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 explore therapeutic effect of sacubitril valsartan sodium combined with Wenxin granule in the treatment of hypertension complicated with paroxysmal atrial fibrillation(AF)and its effect on cardiac electro-physiological structure.Methods:A total of 116 patients with hypertension and paroxysmal atrial fibrillation treated in our hospital from Oct 2021 to Nov 2022 were consecutively selected.According to random number table,they were divided into Wenxin granule group(received Wenxin granule treatment based on routine antihypertensive ther-apy)and combined treatment group(received sacubitril valsartan sodium combined Wenxin granule therapy based on routine antihypertensive therapy)with 58 cases in each group,and both groups were consecutively treated for six months.Clinical symptom score,AF burden,P wave duration,P wave dispersion,left atrial diameter(LAD),left ventricular end-diastolic diameter(LVEDd)and left ventricular ejection fraction(LVEF)were compared between two groups before and after treatment.Results:After treatment,compared with Wenxin granule group,there were significant reductions in clinical symptom score[(1.66±0.69)scores vs.(1.40±0.53)scores],AF burden[4.43(1.65)％vs.1.62(3.50)％],P wave duration[(112.17±6.46)ms vs.(109.29±8.59)ms],P wave dispersion[(32.47±8.11)ms vs.(29.02±7.49)ms]and LAD[(34.83±3.41)mm vs.(33.40±3.74)mm]in combined treatment group(P＜0.05 or＜0.01).There were no significant difference in LVEDd and LVEF between two groups,P＞0.05 both.Conclusion:Sacubitril valsartan sodium combined with Wenxin granule can significantly im-prove clinical symptoms and atrial fibrillation burden,reduce the susceptibility to atrial fibrillation,and inhibit atrial electrical remodeling and structural remodeling in patients with hypertension complicated with paroxysmal atrial fi-brillation.

Objective:To analyze the clinical characteristics and risk factors for severe disease of hemorrhagic fever with renal syndrome (HFRS) in underage patients, and to construct the severe disease risk model.Methods:A total of 170 HFRS patients (<18 years old) from the Second Affiliated Hospital of Air Force Medical University (153 cases) and the Second Affiliated Hospital of Xi′an Jiaotong University (17 cases) from January 2009 to December 2021 were included. According to the severity of the disease, the patients were divided into mild and severe groups. Baseline demographic data, symptoms, signs, laboratory examination on admission and prognosis were analyzed between the two groups. Statistical comparisons were performed using the Mann-Whitney U test and chi-square test.Binary logistic regression was used to analyze the independent risk factors of patients with severe disease, and the severe disease risk model was built.The receiver operator characteristic curve was used to analyze the value of the risk model in predicting severity of disease. Results:Among the 170 underage patients, 132 (77.6%) were males, aged (14.9±3.1) years, including 124 cases in mild group and 46 cases in severe group. One hundred and sixty-nine cases (99.4%) had fever, 119 cases (70.0%) had headache, 106 cases (62.4%) had lumbago, 158 cases (92.9%) had skin and mucous congestion, and 101 cases (59.4%) had nausea and vomiting. Renal percussive pain was found in 139(81.8%) patients. The incidence of nausea and vomiting and bleeding of skin and mucosa in the severe group were 71.7%(33/46) and 67.4%(31/46), respectively, which were both higher than those in the mild group (54.8%(68/124) and 44.4%(55/124), respectively), and the differences were statistically significant ( χ2=3.97 and 7.12, respectively, both P<0.05). There were significant differences in platelet count, activated partial thromboplastin time (APTT), serum creatinine (SCr), aspartate aminotransferase, alanine aminotransferase, leukocyte count, total bilirubin and albumin levels between the two groups ( Z=-4.14, -4.04, -4.87, -3.90, -4.07, -2.60, -2.78 and t=2.50, respectively, all P<0.05). Binary logistic regression analysis showed that chemosis (odds ratio ( OR)=8.035, 95% confidence interval (95% CI) 2.946 to 21.916), SCr ( OR=1.010, 95% CI 1.006 to 1.015) and APTT ( OR=1.049, 95% CI 1.003 to 1.098) were the independent risk factors for severe HFRS in the underage patients. The risk model was constructed as: Logit(P)=-10.323+ 2.084×chemosis (no=0, grade Ⅰ=1, grade Ⅱ=2, grade Ⅲ=3)+ 0.010×SCr (μmol/L)+ 0.048×APTT (s). The area under the curve to predict severity of disease in underage HFRS patients was 0.868, with an optimal cut-off value of -4.39, with a sensitivity of 73.90% and a specificity of 91.10%. According to the internal verification of the data of the study based on the severe disease risk model, 34 out of 46 patients with severe disease were severe (sensitivity, 73.91%), 113 out of 124 patients with mild disease were mild (specificity, 91.13%). Conclusions:The clinical manifestations of the underage HFRS patients are not typical.The main manifestations are fever, headache and lumbago, nausea and vomiting, and the incidences of skin and mucous congestion and renal percussive pain are high.Chemosis, SCr and APTT are independent risk factors for severe disease in underage patients with HFRS. The severe disease risk model could effectively predict the severity of disease.

