Intra-individual variation of drug metabolism by cytochrome P450s in human liver microsomes

Aim To investigate the intra-individual variation in activities of cytochrome P450 enzymes （CYP） in human liver microsomes （HLM）. Methods CYP＇s relative Kin, VmaX and CLi.t （n = 105） expressing as relative metabolic activities （RMAs） and variations of RMAs in 10 CYPs expressing as intra-individual percentage coeffi- cient of variations （ICV） were calculated. Results The ICVs of relative Vmax, K and CLint were 44.03% （16.79% -127.42% ）, 45.88% （18.31% -140. 14% ） and 52.00% （24.20%-134.81% ）. Overall RMAs for 10 CYPs were sorted. The orders, from highest to lowest, were CYP2D6, 1A2, 2C19, C9, 3A4/5, 2B6, 2A6, 2C8 and 2El for K , CYP3A4/5, 2C19, 2D6, 2C8, 2El, 2B6, 1A2, 2A6 and 2C9 for Vmax, CYP2D6, 2B6, 3A4/5, 2C19, 2C9, 1A2, 2El, 2C8 and 2A6 for CLint. CYP2A6＊ 4, CYP2B6 758A 〉 G and 2D6 100C 〉 T contributed to intra-individual variation in activities of CYPs. Conclusion The conception of ＂intra-individual variation＂ in activities of CYPs which means different CYPs presenting different activities of drug metabolism in one person was first put forward. We demonstrated that intra-individual variation in activities of CYPs were very remark- able in normal HLMs for the first time, which built a substantial foundation for the future development of precision medicine.

Single semen analysis as a predictor of semen quality： clinical and epidemiological implications

It is generally thought that a single ejaculate is a bad predictor of semen quality of a subject, because of significant intra-individual variation. Therefore, we investigated the degree to which the results of a first semen analysis differ from that of a second analysis among men from a how the two different semen results mirrored the overall general population in Norway. In addition, we analysed semen quality assessment. A total of 199 volunteers participated in the study and delivered two semen samples with an interval of 6 months. The semen parameters were determined according to the World Health Organization （WHO） 1999 guidelines, which were also used to determine whether semen quality was normal or abnormal. In addition, the DNA fragmentation index （DFI） was determined using the Sperm Chromatin Structure Assay. The two samples from each individual were very similar with regard to standard semen parameters and DFI （rs： 0.67-0.72）, and there were no significant systematic differences between the two samples. The result of the first sample （normal/abnormal） was highly predictive of the overall conclusion based on the two samples （sperm concentration： in 93% of the cases （95% confidence interval [CI]： 89%-96%）; sperm motility： in 85% of the cases （95% CI： 79%-89%）; overall semen quality： in 85% of the cases （95% CI： 80%-90%）. In epidemiological studies, one ejaculate is a sufficient indicator of semen quality in a group of subjects. In a clinical situation, when the question is whether the semen quality is normal or not, the first ejaculate will, in at least 85% of cases, give a correct overall conclusion.

Multi-omics Analysis of Primary Cell Culture Models Reveals Genetic and Epigenetic Basis of Intratumoral Phenotypic Diversity

