[A Sero-epidemiological Study on Transfusion-Transmissible Infectious among Volunteer Blood Donors From 2016 to 2020 in Nanjing].

OBJECTIVE: To investigate the status of transfusion-transmissible infection (TTI) among voluntary blood donors in Nanjing in recent five years, in order to provide data support for the recruitment of blood donors and formulation and updating of blood screening strategies. METHODS: HIV/HBV/HCV/TP serological markers were detected by ELISA in 487 120 blood donors in Nanjing from 2016 to 2020. Confirmatory assay was applied in anti-HIV positive samples by Nanjing Municipal Center for Disease Control and Prevention. The prevalence of TTI was calculated and the trend of disease was analyzed under different demographic groups. RESULTS: The total positive rate of TTI in blood donors was 0.49% (2 411/487 120), in which the overall seroprevalence rate of HBsAg, anti-HCV, anti-HIV and anti-TP was 0.23%, 0.09%, 0.01% and 0.16%, respectively. The overall prevalence of HIV and TP remained relatively steady (P>0.05), whereas HBV and HCV decreased year by year (P<0.05). The prevalence of TTI was higher among people with lower education level, high age group and first-time blood donation. CONCLUSION: The prevalence of TTI among voluntary blood donors in Nanjing is at a low level from 2016 to 2020, but the risk still exists. The recruitment of regular donors and the improvement of blood screening technology can effectively reduce the risk of TTI.

[Study on Reentry Evaluation Mode for Blood Donors Used to be HBV Reactive in Jiangsu Province].

OBJECTIVE: To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy. METHODS: HBsAg+ or HBV DNA+ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb+ / HBcAb+ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg+ and HBV DNA+ blood donors. RESULTS: From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg+ reactive and 70 HBV DNA+ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb+ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA+ donors was 82.86%, which was significantly higher than 47.98% of HBsAg+ donors. CONCLUSION: Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.

[Prevalence of Human T-Cell Lymphotropic Virus Type 1 and 2 among Blood Donors in Jiangsu from 2016 to 2019].

OBJECTIVE: To investigate the prevalence of human T-cell lymphotropic virus (HTLV) type-I/II infection among voluntary blood donors in Jiangsu (Nanjing, Suzhou, Xuzhou). METHODS: From 2016 to 2019, 408 262 samples of voluntary blood donors from four blood stations in Jiangsu Province (Jiangsu Province Blood Center, Nanjing Red Cross Blood Center, Suzhou Central Blood Station, and Xuzhou Central Blood Station) were screened for HTLV-I/II antibody by ELISA. The positive samples were sent to National Center for Clinical Laboratories for confirmation by RT-PCR and Western blot. RESULTS: The positive rate of HTLV-I/II screened by ELISA was 0.20‰ (82/408 262), and three HTLV-I positive samples were confirmed. The prevalence of HTLV-1 infection was 0.74 per 100 000 (3/408 262). All three donors were female repeated blood donors of childbearing ages. CONCLUSION: Jiangsu is a low prevalence area of HTLV, and a reasonable blood screening strategy for HTLV can further reduce the risk of transfusion-transmitted virus infection.

[Analysis of Reasons Causing False Positive of HBsAg Single-ELISA-Reactive in Blood Donors].

OBJECTIVE: To explore the reasons causing the false positive of HBsAg single-ELISA-reactive in blood donors of Jiangsu province so as to provide reference data for the return of blood donors. METHODS: Serological test: HBsAg ELISA parallel detection was performed on 319 444 samples of blood donors from 2014 to 2017; the ECLIA was employed to confirm the single-ELISA-reactive (S/CO≥0.5) samples, the nucleic acid test was used to detect the HBV DNA on the all single-ELISA-reactive samples in 6/8 people mixed/single. Reagent evaluation: the Receiver-Operating-Characteristic curve (ROCC) was drawn by the ECLIA/NAT results as the gold standard, and the diagnostic performance of reagents A and B under different cut-off was evaluated. RESULTS: A total of 227 (0.71‰) single-ELISA-reactive samples were detected among 319 444 blood donors, including 39 cases (17.2%) of positive HBsAg and 12 cases (5.3%) of positive HBV DNA; Under the maximum YI, the COI (1.0) employed by the manufacturer recommendation has a better diagnostic value than laboratory COI (0.5), and the capability of reagent A was better than that of reagent B (AUC: 0.661 vs 0.632; Youden: 0.329 vs 0.297), but the specificity of both reagents was restricted (＜60%). Under the maximum YI, the best cut-off value of reagents A and B were 2.4 and 1.4 COI, respectively. Compared with the cut-off value of manufacturer, the sensitivity of reagents A decreased by 33% and the false positive rate decreased by 60% while the sensitivity of reagent B increased by 140% and the false positive rate increased by 36%, respectively. CONCLUSION: The false positive of HBsAg single-ELISA-reactive in blood donors is caused by the limited specificity of ELISA reagent and the setting of COI values. According to ROCC maximum YI method, the COI can be set as 2.4 COI and (0.5-1.4) COI for reagent A and B to reduce false positive rate.

