Effect Study of the Recombinant Human Brain Natriuretic Peptide in Patients with Heart Failure Combined with Hypotension

Objective: This paper aims to investigate the effect of applying recombinant human brain natriuretic peptide in patients with heart failure combined with hypotension. Recombinant human brain natriuretic peptide is a synthetic polypeptide drug that is primarily used to treat acute heart failure. Its mechanism of action closely mimics that of human endogenous brain natriuretic peptide. By binding to receptors on cardiomyocytes, it exerts its pharmacological effects. Methods: For the study, 76 heart failure patients with hypotension were selected from our hospital between May 2022 and June 2023. These patients were divided into two groups: a control group and an observation group, each comprising 38 patients. The control group received dopamine treatment, while the observation group was treated with recombinant brain natriuretic peptide. The objective was to compare the effects of the treatments in both groups by analyzing cardiac function indices and levels of vasoactive substances to identify any significant differences in outcomes. Results: The overall response rate of the patients in the observation group and the control group was 94.74% and 73.68%, significantly higher as compared with the observation group (P 0.05). After the following treatment, BNP, ANNP and urine output in the observation group were significantly different compared with the control group, of the statistical significance (P Conclusion: For the treatment of heart failure patients with hypotension, the clinical application of recombinant human brain natriuretic peptide is the most ideal, and significantly improves the cardiac function of patients, which is worth popularizing.

Skin care efficacy study of recombinant humanized collagen based on in vitro level

Studying the skin care efficacy of recombinant humanized collagen based on in vitro level.The stability of the recombinant humanized collagen was first analyzed by treating at different temperatures,then its skincare efficacy based on in vitro level was evaluated by detecting the inhibition rate of elastase,the inhibition rate of collagenase,the protein content of type I collagen in human fibroblasts,the inhibition of reactive oxygen species(ROS)with human keratinocytes,and the effects of the recombinant humanized collagen on the expression of hyaluronic acid(HA),filaggrin(FLG)and transglutaminase 1(TGM1)in keratinocytes.The results showed that recombinant humanized collagen was able to maintain stability at temperatures below 70℃.With regard to its skincare efficacy,recombinant humanized collagen could inhibit elastase and collagenase activities and promote the increase of type I collagen content in human fibroblasts.It also showed good inhibition of ROS in keratinocytes in vitro and could increase the expression of HA,FLG,and TGM1 in keratinocytes.In short,the recombinant humanized collagen exhibited a favourable skin care effect in vitro level.This study proved that it has potential firming,anti-wrinkle,moisturizing,and repairing efficacy,and is a valuable cosmetic raw material.

Efficacy of recombinant human epidermal growth factor plus sodium hyaluronate eye drops in diabetic dry eye post-cataract surgery

BACKGROUND Dry eye syndrome(DES)after diabetic cataract surgery can seriously affect the patient’s quality of life.Therefore,effective alleviation of symptoms in patients with this disease has important clinical significance.AIM To explore the clinical effect of recombinant human epidermal growth factor(rhEGF)plus sodium hyaluronate(SH)eye drops on DES after cataract surgery in patients with diabetes.METHODS We retrospectively evaluated 82 patients with diabetes who experienced DES after cataract surgery at Tianjin Beichen Hospital,Affiliated Hospital of Nankai University between April 2021 and April 2023.They were classified into an observation group(42 cases,rhEGF+SH eye drops)and a control group(40 cases,SH eye drops alone),depending on the different treatment schemes.The therapeutic efficacy,dry eye symptom score,tear film breakup time(TFBUT),basic tear secretion score[assessed using Schirmer I test(SIt)],corneal fluorescein staining(FL)score,tear inflammatory markers,adverse reactions during treat-ment,and treatment satisfaction were compared between the two groups.RESULTS Therapeutic efficacy was higher in the observation group compared with the control group.Both groups showed improved TFBUT and dry eye,as well as improved SIt and FL scores after treatment,with a more pronounced improvement in the observation group.Although no marked differences in adverse reactions were observed between the two groups,treatment satisfaction was higher in the observation group.CONCLUSION rhEGF+SH eye drops rendered clinical benefits to patients by effectively ameliorating dry eye and visual impairment with favorable efficacy,fewer adverse reactions,and high safety levels.Thus,this treatment should be promoted in clinical practice.

