Temat: Mutation - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Multi-operator Differential Evolution with MOEA/D for Solving Multi-objective Optimization Problems
Autorzy:: Aggarwal, Sakshi
Mishra, Krishn K.
Powiązania:: https://bibliotekanauki.pl/articles/2142322.pdf
Data publikacji:: 2022
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: erential evolution
multi-objective
mutation operator
weighted-aggregation
Opis:: In this paper, we propose a multi-operator differentia evolution variant that incorporates three diverse mutation strategies in MOEA/D. Instead of exploiting the local region, the proposed approach continues to search for optimal solutions in the entire objective space. It explicitly maintains diversity of the population by relying on the benefit of clustering. To promowe convergence, the solutions close to the ideal position, in the objective space are given preference in the evolutionary process. The core idea is to ensure diversity of the population by applying multiple mutation schemes and a faster convergence rate, giving preference to solutions based on their proximity to the ideal position in the MOEA/D paradigm. The performance of the proposed algorithm is evaluated by two popular test suites. The experimental results demonstrate that the proposed approach outperforms other MOEA/D algorithms.
Źródło:: Journal of Telecommunications and Information Technology; 2022, 3; 85--95
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Supplementary crossover operator for genetic algorithms based on the center-of-gravity paradigm
Autorzy:: Angelov, P.
Powiązania:: https://bibliotekanauki.pl/articles/205842.pdf
Data publikacji:: 2001
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: algorytm genetyczny
mutacja
środek bezwładności
center of gravity
crossover
genetic algorithms
mutation
selection operators
Opis:: A supplementary crossover operator for genetic algorithms (GA) is proposed in the paper. It performs specific breeding between the two fittest parental chromosomes. The new child chromosome is based on the center of gravity (CoG) paradigm, taking into account both the parental weights (measured by their fitness) and their actual value. It is designed to be used in combination with other crossover and mutation operators (it applies to the best fitted two parental chromosomes only) both in binary and real-valued (evolutionary) GA. Analytical proof of its ability to improve the result is provided for the simplest case of one variable and when the elitist selection strategy is used. The new operator is validated with a number of usually used numerical test functions as well as with a practical example of supply air temperature and flow rate scheduling in a hollow core ventilated slab thermal storage system. The tests indicate that it improves results (the speed of convergence as well as the final result) without a significant increase in computational expenses.
Źródło:: Control and Cybernetics; 2001, 30, 2; 159-176
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Mutations in the COL1A1 and COL1A2 genes associated with osteogenesis imperfecta (OI) types I or III
Autorzy:: Augusciak-Duma, Aleksandra
Witecka, Joanna
Sieron, Aleksander
Janeczko, Magdalena
Pietrzyk, Jacek
Ochman, Karolina
Galicka, Anna
Borszewska-Kornacka, Maria
Pilch, Jacek
Jakubowska-Pietkiewicz, Elzbieta
Powiązania:: https://bibliotekanauki.pl/articles/1038526.pdf
Data publikacji:: 2018
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: osteogenesis imperfecta
COL1A1
COL1A2
mutation
polymorphism
Opis:: Although over 85% of osteogenesis imperfecta (OI) cases are associated with mutations in the procollagen type I genes (COL1A1 or COL1A2), no hot spots for the mutations were associated with particular clinical phenotypes. Eight patients that were studied here, diagnosed with OI by clinical standards, are from the Polish population with no ethnic background indicated. Previously unpublished mutations were found in six out of those eight patients. Genotypes for polymorphisms (Sp1 - rs1800012 and PvuII - rs412777), linked to bone formation and metabolism were determined. Mutations were found in exons 2, 22, 50 and in introns 13 and 51 of the COL1A1 gene. In COL1A2, one mutation was identified in exon 22. Deletion type mutations in COL1A1 that resulted in OI type I had no effect on collagen type I secretion, nor on its intracellular accumulation. Also, a single base substitution in I13 (c.904-9 G>T) was associated with the OI type I. The OI type III was associated with a single base change in I51 of COL1A1, possibly causing an exon skipping. Also, a missense mutation in COL1A2 changing Gly→Cys in the central part of the triple helical domain of the collagen type I molecule caused OI type III. It affected secretion of the heterotrimeric form of procollagen type I. However, no intracellular accumulation of procollagen chains could be detected. Mutation in COL1A2 affected its incorporation into procollagen type I. The results obtained shall help in genetic counseling of OI patients and provide a rational support for making informed, life important decisions by them and their families.
Źródło:: Acta Biochimica Polonica; 2018, 65, 1; 79-86
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Znaczenie kwasu foliowego dla zdrowia organizmu człowieka
The importance of folic acid for the health of the human body
Autorzy:: Banyś, Karolina J.
Knopczyk, Monika W.
