D-dimer testing for safe exclusion and risk stratification in patients with acute pulmonary embolism in primary care.

BACKGROUND: Safe exclusion and risk stratification are currently recommended for the initial management of patients with acute pulmonary embolism (APE). The aim of this study was to assess the safe exclusion and risk stratification value of D-dimer (DD) for APE when tested at the beginning of admission. MATERIALS AND METHODS: All consecutive Chinese APE patients and controls were recruited from January 2010 to December 2012. All measurements of serum indexes were made in duplicate and blinded to the patients' status. All the 40 patients with the first episode of APE were confirmed by multi-detector computed tomographic pulmonary angiography. The plasma prothrombin time (PT), activated partial thromboplastin time, thrombin time, fibrinogen, and DD levels were measured within 24 h of admission. We used the Mann-Whitney U-test to determine the differences between groups and drew receiver operator characteristic curve to evaluate the indexes' value in the APE screening. RESULTS: The PT and DD in the APE group were significantly higher than those in the disease control group (P < 0.05). Taking PT and DD as the useful screening tests for APE and AUC was 0.765 and 0.822, respectively. DD yielded the higher screening efficiency, with DD >1820 µg/L as cut-off value, the sensitivity, specificity, positive and negative predictive value was 82.5%, 75.2%, 56.9%, and 91.6%, respectively. CONCLUSION: The patients with APE showed significant higher DD levels compared with disease controls, suggesting a negative qualitative DD test result can safely and efficiently exclude APE in primary care.

The Defence of Artificial Life by Synthetic Biology From Ethical and Social Aspects.

Synthetic biology opens up exciting new opportunities for research and industry. Although the work of synthetic biologists presents many beneficial applications, it also raises potentially serious ethical concerns. Therefore, clear ideas must be formed regarding its ethical and social implications, e.g., public perception, safety, security, intellectual property rights and so on. In this review, the authors identified four issues relevant to synthetic biology and discussed associated ethical and practical implications. By weighing these perspectives of all sides, this paper clarifies the point that synthetic biology, as an emerging discipline with many anticipated benefits and positive impacts on society, can acquire moral support and ethical defence. Therefore, synthetic biologists should not be shackled with heavy ethical chains, but we must ensure that research is conducted under strict control and effective supervisory methods.

Association between plasma fibrinogen levels and mortality in acute-on-chronic hepatitis B liver failure.

Acute-on-chronic liver failure (AoCLF) is the most common type of liver failure and is associated with high mortality. Fibrinogen is critical in maintaining primary and secondary hemostasis. Therefore, we prospectively analyzed the association between fibrinogen and outcomes in AoCLF patients. Plasma fibrinogen was measured in 169 AoCLF, 173 chronic hepatitis B (CHB), and 171 healthy patients using a coagulation method. The predictive ability of fibrinogen for 3-month mortality in AoCLF patients was assessed using receiver operating characteristic (ROC) curve and multivariable logistic regression analyses. Plasma fibrinogen was significantly lower in nonsurvivor AoCLF patients compared with survivor AoCLF, CHB, and control patients. The sensitivity, specificity, and area under the ROC curve of 1/fibrinogen predicting mortality in AoCLF patients were 66.7%, 72.5%, and 0.746 (95% confidence interval (CI): 0.672-0.820, P < 0.001), and the fibrinogen cutoff value was 0.90 g/L. On multivariate logistic regression analysis, low fibrinogen was an independent factor predicting mortality (odds ratio: 0.304; 95% CI: 0.094-0.983; P = 0.047). Nonsurvivor AoCLF patients had significantly decreased fibrinogen levels, suggesting that low plasma fibrinogen may be a useful predictor of poor prognosis in AoCLF patients.

Fibronectin predicts the outcome of acute-on-chronic hepatitis B liver failure.

