Establishment and evaluation of a fluorescent antibody assay against varicella-zoster virus membrane antigen based on Vero E6 cells / 中国输血杂志

【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 (104.65, 104.95 and 105.25 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 105.25 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.

Hydrogen reduces hyperoxic acute lung injury by inducing heme oxygenase 1 expression / 军事医学

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.

Isolation and purification of human haptoglobin by ion exchange chromatography / 军事医学

Objective To develop an effective process for isolating and purifying haptoglobin ( Hp) from Cohn fractionⅣby a new ion exchange chromatography and to preliminarily identify and analyze the product of each purification step . Methods The fraction was first diluted and impurities were adsorbed with Rivanol .Then, the supernatant was treated with 50%ammonium sulfate.Finally, the precipitate was redissolved , and Hp was purified further with Q Sepharose Fast Flow chromatography .Native-PAGE was used to measure the activity of the haptoglobin-bound hemoglobin , while SDS-PAGE analysis and immunoblot were used for identification of the target protein .Results After pretreatment , some of the impuri-ties were removed from the Cohn fraction Ⅳ, and the target protein was enriched .In our case, the target protein was Hp and Hp2-2 was the main phenotype in the human plasma fraction Ⅳ.Target protein band and high purity were identified by SDS-PAGE.Immunoblot analysis further proved that this method could successfully isolate the target protein Hp , and the activity of 2.8 U/ml was measured by Native-PAGE method.Conclusion Haptoglobin is successfully isolated from human Cohn fractionⅣwith this method.The purification process is simple and suitable for scale-up production with a good prospect.

Molecular differences between recombinant coagulation factors and plasma-derived coagulation factors, and their effects on pharmacology and efficacy / 国际药学研究杂志

Since their successful launch, the recombinant coagulation factors have been effective in the treatment and prophylaxis of respective deficiencies, and started to replace plasma-derived coagulation factors. However, immunogenicity and induction of inhibitors associated with the uses of these recombinant products have drawn certain attention. This manuscript reviews the structural differences between several major recombinant coagulation factors and their plasma-derived counterparts, including sequences and many forms of post-translational modifications, and discusses the possible effects of these structural differences on the pharmacology, efficacy and pharmacokinetics of the products. The demonstration of structural differences and underlying mechanisms helps to improve the production yield and quality of recombinant coagulation factors, which is of significant clinical importance.

Blood products and its applications for the treatment of military trauma and diseases / 军事医学

The first blood product albumin was developed during World War Ⅱ.Since then, blood products began to play an irreplaceable role in military trauma and emergency cares .Currently, the supporting system of blood and blood products has become increasingly sophisticated .Development of novel blood products also improved dramatically .Universal virus inactivated freeze-dried plasma has also been purchased by the military .Albumin is used as antishock blood volume expansion for emergency treatment of military trauma .Different kinds of albumin including albumin of various concentra-tions, high purity albumin and albumin in soft packages are available .Specific immunoglobulin has become the regular stra-tegic storage of some developed countries , used for the prevention and treatment of infection in military trauma , emerging infectious diseases and against the potential threat of bioagents and bioterrorism .Local hemostatic produced upon fibrinogen and thrombin as well as coagulator Factor Ⅶperforming integral hemostasis effect have become increasingly significant for treating hemorrhage in military trauma .Development of anticoagulants including human protein C and antithrombin has got great improvement .These medicines have the potential for preventing and treating sepsis caused by military trauma .Prote-ase inhibitors including α2-macroglobulin are expected to work in the specific medicine .In conclusion , blood products will play a greater role in the future war and non war military operations .

