Establishment and application of sandwich ELISA for detection of specific antigen of Seoul virus L99 strain / 中华微生物学和免疫学杂志

Objective:To establish a double antibody sandwich ELISA for detecting the specific antigen of Seoul virus (SEOV) L99 strain and to provide a means for antigen detection in the development, production and verification of vaccine against hemorrhagic fever with renal syndrome (HFRS).Methods:Monoclonal antibodies (McAbs) aganist L99 virus were induced in mice using four hybridoma cell lines and purified by Protein-A affinity chromatography. The purity, titer and specificity of McAbs were determined by SDS-PAGE, indirect ELISA and Western blot, respectively. Four McAbs were paired with each other and the additivity indices of paired McAbs were analyzed. After labeling McAbs with horseradish peroxidase (HRP), the concentrations of the coated and labeled antibodies were optimized by orthogonal test, and then a double antibody sandwich ELISA for virus antigen detection was established. Type Ⅱ HFRS inactivated vaccine standard was used as a quantitative standard to verify the sensitivity, linearity, specificity, accuracy and precision of the developed method. The applicability of the method was verified by testing three batches of vaccine stock solutions.Results:Four McAbs were at titers of greater than 1∶10 6 and their purity was all greater than 98%. The McAbs secreted by 1D5, 3A4 and 5B7 cells could specifically recognize the nucleocapsid protein of SEOV L99. There was cross-reaction between McAb secreted by 1D5 cells and Hantaan virus PS-6. The McAbs secreted by 3A4 and 1D5 were used as coating and labeling antibodies based on the results of antibody pairs. The working concentrations of the coating antibody and the horseradish peroxidase (HRP)-labeled antibody were 20 μg/ml and 1∶4 000, respectively. The minimum detection limit of the established method for the detection of SEOV L99 antigen was 0.078 1 μg/ml, and the linear range was 0.078 1-2.500 0 μg/ml with a R2 value of more than 0.99. There was no cross reaction with other HFRS vaccine. The virus antigen recovery rate was between 95.8% and 108.7%, and the coefficients of variation of precision was less than 10%. Three batches of Type II HFRS inactivated vaccine stocks were detected by this method and the results was dose-dependent. Conclusions:This study successfully established a double antibody sandwich ELISA method for specific detection of SEOV L99 strain antigen in the production of bivalent HFRS vaccines produced from hamster kidney cells.

The phenotypic and genetic spectrum of colony-stimulating factor 1 receptor gene-related leukoencephalopathy in China / 中华神经科杂志

Objective:To summarize and analyze the clinical data of Chinese patients with colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy, and clarify the phenotypic and genetic characteristics of Chinese patients.Methods:Medical history of patients with CSF1R-related leukoencephalopathy diagnosed from April 1, 2018 to January 31, 2021 in the department of neurology of 22 hospitals in China was collected, and scores of Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment Scale (MoCA), magnetic resonance severity scale were evaluated. Group comparison was performed between male and female patients.Results:A total of 62 patients were included, and the male-female ratio was 1∶1.95. The age of onset was (40.35±8.42) years. Cognitive impairment (82.3%, 51/62) and motor symptoms (77.4%,48/62) were the most common symptoms. The MMSE and MoCA scores were 18.79±7.16 and 13.96±7.23, respectively, and the scores of two scales in male patients (22.06±5.31 and 18.08±5.60) were significantly higher than those in females (15.53±7.41 , t=2.954, P=0.006; 10.15±6.26, t=3.328 , P=0.003). The most common radiographic feature was bilateral asymmetric white matter changes (100.0%), and the magnetic resonance imaging severity scale score was 27.42±11.40, while the white matter lesion score of females (22.94±8.39) was significantly higher than that of males (17.62±8.74 , t=-2.221, P<0.05). A total of 36 CSF1R gene mutations were found in this study, among which c.2381T>C/p.I794T was the hotspot mutation that carried by 17.9% (10/56) of the probands. Conclusions:The core phenotypic characteristics of CSF1R-related leukoencephalopathy in China are progressive motor and cognitive impairment, with bilateral asymmetrical white matter changes. In addition, there exist gender differences clinically, with severer cognitive impairment and imaging changes in female patients. Thirty-six CSF1R gene mutations were found in this study, and c.2381T>C/p. I794T was the hotspot mutation.

Subcellular localization of ataxin-3 and its effect on the morphology of cytoplasmic organoids / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the subcellular localization of ataxin-3 and the effect of polyglutamine (polyQ) expansion mutation on the morphology of mitochondrion, golgi apparatus and endoplasmic reticulum.</p><p><b>METHODS</b>Transient transfection was employed to build cell models expressing wild-type or mutant ataxin-3 proteins. Indirect immunofluorescence was applied to identify markers of organelle membrane. The results were observed under a laser scanning confocal microscope.</p><p><b>RESULTS</b>No co-localization was observed for ataxin-3 protein and mitochondrial marker TOM20, but the percentage of cells with mitochondrial fragmentation has increased in cells expressing mutant ataxin-3 (P<0.05). No co-localization was observed for ataxin-3 protein and golgi marker GM130, and mutant ataxin-3 did not cause golgi fragmentation. Wide type and polyQ-expanded ataxin-3 both showed partial co-localization with ER marker calnexin. The latter showed more overlap with calnexin, and the overlapping signals were mostly located in the places where aggregates were situated.</p><p><b>CONCLUSION</b>PolyQ-expanded ataxin-3 protein may indirectly affect the integrity of mitochondria, but may cause no effect on the structure and functions of golgi apparatus. Endoplasmic reticulum may be another place where extended ataxin-3 protein can induce cytotoxicity in addition to the nucleus.</p>

