1.Assessment of ochratoxin A exposure in the diets of pregnant women in Shanghai
Kailin LI ; Renjie QI ; Hua CAI ; Xia SONG ; Jingjin YANG ; Danping QIU ; Zhenni ZHU ; Yi HE ; Baozhang LUO ; Hong LIU
Shanghai Journal of Preventive Medicine 2026;38(3):181-186
ObjectiveTo investigate the contamination status of ochratoxin A (OTA) in commercially available food products in Shanghai, and to assess OTA exposure levels and the associated non-carcinogenic and carcinogenic risks among pregnant women by integrating dietary consumption data of this population. MethodsThe levels of OTA contamination in 1 520 food samples collected in Shanghai from 2022 to 2023 were determined using liquid chromatography-tandem mass spectrometry. An exposure assessment model was developed based on the dietary consumption levels of pregnant women from the 2016‒2017 Shanghai Pregnant Women Dietary Monitoring Survey to calculate the estimated daily intake (EDI) of OTA, the margin of exposure for non-carcinogenic toxicity (MOE1), and the margin of exposure for carcinogenic toxicity (MOE2). An MOE1 greater than 200 and an MOE2 greater than 10 000 indicate that the non-carcinogenic toxicity and carcinogenic toxicity resulting from exposure are negligible, respectively. For samples with OTA contamination levels below the limit of detection (LOD), which accounted for more than 80% of the samples, the OTA levels were assigned values of 0 and LOD, respectively, for subsequent calculations. ResultsThe detection rates of OTA in cereals, nuts, dried fruits, and alcohol samples collected in 2022 were 2.03%, 0, 0, and 0, respectively. The OTA detection rates in cereals, nuts, dried fruits, beans, and alcohol samples collected in 2023 were 2.50%, 0.39%, 2.47%, 1.67%, and 13.33%, respectively. For pregnant women in Shanghai in 2022, simulation results indicated that when assigning a value of 0 and the LOD, theP50 values of EDI for dietary OTA exposure were 0.05 and 0.72 ng·(kg·d)-1, respectively, and the P95 values of EDI for dietary OTA exposure were 0.25 and 2.40 ng·(kg·d)-1, respectively. For pregnant women in Shanghai in 2023, the P50 values of EDI for dietary OTA exposure were 0.04 and 1.00 ng·(kg·d)-1, respectively, and the P95 values of EDI for dietary OTA exposure were 0.23 and 2.67 ng·(kg·d)-1, respectively, both substantially below the tolerable daily intake (TDI) for OTA [17 ng·(kg·d)-1]. The EDI for dietary OTA exposure in 100.0% of Shanghai pregnant women was lower than the TDI, indicating an overall low level of dietary OTA exposure among this population. For 100.0% of pregnant women, the MOE₁ for dietary OTA exposure exceeded 200. When assigned a value of 0, the MOE₂ for 100.0% of pregnant women in both 2022 and 2023 exceeded10 000. When assigned the LOD value, 72.3% and 81.8% of pregnant women in 2022 and 2023, respectively, had an MOE₂ exceeding 10 000. ConclusionFrom 2022 to 2023, samples of cereals, nuts, dried fruits, beans, and alcohol sold in Shanghai exhibited varying degrees of OTA contamination. The overall EDI of OTA exposure among pregnant women in Shanghai remained at a low level. The non-carcinogenic and carcinogenic risks associated with OTA exposure were generally low and at controllable levels.
2.Differences in deltamethrin resistance and kdr gene mutation in Culex tritaeniorhynchus population in and outside the Yellow Sea wetland
Xiao-er ZHANG ; Zhi-ming WU ; Ye TIAN ; Qian CUI ; Yu-qian JI ; Huan WANG ; Shu-juan YANG ; Yi-chao ZHAO ; Yu WANG ; Hua-yu YIN ; Yu DING ; Guo-jin YAN ; Min-sen ZHAO ; Shou-gang ZHANG ; Bing-dong SONG ; Hong-na CHEN ; Jian GAO ; Wei-fang YANG ; Yu-fu ZHANG ; Hui LIU ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):101-107
Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.
3.Thermal sensitization of acupoints in patients with knee osteoarthritis: A cross-sectional case-control study.
