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Polymorfismus v genu MDR1 u border kolií
Trýznová, Alena
This thesis is focused on polymorphism of MDR1 gene c.-6-180T>G, which causes phenobarbital resistance. Phenobarbital is one of the most commonly used drug against epilepsy, which is one of the most common neurological disease in dogs with frequency between 0,5-5 % according to breed. This mutation has so far been detected only in the border collie breed, which manifests up to 30 percent resistance to the treatment of epilepsy. In the text is subscribed border collie breed, dog epilepsy and gene MDR1. Methodical part is focused on detection of the polymorphism in model population of 82 dogs. The results agree with previous studies and confirm frequency of mutant alleles 32 % within the population.
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Role of drug transporters in placental transfer of entecavir
Křečková, Veronika ; Červený, Lukáš (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Křečková Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Role of drug transporters in placental transfer of entecavir Entecavir (ETV), an analogue of guanosine, is a highly efficient anti-hepatitis B antiviral drug. It is the first-line therapy for both adults and children. Its use in pregnancy is limited due to a number of factors, including lack of data on placental pharmacokinetics. The placental transition of drugs is frequently controlled by drug transporters. ATP-binding (ABC) transporters, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) or multidrug resistance-associated protein 2 (MRP2) localized in the apical membrane of syncytiotrophoblast and pumping their substrates in the feto-maternal direction belong to most significant determinants of placental pharmacokinetics. Moreover placental transport of nucleoside-derived drugs can be affected by the activity of nucleoside transporters (NTs); equilibrative nucleoside transporters (ENTs) mediate facilitated diffussion, while the concentrative nucleoside transporters (CNTs) control active influx of their substrates. The aim of the diploma thesis was to describe the role of P-gp, BCRP, MRP2 and NTs (ENTs and...
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Study of drug-drug interactions of antiviral drugs on intestinal transporters
Záboj, Zdeněk ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Zdeněk Záboj Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Study of drugs interactions of antiviral drugs with intestinal transporters Sofosbuvir is an antiviral agent widely used in the treatment of chronic hepatitis C. This orally administered prodrug is a designed substrate of ATP-binding (ABC) efflux transporters, P- glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). ABCB1 and ABCG2 are important determinants of intestinal absorption and are the site of significant pharmacokinetic drug interactions, leading to changes in drug exposure. Pharmacokinetic drug interactions may be undesirable (increasing the toxicity of the treatment) or desirable (allowing dose reduction). Because sofosbuvir is often administered in combination regimens with other anti(retro)virotics, the aim of this thesis was to study the ability to enhance intestinal absorption of sofosbuvir. To study the pharmacokinetic drug interactions on ABCB1 and ABCG2, a widely established in vitro bi-directional transport method through a polarized monolayer formed by the Caco-2 cell line derived from colorectal cancer has been used. We analyzed the drug interactions of sofosbuvir on these efflux...
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Pharmacogenetic prediction of tamoxifen efficiacy and adverse effects in hormonal dependent breast karcinoma patients.
Argalácsová, Soňa ; Slanař, Ondřej (advisor) ; Vrána, David (referee) ; Paluch, Zoltán (referee)
ABSTRACT/SUMMARY Background: The clinical efficacy of tamoxifen therapy may be modified by the drug-metabolizing enzymes and transporting molecules involved into the pharmacokinetics of tamoxifen. The aim of this study was to evaluate the association of CYP2D6, ABCB1 polymorhisms and comedication with efficacy and safety of tamoxifen treatment. Methods: Totally 258 women with hormonal positive breast carcinoma were retrospectively evaluated in relation to CYP2D6, ABCB1 polymorphisms and comedication. Results: CYP2D6 polymorphisms or co-medication affecting CYP2D6 activity demonstrated no statistically significant effect on the efficacy of tamoxifen therapy or adverse event incidence; there was only a trend towards shortening the time to event (TTE) in CYP2D6 poor metabolizers. ABCB1 polymorphism rs2032582 was not associated with clinical outcomes, while a trend towards an increase of TTE in variant allele carriers was noted. The ABCB1 polymorphism rs1045642 demonstrated statistical significance in premenopausal patients (p = 0.0012, HR 0.69 (95% CI 0.21 to 2.31), and its significant association was noted with gynaecological /vasomotor adverse events (p = 0.0221, HR = 1.0588), with no evidence of the influence on the incidence and onset of venous complications. Conclusions: Although this work did not show...
