2.Prognosis and influencing factors analysis of patients with initially resectable gastric cancer liver metastasis who were treated by different modalities: a nationwide, multicenter clinical study
Li LI ; Yunhe GAO ; Liang SHANG ; Zhaoqing TANG ; Kan XUE ; Jiang YU ; Yanrui LIANG ; Zirui HE ; Bin KE ; Hualong ZHENG ; Hua HUANG ; Jianping XIONG ; Zhongyuan HE ; Jiyang LI ; Tingting LU ; Qiying SONG ; Shihe LIU ; Hongqing XI ; Yun TANG ; Zhi QIAO ; Han LIANG ; Jiafu JI ; Lin CHEN
Chinese Journal of Digestive Surgery 2024;23(1):114-124
Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.
3.Protective mechanism of rhubarb decoction against inflammatory damage of brain tissue in rats with mild hepatic encephalopathy: A study based on the PI3K/AKT/mTOR signaling pathway
Guangfa ZHANG ; Yingying CAI ; Long LIN ; Lei FU ; Fan YAO ; Meng WANG ; Rongzhen ZHANG ; Yueqiao CHEN ; Liangjiang HUANG ; Han WANG ; Yun SU ; Yanmei LAN ; Yingyu LE ; Dewen MAO ; Chun YAO
Journal of Clinical Hepatology 2024;40(2):312-318
ObjectiveTo investigate the role and possible mechanism of action of rhubarb decoction (RD) retention enema in improving inflammatory damage of brain tissue in a rat model of mild hepatic encephalopathy (MHE). MethodsA total of 60 male Sprague-Dawley rats were divided into blank group (CON group with 6 rats) and chronic liver cirrhosis modeling group with 54 rats using the complete randomization method. After 12 weeks, 40 rats with successful modeling which were confirmed to meet the requirements for MHE model by the Morris water maze test were randomly divided into model group (MOD group), lactulose group (LT group), low-dose RD group (RD1 group), middle-dose RD group (RD2 group), and high-dose RD group (RD3 group), with 8 rats in each group. The rats in the CON group and the MOD group were given retention enema with 2 mL of normal saline once a day; the rats in the LT group were given retention enema with 2 mL of lactulose at a dose of 22.5% once a day; the rats in the RD1, RD2, and RD3 groups were given retention enema with 2 mL RD at a dose of 2.5, 5.0, and 7.5 g/kg, respectively, once a day. After 10 days of treatment, the Morris water maze test was performed to analyze the spatial learning and memory abilities of rats. The rats were analyzed from the following aspects: behavioral status; the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) and the level of blood ammonia; pathological changes of liver tissue and brain tissue; the mRNA and protein expression levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR) in brain tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the MOD group, the RD1, RD2, and RD3 groups had a significantly shorter escape latency (all P<0.01), significant reductions in the levels of ALT, AST, IL-1β, IL-6, TNF-α, and blood ammonia (all P<0.05), significant alleviation of the degeneration, necrosis, and inflammation of hepatocytes and brain cells, and significant reductions in the mRNA and protein expression levels of PI3K, AKT, and mTOR in brain tissue (all P<0.05), and the RD3 group had a better treatment outcome than the RD1 and RD2 groups. ConclusionRetention enema with RD can improve cognitive function and inflammatory damage of brain tissue in MHE rats, possibly by regulating the PI3K/AKT/mTOR signaling pathway.
4.Study on Rapid Detection Methods of Acid Yellow 36 in Moxibustion
Peijing ZHAO ; Lin CHEN ; Ying SONG ; Zhong' ; e LI ; Han HUANG
Chinese Journal of Modern Applied Pharmacy 2024;41(11):1524-1528
OBJECTIVE
To establish a rapid method for determining of acid yellow 36 in moxibustion.
METHODS
Based on the principle of acid yellow 36 as an acid-base indicator and discoloration in the pH range of 1.2(red) to 2.3(yellow), 15% sulfuric acid solution was used as the color developing agent to screen the ethanol extract of the sample, and then HPLC method was used to verify the suspicious positive samples in the initial screening, and finally LC-MS method was used to confirm the accuracy of the established rapid physicochemical detection method.
