1.Role of"HA coat"in modulating stemness and endocrine resistance in ER+breast cancer
Shiyi WU ; Si CHEN ; Bohan LIU ; Yuting LIU ; Yiwen LIU ; Yiqing HE ; Yan DU ; Guoliang ZHANG ; Qian GUO ; Feng GAO ; Cuixia YANG
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(10):1298-1307
Objective·To determine hyaluronan(HA)expression in the endocrine-resistant microenvironment of estrogen receptor-positive(ER+)breast cancer and elucidate its impact on the acquired resistance.Methods·Chemiluminescent immunoassay was used to quantify HA levels in the culture supernatants of fulvestrant-resistant breast cancer cells.An immunofluorescence(IF)assay was performed to visualize the colocalization of CD44 and HA in MCF7/FulR cells.Using an established adaptive endocrine-resistant breast cancer mouse model,HA expression in resistant breast cancer tissues was assessed by immunohistochemistry(IHC)assay.Single-cell RNA sequencing(scRNA-seq)and RNA sequencing(RNA-seq)were conducted to examine transcriptomic profiles and alterations in HA-related genes in resistant breast cancer cells.Flow cytometry(FCM)was utilized to measure the proportion of CD44+CD24-cells in MCF7/FulR.The correlation between HA synthesis genes and cell stemness was investigated in clinical ER+breast cancers from GEO data sets.Hyaluronidase(HAase)treatment was applied to remove the"HA coat",and RT-qPCR and Western blotting analysis were carried out to monitor changes in stemness-related molecules.CCK-8 assays,flow cytometry(FCM),and Hoechst 33258 staining were performed to determine changes in apoptosis and fulvestrant efficiency after HAase treatment.Results·IF results revealed that compared with MCF7 cells,the"HA coat"on the surface of MCF7/FulR cells was significantly thickened.IHC demonstrated markedly increased HA retention in fulvestrant-resistant mouse breast cancer tissues.ScRNA-seq and RNA-seq analyses indicated elevated expression of stemness-related genes and HA synthesis-associated genes in fulvestrant-resistant breast cancer cells.Correlation analysis revealed a positive association between HA synthesis and cancer stemness in ER+breast cancer.IF and RT-qPCR results demonstrated that removing the HA coating from the surface of MCF7/FulR cells led to a significant reduction in the expression of stemness-related molecules;concurrently,CCK-8 assays,FCM analysis,and Hoechst 33258 staining revealed that"HA coat"clearance reduced MCF7/FulR'tolerance to fulvestrant and increased apoptosis.Conclusion·Endocrine-resistant breast cancer cells develop an enriched"HA coat",which promotes stemness in fulvestrant-resistant tumors.Disruption of this HA coat through HAase treatment effectively reduces cell stemness,induces apoptosis,and re-sensitizes breast cancer cells to fulvestrant.
2.Role of"HA coat"in modulating stemness and endocrine resistance in ER+breast cancer
Shiyi WU ; Si CHEN ; Bohan LIU ; Yuting LIU ; Yiwen LIU ; Yiqing HE ; Yan DU ; Guoliang ZHANG ; Qian GUO ; Feng GAO ; Cuixia YANG
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(10):1298-1307
Objective·To determine hyaluronan(HA)expression in the endocrine-resistant microenvironment of estrogen receptor-positive(ER+)breast cancer and elucidate its impact on the acquired resistance.Methods·Chemiluminescent immunoassay was used to quantify HA levels in the culture supernatants of fulvestrant-resistant breast cancer cells.An immunofluorescence(IF)assay was performed to visualize the colocalization of CD44 and HA in MCF7/FulR cells.Using an established adaptive endocrine-resistant breast cancer mouse model,HA expression in resistant breast cancer tissues was assessed by immunohistochemistry(IHC)assay.Single-cell RNA sequencing(scRNA-seq)and RNA sequencing(RNA-seq)were conducted to examine transcriptomic profiles and alterations in HA-related genes in resistant breast cancer cells.Flow cytometry(FCM)was utilized to measure the proportion of CD44+CD24-cells in MCF7/FulR.The correlation between HA synthesis genes and cell stemness was investigated in clinical ER+breast cancers from GEO data sets.Hyaluronidase(HAase)treatment was applied to remove the"HA coat",and RT-qPCR and Western blotting analysis were carried out to monitor changes in stemness-related molecules.CCK-8 assays,flow cytometry(FCM),and Hoechst 33258 staining were performed to determine changes in apoptosis and fulvestrant efficiency after HAase treatment.Results·IF results revealed that compared with MCF7 cells,the"HA coat"on the surface of MCF7/FulR cells was significantly thickened.IHC demonstrated markedly increased HA retention in fulvestrant-resistant mouse breast cancer tissues.ScRNA-seq and RNA-seq analyses indicated elevated expression of stemness-related genes and HA synthesis-associated genes in fulvestrant-resistant breast cancer cells.Correlation analysis revealed a positive association between HA synthesis and cancer stemness in ER+breast cancer.IF and RT-qPCR results demonstrated that removing the HA coating from the surface of MCF7/FulR cells led to a significant reduction in the expression of stemness-related molecules;concurrently,CCK-8 assays,FCM analysis,and Hoechst 33258 staining revealed that"HA coat"clearance reduced MCF7/FulR'tolerance to fulvestrant and increased apoptosis.Conclusion·Endocrine-resistant breast cancer cells develop an enriched"HA coat",which promotes stemness in fulvestrant-resistant tumors.Disruption of this HA coat through HAase treatment effectively reduces cell stemness,induces apoptosis,and re-sensitizes breast cancer cells to fulvestrant.
