The Value of CSF Level of β- amyloid Protein in the Diagnosis of Alzheimer's Disease

Objective:To evaluate the diagnostic potential of cerebrospmal fluid (CSF) levels of β-amyloid protein (Aβ) as biochemical marker for senile dementia in clinical practice. Methods : Sensitive enzyme-linked immunosorbent assay (ELISA) was performed in our lalxrratory to delect the CSF levels of Aβt-40, Aβ1-42 in 54 patients with Alzlteimer's disease (AD), and 30 normal controls (NC). Results: The cut off value of Aβ ratio and Aβ1-42 concentration in NC group provided 54. 51%, 90. 00% sensitivity and 81. 25%, 84. 38% specificity respectively in diagnosis of AD. Conclusion : AD group had a significant decreased level of Aβ1-42 and an increased level of Aβ ratio, compared with NC group.

哈尔滨港局1993年处理一起违反检疫法规案例的报告

1 案例 哈尔滨轮船公司龙推332货轮,在向俄罗斯哈巴罗夫斯克运输货物航程中,被举报偷拿货主货物,并且涉嫌走私。轮船公司领导决定派调查组在货轮未返回哈尔滨港前突击松果;并且成立了八人调查组。在1993年9月22日该货轮进哈尔滨港联检前,货轮由哈巴罗夫斯克行至大顶子山时。

The Value of the Measurement of Urinary Hyaluronic Acid Levels for the Diagnosis of Bladder Cancer

Objective To investigate the value of the measurement of urinary hyaluronic acid (HA) levels for the diagnosis of bladder cancer and the possibility of replacing ELISA-like assay with radioimmunoassay to detect the levels of urinary HA. Methods Using the ELISA-like assay and radioimmunoassay at the same time to measure the HA levels in the urine specimens from 49 bladder cancer patients, 12 benign bladder tumor patients, 30 other genitourinary disease patients and 20 normal controls. Results There is not much difference between the consequences of the urinary HA levels whether we used the ELISA-like assay or radioimmunoassay to detect every specimen (P>0.05). When we used the results with radioimmunoassay for analysis, we found the levels of urinary HA of bladder cancer patients were 2–4 times than those of the benign bladder tumor patients, other genitourinary disease patients or normal individuals (P<0.01); With 137.5 ngHA/mg protein (113.6±23.9 ng/mg) as a minimum cutoff limit, this assay had a good sensitivity (91.8%) and specificity (91.9%) for the diagnosis of bladder cancer. Its difference in sensitivity meant a lot when compared with urine cytology (48.9%,P<0.01). Conclusion The urinary HA assay is a simple, convenient, noninvasive credible and cheap method with satisfactory sensitivity and specificity for the diagnosis of bladder carcinoma; radioimmunoassay is also a good means to measure the urinary HA levels. Key words Bladder carcinoma - Hyaluronic acid - Urine

Science Letters： Radio frequency heating： a potential method for post-harvest pest control in nuts and dry products

The multi-billion dollar US tree nut industries rely heavily on methyl bromide fumigation for postharvest insect control and are facing a major challenge with the mandated cessation by 2005 of its use for most applications. There is an urgent need to develop effective and economically viable alternative treatments to replace current phytosanitary and quarantine practices in order to maintain the competitiveness of US agriculture in domestic and international markets. With the reliable heating block system, the thermal death kinetics for fifth-instar codling moth, Indianmeal moth, and navel orangeworm were determined at a heating rate of 18℃/min. A practical process protocol was developed to control the most heat resistant insect pest, fifth-instar navel orangeworm, in in-shell walnuts using a 27 MHz pilot scale radio frequency (RF) system. RF heating to 55℃ and holding in hot air for at least 5 min resulted in 100% mortality of the fifth-instar navel orangeworm. Rancidity, sensory qualities and shell characteristics were not affected by the treatments. If this method can be economically integrated into the handling process, it should have excellent potential as a disinfestation method for in-shell walnuts.

