Anti-retroviral (ARV) drugs have been successfully used for HIV/AIDS therapy,and their uses in pre-exposure prophylaxis (PrEP) for HIV infection is becoming increasingly important,and is drawing more attentions.Reports on seven large scale,multicentric clinical trials provide significant clinical data for further study and implementation of PrEP.This article reviews the current situation,necessity,questions,problems and prospects of PrEP for HIV infection.

BACKGROUND:Discogenic pain is a major cause of chronic low back pain,and its inflammation mechanism that is participated by many cytokines is well known by more and more people. However,what is the role of these cytokines in the occurrence and development of pain and how we use them to control pain are still not consistent. OBJECTIVE:To completely learn about the pathogenesis of intervertebral disk herniation,the relative cytokines in the occurrence and development of pain and the advances in the treatment of chronic pain with cytokines. RETRIEVE STRATEGY:A computer-based online search of CNKD was undertaken to identify the relevant articles dated from January 1994 to June 2007 with the Chinese of "cytokine,pain". And totally 153 articles were collected. Meanwhile,PubMed database was searched for English articles published from January 2002 to June 2007 with the keywords of "gene,chronic pain" and 36 were collected. The articles that involved the basic and clinical researches closely related with cytokine were selected. Repetitive articles were excluded. After the trail,6 Chinese and 24 English articles were involved. LITERATURE EVALUATION:Of the 30 articles,10 were focused on the basic research and animal experiment,and 20 were about clinical research. There were 7 of RCT,1 of EBM review,10 of summary analysis,2 of case report,and 10 of experience exchange. DATA SYNTHESIS:The mechanisms of discogenic pain include inflammation and immune ones besides mechanical pressure. Inflammation mechanism of discogenic pain is well known by more and more people,in which many cytokines such as substance P,phospholipase A2,tumor necrosis factor,interleukin,growth factor and NO participate. Meanwhile,the role of immunities should not be ignored. Some researchers have used some cytokines(interleukin 1 receptor antagonist,vascular endothelial growth factor,etc) in clinic to treat pains and got good effect. CONCLUSION:The mechanism of pain and various effects of pain-killer are based on gene. Cytokines play important roles in the occurrence,development and treatment of discogenic pain.

Isotope dilution mass spectrometry is a reliable principle for small molecule analyte measurements.It is a precise,accurate method with very high specificity,which is very suitable for lowconcentration steroid hormones tests.The published reference methods are all based on this principle so far.In this paper,the applications of isotope dilution mass spectrometry in the determination of steroid hormones were reviewed.

