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.

OBJECTIVES: To explore the cytotoxicity of four wild mushrooms involved in a case of Yunnan sudden unexplained death (YNSUD), to provide the experimental basis for prevention and treatment of YNSUD. METHODS: Four kinds of wild mushrooms that were eaten by family members in this YNSUD incident were collected and identified by expert identification and gene sequencing. Raw extracts from four wild mushrooms were extracted by ultrasonic extraction to intervene HEK293 cells, and the mushrooms with obvious cytotoxicity were screened by Cell Counting Kit-8 (CCK-8). The selected wild mushrooms were prepared into three kinds of extracts, which were raw, boiled, and boiled followed by enzymolysis. HEK293 cells were intervened with these three extracts at different concentrations. The cytotoxicity was detected by CCK-8 combined with lactate dehydrogenase (LDH) Assay Kit, and the morphological changes of HEK293 cells were observed under an inverted phase contrast microscope. RESULTS: Species identification indicated that the four wild mushrooms were Butyriboletus roseoflavus, Boletus edulis, Russula virescens and Amanita manginiana. Cytotoxicity was found only in Amanita manginiana. The raw extracts showed cytotoxicity at the mass concentration of 0.1 mg/mL, while the boiled extracts and the boiled followed by enzymolysis extracts showed obvious cytotoxicity at the mass concentration of 0.4 mg/mL and 0.7 mg/mL, respectively. In addition to the obvious decrease in the number of HEK293 cells, the number of synapses increased and the refraction of HEK293 cells was poor after the intervention of Amanita manginiana extracts. CONCLUSIONS The extracts of Amanita manginiana involved in this YNSUD case has obvious cytotoxicity, and some of its toxicity can be reduced by boiled and enzymolysis, but cannot be completely detoxicated. Therefore, the consumption of Amanita manginiana is potentially dangerous, and it may be one of the causes of the YNSUD.
Humans ; HEK293 Cells ; Sincalide ; China ; Amanita ; Death, Sudden

It is well established that increased excitability of the presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) during hypertension leads to heightened sympathetic outflow and hypertension. However, the mechanism underlying the overactivation of PVN presympathetic neurons remains unclear. This study aimed to investigate the role of endogenous corticotropin-releasing factor (CRF) on the excitability of presympathetic neurons in PVN using Western blot, arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) recording, CRISPR/Cas9 technique and patch-clamp technique. The results showed that CRF protein expression in PVN was significantly upregulated in spontaneously hypertensive rats (SHRs) compared with normotensive Wistar-Kyoto (WKY) rats. Besides, PVN administration of exogenous CRF significantly increased RSNA, heart rate and ABP in WKY rats. In contrast, knockdown of upregulated CRF in PVN of SHRs inhibited CRF expression, led to membrane potential hyperpolarization, and decreased the frequency of current-evoked firings of PVN presympathetic neurons, which were reversed by incubation of exogenous CRF. Perfusion of rat brain slices with artificial cerebrospinal fluid containing CRF receptor 1 (CRFR1) blocker, NBI-35965, or CRF receptor 2 (CRFR2) blocker, Antisauvagine-30, showed that blocking CRFR1, but not CRFR2, hyperpolarized the membrane potential and inhibited the current-evoked firing of PVN presympathetic neurons in SHRs. However, blocking CRFR1 or CRFR2 did not affect the membrane potential and current-evoked firing of presympathetic neurons in WKY rats. Overall, these findings indicate that increased endogenous CRF release from PVN CRF neurons enhances the excitability of presympathetic neurons via activation of CRFR1 in SHRs.
Rats ; Animals ; Rats, Inbred SHR ; Paraventricular Hypothalamic Nucleus/physiology* ; Receptors, Corticotropin-Releasing Hormone/metabolism* ; Rats, Inbred WKY ; Corticotropin-Releasing Hormone/metabolism* ; Neurons/physiology* ; Hypertension ; Sympathetic Nervous System

Since the emergence of CRISPR/Cas9, gene editing technologies have attracted increasing attention, in particular type II systems, in which nucleases consist of only a single protein. The effectors include type II Cas9, type V Cas12 and type VI Cas13, which allow precise genomic DNA or RNA editing. Catalytically inactive CRISPR/Cas9 can also be used as a platform to recruit effectors such as transcription factors, epigenetic factors, and/or base modification enzymes to target gene loci. On the other hand, optogenetics offers spatial, temporal, and reversible control of biological processes. CRISPR and optogenetics can enable precise gene editing in vitro and in vivo at the spatiotemporal level, which has a broad applicability in biology and medicine. This article has provided a review for the research advance in photoactivatable CRISPR systems, with details for the design and application of such tools and a discussion over the limitations of the current methods, which may shed light on this emerging field.
CRISPR-Cas Systems ; DNA ; Gene Editing ; Humans ; Technology

