Human health risk assessment based on a total diet study of daily mercury intake in Chengdu, China.

To assess the total daily mercury intake and main exposure sources of residents, six food groups, including marine fish, freshwater fish, poultry, livestock, vegetables, and cereals, were collected from five districts of Chengdu, China. The median concentrations of total mercury (THg) and methylmercury (MeHg) were 12.8 and 6.94 µg kg-1 ww, respectively. Cereals (32.2%), vegetables (30.5%), and livestock (16.2%) contributed to a much larger extent to the total consumption for the participants in Chengdu. All food categories that contributed the most of THg (2.16 µg day-1) and MeHg 1.44 (µg day-1) to the daily intake in Chengdu were cereals and marine fish, respectively. The total Hazard Ratios values below 1 in this study indicate that there is no health risk associated with Hg ingestion from the consumption of these foods for the residents in Chengdu.

Direct interaction of platelet with tumor cell aggravates hepatocellular carcinoma metastasis by activating TLR4/ADAM10/CX3CL1 axis.

Metastasis is the main culprit of cancer-related death and account for the poor prognosis of hepatocellular carcinoma. Although platelets have been shown to accelerate tumor cell metastasis, the exact mechanism remained to be fully understood. Here, we found that high blood platelet counts and increased tumor tissue ADAM10 expression indicated the poor prognosis of HCC patients. Meanwhile, blood platelet count has positive correlation with tumor tissue ADAM10 expression. In vitro, we revealed that platelet increased ADAM10 expression in tumor cell through TLR4/NF-κB signaling pathway. ADAM10 catalyzed the shedding of CX3CL1 which bound to CX3CR1 receptor, followed by inducing epithelial to mesenchymal transition and activating RhoA signaling in cancer cells. Moreover, knockdown HCC cell TLR4 (Tlr4) or inhibition of ADAM10 prevented platelet-increased tumor cell migration, invasion and endothelial permeability. In vivo, we further verified in mice lung metastatic model that platelet accelerated tumor metastasis via cancer cell TLR4/ADAM10/CX3CL1 axis. Overall, our study provides new insights into the underlying mechanism of platelet-induced HCC metastasis. Therefore, targeting the TLR4/ADAM10/CX3CL1 axis in cancer cells hold promise for the inhibition of platelet-promoted lung metastasis of HCC.

Determination of heterocyclic amines in braised sauce beef and the effects of different cooking conditions on the formation of heterocyclic amines.

BACKGROUND: Cooked meat is a good source of high-quality protein. However, during long-term cooking of meat, radical-induced lipid and protein oxidation may lead to the formation of poisonous compounds, such as heterocyclic amines (HAs). This work investigated a testing method for HAs and it describes that cooking temperature, cooking time and repeated cooking times have influences on the overall quality of braised sauce beef and the effect of HAs formation. RESULTS: The improved method has a good separation effect on nine kinds of HAs. The average recovery of HAs at two spiked levels is between 51.70% and 88.25% (n = 6). The detection limit is 0.025-0.060 ng g-1 , and the limit of quantitation is 0.070-0.160 ng g-1 . Only harman and norharman were detected in samples. Cooking time and cooking temperature will affect the quality and HA content of samples. When the braised sauce beef soup was cooked 20 times, the HA content was the highest - as high as 21.43 ng g-1 . The more times the beef was cooked repeatedly, the higher was the HA content. Under different cooking conditions, glucose has a significant effect on the formation of ß-carboline. CONCLUSION: We have established a detection method for HAs with good repeatability and accuracy. HAs were more easily formed in braised sauce beef by high temperature, long heating and repeated brine cooking. © 2021 Society of Chemical Industry.

Targeted exome sequencing identifies mutational landscape in a cohort of 1500 Chinese patients with non-small cell lung carcinoma (NSCLC).

BACKGROUND: Non-small cell lung carcinoma (NSCLC) is one of the most common human cancers, comprising approximately 80-85% of all lung carcinomas. An estimated incidence of NSCLC is approximately 2 million new cases per year worldwide. RESULTS: In recent decade, the treatment of NSCLC has made breakthrough progress owing to a large number of targeted therapies which were approved for clinical use. Epidemiology, genetic susceptibility, and molecular profiles in patients are likely to play an important factor in response rates and survival benefits to these targeted treatments and thus warrant further investigation on ethnic differences in NSCLC. In this study, a total number of 1500 Chinese patient samples,1000 formalin fixed paraffin-embedded (FFPE) and 500 blood samples, from patients with NSCLC were analyzed by targeted sequencing to explore mutational landscape in ethnic groups associated with China. CONCLUSIONS: Overall, the data presented here provide a comprehensive analysis of NSCLC mutational landscape in Chinese patients and findings are discussed in the context of similar studies on different ethnic groups.