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Detekce polymorfismu v genu MDR1 u ovčáckých a honáckých psů
Staroveská, Marieta
This thesis is focused on polymorphism of MDR1 gene and related drug resistance. Resistance is caused by deletion of four nucleotids, that resulting in a frame shift and synthesis of nonfunctional transport of P-glycoprotein. The text describes a polymorphism of MDR1 (ABCB1) gene, which results in reduced resistance to drugs belonging to the group of macrocyclic lactones. It also describes inheritance of this phenomenon and it deals with the detection of mutation using PCR (polymerase chain reaction) and by fragmentation analyses. A review of literature study is a form of research solely from scientific publications. 128 dogs were included into the own analysis. The results confirmed that Collies had the highest presence of deletions (29,73 %) with a high number of carriers in the study population of dogs (54,05 %). The percentage of affected individuals in the breed of Australian Shepherd and Sheltie was significantly lower (7,32 % and 6 %), but the percentage of carriers were also high in both Australian Shepherds (34,14 %) and the breed Sheltie (48 %).
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Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro
Machan, Radek ; Červený, Lukáš (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Radek Machan Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro European Medicine Agency (EMA) and Food and Drug Administration agency (FDA) emphasise drug membrane permeability and drug-drug interactions on ABC transporters expressed in physiological barriers should be investigated for compounds in preclinical studies or for those already clinically used but evidence free. In this work we aimed to assess the capability of several experimental butyrylcholinesterase inhibitors that had been designed to treat dementia to permeate blood-brain barrier and to elucidate role of ATP-binding (ABC) cassette transporters in this transport. For this purpose, we employed in vitro bidirectional transport study across monolayers formed by polarized and highly differentiated Caco-2 cells. The permeability values gained from measurements were similar to values of several commonly used drugs for treatment of CNS disorders (e.g. antidepressants, antiepileptics). In addition, the compounds showed values of efflux ratio (basolateral- to-apical/apical-to-basolateral) approximately one...
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Study of effects of prolonged administration of emtricitabine on expression of ABC efflux transporters in maternal and fetal organs
Havlová, Ivana ; Červený, Lukáš (advisor) ; Hofman, Jakub (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Ivana Havlová Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Study of effects of prolonged administration of emtricitabine on expression of ABC efflux transporters in maternal and fetal organs The aim of this thesis was to evaluate the effect of chronic administration of antiretroviral substance emtricitabine (FTC) on expression of drug efflux ABC-binding cassette (ABC) transporters in the placenta, maternal and fetal organs (brain, liver, kidney, small intestine) of pregnant rats. We focused on two most important representatives of drug efflux ABC transporters, P-glycoprotein (MDR1) and Breast Cancer Resistance Protein (BCRP). Knowledge of FTC effects on gene expression of these transporters is crucial especially when using FTC in combination therapy, known as Highly Active Antiretroviral Therapy (HAART). Changes in MDR1/BCRP expression may lead to significantly altered pharmacokinetics of concomitantly administered drugs. First, bioavailability was analyzed. AUC of FTC (3,5 mg/kg) following i.m. administration was comparable to that one after i.v. administration allowing us to use i.m. application as a route of FTC administration to rats. Subsequently,...
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Monitoring the effect of medically important drugs on activity of human P-glycoprotein using fluorescent probes
Veľas, Lukáš ; Gášková, Dana (advisor) ; Sigler, Karel (referee)
One of the main causes of failure in cancer treatment when using chemotherapy is the phenomenon of multidrug resistance - MDR. The most important protein mediating MDR in human cells is P-glycoprotein. The main goal of this thesis was the modification of fluorescent method - developed for studying yeast MDR pumps at the Department of Biophysics at the Institute of Physics of Charles University - to study the activity of P-glycoprotein in human tumor cells. The fluorescent method is based on the use of redistribution potentiometric probe diS-C3(3) which we found to be a substrate of P-glycoprotein. The optimalization of the method (experimental window) allowed sensitive monitoring of changes in the activity of P-glycoprotein caused by the effect of its several known inhibitors/substrates: oligomycin, amiodarone, verapamil, vinblastine, ketoconazole, itraconazole and FK506. New important results regarding the effect of these medically significant drugs on human cells were obtained. The developed method will undoubtedly be of great benefit in the search for new effective inhibitors and the study of their mechanisms in the future.
