Detection and analysis of antibodies against SARS-CoV-2 in blood donors at different periods in Guangzhou / 中国输血杂志

【Objective】 To detect the anti-SARS-CoV-2 antibody levels in blood donors in Guangzhou, so as to provide laboratory data support for the collection and clinical use of convalescent plasma. 【Methods】 Anti-SARS-CoV-2 antibodies were measured by ELISA in qualified donors. Among them, 326 donors who gave blood in February 2023 were tested for IgG antibodies, 444 donors were tested for neutralizing antibodies. In July 2023, 398 donors were tested for IgG and IgM. 【Results】 399 of 724 blood samples diluted with normal saline (1∶160) were IgG reactive, with a reactive rate of 55.11%. Chi-square test showed that there was a significant difference in the reactive rate of IgG among samples collected at different times (25.46% in February vs 79.40% in July, χ2=210.74, P<0.01, 95%CI: 7.97, 15.98), but there was no significant difference in the reactive rate between different genders and different age groups. IgM was detected in 5 of 398 blood samples, with a reactive rate of 1.26%. The IgG test results of these five blood donors were all reactive, whereas the nucleic acid test results were negative. Neutralizing antibody was detected in 440 of 444 blood samples, with a reactive rate of 99.10%, and 71.59% of the reactive donors had a neutralizing antibody level of 10 μg/mL or more. 【Conclusion】 Blood donors in Guangzhou have a high level of SARS-CoV-2 antibody, which is sufficient to provide convalescent plasma for clinical treatment.

Viral selection pressure and CD4+T cell epitope in HLA-DRB1 * 11:01 of HCV infected patients / 中国输血杂志

【Objective】 HLA-DRB1 * 11:01, as a class HLA-Ⅱ gene, was reported to be associated with spontaneous clearance of HCV in Han and Li population. Our study was to investigate the effects of viral selection pressure and CD4+T cell epitope on the natural outcome of HCV infection in HLA-DRB1 * 11:01 positive infected patients. 【Methods】 The positive selection sites and population growth of E1E2 and NS3 genes of common HCV 6a in HLA-DRB1 * 11:01 positive and negative groups in Guangdong were respectively analyzed. The peptide library covering the conserved regions of common HCV genotypes was used to stimulate HCV spontaneous clearance group and chronic infection group using ELISPOT method. Reactive peptides were obtained according to the number of spot-forming cells per well and the frequency of occurrence in different groups. 【Results】 The positive selection sites (PSSs) of E1E2 and NS3 of common HCV 6a in HLA-DRB1 * 11:01 negative group were greater than those in HLA-DRB1 * 11:01 positive group. Furthermore, the number of PPSs in CD4+T cell peptide in HLA-DRB1 * 11:01 negative group were also greater than those in HLA-DRB1 * 11:01 positive group; Both groups of HCV 6a had a population growth in Guangdong, and the expansion trend of HLA-DRB1 * 11:01 negative group was significantly higher than that of HLA-DRB1 * 11 :01 positive group. Compared to HCV chronic infection group, the response rate of HCV spontaneous clearance group to five peptides (C-52 E2691-707, C-119 NS31545-1560, C-134 NS4A1669-1684, C-154 NS4B1912-1927, C-159 NS4B1929-1944) was higher. However, the HCV chronic infection group showed a higher response rate to two of the peptides(C-111 NS31497-1512, C-130 NS31650-1665). When HLA-DRB1 * 11:01 typing was considered, there was no significant difference in HCV-specific immune response generated by PBMCs between HLA-DRB1 * 11:01 positive and HLA-DRB1 * 11:01 negative groups. 【Conclusion】 This study revealed the relationship between viral selection pressure of HLA-DRB1 * 11:01 HCV infected persons and CD4+T cell antigen epitopes. At the same time, CD4+ T cell antigen epitopes of HCV pan-genotype were obtained, providing basic data for the development of T cell vaccine suitable for HCV pan-genotype.

Preliminary identification of CD4 T cell epitopes in genotype 1 and 6 of hepatitis C virus / 中国输血杂志

【Objective】 To study the CD4 T cell epitopes in Core and NS3 protein of genotype 1(GT1) and 6(GT6) of hepatitis C virus(HCV). 【Methods】 A total of 298 overlapping peptides(16-mer) spanning Core and NS3 protein of GT1 and GT6 HCV were synthesized. Peripheral blood mononuclear cells(PBMCs) from 17 HCV+ and 7 healthy blood donors were stimulated by peptide pools, followed by evaluating T cell response by IFN-γ ELISPOT, by which 21 peptides with positive results were found. These peptides were further applied to individually stimulate 20 HCV+ and 18 healthy PBMCs. The differences of responsive frequencies to the 21 positive peptides between the two study groups were compared. 【Results】 Pooled and individual peptide stimulation tests showed that HCV+ PBMCs were responsive to the stimulation of 5 peptides(GT1 NS31273-1288 and NS31315-1330; GT6 NS31033-1048, NS31087-1102 and NS31351-1366), with a responsive frequency ranging 18.9%-27.0%. In contrast, healthy PBMCs were not or low responsive(0%-4.0%) to these five peptides. The responsive frequencies were statistically different between the two groups(P<0.05). No reported epitopes in IEDB were found identical with these 5 peptides via sequence alignment. 【Conclusion】 Our study identified novel CD4 T cell epitopes in NS3 protein of GT1 and GT6 HCV, which has potential application value for the research and development of HCV vaccine.

