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 demographic characteristics and clinical influencing factors which associates with the occurrence probability of persistent or intermittent hypoviremia (LLV) in patients with chronic hepatitis B (CHB) treated with nucleos(t)ide analogues (NAs). Methods: A single-center retrospective analysis was performed on patients with CHB who received outpatient NAs therapy for≥48 ± 2 weeks. According to the serum hepatitis B virus (HBV) DNA load at 48±2 weeks treatment, the study groups were divided into LLV (HBV DNA < 20 IU/ml and < 2 000 IU/ml) and MVR group (sustained virological response, HBV DNA < 20 IU/ml). Demographic characteristics and clinical data at the start of NAs treatment (considered as baseline) were retrospectively collected for both patient groups. The differences in the reduction of HBV DNA load during treatment was compared between the two groups. Correlation and multivariate analysis were further conducted to analyze the associated factors influencing the LLV occurrence. Statistical analysis was performed using the independent samples t-test, c2 test, Spearman analysis, multivariate logistic regression analysis, or area under the receiver operating characteristic curve. Results: A total of 509 cases were enrolled, with 189 and 320 in the LLV and MVR groups, respectively. Compared to patients with MVR group at baseline: (1) the demographics characteristics of patients showed that LLV group was younger in age (39.1 years, P = 0.027), had a stronger family history (60.3%, P = 0.001), 61.9% received ETV treatment, and higher proportion of compensated cirrhosis (20.6%, P = 0.025) at baseline; (2) the serum virological characteristics of patients showed that LLV group had higher HBV DNA load, qHBsAg level, qHBeAg level, HBeAg positive rate, and the proportion of genotype C HBV infection but decreased HBV DNA during treatment (P < 0.001) at baseline; (3) the biochemical characteristics of patients showed that LLV group had lower serum ALT levels (P = 0.007) at baseline; (4) the noninvasive fibrosis markers of patients showed that LLV group were characterized by high aspartate aminotransferase platelet ratio index (APRI) (P = 0.02) and FIB-4 (P = 0.027) at baseline. HBV DNA, qHBsAg and qHBeAg were positively correlated with LLV occurrence (r = 0.559, 0.344, 0.435, respectively), while age and HBV DNA reduction were negatively correlated (r = -0.098, -0.876, respectively). Logistic regression analysis showed that ETV treatment history, high HBV DNA load at baseline, high qHBsAg level, high qHBeAg level, HBeAg positive, low ALT and HBV DNA level were independent risk factors for patients with CHB who developed LLV with NAs treatment. Multivariate prediction model had a good predictive value for LLV occurrence [AUC 0.922 (95%CI: 0.897 ~ 0.946)]. Conclusion: In this study, 37.1% of CHB patients treated with first-line NAs has LLV. The formation of LLV is influenced by various factors. HBeAg positivity, genotype C HBV infection, high baseline HBV DNA load, high qHBsAg level, high qHBeAg level, high APRI or FIB-4 value, low baseline ALT level, reduced HBV DNA during treatment, concomitant family history, metabolic liver disease history, and age < 40 years old are potential risk factors for developing LLV in patients with CHB during the therapeutic process.
Humans ; Adult ; Hepatitis B, Chronic/complications* ; Retrospective Studies ; Cross-Sectional Studies ; Hepatitis B e Antigens ; DNA, Viral ; Antiviral Agents/therapeutic use* ; Hepatitis B virus/genetics* ; Demography

Objective: To study the influence of steroid withdrawal protection strategy on height growth in pediatric patients after kidney transplantation. Methods: The prospective cohort study enrolled 40 stage 5 chronic kidney disease children receiving kidney transplantation from July 2017 to September 2022 at Guangzhou Women and Children's Medical Center. Based on the primary preoperative disease, patients with immune abnormality-associated glomerular diseases or unknown causes were assigned to the steroid maintenance group, in which patients received steroid tapering within 3 months after surgery to a maintenance dose of 2.5 to 5.0 mg/d. While patients with hereditary kidney disease or congenital urinary malformations were assigned to the steroid withdrawal group, in which patients had steroids tapered off within 3 months. The characteristics of height catch-up growth and clinical data were compared between the 2 groups at baseline, 6, 12, 18 and 24 months after kidney transplantation. T-test, repeated measurement of variance analysis, Mann-Whitney U test, and Fisher exact test were used for the comparison between the 2 groups. Results: Among the 40 children, 17 were males, 23 were females, 25 were in the steroid withdraw group ((7.8±2.8) years old when receiving kidney transplantation) and 15 cases were in the steroid maintenance group ((7.6±3.5) years old when receiving kidney transplantation). The study population was followed up for (26±12) months. The total dose per unit body weight of steroids in the steroid withdrawal group was lower than that in the steroid maintenance group ((0.13±0.06) vs. (0.36±0.19) mg/(kg·d), t=5.83, P<0.001). The height catch-up rate (ΔHtSDS) in the first year after kidney transplantation in the steroid withdraw and steroid maintenance groups was 1.0 (0.7, 1.4) and 0.4 (0.1, 1.0), respectively; in the second year, the ΔHtSDS in the steroid withdraw group was significantly higher than that in the steroid maintenance group (1.1 (0.2, 1.7) vs. 0.3 (0, 0.8), U=28.00, P=0.039). The HtSDS in the steroid withdrawal group at the five follow-up time points was -2.5±0.8, -2.0±0.8, -1.5±0.8, -1.3±0.9 and -0.5±0.3, respectively, while in the steroid maintenance was -2.4±1.3, -2.2±1.1, -2.0±1.0, -1.8±1.0 and -1.6±1.0, respectively. There were statistically significant differences in HtSDS at different follow-up time points in both 2 groups (F=19.81, P<0.01), but no statistical differences in overall impact between the 2 groups (F=1.13, P=0.204). The steroid treatment was interaction with the increase of follow-up time (F=3.62, P=0.009). At the 24^th month after transplantation, the HtSDS in the steroid withdrawal group was significantly higher than that in the steroid maintenance group (P=0.047). Six patients in the steroid withdrawal group experienced antibody-mediated immune rejection (AMR), while 3 did in the steroid maintenance group. Moreover, there was no significant difference in AMR between the two groups (χ²=0.06, P=0.814). Conclusion: The steroid withdrawal protection strategy favors the height catch-up growth in pediatric patients after kidney transplantation and does not increase the risk of postoperative antibody-mediated immune rejection.
Male ; Humans ; Child ; Female ; Child, Preschool ; Kidney Transplantation ; Prospective Studies ; Steroids/therapeutic use* ; Antibodies ; Body Weight

