Roles of reference method in clinical biochemistry were introduced.Reference method is an important component of the reference system.Reference methods are primarily used for the establishment and assurance of the traceability of measurement results through calibrating and evaluating routine methods and assigning values to reference materials.Calibration biases and non-specificities of routine methods and the commutability of reference materials are the major issues in the standardization of clinical biochemistry.Standardization also requires availability of commutable reference materials.Reference methods are irreplaceable tools to identify the issues and to characterize reference materials.

Good patient care requires accurate and comparable laboratory test results. To achieve standardization, a reference system consisting of a hierarchal framework of validated and reliable analytical methods linked by reference materials must be in place. Supported by national and municipal research programs, construction of reference systems has been pursued and progress been made. Candidate reference methods have been set up or developed for some important tests, and the methods have been used in the calibration or evaluation of routine methods, study of commutability of control materials and characterization of reference materials. Phenomenal roles of reference systems are expected in diagnostic reagent manufacturing, internal quality assurance and external quality assessments.

specifications are essential for total quality management in laboratory medicine. A consensus among worldwide professionals has been achieved and a hierarchy of strategies for setting analytical quality specifications has been proposed based on their relevance to medical decision-making. Quality specifications derived from biological variations have been widely accepted because of their objectivity and practicability and have more and more been used in the quality management in laboratory medicine.

Objective To evaluate CT and MRI findings of portal vein aneurysm(PVA)in order to improve its diagnostic accuracy.Methods CT and MRI findings of 9 patients with PVA proved by pathology and direct angiography were reviewed retrospectively.CT scanning was performed in 7 patients,including plain scan (n=2),both plain and enhanced scan (n=5),CT angiography (CTA)(n=3).Plain and enhanced MRI scan were performed in 3 patients.Results (1 )PVA showed a high predilection for old adults.(2 )Of the 9 tumors,4 located in portal vein trunk,2 located in junction of superior mesenteric vein and portal vein trunk,1 located in intrahepat-ic-extrahepatic portal vein,2 located in intra-hepatic portal vein.(3)8 tumors were characterized as well-defined and quasi-circular mass.1 patient occurred portal hypertension,thrombus as the portal vein trunk was oppressed by the tumor.(4)Plain CT showed the mass was slightly higher than pancreas parenchyma density,and uniform with the density of the liver parenchyma.Enhancement scanning showed 4 tumors represented mild or moderate enhancement in portal venous phase except for 1 patient accompany with portal vein thrombus.CTA showed clearly the relationship mass with portal vein,and classified the type of PVA .The 3 lesions represented hypo-intensity on T1 WI and even hyper-intensity on T2 WI.Enhancement scanning showed the tumor was significantly enhancement in portal venous phase on T1 WI.Conclusion CT and MRI have their own advantages in the diagnosis of portal vein aneurysm.Com-bination of CT and MRI could improve the diagnostic accuracy of portal vein aneurysm.

Hepatic perfusion parameters play an important role in detecting and diagnosing diffusion diseases of liver. Based on a hemodynamic model. In this study, we described a fast and accurate method to calculate the perfusion parameters. First, we used a dual-input one-compartment kinetics model to illustrate the distribution of the contrast agent concentration among the body. Then, we used the Gaussian function to fit the scatter concentration data of portal vein and aorta, to obtain a liver agent concentration on function of time. Finally, we solved the model parameters by using Levenberg-Marquardt algorithm, and calculated the perfusion parameters. The results showed that the method proposed in this study could calculate the parameters precisely, and had a prosperous future application possibility.
Algorithms ; Contrast Media ; Hemodynamics ; Humans ; Liver ; physiology ; Models, Biological ; Perfusion

OBJECTIVE To find out the situation of antimicrobial usage in cardiac surgical perioperative period.METHODS The use of antimicrobials in cardiac surgical perioperative patients during Jan-Jun 2007,and the data of reasonable use of antibacterial were surveyed and evaluated.RESULTS Of the 276 patients,100.00% of them had received antimicrobials involving 12 kinds,59.78% of them used one kind only and 34.78% used two kinds antibiotics and 5.43% used more three kinds.CONCLUSIONS The use of antimicrobials in cardiac surgical perioperative period is reasonable and scientific.

OBJECTIVE To find out the actual situations of antibiotics utilization in Respiratory Department of our hospital and provide feedback of improper applications to the clinic,so as to promote proper utilization of antibiotics.METHODS To take samples from clinical cases of 141 samples in Oct to Nov 2006 and fill the forms of the basic information and investigation items of General Hospital of Chinese People′s Armed Police Forces,the cases were finally sorted and summarized with Excel.RESULTS The antibiotics utilization ratio was 96.5%,their combination usage accounted for 70.2%,the etiology detection rate was 61.7%,the improper usage accounted for 34.8%.CONCLUSIONS The situation of antibiotics utilization in our hospital has changed a lot.Hospitals should define regulations and reinforce the management according to The Principle Guidelines of Antibiotics Utilization and actual situations.