Establishment and evaluation of a universal nucleic acid test method for detecting human parvovirus B19 / 军事医学

Objective To establish and evaluate a universal real-time fluorescent quantitative PCR(qPCR)method for identifying and quantifying three human parvovirus B 19 ( B19V) genotypes.Methods Firstly, following a bioinformatic analysis of a subset of B19V genomic sequences available in the NCBI nucleotide database ,representative of genotypes 1 to 3,a set of suitable universal primers and TaqMan probes was designed from the NS 1 gene of B19V.Aplasmid was used as a quantitative standard that contained the identical sequence of the B 19 target sequence .An internal control ( IC ) was included to prevent false negative results .Then,serial 1-log dilutions of quantitative standards were prepared and used in the qPCR assays for generation of a standard curve .Finally,the specificity,sensitivity and reproducibility of the assay were assessed.Results A linear relationship of the real-time PCR method for detecting B19V from 1 ×109copies/μl to 1 ×103 copies/μl was observed .The developed qPCR protocols allowed for the detection of genotypes 1 to 3 with a limit of detection ( LOD) of 10 copies/μl.Furthermore, the assay did not amplify other blood-borne viruses.The inter-and intra-assay variability analyses showed good reproducibility of the assay .Conclusion A universal real-time qPCR method for the detection of B19V DNA is established,which will facilitate the diagnosis of B19V infections and the screening of blood and plasma-derived products , thereby improving the viral safety of transfusion and plasma-derived products .

Establishment and preliminary application of a rapid microneutralization test for screening varicella-zoster virus special hyperimmune globulin in plasma donations / 军事医学

Objective To promote the progress in varicella-zoster virus (VZV) immunoglobulin preparation,a rapid microneutralization test ( RMNt) was set up for screening plasmapheresis donations with high titers of special neutralizing antibodies to VZV.Methods With reference to the VZV immunoglobulin (VZIG) preparation standard of FDA and VZIG international unit ( IU) , a screening standard was formulated; the amount of virus was analyzed to determine the optimal conditions for RMNt;screening technology was established and the IU was introduced as quality control ;twenty samples of apheresis plasma and fifteen samples of pooled plasma were diluted at 1∶2 to 1∶256 and tested by RMNt respectively;and the sensitivity of RMNt was also analyzed by the commercial ELISA kit .Results Plasma samples that were diluted at 1∶16 and had a titer more than 0.4 U/ml could be used in the production of VZIG .1500 PFU/ml titers of virus in RMNt pro-duced readable results in plasma screening .Eight apheresis plasma samples tested met the screening standard , but none of the pooled samples tested positive .RMNt had a good linear relationship with ELISA (r=0.895 24,P<0.0001).Conclu-sion The sensitivity, throughput and operability of the established RMNt can be used in the screening of plasma donations as key techniques for the production of VZIG .

Establishment and optimization ofα2-macroglobulin activity detection assay / 军事医学

Objective To establish an assay for detecting α2-macroglobulin activity in Cohn fraction Ⅳ.Methodsα2-M reacted with trypsin to form α2-M-trypsin complex.After the chromogenic substrate Na-benzoyl-DL-arginine 4-nitroanilide hydrochloride ( BAPNA) was added, absorption at 410 nm was detected with the microplate reader .α2-M activity in Cohn fractionⅣwas quantitatively detected according to the established standard curve of plasma α2-M activity. Result Several critical parameters in this assay were optimized .A standard curve of plasma α2-M activity was established . According to this standard curve ,α2-M activity in Cohn fraction Ⅳsample was detected to be 1.578 PU/ml.Conclusion Using normal human plasma as the reference material , theα2-M activity in Cohn fractionⅣcan be detected through chro-mogenic substrate assay.This study provides a simple method to detect α2-M activity during the purification process of α2-M from Cohn fraction Ⅳ.

Specific human immunoglobulin in prevention and treatment of infectious diseases / 军事医学

The specific human immunoglobulin is a hyperimmune globulin against a particular pathogen or biotoxin .It′s an important variety in plasma derivatives .Specific human immunoglobulin is usually used to prevent and treat pathogen in -fections with high morbidity , severe outcomes and no efficient treatment available .Thus it has unique advantages in preven-tion and management of infectious diseases .A variety of specific human immunoglobulins have been licensed abroad , but the development of new specific human immunoglobulins is slow in China due to technical constraints , limited economic benefits or for other reasons .Here we reviewed some specific human immunoglobulins and their preventive and therapeutic effect on infectious diseases .

