Objective·To construct a probiotic(Escherichia coli Nissle1917,EcN)system(EcN@PVA-ALG)loaded on polyvinyl alcohol(PVA)/alginate(ALG)hydrogel(PVA-ALG)rich in negative hydroxyl groups,and to explore its colonization in the inflammatory site of colon and its therapeutic effect on dextran sulfate sodium salt(DSS)-induced inflammatory bowel disease(IBD).Methods·EcN suspension was added to the PVA-ALG hydrogel,and then EcN@PVA-ALG hydrogel probiotic complex was obtained after screening and centrifugation.The synthesis of PVA-ALG hydrogel was verified by rheometer.The surface charge of EcN@PVA-ALG was detected by potentiometer and the load of EcN on PVA-ALG was observed by fluorescence microscope.The absorbance of EcN@PVA-ALG at 600 nm was detected by enzyme labeling instrument.Meanwhile,the bacterial plate count of EcN@PVA-ALG complex suspension was taken to study the growth activity of EcN in EcN@PVA-ALG.The CCK-8 kit was used to assess the inhibitory ability of EcN@PVA-ALG on HEK cell proliferation.In vivo imaging system(IVIS)was used to firstly analyze the enrichment of PVA-ALG on inflammatory colon to study its inflammatory targeting property;then EcN was loaded on PVA-ALG,and IVIS was used to observe the enrichment of EcN@PVA-ALG on inflammatory colon to study its ability to colonize the inflammatory site.To establish the model of IBD mice induced by DSS,EcN@PVA-ALG group(n=5)was given 1×108CFU EcN@PVA-ALG every day for 5 d,and PVA-ALG group,EcN group,PBS group and healthy control group with 5 mice were set up.During the treatment,the body mass of the mice was recorded every day.After treatment,the colonic tissue was taken,and the length of colon was measured.The disease activity index(DAI)score was graded.The levels of inflammatory cytokines,including tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-10 and transforming growth factor-β(TGF-β)were detected,and the pathological evaluation of colonic tissue was made by H-E staining.Results·Both PVA-ALG and EcN@PVA-ALG were negatively charged.EcN was successfully loaded onto PVA-ALG and PVA-ALG did not affect the growth viability of EcN,which contributed to the subsequent colonization of inflammatory colons.PVA-ALG had a favorable safety profile on normal cells.Compared with healthy controls,PVA-ALG had more than 2-fold enrichment effect on inflammatory colon tissue.In vitro and in vivo experiments revealed that EcN@PVA-ALG complex loaded with EcN had 8 times higher enrichment effect on inflammatory tissue than EcN without any modification.After EcN@PVA-ALG treatment,the body weight of mice recovered rapidly.The increase of DAI was significantly inhibited.The length of colon was similar to that of healthy mice.The levels of TNF-α and IL-6 decreased,while the levels of IL-10 and TGF-β increased.The crypt structure of colon tissue recovered.Conclusion·Compared to unmodified EcN,EcN@PVA-ALG promotes the colonization of EcN at inflammatory sites of colon and allows it to exert better efficacy on treating DSS-induced IBD.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

ObjectiveTo establish a dose-effect curve for semi-automatic analysis of dicentric chromosomes(DC) based on an automatic chromosome analysis system. Methods A total of three healthy volunteers were recruited as the study subjects, and their peripheral blood was collected and stimulated by X-ray at doses of 0.00, 0.10, 0.25, 0.50, 0.75, 1.00, 2.00, 3.00, 4.00, and 5.00 Gy, with the absorbed dose rate of 1.0 Gy/min. Images of DC in the mid-stage of cell division were collected using a high-throughput automatic chromosome analysis system. The DCScore software was used to automatically analyze DC aberrations, and a dose-effect curve for semi-automatic analysis of DC was fitted after manual confirmation. The fitted dose-effect curve for semi-automatic analysis of DC was validated for accuracy using three proficiency test samples from the national quality assessment of biological dose. Results The incidence of DC increased with increasing irradiation doses in the range of 0.00-5.00 Gy (P<0.01). The dose-effect curve for the fitted semi-automatic analysis of DC was ŷ =0.000 8 (±0.000 2) +0.009 2(±0.000 9) D+0.014 2(±0.000 4) D² (R²= 0.999 8). The relative deviation between the estimated dose and the actual dose of the three test samples was about 20.00%, indicating curve applicability for biological dose estimation. Moreover, excluding the time spent on manual analysis, the semi-automatic analysis method increased the analysis efficiency by 26.0 times. Conclusion The semi-automatic analysis dose-effect curve for DC stimulated by X-ray is constructed for biological dose estimation, which can reduce the manual analysis time, and holds great potential for application in nuclear emergency response to large-scale radiation accidents.