Clinical observations of spraying Zhikang Capsules guided by gastroscopy in treatment elderly upper gastrointestinal bleeding / 中国综合临床

Objective To investigate the clinical effect and security of spraying Zhikang Capsules guided by gastroscopy in treatment elderly upper gastrointestinal bleeding.Methods Eighty-four elderly gastric duodenal ulcer bleeding patients were randomly assigned to group A,B and C (n =28 for each group).Patients in group A were used noradrenalin to spray with gastroscopy,in group B were used thrombin and in group C were used Zhikang Capsules.The total effective,the immediate homeostasis rate,the incidence of rebleeding,the emergency operation rate and the incidence of adverse reaction were recorded and analyzed.Results Total effective rate of group C was 96.4％ (27/28),significantly higher than that in group A (71.4％,20/28),B (75.0％,21/28) and the difference was significant(P＜0.05).The incidence of rebleeding in group A,B,C were 28.6％ (8/28),17.9％ (6/28),3.6％ (1/28) respectively,and the difference was significant (P ＜0.05).The same trend was seen regarding of the incidence of adverse reaction among three groups (25.0％,7/28;10.7％,3/28;0,0/28;P＜0.05).Conclusion Spraying Zhikang Capsules guided by gastroscopy is showed with good therapeutic effect in treating elderly upper gastrointestinal bleeding and high safety,and with less adverse reaction.

Polyglutamine-expanded ataxin-3 is degraded by autophagy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the role of autophagy on the pathogenesis of spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD).</p><p><b>METHODS</b>HEK293 cells expressing polyglutamine-expanded ataxin-3 were used as cell model for SCA3/MJD. The level of polyglutamine-expanded ataxin-3 was detected after cells were treated with different inhibitors or inducer of autophagy.</p><p><b>RESULTS</b>Inhibition of autophagy increased aggregate formation and cell death in HEK293 cells expressing mutated ataxin-3, and vice versa.</p><p><b>CONCLUSION</b>The data suggested that autophagy is involved in the degradation of mutant ataxin-3, resulting in a decrease in the proportions of aggregate-containing cells and cell death in HEK293 cells expressing polyglutamine-expanded ataxin-3. It is possible that autophagy may be applied as a potential therapeutic approach for SCA3/MJD.</p>

ATM gene mutations in Chinese patients with ataxia telangiectasia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mutation characteristics of ATM gene in Chinese patients with ataxia-telangiectasia (AT).</p><p><b>METHODS</b>Mutation of ATM gene was screened by polymerase chain reaction, reverse transcription-polymerase chain reaction, polyacrylamide gel electrophoresis combined with DNA direct sequencing in two Chinese AT patients.</p><p><b>RESULTS</b>A missense mutation of 1346(G>C) in exon 11, which was a homozygotic mutation, was identified in one patient; a nonsense mutation of 610 (G>T) in exon 6 combined with a missense mutation of 6679 (C>T) in exon 47, which was a compound heterozygotic mutation, were identified in the other patient. They were co-segregated with the disease and were localized within the functional domain of ATM gene.</p><p><b>CONCLUSION</b>Totally three novel ATM gene mutations were identified in two Chinese AT patients.</p>

Studies on PANK2 gene mutations in Chinese patients with Hallervorden-Spatz syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study pantothenate kinase 2 (PANK2) gene mutations in Chinese patients with Hallervorden-Spatz syndrome (HSS).</p><p><b>METHODS</b>PANK2 gene mutations were detected by PCR, DNA sequence analyses, restriction enzyme digestion and PCR-single strand conformation polymorphism in 5 patients, 3 unaffected family members and 51 unrelated healthy persons.</p><p><b>RESULTS</b>Novel compound heterozygous PANK2 gene mutations, A803G and T1172A, in exons 3 and 5, respectively, were found in one patient. At the same time, 3 types of single nucleotide polymorphisms, -38 t>a in 5'-UTR, IVS1+42 c>a and G77C in exon 1, were confirmed; among them, -38 t>a, IVS1+42 c>a, were first reported.</p><p><b>CONCLUSION</b>PANK2 gene mutations can cause HSS in Chinese patients.</p>

Knockdown of Survivin Gene Expression in Neuroblastoma Cells by RNAi / 中国医师杂志

Objective To construct the short hairpin RNA(shRNA) expression vector of survivin and down-regulate the expression of survivin through RNA interference in neuroblastoma cell line SH-SY5Y. Methods Two pairs of oligonucleotide sequences specific for human survivin mRNA were designed and synthesized. The annealed oligonucleotide fragments were subcloned into pBSHH1 plasmid. After being identified by restriction enzyme digestion and sequencing, the recombinant plasmids pBSHH1-S1 and pBSHH1-S2 were transfected into SH-SY5Y cells, respectively. Survivin expression in the transfected cells was assayed by both RT-PCR and western blot. Results Enzyme digestion analysis and DNA sequencing showed that the oligonucleotide fragments were correctly inserted into pBSHH1 plasmid, and survivin expression in the transfected cells was knocked down significantly by pBSHH1-S1 or pBSHH1-S2 at both the protein and mRNA level. Conclusion The shRNA expression vectors of survivin were successfully constructed, and could down-regulate survivin expression in SH-SY5Y cells, which lay a foundation for further research on gene therapy for tumors such as neuroblastoma.