RESULTS
The established method was applied to 67 batches of samples, and 3 positive samples were detected. The results were consistent with those of HPLC and LC-MS.
CONCLUSION
The method is accurate and sensitive, which can be used for rapid detection of acid yellow 36 in moxibustion.
5.Application of quality monitoring indicators of blood testing in blood banks of Shandong province
Xuemei LI ; Weiwei ZHAI ; Zhongsi YANG ; Shuhong ZHAO ; Yuqing WU ; Qun LIU ; Zhe SONG ; Zhiquan RONG ; Shuli SUN ; Xiaojuan FAN ; Wei ZHANG ; Jinyu HAN ; Lin ZHU ; Xianwu AN ; Hui ZHANG ; Junxia REN ; Xuejing LI ; Chenxi YANG ; Bo ZHOU ; Haiyan HUANG ; Guangcai LIU ; Ping CHEN ; Hui YE ; Mingming QIAO ; Hua SHEN ; Dunzhu GONGJUE ; Yunlong ZHUANG
Chinese Journal of Blood Transfusion 2024;37(3):258-266
【Objective】 To objectively evaluate the quality control level of blood testing process in blood banks through quantitative monitoring and trend analysis, and to promote the homogenization level and standardized management of blood testing laboratories in blood banks. 【Methods】 A quality monitoring indicator system covering the whole process of blood collection and supply, including blood donation service, blood component preparation, blood testing, blood supply and quality control was established. The questionnaire Quality Monitoring Indicators for Blood Collection and Supply Process with clear definition of indicators and calculation formulas was distributed to 17 blood banks in Shandong province. Quality monitoring indicators of each blood bank from January to December 2022 were collected, and 31 indicators in terms of blood testing were analyzed using SPSS25.0 software. 【Results】 The proportion of unqualified serological tests in 17 blood bank laboratories was 55.84% for ALT, 13.63% for HBsAg, 5.08% for anti HCV, 5.62% for anti HIV, 18.18% for anti TP, and 1.65% for other factors (mainly sample quality). The detection unqualified rate and median were (1.23±0.57)% and 1.11%, respectively. The ALT unqualified rate and median were (0.74±0.53)% and 0.60%, respectively. The detection unqualified rate was positively correlated with ALT unqualified rate (r=0.974, P<0.05). The unqualified rate of HBsAg, anti HCV, anti HIV and anti TP was (0.15±0.09)%, (0.05±0.04)%, (0.06±0.03)% and (0.20±0.05)% respectively. The average unqualified rate, average hemolysis rate, average insufficient volume rate and the abnormal hematocrit rate of samples in 17 blood bank laboratories was 0.21‰, 0.08‰, 0.01‰ and 0.02‰ respectively. There were differences in the retest concordance rates of four HBsAg, anti HCV and anti HIV reagents, and three anti TP reagents among 17 blood bank laboratories (P<0.05). The usage rate of ELISA reagents was (114.56±3.30)%, the outage rate of ELISA was (10.23±7.05) ‰, and the out of range rate of ELISA was (0.90±1.17) ‰. There was no correlation between the out of range rate, outrage rate and usage rate (all P>0.05), while the outrage rate was positively correlated with the usage rate (r=0.592, P<0.05). A total of 443 HBV DNA positive samples were detected in all blood banks, with an unqualified rate of 3.78/10 000; 15 HCV RNA positive samples were detected, with an unqualified rate of 0.13/10 000; 5 HIV RNA positive samples were detected, with an unqualified rate of 0.04/10 000. The unqualified rate of NAT was (0.72±0.04)‰, the single NAT reaction rate [(0.39±0.02)‰] was positively correlated with the single HBV DNA reaction rate [ (0.36±0.02) ‰] (r=0.886, P<0.05). There was a difference in the discriminated reactive rate by individual NAT among three blood bank laboratories (C, F, H) (P<0.05). The median resolution rate of 17 blood station laboratories by minipool test was 36.36%, the median rate of invalid batch of NAT was 0.67%, and the median rate of invalid result of NAT was 0.07‰. The consistency rate of ELISA dual reagent detection results was (99.63±0.24)%, and the median length of equipment failure was 14 days. The error rate of blood type testing in blood collection department was 0.14‰. 【Conclusion】 The quality monitoring indicator system for blood testing process in Shandong can monitor potential risks before, during and after the experiment, and has good applicability, feasibility, and effectiveness, and can facilitate the continuous improvement of laboratory quality control level. The application of blood testing quality monitoring indicators will promote the homogenization and standardization of blood quality management in Shandong, and lay the foundation for future comprehensive evaluations of blood banks.