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Frequency of occurrence of selected single nucleotide polymorphisms of CYP2C8 and MDR1 in the Czech population and their influence on the effect of amiodarone
Pechandová, Kristina ; Perlík, František (advisor) ; Král, Jiří (referee) ; Anzenbacher, Pavel (referee)
Frequency of occurrence of selected single nucleotide polymorphisms of CYP2C8 and MDR1 in the Czech population and their influence on the effect of amiodarone Introduction: Variability in drug response is sometimes conditioned by genetic differences in the metabolism and the transport of drugs. Interindividual differences are often caused by polymorphisms affecting biotransformation activity of enzymes and expression of transporters. In the thesis we paid attention to the cytochrome P450 CYP2C8 and MDR1. First, we described the frequency of occurrence of selected variant alleles CYP2C8 * 2, CYP2C8 * 3 (2 substitution in exon 3 and 8, CYP2C8 and CYP2C8 * 3G416A * 3A1196G), CYP2C8 * 4, CYP2C8 P404A in the healthy Czech population and MDR1 variant alleles in these exons: 26 C3435T, 21 G2677A/T, 12 C1236T a 17 T-76A. Subsequently, we studied the influence of these polymorphisms on effects of amiodarone in the selected group of patients. Methods: We determined genotypes MDR1 a CYP2C8 by PCR-RFLP by using restriction enzymes and specific primers. We determined the frequency of MDR1 genotypes in 189 healthy volunteers and CYP2C8 in 161 healthy subjects. Further we included into the study 63 patients treated with amiodarone for longer than two months. Their treatment was assessed from medical records and...
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Frequency of occurrence of selected single nucleotide polymorphisms of CYP2C8 and MDR1 in the Czech population and their influence on the effect of amiodarone
Pechandová, Kristina ; Perlík, František (advisor) ; Král, Jiří (referee) ; Anzenbacher, Pavel (referee)
Frekvence výskytu vybraných bodových polymorfismů CYP2C8 a MDR1 v české populaci a jejich vliv na působení amiodaronu Úvod: Variabilita lékové odpovědi je někdy podmíněna genetickými rozdíly v metabolismu a transportu léčiv. Interindividuální rozdíly jsou často způsobeny polymorfismy, které ovlivňují biotransformační aktivitu enzymů a expresi transportérů. V disertační práci jsme věnovali pozornost cytochromu P450 izoenzymu CYP2C8 a MDR1. Nejprve jsme popsali frekvenci výskytu vybraných variantních alel CYP2C8*2, CYP2C8*3 (2 substituce v exonu 3 a 8, CYP2C8*3G416A a CYP2C8*3A1196G), CYP2C8*4, CYP2C8 P404A u zdravé české populace a variantních alel MDR1 v exonech: 26 C3435T, 21 G2677A/T, 12 C1236T a 17 T-76A. Následně jsme sledovali vliv těchto polymorfismů na působení amiodaronu u vybraného souboru pacientů. Metody: Genotyp MDR1 a CYP2C8 jsme stanovili pomocí PCR-RFLP za využití specifických restrikčních enzymů a primerů. Frekvence genotypů MDR1jsme určili u 189 zdravých dobrovolníků a CYP2C8 u 161 zdravých osob. Do sledování jsme dále zařadili 63 pacientů užívajících amiodaron déle než dva měsíce. Jejich léčbu jsme posuzovali ze záznamů lékařské dokumentace, s využitím standardních biochemických a hematologických vyšetření a záznamů EKG. Koncentrace amiodaronu a jeho metabolitu N-...
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