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Wyświetlanie 1-48 z 48
Tytuł:
Using capillary electrophoresis to study methylation effect on RNA-peptide interaction.
Autorzy:
Mucha, Piotr
Szyk, Agnieszka
Rekowski, Piotr
Agris, Paul
Powiązania:
https://bibliotekanauki.pl/articles/1043465.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
methylated nucleosides
methylation
arginine methylation
RN-peptide interaction
capillary electrophoresis
Opis:
Methylation of RNA and proteins is one of a broad spectrum of post-transcriptional/translational mechanisms of gene expression regulation. Its functional signification is only beginning to be understood. A sensitive capillary electrophoresis mobility shift assay (CEMSA) for qualitative study of the methylation effect on biomolecules interaction is presented. Two RNA-peptide systems were chosen for the study. The first one consists of a 17-nucleotide analogue (+27-+43) of the yeast tRNAPhe anticodon stem and loop domain (ASLPhe) containing three of the five naturally occurring modifications (2'-O-methylcytidine (Cm32), 2'-O-methylguanine (Gm34) and 5-methylcytidine (m5C40)) (ASLPhe-Cm32,Gm34,m5C40) and a 15-amino-acid peptide (named tF2 : Ser1-Ile-Ser-Pro-Trp5-Gly-Phe-Ser-Gly-Leu10-Leu- Arg-Trp-Ser-Tyr15) selected from a random phage display library (RPL). A peptide-concentration-dependent formation of an RNA-peptide complex was clearly observable by CEMSA. In the presence of the peptide the capillary electrophoresis (CE) peak for triply methylated ASLPhe shifted from 18.16 to 20.90 min. Formation of the complex was not observed when an unmethylated version of ASLPhe was used. The second system studied consisted of the (+18)-(+44) fragment of the trans-activation response element of human immunodeficiency virus type 1 (TAR RNA HIV-1) and a 9-amino-acid peptide of the trans-activator of transcription protein (Tat HIV-1) Tat(49-57)-NH2 (named Tat1 : Arg49-Lys-Lys-Arg52-Arg-Gln-Arg-Arg- Arg57-NH2). In the presence of Tat(49-57)-NH2 a significant shift of migration time of TAR from 18.66 min to 20.12 min was observed. Methylation of a residue Arg52→Arg(Me)2, crucial for TAR binding, strongly disrupted formation of the complex. Only at a high micromolar peptide concentration a poorly shaped, broad peak of the complex was observed. CE was found to be an efficient and sensitive method for the analysis of methylation effects on interaction of biomolecules.
Źródło:
Acta Biochimica Polonica; 2003, 50, 3; 857-864
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mammalian DNA methyltransferases
Autorzy:
Siedlecki, Pawel
Zielenkiewicz, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1041231.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
DNA methyltransferases
DNA methylation
Opis:
DNA methylation is an epigenetic process affecting gene expression and chromatin organization. It can heritably silence or activate transcription of genes without any change in their nucleotide sequences, and for a long time was not recognized as an important regulatory mechanism. However, during the recent years it has been shown that improper methylation, especially hypermethylation of promoter regions, is observed in nearly all steps of tumorigenesis. Aberrant methylation is also the cause of several major pathologies including developmental disorders involving chromosome instabilities and mental retardation. A great progress has been made in our understanding of the enzymatic machinery involved in establishing and maintaining methylation patterns. This allowed for the development of new diagnostic tools and epigenetic treatment therapies. The new approaches hold a great potential; several inhibitors of DNA methyltransferases have already shown very promising therapeutic effects.
Źródło:
Acta Biochimica Polonica; 2006, 53, 2; 245-256
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DNA methylation dynamics under drought stress in barley
Autorzy:
Chwialkowska, K.
Szarejko, I.
Kwasniewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/81198.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
DNA methylation
gene expression
Hordeum vulgare
drought stress
spring barley
cytosine methylation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of C677T & A1298C mutations within the MTHFR gene by PCR and RFLP assays and assessment of risk factor of Hyperhomocysteinemia
Autorzy:
Amarakoon, A. A. D. Gayathri Upeksha
Fernandopulle, Neil
Powiązania:
https://bibliotekanauki.pl/articles/1182887.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
mthfr gene
dna methylation
hyperhomocysteinemia
Opis:
The MTHFR gene within the human genome, codes for the synthesis of Methylenetetrahydrofolate Reductase enzyme, which reduces 5,10-Methylenetetrahydrofolate to 5-Methyltetrahydrofolate, which in turn, is the major circulatory form of folate in the blood. Folate, in this form, among it’s other functions, is involved in reducing the homocysteine levels in the blood, whose elevated levels lead to Hyperhomocysteinemia, causing various major disorders. Mutations within the gene lead to impairment of gene function, in turn causing the homocysteine levels to rise. The C677T and A1298C mutations are the main causative agents for MTHFR gene disruption. During the course of the project, a total of 79 samples were analyzed for the presence of these mutations. The blood samples were first subjected to PCR, giving two separate DNA fragments each responsible for either of the conditions. The fragments were then subjected to RFLP analysis to detect the mutations. The results were finally given with respect to the risk factor faced by each individual based on a molecular diagnostic point of view.
Źródło:
World Scientific News; 2016, 53, 3; 253-274
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Olsalazine inhibits cell proliferation and DNA methylation in canine lymphoid tumor cell lines
Autorzy:
Itoh, S.
Yamazaki, J.
Iwahana, M.
Tsukamoto, A.
Powiązania:
https://bibliotekanauki.pl/articles/2087141.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DNA methylation
lymphoid tumors
olsalazine
canines
Źródło:
Polish Journal of Veterinary Sciences; 2021, 24, 4; 515-523
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global quantification of heterochromatin-associated histone methylations in cell lines with differential sensitivity to ionizing radiation
Autorzy:
Cetinkaya, Merve
Özgür, Emre
Dalay, Nejat
Gezer, Ugur
Powiązania:
https://bibliotekanauki.pl/articles/1039084.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
histone methylation
heterochromatin
radiosensitivity
ELISA immunoassay
Opis:
Histone modifications are involved in the DNA damage response (DDR). Here, by utilizing an ELISA immunoassay we assessed the methylation at H3K9 (H3K9me2 and H3K9me3) in two cell lines with differential sensitivity to radiation-induced apoptosis, HeLa (sensitive) and MCF-7 (resistant). We found that DNA damage induction by γ-irradiation leads to considerable accumulation (up to 5-fold) of H3K9me2 and H3K9me3, but not of H4K20me3 (control modification) in MCF-7 cells (p<0.05). Interestingly, a lower dose (2 Gy) was more effective than 5 Gy. In HeLa cells a smaller effect (approx. 1.5-1.8-fold) was evident only at 5 Gy. In conclusion, our findings reveal that DNA damage leads to specific accumulation of H3K9me2 and H3K9me3 in a cell-type specific manner.
Źródło:
Acta Biochimica Polonica; 2015, 62, 2; 173-176
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetyka zachowania: co wnosi do wiedzy o człowieku?
Autorzy:
Oniszczenko, Włodzimierz
Powiązania:
https://bibliotekanauki.pl/articles/1167863.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Kazimierza Wielkiego w Bydgoszczy
Tematy:
DNA
behavioural genetics
genetic correlation
heritability
methylation
Opis:
The aim of this article is to highlight the achievements of human behavioural genetics. It begins with a brief overview of the field of contemporary human behaviour genetics. Then, the general principles of behavioural genetics, research methods used, the concept of heritability and areas of rapid advancement in the field are identified. While classical twin studies have been a powerful tool to find heritability or the genetic correlation between different human behaviours, new tools are now available to help identify the genes responsible for individual differences. In particular, association studies and DNA methylation studies are crucial to advancing knowledge on the genetic basis of human behaviour as well as on the epigenetic factors that mediate genetic and environmental effects on behaviour. Several results on the heritability of human behaviour, relationships between genetic polymorphisms and behaviour as well as the consequences of DNA methylation are reported in this article.