Jian-Feng TU ; Xue-Zhou WANG ; Shi-Yan YAN ; Yi-Ran WANG ; Jing-Wen YANG ; Guang-Xia SHI ; Wen-Zheng ZHANG ; Li-Na JIN ; Li-Sha YANG ; Dong-Hua LIU ; Li-Qiong WANG ; Bao-Hong MI
Journal of Integrative Medicine 2025;23(3):289-296
OBJECTIVE:
Varied acupoint selections represent a potential cause of the uncertainty surrounding the efficacy of acupuncture for knee osteoarthritis (OA). Skin temperature, a guiding factor for acupoint selection, may help to address this issue. This study explored thermal sensitization of acupoints used for the treatment of knee OA.
METHODS:
This cross-sectional case-control study enrolled cases aged 45-75 years with symptomatic knee OA and age- and gender-matched non-knee OA controls in a 1:1 ratio. All participants underwent infrared thermographic imaging. The primary outcome was the relative skin temperature of acupoint (STA), and the secondary outcome was the absolute STA of 11 acupoints. The Z test was used to compare the relative and absolute STAs between the groups. Principal component analysis was used to extract the common factors (CFs, acupoint cluster) in the STAs. A general linear model was used to identify factors affecting the STA in the knee OA cases. For the group comparisons of relative STA, P < 0.0045 (adjusted for 11 acupoints through Bonferroni correction) was considered to indicate statistical significance. For other analyses, P < 0.05 was used as the threshold for statistical significance.
RESULTS:
The analysis included 308 participants, consisting of 151 cases (mean age: [64.58 ± 6.67] years; male: 25.83%; mean body mass index: [25.70 ± 3.16] kg/m2) and 157 controls (mean age: [63.37 ± 5.96] years; male: 26.11%; mean body mass index: [24.47 ± 2.84] kg/m2). The relative STAs of ST34 (P = 0.0001), EX-LE2 (P < 0.0001), EX-LE5 (P = 0.0006), SP10 (P < 0.0001), BL40 (P = 0.0012) and GB39 (P = 0.0037) were higher in the knee OA group. No difference was found in the STAs of ST35, ST36, SP9, GB33 and GB34. Four CFs were identified for relative STA in both groups. The acupoints within each CF were consistent between the groups. The mean values of the relative STAs across each CF were higher in the knee OA group. In the knee OA cases, no factors were observed to affect the relative STA, while age and gender were found to affect the absolute STA.
CONCLUSION
Among patients with knee OA, thermal sensitization occurs in the acupoints of the lower extremity, exhibiting localized and regional thermal consistencies. The thermally sensitized acupoints that we identified in this study, ST34, SP10, EX-LE2, EX-LE5, GB39 and BL40, may be good choices for the acupuncture treatment of knee OA. Please cite this article as: Tu JF, Wang XZ, Yan SY, Wang YR, Yang JW, Shi GX, Zhang WZ, Jing LN, Yang LS, Liu DH, Wang LQ, Mi BH. Thermal sensitization of acupoints in patients with knee osteoarthritis: A cross-sectional case-control study. J Integr Med. 2025; 23(3): 289-296.
Humans
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Osteoarthritis, Knee/physiopathology*
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Male
;
Cross-Sectional Studies
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Middle Aged
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Female
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Acupuncture Points
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Case-Control Studies
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Aged
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Skin Temperature
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Acupuncture Therapy
4.A Retrospective Study of Pregnancy and Fetal Outcomes in Mothers with Hepatitis C Viremia.
Wen DENG ; Zi Yu ZHANG ; Xin Xin LI ; Ya Qin ZHANG ; Wei Hua CAO ; Shi Yu WANG ; Xin WEI ; Zi Xuan GAO ; Shuo Jie WANG ; Lin Mei YAO ; Lu ZHANG ; Hong Xiao HAO ; Xiao Xue CHEN ; Yuan Jiao GAO ; Wei YI ; Yao XIE ; Ming Hui LI
Biomedical and Environmental Sciences 2025;38(7):829-839
OBJECTIVE:
To investigate chronic hepatitis C virus (HCV) infection's effect on gestational liver function, pregnancy and delivery complications, and neonatal development.