Clinical Observation of Recombinant Bovine Basic Fibroblast Growth Factor Eye Gel Combined with Tobramycin Dexamethasone Eye Drops in the Treatment of Dry Eye Syndrome in Patients after Cataract Surgery

Objective:To evaluate the therapeutic effect of recombinant bovine basic fibroblast growth factor(rbFGF)eye gel combined with tobramycin-dexamethasone(TOB-Dex)eye drops on dry eye syndrome(DES)after cataract surgery.Methods:86 patients with DES after cataract surgery,admitted from November 2021 to November 2023,were randomly divided into groups.The observation group included 43 patients treated with rbFGF eye gel combined with TOB-Dex eye drops.The reference group included 43 patients treated with TOB-Dex eye drops alone.Multiple indicators,including total effective rate and clinical symptom scores,were compared between the two groups.Results:The total effective rate in the observation group was higher than in the reference group(P<0.05).Before treatment,there were no differences in clinical symptom scores,serum factors,or disease severity scores between the two groups(P>0.05).Three weeks after treatment,the observation group had lower clinical symptom scores,serum factors,and disease severity scores compared to the reference group(P<0.05).The adverse reaction rate in the observation group was lower than in the reference group(P<0.05).Conclusion:rbFGF eye gel combined with TOB-Dex eye drops can improve the clinical efficacy for patients with DES after cataract surgery,alleviate disease symptoms,reduce inflammatory responses,and have fewer adverse reactions.

Lyophilized recombinant human brain natriuretic peptide for chronic heart failure:Effects on cardiac function and inflammation

BACKGROUND Chronic heart failure(CHF)is a serious and prevalent condition characterized by impaired cardiac function and inflammation.Standard therapy for CHF has limitations,prompting the exploration of alternative treatments.Recombinant human brain natriuretic peptide(BNP)has emerged as a potential therapy,with evidence suggesting that it can improve cardiac function and reduce inflammation in patients with CHF.However,further research is required to determine the efficacy and safety of lyophilized recombinant human BNP in CHF patients and its impact on microinflammatory status.This study aimed to investigate the effects of lyophilized recombinant human BNP therapy on CHF patients’cardiac function and microinflammatory status.AIM To investigate the effects of freeze-dried recombinant human BNP therapy on cardiac function and microinflammatory status in patients with CHF.METHODS In total,102 CHF patients admitted to our hospital from January 2021 to January 2022 were randomly assigned to control and observation groups(n=51 patients/group).The control patients were treated with standard HF therapy for 3 d,whereas the observational patients were injected with the recombinant human BNP for 3 d.Clinical efficacy,inflammatory factor levels,myocardial damage,cardiac function before and after the treatment,and adverse reactions during treatment were compared between the two groups.RESULTS The overall clinical efficacy was higher in the observation group than in the control group.Compared with baseline,serum hypersensitive C-reactive protein,N-terminal proBNP,and troponin I level,and physical,emotional,social,and economic scores were lower in both groups after treatment,with greater reductions in levels and scores noted in the observation group than in the control group.The overall incidence of adverse reactions in the observation group was not significantly different compared with that in the control group(P>0.05).CONCLUSION Freeze-dried recombinant human BNP therapy can improve heart function and enhance microinflammatory status,thereby improving overall quality of life without any obvious side effects.This therapy is safe and reliable.

Lyophilized recombinant human brain natriuretic peptide: A promising therapy in patients with chronic heart failure

Lyophilized recombinant brain natriuretic peptide(BNP)is an exogenous peptide synthesized by artificial recombination technology,with a similar structure and similar physiological effects with the endogenous natriuretic peptide secreted by the human body.It’s main mechanism of action is to increase cyclic guanosine monophosphate by binding with its corresponding receptor in the body,regulating,thus,the imbalance of the vascular system and cardiac hemodynamics,improving the heart’s pumping capacity,and inhibiting sympathetic excitability and myocardial remodeling.Moreover,it can promote mitochondrial metabolism and enhance the use of adenosine triphosphate in cardiomyocytes.In the present study,102 chronic heart failure(HF)patients were randomly assigned to a control and an observation group consisting of 51 patients each.Patients of the control group were treated with standard HF therapy for 3 d including oral metoprolol tartrate tablets,spironolactone,and olmesartanate while patients of the observation group were administered the recombinant human BNP injection for the same time-period,plus the standard HF therapy.The recombinant human BNP group(observation group)demonstrated better physical,emotional,social,and economic scores,as well as cardiac and inflammatory biomarkers such as serum hypersensitive C-reactive protein,N-terminal pro BNP and troponin I levels,compared to the control group.Moreover,cardiac function was also improved,as left ventricular ejection fraction and stroke volume were significantly higher in the observation group than in the control group.Interestingly,adverse reactions were not different between the 2 groups.However,these results are not generalizable and the need of large multicenter randomized controlled trials examining the safety and efficacy of recombinant human BNP in HF patients is of major importance.