HCV evolution and positive selection sites of HCV NS5B region among intravenous drug users in Guangdong / 中国输血杂志

【Objective】 To learn the situation of the evolution process of HCV virus population and the selection pressure of HCV NS5B in intravenous drug users (IDUs) in Guangdong. 【Methods】 141 blood samples from hepatitis C virus (HCV) RNA-positive blood donors and 58 from HCV patients in Guangdong were randomly collected for HCV NS5B sequence amplification, combined with HCV NS5B sequences from blood donors and IDUs obtained by sequencing previously(between 2009 and 2011). Homology analysis was performed by Molecular Evolutionary Genetics Analysis (MEGA) software, evolutionary analysis were performed by Bayesian Evolutionary Analysis Sampling Trees (BEAST) software package. Selection pressure analysis was performed on sequences isolated from IDUs by Datamonkey online software package with Mixed Effects Model Evolution (MEME) method, and the population expansion of species were analyzed using Tajima and Fu neutrality test by Arlequin software. 【Results】 The comparison results of internal homology among different subtypes of IDUs in this group were as follows : HCV-3b had the highest homology (97%), followed by HCV-3a (96%), HCV-6a (95%) and HCV-1b (94%); HCV evolution rate analysis showed that HCV-1b had the fastest evolution rate [2.17E-03 substitutions/site/year (y/y/y)], followed by HCV-3b (2.12E-0 y/y/y), HCV-3a (1.58E-03 y/y/y) and HCV-6a (1.28E-03 y/y/y). The analysis on effective population of HCV: 1980~1990 was rapid growth period for HCV-6a, 1990~1995 period for HCV-1b, and 2000~2007 period for HCV-3a. HCV population genetic characteristics was as follows: HCV-1b, 3a, 3b and 6a experienced population expansion, among which 3a and 3b were the most obvious. As to the analysis of HCV selection pressure, two positive selection sites (235 and 243)were found in the 339 nucleotide fragment of the NS5B sequence in injecting drug users, but mutation only occurred at position 316 [mutation rate 1.24% (14/1 130)] among 5 direct antiviral drug (DAA) sites in this gene. 【Conclusion】 The evolution of HCV-3b in Guangdong has showed an obvious trend of population expansion, with a high proportion and homology especially in the local IDUs. HCV-3b should be the focus of HCV prevention and control in this region. Given that the positively selected sites of the HCV NS5B gene region of IDUs in Guangdong are non-DAA binding sites, DAA is expected to demonstrate a good effect on these patients.

CMV-IgG yeild in Guangzhou blood donors and comparison of different test reagents / 中国输血杂志

【Objective】 To investigate the CMV-IgG positive yeild among blood donors in Guangzhou and explore the differences in the efficacy of three test reagents, aimed at improving blood safety and service capacity of blood centers. 【Methods】 A total of 630 blood samples from eligible blood donors from July to October 2020 in our center were randomly selected and screened for CMV-IgG by one ELISA reagent.Among them, 180 samples were tested in parallel using three reagents (two ELISA reagents and one ECLIA reagent), and those tested negative were conducted quantitative CMV-DNA detection.The test results of different reagents were compared and analyzed. 【Results】 Out of the 630 samples, a total of 598 positive samples were screened out, including 180 samples yielded by three reagents, 171 and 175 by the two ELISA reagents, respectively, and 175 by ECLIA.The results given by three reagents were consistent (Kappa>0.4), and no significant difference in the positive yeild by three reagents was found.In the 180 samples, 11 were negative, among which 3, 2 and 6 samples were negative by all three reagents, two reagents and one reagent (ELISA), respectively.All the 11 samples were tested negative for CMV-DNA. 【Conclusion】 The yeild of positive CMV-IgG in blood donors was 94.9% (598/630), suggesting a high prevalence of CMV in Guangzhou. CMV serologically negative blood should be considered when providing blood products to immunocompromised patients to improve the safety of recipients.The detection results of ELISA reagents and ECLIA reagent for CMV- IgG are consistent, but ECLIA reagent has better detection efficacy.