The development and optimization of ELISA for the determination of tetrodotoxin

Objective： To optimize the ELISA for the determination of tetrodotoxin. Methods： A competitive enzyme-linked immunosorbent assay （ELISA） was used. In the ELISA, 100 μl antigen （1. 0 μg/ml） was coated on the microtiter plate for 60 min at 37 C or over night at 4 C. The plate was then washed 3 times with PBS-T for 3-5 s each time. The optimal incubation time for monoclonal antibody （mAb）, goat anti-mice IgG peroxidase conjugate and OPD were 30 min, 20 min and 10 min at 37 C, re- spectively. Results.. The detection limit is 0. 05 ng in each well. The curve was linear for TTX doses be- tween 5-5 000 ng/ml （0. 25-250 ng for every assay）. The linear regress equation was Y = 0. 30 88X-0.17 41 （R=0.99 01）. The average callback for TTX of muscles and gonads were 99.74% and 100.30%, respectively. The sensitivity of optimization ELISA was 5 times than traditional method and the time of 1.8 h were saved. Conclusion： The optimized ELISA is an ideal method for the determination of tetrodotoxin.

Secretory Expression of E2 Main Antigen Domain of CSFV C Strain and the Establishment of Indirect ELISA Assay

The sequence encoding an E2 main antigen glycoprotein of the C strain of classical swine fever virus (CSFV) was highly expressed in the host cell E. coli BL21–CodonPlus (DE3)–RIL using the pGEX-4T-1 expression vector and the soluble recombinant product was purified with Glutathione Sepharose TM4B by centrifugation. The soluble recombinant protein showed good immune reactions and was confirmed by Western blot using anti-CSFV-specific antibodies. Then an indirect ELISA with the purified E2 protein as the coating antigen was established to detect antibody against CSFV. The result revealed that the optimal concentration of coated antigen was 0.6 μg/well and the optimal dilution of serum was 1:80. The positive cut-off value of this ELISA assay was OD tested serum / OD negative serum≥2.1. The E2-ELISA method was evaluated by comparison with the indirect hemagglutination test (IHAT). When a total of 100 field serum samples were tested the sensitivity and specificity were 90.3% and 94.7% respectively. Specificity analysis showed that there were no cross-reactions between BVD serum and the purified E2 protein in the E2-ELISA.

Interactions of the HSV-1 UL25 Capsid Protein with Cellular Microtubule-associated Protein

An interaction between the HSV-1 UL25 capsid protein and cellular microtubule-associated protein was found using a yeast two-hybrid screen and β-D-galactosidase activity assays. Immunofluorescence microscopy of the UL25 protein demonstrated its co-localization with cellular microtubule-associated protein in the plasma membrane. Further investigations with deletion mutants suggest that UL25 is likely to have a function in the nucleus.

Checkpoint inhibitors in gastrointestinal cancers:Expectations and reality

Immune checkpoint inhibitors represent revolutionary anti-cancer agents, being rapidly approved in different malignancies and settings. Gastrointestinal(GI) cancers represent a wide variety of tumors with specific characteristics and different responses to various therapeutic alternatives; while some are chemosensitive others are chemo-resistant and only respond to more aggressive cytotoxic regimens, targeted therapies or a combination of both. Preliminary results of immune checkpoint inhibitors in some GI cancers are promising, namely in hepatocellular carcinoma, anal cancers and microsatellite instability high colorectal cancers. An impressive instead of a impressive number of immune checkpoint inhibitors are being evaluated in different indications in GI cancers as single agents or in combination with other agents. We reported in this paper ongoing and published trials evaluating immune checkpoint inhibitors in hepatocellular carcinoma and biliary tract cancers, esophageal, gastric, pancreatic, colorectal and anal cancers and we discussed the future perspectives of these agents in GI cancers.

Correlation of p53 over-expression and alteration in p53 gene detected by polymerase chain reaction-single strand conformation polymorphism in adenocarcinoma of gastric cancer patients from India

AIM： To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS： A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） analysis. We only studied four （exon 5, 6, 7, and 8） of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS： Among 103 cases, p53 over-expression and alteration were detected in 37 （35.92%） and 19 （18.44%） cases, respectively. Most of the ,p53 alterations were found at exon 5 （31.54%）, followed by exon 6 （26.31%）, exon 7 （21.04%） and exon 8 （21.04%）. A significant correlation of p53 overexpression was found with p53 alteration （P = 0.000）. Concordance between ,p53 alteration （as detected by SSCP） and over-expression [as detected by immunohistochemistry （IHC）] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION： Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.