METHODS:
A total of 157 HCV antibody-positive (anti-HCV[+]) and HCV RNA(+) patients (Group C) and 121 anti-HCV(+) and HCV RNA(-) patients (Group B) were included as study participants, while 142 anti-HCV(-) and HCV RNA(-) patients (Group A) were the control group. Data on biochemical indices during pregnancy, pregnancy complications, delivery-related information, and neonatal complications were also collected.
RESULTS:
Elevated alanine aminotransferase (ALT) rates in Group C during early, middle, and late pregnancy were 59.87%, 43.95%, and 42.04%, respectively-significantly higher than Groups B (26.45%, 15.70%, 10.74%) and A (23.94%, 19.01%, 6.34%) ( P < 0.05). Median ALT levels in Group C were significantly higher than in Groups A and B at all pregnancy stages ( P < 0.05). No significant differences were found in neonatal malformation rates across groups ( P > 0.05). However, neonatal jaundice incidence was significantly greater in Group C (75.16%) compared to Groups A (42.25%) and B (57.02%) ( χ 2 = 33.552, P < 0.001). HCV RNA positivity during pregnancy was an independent risk factor for neonatal jaundice ( OR = 2.111, 95% CI 1.242-3.588, P = 0.006).
CONCLUSIONS
Chronic HCV infection can affect the liver function of pregnant women, but does not increase the pregnancy or delivery complication risks. HCV RNA(+) is an independent risk factor for neonatal jaundice.
Humans
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Female
;
Pregnancy
;
Adult
;
Pregnancy Complications, Infectious/epidemiology*
;
Retrospective Studies
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Pregnancy Outcome
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Infant, Newborn
;
Viremia/virology*
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Hepatitis C
;
Hepacivirus/physiology*
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Hepatitis C, Chronic/virology*
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Young Adult
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Alanine Transaminase/blood*
5.Role of miR-140-5p/BCL2L1 in apoptosis and autophagy of HFOB1.19 and effect of Bushen Jianpi Huoxue Decoction.
Tong-Ying CHEN ; Sai FU ; Xiao-Yun LI ; Shu-Hua LIU ; Yi-Fu YANG ; Dong-Sheng YANG ; Yun-Jie ZENG ; Yang-Bo LI ; Dan LUO ; Hong-Xing HUANG ; Lei WAN
China Journal of Chinese Materia Medica 2025;50(3):583-589
Osteoporosis(OP) is a senile bone disease characterized by an imbalance between bone remodeling and bone formation. Targeting pathogenesis of kidney deficiency, spleen deficiency, and blood stasis, Bushen Jianpi Huoxue Decoction has a significant effect on the treatment of OP by tonifying kidney, invigorating spleen, and activating blood circulation. MicroRNA(miRNA) and the anti-apoptotic protein B-cell lymphoma-2-like protein 1(BCL2L1) are closely related to bone cell metabolism. Therefore, in this study, the binding of miR-140-5p to BCL2L1 was detected by dual luciferase assay and polymerase chain reaction(PCR). After silencing or overexpressing miR-140-5p, the apoptosis, autophagy, and osteogenic function of human fetal osteoblast cell line 1.19(HFOB1.19) were observed by flow cytometry and Western blot. Bushen Jianpi Huoxue Decoction-containing serum was prepared by intragastric administration of Bushen Jianpi Huoxue Decoction in rats. Different concentrations of Bushen Jianpi Huoxue Decoction-containing serum were used to treat HFOB1.19 with or without miR-140-5p mimic. The expression of osteogenic proteins in each group was observed, and the role of miR-140-5p/BCL2L1 in apoptosis and autophagy of HFOB1.19 was studied, along with the effect of Bushen Jianpi Huoxue Decoction on these processes. As indicated by the dual luciferase assay, miR-140-5p bound to BCL2L1. Flow cytometry and Western blot showed that miR-140-5p promoted apoptosis and inhibited autophagy in HFOB1.19. After intervention with high, medium, and low doses of Bushen Jianpi Huoxue Decoction-medicated serum, compared with the miR-140-5p NC group, the expression of osteocalcin(OCN), osteopontin(OPN), Runt-related transcription factor 2(RUNX2), and transforming growth factor beta 1(TGF-β1) decreased in the miR-140-5p mimic group, while the expression of bone morphogenetic protein 2(BMP2) showed no significant difference under high-dose intervention. Therefore, miR-140-5p/BCL2L1 can promote apoptosis and inhibit autophagy in HFOB1.19. Bushen Jianpi Huoxue Decoction can affect the osteogenic effect of miR-140-5p through BMP2.