[Evaluation of the Cutoff of Anti-HCV Antibody Enzyme-Linked Immunosorbent Assay in 7 Blood Station Laboratories].

OBJECTIVE: To evaluate the necessity and suitability of the anti-HCV ELISA teot gray zone setted up by 7 blood station laboratories. METHODS: 7 blood station laboratories were coded as 1, 2, 3, 4, 5, 6 and 7 respectively; 8 kinds of ELISA reagents were coded as A, B, C, D, E, F, G and H respectively. 1 or 2 of 8 ELISA reagents produced by different manufactories were used to detect the anti-HCV in specimens of same group by 7 blood station laboratories; the Westen blot was used to detect the specimens with difference of detected results so as to difine the serological status of specimens. The true positive rate of specimens detected by laboratories and gray zone-comfirined positive rate of specimens were accounted so as to analyze the necessity of setting up the gray zone for anti-HCV ELISA test of 7 blood station laboratories; the optimal cut-off value for anti-HCV ELISA test was determined in 7 blood station laborafories by ROC curve and the changes of sensitivity and specificity of 3 different cut-off value(laboratory work cut-off value, manifactory-recommended cun-off value and optimal cut-off value) were compared so as to analyze the suitability of gray zone for anti-HCV ELISA test in 7 blood station laboratories. RESULTS: The true positive rate detected by 7 blood station laboratories, out of which coded 1 laboratory used 2 kinds of coded A, B reagents was 95.40%(1A), 99.23% (1B), 94.25% (2C), 96.17% (3D), 98.08% (4E), 96.93% (5F), 97.32%(6G) and 93.10%(7H). Except for 2C(94.25%) and 7H(93.10%), the true positive rate detected by laboratoies which not sutted up gray zone, the gray zone-con-firmed positive rate in 6 blood station laboratories setted up gray zone: was 0.00%, 0.00%, 21.43%, 0.00%, 0.00%, 0.00% and 38.89%. The comparison of 3 different cut-off valuces by ROC curve showed that the anti-HCV cut-off values in 5 laboratories(1B, 2C, 4E, 5F and 6G) were as follows: optimal cut-off value＞manufactory recommeded cut-off value＞laboratory work cut-off value, thus use of manufactory-recommeded cut-off value abreadly has reached the high sensitivity requinements for laboratory screening; however, the optimal cut-off value in laboratories 1A, 3B and 7H, thas the appropriate gray zone should be used. In 6 laboratories setting up gray zone, the gensitivity in 3D, 7H laboratories only a little improved (1.60% and 2.70% raspectively) in Eamparison between laboratory work cut-off value and manufactorg-recommeded cut-off value; moreover, the sensitivity in other laboratories not is changed, but the specificity decreased (0.20%-0.50%). CONCLUSION: In addition to setting up the appropriate gray zone in laboratories 1A, 3D and 5H, the gray zone in other laboratories may be cancelled. Even in the same laboratory, the setting up the gray zone also should be scientifically assessed, the same scale cannot be blindly used, thus appropniate strategies should be established.

Does Distal Clavicle Resection Decrease Pain or Improve Shoulder Function in Patients With Acromioclavicular Joint Arthritis and Rotator Cuff Tears? A Meta-analysis.