Bobrowska-Korczak, Barbara
Powiązania:: https://bibliotekanauki.pl/articles/762697.pdf
Data publikacji:: 2020-03-15
Wydawca:: Polskie Towarzystwo Farmaceutyczne
Tematy:: kwas foliowy
MTHFR
niedobór
mutacja
aktywny kwas foliowy
folic acid
mutation
deficiency
active folic acid
Opis:: A well-balanced diet is undoubtedly a key factor to maintain your body's normal state of health. A deficiency or excess of any nutrient can cause negative effects on human health. Folic acid is one of the elements of the diet, which is often supplied in insufficient quantities. This vitamin and its derivatives participate in the metabolism of amino acids and nucleic acids. Therefore, it is necessary for the proper functioning of the body's cells and for maintaining homeostasis, especially of the nervous, circulatory and cardiovascular systems. The biological activity of folic acid and its derivatives essentially affects the metabolism of important amino acids, such as methionine, homocysteine, serine, glycine, pyrimidine and purine synthesis and DNA methylation. The synthetic form of folic acid (most oxidized), which can be found in fortified foods, dietary supplements or pharmaceuticals, does not show biological activity. It is transformed in a series of reactions with the participation of many enzymes to form folates, which differ in the number of glutamic acid residues and the degree of oxidation. The actively biological form is reduced folate (L-5-MTHF), which is transported together with the blood to cells where it undergoes biological processes important for our health. The MTHFR gene, coding for the enzyme protein of the same name - methylene tetrahydrofolate reductase, is located on chromosome 1 at the 1p36.3 locus. This protein is responsible for the catalysis of the enzymatic reaction, which is the reduction of 5,10-methylenetetrahydrofolate to L-5-methyltetrahydrofolate, i.e. the active form of folate. This form is necessary in the process of homocysteine degradation, in the aftermath remethylation to methionine. This protein is responsible for the catalysis of the enzymatic reaction, which is the reduction of 5,10-methylenetetrahydrofolate to L-5-methyltetrahydrofolate, i.e. the active form of folate. This form is necessary in the process of homocysteine degradation, in the aftermath remethylation to methionine. However, according to available literature, mutation of the MTHFR 677C> T gene occurs in even 53% of the population. Among carriers of the TT genotype, it can cause about 70% reduction of MTHFR reductase activity. It is especially dangerous for people who do not provide adequate amounts of folic acid along with their diet and for those who need a high amount of this vitamin, e.g. due to taking medications that reduce its absorption, i.e. metformin or oral contraceptives. Many people metabolize folic acid on insufficient levels. For medical reasons, not the mutation itself is a problem, but too low the folate levels. In recent years, there is more and more discussion about the active form of folic acid and the possibility of effective supplementation with metapholine, which is a combination of calcium with L-5-MTHFR. It is a natural and reduced form of folate, which hydrolized and then transforms into L-5-MTHFR. Metapholine, in comparison to folic acid, is not reduced to be incorporated into metabolic processes in the cell, which is catalyzed by DHFR and MTHFR enzymes. In addition, the absorption of the active form of folic acid is faster because some metabolic pathways are missed. This is particularly important for people who have a MTHFR gene mutation homozygous with 665C> T and / or 1298A> C polymorphism and a mutation of the DHFR gene with 458A> T polymorphism. Numerous clinical studies have confirmed the efficacy and safety of the active form of folic acid. In a study by Houghton et al., which was conducted among pregnant Canadian women, L-5-MTHFR was shown to be at least as effective in lowering homocysteine levels as folic acid supplementation. In addition, the active form of folic acid was more effective at storing folate in erythrocytes. In a study conducted by Lamers et al. on 135 women after a period of 24 weeks, L-5MTHR was shown to be a suitable alternative in reducing plasma homocysteine levels compared to folic acid and placebo. In addition, Bentley et al. analyzed the results of 112 pregnant women from the USA. Patients were assigned to two groups in which each took vitamin B12. In addition, in one of them women supplemented with L-5-MTHFR, and in the other - folic acid. The results showed that patients who supplemented the active form of folic acid not only had higher hemoglobin levels, but also less often had anemia. When analyzing clinical trials of patients with the MTHFR mutation, the same trend was observed. Metafoline increased plasma folate levels and decreased homocysteine levels. In one study on German women, there was a decrease in homocysteine levels and an increase in folate levels in both plasma and red blood cells in patients who supplemented the active form of folic acid. In another study involving Swiss patients with the current 677CC MTHFR or 677TT MTHFR mutation, it was demonstrated that using L-5-MTHFR significantly reduces homocysteine levels compared to folic acid. It is also worth mentioning that Prinz-Langenhol et al. in a study on women with the 677CC and 677TT mutations proved that the active form of folic acid has a better effect on increasing folate levels than folate. It is also worth mentioning that folic acid at high doses can mask ailments or even diseases caused by vitamin B12 deficiency. In addition, folic acid administered at high doses in patients with the MTHFR mutation is not reduced to an oxidized, inactive form and is not properly transported to plasma. Non-metabolised folic acid can be dangerous to the human body and contribute to the development of cancer. Supplementation, in particular the active form of folic acid, should be considered by patients who are carriers of the MTHFR or DHFR mutation. In addition, the use of stimulants such as alcohol or nicotine also negatively affects the absorption of this vitamin. Taking some medications weakens the absorption of folic acid - these include folic acid antagonists, anti-tuberculosis drugs, hormonal oral contraceptives, nonsteroidal anti-inflammatory drugs or metformin widely used. Folic acid is necessary for the proper functioning