Characterization of Mg2+-regulated TRPM7-like current in human atrial myocytes

BACKGROUND: TRPM7 (Transient Receptor Potential of the Melastatin subfamily) proteins are highly expressed in the heart, however, electrophysiological studies, demonstrating and characterizing these channels in human cardiomyocytes, are missing. METHODS: We have used the patch clamp technique to characterize the biophysical properties of TRPM7 channel in human myocytes isolated from right atria small chunks obtained from 116 patients in sinus rhythm during coronary artery and valvular surgery. Under whole-cell voltage-clamp, with Ca(2+) and K(+) channels blocked, currents were generated by symmetrical voltage ramp commands to potentials between -120 and +80 mV, from a holding potential of -80 mV. RESULTS: We demonstrate that activated native current has dual control by intracellular Mg(2+) (free-Mg(2+) or ATP-bound form), and shows up- or down-regulation by its low or high levels, respectively, displaying outward rectification in physiological extracellular medium. High extracellular Mg(2+) and Ca(2+) block the outward current, while Gd(3+), SpM(4+), 2-APB, and carvacrol inhibit both (inward and outward) currents. Besides, divalents also permeate the channel, and the efficacy sequence, at 20 mM, was Mg(2+)>Ni(2+)>Ca(2+)>Ba(2+)>Cd(2+) for decreasing outward and Ni(2+)>Mg(2+)>Ba(2+)≥Ca(2+)>Cd(2+) for increasing inward currents. The defined current bears many characteristics of heterologously expressed or native TRPM7 current, and allowed us to propose that current under study is TRPM7-like. However, the time of beginning and time to peak as well steady state magnitude (range from 1.21 to 11.63 pA/pF, n(cells/patients) = 136/77) of induced TRPM7-like current in atrial myocytes from different patients showed a large variability, while from the same sample of human atria all these parameters were very homogenous. We present new information that TRPM7-like current in human myocytes is less sensitive to Mg(2+). In addition, in some myocytes (from 24 out of 77 patients) that current was already up-regulated at membrane rupture. CONCLUSIONS: This study provides the first electrophysiological description of TRPM7-like current in native human atrial myocytes. Less sensitivity to intracellular Mg(2+) suggests for channel operation under physiological conditions. The TRPM7-like current up-regulation indicates the pathophysiological evidence of that current in human heart

Procjena utjecaja niskih doza ionizirajućeg zračenja izvora 137Cs na toksičnost i genotoksičnost u biljaka

The aim of this study was to evaluate the impact of low internal exposure to 137Cs on L. sativum meristem cells and Tradescantia stamen hair cells. It also compared the impact of 137Cs internal and external irradiation of similar level on the plant seed germination and root growth. Compared to control, the tested internal (0.0007 mGy to 0.7 mGy) and external (0.04 mGy to 5.5 mGy) 137Cs ionising radiation doses stimulated the elongation of L. sativum roots by 11 % to 12 % and 24 % to 33 %, respectively. Internal 137Cs exposure (0.0003 mGy to 0.5 mGy) for 14 days caused 1.2 % to 1.6 % of somatic mutations and 19 % to 87 % of non-viable stamen hair in Tradescantia.Radom je istražen učinak izlaganja čitavih biljaka ionizirajućem zračenju izvora 137Cs na stanice meristema vegetativnog tkiva (korijen) i generativnog tkiva (stanice dlaka filamenata prašnika). Istraživanjem su se, također, pokušale utvrditi razlike u učinku zračenja na klijavost sjemena i rast korijena biljaka u ovisnosti o tome je li izvor zračenja u samoj biljci ili izvan nje. Značajan toksičan učinak zračenja utvrđen je samo u biljaka vrste Lepidium sativum L., i to na rast korijena. Neovisno o položaju izvora zračenja, doze od 0.0007 mGy do 0.7 mGy povećale su izduživanje korijena za 11 % do 12 %, a doze od 0.04 do 0.5 mGy za 24 % do 33 % u odnosu na kontrolu. Interne doze zračenja izvora 137Cs od 0.0003 mGy do 0.5 mGy tijekom 14-dnevnog izlaganja dovele su do pojave somatskih mutacija u 1.2 % do 1.6 % stanica dlaka prašničkih filamenata roda Tradescantia. Ujedno, 19 % do 87 % stanica izgubilo je vijabilnost, što upućuje na inhibiciju reproduktivne sposobnosti biljaka djelovanjem ionizirajućeg zračenja