3.Establishment and validation of a risk prediction model for pulmonary embolism in severe burn patients
Shengpan JIANG ; Xiaoqing GAO ; Xiagang LUAN ; Yiqing TAN
Chinese Journal of Burns 2024;40(12):1114-1122
Objective:To screen the risk factors for pulmonary embolism in severe burn patients, based on which, a risk prediction model was established and validated.Methods:This study was a retrospective case series study. The clinical data of 267 severe burn patients who met the inclusion criteria and were admitted to the Department of Burns of Wuhan Third Hospital from March 2020 to March 2023 were collected, including 159 males and 108 females, aged 18-82 years. The patients were divided into pulmonary embolism group (26 cases) and non-pulmonary embolism group (241 cases) according to whether they were complicated with pulmonary embolism. The following data of patients in the 2 groups were collected and compared, including gender, age, body mass index, bedtime during treatment, cause of burn, albumin level on admission, combination of chronic obstructive pulmonary disease (COPD), combination of diabetes mellitus, combination of hypertension, combination of inhalation injury, and the abbreviated burn severity index (ABSI) on admission. The indicators with statistically significant differences between the two groups were conducted with univariate and multivariate logistic regression analyses to identify the independent risk factors for pulmonary embolism in 267 severe burn patients. Based on these findings, a nomogram prediction model was established. The performance of the prediction model was evaluated by the receiver operating characteristic (ROC) curve, while its validation was conducted through calibration curve and clinical decision curve analysis.Results:The proportions of beyond 60 years old, bedtime over 7 days during treatment, combination of COPD, and combination of diabetes mellitus (with χ2 values of 7.75, 29.15, 29.86, and 5.94, respectively), and ABSI score on admission ( t=6.01) of patients in pulmonary embolism group were significantly higher than those in non-pulmonary embolism group ( P<0.05). There were no statistically significant differences in the other indicators between the two groups of patients ( P>0.05). The univariate logistic regression analysis showed that age, bedtime during treatment, combination of COPD, combination of diabetes mellitus, and ABSI score on admission were the risk factors for pulmonary embolism in severe burn patients (with odds ratios of 3.40, 14.87, 17.78, 2.80, and 1.88, respectively, 95% confidence intervals of 1.38-8.39, 4.34-50.98, 4.63-68.22, 1.19-6.58, and 1.47-2.41, respectively, P<0.05). The multivariate logistic regression analysis showed that bedtime over 7 days during treatment, combination of COPD, and high ABSI score on admission were the independent risk factors for pulmonary embolism in severe burn patients (with odds ratios of 11.02, 30.82, and 1.86, respectively, 95% confidence intervals of 2.76-43.98, 3.55-267.33, and 1.38-2.50, respectively, P<0.05). Based on the three aforementioned independent risk factors, a nomogram prediction model for the risk of pulmonary embolism in severe burn patients was established. The ROC curve of prediction model showed that the area under the ROC curve was 0.91 (with 95% confidence interval of 0.82-0.99). When the optimal cut-off value of 25% was taken, the sensitivity and specificity of prediction model was 84.6% and 93.4%, respectively. The calibration curve showed that the calibration curve of prediction model was around the ideal curve, with a consistency index of 0.80 in Cox regression (with 95% confidence interval of 0.74-0.87). The clinical decision curve showed that the threshold probability value of the prediction model was in the range of 1% to 98%, with net return rate over 0. Conclusions:The independent risk factors for pulmonary embolism in severe burn patients include bedtime over 7 days during treatment, combination of COPD, and high ABSI score on admission. The nomogram prediction model established based on this has good predictive value for complicated pulmonary embolism in severe burn patients.
