Joule-class THz pulses from microchannel targets.

Inference of joule-class THz radiation sources from microchannel targets driven with hundreds of joule, picosecond lasers is reported. THz sources of this magnitude are useful for nonlinear pumping of matter and for charged-particle acceleration and manipulation. Microchannel targets demonstrate increased laser-THz conversion efficiency compared to planar foil targets, with laser energy to THz energy conversion up to ∼0.9% in the best cases.

[Research progress of vaccination status, efficacy and safety in children with tumor].

Malignant tumors in children are one of the most important diseases that threaten the health and quality of life of children and are the second most common cause of death in children.With the continuous improvement and progress of treatment technology, the long-term survival rate of children with tumor has been significantly improved, but both the disease itself and the treatment can impair the immune function of children, which makes them vulnerable to various infectious diseases and secondary serious complications, and even become a source of infection, endangering the health of others. Vaccination is the most cost-effective measure to prevent infectious diseases. For children with normal immune functions, the benefits of vaccination usually outweigh the disadvantages. However, there is a lack of detailed data on the vaccination situation, efficacy and safety of vaccine use for such immunocompromised tumor survivors, and there are no authoritative and uniform vaccination recommendations. This article reviewed and summarized the literature and consensus of some domestic and foreign scholars on current status of post-treatment vaccination status, efficacy and safety of vaccination for children with tumors after treatment, with the aim of providing a reference for the practice in this field in China.

Enhanced second harmonic generation in laser-induced air plasma.

We report a systematic investigation into the processes behind a near hundred-fold enhanced second harmonic wave generated from a laser-induced air plasma, by examining the temporal dynamics of the frequency conversion processes, and the polarization of the emitted second harmonic beam. Contrary to typical nonlinear optical processes, the enhanced second harmonic generation efficiency is only observed within a sub-picosecond time window and found to be nearly constant across fundamental pulse durations spanning from 0.1 ps to over 2 ps. We further demonstrate that with the adopted orthogonal pump-probe configuration, the polarization of the second harmonic field exhibits a complex dependence on the polarization of both input fundamental beams, contrasting with most of the previous experiments with a single-beam geometry.

[Prognostic factors for non-small cell lung cancer patients with central nervous system metastasis with positive driver genes].

Objective: To investigate the prognostic factors of patients with central nervous system (CNS) metastatic non-small cell lung cancer (NSCLC) with positive driver genes. Methods: The clinical data of 103 patients with CNS metastatic NSCLC admitted to Beijing Tongren Hospital from January 2016 to December 2020 were retrospectively analyzed, and the patients were divided into positive driver gene group (patients with driver genes mutation and receiving corresponding targeted therapy) and negative driver gene group. Cox univariate and multivariate regression analyses were performed to identify the factors affecting patients' prognosis, and the receiver operating characteristic curve (ROC) was used to compare the predictive ability of 4 scoring systems [recursive partitioning analysis (RPA) classes, diagnosis-specific graded prognostic assessment (DS-GPA) index, basic score for brain metastasesn (BS-BM) and (lung-molecular graded prognostic assessment (lung-mol GPA)]on patients' prognosis. Results: Among the 103 patients, 48 were males and 55 were females, and aged (64.6±9.7) years old. The median survival time of the 103 patients was 24.0 (95%CI: 20.0-28.0) months, the median survival time of the 59 patients in the positive driver gene group was 33.0 (95%CI: 23.4-42.6) months, the median survival time of the 44 patients in the negative driver gene group was 17.0 (95%CI: 14.4-19.6) months, and the difference was statistically significant (χ2=24.69, P<0.001). The results of Cox multivariate analysis showed that the negative driver genes (HR=3.788, 95%CI: 1.951-7.301, P=0.001), Karnofsky performance status (KPS) score<70 (HR=2.613, 95%CI: 1.185-5.761, P=0.017) and neutrophil-to-lymphocyte ratio (NLR)>3.22 (HR=2.714, 95%CI: 1.157-6.365, P=0.022) were independent risk factors affecting the prognosis of patients with CNS metastatic NSCLC. KPS score<70 (HR=3.719, 95%CI: 1.165-11.876, P=0.027) and no radiotherapy (HR=2.032, 95%CI: 1.033-11.364, P=0.041) were independent risk factors affecting the prognosis of patients with CNS metastatic NSCLC with positive driver genes. ROC curve analysis showed that the area under curve (AUC) value of lung-mol GPA was the highest among the 4 scoring systems (AUC=0.843, 95%CI: 0.731-0.956, P<0.001), and the AUC value of the lung-mol GPA combined scoring system (AUC=0.904, 95%CI: 0.816-0.991, P<0.001) was higher than lung-mol GPA. Conclusions: A low KPS score and no cranial radiation therapy are independent risk factors for the prognosis of patients with CNS metastatic NSCLC with positive driver genes; the lung-mol GPA joint scoring system is more conducive to the prognostic assessment of patients with CNS metastatic NSCLC with positive driver genes.