Objective To evaluate the clinical effect of different doses of leuprorelin acetate in in vitro fertilization-embryo transfer(IVF-ET).Methods From January 2011 to December 2011,the data of 268 patients undergoing IVF and (or) intracytoplasmic sperm injection (ICSI) in Reproductive Medical Center,Clinical College of PLA,Anhui Medical University were studied retrospectively.All the patients were divided into three groups based on with long protocol and controlled ovarian stimulation (COH) including 83cycles with 1.25 mg of leuprorelin in low dose group,68 cycles with 1.88 mg of leuprorelin in high dose group,117 cycles with 1.25 mg of diphereline in control group.The serum follicle stimulating hormone (FSH),luteinizing hormone (LH),estradiol (E2) and progesterone (P) before gonadotropin (Gn)administration on the days 3-5 of the menstrual cycle and on the day of hCG administration were detected,the dose and duration of Gn,number of oocytes retrieved,number of mature oocytes,the rates of fertilization,embryo cleaved,good-quality embryos clinical pregnancy and early miscarriage were compared among three groups.Results There were no significant differences in age,the level of LH and P on the day of hCG administration among three groups (P ＞ 0.05).The level of FSH was (3.8 ± 1.6) U/L in low dose leuprorelin group,(3.1 ± 1.4) U/L in high dose of leuprorelin group and (2.4 ± 1.3) U/L in diphereline group before Gn administration,which reached statistical difference (P ＜ 0.05).The mean length of Gn stimulation were (9.8 ± 1.7) days in low dose leuprorelin group,(10.5 ± 1.8) days in high dose of leuprorelin group and (11.1 ± 1.4) davs in diphereline group,which reached statistical difference (P ＜0.05).The mean dose of Gn was (24 ± 7) in low dose of leuprorelin group,which was significantly higher than (27 ± 9) in high dose of leuprorelin group and (28 ± 7) in diphereline group (P ＜ 0.05).The level of LH was (2.7 ± 1.6) U/L in low dose of leuprorelin group and (2.2 ± 1.0) U/L in diphereline group before Gn administration,which reached statistical difference(P ＜ 0.05).The cancel cycles were 5 in low dose of leuprorelin group,4 in high dose of leuprorelin group and 7 in diphereline group.The number of ovum was (14 ±7) low dose of leuprorelin group,(13 ±6) in high dose of leuprorelin group,(14 ±6) in diphereline group.The rates of fertilization was 66.26％ (758/1144)in low dose of leuprorelin group,67.01％ (589/879) in high dose of leuprorelin group and 68.54％ (1111/1621) in diphereline group,the rates of goodquality embryos was 64.22％ (472/735) in low dose of leuprorelin group,60.50％ (340/562) in high dose of leuprorelin group and 59.59％ (640/1074) in diphereline group,clinical pregnancy was 49％ (38/78) in low dose of leuprorelin group,42％ (27/64) in high dose of leuprorelin group and 50％ (55/110) in diphereline group,early miscarriage was 18％ (7/38) in low dose of leuprorelin group,15％ (4/27) in high dose of leuprorelin group and 15％ (8/55) in diphereline group,which did not show significant differences (P ＞0.05).Conclusions Both 1.25 mg and 1.88 mg leuprorelin acetate could obtain good downregulation effect and clinical outcomes.1.25 mg leuprorelin acetate could decrease patient's costs by reducing Gn dose and duration.

Objective To investigate the effect of EGB on SOD, MDA of ventilator-induced lung injury in rats and its possible mechanisms. Methods Thirty male SD rats were randomly divided into 3 groups: control group (C group), high tidal ventilation group (H group) and EGB group (E group). The setting mechanical ventilation was VT=30 mL/kg, RR=40/min, I/E=1/3, PEEP=0 cmH2 O and FiO2=21%. The broncho-alveolar lavage fluid (BLAF) and serum were obtained for determination of the levels of SOD and MDA at the end of 4 h mechanical ventilation. The Lungs were removed, and the wet-to-dry weight ratio (W/D) and pulmonary pathologic changes were measured. Results As compared with C group, W/D and the levels of MDA were significantly increased in H group, but the levels of SOD were reduced in H group. As compared with H group, W/D and the levels of MDA were significantly decreased in E group, but the levels of SOD were increased in E group. Pulmonary pathologic changes were alleviated in E group comparing with H group. Conclusion EGB injection may have a protective role against hyperoxia and induced pulmonary damage in rats.

Objective To investigate the disinfectant-resistant gene qacA in Staphylococcus aureus isolates from the First Affiliated Hhospital of Chongqing Medical University. Methods A total of 126 S. aureus strains were isolated. The minimum inhibitory concentrations (MICs) of 4 representative monovalent and bivalent disinfectants were determined. Polymerase chain reaction (PCR) was employed to analyze the prevalence of qacA gene in these strains. Disk diffusion method was used to identify methicillin-resistant S. aureus (MRSA).Results Of the 126 S. aureus strains, 12 were positive for qacA gene. The prevalence of qacA in these strains was 9.5%. The prevalence of qacA gene in MRSA was 17.3%. Conclusions qacA gene is prevalent in the clinical isolates of S. aureus.