Źródło:
Polskie Forum Psychologiczne; 2017, XXII, 1; 5-19
1642-1043
Pojawia się w:
Polskie Forum Psychologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sperm epigenetic profile and risk of cancer
Autorzy:
Wdowiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/3579.pdf
Data publikacji:
2014
Wydawca:
Instytut Medycyny Wsi
Tematy:
sperm
epigenetics
disease risk
cancer
DNA damage
methylation
Opis:
Introduction and objective. The integrity, stability and composition of sperm chromatin are of great importance in the fertilizing potential of male gametes and their capacity to support normal embryonic development. In this study, the author presents the current state of knowledge about the sperm epigenetic profile and risk of cancer. Abbreviated description of the state of knowledge. The obtaining of pregnancy and the state of health of the baby depends on the quality of the genetic material of both the female and the male. Health behaviours and environmental factors directly affect the quality of sperm, as well as the human egg cell and, consequently, on the reproductive capabilities, the course of pregnancy and the state of the newborn. There exist two thoroughly investigated epigenetic modifications: DNA methylation and histone modifications. The process of DNA methylation can be also a fundamental factor contributing to the development of cancer, where epigenotype undergoes significant modifications. When considering numerous DNA aberrations in the male gamete, the most commonly encountered is DNA fragmentation, particularly in infertile subjects. Surprisingly, an intracytoplasmatic sperm injection study of mice oocytes, using spermatozoa with a high DNA Fragmentation Index (DFI), revealed that a considerable percentage of adults born as a result of this method, showed a significant increase in the incidence of abnormal behavioural tests, malformations, cancer and signs of premature aging. Summary. The issue of assisted procreation raises the need to look for an appropriate treatment for males with sperm chromatin abnormalities. As a result, the fight against smoking addiction becomes the obvious necessity. Moreover, the reasonable solution nowadays seems to be supplementation with micronutrients and folic acid. It has been proved that the process of DNA fragmentation is a phenomenon that intensifies over time. Therefore, there should be a pursuance for, as close as possible, to the moment of ejaculation, application of semen to reproductive techniques. Finally, epigenetic changes are suspected of being one of the factors responsible for the deterioration of male sperm parameters observed in recent decades.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2014, 08, 2
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SOCS3 is epigenetically up-regulated in steroid resistant nephrotic children
Autorzy:
Zaorska, Katarzyna
Zawierucha, Piotr
Ostalska-Nowicka, Danuta
Nowicki, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1038853.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
methylation
nephrotic syndrome
single nucleotide polymorphism
steroid resistance
Opis:
Background. The mechanism of steroid resistance in children with the nephrotic syndrome is yet unknown. About 20% of patients demonstrate steroid unresponsiveness and progress to end stage renal disease. Aberrant SOCS3 and SOCS5 expression in steroid resistant and sensitive patients has previously been demonstrated. Here, we investigate genetic and epigenetic mechanisms of regulation of SOCS3 and SOCS5 transcription in nephrotic children. Methods. 76 patients with the nephrotic syndrome (40 steroid resistant and 36 steroid sensitive) and 33 matched controls were included in this study. We performed genotyping of a total of 34 single nucleotide polymorphisms for SOCS3 and SOCS5 promoters and evaluated their methylation status using MS-PCR and QMSP methods. Results. Steroid resistant patients had a significantly lower methylation of one region of SOCS3 promoter in comparison with steroid sensitive patients and controls (p < 0.0001). However, the relative methylation level in the steroid sensitive patients and controls differed significantly even before the first steroid dose (p = 0.001758). Other SOCS3 and SOCS5 promoter regions displayed no differences in methylation or were fully methylated/unmethylated in all study groups, showing site-specific methylation. The allele and genotype distribution for SOCS3 and SOCS5 markers did not differ statistically between the groups. Conclusions. We demonstrate an epigenetic mechanism of SOCS3 up-regulation in steroid resistant children with the nephrotic syndrome. The assessment of methylation/unmethylation of SOCS3 promoter might be an early marker for steroid responsiveness in NS patients.
Źródło:
Acta Biochimica Polonica; 2016, 63, 1; 131-138
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exogenous steroid hormones stimulate full development of autonomous endosperm in Arabidopsis thaliana
Autorzy:
Rojek, J.
Pawelko, L.
Kapusta, M.
Naczk, A.
Bohdanowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/59176.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
steroid hormone
endosperm
Arabidopsis thaliana
apomixis
DNA methylation
Opis:
Most flowering plants, including important crops, require double fertilization to form an embryo and endosperm, which nourishes it. Independence from fertilization is a feature of apomictic plants that produce seeds, from which the plants that are clones of the mother plant arise. The phenomenon of apomixis occurs in some sexual plants under specific circumstances. Since the launch of a fertilization-independent mechanism is considered a useful tool for plant breeding, there have been efforts to artificially induce apomixis. We have been able to produce fertilization-independent endosperm in vitro in Arabidopsis over the last few years. This paper demonstrates the methods of improving the quality of the endosperm obtained using plant and mammalian steroid hormones. Additionally, it shows the study on the autonomous endosperm (AE) formation mechanism in vitro. This paper examines the effect of exogenous steroid hormones on unfertilized egg and central cell divisions in culture of unpollinated pistils of Arabidopsis Col-0 wild-type andfie-1 mutant. All media with hormones used (estrone, androsterone, progesterone, and epibrassinolide) stimulated central cell divisions and fertilization-independent endosperm development. The stages of AE development followed the pattern of Arabidopsis thaliana wild type after fertilization. Subsequent stages of AE were observed from 2-nuclear up to cellular with the most advanced occurring on medium with 24-epibrassinolide and progesterone. The significant influence of mammalian sex hormones on speed of AE development and differentiation was noticed. Using restriction analysis, the changes in methylation of FIE gene was established under in vitro condition. The authors of this paper showed that Arabidopsis thaliana has a high potency to fertilization-independent development.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated statistical and rule-mining techniques for dna methylation and gene expression data analysis
Autorzy:
Mallik, S.
Mukhopadhyay, A.
Maulik, U.
Powiązania:
https://bibliotekanauki.pl/articles/1396742.pdf
Data publikacji:
2013
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
statistical analysis
gene marker
methylation
genetic algorithm
DNA
Opis:
For determination of the relationships among significant gene markers, statistical analysis and association rule mining are considered as very useful protocols. The first protocol identifies the significant differentially expressed/methylated gene markers, whereas the second one produces the interesting relationships among them across different types of samples or conditions. In this article, statistical tests and association rule mining based approaches have been used on gene expression and DNA methylation datasets for the prediction of different classes of samples (viz., Uterine Leiomyoma/class-formersmoker and uterine myometrium/class-neversmoker). A novel rule-based classifier is proposed for this purpose. Depending on sixteen different rule-interestingness measures, we have utilized a Genetic Algorithm based rank aggregation technique on the association rules which are generated from the training set of data by Apriori association rule mining algorithm. After determining the ranks of the rules, we have conducted a majority voting technique on each test point to estimate its class-label through weighted-sum method. We have run this classifier on the combined dataset using 4-fold cross-validations, and thereafter a comparative performance analysis has been made with other popular rulebased classifiers. Finally, the status of some important gene markers has been identified through the frequency analysis in the evolved rules for the two class-labels individually to formulate the interesting associations among them.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2013, 3, 2; 101-115
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes of DNA methylation and hydroxymethylation in plant protoplast cultures
Autorzy:
Moricová, Pavla
Ondřej, Vladan
Navrátilová, Božena
Luhová, Lenka
Powiązania:
https://bibliotekanauki.pl/articles/1039600.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Brassica oleracea
DNA hydroxymethylation
Cucumis sativus
protoplasts
DNA methylation
Opis:
Cytosine methylation patterns in higher eukaryotes are important in gene regulation. Along with 5-methylcytosine (5-mC), a newly discovered constituent of mammalian DNA, 5-hydroxymethylcytosine (5-hmC), is the other modified base in higher organisms. In this study we detected 5-hmC in plant protoplast DNA and demonstrated its increasing content during the first 72 hrs. of protoplast cultivation. In contrast to 5-hmC, the amount of 5-mC decreased during protoplast cultivation. It was also found that 5-hmC did not primarily arise as a product of oxidative DNA damage following protoplast culture.
Źródło:
Acta Biochimica Polonica; 2013, 60, 1; 33-36
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Link between methyl nutrients and the DNA methylation process in the course of selected diseases in adults
Autorzy:
Lobos, P.
Regulska-Ilow, B.