In the outbreak of COVID-19,triage procedures based on epidemiology were implemented in a local hospital in Changsha to control the transmission of SARS-CoV-2 and avoid healthcare-associated infection.This re-trospective study analyzed the data collected during the triage period and found that COVID-19 patients were en-riched 7 folds into the Section A designated for patients with obvious epidemiological history.On the other side,nearly triple amounts of visits were received at the Section B for patients without obvious epidemiological history.8 COVID-19 cases were spotted out of 247 suspected patients.More than 50％of the suspected patients were submi-tted to multiple rounds of nucleic acid analysis for SARS-CoV-2 infection.Of the 239 patients who were diagnosed as negative of the virus infection,188 were successfully revisited and none was reported as COVID-19 case.Of the 8 COVID-19 patients,3 were confirmed only after multiple rounds of nucleic acid analysis.Besides comorbidities,delayed sharing of epidemiological history added complexity to the diagnosis in practice.The triaging experience and strategy will be helpful for the control of infectious diseases in the future.

OBJECTIVE: To investigate the safety and the short-term efficacy of venetoclax combined with azacitidine followed by cladribine (VAC regimen) in children with refractory/ relapsed acute myeloid leukemia (AML). METHODS: The clinical data, treatment outcomes, complications, and blood product consumption of 6 children with refractory/relapsed AML treated with VAC regimen in the Children's Hospital of Soochow University from August 2021 to December 2021 were retrospectively analyzed. RESULTS: Among the 6 children, there were 1 male and 5 females. 5 cases were refractory AML, and 1 case was relapsed AML, which recurred again 16 months after allogeneic hematopoietic stem cell transplantation. 4 children were accompanied by chromosomes or genes that predicted poor prognosis, such as RUNX1, FLT3-ITD, KMT2A exon 2-exon 8 dup, MLL-AF6, 7q-, KMT2A exon 2-exon 10 dup, etc. After received VAC regimen, 4 cases achieved CR+CRi, 1 case achieved PR (only MRD did not relieve, MRD was 0.59%), and 1 case was NR (but the proportion of bone marrow blasts decreased). All 6 patients had grade Ⅳ neutropenia, and 4 patients had grade Ⅳ thrombocytopenia. During the period of neutropenia, none of the 6 children developed symptoms of infection such as fever, cough, and diarrhea. No treatment-related death occurred. CONCLUSION Venetoclax combined with azacitidine followed by cladribine provides a new treatment option for patients with relapsed/refractory AML who have poor efficacy in early induction remission theragy, showing good efficacy and safety.
Child ; Female ; Humans ; Male ; Azacitidine/therapeutic use* ; Cladribine/therapeutic use* ; Retrospective Studies ; Leukemia, Myeloid, Acute/genetics* ; Neutropenia ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use*

The joint application of traditional Chinese medicine injection containing chlorogenic acid (CA) and cefotaxime sodium (CS) is sometimes appeared in clinical practice, but the scientific basis of drug molecular compatibility is still weak. This study proposes a sequential analysis strategy based on isothermal titration calorimetry (ITC), cold-spray ionization mass spectrometry (CSI-MS) and antibacterial activity test to evaluate the molecular interactions between CA and CS. The results of ITC experiments showed that the Gibbs free energy ΔG < 0 and it was driven by enthalpy change when CA titrated CS, suggesting CA could spontaneously chemically react with CS. Subsequently, the parent ions (m/z 808.143 5) of binding molecular of CA and CS was detected by CSI-MS, indicating CA could chemically bond with CS. Furtherly, the antibacterial experiments found the antibacterial ability of CS against Klebsiella pneumonia was significantly reduced (P < 0.01) by CA in mixed solution. Finally, molecular docking technology showed CA and CS have a common target of penicillin binding protein 3 (PBP3), suggesting that the phenomenon of CA reduced the antibacterial ability of CS may be related to the competitive binding of two components with PBP3. Our studies have shown that CA could spontaneously chemically bond to CS and reduced its antibacterial ability, providing scientific data for molecular interaction evaluation of CA and CS.

