OBJECTlVE To investigate the myocardiaI toxicity of doxorubicin on the myocardium of rabbits and mechanism. METHODS Doxorubicin 2 mg·kg-1 was injected once a week for eight weeks. After discontinuation of doxorubicin,observation was performed for another 8 weeks. Every weekend, uItrasound examination,cardiac catheterization,angiotensinⅡ(AngⅡ)Western bIotting and pathoIogi-caI examination were performed to anaIyze eject fraction( EF),maximaI rate of rise of Ieft ventricuIar pressure(+dp/ dtmax ),AngⅡexpression IeveI,apoptosis index(AI)and the structure of the myocardium. RESULTS At the 7th injection,EF decreased( P ﹤0.05),but reached the bottom vaIue at the 8th injection. At the 3rd injection,Ieft ventricuIar +dp/ dtmax decreased( P ﹤0.05)and reached the bottom vaIue one week after withdrawaI. After that,it increased and reached a high vaIue six weeks after withd-rowaI. But it was stiII Iower than before administration. At the 2nd injection,AngⅡ expression increased (P﹤0.05). At 1 week after withdrawaI,it reached the top vaIue,but than decreased and reached a Iow vaIue six weeks after withdrowaI,but was stiII higher than before administration. At the 1st injection,AI increased( P ﹤ 0.05). At 1 week after withdrawaI,it reached the top vaIue,but then decreased and reached a Iow vaIue 5 weeks after withdrawaI. But it was stiII higher than before administration. CONCLUSlON Doxorubicin cardiac toxicity can induce an eIevated IeveI of myocardiaI AngⅡ,possibIy associated with increased aIdosterone and myocardiaI tension. Increased Ang Ⅱ may induce further myocardiaI structuraI damage and ventricuIar remodeIing through the ROS and caIcium imbaIance.

Objective:To investigate the clinical outcome after surgery and first 131I treatment in patients with moderate-risk papillary thyroid cancer (PTC), and analyze the relevant factors that affect the therapeutic effect. Methods:From January 2018 to April 2019, 135 patients (48 males, 87 females; age (42.7±11.1) years) with moderate-risk PTC in the Second Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. According to the 2015 American Thyroid Association (ATA) guidelines, patients were divided into excellent response (ER) group, inderteriminate response (IDR) group, biochemical incomplete response (BIR) group and structural incomplete response (SIR) group, of which IDR, BIR, SIR were collectively referred to as the non-ER group. χ2 test and Mann-Whitney U test were used to compare the general clinical features between the ER and non-ER groups, and then multivariate logistic regression analysis was performed. The predicted value of pre-ablation stimulated thyroglobulin (ps-Tg) to ER was assessed by ROC curve analysis. Results:The treatment responses of 94 patients were ER, and those of 41 were non-ER. The differences in tumor size (0.80(0.50, 1.10) vs 1.00(0.55, 1.50) cm; U=1 491.50, P=0.036), the number of metastatic lymph nodes (3(2, 5) vs 4(2, 12); U=1 422.00, P=0.015), metastatic lymph node size (0.50(0.30, 0.65) vs 0.50(0.30, 1.45) cm; U=1 396.50, P=0.013), metastatic lymph node involvement rate (50%(30%, 70%) vs 60%(50%, 85%); U=1 441.50, P=0.024), metastatic lymph node location (central/lateral: 76/18 vs 24/17; χ2=7.40, P=0.007) and ps-Tg level (2.1(0.8, 5.3) vs 14.0(3.2, 35.2) μg/L; U=680.00, P<0.001) were statistically significant between the ER and non-ER groups. Multivariate logistic regression analysis showed that ps-Tg (odds ratio ( OR)=1.200, 95% CI: 1.107-1.302, P<0.001) was an independent factor influencing ER. The cut-off value of ps-Tg for predicting ER was 7.38 μg/L, with the sensitivity and specificity of 68.3%(28/41) and 87.2%(82/94) respectively. Conclusion:Moderate-risk PTC patients with smaller tumor size, fewer metastatic lymph nodes, lower metastatic lymph node involvement rate, metastatic lymph nodes in central area, smaller metastatic lymph node size, and ps-Tg<7.38 μg/L have better therapeutic effect after initial 131I treatment.

