Objective To evaluate the application of Cystatin C(Cys C)international primary reference material and national secondary reference materials for quantity transfer in seven conventional systems.Methods Seven Cys C reagents from different manufacturers commonly used in clinical laboratories were used to simultaneously measure two standard substances[ERM-DA471/IFCC,GBW(E)091173～6]and 42 individual serum samples.The theoretical and measured values of the standard substances were linearly fitted,and the measured values of the single serum samples were substituted into the fitting equation to obtain the calibrated values,and the measured values and calibrated values were compared with CLSI EP9-A3 file.Results The theoretical and measured values of ERM-DA471/IFCC and GBW(E)091173～6 were linearly fitted,and the regression equations were Y=0.941X+0.159,Y=0.963X+0.162,respectively,with correlation coefficients of 1.000(taking system B as an example).All system analysis models were analyzed using Passing-Bablok regression analysis.The comparison bias between the calibration values and measurement values of two standards in seven systems were-20.38%～10.58%and-16.76%～9.90%,respectively,with the same bias trend.The comparison bias of the calibrated values of the two standard substances was-4.18%～2.31%.The calibration of the standards had a significant improvement for the bias between calibration value and measurement value exceeding±4%.The bias of the measured values in the pairwise combinations of each system at each medical decision level was-17.87%～14.97%and the bias range of GBW(E)091173～6 calibration values at each medical decision level was-4.96%～4.51%,with most values being less than 3%.The bias of ERM-DA471/IFCC calibration values was-3.92%～6.30%,with most values being less than 4%.Among them,the most common situation was that the bias of ERM-DA471/IFCC calibration value was less than that of measurement value,and the bias of GBW(E)091173～6 calibration value was less than that of ERM-DA471/IFCC calibration value,with 51.19%(43/84)of the comparison bias bata at the level of medical decisionmaking.Conclusion Both reference materials can improve the alignment bias of conventional system,and GBW(E)091173～6 calibration effect is better than ERM-DA471/IFCC.

Objective To evaluate the application of Cystatin C(Cys C)international primary reference material and national secondary reference materials for quantity transfer in seven conventional systems.Methods Seven Cys C reagents from different manufacturers commonly used in clinical laboratories were used to simultaneously measure two standard substances[ERM-DA471/IFCC,GBW(E)091173～6]and 42 individual serum samples.The theoretical and measured values of the standard substances were linearly fitted,and the measured values of the single serum samples were substituted into the fitting equation to obtain the calibrated values,and the measured values and calibrated values were compared with CLSI EP9-A3 file.Results The theoretical and measured values of ERM-DA471/IFCC and GBW(E)091173～6 were linearly fitted,and the regression equations were Y=0.941X+0.159,Y=0.963X+0.162,respectively,with correlation coefficients of 1.000(taking system B as an example).All system analysis models were analyzed using Passing-Bablok regression analysis.The comparison bias between the calibration values and measurement values of two standards in seven systems were-20.38%～10.58%and-16.76%～9.90%,respectively,with the same bias trend.The comparison bias of the calibrated values of the two standard substances was-4.18%～2.31%.The calibration of the standards had a significant improvement for the bias between calibration value and measurement value exceeding±4%.The bias of the measured values in the pairwise combinations of each system at each medical decision level was-17.87%～14.97%and the bias range of GBW(E)091173～6 calibration values at each medical decision level was-4.96%～4.51%,with most values being less than 3%.The bias of ERM-DA471/IFCC calibration values was-3.92%～6.30%,with most values being less than 4%.Among them,the most common situation was that the bias of ERM-DA471/IFCC calibration value was less than that of measurement value,and the bias of GBW(E)091173～6 calibration value was less than that of ERM-DA471/IFCC calibration value,with 51.19%(43/84)of the comparison bias bata at the level of medical decisionmaking.Conclusion Both reference materials can improve the alignment bias of conventional system,and GBW(E)091173～6 calibration effect is better than ERM-DA471/IFCC.