This study was designed to evaluate the protective effect of CPD1, a novel phosphodiesterase 5 inhibitor, on renal interstitial fibrosis after unilateral renal ischemia-reperfusion injury (UIRI). Male BALB/c mice were subjected to UIRI, and treated with CPD1 once daily (i.g, 5 mg/kg). Contralateral nephrectomy was performed on day 10 after UIRI, and the UIRI kidneys were harvested on day 11. Hematoxylin-eosin (HE), Masson trichrome and Sirius Red staining methods were used to observe the renal tissue structural lesions and fibrosis. Immunohistochemical staining and Western blot were used to detect the expression of proteins related to fibrosis. HE, Sirius Red and Masson trichrome staining showed that CPD1-treated UIRI mice had lower extent of tubular epithelial cell injury and deposition of extracellular matrix (ECM) in renal interstitium compared with those in the fibrotic mouse kidneys. The results from immunohistochemistry and Western blot assay indicated significantly decreased protein expressions of type I collagen, fibronectin, plasminogen activator inhibitor-1 (PAI-1) and α-smooth muscle actin (α-SMA) after CPD1 treatment. In addition, CPD1 dose-dependently inhibited the expression of ECM-related proteins induced by transforming growth factor β1 (TGF-β1) in normal rat kidney interstitial fibroblasts (NRK-49F) and human renal tubular epithelial cell line (HK-2). In summary, the novel PDE inhibitor, CPD1, displays strong protective effects against UIRI and fibrosis by suppressing TGF-β signaling pathway and regulating the balance between ECM synthesis and degradation through PAI-1.
Animals ; Humans ; Male ; Mice ; Rats ; Extracellular Matrix Proteins ; Fibrosis ; Kidney ; Kidney Diseases ; Phosphodiesterase 5 Inhibitors ; Plasminogen Activator Inhibitor 1

