commitment point
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This work represents a detailed guide for commitment point analysis in microalgae dividing by multiple fission. The method is based on allowing the committed cells to divide in favorable conditions in the dark. This protocol offers a strategy to monitor cell cycle progression, both in control cultures and cultures treated with compounds affecting cell cycle length and/or progression. As the variety of such compounds is wide, our aim was to make the protocol easily modifiable to various research aims. The technique is easy to follow, low-cost, does not require any special equipment and offers reliable results in a reasonable time. The protocol offers step-by-step instructions, explains the theory behind these steps and offers solutions to some of the problems that may arise during the procedure.
- Klíčová slova
- Cell cycle, Cell division, Chlamydomonas, Commitment point, Green algae, Multiple fission,
- MeSH
- buněčné dělení * MeSH
- buněčný cyklus * MeSH
- Viridiplantae MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Chlamydomonas reinhardtii cells can double their size several times during the light period before they enter the division phase. To explain the role of the commitment point (defined as the moment in the cell cycle after which cells can complete the cell cycle independently of light) and the moment of initiation of cell division we investigated whether the timing of commitment to cell division and cell division itself are dependent upon cell size or if they are under control of a timer mechanism that measures a period of constant duration. The time point at which cells attain commitment to cell division was dependent on the growth rate and coincided with the moment at which cells have approximately doubled in size. The timing of cell division was temperature-dependent and took place after a period of constant duration from the onset of the light period, irrespective of the light intensity and timing of the commitment point. We concluded that at the commitment point all the prerequisites are checked, which is required for progression through the cell cycle; the commitment point is not the moment at which cell division is initiated but it functions as a checkpoint, which ensures that cells have passed the minimum cell size required for the cell division.
Methods for determining the points of commitment for cell division are described for species of green algae dividing by multiple fission, both forming coenobia (Scenedesmus quadricauda) and releasing single daughter cells (Chlamydomonas eugametos, Scenedesmus armatus). The timing of commitment points was followed in detail in synchronous cultures of S. quadricauda grown under various light intensities, illumination regimes, and temperatures. The pre-commitment periods were rate limiting, while the post-commitment periods remained more or less constant under various light intensity. Temperature, on the other hand, affected both periods in a similar manner and they were prolonged with decreasing temperature.
- MeSH
- buněčné dělení * fyziologie účinky záření MeSH
- buněčný cyklus * MeSH
- Chlamydomonas cytologie růst a vývoj MeSH
- kultivační média MeSH
- Scenedesmus cytologie růst a vývoj MeSH
- světlo MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kultivační média MeSH
The political abuse of psychiatry in the former USSR was enabled by: 1. a disproportionate pointing up of the medical criteria of mental disorder to the detriment of the social ones, above all by circumventing the sociological labelling process; 2. lack of control of involuntary psychiatric hospitalisation by the law; 3. an obsolete definition of psychiatry. The author suggests a definition of psychiatry taking into consideration both the above mentioned criteria and making the importance of the legal control of involuntary psychiatric hospitalisation more evident.