4.Summary of best evidences for oral health management in community elderly people
Yiqing LIANG ; Songhai CAO ; Huiling XU ; Peng GAO ; Jingjing WANG ; Yimeng FAN
Chongqing Medicine 2024;53(2):270-275
Objective To retrieve,evaluate and summarize the relevant evidences of oral health manage-ment in the community elderly people to provide reference for community medical staffs.Methods The evi-dences on oral health management of the comunity elderly people were systematically retrieved from various guide websites and Chinese and English databases.The retrieval limit was from the database establishment to September 2021.The research group conducted the evaluation and extracted the evidences according to the rel-evant literature evaluation criteria.Results A total of 17 literatures were included,including 5 guidelines,4 expert consensuses and 8 systematic reviews.A total of 28 pieces of evidences were summarized from the five aspects of assessment and examination,daily life management,management of special oral problems,denture management,and education and training.Conclusion Community medical staffs should fully consider the clin-ical situation,department resources and patient wishes,and conduct the evidence application to increase the o-ral health level of the community elderly people.
5.Quality assessment of global obstructive sleep apnea guidelines
Yiqing GAO ; Yu PENG ; Huajun XU ; Hongliang YI ; Jian GUAN ; Shankai YIN
Journal of Shanghai Jiaotong University(Medical Science) 2024;44(2):237-249
Objective·To evaluate the quality of clinical practice guidelines of obstructive sleep apnea(OSA)published worldwide.Methods·The guidelines of OSA were retrieved in PubMed,Embase,China National Knowledge Infrastructure(CNKI),Wanfang Data,SinoMed,MedSci,The Cochrane Library,and the websites such as Medlive,U.S.Preventive Services Task Force(USPSTF),National Institute for Health and Care Excellence(NICE),New Zealand Guidelines Group(NZGG),Scottish Intercollegiate Guidelines Network(SIGN),and Guidelines International Network(GIN)from establishment to December 2022.Two reviewers screened the literature and extracted the main information independently,using the Appraisal of Guidelines for Research and Evaluation Ⅱ(AGREE Ⅱ)and Reporting Items for Practice Guidelines in Healthcare(RIGHT)to evaluate the quality of the included OSA guidelines.Subgroup analysis was performed according to the publication regions of guidelines.The inter-evaluator consistency test was also performed and the results were expressed as the intra-class correlation coefficient(ICC).All the included guidelines were read entirely and the clinical questions they raised were summarized.Results·A total of 35 OSA guidelines were included.The ICC value of 0.975 showed a good inter-evaluator agreement.The results of AGREE Ⅱ showed that the average score of all guidelines was(63.60±16.45)%,with a minimum of 23.40%and a maximum of 91.67%.In the six domains,the scores of"Rigor of development"[(56.07±25.89)%]and"Applicability"[(53.57±15.52)%]were relative low.The average reporting rate of RIGHT of all the included guidelines was(67.84±20.03)%,with a minimum of 14.29%and a maximum of 94.29%,and the three domains with the lowest reporting rates were"Review and quality assurance"[(31.40±45.51)%],"Funding and conflict of interest declaration and management"[(56.43±33.95)%]and"Other aspects"[(56.19±36.85)%].Subgroup analysis showed that guidelines in Asian had a lower score in"Rigor of development"and a lower overall score of AGREE Ⅱ than the guidelines in America and Europe(both P<0.05),and the reporting rates in the domains of"Evidence"and"Other information"of RIGHT of the Asian guidelines were also lower than those in the guidelines in America and Europe(P<0.05).These guidelines focused on 42 clinical questions which were classified to 3 aspects,i.e.screening and diagnosis,treatment and long-term management of OSA.Conclusion·The quality of current global OSA guidelines varies a lot,and they need to be strengthened in terms of rigor of development,applicability,review and quality assurance,funding and conflict of interest declaration and management,especially those in Asia.
