Objective:To study the effect of Ginkgo biloba extract (EGb761) on metabolism of aflatoxin B_1(AFB_1) in Wistar rats. Methods:Seventy one Wistar rats were divided into three groups at random: group A (AFB_1 group), group B (AFB_1+EGb761 group), and group C (control group). The rats in groups A and B were given AFB_1(intraperitoneal injection, 100-200 μg/ kg body weight, 1-3 times/week). The rats in group B were fed the food containing EGb761 while the rats in groups A and C were given normal food. Blood samples were collected and liver biopsy was performed on the 14th, 28th and 42nd week. All the rats were sacrificed at the 64th week. The incidence of hepatoma was observed. The hepatic phase Ⅰ drug-metabolizing enzyme CYP450 and phase Ⅱ enzyme GST were detected by spectrometry. The serum AFB_1-lysine adduct was determined by high performance liquid chromatography (HPLC). The expression of 8-hydroxydeoxyguanosine(8-OHdG) was measured by immunohistochemistry. Results:The incidence of hepatocellular carcinoma (HCC) in group B was significantly lower than that in group A (26.92% vs 76.00%,P<0.001). No hepatocellular carcinoma developed in group C. EGb761 had no effects on the activities of CYP450 and GST in rat liver tissues. The level of AFB_1-lysine adduct reached the peak (4 356.01 pg/mg albumin) at the 14th week in group A. EGb761 significantly inhibited the formation of AFB_1-lysine adducts in serum by 13.07% at the 14th week (P＝0.033), and 73.63% at the 42nd week (P＝0.002). The expression of 8-OHdG protein in rat liver tissues in group B was significantly lower than that in group A at the 28th, 42nd, and 64th week (P<0.05). Conclusion:The main mechanism underlying the effect of EGb761 in blocking hepatogenesis induced by AFB_1 may not be fully related with its influence on the activity of liver phase Ⅰ and phase Ⅱ metabolizing enzymes. EGb761 inhibites the production of AFB_1-lysine addcuts, decreases the expression of 8-OHdG protein, and finally alleviates the DNA oxidative injury, which may be one of the mechanisms for the effects of EGb761 in inhibiting or delaying hepatogenesis induced by AFB_1.

Objective To provide a better cell model of closely nature infectious state for further research of hepatitis B virus(HBV). Methods Primary tupaia hepatocytes were isolated by the two-step perfusion method. The hepatocytes were then infected with purified serum from patients with hepatitis B. DNA and RNA isolated from the hepatocytes were detected with Southern blot and Northern blot. HBsAg in supernatant was tested by immunohistochemical method. Results cccDNA, pgRNA and sgRNA could be detected by Southern blot and Northem blot, and strong signals could be seen from day 7 to day 14 post-in-fection. The S/CO value of HBsAg in supernatant decreased from day 1 to day 5 and then increased after 5 day. Conclusion Primary tupaia hepatocytes are competent for infection with HBV. HBV can stably repli-cate and express in HBV-infected tupaia hepatocytes.

