1.Research on BP Neural Network Method for Identifying Cell Suspension Concentration Based on GHz Electrochemical Impedance Spectroscopy
An ZHANG ; A-Long TAO ; Qi-Hang RAN ; Xia-Yi LIU ; Zhi-Long WANG ; Bo SUN ; Jia-Feng YAO ; Tong ZHAO
Progress in Biochemistry and Biophysics 2025;52(5):1302-1312
ObjectiveThe rapid advancement of bioanalytical technologies has heightened the demand for high-throughput, label-free, and real-time cellular analysis. Electrochemical impedance spectroscopy (EIS) operating in the GHz frequency range (GHz-EIS) has emerged as a promising tool for characterizing cell suspensions due to its ability to rapidly and non-invasively capture the dielectric properties of cells and their microenvironment. Although GHz-EIS enables rapid and label-free detection of cell suspensions, significant challenges remain in interpreting GHz impedance data for complex samples, limiting the broader application of this technique in cellular research. To address these challenges, this study presents a novel method that integrates GHz-EIS with deep learning algorithms, aiming to improve the precision of cell suspension concentration identification and quantification. This method provides a more efficient and accurate solution for the analysis of GHz impedance data. MethodsThe proposed method comprises two key components: dielectric property dataset construction and backpropagation (BP) neural network modeling. Yeast cell suspensions at varying concentrations were prepared and separately introduced into a coaxial sensor for impedance measurement. The dielectric properties of these suspensions were extracted using a GHz-EIS dielectric property extraction method applied to the measured impedance data. A dielectric properties dataset incorporating concentration labels was subsequently established and divided into training and testing subsets. A BP neural network model employing specific activation functions (ReLU and Leaky ReLU) was then designed. The model was trained and tested using the constructed dataset, and optimal model parameters were obtained through this process. This BP neural network enables automated extraction and analytical processing of dielectric properties, facilitating precise recognition of cell suspension concentrations through data-driven training. ResultsThrough comparative analysis with conventional centrifugal methods, the recognized concentration values of cell suspensions showed high consistency, with relative errors consistently below 5%. Notably, high-concentration samples exhibited even smaller deviations, further validating the precision and reliability of the proposed methodology. To benchmark the recognition performance against different algorithms, two typical approaches—support vector machines (SVM) and K-nearest neighbor (KNN)—were selected for comparison. The proposed method demonstrated superior performance in quantifying cell concentrations. Specifically, the BP neural network achieved a mean absolute percentage error (MAPE) of 2.06% and an R² value of 0.997 across the entire concentration range, demonstrating both high predictive accuracy and excellent model fit. ConclusionThis study demonstrates that the proposed method enables accurate and rapid determination of unknown sample concentrations. By combining GHz-EIS with BP neural network algorithms, efficient identification of cell concentrations is achieved, laying the foundation for the development of a convenient online cell analysis platform and showing significant application prospects. Compared to typical recognition approaches, the proposed method exhibits superior capabilities in recognizing cell suspension concentrations. Furthermore, this methodology not only accelerates research in cell biology and precision medicine but also paves the way for future EIS biosensors capable of intelligent, adaptive analysis in dynamic biological research.
2.TSHR Variant Screening and Phenotype Analysis in 367 Chinese Patients With Congenital Hypothyroidism
Hai-Yang ZHANG ; Feng-Yao WU ; Xue-Song LI ; Ping-Hui TU ; Cao-Xu ZHANG ; Rui-Meng YANG ; Ren-Jie CUI ; Chen-Yang WU ; Ya FANG ; Liu YANG ; Huai-Dong SONG ; Shuang-Xia ZHAO
Annals of Laboratory Medicine 2024;44(4):343-353
Background:
Genetic defects in the human thyroid-stimulating hormone (TSH) receptor (TSHR) gene can cause congenital hypothyroidism (CH). However, the biological functions and comprehensive genotype–phenotype relationships for most TSHR variants associated with CH remain unexplored. We aimed to identify TSHR variants in Chinese patients with CH, analyze the functions of the variants, and explore the relationships between TSHR genotypes and clinical phenotypes.
