Frequency distribution of thiopurine S-methyltransferase alleles in a polish population

Thiopurine S-methyltransferase (TPMT) is an enzyme that catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine, 6-thioguanine, and azathioprine. TPMT activity exhibits an interindividual variability mainly a result of genetic polymorphism. Patients with intermediate or deficient TPMT activity are at risk for toxicity after receiving standard doses of thiopurine drugs. It has previously been reported that 3 variant alleles:TPMT*2, *3A, and *3C are responsible for over 95% cases of lower enzyme activity. The purpose of this study was to determine the frequency of TPMT variant alleles in a Polish population. DNA samples were obtained from 358 unrelated healthy Polish subjects of white origin, and TPMT genetic polymorphism was determined using PCR-RFLP and allele-specific PCR methods. The results showed that allelic frequencies were 0.4% for TPMT*2, 2.7% for TPMT*3A, and 0.1% for TPMT*3C, respectively. A TPMT*3B allele was not found in the studied population. The general pattern of TPMT allele disposition in the Polish population is similar to those determined for other white populations, but the frequency of total variant alleles is lower than in other European populations studied to date.     

Teleneurology in stroke management: costs of service in different organizational models

Telemedicine is in increasing use in clinical neuroscience such as acute stroke care, especially by applying remote audiovisual communication for patient evaluation. However, telephone consultation was also used linking stroke centres to smaller hospitals. We compared costs of telestroke services using audiovisual and telephone communication in different organizational models. Within a small network in Northern Bavaria video-based teleconsultation (VTC) and telephone advice (TA) was provided for evaluation of acute stroke patients on a weekly rotation. The costs of the admissions process with or without one of both methods of telemedicine were calculated and compared from the perspective of the spoke hospital. Different levels of service and network size were modelled and costs of transfers as well as loss of revenues were calculated. Yearly total labour costs were 415,000 € for an on-site service VTC-service compared to 61,000 € in an on-call service. Additional costs for one teleconsultation were 109.55 € in VTC and 49.82 € in TA (VTC/TA ratio 2.2). The ratio decreased to 0.8 when accounting for costs of transfer and loss of reimbursement for all patients transferred as transfer of patients to the stroke centre was more frequent after TA (9.1 vs. 14.9 %full-time on-site ser). Costs of one QALY gained by using VTC instead of TA ranged from 115.00 € to 515.86 € depending on the different models. In the first view TA looks like the less expensive method as it is easy to access and works without additional costs. When accounting for all disadvantages TA becomes slightly more expensive. In telestroke care VTC should be recommended as the method of choice also from an economic perspective.     

Differences in working memory coding of biological motion attributed to oneself and others

The question how the brain distinguishes between information about self and others is of fundamental interest to both philosophy and neuroscience. In this functional magnetic resonance imaging (fMRI) study, we sought to distinguish the neural substrates of representing a full‐body movement as one''s movement and as someone else''s movement. Participants performed a delayed match‐to‐sample working memory task where a retained full‐body movement (displayed using point‐light walkers) was arbitrarily labeled as one''s own movement or as performed by someone else. By using arbitrary associations we aimed to address a limitation of previous studies, namely that our own movements are more familiar to us than movements of other people. A searchlight multivariate decoding analysis was used to test where information about types of movement and about self‐association was coded. Movement specific activation patterns were found in a network of regions also involved in perceptual processing of movement stimuli, however not in early sensory regions. Information about whether a memorized movement was associated with the self or with another person was found to be coded by activity in the left middle frontal gyrus (MFG), left inferior frontal gyrus (IFG), bilateral supplementary motor area, and (at reduced threshold) in the left temporoparietal junction (TPJ). These areas are frequently reported as involved in action understanding (IFG, MFG) and domain‐general self/other distinction (TPJ). Finally, in univariate analysis we found that selecting a self‐associated movement for retention was related to increased activity in the ventral medial prefrontal cortex.     

Association of the MDR1 (ABCB1) gene 3435C> T polymorphism with male infertility

Infertility is a common problem affecting one in six couples, and in 30% of infertile couples, the male factor is a major cause due to defective sperm quality. P-glycoprotein (P-gp), a product of the MDR1 (ABCB1) gene, may be a link between genetic and environmental factors contributing to the development of male infertility because pesticides (P-gp substrates) are well established factors of male infertility. The aim of the present study was to examine the effect of the MDR1 gene 3435C>T polymorphism on male infertility. In total, 162 male patients undergoing semen analysis due to initial infertility workup were included in the study. The control group consisted of 191 healthy males with proven fertility. MDR1 3435C>T genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Assessment of MDR1 genotypes among the infertile men showed that 17.9% of subjects were carriers of the CC genotype, 58.0% were CT and 24.1% were TT. Among fertile men, 30.4% of subjects were characterised by the CC genotype, 49.7% were CT and 19.9% were TT. In addition, the frequency of carriers of at least one T allele (i.e., CT and TT genotypes) among infertile and fertile subjects was 82.1% and 69.6%, respectively. The risk of infertility was significantly elevated by two-fold in individuals carrying at least one T allele (CT and TT genotypes: p = 0.009, OR = 2.00, 95% CI: 1.20–3.32). Furthermore, this elevated risk was still found when considering each of the CT and TT genotypes alone (TT genotype: p = 0.027, OR = 2.05, 95% CI: 1.09–3.86; CT genotype: p = 0.013, OR = 1.98, 95% CI: 1.16–3.36). This preliminary report suggests that P-gp may play some role in male infertility, mediating detrimental effects of environmental factors.     