BACKGROUND: Acromioclavicular joint arthritis is a common, painful, and often missed diagnosis, and it often accompanies other shoulder conditions such as rotator cuff disease. Whether distal clavicle resection is important to perform in patients undergoing surgery for rotator cuff tears and concomitant acromioclavicular joint arthritis is controversial. QUESTIONS/PURPOSES: The purpose of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of distal clavicle resection on (1) outcome scores; (2) shoulder ROM, joint pain or tenderness, and joint instability; and (3) risk of reoperation among patients treated surgically for rotator cuff tears who had concomitant acromioclavicular joint arthritis. METHODS: We systematically searched the PubMed, EMBASE, and Cochrane databases to find RCTs that met our eligibility criteria, which, in summary, (1) compared rotator cuff repair plus distal clavicle resection with isolated rotator cuff repair for patients who sustained a full- or partial-thickness rotator cuff tear and concomitant acromioclavicular joint arthritis; and (2) the followup period was at least 2 years. Two reviewers screened the studies, extracted the data and evaluated the methodological quality, and performed data analysis. Statistical heterogeneity among studies was quantitatively evaluated with the I index. No heterogeneity was detected (I = 0%; p = 0.75) in terms of acromioclavicular joint pain or tenderness, Constant score, forward flexion, external rotation, and risk of reoperation, so fixed-effect models were used in these endpoints. Heterogeneity was moderate for the American Shoulder and Elbow Surgeons (ASES) score (I = 53%; p = 0.12) and low for the visual analog scale (VAS) score (I = 35%; p = 0.22), so random-effect models were used in these endpoints. Subgroup analysis was stratified by the symptom of acromioclavicular joint arthritis. Three RCTs with 208 patients were included. We evaluated the risk of bias using the Cochrane risk-of-bias tool; in aggregate, the three RCTs included showed low to intermediate risk, although not all parameters of the Cochrane tool could be assessed for all studies. RESULTS: There was no difference between the distal clavicle resection plus rotator cuff repair group and the isolated rotator cuff repair group in ASES score (mean difference =1.41; 95% confidence interval [CI], -3.37 to 6.18; p = 0.56) nor in terms of the VAS score and Constant score. Likewise, we found no difference in ROM of the shoulder (forward flexion, internal rotation, and external rotation) or acromioclavicular joint pain or tenderness between the groups (pooled results of acromioclavicular joint pain or tenderness: risk ratio [RR], 1.59; 95% CI, 0.67-3.78; p = 0.30). Acromioclavicular joint instability was only detected in the rotator cuff repair plus distal clavicle resection group. Finally, we found no difference in the proportion of patients undergoing repeat surgery between the study groups (pooled results of risk of reoperation for the rotator cuff repair plus distal clavicle resection and isolated rotator cuff repair: one of 52 versus two of 78; RR, 0.86; 95% CI, 0.11-6.48; p = 0.88). CONCLUSIONS: Distal clavicle resection in patients with rotator cuff tears did not result in better clinical outcome scores or shoulder ROM and was not associated with a lower risk of reoperation. Distal clavicle resection might cause acromioclavicular joint instability in patients with rotator cuff tears and concomitant asymptomatic acromioclavicular joint arthritis. Arthroscopic distal clavicle resection is not recommended in patients with rotator cuff tears and concomitant acromioclavicular joint arthritis. Additional well-designed RCTs with more participants, long-term followup, and data on patient-reported outcomes are needed. LEVEL OF EVIDENCE: Level I, therapeutic study.

Increased long noncoding RNA SNHG20 predicts poor prognosis in colorectal cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been suggested to be involved in the development and progression of malignancies. However, the investigation of small nucleolar RNA host gene 20 (SNHG20) on cancer progression remains unknown. The present study aims to explore the clinical significance of SNHG20 and its potential molecular mechanism in colorectal cancer (CRC). METHODS: Quantitative real-time PCR (qRT-PCR) was used to measure the SNHG20 expression in a total of 107 CRC tissues and CRC cell lines. Loss of function approach was employed to explore the biological roles of SNHG20 in vitro. Its potential molecular mechanism was further verified by western blotting and qRT-PCR. RESULTS: The results suggested that SNHG20 expression was significantly upregulated in CRC tissues compared to corresponding normal tissues from 107 CRC patients. High expression of SNHG20 was remarkably associated with advanced TNM stage in patients with CRC. Multivariate analyses unraveled that SNHG20 expression was an independent prognostic factor for overall survival in CRC patients. Further functional assays revealed that knockdown of SNHG20 suppressed cell proliferation, invasion and migration, and cell cycle progression in CRC cells. Moreover, SNHG20 regulated cell growth through modulation of a series of cell cycle-associated genes. CONCLUSIONS: Our findings suggest that dysregulation of SNHG20 participates in CRC progression and may serve as a potential therapeutic target in CRC patients.