Objective To compare dose distribution in gamma knife radiotherapy plan, conformal radiotherapy(CRT)plan and intensity modulated radiotherapy(MRT)plan for patients with small mass in lung, and evaluate their characters. Methods Fourteen patients with small mass in lung participated in the study. Gamma knife radiotherapy plan(plan 1), CRT plan(plan 2)and IMRT plan(plan 3)were made for each mass. The planning target volume(PTV)and the dose include 95% PTV were consistent.Conformal index(CI), homogeneity index(HI), lung V5 ,V10 ,V20 ,V30 and the max dose of esophagus and spinal cord were analyzed. Paired samples t-test was used for comparison between each two plans. Results The CI of the plan 1,2 and 3 were 0. 58,0. 46 and 0. 63, respectively. CI of the plan 1 ＞ that of the plan 2 (t= -3.95,P =0.000),plan 3 ＞ plan 2(t = -6.01 ,P =0.000),plan 1 =plan 3(t =1.64,P =0.116);HI of the plan 1,2 and 3 were 1.66,1.10 and 1.07 respectively. HI of the plan 1 ＞ plan 2 ,plan 1 ＞ plan 3(t= -20.52,21.41 respectively, both P=0. 000),plan 2 = plan 3(t= -1.08,P=0.294). The wholelung V5 ,V10 ,V20 and V30 were 10.0% ,5.6% ,2. 4% and 1.2%, respectively, in plan 1 ;20. 2% ,13. 4%,6. 9% ,3.0%, respectively, in plan 3; and 26. 5%, 18. 0%, 11.4% and 4. 6%, respectively, in plan 2.The V5, V10, V20 and V 30 of the plan 1 ＜ in plan 2(t = 9. 68,8. 41,5. 45,5. 14, all P = 0. 000), the V5,V10,V20 and V30 of the plan 1 ＜ in plan 3(t=7.58,8.95,6. 15,4.78, respectively, all P=0.000),the V5 ,V10, V20andV30 oftheplan2 ＞ inplan3(t =9. 71,5. 91,4. 13,3.91, respectively, allP =0.000).The max dose of esophagus in plan 1 ,2 and 3 were 24.93 ± 21.54, 31.90 ± 18. 75, 29. 19 ± 23.09 Gy,respectively, plan 1 ＜ plan 2(t = -2. 71 ,P=0.013),plan 1 = plan 3(t = - 1.49,P =0. 152),plan 2 =plan 3(t = 1.35, P = 0. 193). The max dose of spinal cord in plan 1,2 and 3 were 12.07 ± 10. 67,17.70 ±11.35 and 8.92 :± 10. 04 Gy, respectively, plan 2 ＞ plan 1 ＞plan 3(t = -2. 38,2. 29,4. 83,P=0. 1027,0.033,0.000);All three plans of each mass meet the needs that the max dose of the esophagus≤60 Gy and the max dose of spinal cord ≤40 Gy. Conclusions The dose of the normal lung was lower, but the HI and the max dose of spinal cord were higher in Gamma knife radiotherapy plan than those in the CRT and the IMRT plan of the small mass in lung.

A 3-week practice-oriented training course on chronic obstructive pulmonary disease (COPD) management was conducted in December 2020, 34 primary care physicians from township or community health service centers attended the course. The impact of the training course on the knowledge levels of COPD management was evaluated with a questionnaire survey, the questionnaire contained the knowledge of COPD and its management. The survey showed that before the training, the participants had low knowledge levels on the definition of COPD and its risk factors; 67.6% (23/34) were not aware of COPD-related guidelines and new developments, and 17.6%(6/34) had conducted COPD follow-up assessments, pulmonary rehabilitation, and health education; only 8.8% (3/34) had used the improved British Medical Research Council Dyspnea Index (mMRC) and the chronic obstructive pulmonary disease assessment test (CAT) for patient self-assessment; there was no pulmonary function instrument in their units, and only 3 doctors (8.8%) had previously participated in pulmonary function training and knew indications and contraindications of the pulmonary function test, and complete report interpretation; all participants were unable to use common inhalation devices and master inhalation techniques completely and correctly; 11.8% (4/34) had assessed patients′ handling inhalation devices and performing inhalation. After the training, the knowledge levels of COPD clinical features, lung function and inhalation technique were significantly improved, and the scores were significantly increased compared with those before the training ( P<0.001). The study shows that primary care physicians have insufficient knowledge and management skill of COPD. The practice-oriented training can significantly improve the knowledge and skills of primary care physician for COPD management in the community.

ObjectiveAn analytical method was developed for the qualitative screening of 52 illegally adulterated weight-losing compounds in foods by ultra high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. MethodsThe samples were extracted by methanol. Waters CORTECS T3 column （100 mm×2.1 mm， 2.7 μm） was used with acetonitrile -0.1% formic acid aqueous solution as mobile phases by gradient elution. The compounds were detected by electrospray ionization mass spectrometry and Q-TOF-MS detector in positive and negative ion mode. A standard spectrum library was established by reference standards， and the qualitative analysis was finished by the comparison of the retention time， parent ion and fragment ion accurate molecular mass of each compound in the sample and the library. ResultsThe method was specific without interference of blank matrix， and repeatable in sextuplicate. The detection limits of 52 compounds in 5 matrix were 1‒100 mg‧kg^-1. The method was successfully applied to the analysis of actual samples，and 16 compounds were checked out in 246 samples. ConclusionThe method is accurate， specific and sensitive， which can be used to combat the illegal adulteration behavior effectively.