BACKGROUND: Acute-on-chronic hepatitis B liver failure (ACHBLF) is a serious condition with varied etiologies and manifestations, and is associated with a high mortality rate. Fibronectin is involved in a number of biological processes, including cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing and ischemic injury. Serum fibronectin concentrations may provide prognostic information in ACHBLF; however, as a prognostic marker of mortality in patients with ACHBLF, it needs further validation. METHODS: The aim of this study was to examine whether admission levels of fibronectin in ACHBLF patients are correlated with outcomes. In this prospective study, 78 ACHBLF patients were compared to 70 matched healthy controls. Fibronectin levels were determined using a commercial enzyme-linked immunosorbent assay kit to determine the prognostic value of fibronectin levels on admission. RESULTS: The median (range) fibronectin level at admission for ACHBLF patients was significantly reduced compared with that of healthy controls (142 [62-275] mg/l vs 265 [190-346] mg/l, respectively; p<0.001). Fibronectin levels were significantly higher in surviving patients than in those who died (155 [70-275] mg/l vs 119 [62-235] mg/l; p=0.020). Receiver operating characteristic curve analysis showed that a cut-off level of 135 mg/l was the best prognostic indicator, yielding positive and negative predictive values of 60% (18/30) and 71% (30/42), respectively. CONCLUSIONS: Our results suggested that decreased serum fibronectin levels in patients with ACHBLF were correlated to hepatic injury and inflammation. However, because of the lack of specificity, the use of fibronectin as an independent prognostic indicator is limited.

Can hospital promotional activities be more ethical?

At present, there exist a lot of violations of medical ethics in advertising and promotional activities, which have been infringing the rights of patients. Therefore, the ethical criteria should be established as soon as possible to regulate the hospital promotional activities, to regain the trust of people.

Effects of storage time and temperature on coagulation tests and factors in fresh plasma.

Coagulation tests and factors measurements have been widely applied in clinical practice. Pre-analytical conditions are very important in laboratory assessment.Here,we aim to determine the effects of storage time and temperature on activated partial thromboplastin time (APTT), fibrinogen (Fbg), prothrombin time (PT), the international normalized ratio (INR), thrombin time (TT), factor VIII activity (FVIII:C), and factor IX activity (FIX:C) in fresh plasma. Seventy-two blood samples were tested after storage for 0 (baseline), 2, 4, 6, 8, 12, and 24 h at 25°C (room temperature) and 4°C (refrigeration) in two centers. The mean percentage change of greater than 10% and the numbers of samples with greater than 10% percentage changes more than 25% were used to determine clinically relevant difference. We demonstrated that samples for Fbg, PT/INR, and TT could be safely stored for ≤24 h; FVIII:C for ≤2 h; FIX:C for ≤4 h both at 4°C and 25°C; and APTT for ≤12 h at 4°C and ≤8 h at 25°C.

The value of serum alpha-fetoprotein in predicting tumor recurrence after liver transplantation for hepatocellular carcinoma.

BACKGROUND: Many patients with hepatocellular carcinoma (HCC) who undergo liver transplantation (LT) subsequently develop tumor recurrence; this is the main factor affecting long-term survival after LT. Factors associated with tumor recurrence should be determined to improve the outcome of LT. The purpose of the study was to evaluate the value of alpha-fetoprotein (AFP) in forecasting tumor recurrence after LT for patients with HCC. METHODS: AFP data before and after LT for 97 patients with HCC who underwent LT in our center were analyzed retrospectively. RESULTS: The mean follow-up time was 17.1 +/- 2.1 months for all 97 patients, overall tumor recurrence rate was 32.9% (32/97), and mean recurrence time was 7.2 +/- 3.2 months. The most common tumor recurrence sites were liver, lung, skeleton, and other sites. Pre-transplant AFP levels >400 ng/ml were associated with higher tumor recurrence. Post-transplant AFP levels not decreasing to

[Change of cytoskeleton and variance of Ca2+ in cultured cells during the invasion of Toxoplasma gondii].

OBJECTIVE: To explore the change of cytoskeleton and the variance of Ca2+ in cultured cells during the invasion of Toxoplasma gondii. METHODS: Tachyzoites suspensions were gathered by routine method and used to infect phagocytic cells (J774A.1) and non-phagocytic cells (HUVEC). The ability of T. gondii invading into the cells and the influence of cytoskeleton inhibitor, colchicine and cytochalasin D, were observed by microscopy. The rearrangement of cytoskeleton of cells was observed by fluoromicroscopy. By using laser scanning confocal microscope, the variance of Ca2+ in J774A.1 and HUVEC was detected. RESULTS: Ca2+ increased greatly in J774A.1 during the invasion of T. gondii (P<0.01) and PLC inhibitor, U73122, could block the increase of Ca2+ (P>0.05). The microfilaments of J774A.1 were agglomerated during the invasion of T. gondii. Cytoskeleton inhibitor, cytochalasin D (P<0.01) and colchicine (P< 0.05) significantly reduced the infection rate of J774A.1 cells. No considerable change of Ca2+ in HUVEC was found (P>0.05) during the invasion and cytoskeleton was not changed. Cytochalasin D and colchicine showed little effect on the infection rate of HUVEC. CONCLUSION: The concentration of Ca2+ increases greatly and cytoskeleton (mainly the microfilament) has been rearranged in phagocytic cell during the invasion of T. gondii, while both of them show no significant change in non-phagocytic cell.