Objective:To investigate the clinical characteristics of Guillain-Barré syndrome (GBS) combined with hyponatremia in Southern China and its risk factors for prognosis.Methods:The retrospective cohort study involved patients who met the diagnostic criteria of GBS from 18 upper first-class hospitals of 6 provinces/cities in southern China (south of Huaihe River) from January 1, 2013 to September 30, 2016. The clinical data of these patients were collected. According to serum sodium levels, they were divided into hyponatremia group (serum sodium concentration<135 mmol/L) and normal serum sodium group (serum sodium concentrations≥135 mmol/L). Based on Medical Research Coucil sum scores at nadir, these patients were divided into mild GBS group (>40), moderate GBS group (30-40), and severe GBS group (<30). Furthermore, according to the Hughes GBS disability scale (H-GBS-DS) scores at discharge, these GBS patients with hyponatremia were divided into favorable prognosis group (H-GBS-DS<3) and poor prognosis group (H-GBS-DS≥3). The incidence of hyponatremia in patients from the mild GBS group, moderate GBS group, and severe GBS group were compared. Multivariate Logistic regression analysis was performed to determine the clinical risk factors for hyponatremia in GBS patients. The clinical data of hyponatremia patients from favorable prognosis group and poor prognosis group were compared; multivariate Logistic regression analysis was used to determine the risk factors for poor prognosis in GBS patients with hyponatremia.Results:(1) Among the 570 patients, 354 had mild GBS, 94 had moderate GBS, and 122 had severe GBS; 134 GBS patients were combined with hyponatremia, 436 GBS patients had normal serum sodium. The hyponatremia incidence in mild, moderate and severe GBS groups increased successively, ( P<0.05). Multivariate Logistic regression analysis showed that facial paralysis ( OR=1.979, 95%CI: 1.172-3.342, P=0.011), respiratory muscle paralysis ( OR=3.218, 95%CI: 1.611-6.428, P=0.001), secondary pulmonary infection ( OR=4.822, 95%CI: 2.835-8.201, P=0.000), severe GBS ( OR=2.611, 95%CI: 1.444-4.721, P=0.001) and length of hospital stay ( OR=1.029, 95%CI: 1.009-1.050, P=0.004) were risk factors for hyponatremia in GBS patients. (2) Among 134 GBS patients with hyponatremia, 80 had poor prognosis and 54 had favorable prognosis. As compared with the favorable group, the poor prognosis group had significantly lower proportion of patients with extraocular muscle paralysis, statistically higher proportions of patients with respiratory muscle paralysis and secondary pulmonary infection, significantly different severities of GBS, signficantly higher proportion of patients accepted intravenous immunoglobulin (IVIG) and hormone treatments, statistically longer length of hospital stay ( P<0.05). Respiratory muscle paralysis ( OR=25.590, 95%CI: 9.433-69.423, P=0.000), moderate GBS ( OR=17.030, 95%CI: 8.441-34.361, P=0.000), and severe GBS ( OR=51.042, 95%CI: 24.596-105.926, P=0.000) were independent risk factors for poor short-term prognosis of GBS patients with hyponatremia. Conclusions:Severe GBS patients with facial paralysis, respiratory muscle palsy, secondary pulmonary infection, and long hospital stay trend to have hyponatremia. Hyponatremia patients with respiratory muscle paralysis and moderate/severe GBS have poor short-term prognosis.

Objective To analyze the clinical features and validation of Brighton criteria in Guillain-Barré syndrome (GBS) patients from southern China.Methods The clinical data of hospitalized GBS patients from 69 hospitals of 14 provinces/cities in southern China,the area south of the Huaihe River,between 1 January 2013 and 30 September 2016,were collected and analyzed retrospectively,and patients were classified according to the Brighton criteria of case definition,ranging from a highest (defined as level one) to a lowest (level four) level of diagnostic certainty.Results A total of 1 358 GBS patients were collected,including 51 cases with cranial nerve variants,157 with Miler-Fisher syndrome and 1 150 with classic GBS characterized by flaccid weakness of limbs.Among 1 150 cases of classic GBS,49.57％ (570/1 150) patients had antecedent events,with respiratory infection predominated (71.23％,406/570);83.74％ (963/1 150) presented limb weakness at onset,99.21％ (1 124/1 133) reached the peak within four weeks,with a score of 3.15 ± 1.16 for Hughes Disability Scale;99.56％ (1 128/1 133)developed bilateral weakness and 95.39％ (1 097/1 150) manifested flexia or hyporeflexia;the cerebrospinal fluid showed albuminocytologic dissociation in 80.58％ (772/958) patients whose lumbar puncture was performed;demyelinating GBS accounted for 48.14％ (401/833) and axonal subtype 18.01％ (150/833) respectively in patients with findings of nerve conduction studies available.According to Brighton criteria,the patients were stratified as level one in 44.09％ (507/1 150),level two in 45.74％ (526/1 150),level three in 7.57％ (87/1 150) and level four in 2.61％ (30/1 150) of all the patients,and 69.55％ (507/729),28.67％ (209/729),0％ (0/729) and 1.78％ (13/729),respectively in the patients with complete data (n =729).Conclusions In southern China,demyelinating subtype of GBS is predominant,whereas the proportion of axonal subtype is remarkably lower than that in northern China.The Brighton criteria have a high sensitivity for the diagnosis of GBS in southern China,and examination of cerebrospinal fluid and electrodiagnostic studies are necessary for stratified diagnosis.