[Application progress of implementation research on diabetes management].

Diabetes is one of the most important non-communicable chronic diseases. Although a large amount of clinical evidence on the effectiveness of diabetes prevention and treatment interventions has been established, the current quality of care and results are still insufficient. Implementation Research can bridge the gap between research and practice. Implementation Research on diabetes management can clarify what is effective and what is ineffective in management, and promote the transformation of complex, multi-component interventions into medical practice faster and more effectively. This paper reviews the main research contents and application of implementation research of diabetes management at home and abroad, aiming to provide reference for related research and promote the application of implementation research in diabetes management in China.

[The sleep condition and its association with cognitive function of the elderly in six provinces of China].

Objective: To analyze the association between sleep duration and cognitive function of the elderly in six provinces of China. Methods: Based on the cross-sectional survey data of the elderly from the Healthy Ageing Assessment Cohort Study in 2019, 4 644 participants' sociodemographic and economic indicators, lifestyle, prevalence of major chronic diseases, and sleep status, including night-time sleep duration, daytime sleep duration and insomnia, were collected by questionnaires. Cognitive function was evaluated by the Mini-Mental State Examination. Multivariate logistic regression was used to analyze the association between night-time sleep duration, daytime sleep duration and cognitive function. Results: The mean age of 4 644 respondents was (72.3±5.7) years, and 2 111 of them were males (45.5%). The mean total daily sleep time of the elderly was (7.9±1.9) hours, and the proportion of those who slept less than 7.0, 7.0-8.9 and≥9.0 hours was 24.1% (1 119), 42.1% (1 954) and 33.8% (1 571), respectively. The mean sleep time at night was (6.9±1.7) hours. About 23.7% (1 102) of the elderly did not sleep during the day, and the mean duration of the elderly who slept during the day was (78±51) minutes. Among the elderly with insomnia, 47.9% were still satisfied with their sleep quality. The mean value of MMSE score of 4 644 respondents was (24.5±5.3), and the cognitive impairment rate was 28.3% (1 316). The results of multivariate logistic regression model analysis showed that the OR (95%CI) value of the risk of cognitive impairment in older people who did not sleep, slept for 31 to 60 minutes and slept more than one hour was 1.473 (1.139 to 1.904), 1.277 (1.001 to 1.629) and 1.496 (1.160 to 1.928), respectively, compared with those who slept for 1 to 30 minutes during the daytime. Compared with those who slept for 7.0‒8.9 hours at night, the OR (95%CI) value of the risk of cognitive impairment in older people who slept more than 9.0 hours was 1.239 (1.011 to 1.519). Conclusion: The cognitive function is related to sleep duration in the Chinese elderly.

[Effectiveness of 13-valent pneumococcal conjugate vaccine against invasive disease caused by serotype 19A in children: a meta-analysis].