Correlation of peripheral myeloid-derived suppressor cells with hepatitis c virus infection / 中国输血杂志

【Objective】 To investigate the correlation of peripheral myeloid-derived suppressor cells (MDSC) with hepatitis c virus (HCV) infection. 【Methods】 109 voluntary blood donors who donated blood during February 2018 to September 2020 at Guangzhou Blood Center were recruited in this study. They were assigned to chronic hepatitis c (CHC) group (n=48), spontaneous clearance (SC) group (n=29) and healthy donors (control) group (n=32) according to the results of anti-HCV and HCV RNA tests. Blood samples were drawn from the participants and peripheral blood mononuclear cells (PBMC) were freshly isolated, followed by staining with fluorescently-labeled antibody against cell surface markers of MDSC, which were then applied to the detection of monocytic- (M) and polymorphonuclear (PMN)-MDSC by flow cytometry. Parameters for liver function including alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), total bilirubin (TBIL) and direct bilirubin (DBIL) were also measured. One-way ANOVA tests were applied to compare the differences of M- and PMN-MDSC and liver function between three study groups. For pairwise comparisons, P values were adjusted for multiple comparisons by Bonferroni correction (Pc). 【Results】 The frequencies of M-MDSC (%) in CHC, SC and HC were 1.39±0.86, 0.85±0.63 and 0.57±0.23, respectively (P0.05). In addition, AST (34.4±19.2 vs 23.0±7.78 U/L) and GGT (40.8±31.4 vs 22.3±7.40 U/L) level were higher in CHC compared with control (Pc<0.05 and Pc<0.01, respectively). 【Conclusion】 The level of peripheral M-MDSC was significantly elevated in chronic HCV infected donors, which would related to the progression of chronicity after HCV infection.

Advances in genetics research in the pathogenesis of amyotrophic lateral sclerosis / 中南大学学报(医学版)

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease affecting the upper and lower motor neurons. It is characterized by progressive muscle weakness, atrophy and ultimate death due to dysphagia and dyspnea. There are many causes of ALS, among which the genetic factors show great relevance. Imbalance of protein homeostasis in neurons, prion-like proliferation and propagation of abnormal proteins, mitochondrial dysfunction, glutamate mediated excitotoxicity, and intraneuronal substance transport disorders are recognized as the pathogenesis.The study on gene mutation related to pathogenesis will bridge the molecular and cellular research of ALS, which can deepen the understanding of the occurrence and development of ALS and the role of gene mutation in ALS, and provide new ideas and enlightenment for the treatment of ALS.

Full-length sequencing and baseline resistance-associated substitution of hepatitis C virus subtype 3b / 临床肝胆病杂志

ObjectiveTo investigate the application of next-generation sequencing (NGS) in determining the full-length sequence and baseline resistance-associated substitution (RAS) of hepatitis C virus (HCV) subtype 3b. MethodsNucleic acid was extracted from plasma of a HCV RNA-positive blood donor, and after sequence-independent amplification, a sequencing library was constructed and NGS was performed using Illumina Hiseq. Bioinformatics methods were used to analyze full-length HCV sequence, viral genotype, and baseline RAS to direct-acting antivirals (DAAs). ResultsA total of 8.4 Gb data with more than 56 million reads were obtained. The full-length HCV sequence was obtained by bioinformatics analysis, with an average sequencing depth of 488 007 and a genotype of 3b subtype. A total of 12 RASs were identified in HCV amino acid sequence, i.e., Y56H, Q80K, Q80R, and A156G located in NS3, M28G, Q/A30G, Q/A30K, L31F, L31M, and Y93H located in NS5A, and S282T and V321A located in NS5B, among which Q/A30K and L31M located in NS5A had high frequencies of 99.16% and 98.37%, respectively, while the other 10 RASs had low frequencies of ＜0.5%. ConclusionNGS can be used to determine the full-length sequence and genotype of HCV subtype 3b and identify baseline RASs, which has great significance in the epidemiological study of HCV subtype 3b and the development of DAA treatment regimens.

Mutations of G38R and D40G cause amyotrophic lateral sclerosis by reducing Annexin A11 protein stability / 中南大学学报(医学版)

To explore the role of the mutations G38R and D40G of Annexin A11 (ANXA11) in the onset of amyotrophic lateral sclerosis (ALS).
 Methods: The plasmids expressing ANXA11 wild type protein, ANXA11 G38R protein and ANXA11 D40G protein were constructed, respectively. The recombinant plasmids were then transfected into HEK293 cells respectively followed by cycloheximide (CHX) treatment for 0, 2, 4 and 8 h. The protein expressions of ANXA11 wild type, ANXA11 G38R and ANXA11 D40G mutations were determined by Western blot. Gray analysis by Image J was performed to compare the half-life of each protein. The NSC-34 cell lines constantly expressing ANXA11 wild type protein, ANXA11 G38R protein and ANXA11 D40G protein were established. The cells were treated with NP-40 lysis buffer to examine the protein solubility by Western blot.
 Results: Both ANXA11 G38R protein and ANXA11 D40G protein showed a shorter half-life than ANXA11 wild type protein (P0.05). There was no visible insoluble substance in the NP-40 lysates for ANXA11 wild type protein, ANXA11 G38R protein and ANXA11 D40G protein.
 Conclusion: G38R and D40G mutations reduce the stability of ANXA11 protein. G38R and D40G mutations do not alter ANXA11 solubility.

