Objective To investigate the precision and trueness of results from six imported commercial systems for measurement of gamma-glutamyltransferase (GGT) in serum in order to provide reference for the clinical laboratories to verify the target accuracy. Methods Five fresh frozen human serum samples that differed in catalytic concentration were analyzed in two candidate domestic reference laboratories and the target values for GGT were assigned using IFCC reference measurement procedure. The same samples were tested by six commercial systems which were calibrated using the matched calibrator. Each system consisted of five instruments in five laboratories, which had been well maintained before measurement. The data was collected. Precision from the same manufacturer and different manufacturers and biases between target values and mean values from each system were calculated. Results The differences of the mean values for five levels of commercial systems varied from 16. 1% to 35.4%. For the five levels, the coefficients of variation (CVs) of the results from all measurement system were from 5.3% to 8. 8% , and CVs from each level were A 2. 17%- 5.07%, B 4. 21%-10. 98%, C 0. 52%-2. 38%, D 1.35%-2. 59%, E 0. 23%-1..54%-), F 1.83%-2. 38%. Biases between the mean values of each commercial systems and the target values were A 0. 43% -8.41% ), B -1.49% - -13.04% ), C 11.20% -17.73% ), D 0. 19% -4. 62% ), E -0. 30% - -2. 63% ), F 4). 46%-7.90%, respectively. The investigation showed that biases of two manufacturers were less than a quarter of the total allowable error (TAE) of The Clinical Laboratory Improvement Amendments of 1988 (CLIA'88) in the whole range of investigated concentrations and the other two manufacturers' biases could meet a quarter of TAE in a relative limited range. The biases of two manufacturers were near or more than half of TAE in most levels. It also revealed that the biases of more than half of manufacturers were more than a quarter of TAE in the low or high level of investigated concentrations. Conclusions The mean values of each manufacturer were significantly different. The variances of commercial systems from different manufacturers were much higher than those from the same manufacturer. Some imported commercial systems for measurement GGT should be better calibrated with the reference method, especially in the whole measurement linearity.

BACKGROUND: Schwann cells play an important role in axonal growth and myelin sheath formation of the peripheral nerve. Whether Schwann cells play the same role in the spinal cord had attracted considerable attention. Microencapsulation technology as an effective immune isolation technique can effectively keep Schwann cell activity to play the repair effect of Schwann cell in the spinal cord.OBJECTIVE: To observe the changes of myelin sheath in the injured transection of rats after transplantation of the alginic acid microencapsulated Schwann cells.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Basic Medical School of Nanchang University from March 2005 to February 2008.MATERIALS: Sciatic nerve trunk was obtained from adult rabbits to harvest Schwann cells in vitro using repeatedly differential velocity adherent technique, and to prepare Schwann cell suspension and microencapsulated Schwann cell suspension.METHODS: A total of 146 adult Sprague Dawley rats were used to establish models of right hemi-transection damage at T_(10) level and randomly assigned to four groups: simple injury group (n=44), cell transplantation group (n=44), microencapsulated cell transplantation group (n=44) and normal control group (n=14). At 1, 3, 7,14 and 28 days following surgery, 8 rats were selected from each group at each time point (2 from the normal control group) for perfusion and fixation. Spinal cord tissue was collected to make paraffin section, and then subjected to hematoxylin-eosin staining and Loyez myelin staining. In addition, 2 rats were selected from each group at 2 and 8 weeks. The spinal cord tissue was fixed, embedded in Epon816, stained using uranyl acetate and aluminum citrate, and then observed using an electron microscope.MAIN OUTCOME MEASURES: Neuron number and survival were observed surrounding the damaged region. Structural changes in the myelin sheath from spinal cord white substance at the damage site were measured.RESULTS: At 1 and 3 days following spinal cord injury, spinal neurons were degenerated and necrotic at damaged site, with reduced number of myelin sheath, loose structure, but above-mentioned was rare in the cell transplantation and microencapsulated cell transplantation groups. At 7 days, the reduced number of myelin sheath, with damaged structure was seen. The microencapsulated cell transplantation group was light. At 14 days, number of neurons was increased, with increased cell body, especially in the microencapsulated cell transplantation group. At 28 days, neurons gradually recovered, myelin sheath was gradually complete, with increased number in the microencapsulated cell transplantation group. There were significant differences compared with the simple injury and cell transplantation groups (P < 0.01). At 8 weeks, abundant myelin sheath was repaired, with new myelin sheath in the microencapsulated cell transplantation group.CONCLUSION: Microcapsule has immune isolation effects. Microencapsulated rabbit Schwann cells can promote the repair of rat spinal cord neurons and axonal myelinization.

