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OBJECTIVE: To evaluate the bacteriostatic effect of ε-polylysine( ε-PL) on four common putrefactive bacteria including Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli and its effect on urine lead level. METHODS: Broth dilution method was used for the determination of the minimum inhibitory concentration( MIC) ofε-PL on the four kinds of putrefactive bacteria; the inhibitory effects of ε-PL with final mass concentration of 40. 000 mg / L on the urine sample were observed; graphite furnace atomic absorption spectrometry was used for determining the lead level in the 40. 000 mg / L( mass concentration) ε-PL solution and the urine lead level in normal healthy groups; the bacteriostatic effects of ε-PL and nitric acid were compared. RESULTS: The MIC of ε-PL on Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli was 40. 000 mg / L. There was no bacterial growth in the urine sample with40. 000 mg / L( mass concentration) ε-PL when urine was kept at room temperature for 24 hours to 15 days. The lead level was < 2. 0 μg / L in the 40. 000 mg / L( mass concentration) ε-PL solution. When the ε-PL with final mass concentration of 40. 000 mg / L and the nitric acid with a volume fraction of 1. 0% were respectively used as the antiseptics,the descending rates of the lead levels in the urine samples were similar,and after the urine sample was preserved for 15 days,the descending rates of the urine lead were both smaller than 10. 0% after be stored for 15 days. CONCLUSION: ε-PL can substitute nitric acid as a new natural preservative for preservation of samples for urine lead determination.
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Objective To provide the scientific basis for realizing the inter-accreditation of laboratory electrolyte detection results by comparing the electrolyte detection results in 5 grade 3A hospitals of Zhuhai city .Methods Each 10 serum samples with low , middle and high concentrations of electrolyte were collected for simultaneously detecting the electrolyte kalium (K) ,natrium (Na) and chlorinum (Cl) .The detection results were performed the statistical analysis and comparison .The mutual bias within 1/2 of al-lowable error of CLIA′88 indicated that the detection results were mutually accredited ,if the mutual bias exceeding 1/2 of allowable error ,the detection results could not be mutually accredited .Results The difference of electrolyte detection results in 5 hospitals accorded with the stipulation requirement of CLIA′88 .Conclusion The electrolyte detection results of 5 hospitals could be mutually accredited .
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Objective To evaluate whether the comparability of 3 automatic blood cell analyzers meet the clinical requirements by conducting the comparative study on the detection results of these instruments.Methods With the Sysmex 2100 automatic blood cell analyzer as the reference instrument,Sysmex 1000i and Abbott 1800 as the experimental instrument,the original quality control provided by the instrument factory and the patient′s fresh anticoagulant blood samples in the laboratory were adopted to monitor for continuous 40 d by these three instruments and the detection results of WBC,RBC,HGB,HCT and PLT were analyzed.Results The detection results of these 3 instruments were statistically tested by the F test,the differences showed no statistical significance (P >0.05)and the bias was in 1/2 of the maximum permissible error range in America department clinical test revised regulations (CLIA′88).Conclusion The detection results by these 3 instruments are comparable and can meet the clinical requirements.
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Ticks transmit various diseases to livestock and human beings. The researches on ticks are of great importance in medical and veterinary sciences. To express a glutathione peroxidase gene (HlGPx) from Hemaphysalis longicornis in Escherichia coli (E. coli) so as to provide basis for further studies, the gene was amplified from cDNAs of H. longicornis adult ticks by PCR prompted by information from EST library. The TGA codon encoding selenocysteine in the gene was mutated into the universal genetic code for cysteine,TGC, by site-directed mutagenesis. E. coli was transformed with the recombinant expression vector pGEX-4T-1/HlGPx'(the mutated HlGPx) and induced to express recombinant HlGPx', which was then analyzed by sodium dodecylsulphate-polyacrylamide gel electrophoresis and Western blotting. The result showed that the complete coding sequence of HlGPx was obtained successfully, the deduced polypeptide was 223 aa, with a calculated molecular mass of 25.0 kDa; the recombinant fusion protein was approximately 51 kDa, correspondent to the calculated. The antibody against glutathione S-transferase (GST) recognized the recombinant protein fused with GST in a Western blotting assay, which confirmed the result above-mentioned. In conclusion, the mutated HlGPx was expressed in E. coli successfully and it could be used for further preparation of immune serum and functional analysis.
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Objective To study the expression and clinical significance of TNF related apoptosis-inducing ligand(TRAIL) and Caspase-3 in the bone marrow mononuclear cell(BMMNC) of aplastic anemia(AA) ,and to approach their effect on the apoptosis of haemopoietic stem cell in AA patients.Methods The TRAIL and Caspase-3 expression in 15 cases with newly diagnosed AA patients and remission patients,and 15 cases with normal bone marrow patients were detected by flow cytometry and microplate reader. Results The TRAIL expression of newly diagnosed AA patient, emission AA patients and control group was ( 5.94 ± 2. 57 ) ％, ( 2. 87 ± 1. 72 ) ％ and ( 3.01 ±2. 06)％ respectively,the Caspase-3 expression of newly diagnosed AA patient, emission AA patients and control group was ( 1. 3840 ± 0. 0236), (0. 8018 ± 0. 0126) and ( 0. 7441 ± 0. 0112 ) respectively. The TRAIL and Caspase-3 expression of newly diagnosed AA patient were significantly higher than the remission AA patients and control group,the difference was significant( all P ＜0. 05) ;The TRAIL and Caspase-3 expression of control group were higher than the remission AA patients, but the difference was not significant ( all P ＞ 0. 05 ). Conclusion The TRAIL and Caspase-3 had high expression in the BMMNC of AA patients, and the apoptosis induced by TRAIL and Caspase-3 should play an important role in the pathogenesis of AA.