Objective: Using Meta-analysis to evaluate the vaccine effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) against invasive Streptococcus pneumoniae disease (IPD) caused by serotype 19A in children <5 years old. Methods: "Streptococcus pneumoniae infection""invasive pneumococcal disease""13-valent pneumococcal polysaccharide conjugate vaccine""PCV13""effectiveness""infant""child" and related terms were searched from China National Knowledge Infrastructure (CNKI), WANFANG DATA, PubMed, SCOPUS and Web of science with no limited on language, region and research institution. The retrieval time was limited from January 2010 to February 2023 and cohort study, case-control study and randomized controlled trial were included. Data were extracted from eligible studies by two independent reviewers, and after study quality assessment by NOS scale, Meta-analysis was completed using Stata 16.0 software. Results: A total of 2 340 related literatures were searched, and 10 literatures were finally included, including 5 case-control studies and 5 indirect cohort studies, which showed good literature quality. The vaccine effectiveness against serotype 19A IPD of PCV13 in children was 83.91% (95%CI: 78.92%-88.89%), and the subgroup analysis (P=0.240) showed there was no significant difference among the case-control study (VE=87.34%, 95%CI:79.74%-94.94%) and the indirect cohort study (VE=81.30%, 95%CI:74.69%-87.92%). The funnel plot and Egger test suggested that the possibility of publication bias was small. Conclusion: The present evidence indicates that PCV13 has a good vaccine effectiveness against serotype 19A IPD in children, and it is recommended to further increase the vaccination rate of PCV13 to reduce the disease burden of IPD in children <5 years old.

[Study of the predictive role of serum HBV RNA on HBeAg serological conversion in children with chronic hepatitis B].

Objective: To investigate the role of serum hepatitis B virus RNA (HBV RNA) in predicting HBeAg serological conversion in children with chronic hepatitis B. Methods: 175 children aged 1~17 years with chronic hepatitis B who received interferon α (IFNα) for 48 weeks were selected. Patients were divided into HBeAg seroconversion and non-conversion based on whether HBeAg seroconversion occurred at 48 weeks of treatment.T-test and Mann-Whitney U test were used to compare between groups; chisquare test or Fisher exact probability method was used to compare the frequency between groups of classified variables; and Pearson correlation was used to analyze the correlation between indicators. Univariate and multivariate logistic regression analyses were used to identify influencing factors associated with HBeAg serological conversion. The predictive effect of HBV RNA, HBV DNA, and HBsAg on HBeAg serological conversion was compared and analyzed by the receiver operating characteristic curve (ROC). Results: The seroconversion rate of HBeAg at 48 weeks was 36.0% (63/175). The reduction in HBVRNA levels from baseline to the 12th, 24th, 36th, and 48th weeks of antiviral therapy was significantly greater in the HBeAg serological conversion group than that in the non-conversion group, and the difference was statistically significant between the two groups (P < 0.05). Univariate and multivariate regression analyses showed that age and a decline in HBV RNA levels at week 12 were independent predictors of HBeAg serological conversion. The area under the ROC curve (AUROC) of HBV RNA decline at week 12 was 0.677(95% CI∶0.549-0.806, P = 0.012), which was significantly better than the same period of AUROC of HBV DNA (0.657, 95% CI∶0.527-0.788, P = 0.025) and HBsAg (0.660, 95% CI∶0.526-0.795, P = 0.023) decline. HBV RNA levels decreased (>1.385 log10 copies/ml) at week 12, with a positive predictive value of 53.2%, a negative predictive value of 72.2%, a sensitivity of 77.4%, and a specificity of 57.9% for HBeAg seroconversion. Conclusion: HBV RNA level lowering during the 12th week of antiviral therapy can serve as an early predictor marker for HBeAg serological conversion in children with chronic hepatitis B.

Observation of strong terahertz field-induced second harmonic generation in plasma filaments.

We report the observation of terahertz field-induced second harmonic (TFISH) generation produced by directly mixing an optical probe beam onto femtosecond plasma filaments. The produced TFISH signal is spatially separated from the laser-induced supercontinuum by impinging on the plasma at a noncollinear angle. The conversion efficiency of the fundamental probe beam to its second harmonic (SH) beam is greater than 0.02%, which represents a record in optical probe to TFISH conversion efficiency that is nearly five orders of magnitude larger than previous experiments. We also present the terahertz (THz) spectral buildup of the source along the plasma filament and retrieve coherent terahertz signal measurements. This method of analysis has the potential to provide local electric field strength measurements inside of the filament.