Objective To provide information and assistance for research of bile duct injury in OLT through endoscopic observation and treatment of biliary complications after liver transplantation.Methods After OLT, all the cases in normal group, bile duct injury group and hepatic artery injury group were observed, diagnosed and recorded respectively. Meanwhile, the biopsy was performed through the endoscopy for pathological examination. For those cases without T tube, the biopsy was conducted by choledochoscopy in combination with duodenoscopy. Results The exterior and interior bile duct anatomy of the 9 cases in the normal group was normal. They had no bile duct stenosis and scar, their bile duct mucous membrane looked good and the anastomosis of the donor-receptor bile duct healed well. Restored mucous tissue coating with intact epithelium was found by pathological examination. Fibrous tissue and small vascular proliferation happened under epithelium scattered with plasmocyte and lymphocyte. Various kinds of bile duct stones-simple, multiple and casting mould type, were found in 12 cases with bile duct injury. Bile duet mucous membrane injured in different degrees was repaired after stone removed and obstruction relieved by endoscope. Bile duct tree becoming normal was seen by pacification examination. Three cases in the hepatic injury group had bile duct ischemic necrosis, losing of normal structure without bile duct wall and mucous membrane. Conclusion Bile ducts are injured in different degrees in OLT. The choledochofibroscopy is of the first choice for diagnosis and treatment of complications after OLT.

Objective To reproduce and validate the hexokinase reference method for glucose detection and compare other 5 routine glucose kits with this reference method. Methods The CDC hexokinase reference method for glucose detection was established and the performance was validated through testing a standard reference material (SRM) and participating in the IFCC ring-trial for reference laboratories for glucose evaluation. The CLSI EP 9-A2 protocol was used to compare the 5 routine glucose kits with the hexokinase reference method. Forty serum samples were analyzed by 5 routine kits and the hexokinase reference method. Results When SRM 965a was determined by the reference method,the bias of level 2 and level 3 were 0. 93%, -0. 23% respectively. The results for IFCC ring trial were within the accepted range. For the 5 routine kits, the confidence intervals of the predictive bias at the medical decision point Xc (Xc = 6. 11 mmol/L) were all within the range of defined acceptable error (10%) and the range of biological variation bias (6.9%). Conclusions The hexokinase reference method for serum glucose was reproduced in our lab. The serum glucose results measured with 5 routine kits were different from results detected with the reference method, but the bias was acceptable,and it will not affect the detection results.

Objective To investigate preanalytical and intraindividual biological variations of 19 biochemistry analytes. Methods For the study of preanalytical variations, 10 consecutive blood specimens were taken from each of 21 individuals and the specimens were taken from different arms and with various evacuated blood tubes and venous occlusion durations and processed with different storages before and after centrifugal separation of serum. Another 3 aliquots of blood, each at an interval of 1 week, were taken from the individuals for the study of intraindividual biological variations. All the serum samples were analyzed in duplicate for 19 biochemistry analytes. Analysis of variance was performed on the results for the estimation of preanalytical and biological variations. Results Various preanalytical treatments or factors caused some systematic variations but random specimen errors were the main contributors of preanalytical variations. Chloride, sodium and calcium showed preanalytical variations of less than 1% and other analytes ranging from 1%-7%. Different analytes showed varied intraindividual biological variations. The least biological variations ( <2% ) were observed on chloride, sodium and calcium and the largest ( >20% ) on bilirubin,triglycerides, alanine aminotransferase and creafine kinase. Conclusions Preanalytical variations under laboratory settings in China and intraindividual biological variations in Chinese for 19 biochemistry analytes have been estimated. These data will be useful in the estimation of measurement uncertainty and the interpretation of clinical laboratory results.

Objective To investigate the prevalence of virulence genes(ply, pspA, nanA, lytA, psaA) among Streptococcus pneumoniae recently isolated from clinical patients. Methods The 133 strains were isolated from patients in three teaching hospitals in Chongqing from 2006 to 2008. Polymerase chain reaction was used to screen for virulence genes (ply, pspA, nanA, lytA, psaA). Results The positive rate of lytA, psaA, ply, nanA and pspA in 133 clinical isolates were 94.7%, 85.0%, 82.7%, 84. 2% and 60.2%, respectively. The positive rates of the lytA, psaA, ply, nanA and pspA genes in 87 common serotypes isolates was 100%, 87.4%, 86.2%, 89.7%, 67.8%, respectively. Conclusion The total positive rates of five virulence genes in the 133 clinical strains were high. The positive rates of five genes in the com-mon serotypes isolates were higher than those in the no-common serotypes. These genes are important virulence genes of Streptococcus pneumoniae. They could be candidates for protein vaccine of Streptococcus pneumoniae.