OBJECTIVES: To investigate the genetic information of 57 autosomal InDel loci (A-InDels) included in AGCU InDel 60 fluorescence detection kit in the Beichuan Qiang population of Sichuan Province and evaluate its application value in forensic medicine. METHODS: A total of 200 unrelated healthy individuals from Beichuan Qiang population of Sichuan Province were typing detected by AGCU InDel 60 fluorescence detection kit. Allele frequencies and population genetic parameters of the 57 A-InDels were statistically analyzed and compared with the available data of 26 populations. RESULTS: After Bonferroni correction, there was no linkage disequilibrium between the 57 A-InDels, and all loci were in Hardy-Weinberg equilibrium. Except for rs66595817 and rs72085595, the minor allele frequencies of 55 A-InDels were above 0.3. PIC ranged from 0.298 3 to 0.375 0, CDP was 1-2.974 8×10^-24, CPE_duo was 0.999 062 660, and CPE_trio was 0.999 999 999. The calculation of the genetic distance showed that Beichuan Qiang population had the closest genetic distances with Beijing Han and South China Han populations, but far away from African populations. CONCLUSIONS The 57 A-InDels in AGCU InDel 60 fluorescence detection kit have a good genetic polymorphism in Beichuan Qiang population of Sichuan Province, which can be used as effective supplemental for individual identification and paternity identification in forensic medicine.
Humans ; Genetics, Population ; Asian People/genetics* ; Polymorphism, Genetic ; Gene Frequency ; INDEL Mutation ; China ; Microsatellite Repeats ; Genetic Loci

Arsenic/toxicity* ; Bangladesh ; Female ; Humans ; Infant, Newborn ; Pregnancy ; Premature Birth/chemically induced* ; Rural Population ; Zinc

Objective    To evaluate the expression level of histone deacetylase 9 (HDAC9) in lung squamous cell carcinoma (LUSC) tissues, to analyze its correlations with clinicopathological characteristics and prognosis of LUSC patients, and to explore the effect it exerts on the proliferation of LUSC cells. Methods    The expression level of HDAC9 was detected by immunohistochemistry staining (IHC), and its correlations with clinicopathological characteristics were analyzed by χ2 test. Survival analysis was performed using Kaplan-Meier method. Univariate and multivariate Cox proportional hazards model were employed to analyze independent predictors for overall survival (OS) of LUSC patients. CRISPR/dCas9 activation system was used to activate the transcription of HDAC9 gene in LUSC cell line EBC-1. CCK8 cell proliferation assay and colony formation test were performed to investigate the effect that transcriptional activation of HDAC9 exerts on the proliferation of LUSC cells. Results    Of the 129 LUSC patients, 39 (30.2%) were in the HDAC9 low expression group and 90 (69.8%) were in the HDAC9 high expression group. The OS of the patients with HDAC9 high expression was shorter than that of patients with HDAC9 low expression (P=0.032). The expression level of HDAC9 was associated with tumor grade (P=0.035), primary tumor size (P=0.041), and lymph node metastasis (P=0.013). The expression level of HDAC9 (P=0.023), tumor grade (P=0.003), primary tumor size (P=0.003), and lymph node metastasis (P=0.002) were independent predictors for OS of LUSC patients. Transcriptional activation of HDAC9 promoted colony formation of LUSC cells and cell proliferating curves showed that LUSC cells with HDAC9 transcriptional activation proliferated faster than non-targeting cells (F=52.7, P=0.002). Conclusion    LUSC patients with HDAC9 high expression have poorer prognosis than HDAC9 low expression ones. The expression level of HDAC9 is associated with tumor grade, primary tumor size, and lymph node metastasis, and is identified as an independent predictor for prognosis of LUSC. Transcriptional activation of HDAC9 promotes cell proliferation in LUSC. These results suggest that HDAC9 may serve as a promising biomarker for prognosis in LUSC.