High level of ezrin expression in colorectal cancer tissues is closely related to tumor malignancy

AIM:To investigate the ezrin expression in normal colorectal mucosa and colorectal cancer tissues, and study the correlation between ezrin expression in colorectal cancer tissues and tumor invasion and metastasis.METHODS: Eighty paraffin-embedded cancer tissue samples were selected from primary colorectal adenocarcinoma. Twenty-eight patients had well-differentiated, 22 had moderately differentiated and 30 had poorly differentiated adenocarcinoma. Forty-five patients and 35 patients had lymph node metastasis. Forty-five patients were of Dukes A to B stage, and 35 were of C to D stage. Another 22 paraffi n-embedded tissue blocks of normal colorectal epithelium (>5 cm away from the edge of the tumor) were selected as the control group. All patients with colorectal cancer were treated surgically and diagnosed histologically, without preoperative chemotherapy or radiotherapy. The immunohistochemistry was used to detect the ezrin expression in paraffin-embedded normal colorectal mucosa tissues and colorectal cancer tissue samples.RESULTS: Ezrin expression in colorectal cancer was significantly higher than in normal colorectal mucosa (75.00% vs 9.09%, P<0.01), and there was a close relationship between ezrin expression and the degree of tumor differentiation, lymph node metastasis and Dukes stage (88.46% vs 50.00%, P<0.01; 94.28% vs 51.11%, P<0.01; 94.28% vs 51.11%, P<0.01).CONCLUSION: Ezrin expression is obviously higher in colorectal cancer tissues than in normal colorectal mucosa tissues, and the high level of ezrin expression is closely related to the colorectal cancer invasion and metastasis process.

Fueling the engine and releasing the break: combinational therapy of cancer vaccines and immune checkpoint inhibitors

Immune checkpoint inhibitors are increasingly drawing much attention in the therapeutic development for cancer treatment. However, many cancer patients do not respond to treatments with immune checkpoint inhibitors, partly because of the lack of tumor-infiltrating effector T cells. Cancer vaccines may prime patients for treatments with immune checkpoint inhibitors by inducing effector T-ceU infiltration into the tumors and immune checkpoint signals. The combination of cancer vaccine and an immune checkpoint inhibitor may function synergistically to induce more effective antitumor immune responses, and clinical trials to test the combination are currently ongoing.

B Cell Epitopes within VP1 of Type O Foot-and-mouth Disease Virus for Detection of Viral Antibodies

In this study, the coding region of type O FMDV capsid protein VP1 and a series of codon optimized DNA sequences coding for VP1 amino acid residues 141-160 （epitopel）, tandem repeat 200-213 （epitope2 （＋2）） and the combination of two epitopes （epitopel-2） was genetically cloned into the prokaryotic expression vector PPRoExHTb and pGEX4T-1, respectively. VP1 and the fused epitopes GST-E1, GST-E2 （＋2） and GST-E1-2 were successfully solubly expressed in the cytoplasm of Escherichia coli and Western blot analysis demonstrated they retained antigenicity. Indirect VP1-ELISA and epitope ELISAs were subsequently developed to screen a panel of 80 field pig sera using LPB-ELISA as a standard test. For VP1-ELISA and all the epitope ELISAs, there were clear distinctions between the FMDV-positive and the FMDV-negative samples. Cross-reactions with pig sera positive to the viruses of swine vesicular disease virus that produce clinically indistinguishable syndromes in pigs or guinea pig antisera to FMDV strains of type A, C and Asia1 did not occur. The relative sensitivity and specificity for the GST-E1 ELISA, GST-E2 （＋2）, GST-E1-2 ELISA and VP1-ELISA in comparison with LPB-ELISA were 93.3% and 85.0%, 95.0% and 90%, 100% and 81.8%, 96.6% and 80.9% respectively. This study shows the potential use of the aforementioned epitopes as alternatives to the complex antigens used in current detection for antibody to FMDV structural proteins.