6.Application of quality control indicator system in blood banks of Shandong
Qun LIU ; Yuqing WU ; Xuemei LI ; Zhongsi YANG ; Zhe SONG ; Zhiquan RONG ; Shuhong ZHAO ; Lin ZHU ; Xiaojuan FAN ; Shuli SUN ; Wei ZHANG ; Jinyu HAN ; Xuejing LI ; Bo ZHOU ; Chenxi YANG ; Haiyan HUANG ; Guangcai LIU ; Kai CHEN ; Xianwu AN ; Hui ZHANG ; Junxia REN ; Hui YE ; Mingming QIAO ; Hua SHEN ; Dunzhu GONGJUE ; Yunlong ZHUANG
Chinese Journal of Blood Transfusion 2024;37(3):267-274
【Objective】 To establish an effective quality monitoring indicator system for blood quality control in blood banks, in order to analyze the quality control indicators for blood collection and supply, and evaluate blood quality control process, thus promoting continuous improvement and standardizing management of blood quality control in blood banks. 【Methods】 A quality monitoring indicator system covering the whole process of blood collection and supply, including blood donation services, component preparation, blood testing, blood supply and quality control was established. The Questionnaire of Quality Monitoring Indicators for Blood Collection and Supply Process was distributed to 17 blood banks in Shandong, which clarified the definition and calculation formula of indicators. The quality monitoring indicator data from January to December 2022 in each blood bank were collected, and 20 quality control indicators data were analyzed by SPSS25.0 software. 【Results】 The average pass rate of key equipment monitoring, environment monitoring, key material monitoring, and blood testing item monitoring of 17 blood banks were 99.47%, 99.51%, 99.95% and 98.99%, respectively. Significant difference was noticed in the pass rate of environment monitoring among blood banks of varied scales(P<0.05), and the Pearson correlation coefficient (r) between the total number of blood quality testing items and the total amount of blood component preparation was 0.645 (P<0.05). The average discarding rates of blood testing or non-blood testing were 1.14% and 3.36% respectively, showing significant difference among blood banks of varied scales (P<0.05). The average discarding rate of lipemic blood was 3.07%, which had a positive correlation with the discarding rate of non testing (r=0.981 3, P<0.05). There was a statistically significant difference in the discarding rate of lipemic blood between blood banks with lipemic blood control measures and those without (P<0.05). The average discarding rate of abnormal color, non-standard volume, blood bag damage, hemolysis, blood protein precipitation and blood clotting were 0.20%, 0.14%, 0.06%, 0.06%, 0.02% and 0.02% respectively, showing statistically significant differences among large, medium and small blood banks(P<0.05).The average discarding rates of expired blood, other factors, confidential unit exclusion and unqualified samples were 0.02%, 0.05%, 0.003% and 0.004%, respectively. The discarding rate of blood with air bubbles was 0.015%, while that of blood with foreign body and unqualified label were 0. 【Conclusion】 The quality control indicator system of blood banks in Shandong can monitor weak points in process management, with good applicability, feasibility, and effectiveness. It is conducive to evaluate different blood banks, continuously improve the quality control level of blood collection and supply, promote the homogenization and standardization of blood quality management, and lay the foundation for comprehensive evaluation of blood banks in Shandong.
