Currently,there are practical and technical difficulties in the construction of clinical ques-tions in the development of clinical practice guidelines.Clinicians or guideline developers seldom construct clin-ical questions based the actual case scenario,leading to some information loss between structured and actual clinical connotation.To overcome this challenge,we proposed a case-guided questions construction approach,and carried out case research and verification in the formulation of the guideline.We found that this method could more efficiently and scientifically assist the formulation of clinical questions,and provide reference for clinicians or guideline developers.

Objective To conduct a quantitative risk assessment of Listeria monocytogenes(LM)in prepackaged,non-vacuum sealed,short shelf-life,ready-to-eat meat products in Chengdu using the@Risk software.Methods Based on monitoring data of LM contamination in pre-packaged,non-vacuum sealed,refrigerated ready-to-eat meat products in Chengdu obtained from a previous study,a risk assessment model was established.The risk of LM infection caused by consuming cooked meat products in different groups of people was quantitatively assessed.In addition,the growth of LM in cooked meat products,from retail to consumption,was also taken into consideration in the assessment.Results In Chengdu,the numbers of potential cases of listeriosis caused by consumption of prepackaged,non-vacuum sealed,refrigerated ready-to-eat meat products were 0.01(95％confidence interval[CI]:0-1.71 × 10-2)per year per million in healthy individuals aged 5-＜65 years old,0.22(95％CI:0-2.67 × 10-1)in healthy individuals aged 65 and above,and 2.88(95％CI:3.85 × 10-8-4.35)in pregnant women.According to the results of the sensitivity analysis,the initial pollution level of LM in the retail stage was the most important factor affecting the prevalence(R=0.25),followed by retail temperature(R=0.08),retail time(R=0.07),and amount of consumption per meal(R=0.07).Conclusions For pre-packaged,non-vacuum sealed,cooked meat products,the most important measure to reduce the prevalence of listeriosis is to control the initial contamination level,which requires food processing plants to regularly clean and strictly disinfect the processing environment and equipment to minimize LM contamination at the source.Retail delicatessens should strictly maintain a storage temperature below 5.0℃ and strictly adhere to product shelf-life recommendations.As for consumers,they should consume these meat products as soon as possible after purchase or store them under refrigerated conditions and shorten the storage time.Pregnant women should thoroughly heat the meat products before eating to reduce the risk of listeriosis.

Objective To analyze the effect of Hsa-circ-0101216 on gemcitabine(GEM)chemotherapy resistance in pancreatic cancer and its mechanism.Methods Differentially expressed circRNAs between GEM-resistant pancreatic cancer cells and parent cells were screened using the GEO database.Pancreatic cancer GEM resistant cell lines(BxPC-3-GEM and Capan-1-GEM)were constructed by intermittent concentration gradient method.qRT-PCR was used to detect the expression of Hsa-circ-0101216 in cells.GEM resistant pancreatic cancer cell lines were taken and divided into sh-circ-0101216 group(knockdown of circ-0101216),sh-NC group(transfected with sh-NC),and blank control group(untreated).CCK-8 assay and EdU proliferation assay were used to detect the half inhibitory concentration(IC50)of GEM and proliferation ability of cells in each group.Western blotting was performed to detect the expression of multidrug resistance-related protein 1(MRP1),breast cancer resistance protein(BCRP),and human equilibrative nucleoside transporter-1(hENT-1).A subcutaneous xenograft tumor model of human pancreatic cancer in nude mice was constructed,and sh-NC+GEM group and sh-circ-0101216+GEM group(n=6)were set up.The volume and weight of xenograft tumor in nude mice were compared between the two groups.Western blotting and immunohistochemistry were used to detect the expression of MRP1,BCRP,and hENT-1 proteins in xenograft tumor tissues,and EDU proliferation assay was used to detect the proliferation ability of tumor cells.Results The GEO database screening showed that Hsa-circ-0101216 was up-regulated in GEM-resistant pancreatic cancer cell lines.Pancreatic cancer GEM-resistant cell lines were successfully constructed,and the expression levels of Hsa-circ-0101216 and the IC50 value in GEM-resistant pancreatic cancer cells BxPC-3-GEM and Capan-1-GEM were significantly higher than those in parental cells(P<0.05).In sh-circ-0101216 group,the IC50 values of GEM,cell viability,EdU positivity rate,and the expression levels of MRP1 and BCRP proteins in GEM-resistant pancreatic cancer cells BxPC-3-GEM and Capan-1-GEM were significantly lower than those in blank control group and sh-NC group,while the expression level of hENT-1 protein was significantly higher(P<0.05 or P<0.001).In sh-circ-0101216+GEM group,the weight and volume of subcutaneous xenograft tumors in nude mice,the expression levels and positive expression rates of MRP1 and BCRP proteins in tumor tissues,and the EdU positive rate were significantly lower than those in sh-NC+GEM group,while the expression level and positive expression rate of hENT-1 protein were significantly higher(P<0.05).Conclusions Hsa-circ-0101216 is highly expressed in GEM-resistant pancreatic cancer cell lines.Its knockdown can inhibit the proliferation of pancreatic cancer cells and enhance the chemosensitivity of pancreatic cancer cells to GEM.The mechanism may be related to the regulation of transmembrane transporter protein expression.