Objective To explore the association of cardiac disease associated genetic variants and the high incidence of Yunnan sudden unexplained death （YNSUD） in Yi nationality. Methods The genomic DNA was extracted from peripheral blood samples collected from 205 Yi villagers from YNSUD aggregative villages （inpatient group） and 197 healthy Yi villagers from neighboring villages （control group）. Fifty-two single nucleotide variants （SNVs） of 25 cardiac disease associated genes were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. The SPSS 17.0 was used to analyze data. The pathogenicities of variants with differences between the two groups that have statistical significance were predicted by protein function prediction software PolyPhen-2 and SIFT. All villagers from inpatient group were given electrocardiogram （ECG） examination using a 12-lead electrocardiograph. Results The allele frequency and the genotype frequency of missense mutation DSG2 （rs2278792, c.2318G>A, p.R773K） of pathogenic genes of arrhythmogenic right ventricular cardiomyopathy （ARVC） in inpatient group was higher than that in control group （P<0.05）. Abnormal ECG changes were detected in 71 individuals （34.6%） in the inpatient group, among which 54 individuals carried R773K mutation, including clockwise （counterclockwise） rotation, left （right） axis deviation, ST segment and T wave alteration and heart-blocking. Conclusion Definite pathogenic mutations have not been found in the 52 cardiac disease genes associated SNVs detected in Yi nationality in regions with high incidence of YNSUD. The cause of high incidence of YNSUD in Yi nationality needs further study.
Arrhythmogenic Right Ventricular Dysplasia ; China/epidemiology* ; Death, Sudden/etiology* ; Death, Sudden, Cardiac/etiology* ; Ethnicity/genetics* ; Humans ; Incidence ; Mutation

Objective To study the influence of halogenated hydroxyl-alkanes inhalation anesthetic on the determination of ethanol content in blood. Methods Halogenated hydroxyl-alkanes were analyzed by headspace gas chromatography with double column confirmatory detection method. The influence of halogenated hydroxyl-alkanes on determination of ethanol content in blood sample by headspace gas chromatography was explored under the different detection conditions of KB-BAC1/ KB-BAC2 and J&W DB-ALC1/DB-ALC2 gas chromatographic column. Results The retention time of sevoflurane and enflurane was similar to that of ethanol and tert butanol respectively when using the J&W DB-ALC1/DB-ALC2 gas chromatographic column, and interfered with the detection of ethanol content in blood; only J&W DB-ALC1 gas chromatographic column can separate the sevoflurane and ethanol components, so as to eliminate their influence on the detection of ethanol content in blood. When using KB-BAC1/KB-BAC2 gas chromatographic column, the retention time of sevoflurane, isoflurane and ethanol is similar, especially that of sevoflurane and ethanol, and sevoflurane obviously interferes with the determination of ethanol content in blood. Conclusion Halogenated hydroxy-alkanes interfere with determination of ethanol content in blood by headspace gas chromatography. The interference can be discriminated effectively by choosing the suitable chromatographic column and double column confirmatory detection.
Alkanes ; Anesthetics, Inhalation ; Ethanol ; Isoflurane ; Sevoflurane

Objective To analyze the correlation between the fractional exhaled nitric oxide (FeNO) levels and blood eosinophil (EOS) count and the frequency of wheeze in infants with recurrent wheezing.Methods From February 2015 to August 2016 in the General Hospital of Northern War Zone,outpatient department of Pediatrics treatment and hospitalization of age less than or equal to 3 year old children with recurrent wheezing,101 cases were induded as the research object.On the basis of asthma predictive index (API) score were divided into API positive group (n =55) and API negative group (n =46),according to the wheeze frequency of the two groups children were divided into 3 ～ 4 times wheezing groups and more than 5 times.Select 37 cases of healthy children as control group.The concentration of FeNO and blood EOS count are detected in all the children.The correlation between the three groups of children with FeNO concentration,the correlation between FeNO and blood EOS count,the correlation between the the frequency of wheeze and FeNO in experimental groups were analyzed.Results (1) API positive group mean FeNO (19.3 ± 6.2) ppb was significantly higher than API negative group (7.7 ± 2.9) ppb,there was no difference (P ＞ 0.05).API negative group mean FeNO (7.7 ± 2.9) ppb is lower than the normal control group (9.5 ± 2.0) ppb,there was no difference (P ＞0.05).(2) API positive group mean EOS count (124.7 ± 1.6) x 106/L is higher than API negative group (86.1 ± 1.9) x 106/L,there was significant difference (P ＜ 0.01);(3) There was a correlation between FeNO level and blood EOS count in API positive group,there was no correlation between FeNO level and blood EOS count in API negative group and con~ol group.(4) No statistical differences were found in ≤4 times wheezing groups and more than 5 times of the mean FeNO.Conclusion There is no significant difference in the mean value of FeNO between different times of wheezing in children with recurrent wheezing.The combination of medical history,EOS,FeNO and API might be used to predict the wheezing episode of infants.