7.Quality monitoring indicator system in blood banks of Shandong: applied in blood donation services, component preparation and blood supply process
Yuqing WU ; Hong ZHOU ; Zhijie ZHANG ; Zhiquan RONG ; Xuemei LI ; Zhe SONG ; Shuhong ZHAO ; Zhongsi YANG ; Qun LIU ; Lin ZHU ; Xiaojuan FAN ; Shuli SUN ; Wei ZHANG ; Jinyu HAN ; Haiyan HUANG ; Guangcai LIU ; Ping CHEN ; Xianwu AN ; Hui ZHANG ; Junxia REN ; Xuejing LI ; Chenxi YANG ; Bo ZHOU ; Hui YE ; Mingming QIAO ; Hua SHEN ; Dunzhu GONGJUE ; Yunlong ZHUANG
Chinese Journal of Blood Transfusion 2024;37(3):275-282
【Objective】 To establish an effective quality indicator monitoring system, scientifically and objectively evaluate the quality management level of blood banks, and achieve continuous improvement of quality management in blood bank. 【Methods】 A quality monitoring indicator system that covers the whole process of blood collection and supply was established, the questionnaire of Quality Monitoring Indicators for Blood Collection and Supply Process with clear definition of indicators and calculation formulas was distributed to 17 blood banks in Shandong. Statistical analysis of 21 quality monitoring indicators in terms of blood donation service (10 indicators), blood component preparation (7 indicators ), and blood supply (4 indicators) from each blood bank from January to December 2022 were conducted using SPSS25.0 software The differences in quality monitoring indicators of blood banks of different scales were analyzed. 【Results】 The average values of quality monitoring indicators for blood donation service process of 17 blood banks were as follows: 44.66% (2 233/5 000) of regular donors proportion, 0.22% (11/50) of adverse reactions incidence, 0.46% (23/5 000) of non-standard whole blood collection rate, 0.052% (13/25 000) of missed HBsAg screening rate, 99.42% (4 971/5 000) of first, puncture successful rate, 86.49% (173/200) of double platelet collection rate, 66.50% (133/200) of 400 mL whole blood collection rate, 99.25% (397/400) of donor satisfaction rate, 82.68% (2 067/2 500) of use rate of whole blood collection bags with bypass system with sample tube, and 1 case of occupational exposure in blood collection.There was a strong positive correlation between the proportion of regular blood donors and the collection rate of 400 mL whole blood (P<0.05). The platelet collection rate, incidence of adverse reactions to blood donation, and non-standard whole blood collection rate in large blood banks were significantly lower than those in medium and small blood banks (P<0.05). The average quality monitoring indicators for blood component preparation process of 17 blood banks were as follows: the leakage rate of blood component preparation bags was 0.03% (3/10 000), the discarding rate of lipemic blood was 3.05% (61/2 000), the discarding rate of hemolysis blood was 0.13%(13/10 000). 0.06 case had labeling errors, 8 bags had blood catheter leaks, 2.76 bags had blood puncture/connection leaks, and 0.59 cases had non-conforming consumables. The discarding rate of hemolysis blood of large blood banks was significantly lower than that of medium and small blood banks (P<0.05), and the discarding rate of lipemic blood of large and medium blood banks was significantly lower than that of small blood banks (P<0.05). The average values of quality monitoring indicators for blood supply process of 17 blood banks were as follows: the discarding rate of expired blood was 0.023% (23/100 000), the leakage rate during storage and distribution was of 0.009%(9/100 000), the discarding rate of returned blood was 0.106% (53/50 000), the service satisfaction of hospitals was 99.16% (2 479/2 500). The leakage rate of blood components during storage and distribution was statistically different with that of blood component preparation bags between different blood banks (P<0.05). There were statistically significant differences in the proportion of regular blood donors, incidence of adverse reactions, non-standard whole blood collection rate, 400 mL whole blood collection rate, double platelet collection rate, the blood bag leakage rate during preparation process, the blood components leakage rate during storage and distribution as well as the discarding rate of lipemic blood, hemolysis blood, expired blood and returned blood among large, medium and small blood banks (all P<0.05). 【Conclusion】 The establishment of a quality monitoring indicator system for blood donation services, blood component preparation and blood supply processes in Shandong has good applicability, feasibility and effectiveness. It can objectively evaluate the quality management level, facilitate the continuous improvement of the quality management system, promote the homogenization of blood management in the province and lay the foundation for future comprehensive evaluation of blood banks.