Acute Subcortical Infarcts Cause Secondary Degeneration in the Remote Non-involved Cortex and Connecting Fiber Tracts.

Background and Purpose: Remote white matter and cortex reorganization may contribute to functional reorganization and clinical outcome after acute infarcts. To determine the microstructural changes in the remote intact corticospinal tract (CST) and precentral gyrus cortex connected to the acute infarct after subcortical stroke involving the CST over 6 months. Methods: Twenty-two patients with subcortical stroke involving the CST underwent magnetic resonance imaging (MRI) and clinical assessment in the acute phase (baseline) and 6 months (follow-up) after the stroke. The MRI sequences included T1-weighted imaging, T2-weighted imaging, fluid-attenuated inversion recovery, diffusion tensor imaging (DTI), and diffusion kurtosis imaging. Fractional anisotropy (FA) and track-density imaging (TDI) values were generated using DTI data for the centrum semiovale, corona radiata, posterior limb of internal capsule, and cerebral peduncle. The mean kurtosis (MK) value of the precentral gyrus cortex was calculated. Changes in the FA, TDI, and MK values between the baseline and follow-up and the relationship between these changes were analyzed. Results: The TDI and FA values of all parts of the ipsilesional (IL) CST, including the noninvolved upper and lower parts, decreased at the 6-month follow-up (P < 0.001). The MK values of the stroke lesion (P < 0.001) and IL precentral gyrus cortex (P = 0.002) were lower at follow-up than at the baseline. The ΔTDI (r = 0.689, P < 0.001) and Δ FA values (r = 0.463, P = 0.03) of the noninvolved upper part of the IL CST were positively correlated with the ΔMK value of the IL precentral gyrus cortex. Conclusion: Secondary degeneration occurred in the remote part of the CST and the remote IL precentral gyrus cortex after subcortical stroke involving the CST. The secondary degeneration in the upper part of the CST was correlated with that in the IL precentral gyrus cortex.

Pharmacological actions of neferine in the modulation of human platelet function.

Neferine has long been recognized as a medicinal herbal ingredient with various physiological and pharmacological activities. Although previous studies have reported its antithrombotic effect, the underlying mechanisms have not been thoroughly investigated. Since platelets play a key role in thrombosis, we investigated the effects of neferine on human platelet function and the potential mechanisms. Platelet aggregation, adhesion and spreading were performed to investigate the effect of neferine on inhibition of platelet function. Flow cytometry was used to determine platelet alpha granule secretion and integrin IIb/IIIa activation, as detected by CD62P (P-selectin) expression, PAC-1 and fibrinogen binding. Western blotting was utilized to investigate the effect of neferine on intracellular signaling of activated platelet. We found that neferine significantly suppressed platelet aggregation and remarkably promoted the dissociation of platelet aggregates induced by collagen, thrombin, U46619, ADP and adrenaline in a dose-dependent manner. Flow cytometry analysis showed that neferine inhibited thrombin-induced platelet P-selectin expression, PAC-1 and fibrinogen binding. In addition, neferine reduced the adhesion of human platelets on coated collagen under both static and shearing condition at an arterial shear rate of 40 dyne/cm2. Neferine also inhibited the spreading of human platelets on immobilized fibrinogen. Western blot analysis showed that neferine inhibited PI3K activation, and decreased the levels of phosphorylation of Akt, GSK3ß and p38 MAPK in platelets. In summary, neferine has the potential to be an antiplatelet and antithrombotic agent by inhibiting the PI3K-Akt-GSK3ß/p38 MAPK signaling pathway.

Real-time activity assays of ß-lactamases in living bacterial cells: application to the inhibition of antibiotic-resistant E. coli strains.