Objective To compare the production of farnesol between Candida albicans (C.albicans) biofilms formed by resistant and standard strains in different media,and to investigate the changing trend of farnesol production in different phases of biofilm formation and the features of farnesol production by resistant C.albicans.Methods Fluconazole-resistant C.albicans strains were induced in vitro.Standard strains and fluconazole-resistant strains of C.albicans were separately inoculated onto different media,including RPMI 1640 medium,yeast extract peptone dextrose (YPD) medium,yeast nitrogen base (YNB) + 0.5％ glucose medium,RPMI 1640 + 10％ fetal calf serum (FCS),so as to form C.albicans biofilms.Morphological changes of C.albicans biofilms at 24 hours were observed under an inverted microscope,and gas chromatography-mass spectrometry (GC/MS)was performed to detect the level of farnesol at 1.5,3,6,12,24,36 and 48 hours.Results There were no obvious differences in the morphology of C.albicans biofilms between the resistant and standard strains when they were cultured in the same medium,while the morphology of C.albicans biofilms markedly differed between the 2 kinds of strains in the different media.Three-factor analysis of variance showed that the production of farnesol in the C.albicans biofilms changed over time (F =70.628,P ＜ 0.001).Concretely speaking,during the formation of resistant and standard C.albicans biofilms,the production of farnesol gradually increased in the RPMI 1640,YPD and YNB + 0.5％ glucose media until the biofilms matured,then showed a decreasing trend.However,the time to peak levels of farnesol was different between the 2 kinds of strains in these media.Moreover,the levels of farnesol in the 2 kinds of strains both slowly increased in the RPMI 1640 + 10％ FCS medium within 12-48 hours.Culture media also significantly affected the production of farnesol (F =176.665,P ＜ 0.001),and the levels of farnesol in the resistant and standard C.albicans biofilms were both higher in the YNB + 0.5％ glucose medium.When resistant and standard strains were separately cultured in the RPMI 1640 media and the YPD media,the level of farnesol was significantly higher in the resistant strains than in the standard stains (RPMI 1640 media at 36 hours:1.157 ± 0.064 vs.0.250 ± 0.075,P ＜ 0.05;YPD media at 6 hours:0.262 ± 0.036 vs.0.055 ± 0.062,P ＜ 0.05;YPD media at 12 hours:0.730 ± 0.030 vs.0.482 ± 0.024,P ＜ 0.05).However,when they were separately cultured in the YNB + 0.5％ glucose media,the farnesol level was significantly higher in the standard stains than in the resistant strains (36 hours:2.950 ± 0.677 vs.0.523 ± 0.266,P =0.020).Conclusion The media markedly affect the production of farnesol in the C.albicans biofilms,and there is a certain difference in the production of farnesol between resistant and standard C.albicans strains.

Objective To investigate the prevalence of Echinococcus infections in small rodents around human residential areas in Yushu City, Qinghai Province in 2023, so as to provide insights into precision echinococcosis control. Methods One or two quadrats, each measuring 50 m × 50 m, were randomly assigned in Shanglaxiu Township and Longbao Township, Yushu City, Qinghai Province on June 2023, respectively, and 300 plate-type mouse traps, each measuring 12.0 cm × 6.5 cm, were assigned in each quadrat. Small rodents were captured during the period between 10 : 00 and 18 : 00 each day for 4 days. Then, all captured small rodents were identified and dissected, and liver specimens with suspected Echinococcus infections were subjected to pathological examinations. The Echinococcus cytochrome c oxidase 1 (cox1) gene was amplified using PCR assay, and the sequence of the amplified product was aligned to that was recorded in the GenBank to characterize the parasite species. In addition, a phylogenetic tree of Echinococcus was generated based on the cox1 gene sequence using the neighbor-joining method. Results A total of 236 small rodents were captured in Shanglaxiu and Longbao townships, Yushu City, including 65 Qinghai voles and 51 plateau pikas in Shanglaxiu Township, and 62 Qinghai voles and 58 plateau pikas in Longbao Township, and there was no significant difference in the constituent ratio of small rodents between the two townships (χ² = 0.294, P > 0.05). Seven plateau pikas and 12 Qinghai voles were suspected to be infected with Echinococcus by dissection, and pathological examinations showed unclear structure of hepatic lobules and disordered hepatocyte arrangement in livers of small rodents suspected of Echinococcus infections. PCR assay identified E. shiquicus DNA in 7 Qinghai voles, which were all captured from Shanglaxiu Township. Phylogenetic analysis showed that the cox1 gene sequence of Echinococcus in small rodents was highly homologous to the E. shiquicus cox1 gene sequence reported previously. Conclusion Plateau pika and Qinghai vole were predominant small rodents around human residential areas in Yushu City, Qinghai Province in 2023, and E. shiquicus infection was detected in Qinghai voles.