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.

Objective:To investigate the value of serum free light chain(sFLC)and serum calcium ion in the diagnosis and prognosis of multiple myeloma(MM).Methods:Forty patients with MM treated in Henan Provincial People's Hospital from January 2018 to January 2022 were selected as the observation group,and 40 healthy volunteers were selected as the control group.The differences of sFLC-κ,sFLC-λ,sFLC-κ/λ,serum calcium ions,etc between the two groups were compared.Meanwhile,the differences of sFLC-κ,sFLC-λ,sFLC-κ/λ,serum calcium ions,etc in different international staging systems(ISS),chemotherapy efficacy and prognosis patients were analyzed.Results:The levels of sFLC-κ[(98.39±21.19)vs(12.01±4.45)mg/L],sFLC-λ[(210.20±45.54)vs(14.10±5.11)mg/L]and proportions of hypocalcemia(65％vs 0)in the observation group were significantly higher than those in the control group(P＜0.05),while sFLC-κ/λ ratio[(0.44±0.10)vs(0.87±0.12)]and serum calcium ions[(1.98±0.46)vs(2.42±0.40)mmol/L]were significantly lower than those in the control group(P＜0.05).The sFLC-κ,sFLC-λ,the proportion of hypocalcemia and the course of hypocalcemia in ISS stage Ⅲ patients in the observation group were significantly higher than those in stage Ⅰ and Ⅱ patients(P＜0.05),while sFLC-κ/λ ratio,and serum calcium ions were significantly lower than those in stage Ⅰ and Ⅱ patients(P＜0.05).The levels of sFLC-κ[(107.76±21.22)vs(94.67 ±20.11)mg/L],sFLC-λ[(245.54±41.12)vs(205.54±50.22)mg/L]of patients with hypocalcemia in the observation group was significantly higher than those without hypocalcemia(P＜0.05),while the sFLC-κ/λ ratio was significantly lower than those without hypocalcemia[(0.42±0.04)vs(0.47±0.06);P＜0.05].The levels of sFLC-κ[(107.29±20.14)vs(91.11±18.92)mg/L],sFLC-λ[(247.98±42.26)vs(179.29±39.32)mg/L]in patients with ineffective chemotherapy were significantly higher than those in patients with effective chemotherapy(P＜0.05),while the sFLC-κ/λ ratio was significantly lower than those in patients with effective chemotherapy[(0.43± 0.10)vs(0.50±0.09);P＜0.05)].The area under the ROC curve for sFLC-κ,sFLC-λ,sFLC-κ/λ predicting ineffective chemotherapy was 0.803,0.793 and 0.699 respectively,P＜0.05.There was no significant difference in sFLC-κ,sFLC-λ,sFLC-κ/λ ratio,serum calcium ion,hypocalcemia ratio and hypocalcemia course between survival and death patients(P＞0.05).Conclusion:sFLC and serum calcium are related to 1SS stage of MM patients.sFLC level has a certain value to predict the curative effect of chemotherapy in MM patients.However,the prognostic values of sFLC and serum calcium are not yet confirmed for MM patients.

Humans ; Child ; Primary Myelofibrosis/genetics* ; Prognosis ; Mutation

In this study, a high-performance liquid chromatography method was established to simultaneously determine three flavonoids including hesperidin (HES), nobiletin (NOB) and tangeretin (TAN) in 10 batches of Citrus reticulata 'Chachi' planted and collected in Xinhui District, Jiangmen City, Guangdong Province. Moreover, we studied the metabolism and transformation of three flavonoids in liver and intestinal flora in vitro, and sequenced 16S rRNA of bacteria flora samples after incubation. The RP-HPLC system consisted of Alltima C18 column (250 mm × 4.6 mm, 5 μm) and a mobile phase of water (A) - methanol (B). The column temperature was 25 ℃ and the detection wavelength was both 283 nm and 330 nm while the flow rate was 1.0 mL·min^-1. The results showed that the retention time of HES, NOB and TAN ranged from 12.313 min to 34.271 min. The content of HES, NOB and TAN in 10 batches of Citrus reticulata 'Chachi' was 26.81-39.80 mg·g^-1, 4.06-7.90 mg·g^-1 and 1.81-3.93 mg·g^-1, respectively. There were differences in the content of flavonoids in different batches and growing areas. The three flavonoids were metabolized in various degrees after incubation of rat and human liver S9, cytosol, microsomes or intestinal flora in vitro, especially HES. The results of 16S rRNA showed that the main flavonoids of Citrus reticulata 'Chachi' could regulate lipid metabolism by regulating intestinal flora related to energy metabolism. This study established a rapid, simple, reproducible and stable quantitative analysis method for detecting the main flavonoids in Citrus reticulata 'Chachi' which evaluated the content of flavonoids from Citrus reticulata 'Chachi' in different growing areas and different storage periods. The intestinal bacteria can metabolize and transform the flavonoids of Citrus reticulata 'Chachi' to varying degrees, which provides a valuable scientific basis for the subsequent study on the material basis of the efficacy of Citrus reticulata 'Chachi' from the perspective of metabolism. Animal experiments were approved by the Medical Ethics Committee of Guangdong Jiangmen Chinese Medicine College (No. 20190419).