MicroRNAs/metabolism*
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Autophagy/drug effects*
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Apoptosis/drug effects*
;
Humans
;
Drugs, Chinese Herbal/administration & dosage*
;
Animals
;
Cell Line
;
bcl-X Protein/metabolism*
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Osteoblasts/metabolism*
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Rats
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Osteoporosis/physiopathology*
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Male
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Rats, Sprague-Dawley
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Osteogenesis/drug effects*
6.Randomized, double-blind, parallel-controlled, multicenter, equivalence clinical trial of Jiuwei Xifeng Granules(Os Draconis replaced by Ostreae Concha) for treating tic disorder in children.
Qiu-Han CAI ; Cheng-Liang ZHONG ; Si-Yuan HU ; Xin-Min LI ; Zhi-Chun XU ; Hui CHEN ; Ying HUA ; Jun-Hong WANG ; Ji-Hong TANG ; Bing-Xiang MA ; Xiu-Xia WANG ; Ai-Zhen WANG ; Meng-Qing WANG ; Wei ZHANG ; Chun WANG ; Yi-Qun TENG ; Yi-Hui SHAN ; Sheng-Xuan GUO
China Journal of Chinese Materia Medica 2025;50(6):1699-1705
Jiuwei Xifeng Granules have become a Chinese patent medicine in the market. Because the formula contains Os Draconis, a top-level protected fossil of ancient organisms, the formula was to be improved by replacing Os Draconis with Ostreae Concha. To evaluate whether the improved formula has the same effectiveness and safety as the original formula, a randomized, double-blind, parallel-controlled, equivalence clinical trial was conducted. This study enrolled 288 tic disorder(TD) of children and assigned them into two groups in 1∶1. The treatment group and control group took the modified formula and original formula, respectively. The treatment lasted for 6 weeks, and follow-up visits were conducted at weeks 2, 4, and 6. The primary efficacy endpoint was the difference in Yale global tic severity scale(YGTSS)-total tic severity(TTS) score from baseline after 6 weeks of treatment. The results showed that after 6 weeks of treatment, the declines in YGTSS-TSS score showed no statistically significant difference between the two groups. The difference in YGTSS-TSS score(treatment group-control group) and the 95%CI of the full analysis set(FAS) were-0.17[-1.42, 1.08] and those of per-protocol set(PPS) were 0.29[-0.97, 1.56], which were within the equivalence boundary [-3, 3]. The equivalence test was therefore concluded. The two groups showed no significant differences in the secondary efficacy endpoints of effective rate for TD, total score and factor scores of YGTSS, clinical global impressions-severity(CGI-S) score, traditional Chinese medicine(TCM) response rate, or symptom disappearance rate, and thus a complete evidence chain with the primary outcome was formed. A total of 6 adverse reactions were reported, including 4(2.82%) cases in the treatment group and 2(1.41%) cases in the control group, which showed no statistically significant difference between the two groups. No serious suspected unexpected adverse reactions were reported, and no laboratory test results indicated serious clinically significant abnormalities. The results support the replacement of Os Draconis by Ostreae Concha in the original formula, and the efficacy and safety of the modified formula are consistent with those of the original formula.
Adolescent
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Child
;
Child, Preschool
;
Female
;
Humans
;
Male
;
Double-Blind Method
;
Drugs, Chinese Herbal/therapeutic use*
;
Tic Disorders/drug therapy*
;
Treatment Outcome
7.Fangxia Dihuang Formula regulates PERK/eIF2α axis-mediated microglial polarization in treatment of breast cancer complicated by depression.