This article was aimed to study the effect of Baohe granules for patients with chronic heart failure (CHF) of traditional Chinese medicine (TCM) syndrome and the effect of gastrointestinal hormone secretion. Patients with CHF were used as the object of study. A total of 80 selected patients were divided into 2 groups. The control group was treated with western medicine anti-heart failure therapy. The treatment group was treated with the combination of Baohe granules. All patients were compared in aspects of TCM efficacy, symptom score and serum gastrin, motilin secretion after two-week medication. The results showed that both treatments can significantly improve the TCM syn-drome and symptom total score of CHF patients. And the effect of the treatment group with Baohe granules was bet-ter. The TCM single symptom integral was also obviously improved in the treatment group combined with Baohe granules, which included heart palpitations, shortness of breath, abdominal distension, and loss of appetite. The GAS and MTL levels of CHF patients were significantly increased in the treatment group. It was concluded that the treat-ment combined with Baohe granules can improve CHF patients with TCM syndromes, symptoms and gastrointestinal hormone secretion. Thus, it contributed to the stability of the disease condition. It can slow the disease progression and improve prognosis. So it is worth using widely in the clinical practice.

Objective To evaluate the accuracy of Cr measurement value from commonly used homogenous detection systems,to investigate the variation among different systems and the corresponding bias of eGFR.Methods According to the CLSI EP14-A2 protocol,commutability of LN24 was validated among 10 enzymatic assays and 1 picrate assay.LN24 included 6 vials of solution with Cr values assigned by IDMS at NIST,and concentrations of Cr for each vial were 68.1,126.9,185.7,244.5,303.2 and 361.9μmol/L LN24 was used to evaluate the accuracy of the included systems and the variation among them,and the assigned values were taken as the target values.eGFR were calculated by MDRD equation using IDMStraced picrate Cr and CKD-EPI equation using enzymatic Cr.Results Commutability was exist among the 11 systems for LN24 detection.Four systems showed bias ＜ 4.4 μmol/L at each level of LN24,two system showed bias ＞4.4 μmol/L at each level of LN24,one system showed a fixed negative bias( -4.2 ±0.7)μ mol/L,the other 4 systems showed diverse bias at different levels.Cr-bias-caused eGFR bias could reach 14.9 ml · min-1 · (1.73 m2) -1 at Cr level of 68.1 μmol/L SD among systems ascended with Cr level (2.6 -6.1 μmol/L) ;CV among systems descended with Cr level(4.0％ - 1.7％ ) ;After the 2 systems with obvious negative bias were removed,SD,CV among systems and eGFR bias decreased obviously.By measuring fresh serum,it was found that Cr bias among enzymatic systems was mostly ＜ 10 μmol/L;that between enzymatic assays and picrate assay was much diffused(from - 15 to 20 μmol/L).When Cr ＜ 100μmol/L,the eGFR difference between result of MDRD equation and that of CKD-EPI equation ranged from - 18 to 40 ml · min-1 (1.73 m2) -1.Conclusions Some enzymatic systems show good accuracy.Difference of Cr value is relatively fixed among enzymatic systems,and comparability can be reached through mathematic way.Un-acceptable difference between picrate assay and enzymatic assays still exists,thus comparability cannot be reached through mathematic way.At low Cr level,bias of Cr and using different equations may lead to significant bias of eGFR.We recommend that clinical laboratory should pay much attention to the accuracy and comparability at low level of Cr,and use uniform equation to calculate eGFR.

BACKGROUND: Commutable reference materials (RMs) are suitable for end-users for evaluating the metrological traceability of values obtained using routine measurement systems. We assessed the performance of 6 routine measurement systems with validated secondary RMs. METHODS: We tested the homogeneity, stability, and commutability of 5 minimally processed human serum pools according to the standard guidelines. The serum pools were assigned values as per the reference procedure of the United States Centers for Disease Control and were used to evaluate the trueness of results from 6 commercial measurement systems based on enzymatic methods: 3 glucose oxidase (GOD) and 3 hexokinase (HK) methods. RESULTS: The prepared RMs were validated to be sufficiently homogenous, stable, and commutable with the patient samples. Method bias varied for different systems: GOD01, -0.17 to 2.88%; GOD02, 1.66 to 4.58%; GOD03, -0.17 to 3.14%; HK01, -3.48 to -0.85%; HK02, -3.83 to -0.11%, and HK03, -1.82 to -0.27%. CONCLUSIONS: We observed that the prepared serum glucose RMs were qualified for trueness assessment. Most of the measurement systems met the minimal quality specifications.
Blood Chemical Analysis/instrumentation/*standards ; Blood Glucose/*analysis ; Glucose Oxidase/metabolism ; Hexokinase/metabolism ; Humans ; Reagent Kits, Diagnostic ; Reference Standards ; Regression Analysis