Clinical observation of recombinant human nerve growth factor in the treatment of neurotrophic keratitis

AIM:To characterize changes of corneal nerve morphology and tear indices in patients with neurotrophic keratitis(NK)treated with recombinant human nerve growth factor(rhNGF).METHODS:In a prospective observational study,six patients(nine eyes)were locally treated with rhNGF.Visual acuity,corneal fluorescein staining score,the heights of the tear river,lipid layer thickness(LLT),tear ferning(TF)test,conjunctival impression cytology(CIC)examination,the densities of cornea subbasal nerve fibers were determined before and after treatment.RESULTS:Compared with baseline,there was a significant difference in corneal fluorescence staining scores(P<0.01);all patient corneal epithelial defects recovered completely within 8wk,but there was no significant improvement in the height of the tear river(P=0.202).LLT was significantly increased when compared with baseline(P=0.042);however,the function of conjunctival goblet cells and mucin content did not significantly improve using the TF test and CIC examination(P=0.557,P=0.539).After 8wk of treatment,the average corneal subbasal nerve fiber density increased significantly(P<0.01),as did the number of corneal nerve fiber branches(P=0.001).CONCLUSION:RhNGF can increase the density of corneal subbasal nerve fibers,promote the healing of persistent corneal epithelial defects and corneal ulcers in patients with NK,also improving tear function partially.

Expression and Evaluation of Wb-SXP-1 and Wb-123 Recombinant Antigens as Potential Diagnostic Biomarkers for Lymphatic Filariasis

Lymphatic filariasis (LF) remains a public health concern as it can cause permanent morbidity and disability to those infected. While the global elimination of LF in these endemic areas is ongoing through mass drug administration, there is the need to develop diagnostic tools that would be utilized to track the progress of total global eradication as well as perform surveillance for the recurrence of lymphatic filariasis transmission. Currently, approved LF diagnosis tools are faced with lack of specificity, low sensitivity, and periodicity dependence. Recombinant filarial antigen-based assays can address these drawbacks and offer practical instruments for LF diagnosis and surveillance. This present study, evaluated rWb-SXP-1 and rWb-123 antigens as potential diagnostic biomarker tools for Wuchereria banchrofti in human sera using microspheres-based multiplex serological assay. Based on statistical analysis using XLSTAT 2019 (Addinsoft) on data generated from multiplex technology assay, generated ROC curves for both rWb-SXP-1 and rWb-123 demonstrated 87.1% sensitivity to Wuchereria banchrofti human sera with rWb-SXP-1 antigens having the highest specificity of 96%. Indication that rWb-SXP-1 and rWb-123 antigens are capable of detecting immunoglobulin G4 (IgG4) antibodies in human sera synthesized specifically against W. banchrofti infections. Therefore, rWb-SXP-1 and rWb-123 antigens can be utilized to detect W. banchrofti infections by antibody profiling with excellent diagnostic sensitivity and specificity using microsphere-based multiplex serological tests. This method can be particularly practical for screening a large number of sera samples and/or for quick, extensive field-testing due to the high-throughput and quick formats applied.

Tensile Properties and Prediction Model of Recombinant Bamboo at Different Temperatures

The destruction of recombinant bamboo depends on many factors,and the complex ambient temperature is an important factor affecting its basic mechanical properties.To investigate the failure mechanism and stress–strain relationship of recombinant bamboo at different temperatures,eighteen tensile specimens of recombinant bamboo were tested.The results showed that with increasing ambient temperature,the typical failure modes of recombinant bamboo were flush fracture,toothed failure,and serrated failure.The ultimate tensile strength,ultimate strain and elastic modulus of recombinant bamboo decreased with increasing temperature,and the ultimate tensile stress decreased from 154.07 to 96.55 MPa,a decrease of 37.33%,and the ultimate strain decreased from 0.011 to 0.008,a decrease of 26.57%.Based on the Ramberg-Osgood model and the pseudo‒elastic design method,a predictive model was established for the tensile stress–strain relationship of recombinant bamboo considering the temperature level.The model can accurately evaluate the tensile stress–strain relationship of recombinant bamboo under different temperature conditions.