Objective:To analyze the contamination characteristics and pathogenic potential of Listeria monocytogenes (LM) in pre-packaged and refrigerated ready-to-eat cooked meat products in Chengdu City. Methods:From September 2022 to May 2023, pre-packaged and refrigerated ready-to-eat cooked meat products were collected from six districts and counties in Chengdu City. Qualitative and quantitative determination of LM was performed on these samples. Whole genome sequencing was carried out on the isolated strains. Different ST strains were selected for cell adhesion and invasion experiments. The results were expressed as adhesion rate and invasion rate. One-way ANOVA was used for comparison between groups, and the Dunnett t-test was used for pairwise comparison. Results:A total of 145 samples were collected, and LM was detected and isolated in 29 samples. The total detection rate was 20.00%, and the detection rate of braised pork was the highest (68.18%). The contamination level of LM in 9 samples (31.03%) was greater than 100.00 MPN/g. The 29 strains of Listeria monocytogenes belonged to 7 STs, including ST 3 (27.59%), ST 8 (17.24%) and ST 87 (13.79%). The strain of ST 87 carried Listeria pathogenicity islands 4 (LIPI-4), which was a highly virulent strain. The medium and high virulence strains accounted for 79.31%. Some moderately virulent and highly virulent strains of ST 8 and ST 87 were closely related to clinical patient strains. Some LM isolates of the same ST type had little SNP differences (1-6) in the same manufacturer at different stages. In vitro cell experiments showed that the highly virulent strain ST 87 had the strongest adhesion and invasion ability towards Caco-2 cells. Conclusion:The pre-packaged and refrigerated cooked meat products have a high contamination rate. Some samples have high contamination levels and carry medium and high virulence strains, posing potential health risks to human beings. LM residues continue to persist in some manufacturers′ production and processing stages.

Objective:To analyze the effects of the disease and injury spectrum on health-adjusted life expectancy (HALE) among permanent residents aged 55 and above in Shenzhen from 2016 to 2030.Methods:Based on the mortality surveillance data and the permanent resident population data in Shenzhen from 2016 to 2022, the Sullivan method was used to calculate the HALE during 2016—2022. The Bayesian age-period-cohort model and the grey system model were used to predict the HALE during 2023—2030. The HALE changes in the two periods were decomposed into the contributions of 20 categories of diseases and injuries, respectively.Results:From 2016 to 2022, the HALE increased from 31.41 years (95% CI: 30.50-32.32) to 33.57 years (95% CI: 32.47-34.67). During this period, the mortality effect of neurological disorders slowed the increase of HALE, with a reduction of 0.27 years. By 2030, it is anticipated that the HALE will reach 36.40 years (95% CI: 34.78-38.01). This is expected to be influenced by the mortality effects of nutritional deficiencies (-0.40 years) and mental disorders (-0.29 years), as well as the disability effects of musculoskeletal disorders (-0.66 years), skin and subcutaneous diseases (-0.21 years) and nutritional deficiencies (-0.13 years). Conclusion:The HALE of permanent residents aged 55 years and above in Shenzhen demonstrated an increasing trend over time. Greater attention should be paid to the adverse effects of neurological disorders, nutritional deficiencies, mental disorders, musculoskeletal disorders, and skin and subcutaneous diseases on the continuous increase of HALE in this population.

