1.Three-dimensional Electrical Impedance Tomography for Monitoring Gastric Hemorrhage
Zi-Han ZHAO ; Bo SUN ; Jing-Shi HUANG ; Zhi-Wei LI ; Yang WU ; Nan LI ; Jia-Feng YAO ; Tong ZHAO
Progress in Biochemistry and Biophysics 2026;53(4):1062-1075
ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.
2.Olfactory Receptors Expressed in The Intestine and Their Functions
Pei-Wen YANG ; Meng-Meng YUAN ; Ying ZHOU ; Peng LI ; Gui-Hong QI ; Ying YANG ; Zhong-Yi MAO ; Meng-Sha ZHOU ; Xiao-Shuang MAO ; Jian-Ping XIE ; Yi-Nan YANG ; Shi-Hao SUN
Progress in Biochemistry and Biophysics 2026;53(3):534-549
Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of “chemosensors” to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut’s sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.
3.Effect of sitravatinib on a mouse model of carbon tetrachloride-induced liver fibrosis and its mechanism
Huan ZHANG ; Xiangyu WU ; Qianwen ZHAO ; Fajuan RUI ; Nan GENG ; Rui JIN ; Jie LI
Journal of Clinical Hepatology 2026;42(3):600-607
ObjectiveTo investigate the therapeutic effect of sitravatinib on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. MethodsA total of 30 male C57BL/6J mice, aged 8 weeks, were randomly divided into control group, CCl4 model group, and low- (5 mg/kg), middle- (10 mg/kg), and high-dose (20 mg/kg) sitravatinib groups. All mice except those in the control group were given intraperitoneal injection of CCl4 for 4 consecutive weeks to induce liver fibrosis, and since the first day of modeling, the mice in the low-, middle-, and high-dose sitravatinib groups were given sitravatinib at the corresponding dose by gavage every day. The serum levels of total cholesterol (TC), triglyceride (TG), and alanine aminotransferase (ALT) were measured for the mice in each group; hepatic hydroxyproline content was measured; HE staining, Masson staining, and Sirius Red staining were used to observe liver histopathological changes; quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression levels of α-smooth muscle actin (α-SMA) and collagen type I alpha 1 (Col1a1) in liver tissue. The therapeutic effect of sitravatinib was assessed based on the above results. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the control group, the model group had significant increases in the levels of TC, TG, and ALT (all P<0.05), and there were no significant differences in the levels of TC, TG, and ALT between the model group and the low-, middle-, and high-dose sitravatinib groups (all P>0.05). Hepatic hydroxyproline content decreased after sitravatinib intervention, with a significant difference between the middle-/high-dose sitravatinib groups and the CCl4 model group (both P<0.05). Histopathological staining showed that the sitravatinib treatment groups had a reduction in collagen deposition, along with thinning and fragmentation of fibrous septa, and in the high-dose sitravatinib group, 4 mice had a fibrosis stage of S0—S1 and 2 mice had a fibrosis stage of S2—S3, suggesting a certain degree of alleviation of liver fibrosis degree compared with the CCl4 model group (mainly S3—S4). The measurement of related molecules showed that sitravatinib downregulated the mRNA and protein expression levels of α-SMA and Col1a1 (all P<0.05). ConclusionSitravatinib can effectively alleviate CCl4-induced liver fibrosis in mice, possibly by inhibiting hepatic stellate cell activation and collagen synthesis.