Hong-Qiao FAN ; Ying-Yi FAN ; Xiao-Hua PEI
China Journal of Chinese Materia Medica 2025;50(14):4015-4025
Study on the mechanism of Fangxia Dihuang Formula(FXDH) in treating breast cancer complicated with depression through the regulation of M1/M2 microglial polarization via the PERK/eIF2α axis. In addition to control group and 4T1 group, a mouse model of breast cancer complicated with depression was established using 4T1 cells combined with corticosterone. The mice were divided into model group, PERK/eIF2α signaling axis agonist(CCT020312, 2 mg·kg~(-1)·d~(-1)) group, CCT020312(2 mg·kg~(-1)·d~(-1)) + FXDH(13.65 g·kg~(-1)·d~(-1)) group, FXDH(13.65 g·kg~(-1)·d~(-1)) group, FXDH(13.65 g·kg~(-1)·d~(-1)) + Capecitabine Tablets(CAP, 390 mg·kg~(-1)·d~(-1)) group, and Fluoxetine Hydrochloride Capsules(FXT, 2.6 mg·kg~(-1)·d~(-1)) + CAP(390 mg·kg~(-1)·d~(-1)) group, with continuous intervention for 21 d. Depression-like behaviors in mice were assessed through sugar preference test and open field test. Hematoxylin-eosin(HE) staining was used to evaluate the morphology of tumor and hippocampal DG region neurons. Nissl staining was employed to detect changes in Nissl bodies in the hippocampal CA3 region. Immunofluorescence was used to observe cluster of differentiation 86(CD86)/ionized calcium-binding adapter molecule 1(Iba-1) and cluster of differentiation 206(CD206)/Iba-1 in hippocampal tissue. Real-time fluorescence quantitative polymerase chain reaction(RT-qPCR) was used to detect the mRNA expression of M1-type microglia [interleukin-6(IL-6), tumor necrosis factor-α(TNF-α)] and M2-type [arginase-1(Arg-1), IL-10] in hippocampal tissue. Western blot was used to detect the protein expression of key factors in the PERK/eIF2α axis, including PERK, eIF2α, activating transcription factor 4(ATF4), and C/EBP homologous protein(CHOP) in hippocampal tissue. The results showed that compared to model group/CCT020312 + FXDH group, FXDH group increased sugar preference index, total movement distance, central zone distance, and central zone entries; reduced tumor mass and volume; tumor cells were sparsely arranged, with a smaller nuclear-to-cytoplasmic ratio and reduced nuclear division figures, increased Nissl body count, and alleviated neuronal nuclear pyknosis; increased CD206-positive M2-type microglia expression, decreased CD86/Iba-1-positive M1-type microglia expression; reduced IL-6 and TNF-α mRNA expression, and increased Arg-1 and IL-10 mRNA expression; downregulated PERK, eIF2α, ATF4, and CHOP protein expression levels. The results indicate that the mechanism of FXDH in treating breast cancer complicated with depression may be related to inhibiting the activity of the PERK/eIF2α axis, reducing the proportion of M1-type microglia, increasing the proportion of M2-type microglia, thereby suppressing neuronal immune inflammation, improving depressive symptoms, and subsequently delaying the progression of breast cancer.
Animals
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Drugs, Chinese Herbal/administration & dosage*
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Female
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Microglia/cytology*
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Mice
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Depression/complications*
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eIF-2 Kinase/genetics*
;
Humans
;
Breast Neoplasms/psychology*
;
Eukaryotic Initiation Factor-2/genetics*
;
Mice, Inbred BALB C
;
Signal Transduction/drug effects*
;
Cell Line, Tumor
9.Thalassemia screening and genotype analysis in 488 sperm donors in Chongqing Human Sperm Bank
Weiqiong SHENG ; Jing HUANG ; Tianfeng ZHANG ; Yi ZHANG ; Hua HUANG ; Hong WANG ; Guoqing JIA ; Chengjiang KANG
Journal of Chongqing Medical University 2025;50(4):511-515