PI3K expression and PIK3CA mutations are related to colorectal cancer metastases

AIM: To assess the significance of phosphatidylinositol 3-kinase (PI3K) in colorectal cancer (CRC) and toxicity of LY294002 in CRC cells with different metastatic abilities. METHODS: Sixty formalin-fixed and paraffin-embedded CRC tumor specimens were investigated. Adjacent normal colonic mucosa specimens from 10 of these cases were selected as controls. PI3K protein was detected by immunohistochemistry and PIK3CA mutations were investigated by gene sequencing analysis. A flowcytometry-based apoptosis detection kit was used to determine PI3K inhibitor-induced apoptosis in CRC cell lines SW480 and SW620. Expression of phosphorylated protein kinase B in CRC cell lines was detected by Western blotting. RESULTS: There was a significant difference in the proportion of primary lesions (30%, 18/60) vs metastatic lesions (46.7%, 28/60) that were positive for PI3K (P < 0.05). Mutations were detected in exon 9 (13.3%) and exon 20 (8.3%). Out of 60 cases, seven mutations were identified: two hotspot mutations, C.1633G>A resulting in E545A, and C.3140A>G resulting in H1047R; two novel missense mutations C.1624G>A and C.3079G>A; and three synonymous mutations (C.1641G>A, C.1581C>T and C.3027T>A). Exposure of SW480 cells to PI3K inhibitor for 48 h resulted in a significant increase of apoptotic cells in a dose-dependent manner [3.2% apoptotic cells in 0 μmol/L, 4.3% in 5 μmol/L, 6.3% in 10 μmol/L (P < 0.05), and 6.7% in 20 μmol/L (P < 0.05)]. Moreover, PI3K inhibitor induced a similar significant increase of apoptotic cells in the SW620 cell line for 48 h [3.3% apoptotic cells in 0 μmol/L, 13.3% in 5 μmol/L (P < 0.01), 19.2% in 10 μmol/L (P < 0.01), and 21.3% in 20 μmol/L (P < 0.01)]. CONCLUSION: High PI3K expression is associated with CRC metastasis. PI3K inhibitor induced apoptosis in CRC cells and displayed strong cytotoxicity for highly metastatic cells. PI3K inhibition may be an effective treatment for CRC.

A Simple and Rapid Colloidal Gold-based Immunochromatogarpic Strip Test for Detection of FMDV Serotype A

A sandwich format immunochromatographic assay for detecting foot-and-mouth disease virus (FMDV) serotypes was developed. In this rapid test,affinity purified polyclonal antibodies from Guinea pigs which were immunized with sucking-mouse adapted FMD virus (A/AV88(L) strain) were conjugated to colloidal gold beads and used as the capture antibody,and affinity purified polyclonal antibodies from rabbits which were immunized with cell-culture adapted FMD virus (A/CHA/09 strain) were used as detector antibody. On the nitrocellulose membrane of the immunochromatographic strip,the capture antibody was laid on a sample pad,the detector antibody was printed at the test line(T) and goat anti-guinea pigs IgG antibodies were immobilized to the control line(C). The lower detection limit of the test for a FMDV 146S antigen is 11.7ng/ml as determined in serial tests after the strip device was assembled and the assay condition optimization. No cross reactions were found with FMDV serotype C,Swine vesicular disease (SVD),Vesicular stomatiti svirus (VSV) and vesicular exanthema of swine virus (VES) viral antigens with this rapid test. Clinically,the diagnostic sensitivity of this test for FMDV serotypes A was 88.7% which is as same as an indirect-sandwich ELISA. The specificity of this strip test was 98.2% and is comparable to the 98.7% obtained with indirect-sandwich ELISA. This rapid strip test is simple,easy and fast for clinical testing on field sites; no special instruments and skills are required,and the result can be obtained within 15 min. To our knowledge,this is the first rapid immunochromatogarpic assay for serotype A of FMDV.