4.Application Analysis of Rehmanniae Radix in Medical Cases of Qing Court
Yan JIN ; Tiegui NAN ; Yihan WANG ; Zhilai ZHAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):232-238
To gain an in-depth understanding of the clinical application of Rehmanniae Radix during the Qing Dynasty and to clarify its specifications and corresponding therapeutic effects, this study took Rehmanniae Radix in the prescriptions documented in Research on Medical Cases of the Qing Imperial Court as the research subject. According to historical medical literature, a comprehensive investigation was conducted on the specifications, therapeutic efficacy, frequency of use, dosage, and seasonal patterns of Rehmanniae Radix employed by imperial physicians. The findings revealed that Rehmanniae Radix in the medical cases of the Qing court was primarily classified into three categories: Xiaoshengdi, Zhongshengdi, and Dashengdi. Xiaoshengdi was also referred to as Xishengdi or Cishengdi, all denoting dried Rehmanniae Radix. The term Xishengdi was inconsistently defined in the literature. It should refer to the slender variant of dried Rehmanniae Radix and was utilized as a specific specification in the medical cases of the Qing court. In contrast, the wild fresh roots of Rehmanniae Radix, described as "as slender as fingers", were commonly documented as fresh Rehmanniae Radix in these medical cases. There were variations in Rehmanniae Radix size and grading between historical and contemporary standards. Furthermore, therapeutic differences were observed among Rehmanniae Radix specifications in the medical cases of the Qing court. Xiaoshengdi and Zhongshengdi exhibited slightly stronger blood-cooling and heat-clearing effects while maintaining a non-cloying Yin-nourishing property. In contrast, Dashengdi demonstrated a greater emphasis on Yin supplementation with relatively milder heat-clearing activity. In the medical cases of the Qing court, the dosage of Rehmanniae Radix in different specifications was usually 11.2-18.7 g per dose, typically administered twice daily. Rehmanniae Radix in different specifications exhibits variations in efficacy, which can provide evidence-based insights for precise clinical application.
5.Application Analysis of Rehmanniae Radix in Medical Cases of Qing Court
Yan JIN ; Tiegui NAN ; Yihan WANG ; Zhilai ZHAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):232-238
To gain an in-depth understanding of the clinical application of Rehmanniae Radix during the Qing Dynasty and to clarify its specifications and corresponding therapeutic effects, this study took Rehmanniae Radix in the prescriptions documented in Research on Medical Cases of the Qing Imperial Court as the research subject. According to historical medical literature, a comprehensive investigation was conducted on the specifications, therapeutic efficacy, frequency of use, dosage, and seasonal patterns of Rehmanniae Radix employed by imperial physicians. The findings revealed that Rehmanniae Radix in the medical cases of the Qing court was primarily classified into three categories: Xiaoshengdi, Zhongshengdi, and Dashengdi. Xiaoshengdi was also referred to as Xishengdi or Cishengdi, all denoting dried Rehmanniae Radix. The term Xishengdi was inconsistently defined in the literature. It should refer to the slender variant of dried Rehmanniae Radix and was utilized as a specific specification in the medical cases of the Qing court. In contrast, the wild fresh roots of Rehmanniae Radix, described as "as slender as fingers", were commonly documented as fresh Rehmanniae Radix in these medical cases. There were variations in Rehmanniae Radix size and grading between historical and contemporary standards. Furthermore, therapeutic differences were observed among Rehmanniae Radix specifications in the medical cases of the Qing court. Xiaoshengdi and Zhongshengdi exhibited slightly stronger blood-cooling and heat-clearing effects while maintaining a non-cloying Yin-nourishing property. In contrast, Dashengdi demonstrated a greater emphasis on Yin supplementation with relatively milder heat-clearing activity. In the medical cases of the Qing court, the dosage of Rehmanniae Radix in different specifications was usually 11.2-18.7 g per dose, typically administered twice daily. Rehmanniae Radix in different specifications exhibits variations in efficacy, which can provide evidence-based insights for precise clinical application.
6.From Gene Expression to Transcriptome-wide Association Study: Development and Comparison of Methodology
Kun FANG ; Guozhuang LI ; Linting WANG ; Qing LI ; Kexin XU ; Lina ZHAO ; Zhihong WU ; Jianguo ZHANG ; Nan WU
Medical Journal of Peking Union Medical College Hospital 2026;17(1):223-229
Over the past two decades, genome-wide association study(GWAS) has identified numerous genetic variants and loci associated with heritable diseases. With the gradual maturation and saturation of GWAS methodologies, transcriptome-wide association study(TWAS) offers a novel perspective by linkinggenetic phenotypes to gene expression levels. By integrating TWAS with other multi-omics analyses, researchers can gain a deeper understanding of heritable diseases. This article provides an overview of recent groundbreaking and representative TWAS methods and tools, analyzes their strengths and limitations, and discusses future trends in TWAS development.
