Objective To conduct a survey on students for their common needs for the course and the support to their research training,to provide reference for course reform and curriculum of ideology and politics.Methods A survey before and after course was conducted in 704 graduates who selected the course of"Experiments of Molecu-lar Biology"from the autumn of 2018 to the spring of 2024.After collecting the survey,they were summarized,counted,and analyzed.Results The students selected this course were mainly research-oriented graduate students.Their professional background was mainly in clinical medicine,and there was a relatively lack of training in tech-nology and laboratory skill in molecular biology experiment.The follow-up survey showed that experimental operation and implementation as well as analysis of experimental results were the two most helpful aspects for students;PCR,RNA extraction and detection,and Western blot were the most useful techniques for student learning and scientific research.Conclusions Through the survey,the professional background of students,dynamic changes in their course selection needs are well acknowledged and so thus able to optimize,provide good reference for teaching and learning in this field,and provide a basis for curriculum reform and construction of ideological and political courses.

Objective:To investigate the clinical characteristics of 130 children with severe SARS-CoV-2 infection in Yunnan province after the relaxation of non-pharmaceutical interventions, and analyze the risk factors for mortality.Methods:This study is a retrospective case summary that analyzed the demographic data, underlying diseases, clinical diagnoses, disease outcomes, and laboratory results of 130 children with severe COVID-19 infections admitted to nine top-tier hospitals in Yunnan Province from December 2022 to March 2023. According to the prognosis, the patients were divided into survival group and death group. The clinical and laboratory data between the two groups were compared, and the risk factors of death were evaluated. The χ2 test and Mann-Whitney U test were employed to compare between groups, while Spearman correlation test and multiple Logistic regression were used to analyze the risk factors for death. The predictive value of independent risk factors was evaluated by receiver operating characteristic curve. Results:The 130 severe patients included 80 males and 50 females with an onset age of 28.0 (4.5, 79.5) months. There were 97 cases in the survival group and 33 cases in the death group with no significant differences in gender and age between the two groups ( P>0.05). Twenty-five cases (19.2%) out of the 130 patients had underlying diseases, and the number with underlying diseases was significantly higher in death group than in survival group (36.4% (12/33) vs. 13.4%(13/97), χ2=8.36, P=0.004). The vaccination rate in the survival group was significantly higher than that in the death group (86.1% (31/36) vs. 7/17, χ2=9.38, P=0.002). A total of 42 cases (32.3%) of the 130 patients were detected to be infected with other pathogens, but there was no significant difference in the incidence of co-infection between the death group and the survival group (39.3%(13/33) vs. 29.9% (29/97), χ2=1.02, P>0.05). Among the 130 cases, severe respiratory cases were the most common 66 cases (50.8%), followed by neurological severe illnesses 34 cases (26.2%) and circulatory severe 13 cases (10%). Compared to the survival group, patients in the death group had a significantly higher levels of neutrophil, ferritin, procalcitonin, alanine aminotransferase, lactate dehydrogenase, creatine kinase isoenzyme, B-type natriuretic peptide, interleukin-6 and 10 (6.7 (4.0, 14.0) vs. 3.0 (1.6, 7.0)×10 9/L, 479 (298, 594) vs. 268 (124, 424) μg/L, 4.8 (1.7, 10.6) vs. 2.0 (1.1, 3.1) μg/L, 66 (20, 258) vs. 23 (15, 49) U/L, 464 (311, 815) vs. 304 (252, 388) g/L, 71(52, 110) vs. 24(15, 48) U/L, 484 (160, 804) vs. 154 (26, 440) ng/L, 43 (23, 102) vs. 19 (13, 27) ng/L, 216 (114, 318) vs. 86 (45, 128) ng/L, Z=-4.21, -3.67, -3.76, -3.31, -3.75, -5.74, -3.55, -4.65, -5.86, all P<0.05). The correlated indexes were performed by multivariate Logistic regression and the results showed that vaccination was a protective factor from death in severe cases ( OR=0.01, 95% CI 0-0.97, P=0.049) while pediatric sequential organ failure assessment (PSOFA) ( OR=3.31, 95% CI 1.47-7.47, P=0.004), neutrophil-to-lymphocyte ratio (NLR) ( OR=1.56, 95% CI 1.05-2.32, P=0.029) and D dimer ( OR=1.49, 95% CI 1.00-1.02, P=0.033) were independent risk factors for death (all P<0.05). The area under the curve of the three independent risk factors for predicting death were 0.86 (95% CI 0.79-0.94), 0.89 (95% CI 0.84-0.95) and 0.87 (95% CI 0.80-0.94), all P<0.001, and the cut-off values were 4.50, 3.66 and 4.69 mg/L, respectively. Conclusions:Severe SARS-CoV-2 infection can occur in children of all ages, primarily affecting the respiratory system, but can also infect the nervous system, circulatory system or other systems. Children who died had more severe inflammation, tissue damage and coagulation disorders. The elevations of PSOFA, NLR and D dimer were independent risk factors for death in severe children.