Objective: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. Methods: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1–4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). Results: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1–4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552–8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). Conclusion The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

The senescence accelerate mouse prone strain was identified by Professor T.Takeda's laboratory in Japan from the offspring produced by the brother-sister inbred line of AKR/J mice donated by Jackson Laboratory in the United States SAMP),and SAMP8 mice showed a variety of aging characteristics,such as:Pathological changes such as memory and learning disorders,behavioral abnormalities,skin roughness,aging,hair loss,eye lesions(visual impairment,cataract,periocular lesions),hearing impairment,weight loss,muscle strength loss,reproductive system aging,liver and fat metabolism disorders,etc.,are widely used in experimental studies of related diseases or pathology,and have made considerable contributions to the research of diseases.However,there are also many problems in its application,such as the selection of month age,the use of intervention methods,the suitability of pathological changes and research content,and the understanding of models under different theoretical backgrounds,which are of great research value.Therefore,this paper systematically analyzes the above problems based on existing literature,in order to provide relevant basis for the application of SAMP8 mice in different fields and different mechanisms.

The senescence accelerate mouse prone strain was identified by Professor T.Takeda's laboratory in Japan from the offspring produced by the brother-sister inbred line of AKR/J mice donated by Jackson Laboratory in the United States SAMP),and SAMP8 mice showed a variety of aging characteristics,such as:Pathological changes such as memory and learning disorders,behavioral abnormalities,skin roughness,aging,hair loss,eye lesions(visual impairment,cataract,periocular lesions),hearing impairment,weight loss,muscle strength loss,reproductive system aging,liver and fat metabolism disorders,etc.,are widely used in experimental studies of related diseases or pathology,and have made considerable contributions to the research of diseases.However,there are also many problems in its application,such as the selection of month age,the use of intervention methods,the suitability of pathological changes and research content,and the understanding of models under different theoretical backgrounds,which are of great research value.Therefore,this paper systematically analyzes the above problems based on existing literature,in order to provide relevant basis for the application of SAMP8 mice in different fields and different mechanisms.

Objective:To analyze the level of chromosome aberration in lymphocytes of medical radiation workers and its influencing factors.Methods:From July to September 2020, 252 medical workers in a tertiary hospital were selected as the study subjects and 107 preserviceworkers were selected as the control group. The Chromosomal aberrations of peripheral blood lymphocytes were measured using conventional cytogenetic analysis method, and the differences were analyzed.Results:The frequencies of dicentric puls centric ring, total chromosome-type aberrations, and abnormal detection rate in the radiation group were significantly higher than those in the control group ( Z=2.59, 3.74, 9.99, P<0.05). There was significant difference in the frequencies of dicentric plus centric ring and total chromosome-type aberrations among different types of work (χ 2=8.59, 8.17, 11.39, P<0.05), and the frequencies of dicentric plus centric ring were significantly higher in the interventional radiology group than those in diagnostic radiology (χ 2=2.90, P<0.05), While the rates of acentric fragment and total chromosome-type aberrations were significantly higher in the nuclear medicine group than those in diagnostic radiology (χ 2=2.81, 3.19, P<0.05). The difference in the abnormal detection rate of chromosome aberrations between different types of work was statistically significant ( P<0.05), and the rate in the interventional radiology group was significantly higher than that in the diagnostic radiology group (χ 2=7.66, P<0.05). There was no significant difference in chromosome aberration level and abnormal detection rate among different working ages ( P>0.05). Poisson regression analysis indicated that the type of work is a risk factor for chromosomal aberration [ IRR=2.31 (nuclear medicine group), 1.66 (Radiation therapy), and 1.78 (interventional group) ; P<0.05]. Conclusion:Ionizing radiation causes certain radiation damage to medical radiology workers, and the frequencies of chromosome aberration in the radiation workers of nuclear medicine and interventional radiology groups are relatively high, so radiation protection should be strengthened to ensure the health of relevant workers.