionizing radiation. Telomeres are important in aging processes and carcinogenesis. The aim of this study was to investigate the long-term effect of protracted ionizing radiation exposure on telomere length in CNPP clean-up workers. Relative telomere length (RTL) was measured in peripheral blood leukocytes of 595 CNPP clean-up workers and 236 gender- and agematched controls using real-time quantitative polymerase chain reaction (q-PCR). Close attention was paid to participation year and tasks performed during the worker's stay in Chernobyl, health status, and RTL differences between subgroups. Telomere shortening was not found in CNPP clean-up workers; on the contrary, their RTL was slightly greater than in controls (P = 0.001). Longer telomeres were found in people who worked during 1986, in those undertaking 'dirty' tasks (digging and deactivation), and in people with cancer. Shorter telomeres appeared frequently in those with cataract, osteoporosis, atherosclerosis, or coronary heart disease. We conclude that the longer telomeres revealed in people more heavily exposed to ionizing radiation probably indicate activation of telomerase as a chromosome healing mechanism following damage, and reflect defects in telomerase regulation that could potentiate carcinogenesis.publishersversionPeer reviewe

Pathogenic APC variants in latvian familial adenomatous polyposis patients

Funding Information: This research was funded by the state research program ?Biomedicine for Public Health (BIOMEDICINE)" project 5 ?Personalized cancer diagnostics and treatment effectiveness evaluation?. Publisher Copyright: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.Background and objectives: Familial adenomatous polyposis is one of the APC-associated polyposis conditions described as genetically predetermined colorectal polyposis syndrome with a variety of symptoms. The purpose of this study was to determine sequence variants of the APC gene in patients with familial adenomatous polyposis (FAP) phenotype and positive or negative family history. Materials and Methods: Eight families with defined criteria of adenomatous polyposis underwent molecular genetic testing. Coding regions and flanking intron regions of the APC gene were analyzed by Sanger sequencing. Results: Eight allelic variants of the APC gene coding sequence were detected. All allelic variants of the APC gene were predicted to be pathogenic based on criteria according to the “Joint Consensus Recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology” (2015), four of them c.1586_1587insAT, c.2336delT, c.3066_3067insGA, and c.4303_4304insC, were considered novel. Conclusions: The timely molecular genetic analysis of APC germline variants and standardized interpretation of the pathogenicity of novel allelic variants has a high impact on choice for treatment, cancer prevention, and family genetic counseling.Peer reviewe

The outcomes after transfers of embryos with chromosomal mosaicism : a single reproductive medicine center experience at iVF Riga clinic

Publisher Copyright: © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the UR MED GRUPP (LLC). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Aim: The aim of this study is to summarize the outcomes of transfers of mosaic embryos, which were classified according to guidelines and in strong collaboration of reproductologists, clinical geneticists and patients approved as suitable for transfer. Material and Methods: Retrospective data were collected from 70 patients from a private IVF center to whom embryos with mosaic changes in chromosomal material were transferred from 2015 to 2019. Results and Conclusion: Implantation outcomes and continuing pregnancies showed slight differences, when compared to fully normal embryos. Artifacts have to be differentiated from undeniable aberrations, and correct interpretation of results must be done with following patient counselling and prenatal testing if necessary.publishersversionPeer reviewe

Case of Inherited Partial AZFa Deletion without Impact on Male Fertility

Male factor infertility accounts for 40–50% of all infertility cases. Deletions of one or more AZF region parts in chromosome Y are one of the most common genetic causes of male infertility. Usually full or partial AZF deletions, including genes involved in spermatogenesis, are associated with spermatogenic failure. Here we report a case of a Caucasian man with partial AZFa region deletion from a couple with secondary infertility. Partial AZFa deletion, involving part of USP9Y gene appears to be benign, as we proved transmission from father to son. According to our results, it is recommended to revise guidelines on markers selected for testing of AZFa region deletion, to be more selective against DDX3Y gene and exclude probably benign microdeletions involving only USP9Y gene.publishersversionPeer reviewe

