1.Enzyme-directed Immobilization Strategies for Biosensor Applications
Xing-Bao WANG ; Yao-Hong MA ; Yun-Long XUE ; Xiao-Zhen HUANG ; Yue SHAO ; Yi YU ; Bing-Lian WANG ; Qing-Ai LIU ; Li-He ZHANG ; Wei-Li GONG
Progress in Biochemistry and Biophysics 2025;52(2):374-394
Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.
2.Terms Related to The Study of Biomacromolecular Condensates
Ke RUAN ; Xiao-Feng FANG ; Dan LI ; Pi-Long LI ; Yi LIN ; Zheng WANG ; Yun-Yu SHI ; Ming-Jie ZHANG ; Hong ZHANG ; Cong LIU
Progress in Biochemistry and Biophysics 2025;52(4):1027-1035
Biomolecular condensates are formed through phase separation of biomacromolecules such as proteins and RNAs. These condensates exhibit liquid-like properties that can futher transition into more stable material states. They form complex internal structures via multivalent weak interactions, enabling precise spatiotemporal regulations. However, the use of inconsistent and non-standardized terminology has become increasingly problematic, hindering academic exchange and the dissemination of scientific knowledge. Therefore, it is necessary to discuss the terminology related to biomolecular condensates in order to clarify concepts, promote interdisciplinary cooperation, enhance research efficiency, and support the healthy development of this field.
3.Research on BP Neural Network Method for Identifying Cell Suspension Concentration Based on GHz Electrochemical Impedance Spectroscopy
An ZHANG ; A-Long TAO ; Qi-Hang RAN ; Xia-Yi LIU ; Zhi-Long WANG ; Bo SUN ; Jia-Feng YAO ; Tong ZHAO
Progress in Biochemistry and Biophysics 2025;52(5):1302-1312
ObjectiveThe rapid advancement of bioanalytical technologies has heightened the demand for high-throughput, label-free, and real-time cellular analysis. Electrochemical impedance spectroscopy (EIS) operating in the GHz frequency range (GHz-EIS) has emerged as a promising tool for characterizing cell suspensions due to its ability to rapidly and non-invasively capture the dielectric properties of cells and their microenvironment. Although GHz-EIS enables rapid and label-free detection of cell suspensions, significant challenges remain in interpreting GHz impedance data for complex samples, limiting the broader application of this technique in cellular research. To address these challenges, this study presents a novel method that integrates GHz-EIS with deep learning algorithms, aiming to improve the precision of cell suspension concentration identification and quantification. This method provides a more efficient and accurate solution for the analysis of GHz impedance data. MethodsThe proposed method comprises two key components: dielectric property dataset construction and backpropagation (BP) neural network modeling. Yeast cell suspensions at varying concentrations were prepared and separately introduced into a coaxial sensor for impedance measurement. The dielectric properties of these suspensions were extracted using a GHz-EIS dielectric property extraction method applied to the measured impedance data. A dielectric properties dataset incorporating concentration labels was subsequently established and divided into training and testing subsets. A BP neural network model employing specific activation functions (ReLU and Leaky ReLU) was then designed. The model was trained and tested using the constructed dataset, and optimal model parameters were obtained through this process. This BP neural network enables automated extraction and analytical processing of dielectric properties, facilitating precise recognition of cell suspension concentrations through data-driven training. ResultsThrough comparative analysis with conventional centrifugal methods, the recognized concentration values of cell suspensions showed high consistency, with relative errors consistently below 5%. Notably, high-concentration samples exhibited even smaller deviations, further validating the precision and reliability of the proposed methodology. To benchmark the recognition performance against different algorithms, two typical approaches—support vector machines (SVM) and K-nearest neighbor (KNN)—were selected for comparison. The proposed method demonstrated superior performance in quantifying cell concentrations. Specifically, the BP neural network achieved a mean absolute percentage error (MAPE) of 2.06% and an R² value of 0.997 across the entire concentration range, demonstrating both high predictive accuracy and excellent model fit. ConclusionThis study demonstrates that the proposed method enables accurate and rapid determination of unknown sample concentrations. By combining GHz-EIS with BP neural network algorithms, efficient identification of cell concentrations is achieved, laying the foundation for the development of a convenient online cell analysis platform and showing significant application prospects. Compared to typical recognition approaches, the proposed method exhibits superior capabilities in recognizing cell suspension concentrations. Furthermore, this methodology not only accelerates research in cell biology and precision medicine but also paves the way for future EIS biosensors capable of intelligent, adaptive analysis in dynamic biological research.