6.Mechanism of intestinal injury induced by acute diquat poisoning in rats
Jianshuang ZHANG ; Yiqing SUN ; Hengbo GAO ; Lin YUAN ; Dongqi YAO ; Liang LIU ; Baopu LYU ; Yingping TIAN
Chinese Critical Care Medicine 2024;36(3):293-297
Objective:To investigate the effects of diquat (DQ) on the expression of intestinal pyroptosis-related proteins and tight junction proteins in rats, and to analyze the role of pyroptosis in the intestinal injury of rats with acute DQ poisoning.Methods:A total of 36 Wistar male rats were randomly divided into control group, and 3 hours, 12 hours, 36 hours and 3 days exposure groups, with 6 rats in each group. Each exposure group was given 1/2 median lethal dose (LD50) of 115.5 mg/kg DQ by one-time gavage. The control group was given the same amount of normal saline by gavage. The control group was anesthetized at 3 hours after DQ gavage to take jejunal tissues; each exposure group was anesthetized at 3 hours, 12 hours, 36 hours, and 3 days after DQ gavage to take jejunal tissues, respectively. The general conditions of the rats were recorded. The pathological changes of jejunum tissue were observed by hematoxylin-eosin (HE) staining. The expression of intestinal pyroptosis-related proteins [NOD-like receptor protein 3 (NLRP3), cysteine aspartate-specific protease 1 (caspase-1), Gasdemin D (GSDMD)] in the intestinal tissues was observed by immunohistochemical staining. Western blotting was used to detect the expression of intestinal pyroptosis-related proteins and intestinal tight junction proteins (Occludin and Claudin-1).Results:Light microscopy showed that pathological changes occurred in jejunum tissue at the early stage of exposure (3 hours), and the injury was the most serious in the 12 hours exposure group, with a large number of inflammatory cells infiltrating in the tissue, and the damage was significantly reduced after 3 days exposure. Immunohistochemical results showed that NLRP3, caspase-1 and GSDMD were expressed in the jejunal mucosa of the control group and the exposure groups, and the positive cells in the control group were less expressed with light staining. The expression of the above proteins in the exposed group was increased significantly and the staining was deep. Western blotting results showed that compared with the control group, the expression of NLRP3 protein in jejunum tissues of all groups was increased, with the most significant increase in the 36 hours group (NLRP3/β-actin: 1.47±0.06 vs. 0.43±0.14, P < 0.01). Compared with the control group, the expression of GSDMD protein in the 3 hours, 12 hours and 36 hours exposure groups increased, and the expression of GSDMD protein in the 3 hours and 12 hours exposure groups increased significantly (GSDMD/β-actin: 1.04±0.40, 1.25±0.15 vs. 0.65±0.25, both P < 0.05). The expression of caspase-1 protein was increased in 36 hours exposure group compared with the control group (caspase-1/β-actin: 1.44±0.34 vs. 0.98±0.19, P > 0.05). Compared with the control group, the expression of Occludin and Claudin-1 proteins in each exposure group decreased, and the expression of Occludin proteins was significantly decreased in the 3 hours, 12 hours, and 36 hours exposure groups decreased significantly (Occludin/β-actin: 0.74±0.17, 0.91±0.20, 0.79±0.23 vs. 1.41±0.08, all P < 0.05). Although the protein expression of Claudin-1 decreased in each exposure group, the difference was not statistically significant. Conclusion:The intestinal injury caused by acute DQ poisoning may be related to the activation of pyroptosis pathway of small intestinal cells and the reduction of the density of intercellular junctions.