of the human body and its deficiency may induce various disease processes in the body, which include: the formation of neural tube defects, disorders in the nervous system, megaloblastic anemia, a negative effect on the functioning of the cardiovascular system and the development of atherosclerosis and cancer. More and more people have anemia, including megaloblastic anemia, which is characterized by abnormal nucleic acid synthesis. The consequence of too low folate levels is impaired red blood cell production, an increase in their volume, and premature death. Extremely dangerous is megaloblastic anemia, the so-called malignant anemia in pregnant women, as it can lead to serious complications such as hemorrhage, infection, and even intrauterine fetal death. A significant influence of folic acid on the functioning of the nervous system has been proven in many clinical studies. This vitamin is involved in the formation of important neurotransmitters such as: adrenaline, dopamine and noradrenaline, therefore its deficiency may lead to the development of neuropsychiatric disorders (dementia, epilepsy, depression and psychosis). These disorders are often caused by high levels of homocysteine, which is not properly metabolized to methionine due to folate deficiency. An excess of homocysteine, as a consequence, leads to atherosclerosis in the cerebral arteries and, as a result of insufficient blood supply, transient ischaemic attack occur, which can contribute to the development of dementia or Alzheimer's disease. Nutritional observations indicate that eating fresh vegetables rich in folic acid protects against the formation of some cancers, e.g. large intestine, breast, ovary, uterus, lungs, pancreas. Deficiency of folic acid promotes the activation of protooncogenes to oncogenes, which in consequence results in a decrease in the stability of cellular DNA. A study carried out by Giovannicci et al. showed that excessive alcohol consumption and folic acid deficiency associated with it increased the risk of developing colorectal cancer by almost four times. However, what cannot be overlooked, the results of clinical trials show us that very high doses and folic acid accumulation favor the development of some cancers. It is thought that excess of folic acid may lead to hypermethylation of DNA and, consequently, to inactivation of the suppressor genes responsible for controlling cell division. Women in the pre-contraceptive period, during pregnancy and breastfeeding are included in the group of people with a special need for folic acid, in whom deficiency can cause many negative effects. The presence of folic acid is necessary in the process of cell formation and growth in the developing fetus, especially when the neural tube is forming. Moreover adequate folic acid concentration decreases risk of fetal heart and urinary tract defects, and also reduces the occurrence of thrombosis and miscarriage in pregnant women. Steeweg-de Graaff J. et al. conducted evaluation of emotional and behavioral development at the age of 3 depending on the concentration of folates and homocysteine in the mother's blood plasma at an early stage of the pregnancy. It was noted that with insufficient folate supply, associated with a lack of or its late supplementation increases the risk of emotional problems in children. In addition, defects of the nervous system may occur as a result of dysfunction of folate metabolism. In its transformation pathway MTHFR reductase takes a particular role. Its reduced activity contributes to the impairment of folic acid metabolism, and the MTHFR gene - type 677CC is considered a risk factor for the development of neural tube defects. Randomized study compared pharmacokinetic parameters of [6S]-5-MTHF and folic acid in healthy women of childbearing age with different MTHFR genotypes (677TT n = 6, 677CC n = 8). Higher peak folate concentrations in plasma with [6S]-5-MTHF supplementation was found, in comparison with folic acid and not depending in the MTHFR genotype, as well as a shorter time needed to reach maximum concentration. In a different randomized, double-blind trial significantly higher folate levels in red blood cells were obtained in women receiving [6S]-5-MTHF. Studies confirm the hypothesis that nutritional deficiencies are of great importance in terms of fetal development. The results testify the need of folic acid supplementation, in which it is worth to consider the use of biologically active form, 12 weeks before planned pregnancy. In the second and third trimesters, the supplementation of folic acid is an important element in prevention of anemia caused by vitamin B12 and folic acid deficiency, i.e. megaloblastic anemia. Moreover, it was found that folic acid at a daily dose of 400 - 800 μg reduce the risk of fetal neural tube defects. In its guidelines, Polish Society of Gynecologists and Obstetricians (PTGiP) recommends supplementation of 400 μg / day of folic acid in women in low risk group in the pre-contraceptive period, pregnancy and during breastfeeding and supplementation of 800 μg/ day of folic acid in women in intermediate risk group and also high risk group in II and III trimester and during breastfeeding. It is worth emphasising that in most recent guidelines, PTGiP pays attention to the problem of folic acid metabolism and emphasizes the appropriateness of supplementation with its active form, especially at high doses. In folic acid metabolism, MTHFR catalyzes the synthesis to the active form of folate (L-5-MTHFR). It is necessary in the process of homocysteine degradation following remethylation to methionine. Unfortunately, as a result of inappropriate methylation, e.g. as a result of active form of folic acid deficiency, the concentration of homocysteine in the blood serum increases, which is responsible for various pathogenic processes in the body. Insufficient supply and improper metabolism of folic acid, as well as vitamins B6, B12 deficiency may be factors favorable for development of atherosclerosis and other diseases related to the cardiovascular system (e.g. heart attack, stroke, coronary artery disease). Excessively high concentration of homocysteine in the blood plasma, caused by disorders of its metabolic pathway in the body, is one of the reasons for the formation of atherosclerotic changes in blood vessels. Excess of homocysteine, with a simultaneous deficiency of folate and vitamin