The clinical data and imaging findings of 10 patients with reversible splenial lesion syndrome ( RESLES ) admitted in Shanxi people′s Hospital from August 2014 to August 2016 were retrospectively analyzed .All 10 patients were acute or subacute onset , the etiology included viral meningitis ( n =5 ) , purulent meningitis ( n =2 ) , tuberculous meningitis ( n =1 ); and one schizophrenic patient receiving antipsychotic drug and one epileptic patient treated with phenytoin .There were 8 patients under 30 years.The clinical manifestations included headache , fever, disorder of consciousness and mental symptoms.Seven patients had prodromic infections before the onset of the disease and focal neurological defects were present in the early stage .The initial MRI showed isolated splenium of corpus callosum (SCC) lesions with homogeneous hyperintense on T 2WI, hypointense on T1WI, and patchy, round, ovoid, schistose diffusion with hyperintense on DWI in all 10 cases;and there was no significant strengthening on enhanced MRI in 4 cases.The follow-up MRI showed that SCC abnormalities disappeared after treatment in 9 cases and the neurological symptoms disappeared after one-month follow up in 6 cases.The results indicate that RESLES is frequently secondary to infections , and presents the symptoms of mild encephalitis or encephalopathy .

Objective To analyze the characteristics of early cognitive impairment in leukoaraiosis (LA) patients and fractional anisotropy (FA) changes by diffusion tensor imaging (DTI) in various regions of interest (ROIs), and explore the relationship between FA values and cognitive impairment. Methods A total of 38 chronic ischemic LA patients, admitted to our hospital from August 2015 to August 2016, and 20 healthy elderly controls were chosen in our study. Comprehensive assessment of cognitive functions, and MRI and DTI examinations were performed in subjects from these two groups. The cognitive functions, and FA values in ROIs were compared between the two groups;the FA values in ROIs of mild, moderate, and severe ischemic LA patients were compared. The correlations between FA values in ROIs and cognitive functions in LA patients were analyzed. Results As compared with the healthy control group, the patient group had significantly lower Mimi Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores, statistically longer time of Stroop test C, lower scores of verbal fluency test (VFT), digit span (DS)-inverted sequence, word similarity test in Chinese Revision of Wechsler Intelligence Scale for Children (WISC-CR), auditory verbal learning test (AVLT), clock drawing test and block testing, and significantly longer time of Trail Marking Test A (TMTA) and Stroop test B (P<0.05), suggesting that the overall cognitive function, executive function, memory, visual-spatial ability, information processing capability of LA patients decreased greatly. Significantly decreased FA values in bilateral anterior horn of lateral ventricle, left superior frontal gyrus, left inferior frontal gyrus, bilateral frontal orbital gyrus, right deep temporal lobe, right cingulate gyrus, and genu of corpus callosum in the LA patient group were noted as compared with those in the control group (P<0.05). In mild, moderate and severe LA patients, the FA values of these ROIs decreased in turn, with statistically significant differences (P<0.05). In the LA patient group, correlation analysis showed that the scores of auditory verbal learning test were positively correlated with FA values in the brain regions of left anterior horn of lateral ventricle, bilateral frontal orbital gyrus, deep white of right temporal lobe, right cingulate gyrus, and genu of corpus callosum (P<0.05), and negatively correlated with FA values in left inferior frontal gyrus (P<0.05); the scores of trail making test A were negatively related with FA values in right anterior horn of lateral ventricle (P<0.05); the Stroop test B scores were negatively correlated with FA values in deep white matter of the right temporal lobe (P<0.05); the Stroop test C scores were negatively related with FA values in left orbital frontal cortex, deep white of right temporal lobe, right cingulate gyrus, and genu of corpus callosu (P<0.05); and the block testing scores were positively related with FA values in left frontal orbital gyrus, right temporal lobe deep, and genu of corpus callosu (P<0.05). Conclusions The early cognitive impairment and decreased FA values are noted in LA patients. FA values are related to cognitive impairment. DTI contributes to diagnose early cognitive impairment in LA patients.