4.Correlation between depressive symptom and traditional Chinese medicine constitution among school aged children and adolescents
Chinese Journal of School Health 2025;46(9):1222-1225
Objective:
To explore the correlation between traditional Chinese medicine (TCM) constitution and depressive symptom among school aged children and adolescents, so as to provide evidences for informing constitution based regulation and prevention of depressive symptom.
Methods:
From June to December 2024, a total of 4 729 students aged 6-14 were recruited by cluster random sampling from 10 primary schools in Baoding (Hebei Province), Heze and Liaocheng (Shandong Province). General information, TCM constitution and depressive symptom were collected. Restricted cubic spline (RCS) models were used to analyze related factors and threshold effects of depressive symptom. Binary Logistic regression was applied to examine the association between depressive symptom and TCM constitution, with subgroup analyses conducted.
Results:
The detection rate of depressive symptom among the included children and adolescents was 25.82%. RCS analyses indicated non linear associations between depressive symptom and age (inflection point at 10 years old), bedtime (inflection point at 22:00), and wake up time (inflection point at 6:30 ) (all P non linearity <0.01). Linear associations were observed with body mass index (BMI) and sleep duration (all P non linearity > 0.05 ). After adjusting for covariates such as age, BMI and sleep status, binary Logistic regression analyses showed that Yin deficient constitution ( OR =1.26, 95% CI =1.09-1.45) and Phlegm-dampness constitution ( OR =1.42, 95% CI =1.11-1.82) were significantly associated with depressive symptom among children and adolescents (all P <0.05).
Conclusions
Depressive symptom among school aged children and adolescents is primarily associated with Yin deficiency and Phlegm dampness constitutions in TCM constitution. Active attention should be paid to susceptible TCM constitution among children and adolescents. Targeted health guidance and interventions should be implemented to improve TCM constitution health status for preventing the occurrence of depressive symptom.
5.Oxidative Stress-related Signaling Pathways and Antioxidant Therapy in Alzheimer’s Disease
Li TANG ; Yun-Long SHEN ; De-Jian PENG ; Tian-Lu RAN ; Zi-Heng PAN ; Xin-Yi ZENG ; Hui LIU
Progress in Biochemistry and Biophysics 2025;52(10):2486-2498
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, functional impairment, and neuropsychiatric symptoms. It represents the most prevalent form of dementia among the elderly population. Accumulating evidence indicates that oxidative stress plays a pivotal role in the pathogenesis of AD. Notably, elevated levels of oxidative stress have been observed in the brains of AD patients, where excessive reactive oxygen species (ROS) can cause extensive damage to lipids, proteins, and DNA, ultimately compromising neuronal structure and function. Amyloid β‑protein (Aβ) has been shown to induce mitochondrial dysfunction and calcium overload, thereby promoting the generation of ROS. This, in turn, exacerbates Aβ aggregation and enhances tau phosphorylation, leading to the formation of two pathological features of AD: extracellular Aβ plaque deposition and intracellular neurofibrillary tangles (NFTs). These events ultimately culminate in neuronal death, forming a vicious cycle. The interplay between oxidative stress and these pathological processes constitutes a core link in the pathogenesis of AD. The signaling pathways mediating oxidative stress in AD include Nrf2, RCAN1, PP2A, CREB, Notch1, NF‑κB, ApoE, and ferroptosis. Nrf2 signaling pathway serves as a key regulator of cellular redox homeostasis, exerts important antioxidant capacity and protective effects in AD. RCAN1 signaling pathway, as a calcineurin inhibitor, and modulates AD progression through multiple mechanisms. PP2A signaling