The preparation of polyclonal antibody against chlordimeform and establishment of detection by indirect competitive ELISA.

Objective: Chlordimeform is a chemical pesticide that is highly carcinogenic and toxic. The purpose of this study was to establish an enzyme-linked immunosorbent assay (ELISA) method for the detection of chlordimeform in aquaculture and fish farming. METHODS: Chlordimeform was coupled with bovine serum albumin (BSA) and ovalbumin (OVA) as carrier proteins. A chlordimeform-BSA conjugate was used as an immunogen, and chlordimeform-OVA was used as a coating antigen. Chlordimeform-BSA was used to immunize rabbits, and a polyclonal antibody was prepared. An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was established to detect chlordimeform. RESULTS: The working range of the established IC-ELISA method for chlordimeform detection was 1-20 ng/mL. The IC50 was 3.126 ng/mL, and the lower limit of detection (LOD) of chlordimeform was 0.637 ng/mL. The recovery of chlordimeform from spiked water samples ranged from 81% to 107%. CONCLUSION: An anti-chlordimeform polyclonal antibody was successfully developed, and a novel IC-ELISA was established to detect chlordimeform in aquaculture.

[A point mutation of protein C gene in a congenital protein C deficiency pedigree].

OBJECTIVE: To study the phenotypes and genotypes of a protein C (PC) deficiency pedigree. METHODS: Immunoassay (ELISA) was used for PC antigen and activated PC (APC) detection, PCR for amplification of the fragment of protein C gene exon II to exon IX, single-strand conformation polymorphism (SSCP) for difference of denatured cDNA and DNA sequencing for gene mutation. RESULTS: Four members in the pedigree were found to be PC antigen levels between 34.3% - 67.8% and PC activity between 22% - 49% which are lower in comparison with normal references (80% - 120% and 70% - 130%, respectively). A G-to-A mutation in exon VII of the protein C gene at 6 219 position was identified in 9 members. This mutation resulted in the substitution of Arg for Gln at 169 amino acid. CONCLUSION: The proband is of heterozygosity. The G6219 A mutation in exon VII of the protein C gene leads to the substitution of Arg 169 Gln. This mutation is reported for the first time in China.

[Clinical and molecular-biological study of a May-Hegglin anomaly family].

OBJECTIVE: To study the changes of platelet in May-Hegglin anomaly (MHA) and the molecular pathogenesis mechanism. METHODS: Peripheral blood was drawn from the MHA proband, her father and her uncle. Platelet count and morphology were examined by automatic blood cell counter and microscopy, respectively. The platelet membrane protein was examined by flow cytometry. Membrane antibodies were determined by ELISA. PCR was used to amplify the exons 25, 31 approximately 32, 38 and 40 of the MYH 9 gene in the MHA patient and her diseased father. Furthermore, PCR products were sequenced, a specific point mutation was identified and inclusions (Dohle's body) in the neutrophil was detected by indirect immunofluorescence technique. RESULTS: It was proved that in MHA patients, platelet count was higher by cell counter than by microscope (P < 0.01). Giant platelet was 94% but platelet membrane proteins (CD41, CD61, CD42A, CD42b) were in normal range. Membrane antibodies was undetectable. An A5521G mutation (GAG-->AAG) in the exon 38 was found in the proband and her diseased father, resulting in a characteristic change of NMMHC-A1841 (Glutamic acid-->Arginine), which was not found in other members of the family and in normal controls. Spindle-like inclusions with fluorescence were clearly displayed in neutrophil cytoplasm. CONCLUSION: The molecular pathogenesis mechanism of May-Hegglin anomaly is the mutation in MYH 9 gene.