The emergence of antibiotic resistance caused by ß-lactamases, including serine ß-lactamases (SßLs) and metallo-ß-lactamases (MßLs), is a global public health threat. L1, a B3 subclass MßL, hydrolyzes almost all of known ß-lactam antibiotics. We report a simple and straightforward UV-Vis approach for real-time activity assays of ß-lactamases inside living bacterial cells, and this method has been exemplified by choosing antibiotics, L1 enzyme, Escherichia coli expressing L1 (L1 E. coli), Escherichia coli expressing extended-spectrum ß-lactamases (ESBL-E. coli), clinical bacterial strains, and reported MßL and SßL inhibitors. The cell-based studies demonstrated that cefazolin was hydrolyzed by L1 E. coli and clinical strains, and confirmed the hydrolysis to be inhibited by two known L1 inhibitors EDTA and azolylthioacetamide (ATAA), with an IC50 value of 1.6 and 18.9 µM, respectively. Also, it has been confirmed that the breakdown of cefazolin caused by ESBL-E. coli was inhibited by clavulanic acid, the first SßL inhibitor approved by FDA. The data gained through this approach are closely related to the biological function of the target enzyme in its physiological environment. The UV-Vis method proposed here can be applied to target-based whole-cell screening to search for potent ß-lactamase inhibitors, and to assays of reactions in complex biological systems, for instance in medical assays.

Antibiotic resistance mechanisms of Myroides sp.

Bacteria of the genus Myroides (Myroides spp.) are rare opportunistic pathogens. Myroides sp. infections have been reported mainly in China. Myroides sp. is highly resistant to most available antibiotics, but the resistance mechanisms are not fully elucidated. Current strain identification methods based on biochemical traits are unable to identify strains accurately at the species level. While 16S ribosomal RNA (rRNA) gene sequencing can accurately achieve this, it fails to give information on the status and mechanisms of antibiotic resistance, because the 16S rRNA sequence contains no information on resistance genes, resistance islands or enzymes. We hypothesized that obtaining the whole genome sequence of Myroides sp., using next generation sequencing methods, would help to clarify the mechanisms of pathogenesis and antibiotic resistance, and guide antibiotic selection to treat Myroides sp. infections. As Myroides sp. can survive in hospitals and the environment, there is a risk of nosocomial infections and pandemics. For better management of Myroides sp. infections, it is imperative to apply next generation sequencing technologies to clarify the antibiotic resistance mechanisms in these bacteria.

Antiplatelet activity of loureirin A by attenuating Akt phosphorylation: In vitro studies.

Loureirin A is a flavonoid extracted from Dragon׳s Blood that has been used to promote blood circulation and remove stasis in Chinese traditional medicine. However, the mechanisms of these effects are not fully understood. We explored the anti-platelet activity and underlying mechanism of loureirin A in vitro. Our results indicated that loureirin A negatively affected agonist-induced platelet aggregation such as collagen, collagen-related peptide (CRP), ADP and thrombin. Loureirin A inhibited collagen-induced platelet ATP secretion and thrombin-stimulated P-selectin expression in a dose-dependent manner. Platelet spreading on immobilized fibrinogen was significantly impaired in the presence of loureirin A. Immunoblotting analysis indicated that 100µM of loureirin A almost completely eliminated collagen-induced Akt phosphorylation at Ser473. Interestingly, a submaximal dose (50µM) of loureirin A had an additive inhibitory effect with the phosphoinositide 3-kinase (PI3K) inhibitor Ly294002 on collage-induced Akt phosphorylation in platelets. Taken together, loureirin A had an inhibitory effect on platelet activation, perhaps through an impairment of PI3K/Akt signaling.

Timing of recanalization and outcome in ischemic-stroke patients treated with recombinant tissue plasminogen activator.

BACKGROUND: Intravenous administration of recombinant tissue plasminogen activator (rtPA) is approved treatment for acute ischemic stroke <3 h of symptom onset. PURPOSE: To determine the impact of the timing and degree of recanalization on clinical outcome after rtPA infusion in patients. MATERIAL AND METHODS: Seventy-five patients with ischemic stroke in the middle cerebral artery territory treated with intravenous rtPA within 3 h were studied consecutively. Magnetic resonance imaging (MRI), including magnetic resonance angiography (MRA), before, 6 h, and 24 h after thrombolytic therapy was undertaken. Depending on the MRA results acquired 6 h after rtPA infusion, recanalization was graded as: early recanalization (ER), delayed recanalization (DR), and no recanalization (NR). Clinical outcome was assessed using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). RESULTS: Of patients in the ER, DR and NR groups, 71.4% (15/21), 13.3% (2/15), and 30.7% (12/39), respectively, showed dramatic improvement in NIHSS score 7 days after rtPA administration compared with those scores upon hospital admission. The 6-h and 24-h NIHSS scores and 3-month mRS scores of ER patients were significantly lower than those of the other two groups (P < 0.05). The 24-h, 7-d NHISS and mRS scores of DR patients were significantly higher than NR patients (P = 0.001, 0.002, 0.049, respectively). Three patients in the DR group died during follow-up. CONCLUSION: These data suggest that DR is associated with clinical deterioration. Patients treated with rtPA thrombolysis should be under close observation for 6-24 h. Corresponding treatment should be considered once DR appears.