[Prediction of 6-year risk of activities of daily living disability in elderly aged 65 years and older in China].

Objective: To construct an easy-to-use risk prediction tool for 6-year risk of activities of daily living(ADL) disability among Chinese elderly aged 65 and above. Methods: A total of 34 349 elderly aged 65 and above were recruited from the Chinese Longitudinal Healthy Longevity Survey. Demographic characteristics, lifestyle and chronic diseases of the elderly were collected through face-to-face interviews. The functional status of the elderly was evaluated by the instrumental activities of daily living(IADL) scale. The mental health status of the elderly was evaluated by the Mini-Mental State Examination. The height, weight, blood pressure and other information of the subjects were obtained through physical examination and body mass index(BMI) was calculated. The ADL status was evaluated by Katz Scale at baseline and follow-up surveys. Taking ADL status as the dependent variable and the key predictors were selected from Lasso regression as the independent variables, a Cox proportional risk regression model was constructed and visualized by the nomogram tool. Area under the receiver operating characteristic curve(AUC) and calibration curve were used to evaluate the discrimination and calibration of the model. A total of 200 bootstrap resamples were used for internal validation of the model. Sensitivity analysis was used to evaluate the robustness of the model. Results: The M(Q1, Q3) of subjects' age as 86(75, 94) years old, of which 9 774(46.0%) were males. A total of 112 606 person-years were followed up, 4 578 cases of ADL disability occurred and the incidence density was 40.7/1 000 person-years. Cox proportional risk regression model analysis showed that older age, higher BMI, female, hypertension and history of cerebrovascular disease were associated with higher risk of ADL disability [HR(95%CI) were 1.06(1.05-1.06), 1.05(1.04-1.06), 1.17(1.10-1.25),1.07(1.01-1.13) and 1.41(1.23-1.62), respectively.]; Ethnic minorities, walking 1 km continuously, taking public transportation alone and doing housework almost every day were associated with lower risk of ADL disability [HR(95%CI): 0.71(0.62-0.80), 0.72(0.65-0.80), 0.74(0.68-0.82) and 0.69(0.64-0.74), respectively]. The AUC value of the model was 0.853, and the calibration curve showed that the predicted probability was highly consistent with the observed probability. After excluding non-intervening factors(age, sex and ethnicity), the AUC value of the model for predicting the risk of ADL disability was 0.779. The AUC values of 65-74 years old and 75 years old and above were 0.634 and 0.765, respectively. The AUC values of the model based on walking 1 km continuous and taking public transport alone in IADL and the model based on comprehensive score of IADL were 0.853 and 0.851, respectively. Conclusion: The risk prediction model of ADL disability established in this study has good performance and robustness.

[Association of blood arsenic level with hyperuricemia among elderly aged 65 years and older in 9 longevity areas of China].

Objective: To investigate the association of blood arsenic level with hyperuricemia among elderly aged 65 years and older. Methods: Data was collected in 9 longevity areas from Heathy Aging and Biomarkers Cohort Study between 2017 and 2018. 2 438 participants aged 65 years and older with complete information on blood arsenic and uric acid were included in this study. Information including demographics characteristic, life style and health status was collected by questionnaire and physical examination. Meanwhile, venous blood was collected to detect the levels of blood arsenic and uric acid. Subjects were stratified into three groups (low, middle and high) by tertiles of blood arsenic level. Logistic regression models were used to analyze the association of blood arsenic level with hyperuricemia. Results: The age of participants was (84.57±11.41) years, of which 1 172 (48.07%) were male and 1 525 (62.55%) were over 80 years old. The detection rate of hyperuricemia was 17.23% (420), and the detection rates of hyperuricemia were 11.77%, 19.25% and 20.62% among participants with low, middle and high blood arsenic, respectively (P<0.001). After controlling confounding factors, compared with participants who had low blood arsenic, the ORs (95%CI) of hyperuricemia for the participants with middle and high blood arsenic were 1.57 (1.12-2.23) and 2.08 (1.46-2.99), respectively. Subgroups analysis showed that compared with female, the association between blood arsenic level and hyperuricemia was more obvious in males (Pinteraction<0.05). Conclusion: Blood arsenic level is associated with the risk for hyperuricemia among the elderly aged 65 years and older in 9 longevity areas in China.