Production of recombinant VP1-derived virus-like particles from novel human polyomaviruses in yeast

Background: Eleven new human polyomaviruses (HPyVs) have been identified in the last decade. Serological studies show that these novel HPyVs sub-clinically infect humans at an early age. The routes of infection, entry pathways, and cell tropism of new HPyVs remain unknown. VP1 proteins of polyomaviruses can assembly into virus-like particles (VLPs). As cell culturing systems for HPyV are currently not available, VP1-derived VLPs may be useful tools in basic research and biotechnological applications. Results: Recombinant VP1-derived VLPs from 11 newly identified HPyVs were efficiently expressed in yeast. VP1 proteins derived from Merkel cell polyomavirus (MCPyV), trichodysplasia spinulosa-associated polyomavirus (TSPyV), and New Jersey polyomavirus (NJPyV) self-assembled into homogeneous similarly-sized VLPs. Karolinska Institutet polyomavirus (KIPyV), HPyV7, HPyV9, HPyV10, and St. Louis polyomavirus (STLPyV) VP1 proteins formed VLPs that varied in size with diameters ranging from 20 to 60 nm. Smaller-sized VLPs (25–35 nm in diameter) predominated in preparations from Washington University polyomavirus (WUPyV) and HPyV6. Attempts to express recombinant HPyV12 VP1-derived VLPs in yeast indicate that translation of VP1 might start at the second of two potential translation initiation sites in the VP1-encoding open reading frame (ORF). This translation resulted in a 364-amino acid-long VP1 protein, which efficiently self-assembled into typical PyV VLPs. MCPyV-, KIPyV-, TSPyV-, HPyV9-, HPyV10-, and HPyV12-derived VLPs showed hemagglutination (HA) assay activity in guinea pig erythrocytes, whereas WUPyV-, HPyV6-, HPyV7-, STLPyV- and NJPyV-derived VP1 VLPs did not. Conclusions: The yeast expression system was successfully utilized for high-throughput production of recombinant VP1-derived VLPs from 11 newly identified HPyVs. HPyV12 VP1-derived VLPs were generated from the second of two potential translation initiation sites in the VP1-encoding ORF. Recombinant VLPs produced in yeast originated from different HPyVs demonstrated distinct HA activities and may be useful in virus diagnostics, capsid structure studies, or investigation of entry pathways and cell tropism of HPyVs until cell culture systems for new HPyVs are developed

The foot arch and viscoelastic properties of plantar fascia and Achilles tendon

Plantar fascia reduces ground reaction force on metatarsal heads. It serves to stiffen medial and lateral longitudinal arches and reduce longitudinal arch flattening. Mechanical characteristics of plantar fascia and Achilles tendon can provide significant information on fascia and tendon functional condition as well as the risks of irregularities. The objectives of this study were: (a) to identify plantar fascia and Achilles tendon oscillation frequency, decrement and stiffness, and to evaluate the reliability of differences between normal, low and high foot arch; (b) to identify the relation between plantar fascia and Achilles tendon mechanical characteristics. 42 feet of 21 soccer players were investigated in order to determine plantar fascia and Achilles tendon oscillation frequency, decrement and stiffness of feet with normal, low and high foot arch. 164 feet of 32 soldiers, 21 football players and 29 basketball players were analyzed to determine the link between plantar fascia and Achilles tendon mechanical characteristics. The medial longitudinal foot arch was evaluated according to arch index by Williams (WAI). The Achilles tendon and plantar fascia oscillation frequency, decrement and stiffness were evaluated using Myoton-3 system. This study revealed that relaxed plantar fascia of feet with normal arch is statistically reliably more elastic than fascia of feet with low arch. A very strong relationship was discovered between mechanical characteristics of plantar fascia and Achilles tendon