Lipase and pancreatic amylase activities in diagnosis of acute pancreatitis in patients with hyperamylasemia.

BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical diagnosis of acute pancreatitis, lipase (LIP) and pancreatic amylase (PAMY) have been tested in recent years. The present study was designed to evaluate whether serum LIP and pancreatic PAMY tests could replace total amylase test to improve diagnostic efficiency in the evaluation of acute pancreatitis in patients with hyperamylasemia. METHODS: LIP and PAMY values were determined in serum samples from 92 patients with hyperamylasemia. Reference values for each enzyme were derived from serum samples of 147 healthy subjects. The activities of LIP and PAMY in patients with various diseases were shown directly by the boxplot graph. The diagnostic accuracy of LIP and PAMY was defined as the area under the receiver operating characteristic (ROC) curve. Their sensitivity and specificity in detecting acute pancreatitis at varying cutoff points were shown by the curve, and the best cutoff value for each enzyme was shown by the modified ROC curve. The diagnostic values of LIP, PAMY and LIP+AMY with each upper limit of reference range (ULR) were compared with the corresponding best cutoff values. RESULTS: The references values of LIP and PAMY were 12.2-47.6 U/L and 28-95 U/L, respectively. These values in patients with acute pancreatitis were higher than those patients with other diseases. The areas under the ROC curve (AUC) of LIP and PAMY were 0.799 and 0.792, respectively. With the best diagnostic cutoff point of maximum (sensitivity + specificity)-100%, we obtained values of 97.9 U/L (LIP(97.9)=2.06 X ULR) for LIP and 209 U/L (PAMY(209)=2.20 X ULR) for PAMY. The best cutoff values for LIP, PAMY and LIP+AMY demonstrated the specificity, positive predictive value, and diagnostic efficiency higher than the corresponding ULRs. CONCLUSIONS: Serum LIP and PAMY are specific for the pancreas and might replace total amylase for the diagnosis of acute pancreatitis in hyperamylasemia patients. LIP(97.9) is more efficient than PAMY(209) in the diagnosis of acute pancreatitis. A combined test of both enzymes is not superior to single test of either enzyme in diagnostic accuracy.

[Liver transplantation for hepatocellular carcinoma: prognostic analysis of 89 cases].

OBJECTIVE: To summarize the experience of liver transplantation (LT) for hepatocellular carcinoma (HCC) in one center and identify prognostic factors for survival. METHODS: The clinical data and survival results of 89 patients with HCC receiving LT from January 1999 to December 2003 were retrospectively analyzed and various clinicopathologic risk factors for actuarial survival and tumor free survival were evaluated by univariate and multivariate analysis. RESULTS: Six-month, 1-, and 2-year survival rates were 81.8%, 55.3% and 43.7%, respectively. The 6-month, 1-, and 2-year tumor free survival rates were 62.4%, 35.6% and 24.9%, respectively. The overall tumor recurrence and metastasis rate was 52.8%. In the univariate analysis, portal vein tumor thrombi (PVTT) (chi(2) = 15.14, P = 0.0001), tumor size (chi(2) = 15.05, P = 0.0001), hepatic cirrhosis background (chi(2) = 6.14, P = 0.0132), preoperative alpha-fetoprotein (AFP) level (chi(2) = 5.82, P = 0.0159) and histopathologic grading (chi(2) = 4.61, P = 0.0319) were found to be significantly associated with actuarial survival rate. Seven factors influencing tumor free survival included PVTT (chi(2) = 26.30, P < 0.0001), tumor size (chi(2) = 25.25, P < 0.0001), preoperative AFP level (chi(2) = 14.83, P = 0.0001), histopathologic grading (chi(2) = 12.54, P = 0.0004), tumor distribution (chi(2) = 12.73, P = 0.0004), number of nodules (chi(2) = 9.81, P = 0.0017) and cirrhosis background (chi(2) = 9.76, P = 0.0018). In the multivariate Cox regression analysis, the prognostic factors independently associated with patient survival were identified to be PVTT (RR = 4.721, P = 0.001), age (RR = 3.282, P = 0.007) and histopathologic grading (RR = 2.368, P = 0.037). For tumor free survival, histopathologic grading (RR = 3.739, P < 0.0001), PVTT (RR = 4.382, P = 0.001), cirrhosis background (RR = 0.421, P = 0.011), age (RR = 2.312, P = 0.027) and AFP (RR = 2.301, P = 0.047) were identified as prognostic parameters. CONCLUSIONS: LT is a good therapeutic option for strictly selected patients with HCC. PVTT and histopathologic grading are the most important factors of predicting outcomes of HCC patients undergoing LT. Further studies should be strengthened to establish a reliable and feasible selection criteria and an optimal prognosis scoring system for LT.

