1.Exploring of pH conditions for HIV detection(ELISA) in IVIG finished products
Chinese Journal of Biologicals 2024;37(12):1463-1469
Objective To explore the pH conditions for human immunodeficiency virus(HIV) detection(ELISA) in the finished products of human immunoglobulin(pH 4) for intravenous injection(IVIG), in order to control the residual HIV risk of IVIG and ensure the safety of blood products.Methods The HIV antibody reference materials and antigen reference materials were diluted to the detection limit level using different pH buffer solutions. The detection of HIV reference materials at different pH and detection limit levels by the reagent kit were observed to determine the appropriate pH detection range of the reagent kit. The pH range of the finished product was adjusted to the appropriate range of the reagent kit by using different concentrations of Tris-HCl solutions, and then the HIV antibody reference materials and HIV antigen reference materials were diluted to the detection limit level to obtain the appropriate pH detection range of the product.Results The A450/630 values of the HIV antibody reference materials and HIV antigen reference materials with detection buffer at pH 7. 0-9. 0 were similar to those of the normal saline(NS) group, and the suitable pH range for the HIV kit used was pH 7. 0-9. 0. IVIG 4. 0 was diluted with0. 1 mol/L Tris-HCl solution to the appropriate pH range of the reagent kit as the diluent. The A450/630 value of antibody 0. 25 NCU/mL in IVIG pH 7. 0-8. 0 group was higher than the cutoff value and significantly higher than that in the IVIG pH 4. 0 group.The amount of 0. 1 mol/L Tris-HCl solution added accounted for more than 1/5 of the IVIG volume. IVIG 4. 0 was diluted with 1 mol/L Tris-HCl solution to the appropriate pH range of the reagent kit as the diluent. The A450/630value of antibody 0. 25 NCU/mL and antigen 1. 5 U/mL levels was higher than the cutoff value in the IVIG pH 7. 0-9. 0 group. The amount of 1 mol/L Tris-HCl solution added was only 1/28-1/37 of the total detection volume, and had little effect on the effective detection content of the test sample.Conclusion Compared to the detection conditions of pH 4. 0, pH 7. 5-8. 0 is more suitable for HIV detection in IVIG. 1 mol/L Tris-HCl solution was used to adjust the pH of IVIG to 7. 5-8. 0 for HIV detection(ELISA)in IVIG, which effectively solves the problem that the pH bias in IVIG finished product is not conducive to HIV detection, with no effect on the detection volume of the finished product, thus significantly improving the accuracy and reliability of the detection results.
2.GC Fingerprints of High-yield Pinellia ternata from the West of Hubei Province
China Pharmacy 1991;0(03):-
OBJECTIVE:To establish a fingerprint analysis method of Pinellia ternata from the west of Hubei province.METHODS:The samples of Pinellia ternata from different areas harvested at different time and processed by different methods were analyzed by GC method to establish their fingerprint data.RESULTS: The fingerprints of Pinellia ternata have been established using GC data of the chromatographic peaks of five phytosterols from various samples,and these samples had a similarity of between 0.877 and 0.999.CONCLUSION: The fingerprints of phytosterols of Pinellia ternata are stable thus can be used as a new method for the quality control of Pinellia ternata.