miR-9 Modulates Osteosarcoma Cell Growth by Targeting the GCIP Tumor Suppressor.

Osteosarcoma is the most common primary bone tumor in humans, especially in childhood. However, the genetic etiology for its pathogenesis remains elusive. It is known that microRNAs (miRNAs) are involved in the development of tumor progression. Here we show that microRNA-9 (miR-9) is a potential oncogene upregulated in osteosarcoma cells. Knockdown of miR-9 in osteosarcoma resulted in suppressed colony formation and cell proliferation. Further study identified GCIP, a Grap2 and cyclin D interacting protein, as a direct target of miR- 9. In addition, GCIP overexpression activated retinoblastoma 1 (Rb) and suppressed E2F transcriptional target expression in osteosarcoma cells. Moreover, GCIP depletion reversed miR-9 knockdown induced colony formation and cell proliferation suppression. In sum, these results highlight the importance of miR-9 as an oncogene in regulating the proliferation of osteosarcoma by directly targeting GCIP and may provide new insights into the pathogenesis of osteosarcoma.

[Analysis on HIV infection status of voluntary blood donors in Chinese Nanjing area from 2003 to 2013].

This study was purposed to analyze HIV infections status among the unpaid blood donation population in Chinese Nanjing area from 2003 to 2013, to understand the HIV antibody positive and/or HIV-RNA positive population characteristics in order to provide evidence for recruiting strategy of blood donation without compensation. The whole blood samples of unpaid donors and the platelet donors were tested by ELISA, from June 2010 the NAT test was added for the samples that were ELISA test with unilateral negative. Every HIV reactive sample (HIV-antibody and/or HIV-RNA) was sent to confirm in the Centers for Disease Control and Prevention in Nanjing, including 1 case of enzyme bilateral positive and HIV-RNA reactivity has been sentenced as indeterminacy; another 1 case of enzyme bilateral negative and HIV-RNA reactive was sent to the Centers for Disease Control and Prevention in Jiangsu Province to test nucleic acid quantification to be positive; The unpaid donor HIV screening results from 2003 to 2013 in Chinese Nanjing area were analysed statistically. The results showed that from 2003 to 2013 years 641401 unpaid blood donors were tested,out of them 57 cases were contirmed to be HIV antibody positive (HIV-1),the total positive rate was 8.89/100 000. Since 2010 years, the HIV antibody positive rate increased significantly (P < 0.01), then it was stable until to 2012 years, the HIV antibody positive rate was 15.43/100 000. In the 2013 year, the HIV antibody positive rate was 10.03/100 000. The HIV antiboby positive rates in male and female were 13.25: 1. The years of male cases were 18-30 that accounted for 56.14%, and the years of male cases were 31-40 that accounted for 31.58%. The men who first time donated blood were 46 cases and accounted for 80.70%. The men who donated blood again were 11 cases and accounted for 19.30%. The men who donated blood on streets of blood donation accounted for 80.70% and their HIV antibody positive rate was 11.88/100 000. The men who donated blood in the plan organization of donators were 8.78%, and their HIV antibody possitive rate was 2.33/100 000. The HIV antibody positive rate were different in the different times and different donation types, and were statistical significance (P < 0.01). It is concluded that based on the present status of HIV antibldy positive rate in Chinese Nanjing area, the HIV antibody possitive donors are more observed in the first blood donation population, especially in the higher educated young men. This situation or tendency indicates that the voluntary blood donors should be organized or selected from low risk population, and should popularize the knowlege of unpaid blood donation, especiatly the knowlege of AIDS, strengthen cosulting work on the mobile donation points in streets before donating blood, and should establish the cyber-database to ensure blood safety.

