Objective: To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with cation exchange-based solid phase extraction (SPE) for determination of tetrodotoxin (TTX) in salted pufferfish. Methods: Evenly crushed salted pufferfish samples were subjected to ultrasound-assisted extraction with 0.5% acetic acid/50% methanol/water. The extract was cleaned with cation exchange-based SPE cartridge and eluted with 0.3% hydrochloric acid and 50% acetonitrile/water. The eluent was neutralized with ammonia and separated with a Waters XBridgeTM BEH Amide column (150 mm×3.0 mm, 1.7 μm), and determined using LC-MS/MS in a multiple reaction monitoring mode. Results: The matrix effects of TTX were 85.7%-92.4%, and the matrix suppression effect was under effective control following clean-up procedures using the optimized SPE method. The TTX showed a good linear relationship at the range of 2.0 to 4 000 μg/kg, with a correlation coefficient (r2) of 0.999 2. The limits of detection and quantitation for TTX in sample matrix were 1.0 μg/kg and 2.0 μg/kg, respectively. The mean spiked-recovery rates were 81.2% to 96.5% at spiked amounts of 2.0, 200 μg/kg and 2 200 μg/kg, with relative standard deviations (RSDs) of 4.3% to 7.5%. The intraday accuracy and precision of TTX were 84.4% to 95.6% and 4.9% to 5.8% in quality control samples, and the interday accuracy and precision of TTX were 86.1% to 94.9% and 5.5% to 8.5% in quality control samples. The detection of TTX was 60.5% in 38 market-sold salted pufferfish products using the established LC-MS/MS method. Conclusion The established LC-MS/MS method is effective for accurate quantitative determination of TTX in salted pufferfish.

Objective: To develop an approach for simultaneous detection of multi-mycotoxins in fresh fruits, so as to provide technical supports for mycotoxins surveillance in fresh fruits. Methods: Fresh fruits were collected from markets and homogenized. Then, 2 g of fresh fruits were added with 10 mL of 0.1% formic acid ( 99∶1, v/v ) in acetonitrile and wortexed for 10 min. Following extraction with 1 g of sodium chloride and 4 g of anhydrous sodium sulfate, samples were centrifuged and 5 mL of the supernatant was cleaned up with 25 mg C18. Following centrifugation, the supernatant was dried under nitrogen. The residue was dissolved in 300 μL of methanol-acetonitrile mixture solution ( 1∶1, v/v ), and mixed evenly in 700 μL of the distilled water. Samples were then eluted in gradient series of 0.1% formic acid and 5 mmol ammonium formate and methanol-acetonitrile mixture solution ( 1∶1, v/v ). The 15 mycotoxins were determined using liquid chromatography-tandem mass spectrometry ( LC-MS/MS ) with electrospray ion source (ESI+/ESI-) under multiple reaction monitoring. In addition, a matrix-matched standard curve was employed for quantitative analysis. Results: There was a good linear relationship for 15 mycotoxins at concentrations of 0.25 to 10 ng/mL ( R2>0.992 ), the LC-MS/MS method showed the detection limits of 0.1-1.0 μg/kg, the spiked recovery rates of 71.68%-117.50%, and the relative standard deviations ( RSDs ) of 0.01%-13.60%. The detection rate of mycotoxins was 27.09% in 203 fresh fruits sold in markets. Conclusions The optimized LC-MS/MS method can be used for simultaneous determination of multi-mycotoxins in fresh fruits.

Objective To investigate the potential relationship between the paroxysmal Atrial Fibrillation(PAF) and serum uric acid level.Methods Consecutive patients with (patient group,n =65) and without(control group,n =41) PAF,who were hospitalized in the Second Hospital of Tianjin Medical University from September 2011 to June 2012,were included in this study.We excluded subjects with congestive heart failure,acute coronary syndrome,congenital heart disease,valvular heart disease,cardiomyopathy,thyroid dysfunction and acute infection or inflammatory conditions.Baseline clinical data,complications and laboratory examination results were collected.Left atrium diameter (LAD),left ventricular end-diastolic dimension (LVEDD) and left ventricular ejection fraction (LVEF) were determined by echocardiography.Univariate and logistic regression was conducted to detect risk factors for PAF.Results Serum uric acid level were significantly increased in patients with PAF compared with controls ((360.2 ± 103.9) μmol/L vs (296.0 ±68.1) μmol/L,P =0.001).Multivariate logistic regression analysis showed that higher level of serum uric acid (OR:1.007,95％ CI:1.000-1.015) and LAD (OR:1.142,95％ CI:1.031-1.265) were independent risk factors for the occurrence of PAF.Conclusion High serum uric acid level is an independent risk factor for the development of PAF.Future larger studies should further evaluate this potential association as well as the underlying mechanisms.