Objective:To investigate the carriage of the thalassemia gene in sperm donors in Chongqing,China by analyzing the thalas-semia screening and gene mutation types of sperm donors in Chongqing Human Sperm Bank(CHSB),and to provide a reference for thalassemia screening in sperm donors in Chongqing.Methods:Blood samples were collected from 488 sperm donors in CHSB(donors with all tests qualified during the quarantine)from December 2021 to August 2024.A complete blood count analysis was performed to measure the mean corpuscular volume(MCV)and mean corpuscular hemoglobin(MCH).Polymerase chain reaction(PCR)/agarose gel electrophoresis was used to detect deletional α-thalassemia mutations.PCR and DNA reverse dot blot hybridization were used to detect 3 common non-deletional α-thalassemia mutations and 17 common β-thalassemia mutations.The test results were then analyzed.Results:Among the 488 sperm donors aged 25.64±4.95 years,15(3.07%,all Han nationality)tested positive for thalassemia.This carriage rate was lower than that of the thalassemia population in Chongqing(9.24%).Among the 15 thalassemia carriers,13 had deletional α-gene mutations(-α3.7 genotype in 11 cases[73.33%],-α4.2 genotype in 1 case[6.67%],and-SEA genotype in 1 case[6.67%]),and 2 had non-deletional α-gene mutations(both with the WSM heterozygous mutation).There was only 1 case of abnor-mal MCV and MCH2 indicators among thalassemia carriers(screening positive rate was 6.67%).Conclusion:Thalassemia screening in sperm donors in CHSB reveals a low thalassemia carriage rate,reflecting geographic(predominantly Sichuan and Chongqing ori-gins)and demographic(healthy men of childbearing potential)characteristics.Given the significant impact of thalassemia on the off-spring conceived through sperm donation,it is recommended to conduct thalassemia gene screening among sperm donors in human sperm banks.
10.Antimicrobial resistance profiles of Escherichia coli based on molecular typing and public health prevention and control strategy
Hua ZONG ; Caiyun LI ; Lingyu GONG ; Yi LUO ; Hong XIAO
Journal of Army Medical University 2025;47(21):2706-2716
Objective The pathogenic characteristics of Escherichia coli(E.coli)in bacterial infections were analyzed using a combination of multiple molecular typing techniques in order to provide evidence for the management of clinical medication safety.Methods Samples from some bacterial infection-related cases in a district of Chongqing in 2021 were collected.A total of 30 E.coli strains were selected by a completely random method,and phoA gene PCR assay was performed for identification.Molecular typing of the strains was analyzed using pulsed-field gel electrophoresis(PFGE)and multilocus sequence typing(MLST).Antimicrobial susceptibility testing was conducted to determine the drug resistance of the strains,and four β-lactamase-encoding genes(blaCTX-M,blaTEM,blaSHV,blaZ)were selected to detect the carriage of resistance genes.Results All 30 E.coli strains displayed the phoA gene target band.Their PFGE banding patterns,with a similarity of 50%~98%,could be classified into 8 clusters.Cluster C was the dominant group,accounting for 53.3%(16/30).C1 and C2 exhibited high genetic correlation,indicating a close phylogenetic relationship.One E.coli strain could not be assigned a sequence type(ST)by MLST,while the remaining 29 E.coli isolates were classified into 16 different STs,demonstrating a polymorphic distribution.Among them,10 isolates belonged to ST131(10/30,33.33%).Evolutionary analysis of the 10 ST131 E.coli strains revealed their distribution across different branches,indicating varying degrees of genetic relatedness.Antimicrobial susceptibility testing revealed that all 30 E.coli strains exhibited varying degrees of resistance,with the highest resistance rate observed against the β-lactam antibiotic ampicillin(25/30,83.33%).Among them,60.0%were multidrug-resistant bacteria(MDRB).These MDRB strains exhibited 16 distinct resistance profiles,displaying a scattered distribution without a dominant resistance pattern.50.0%(9/18)of the MDRB strains exhibited six-drug resistance,while the most drug-resistant strain showed eight-drug resistance.Furthermore,the blaCTX-M gene carriage rate among the 30 E.coli strains was 86.67%(26/30),while no blaZ gene was detected.Conclusion E.coli related to bacterial infections from a Chongqing district exhibited diverse PFGE/MLST patterns and significant drug resistance.The application of multiple molecular typing techniques can reveal the genetic diversity,evolutionary relationships,and antimicrobial resistance characteristics of pathogenic bacteria.Countermeasures It is recommended to enhance the molecular typing and drug resistance surveillance network for pathogenic bacteria,establish an early warning mechanism,and implement hierarchical management of antibiotics,thereby improving targeted prevention and epidemic traceability capabilities for key drug-resistant bacteria such as ST131.


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