Diaryl-substituted azolylthioacetamides: Inhibitor discovery of New Delhi metallo-ß-lactamase-1 (NDM-1).

The emergence and spread of antibiotic-resistant pathogens is a global public health problem. Metallo-ß-lactamases (MßLs) such as New Delhi MßL-1 (NDM-1) are principle contributors to the emergence of resistance because of their ability to hydrolyze almost all known ß-lactam antibiotics including penicillins, cephalosporins, and carbapenems. A clinical inhibitor of MBLs has not yet been found. In this study we developed eighteen new diaryl-substituted azolylthioacetamides and found all of them to be inhibitors of the MßL L1 from Stenotrophomonas maltophilia (Ki < 2 µM), thirteen to be mixed inhibitors of NDM-1 (Ki < 7 µM), and four to be broad-spectrum inhibitors of all four tested MßLs CcrA from Bacteroides fragilis, NDM-1 and ImiS from Aeromonas veronii, and L1 (Ki < 52 µM), which are representative of the B1a, B1b, B2, and B3 subclasses, respectively. Docking studies revealed that the azolylthioacetamides, which have the broadest inhibitory activity, coordinate to the Zn(II) ion(s) preferentially via the triazole moiety, while other moieties interact mostly with the conserved active site residues Lys224 (CcrA, NDM-1, and ImiS) or Ser221 (L1).

Microbleeds on susceptibility-weighted MRI in depressive and non-depressive patients after mild traumatic brain injury.

The aim of this study was to explore the relationship between abnormality on susceptibility-weighted imaging (SWI) and newly-developed depression after mild traumatic brain injury. The study registered 200 patients with closed TBI and normal finding at CT and conventional MRI. All patients underwent MRI including conventional MR sequences and SWI. The number and volume of microbleed lesions were semi-automatically outlined and manually counted. All patients were followed up with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-IV) within 1 year after TBI. The difference in microbleed lesions on SWI was compared between the depressive and non-depressive groups. The depressive group had a higher rate of abnormality on SWI than did the non-depressive group (p < 0.001). Among patients that had exhibited microbleed lesions, the number and volume of lesions were greater in the depressive group than the non-depressive group (both p < 0.001). These differences in numbers and volume of lesions were found only at the frontal, parietal and temporal lobes (all p < 0.001). Among patients that had exhibited microbleed lesions, the number and volume of lesions in other areas were not significantly different between the depressive and non-depressive groups (all p > 0.05). In conclusion, SWI was useful to identify the microbleed lesions after mild TBI. The distribution range and location of microbleed lesions were correlated with depression after TBI.

2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (THSG) attenuates human platelet aggregation, secretion and spreading in vitro.

INTRODUCTION: 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside(THSG) is a water-soluble component of the rhizome extract from the traditional Chinese herb Polygonum multiflorum. Recent studies have demonstrated that THSG has potent anti-oxidative and anti-inflammatory effects. In this study, we investigated the anti-platelet aggregation, secretion and spreading of THSG with different methods. The purpose was to explore the anti-platelet effect of THSG and the underlying mechanism. MATERIALS AND METHODS: We investigated the anti-platelet activity of THSG on platelet aggregation induced by collagen (2 µg/mL), thrombin(0.04U/mL), U46619 (3 µM) and ADP (2 µM). ATP secretion induced by collagen (2 µg/mL) was also investigated. P-selectin expression and PAC-1 binding were measured by flow cytometry. In addition, human platelet spreading on immobilized fibrinogen and immunoblotting were also tested. RESULTS: THSG dose-dependently inhibited platelet aggregation and ATP secretion induced by collagen. It inhibited platelet P-selectin expression and PAC-1 binding induced by thrombin(0.1U/mL). THSG also inhibited human platelet spreading on immobilized fibrinogen, a process mediated by platelet outside-in signaling. Western blot analysis showed that THSG could inhibit platelet Fc γ RIIa, Akt(Ser473)and GSK3ß(Ser9) phosphorylation. CONCLUSIONS: Our study indicates that THSG has potent anti-platelet activity to collagen induced aggregation. THSG is likely to exert protective effects in platelet-associated thromboembolic disorders by modulating human platelet.