8.Application strategy of the"You Gu Wu Yun"theory to reduce the toxicity of traditional Chinese medicine from the perspective of"traditional Chinese medicine state"
Shijie QIAO ; Zongchen WEI ; Ziyao CAI ; Chao FU ; Shunan LI ; Zhanglin WANG ; Liqing HUANG ; Kang TONG ; Wen TANG ; Zhibin WANG ; Hairui HAN ; Duoduo LIN ; Shaodong ZHANG ; Huangwei LEI ; Yang WANG ; Candong LI
Journal of Beijing University of Traditional Chinese Medicine 2024;47(11):1506-1511
Based on the"You Gu Wu Yun"theory in traditional Chinese medicine(TCM),this paper believes that"Gu"in"You Gu Wu Yun"is extended to"state"from the perspective of"TCM state".In order to avoid the adverse reactions of TCM,the macro,meso,and micro three views should be used together,and macro,meso,and micro parameters should be integrated.We should also carefully identify the physiological characteristics,pathological characteristics,constitution,syndrome,and disease of human body by combining qualitative and quantitative method,highlighting the relationship between the prescription and the"state".The correspondence between prescription and the"state"will reduce the risk of adverse reactions of TCM.In this paper,we hope to focus on the guiding role of the"You Gu Wu Yun"theory in TCM research,to give full play to the characteristics and advantages of TCM,and to dialectically treat the role of TCM.
9.Expert consensus on clinical application of 177Lu-prostate specific membrane antigen radio-ligand therapy in prostate cancer
Guobing LIU ; Weihai ZHUO ; Yushen GU ; Zhi YANG ; Yue CHEN ; Wei FAN ; Jianming GUO ; Jian TAN ; Xiaohua ZHU ; Li HUO ; Xiaoli LAN ; Biao LI ; Weibing MIAO ; Shaoli SONG ; Hao XU ; Rong TIAN ; Quanyong LUO ; Feng WANG ; Xuemei WANG ; Aimin YANG ; Dong DAI ; Zhiyong DENG ; Jinhua ZHAO ; Xiaoliang CHEN ; Yan FAN ; Zairong GAO ; Xingmin HAN ; Ningyi JIANG ; Anren KUANG ; Yansong LIN ; Fugeng LIU ; Cen LOU ; Xinhui SU ; Lijun TANG ; Hui WANG ; Xinlu WANG ; Fuzhou YANG ; Hui YANG ; Xinming ZHAO ; Bo YANG ; Xiaodong HUANG ; Jiliang CHEN ; Sijin LI ; Jing WANG ; Yaming LI ; Hongcheng SHI
Chinese Journal of Clinical Medicine 2024;31(5):844-850,封3
177Lu-prostate specific membrane antigen(PSMA)radio-ligand therapy has been approved abroad for advanced prostate cancer and has been in several clinical trials in China.Based on domestic clinical practice and experimental data and referred to international experience and viewpoints,the expert group forms a consensus on the clinical application of 177Lu-PSMA radio-ligand therapy in prostate cancer to guide clinical practice.