[Infection status of HBV, HCV and HIV in voluntary blood donors of Chinese Nanjing area during 2010-2013].

This study was purposed to understand the infection of HBV, HCV, HIV among the voluntary blood donors and the epidemic trend in infectious population in Chinese Nanjing area, and to guide the mobilization and recruitment of blood donors. A total of 199777 whole blood samples of voluntary blood donors were tested by ELISA, the nucleic acid technology (NAT) combined detection (HBV-DNA, HCV-RNA, HIV-RNA) was added for detection of the samples with HBsAg,anti-HCV, anti-HIV at least unilateral negative donors from June 10, 2010 to June 9, 2013 years, and these statistic data were analyzed. Every HIV reactive sample(HIV-antibody and/or HIV-RNA) was sent to be confirmed in the Centers for Disease Control and Prevention in Nanjing. The results showed that the voluntary donors' infection rate of HBsAg, anti-HCV, anti-HIV were 0.45%, 0.28%, 0.11% respectively; NAT positive rate was 0.07%, 32 cases were confirmed with anti-HIV positive, in which 30 cases were male (6 cases were repeated blood donors) and 2 cases were female, 3 cases were unconfirmed, in which 2 cases were males and 1 case was female. The statistical analysis demonstrated that the difference of unqualitative rate of HBsAg, anti-HCV, anti-HIV was statistically significant between the first-time and repeated blood donors.It is concluded that the positive rate of anti-HCV and anti-HIV displayed a declining trend year by year in Nanjing voluntary blood donation population from June 10,2010 to June 9, 2013 years. The unqualitative rate of HBsAg and NAT increased with the age increasing, while that of anti-HCV, anti-HIV decreased with age increasing. The unqualitative rate of the repeated blood donors is far lower than that of the first-time blood donors. The ELISA positive rate of anti-HIV testing in females is higher than that in males, but the confirmed positive rate of male is significantly higher than that of female. Therefore the consulting skills before donating should be improved, concerning the link of recruiting donors, focusing on strengthening the first-time donors' consultation, evaluating and developing the fixed voluntary blood donors, and vigorously popularizing NAT technology in blood screening to improve the blood safety effectively.

Biomechanical analysis of four types of internal fixation in subtrochanteric fracture models.

OBJECTIVE: To compare the biomechanical properties of four types of internal fixation (proximal femoral nail [PFN], dynamic hip screw [DHS], dynamic condylar screw [DCS], and proximal femoral locking plate [PFLP]) for different types of subtrochanteric fractures. METHODS: Thirty-two antiseptic femurs were randomly divided into four groups. After internal fixation had been implanted, different types of subtrochanteric fracture models were produced and each tested under vertical, torsional and vertical damage loads. RESULTS: The stiffness ratio of PFN in each fracture model and failure load were the highest in the four groups; however, the torsional stiffness ratio was the lowest. Tension strain ratios of DHS and DCS on the lateral side became compression strain ratios with restoration of the medial fragment. The stiffness ratio of DHS was lower than PFLP in each fracture model, torsional stiffness ratio was the highest in fracture models II to V and the failure load was lower only than PFN. The stiffness ratio and failure load of DCS were both the lowest, torsional stiffness ratio was similar to PFLP's in fracture models II to V. The stiffness ratio of PFLP was only lower than PFN's in each fracture model, but the failure load was lower than DHS's. CONCLUSION: Four types of internal fixation achieve better stabilities for type I subtrochanteric fractures. PFN and PFLP produce reliable stability in type IIIA subtrochanteric fractures. If the medial buttress is restored, DCS can be considered. For type IV subtrochanteric fractures, only PFN provides stable fixation. PFLP is suitable for comminuted fractures with large fragments.

[Biomechanical study on open fracture model with plate fixation compared with closed fracture model with intramedullary nail fixation in rats].