Powiązania:
https://bibliotekanauki.pl/articles/2086571.pdf
Data publikacji:
2021
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
DNA methylation
diet
methyl nutrients
one-carbon metabolism
epigenetics
Opis:
DNA methylation is a reversible epigenetic modification that plays a crucial role in transcriptional gene silencing. Both excessive (hypermethylation) and reduced DNA methylation (hypomethylation) can contribute to the disturbance of the proper course of many important processes in the human body. The aim of the study was to discuss the relationship between methyl nutrients and the DNA methylation process in the course of selected diseases in adults. Methyl nutrients include folates (vitamin B9), riboflavin (vitamin B2), cobalamin (vitamin B12), pyridoxine (vitamin B6) and choline (vitamin B4), as well as methionine and betaine. These substances play the role of both substrates and cofactors in transformations related to one-carbon metabolism. The deficiency of methyl nutrients in the body can lead to disturbances in SAM synthesis, which is the primary donor of methyl groups in the DNA methylation process. However, the mechanism explaining the discussed relationship has not been fully explained so far. Both the concentration in the body and the intake of folate and vitamin B12 in the diet can, to some extent, have an effect on the level of DNA methylation in healthy people. In comparison, data on the effect of excessive intake of vitamin B12 in the diet on the risk of cancer development are inconsistent. An adequate betaine and choline intake in the diet might not only affect the overall improvement of the DNA methylation profile, but, to some extent, also reduce the risk of cancer, the effect of which can depend on the content of folic acid in the body. Research results on the effect of supplementation of methyl nutrients on the DNA methylation process are inconclusive. It is therefore necessary to conduct further research in this area to draw clear conclusions
Źródło:
Roczniki Państwowego Zakładu Higieny; 2021, 72, 2; 123-136
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
H3K4 histone methylation in oral squamous cell carcinoma
Autorzy:
Mancuso, Marta
Matassa, Danilo
Conte, Mariachiara
Colella, Giuseppe
Rana, Gina
Fucci, Laura
Piscopo, Marina
Powiązania:
https://bibliotekanauki.pl/articles/1040528.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
oral squamous carcinoma
histone methylation
H3K4
Opis:
Methylation of specific lysine residues in histone tails has been proposed to function as a stable epigenetic marker that directs biological functions altering chromatin structure. Recent findings have implicated alteration in heterochromatin formation as a contributing factor in cancer development. In order to verify whether changes in the overall level of H3K4 histone methylation could be involved in oral squamous carcinoma, the levels of H3K4me1, me2 and me3 were measured in oral squamous carcinoma, leukoplakias and normal tissues. The levels of H3K4me2 and me3 were significantly different in oral squamous cell carcinoma in comparison with normal tissue: the level of H3K4me2 was increased while that of H3K4me3 decreased. No significant differences could be found between the two types of tissues in the level of H3K4me1. A similar trend was found in the leukoplakias that appeared more like the pathological than normal tissue. These results support the idea that alteration of chromatin structure could contribute to oncogenic potential.
Źródło:
Acta Biochimica Polonica; 2009, 56, 3; 405-410
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methylenetetrahydrofolate reductase gene polymorphisms in Egyptian Turner Syndrome patients
Autorzy:
Ismail, Manal
Zarouk, Waheba
Ruby, Mona
Mahmoud, Wael
Gad, Randa
Powiązania:
https://bibliotekanauki.pl/articles/1038999.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
chromosomal nondisjunction
DNA methylation
folate
MTHFR gene
Turner Syndrome
Opis:
Background: Folate metabolism dysfunctions can result in DNA hypomethylation and abnormal chromosome segregation. Two common polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) encoding gene (C677T and A1298C) reduce MTHFR activity, but when associated with aneuploidy, the results are conflicting. Turner Syndrome (TS) is an interesting model for investigating the association between MTHFR gene polymorphisms and nondisjunction because of the high frequency of chromosomal mosaicism in this syndrome. Objective: To investigate the association of MTHFR gene C677T and A1298C polymorphisms in TS patients and their mothers and to correlate these polymorphisms with maternal risk of TS offspring. Subjects and Methods: MTHFR C677T and A1298C polymorphisms were genotyped in 33 TS patients, their mothers and 15 healthy females with their mothers as controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing technique. Results: Genotype and allele frequencies of both C677T and A1298C were not significantly different between TS cases and controls. There were no significant differences in C677T genotype distribution between the TS mothers and controls (p=1). The MTHFR 1298AA and 1298AC genotypes were significantly increased in TS mothers Vs. control mothers (p=0.002). The C allele frequency of the A1298C polymorphism was significantly different between the TS mothers and controls (p=0.02). The association of A1298C gene polymorphism in TS patients was found to increase with increasing age of both mothers (p=0.026) and fathers (p=0.044) of TS cases. Conclusion: Our findings suggest a strong association between maternal MTHFR A1298C and risk of TS in Egypt.
Źródło:
Acta Biochimica Polonica; 2015, 62, 3; 529-532
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of CpG islands in two genotypes of African swine fever virus
Autorzy:
Yu, Y.-Y.
X, M.-S.
Liu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/16539329.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
African Swine Fever Virus (ASFV)
genotype
DNA methylation
CpG island
Opis:
African swine fever (ASF) is an acute, hemorrhagic, and devastating viral infectious disease that causes important economic losses to the swine industry. Currently, there are no effective vaccines or drugs available. Epigenetic mechanisms, especially cytosine methylation of cytosine-phosphate-guanine (CpG) islands, have a significant impact on the life cycle of several viruses. Hence, drugs targeting DNA methylation may potentially be used for the treatment of ASF. Here, we selected the inner core, core shell, inner membrane, capsid, and external envelope membrane, to analyze the characteristics of CpG islands in the ASF virus (ASFV) genomes. Furthermore, we analyzed the promoters and CpG islands in the upstream regions of these genes. Results showed that the CpG islands of seven genes were conserved in the genomes of two genotype of ASFV strains, whereas the CpG islands of other genes were relatively conserved (ASFV strains differed mainly in the quantity of CpG islands). The different distribution of CpG islands in the genomes of different ASFV strains may affect their methylation status, which may in turn affect the regulation of viral gene expression, leading to different clinical outcomes. In addition, the predicted promoter regions based on the upstream sequences of most genes overlapped with CpG island positions. Methylation of the binding sites of the promoter regions inhibits the binding of the transcription factors to the promoters, thus inhibiting the activation of the promoters and limiting the synthesis of viral proteins. The results of this study provide a basis for exploring new antiviral therapeutic strategies from an epigenetic perspective.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 3; 455-462
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation of chromosome damage and promoter methylation status of the DNA repair genes MGMT and hMLH1 in Chinese vinyl chloride monomer (VCM)-exposed workers
Autorzy:
Wu, Fen
Liu, Jing
Qiu, Yu-Lan
Wang, Wei
Zhu, Shou-Min
Sun, Pin
Miao, Wen-Bin
Li, Yong-Liang
Brandt-Rauf, Paul W.
Xia, Zhao-Lin
Powiązania:
https://bibliotekanauki.pl/articles/2179802.pdf
Data publikacji:
2013-03-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
vinyl chloride monomer
chromosome damage
MGMT
hMLH1
DNA methylation
Opis:
Objective: To explore the association of the methylation status of MGMT and hMLH1 with chromosome damage induced by vinyl chloride monomer (VCM). Materials and Methods: Methylation of MGMT and hMLH1 was measured in 101 VCM-exposed workers by methylation-specifi c PCR. Chromosome damage in peripheral blood lymphocytes was measured by the cytokinesis-block micronucleus assay. The subjects were divided into chromosome damaged and non-damaged groups based on the normal reference value of micronuclei frequencies determined for two control groups. Results: MGMT promoter methylation was detectable in 5 out of 49 chromosome damaged subjects, but not in the chromosome non-damaged subjects; there was a signifi cant difference in MGMT methylation between the two groups (p < 0.05). Conclusions: We detected aberrant promoter methylation of MGMT in a small number of chromosome damaged VCM-exposed workers, but not in the chromosome non-damaged subjects. This preliminary observation warrants further investigation in a larger study.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2013, 26, 1; 173-182
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Paidagogos (παιδαγωγός) i ars educandi (αρς εδυκανδι) w kontekście epigenetyki
Paidagogos (παιδαγωγός) and ars educandi (αρς εδυκανδι) in the context of epigenetics
Autorzy:
Dyk, Wiesław
Powiązania:
https://bibliotekanauki.pl/articles/2011184.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
epigenetics
nutrigenomics
nutrigenetics
DNA methylation
parenting
epigenetyka
nutrigenomika
nutrigenetyka
metylacja
wychowanie
Opis:
Ewolucyjnie każdy żywy organizm związany jest ze swym naturalnym środowiskiem. Dostosowanie się do otoczenia i jego zmian, by przeżyć, zawsze towarzyszyło człowiekowi. Dbałość o pokarm, ale nie przejadanie się, było przepustką do obecnego i przyszłego życia. Przeżyły te gatunki, które dostosowały pokarm do potrzeb swojego organizmu. Wśród Homo sapiens przeżył gatunek Homo sapiens sapiens, kromaniończyk, gdyż dzięki wysokiej inteligencji dbał o jakość pożywienia. Współczesne technologie żywności i pęd życia wprowa¬dził degradację ludzkiej natury. Powstała niezgodność między genami i pożywieniem. Nie zawsze wyżywienie służy organizmowi człowieka i nie zawsze umożliwia jego osobowościowe, kreatywne trwanie w środowisku naturalnym. Aby działać i tworzyć najpierw trzeba się właściwie odżywiać. Kształtowanie osobowości wsparte jest rodzajem, jakością i wartością pożywienia.
From evolution standpoint, every living organism is bound with its environment. Adaptation to the environment and its changes had always accompanied Man. Taking care of food but not overeating was a pass to current and future life. The species which did not overeat, had survived. Amongst Homo sapiens, Homo sapiens sapiens and Homo Cro-Magnon survived, because having future in mind, it took care of the food’s quality. Contemporary food technologies and rate of living introduced degeneration of human nature. A chaos had occurred between genes and food. Food is not always in benefit of human organism and its personal, creative existence in natural environment. To act and create you must be first full. Shaping the personality is supported by the type, quality and value of food.