Methods:
In total, 367 patients with CH were recruited for TSHR variant screening using whole-exome sequencing. The effects of the variants were evaluated by in-silico programs such as SIFT and polyphen2. Furthermore, these variants were transfected into 293T cells to detect their Gs/cyclic AMP and Gq/11 signaling activity.
Results:
Among the 367 patients with CH, 17 TSHR variants, including three novel variants, were identified in 45 patients, and 18 patients carried biallelic TSHR variants. In vitro experiments showed that 10 variants were associated with Gs/cyclic AMP and Gq/11 signaling pathway impairment to varying degrees. Patients with TSHR biallelic variants had lower serum TSH levels and higher free triiodothyronine and thyroxine levels at diagnosis than those with DUOX2 biallelic variants.
Conclusions
We found a high frequency of TSHR variants in Chinese patients with CH (12.3%), and 4.9% of cases were caused by TSHR biallelic variants. Ten variants were identified as loss-of-function variants. The data suggest that the clinical phenotype of CH patients caused by TSHR biallelic variants is relatively mild. Our study expands the TSHR variant spectrum and provides further evidence for the elucidation of the genetic etiology of CH.
3.Preconceptional exposure levels and determinants of multiple pesticides among women undergoing assisted reproductive technology in Shanghai
Zhuanning XIA ; Yan ZHANG ; Peipei HU ; Jiuru ZHAO ; Zhiwei LIU ; Ying TIAN ; Yu GAO
Journal of Environmental and Occupational Medicine 2024;41(6):640-647
Background Pesticide exposure may impact the reproductive health of women undergoing assisted reproductive technology (ART). However, data on pesticide exposure levels in women undergoing ART in China are scarce, and current research on influencing factors is limited. Objective To evaluate the preconceptional pesticide exposure levels and identify potential determinants among women undergoing ART. Methods This study was designed as a cross-sectional survey and recruited 508 women undergoing ART from July 2017 to December 2018 at the fertility clinic of the International Peace Maternity and Child Health Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Gas chromatography/liquid chromatography-tandem mass spectrometry was used to determine the metabolite concentrations of organophosphate pesticides (OPs), pyrethroid pesticides (PYRs), and neonicotinoid pesticides (NEOs) in urine. The sum of molar concentrations of the three pesticide classes (∑2OPs, ∑2PYRs, and ∑2NEOs) were calculated. A questionnaire was used to collect demographic characteristics, dietary habits, and behavioral information. Multiple linear regression was employed to analyze the associations of demographic characteristics, dietary habits, and behavioral variables with the concentrations of pesticide metabolites in urine among the participants. Results The median creatinine-adjusted concentrations of ∑2OPs, ∑2PYRs, and ∑2NEOs in this study were 419.77, 2.95, and 20.36 nmol·g−1, respectively. The multiple linear regression results showed that the urinary concentration of ∑2OPs was 42.88% higher in the participants with daily vegetable intake than in those who consumed vegetables ≤3 d per week (P<0.05), and the urinary concentration of ∑2PYRs was 37.24% higher in the participants with daily fruit intake than in those who consumed fruits ≤3 d per week (P<0.01). Similarly, the urinary concentrations of ∑2NEOs were 24.51% and 29.30% higher in the participants who consumed fruits daily and 4-6 d per week, respectively, than in those who consumed fruits ≤3 d per week (P<0.05). Besides, we also found that the urinary concentration of ∑2PYRs was negatively correlated with body mass index (BMI) in the participants (P<0.05). Furthermore, the urinary concentration of ∑2NEOs was not only positively correlated with age (P<0.05), but also significantly associated with pet ownership and infertility causes among the participants. Specifically, the participants who continued to own pets after conception had a 30.11% higher urinary concentration of ∑2NEOs than those who never owned pets (P<0.05), and the participants with infertility due to female factors had a 24.10% lower urinary concentration of ∑2NEOs than those who received ART treatment for infertility caused by male factors (P<0.05). Conclusion The women undergoing ART in Shanghai are widely exposed to pesticides. Age, BMI, frequency of vegetable and fruit intake, pet ownership, and infertility causes may be related to the pesticide exposure levels in this population. However, more human data are needed to confirm these findings.
