CYP2C9*3(1075A>C), MDR1 G2677T/A and MDR1 C3435T are determinants of inter-subject variability in fluvastatin pharmacokinetics in healthy Chinese volunteers

To evaluate the impact of single-nucleotide polymorphisms (SNPs) in CYP2C9, MDR1, SLCO1B1 and ABCG2 on the pharmacokinetics of fluvastatin in Chinese participants.A pharmacokinetic study of fluvastatin (single dose 40 mg) was conducted in 12 healthy Chinese volunteers. Plasma concentrations of fluvastatin were determined by a high-performance liquid chromatography with fluorescence detection. Pharmacokinetic parameters were calculated by non-compartmental method. The SNPs were determined by TaqMan®(MGB) genotyping assay.Effect of CYP2C9*3 (c.1075A>C) on area under the plasma concentration-time curve (AUC) of fluvastatin was statistically significant. Heterozygous variant (C/A) carriers had higher AUC values compared to homozygous wild type (A/A) carriers (922.03±148.17 µg · h · L - 1 vs. 496.00±168.93 µg · h · L - 1, P=0.003092). The elimination half-life (T 1/2) values of fluvastatin were longer in MDR1 2677non-G carriers than in MDR1 2677G carriers (2.21±0.47 h vs. 1.25±0.62 h, P=0.02319), and also they were longer in MDR1 1236T-2677non-G-3435T carriers than in MDR1 1236C-2677G-3435C carriers (2.31±0.51 h vs. 1.32±0.62 h, P=0.03320). MDR1 C3435T polymorphism had a significant effect on maximal plasma concentrations (C max) of fluvastatin. Mutation gene T (TT+CT) carriers had higher C max values compared to homozygous wild type (C/C) carriers (688.54±142.67 µg · L - 1 vs. . 413.78±177.83 µg · L - 1, P=0.01448). Some SNPs such as MDR1 C1236T, ABCG2 c.34G>A, ABCG2 c.421C>A, SLCO1B1 c.388 A>G, SLCO1B1 c.521 T>C, SLCO1B1 c.571 T>C and SLCO1B1 c.597 C>T have no significant effects on fluvastatin pharmacokinetics.CYP2C9*3(1075A>C), MDR1 C3435T and MDR1 G2677T/A were determinants of inter-subject variability in fluvastatin pharmacokinetics in healthy Chinese volunteers.

Distribution of brachial-ankle pulse wave velocity values and optimal cut-off in distinguishing subjects with clinical condition in Chinese population

AIM

The present study aims to examine the distribution and gender- and age-specific reference ranges of brachial-ankle pulse wave velocity (baPWV) in Chinese population.

METHODS

A total of 21094 subjects were recruited into a cross-sectional study from June 2007 to June 2008 in China. Participants were divided into three clinical subgroups: 1) subgroup 1: subjects with atherosclerotic cardiovascular diseases; 2) subgroup 2: subjects with atherosclerotic risk factors; and 3) subgroup 3: "healthy subjects" without any atherosclerotic cardiovascular diseases and atherosclerotic risk factors.

RESULTS

The average baPWV among subgroups one through 3 was 1724.3±429.1, 1603.5±358.8, and 1389.9±288.4 cm/s, respectively. BaPWV did not fit as a normal distribution in both genders. There was no significant difference between male and female for baPWV in subgroup 1 (P>0.05). While baPWV was higher in females than males in subgroup 2, it was lower in females than in males in subgroup 3 (all P<0.05). Notably, BaPWV significantly increased with age in both genders (all P for trend<0.05). The receiver operator characteristic curve demonstrated that a baPWV of 1450 cm/s was useful to discriminate either cardiovascular diseases or atherosclerotic risk factors (sensitivity 62.1%, specificity 69.5%), a baPWV of 1551 cm/s was useful to discriminate cardiovascular diseases (sensitivity 62%, specificity 61%), and a baPWV of 1566 cm/s was useful to discriminate either cardiovascular diseases or chronic kidney disease (sensitivity 60%, specificity 63%).

CONCLUSION

The reference ranges and cut-off values of baPWV can be used to screen atherosclerotic cardiovascular diseases in clinical practices.