Objective:To study the real-world outcome of China FDA-approved Sofosbuvir (SOF)/Velpatasvir (VEL) in Northwest China.Methods:In this multicenter, prospective, real-world cohort study, we recruited patients from 10 sites from Northwest China, who were chronically infected with HCV GTs 1-6 from 06/2018 to 09/2019. Patients received SOF (400mg)/VEL (100mg) for 12 weeks, and with ribavirin 900-1200 mg for GT3 cirrhosis and for any genotype decompensated cirrhosis. The primary endpoint was sustained virological response at 12-weeks post-treatment (SVR12) and safety. The secondary endpoint was the change of liver function after the achievement of SVR12.Results:Totally, 143 patients were enrolled in the study, four patients were lost to follow-up and one died during the follow-up, 138 patients were included in per-protocol analysis. Of the 138 patients, the mean age 53 years, 53.6% male, 94.2% Han nationality, 53.6% liver cirrhosis, 10.1% HBsAg +, 6.5% renal dysfunction, 5.1% treatment-experienced, and 16.7% patients received ribavirin treatment. The genotype distribution was as follows: 35.5% GT1, 42.8% GT2, 15.9% GT3, and 5.8% un-typed. The SVR12 rate was 96.5% (138/143, 95% CI: 93.5%-99.6%) for intention-to-treat analysis, and in per-protocol analysis, all 138 patients obtained SVR12 (100%). Compared with baseline, the serum total bilirubin, ALT and AFP levels decreased (all P < 0.05), as well as increased ALB and platelet count (all P < 0.001) at post-treatment 12-weeks. Overall adverse events (AEs) rate is 29.0%, and the most common AEs were anemia (14.5%) and fatigue (8.0%). Severe side effects (edema and fatigue) occurred in 2 patients, one of whom needed a short-term interruption of treatment due to fatigue. Conclusion:In this real-world cohort study, 12-week SOF/VEL regimen with or without ribavirin achieved high SVR12 rates (96.5%-100% overall) with excellent safety profile among patients with HCV GT1/2/3 infection including patients with GT3 and cirrhosis, and led to improvement of liver function.

OBJECTIVE： To establish a method for the determination of adefovir （PMEA） and study the pharmacokinetics of metabolites PMEA in rats after intragastric administration of PMEA derivatives [PMEA prodrug， adefovir-ursodeoxycholic acid-3-propyl ester， L-leucine-3-propyl ester （PMEA-1c）] in rats. METHODS： HPLC-MS/MS method was adopted. The determination was performed on BEH C18 column with mobile phase consisted of 0.1％ formic acid acetonitrile-0.1％ formic acid water （gradient elution） at the flow rate of 0.25 mL/min. The column temperature was 30 ℃， and sample size was 1 μL. The quantitative ions were PMEA m/z 274.1→162.1， puerarin （internal standard） m/z 417.1→267.1. 12 rats were randomly divided into adefovir dipivoxil （ADV） group （positive control， 90 mg/kg） and PMEA-1c group （160 mg/kg）， with 6 rats in each group. They were given relevant medicine once intragstrically， and the blood samples were collected from tail vein 0.083， 0.25， 0.5， 0.75， 1， 2， 4， 6， 8， 10， 12， 24 h after administration to determine the plasma concentration of PMEA. Relevant pharmacokinetic parameters were calculated by using DAS 2.0 software. RESULTS： The linear range of PMEA was 6.1-440.0 ng/mL （r＝0.998 5）. RSDs of intra and inter day of precision and stability tests were all less than 10％ （n＝3， 5， 6）， and the accuracy was 82.16％-97.33％ （RSD≤6.4％， n＝5）. Matrix effects ranged from 95.96％-106.35％ （RSD≤4.9％， n＝5）. The pharmacokinetic parameters of PMEA in ADV group and PMEA-1c group were as follows as t1/2 were （1.762±0.117） and （2.548±0.174） h； AUC0-24 h were （2 170.059±146.091） and （4 704.257±176.792） μg·h/L； cmax were （613.092±9.504） and （697.295±15.275） μg/L， respectively. Compared with ADV group， t1/2， AUC0-24 h， AUC0-∞ and cmax of rats in PMEA-1c group were increased significantly （P＜0.01 or P＜0.001）. CONCLUSIONS： Established method is accurate and reliable. The trial indicates that PMEA-1c metabolism is single compartment model， show that can be used as a potential prodrug for adefovir， which lay a foundation for the further study of adefovir prodrug.