7.Mechanism Exploration of Doxorubicin and Sepsis Induced Myocardial Injury: Differences and Convergences
Tao ZHANG ; Zihan NAN ; Lixia LIU ; Jiaqi LIU ; Xiukai CHEN ; Xiaoting WANG ; Suwen SU
Medical Journal of Peking Union Medical College Hospital 2026;17(1):23-32
Doxorubicin (DOX)-induced cardiotoxicity and sepsis-induced myocardial injury (SIMI) represent significant clinical challenges in patients undergoing chemotherapy, sharing a common pathological basis of oxidative stress and mitochondrial dysfunction. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has recently been shown to play a critical role in DOX-induced cardiotoxicity and lipopolysaccharide (LPS)-induced SIMI. This article systematically reviews the mechanisms underlying myocardial injury caused by DOX and sepsis, identifying ferroptosis as a central common pathway. DOX triggers a burst of reactive oxygen species within mitochondria and inhibits glutathione peroxidase 4 (GPX4) activity through redox cycling of its quinone group and high-affinity accumulation in mitochondrial cardiolipin. LPS, by activating pattern recognition receptors and related inflammatory signaling pathways, provokes a cytokine storm and mitochondrial dysfunction. Both can disrupt the core regulatory axis of cysteine-glutathione (GSH)-GPX4, synergistically promoting ferroptosis in cardiomyocytes. Moreover, epigenetic regulation plays a key role in DOX- and LPS-induced cardiomyocyte ferroptosis and may serve as a promising therapeutic target. A deeper understanding of the ferroptosis mechanism and its epigenetic regulatory network in the synergistic injury induced by DOX and sepsis is of great importance for developing novel strategies to mitigate chemotherapy-related cardiotoxicity and improve outcomes in cancer patients with concurrent infections.
8.Explainable Machine Learning Model for Predicting Prognosis in Patients with Malignant Tumors Complicated by Acute Respiratory Failure: Based on the eICU Collaborative Research Database in the United States
Zihan NAN ; Linan HAN ; Suwei LI ; Ziyi ZHU ; Qinqin ZHU ; Yan DUAN ; Xiaoting WANG ; Lixia LIU
Medical Journal of Peking Union Medical College Hospital 2026;17(1):98-108
To develop and validate a model for predicting intensive care unit (ICU) mortality risk in patients with malignant tumors complicated by acute respiratory failure (ARF) based on an explainable machine learning framework. Clinical data of patients with malignant tumors and ARF were extracted from the eICU Collaborative Research Database in the United States, including demographic characteristics, comorbidities, vital signs, laboratory test indicators, and major interventions within the first 24 hours after ICU admission.The study outcome was ICU death.Enrolled patients were randomly divided into a training set and a validation set at a ratio of 7:3.Predictor variables were selected using least absolute shrinkage and selection operator (LASSO) regression.Five machine learning algorithms-extreme gradient boosting (XGBoost), support vector machine (SVM), Logistic regression, multilayer perceptron (MLP), and C5.0 Decision Tree-were employed to construct predictive models.Model performance was evaluated based on the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and other metrics.The optimal model was further interpreted using the Shapley additive explanations (SHAP) algorithm. A total of 3196 patients with malignant tumors complicated by ARF were included.The training set comprised 2, 261 patients and the validation set 935 patients; 683 patients died during ICU stay, while 2513 survived.LASSO regression ultimately selected 12 variables closely associated with patient ICU outcomes, including sepsis comorbidity, use of vasoactive drugs, and within the first 24 hours after ICU admission: minimum mean arterial pressure, maximum heart rate, maximum respiratory rate, minimum oxygen saturation, minimum serum bicarbonate, minimum blood urea nitrogen, maximum white blood cell count, maximum mean corpuscular volume, maximum serum potassium, and maximum blood glucose.After model evaluation, the XGBoost model demonstrated the best performance.The AUCs for predicting ICU mortality risk in the training and validation sets were 0.940 and 0.763, respectively; accuracy was 88.3% and 81.2%;sensitivity was 98.5% and 95.9%.Its predictive performance also remained optimal in sensitivity analyses.SHAP analysis indicated that the top five variables contributing to the model's predictions were minimum oxygen saturation, minimum serum bicarbonate, minimum mean arterial pressure, use of vasoactive drugs, and maximum white blood cell count. This study successfully developed a mortality risk prediction model for ICU patients with malignant tumors complicated by ARF based on a large-scale dataset and performed explainability analysis.The model aids clinicians in early identification of high-risk patients and implementing individualized interventions.
