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Pengfei Song

Publications and source records attributed to Pengfei Song.

7 recordsLinked to original sources

A Deep Model Framework for Morphological Trait Imputation Across Taxonomic Groups.

Incomplete morphological trait data pose major hurdles for trait-based analyses, particularly when missing values, multicollinearity, and sparse sampling constrain inference. These issues limit our ability to quantify trait variation and explore broad patterns of functional differentiation across taxa. Here, we introduce FS-DeepRBFNet, which overcomes these pitfalls through integrating correlation-based feature selection with a dual-layer adaptive radial basis function (RBF) network. This end-to-end approach effectively reduces noise and captures both linear allometric trends and nonlinear morphological relationships. We tested the framework on a large species-level morphological trait dataset of Chinese birds and further validated its cross-taxon transferability using the Amphibian Database (Caudata). FS-DeepRBFNet consistently outperformed conventional methods such as KNN, Random Forest, and XGBoost, demonstrating superior predictive accuracy across multiple traits. Beyond improvements, the model revealed biologically interpretable trait associations and stable cross-taxon generalization. These results demonstrate that FS-DeepRBFNet provides a robust and biologically grounded solution for morphological trait prediction, enabling reliable imputation for comparative phylogenetics, functional ecology, and biodiversity forecasting in data-limited situations.

cross‐taxon transferability↗

Human biopsy-defined ischemia-reperfusion injury-selective reperfusion signature prioritizes reperfusion-timed mitogen-activated protein kinase kinase inhibition after donation after circulatory death liver transplantation.

Early post-liver transplant ischemia-reperfusion injury (IRI) in donation after circulatory death grafts lacks therapies targeted to the immediate postreperfusion window, in part because generic reperfusion transcription obscures IRI-selective amplification. We analyzed paired prereperfusion/postreperfusion liver biopsies from 2 cohorts (GSE151648 and GSE87487) using a difference-in-differences interaction estimand (&#x394;&#x394; = [Post-Pre]IRI+ - [Post-Pre]IRI-) to define an IRI-selective early reperfusion program. Genome-wide &#x394;&#x394; effects were summarized using pathway-responsive genes, and pathway concordance was tested using permutation (B = 5000). The reproducible &#x394;&#x394; footprint highlighted epidermal growth factor receptor-mitogen-activated protein kinase signaling (Spearman &#x3c1; = 0.811; P = .001). Directional &#x394;&#x394; gene sets (interaction P < .05) were submitted to the L1000 characteristic direction signature search engine2; cross-cohort overlap identified 8 shared perturbagens, including 3 mitogen-activated protein kinase kinase (MEK)1/2 inhibitors. In a hepatic ischemia/reperfusion time course (GSE117915), epidermal growth factor receptor and mitogen-activated protein kinase activities increased within 0.5 hours of reperfusion, and transplant single-cell RNA sequencing (GSE189539) localized MEK/extracellular signal-regulated kinase pathway engagement predominantly to parenchymal cells. A representative MEK inhibitor, PD-0325901, reduced hepatocyte oxygen-glucose deprivation/reoxygenation injury and, when administered at reperfusion in a rat donation after circulatory death liver transplantation model (5-20 mg/kg), attenuated histologic and biochemical injury, apoptosis, and redox-inflammatory readouts and improved 7-day survival. Collectively, this biopsy-anchored &#x394;&#x394; interaction-phenotype framework, with cross-cohort concordance as a prespecified robustness gate, nominates reperfusion-timed MEK inhibition as a mechanism- and window-aligned strategy to blunt early post-liver transplant IRI.

difference-in-differences (time &#xd7; IRI interac↗

Real-time PCR-based genotyping assay for CXCR2 polymorphisms.