Correlation of IL-28B gene polymorphism and natural outcome of hepatitis C / 中国免疫学杂志

Objective:To explore the association between interleukin(IL)-28B single nucleotide polymorphisms and natural outcome of hepatitis C virus.Methods:The IL-28B rs12979860 locus was genotyped in 266 HCV infected volunteer blood donors(107 spontaneous cleared and 159 chronic infection) and 97 healthy controls using Sanger sequencing assay.The difference in rs12979860 genotypes and allele frequencies between the six groups(107 spontaneous cleared and 159 chronic infection,266 HCV infection and 97 healthy controls,159 chronic infection and 97 healthy controls) were analyzed by statistics.Results:159 HCV chronic infection,107 spontaneous cleared and 97 healthy controls,were shown more CC genotype,accounting for 83.6%,95.3%and 86.6%,respectively, while the CT genotype accounted for 16.4%,4.7%and 13.4%respectively.No TT genotype was found.The CC/CT genotype was not significant difference between HCV infection and healthy controls,chronic infection and healthy controls(χ2=0.204,P=0.652;χ2=0.406,P=0.524),but between chronic infections and spontaneous clearance had statistically significant(χ2=8.474,P=0.004),the frequence of C allele in spontaneous cleared was higher than HCV chronic infection(χ2=7.949,P=0.005).Conclusion: The gene polymorphism of IL-28B rs12979860 is not related to HCV susceptibility,but there are differences in chronic infection and spontaneous cleared,showing the C allelic in favor of HCV spontaneous cleaed.

Pharmacokinetics behavior of raltitrexed in rats after repeatedly injected with Huangqi injection / 中国中药杂志

In this study, the variation of pharmacokinetics behavior of raltitrexed (RTX) in rats after repeatedly injected with Huangqi injection was investigated. Twelve SD rats were divided into two groups: the multidose group and the RTX group. Rats in multidose group were iv. injected with Huangqi injection (dose of 1.575 mL x kg(-1)) everyday at 8 am for a week, and had free accesses for food and water. The rats were fasted for food but not water since 8 h before the eighth day. At the eighth morning, firstly, rats were injected with Huangqi injection (dose of 1.575 mL x kg(-1)), and 5 min later, were injected with RTX (dose of 0.467 mg x kg(-1)); rats in RTX group were not disposed in the previous seven days, also had free accesses for food and water, and were iv. injected with raltitrexed at the same time as Multidose group at the eighth day morning. Rat plasma was collected at different time and processed with methanol to precipitate the protein before HPLC assays. The pharmacokinetics parameters for two groups were calculated by software 3P97. Through the observation of drug concentration in plasma and time curve, we found that at almost every time point the concentration of RTX in plasma in multidose group was lower than the RTX group. When comparing the pharmacokinetics parameters between the multidose group and the RTX group, the average of AUC(0-t) and half-life(t1/2) of multidose group were decreased from 56 080 microg x min x L(-1) and 15.07 min to 35 834 microg x min x L(-1) and 8.95 min, respectively, while the clearance (CL) was increased from 0.51 to 0.83 mL x h(-1). Therefore, it could be deduced that repeatedly injected with AR injection may influence the renal excretion and glycometabolism of RTX, thus change pharmacokinetics behavior of raltitrexed in rats plasma. This result may give us a hint to prudantly manage the drug combination of RTX and Huangqi injection.

The transplantation of latissimus dorsi flap of the base of T shape artery with the pedicle of the thoracodorsal artery / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the possibility that the free latissimus dorsi musculo-cutaneous flap to repair the forearm leg wound.</p><p><b>METHODS</b>To design latissimus dorsi musculo-cutaneous flap which is foundation on T form thoracodorsal artery stalk. To set the short arm into the receiver artery break and anastomos them. It is not only reassure the blood of free musculo-cutaneous flap, but also reconstruct the continuation of the receiver main artery.</p><p><b>RESULTS</b>In 16 patients, 15 patients success completely, 1 patient main success. The blood supply of receiver is adequate.</p><p><b>CONCLUSIONS</b>The free T form thoracodorsal artery stalk musculo-cutaneous flap free grafting is a good method to repair the skin and soft tissues defection of forearm and leg.</p>