pathway is involved in regulating tau phosphorylation and neuroinflammation processes. CREB signaling pathway contributes to neuroplasticity and memory formation; activation of CREB improves cognitive function and reduce oxidative stress. Notch1 signaling pathway regulates neuronal development and memory, participates in modulation of Aβ production, and interacts with Nrf2 toco-regulate antioxidant activity. NF‑κB signaling pathway governs immune and inflammatory responses; sustained activation of this pathway forms “inflammatory memory”, thereby exacerbating AD pathology. ApoE signaling pathway is associated with lipid metabolism; among its isoforms, ApoE-ε4 significantly increases the risk of AD, leading to elevated oxidative stress, abnormal lipid metabolism, and neuroinflammation. The ferroptosis signaling pathway is driven by iron-dependent lipid peroxidation, and the subsequent release of lipid peroxidation products and ROS exacerbate oxidative stress and neuronal damage. These interconnected pathways form a complex regulatory network that regulates the progression of AD through oxidative stress and related pathological cascades. In terms of therapeutic strategies targeting oxidative stress, among the drugs currently used in clinical practice for AD treatment, memantine and donepezil demonstrate significant therapeutic efficacy and can improve the level of oxidative stress in AD patients. Some compounds with antioxidant effects (such asα-lipoic acid and melatonin) have shown certain potential in AD treatment research and can be used as dietary supplements to ameliorate AD symptoms. In addition, non-drug interventions such as calorie restriction and exercise have been proven to exerted neuroprotective effects and have a positive effect on the treatment of AD. By comprehensively utilizing the therapeutic characteristics of different signaling pathways, it is expected that more comprehensive multi-target combination therapy regimens and combined nanomolecular delivery systems will be developed in the future to bypass the blood-brain barrier, providing more effective therapeutic strategies for AD.
6.Effects of esketamine for multimodal analgesia on opioid consumption and gastric motility in mechanically ventilated non-surgical ICU patients
Yi LONG ; Qian LIU ; Rui LI ; Guixin WU ; Aiting HE ; Zhengying JIANG
China Pharmacy 2024;35(4):468-471
OBJECTIVE To investigate the effects of esketamine for multimodal analgesia on opioid consumption and gastric motility in mechanically ventilated non-surgical intensive care unit (ICU) patients. METHODS Forty cases of mechanically ventilated non-surgical patients in the ICU of our hospital from February 1st, 2023 to July 31st, 2023 were selected and randomly divided into control group and esketamine (S-K) group using grouping method with opaque envelopes, with 20 cases in each group. Control group was given sufentanil, and S-K group was infused with Esketamine hydrochloride injection at a constant rate of 0.2 mg/(kg·h)+ sufentanil. The treatment period length, analgesic compliance rate, sedation level, analgesic and sedative consumption, and gastric motility indexes were compared between the two groups. RESULTS There was no statistically significant difference in the treatment period length, analgesic compliance rate, sedation level, or the consumption of propofol and midazolam between the two groups (P>0.05). The consumption of sufentanil in the S-K group was significantly less than control group (P< 0.05). Compared with 1 h after randomization, the antral contraction frequency, antral contraction amplitude and antral motility index of patients in the S-K group were significantly higher at 72 h after randomization and were significantly higher than control group (P<0.05). CONCLUSIONS Esketamine may reduce opioid consumption and improve gastric motility in mechanically ventilated non-surgical ICU patients while ensuring a level of analgesic sedation.
