The accreditation of Proficiency Testing Provider ( PTP) has gone through more than a decade in China.Over the past ten years, from nonexistence to existence, the domestic PTPs in the area of laboratory medicine have gradually standardized and developed.By reviewing the international and domestic practice, this paper gives an outline of the present status of the accreditation of PTP in the area of laboratory medicine, explores the difference with other countries, the main problems and some suggestions for improvement, and makes a prospect of the development of the accreditation of PTP in the area of laboratory medicine in China.

The activity of the NK cells in patients with preeclampsia was studied to investigate the pathogenesis of preeclampsia. By using MTT and 51Cr releasing technique, the proliferation and killing ability of the NK cells in maternal and umbilical blood from preeclampsia patients (n = 18) and normal third trimester pregnant women (n = 18) were detected. The NK-92 cell line was as the positive control. The results showed that the NK cell counts of umbilical blood in preeclampsia patients and normal third trimester pregnant women were significantly greater than those of maternal blood (both P<0.05). Compared with that in normal third trimester pregnant women, the proliferative ability of the NK cells in preeclampsia patients was apparently increased (P<0.05). Compared with that in maternal blood, the proliferative ability of the NK cells in umbilical blood from both preeclampsia patients and normal third trimester pregnant women was dramatically increased. The killing ability of the NK cells in preeclampsia patients was significantly higher than that in normal third trimester pregnant women (P <0.05). It was suggested that both number and function of the NK cells in preeclampsia women were increased, and that in umbilical blood was greater than that in maternal blood, speculating that the function of the NK cells may affect the maintenance of the maternal and fetal immune tolerance during pregnancy.
Cytotoxicity, Immunologic/*immunology ; Fetal Blood/cytology ; Immune Tolerance ; Killer Cells, Natural/*immunology ; Killer Cells, Natural/pathology ; Pre-Eclampsia/blood ; Pre-Eclampsia/*immunology ; Pregnancy Trimester, Third

The spike (S) and nucleocapsid (N) proteins, which are responsible for viral binding to cell surface receptors and the formation of ribonucleoprotein complexes during virion assembling, are major structure proteins of severe acute respiratory syndrome coronavirus (SARS-CoV). The expression of recombinant protein may give more accurate result for detecting SARS-CoV infection. A novel fusion protein,comprising of two fragments of N and S proteins from SARS-CoV, was prepared. Our computer-assisted analysis suggested that the immunodominant domains were located in the amino acid residues 1-227 of N protein and 450-650 of S protein, further the fusion of the two fragments did not change the immunochemical characteristics. The complementary DNA(cDNA) encoding N1-227 fused with S450-650 was obtained by sequence overlapping extension (SOE), and named NLS. It was cloned into pET-28a ( + ), an expression vector for His-tag fusion protein. This new constructed fusion protein was prokaryotic expressed in E. coli,and purified by metal chelate affinity chromatography with the purity over 95 %. The purified fusion protein was identified by anti-His monoclonal antibody and convalescence SARS patients serum. The NLS protein based ELISA showed that NLS maintained appropriate antigenicity and specificity to react with the sera of convalescent SARS patients. The functional NLS protein were successfully expressed and purified. And the fusion protein based ELISA can be used for detection of antibodies (Abs) against the S and N proteins of SARS-CoV. It may provided a novel diagnostic tool and have the potential application in developing of anti-SARS vaccine.

The activity of the NK cells in patients with preeclampsia was studied to investigate the pathogenesis of preeclampsia. By using MTT and 51Cr releasing technique, the proliferation and killing ability of the NK cells in maternal and umbilical blood from preeclampsia patients (n = 18) and normal third trimester pregnant women (n = 18) were detected. The NK-92 cell line was as the positive control. The results showed that the NK cell counts of umbilical blood in preeclampsia patients and normal third trimester pregnant women were significantly greater than those of maternal blood (both P<0.05). Compared with that in normal third trimester pregnant women, the proliferative ability of the NK cells in preeclampsia patients was apparently increased (P<0.05). Compared with that in maternal blood, the proliferative ability of the NK cells in umbilical blood from both preeclampsia patients and normal third trimester pregnant women was dramatically increased. The killing ability of the NK cells in preeclampsia patients was significantly higher than that in normal third trimester pregnant women (P <0.05). It was suggested that both number and function of the NK cells in preeclampsia women were increased, and that in umbilical blood was greater than that in maternal blood, speculating that the function of the NK cells may affect the maintenance of the maternal and fetal immune tolerance during pregnancy.
Adult ; Cytotoxicity, Immunologic ; immunology ; Female ; Fetal Blood ; cytology ; Humans ; Immune Tolerance ; Killer Cells, Natural ; immunology ; pathology ; Pre-Eclampsia ; blood ; immunology ; Pregnancy ; Pregnancy Trimester, Third

Objective To investigate the effects of dorsal hippocampal lesions (DH) or fimbria-fornix transection (FF) on the learning and memory of conditioned fear and the heart rate and blood pressure in rats.Methods Nineteen male adult Wistar rats were used in this experiment.They were implanted telemetry sensors in their abdominal aortas.Two week later,six of the rats were subjected to permanent NMDA-induced neurotoxic lesions to the dorsal hippocampus (DH) and seven for the fimbria-fornix transection (FF)through stereotactic brain surgery,the left six were treated with saline as the control (Sham).All rats were subjected to a conditioned fear experiment.Meanwhile,changes in heart rate and blood pressure were measured.Results There was no significant difference in heart rate and blood pressure among the rats with the hippocampal operation or fimbria-fornix transection.In the acquisition of conditioned fear,there were significant difference in freezing time among the three group in both inter-trial-interval (ITI) and conditioned stimulus (CS) process (all P＜0.05).The freezing time of the FF group showed significantly lower than that of the Sham group (P＜0.05).There was no significant difference in heart rate and blood pressure among the three group(P＞0.05).In the test of conditioned contextual fear memory,the freezing time percentage in the FF group ((0.31±0.16) ％) significantly lower than that in the Sham group ((2.78± 1.23) ％) (P＜0.05)at the first 3 min of the test.There was a significant difference in heart rate among the three group.The heart rate of FF group ((436.42± 10.16) times/min) was significantly lower than that of the Sham group ((472.48±4.43) times/min,P＜0.01) and the DH group ((469.94 ±7.36)times/min,P＜0.01).In the test of conditioned tone fear memory.The freezing time percentage in FF group ((18.78±6.29) ％) was significantly lower than that in the Sham ((51.77±9.33)％,P＜0.01) and DH group ((59.19±8.13)％,P＜0.01),but the freezing time percentage between the later two groups had no difference (P=0.52).The synchronous telemetry measurement showed there was no significant difference both in the heart rate and the blood pressure among the groups (all P＞0.05) during the conditioned tone test.Conclusion The dorsal hippocampal lesions and fimbria-fornix transection in rats can significantly reduce the learning and memory ability in conditioned fear and scene fear in rats,and the effect of fimbria-fornix transection is more obvious.The decrease in,fear memory is not synchronously reflected in heart rate and blood pressure in rats.