OBJECTIVE: To compare biomechanical effect of the closed fracture model with intramedullary nail fixation and the open fracture model with plate fixation in rats. METHODS: Forty 8-week-old Spragu-Dawley male rats were divided into two groups randomly. Left femoral shaft closed fractures model was created in 20 rats, and treated with intramedullary nail. Other 20 rats received open osteotomy on the left femoral shaft, and were fixed by plate. Rats were sacrificed and draw the materials at 4, 6, 8 and 12 weeks in batch. Across section area and volume of callus were measured, peak load, restoration rate of peak load were tested. The biomechanical efficency of two methods of femoral shaft fracture fixation were compared. RESULTS: The difference of surgical duration was statistically significant between two groups (P < 0.001). At 4, 6, 8 and 12 weeks, the difference of peak load, restoration rate of peak load, volume and area of callus was also statistically significant between two groups (P < 0.05). CONCLUSION: Open fracture model with plate fixation led to delayed healing compared with closed fracture model with intramedullary nail. However, open fracture model with plate fixation model could be a valuable research tool to study the healing consequences of cortical bone, which may provide insight into the pathogenesis and ideal treatment of fractures or nonunions.

Qualitative evidence from a systematic review of prognostic predictors for surgical outcomes following cervical ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament (OPLL) is a pathological ectopic ossification of this ligament that usually occurs in the cervical spine. For patients with cervical OPLL and neurological symptoms, surgical intervention is necessary but not always effective. Various prognostic factors influence the surgical outcome. The results of studies identifying these prognostic predictors are often inconclusive or contradictory. These predictors have not been well identified or summarized. The present study was designed to identify the prognostic predictors for the surgical outcome of cervical OPLL based on the available evidence in the literature. Non-interventional studies were searched in Medline, Embase, Science Direct, OVID and the Cochrane library. Forty-two observational studies involving 2791 patients were included. The quality of the included studies was assessed with a modified quality assessment tool, which was originally designed for use with observational studies. The effects of the studies were combined with the study quality score using a model of best-evidence synthesis. There was strong evidence for five predictors: (i) age, (ii) duration of symptoms, (iii) pre-operative neurological score, (iv) transverse area of the spinal cord, and (v) intramedullary high signal intensity on the T2-weighted MRI. We also identified eight predictors with moderate supporting evidence, seven with limited evidence, four with conflicting evidence and four predictors without supporting evidence. While there is no conclusive evidence regarding the surgical outcomes following cervical OPLL, these data provide evidence to guide the clinician in choosing an optimal therapeutic strategy for patients with cervical OPLL. Further research is necessary to fully evaluate the effects of the predictors described in this study.

A methodological, systematic review of evidence-based independent risk factors for surgical site infections after spinal surgery.

OBJECTIVE: To identify the independent risk factors, based on available evidence in the literature, for patients developing surgical site infections (SSI) after spinal surgery. METHODS: Non-interventional studies evaluating the independent risk factors for patients developing SSI following spinal surgery were searched in Medline, Embase, Sciencedirect and OVID. The quality of the included studies was assessed by a modified quality assessment tool that had been previously designed for observational studies. The effects of studies were combined with the study quality score using a best-evidence synthesis model. RESULTS: Thirty-six observational studies involving 2,439 patients with SSI after spinal surgery were identified. The included studies covered a wide range of indications and surgical procedures. These articles were published between 1998 and 2012. According to the quality assessment criteria for included studies, 15 studies were deemed to be high-quality studies, 5 were moderate-quality studies, and 16 were low-quality studies. A total of 46 independent factors were evaluated for risk of SSI. There was strong evidence for six factors, including obesity/BMI, longer operation times, diabetes, smoking, history of previous SSI and type of surgical procedure. We also identified 8 moderate-evidence, 31 limited-evidence and 1 conflicting-evidence factors. CONCLUSION: Although there is no conclusive evidence for why postoperative SSI occurs, these data provide evidence to guide clinicians in admitting patients who will have spinal operations and to choose an optimal prophylactic strategy. Further research is still required to evaluate the effects of these above risk factors.

Purification, characterization and primary structure of a chymotrypsin inhibitor from Naja atra venom.