4.Glycyrrhizic Acid Showed Therapeutic Effects on Severe Pulmonary Damages in Mice Induced by Pneumonia Virus of Mice Infection
Yun LIU ; Tingting FENG ; Wei TONG ; Zhi GUO ; Xia LI ; Qi KONG ; Zhiguang XIANG
Laboratory Animal and Comparative Medicine 2024;44(3):251-258
Objective In this study,inbred BALB/c mice infected with the pneumonia virus of mice(PVM)were used to establish an animal model of viral pneumonia,and the changes in the pro-inflammatory alarmin molecule,high mobility group box 1 protein(HMGB1),during PVM infection were observed,as well as the in vivo intervention effects of the HMGB1 inhibitor,glycyrrhizic acid(GA),on PVM-induced lung injury.Methods Three-week-old female BALB/c mice were randomly divided into three groups,each consisting of 6 mice.One group,uninfected by PVM,served as the control group(Control).The other two groups were inoculated intranasally with PVM at a dose of 1×104 50%tissue culture infective dose(TCID50)/25 μL,and subsequently treated with GA saline solution(GA group)or plain saline solution(normal saline,NS group)via gavage for 15 consecutive days.During this period,changes in body weight and appearance were monitored in each group.At the end of the experiment,lung tissue samples were collected from all groups.The distribution of PVM and HMGB1 proteins in the lung tissues was analyzed using hematoxylin-eosin staining and immunohistochemistry.The expression levels of HMGB1 and its Toll-like receptor 4(TLR-4),advanced glycosylation end-product-specific receptor(AGER),and inflammatory cytokines such as interleukin(IL)-1β,IL-2,and tumor necrosis factor-α(TNF-α)in lung tissues of mice were measured using real time fluorescence quantitative PCR.Results Compared with the Control group,the NS group showed a significant weight loss after 6 days(P<0.05).Histopathological tests revealed pronounced inflammatory lesions in their lungs.Immunohistochemistry results showed that HMGB1 was released from the nucleus to the cytoplasm,and real time fluorescence quantitative PCR results indicated that the expression levels of HMGB1,IL-1β,and IL-2 were significantly upregulated(P<0.05).In the GA group,there was no significant change in the clinical symptoms or body weight.However,compared with the NS group,the pathological damages of lung tissues in the GA group were significantly reduced,and the expression levels of HMGB1,IL-1 β,IL-2,and interferon-γ(IFN-γ)in lung tissues were also significantly decreased(P<0.05),although the expression level of AGER was significantly increased(P<0.05).Conclusion PVM infection can cause significant inflammatory pathological lung damages in mice,and GA can effectively alleviate the damages.Its therapeutic effect may be related to the activation of HMGB1 signaling pathway.