Frequencies of the expression of main protein antigens from Helicobacter pylori isolates and production of specific serum antibodies in infected patients.

AIM: To investigate the frequencies of the expression of main protein antigens of Helicobacter pylori (H pylori) isolates, such as UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB and the production of specific antibodies in sera from H pylori-infected patients, and to understand the correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori. METHODS: H pylori strains in biopsy specimens from 157 patients with chronic gastritis and peptic ulcer were isolated and serum samples from the patients were also collected. The target recombinant proteins rUreB, rVacA, rCagA1, rHpaA, rNapA, rFlaA and rFlaB expressed by the prokaryotic expression systems constructed in our previous studies were collected through Ni-NTA affinity chromatography. Rabbit antisera against rUreB, rVacA, rCagA1, rHpaA, rNapA, rFlaA and rFlaB were prepared by using routine subcutaneous immunization. By using ultrasonic lysates of the isolates as coated antigens, and the self-prepared rabbit antisera as the first antibodies and commercial HRP-labeling sheep anti-rabbit IgG as the second antibody, expression frequencies of the seven antigens in the isolates were detected by ELISA. Another ELISA was established to detect antibodies against the seven antigens in sera of the patients by using the corresponding recombinant proteins as coated antigens, and the sera as the first antibody and HRP-labeling sheep anti-human IgG as the second antibody respectively. Correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori were statistically analysed. RESULTS: In the 125 isolates of H pylori, the positive rates of UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB were 100%, 65.6%, 92.8%, 100%, 93.6%, 100% and 99.2% respectively. In the 125 serum samples from the H pylori-infected patients, the positive rates of antibodies against recombinant UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB were 100%, 42.4%, 89.6%, 81.6%, 93.6%, 98.4% and 92.8% respectively. H pylori strains were isolated from 79.6% (125/157) of the biopsy specimens, but no close correlations among the H pylori infection frequencies and different types of chronic gastritis and peptic ulcer could be found (P>0.05, chi2 = 0.01-0.87). The VacA positive rate (82.40%) in the strains isolated from the specimens of patients with peptic ulcer and the anti-VacA positive rate (54.3%) in the sera from the patients were significantly higher than those (51.5%, 32.3%) from the patients with chronic gastritis (P<0.01, chi2 = 13.19; P<0.05, chi2 = 6.13). When analysis was performed in the different types of chronic gastritis, the VacA in the strains isolated from the specimems of patients with active gastritis showed a higher expression frequency (90.0%) than those from superficial (47.9%) and atrophic gastritis (30.0%) (P<0.05, chi2 = 5.93; P<0.01, chi2 = 7.50). While analysis was carried out in the strains isolated from the specimens with superficial (93.8%) and active gastritis (100%), NapA showed a higher expression frequency compared to that from atrophic gastritis (60.0%) (P<0.01, chi2 = 8.88; P<0.05, chi2 = 5.00). CONCLUSION: The types of chronic gastritis and peptic ulcer and their severity are not associated with H pylori infection frequency but closely related to the infection frequency of different virulent H pylori strains. The optimal antigens for developing vaccine and diagnostic kit are UreB, FlaA, HpaA, FlaB, NapA and CagA1, but not VacA.