Źródło:
Studia Koszalińsko-Kołobrzeskie; 2020, 27; 359-370
1230-0780
2719-4337
Pojawia się w:
Studia Koszalińsko-Kołobrzeskie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epi-genes potentiate plant biodiversity
Autorzy:
Szopa, J.
Powiązania:
https://bibliotekanauki.pl/articles/951285.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biodiversity
oligonucleotide
DNA methylation
gene expression
protein
methylase
polymerase
RNA polymerase
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in DNA methylation in maize under herbicide stress conditions
Autorzy:
Tyczewska, A.
Gracz, J.
Szymkowiak, J.
Twardowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/951318.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DNA methylation
chromatin modification
gene silencing
gene transcription
maize
herbicide stress
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Znaczenie epigenetyki w patogenezie czerniaka
The role of epigenetics in the pathogenesis of melanoma
Autorzy:
Chodurek, Ewa
Gołąbek, Karolina
Orchel, Joanna
Orchel, Arkadiusz
Dzierżewicz, Zofia
Powiązania:
https://bibliotekanauki.pl/articles/1038734.pdf
Data publikacji:
2012
Wydawca:
Śląski Uniwersytet Medyczny w Katowicach
Tematy:
epigenetyka
czerniak
metylacja dna
acetylacja histonów
epigenetics
melanoma
dna methylation
histone acetylation
Opis:
Epigenetics represents the mechanisms that influence the regulation and modification of the expression of genetic material not related to the alterations in DNA sequences. These mechanisms include both DNA methylation and histone modifications. In the present article, we review current views on the role of aberrations of DNA hyper- and hypomethylation processes and the acetylation of histones, associated with genes that control the cell cycle, cell differentiation, DNA repair, apoptosis, cell signaling, angiogenesis, metabolism of xenobiotics and invasion, in the pathogenesis of melanoma. In addition, new strategies for treatment of melanoma associated with epigenetics are presented.
Przez pojęcie epigenetyka należy rozumieć mechanizmy wpływające na regulację i modyfi kację ekspresji materiału genetycznego, jednocześnie niezmieniające sekwencji nukleotydów. Mechanizmy te obejmują zarówno metylację DNA, jak i modyfikacje histonów. W artykule dokonano przeglądu aktualnych poglądów dotyczących zaburzeń procesów hiperihipometylacji DNA oraz acetylacji histonów w patogenezie czerniaka, związanych z genami kontrolującymi cykl komórkowy, różnicowanie, naprawę DNA, apoptozę, sygnalizację komórkową, angiogenezę, metabolizm ksenobiotyków i powstawanie przerzutów. Ponadto przedstawiono nowe strategie leczenia czerniaka związane z epigenetyką.
Źródło:
Annales Academiae Medicae Silesiensis; 2012, 66, 3; 44-56
1734-025X
Pojawia się w:
Annales Academiae Medicae Silesiensis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epigenetics is promising direction in modern science
Autorzy:
Fartushok, Tetiana
Kovalyshyn, Orysia
Fedevych, Yuri
Tanchyn, Igor
Zhykovskiy, Volodymyr
Powiązania:
https://bibliotekanauki.pl/articles/2175208.pdf
Data publikacji:
2021
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
epigenetics
5-methylcytosine
DNA methylation
histone
epigenetyka
5-metylocytozyna
metylacja DNA
histon
Opis:
Epigenetics studies the inherited changes in a phenotype or in expression of genes caused by other mechanisms, without changing the nucleotide sequence of DNA. The most distinguished epigenetic tools are: modifications of histones, enzymatic DNA methylation, and gene silencing mediated by small RNAs (miRNA, siRNA). The resulting m5C residues in DNA substantially affect the cooperation of proteins with DNA. It is organized by hormones and aging-related alterations, one of the mechanisms controlling sex and cellular differentiation. DNA methylation regulates all genetic functions: repair, recombination, DNA replication, as well as transcription. Distortions in DNA methylation and other epigenetic signals lead to diabetes, premature aging, mental dysfunctions, and cancer.
Źródło:
Chemistry-Didactics-Ecology-Metrology; 2021, 26, 1-2; 123--135
2084-4506
Pojawia się w:
Chemistry-Didactics-Ecology-Metrology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of selected amino acids on the dynamic properties of the liposome membranes : ESR study
Autorzy:
Man, D.
Broda, M.
Buczek, A.
Kawecka, A.
Siodłak, D.
Powiązania:
https://bibliotekanauki.pl/articles/146690.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
EYL liposomes
electron spin resonance (ESR) method
N-methylation
amino acids
peptides
Opis:
In this work the changes in the fluidity of liposome membranes caused by alanine and butyrine derivatives (Ac-Ala-NMe2 and Ac-Abu-NMe2) were investigated. Liposomes were obtained in the process of egg yolk lecithin (EYL) sonication. The concentration of the admixture in the proportion to EYL varied from 0 to 25% mole. The electron spin resonance (ESR) spectroscopy was used with two different spins probes. Each spin probe penetrates different regions of liposome membrane. The TEMPO probe occurs both in the hydrophobic part of the membrane and in the water environment what allows to determine the spectroscopic parameter F of division of this probe into the membrane and its water surrounding. DOXYL is localized in the central part of the lipid bilayer and is used to obtain the spectroscopic parameter τ – rotation correlation time – whose value gives information about fluidity changes in the middle of the lipid bilayer. The study indicated that the tested as admixtures N-methylated model peptides significantly changed the fluidity of liposome membranes. The dynamic of this process depends both on amino acids derivative and on the membrane region. Both studied compounds increased the fluidity of the surface layer of liposome membrane. At the same time, butyrine derivative caused the stiffening of the middle part of liposome bilayer, but alanine derivative slightly increased the fluidity of this region.
Źródło:
Nukleonika; 2013, 58, 3; 443-446
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of the in vitro genotoxicity of anticancer drugs idarubicin and mitoxantrone.
Autorzy:
Błasiak, Janusz
Gloc, Ewa
Warszawski, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1043821.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mitoxantrone
oxidative DNA damage
DNA damage
idarubicin
comet assay
DNA methylation
DNA repair
Opis:
Idarubicin is an anthracycline antibiotic used in cancer therapy. Mitoxantrone is an anthracycline analog with presumed better antineoplastic activity and lesser toxicity. Using the alkaline comet assay we showed that the drugs at 0.01-10 μM induced DNA damage in normal human lymphocytes. The effect induced by idarubicin was more pronounced than by mitoxantrone (P < 0.001). The cells treated with mitoxantrone at 1 μM were able to repair damage to their DNA within a 30-min incubation, whereas the lymphocytes exposed to idarubicin needed 180 min. Since anthracyclines are known to produce free radicals, we checked whether reactive oxygen species might be involved in the observed DNA damage. Catalase, an enzyme inactivating hydrogen peroxide, decreased the extent of DNA damage induced by idarubicin, but did not affect the extent evoked by mitoxantrone. Lymphocytes exposed to the drugs and treated with endonuclease III or formamidopyrimidine-DNA glycosylase (Fpg), enzymes recognizing and nicking oxidized bases, displayed a higher level of DNA damage than the untreated ones. 3-Methyladenine-DNA glycosylase II (AlkA), an enzyme recognizing and nicking mainly methylated bases in DNA, increased the extent of DNA damage caused by idarubicin, but not that induced by mitoxantrone. Our results indicate that the induction of secondary malignancies should be taken into account as side effects of the two drugs. Direct strand breaks, oxidation and methylation of the DNA bases can underlie the DNA-damaging effect of idarubicin, whereas mitoxantrone can induce strand breaks and modification of the bases, including oxidation. The observed in normal lymphocytes much lesser genotoxicity of mitoxantrone compared to idarubicin should be taken into account in planning chemotherapeutic strategies.
Źródło:
Acta Biochimica Polonica; 2002, 49, 1; 145-155
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantification of 5-methyl-2-deoxycytidine in the DNA
Autorzy:
Giel-Pietraszuk, Małgorzata
Insińska-Rak, Małgorzata
Golczak, Anna
Sikorski, Marek
Barciszewska, Mirosława
Barciszewski, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1039105.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
DNA methylation
3,N4-etheno-5-methyl-2'deoxcytidine
fluorescence
RP-HPLC
Opis:
Methylation at position 5 of cytosine (Cyt) at the CpG sequences leading to formation of 5-methyl-cytosine (m5Cyt) is an important element of epigenetic regulation of gene expression. Modification of the normal methylation pattern, unique to each organism, leads to the development of pathological processes and diseases, including cancer. Therefore, quantification of the DNA methylation and analysis of changes in the methylation pattern is very important from a practical point of view and can be used for diagnostic purposes, as well as monitoring of the treatment progress. In this paper we present a new method for quantification of 5-methyl-2'deoxycytidine (m5C) in the DNA. The technique is based on conversion of m5C into fluorescent 3,N4-etheno-5-methyl-2'deoxycytidine (εm5C) and its identification by reversed-phase high-performance liquid chromatography (RP-HPLC). The assay was used to evaluate m5C concentration in DNA of calf thymus and peripheral blood of cows bred under different conditions. This approach can be applied for measuring of 5-methylcytosine in cellular DNA from different cells and tissues.