7.Phenolic constituents of Sanguisorba officinalis and their Nrf2 agonistic effect
Long-long WU ; Jing-wen LIU ; Zhong-lian YU ; Liu-qiang ZHANG ; Yi-ming LI
Acta Pharmaceutica Sinica 2024;59(1):170-182
Thirty-one phenolic constituents were isolated and purified from the 95% ethanol extract of Sanguisorbae Radix by using various chromatographic techniques, including macroporous resin, silica gel, ODS, Sephadex LH-20 and semi-preparative HPLC. Their structures were elucidated by physicochemical properties, spectroscopic data (MS and NMR) and electronic circular dichroism (ECD) spectra, and identified as 3-methoxyl-2
8.OCT and IVUS evaluating stent apposition and endothelialization after FD implantation in aneurysm animal models
Ji MA ; Shuhai LONG ; Jie YANG ; Zhen LI ; Haiqiang SANG ; Yi TANG ; Yuncai RAN ; Yong ZHANG ; Baohong WEN ; Shanshan XIE ; Ke CHEN ; Enjie LIU ; Xinwei HAN ; Tengfei LI
Chinese Journal of Neuromedicine 2024;23(3):256-262
Objective:To investigate the application value of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in evaluating flow diverter (FD) apposition and endothelialization in aneurysm animal models, and analyze the effect of incomplete stent apposition (ISA) on aneurysm lumen healing and stent endothelialization.Methods:Lateral common carotid artery aneurysm models in swines were established by surgical method and then FD was implanted. Immediately after surgery, OCT and IVUS were used to evaluate the locations and degrees of ISA, and difference between these 2 methods in evaluating FD apposition was compared. DSA was performed at 12 weeks after surgery to evaluate the aneurysm occlusion (Kamran grading) and stent patency. OCT and IVUS were used again to observe the stent endothelial situation; by comparing with histopathologic results, effect of ISA on aneurysm healing and stent endothelialization was analyzed.Results:Lateral common carotid artery aneurysm models in 6 swines were established, and 6 Tubridge FDs were successfully implanted. Compared with IVUS (3 stents, 4 locus), OCT could detect more ISA (6 stents, 14 locus); and the vascular diameter change area (7 locus), aneurysm neck area (4 locus) and the head and tail of FD (3 locus) were the main sites of FD malapposition; average distance between stent wire and vessel wall was (560.14±101.48) μm. At 12 weeks after surgery, DSA showed that 1 patient had a little residual contrast agent at the aneurysm neck (Kamran grading 3), and the remaining 5 had complete aneurysm occlusion (Kamran grading 4). One FD had moderate lumen stenosis, and the other 5 FDs had lumen patency. OCT indicated mostly disappeared acute ISA; ISA proportion decreased to 21.4 % (3/14), including 2 in the aneurysm neck and 1 in the partial stent. Histopathological results showed bare stent woven silk, without obvious endothelial coverage; in one FD with luminal stenosis, intimal hyperplasia was mainly composed of vascular smooth muscle cells.Conclusion:In carotid artery aneurysm model with FD implantation, OCT can detect more ISA than IVUS; most acute ISA have good outcome at 12 th week of follow-up, while severe ISA can cause delayed FD endothelialization and delayed aneurysm occlusion.