- MeSH
- dějiny 20. století MeSH
- komunismus * dějiny MeSH
- lidé MeSH
- psychiatrie * dějiny MeSH
- zodpovědnost duševně nemocného dějiny zákonodárství a právo MeSH
- Check Tag
- dějiny 20. století MeSH
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- historické články MeSH
- Geografické názvy
- SSSR MeSH
BACKGROUND: Despite the recent increase of research interest in involuntary treatment and the use of coercive measures, gender differences among coerced schizophrenia patients still remain understudied. It is well recognized that there are gender differences both in biological correlates and clinical presentations in schizophrenia, which is one of the most common diagnoses among patients who are treated against their will. The extent to which these differences may result in a difference in the use of coercive measures for men and women during the acute phase of the disease has not been studied. METHODS: 291 male and 231 female coerced patients with schizophrenia were included in this study, which utilized data gathered by the EUNOMIA project (European Evaluation of Coercion in Psychiatry and Harmonization of Best Clinical Practice) and was carried out as a multi-centre prospective cohort study at 13 centers in 12 European countries. Sociodemographic and clinical characteristics, social functioning and aggressive behavior in patients who received any form of coercive measure (seclusion and/or forced medication and/or physical restraint) during their hospital stay were assessed. RESULTS: When compared to the non-coerced inpatient population, there was no difference in sociodemographic or clinical characteristics across either gender. However coerced female patients did show a worse social functioning than their coerced male counterparts, a finding which contrasts with the non-coerced inpatient population. Moreover, patterns of aggressive behavior were different between men and women, such that women exhibited aggressive behavior more frequently, but men committed severe aggressive acts more frequently. Staff used forced medication in women more frequently and physical restraint and seclusion more frequently with men. CONCLUSIONS: Results of this study point towards a higher threshold of aggressive behavior the treatment of women with coercive measures. This may be because less serious aggressive actions trigger the application of coercive measures in men. Moreover coerced women showed diminished social functioning, and more importantly more severe symptoms from the "excitement/hostile" cluster in contrast to coerced men. National and international recommendation on coercive treatment practices should include appropriate consideration of the evidence of gender differences in clinical presentation and aggressive behaviors found in inpatient populations.
- MeSH
- agrese psychologie MeSH
- dospělí MeSH
- hospitalizovaní pacienti psychologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- pohlavní dimorfismus * MeSH
- prospektivní studie MeSH
- schizofrenie (psychologie) * MeSH
- schizofrenie terapie MeSH
- stupeň závažnosti nemoci MeSH
- ústavy pro duševně nemocné MeSH
- zodpovědnost duševně nemocného * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Histone variants confer chromatin unique properties. They have specific genomic distribution, regulated by specific deposition and removal machineries. Histone variants, mostly of canonical histones H2A, H2B and H3, have important roles in early embryonic development, in lineage commitment of stem cells, in the converse process of somatic cell reprogramming to pluripotency and, in some cases, in the modulation of animal aging and life span. MacroH2A1 is a variant of histone H2A, present in two alternatively exon-spliced isoforms macroH2A1.1 and macroH2A1.2, regulating cell plasticity and proliferation, during pluripotency and tumorigenesis. Furthermore, macroH2A1 participates in the formation of senescence-associated heterochromatic foci (SAHF) in senescent cells, and multiple lines of evidence in genetically modified mice suggest that macroH2A1 integrates nutritional cues from the extracellular environment to transcriptional programs. Here, we review current molecular evidence based on next generation sequencing data, cell assays and in vivo models supporting different mechanisms that could mediate the function of macroH2A1 in health span and life span. We will further discuss context-dependent and isoform-specific functions. The aim of this review is to provide guidance to assess histone variant macroH2A1 potential as a therapeutic intervention point.
- Klíčová slova
- fasting, histone variant macroH2A1, regeneration, senescence,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
There is no doubt, that the medical staff has often to face aggressive patients, their threats and event their violent physical attacks today. More frequently than ever they are faced with the necessity to think over and consider very carefully the way to defend against imminent or persistent attack on them. First, I would attempt to qualify patients' aggressive behaviour - from lesser acts, when the violent attack is not imminent, through threatening with killing, inflicting aggravated bodily harm or causing exceptionally serious damage or enforcement by violence, the threat of violence or the threat of causing another serious damage, to do something, to desist from doing something or tolerate something. to the imminent or persistent attack. Then I would try to describe the best ones of possible ways of self-defence against various levels of aggressive behaviour.
