Calcium phosphate bioceramics prepared from wet chemically precipitated powders

In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], β-tricalcium phosphate [β-TCP] and HAp/β-TCP) by modified wet-chemical precipitation route. The β-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300°C) HAp bioceramics with homogenous grainy microstructure, grain size up to 200–250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70°C and stabilizing ending pH at 9

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

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

The European Insomnia Guideline : An update on the diagnosis and treatment of insomnia 2023

Publisher Copyright: © 2023 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.Progress in the field of insomnia since 2017 necessitated this update of the European Insomnia Guideline. Recommendations for the diagnostic procedure for insomnia and its comorbidities are: clinical interview (encompassing sleep and medical history); the use of sleep questionnaires and diaries (and physical examination and additional measures where indicated) (A). Actigraphy is not recommended for the routine evaluation of insomnia (C), but may be useful for differential-diagnostic purposes (A). Polysomnography should be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders, etc.), treatment-resistant insomnia (A) and for other indications (B). Cognitive-behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (including patients with comorbidities), either applied in-person or digitally (A). When cognitive-behavioural therapy for insomnia is not sufficiently effective, a pharmacological intervention can be offered (A). Benzodiazepines (A), benzodiazepine receptor agonists (A), daridorexant (A) and low-dose sedating antidepressants (B) can be used for the short-term treatment of insomnia (≤ 4 weeks). Longer-term treatment with these substances may be initiated in some cases, considering advantages and disadvantages (B). Orexin receptor antagonists can be used for periods of up to 3 months or longer in some cases (A). Prolonged-release melatonin can be used for up to 3 months in patients ≥ 55 years (B). Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon and phytotherapeutics are not recommended for insomnia treatment (A). Light therapy and exercise interventions may be useful as adjunct therapies to cognitive-behavioural therapy for insomnia (B).Peer reviewe

Improving quality of psychiatric care in Latvia by measuring patient experiences

Publisher Copyright: © 2018 The Author(s)In Latvia, as in many former Soviet Union countries, there used to be little priority given to systematic assessments of the quality of psychiatric care. Furthermore, using the experiences of patients as a measure of quality was unthinkable because psychiatric patients were seen as incapable of assessing quality of psychiatric services. Over the past few years, and facilitated by Latvia's progress along the route of Western democracy and participation in international organizations (EU, OECD), as well as funding support from the EU, several policy documents have been developed with the aim of improving healthcare quality. Simultaneously, several small-scale initiatives have emerged aiming at the promotion of quality of care, such as the quality award, and the quality comparison of psychiatric hospitals. Furthermore, the Psychiatric Inpatient Patient Experience Questionnaire for on-site measurement (PIPEQ-OS) has recently been adapted for use in Latvia. The first application of PIPEQ-OS in a psychiatric hospital in Riga reveals high patient responsiveness, interest and surprise about being asked to participate in the decision-making process regarding treatment and pharmaceutical choices. More widespread use of the PIPEQ-OS has considerable potential for (1) improving information about treatment shortcomings from the patients’ perspective and (2) improving the treatment process by opening doors of cooperation with patients and changing deep-rooted paradigms.publishersversionPeer reviewe

The Study of Magnesium Substitution Effect on Physicochemical Properties of Hydroxyapatite

In the present study, pure and Mg-substitutedhydroxyapatite powders made up of needle-like and plate-likeparticles, respectively, have been synthesized by wet chemicalprecipitation of CaO, MgO and H3PO4. The influence of differentamounts of MgO addition into synthesis media on properties ofas-synthesized and sintered powders has been evaluated.Through the phase and chemical composition analysis it hasbeen determined that the prepared powders contain variousamounts of Mg (in the range between 0.21–4.72 wt%). Thesubstitution of Mg promoted the decomposition ofhydroxyapatite to β-tricalcium phosphate