B12, damages the endothelium of blood vessels and increases oxidation processes, which are associated with the development of inflammation, oxidation of LDL cholesterol and change in the structure of the walls of blood vessels. In addition, the risk of developing peripheral thrombosis and hypertension increases. In the meta-analysis of Linda L. et al. it was found that high concentration of homocysteine is an independent factor of developing coronary heart disease. In the majority of studies, the risk of this disease is increased by 20% to 50% with every increase of concentration of homocysteine by 5 μmol /L in the blood of the examined persons. To ensure proper functioning of blood vessels and to reduce the risk of cardiovascular disease, one needs to provide adequate concentration of homocysteine in the body. Folates and their adequate supply with diet or supplementation play a key role in this process. Looking at the numerous clinical studies, available literature and the function of folic acid, it can be stated that it is an essential compound with multidirectional biological action, which is involved in the synthesis of amino acids and nucleic acids important for health. It plays an important role in tissues, such as: the fetus, hematopoietic system and gastrointestinal epithelium, in which cell divisions occur. For this reason, the presence of folic acid in the right amounts, ensures the proper functioning of our body. A deficiency of folic acid in the diet leads to a reduced concentration of folate in plasma and red blood cells. It is a condition that contributes to the formation of many serious diseases in our body and congenital neural tube defects in the fetus. As clinical studies have shown, the optimal concentration of folates in the blood reduces the risk of cardiovascular, circulatory, central nervous system diseases and certain types of cancer. To reduce the risk of diet-related diseases caused by folic acid deficiency, daily diet should be optimally balanced and contain products rich in natural folates. If diet is an insufficient source of folic acid, its supplementation should be considered, with the possible inclusion of its active form. Supplementation is recommended, in particular, for people with: megaloblastic anemia, diabetes mellitus, malabsorptions (e.g. Crohn's disease), alcoholism, malnutrition, neurodegenerative diseases (e.g. Alzheimer's disease), cardiovascular diseases, elevated homocysteine levels and using certain medications (e.g. oral contraceptives, metformin, methotrexate). It is also worth mentioning that metapholine supplementation bypasses the multistage metabolic process before incorporating folates into the cell cycle, as opposed to the inactive form of folic acid. This is particularly important for patients with the DHFR and MTHFR mutation, which depending on the polymorphism, may occur in up to 53% of the Caucasian population. Consequently, MTHFR reductase activity is reduced by up to 70%.
Kwas foliowy jest niezbędny do właściwego funkcjonowania organizmu i zachowania homeostazy. Uczestniczy w metabolizmie kwasów nukleinowych, aminokwasów, syntezie pirymidyn i puryn. Syntetyczna postać kwasu foliowego nie wykazuje aktywności biologicznej. Przekształcana jest w szeregu reakcji do postaci folianów (L-5-MTHF) które, są transportowane do komórek, gdzie bierze udział w ważnych procesach biologicznych. Gen MTHFR odpowiedzialny jest za katalizę reakcji enzymatycznej: redukcję 5,10-metylenotetrahydrofolianu do aktywnej formy. Mutacja genu MTHFR 677C>T występuje nawet u 53% populacji czego konsekwencją jest zmniejszenie aktywności reduktazy – MTHFR nawet o 70%. Metafolina (aktywna forma) w przeciwieństwie do kwasu foliowego, aby zostać włączona do procesów metabolicznych w komórce, nie ulega redukcji, katalizowanej przez DHFR oraz MTHFR. Jest to istotne w szczególności dla osób, które mają mutację genu MTHFR oraz DHFR. Przyjmowanie niektórych leków osłabia wchłanialność kwasu foliowego. Kwas foliowy jest niezbędny do prawidłowego funkcjonowania organizmu człowieka a jego niedobór może indukować różne procesy chorobowe w organizmie, do których zaliczamy: powstawanie wad cewy nerwowej, zaburzenia w układzie nerwowym, niedokrwistość megaloblastyczną, negatywny wpływ na funkcjonowanie układu sercowo – naczyniowego oraz rozwój miażdżycy i nowotworów. Witamina ta bierze udział w powstawaniu ważnych neuroprzekaźników, takich jak: adrenalina, dopamina i noradrenalina, dlatego jej niedobór może prowadzić do powstania zaburzeń neuropsychiatrycznych. Niedobór kwasu foliowego sprzyja aktywacji protoonkogenów do onkogenów. Liczne badania kliniczne i dostępna literatura potwierdzają funkcję kwasu foliowego, że jest to niezbędny związek o wielokierunkowym działaniu biologicznym, który pełni istotną rolę w tkankach. Suplementacja metafoliną omija wieloetapowy proces metaboliczny w przeciwieństwie do nieaktywnej postaci kwasu foliowego.
Źródło:: Farmacja Polska; 2020, 76, 2; 79-87
0014-8261
2544-8552
Pojawia się w:: Farmacja Polska
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Paralele indoeuropejskie polskich gwarowych procesów fonetycznych
The Indo-European Parallels of the Polish Dialect Phonetic Processes
Autorzy:: Bednarczuk, Leszek
Powiązania:: https://bibliotekanauki.pl/articles/2127761.pdf
Data publikacji:: 2002
Wydawca:: Katolicki Uniwersytet Lubelski Jana Pawła II. Towarzystwo Naukowe KUL
Tematy:: fonetyka
paralela
przegłos
palatalizacja
sandhi
phonetics
parallel
vowel mutation
palatalization
Opis:: The paper seeks to make a typological interpretation of the more important phonetic processes, which have occured in Polish local dialects, their confrontation with parallel phenomena in other Indo-European languages and dialects. Some of those parallels deal with the whole series of changes, other refer only to some details, but shed light on the processes postulated for a pre-historic epoch. One should emphasize here that the most characteristic innovations in the Polish language and its dialects (vowel mutation, consonant shift external sandhi) do not have in the Indo-European languages exact counterparts, but merely approximate parallels. As regards areas common to other languages, apart from numerous references to neighbour languages, West-Slavonic dialects, Byelorussian and Ukrainian, there are some similarities to the German linguistic area, embracing partly also the Czech and Luzatian languages.