Neferine exerts its antithrombotic effect by inhibiting platelet aggregation and promoting dissociation of platelet aggregates.

INTRODUCTION: Neferine, a kind of isoquinoline alkaloid, extracted from the seed embryo of Nelumbo nucifera Gaertn, has long been recognized in traditional medicine as a medicinal plant with various usages. Neferine has many biological activities, including anti-hypertensive, anti-arrhythmic, negative inotropic effect and relaxation on vascular smooth muscle. Although previous studies have reported its antithrombotic effect, the mechanisms by which it exerts antithrombotic effect have not been thoroughly studied. METHOD: Washed mice platelets and mice platelet-rich-plasma (PRP) were used to investigate the effects of neferine on platelet aggregation, secretion induced by various agonists and dissociation of agonist-formed platelet aggregates. Bioflux plates coated with collagen were used to investigate the effect of neferine on platelet adhesion and thrombosis in vitro. With collagen-epinephrine-induced acute pulmonary thrombus formation mouse model, the effect of neferine on thrombosis in vivo was also examined. RESULTS: Neferine, significantly and dose-dependently, inhibited collagen-, thrombin-, U46619-induced platelet aggregation in mice washed platelets, or ADP-induced platelet aggregation in PRP. Neferine treatment decreased platelet dense granule secretion initiated by collagen, thrombin and U46619. Also, Neferine dramatically and dose-dependently promoted the dissociation of platelet aggregates pre-formed by various agonists including collagen, thrombin, U46619 or ADP. Neferine can significantly reduce the area of mice platelets adhesion to the collagen and inhibit thrombosis in vitro. In collagen-epinephrine-induced acute pulmonary thrombus mouse model, neferine, at 6 mg/kg, significantly attenuated thrombus formation. CONCLUSIONS: Neferine remarkably prevents thrombus formation by inhibiting platelet activation, adhesion and aggregation, as well as promoting disassembly of pre-formed platelet aggregates. The inhibitory effects of neferine on platelet activation might be relevant in cases involving aberrant platelet activation where neferine could be used as an anti-platelet and antithrombotic agent.

[Curcumin inhibits iron overload-induced hepatocytic apoptosis and nuclear factor-κB activity].

OBJECTIVE: Iron is an essential micronutrient for human beings but its overload induces various diseases of liver, the main body storage site for iron, such as liver fibrosis. Curcumin is a natural polyphenol derived from turmeric and has been used widely. Its pharmacological action has attracted great attention in recent years. The apoptosis of rat cultured hepatocytes was induced by FeNTA (ferric nitrilotriacetate)-induced Iron overload. The present study was to examine the effect of curcumin at low concentrations on FeNTA-induced apoptosis of hepatocytes and elucidate the underlying mechanisms. METHODS: After the incubation of hepatocytes with 100 µmol/L FeNTA in the presence or absence of 1 - 10 µmmol/L of curcumin, a series of analyses were performed, including the analyses of hepatocytic apoptosis, the expressions of proteins relating with the regulations of cell apoptosis, caspase-3 activity, the production of reactive oxygen species (ROS) and nuclear factor NF-κB activity. RESULTS: Curcumin reduced the FeNTA-induced hepatocytic apoptosis by 46.65% and significantly down-regulated the protein levels of Bcl-2 and Bcl-XL. In contrast, it had no effect on the protein levels of Bax and Bad. The curcumin treatment reduced FeNTA-caused production of ROS and caspase-3 activity by 45.01% and 59.71% respectively. And the NF-κB activity was also inhibited. CONCLUSION: Curcumin at low concentrations reduces iron overload-caused hepatocytic apoptosis and NF-κB activity, the key regulatory transcription factor for the inflammation-related gene expression in cultured hepatocyte.

Inhibitory effects of idoxifene on hepatic fibrosis in rats.