7.Analysis of the factors influencing the pregnancy rate after fallopian tube recanalization and its nomogram model validation
Shengpan JIANG ; Shilin ZHENG ; Xiaoqing GAO ; Yiqing TAN
Journal of Interventional Radiology 2024;33(8):860-864
Objective To explore the factors influencing the pregnancy rate after fallopian tube recanalization(FTR),and to construct and validate a nomogram prediction model.Methods The clinical data of a total of 322 female patients with tubal obstructive infertility,who received FTR at the Wuhan Municipal Third Hospital of China between January 2018 and December 2022,were retrospectively analyzed.According to whether the female patient had natural pregnancy or not within 12 months after FTR treatment,the female patients were divided into the pregnant group and the non-pregnant group.Logistic regression analysis was used to determine the independent factors influencing pregnancy.The female patients were randomly divided into training group and validation group at 1∶1 ratio.A nomogram model was constructed in the training group,and the predictive efficacy of the model was verified in the validation group by using receiver operating characteristic(ROC)curves,calibration curves and decision curve analysis(DCA).Results The natural pregnancy rate at one year after FTR was 45.34%(146/322).Age>35 years,primary infertility,duration of infertility>3 years,distal fallopian tube obstruction,and moderate to severe tubal lesion were the independent risk factors affecting the pregnancy rate after FTR(all P<0.05).The constructed nomogram model had a good differentiation and calibration ability and it carried a high degree of clinical utility.Conclusion The nomogram model constructed in this study can effectively predict the risk of infertility within one year after FTR treatment,which is helpful for formulating the individualized therapeutic scheme for infertility female patients.
8.Analysis of the Clinical Characteristics and Risk Factors for Deep Venous Thrombosis of Lower Limbs in Burn Patients
Shengpan JIANG ; Xiaoqing GAO ; Yiqing TAN
Acta Medicinae Universitatis Scientiae et Technologiae Huazhong 2024;53(5):670-675
Objective To investigate the clinical features and risk factors for deep vein thrombosis(DVT)of the lower ex-tremities in burn patients.Methods The clinical data of 155 burn patients admitted to Wuhan Third Hospital from January 2021 to January 2023 were retrospectively analyzed.The patients were divided into DVT group and non-DVT group according to whether they had concurrent DVT during hospitalization.Two groups of baseline data were compared[sex,age,body mass in-dex(BMI),coexisting diseases,smoking,drinking,DVT history of the lower limbs,burn cause,burn site,burn degree,central venous catheter retention in the femoral vein,wound infection,low-molecular-weight heparin application,time in bed,and labora-tory indicators[D-dimer(D-d),fibrinogen(FIB),homocysteine(Hey)].The levels of tumor necrosis factor α(TNF-α)and C-reac-tive protein(CRP)differed,and the risk factors for DVT in burn patients were determined via multivariate logistic regression a-nalysis.Finally,this study analyzed the value of BMI,time in bed,D-dimer,fibrinogen,Hcy,TNF-α,and CRP in predicting DVT in burn patients via receiver operating characteristic(ROC)curves.Results There were no significant differences between the two groups in terms of sex,combined disease,smoking or drinking,or cause of burn(all P>0.05).The following risk factors were found to be significantly greater in the group with deep vein thrombosis(DVT)than in the group without DVT:age 60 years or older,history of lower limb DVT,lower limb burn of degree Ⅱ or above covering 30%or more of the area,femoral vein indentation central venous catheter,wound infection,and lack of low-molecular-weight heparin treatment.Additionally,BMI,D-dimer levels,fibrinogen levels(FIB),homocysteine(Hcy)levels,TNF-α levels,and C-reactive protein(CRP)levels were signifi-cantly higher in the DVT group than in the non-DVT group.The time in bed was significantly longer in the DVT group than in the non-DVT group(P<0.01).Multivariate logistic regression analysis confirmed that the risk factors for DVT in burn pa-tients included age ≥60 years,history of lower extremity DVT,lower extremity burn,burn degree Ⅱ or above,burn area≥30%,femoral vein indwelling central venous catheter,wound inf ection,lack of low-molecular-weight heparin application,increased BMI,elevated levels of D-dimer,FIB,Hcy,TNF-α,and CRP,and prolonged time in bed.ROC analysis confirmed that BMI,time in bed,D-d,FIB,Hcy,TNF-α and CRP could all be used to predict DVT in burn patients,and the areas under the curve were 0.844,0.853,0.890,0.817,0.892,0.962 and 0.776,respectively,(all P<0.01).Conclusion Burn patients complicated with DVT are affected by many factors.Moreover,ROC analysis confirmed that BMI,time in bed,D-d,FIB,Hcy,TNF-α and CRP could be indicators for predic-ting DVT,which should be considered in the subsequent clinical treatment of such patients.
