Objective:To construct a fusion protein of extracellular domain peptide fragment of muscle specific kinase ( MuSK) and fluorescent protein mCherry ,and used as antigen in the detection of antibodies against MuSK ( MuSKAb ) in the sera of patients with myasthenia gravis ( MG).Methods:The mCherry gene was amplified by PCR from vector pRSET-B and cloned into pGEM-T Easy Vector,and furthermore, cloned into Eukaryotic expression vector pMT /BiP/V5-His ( MuSK), which contains MuSK extracellular domain 22-452 amino acid peptide fragment gene to construct the fluorescent fusion protein gene MuSK -mCherry.The recombinant vector was subsequently transfected into drosophila S 2 cells for expression.The expressed fusion proteins were verified in confocal mi-croscope ,and used as antigen in the detection of MuSKAb in sera of MG patents in fluorescence immunoprecipitation test .Results:The fluorescent fusion protein MuSK-mCherry was successfully constructed and expressed.The MuSKAb in sera of patents with MG could be detected in fluorescence immunoprecipitation test using the constructed MuSK-mCherry fusion protein as antigen.Conclusion: It is available to use the constructed fluorescent fusion protein MuSK-mCherry as antigen in fluorescence immunoprecipitation test for the detection of MuSKAb in sera of patents with MG.

Objective To investigate the effects of mannan-binding lectin(MBL) on TNF-α production induced by peptidoglycan (PGN) and its mechanism in human THP-1/CD14 monocytes.Methods The THP-1/CD14 cells were stimulated for 24 h with PGN at the indicated ratios after pretreated with human natural MBL at concentrations ranging from 1 to 20 mg/L for 2 h.The content of TNF-α and IL-6 in culture supernatants were detected by ELISA,and the levels of TNF-α and IL-6 mRNA expressions in these cells were determined by RT-PCR.FACS was used to investigate the interaction of MBL with THP-1/CD14 cells and the impact of MBL on PGN binding to THP-1/CD14 cells.Western blot was used to detect PGN-induced NF-κB translocation in THP-1/CD14 cells.Results ELISA showed that secretion of TNF-α and IL-6 from THP-1/CD14 cells could be induced by PGN ;The productions of TNF-α and IL-6 by THP-1/CD14 cells induced with PGN were profoundly inhibited by MBL at higher concentrations (10-20 mg/L) but not MBL at lower concentrations (1 mg/L).RT-PCR analysis also indicated that the mRNA expressions of TNF-α and IL-6 in THP-1/CD14 cells were decreased by MBL at higher concentration,compared to the corresponding THP-1/CD14 cells stimulated with PGN only.FACS showed that the binding of MBL to THP-1/CD14 cells was evident in a Ca2+-dependent manner.PGN could competitively inhibit the binding of MBL to THP-1/CD14 cells.MBL could competitively inhibit the binding of PGN to THP-1/CD14 cells by binding to THP-1/CD14 cells directly.Similarly,MBL at higher concentration (20 mg/L) decreased the NF-κB translocation in THP-1/CD14 cells.Conclusion MBL may inhibit TNF-α and IL-6 production induced by PGN in THP-1/CD14 cells through NF-κB signaling pathways,suggesting that MBL can play some roles in the regulation of PGN-induced inflammatory response.

Free radicals are the intermediates of metabolism,widely exist in the human bodies.Under normal circumstances,the free radicals play an important role in the metabolic process on human body,cell signal pathway,gene regulation,induction of cell proliferation and apoptosis,so as to maintain the normal growth and development of human body and to inhibit the growth of bacteria,virus and cancer.However,when organic lesion occurs affected by external factors or when equilibrium of the free radicals is tipped in the human body,the free radicals will respond integratedly with lipids,protein or nucleic acid which may jeopardize the health of human bodies.This paper summarizes the research progress of the free radicals conducted in recent years,in relations to the perspective of the types,origins,test methods of the free radicals and their relationship with human's health.In addition,the possible mechanisms of environmental pollutants (such as polycyclic aromatic hydrocarbons) mediating oxidative stress and free radicals scavenging in the body were also summarized.