5.Relationship between responsive caregiving for infants and young children and parenting confidence among caregivers
Panting LIU ; Lei ZHANG ; Qin HONG ; Xia CHI ; Meiling TONG ; Jun QIAN
Chinese Journal of Child Health Care 2024;32(2):133-137
【Objective】 To investigate the current state of infant responsive caregiving and to analyze its correlation with caregiver parenting confidence, in order to provide theoretical basis for improving the level of responsive care for infants and young children. 【Methods】 A cross-sectional survey was conducted from October 2022 to February 2023 to select 1 028 infants and young children under 3 years old who underwent health examinations in the Department of Child Healthcare. Participants completed a general data questionnaire, the Karitane Parenting Confidence Scale, and the Infant Responsive Caregiving Scale. Hierarchical multiple linear regression analysis was used to investigate the related influencing factors of infant responsive care and to analyze the relationship between caregiver parenting confidence and responsive caregiving. 【Results】 The level of responsive caregiving was found to be associated with various factors such as infant age(χ2=21.196), mode of pregnancy(Z=-2.072), history of pregnancy protection during pregnancy(Z=-4.713), history of pregnancy complications (Z=-4.504), gestational week at birth(χ2=41.358), small for term infants(Z=-3.497), neonatal intracranial hemorrhage(Z=-5.425), neonatal hyperbilirubinemia(Z=-2.184), maternal education level(χ2=9.419), family income(χ2=11.211) as well as type of family (χ2=15.360)(P < 0.05). Additionally, a significant correlation was observed between parenting confidence and responsive caregiving(r=0.421,P<0.001). Hierarchical multiple linear regression analysis revealed that caregiver parenting confidence had a significant positive effect on the level of responsive caregiving (B=0.623, P<0.05), even after controlling for the effect of demographic factors. 【Conclusion】 The level of infant responsive caregiving is influenced by caregiver parenting confidence, and increasing caregiver parenting confidence can effectively improve the quality of responsive caregiving for infants and young children.
6.Clinical trial on prognosis prediction of ovarian cancer patients based on tumor proliferation and immune-related biomarkers
Yi-Long LIU ; Xia HE ; Xue-Wu SONG ; Rong-Sheng TONG
The Chinese Journal of Clinical Pharmacology 2024;40(2):195-199
Objective To integrate tumor proliferation and immune-related biomarkers to construct a nomogram prediction model for predicting the prognosis of ovarian cancer patients.Methods We collected clinical information from patients diagnosed with epithelial ovarian cancer(EOC)between 2009 and 2013.Immunohistochemical staining was performed to detect the expression levels of KI67,epidermal growth factor receptor(EGFR)and programmed death-ligand 1(PD-Ll)in tumor tissues.We employed Lasso-Cox regression to identify variables and construct the nomogram model.We used time-dependent receiver operating characteristic(ROC)curves,concordance index,calibration curves,and decision curve analysis(DC A)curves to assess the model's discrimination,calibration,and net clinical benefit ability,respectively.Additionally,we conducted Kaplan-Meier survival analysis to assess the prognostic value of the model's risk score.Results We included a total of 131 EOC patients who were randomly assigned to the training set(n=79)and validation set(n=52)in a 6∶4 ratio.Lasso-Cox regression identified seven variables for constructing the nomogram prediction model.The AUCs for 1-,4-,and 6-year overall survival in the training set were 0.911,0.943,and 0.968,respectively,with a consistency index of 0.86[95%confidence interval(CI):0.81-0.91].In the validation set,the AUCs for 1-,4-,and 6-year overall survival were 0.830,0.797,and 0.828,respectively,with a consistency index of 0.71(95%CI:0.64-0.78).The calibration curves in both training and validation sets demonstrated strong agreement between model-predicted survival and actual outcomes(all P>0.05).DCA curves indicated that the modeled net clinical benefit outperformed TNM staging.Patients with high-risk scores in the model exhibit poorer overall survival(P<0.01)and progression-free survival(P<0.01).Conclusion The successful development and validation of a nomogram prediction model based on tumor proliferation and immune-related biomarkers offer an efficient and straightforward clinical tool.This tool holds promise for enabling personalized treatment strategies for patients with ovarian cancer.