Overview of Recombinant Skin Models and Progress in Their Application in Vitro Assessment of Toxicity and Efficacy

A recombinant skin model is a model in which skin cells are grown in vitro on a bioactive scaffold and provided with adequate nutrition to promote cell proliferation and differentiation to produce a mock skin structure and biological features. The development of recombinant skin models allows for effective and scientifically sound in vitro evaluation tests. This review briefly summarizes the overview of recombinant skin models and the progress of their application in in vitro evaluation which focuses on three aspects: skin irritation, skin corrosivity, and anti-skin aging. Moreover, an outlook on the future development of recombinant skin models is also provided in this review.

Effects of Mercury on the Structure and Activity of BLM642-1290 Recombinant Helicase

Objective Bloom’s syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene （encoding a BLM helicase） may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg^2＋ on the structure and activity of BLM642‐1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase. Methods The effects of Hg^2＋ on biological activity and structure of BLM642‐1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free‐phosphorus assay technologies, respectively. Results The helicase activity, the DNA‐binding activity, and the ATPase activity of BLM642‐1290 recombinant helicase were inhibited by Hg^2＋ treatment. The LMCT （ligand‐to‐metal charge transition） peaks of the helicase were enhanced with the increase of the Hg^2＋ level. The LMCT peaks of the same concentration of helicase gradually increased over time. Conclusions The biological activity of BLM642‐1290 recombinant helicase is inhibited by Hg^2＋ treatment. The conformation of the helicase is significantly altered by Hg^2＋ . There exist two binding sites between Hg^2＋ and the helicase, which are located in the amino acid residues 1063‐1066 and 940‐944 of the helicase, respectively.

Optimization for Purification and Characterization of Recombinant Hirudin Ⅲ from E. coli

Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column chromatography steps with macroporous resin,DEAE cellulose DES2 and preparative RP-HPLC, respectively, and the optimal conditions were obtained.Purity of the product was determined by SDS-PAGE and analytical RP-HPLC. The molecular weight wasdetermined by mass spec-trometry. The structure of the product was analyzed by peptide map.ResultsThe product with purity of 95.4786% was obtained after three purification steps in the optimumconditions with a total yield of 39%. The molecular weight of the product was 6 913.32 ± 6.55 Da,coincident to the theoretical molecular weight of r-hirudin 3. The structure of the product wascoincident to r-hirudin 3 either. Conclusion The optimized purification steps can be successfullyemployed for purification of r-hirudin 3 from E. coli using batch-type approaches. The productobtained with high purity was confirmed to be r-hirudin 3.

EFFECTS OF CHINA-MADE RECOMBINANT HUMAN GROWTH HORMONE ON THE TREATMENT OF GROWTH HORMONE DEFICIENCY

To evaluate the therapeutic effect of China-made recombinant human growth hormone (r-hGH) in children with growth hormone deficiency (GHD) and to investigate the utilities of various biochemical parameters in GHD diagnosis and treatment. Methods Our study comprises of 30 normal children and 71 GHD children treated with China-made r-hGH substitution therapy 0.1 IU·kg-1·d-1 for 6 months. Serum insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), bone turnover markers (Ost, ICTP), and anti-growth hormone antibody (GHAb) were detected before and after r-hGH treatment. Results After the first 3 and 6 months of treatment, growth velocities of GHD children were significantly increased (13.1 ± 3.7 and 12.6 ± 3.6 cm/year) compared with pretreatment values (2.9 ± 0.8 cm/year, P < 0.01). GHD Children had obviously reduced serum levels of IGF-1, IGFBP-3, and bone turnover markers (Ost, ICTP) compared with normal controls (P < 0.01), and these biochemical parameters improved significantly after treatment (P < 0.01). Growth hormone antibodies were positive in 17 of 45 cases after treatment by binding capacity detection. The binding percentage of growth hormone an-tibody which was increased more than 30% after the treatment showed a negative correlation with growth velocity (P < 0.01). Conclusions (1) The growth stimulating effect and safety were confirmed in using China-made r-hGH in the treatment of GHD children for 6 months. (2) The measurements of serum IGF-1 and IGFBP-3 may serve as useful parameters in the diagnosis of GHD. (3) Serum Ost and ICTP are useful laboratory criteria for evaluating the effect of r-hGH therapy in the early stage. (4) It is necessary to monitor serum levels of GHAb during r-hGH therapy.