Źródło:
Acta Biochimica Polonica; 2015, 62, 2; 281-286
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Psychology goes molecular. Epigenetics of learning
Autorzy:
Barciszewski, jan
Gurda, Dorota
Paluchowski, Władysław Jacek
Hornowska, Elżbieta
Jasielska, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/703903.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
behavioral epigenetics
cognitive functions
DNA methylation
epigenetic inheritance
epigenetics
gene-environment interplay
learning
memory
Opis:
The challenge for psychology is to integrate findings from genetics and environmental (social, biological, chemical) factors, into the study of human behavior and deep understanding of the emergence of different changes in the anatomy, physiology, and chemistry of the nervous system that influence the mental health. Currently, cognitive abilities associated with learning and memory, reasoning, problem solving, and developing relationships are in scope of molecular psychology, which is the study of behavior and its underlying brain systems using the tools of molecular biology. However, studies have demonstrated that DNA sequence variations and rare mutations account for only a small fraction of the risk for inheritance of personality traits and mental illness. The large unaccounted heritability of personality traits and mental health suggest that additional molecular and cellular mechanisms are involved. Various complex gene-environment interactions can lead to different phenotypes. These structural changes may be crucial for the development of mature neural networks that support emotional, cognitive, and social behavior. The generation of different morphology, physiology, and behavioral outcomes from a single genome in response to changes in the environment forms the basis for phenotypic plasticity, which is fundamental to the way organisms cope with environmental variation, navigate the present world, and solve future problems. Epigenetics has major implications for psychology and gives the new answer for the old question- what is the biochemical basis of learning. It is bringing back the leading role of environment and behavior, by including their effects on genome function. In addition, it opens up the possibility of memory being stored in the epigenome, so that our experiences may be embedded in our genome by epigenetic mechanisms. Epigenetics can be described as the study of the complex interactions underlying the development of an organism over its lifetime.
Źródło:
Nauka; 2016, 4
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of DNA methyltransferase and histone deacetylase inhibitors on αKlotho gene expression in bladder cancer T24 cell line
Wpływ inhibiotorów metylotransferaz DNA oraz deacetylaz białek histonowych na kspresję genu αKlotho w komórkach raka pęcherza moczowego linii T24
Autorzy:
Szymczyk, Agnieszka
Forma, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/1032842.pdf
Data publikacji:
2014
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
bladder cancer
klotho
dna methylation
histone deacetylation
rak pęcherza moczowego
metylacja dna
deacetylacja histonów
Opis:
Introduction: αKlotho gene was originally identified as a putative agesuppressing gene in mice. Recently it is known that αKlotho gene functions as a tumor suppressor in many types of cancer, including breast, pancreas, gastric, colon, lung and cervical cancer. The downregulation of αKlotho expression was associated with CpG hipermethylation of promoter region and histone deacetylation. Bladder cancer is the most common cancer of the urinary tract in Polish population. The aim of this study was the analysis of the effect of DNA methyltransferase and histone deacetylase inhibitors on αKlotho gene expression in bladder cancer cells. Materials and methods: In this study T24 bladder cancer cell line was used. The analysis of the effect of DNA methyltransferase and histone deacetylase inhibitors on αKlotho gene expression was performed using Real Time PCR method with TaqMan probes. To determine the methylation profile of αKlotho gene promoter region quantitive Methylation-Specific Polymerase Chain Reaction technique was used. Results: The treatment of T24 cells with DNA methyltransferase inhibitor (AZA) restored the expression of αKlotho gene. After AZA treatment, the methylation level of CpG island in the promoter region of αKlotho gene was nearly half lower (p<0.05) than control cells. In case of the treatment of T24 cells with histone deacetylase inhibitor (TSA) we did not observe any changes in αKL gene expression in respect to the control cells. Treatment cells with both the inhibitors led to the significant increase of mRNA αKlotho gene expression level (p<0.001). Conclusions: The changes in αKlotho gene expression on mRNA level are associated with epigenetic changes.
Wstęp: Gen αKlotho pierwotnie zidentyfikowany został u myszy jako gen, którego ekspresja wpływa na długość ich życia. Obecnie wiadomo, że αKlotho spełnia funkcję genu supresorowego w przypadku wielu typów nowotworów, m.in. w raku piersi, trzustki, żołądka, płuc, okrężnicy i raku szyjki macicy. Wykazano, że spadek ekspresji genu αKlotho związany jest z hipermetylacją wysp CpG w obrębie regionu promotorowego oraz deacetylacją histonów. Rak pęcherza moczowego jest najczęściej występującym nowotworem układu moczowego w Polsce. Celem prowadzonych badań była analiza wpływ inhibitorów metylotransferaz DNA oraz deacetylaz białek histonowych na ekspresję genu αKlotho w komórkach raka pęcherza moczowego. Materiały i metody: Materiał do badań stanowiła linia komórek raka pęcherza moczowego T24. Analizę wpływu inhibitorów metylotransferaz DNA oraz deacetylaz białek histonowych na ekspresję genu αKlotho prowadzono techniką Real Time PCR z użyciem sond fluorescencyjnych TaqMan. Ocenę stopnia metylacji regionu promotorowego badanego genu prowadzono przy użyciu techniki ilościowego MSP-PCR (ang. Methylation-Specific Polymerase Chain Reaction). Wyniki: W wyniku traktowania komórek linii T24 inhibitorem metylotransferaz DNA (AZA) obserwowano przywrócenie ekspresji genu αKlotho. W porównaniu do komórek kontrolnych, komórki traktowane 5-aza-2′-deoksycytydyną wykazywały blisko o połowę niższy stopień metylacji wysp CpG w regionie promotorowym genu αKlotho (p<0,05). W wyniku traktowania komórek inhibitorem deacetylaz białek histonowych (TSA) nie obserwowano zmian w ekspresji genu αKL. Zastosowanie obu inhibitorów prowadziło do istotnego wzrostu ekspresji genu αKlotho na poziomie mRNA (p<0,001). Wnioski: Zmiany ekspresji genu αKlotho na poziomie mRNA związane są ze zmianami we wzorze modyfikacji epigenetycznych.
Źródło:
Folia Medica Lodziensia; 2014, 41, 2; 111-119
0071-6731
Pojawia się w:
Folia Medica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in DNA methylation of embryonic axes of seeds of oak and beech during in vitro culture and cryopreservation
Autorzy:
Nuc, K.
Marszalek, M.
Pukacki, P.M.
Powiązania:
https://bibliotekanauki.pl/articles/80269.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
DNA methylation
plant growing
embryonic axis
seed
oak
beech
in vitro culture
cryopreservation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of epigenetic changes induced by particular phytohormones and oligonucleotide sequences in flax
Autorzy:
Dzialo, M.
Zuk, M.
Szopa-Skorkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/951289.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
epigenetic change
phytohormone
oligonucleotide
flax
Linum usitatissimum
DNA sequence
methylation
flavonoids
chalcone synthase
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of temperature on o-cresol methylation in a fluidized bed of commercial iron-chromium catalyst TZC-3/1
Autorzy:
Berkowicz, G.
Żukowski, W.
Baron, J.
Powiązania:
https://bibliotekanauki.pl/articles/778096.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
2,6-dimethylphenol
o-cresol methylation
iron-chromium catalyst TZC-3/1
fluidized bed
Opis:
The paper presents the results of the synthesis of 2,6-dimetyhlphenol (26DMP) from o-cresol. The target compound is an important substrate for polymer chemistry. Due to a large amount of o-cresol which is generated as a by-product, during the synthesis of 2,6-dimethylphenol from phenol, the methylation of o-cresol to 2,6-dimethylphenol should be examined as a separate process. The alkylation of o-cresol was carried out in a fluidized bed of commercial iron-chromium catalyst TZC-3/1. Undesirable decomposition of methyl alcohol on the catalyst generates a number of environmentally dangerous by-products such as methane, carbon dioxide, carbon monoxide. The effect of temperature on the yield of the synthesis was investigated. The synthesis process was monitored on-line in the temperature range 310-380°C, completely covering the maximum efficiency of the process. Online analysis of the process by FTIR spectroscopy gave information about products of both methylation of o-cresol and pyrolysis of methanol. The maximum 85% yield of desired 2,6-dimethylphenol with more than 85% conversion of o-cresol was achieved at 340°C, at 1:6 molar ratio of o-cresol:methanol.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 3; 100-102
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sequence determination and analysis of S-adenosyl-L-homocysteine hydrolase from yellow lupine (Lupinus luteus).
