Search results for " Genetics"
showing 10 items of 4169 documents
The role of polymorphisms of thiopurine methyltransferase in therapy with Azathioprine: preliminary study
2018
Azathioprine is an immunosuppressant drug belonging to the class of thiopurines widely used in clinical therapy. Its immunosuppressive action is linked to the substantial action mechanism in the inhibition of the synthesis of nitrogenous bases purine carried out in T-lymphocyte. The level of such medication limit resides in side effects such as myelosuppression and the development of tumours. The occurrence of side effects is linked to the presence of genetic polymorphisms of Thiopurine methyltransferase (TPMT). To date, 40 allelic variants for TPMT have been detected. However, those responsible for the reduction of enzyme activity are three: *2, *3A, *3C. The presence of one of the three p…
JNK phosphorylation relieves HDAC3-dependent suppression of the transcriptional activity of c-Jun
2003
The AP-1 transcription factor c-Jun is a prototypical nuclear effector of the JNK signal transduction pathway. The integrity of JNK phosphorylation sites at serines 63/73 and at threonines 91/93 in c-Jun is essential for signal-dependent target gene activation. We show that c-Jun phosphorylation mediates dissociation of an inhibitory complex, which is associated with histone deacetylase 3 (HDAC3). The subsequent events that ultimately cause increased mRNA synthesis are independent of c-Jun phosphorylation and its interaction with JNK. These findings provide an 'activation by de-repression' model as an explanation for the stimulatory function of JNK on c-Jun.
Time-Lapse Dynamics of the Mouse Oocyte Chromatin Organisation during Meiotic Resumption
2014
In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete’s developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9 hr time-lapse observation. The main significant differences recorded are: (1) reduction of the nuclear area only in SN oocytes; (2) ~17…
Unveiling distribution patterns of freshwater phytoplankton by a next generation sequencing based approach.
2012
The recognition and discrimination of phytoplankton species is one of the foundations of freshwater biodiversity research and environmental monitoring. This step is frequently a bottleneck in the analytical chain from sampling to data analysis and subsequent environmental status evaluation. Here we present phytoplankton diversity data from 49 lakes including three seasonal surveys assessed by next generation sequencing (NGS) of 16S ribosomal RNA chloroplast and cyanobacterial gene amplicons and also compare part of these datasets with identification based on morphology. Direct comparison of NGS to microscopic data from three time-series showed that NGS was able to capture the seasonality in…
Expression and possible functions of the cholinergic system in a murine embryonic stem cell line.
2007
The expression of a cholinergic system during embryonic development is a widespread phenomenon. However, no precise function could be assigned to it during early pre-neural stages and there are only few studies that document when it precisely starts to be expressed. Here, we examined the expression of cholinergic components in a murine embryonic stem cell line by RT-PCR, histochemistry, and enzyme activity measurements; the acetylcholine (ACh) content was measured by HPLC. We have demonstrated that embryonic stem cells express ACh, acetylcholine receptors, choline acetyltransferase (ChAT), acetyl- and butyryl-cholinesterase (AChE and BChE). Butyryl-cholinesterase (BChE) expression was highe…
Secretion of neutral and acid DNases in cultivated human lymphocytes after incubation with DNA; possible consequences for inhalation anesthesia.
1995
Abstract After incubation with DNA human lymphocytes release neutral and acid DNase activities into the culture medium; the release depends on DNA concentration and time of cultivation. The electrophoretic mobility of the released neutral DNase activity is in accordance with DNase I and the electrophoretic mobility of the released acid DNase activity with DNase II. The released DNase activities do not originate from dead cells and are not influenced by blast cell formation. The anesthetic halothane can inhibit the released neutral and acid DNase activities. Inhalation anesthesia can possibly disturb the correlation between DNA and DNases in human blood.
Species-specific aggregation factor in sponges V. Influence on programmed syntheses
1976
Isolated cells from the siliceous sponge Geodia cydonium as well as small primary aggregates (diameter: 70 mum) consisting of them show no increase in rates of programmed syntheses and mitotic activity with time. After addition of a highly purified aggregation factor to a culture with primary aggregates which subsequently form secondary aggregates (diameter: larger than 1000 mum), a dramatic increase of DNA, RNA and protein synthesis occurs. Together with this increase, the cells show a high mitotic activity. The values for the mitotic coefficient reach a first maximum 8 h after the beginning of the secondary aggregation process. The stimulation of the mitotic activity of cells during the a…
Quaternary diversification in European alpine plants: pattern and process
2004
Molecular clock approaches applied previously to European alpine plants suggest that Primula sect. Auricula , Gentiana sect. Ciminalis and Soldanella diversified at the beginning of the Quaternary or well within this period, whereas Globularia had already started diversifying in the (Late–)Tertiary. In the first part of this paper we present evidence that, in contrast to Globularia and Soldanella , the branching patterns of the molecular internal transcribed spacer phylogenies of both Primula and Gentiana are incompatible with a constant–rates birth–death model. In both of these last two taxa, speciation probably decreased through Quaternary times, perhaps because of some niche–filling pro…
Tracing European Founder Lineages in the Near Eastern mtDNA Pool
2000
Founder analysis is a method for analysis of nonrecombining DNA sequence data, with the aim of identification and dating of migrations into new territory. The method picks out founder sequence types in potential source populations and dates lineage clusters deriving from them in the settlement zone of interest. Here, using mtDNA, we apply the approach to the colonization of Europe, to estimate the proportion of modern lineages whose ancestors arrived during each major phase of settlement. To estimate the Palaeolithic and Neolithic contributions to European mtDNA diversity more accurately than was previously achievable, we have now extended the Near Eastern, European, and northern-Caucasus d…
The aryl hydrocarbon receptor modulates acute and late mast cell responses.
2012
Abstract The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor whose activity is modulated by xenobiotics as well as physiological ligands. These compounds may modulate inflammatory responses and contribute to the rising prevalence of allergic diseases observed in industrialized countries. Mast cells (MCs), located within tissues at the boundary of the external environment, represent a potential target of AhR ligands. In this study, we report that murine and human MCs constitutively express AhR, and its activation by the high-affinity ligand 6-formylindolo[3,2-b]carbazole (FICZ) determines a boost in degranulation. On the contrary, repeated exposure to FICZ inhibits…