Educational innovations in Eastern countries. Final Conference of Erasmus + project Fostering Competencies Development in Belarusian Higher Education

Erasmus + KA2 programme project ?Fostering Competencies Development in Belarusian Higher Education ? FOSTERC? consortium partners have met for the Final Conference in Minsk, Belarus, on the 6th of December 2019. It was an exciting moment.  ?FOSTERC? consortium worked together since 2016, many meetings, trainings, common research and creative work have been implemented in a cooperative way. The final ?FOSTERC? event has summarised transformations and novelties that have been created in Belarus higher education institutions during the last three years. This article shortly reviews some insights and solutions that have been discussed during the ?FOSTERC? conference in Minsk

THE RELATIONSHIP BETWEEN THE TEACHING STYLE OF SWIMMING COACHES AND THEIR ATHLETES’ MOTIVATION FOR SPORT

The paper presents a research dealing with one of the most relevant problems in sports education science, the coach’s influence on young athletes’ motivation. The aim of the research is to investigate the correlations between manifestation of the teaching style applied by coaches and motivation of their athletes for sport. The research raises a hypothesis that the teaching styles applied by coaches may be related to the motivation for sport in the athletes being trained. The research is based on the provisions of reproductive and productive teaching methods as well as the self-determination theory. The research involved 14–18-year-old swimmers and their coaches. Two questionnaires have been employed: description of the teaching style (Curtner-Smith et al., 2001; Hein et al., 2012) and sport motivation scale (SMS–II; Pelletier et al., 2013). Referring to the responses in relation to manifestation of the teaching style, the coaches have been divided into three groups. The one factor analysis of variance (ANOVA) was applied to test the research hypothesis. The research hypothesis was proven only partly. It was found that application of different teaching styles may have had effect on young athletes’ external motivation only. It can be substantiated that the teaching style employed by swimming coaches and related both reproductive and reproductive teaching methods have no significant effect on young athletes’ intrinsic motivation for sport in the coaching practise.

Täiskasvanute vabahariduslik õpe eesti muusikakoolides

Maailmas on viimasel ajal väga populaarne nähtus ja ütlus „elukestev õpe“. Tegelikult on see väga lai mõiste, kuhu mahuvad nii formaalsed kui ka mitteformaalsed täiskasvanute hariduslikud võimalused. Kuigi täiskasvanute haridusele on Eestis juba palju tähelepanu pööratud, on siiski teatud valdkonnad, kus on vaja veel uurida ja välja tuua kitsad kohad. Näiteks on väga vähe tähelepanu saanud täiskasvanute muusikaalane haridus, kuid olen kindel, et ka selle uurimine on hetkel vajalik.http://tartu.ester.ee/record=b2610800~S13*es

HTA Implementation Roadmap in Central and Eastern European Countries.

The opportunity cost of inappropriate health policy decisions is greater in Central and Eastern European (CEE) compared with Western European (WE) countries because of poorer population health and more limited healthcare resources. Application of health technology assessment (HTA) prior to healthcare financing decisions can improve the allocative efficiency of scarce resources. However, few CEE countries have a clear roadmap for HTA implementation. Examples from high-income countries may not be directly relevant, as CEE countries cannot allocate so much financial and human resources for substantiating policy decisions with evidence. Our objective was to describe the main HTA implementation scenarios in CEE countries and summarize the most important questions related to capacity building, financing HTA research, process and organizational structure for HTA, standardization of HTA methodology, use of local data, scope of mandatory HTA, decision criteria, and international collaboration in HTA. Although HTA implementation strategies from the region can be relevant examples for other CEE countries with similar cultural environment and economic status, HTA roadmaps are not still fully transferable without taking into account country-specific aspects, such as country size, gross domestic product per capita, major social values, public health priorities, and fragmentation of healthcare financing