Autorzy:
Brzeziński, Krzysztof
Janowski, Robert
Podkowiński, Jan
Jaskólski, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1044143.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Southern blot
S-adenosyl-L-homocysteinase
Northern blot
biological methylation
screening of cDNA library
phylogeny
Opis:
The coding sequences of two S-adenosyl-L-homocysteine hydrolases (SAHases) were identified in yellow lupine by screenig of a cDNA library. One of them, corresponding to the complete protein, was sequenced and compared with 52 other SAHase sequences. Phylogenetic analysis of these proteins identified three groups of the enzymes. Group A comprises only bacterial sequences. Group B is subdivided into two subgroups, one of which (B1) is formed by animal sequences. Subgroup B2 consist of two distinct clusters, B2a and B2b. Cluster B2b comprises all known plant sequences, including the yellow lupine enzyme, which are distinguished by a 50-residue insert. Group C is heterogeneous and contains SAHases from Archaea as well as a new class of animal enzymes, distinctly different from those in group B1.
Źródło:
Acta Biochimica Polonica; 2001, 48, 2; 477-483
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of Fanconi anemia/BRCA pathway genesin laryngeal carcinoma
Autorzy:
Szaumkessel, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/1401931.pdf
Data publikacji:
2014
Wydawca:
Index Copernicus International
Tematy:
Fanconi anemia/BRCA pathway
DNA repair
Laryngeal carcinoma
DNA methylation
microRNA
mRNA level
FANCA gene
Opis:
Summary of Doctoral Thesis/Streszczenie pracy doktorskiej
Źródło:
Polski Przegląd Otorynolaryngologiczny; 2014, 3, 4; 250-252
2084-5308
2300-7338
Pojawia się w:
Polski Przegląd Otorynolaryngologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
LBP gene methylation involved in mRNA expression and resistance to E. coli F18 in weaned piglets
Autorzy:
Gan, L.N.
Bao, W.B.
Wu, S.L.
Qin, W.Y.
Sun, L.
Zhao, C.X.
Powiązania:
https://bibliotekanauki.pl/articles/2087872.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
LBP gene
methylation analysis of the LBP region
E.coli F18 strain
weaned piglets
Źródło:
Polish Journal of Veterinary Sciences; 2017, 4; 643-650
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reactive oxygen species and DNA methylation changes in wounded maize leaves
Autorzy:
Lewandowska-Gnatowska, E.
Polkowska-Kowalczyk, L.
Barciszewska, M.
Szczegielniak, J.
Barciszewski, J.
Muszynska, G.
Powiązania:
https://bibliotekanauki.pl/articles/80319.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
reactive oxygen species
DNA methylation
leaf
maize
dynamic change
5-methylcytosine
ELISA test
gene expression
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modyfikacje epigenetyczne jako potencjalne cele terapii antynowotworowych
Epigenetic modifications as potential targets of anti-cancer therapy
Autorzy:
Kulczycka, Anna
Bednarek, Ilona
Dzierżewicz, Zofia
Powiązania:
https://bibliotekanauki.pl/articles/1034844.pdf
Data publikacji:
2013
Wydawca:
Śląski Uniwersytet Medyczny w Katowicach
Tematy:
epigenetyka
dna
histony
metylacja
acetylacja
fosforylacja
terapie antynowotworowe
epigenetics
histones
methylation
acetylation
phosphorylation
anti-cancer treatments
Opis:
Epigenetics analyses inherited characteristics not directly connected to the DNA nucleotide sequence. It investigates the relationships between biochemical modifications and the expression of selected genes. Initially, it was thought that gene expression depends on information encoded in the DNA sequence. However, it was discovered that the activity of many enzymes like methylases, demethylases, acetylases, deacetylases is necessary to regulate this process and its dysregulations may lead to e.g. cancer initiation and progression. Epigenetics has an impact on neoplastic transformation by reducing the global level of DNA methylation and increasing the methylation level within tumour suppressor gene promoters, which significantly impairs the repression of carcinogenesis. Additionally, modifications of histone proteins, based on disorders of acetylation-deacetylation and methylation-demethylation processes, may lead to overexpression of genes involved in cancer development. Numerous examples have been described, among others breast, prostate and colon cancers, depending on the modification of histone amino tails, primarily of histone H3. For such reasons, the possibility of using many therapies which can reverse the negative effect of these modifications by e.g. DNA demethylation (DNA demethylating drugs) or re-acetylation of histone lysine resides (histone deacetylase inhibitors) is examined. In the near future, epigenetics probably will allow the effective treatment of some cancer diseases, although further research on the impact of enzymatic modifications on the development of carcinogenesis is still needed.
Epigenetyka zajmuje się badaniem cech dziedzicznych, które nie zależą bezpośrednio od sekwencji nukleotydowej w DNA, ale są rezultatem modyfikacji biochemicznych na ekspresję wybranych genów. Początkowo uważano, że ekspresja genów zależy tylko od informacji zapisanej zawartej w sekwencji DNA, z czasem okazało się, że liczne modyfikacje będące rezultatem działania różnych grup enzymów, w tym metylaz, demetylaz, acetylaz czy deacetylaz, wpływają na regulację tego procesu, a zaburzenia regulacji aktywności tych enzymów mogą prowadzić do wystąpienia i rozwoju m.in. nowotworów. Epigenetyczny aspekt rozwoju transformacji nowotworowej wskazuje na obniżenie globalnego poziomu metylacji DNA oraz podwyższenie poziomu metylacji w obrębie promotorów genów supresorowych, co znacząco upośledza represję nowotworzenia. Dodatkowo, modyfikacje białek histonowych, opierające się na dysregulacji procesów acetylacji–deacetylacji i metylacji – demetylacji, prowadzą do nadekspresji genów zaangażowanych w rozwój kancerogenezy. Opisane zostały liczne przykłady zależności wystąpienia nowotworów, m.in. raka sutka, stercza czy okrężnicy od wystąpienia danej modyfikacji reszt aminokwasowych białek histonowych, w tym głównie histonu H3. Z takich też przyczyn podejmowane są próby zastosowania terapii odwracających negatywny skutek wybranych modyfikacji, np. poprzez demetylację DNA (leki demetylujące DNA) czy reacetylację reszt lizynowych histonów (inhibitory decetylaz histonów). W niedalekiej przyszłości epigenetyka najprawdopodobniej u możliwi skuteczne leczenie części chorób nowotworowych, aczkolwiek konieczne są dalsze badania wpływu modyfikacji enzymatycznych na mechanizm rozwoju kancerogenezy.
Źródło:
Annales Academiae Medicae Silesiensis; 2013, 67, 3; 201-208
1734-025X
Pojawia się w:
Annales Academiae Medicae Silesiensis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Konformacyjne właściwości modyfikowanych reszt aminokwasowych
Conformational properties of modified amino acid residues
Autorzy:
Wałęsa, R.
Buczek, A.
Broda, A.
Powiązania:
https://bibliotekanauki.pl/articles/143003.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
dehydrofenyloalanina
N-metylowanie
analiza konformacyjna
obliczenia DFT
wpływ rozpuszczalnika
dehydrophenylalanine
N-methylation
conformational analysis
DFT calculations
solvent impact
Opis:
Konformacyjnie usztywnione aminokwasy są szeroko stosowane przy konstruowaniu peptydowych analogów o lepszych właściwościach farmako-kinetycznych. Jednym z sposobów modyfikacji peptydów jest wprowadzenie reszt a,b-dehydroaminokwasowych w łańcuch peptydowy. Podwójne wiązanie Ca=Cb usztywnia łańcuch boczny i umożliwia występowanie izomerii geometrycznej Z/E. Innym rodzajem modyfikacji jest zastąpienie amidowej grupy –NH grupą –NCH3, czyli tzw. N-metylowanie. Autorzy określili wpływ tych dwóch modyfikacji strukturalnych na konformację łańcucha peptydowego. Przeprowadzone badania pozwoliły ustalić, że reszta a,b-dehydrofenyloalaniny aminokwasów konformacji H. Wykazano również, że polarny rozpuszczalnik zwiększa wyraźnie udział konfiguracji cis wiązania amidowego w N-metylowanych peptydach.
Conformationally constrained amino acids are widely used in the design of peptide analogues with better pharmacokinetic properties. One of the methods of peptide modification is the introduction of a, b -dehydroamino acid residues into peptide chain. The double bond Ca=Cb constrains side chain and enables occurrence of geometrical isomerism Z/E. The other type of modification is the replacement of amide group –NH with group –NCH3, i.e. so called N-methylation. The Authors have determined the impact of these two structural modifications on peptide chain conformation. Conducted research has lead to the conclusion that -dehydrophenylalanine residue has the ability to exhibit atypical for standard amino acids H conformation. It has also been shown that polar solvent clearly increase percentage of cis configuration of amide bond in N-methylated peptides.
Źródło:
Chemik; 2014, 68, 4; 329-334
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Brachypodium distachyon – a model plant to study grass genome structure, dynamics and evolution
Autorzy:
Idziak, D.
Hasterok, R.
Betekhtin, A.
Borowska-Zuchowska, N.
Braszewska-Zalewska, A.
Chwialkowska, K.
Gorkiewicz, R.
Kus, A.
Kwasniewska, J.