Objective: To investigate the repair effect and JNK/NF-κB,SOX9 mechanisms of vibration exercise with different frequencies on articular cartilage in rats with early knee osteoarthritis. Methods: Forty-eight adult male SD rats were randomly divided into six groups(n=8):model control group(MC),high frequency vibration group 1 (GP₁,60 Hz),high frequency vibration 2 group (GP₂,40 Hz),medium frequency vibration group (ZP,20 Hz),minor frequency group(DP,10 Hz)and normal control group(NC). Except for NC group,the rats in each group were made into early knee osteoarthritis model after six weeks of knee joint cavity injection of papain solution and 2% mixture l-cysteine on the 1^st,4 ^th and 7^th day. Each exercise group was subjected vibration to 40 minutes a day with amplitude of 2～5 mm and 5 days a week. Four weeks later, the articular cartilage of the lateral femoral condyle of the both back leg knee joints were detected by HE staining,serine O staining and Mankin scores for morphological observation. The expression levels of JNK,NF-κB p65 and Sox9 mRNA in articular cartilage of the medial femoral condyle were detected by RT-qPCR,and the protein expressions of JNK,NF-κB p65 and Sox9 were detected by Western blot. Results: Compared with the NC group,the Mankin score in other groups was significantly higher (P＜0.01). Compared with the MC group,the Mankin score of each vibration group was significantly lower(P＜0.05),the mRNA and protein expressions of JNK and NF-κB p65 in each vibration training group were significantly lower (P＜0.01),the expressions of Sox9 mRNA and protein in vibration training group were increased significantly (P＜0.01). Compared with the higher frequency group,the Mankin score,the mRNA and protein expressions of JNK and NF-κB p65 of lower frequency group were significantly lower (P＜0.05 or P＜0.01). But the expressions of Sox9 mRNA and protein were significantly higher (P＜ 0.05 or P＜0.01). Conclusion: Vibration exercise of different frequencies may present varying degrees of cartilage repair impact in rats with early knee osteoarthritis,and the cartilage repair by low-frequency vibration training is better than that by high-frequency vibration. This can be one of the mechanisms on controlling collagen synthesis by down-regulating JNK/NF-κB expression and increasing SOX9 activity of OA articular cartilage.
Animals ; Cartilage, Articular/metabolism* ; MAP Kinase Kinase 4 ; Male ; NF-kappa B/metabolism* ; Osteoarthritis, Knee/therapy* ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; SOX9 Transcription Factor ; Vibration