Clinical significance of human kallikrein 12 gene expression in gastric cancer

AIM:To investigate whether the expression of kallikrein 12(KLK12) is related to the development of gastric cancer(GC) and to determine the role of KLK12 in gastric cancer cells growth,invasion and migration.METHODS:Between September 2007 and March 2008,133 patients with histologically confirmed GC were recruited for the study.Expression of KLK12 was detected in samples from GC patients by quantitative real-time reverse transcription polymerase chain reaction and immunohistochemistry.The relationship between KLK12 protein expression and clinicopathological features of GC was analyzed.The difference in 5-year survival rates between the high KLK12 protein expression group and the low KLK12 expression group was compared.Additionally,the expression of KLK12 was examined in various human GC cell lines,including MKN-28,SGC-7901 and MKN-45.Small interfering RNA(siRNA) was used to inhibit KLK12 expression in MKN-45 cells.Cell clones stably transfected with KLK12 siRNA were tested for KLK12 expression by quantitative real-time reverse transcription-polymerase chain reaction and Western blotting.Furthermore,a series of functional assays were performed in this study to assess the biological features of transfected cells.Cell proliferation was assessed using the methylthiazolyltetrazoliumassay.Finally,cell migration and invasion were assessed using transwell chamber assays.RESULTS:Of the 133 GC patients included in the study,126(94.7%) showed a higher expression level of KLK12 mRNA when compared to noncancerous tissue specimens.Expression of KLK12 mRNA was significantly higher in GC tissues than in normal tissue(P < 0.001).KLK12 protein expression was detected in 96 of 133(72.2%) GC samples with moderate or strong staining primarily in the cytoplasm.In contrast,negative immunostaining for KLK12 protein was observed in the corresponding normal gastric mucosal tissue.Overexpression of KLK12 protein was significantly associated with lymph node metastasis(P = 0.001),histological type(P < 0.001) and tumor-node-metastasis stage(P = 0.005),while no significant correlation was observed between expression of KLK12 protein and sex,age,depth of invasion,tumor size or lymphatic invasion.Furthermore,patients with high KLK12 expression had a significantly poorer 5-year survival rate than those with low KLK12 expression(P = 0.002).Expression of KLK12 mRNA was significantly higher in MKN-45 GC cells compared to normal mucosal cells or two other GC cell lines(P < 0.01).Expression of KLK12 in MKN-45 cells was downregulated after transfection with siRNA.Knockdown of KLK12 markedly decreased the proliferation of MKN-45 cells when compared with parent or mock-transfected cells(P = 0.001),especially from the 3rd to the 5th day of the assay.In migration assays,fewer KLK12 siRNA cells migrated through the chambers(22.00 ± 1.81) when compared to the parent(46.47 ± 2.42) or mock-transfected cells(45.40 ± 1.99);these differences were statistically significant(P < 0.001).However,in the invasion assay,the number of KLK12 siRNA cells that invaded the chambers was 18.40 ± 1.12,closely similar to both the parent(18.67 ± 0.98) and mock-transfected cells(18.53 ± 0.92).There was no significantly difference between the three groups in the invasion assay(P = 0.054).CONCLUSION:The KLK12 gene is markedly overexpressed in GC tissue,and its expression status may be a powerful prognostic indicator for patients with GC.KLK12 might serve as a novel diagnosis and prognosis biomarker in GC.

Detection of Intracellular Cytokine Production in Peripheral Blood CD_^+ T Cells of Patients with Recurrent Genital Herpes

Objective: To study the role of Th1/Th2 cytokines in thepathogenesis of recurrent genital herpes (RGH), and tobetter understand the relationship between them. Methods: A two-color immunofluorescent staining of cellsurface antigen and intracellular cytokines for flowcytometric analysis was used for CD_3, IL-2, IL-10, IL-12,IFN-γ and TNF-α in CD_3^+ T-lymphocytes in activatedperipheral blood mononuclear cells of patients with RGH. Results: Compared to controls, patients with RGHshowed fewer CD_3^+ T cells (P<0.05) and IL-2 producing andIFN-γ producing T cells (P<0.02 and P<0.001, respectively)after in vitro stimulation with PMA and ionomycin in thepresence of a protein transport inhibitor. More IL-10producing and IL-12 producing T cells were found inpatients with RGH (P<0.01). There was no significantdifference in the number of TNF-α producing cells betweenRGH patients and controls (P<0.05). Conclusion: RGH patients showed relatively more Th2cytokines. The imbalance between Th1 and Th2 cytokinesresults in inhibitory effects on a series of cell-immuneresponses, which may play an important role in thepathogenesis of RGH.