9.Phenotypic distribution and population genetic frequency analysis of ABO and Rh blood group antigens among voluntary blood donors in Yantai
Hewei SONG ; Xiaojun ZHANG ; Qun XU ; Xiangzhong LIU ; Nan GUO ; Di SUN
Chinese Journal of Blood Transfusion 2026;39(1):69-75
Objective: To investigate the distribution characteristics of ABO and Rh blood group antigen phenotypes among blood donors in the Yantai, Shandong. Methods: Blood samples from 310 180 voluntary blood donors in Yantai collected from January 2019 to December 2023 were tested for ABO and Rh blood group antigens using standard serological methods. RhD-negative samples were further typed for C, c, E, and e antigens. Population genetic analysis of blood groups was performed: allele frequencies were inferred from ABO phenotypes, and Rh allele/haplotype frequencies were estimated based on the proportion of RhD-negative donors and CcEe antigen typing, followed by Hardy-Weinberg equilibrium testing. Results: The phenotypic distribution frequency of ABO blood groups was B(32.72%)>O(28.93%)>A(27.65%)>AB(10.70%). The inferred allele frequencies were r(53.74%)>q(24.78%)>p(21.48%), consistent with Hardy-Weinberg equilibrium (P>0.05). A total of 1 872 Rh-negative donors (0.603%) were identified. The most common Rh phenotypes were ccdee (59.56%) and Ccdee (30.18%). The distribution of Rh antigen phenotypes deviated significantly from Hardy-Weinberg equilibrium (χ
=37.15, P<0.001), with the cde haplotype showing the highest frequency. There was no statistically significant difference in ABO blood group distribution between RhD-positive and RhD-negative donors (P>0.05). Conclusion: The ABO blood group distribution among voluntary blood donors in Yantai is generally stable and consistent with population genetic equilibrium, whereas the Rh antigen phenotype distribution deviates from equilibrium, indicating potential underlying genetic structural differences.
10.Effects of oral non-peptidic thrombopoietin receptor agonists on hepatic enzyme in adult patients with immune thrombocytopenia:a meta-analysis
Tiantian LU ; Nan SHEN ; Suyue ZHU ; Jingjing YAN
China Pharmacy 2026;37(4):510-515
OBJECTIVE To systematically evaluate the effects of oral non-peptidic thrombopoietin receptor agonists (TPO-RAs) on hepatic enzyme in adult patients with immune thrombocytopenia. METHODS A comprehensive literature search was conducted in PubMed, Web of Science, CNKI, Wanfang database and the Chinese Medical Association Journal Full-Text Database to collect randomized controlled trials (RCTs) comparing oral non-peptidic TPO-RAs (intervention group) with placebo or conventional therapy (control group). All databases were searched from their inception to June 2025. After literature screening, data extraction and quality assessment of the included studies, meta-analysis was conducted using RevMan 5.4.1 software. RESULTS Twelve RCTs comprising 1 388 patients were included, with 971 in the intervention group and 417 in the control group. Meta-analysis results showed that there were no significant differences between the two groups in terms of the incidence of hepatic enzyme elevation[OR=1.24, 95%CI (0.77, 1.99), P =0.37 ] , the incidence of hepatic enzyme elevation in patients treated for ≥6 weeks[OR=1.21, 95%CI (0.73, 1.99), P =0.46 ] , and the incidence of severe hepatic enzyme elevation[OR=1.39, 95%CI(0.46, 4.20), P =0.55 ] . Subgroup analysis showed that there were no significant differences in the incidence of hepatic enzyme elevation between the intervention group and control group among patients using eltrombopag[OR=1.57,95%CI(0.85,2.87), P =0.15 ] , avatrombopag[OR=0.88,95%CI (0.09,8.46), P =0.91 ] , and hetrombopag[OR=1.04,95%CI(0.30,3.65), P =0.95 ] , respectively. CONCLUSIONS Oral non-peptidic TPO-RAs do not significantly increase the risk of hepatic enzyme elevation in adult patients with immune thrombocytopenia, and show an overall favorable hepatic safety profile.

Result Analysis
Print
Save
E-mail