Objective To assess the impact of freeze-drying and dry heat virus inactivation processes on the activity ofα2-macroglobulin(A2M)derived from human plasma Cohn fraction Ⅳ.Methods A2M derived from human plasma Cohn fraction Ⅳ was prepared and subjected to programmed freeze-drying with dry heat virus inactivation.The lyophilized products were evaluated for their appearance,water content,and validation of the viral inactivation process.The bioactivity of the products before and after lyophilization as well as before and after dry heat inactivation was determined via trypsin inhibition,and the comparisons were studied.Results The appearance of the lyophilized product was fluffy,and the water content was(5.83±0.45)％.The specific activities of the samples before and after lyophilization were(10.199±0.137)and(10.033±0.201)μg/mg,respectively,with no statistically significantdifference between the two groups(P＞0.05).The viral inactivation of the samples was carried out by using dry heat inactivation conditions at 100 ℃ for 30 min.After inactivation,the reduction was ≥5.125 LgTCID50/0.1 mL in Pseudorabies virus(PRV)titers,≥4.500 LgTCID50/0.1 mL in Sindbis virus(SinV)titers,≥6.375 LgTCID50/0.1 mL in encephalomyocarditis virus(EMCV)titers,and≥4.500 LgTCID50/0.1 mL in porcine parvovirus(PPV)titers.The specific activities of the samples before and after dry heat were(9.921±0.292)and(10.091±0.278)μ g/mg,respectively,with no statistically significant difference between the two groups.Conclusion A2M derived from human plasma Cohn fraction Ⅳ,when subjected to freeze-drying followed by dry heat inactivation at 100 ℃ for 30 minutes,can effectively inactivate viruses without altering the biological activity of the product.

α2-Macroglobulin(A2M)is a high-abundance plasma protein with a molecular weight of 720×103,containing 1451 residues and 11 domains,and was isolated and identified for the first time in 1946.The capture and inhibitory effect on proteases is the classical biological function of A2M.However,A2M can also interact with membrane receptors,cytokines,and growth factors,and act as a molecular chaperone to affect extracellular protein homeostasis so that it is involved in a wide range of physiological and pathological processes such as immunity,inflammation,and degeneration.This article reviews the structural characteristics of A2M,the reported molecular targets,the mechanism of action,and its biological effects in the hope of providing a new line of thought for the functional exploration and clinical applications of A2M.

Objective:To describe the epidemiological characteristics and changes of febrile seizure(FS)among children under 6 years old in Ningbo City,Zhejiang Province from 2015 to 2021.Methods:Based on the Ningbo Regional Health Information Platform,a dynamic cohort was established using vacci-nation registration information,and the cases of FS were identified by the diagnostic results of Chinese terms or International Classification of Diseases 10th revision(ICD-10)R56.0 code in the electronic medical records.The first visit of FS during the observation period was defined as a new case,and a re-currence case was defined as the case with a visit interval of more than 7 days.The 95％confidence in-terval(CI)of FS incidence density was calculated by the Poisson distribution.Results:From January 2015 to June 2020,there were 1.3 million children under 6 years old in Ningbo,with male accounting for 52.87％.The median follow-up time was 2.83(1.55-4.00)years.During the follow-up period,12 776 new onset cases had FS,with more males than females,with an overall incidence density of 4.34(95％CI:4.27-4.40)/1 000 person-years and a recurrence rate of 21.63％.There was a higher inci-dence density in children who were male,born in Ningbo and of non-mobility.The incidence density of FS was higher in urban areas than in rural and rural-urban fringe areas,and the incidence density was different among districts and counties.The peak density was found in children aged 18-23 months[8.42(95％CI:8.11-8.74)/1 000 person-years].From 2015 to 2019,the incidence density in-creased with calendar year(Ptrend＜0.001),and the highest was 5.62(95％CI:5.43-5.81)/1 000 person-years.The incidence density of FS decreased significantly during the period between 2020 and 2021.The incidence density was higher in winter.Conclusion:From 2015 to 2019,the overall inci-dence density of FS in children under 6 years old in Ningbo City presented an increasing trend.More at-tention should be paid to the health education,the improvement of the health maintenance model,the en-hancement of the cognition of FS,the identification and treatment of FS among high-risk population and regions so as to prevent its recurrence and reduce the disease burden during the corona virus disease 2019(COVID-19)epide-mic.