Influence of 825 C>T polymorphism of G protein β3 subunit gene (GNB3) on hemodynamic response during dobutamine stress echocardiography

There is a wide interpersonal difference to dobutamine response during dobutamine stress echocardiography (DSE). The aim of this study was to determine an association between GNB3 825C>T gene polymorphism, encoding the β3-subunit of G protein, and heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) response to dobutamine during DSE. The study involved 119 patients with clinical indications for DSE. Genotyping of GNB3 825C>T (rs5443) polymorphism was based on PCR-RFLP method with BseDI restriction enzyme. Significantly higher levels of both resting SBP and DBP in 825T allele carriers vs. 825CC patients were revealed. HR of 825CC vs. CT + TT subjects was slower along the test period reaching marked difference at dobutamine level 30 μg/kg/min (109 ± 20 vs. 116 ± 18 bpm, respectively, p = 0.047). SBP and DBP were markedly lower in 825CC homozygotes compared to 825T allele carriers throughout DSE. It can be concluded that GNB3 825C>T polymorphism is associated with resting SBP and DBP in Polish Caucasian patients subjected for diagnostic DSE. The polymorphism also modulate HR, SBP and DBP response during DSE.     

Expression of genes involved in xenobiotic metabolism and transport in end-stage liver disease: up-regulation of ABCC4 and CYP1B1

BackgroundExpression of drug-metabolizing enzymes and drug transporters in liver is mainly regulated by a system of nuclear receptors. The aim of the current study was to investigate the expression of nuclear receptors, as well as these enzymes and transporters, in liver samples from patients suffering from end-stage liver disease of various etiologies (HCV infection, alcohol liver disease, and primary sclerosis cholangitis).MethodsGene expression was measured using quantitative real-time PCR with surgical specimens from livers of patients with end-stage liver disease, and non-tumoral liver tissue that served as control.ResultsOur study confirmed that the expression of most phase I enzymes is suppressed in end-stage liver disease, and is correlated with a decrease in NR1I2 and NR1I3, the main regulators of xenobiotic metabolism. While mRNA levels of phase II enzymes were generally unchanged, some ABC transporters were up-regulated. The most spectacular increases in expression were observed with ABCC4 (MRP4) – at the mRNA level, and CYP1B1 – at both the mRNA and protein levels. We also demonstrated that IL-6 can induce CYP1B1 expression independently of CYP1A1, in a human hepatocellular liver carcinoma cell line.ConclusionsAs CYP1B1 is an enzyme which converts various substrates into carcinogenous metabolites, its overexpression in liver may be one of the factors increasing the risk of hepatic cancers inpatients with liver disease. CYP1A1 and CYP1B1 are often referred to as model AHR target genes, but CYP1A1 was down-regulated in diseased liver samples. This points to the existence of differences in regulation of these two genes.     

Oxidative modulation of marcaine and lekoptin in H9C2 rat myoblasts

Aim： The cytotoxicity of marcaine was estimated in combination with a calcium channel blocker. In addition, the influence of marcaine and marcaine plus lekoptin on a model system using the H9C2 cardiac cell line was investigated. Methods： Cells were incubated for five hours with marcaine, lekoptin, or with both drugs simultaneously. Apoptotic cells were detected using the TUNEL assay and the alkaline comet assay. Mitochondrial cell function after drug uptake was examined using the MTT assay. The concentration of MDA （malondialdehyde） - the final product of fatty-acid peroxidation, was quantified spectrophotometrically. The expression of glutathione S-transferase n （GST-rI） was detected by immunofluorescence （IF） and Western blotting （WB） and inducible nitric oxide synthase （iNOS） was assessed by immuno-cytochemical staining （ABC）. Results： Incubation with marcaine resulted in the highest number of apoptotic cells. After incubation with both marcaine and lekoptin, moderate damage to cells （54.2%＋1.775% of DNA destruction） was observed. The highest levels of iNOS and GST-n expression were observed in cells treated with marcaine and marcaine plus lekoptin. The characteristic nuclear GST-n expression was observed in cells treated with both drugs. Conclusion： Lekoptin stimulated cells to proliferate. Marcaine caused membrane damage and ultimately cell death.