9.Comprehensive Analysis of Proteins and Their Phosphorylation in Milk-derived Exosomes From Different Species
Chang-Mei LIU ; Yi-Fan HU ; Wen-Yan CHEN ; Dan LIU ; Jie SHI ; Gang-Long YANG
Progress in Biochemistry and Biophysics 2024;51(7):1697-1710
ObjectiveExosomes are microvesicles which could be secreted by all cell types with diameters between 30 and 150 nm. It was widely distributed in body fluids including blood, urine, and breast milk. Exosomes are considered as potential biomarkers and drug carriers by reason of containing nucleic acids, lipids, proteins and other bioactive molecules. Milk-derived exosomes have been widely used as drug delivery carriers to treat targeted diseases with a lower cost, higher biocompatibility and lower immunogenicity. Until now, there is no research about the milk-derived exosomes phosphorylation to reveal the difference of protein phosphorylation in different species of milk. To investigate the pathways and proteins with specific functions, phosphorylated proteomic analysis of milk-derived exosomes from different species is performed, and provide new ideas for exploring diversified treatments of disease. MethodsWhey and exosomes derived from bovine, porcine and caprine milk were performed for proteomics and phosphoproteomics analysis. The relationship between milk exosome proteins from different species and signaling pathways were analyzed using bioinformatics tools. ResultsA total of 4 191 global proteins, 1 640 phosphoproteins and 4 064 phosphosites were identified from 3 species of milk-derived exosomes, and the exosome proteins and phosphoproteins from different species were significantly higher than those of whey. Meanwhile, some special pathways were enriched like Fcγ-mediated phagocytosis from bovine exosomes, pathways related with neural and immune system from caprine exosomes, positive and negative regulation of multiple activities from porcine exosomes. ConclusionIn this study, the proteomic and phosphoproteomic analyses of exosomes and whey from bovine, porcine and caprine milk were carried out to reveal the difference of composition and related signaling pathways of milk exosome from different species. These results provided powerful support for the application of exosomes from different milk sources in the field of disease treatment.
10.Antimicrobial resistance and related risk factors of carbapenem-resistant Klebsiella pneumoniae isolated from blood
Pei-Juan TANG ; Peng-Wen OUYANG ; Sheng LONG ; Na PENG ; Zi-Han WANG ; Qiong LIU ; Wen XU ; Liang-Yi XIE
Chinese Journal of Infection Control 2024;23(1):49-57
Objective To explore the antimicrobial resistance of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from blood and the related risk factors for infection in patients.Methods Clinical data of 383 KP-infected patients from whose blood Klebsiella pneumoniae(KP)were isolated during hospitalization period in a hos-pital from January 2018 to December 2021 were retrospectively analyzed.Patients were divided into CRKP group(n=114)and non-CRKP group(n=269)based on antimicrobial resistance.According to the prognosis,114 patients in the CRKP group were subdivided into the death group(n=30)and the survival group(n=84).General informa-tion,underlying diseases,antimicrobial use,and infection outcomes of two groups of patients were compared,and risk factors for infection and death after infection were analyzed.Results The resistance rates of KP to tigecycline and compound sulfamethoxazole showed upward trends,with statistically significant differences(both P=0.008).The CRKP group had higher resistance rates to amikacin,aztreonam,compound sulfamethoxazole,ciprofloxacin,cefepime,cefoperazone/sulbactam,piperacillin/tazobactam,tigecycline,ceftazidime,tobramycin,and levofloxacin,as well as higher in-hospital mortality than the non-CRKP group,with statistically significant differences(all P<0.05).Acute pancreatitis prior to infection(OR=16.564,P<0.001),hypoalbuminemia(OR=8.588,P<0.001),stay in in-tensive care unit prior to infection(OR=2.733,P=0.017),blood transfusion(OR=3.968,P=0.001),broncho-scopy(OR=5.194,P=0.014),surgery within 30 days prior to infection(OR=2.603,P=0.010),and treatment with carbapenems(OR=2.663,P=0.011)were independent risk factors for the development of CRKP blood-stream infection(BSI).Cardiac insufficiency before infection(OR=11.094,P=0.001),combined with pulmonary infection(OR=20.801,P=0.010),septic shock(OR=9.783,P=0.002),disturbance of consciousness(OR=11.648,P=0.001),and receiving glucocorticoid treatment(OR=5.333,P=0.018)were independent risk factors for mortality in patients with CRKP BSI.Conclusion The resistance rate of KP from BSI to tigecycline and com-pound sulfamethoxazole presents upward trend.Underlying diseases,invasive procedures,and carbapenem treat-ment are closely related to CRKP BSI.Cardiac insufficiency,pulmonary infection,septic shock,disturbance of con-sciousness,and glucocorticoid treatment can lead to death of patients with CRKP BSI.


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