Serum detection of epidermal growth factor receptor gene mutations using mutant-enriched sequencing in Chinese patients with advanced non-small cell lung cancer

Epidermal growth factor receptor gene (EGFR) mutations are among the best predictive markers of the efficacy of EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment. Mutations in the EGFR gene confer sensitivity to EGFR-TKIs in patients with advanced non-small cell lung cancer (NSCLC). This study determined the concordance rate of EGFR mutations in serum samples and tumour tissue from Chinese patients with advanced NSCLC and compared two detection methods: mutant-enriched polymerase chain reaction-based DNA sequencing and non-enriched sequencing. The EGFR mutation status in serum was consistent with that in paired tumour samples, with a concordance rate of 93.1% for mutant-enriched sequencing. In serum samples, mutant-enriched sequencing demonstrated sensitivity and specificity of 77.8% and 100%, respectively, and was more sensitive than the non-enriched assay. Mutant-enriched sequencing in serum may provide a non-invasive and sensitive method for detecting EGFR mutation status in patients with unresectable NSCLC.

Association between XPD Lys751Gln polymorphism and risk of head and neck cancer: a meta-analysis

Several studies have investigated the association between Lys751Gln polymorphism in the xeroderma pigmentosum group D (XPD) gene and risk of head and neck cancer; however, the published results are conflicting. We conducted a meta-analysis that comprised 15 published case-control studies examining the association of head and neck cancer risk with XPD Lys751Gln polymorphism in different populations, based on the data identified in Medline up to November 2010. Odds ratios (ORs) with 95% confidence intervals (CI) were used to assess the strength of the association. Overall, significantly elevated head and neck cancer risk was associated with XPD Lys751Gln polymorphism when all studies were pooled into the meta-analysis [(Gln/Gln + Lys/Gln) vs Lys/Lys: OR = 1.12, 95%CI = 1.03-1.22, P < 0.01, heterogeneity P = 0.11]. In the subgroup analysis by ethnicity, borderline significantly increased risk was found for Europeans [(Gln/Gln + Lys/Gln) vs Lys/Lys: OR = 1.11, 95%CI = 1.00-1.23, P < 0.05]. In conclusion, our meta-analysis demonstrated that XPD Lys751Gln polymorphism could be a prediction marker for risk of head and neck cancer.

Meal-induced increases in C-reactive protein, interleukin-6 and tumour necrosis factor α are attenuated by prandial + basal insulin in patients with Type 2 diabetes

AIM

To determine if a regimen with prandial + basal insulin compared with basal insulin attenuates post-meal inflammatory and glycative biomarkers in patients with Type 2 diabetes.

METHODS

This test-meal sub-study in the USA is from a previously reported clinical trial comparing the effect on glycaemic control of 24 weeks of thrice-daily pre-meal insulin lispro mix 50 (50% insulin lispro, 50% insulin lispro protamine suspension) or bedtime insulin glargine, both plus metformin. In the sub-study, glucose, insulin, triglycerides, high-sensitivity C-reactive protein, tumour necrosis factor α, interleukin-6, methylglyoxal and 3-deoxyglucosone were measured during the post-meal period of a mixed-meal breakfast at the final visit. Prandial + basal (n = 25) and basal (n = 21) insulin were administered at the same times as during the previous 24 weeks.

RESULTS

Post-meal, the prandial + basal insulin group had significantly higher insulin, lower glucose and triglycerides, as well as lower high-sensitivity C-reactive protein, tumour necrosis factor α and interleukin-6, than the basal insulin group. Glucose incremental area under the concentration curve significantly correlated with high-sensitivity C-reactive protein, tumour necrosis factor α, interleukin-6, methylglyoxal and 3-deoxyglucosone incremental area under the concentration curve. Insulin incremental area under the concentration curve correlated inversely with high-sensitivity C-reactive protein and tumour necrosis factor α incremental area under the concentration curve. However, after adjusting for glucose incremental area under the concentration curve, these inverse correlations were no longer significant. Triglyceride incremental area under the concentration curve was not correlated with any biomarker incremental area under the concentration curve.

CONCLUSIONS

Controlling post-meal hyperglycaemia with prandial + basal insulin in patients with Type 2 diabetes attenuates meal-induced increases in high-sensitivity C-reactive protein, interleukin-6 and tumour necrosis factor α compared with basal insulin. The rise in post-meal glucose, but not triglycerides, significantly correlated with the rise in post-meal inflammatory and glycative biomarkers.

Imaging the social brain: multi-subjects EEG recordings during the "Chicken's game"

In this study we measured simultaneously by EEG hyperscannings the neuroelectric activity in 6 couples of subjects during the performance of the "Chicken's game", derived from game theory. The simultaneous recording of the EEG in couples of interacting subjects allows to observe and model directly the neural signature of human interactions in order to understand the cerebral processes generating and generated by social cooperation or competition. Results suggested that the one of the most consistently activated structure in this particular social interaction paradigm is the left orbitofrontal cortex. Connectivity results also showed a significant involvement of the orbitofrontal regions of both hemispheres across the observed population. Taken together, results confirms that the study of the brain activities in humans during social interactions can take benefit from the simultaneous acquisition of brain activity during such interaction.