Objective: To analyze the efficacy, safety, and long-term prognosis of intermediate-dose cytarabine (Ara-c) regimen in the treatment of children with refractory risk organ involvement Langerhans cell histiocytosis (LCH). Methods: Clinical data of 17 children with multisystem and risk organ involvement LCH who failed the first-line therapy and were treated with intermediate-dose Ara-c (250 mg/m², twice daily) regimen in the Hematology Center, Beijing Children's Hospital from January 2013 to December 2016 were analyzed retrospectively. In addition to the basic treatment of vindesine and dexamethasone, the patients received two regimens: regimen A: the intermediate-dose Ara-c combined with cladribine and regimen B: the intermediate-dose Ara-c alone. The efficacy, safety and prognosis of the two regimens were analyzed. Results: Among all 17 patients, there were 11 males and 6 females, with the diagnosis age of 2.1 (1.6, 2.7) years. Ten children received regimen A, all of them achieved active disease-better (AD-B) after 8 courses of induction therapy. The disease activity scores (DAS) decreased from 5.5 (3.0, 9.0) to 1.0 (0, 2.3). Seven children received regimen B, and 6 of them achieved AD-B after 8 courses of induction therapy. The DAS decreased from 4.0 (2.0, 4.0) to 1.0 (0, 2.0). The follow-up time was 6.2 (4.9,7.2) and 5.2 (3.7,5.8) years in group A and B. The 5-year overall survival rate was 100.0% in both groups, and the 5-year event free survival rate was (88.9±10.5)% and (85.7±13.2)% in group A and B. Grade 3 or 4 myelosuppression was observed in 8 patients in group A and 2 patients in group B. Conclusions: The intermediate-dose Ara-c regimen (with or without cladribine) is effective and safe for patients with refractory high-risk LCH, with a good long-term prognosis.
Male ; Female ; Child ; Humans ; Cytarabine/adverse effects* ; Cladribine/adverse effects* ; Retrospective Studies ; Antineoplastic Combined Chemotherapy Protocols/adverse effects* ; Histiocytosis, Langerhans-Cell/drug therapy* ; Prognosis

Aim To investigate the effects of CPD1, a novel phosphodiesterase 5 inhibitor, on liver pathological phenotype and hepatic stellate cells (HSCs) activation in hepatic fibrosis model mice caused by carbon tetrachloride ( CCl

Objective: To evaluate the efficacy and safety of Beijing Children's Hospital (BCH) modified hemophagocytic lymphohistiocytosis (HLH) 04 regimen in the treatment of childhood HLH. Methods: A retrospective cohort study was conducted. From January 2016 to December 2017, 110 children with HLH who were treated with the modified HLH-04 regimen (replacing dexamethasone with methylprednisolone during the induction period, reducing the dose and frequency of etoposide, and not using cyclosporine except for autoimmune-related HLH) at the Hematology Oncology Center of Beijing Children's Hospital were selected as the modified group, while 102 children treated with the standard HLH-04 regimen from January 2012 to December 2015 were selected as the control group. The early remission rate, survival rate and adverse reactions of two groups were compared. Rank sum test and chi square test were used for comparison between groups. Results: The age of onset in the modified group was 1.9 (1.1, 3.5) years, with 65 males and 45 females. The age of onset in the control group was 2.0 (1.2, 4.6) years, with 47 males and 55 females. No significant difference was found in age and gender between 2 groups (both P>0.05). Except for fibrinogen (1.3 (1.0, 1.7) vs. 1.1 (0.8, 1.4) g/L, Z=-2.67, P=0.008) and natural killer cell activity (13.9 (13.4, 16.3) % vs.14.9 (12.0, 16.1) %, Z=-2.34, P=0.028), there were no statistically significant differences in etiology, disease duration, first clinical presentation, or laboratory tests between 2 groups (all P>0.05). At 2 months and 3 years, there were no statistically significant differences in overall survival between 2 groups (84.5% (93/110) vs.76.5% (78/102), 78.2% (86/110) vs. 67.6% (69/102), χ²=2.28, 3.07, P=0.131, 0.080). The first 3 weeks were the most common time for bone marrow suppression in the modified group, with a lower incidence than in the control group (47.3% (52/110) vs. 62.7% (64/102), χ²=5.11, P=0.024). The modified group had a lower rate of fungal infections than the control group (3.6% (4/110) vs. 13.7% (14/102), χ²=6.93, P=0.008). Compared with the control group, fewer children in the modified group died as a result of side effects from chemotherapy (8.0% (2/25) vs.30.3% (10/33), χ²=4.31, P=0.038). Conclusion: The BCH modified HLH-04 regimen reduced the intensity of chemotherapy, with overall efficacy no worse than the standard HLH-04 regimen, and significantly reduced the rate of chemotherapy-related myelosuppression, fungal infection and mortality.
Child ; Cyclosporine/therapeutic use* ; Etoposide ; Female ; Hospitals ; Humans ; Lymphohistiocytosis, Hemophagocytic/etiology* ; Male ; Retrospective Studies