OBJECTIVE: To investigate the short-term clinical effect of lumbar nerve root canal injection under X-ray angiography in the treatment of sciatica. METHODS: The clincal data of 78 patients with sciatica underwent lumbar nerve root canal injection under X-ray angiography from December 2017 to February 2020 was retrospectively analyzed. Including 31 males and 47 females, aged from 22 to 88 years old with a median of 65 years. There were 55 cases of lumbar disc herniation and 23 cases of lumbar spinal stenosis, the course of disease ranged from 1 to 8 weeks with a median of 3 weeks. There were 71 cases of single segment disc herniation or stenosis, including L_3,4 of 5 cases, L_4,5 of 61 cases, L₅S₁ of 5 cases, and 7 cases of multisegment herniation or stenosis. The pain visual analogue scale (VAS) was recorded and Macnab was used to evaluate the clinical effect. RESULTS: All patients completed standardized treatment without serious adverse reactions. VAS were (3.21±0.76) scores immediately after treatment, (2.89±0.33) scores 1 hour after treatment, (1.80±0.27) scores 6 hours after treatment, (1.10±0.20) scores 24 hours after treatment, (2.53±0.35) scores 1 week after treatment and (4.27±0.36) scores 1 month after treatment. There were significant differences in VAS between before treatment(7.83±0.56) and each time period after treatment(P<0.05). According to Macnab low back pain evaluation standard, 42 cases were effective, 34 cases were markedly effective and 2 cases were ineffective within 24 hours after treatment, with an effective rate of 97.4%;38 cases were effective, 25 cases were markedly effective, 15 cases were ineffective within one week after treatment, the effective rate was 80.0%;32 cases were effective, 22 cases were markedly effective, 24 cases were ineffective within one month after treatment, the effective rate was 69.2%. CONCLUSION The short-term clinical effect of nerve root canal injection under X-ray radiography in the treatment of sciatica is good and it is an effective method to relieve sciatica.
Adult ; Aged ; Aged, 80 and over ; Angiography ; Dental Pulp Cavity ; Female ; Humans ; Intervertebral Disc Displacement/diagnostic imaging* ; Lumbar Vertebrae/diagnostic imaging* ; Male ; Middle Aged ; Retrospective Studies ; Sciatica/drug therapy* ; Treatment Outcome ; X-Rays ; Young Adult

This study investigated the effect of puerarin on human umbilical vein endothelial cells (HUVEC) injured with hydrogen peroxide (H₂O₂). HUVEC were divided into three groups: a control group, a model group (H₂O₂ 400 μmol·L^-1) and a puerarin-treated group (3, 10, 30 and 100 μmol·L^-1). HUVEC were cultured with varied concentration of puerarin for 2 h and treated with H₂O₂ for another 24 h. Cell proliferation was detected by a CCK-8 assay. The mitochondrial membrane potential was measured by a JC-1 fluorescent probe. A transwell chamber assay was adopted to observe cell migration ability. Mitochondrial respiratory function was measured in a two-chamber titration injection respirometer (Oxygraph-2k). The expression of interleukin-1β (IL-1β), interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) was detected by quantitative real-time PCR. The expression of pyroptosis-mediated proteins, including cleaved-cysteinyl aspartate-specific proteinase-1 (caspase-1), N-gasdermin D (N-GSDMD), NOD-like receptor protein 3 (NLRP3) and purinergic ligand-gated ion channel 7 receptor (P2X7R) was detected by Western blot. The results show that 400 μmol·L^-1 H₂O₂ treatment for 24 h causes obvious damage to HUVEC. Compared with the model group, puerarin protected against cellular injury in a dose-dependent manner, with the greatest effect at a dose of 30 and 100 μmol·L^-1. Puerarin significantly decreased the mitochondrial membrane potential and improved mitochondrial function. Puerarin inhibited cell migration induced by H₂O₂, suppressed the expression of IL-1β, IL-18 and TNF-α, and down-regulated the pyroptosis-mediated protein. These changes are statistically significant (P < 0.05). These findings demonstrate that puerarin has a protective effect against H₂O₂-induced oxidative damage of HUVEC by inhibiting the migration of HUVEC cells. The mechanism may be related to improved mitochondrial respiratory function and inhibition of pyroptosis.

【Objective】 To evaluate the curative effect of posterior atlantoaxial joint release and internal fixation in treating unstable craniocervical junction malformation （UCVJM）. 【Methods】 This study retrospectively enrolled 31 patients with UCVJM， who received posterior atlantoaxial joint release and internal fixation between January 2015 and December 2018. The pre- and postoperative changes of the Japanese Orthopaedic Association （JOA） scores， the cervicomedullary angle （CMA）， the atlantodental interval （ADI） and the height above the Chamberlain line of the odontoid （H） were traced to evaluate whether clinical symptoms， compression of spinal cord， horizontal and vertical dislocation of atlantoaxial were improved postoperatively. 【Results】 The average operation duration， bleeding during operation and the average days of hospitalization were （168.38±38.21）min， （147.09±59.84）mL， and （9.54±2.81） days， respectively. None of the patients had vertebral artery or spinal cord injury during operation. JOA score， ADI， H， and CMA were （11.94±1.37） points， （2.72±1.08）mm， （3.03±0.78）mm， and （145.35±8.00）° respectively on the 6th days after operation compared with the preoperative （9.94±1.26） points， （4.96±1.60）mm， （6.89±1.36） mm and （122.16±9.58）°， with statistical differences， which indicated all indexes were improved （all P<0.001）. During 6-25 months’ follow-up， there was no internal fixation looseness or displacement and JOA score was increased to （13.16±1.19） for all the patients in the last follow-up （all P<0.001）. 【Conclusion】 The posterior atlantoaxial joint release combined with internal fixation is safe and effective for patients with UCVJM.