Simultaneous estimation of cortical activity during social interactions by using EEG hyperscannings

In this paper we show how the possibility of recording simultaneously the cerebral neuroelectric activity in different subjects (EEG hyperscanning) during the execution of different tasks could return useful information about the "internal" cerebral state of the subjects. We present the results obtained by EEG hyperscannings during ecological task (such as the execution of a card game) as well as that obtained in a series of couples of subjects during the performance of the Prisoner's Dilemma Game. The simultaneous recordings of couples of interacting subjects allows to observe and to model directly the neural signature of human interactions in order to understand the cerebral processes generating and generated by social cooperation or competition. Results obtained in a study of different groups recorded during the card game revealed a larger activity in prefrontal and anterior cingulated cortex in different frequency bands for the player that leads the game when compared to other players. Results collected in a population of 10 subjects during the performance of the Prisoner's Dilemma suggested that the most consistently activated structure is the orbitofrontal region (roughly described by the Brodmann area 10) during the condition of competition in both the tasks. It could be speculated whether the pattern of cortical connectivity between different cortical areas in different subjects could be employed as a tool for assessing the outcome of the task in advance.

Vitamin Bs, one carbon metabolism and prostate cancer

Somatic genetic and epigenetic alterations have been suggested to be crucially involved in development and progression of cancers including prostate cancer (PCa). Epigenetic alterations such as chemical modification of chromatin associated proteins and DNA methylation can largely affect gene expression that may be important for early normal organ development, and also produces favorable conditions for cancer cell formation, growth, and survival. Aberrant DNA methylation (hyper- or hypo-methylation) may lead to chromosomal instability, and transcriptional gene silencing for tumor suppressors or overexpression for oncogenes. Vitamin Bs play important roles in one carbon metabolism that provides critical metabolites for DNA methylation, DNA repair and nucleic acid synthesis. Nutrition uptake and circulating levels of these vitamin Bs as well as genetic polymorphisms of related key enzymes in the one carbon metabolism pathway may govern bioavailability of the metabolites, and therefore to affect the phenotypic changes (e.g., cellular malignancy) via genetic and epigenetic alterations. This article will summarize recent new findings from laboratory, epidemiological or clinical trial studies regarding influence of vitamin B and one carbon metabolism on PCa development or progression.

Advances in Holographic Polymer Dispersed Liquid Crystal Technology

We discuss recent advances in reflective holographically-formed polymer dispersed liquid crystal materials in the context of their suitability for reflective display applications. A dual-domain phenomenon resulting in a broadened reflection peak is presented. A simple phenomenological model is developed to explain this unusual effect The effect of monomer functionality on the reflectance characteristics of these materials is also discussed. Monomers of effective functionality ∼4.5 yield the brightest holograms, however, the data suggests that these systems are currently far from optimal.

Characteristics of prevalence in peripheral arterial disease and correlative risk factors and comorbidities among female natural population in China

BACKGROUND

To investigate the prevalence of peripheral arterial disease (PAD) and correlating risk factors and comorbidities in a natural female population in China, and to study the characteristics of atherosclerotic disease in females.

PATIENTS AND METHODS

Natural population from communities in several cities and districts including Beijing, Shanghai, Changsha, Guangdong, Inner Mongolia, and Xinjiang in China were investigated as study subjects through cluster multistage and random sampling. Ankle-brachial index (ABI) was measured among participants in the communities by trained investigators and correlative information and clinical data were collected. PAD was defined as an ABI≤0.9 in either leg.

RESULTS

21,152 eligible participants were included in the survey. The prevalence in males and females was 2.52 % and 3.66 %, the standardized prevalence was 1.84% and 4.31% respectively, and the prevalence in females was higher than that in males (p<0.01). The prevalence in females obviously increased (p<0.01) with increasing age. More female participants with PAD were over 69 years old compared with those without PAD (18.8% vs. 10.0%, p=0.000) and more frequently have a smoking habit (11.1% vs. 2.5%, p=0.000), lipid disorders (34.8% vs. 29.2%, p=0.047), diabetes mellitus (14.8% vs. 8.6%, p=0.000), coronary heart disease (16.9% vs. 10.0%, p=0.000) and a history of stroke (6.8% vs. 2.3%, p=0.000). Using multiple logistic regression analysis, older age (>69 years old, OR: 1.60, 95% CI: 1.11-2.29), a smoking habit (OR: 5.98, 95% CI: 3.88-9.21), comorbidities of lipid disorders (OR: 1.45, 95% CI: 1.10-1.91), diabetes mellitus (OR: 1.46, 95% CI: 1.02-2.11), coronary heart disease (OR: 1.50, 95% CI: 1.02-2.19)and a history of stroke (OR: 1.71, 95% CI: 1.01-2.91) were correlated with the prevalence of PAD in females in China. Only 0.8% of female patients with PAD had been diagnosed previously.