Identification for Heat Tolerance in Backcross Recombinant Lines and Screening of Backcross Introgression Lines with Heat Tolerance at Milky Stage in Rice

The present study aimed at breeding new rice germplasms with similar genome but significantly differed in heat tolerance during the grain filling stage.A total of 791 BC1F8 backcross recombinant lines,derived from the cross of Xieqingzao B /N22 //Xieqingzao B,were used as materials.Each rice line was separated evenly into two groups,and the heat tolerance of all rice lines were evaluated at natural high temperature in fields.The rice lines with heat tolerant index higher than 90% or lower than 40% were selected to compare the phenotypic characters and further identify heat tolerance at the early milky stage in a phytotron.Rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were analyzed by 887 simple sequence repeat markers that were evenly distributed on the 12 rice chromosomes.In the result,12(6 pairs) rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were obtained.Molecular marker analysis indicated that the genomic polymorphism between 703T and 704S was the smallest in the 6 pairs of rice lines,with only 16 polymorphic sites,including 22 different alleles.The application of these two backcross introgression rice lines for future study on the mechanisms of heat tolerance in rice at the milky stage will be theoretically beneficial in reducing the interference caused by genetic differences from experimental materials.

Chronic Toxicity of a Novel Recombinant Human Granulocyte Colony-stimulating Factor in Rats

Objective To assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.Methods A total of 100 Sprague-Dawley rats (equal numbers of male and female) were randomly divided into five groups (20 rats in each group):four groups were treated with rhG-CSFa at 500,100,10,1 μg/kg,respectively,and one group was treated with vehicle only to serve as the control.The rats were received subcutaneous injections of rhG-CSFa or vehicle daily for 13 weeks.During the course of the chronic toxicity study,the physical status,body weight,and food consumption were monitored.Half of the rats in each group (n=10) were sacrificed after the last rhG-CSFa administration,and the other half were sacrificed at five weeks after the last rhG-CSFa administration.Urinalyses,blood biochemistry,hematological analysis,histopathological examination,and immunological tests were performed for each of the rats.Results The hematological analyses revealed that the mean white blood cells count,neutrophils count,and neutrophils percentage were increased in male rats at the dose of 10 μg/kg or higher,and these were related with the biological activity of rhG-CSFa.Some small abnormalities were observed in the spleen of a few rats when used highest dose (500 μg/kg,a dosage of 200 folds higher than the normal clinical dosage),but these abnormalities were recovered within 5-week recovery period.No other rhG-CSFa-related abnormalities were observed in this chronic toxicity study.Conclusion No significant toxicity and immunogenicity are observed with rhG-CSFa administration to rats in the chronic toxicity studies.

Construction of adenovirus vectors encoding the lumican gene by gateway recombinant cloning technology

AIM： To construct adenovirus vectors of lumican gene by gateway recombinant cloning technology to further understand the role of lumican gene in myopia. METHODS： Gateway recombinant cloning technology was used to construct adenovirus vectors. The wild-type （wt） and mutant （mut） forms of the lumican gene were synthesized and amplified by polymerase chain reaction （PCR）. The lumican cDNA fragments were purified and ligated into the adenovirus shuttle vector pDown- multiple cloning site （MCS）-/internal ribozyme entry site （IRES）/enhanced green fluorescent protein （EGFP）. Then the desired DNA fragments were integrated into the destination vector pAV.Desld yielding the final expression constructs pAV.Exld-CMV〉wt-lumican/IRES/ EGFP and pAV.Exld-cytomegalovirus （CMV） 〉mutlumican/IRES/EGFP, respectively.RESULTS： The adenovirus plasmids pAV.Exld-CMV〉 wt-lumican/IRES/EGFP and pAV.Exld-CMV 〉mutlumican/IRESlEGFP were successfully constructed by gateway recombinant cloning technology. Positive clones identified by PCR and sequencing were selected and packaged into recombinant adenovirus in HEK293 cells. CONCLUSION： We construct adenovirus vectors containing the lumican gene by gateway recombinant cloning technology, which provides a basis for investigating the role of lumicangene in the pathogenesis of high myopia.