9.Establishment and validation of a risk prediction model for pulmonary embolism in severe burn patients
Shengpan JIANG ; Xiaoqing GAO ; Xiagang LUAN ; Yiqing TAN
Chinese Journal of Burns 2024;40(12):1114-1122
Objective:To screen the risk factors for pulmonary embolism in severe burn patients, based on which, a risk prediction model was established and validated.Methods:This study was a retrospective case series study. The clinical data of 267 severe burn patients who met the inclusion criteria and were admitted to the Department of Burns of Wuhan Third Hospital from March 2020 to March 2023 were collected, including 159 males and 108 females, aged 18-82 years. The patients were divided into pulmonary embolism group (26 cases) and non-pulmonary embolism group (241 cases) according to whether they were complicated with pulmonary embolism. The following data of patients in the 2 groups were collected and compared, including gender, age, body mass index, bedtime during treatment, cause of burn, albumin level on admission, combination of chronic obstructive pulmonary disease (COPD), combination of diabetes mellitus, combination of hypertension, combination of inhalation injury, and the abbreviated burn severity index (ABSI) on admission. The indicators with statistically significant differences between the two groups were conducted with univariate and multivariate logistic regression analyses to identify the independent risk factors for pulmonary embolism in 267 severe burn patients. Based on these findings, a nomogram prediction model was established. The performance of the prediction model was evaluated by the receiver operating characteristic (ROC) curve, while its validation was conducted through calibration curve and clinical decision curve analysis.Results:The proportions of beyond 60 years old, bedtime over 7 days during treatment, combination of COPD, and combination of diabetes mellitus (with χ2 values of 7.75, 29.15, 29.86, and 5.94, respectively), and ABSI score on admission ( t=6.01) of patients in pulmonary embolism group were significantly higher than those in non-pulmonary embolism group ( P<0.05). There were no statistically significant differences in the other indicators between the two groups of patients ( P>0.05). The univariate logistic regression analysis showed that age, bedtime during treatment, combination of COPD, combination of diabetes mellitus, and ABSI score on admission were the risk factors for pulmonary embolism in severe burn patients (with odds ratios of 3.40, 14.87, 17.78, 2.80, and 1.88, respectively, 95% confidence intervals of 1.38-8.39, 4.34-50.98, 4.63-68.22, 1.19-6.58, and 1.47-2.41, respectively, P<0.05). The multivariate logistic regression analysis showed that bedtime over 7 days during treatment, combination of COPD, and high ABSI score on admission were the independent risk factors for pulmonary embolism in severe burn patients (with odds ratios of 11.02, 30.82, and 1.86, respectively, 95% confidence intervals of 2.76-43.98, 3.55-267.33, and 1.38-2.50, respectively, P<0.05). Based on the three aforementioned independent risk factors, a nomogram prediction model for the risk of pulmonary embolism in severe burn patients was established. The ROC curve of prediction model showed that the area under the ROC curve was 0.91 (with 95% confidence interval of 0.82-0.99). When the optimal cut-off value of 25% was taken, the sensitivity and specificity of prediction model was 84.6% and 93.4%, respectively. The calibration curve showed that the calibration curve of prediction model was around the ideal curve, with a consistency index of 0.80 in Cox regression (with 95% confidence interval of 0.74-0.87). The clinical decision curve showed that the threshold probability value of the prediction model was in the range of 1% to 98%, with net return rate over 0. Conclusions:The independent risk factors for pulmonary embolism in severe burn patients include bedtime over 7 days during treatment, combination of COPD, and high ABSI score on admission. The nomogram prediction model established based on this has good predictive value for complicated pulmonary embolism in severe burn patients.
10.Experimental study on the toxicokinetics and gastrointestinal damage in rats poisoned with acute diquat poisoning at different exposure doses.
Jianshuang ZHANG ; Yiqing SUN ; Hengbo GAO ; Lin YUAN ; Dongqi YAO ; Liang LIU ; Baopu LYU ; Yingping TIAN
Chinese Critical Care Medicine 2023;35(6):651-657
OBJECTIVE:
To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ).
METHODS:
Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated.
RESULTS:
DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin.
CONCLUSIONS
The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.
Animals
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Male
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Rats
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Diquat/toxicity*
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Gastrointestinal Diseases
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Intestines
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Poisons
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Rats, Wistar
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Toxicokinetics

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