Establishment and application of viral inactivation/removal technology for blood products / 军事医学

Objective To establish viral inactivation/removal techniques for blood products , and apply them to inacti-vation/removal process validation of blood products .Methods Enveloped and non-enveloped model viruses were propaga-ted.Viral inactivation/removal techniques for blood products ,including solvent/detergent (S/D) treatment, low pH incuba-tion, dry heat method, pasteurization,and nanofiltration, were established.The virus titer was evaluated using cytopathic effects ( CPE) and Spearman and Karber method .The viral inactivation/removal techniques were believed to be effective when LRV≥4.These techniques were used in viral inactivation /removal validation of blood products .Results Enveloped model viruses were inactivated through S/D treatment and the low pH incubation method .Enveloped and non-enveloped model viruses were inactivated through dry heat and pasteurization .Within a certain range of filtration capacity , PPV was removed through nanofiltration .Conclusion The established viral inactivation/removal techniques can be used in viral inactivation/removal process validation of blood products , which can improve viral safety of blood products .

Contamination of human parvovirus B19 in source plasma and coagulation factor products / 军事医学

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 .

B cell line epitopes prediction of human cytomegalovirus glycoprotein B / 军事医学

Objective To predict the B cell line epitopes of human cytomegalovirus glycoprotein (gB)by analyzing its structure and physicochemical properties using bioinformatics approaches .Methods Based on the sequence of the HCMV gB,the probable B cell epitopes are predicted using two online prediction programs and DNAstar software .Meanwhile,the tertiary structure of gB was constructed by homologous modeling with the assistance of SWISS -MODEL server to rule out im-possible B cell epitopes .Results and Conclusion The B cell line epitopes of gB are predicted , which provides a theoreti-cal basis for further verification of gB immunodominant epitopes and screening the source plasma with high HCMV IgG titer .

Detection ofα1 antitrypsin activity by chromogenic substrate assay with initial veloci-ty of enzymatic reaction / 军事医学

Objective To detect the activity of α1 antitrypsin(AAT) with initial velocity of enzymatic reaction in order to detect the activity of samples in the process of separating and purifying plasma protein ,chromogenic substrate assay was optimized.Methods The effect of trypsin concentration and reaction time on enzymatic reaction was acquired by the kinetic monitoring mode of the microplate reader .Initial velocity was calculated to confirm the largest concentration of trypsin which was saturated by substrate .AAT was incubated with trypsin and absorbance produced by enzymatic reaction of remaining trypsin and substrate could reflect the activity of AAT .A standard curve was established with △D fitting with the activity of AAT standard.The activity of related samples was detected and the precision and accuracy of the method were evaluated . Results Trypsin concentration was 0.0625 mg/ml.Within 20 minutes, enzymatic reaction was with initial velocity .The range of the standard curve was 200-1200 IU/ml.Correlation coefficient was more than 0.99.The activity of Cohn Ⅳ, samples of pre-processing and elution were (720.59 ±18.63), (601.84 ±19.18),and (568.09 ±24.83)IU/ml, respec-tively.The relative standard deviation was less than 10%. Sample recovery rate was 90%-110%.Conclusion The optimized chromogenic substrate assay greatly improves accuracy and precision .The method can be used for the detec-tion of AAT activity of samples in laboratories and workshops .