Źródło:: Roczniki Humanistyczne; 2002, 49-50, 6; 55-64
0035-7707
Pojawia się w:: Roczniki Humanistyczne
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Wrodzony rodzinnie występujący zespół wydłużonego QT – trudności diagnostyczne
Congenital familial long QT syndrome – diagnostic problems
Autorzy:: Bieganowska, Katarzyna
Miszczak-Knecht, Maria
Rękawek, Joanna
Borucka-Mankiewicz, Maria
Brzezińska-Paszke, Monika
Pręgowska, Katarzyna
Gałązka, Adam
Powiązania:: https://bibliotekanauki.pl/articles/1030795.pdf
Data publikacji:: 2009
Wydawca:: Medical Communications
Tematy:: lqt1 syndrome
electrocardiographic diagnosis
molecular tests
familiar mutation
treatment
lqt1
diagnostyka elektrokardiograficzna
badania molekularne
mutacja rodzinna
leczenie
Opis:: Congenital long QT syndrome (LQTS) is characterized by prolongation of the QT interval and T wave abnormalities on electrocardiogram (ECG). The prolongation of QT interval (manifestation of prolongation of ventricular repolarization) predisposes to syncope, seizure and sudden cardiac death due to typical polymorphic ventricular tachycardia torsade de pointes or ventricular fibrillation. Long QT syndrome may associate with deafness as Jervell and Lange-Nielsen syndrome, described in 1957, which is very rare and later described Romano-Ward syndrome without deafness affecting 1 in 2500-5000 persons. LQTS is hereditary disorder, genetically heterogeneous, caused by mutations in specific cardiac ion channel genes. The most prevalent form of LQTS is LQT1 with mutation on KCNQ1 gene encoding cardiac potassium IKs channel protein. The result of the mutation is incorrect function of the channel. Genetic tests are important for identification of a mutation. Diagnosis of long QT syndrome may be difficult and sometimes we need several recorded electrocardiograms to find QT interval prolongation. The Schwartz and Moss clinical criteria may be steel useful for LQTS diagnosis. Beta-blockers are effective in patients with long QT syndrome and should be administered at diagnosis. Patients should avoid as physical and emotional stresses, as drugs prolonged corrected QT interval. It is necessary to examine the family members. We present a patient with genetically documented familiar LQT1 syndrome. Diagnostic problems, symptoms and therapy are discussed.
Wrodzony zespół wydłużonego QT (long QT syndrome, LQTS) jest uwarunkowaną genetycznie chorobą charakteryzującą się istotnym wydłużeniem odstępu QT oraz nieprawidłowymi załamkami T w zapisie elektrokardiograficznym. Wydłużenie odstępu QT (odzwierciedla wydłużenie repolaryzacji komór) sprzyja zasłabnięciom, omdleniom lub nagłej śmierci sercowej w wyniku typowego częstoskurczu komorowego torsade de pointes lub migotania komór. W 1957 roku jako pierwszy został opisany zespół wydłużonego QT z głuchotą – zespół Jervella i Lange-Nielsena – który występuje bardzo rzadko. Niedługo później opisano występujący z częstością ok. 1:2500-5000 zespół Romano-Warda bez głuchoty. Zespół jest genetycznie zróżnicowany, spowodowany mutacjami genów kodujących białka sercowych kanałów jonowych. Najczęściej występujący typ LQT1 zespołu wydłużonego QT (powyżej 50% przypadków) jest wynikiem mutacji genu KCNQ1 kodującego białko kanału potasowego IKs, co powoduje nieprawidłową jego funkcję. Badania molekularne są ważne dla ustalenia mutacji. Rozpoznanie zespołu wydłużonego QT bywa trudne, niekiedy konieczne jest wykonanie wielu zapisów EKG, aby udokumentować wydłużenie odstępu QT. Klinicznie wciąż przydatne mogą być kryteria Schwartza i Mossa. Leczenie beta-blokerami jest skuteczne i powinno być wdrażane z chwilą rozpoznania. Należy przede wszystkim unikać wysiłku, stresu oraz leków mogących wydłużyć skorygowany odstęp QT. Niezbędne jest przebadanie rodzin pacjentów z rozpoznanym zespołem wydłużonego QT. W pracy prezentujemy udokumentowany genetycznie przypadek rodzinnie występującego zespołu wydłużonego QT typu 1 (LQT1). Przedstawione zostały problemy diagnostyczne, przebieg kliniczny i wdrożone postępowanie lecznicze.