- MeSH
- agrese MeSH
- lidé MeSH
- násilí zákonodárství a právo MeSH
- trestní zákon * MeSH
- vztahy mezi lékařem a pacientem * MeSH
- vztahy mezi zdravotnickým pracovníkem a pacientem MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Extensive in vivo replacement of hydrogen by deuterium, a stable isotope of hydrogen, induces a distinct stress response, reduces cell growth and impairs cell division in various organisms. Microalgae, including Chlamydomonas reinhardtii, a well-established model organism in cell cycle studies, are no exception. Chlamydomonas reinhardtii, a green unicellular alga of the Chlorophyceae class, divides by multiple fission, grows autotrophically and can be synchronized by alternating light/dark regimes; this makes it a model of first choice to discriminate the effect of deuterium on growth and/or division. Here, we investigate the effects of high doses of deuterium on cell cycle progression in C. reinhardtii. Synchronous cultures of C. reinhardtii were cultivated in growth medium containing 70 or 90% D2O. We characterize specific deuterium-induced shifts in attainment of commitment points during growth and/or division of C. reinhardtii, contradicting the role of the "sizer" in regulating the cell cycle. Consequently, impaired cell cycle progression in deuterated cultures causes (over)accumulation of starch and lipids, suggesting a promising potential for microalgae to produce deuterated organic compounds.
- Klíčová slova
- Chlamydomonas reinhardtii, cell cycle, cell division, commitment point, deuterium, heavy water, multiple fission, stress,
- MeSH
- buněčné dělení účinky léků MeSH
- buněčný cyklus účinky léků MeSH
- Chlamydomonas reinhardtii růst a vývoj metabolismus MeSH
- deuterium škodlivé účinky chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- deuterium MeSH
Cyclin-dependent kinases (CDKs) are key regulators of the cell cycle in eukaryotes. Assessing their activity is one of the basic methods used to analyze their function. This is particularly true in synchronized cultures of unicellular organisms, where the entire culture is in the same physiological state. In this chapter, I describe a simple biochemical method to assess CDK activity in algae. Although the results are easier to interpret in the context of synchronized cultures, the method is not limited to them. The protocol requires only standard laboratory equipment and access to a radioactivity working room. The method is applicable to any algal species, including newly developed ones, as it does not require any specific tools. The method can, therefore, be used to widen the portfolio of cell cycle regulatory models within algae.
- Klíčová slova
- Cell division, Commitment point, DNA replication, Green algae, Kinase activity, Multiple fission cell cycle, Nuclear division, Synchronization,
- MeSH
- buněčné dělení MeSH
- buněčný cyklus MeSH
- cyklin-dependentní kinasa 2 MeSH
- cyklin-dependentní kinasy metabolismus MeSH
- fosforylace MeSH
- Heterokontophyta MeSH
- proteiny buněčného cyklu metabolismus MeSH
- Viridiplantae MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cyklin-dependentní kinasa 2 MeSH
- cyklin-dependentní kinasy MeSH
- proteiny buněčného cyklu MeSH
T cell memory relies on the generation of antigen-specific progenitors with stem-like properties. However, the identity of these progenitors has remained unclear, precluding a full understanding of the differentiation trajectories that underpin the heterogeneity of antigen-experienced T cells. We used a systematic approach guided by single-cell RNA-sequencing data to map the organizational structure of the human CD8+ memory T cell pool under physiological conditions. We identified two previously unrecognized subsets of clonally, epigenetically, functionally, phenotypically and transcriptionally distinct stem-like CD8+ memory T cells. Progenitors lacking the inhibitory receptors programmed death-1 (PD-1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT) were committed to a functional lineage, whereas progenitors expressing PD-1 and TIGIT were committed to a dysfunctional, exhausted-like lineage. Collectively, these data reveal the existence of parallel differentiation programs in the human CD8+ memory T cell pool, with potentially broad implications for the development of immunotherapies and vaccines.
- MeSH
- biologické markery MeSH
- buněčná diferenciace imunologie MeSH
- CD8-pozitivní T-lymfocyty imunologie metabolismus MeSH
- homeostáza telomer MeSH
- imunofenotypizace MeSH
- imunologická paměť * MeSH
- lidé MeSH
- lymfoidní progenitorové buňky cytologie imunologie metabolismus MeSH
- myši MeSH
- stanovení celkové genové exprese MeSH
- T-lymfocyty - podskupiny imunologie metabolismus MeSH
- výpočetní biologie metody MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
