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Biomedical subjects

Xiaochuan Liu

Publications and source records attributed to Xiaochuan Liu.

3 recordsLinked to original sources

Comprehensive Evaluation and Explainable Interpretation of Peptide-HLA Binding Prediction Tools.

Accurate prediction of peptide binding to human leukocyte antigen class I (HLA-I) molecules is critical for advancing immunological research, particularly in vaccine design and immunotherapy. However, limitations in model performance, interpretability, and dataset quality impede the widespread adoption of existing predictive tools. Here, we present a comprehensive evaluation of 17 HLA-I peptide binding prediction models, utilizing a meticulously curated dataset comprising over 290,000 peptides spanning 44 HLA-I alleles. We assessed model accuracy, robustness, and interpretability, employing explainability techniques such as SHAP (SHapley Additive exPlanations) and LIME (Local Interpretable Model-agnostic Explanations) to elucidate underlying prediction mechanisms. Our results reveal substantial performance disparities, with self-attention-based models, including STMHCpan and BigMHC, exhibiting superior accuracy. Notably, the capsule network model CapsNet-MHC_AN demonstrated robust performance. Models trained on eluted ligand datasets outperformed those relying on binding affinity data, underscoring the critical role of high-quality training data. Ensemble and multi-algorithm approaches further improved prediction reliability. These findings highlight the need for ongoing innovation in model architecture, integration of diverse and high-quality datasets, and incorporation of structural predictors to develop more accurate, interpretable, and clinically applicable HLA-I peptide binding prediction tools.

HLA-I binding↗

Thin-film microextraction.

The properties of a thin sheet of poly(dimethylsiloxane) (PDMS) membrane as an extraction phase were examined and compared to solid-phase microextraction (SPME) PDMS-coated fiber for application to semivolatile analytes in direct and headspace modes. This new PDMS extraction approach showed much higher extraction rates because of the larger surface area to extraction-phase volume ratio of the thin film. Unlike the coated rod formats of SPME using thick coatings, the high extraction rate of the membrane SPME technique allows larger amounts of analytes to be extracted within a short period of time. Therefore, higher extraction efficiency and sensitivity can be achieved without sacrificing analysis time. In direct membrane SPME extraction, a linear relationship was found between the initial rate of extraction and the surface area of the extraction phase. However, for headspace extraction, the rates were somewhat lower because of the resistance to analyte transport at the sample matrix/headspace barrier. It was found that the effect of this barrier could be reduced by increasing either agitation, temperature, or surface area of the sample matrix/headspace interface. A method for the determination of PAHs in spiked lake water samples was developed based on the membrane PDMS extraction coupled with GC/MS. A linearity of 0.9960 and detection limits in the low-ppt level were found. The reproducibility was found to vary from 2.8% to 10.7%.

Chromatography, Gas↗

Cholesteryl ester transfer protein levels and gene deficiency in Chinese patients with cardio-cerebrovascular diseases.

OBJECTIVE: To detect cholesteryl ester transfer protein (CETP) levels, frequencies of CETP D442G and I 14A mutations and characteristics of abnormal lipids in patients with cardio-cerebro vascular diseases. METHODS: Ninety-four myocardial infarction (MI) patients, 110 stroke patients and 335 healthy controls were selected. The CETP concentration was determined using ELISA. The CETP activity was measured using a substrate of (14)C-radiolabeled discoidal bilayer particles. The CETP gene mutations were detected by PCR-RFLP. RESULTS: The CETP concentrations in the MI and stroke group, were higher than those in the controls. The gene mutation frequencies of D442G in the MI, stroke and control group were 3.5%, 3.6% and 5%, respectively, and the frequencies of I 14A were 1.05%, 0.91% and 1%, respectively. One case of D442G homozygote was detected in the healthy group. The frequency of two CETP gene mutations showed no significant difference among the patients and controls. The CETP concentration and activity in subjects with CETP mutations were one-third of those in the control group. The level of HDL-C, apo-A1 increased in the mutation subjects, while the TG level decreased. CONCLUSIONS: The CETP level increased significantly in patients with cardio-cerebrovascular diseases. The carriers of CETP deficiency had CETP and lipid abnormalities.

Carrier Proteins↗