Dynamics of specific antibody and circulating antigen in serum from the mice infected with Armillifer agkistrodontis / 中国人兽共患病学报

In this study,adults of Armillifer agkistrodontis (A.agkistrodontis) were collected from Agkistrodon acutus,and then the eggs were separated to feed mice.In the next step,when the infection model was established,blood serum of infected mice were collected after 1,2 and 3 weeks,respectively.Furthermore,ELISA and dot- ELISA were used to detect the dynamic change of specific antibodies and circulating antigens respectively.The specific antibodies increased from 8th week,reached the top at 12th week,decreased from 16th week,and then maintain at the same level constantly.Meanwhile,the specific antibodies were typed.It is evident that IgM antibody appeared first.However,it was substitute by IgG1 after 16 weeks.Moreover,the circulating antigens have been detected in the 1st week by dot-ELISA.Then,the dilution between 1:8 to 1:128were founded in 3rd week.The highest dilution with 1:256 appeared at 8th week,maintained before 11th week and then decreased gradually,which might provide a significant clinical implication for early diagnosis of circulating antigens.

Parallel detection of the circulating antigens and antibodies in the diagnosis of schistosomiasis / 中国人兽共患病学报

To determine the diagnostic efficiency of parallel detection of the circulating antigens and antibodies in schistosomiasis, sandwich ELISA and indirect ELISA by using the labeled McAb JPG3 were used to detect the presence of the circulating antigens and the circulating IgG antibodies in serum samples from different kinds of population. and then the sensitivity and specificity of this method of testing as well as the efficiency of the application of this method in heavy endemic area. were determined in comparison with serial test. It was found that the sensitivity and specificity of the parallel test were 97.9% and 92.2% , however, those of the serial test were 76.0% and 99.2% respectively. The positive rates of parallel test and serial test to detect the stool examination-positive for schistosoma eggs in population of the endemic area were 94.6% (35/37) and 67.6% (25/37), while those to detect the stool examination-negative for schitosoma eggs were 69.8% (97/139) and 39.6% (55/139) respectively. It is apparent the parallel test for the detection circulating antigens and antibodies in schistosomiasis shows its high diagnostic efficiency, especially in the heavy endemic area of schitosomiasis.

Determination of Circulating Antigen in Neurocysticercosis Patients by Monoclonal Antibody / 热带医学杂志

Objective To detect circulating antigen (Cag) for diagnosing neurocysticercosis. Method ELISA was performed with monoclonal antibody 4B6 against the cyst fluid antigen of Cyticercus cellulosae for detecting Cag in serum and/or cerebrospinal fluid (CSF) of patients with neurocysticercosis or with other diseases. Results In the group of 82 cases of neurocysticercosis, the positive rate of serum Cag was 79.2% (65/82) and the positive rate of CSF Cag was 100% (26/26). After chemotherapy for 20 cases with positive serum Cag, the titer of serum Cag in 17 cases dropped to zero(85% ). Cag could not be detected in specimens from patients with other diseases. Conclusion These results indicate that the determination of Cag, especially of the CSF Cag, is useful for the diagnosis of neurocysticercosis and the drop in serum Cag is a good parameter for the evaluation of the effectiveness of chemotherapy.

Highly sensitive Immuno-PCR assay for the detection of the circulating antigens in trichinellosis / 中国人兽共患病学报

A highly sensitive immuno-PCR assay based on sandwich ELISA and PCR was developed to detect the circulating antigen in trichinellosis. Antigens were purified from the muscle larvae of Trichinella spiralis, and the myeloma cells were fused with spenocytes immunized with T. spiralis antigens to product the specific monoclonal antibodies. Indirect ELISA was used to select the antibody-secreting hybrodoma cells. By this method of procedure, monoclonal antibody F4C6 against the T. spiralis ES antigen was obtained, which was used as the indicator antibody, while the rabbit polyclonal antibodies against T. spiralis were to be used as capturing antibodies. The plasmid Bluecript Ⅱ KS was amplified by PCR with biotin-labeled primer M13-20, and thus the biotin-labeled DNA was obtained. Both the second antibody and DNA labeled with biotin were to be linked with 100 ng/ml avidin. The whole procedures of assay consisted of two steps, in which the circulating antigens were captured by monoclonal antibody through sandwich ELISA in the first step, and the DNA linked by monoclonal antibody was amplified by PCR in the second step. The sensitivity of this method was compared with that of the ELISA assay. It was found that the measuring ranges to detect the circulating antigens in trichinellosis were 50 pg/L to 0.005 pg/L for the immuno-PCR assay, and 5 μg/L to 0.05 μg/L for ELISA assay, the former was quite higher than that of the latter. It is evident that this method is highly sensitive for the detection of circulating antigens in trichinellosis.

Preparation and Preliminary Application of Monoclonal Antibodies Against Adult Worm of Angiostrongylus cantonensis / 中国寄生虫学与寄生虫病杂志

Objective To develop and identify monoclonal antibodies (McAbs) against adult worm of Angiostrongylus cantonensis and observe its applicability. Methods BALB/c mice were immunized with soluble antigen of adult worms of A.cantonensis. The spleen cells of immunized mice were fused with myeloma cell, and the hybridoma secreting high titer of McAbs with high specificity was screened. By using the McAbs, serum of angiostrongyliasis patient and sera of the rats infected with A.cantonensis were detected by Western blotting and double antibody sandwich ELISA respectively. Results Three McAbs were established (2A2,3F1,4H2), which all showed no cross reaction with antigens of Schistosoma japonicum, Paragonimus westermani, Cysticercus cellulosae and Trichinella spiralis. Western blotting analysis demonstrated that the three McAbs recognized a Mr 15 000 soluble antigen of adult worm of A.cantonensis and recognized the Mr 24 000 and Mr 15 000 circulating antigens from the serum of angiostrongyliasis patient. The double antibody sandwich ELISA detection showed a positive rate of 76

DETECTION OF CAg IN CSF OF 231 CEREBRAL CYSTICERCOSIS PATIENTS / 中国寄生虫学与寄生虫病杂志

The results of detection of circulating antigen(CAg) in cerebrospinal fluids(CSF) of 231 cerebral cysticercosis patients with McAb(4F8)-based ELISA were reported and compared with the case histories , clinical manifestations and CT scans. No relationship was found between CAg detected in CSF of these cases and history of taeniasis. However, the positive rate of CAg in cerebral cysticercosis patients with subcutaneous nodules was found significantly higher than those in cases with simple cerebral cysticercosis and in cases with subcutaneous nodules disappeared after anti-Cysticercus therapy before CSF collection. The results of CAg detection in CSF were related with the CT findings as well as the stage of the disease. It is thus indicated that MeAb(4F8)-based ELISA might be useful not only for diagnosis of neurocysticercosis, but also for the evaluation of efficacy of anti-Cysticercus therapy.