Źródło:: Pediatria i Medycyna Rodzinna; 2009, 5, 1; 43-49
1734-1531
2451-0742
Pojawia się w:: Pediatria i Medycyna Rodzinna
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Dziedziczenie cechy wiechowatości kwiatostanów lucerny mieszańcowej (Medicago x varia T. Martyn)
Inheritance of spontaneous panicle inflorescence mutation in alfalfa (Medicago x varia T. Martyn)
Autorzy:: Bodzon, Zbigniew
Powiązania:: https://bibliotekanauki.pl/articles/2198474.pdf
Data publikacji:: 2013-03-31
Wydawca:: Instytut Hodowli i Aklimatyzacji Roślin
Tematy:: cecha regresywna
dziedziczenie
geny regresywne
kwiatostan
lucerna
mutacja spontaniczna
wiechowatość kwiatostanów
alfalfa
inheritance
lucerne
panicle inflorescence
recessive gene
recessive trait
spontaneous mutation
Opis:: Obiektem badań była spontaniczna mutacja lucerny, polegająca na wyrastaniu dodatkowych gron w miejscu kwiatów. Kwiatostan zmutowanych form przybiera kształt wiechy (pi — panicle inflorescence) złożonej z kilkunastu rozgałęzień, na których wyrastają kwiaty. Liczba kwiatów w wiechach, w porównaniu z gronami, ulega zwielokrotnieniu osiągając liczbę kilkudziesięciu. Wykorzystanie tej cechy w hodowli lucerny stwarza nowe możliwości zwiększenia jej potencjału plonowania nasiennego. Celem badań, wykonanych w latach 2005–2010, było określenie sposobu dziedziczenia cechy wiechowatości kwiatostanów. Ocenę ekspresji tej cechy przeprowadzono w obrębie potomstw S1 i S2, pochodzących z samozapyleń rośliny zmutowanej oraz mieszańców F1, F2 i F3, uzyskanych ze skrzyżowania roślin wytwarzających typowe kwiatostany (grona) z roślinami zmutowanymi. Analiza stosunków rozszczepień fenotypowych, przeprowadzona z użyciem testu chi-kwadrat, wykazała, że cecha wiechowatości kwiatostanów lucerny dziedziczy się jednym genem w układzie czterech alleli recesywnych (pi pi pi pi).
The aim of research was to explain mode of inheritance of the lucerne mutation that causes the formation of panicles instead of racemes on stems. Panicles on mutant plants consisted of a lot of branches that caused several fold increase of flower numbers in inflorescences. Application of this character in lucerne breeding creates new opportunities to increase its seed yield potential. The inheritance of this character was studied in S1 and S2 progenies obtained by selfing a mutant plant, as well as in F1, F2 and F3 generations of hybrids obtained by crossing plants that produce racemes with S2 mutant progenies. The analysis of segregation in the selfed progenies of the mutant plants and in F1 – F3 progenies of the hybrids showed that the character of panicle inflorescence is controlled by single gene in the configuration of four recessive alleles pi pi pi pi (pi — panicle inflorescence)
Źródło:: Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin; 2013, 267; 153-159
0373-7837
2657-8913
Pojawia się w:: Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Dziedziczenie cechy zdeterminowanego wzrostu lucerny siewnej (Medicago sativa L.)
Inheritance of determinate growth habit in alfalfa (Medicago sativa L.)
Autorzy:: Bodzon, Zbigniew
Powiązania:: https://bibliotekanauki.pl/articles/2199276.pdf
Data publikacji:: 2017-09-05
Wydawca:: Instytut Hodowli i Aklimatyzacji Roślin
Tematy:: cecha recesywna
cecha zdeterminowanego wzrostu
dziedziczenie
kwiatostan wierzchołkowy
lucerna
mutacja spontaniczna
alfalfa
determinate growth
inheritance
lucerne
recessive trait
spontaneous mutation
top inflorescence
Opis:: Obiektem badań była spontaniczna mutacja lucerny polegająca na wytwarzaniu kwiatostanów na wierzchołkach pędów form z długim gronem, prowadzącym w konsekwencji do zakończenia dalszego wzrostu roślin. Celem przeprowadzonych badań było określenie sposobu dziedziczenia cechy zdeterminowanego wzrostu. Ocenę ekspresji tej cechy przeprowadzono w obrębie potomstw S1 i S2, pochodzących z samozapyleń rośliny zmutowanej oraz mieszańców F1, F2 i F3, uzyskanych ze skrzyżowania roślin o typowym, niezdeterminowanym pokroju z roślinami zmutowanymi. Analiza stosunków rozszczepień fenotypowych, przeprowadzona z użyciem testu chi-kwadrat wykazała, że cecha zdeterminowanego wzrostu lucerny warunkowana jest jednym genem w układzie czterech alleli recesywnych (ti ti ti ti).
The aim of research was to explain mode of inheritance of the alfalfa spontaneous mutation that causes the formation of inflorescence on the stem top of the forms with long racemes, thus leading to termination of the plant growth. The inheritance of this character was studied in S1 and S2 progenies obtained by selfing a mutant plant, as well as in F1, F2 and F3 generations of hybrids obtained by crossing indeterminate plants with S2 mutant progenies. The analysis of segregation in the selfed progenies of the mutant plants and in F1 – F3 progenies of the hybrids showed that the determinate growth character is controlled by a single gene in the configuration of four recessive alleles ti ti ti ti (ti — top inflorescence).
Źródło:: Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin; 2017, 281; 77-83
0373-7837
2657-8913
Pojawia się w:: Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Mutagenicity induced in Salmonella strains TA98 and TA100 by diphenylthiophenes
Autorzy:: Budzikur, K. A.
Góra, M.
Chachaj, A.
Mielżyńska-Švach, D.
Tejs, S.
Łuczyński, M. K.