In order to search for new adefovir analogues as anti-HBV agents with enhanced antiviral activity and hepatotrophic property,adefovir bis L-amino acid ester was used as lead compound to produce ten adefovir mono L-(thio)amino acid ester, mono bile acid ester derivatives(6a-6j). The design based on bile acid prodrug strategy,which can improve drug oral bioavaliability and liver-targeted enrichment by using enterohepatic circula-tion of bile acid.Sub-structure combination method was adopted to introduce L-(thio)amino acid ester and bile acid ester fragments on the phosphonate functionality of adefovir. The structures of target compounds were confirmed by 1H NMR, 13C NMR,ESI-MS and ESI-HRMS.HepG 2.2.15 cell were used for in vitro anti-HBV activity assessment.Compound 6c with high antiviral activity(EC500.92μmol/L,SI 512.63)was further investi-gated for its tissue distribution in mice.The results showed that content of compound 6c in liver was higher than that of adefovir dipivoxil,and in contrast its content in kidney was lower than that in positive control at all time points(0.25-12 h).Compound 6c exhibits higher antiviral activity,selective index and higher liver distribution,making it a potential anti HBV agent for further investigation.

A, UPLC-QTOF-MS/MS and UPLC-MS/MS were used to investigate the derivative of adefovir mixed phosphonate Q3-I2. Stability and in vitro metabolites of Q3-I2, and the control drug adefovir dipivoxil were co-inculbated with artificial gastric juice, artificial intestinal juice, rat blank plasma and rat liver microsomes, using UPLC-MS/MS and UPLC-QTOF-MS/MS measure the residual concentration of the compounds in each incubation system and the metabolites in the liver microsomal system, respectively, and calculate the half-life and clearance rate by the substrate elimination method. The compounds designed and synthesized in this experiment are stable in the gastrointestinal tract, prolonging t1/2 of plasma and liver microsomes and rapidly degrading the active meta-bolites. In the liver microsomal system, a total of 8 metabolites were detected by positive and negative ion mode, including hydrolysis, oxidation, acetylation, and glucuronidation.

Aim To screen a more suitable transfection recep-tor,and improve the efficiency of constructing cell lines highly expressing human peptide transporters 1 (hPepT1 ).Methods The recombinant plasmid pcDNA3.1 (+)-hPepT1 was transfect-ed into MDCK cells and HeLa cells by LipofectamineTM 2000 transfection reagent,respectively.The monoclonal cells were se-lected and cultured.Expression of hPepT1 mRNA and protein were determined by qRT-PCR and Western blot,respectively. The uptake capacity of Glysar in transfected cells was examined. Results Compared with wild type cells,the expression of hPepT1 and the uptake of Glysar in transfected MDCK cells and HeLa cells significantly increased (P <0.05).Although the up-take of Glysar in HeLa cells was higher than that of MDCK cells,on the contrary,the expression of hPepT1 and the uptake of Glysar in MDCK-hPepT1 cells was higher than that of HeLa-hPepT1 cells.Conclusion MDCK cells may serve as a more suitable transfected receptor for the construction of a cellular model with high expression of hPepT1 ,which would make the construction of a cell model highly expressing hPepT1 more effi-cient.