Kwasniewski, M.
Robaszkiewicz, E.
Siwinska, D.
Wolny, E.
Chrominski, K.
Tkacz, M.
Powiązania:
https://bibliotekanauki.pl/articles/951271.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Brachypodium distachyon
model plant
grass
genome structure
Expressed Sequence Tag programme
fluorescent in situ hybridization
chromosome painting
DNA methylation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular mechanisms of lead toxicity
Autorzy:
Szymanski, M.
Powiązania:
https://bibliotekanauki.pl/articles/80273.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lead toxicity
molecular mechanism
heavy metal
oxidative stress
DNA damage
calcium binding protein
zinc finger protein family
DNA methylation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2014, 95, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study on tissue culture induced variation identified with metAFLP and RP – HPLC in barley and triticale regenerants
Autorzy:
Machczynska, J.
Orlowska, R.
Ogorek, K.A.
Bednarek, P.T.
Powiązania:
https://bibliotekanauki.pl/articles/951298.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
tissue culture
in vitro culture
plant regeneration
genetic change
DNA methylation
histone modification
high performance liquid chromatography
barley
triticale
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A stable density approach to probe selection for a custom aCGH design
Autorzy:
Gambin, T.
Stankiewicz, P.
Gambin, A.
Powiązania:
https://bibliotekanauki.pl/articles/81185.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
genomic region
probe
copy number alternation
comparative genomic hybridization
human genome
microarray
wide range application
gene expression
methylation
binding protein
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2011, 92, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modyfikacje epigenetyczne a ekspresja genów w nowotworzeniu
Epigenetic modifications and gene expression in cancerogenesis
Autorzy:
Poczęta, Marta
Nowak, Ewa
Bieg, Dominik
Bednarek, Ilona
Powiązania:
https://bibliotekanauki.pl/articles/1035756.pdf
Data publikacji:
2018
Wydawca:
Śląski Uniwersytet Medyczny w Katowicach
Tematy:
zmiany epigenetyczne
nowotwory
metylacja dna
białka histonowe
mikrorna
ekspresja genów
epigenetic modifications
cancers
dna methylation
histone proteins
microrna
gene expression
Opis:
Modyfikacje epigenetyczne są zmianami regulującymi ekspresję genów. Spośród tych modyfikacji metylacja DNA w regionach promotorowych genów jest najlepiej poznaną zmianą. Za metylację DNA odpowiada rodzina metylo-transferaz DNA. Proces ten jest odwracalny w wyniku reakcji demetylacji, w których pośrednią rolę odgrywają białka TET. Hipometylacja DNA oraz hipermetylacja regionów promotorowych genów bogatych w wyspy CpG należy do epigenetycznych mechanizmów powszechnie występujących w wielu typach nowotworów. Epigenetyczny mechanizm transformacji nowotworowej związany jest nie tylko ze zmianami w poziomie metylacji poszczególnych onkogenów czy też genów supresorowych, ale także z potranslacyjnymi modyfikacjami białek histonowych wymuszających zmia-ny w strukturze chromatyny. Określone modyfikacje, takie jak: metylacja, acetylacja, fosforylacja, ubikwitynacja, biotynylacja, ADP-rybozylacja oraz sumoilacja, mogą wpływać na kondensację chromatyny oraz na białka i kom-pleksy enzymatyczne decydujące o dostępności DNA, co z kolei wpływa na upakowanie, replikację, rekombinację, procesy naprawy oraz ekspresję DNA. W mechanizmach modulacji ekspresji genów zaangażowanych w procesy prowadzące do rozwoju nowotworów znaczącą rolę odgrywają dwa główne rodzaje małych interferencyjnych RNA siRNA oraz miRNA. Uzyskiwane dane z prowadzonych badań pokazują, że mechanizmy epigenetyczne uczestniczą w procesach pro- wadzących do rozwoju nowotworów, a poszukiwanie epigenetycznych biomarkerów może być przydatne w terapii nowotworów.
Epigenetic modifications are changes which can regulate gene expression. DNA methylation in gene promoter regions is the most well-known change among epigenetic modifications. The family of DNA methyltransferases is responsible for DNA methylation. Methylation is reversible due to the demethylation reaction, executed by TET proteins. DNA hypomethylation and hypermethylation of gene promoter regions rich in CpG islands belonging to epigenetic mechanisms commonly occur in many tumors. The epigenetic mechanism of malignant transformation is related not only to changes in the level of methylation of oncogenes or tumor suppressor genes, but also to post-translational modifications of histone proteins, forcing changes in the chromatin structure. Certain modifications, such as methy-lation, acetylation, phosphorylation, ubiquitination, biotinylation, ADP–ribosylation, and sumoylation may affect chro-matin condensation, protein and enzyme complexes that determine the availability of DNA, which then affects the condensation, replication, recombination and repair processes, as well as gene expression. Among the modulatory mechanisms of the expression of genes involved in the processes leading to cancer development, two main types of small interfering RNA play an important role: siRNA and miRNA. Research data Show that epigenetic mechanisms are involved in the processes leading to tumor development, and searching for epigenetic biomarkers may be useful in epigenetic cancer therapy.
Źródło:
Annales Academiae Medicae Silesiensis; 2018, 72; 80-89
1734-025X
Pojawia się w:
Annales Academiae Medicae Silesiensis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural enzymology at the legume-microbe interface: S-adenosyl-L-homocysteine hydrolase of rhizobia
Autorzy:
Manszewski, T.
Singh, K.
Imiolczyk, B.
Jaskolski, M.
Powiązania:
https://bibliotekanauki.pl/articles/80810.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
S-adenosyl-L-homocysteine hydrolase
rhizobia
biological methylation
methyl group
enzymatic hydrolysis
enzymatic process
crystal structure
phylogenetic analysis
biochemical analysis
legume plant
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie reaktora fluidalnego do syntezy 2,6-dimetylofenolu
Use of fluidized bed reactor in 2,6-dimethylphenol synthesis
Autorzy:
Jamanek, D.
Zielecka, M.
Wielgosz, Z.
Cyruchin, K.
Kępska, B.
Wenda, M.
Górska, A.
Krakowiak, J.
Łukomska, A.
Baran, P.
Powiązania:
https://bibliotekanauki.pl/articles/141847.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
2,6-dimetylofenol
fenol
reaktor fluidalny
tlenek krzemu
reakcja metylowania fenolu
2,6-dimethylphenol
phenol
fluidized bed reactor
silicon oxide
phenol methylation reaction
Opis:
Prace badawcze dotyczyły otrzymywania i przetestowania katalizatorów do syntezy 2,6-dimetylofenolu, które mogłyby pracować jako złoże fluidalne. Zsyntezowano tlenek krzemu, na który nanoszono w różnych wariantach tlenki: żelaza(III), magnezu(II), chromu(III) i miedzi(II). Ponadto przebadano katalizator TZC-3/1 produkowany przez Grupę Azoty S.A. Tlenek krzemu z naniesionym na powierzchnię tlenkiem magnezu umożliwił prawie 100% przereagowanie fenolu w temp. 733K, przy selektywności w stosunku do 2,6-dimetylofenolu bliskiej 60%. Podobny stopień przereagowania fenolu otrzymano dla katalizatora przemysłowego TZC-3/1, ale jego selektywność względem 2,6-dimetylofenolu wynosi 90%. Wyniki eksperymentów wskazują, że najlepszym spośród badanych katalizatorów jest przemysłowy katalizator TZC-3/1 pozwalający otrzymać najlepsze wyniki w najniższej temperaturze.
Research works were focused on obtaining and testing of catalysts for 2,6-dimethylphenol synthesis that could be used as fluidized bed. Silicon oxide was synthesized, on which subsequently various variants of iron (III), magnesium (II), chrome (III) and copper (II) oxides were deposited. Moreover, catalyst TZC-3/1 produced by Grupa Azoty SA was tested. Silicon oxide with deposited magnesium oxide allowed almost 100% conversion of phenol at 733K with selectivity towards 2,6-dimethylphenol equal to 60%. Similar degree of conversion for phenol was obtained for industrial catalyst TZC-3/1, but its selectivity towards 2,6-dimethylphenol was equal to 90%. Experimental results indicate that the best one among examined catalyst is the industrial catalyst TZC-3/1 that allows obtaining best results at lowest temperature.
Źródło:
Chemik; 2014, 68, 5; 468-477
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody określania struktury polisacharydów
Methods for determining polysaccharides structure
Autorzy:
Samaszko-Fiertek, J.
Kuźma, M.
Dmochowska, B.
Ślusarz, R.
Madaj, J.