The application of PGT-A for carriers of balanced structural chromosomal rearrangements

The aim of this study was to analyze differences in chromosomal aberrations and euploidy in embryos of each translocation type and gender of carrier in the case series of 10 couples with balanced translocations who underwent IVF with embryos trophectoderm (TE) biopsy and PGT-A to detect chromosomal aberrations. This is a Case Series (Retrospective study). In each case, controlled ovarian hyperstimulation, oocyte insemination with intracytoplasmic sperm injection (ICSI) and cultivation gave multiple blastocysts, that underwent trophectoderm (TE) biopsy with PGT-A analysis using aCGH and NGS. Number of total unbalanced translocations compared to the number of sporadic aneuploid embryos was 39.6% to 39.6% (50% to 50% of all 37 aneuploid embryos). The highest euploidy rate was in male carrier group–26.7% and the lowest in the Robertsonian translocation carrier group–18.2%. Sporadic aneuploidy–68.2% was highest in Robertsonian translocation carrier group and lowest in female group–11.1%. Chromosomal aberrations related to translocation were highest in female carrier group–77.8% and lowest in Robertsonian translocation carrier group–13.6%. Our study showed that expectancy of total embryo aneuploidy rates will be higher in carriers, than in people with normal karyotype. The prevalence of chromosomal aberrations related to translocation was 4.5 times higher in Reciprocal carrier group than in Robertsonian translocation carrier group. Among maternal and paternal carrier groups, the embryos from female carriers had the lowest euploidy rate, unbalanced translocation rate 4.7 times higher than in the male carrier group and higher total aneuploidy rates.publishersversionPeer reviewe

BRCA1/2 mutation screening in high-risk breast/ovarian cancer families and sporadic cancer patient surveilling for hidden high-risk families

Background: The estimated ratio of hereditary breast/ovarian cancer (HBOC) based on family history is 1.5% in Latvia. This is significantly lower than the European average of 5-10%. Molecular markers like mutations and SNPs can help distinguish HBOC patients in the sporadic breast and ovarian cancer group.Methods: 50 patients diagnosed with HBOC in the Latvian Cancer Registry from January 2005 to December 2008 were screened for BRCA1 founder mutation-negatives and subjected to targeted resequencing of BRCA1 and BRCA2 genes. The newly found mutations were screened for in the breast and ovarian cancer group of 1075 patients by Real Time-PCR/HRM analysis and RFLP.Results: Four BRCA2 mutations including three novel BRCA2 frameshift mutations and one previously known BRCA2 frameshift mutation and one BRCA1 splicing mutation were identified. Two of the BRCA2 mutations were found in a group of consecutive breast cancer patients with a frequency of 0.51% and 0.38%.Conclusions: Molecular screening of sequential cancer patients is an important tool to identify HBOC families.publishersversionPeer reviewe

Territory planning perspective in flood-prone areas in Riga / Teritorinio planavimo perspektyvos potvynių užliejamuose Rygos plotuose

The flood risk problems in Riga city due to global warming and climate change are studied based on the European experience incorporated in European and Latvian legislation. Amendment to the Protection Zone Law of Latvia is studied and compared with the likelihood of the flood risk and development possibilities in the flood risk zones. The study focuses on the case of the Vecdaugava River neighbourhood as the potential flood risk zone in Riga city. Santrauka   Tiriamos potvynio rizikos Rygos mieste keliamos problemos, atsiradusios dėl globalinio atšilimo ir klimato pokyčių, remiantis Europos patirtimi, atspindėta Europos ir Latvijos įstatyminėje bazėje. Analizuojami Latvijos Respublikos apsaugos zonų įstatymo pakeitimai, potvynio rizikos galimybės tam tikrose zonose. Tyrimas skirtas nagrinėti Vecdaugavos upės atvejį kaip potencialią potvynių zoną Rygos mieste. Reikšminiai žodžiai: miesto pakrantės zona, potvynio rizika, urbanistinis planavimas Rygoje, tvarumas