Objective: To investigate serum level changes of heart-type fatty acid-binding protein(H-FABP)and S100 calcium-binding protein B(S-100B)protein in elderly patients with chronic heart failure and their clinical significance. Methods: A total of 160 patients with chronic heart failure treated at our hospital were recruited, and 80 healthy individuals receiving regular check-ups were enrolled as normal controls.Serum levels of H-FABP and S-100B and cardiac function index scores were compared between patients with different cardiac function grades.Correlations of serum H-FABP and S-100B levels with N-terminal pro-B-type natrlure tiepeptide(NT-proBNP)and with cardiac function index scores in heart failure patients were analyzed.The sensitivity, specificity and accuracy of serum H-FABP, S-100B and NT-proBNP for heart failure detection were compared. Results: Serum levels of H-FABP, S-100B and NT-proBNP in elderly patients with chronic heart failure were elevated with increased cardiac function grading(F=9.823, 11.573 and 13.056, P=0.013, 0.000 and 0.000), and serum levels of H-FABP, S-100B and NT-proBNP were higher in elderly patients with heart failure than in the control group(P<0.05). Serum levels of H-FABP and S-100B were positively correlated with serum NT-proBNP levels, cardiac function grading and left ventricular end-diastolic diameter(LVEDd)(r=0.527, 0.510 and 0.487, P=0.008, 0.003 and 0.002; r=0.604, 0.496 and 0.533, P=0.006, 0.005 and 0.003), and were negatively correlated with left ventricular ejection fraction(LVEF)(r=-0.536 and-0.528, P=0.005 and 0.008). The sensitivity, specificity and accuracy of serum H-FABP combined with S-100B for heart failure detection were 93.2%, 91.6% and 95.7%, respectively. Conclusions Serum levels of H-FABP and S-100B are high in elderly patients with heart failure, and they are correlated with serum NT-proBNP levels, cardiac function grading and LVEDd.H-FABP combined with S-100B has a high positive rate for heart failure detection.

ObjectiveTo tentatively understand the status of radioactive contamination in nuclear medicine personnel. MethodsA total of 34 radiation staff engaged in nuclear medicine diagnosis and treatment were selected from two hospitals in Shanghai as the survey subjects.Among the 34 medical staff， 8 were nuclear medicine doctors， 14 were nuclear medicine technicians and 12 were nuclear medicine nurses. After surface contamination monitoring was first carried out to confirm that they had no surface radioactivity contamination， whole body scanning was performed with a whole body counter to determine whether they were internally contaminated with artificial radionuclides. ResultsThe α surface contamination was not detected in the nuclear medical staff. The β surface contamination of the nuclear medicine doctors， technicians and nurses was （13.8±0.8）， （14.1±0.8） and （14.0±0.7） times per second， respectively. There were 2， 2， and 4 nuclear medicine doctors who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， 3， 5， and 2 nuclear medicine technicians who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， and 6， 8， and 5 nuclear medicine nurses who were contaminated with ¹⁸F， ^99mTc and ¹³¹I， respectively. The ¹⁸F activity of nuclear medicine technicians was 1 997‒9 401 Bq， and the ^99mTc activity of nuclear medicine technicians and nurses was 3 699‒18 692 and 652‒388 22 Bq， respectively. One nuclear medicine nurse had a ^99mTc activity of 35 389 Bq. According to the preliminary estimation of ¹³¹I internal irradiation dose， the maximum committed effective dose of nuclear medicine doctors， technicians and nurses could reach 0.370， 0.018 and 0.584 mSv， respectively. ConclusionThe nuclear medicine staff are exposed to radioactive contamination， and it is important to monitor and evaluate their internal radiation doses.