OBJECTIVE: KRAS gene is one of the most common mutations of proto-oncogenes in human tumors, G12V is one of the most common mutation types for KRAS. It's challenging to chemically acquire the targeted drug for this mutation. Recent studies reported that this mutation peptides can form a neoepitope for T cell recognition. Our study aims to clone the T cell receptor (TCR) which specifically recognizes the neoepitope for KRAS G12V mutation and constructs TCR engineered T cells (TCR-T), and to investigate if TCR-Ts have strong antitumor response ability. METHODS: In this study, tumor infiltrating lymphocytes were obtained from one colorectal cancer patient carrying KRAS G12V mutation. Tumor-reactive TCR was obtained by single-cell RT-5' rapid-amplification of cDNA ends PCR analysis and introduced into peripheral blood lymphocytes to generate TCR-Ts. RESULTS: We obtained a high-affinity TCR sequence that specifically recognized the HLA-A^*11:01-restricted KRAS G12V_8-16 epitope: KVA11-01. KVA11-01 TCR-T could significantly kill various tumor cells such as PANC-1, SW480 and HeLa (overexpressing HLA-A^*11:01 and KRAS G12V), and secreting high levels of interferon-γ (IFN-γ). Non-specific killing experiments suggested KVA11-01 specifically recognized tumor cells expressing both mutant KRAS G12V and HLA-A^*11:01. In vivo assay, tumor inhibition experiments demonstrated that infusion of approximately 1E7 KVA11-01 TCR-T could significantly inhibit the growth of subcuta-neously transplanted tumors of PANC-1 and HeLa (overexpressing HLA-A^*11:01 and KRAS G12V) cells in nude mice. No destruction of the morphologies of the liver, spleen and brain were observed. We also found that KVA11-01 TCR-T could significantly infiltrate into tumor tissue and had a better homing ability. CONCLUSION KVA11-01 TCR-T cells can effectively target a variety of malignant tumor cells carrying KRAS G12V mutation through in vitro and in vivo assay. KVA11-01 TCR-T cells have excellent biological activity, high specificity of target antigen and homing ability into solid tumor tissue. KVA11-01 TCR-T is expected to be an effective treatment for patients with KRAS G12V mutant solid malignancies.
Animals ; DNA, Complementary ; Epitopes ; HLA-A Antigens ; Humans ; Interferon-gamma ; Mice ; Mice, Nude ; Mutation ; Neoplasms ; Proto-Oncogene Proteins p21(ras)/genetics* ; Receptors, Antigen, T-Cell/genetics*

This study aimed to evaluate the vasorelaxant effect and mechanisms of compound reserpine and triamterene tablets (CRTTs) and its component triamterene on isolated rat thoracic aorta rings. Isolated rat thoracic aorta rings pre-contracted by high potassium or norepinephrine (NE) were used to evaluate the vasodilatory effect of CRTTs and its component triamterene. The mechanisms concerning endothelium, potassium channels and calcium channels were studied through the interventions of several tool drugs. Animal welfare and experimental procedures followed the requirements of the Laboratory Animal Management and Animal Welfare Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College. The results showed that both CRTTs and triamterene had potent relaxant effect on KCl and NE pre-contracted vessels. Triamterene showed partial endothelium dependency, and N-nitro-L-argininemethyl ester hydrochloride (L-NAME) could influence the relaxant effect, which may be related to the opening of calcium-activated potassium channels. Meanwhile, CRTTs could inhibit intracellular Ca²⁺ release and extracellular Ca²⁺ influx. Overall, CRTTs and its component triamterene have vasorelaxant effects on vessels in vitro, and the vasorelaxant effect of CRTTs may be related to intracellular Ca²⁺ release and extracellular Ca²⁺ influx, while this effect of triamterene may depend on vascular endothelial function and may also be related to the opening of calcium-activated potassium channels.