3.Construction of a Questionnaire of Attitudes toward Homosexuals in Chinese University Students
Xiaobei ZHENG ; Qiumei ZHANG ; Yuebiao CHEN
Chinese Mental Health Journal 2002;0(07):-
Objective: To develop a scale to measure attitudes toward homosexuals in Chinese university students.Methods:Based on surveys and literatures, we conducted the pre-test and test for accessing the construct validity of the scale by EFA ( exploratory factor analysis) and CFA (confirmatory factor analysis) in 1010 Chinese university students.Results: There were three components that could explain 63.84% of the total variance with loading between 0.501 and 0.851 in the scale.The three components could explain 46.67%,10.27% and 6.90% of the variance separately.They were named cognitive tolerance, emotional tolerance and behavior tolerance.The scale had NFI 0.979,NNFI 0.981,CFI 0.985,RMSEA 0.073 by CFA.The Cronbach'?coefficient was 0.931 and the test-retest reliability was 0.839 (with P
4.Loneliness of University Students and Its Relationship with Serf-concealment,Serf-disclosure,Coping Style and Perceived Social Support
Miao-Zi YU ; Dong-Ping LI ; Cai-Kang WANG ; Xijun XIE ; Liumei ZHOU ; Xiaobei ZHENG ;
Chinese Mental Health Journal 2002;0(11):-
Objective:To investigate the impact of self-concealment,self-disclosure,coping style and per- ceived social support on university students'loneliness.Methods:Loneliness and related factors were assessed among 482 university students using scales including UCLA Loneliness Scale,Self-concealment Scale(SCS),Self-disclosure Index(SDI),Simplified Coping Style Questionnaire(SCSQ)and Perceived Social Support Scale(PSSS).Results: The level of university students'loneliness was not high(36.5?7.4);males experienced more loneliness than fe- males(37.4?7.5/35.4?7.3,F=8.25,P0.05). Regression analysis showed that SCS,SCSQ and PSSS predicted UCLA effectively(?=0.207,-0.218,0.157, -0.380).The testing of mediating effect indicated that SCS had direct and indirect impact on UCLA through nega- tive coping style and PSSS;SDI had only indirect impact on UCLA through positive coping style and PSSS.Conclusion:SCS,SDI,SCSQ and PSSS are important factors influencing UCLA,and the intervention of univer- sity students'loneliness should focus on these variables.
5.Enhanced production of curdlan by Alcaligenes faecalis by selective feeding with ammonia water during the cell growth phase of fermentation.
Jianrong WU ; Xiaobei ZHAN ; Hui LIU ; Zhiyong ZHENG
Chinese Journal of Biotechnology 2008;24(6):1035-1039
Curdlan is a water insoluble exopolysaccharide produced by Alcaligenes faecalis under nitrogen-limiting conditions. After excretion, the polysaccharide is attached the cell wall. Thus enhancement of biomass production during the cell growth phase is important to curdlan production. A strategy of increasing nitrogen source to improve biomass production was adopted for curdlan production by Alcaligenes faecalis (ATCC 31749). In the batch fermentation of curdlan, a relatively higher NH4Cl level of 3.6 g/L with continuous glucose feeding increased the cell density leading to improvement of curdlan production. However, excessive NH4Cl would inhibit curdlan production and biomass production was not improved significantly. In addition, feeding of ammonia water at the initial phase replaced NaOH solution to control pH at 7.0. Subsequently, feeding of NaOH solution was resumed to control pH at 5.6 for curdlan production after ammonia was consumed. As a result, biomass production and curdlan yield were both enhanced remarkably. Feeding of ammonia water during the first 24 h led to biomass production of 18.8 g/L. However, higher cell density did not lead to increase in curdlan production. The maximum curdlan production (72 g/L) was obtained by feeding ammonia water for the first 14 h, during which the cell density was about 11.9 g/L.
