Objective To develop europium (Ⅲ) [Eu (Ⅲ)] chelated microparticles for homogeneous immunoassay.Methods Anti-human PCT antibodies were labeled with Eu (Ⅲ) chelated nanoscale microparticles as the detection antibody,and another anti-human PCT antibody was labeled with biotin as the solid-phase antibody.Magnetic microspheres labeled with streptavidin were used to separate the complexes of Eu-IgM-PCT-IgM-Biotin.Results In the homogeneous immunoassay,the standard curve fit was not linear.The quadratic curve was Y =19170.12 + 75493.74X-26.00X2(r =0.9986).According to the standard curve,the limit of detection for PCT was 0.04 ng/ml.Conclusion The homogeneous immunoassay which uses Eu (Ⅲ) chelated microparticles is highly sensitive for detection of PCT recombinant antigens and may serve as a promising method to measure serum PCT levels in the future.

Objective To explore the distribution of arsenic speciafion and to estimate the effect of arsenic on glutathione(GSH)levels in the blood and liver of mice exposed to different concentrations of inorganic AsⅢ through drinking water.Methods Mice drank water containing arsenite at concentrations of iAsⅢ of 0(contr01),25,50,100 ms/L for 6 weeks.Blood and liver were sampled to asses$the levels of inorganic arsenic(iAs),monomethylarsenic acid(MMA),dimethylarsenic acid(DMA)by the method of hydride generation trapping and ultra-hypothermia coupled with atomic absorption spectrometry,and the level of GSH by the method of 5,5'-Dithio-bis (2-Nitrobenzoic acid).Results Leveh of iAs.MMA and DMA in blood and in liver increased along with the increase of iAs concentrations in drinking water.Primary methylated index(PMI)and secondary methylation index (SMI)of liver and blood were significantly higher in exposed groups than those in control group(P＜0.05).SMI of liver in 50 mg/L exposed group[(50.45±2.94)%]was significantly higher than those in 25 mg/L and 100 mg/Lgroups[(41.68±7.09)%and(41.19±8.87)%,respectively],the difference being statistically significant(P＜0.05).The ratio of iAs.MMA and DMA in blood and liver in exposed group were 2:3:5 and 4:3:3,the percentage of level of organic arsenic(MMA+DMA)were 80%and 60%.GSH in blood and liver in exposed group decreased along with iAs concentrations in drinking water and had significant differences compared with those in control group (P＜0.05).However,levels of GSH in liver and blood did not differ significantly between exposed groups and control group(P＞0.05).Conclusions Membolism of iAs in liver is maximized when the iAs concentrations in drinking water increases to a certain level.However,the percentage of arsenic speciation in blood is different from that in liver,suggesting that other organs and tissues may be capable of methylation of inorganic arsenic.The level of GSH in liver and blood in mice is a good mark tO reflect the toxicity of arsenic.

Objective To investigate the effect of exogenous kallikrein on apoptosis of the neurons aroundthe cerebralinfarctareain rats. Methods Thirty rats wjth cerebral infarction induced by middle cerebral artery occlusion(MCAO)were assigned randomly into 3 groups(n=10),namely the blank control group,saline group,and pAdCMV-HTK group.In the pAdCMV-HTK group,kallikrein gene was delivered into the cerebral ischemie lesion via a replication-defective adenovims using stereotaetic injection technique, and the expression of exogenous kallikrein was detected immunohistoehemically.TUNEL staining was performed to evaluate the neuronal apoptosis around the infarct area,and RT-PCR used to detect the mRNA expressions ofbcl-2,bax and caspase-3 in the brain tissues. Results At 24 h aftertreatment there were some HTK expressed cells found in group C and peal(at 72 h after treatment.While compare with group B and group C,there existed significant difference(112±6.1,68±4.2,59±3.9,P<0.05).At 72 h after treatment,the NSS of group C was significantly lower than that ofgruop B and A(6.70±0.16,8.13±0.16,7.93±0.20,P<0.05);7 days after the treatment,the difference was more significant(5.14±0.18,7.82±0.14,7.91±0.10,P<0.01).Apoptotic cells were mostly seen around the infarct area.The ratsinpAdCMV-HTK group showed significantly reduced number of cells positive for TUNEL staining as compared to those in the saline and blank control groups at 3 days(10.1±0.9,16.7±1.1,and 20.4±0.8,respectively)and 7 days after the treatment(15.2±1.2,33.6±1.3,and 28.8±1.7,respectively)(P<0.05).The mRNA levels ofbc1-2.bax and caspasc-3 were elevated in all the groups at 24 h,peaked at 72 h,and decreased gradually till 7 days alter the treatment.Compared with those in the other two groups，bcl-2 mRNA level in the pAdCMV-HTK group increased slightly P>0.05) while bax and caspase-3 mRNA levels decreased markedly(P<0.05) 72 h and 7 days after the treatment.Conclusion Kallikrein can inhibit neuronal apoptosis around the cerebral infarct and improve the neurological fimction of rats following cerebral infarction probably by reducing the expressions of such apoptotic factors as bax and caspase-3.