Objective To study the value of the technique of "Push-pull traction-relax homingrepeatedly confirmed" in the prevention of bile duct injury in LC. Methods From March 2001-August 2009, we applied this technique in 4800 cases of LC. The technique of "Push-pull traction" showed the structures of in the Calot's triangle. The technique of "relax homing" was to restore the cystic duct,hepatic duct and common bile duct to their original anatomical positions. The technique of "repeatedly confirmed" repeatedly identified the positions of the cystic duct, the common hepatic duct and the common bile duct. Results There was no bile duct injury. Conversion to open surgery happened in 118patients due to difficulties in identifying the Calot's triangle structures, bile duct stones, gallbladder cancer, and gallbladder-duodenal fistula. Conclusions The "Push-pull traction-relax homing-repeatedly confirmed" technique could effectively prevent bile duct injury in LC. The method is simple, easy to master and worthy of promotion.

Objective To investigate the intralaboratury and interlabomtory variations of measurements for ALT and AST among four domestic reference laboratories. Methods The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference procedures and IFCC procedures without pyridoxal 5-phosphate (PLP) were performed in the reference laboratories. Intralaboratory and interlaboratory CVs were compared with those in 2006 and 2007 IFCC External Quality Assessment Scheme for Reference Laboratories (RELA). Meanwhile, deviations of results for ALT, AST and AST/ALT between two methods were calculated. Results Interlaboratory CVs were generally higher than intralaboratory CVs. Interlaboratory CVs among the 41 laboratories were lower than these in RELA. Results of ALT and AST using method with PLP were higher than those using method without PLP. Difference of AST/ALT ratio between the two methods was significant. Conclusions For reference measurement of the 2 enzymes, interlaboratory CVs of < 3.5 are achievable on frozen serum materials. Measurements on lyophilized materials may have higher CVs. Further studies are needed for the investigation of the differences between results obtained in the absence and presence of PLP.

Objective: To effectively reduce the concentration of poisons in cleanroom, protect the health of workers, realize the optimization and automatic control of the new return air device. And the influence of initial concentration, air volume, temperature and relative humidity of formaldehyde on the purification effect of the new return air device was explored. Methods: The purification effect of the new return air device installed with the activated carbon and the photocatalyst purification net or ordinary activated carbon purification network was tested in a 60 m³ simulated cleanroom. The concentration of formaldehyde was determined by solution absorption-phenol reagent spectrophotometry. Based on the single factor experiment to determine the combination of two purification nets. The effects of air volume, initial formaldehyde concentration, temperature and relative humidity on the purification effect of the new return air device were investigated by orthogonal test. Then, the performance parameters of the return air device to purify formaldehyde were determined. Results: The formaldehyde purification efficiency of the two types of purification nets in the new return air device was higher than that of the ordinary activated carbon purification network (P<0.05) . The combination of activated carbon and photocatalyst purification net has no effect on the formaldehyde purification efficiency of the return air device (P>0.05) . According to the direct analysis and variance analysis, air volume was the most sensitive factor (F value is 18.894, P<0.05) , followed by initial concentration (F value is 16.128, P<0.05) , while temperature and relative humidity have little effect (F value is 0.041 and 0.599, respectively, P>0.05) . LSD analysis showed that there was no significant difference in the purification efficiency of formaldehyde between 475 m³/h and 626 m³/h (P>0.05) . From the perspective of formaldehyde purification efficiency and energy saving, when the air volume is set to 475 m³/h, the new return air device has higher purification efficiency for high concentration of formaldehyde. Conclusion The new return air device consisting of activated carbon and photocatalyst purification net can play a good purification role in cleanroom with different temperatures and different humidity. Its formaldehyde purification efficiency is affected by air volume and initial concentration.