A chymotrypsin inhibitor, designated NA-CI, was isolated from the venom of the Chinese cobra Naja atra by three-step chromatography. It inhibited bovine alpha-chymotrypsin with a Ki of 25 nM. The molecular mass of NA-CI was determined to be 6403.8 Da by matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) analysis. The complete amino acid sequence was determined after digestion of S-carboxymethylated inhibitor with Staphylococcus aureus V8 protease and porcine trypsin. NA-CI was a single polypeptide chain composed of 57 amino acid residues. The main contact site with the protease (P1) has a Phe, showing the specificity of the inhibitor. NA-CI shared great similarity with the chymotrypsin inhibitor from Naja naja venom (identities=89.5%) and other snake venom protease inhibitors.

Characterization of a new bradykinin-potentiating peptide (TmF) from Trimeresurus mucrosquamatus.

A novel bradykinin-potentiating peptide (BPP), designated as TmF, has been purified to homogeneity from the venom of Trimeresurus mucrosquamatus by 70% cold methanol extraction, Sephadex G-15 gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). The amino acid sequence of TmF was determined to be pGlu-Gly-Arg-Pro-Leu-Gly-Pro-Pro-Ile-Pro-Pro (pGlu denotes pyroglutamic acid), which shared high homology with other BPPs. The molecular mass of TmF was 1.1107 kD as determinated by electrospray ionization-mass spectrometry (ESI-MS), which was in accordance with the calculated value of 1.1106 kD. The potentiating unit of TmF to bradykinin-induced (BK-induced) contraction on the guinea-pig ileum in vitro was (1.13 +/-0.3) unit (mg/L), and TmF (5.0 x10(-4) mg/kg) increased the pressure-lowering-effect of bradykinin (5.0 x10(-5 )mg/kg) with approximate descent value of (14 +/-2) mmHg. In addition, TmF inhibited the conversion of angiotensin I to angiotensin II, 2 x10(-3) mg of TmF caused 50% inhibition (IC(50)) of angiotensin- converting enzyme (ACE) hydrolyzing activity to bradykinin.

Characterization and cloning of a novel phospholipase A(2) from the venom of Trimeresurus jerdonii snake.

A phospholipase A(2) (PLA(2)), called jerdoxin, was isolated from Trimeresurus jerdonni snake venom and partially characterized. The protein was purified by three chromatographic steps. SDS-polyacrylamide gel electrophoresis in the presence or absence of dithiothreitol showed that it had a molecular mass of 15 kDa. Jerdoxin had an enzymatic activity of 39.4 micro mol/min/mg towards egg yolk phosphatidyl choline (PC). It induced edema in the footpads of mice. In addition, jerdoxin exhibited indirect hemolytic activity. About 97% hemolysis was observed when 2 micro g/ml enzyme was incubated for 90 min in the presence of PC and Ca(2+). No detectable hemolysis was noticed when PC was not added. Ca(2+) was necessary for jerdoxin to exert its hemolytic activity, since only 52% hemolysis was seen when Ca(2+) was absent in the reaction mixture. Furthermore, jerdoxin inhibited ADP induced rabbit platelet aggregation and the inhibition was dose dependent with an IC(50) of 1.0 micro M. The complete amino acid sequence of jerdoxin deduced from cDNA sequence shared high homology with other snake venom PLA(2)s, especially the D 49 PLA(2)s. Also, the residues concerned to Ca(2+) binding were conserved. This is the first report of cDNA sequence of T. jerdonii venom PLA(2).

A novel short neurotoxin, cobrotoxin c, from monocellate cobra (Naja kaouthia) venom: isolation and purification, primary and secondary structure determination, and tertiary structure modeling.

A novel short neurotoxin, cobrotoxin c (CBT C) was isolated from the venom of monocellate cobra (Naja kaouthia) using a combination of ion-exchange chromatography and FPLC. Its primary structure was determined by Edman degradation. CBT C is composed of 61 amino acid residues. It differs from cobrotoxin b (CBT B) by only two amino acid substitutions, Thr/Ala11 and Arg/Thr56, which are not located on the functionally important regions by sequence similarity. However, the LD50 is 0.08 mg/g to mice, i.e. approximately five-fold higher than for CBT B. Strikingly, a structure-function relationship analysis suggests the existence of a functionally important domain on the outside of Loop III of CBT C. The functionally important basic residues on the outside of Loop III might have a pairwise interaction with alpha subunit, instead of gamma or delta subunits of the nicotinic acetylcholine receptor (nAChR).