Objective:To analyze measurement results of serum allergen-specific immunoglobulin E (IgE) in patients with eczema/dermatitis.Methods:A retrospective analysis was conducted on serum allergen-specific immunoglobulin E (IgE) levels in 3 051 patients with eczema/dermatitis, who visited the allergy clinic of Huashan Hospital from April 1, 2021 to March 31, 2022. The serum allergen-specific IgE level was detected by using the Phadia allergen detection system, and positive rates of allergens were calculated to determine common inhaled allergens and food allergens in patients with eczema/dermatitis. Comparisons of enumeration data between groups were performed by chi-square test.Results:Among the 3 051 patients with eczema/dermatitis, there were 1 412 with atopic dermatitis and 1 639 were other eczema/dermatitis. Detection of serum allergen-specific IgE showed that 1 629 (53%) patients were positive for allergens, and the number of positive allergen-specific IgEs in each patient was 3.0 ± 1.6. The top 3 common inhaled allergens in patients with eczema/dermatitis were Dermatophagoides farinae (904/1 522, 59%) , Dermatophagoides pteronyssinus (891/1 513, 59%) and Alternaria alternata (206/1 068, 19%) , and the top 3 common food allergens were shrimps (251/1 432, 18%) , egg white (165/992, 17%) and cow milk (149/994, 15%) . Among the 3 051 patients, 25 (1%) were aged < 2 years, 571 (19%) aged 2 - 12 years, 285 (9%) aged 12 - 18 years, and 2 170 (71%) were aged > 18 years. The most common food allergens were both egg white in the age groups of < 2 years and 2 -12 years (77%, 37%, respectively) , and were both shrimps in the age groups of 12 - 18 years and > 18 years (31%, 17%, respectively) . Dermatophagoides pteronyssinus and Dermatophagoides farina were the top 2 common inhaled allergens in all age groups, with the positive rate ranging from 36% to 84%; in addition, the positive rate of molds was relatively high in the age group of 2 - 12 years (mold mixture: 37%; Alternaria alternata: 27%) . From April 2021 to March 2022, the positive rate of outdoor allergens ranged from 10% to 15% among outpatients in every month; the positive rates of tree pollen and grass pollen increased from April 2021, and peaked in October 2021. The patients with atopic dermatitis showed a significantly increased positive rate of allergens (73%) compared with those with other eczema/dermatitis (37%, χ2 = 389.36, P<0.001) , and the rank of common allergens in the patients with atopic dermatitis was basically the same as that in those with eczema/dermatitis. Conclusions:The common allergens were Dermatophagoides farina, Dermatophagoides pteronyssinus and Alternaria alternata in the patients with eczema/dermatitis. Food allergy was more common in infant patients, and inhalation allergy was more common in child, adolescent and adult patients. The positive rate of allergen-specific IgEs was markedly higher in the patients with atopic dermatitis than in those with other eczema/dermatitis.

Objective:To investigate and analyze the epidemiological and clinical characteristics of 46 patients with corona virus disease 2019 (COVID-19) in Beijing City.Methods:A retrospective study was conducted to analyze the data of 46 patients with COVID-19 in Beijing from 20th January 2020 to 8th February 2020 at the Fifth Medical Center of the PLA General Hospital in Beijing City. Twelve, 23 and 11 patients were assigned to the mild group, common group and severe group, respectively. The epidemiological history, clinical characteristics, laboratory tests and imaging inspections were analyzed. Statistical analysis used Fisher exact test. If P<0.05, post- hoc test was used for pairwise comparison, and the statistics were corrected by Bonferroni test. Results:Among the 46 patients included in this study, 27 were male and 19 were female. The age range was between 3-79 years old, and the age was (41.8±16.3) years old. The average incubation period was (4.85±3.00) days. A total of 26 cases (56.5%) were clustered patients, and 26 cases had a history of staying in Wuhan, 10 cases had contact with Wuhan personnel. Fever (39 cases, 84.8%), cough (27 cases, 58.7%), and fatigue (25 cases, 54.3%) were the main clinical symptoms for these patients. The decrease in white blood cell counts occurred in 12 patients, four had the decrease in T lymphocyte percentage, 17 had the decrease in CD4 + T lymphocyte counts, seven had the decrease in CD8 + T lymphocyte counts, 21 had the increase level of C reactive protein (45.7%), and interleukin-6 (IL-6) level increased in 32 cases (69.6%), erythrocyte sedimentation rate (ESR) increased in 23 cases (50.0%), serum ferritin level increased in 26 cases (56.5%), and blood lactic acid level increased in nine cases. There were statistically significant differences in the proportion of cases with decreased absolute value of CD8 + T lymphocytes and T lymphocytes counts among the mild, common and severe groups (all P<0.05). Comparing the proportion of cases in the three groups with elevated C reactive protein, IL-6, ESR, serum ferritin and blood lactic acid levels, the differences were statistically significant (all P<0.05). The proportion of cases with elevated C reactive protein levels in severe group was higher than those in mild and common groups. The proportion of cases with elevated IL-6, ESR, and serum ferritin levels in severe and common group were higher than those in mild group. The proportion of cases with elevated blood lactic acid levels in severe group was higher than those in mild group. The differences between the above groups were statistically significant (all adjusted P<0.017). Analysis of chest X-rays results showed that 34 patients (73.9%) had inflammation in the lungs. Conclusions:The epidemiological characteristics of patients with COVID-19 in Beijing City are mainly imported cases and clustered cases. The clinical manifestations are mainly fever, fatigue and cough. C reactive protein, IL-6, ESR, serum ferritin and blood lactic acid levels are higher in severe patients.