Comparison of four pre-column treatment methods for human plasma coagulation factorⅧpre-purification / 军事医学

Objective To compare four pretreatment methods of human plasma coagulation factor Ⅷ( FⅧ) before column purification.Methods Cryoprecipitate was dissolved in Tris , before the supernatant was treated with glycine precipitation, PEG precipitation, acid precipitation and aluminum hydroxide gel adsorption , respectively.Activated partial thromboplastin (APTT) was used to measure the activity of the supernatant clotting FⅧ after treatment.The total activity recovery and specific activity of the final samples were used to weigh the efficacy of those methods .The purity of the intend-ed protein was estimated by non-reducing SDS-PAGE electrophoresis .Results Total activity recovery of glycine precipitati-on was the highest (94.00%±7.60%), followed by that of acidic precipitation (89.47%±2.60%) and PEG precipita-tion (80.92%±9.67%) methods.The lowest was aluminum hydroxide gel adsorption (78.65%±7.52%).Glycine precipitation and PEG precipitation could more effectively remove contaminating protein than acid precipitation and aluminum hydroxide gel adsorption .Treated by four different methods , the specific activity of FⅧ of glycine precipitation sample was the highest (0.6856 ±0.1258 IU/mg), followed by PEG precipitation (0.5773 ±0.0787 IU/mg) and acidic precipitation (0.3885 ±0.0301 IU/mg).The specific activity of aluminum hydroxide gel adsorption was the lowest (0.2879 ±0.0472 IU/mg).Conclusion PEG precipitation is more effective for the actual production process than the other three methods .

Coagulation factor and traumatic hemostasis / 军事医学

Coagulation factors ,which are involved in the intrinsic and extrinsic coagulation process of organism ,perform mutual coordination with the anticoagulation system .The dynamic balance between them inorder to maintain the normal blood physiological state .The molecular structure , physicochemical properties , physiological function involved in the trau-matic bleeding hemostasis were detailed in this paper .Meanwhile , the importance of coagulation factors for trauma hemo-stasis and coagulation ,the coagulation factor products , and their use were reviewed here to provide reference for the devel-opment of coagulation factors as drugs .

Advances in securing viral safety for plasma products / 军事医学

Plasma products are considered to be special medicinesderived from healthy human plasma .During 1980′s, events of transmission of human immunodeficiency virus through plasma products were frequently reported .Since then, ensuring the viral safety of plasma products has raised great concerns all over the world .So far, with decades of effort , most countries in the world have established rigorous systems with preventive measures to ensure the viral safety of plasma prod -ucts.These measures include control of source plasma , validated inactivation/removal of infectious agents , the adherence to current good manufacturing practices .Nevertheless , new infectious agents which may be threats to viral safety require continuous studies on appropriate countermeasures .

Screening of biological amniotic immunization safety / 国际药学研究杂志

Objective To evaluate the immunity efficacy of human amniotic membranes on rats. Methods One hundred and fifty Wistar rats were randomly divided into five groups:biological amnion group,immunosuppression group,immunostimulation group, sham-operated group and blank control group. According to the study period,each group of thirty rats would be randomly divided into five experimental operation subgroups:the 1st week,the 2nd week,the 4th week,the 8th week group and the 12th week groups. The rats were implanted subcutaneously,then intramuscular injection of gentamicin sulfate for 3 days to resist the infection ,and the immune organ coefficient,and the killing abilities of NK cell ,IL-1β,IL-6 and TNF-αserum levels were detected according to the study period.Results At 1st ,2nd ,4th ,8th and 12th week after amniotic membrane implantation in rats,compared with the sham-operated and blank control groups,the biological amnion group had nonsignificant differences (P>0.05). At 1st week after amniotic membrane implantation in rats, immunosuppression group showed different levels of the immunosuppressive effect,such as the analysis of immune organ coefficient , which had significant differences compared with other groups (P<0.01). At 1st week after amniotic membrane implantation in rats,the imunostimulation group showed a certain degree of the immunostimulant effect,such as the killing abilities of NK cell,which had marked differences compared with other groups (P<0.05). Conclusion The amniotic membranes have satisfactory immune safety with implantation in rats and do not cause significant adverse immune reactions.