CONCLUSIONS

The data suggest that the prevalence of PAD in a female natural population in China is higher than that in males. Many conventional risk factors and comorbidities were correlated with the high prevalence of PAD in females. But only very few female patients with PAD were diagnosed. Thus, more measures should be taken to diagnose, prevent and control PAD in females in China.

The structure and functions of P-glycoprotein

P-glycoprotein (P-gp) is an ATP-driven transmembrane transporter capable of effluxing a wide variety of structurally diverse and functionally unrelated hydrophobic compounds out of the cell. Multidrug resistance (MDR), often associated with the over-expression of P-gp, has been implicated as a major obstacle to effective chemotherapy for cancer, parasitic diseases, AIDS, and other diseases. Drug efflux mediated by P-gp is also involved in decreasing the oral bioavailability of drugs by limiting intestinal absorption. Our appreciation of the structural and functional aspects of P-gp has definitely improved in recent years, benefiting from the deciphering of the structure of some bacterial transporters that paved the way for construction of homology models for more complex transporters. Here, we will review the recent advances in the studies of the structure and functional characteristics of P-gp with the hopes of facilitating rational drug design in developing novel potent MDR modulators.

Heterotopic bone formation by nano-apatite containing poly(D,L-lactide) composites

To render polymeric materials osteoinductive, nano-sized calcium phosphate apatite particles (CaP) were introduced into a low molecular weight poly(D,L-lactide). Homogenous composites were made with 10%, 20% and 40% by weight of apatite content while pure polylactide was used as control. Thereafter porous samples (pore size 300-400 microm, 60% porosity) were fabricated and sterilized. In vitro studies showed that calcium ions were released from the composites depending on the apatite content, while surface mineral deposition was observed only on the 40% CaP composites in simulated body fluid (SBF) within 14 days. After 12 weeks of intramuscular implantation in dogs, only the 40% CaP composite implant retained its shape and showed ectopic bone formation within the pores. In conclusion, adding a content of 40% apatite into poly(D,L-lactide) could lead to an osteoinductive material. Future studies will focus on understanding this phenomenon of material-directed osteoinduction in order to develop a promising bone graft substitute.

Corticotrophin-releasing hormone (CRH) facilitates axon outgrowth

OBJECTIVE

To evaluate the role of corticotrophin-releasing hormone (CRH) in facilitating axon outgrowth.

BACKGROUND

Injured neural tissue is difficult to regenerate; the mechanism has not been fully understood.

METHODS

A rat model of spinal cord transection injury was developed. Levels of BDNF, CRH and oligodendrocyte glycoprotein (OMgp) in injured spinal cord were monitored dynamically after surgery. Cellular interaction among rat dorsal root ganglia (DRG) cells, oligocondrocytes and microglial cells was observed with a coculture model. The axon outgrowth from DRG cells was examined by confocal microscopy.

RESULTS

After spinal cord transection, levels of BDNF and CRH increased the next day and decreased afterward, whereas OMgp levels increased from day 3. Administration with BDNF suppressed the levels of OMgp in vitro. The results from a coculture model showed that CRH increased microglial cells to release BDNF; BDNF inhibited OMgp levels in oligodendrocytes and enhanced the axon outgrowth from DRG cells.

CONCLUSIONS

This study shows that CRH has the ability to facilitate the outgrowth of axon in spinal neurons, which has therapeutic potential in the treatment of spinal cord injury.

Estimation of the cortical activity from simultaneous multi-subject recordings during the prisoner's dilemma

One of the most challenging questions open in Neuroscience today is the characterization of the brain responses during social interaction. A major limitation of the approaches used in most of the studies performed so far is that only one of the participating brains is measured each time. The "interaction" between cooperating, competing or communicating brains is thus not measured directly, but inferred by independent observations aggregated by cognitive models and assumptions that link behavior and neural activation. In this paper, we present the results of the simultaneous neuroelectric recording of 5 couples of subjects engaged in cooperative games (EEG hyperscanning). The simultaneous recordings of couples of interacting subjects allows to observe and model directly the neural signature of human interactions in order to understand the cerebral processes generating and generated by social cooperation or competition. We used a paradigm called Prisoner's dilemma derived from the game theory. Results collected in a population of 10 subjects suggested that the most consistently activated structure in social interaction paradigms is the orbitofrontal region (roughly described by the Brodmann area 10) during the condition of competition.