[Association of neutrophil-to-lymphocyte ratio with depressive symptoms among older adults aged 65 years and above in 9 longevity areas of China].

Objective: To investigate the relationship between the neutrophil-to-lymphocyte ratio (NLR) and the risk of depression symptoms among older adults aged 65 and above in 9 longevity areas of China. Methods: Data was collected in 9 longevity areas of China from Healthy Aging and Biomarkers Cohort Study (HABCS) conducted between 2017 and 2018. Finally,2018 elderly aged 65 years and above with complete information on neutrophil count, lymphocyte count and depressive symptoms were included in this study. Information on demographic characteristics, lifestyle, and health status was collected through questionnaire and physical examination. Complete blood counts which included lymphocytes and neutrophils were obtained by testing venous blood samples. Participants were divided into four groups by the quartile of NLR level, i.e. Q1, Q2, Q3, Q4. Logistic regression model was applied to analyze the association of NLR with depression symptoms. Results: Among 2 018 older adults, the mean(±SD) age was 82.6(±10.73), 1 032(51.14%) were male, 390(19.33%) were detected with depressive symptoms. Compared with participants of NLR in the 1st quartile, the OR(95%CI) of risk for depressive symptoms was 1.47 (0.99, 2.19), 1.67 (1.13, 2.47) and 1.95 (1.32, 2.89), respectively. Conclusion: Increased NLR level is significantly related to depressive symptoms among elderly aged 65 years and above in 9 longevity areas in China.

[Association of blood uric acid and cognitive impairment in oldest-old aged 80 years and older in 9 longevity areas of China].

Objective: To examine the association of blood uric acid (UA) and cognitive impairment (CI) among oldest-old adults in China. Methods: Data was collected in 9 longevity areas of China from Healthy Aging and Biomarkers Cohort Study (HABCS) conducted during 2017-2018. Finally,1, 622 elderly aged 80 years and older with complete information on blood UA and cognitive function score were included in this study. Information on demographic characteristics, lifestyle, and health status were collected through questionnaire and physical examination. Venous blood samples of the participants were collected to test blood UA level. Cognitive impairment (CI) was assessed using the Chinese Mini-Mental State Examination (MMSE) according to personal educational level. Generalized Estimating Equations (GEE) model for binary data was used to analyze the association of blood UA and CI, and further compared the associations among different age and body mass index (BMI) groups. Results: Of the 1 622 oldest-old, the mean age was (92.2±8.1) years, 656 (40.4%) were male, the mean level of blood UA was (343.3±86.2) µmol/L, and 482 (29.7%) oldest-old had CI. Compared with the lowest quartile of UA, the risks of CI in the second, third and highest quartiles were gradually reduced, the corresponding ORs and 95%CI were 0.99 (0.71-1.33), 0.87 (0.68-0.94) and 0.69 (0.48-0.85), respectively; and the linear trend test was statistically significant (P<0.001). Subgroup analysis showed that the effects of higher UA associated with lower risk of CI were stronger in younger oldest-old (aged 80-89 years) and thinner group (BMI<24) (Pinteraction<0.05). Conclusions: Blood UA was negatively associated with the risk of having CI in the oldest-old among the nine longevity areas of China.

[Impact of transcatheter aortic valve replacement on renal function in patients with severe aortic stenosis].

Objective: To explore the impact of transcatheter aortic valve replacement (TAVR) on renal function in patients with severe aortic stenosis. Methods: This is a single-center retrospective study. Consecutive patients with severe aortic valve stenosis and received TAVR in Zhongshan Hospital from December 2014 to December 2019 were included. The patients were divided into four groups according to the estimate glomerular filtration rate (eGFR) measured at one day before TAVR, namely eGFR>90 ml·min-1·1.73m-2 group, 6090 ml·min-1·1.73m-2 group, 60

Mitochondrial DNA Polymorphism in Zhejiang She Population Based on Next Generation Sequencing.