Objective To explore the relationship between the plasma membrane glycoprotein ( PC-1 ) gene and obesity, type 2 diabetes mellitus, insulin resistance in Chinese population. Methods 53 norma1 subjects, 105 simple obesity subjects, 63 type 2 diabetic patients and 114 obesity type 2 diabetics have been genotyped with PCR-RFLP. Results The frequency of PC-1 gene Q allele was 3%, 18%, 4% and 30% in control, obesity subjects, diabetic patients and obesity diabetic individuals, respectively. Compared with control group, the relative risk (RR) in OB group, OBH grop, OBI group, OBL group and OBHIL group was 4. 26,4. 12,7. 36,5. 15 and 9. 70, respectively. Compared with diabetes group, the RR in diabetes with DMOB, diabetes with OBH group, diabetes with OBI group, diabetes with OBL group and diabetes with OBHIL group was 5.23,7. 37,12. 07,8. 53 and 13. 50, respectively. Concluision The frequency of PC-1 gene Q allele were significantly associated with obesity, obesity diabetics and insulin resistance in Chinese. The results suggested that the PC-1 gene Q allele was a potential genetic marker for obesity, type 2 diabetes and insulin resistance.

Objective To compare the efficacy,toxicity and prognosis on treating advanced non-small-cell lung cancer (NSCLC) between using weekly docetaxel (DOC) and using DOC associated with nedaplatin(NDP).Methods 56 cases of NSCLC patients were retrospectively analyzed.Group A included 34 cases who were treated with weekly DOC (35 mg/m2,dl,8).Group B included 22 cases who were treated with DOC associated with NDP (DOC 35 mg/m2,dl,8,NDP 80 mg/m2,d2).One treatment cycle was 21 days.Efficacy,toxicity and prognosis were evaluated after 2 treatment cycles.Results RR of group A was 8.8 ％ (3/34).RR of group B was 27.3 ％ (6/22).DCR of group A was 50.0 ％ (17/34).DCR of group B was 63.6 ％ (14/22).PFS of group A was 2.3 months.PFS of group B was 5.1 months.OS of group A was 8.7 months.OS of group B was 10.5 months.1-year survival rate of group A was 26.5 ％.1-year survival rate of group B was 31.8 ％.The above comparisons were not statistically different (all P ＞ 0.05).In adverse reactions,hematologic toxicity in group B was greater than that in group A (x2 =4.877,P =0.027).Other adverse reactions such as gastrointestinal reactions,fatigue and so on were grade Ⅰ-Ⅱ.Conclusions The treatment of weekly DOC used in advanced NSCLC is safe,effective an low toxicity.There are no significant difference of RR and PFS between single DOC and DOC associated with NDP.

ObjectiveTo evaluate the relationship between the proliferation of parathyroid cell in rabbit with primary hyperparathyroidism (PHPT) and the bone mineral density (BMD). MethodsEighty adult Chinese rabbits were randomly and equally divided into two groups. The contrast group was fed with normal diet ( Ca ∶ P, 1.0 ∶ 0. 7 ) and the experimental group was fed with high phosphate diet ( Ca ∶ P,1.0∶7.0) to establish the animal model of PHPT. At 3, 4, 5, and 6 months after the diet, bone mineral density of the rabbits was measured by the quantity CT (QCT). Then, the parathyroid and bone of the rabbits were removed for pathological examination. The number of parathyroid cell in PHPT was calculated.Proliferation was determined by immunohistochemistry of proliferation cell nuclear antigen ( PCNA ) and Bcl-2. The t test and Logistic regression was used to analyze the difference of data of two groups. ResultThe number of parathyroid cell in PHPT group was 1.61 times than that in the contrast group[ (673 ± 151 ) HP,(418 ± 25 ) HP,P ＜0. 01]. The rate of PCNA positive-cell was significantly increased in PHPT group than that in contrast group [(50.52 ± 11.62)％o, (26.70 ± 2. 78 )％, P ＜ 0.01], and so was Bcl-2[ (460. 37 ± 190. 05 )‰, (67. 02 ±:4. 38 )％‰,P ＜0. 05]. The value of BMD was significantly decreased in PHPT group than that in contrast group [ ( 152. 5 ± 34. 3 ), ( 188.6 ± 12. 2 ) g/cm3, P ＜ 0. 05]. There was a negative correlation between BMD and PCNA (r ＝ -0. 749, P ＜ 0. 05 ) and between BMD and Bcl-2 (r ＝-0.800, P ＜ 0. 05 ) in PHPT group. ConclusionThe BMD of PHPT is related to the parathyroid cells proliferation which provide a reliable method for early diagnosis of PHPT.