Alcaligenes faecalis
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cytology
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metabolism
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Ammonium Chloride
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pharmacology
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Cell Culture Techniques
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methods
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Cell Proliferation
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Fermentation
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beta-Glucans
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metabolism
6.Comparison of clinical effects of endoscopic submucosal dissection and endoscopic mucosal resection in the treatment of elderly patients with early gastric cancer
Xiaobei ZHU ; Zheng CHEN ; Yanhua HUANG
Chinese Journal of Postgraduates of Medicine 2024;47(6):531-535
Objective:To compare the clinical efficacy of endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) in the treatment of elderly patients with early gastric cancer.Methods:Ninety-two elderly patients with early gastric cancer admitted to the 923th Hospital of the Joint Service Support Force of PLA from June 2019 to February 2022 were enrolled, and they were divided into ESD group (60 cases) and EMR group (32 cases) according to different surgical methods. The ESD group was treated with ESD surgery, while the EMR group was treated with EMR surgery. The short-term clinical efficacy of the two groups was compared. The gastric function including pepsinogen Ⅰ(PGⅠ), pepsinogenⅡ(PGⅡ), PGⅠ /PGⅡ ratio and the tumor markers including carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and invasion genes within the lesion including vascular endothelial growth factor C (VEGF-C), E-cadherin, microtubule depolymerin (Stathmin), Krüppel like factor 4 (KLF4) were detected before and 3 d after surgery. Followed up for 1 year, the recurrence rate and complications between the two groups were compared.Results:All of 92 patients successfully removed the diseased tissue as a whole, and the R0 and R1 resection rate between the two groups had no statistical differences ( P>0.05). At 3 d after surgery, the levels of PG Ⅰand PGⅠ/PG Ⅱin the both groups were higher than those before surgery, and the level of PG Ⅱ in the both groups was lower than that before surgery; the levels of PG Ⅰand PGⅠ/PG Ⅱ in the ESD group were higher than those in the EMR group: (86.50 ± 8.23) μg/L vs. (77.47 ± 7.40) μg/L, 5.29 ± 0.54 vs. 3.65 ± 0.50; the level of PG Ⅱ ratio in the ESD group was lower than that in the EMR group: (16.34 ± 3.05) μg/L vs. (21.20 ± 3.27) μg/L, there were statistical differences ( P<0.05). At 3 d after surgery, the levels of CEA, CA19-9 and CA125 in the two groups were decreased, and the levels of the above indicators in the ESD group were lower than those in the EMR group: (2.42 ± 0.45) μg/L vs. (3.29 ± 0.40) μg/L, (8.55 ± 2.10) kU/L vs. (10.62 ± 2.76) kU/L, (13.75 ± 4.28) kU/L vs. (17.20 ± 4.90) kU/L, there were statistical differences ( P<0.05). At 3 d after surgery, the mRNA expression of E-cadherin and KLF4 in the two groups were increased, and the mRNA expression of VEGF-C, Stathmin in the two groups were decreased, and the mRNA expression of E-cadherin and KLF4 in the ESD group were lower than those in the EMR group: 2.89 ± 0.31 vs. 3.03 ± 0.21, 2.90 ± 0.28 vs. 3.12 ± 0.37, and the mRNA expression of VEGF-C, Stathmin in the ESD group were higher than those in the EMR group: 0.45 ± 0.11 vs. 0.41 ± 0.07, 0.52 ± 0.23 vs. 0.43 ± 0.09, there were statistical differences ( P<0.05). The complication rate in the ESD group was lower than that in the EMR group: 5.00%(3/60) vs. 23.33% (14/60) , there was statistical difference ( χ2 = 8.32, P<0.01). The recurrence rate in the 1-year between the two groups had no statistical difference ( P>0.05). Conclusions:Compared with EMR, ESD is effective in the treatment of elderly early gastric cancer, which can better correct the abnormal secretion of pepsinogen, promote the functional recovery of gastric cells and glands, reduce the level of serum tumor markers, inhibit the metastasis and proliferation of tumor cells, and has good safety.