Objective To investigate the effects ofkallikrein gene transfer on microvascularproliferation around the cerebral infarct and on the recovery of regional cerebral blood flow (rCBF)following ischemia/reperfusion injury in rats. Methods The rats with cerebral ischemia/reperfusioninjury induced by middle cerebral artery occlusion (MCAO) were randomly assigned into blank controlgroup, saline group, and pAdCMV-HTK treatment group and received corresponding injections into thetissues around the infarct area. Each group was divided into 3 subgroups (n=10) for observation at 12, 24and 72 h after the treatment. The neurological deficits of the rats before and after the treatment wereevaluated using neurological severity scores (NSS), and the expressions of exogenous human tissuekallikrein (HTK) and vascular endothelial growth factor (VEGF) in the brain tissues were detectedimmunohistochemically. TIC staining was performed to measure the changes in the infarct size.14C-iodoantipyrine tracing technique was used to define the rCBF in the rats. Results Compared tothe blank control group, the cerebral infarct size was significantly reduced in pAdCMV-HTK group 24 hafter the treatment, and was further reduced at 72 h (P<0.05). At 24 h after the treatment, the NSS inpAdCMV-HTK group was significantly lower than that in the blank euntrol and saline groups (P<0.05),and was further reduced at 72 h (P<0.01). After MCAO, the VEGF-positive cells were found mostly inthe cortex and the white matter around the infarct area. The expression of VEGF in pAdCMV-HTK groupwas markedly higher than that in the other two groups at 12, 24, and 72 h after the treatment (P<0.05). Inall the 3 groups, the rCBF around the infarct was slightly decreased as compared to that in thecontralateral hemisphere, pAdCMV-HTK slightly increased the rCBF 12 h after the injection (P>0.05),and significant increase in the rCBF occurred 24 h and 72 h after the injection (P<0.05). ConclusionKallikrein gene transfer following cerebral ischemia/reperfusion injury promotes vascular proliferationaround the infarct and increases the rCBF to reduce the infarct volume and attenuate neurological deficitsin rats.

Objective To summarize our experience with intraoperative neural electrophysiological monitoring during spinal cord surgery. Methods The clinical data of 11 patients undergoing spinal cord surgery with intraoperative neural electrophysioiogical monitoring were retrospectively reviewed, and the monitoring was performed by recording the motor-evoked potential (MEP), somatosensory evoked potential (SEP), and evoked electromyography (EMG). Results Subtotal resection of the intramedullary cystic lesion was performed in 1 case and partial resection of the intramedullary tumor in another. In 9 cases of tethered spinal cord syndrome, obvious improvement was obtained in 8 cases, and the other 1 case showed no obvious changes in the symptoms after the operation. In all the 11 cases, the spinal cord remained intact and its function was totally preserved without damage of the eonus medullaris or the cauda equine. Conclusion Combined monitoring of MEP, SEP, and evoked EMG during spinal cord surgery is useful for protecting the spinal cord and the nerves roots, and may enhance the detection of the tethered tissue and ensure better safety of operations.

Objective To explore the regularity of time-dependent changes in morphology and biomechanical properties of brain tissues in pigs,and value the feasibility of deducing the postmortem interval (PMI).Methods Brain tissues were taken from 42 pigs and kept in an artificial climate chamber with the temperature of 25 ℃ and humidity of 75％.The samples were collected from telencephalon at sequential time intervals (0,12,24,36,48,60 h;n =6) according to the principle of predefined time,position,direction,ratio,quantity and shape.The samples fixed with formaldehyde were then immediately tested by mechanical testing machine to obtain their biomechanical parameters and the histological sections were prepared.Results With the extension of PMI (0-60 h),brain tissues gradually became discolored,weak,mudding and liquefied under the influence of autolysis and putrefaction.Both clearance area of the white matter and its integrated optical density (IOD) significantly increased during 0-48 h.Biomechanical properties of brain tissues including the limit load,average force,elastic modulus and fracture energy all presented a declining tendency at the interval of 12-60 h.The limit load was considered highly statistically significant,and statistical differences were found in average force,elastic modulus and fracture energy.Conclusions There exists a significantly negative structure-activity relationship between the morphology of brain tissues and biomechanical properties.The limit load of postmortem brain tissues in 60 h is the optimum in the window period,which can be used as a new method for estimating PMI.

Objective To analyze the status of quality indicators(QI) on specimen acceptability and establish preliminary qual ity specification.Methods Web based External Quality Assessment system was used to collect data of laboratories partici pated in "Medical quality control indicators in clinical laboratory" from 2015 to 2017,including once in 2015 and 2017 and twice in 2016.Rate and sigma scales were used to evaluate incorrect sample type,incorrect sample container,incorrect fill level and anticoagulant sample clotted.The 25th percentile (P25) and 75th percentile (P75) of the distribution of each QI were employed to establish the high,medium and low specification.Results 5 346,7 593,5 950 and 6 874 laboratories sub mitted the survey results respectively.The P50 of biochemistry (except incorrect fill level),immunology and microbiology reach to 6σ.The P50 of clinical laboratory is 4 to 6σ except for incorrect sample container.There is no significant change of the continuous survey results.Based on results in 2017 to establish the quality specification,the P25 and P75 of the four QIs is 0 and 0.084 4 ％,0 and 0.047 6 ％,0 and 0.114 2 ％,0 and 0.078 4 ％,respectively.Conclusion According to the results of the survey,most laboratories had a faire performance in biochemistry,immunology and microbiology,and clinical laboratory needs to be strengthened.Laboratories should strengthen the laboratory information system construction to ensure the actual and reliable data collection,and make a long time monitoring to achieve a better quality.