SIMPLE METHOD OF PUNCHING AND RE-LOCATING TISSUES FOR MANUAL CONSTRUCTION OF TISSUE MICROARRAY

A series of human tissue samples and cultured cell lines were formalin-fixed and paraffin-embedded. Specimen cylinder （1.2 -1.8ram） were punched by a modified bone marrow biopsy needle and arrayed on a recipient paraffin block. Microscopic analysis on the sections from this tissue microarray （ TMA ） block demonstrated that the spots of tissues and cells were well preserved, and the cultured cell samples were successfully embedded from 5 × 104 to 2 × 105 in number. These TMA sections were also suitable for immunohistochemistry and RNA in situ hybridization.

Reduced Popdc3 expression correlates with high risk and poor survival in patients with gastric cancer

AIM： To investigate the expression of Popeye domain containing 3 （Popdc3） and its correlation with clinicopathological features and prognosis of gastric cancer.METHODS： The method of immunohistochemistry was used to investigate the expression of Popdc3 in 306 cases of human gastric cancer and 84 noncancerous gastric tissues. Simultaneously, the relationship between Popdc3 expression and the survival of the patients was retrospectively analyzed.RESULTS： Popdc3 was detected in 72 （85.71%） of 84 human nontumor mucosa. High expression of Popdc3protein was detected in 78 （25.49%） of 306 human gastric cancer cases, and low expression was detected in 228 （74.51%）. Low expression of Popdc3 correlated with depth of invasion （P 〈 0.0001）, regional lymph nodes （P 〈 0.0001） and distant metastasis （P =0.02）, and tumor, nodes, metastasis （TNM） stages （P 〈 0.0001）. On multivariate analysis, only the patient＇s gender, regional lymph node metastasis, distant metastasis, TNM stages, and the expression of Popdc3 were independent prognostic factors in patients with gastric cancer. The Kaplan-Meier plot showed that low Popdc3 expression had a much more significant effect on the survival of those patients with early-stage tumors X^2 = 104.741, P 〈 0.0001）, with a 〉 51.9% reduction in the three-year survival compared with high Popdc3 expression. In late stages, the difference was also significant X^2 = 5.930, P = 0.015）, with a 32.6% reduction in the three-year survival.CONCLUSION： Reduced expression of Popdc3 may play a significant role in the carcinogenesis and progression of gastric cancer. Popdc3 may be an independent prognostic factor.

THE MEASUREMENT AND APPLICATION OF TSH－IRMA LEVELS AMONG DIFFERENT AGE GROUPS IN AREAS WITH IODINE DEFICIENCY DISORDERS

Using immunoradiornetric TSH assay (TSH-IRMA) to measure whole blood TSH levels spotted onto filter paper, we compared TSH levels among different age groups (neonates, <1 yr infants, schoolchildren aged 7 to 14 yrs, adults,pregnant women and reproductive-age women) in Guiyang, where iodine deficiency has long been a problem. The results showed: 1) The percentage of subjects with TSH levels equal to or greater than 5 mIU/L in the neonate group was 38.9% while the percentages in the other groups were 0-3.3% (P<0.01); 2)The TSH levels of the neonates were inversely related to the urinary iodine values of their mothers (pregnant women). (r=-0. 5, P<0. 01);3)97.6% of the inhabitants in Guiyang ingested salt with less than 20mg/kg iodine. The results indicate that iodine deficiency remains a problem in Guiyang. Neonates are the only ideal population for monitoring iodine deficiency.

A Semi-quantitative Serological Method to Assess the Potency of Inactivated Rabies Vaccine for Veterinary Use

Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the "prescribed methods".Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.