Objective:To describe the epidemiological characteristics and changes of febrile seizure(FS)among children under 6 years old in Ningbo City,Zhejiang Province from 2015 to 2021.Methods:Based on the Ningbo Regional Health Information Platform,a dynamic cohort was established using vacci-nation registration information,and the cases of FS were identified by the diagnostic results of Chinese terms or International Classification of Diseases 10th revision(ICD-10)R56.0 code in the electronic medical records.The first visit of FS during the observation period was defined as a new case,and a re-currence case was defined as the case with a visit interval of more than 7 days.The 95％confidence in-terval(CI)of FS incidence density was calculated by the Poisson distribution.Results:From January 2015 to June 2020,there were 1.3 million children under 6 years old in Ningbo,with male accounting for 52.87％.The median follow-up time was 2.83(1.55-4.00)years.During the follow-up period,12 776 new onset cases had FS,with more males than females,with an overall incidence density of 4.34(95％CI:4.27-4.40)/1 000 person-years and a recurrence rate of 21.63％.There was a higher inci-dence density in children who were male,born in Ningbo and of non-mobility.The incidence density of FS was higher in urban areas than in rural and rural-urban fringe areas,and the incidence density was different among districts and counties.The peak density was found in children aged 18-23 months[8.42(95％CI:8.11-8.74)/1 000 person-years].From 2015 to 2019,the incidence density in-creased with calendar year(Ptrend＜0.001),and the highest was 5.62(95％CI:5.43-5.81)/1 000 person-years.The incidence density of FS decreased significantly during the period between 2020 and 2021.The incidence density was higher in winter.Conclusion:From 2015 to 2019,the overall inci-dence density of FS in children under 6 years old in Ningbo City presented an increasing trend.More at-tention should be paid to the health education,the improvement of the health maintenance model,the en-hancement of the cognition of FS,the identification and treatment of FS among high-risk population and regions so as to prevent its recurrence and reduce the disease burden during the corona virus disease 2019(COVID-19)epide-mic.

【Objective】 To establish and evaluate a fluorescent antibody to membrane antigen (FAMA) method for detecting antibodies against varicella-zoster virus (VZV) based on Vero E6 cells. 【Methods】 Based on the adapted VZV-Oka-E6 strain that VZV-Oka live attenuated varicella vaccine strain grew in Vero E6 cells, Vero E6 cells were infected with VZV-Oka-E6 of three different doses (10^4.65, 10^4.95 and 10^5.25 TCID50), and the cytopathic effect was observed under a microscope to determine the optimal infection dose of VZV-Oka-E6 strain. Then the detectable sensitivity of the infected cell antigen slides prepared after fixing the infected cells with different fixatives was compared to determine the optimal fixative. As a result, the FAMA method based on Vero E6 cells for the determination of neutralizing anti-VZV has been developed. The established FAMA assay was used to detect the international standard for varicella zoster immunoglobulin with different titers to determine the sensitivity of the assay. The specificity of the assay was evaluated by detecting specific antibodies against human herpes simplex virus (HSV) type 1 and type 2. The neutralizing anti-VZV antibodies of the international standard for varicella zoster immunoglobulin were detected using VZV-infected cell antigen slides prepared in the same batch and four different batches, respectively, to determine the intra-assay repeatability and inter-assay repeatability. The international standard for varicella zoster immunoglobulin with three known titers was detected to evaluate the relative accuracy of this assay. The anti-VZV titers in 20 apheresis plasma samples were determined with the newly established FAMA test and ELISA test, respectively, and the detection results of the two methods were compared using Spearman’s correlation test. 【Results】 The optimal infection dose of the VZV-Oka-E6 strain in FAMA assay was determined to be 10^5.25 TCID50, and acetone precooled at -20℃ was used as the fixative. The FAMA test has a high sensitivity with a detecting limit of 31.25 mIU/mL for neutralizing anti-VZV titers. The negative result was observed when detecting herpes simplex virus (HSV) type 1 and 2 specific antibodies. The international standard for varicella zoster immunoglobulin was detected by VZV infected cell antigen slides prepared in the same batch and 4 different batches, with the coefficient of variation being 29.95% and 26.71%, respectively. The detection value of the international standard for varicella zoster immunoglobulin with three different titer levels was consistent with their theoretical value. The correlation coefficient of the detection results of 20 apheresis plasma samples by the FAMA test and ELISA test was 0.268. 【Conclusion】 The VZV FAMA assay has good sensitivity, specificity, repeatability, and relative accuracy in detecting neutralizing anti-VZV titers. It can be applied for detecting neutralizing anti-VZV titers in apheresis plasma samples as well as the varicella-zoster immunoglobulin (VZIG) preparations.