The combination of Shuanghuanglian injection (SHLI) and ciprofloxacin injection (CIPI) is frequently prescribed in clinical practice, but the basis for the combination is weak. In this study, isothermal titration calorimetry and ultraviolet-visible absorption spectrometry were applied to identify the molecular interactions of SHLI and its main components, chlorogenic acid and neochlorogenic acid with CIPI. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and cold-spray ionization mass spectrometry were performed to confirm that this molecular interaction was related to the formation of self-assembled supramolecular systems induced by chlorogenic acid and neochlorogenic acid with CIPI through weak intermolecular bonds. The antibacterial activity toward Pseudomonas aeruginosa (P. aeruginosa) was evaluated via molecular interactions, and the inhibitory ability of SHLI, chlorogenic acid and neochlorogenic acid against P. aeruginosa was significantly reduced after interaction with CIPI. A molecular docking study demonstrated that the reduced antibacterial ability was closely related to the competitive binding of drug molecules to the same binding site of the DNA gyrase B (GyrB) subunit of P. aeruginosa. The present study uncovered the intermolecular interactions of SHLI and its main components chlorogenic acid and neochlorogenic acid with CIPI from the perspective of molecular self-assembly and contribute to the reduction of its antibacterial ability, providing a basis for the clinical combination of SHLI and CIPI.

COVID-19/virology* ; Humans ; Pandemics ; SARS-CoV-2/physiology*

OBJECTIVE: To investigate the current status of antibiotic use for very and extremely low birth weight (VLBW/ELBW) infants in neonatal intensive care units (NICUs) of Hunan Province. METHODS: The use of antibiotics was investigated in multiple level 3 NICUs of Hunan Province for VLBW and ELBW infants born between January, 2017 and December, 2017. RESULTS: The clinical data of 1 442 VLBW/ELBW infants were collected from 24 NICUs in 2017. The median antibiotic use duration was 17 days (range: 0-86 days), accounting for 53.0% of the total length of hospital stay. The highest duration of antibiotic use was up to 91.4% of the total length of hospital stay, with the lowest at 14.6%. In 16 out of 24 NICUs, the antibiotic use duration was accounted for more than 50.0% of the hospitalization days. There were 113 cases with positive bacterial culture grown in blood or cerebrospinal fluid, making the positive rate of overall bacterial culture as 7.84%. The positive rate of bacterial culture in different NICUs was significantly different from 0% to 14.9%. The common isolated bacterial pathogens Klebsiella pneumoniae was 29 cases (25.7%); Escherichia coli 12 cases (10.6%); Staphylococcus aureus 3 cases (2.7%). The most commonly used antibiotics were third-generation of cephalosporins, accounting for 41.00% of the total antibiotics, followed by penicillins, accounting for 32.10%, and followed by carbapenems, accounting for 13.15%. The proportion of antibiotic use time was negatively correlated with birth weight Z-score and the change in weight Z-score between birth and hospital discharge (r=-0.095, -0.151 respectively, P<0.01), positively correlated with death/withdrawal of care (r=0.196, P<0.01). CONCLUSIONS Antibiotics used for VLBW/ELBW infants in NICUs of Hunan Province are obviously prolonged in many NICUs. The proportion of routine use of third-generation of cephalosporins and carbapenems antibiotics is high among the NICUs.
Anti-Bacterial Agents ; Birth Weight ; Humans ; Infant ; Infant, Extremely Low Birth Weight ; Infant, Newborn ; Intensive Care Units, Neonatal ; Surveys and Questionnaires

AIM:To investigate the role of autophagy in inhibition of human lung cancer PC 9 cell proliferation by ursolic acid(UA)as well as the underlying mechanism.METHODS:MTT assay and Trypan blue exclusion test were performed to analyze the effect of UA on the proliferation of PC 9 cells.The PC9 cells were treated with UA,and autophagy was observed under fluorescence microscope through acridine orange staining.The expression of autophagy-associated pro-teins LC3 and ATG5 in the PC9 cells were detected by Western blot.The effect of UA,3-methyladenine(3-MA)3-MA or their combination on the cell viability was measured by MTT assay.RESULTS:The viability of PC9 cells was significantly inhibited by UA(P<0.05 or P<0.01).The number of bright red fluorescence positive cells was significantly increased after treatment with UA.The protein expression of LC3-II and ATG5 was significantly up-regulated compared with control group(P<0.01).Furthermore,combination of UA and 3-MA resulted in a substantial decrease in cell viability compared with using UA alone(P<0.01).CONCLUSION: UA inhibits the proliferation and induces the autophagy of the PC 9 cells,in which autophagy plays a protective role.The inhibition of autophagy significantly promotes the death of the PC 9 cells induced by UA.