Powiązania:: https://bibliotekanauki.pl/articles/363118.pdf
Data publikacji:: 2011
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:: test Amesa
mutacja
monomery tiofenowe
Ames test
mutation
thiophene monomers
Opis:: Mutagenic properties of four different diphenylthiophenes: 3,4-diphenylthiophene, 3,4-di(4'-methylphenyl)thiophene, 3,4-di(4'-methoxyphenyl)thiophene and 3,4-di(4'-pentoxyphenyl)thiophene were investigated applying the Salmonella test. The research was done on two strains of Salmonella Typhimurium: TA98 and TA100, tested in two variants: with (+S9) and without (-S9) enzymatic activation. Only one compound 3,4-di(4'-methylphenyl)thiophene showed mutagenic activity when studied with metabolic activation (+S9) and its mutagenic rate (MR) score was 3.41 for the dose of 10.00µg*plate-1. Other studied compounds did not show any mutagenic activity (+/-S9) and their MR score did not exceed the threshold value of 2.0.
Źródło:: Environmental Biotechnology; 2011, 7, 2; 65-69
1734-4964
Pojawia się w:: Environmental Biotechnology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Urine iodine excretion in patients with papillary thyroid cancer evaluation of the relationship with the presence of BRAF mutation
Autorzy:: Celik, M.
Guldiken, S.
Ayturk, S.
Yilmaz Bulbul, B.
Kucukarda, A.
Can, N.
Tastekin, E.
Sezer, A.
Sut, N.
Tugrul, A.
Gurkan, H.
Tozkir, H.
Demirkan, B.
Powiązania:: https://bibliotekanauki.pl/articles/1192247.pdf
Data publikacji:: 2020
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:: papillary thyroid cancer
BRAF mutation
urine iodine excretion
Opis:: Iodine is an essential element for the production of thyroid hormones. In recent years, it has been suggested that excessive consumption of iodine may play a role in the pathogenesis of papillary thyroid cancer (PTC). In addition, studies have suggested that high iodine consumption is an important risk factor for the formation of a BRAF mutation in the thyroid gland. A prospectively designed study included 132 cases scheduled for thyroidectomy for various reasons. Urine iodine levels of all patients were examined before the operation. The iodine excretion levels of the patients were grouped according to the median urinary iodine concentration determined in community screenings (those with <100 µg L-1 low iodine excretion, those with 100-199 µg L-1 normal iodine excretion, those with 200-299 µg L-1 high iodine excretion). Patients were divided into 3 groups according to the post-operative pathology results. As a result of thyroid histopathology, benign (n: 44), PTC (n: 88) (BRAF (+): 44 and BRAF (-): 44) cases were included in the study. BRAF mutations in patients diagnosed with PTC were evaluated using the “Real Time PCR Melting Curve Analyzer” method. The relationship between urinary iodine excretion levels and clinical, histopathological and BRAF positivity was examined. In our study, no difference was found in urinary iodine excretion between patients with and without PTC. Hashimoto’s thyroiditis was observed more frequently in patients with PTC (p=0.023). In addition, Hashimoto’s thyroiditis was statistically more frequently detected in the BRAF (-) group compared to the BRAF (+) and control group (p=0.034). Despite studies suggesting that high iodine consumption is important in PTC pathogenesis, we did not find a relationship between the mutation and iodine consumption, which plays an important role in the development of PTC.
Źródło:: Journal of Elementology; 2020, 25, 3; 1019-1028
1644-2296
Pojawia się w:: Journal of Elementology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: A common approach to directoids with an antitone involution and D-quasirings
Autorzy:: Chajda, Ivan
Kolařík, Miroslav
Powiązania:: https://bibliotekanauki.pl/articles/728822.pdf
Data publikacji:: 2008
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: directoid
antitone involution
D-quasiring
DN-algebra
a-mutation
Opis:: We introduce the so-called DN-algebra whose axiomatic system is a common axiomatization of directoids with an antitone involution and the so-called D-quasiring. It generalizes the concept of Newman algebras (introduced by H. Dobbertin) for a common axiomatization of Boolean algebras and Boolean rings.
Źródło:: Discussiones Mathematicae - General Algebra and Applications; 2008, 28, 2; 139-145
1509-9415
Pojawia się w:: Discussiones Mathematicae - General Algebra and Applications
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Somaclonal variation in winter wheat [Triticum aestivum L.]: frequency, occurrence and inheritance
Autorzy:: Cheng, X Y
Gao, M.W.
Liang, Z.Q.
Liu, G.Z.
Powiązania:: https://bibliotekanauki.pl/articles/2044461.pdf
Data publikacji:: 1998
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: inheritance
tissue culture
Triticum aestivum
occurrence
in vitro
winter wheat
gene mutation
plant breeding
callus induction
frequency
somaclonal variation
wheat
embryo
Opis:: Plants were regenerated from immature embryo cultures of 35 winter wheat genotypes. General responses of regenerated plants were investigated and a total of 7142 R₂ spike lines from 1593 R₁ plants were assessed in the field for somaclonal variants in 1985/86, 1986/87 and 1987/88. Selected variants were studied for their possible genetic inheritance. From regenerated plantlets, 81% survived and 63% produced fertile plants. Forms with reduced plant height, length of spike and other morphological abnormalities were found in this progeny. Populations of R₁ plants were highly variable due mainly to the physiological disturbances resulting from the in vitro process. Overall somaclonal variation frequencies were 14.2% per plant basis and 5.3% per R₂ spike basis. The variants were similar in the three different R₂ generations with predominant variants being negative in plant height, maturity, awns, spike type and plant type. Both uniform R₂ variant families and spike lines were found in addition to the segregating variants which constituted the majority. On average, in a variant family or line, 18% and 14% of their component lines and plants were variants, respectively. Inheritability was demonstrated for the uniform variant families and spike lines as well as segregated variants. Of those 134 selections, about 70% were classified as inheritable. Both recessive and dominant gene mutations at one, two or three loci were evident in some variants as suggested by the segregating data.