Postzygotic mutations are acquired in normal tissues throughout an individual's lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using optimized ultra-deep exome sequencing of the time-series samples from the same volunteer as well as the samples from different individuals.In blood,sperm,and muscle cells,we resolved three common types of mutational signatures.Signatures A and B represent clock-like mutational processes,and the polymorphisms of epigenetic regulation genes influence the pro-portion of signature B in mutation profiles.Notably,signature C,characterized by C＞T transitions at GpCpN sites,tends to be a feature of diverse normal tissues.Mutations of this type are likely to occur early during embryonic development,supported by their relatively high allelic frequencies,presence in multiple tissues,and decrease in occurrence with age.Almost none of the public datasets for tumors feature this signature,except for 19.6％of samples of clear cell renal cell carcinoma with increased activation of the hypoxia-inducible factor 1(HIF-1)signaling pathway.Moreover,the accumulation of signature C in the mutation profile was accelerated in a human embryonic stem cell line with drug-induced activation of HIF-1α.Thus,embryonic hypoxia may explain this novel signature across multiple normal tissues.Our study suggests that hypoxic condition in an early stage of embryonic development is a crucial factor inducing C＞T transitions at GpCpN sites;and indi-viduals'genetic background may also influence their postzygotic mutation profiles.

Objective To investigate the mechanism by which hydrogen(H2) helps prevent acute lung injury induced by hyperoxia (HALI) in rats.Methods Thirty male Sprague-Dawley rats were randomly divided into three groups: control group, HALI group and H2 group, with 10 rats in each group.The control group was exposed to air at atmospheric pressure.Rats in HALI and H2 groups were exposed continuously to pure oxygen (100%O2) for 60 hours and during this period, 10 ml/kg of normal saline or H2-saturated normal saline was given every 12 hours by intraperitoneal injection to the HALI and H2 groups, respectively.After treatment, the arterial partial pressure of oxygen was examined and histopathological examination was conducted in each group.Then,RT-qPCR and Western blotting were performed to measure the transcriptional level and protein expression of heme oxygenase 1 (human heme oxygenase 1, HO-1) in rat lung tissue.Results Compared with the HALI group, H2 group showed significantly decreased severity of lung injury and a marked increase in the arterial oxygen saturation.Besides, H2 treatment induced up-regulation of HO-1 mRNA and protein levels.Conclusion The findings suggest that HO-1 may play an important role in the protection against HALI by H2.

OBJECTIVETo evaluate the reliability and validity of Professional Quality of Life Scale (ProQOL-30, 4th version, 30 items) among government staff in the Wenchuan earthquake-stricken areas

METHODSA total of 1,175 members of government staff in the Wenchuan earthquake-stricken areas were selected by convenience sampling and required to complete the ProQOL and Self-Reporting Questionnair (SRQ). The reliability and validity of the scale was evaluated by correlation analysis, t-test, and confirmatory factor analysis.