ABSTRACT: Objective To study the genetic polymorphism of whole mitochondrial DNA （mtDNA） genomes in She population in Zhejiang and to explore the maternal genetic structure of the She population. Methods Whole mtDNA genomes of 231 unrelated individuals from She population in Zhejiang Province were sequenced. The number of mutations and population genetics parameters such as, the haplotype diversity （HD）, discrimination power （DP）, and random match probabilities （RMP） were analyzed. The mtDNA haplogroups of Zhejiang She population were classified, and the maternal genetic relationships between She and nine other Chinese populations were estimated. Results In 231 Zhejiang She samples, 8 507 mutations （702 types） were observed and the samples were classified into 94 haplogroups. The HD, DP and RMP values were 0.998 6, 0.994 2 and 0.005 8, respectively. The lowest genetic differentiation degree （Fst=0.006 89） was detected between Zhejiang She population and southern Han population. Principal component analysis （PCA） and median-joining network analysis showed that the genetic distance of Zhejiang She population with Guangxi Yao, Yunnan Dai and Southern Han populations was relatively close, but the population still had some unique genetic characteristics. Conclusion The whole mtDNA genomes are highly polymorphic in Zhejiang She population. The Zhejiang She population contains complex and diverse genetic components and has a relatively close maternal genetic relationship with Guangxi Yao, Yunnan Dai and Southern Han populations. Meanwhile, Zhejiang She population has kept its unique maternal genetic components.

Identification of Cannabis Sativa L. Based on rbcL Sequence.

ABSTRACT: Objective To assess the feasibility of the rbcL sequence of chloroplast DNA as a genetic marker to identify Cannabis sativa L. Methods The rbcL sequences in 62 Cannabis sativa L. samples, 10 Humulus lupulus samples and 10 Humulus scandens DNA samples were detected, and 96 rbcL sequences of the Cannabaceae family were downloaded from Genbank. Sequence alignment was performed by MEGA X software, the intraspecific and interspecific Kimura-2-Parameter （K2P） genetic distances were calculated, and the system clustering tree was constructed. Results The rbcL sequence length acquired by sequencing of Cannabis sativa L. and Humulus scandens were 617 bp and 649 bp, respectively, and two haplotypes of Cannabis sativa L. were observed in the samples. The BLAST similarity search results showed that the highest similarity between the sequences acquired by sequencing and Cannabis sativa L. rbcL sequences available from Genbank was 100%. The genetic distance analysis showed that the maximum intraspecific genetic distance （0.004 9） of Cannabis sativa L. was less than the minimum interspecific genetic distance （0.012 9）. The results of median-joining network and system clustering tree analysis showed that Cannabis sativa L. and other members of the Cannabaceae family were located in different branches. Conclusion The rbcL sequence could be used as a DNA barcode for identifying Cannabis sativa L., and combined with comparative analysis of the rbcL sequence and system cluster analysis could be a reliable and effective detection method for Cannabis sativa L. identification in forensic investigation.

[Depression symtoms and related factors of fire fighters].

Objective: To analysis the status of the mental health and related factors of fire fighters in Tianjin Binhai New District, and to provide suggestions for their psychological health protection. Methods: 399 fire fighters in Tianjin Binhai New District were selected as study subjects in Jan to April 2019. Depression symptoms were measured by the depression module of the Patient Health Questionnaire (PHQ-9) . The Chinese version of Efrort Reword Imbalance (ERI) Questionnnaire were used to investigate and evaluate their occupational stress. Chi-Square test was used to analysis Categorical data. Binary logistic regression model was used to analysis the ralated factors of depression. Results: Among the 399 fire fighters, 71.1% (280/394) were found high level of depression symptom. The detection rates of depression symptoms in the related influceing factors ERI、station、disease、life pressure、eating habits and sleep disorder occupational stress were difierent (P<0.05) . Sleep disorder, life pressure and ERI occupational stress were risk factors for depressive symptoms (OR=1.921, 95% CI=1.002-3.682; OR=2.852, 95% CI=1.561-5.212; OR=2.367, 95% CI=1.163-4.818, P<0.05) . Conclusion: The rate of depression of fire fighters is relatively higher. Government should pay attention to and take measures to improve the psychological condition of fire fighters.