Objective To investigate the influence of helical tomographic radiotherapy plans with different combinations of lead gate width,pitch and algorithms on threading effects.Methods A target model was established with a Cheese Phantom used as the simulated human body,then three lead gate widths(1.0,2.5,and 5.0 cm),six screw pitches(0.143,0.172,0.215,0.287,0.430,and 0.500)and two computational grids(Fine algorithm and Normal algorithm)were respectively combined for designing the helical tomography radiotherapy plans.The radiotherapy plans with a pitch of 0.143,0.172,0.215,0.287 or 0.430 were enrolled into an experimental group,and the plans with a pitch of 0.500 were divided into a control group.The dosimetric parameters including maximum dose(Dmax),minimum dose(Dmin)and mean dose(Dmean)of the target area PTV1 and PTV2 were evaluated by the dose volume histogram(DVH).The dose homogeneity index(HI)of the target area was calculated,and the single rotation time and total treatment time of each plan were recorded and counted.SPSS 27.0 software was used for statistical analysis.Results No significant threading effect appeared regardless of the pitch value when the lead gate width was 1.0 cm.The threading effects in the experimental group were weaker than those in the control group when the lead gate width was 2.5 or 5.0 cm.The threading effect gradually rose with the pitch increased when the lead gate width was 5.0 cm.The most significant difference was found between the threading effect in case of the screw pitch being 0.500 and that with the screw pitch being 0.143,with the differenes being statistically obvious(P<0.05).The lead gate width had significant effects on the Dmax,Dmin,Dmean and HI of PTV1 and PTV2.When the lead gate width was 5.0 cm,high HI value and uneven dose distribution were detected and lowered screw pitch weakened the threading effect.The single rotation time first remained constant and then increased with the screw pitch was enlarged,with the changing points occurring in case of the screw pitches of 0.287 and 0.430.With a certain lead gate width,the treatment time for plans was shortened with the decrease of the pitches in case of the pritches lower than 0.287,and tended to be constant after the screw pitches reached 0.287.The changes of the computational grid had no significant effects on the results of radiotherapy plans when the lead gate width and screw pitch were kept constant.Conclusion When designing a spiral tomotherapy plan with conventional doses,a lead gate width of 1.0 or 2.5 cm and a screw pitch of 0.287 or 0.430 should be selected in order to minimize the threading effect while ensuring the efficiency of plan implementation.[Chinese Medical Equipment Journal,2025,46(8):58-66]

This study was aimed at determining the molecular characteristics of Yersinia pestis in the natural plague foci around Qinghai Lake through single nucleotide polymorphism technology,to lay a foundation for molecular epidemiological and source-tracing analysis of Y.pestis in this area.Using the whole genome sequencing technology,we obtained the whole genome sequences of 84 representative Y.pestis strains.Using the sequences of Y.pestis and Yersinia pseudotuberculosis IP32953 from the NCBI database as references,we compared and analyzed the 2 298 SNP loci of these strains.From 1957 to 2020,84 representative strains of Y.pestis from the natural plague foci around Qinghai Lake were divided into two clades:1.IN2 and 3.ANT1.The 1.IN2 clade was the characteristic population of Y.pestis throughout all epidemic years in this area.Additionally,analysis of the SNP distribution and hosts in the region indicated that the 1.IN2 clade was located in five counties except Wulan,whereas the 3.ANT1 clade was isolated from Himalayan marmot and dog in two counties.In conclusion,the population structure of SNP of Y.pestis in the natural plague foci around Qinghai Lake is relatively simple,and SNP analysis of Y.pestis provided a scientific basis for tracing plague epidemic sources and formulating plague prevention and control measures in this area.