Abstrate:Aim To construct HEK293 cell line with stable and high expression of sodium taurocholate cotransporting polypeptide (NTCP ) efficiently and rapidly.Method Vector expressing EGFP-NTCP fusion protein was constructed and verified by DNA sequencing.The pEGFP-NTCP expression vector was transfected into HEK293 cells by FuGENE 6 transfection reagent. The transfected cells with high expression of green fluorescent protein were selected using fluorescence microscope for screening of G418 for 14 days to obtain cell lines stably and highly expressing NTCP.NTCP expression was detected by RT-PCR,qRT-PCR, Western-blot and the uptake experiment of taurocholic acid.Re-sult RT-PCR,qRT-PCR,Western-blot and the uptake experi-ment revealed that compared to the control cells,the expression of NTCP was significantly positive (P<0.01)in stable trans-fected cells showing green fluorescence (P<0.05 ).Conclusion The HEK293 cell line with stable and high expression of NTCP has been established efficiently and rapidly,which provides a cellular model for the study of the mechanism of the uptake of bile acid derivatives.

Aim To establish in vitro blood-brain barrier (BBB) model with characteristics of simulation of in vivo BBB by primi-tive co-culture of brain-microvessel endothelial cells (BMECs) with brain-microvessel pericytes (BMPC)and astrocytes (AS). Methods BMECs,BMPC and AS from SD rats were primitively isolated,purified and cultured,and then primitive culture cells were identified by cellular morphological and immunocytochemi-cal staining methods.Five types of in vitro BBB models were es-tablished by using Millicell culture insert (pore diameter 0.4μm)and their barrier functions were evaluated by detection of transendothelial electrical resistance (TEER),permeability of sodium fluorescent (Na-FLU ),expression of alkaline phospha-tase (AKP)and γ-glutamyl transpeptidase (γ-GT1 ),and simi-larity of permeation amount for positive drugs in vitro and in vivo BBB conditions.Results Primitive culture of BMECs presented typical pebbles-like structure,BMPC presented larger soma with branching property,AS presented slender synapse and shallower cytoplasm.Moreover,immunocytochemical staining results iden-tified primitive cells were targeted cells.TEER value for co-cul-ture of BMECs,BMPC and AS reached (478 ±25 )Ω· cm2 , permeability coefficients (Papp )value of Na-FLU was [(8.23 ± 0.78) ×10 -6 ]cm·s-1 ,expression of AKP and γ-GT1 were (6.90 ±0.27 )King unit · g-1 Pro and (4.39 ±0.32 )μg · g-1 Pro respectively.Moreover,good correlation could be found in Papp for positive controls in vitro and in vivo BBB models (R2=0.92).Conclusion The established in vitro BBB model by using primitive co-culture of BMECs with BMPC and AS posses-ses in vivo BBB properties in cell morphology,structures and barrier functions,and can be used as a powerful tool for studying physiology,pathology of BBB and screening candidate com-pounds.

Aim To establish a highly purified,active and prac-tical extract and primitive culture method for rat brain microvas-cular endothelial cells ( BMECs) for providing materials for con-struction in vitro blood-brain barrier ( BBB) model. Methods Cerebral cortex of 1-2 week SD rats was collected,and successive digestion with typeⅡcollagenase and collagenase/dispase, sieve filtration and then twice gradient centrifugation in 20% BSA and 44% Percoll condition were used to obtain brain microvascular section. After that brain microvascular section was seeded in cul-ture bottle and then primarily cultured. Inverted microscope and factor-VIII relative antigen immunostaining methods were used for cellular morphological observation and identification. Results BMECs climbed out the vessel segment and proliferated with ad-herence after 2 h in vitro culture,and they became typical peb-bles structure after further 3-4 d culture. Morever, factor-VIII relative antigen immunostaining identified that expression for the endothelial cells was positive,cytoplasm was brown and positive cells account for more than 99%. Conclusion Rat BMECs with high purity could be extracted and cultured by using the above methods,and it has great potential for construction in vitro BBB model and in depth studies on biological characteristics and func-tions of BMECs.