Terahertz nonlinear index extraction via full-phase analysis.

We experimentally show the spectrally averaged nonlinear refractive index and absorption coefficient for liquid water, water vapor, α-pinene, and Si using a full-phase analysis in the terahertz regime through a standard time-domain spectrometer. Our results confirm that the nonlinear index of refraction of the liquid samples in this regime exceeds the near-infrared optical nonlinear index by six orders of magnitude. In the case of liquid water and water vapor at atmospheric pressure, we find a nonlinear index of 7.8×10-10cm2/W and 6×10-11cm2/W, respectively, which are both much larger than expected.

Biological background of the genomic variations of cf-DNA in healthy individuals.

BACKGROUND: Cell-free DNA (cf-DNA)-based liquid biopsy is emerging as a revolutionary new method in individualized cancer treatment and prognosis monitoring, although detecting early-stage cancers using cf-DNA remains challenging, partially because of the undefined biological background of cf-DNA. MATERIALS AND METHODS: We investigated somatic mutations in the cf-DNA of 259 cancer-free individuals with a median age of 47 years using an endogenous barcoding duplex method with an ultralow base error rate (2 × 10-7) and compared the variant allele frequencies (VAFs) of these mutations between the cf-DNA and the corresponding blood cell DNA. RESULTS: Sixty percent (155/259) of the samples showed at least one nonsynonymous mutation on either of two similar target panels covering 508 and 559 cancer-related genes. For individuals older than 50 years of age, the positive rate increased to 76%. Most cf-DNA mutations were also present at similar VAFs in the paired blood cell DNA. The most frequently mutated genes were driver genes of hematologic malignancies, including DNMT3A, TET2, AXSL1, and JAK2. However, the other 58.4% (192/329) of the mutations were likely 'passenger mutations' of clonal hematopoiesis, including mutations in NOTCH2, FAT3, EXT2, ERBB4, and ARID2, which are driver genes of solid tumors. CONCLUSION: Hematopoietic clone-derived mutations, including 'driver mutations' and 'passenger mutations', are prevalent in the cf-DNA of both healthy individuals and cancer patients and may be a potential source of false positives in the liquid biopsy. Our results also suggest the ineffectiveness for distinguishing clonal hematopoietic mutations of low VAF (≤0.1%) from tumor-derived mutations using conventional next-generation sequencing of blood cell DNA. However, an error correction model with an ultralow error rate and high coverage depth is required for blood cell DNA sequencing, which is difficult and costly to achieve with current technologies.

[Diagnostic value of 18F-FDG PET/CT and tumor markers (CEA, CA19-9, CA24-2) in recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma].

OBJECTIVE: To evaluate the diagnostic value of 18F-FDG PET/CT and tumor markers (CEA,CA19-9,CA24-2) in detection for recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma. METHODS: Fifty-five patients were enrolled in this study. All of the patients were tested with serum CEA within 2 weeks when they underwent 18F-FDG PET/CT scan, and some patients were tested with serum CA19-9 and CA24-2 simultaneously. According to the pathology and clinical results of their follow-up, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT and tumor markers were calculated based on different divided groups, respectively. RESULTS: According to the pathology and the results of their clinical follow-up, the sensitivity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 68.09%, 28.57%, 40.00% and 74.47%, respectively. The specificity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 50.00%, 66.67%, 71.43% and 50.00%, respectively. The positive predictive valueof 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 88.89%, 85.71%, 88.89% and 89.74%, respectively. The negative predictive value of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 26.67%, 11.42%, 17.24%, 25.00%, respectively. The accuracy of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 92.73%, 65.47%, 32.65%, 44.68% and 70.91%, respectively. There were 2 cases of false positive and 2 cases of false negative in 18F-FDG PET/CT. CONCLUSION: 18F-FDG PET/CT has high value in detecting recurrence and metastasis of postoperative colorectal carcinoma. Tumor markers have the positive value to imply the recurrence and metastasis of postoperative colorectal carcinoma and are useful to indicate when to perform the 18F-FDG PET/CT. The combination of tumor markers could improve the diagnostic efficiency to some extent.