RESULTSItem-total correlation coefficients of the three subscales were 0.590 - 0.752, 0.389 - 0.603, and 0.340 - 0.647, respectively (P<0.05), and the average coefficients were 0.672, 0.482, and 0.555 respectively (P<0.05). The Cronbach's α coefficients of the three subscales were 0.864, 0.569, and 0.742 respectively, and the split-half reliabilities were 0.829, 0.490, and 0.677, respectively. P value was 0.88 in thE chi-square test of confirmatory factor analysis model. Goodness-of-fit indices of ProQOL-30 included GFI=0.895 NFI=0.856, CFI=0.895, RMSEA=0.063, and AGFI=0.912. For the ProQOL-28 as an optimized version o ProQOL-30, the Cronbach's a coefficients for burnout and trauma/compassion fatigue increased to 0.616 and 0.757, respectively. P value was 0.91 in the chi-square test of confirmatory factor analysis model test. Goodness-of-fit indices of ProQOL-28 were GFI =0.913, AGFI =0.924, NFI =0.900, CFI =0.913, and RMSEA =0.031 CONCLUSION: ProQOL-28 has good reliability and validity among government staff in the earthquake-stricker areas in China.

Objective To observe the influence of swimming training on the expression of nerve growth factor (NGF) and neurotrophins-3 (NT-3) in rats with cerebral infarction,and to explore the underlying neuroprotection mechanism of exercise training on cerebral infarction.Methods Forty-five healthy male Sprague-Dawley rats were randomly divided into a sham-operation group,a control group and a training group,with 15 rats in each group.Each group was further divided into a 3-day,7-day and 14-day subgroups,which amounts to 9 groups.To establish animal model of cerebral ischemia-reperfusion in rats,the intraluminal thread method was applied to cause left middle cerebral artery occlusion (MCAO) for 2 h before reperfusion.The rats of the training group were given swimming training for 10 min,once daily,while those of the sham-operation and control groups were not given any training.Neurological deficits were assessed using Bederson scores.The expression of NGF mRNA and NT-3 mRNA in the ischemiareperfusion pallium was examined using reverse transcription-polymerase chain reaction (RT-PCR).Results The rats of the sham-operation group showed no neurological deficits.At the same time points,the average Bederson scores of the training group were significantly lower than the control group,but significantly higher than the sham group.Moreover,the 14 d training group had the lowest Bederson score (1.20 ±0.45),compared to the value 3 and 7 days after modeling.The expression of NGF mRNA and NT-3 mRNA of ischemic cerebral cortex in the training group was significantly improved when compared to the sham-operation group or the control group.On day 14,the expression of the NGF mRNA (0.66 ± 0.07),and the NT-3 mRNA (0.79 ± 0.06),were significantly higher than those on day 3 and 7.Conclusions Swimming training could increase the expressions of NGF mRNA and NT-3 mRNA in the ischemic cerebral cortex.It might be one of the key mechanisms that exercise training could promote the recovery of damaged neurological function in rats with cerebral infarction.

Objective To detect human parvovirus B19(B19V)DNA in source plasma pools and coagulation factor products and determine its prevalence and the level of contamination .Methods A pair of primers and a probe selected from the highly conserved sequences encoding the non-structural protein(NS1)of B19 were designed and synthesized.With the primer-probe combination ,source plasma pools and four types of coagulation factor products were determined for B 19V DNA by TaqMan real-time quantitative PCR.Results One-hundred and sixteen from 195 (59.49%) source plasma pools contained B19 DNA and concentrations up to 1.35 ×1010 copies/ml were measured.High frequencies of contamination were detected in factor Ⅷ (29 of 31; 93.55%), thrombin (10 of 10; 100%), fibrinogen (6 of 7; 85.71%) and prothrombin complex (8 of 9;88.89%).Conclusion These data show that B19V is a common contaminator in Chinese source plasma pools and coagulation factor products .Thus,B19V screening in Chinese source plasma seems desirable and significant for the safety of plasma derivatives in China .