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent ; Brain Abscess ; Child ; Child, Preschool ; Escherichia coli ; Female ; Humans ; Hydrocephalus ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial/epidemiology* ; Retrospective Studies ; Streptococcus agalactiae ; Streptococcus pneumoniae ; Subdural Effusion ; beta-Lactamases

Objective To explore the mechanism of the intestinal barrier damage caused by Blastocystis hominis infections in rats. Methods Thirty SD rats were randomly divided into the control group, and the 1-, 3-, 6- and 9-week-infection groups, of 6 rats in each group. Rats in each infection group were orally infected with B. hominis trophozoites at a density of 2 × 10⁸ parasites per rat, and the control group was given an equal volume of phosphate buffered saline solution. The 7-hour urine samples were collected 1, 3, 6 and 9 weeks post-infection for the measurement of the intestinal permeability. Then, rats were sacrificed using the cervical dislocation method, and the cecum specimens were collected for the detection of the intestinal epithelial cell permeability. The expression of tight junction-related Occludin and Claudin - 1 genes and apoptosis-related Bcl - 2 and Bax genes was quantified in cecum epithelial cells using the real-time fluorescent quantitative PCR (qPCR) assay, and cell apoptosis was detected in the rat cecum using the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Results The median urinary lactolose to mannitol ratios were 0.29, 0.72, 0.44, 0.46 and 0.38 in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 12.09, P < 0.05). B. hominis invasion and epithelial injury were observed in intestinal epithelial cells of rats infected with B. hominis, and transmission electron microscopy displayed the destruction of tight junctions between intestinal epithelial cells. The relative expression of Occludin, Claudin-1, Bcl-2 and Bax genes was 1.04, 0.62, 0.71, 0.68 and 0.96; 1.03, 0.61, 0.63, 0.76 and 0.86; 1.08, 0.70, 0.75, 0.74 and 1.03; and 1.00, 1.57, 1.33, 1.35 and 1.10 in the control group and the 1-, 3-, 6- and 9-week-infection groups, respectively, and all differences were statistically significant (F = 2.86, 2.85, 3.37 and 4.45, all P values < 0.05). The median number of positive staining cells were 1.00, 13.00, 9.00, 3.50 and 1.00 in rat cecum specimens in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 22.95, P < 0.01). Conclusion B. hominis infection may cause an increase in the rat intestinal permeability through triggering the apoptosis of intestinal epithelial cells to destroy the tight junction between intestinal epithelial cells, thereby destroying the intestinal barrier function.

Purpose: We sought to investigate the effectiveness and safety of dabrafenib in children with BRAFV600E-mutated Langerhans cell histiocytosis (LCH). Materials and Methods: A retrospective analysis was performed on 20 children with BRAFV600E-mutated LCH who were treated with dabrafenib. Results: The median age at which the patients started taking dabrafenib was 2.3 years old (range, 0.6 to 6.5 years). The ratio of boys to girls was 2.3:1. The median follow-up time was 30.8 months (range, 18.9 to 43.6 months). There were 14 patients (70%) in the risk organ (RO)+ group and six patients (30%) in the RO– group. All patients were initially treated with traditional chemotherapy and then shifted to targeted therapy due to poor control of LCH or intolerance to chemotherapy. The overall objective response rate and the overall disease control rate were 65% and 75%, respectively. During treatment, circulating levels of cell-free BRAFV600E (cfBRAFV600E) became negative in 60% of the patients within a median period of 3.0 months (range, 1.0 to 9.0 months). Grade 2 or 3 adverse effects occurred in five patients. Conclusion Some children with BRAFV600E-mutated LCH may benefit from monotherapy with dabrafenib, especially high-risk patients with concomitant hemophagocytic lymphohistiocytosis and intolerance to chemotherapy. The safety of dabrafenib is notable. A prospective study with a larger sample size is required to determine the optimal dosage and treatment duration.