10.Physiological characteristics of Bacillus thuringiensis subspecies israelensis with double mutations of cwlE and sigK and its activity against larvae of Culex pipiens pallens
Lixin HUANG ; Guangjie HAN ; Chuanming LI ; Manman LIN ; Nan ZHANG ; Jian XU
Chinese Journal of Schistosomiasis Control 2024;36(6):606-613
Objective To investigate the physiological characteristics of Bacillus thuringiensis subspecies israelensis (Bti) with double mutations of cwlE and sigK genes and to assess the activity of Bti against larvae of Culex pipiens pallens under different external factors, so as to provide the theoretical evidence for the use of engineered bacteria of Bti for effective mosquito control. Methods B. thuringiensis wild-type strain Bt-59 and Bt-59 strain with cwlE mutation [Bt-59 (ΔcwlE)] were cultured in nutrient broth media for 24 hours, and Bt-59 strains with sigK mutation [Bt-59 (ΔsigK)] and double mutations of cwlE and sigK [Bt-59 (ΔcwlE-sigK)] were cultured in nutrient broth media for 48 hours. Then, 5 μL of culture media were transferred to glass sides, and cell morphology and mother cell lysis were observed under an optical microscope. The optical densities of Bti strain culture media were measured at different time points of culture, and the growth curves of Bt-59, Bt-59 (ΔcwlE), Bt-59 (ΔsigK), and Bt-59 (ΔcwlE-sigK) strains were plotted. The differences in carbon source metabolism of four Bti strains were analyzed using the Biolog microplate culture method, and the metabolic activity of these strains was estimated with average well color development (AWCD). The fermentation media of these four Bti strains were diluted into final concentrations of 2.000, 1.000, 0.500, 0.250, and 0.125 μL/L, and the median lethal concentrations (LC50 values) of these four strains against the third instar larvae of Cx. pipiens pallens were determined. In addition, the fermentation media of Bti strains were processed as follows: pH adjusted to 5, 7 and 9; treated at 30, 40 ℃ and 50 ℃ for 12 hours; and exposed to irradiation with ultraviolet lights for 0 hour and 6 hours. Then, 20 third instar larvae of Cx. pipiens pallens were exposed to the above processed fermentation media at a final concentration of 1 μL/L in 200 mL of water at 26 ℃ for 24 hours, and the mosquito mortality was estimated to evaluate the effects of pH, temperature and ultraviolet irradiation on the larvicidal activity of four Bti strains. Results The growth curves of the Bt-59 strain and its mutants shared a similar changing trend, and both experienced a stable phase 6 hours post-culture. Both spores and crystal proteins were found in Bt-59 and Bt-59 (ΔcwlE) cells, and only crystal proteins were found in Bt-59 (ΔsigK) and Bt-59 (ΔcwlE-sigK) cells. No lysis was found in the cell wall of the Bt-59 (ΔcwlE-sigK) strain, and the crystal protein was embedded in the mother cell. Biolog microplate culture assay showed that the AWCD values of four Bti strains showed a similar changing trend over time, and 33 carbon sources were found to be metabolized by all of the four strains, including dextrin, D-maltose and D-trehalose. The LC50 values of the fermentation media of Bt-59, Bt-59 (ΔcwlE), Bt-59 (ΔsigK), and Bt-59 (ΔcwlE-sigK) strains were 0.60, 0.51, 0.70 μL/L and 0.72 μL/L against Cx. pipiens pallens, respectively. The adjusted mortality of larval Cx. pipiens pallens reduced by 76.60%, 76.00%, 66.67%, and 0 following exposure to the fermentation media of Bt-59, Bt-59 (ΔcwlE), Bt-59 (ΔsigK), and Bt-59 (ΔcwlE-sigK) strains at a pH of 5 relative to at a pH of 7, and the adjusted mortality reduced by 49.02%, 51.06%, 36.36%, and 4.44% following 6-hour exposure to ultraviolet irradiation relative to 0-hour exposure, while the adjusted mortality was 68.33% to 83.33% following treatment with the fermentation media of four Bti strains at different temperatures. Conclusions Bt-59 (ΔcwlE-sigK) strains do not generate spores, and the absence of cwlE and sigK does not affect the growth, carbon source metabolism, and larvicidal activity of Bti strains against larval Cx. pipiens pallens. Cell wall embedding of Bt-59 (ΔcwlE-sigK) strains may protect larvicidal crystal proteins of Bti strains from external environmental factors, including ultraviolet irradiation, and pH alteration.


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