7.Characteristics of subtypes and transmission of HIV-1 infected persons among student MSM in Zhejiang province, 2013-2015
Xiaobei DING ; Xiaohong PAN ; Jiafeng ZHANG ; Lin HE ; Jun JIANG ; Qin FAN ; Wanjun CHEN ; Lin ZHENG ; Yan LUO ; Jianning LIU ; Zhihong GUO ; Jiaming YAO
Chinese Journal of Epidemiology 2020;41(6):940-945
Objective:To investigate the characteristics of subtype diversity and transmission on HIV-1 among 12 to 30 years old student MSM in Zhejiang province.Methods:A total of 290 newly diagnosed HIV infected student MSM were selected as the research objects for molecular studies on HIV, in Zhejiang province during 2013 to 2015. Data on epidemiology and plasma samples of these people were collected. HIV-1 nucleotide sequences of pol gene regions were amplified using the RT-PCR/nested PCR method and sequenced. Phylogenetic analysis was performed to determine the HIV-1 genotypes. Characteristics of transmission mode among these cases were also analyzed. Results:A total of 290 cases, 50.3 % were diagnosed in Hangzhou and 81.0 % had college or above degrees. 178 sequences including 10 subtypes, were obtained, with the main subtypes as CRF01_AE (49.4 %, 88/178) and CRF07_BC (39.3 %, 70/178). A total of 18 molecular transmission clusters were formed (42 cases, cluster size from 2 to 4), with the proportions of clusters as 23.6 % (42/178). 61.9 % (26/42) of student MSM with their schools located in the same district within the transmission clusters. Their sexual partners would include both student MSM and non-student MSM. The proportion of clusters among middle school students was 38.2 % (13/34), higher than that of college students (20.1 %, 29/144) ( χ2=4.996, P<0.05). Conclusions:The HIV-1 subtypes of student MSM in Zhejiang province appeared diversity, which indicated with the diversity of sources of infection. The geographical distribution of cluster cases is relatively centralized. In order to effectively control the spread of AIDS, more attention should be paid to the sexual partners involved and to specific programs on intervention.
8.Establishment and methodological validation of a nucleic acid detection method for human parvovirus B19
Yue WANG ; Xiaobei ZHENG ; Yajing ZHENG ; Yu SUN ; Qin GONG ; Linlin ZHANG ; Ying ZHAO ; Dandan YANG ; Yi YANG ; Lin LI ; Boran LI ; Jin ZHANG
Chinese Journal of Blood Transfusion 2024;37(11):1234-1240
[Objective] To establish a real-time fluorescence quantitative PCR nucleic acid detection method of human parvovirus B19 and validate the method systematically. [Methods] Specific primers and probes for the highly conserved regions of the three genotypes of B19 virus were designed, and B19 quantitative amplification standard curves were established. The accuracy, precision (repeatability and intermediate precision), linear range, quantification limit, detection limit, specificity, anti cross contamination, genotyping and anti-interference ability of this method were verified. [Results] When the quantitative reference range for B19 virus was 2.0×101 to 1.0×108 IU/mL, a double logarithmic regression analysis was performed between the measured values and the theoretical values, and the regression equation R2≥0.98 showed good linear correlation. The quantification limit was 20 IU/mL, with a detection rate of 100%. The detection limit was 10 IU/mL, and the detection rate is 95.23%. Three genotypes of B19 virus samples can be effectively detected. The plasma of seven non B19 pathogens, including hepatitis A virus, hepatitis B virus, hepatitis C virus, human immuno-deficiency virus, human cytomegalovirus, hepatitis E virus and Treponema pallidum, was non reactive and has good species specificity. Simultaneously, in the presence of seven other concurrent pathogens, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. When the hemoglobin concentration was 431 mg/dL, triglycerides (1 269 turbidity) and unconjugated bilirubin concentration was 20 mg/dL, this method was non reactive for all three common plasma interfering substances. In the presence of three common plasma interfering substances, positive samples with a weak positive concentration of E3 IU/mL could be stably detected, and the B19 nucleic acid testing method was not interfered with. The deviation between the detection values of standard substances at two concentration levels of S1 (E5 IU/mL) and S2 (E4 IU/mL) and the target values were≤±0.5 log value. The CV values of positive sample 1 (concentration level E5 IU/mL) and positive sample 2 (concentration level E4 IU/mL) for daily precision confirmation and continuous 5-day intra-day precision confirmation were both≤5%. [Conclusion] This method has strong specificity, high sensitivity, wide linear range, stability, reliability and high accuracy, and can be used for the detection of human parvovirus B19 nucleic acid in plasma.