7.Study on the mechanism of electroacupuncture stimulation to activate the acupoint effect and promote skeletal muscle repair
Yuting HUANG ; Jun LIAO ; Tianyu RAO ; Kezhi LIU ; Jia LIN ; Yuye LIN ; Chufan ZENG ; Guojun ZHANG ; Xia ZHANG ; Xiubing TONG ; Jingyu ZHANG ; Yu KAN ; Yanping FANG ; Xianghong JING ; Xuan WANG
Journal of Beijing University of Traditional Chinese Medicine 2024;47(8):1160-1170
Objective To investigate the mechanism of inducing macrophage polarization induced by acupoint effect of electroacupuncture to promote the repair of acute skeletal muscle injury.Methods 45 SD rats were randomly divided into blank group,model group,electroacupuncture group(EA group),sodium chrominate group (DSCG group) and electroacupuncture+sodium chrominate group (hereinafter referred to as EA+DSCG group),with 9 rats in each group. The rats in the EA group and the EA+DSCG group were subjected to EA intervention at the right "Chengshan" (BL57) and "Yanglingquan"(GB34),with a frequency of 2 Hz/100 Hz. The gait changes of rats were recorded by animal gait analyzer. The morphological changes of the right gastrocnemius were observed by HE staining. The changes of mast cell aggregation and degranulation in local skin muscles of "chengshan" point were observed by toluidine blue staining. The expressions of Pax7,MyoD and skin mast cells and 5-HT in the right gastrocnemius were detected by immunofluorescence method. The positive expressions of CD68 and CD206 in right gastrocnemius macrophage was observed by immunohistochemical staining.Results Compared with blank group,the wiggle time of the right hind leg in model group and DSCG group increased,stride length decreased,HE staining showed inflammatory cell infiltration,myocyte enlargement,degeneration and necrosis. The degranulation rate of local skin mast cells in "Chengshan" (BL57) area increased,and the expressions of mast cell tryptase,5-HT,Pax7,MyoD,CD68 and CD206 increased (P<0.05). Compared with model group,the wiggle time of the right hind leg in EA group and EA+DSCG group decreased,stride length increased,HE staining showed that inflammatory cell infiltration was reduced,muscle cells were uniform in size and arranged neatly. Mast cell degranulation rate increased significantly in EA group,and the expressions of mast cell tryptase,5-HT,Pax7,MyoD and CD206 increased (P<0.05),while CD68 expression decreased (P<0.05). Compared with EA+DSCG group,the degranulation rate of mast cells and the expressions of mast cell tryptase,5-HT,Pax7,MyoD and CD206 increased (P<0.05),while CD68 expression decreased in EA group (P<0.05). Conclusion EA "Chengshan" (BL57) and "Yanglingquan" (GB34) can stimulate acupuncture points to locally induce mast cell degranulation,promote the polarization of macrophages,and then activate muscle satellite cells to play the regulatory process of repairing skeletal muscle injury.
8.Multicenter retrospect analysis of early clinical features and analysis of risk factors on prognosis of elderly patients with severe burns
Qimin MA ; Wenbin TANG ; Xiaojian LI ; Fei CHANG ; Xi YIN ; Zhaohong CHEN ; Guohua WU ; Chengde XIA ; Xiaoliang LI ; Deyun WANG ; Zhigang CHU ; Yi ZHANG ; Lei WANG ; Choulang WU ; Yalin TONG ; Pei CUI ; Guanghua GUO ; Zhihao ZHU ; Shengyu HUANG ; Liu CHANG ; Rui LIU ; Yongji LIU ; Yusong WANG ; Xiaobin LIU ; Tuo SHEN ; Feng ZHU
Chinese Journal of Burns 2024;40(3):249-257
Objective:To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis.Methods:This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924 th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results:Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m 2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions:The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.