Construction of recombinant adeno-associated viral vectors in human neurenergen-3 gene

BACKGROUND： Research of transgene brings hope for gene therapy of various diseases; in addition, some projects have been tested in clinic. Recently, the focus has been to find an ideal vehicle and a suitable therapeutic gene. OBJECTIVE： To explore an effective way to construct recombinant adeno-associated viral vectors expression in human neurnnergen-3 gene. DESIGN： Gene directed cloning. SETTING： Central Laboratory of Northern China Coal Medical College. MATERIALS： DH5a competent bacillus coli strain was provided by Capital Medical University; pCDNA3-NT-3 by professor Chen from Bengbu Medical College; pAAV-Laze, pAAV-Helper, pAAV-RC and pAAV-MCS plasmids by Capital Medical University; HEK293 cells by Cell Center of Basic Medical College of Tongji Medical University. METHODS： NT-3 genes which were selected from pCDNA3-NT-3 plasmids were cloned in pAAV-MCS to form a recombinant adeno-associated viral plasmid （pAAV-NT-3）. pAAV-NT-3, pAAV-RC, pAAV-LacZ and pHelper plasmids were extracted, purified and subjected to enzyme-shearing evaluation. In addition, pAAV-NT-3 and pAAV-LacZ were cotransfected with pHelper and pAAV-RC, respectively into AVV-293 cells with DNA mediated by calcium superphosphate transfection gene; and then, AVV-293 cells were packed into recombinant adeno-associated viral rAAV-NT-3 and rAAV-LacZ. After collection of viral particles, rAAV-LacZ viral stock solution was diluted based on ratio of 10：1 and the mixture was used to infect HT 1080 cells. X-gal stain was used to measure virus titer. MAIN OUTCOME MEASURES： Size of targeted gene fragments, validity of vehicle construction and virus titer. RESULTS： Targeted gene NT-3 was successfully inserted into the relative vehicle pAAV and pAAV-NT-3 was correctly recongnized by enzyme-shearing evaluation. Enzyme-shearing electrophoresis demonstrated that pAAV-NT-3, pAAV-RC, pAAV-LacZ and pHelper plasmids were successfully extracted and purified. β-galactoside staining in situ indicated that LacZ genes were expressed in human fibrosarcoma cells （HT1080） and the recombinant virus titer was measured as 1 ×10^12 virus particles per milliliter. CONCLUSION： Total-length cDNA fragment of NT-3 gene, which is obtained from pCDNA3-NT-3 plasmids, is closely matched to polyclone enzyme-shearing sites of adeno-associated viral vectors, while the combination can be used to construct recombinant adeno-associated viral vectors expression in hNT-3 gene.

Construction and Expression of Tp0453 Recombinant Protein of Treponema pallidum and Development of Indirect ELISA for Diagnosinq Syphilis

Objectives： To clone and express Tp0453 outer membrane protein of Treponema pallidum, and to evaluate its significance in the serodiagnosis of syphilis. Methods： The immuno-dominant epitope of Tp0453 gene was amplified from the complete genome of T.pallidum by polymerase chain reactions （PCR）, subcloned into the expression vector Pqe32 to generate recombinant plasmid Pqe32/Tp0453, and was then expressed in E. coli M15. The fusion protein was purified with Ni-NTA affinity purification. Indirect ELISA was developed to detect human serum IgG antibody to T. pallidum. Results： The recombinant Tp0453 protein was successfully expressed and purified. The recombinant protein had a molecular weight of approximately 32KDa.Indirect ELISA to the recombinant protein was developed.Sixty control sera were tested by ELISA and yielded a sensitivity of 100% （30/30） and a specificity of 100% （30/30）. While testing for T. pallidum in human sera, the sensitivity and specificity of ELISA were 96.8% and 100%, respectively, when compared with TPPA test results. The concordance of results between the ELISA test and the TPPA test was 98.2%. Conclusion： The recombinant Tp0453 outer membrane protein elicited a strong immunoreaction to anti-T.pallidum IgG antibody and has great potential use in ELISA for the serodiagnosis of syphilis.

Acute Toxicity of Recombinant Porcine Interferon-alpha

To observe the acute toxicity of recombinant porcine interferen-alpha （IFN-alpha） in mice and thus provide a basis for the clinical safety. [Method] According to the principles of acute toxicity, all the mice were divided into two major groups （intraperitoneally injected group and intramuscularly injected group） respectively at high dose, moderate dose and low dose. And the normal control group was also set up. Within 14 d after administration, the behavior of mouse and the degree of toxicity were continuously observed. The hematological indexes and biochemical indexes of blood were detected to obtain the preliminary toxicity data of the recombinant porcine IFN-alpha. And at the end of the experiment, mice were sacrificed for autopsy. [ Result] There was not significant difference in external performance, behavioral characteristics, body temperature, weight, pathological anatomy of visceral organs, hematological indexes and biochemical indexes between the experimental groups and the control group. [ Conclusion] The highest dose of porcine interferon （5.0 x 10s IU per mouse） in this experiment or the dose lower than this dosage should not have significant toxic effects on mice, and the recombinant porcine IFN-alpha is safe in clinical application.