Powiązania:
https://bibliotekanauki.pl/articles/172410.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
polisacharydy
monosacharydy
degradacja oksydacyjna
analiza metylacyjna
acetoliza
NMR
magnetyczny rezonans jądrowy
MS
polysaccharides
monosaccharides
oxidative degradation
methylation analysis
acetolysis
nuclear magnetic resonance (NMR)
Opis:
Sequencing of polysaccharides is difficult to achieve because of the heterogeneous nature of the polysaccharide structure, high molecular weight (the size of a polysaccharide varies between approximately 16,000 and 16,000,000 daltons (Da)), and polydispersity of the polymer chains. The following information is essential to determine the primary structure of a polysaccharide: • monosaccharide composition: nature and molar ratios of the monosaccharide building blocks; • relative configuration of monosaccharides: d or l; • anomeric configuration: α- or β-configuration of the glycosidic linkage; • ring size: presence and distinction of furanosidic and pyranosidic rings; • linkage patterns: linkage positions between the monosugars and branches; • sequences of monosaccharide residues in the repeating units; • substitutions: position and nature of OH–modifications, such as O–phosphorylation, acetylation, O-sulfation, etc.; • molecular weight and molecular weight distribution. A polysaccharide extracted from plant materials or food products is usually purified before being subjected to structural analysis. The first step of characterizing a polysaccharide is the determination of its purity, which is reflected by its chemical composition, including total sugar content, level of uronic acids, proteins, ash, and moisture of the preparation. The second step is the determination of monosaccharide composition, which will unveil structural information such as the number of monosaccharides present in the polysaccharide and how many of each sugar unit. NMR spectroscopy has become the most powerful and noninvasive physicochemical technique for determining polysaccharide structures. It can provide detailed structural information of carbohydrates, including identification of monosaccharide composition, elucidation of α- or β-anomeric configurations, establishment of linkage patterns, and sequences of the sugar units in oligosaccharides and/or polysaccharides. Monosaccharide composition can be determined also by analysis of totally acid hydrolyzed polysacharide using high performance liquid chromatography (HPLC) or gas chromatography (GC). The ring size and glycosidic linkage positions of sugar units in a polysaccharide could be established by methylation analysis and/or cleavage reduction. The anomeric configuration is conventionally determined by oxidation, and this method can be combined with mass spectrometry to obtain more structural information.
Źródło:
Wiadomości Chemiczne; 2016, 70, 5-6; 299-318
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in distribution of 5 methylcytosine in male and female gametophyte of Hyacinthus orientalis before and after fertilization
Autorzy:
Kozlowska, M.
Niedojadlo, K.
Bednarska-Kozakiewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/80166.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
gene activity
chromatin structure
5-methylcytosine
female gametophyte
male gametophyte
seed development
flowering plant
Hyacinthus orientalis
fertilization
transcriptional activity
epigenetic factor
DNA methylation
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie spektrometrii mas do analizy modyfikacji nukleotydów i adduktów DNA
Application of mass spectrometry methods for analysis of modified nucleotides and DNA adducts
Autorzy:
Hanus, J.
Jelonek, K.
Pietrowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/171867.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
kancerogeneza
diagnostyka molekularna
spektrometria mas
nukleotydy
uszkodzenia DNA
addukty DNA
metylacja DNA
carcinogenesis
molecular diagnostics
mass spectrometry
nucleotides
DNA damage
DNA adducts
DNA methylation
Opis:
Chemically modified nucleotides, which are not normally present in genetic material, are called DN A adducts. This type of DN A modifications (damage) is directly related to processes of mutagenesis and carcinogenesis. Elevated levels of DN A adducts present in genetic material reflect exposure of humans to carcinogenic factors and are markers of increased risk of cancer [1]. For this reason different methods useful for quantitative and qualitative analyses of DN A adducts are used in the field of cancer prevention and research (Tab. 1). Enzymatically-catalyzed methylation of cytosine, observed mostly in so called CpG islands, is a frequent endogenous modification of genetic material. Such a DN A methylation is a key factor involved in regulation of gene expression, and methylation status of oncogenes and tumor supressor genes is an important biomarker of carcinogenesis. As such, analytical methods for assessment of DN A methylation are of great importance for molecular diagnostics of cancer. During the last decade significant progress has been made in methods available for quantitative, qualitative and structural analyses of biological molecules. Among intensively developed tools for bioanalyses are methods of mass spectrometry. Spectrometers that are based on two methods of ionization, namely electrospray ionization (ESI ) [30] and matrix-assisted laser desorption-ionization (MALDI ) [48], are particularly suitable for analyses of biological macromolecules: proteins and nucleic acids. Currently available mass spectrometers, together with microscale methods for sample preparation and separation, significantly increased sensitivity and accessible mass range of analyses. New generation of “user-friendly” instruments is developed to bring the techniques directly into the workplaces of biological and clinical investigators. This review demonstrates representative examples of mass spectrometry techniques used for qualitative analyses of nucleotide modifications and adducts present in genetic material of humans. In this field several methods base on spectrometers with electrospray ionization. Generated ions are separated according to their mass-to-charge ratio in an analyzer by electric fields; among different ion analyzers frequently used in this methods are single or triple quadrupole and ion traps (Fig. 1). Among other methods available for assessment of DN A adducts is so called Accelerator Mass Spectrometry (Fig. 2) [41]. The most frequently applied method for the assessment of DN A methylation is based on methylation-specific PCR reaction. Products of such PCR reactions are analyzed using MALDI mass spectrometry [54] (Fig. 3). In summary, new powerful methods of mass spectrometry that made available qualitative analyses of damage and modifications of human genetic material found their important place in modern biological and medical laboratories.
Źródło:
Wiadomości Chemiczne; 2011, 65, 3-4; 191-205
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ancient history of X-ray crystal structure of B-DNA oligomers and its perspective
Autorzy:
Grzeskowiak, K.
Ohishi, H.
Powiązania:
https://bibliotekanauki.pl/articles/80367.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ancient history
X-ray crystallography
crystal structure
DNA oligomer
DNA binding protein
DNA binding drug
nanotechnology
methylation
nanotube
antitumour agent
DNA restriction
DNA sequence
protein
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2011, 92, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indukowana fenobarbitalem hipermetylacja rejonu promotorowego genu p53 w watrobie szczurow szczepu Wistar
Phenobarbital-induced hypermethylation of the p53 promoter region in the liver of Wistar rats
Autorzy:
Kostka, G
Urbanek-Olejnik, K.
Wiadrowska, B.
Bankowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/876498.pdf
Data publikacji:
2008
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
zwierzeta doswiadczalne
szczury
watroba
gen p53
hipermetylacja
fenobarbital
synteza DNA
metylotransferaza DNA
metylacja DNA
experimental animal
rat
liver
p53 gene
hypermethylation
phenobarbital
DNA synthesis
DNA methyltransferase
DNA methylation
Opis:
Indukowane niegenotoksycznymi kancerogenami (NGCs) zmiany metylacji DNA rozpatrywane są jako mechanizm ich toksycznego, w tym rakotwórczego działania. Zbadano wpływ fenobarbitalu (PB), na poziom metylacji regionu promotorowego genu p53 w wątrobie szczurów szczepu Wis tar. Zmiany metylacji genu p53 korelowano z syntezą DNA, aktywnością metylotransferaz DNA (DNMTs) oraz z masą wątroby. Samce szczurów szczepu Wistar otrzymywały PB w dawce wynoszącej 98,2 mg/ kg m.c. x dzień-1 jednorazowo, 3-krotnie i 14-krotnie. Wykazano, że PB wywoływał hipermetylację w badanych sekwencjach rejonu promotorowego genu p53. Indukowana PB hipermetylacja genu występowała w przebiegu całego okresu doświadczalnego. Stymulację syntezy DNA, która poprzedzała wzrost masy wątroby oraz indukcję DNMTs, wykazano tylko po 1 i 3 dawkach związku. Kontynuowanie narażenia zwierząt na PB (14 dawek) nie wywoływało zmian w syntezie DNA i aktywności DNMTs w porównaniu do kontroli. Przypuszcza się, że indukowana PB de novo metylacja rejonu promotorowego genu p53, nie była związana z aktywnością DNMTs.
Non-genotoxic carcinogens (NGCs)-induced changes of DNA methylation has been proposed as a mechanism of their toxicity, including carcinogenic action. The effect of phénobarbital (PB), a rodent liver carcinogen on the methylation level of the p53 promoter region in rat liver was studied. Changes in the methylation status of the p53 gene were correlated with changes in DNA synthesis, DNA methyltransferase (DNMTs) activity and liver weight. Male Wistar rats received PB in one, three or fourteen daily oral doses of 92.8 mg/kg b.w. x day-1. We have demonstrated that PB increased the methylation of the p53 gene. Cytosine hypermethylation in the analyzed CpG sites of the p53 gene promoter occurred during the whole period of study. However, an increase in DNA synthesis was only observed after 1 and 3 days of treatment with PB and it preceded liver growth. Treatment of rats with PB for 1 and 3 days also produced an increase in nuclear DNMTs activity. After prolonged administration (14 days), no changes in DNMTs activity nor DNA synthesis were observed. It is proposed that PB- induced de novo methylation of the p53 gene was not associated with DNMTs activity.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2008, 59, 4; 455-465
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
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