Uncovering the functionally essential variations related to tumorigenesis and tumor progression from cancer genomics data is still challenging due to the genetic diversity among patients,and extensive inter-and intra-tumoral heterogeneity at different levels of gene expression regulation,including but not limited to the genomic, epigenomic, and transcriptional levels. To minimize the impact of germline genetic heterogeneities, in this study, we establish multiple primary cultures from the primary and recurrent tumors of a single patient with hepatocellular carcinoma(HCC). Multiomics sequencing was performed for these cultures that encompass the diversity of tumor cells from the same patient. Variations in the genome sequence, epigenetic modification, and gene expression are used to infer the phylogenetic relationships of these cell cultures. We find the discrepancy among the relationships revealed by single nucleotide variations(SNVs) and transcriptional/epigenomic profiles from the cell cultures. We fail to find overlap between sample-specific mutated genes and differentially expressed genes(DEGs), suggesting that most of the heterogeneous SNVs among tumor stages or lineages of the patient are functionally insignificant. Moreover, copy number alterations(CNAs) and DNA methylation variation within gene bodies, rather than promoters, are significantly correlated with gene expression variability among these cell cultures. Pathway analysis of CNA/DNA methylation-related genes indicates that a single cell clone from the recurrent tumor exhibits distinct cellular characteristics and tumorigenicity, and such an observation is further confirmed by cellular experiments both in vitro and in vivo. Our systematic analysis reveals that CNAs and epigenomic changes, rather than SNVs, are more likely to contribute to the phenotypic diversity among subpopulations in the tumor. These findings suggest that new therapeutic strategies targeting gene dosage and epigenetic modification should be considered in personalized cancer medicine. This culture model may be applied to the further identification of plausible determinants of cancer metastasis and relapse.

Behavioral predictability in a lynx spider is interactively influenced by mean behavior, prey density,and an insecticide

Behavioral predictability,i.e.,short-term intra-individual variability under relatively constant environmental conditions,has only recently begun to gain attention.It is unknown,however,whether predictability of individuals with distinct mean behavior changes differently as a response to ecological factors such as resource availability.Moreover,the response might be affected by anthropogenic contaminants that are ubiquitous in the environment and that can affect animals' variability in behavior.Here,we investigated the relationship between mean predatory activity and predictability in predatory activity along a prey density gradient in the lynx spider Oxyopes lineatipes.We further examined how this relationship is influenced by insecticides,azadirachtin,and a plant extract from Embelia ribes.We found that all studied variables affected the predictability.In the control and Embelia treatments,that did not differ significantly,the predictability decreased with increasing prey density in a mean behavior-specific way.Individuals with low mean predatory activity were relatively less predictable than were those with high activity from low to moderate prey densities but more predictable at high prey densities.Azadirachtin altered this pattern and the individuals with low predatory activity were less predictable than were those with high predatory activity along the whole gradient of prey density.Our results show that predictability can change along an environmental gradient depending on a mean behavior.The relative predictability of the individuals with distinct mean behavior can depend on the value of the environmental gradient. In addition,this relationship can be affected by anthropogenic contaminants such as pesticides.

Repeatability and Variability of the 3-Min All-Out Test at the Subject Level

Purpose The constant work-rate to exhaustion tests must be repeated several times at each work-rate to estimate subject-level trial-to-trial variance(intra-individual variability,IIV)of critical power(CP)and work capacity(W').Alternatively,these parameters and their variance can be estimated by repeating the 3-min all-out test(3MT)fewer times.The purpose of this study was to propose a method to determine subject-level repeatability of the 3MT and demonstrate the need to repeat the test multiple times to estimate IIV.Methods Seven cyclists performed a ramp test and four 3MTs on a CompuTrainer.The parameters CP,W',peak power(Pp),and total work(TW)were compared across trials using repeated measures ANOVA,Bland-Altman analysis,Intraclass Cor-relation Coefficients(ICC),Typical Error(TE)of measurement,and Coefficient of Variation(CV).Results For the group,average CP and W'were 284±58 W and 10.214±3.143 kJ.The reliability statistics,CP(ICC=0.97,TE=8 W,CV=2.94%)and W'(ICC=0.88,TE=1.11 kJ,CV=10.87%),indicated strong agreement.Subject-level repeatability was determined by comparing time-to-peak power(TPp),absolute difference in Pp(δPp),and TW(δTW)for pairs of 3MTs.The average IIVs estimated by the 95%confidence intervals were±15 W for CP and±1.68 kJ for W'.Conclusions Thresholds are proposed for TPp(7 s),δPp(10%),andδTW(3%)to determine subject-level repeatability of the 3MT before computing the IIV of CP and W'.It is suggested that the 3MT is repeated at least three times to estimate the IIV,which aids in personalized measurement of training improvements and performance optimization。