BACKGROUND: The human chemokine receptor CXCR2 (IL8RB) is a high affinity receptor for interleukin-8 as well as other CXC chemokines, and is involved in the chemotaxis of immune cells. Genetic variants of CXCR2 have potential relevance in various inflammatory human disorders. We developed a real-time polymerase chain reaction (PCR)-based allelic discrimination assay for the detection of the CXCR2 single nucleotide polymorphisms (SNPs) C785T, T1208C and G1440A. METHODS: Polymorphisms were delineated using PCR amplification of specific alleles (PASA). Allele-specific primers were developed for both wild-type and mutant alleles. An additional nucleotide mismatch at the third position from the 3' end of each primer was used to improve amplification specificity and to prevent generation of nonspecific products. Genotypes were assigned based on PCR growth curves and melt curve analysis performed on a SmartCycler using SYBR Green I chemistry. RESULTS: Genotyping assignments were successfully performed in a set of 20 human DNA samples, and were validated by comparison with results from direct DNA sequencing and agarose gel electrophoresis of PCR products. CONCLUSIONS: Due to its rapid and relatively inexpensive performance and accuracy, the presented allelic discrimination assay for CXCR2 polymorphisms has wide applicability, especially for high-throughput sample analysis in large population genotyping studies.

Black or African American↗

The effect of CYP3A5 and MDR1 polymorphic expression on cyclosporine oral disposition in renal transplant patients.

Variability in CYP3A (CYP3A4/5) and P-glycoprotein (human MDR1 gene product) activity underlies interindividual differences in oral cyclosporine (CsA) bioavailability. Racial differences in polymorphic expression of CYP3A5 and MDR1 may explain observed interracial variability in oral bioavailability. Our objective was to evaluate the effect of CYP3A5 and MDR1 polymorphic expression on CsA oral disposition. Steady-state plasma concentration profiles (n = 19) were sampled in renal transplant recipients receiving concentration-adjusted CsA maintenance therapy. CsA plasma concentrations were measured by fluorescence polarization immunoassay. CYP3A5 and MDR1 genotypes were determined by real-time polymerase chain reaction. Noncompartmental pharmacokinetic analysis and nonlinear mixed-effects modeling (NONMEM) were performed to assess the effect of genotype on CsA pharmacokinetics. MDR1 C3435T genotype was identified as the best predictor of CsA systemic exposure. CsA oral clearance was significantly higher in subjects who carried at least one 3435T allele compared to homozygous wild-type individuals (40.0 +/- 2.2 vs. 26.4 +/- 3.1 L/h, p = 0.007). MDR1 C3435T genotype accounted for 43% of the interindividual variability of CsA oral clearance in the study population after accounting for interoccasion variability. The authors were unable to independently assess whether CYP3A5 correlated with any CsA pharmacokinetic parameter since all CYP3A5 nonexpressors were also 3435T allele carriers. MDR1 3435T allele carriers have enhanced oral clearance compared to individuals with the CC genotype. The frequency of the 3435T allele is lower in African Americans compared to Caucasians. Thus, the MDR1 C3435T genotype offers a potential mechanistic basis to explain interracial differences in CsA oral bioavailability. Further studies are needed to explore the relationship between CYP3A5 and MDR1 genotype and phenotype.

Adult↗

Detection of MDR1 single nucleotide polymorphisms C3435T and G2677T using real-time polymerase chain reaction: MDR1 single nucleotide polymorphism genotyping assay.

The objective of this study was to develop a real-time polymerase chain reaction (PCR) method to detect MDR1 (human multidrug resistance gene) single nucleotide polymorphisms (SNPs) C3435T and G2677T. C3435T and G2677T are linked to MDR1*2, which is associated with enhanced efflux activity in vitro. Using the Smart Cycler, an allele-specific real-time PCR-based genotyping method was developed to detect C3435T and G2677T. The MDR1 genotype of human genomic DNA templates was determined by direct DNA sequencing. PCR reactions for genotyping C3435T and G2677T by using allele-specific primers were conducted in separate tubes. An additional nucleotide mismatch at the third position from the 3' end of each allele-specific primer was used to abrogate nonspecific PCR amplification. The fluorescence emitted by SYBR Green I was monitored to detect formation of specific PCR products. PCR growth curves exceeding the threshold cycle were considered positive. Fluorescence melt-curve analysis was used to corroborate results from PCR growth curves. Using PCR growth curves, our assay accurately determined hetero- and homozygosity for C3435T and G2677T. Genotype assignments based on PCR growth curve, melt-curve analysis, agarose gel electrophoresis, and direct DNA sequencing results of PCR products were in perfect agreement. We have developed a rapid MDR1 genotyping method that can be used to assess the contribution of MDR1*2 to pharmacokinetic and pharmacodynamic variability of P-glycoprotein substrates.

ATP Binding Cassette Transporter, Subfamily B, Mem↗