AIM: To investigate the effects of a tissue-specific selective estrogen receptor modulator, idoxifene, on hepatic fibrosis in rats. METHODS: Hepatic fibrosis was induced by dimethylnitrosamine (DMN) in male rats. The DMN model of hepatic fibrosis and the hepatocytes undergoing oxidative stress were treated with idoxifene respectively. The effect of idoxifene on hepatic fibrosis in the DMN model was examined by immunohistochemistry. Effects of idoxifene on antioxidant enzyme levels of copper, zinc-dependent superoxide dismutase (CuZn-SOD), and cellular glutathione peroxidase (GSHPx) were measured by ELISA. Effects of idoxifene on activation, proliferation, and apoptosis of culture-activated hepatic stellate cells (HSC) were analysed by immunohistochemistry, bromodeoxyuridine (BrdU) uptake, and flow cytometry, respectively. RESULTS: Idoxifene could markedly suppress DMN-induced hepatic fibrosis in male rats. A treatment of 0.4 mg x kg(-1) x d(-1) of idoxifene reduced the protein levels of collagen in the DMN model by 41.19% (P<0.05). Protein level of CuZn-SOD and activitiy of GSHPx in liver treated with DMN plus 0.4 mg/kg/d of idoxifene were 2.65 times (P<0.05) and 2.08 times greater (P<0.05) than that of liver treated with DMN alone respectively. The protein level of CuZn-SOD and activity of GSHPx in cultured rat hepatocytes treated with ferric nitrilotriacetate (FeNTA) plus 1 multiply 10(-7) mol/L of idoxifene were 3.43 times (P<0.05) and 2.52 times (P<0.05) greater than that treated with FeNTA alone. Idoxifene could inhibit HSC activation. Compared with the control, the uptake of BrdU in HSC cultured with 1 multiply 10(-7) mol/L of idoxifene was reduced by 51.87 % (P<0.05), and the number of apoptotic HSCs cultured with 1 multiply 10(-7) mol/L of idoxifene increased by 94.52% (P<0.05). CONCLUSION: Idoxifene showed inhibitory action on hepatic fibrosis in male rats.

[Effect of blocking transforming growth factor beta signalling on culture-activated rat hepatic stellate cells].

OBJECTIVE: To study the effects of blocking transforming growth factor beta (TGF-beta) signalling on culture-activated rat hepatic stellate cells (HSCs). METHODS: After cultured in plastic dish for two days, HSCs were infected with adenovirus vector AdT beta-ExR or AdLacZ (control) at 10 multiplicity of infection (MOI) and incubated for four days. The expression of type I collagen, alpha-smooth muscle actin (alpha-SMA) and the proliferation of HSCs were analyzed by ELISA, western blot, immunocytochemistry and BrdU uptake respectively. RESULTS: The expression level of type I collagen in HSCs infected with AdT beta-ExR was 42.99% of that in HSCs infected with AdLacZ (q = 9.100, P < 0.001). The expression of alpha-SMA in HSCs infected with AdTbeta-ExR was also inhibited evidently. But the BrdU uptake in HSCs infected with AdLacZ was 49.24% of that in HSCs infected with AdTbeta-ExR (q = 7.835, P < 0.001). CONCLUSIONS: The blockade of TGF-beta signalling in cultured rat HSCs can inhibit their activation significantly, but promote their proliferation.

[Effects of short-action hypnotics triazolam and zopiclone on simulated flight performance].

OBJECTIVE: To evaluate the effects of short-action hypnotics triazolam and zopiclone on simulated flight performance so as to provide experimental evidences for the use of these drugs in aircrew. METHOD: Six healthy young male volunteers served as the subjects. They were asked to take triazolam (0.25 mg), zopiclone (7.5 mg) or placebo at noon time (13:00) and sleep for 1 h. Simulated flight performances were tested in a simulator 1 h, 2 h, 3 h, 4 h, 6 b, 8 h, 10 h and 20 h (next morning 9:00) after taking the drugs. The experiments were done once a week for 3 weeks. RESULT: No significant difference was found between simulated flight performances before or after triazolam while simulated flight performances at 2 h and 3 h after taking zopiclone showed significant decrease (P<0.05), but restored to normal 4 h after taking the drug. CONCLUSION: Short-action hypnotics triazolam had no significant effect on simulated flight performance, while zopiclone had significant adverse effects on simulated flight performance at 2 h and 3 h after taking the drug.