Summary about the progress and specifications of FDA regarding intravascular catheters / 中国医疗器械杂志

This article summarizes the progress and specifications of FDA regarding intravascular catheters, and hope this would be helpful to people concerned.

Current status and trends in blood biologicals / 生物工程学报

Blood products are those biologicals derived from plasma or obtained by recombinant technologies. This overview covers the characteristics and classification of plasma proteins, the current status of products (albumin, immunoglobulins, coagulation factors and microcontent proteins), as well as the likely trends in the near future. Human serum albumin is one of the earliest, safest and most widely used proteins in the pharmaceutical field. The approval and development of high-purity plasma albumin, recombinant human albumin and HSA fusion proteins provide a favorable prospect for the therapeutic protein. Normal immunoglobulin contains antibodies to all the micro-organisms prevalent in the donor population. The IMIG is relatively simple to prepare and use, and the side effects are acceptable; IVIG is used mainly to treat patients with primary immunodeficiency syndromes; SCIG preparations can be used in selecting suitable patients for home therapy and have occurred fewer adverse systemic reactions; specific immunoglobulins contain concentrations of antibody to an individual organism or toxin at a higher titer than normal immunoglobulin and can not be replaced in clinical use. The plasma-derived or recombinant coagulation factors are used to treat the patients with congenital or acquired factor deficiency. The products such as Fibrinogen, FVII, FVIII, von Willebrand complex, FIX/PCC, FXI, FXIII and so on, have been widely used and proved to be effective. The development of recombinant FVIIa is now as a good bypassing product to haemophilia with inhibitors. The Fibrinogen and thrombin play a very important role in surgery hemostasis. Moreover, microcontent proteins including protein C, antithrombin, alpha 1-AT, tPA have been licensed and used in clinical treatment; a number of other small field proteins are under produced research or pre-clinical investment. The ongoing development of new recombinant plasma proteins is providing alternatives for patients, but the distinct position and the potential impact of plasma-derived preparations are unique, furthermore the development of new plasma protein is still a hot spot in global pharmaceutics. Nowadays, a relative difference exists in the development of blood products between our nation and developed countries, so the domestic manufacturers are faced with chances and challenges.

Clinical analysis of renal lymphangiectasia / 中华泌尿外科杂志

ObjectiveTo discuss the characters and management of renal lymphangiectasia.MethodsThe clinical data of two cases of renal lymphangiectasia were reviewed. The first patient was a 37-year-old woman with the chief complaint of lumbago in the right flank for 8 days.B-ultrasound showed mixed echo in perinephric space. On CT, similar appearances of fluid collections were seen, but not conspicuous. Conservative treatment was taken for three weeks and the symptoms were relieved. Three month later the patient had right lumbago relapse. CT scan revealed a large amount of fluid collection under the capsule of the right kidney. Percutaneous drainage was carried out. Two months later B-ultrasound showed fluid collection in perinephric space and percutaneous drainage again the fluid was sent to pathology. The second case was a 32-year-old woman with the chief complaint of lumbago in the left flank for the past three years. Ultrasonography revealed hyperechoic surrounding the left kidney. CT scan showed a left perinephric collection of fluid attenuation and circumferentially draping around the kidney. Renal lymphangioma was diagnosed and the patient underwent surgery.ResultsNeedle aspiration of the perinephric fluid was carried out, and laboratory analysis showed most leucocytes were lymphocytes. The pathologic diagnosis of the first case was renal lymphangiectasia. There was no recurrence during follow - up of two months. The second case was diagnosed renal lymphangioma pathologically. Follow - up for nine years, revealed no relapse.ConclusionsUltrasonography and CT contributed to the diagnosis of renal lymphangiectasia. Needle aspiration bioposy and histology could confirm it. Treatment of asymptomatic cases is not required. When collections are very large and cause symptoms, percutaneous drainage may be carried out however there is a risk of relapse.