9.Development of a droplet digital polymerase chain reaction assay for the sensitive detection of total and integrated HIV-1 DNA
Lin YUAN ; Zhiying LIU ; Xin ZHANG ; Feili WEI ; Shan GUO ; Na GUO ; Lifeng LIU ; Zhenglai MA ; Yunxia JI ; Rui WANG ; Xiaofan LU ; Zhen LI ; Wei XIA ; Hao WU ; Tong ZHANG ; Bin SU
Chinese Medical Journal 2024;137(6):729-736
Background::Total human immunodeficiency virus (HIV) DNA and integrated HIV DNA are widely used markers of HIV persistence. Droplet digital polymerase chain reaction (ddPCR) can be used for absolute quantification without needing a standard curve. Here, we developed duplex ddPCR assays to detect and quantify total HIV DNA and integrated HIV DNA.Methods::The limit of detection, dynamic ranges, sensitivity, and reproducibility were evaluated by plasmid constructs containing both the HIV long terminal repeat (LTR) and human CD3 gene (for total HIV DNA) and ACH-2 cells (for integrated HIV DNA). Forty-two cases on stable suppressive antiretroviral therapy (ART) were assayed in total HIV DNA and integrated HIV DNA. Correlation coefficient analysis was performed on the data related to DNA copies and cluster of differentiation 4 positive (CD4 +) T-cell counts, CD8 + T-cell counts and CD4/CD8 T-cell ratio, respectively. The assay linear dynamic range and lower limit of detection (LLOD) were also assessed. Results::The assay could detect the presence of HIV-1 copies 100% at concentrations of 6.3 copies/reaction, and the estimated LLOD of the ddPCR assay was 4.4 HIV DNA copies/reaction (95% confidence intervals [CI]: 3.6-6.5 copies/reaction) with linearity over a 5-log 10-unit range in total HIV DNA assay. For the integrated HIV DNA assay, the LLOD was 8.0 copies/reaction (95% CI: 5.8-16.6 copies/reaction) with linearity over a 3-log 10-unit range. Total HIV DNA in CD4 + T cells was positively associated with integrated HIV DNA ( r = 0.76, P <0.0001). Meanwhile, both total HIV DNA and integrated HIV DNA in CD4 + T cells were inversely correlated with the ratio of CD4/CD8 but positively correlated with the CD8 + T-cell counts. Conclusions::This ddPCR assay can quantify total HIV DNA and integrated HIV DNA efficiently with robustness and sensitivity. It can be readily adapted for measuring HIV DNA with non-B clades, and it could be beneficial for testing in clinical trials.
10.Application of whole genome sequencing in a Clostridium perfringens diarrhea outbreak
Ai-Xia YAN ; Yan-Yan PAN ; Ying KANG ; Shoufei LI ; Miao WANG ; Luo-Tong WANG ; Yuan-Yuan WANG ; Yu-Wei LIU ; Ying LI ; Zhenzhou HUANG
Chinese Journal of Zoonoses 2024;40(8):758-762,773
An etiological analysis of a diarrhea outbreak attributed to C.perfringens was conducted.Anal swab and envi-ronmental smear samples were collected and subjected to fluorescence PCR detection of C.perfringens plc and cpe,as well as isolation and culture of C.perfringens before and after enrichment culture.The isolated colonies underwent fully automated bi-ochemical identification and time-of-flight mass spectrometry analysis.Whole genome sequencing of isolates identified as C.perfringens was performed to analyze the strain carrying virulence and resistance genes,and the genetic aggregation based on single nucleotide polymorphisms in the core genome for all isolates.The positivity rates for plc and cpe genes without bacterial enhancement were 46.15%(6/13)and 53.85%(7/13),respectively.The positivity rates for plc and cpe genes after 24 h anae-robic bacterial enhancement in BHI were 38.46%(5/13)and 53.85%(7/13).All ten isolated CP belonged to the F biotype,with virulence gene characteristics of plc+/cpb-/etx-/iA-/cpe+/cpb2+/netB-.The phylogenomic tree indicated that all ten case-patient isolates except P1 isolate(lineage 1)were closely related and clustered together in a single clade(lineage 2).Lineage 1 belonged to ST589 and carried the macrolide re-sistance gene erm(Q),whereas lineage 2 belonged to ST149 and carried the tetracycline resistance gene tetB(P).The outbreak was caused by type F C.perfringens,and most ca-ses were infected with a group of highly clonogenic cpe+col-onies.Whole genome sequencing technology can be applied to etiology analysis of C.perfringens outbreak events,and the enrichment culture and molecular screening methods for C.per-fringens based on anal swab samples should be further developed and applied.

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