Źródło:: Journal of Applied Genetics; 1998, 39, 1; 59-72
1234-1983
Pojawia się w:: Journal of Applied Genetics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: K-RAS mutations in colorectal cancer in patients from Podlaskie region
Autorzy:: Chomczyk, M.
Czajka, P.
Powiązania:: https://bibliotekanauki.pl/articles/1917750.pdf
Data publikacji:: 2016
Wydawca:: Uniwersytet Medyczny w Białymstoku
Tematy:: colorectal cancer
K-RAS mutation
Ras protein
Podlaskie region
Opis:: Introduction: In Poland, colorectal cancer is the second leading cause of death. The incidence of colorectal cancer increases with age and early onset indicates and increased likelihood for genetic predisposition for this disease. The somatic genetics of tumor development in relation to patients age, gender, sex and morphological factors are unknown in Podlaskie region, Poland. Materials and methods: We investigated seventy five patients (43 men and 32 women) who underwent surgery for cancer of the colorectal in the II Department of General and Gastroenterological Surgery, Medical University of Białystok in 2002- 2007. The average age of patients was 64.8 years (the average age of women 66.7, men 63.1). All patients for the study of molecular research (absence or presence of K-RAS mutations) had histopathology confirmed adenocarcinoma. Results: There was no correlation presence or absence of mutations in K-RAS of the following clinical and morphological factors: gender, age, location, degree of tumor differentiation, tumor size and metastases to lymph nodes and other organs The gene encoding the K-Ras protein is mutated in 20- 50% of cases of colorectal cancer. Such a difference of results is influenced by several factors: differences of the techniques used for detecting mutations, differences in codon of the gene that is considered codon 12 and /or 13 and / or 61 and differences in the selection and study population. Conclusions: These data suggest the clinical and morphological factors in patients with colorectal cancer have no effect on the presence of K-RAS. mutation.
Źródło:: Progress in Health Sciences; 2016, 6(1); 70-77
2083-1617
Pojawia się w:: Progress in Health Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Analysis of modification of the evolutionary algorithm for sequencing production tasks
Autorzy:: Ciepliński, Piotr
Golak, Sławomir
Wieczorek, Tadeusz
Powiązania:: https://bibliotekanauki.pl/articles/29520067.pdf
Data publikacji:: 2022
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:: evolutionary algorithm
task sequencing
mutation operator
algorytm ewolucyjny
operator mutacji
Opis:: Evolutionary algorithms are one of the heuristic techniques used to solve task sequencing problems. An important example of such a problem is the issue of sequencing production tasks. The combinatorial optimization of task sequences allows the minimization of the cost or time of a set of production tasks by reducing the components of these values which are present in the transitions between tasks. This paper aims to analyze the influence of the production nature expressed by a set of production task parameters and a definition of the task transition cost on the effectiveness of the modification of the evolutionary algorithm based on new directed stochastic mutation operators. The research carried out included the influence of the space dimension of the task parameters, the number of levels of the value of the cost function, and a definition of this function. The results obtained allow us to assess the effectiveness of the directed mutation in task sequencing for productions of various natures.
Źródło:: Computer Methods in Materials Science; 2022, 22, 3; 157-166
2720-4081
2720-3948
Pojawia się w:: Computer Methods in Materials Science
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: The effect of Arg209 to Lys mutation in mouse thymidylate synthase.
Autorzy:: Cieśla, Joanna
Gołos, Barbara
Wałajtys-Rode, Elżbieta
Jagielska, Elżbieta
Płucienniczak, Andrzej
Rode, Wojciech
Powiązania:: https://bibliotekanauki.pl/articles/1043728.pdf
Data publikacji:: 2002
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: nucleotide's phosphate binding
thymidylate synthase
mutation
Opis:: Mouse thymidylate synthase R209K (a mutation corresponding to R218K in Lactobacillus casei), overexpressed in thymidylate synthase-deficient Escherichia coli strain, was poorly soluble and with only feeble enzyme activity. The mutated protein, incubated with FdUMP and N5,10-methylenetetrahydrofolate, did not form a complex stable under conditions of SDS/polyacrylamide gel electrophoresis. The reaction catalyzed by the R209K enzyme (studied in a crude extract), compared to that catalyzed by purified wild-type recombinant mouse thymidylate synthase, showed the Km value for dUMP 571-fold higher and Vmax value over 50-fold (assuming that the mutated enzyme constituted 20% of total crude extract protein) lower. Thus the ratios kcat, R209K/kcat, 'wild' and (kcat, R209K/Km, R209KdUMP)/( kcat, 'wild'/Km, 'wild'dUMP) were 0.019 and 0.000032, respectively, documenting that mouse thymidylate synthase R209, similar to the corresponding L. casei R218, is essential for both dUMP binding and enzyme reaction.
Źródło:: Acta Biochimica Polonica; 2002, 49, 3; 651-658
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

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