Evaluating the effects of whole genome amplification strategies for amplifying trace DNA using capillary electrophoresis and massive parallel sequencing

To draw robust conclusions when trace DNA samples are detected in complex cases, it is essential to successfully recover and genotype short tandem repeats (STRs) from trace DNA. However, obtaining complete STR profiles by the conventional polymerase chain reaction-capillary electrophoresis (PCR-CE) method is generally difficult as trace DNA is often less than 100 pg. Previous studies have proven that through whole-genome amplification (WGA), the yield of DNA from trace DNA samples could be improved. In this study, we used two WGA kits, namely, REPLI-g® Single Cell kit and MALBAC® Single Cell DNA Quick-Amp Kit (hereafter referred to as REPLI and MALBAC), to amplify DNA samples with a series of dilutions (from 5.00 ng/μL to 0.391 pg/μL). Typing of STR markers in samples with and without WGA were then performed on a CE platform by the application of Goldeneye® DNA ID System 20 A kit, as well as directly calling sequences from massive parallel sequencing (MPS) for WGA samples with 1.00 ng, 125 pg and 25.0 pg as DNA inputs. Quantification results demonstrated that the yield of samples with WGA could reach the microgram level. The amplification fold was at least > 2000 and > 200 for REPLI and MALBAC, respectively. CE results showed that the number of correctly called loci was improved for trace DNA after WGA when the DNA inputs were lower than 25.0 pg for REPLI and 6.25 pg for MALBAC, respectively. WGA remarkably improved the percentage of called loci with DNA inputs lower than 50.0 pg, although poor performance in repeatability was observed. MPS results suggested that the correctly called loci calculated by MPS reads were mostly more than those calculated by CE, particularly for those of short length, implying MPS of samples after WGA is worth testing in the future. In conclusion, WGA has the potential usability for forensic trace DNA analysis at the single-cell level with good fidelity, although its repeatability requires further improvement.     

Flavonoids and stilbenoids as a promising arsenal for the management of chronic arsenic toxicity

Rapid industrial and technological development has impacted ecosystem homeostasis strongly. Arsenic is one of the most detrimental environmental toxins and its management with chelating agents remains a matter of concern due to associated adverse effects. Thus, safer and more effective alternative therapy is required to manage arsenic toxicity. Based on existing evidence, native and indigenous plant-based active biomolecules appear as a promising strategy to mitigate arsenic-induced toxicity with an acceptable safety profile. In this regard, various phytochemicals (flavonoids and stilbenoids) are considered important classes of polyphenolic compounds with antioxidant and chelation effects, which may facilitate the removal of arsenic from the body more effectively and safely with regard to conventional approaches. This review presents an overview of conventional chelating agents and the potential role of flavonoids and stilbenoids in ameliorating arsenic toxicity. This report may provide a roadmap for identifying novel prophylactic/therapeutic strategies for managing arsenic toxicity.     

Survival among Breast Cancer Patients: Comparison of the U.S. Military Health System with the Surveillance,Epidemiology and End Results Program

IntroductionAccessibility to health care is important to cancer survival. The U.S. military health system (MHS) provides universal health care access. However, whether the universal care has been translated into improved cancer survival is unknown. We compared survival of patients with breast cancer in the MHS with that in the U.S. general population and assessed the differences in cancer stage at diagnosis and treatment receipt between the two populations.MethodsThe MHS patients (n = 31,548) were identified from the Department of Defense's (DoD) Automated Central Tumor Registry (ACTUR). Patients in the U.S. general population (n = 63,096) were identified from the Surveillance, Epidemiology, and End Results (SEER) program. The two populations were matched on age, race, and diagnosis year. Multivariable Cox regression hazard modeling was used to estimate hazard ratios (HRs) comparing ACTUR with SEER. Multivariable logistic regression was used to estimate odds ratios (ORs) comparing stage and treatment receipt.ResultsACTUR patients exhibited a 24% lower overall mortality than the SEER patients (HR = 0.76, 95% CI, 0.71-0.80). They were less likely to present with later stage compared to the SEER patients (OR = 0.61, 95% CI, 0.55-0.67 for stage IV tumors). The ACTUR patients with stages I-III tumors were more likely to receive surgery (OR = 1.35, 95% CI, 1.20-1.52) but less likely to receive radiation (OR = 0.91, 95% CI, 0.88-0.94). The survival advantage of ACTUR patients remained regardless of surgery or radiation receipt.ConclusionsBreast cancer patients with universal health care access had improved survival compared to patients in the general population.     

Putting age-related task activation into large-scale brain networks: A meta-analysis of 114 fMRI studies on healthy aging

Normal aging is associated with cognitive decline and underlying brain dysfunction. Previous studies concentrated less on brain network changes at a systems level. Our goal was to examine these age-related changes of fMRI-derived activation with a common network parcellation of the human brain function, offering a systems-neuroscience perspective of healthy aging. We conducted a series of meta-analyses on a total of 114 studies that included 2035 older adults and 1845 young adults. Voxels showing significant age-related changes in activation were then overlaid onto seven commonly referenced neuronal networks. Older adults present moderate cognitive decline in behavioral performance during fMRI scanning, and hypo-activate the visual network and hyper-activate both the frontoparietal control and default mode networks. The degree of increased activation in frontoparietal network was associated with behavioral performance in older adults. Age-related changes in activation present different network patterns across cognitive domains. The systems neuroscience approach used here may be useful for elucidating the underlying network mechanisms of various brain plasticity processes during healthy aging.     

何首乌肝毒性物质基础探索研究

通过观察何首乌中蒽醌类成分对Hep G2细胞的细胞毒作用,并通过精密肝切片技术对细胞毒成分进行验证,探讨何首乌致肝毒性的物质基础。运用MTT法检测何首乌中游离蒽醌、结合蒽醌及柰类共11个单体成分对Hep G2细胞的毒性。将有明确细胞毒的成分与大鼠肝切片共同培养6 h后制备肝组织匀浆,通过BCA法测定匀浆液中蛋白含量,连续监测法测定并计算每1μg蛋白中丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、γ-谷氨酰氨基转肽酶(GGT)和乳酸脱氢酶(LDH)的漏出率,以考察这些成分对肝组织的毒性作用。细胞试验结果显示,只有大黄酸、大黄素、大黄素甲醚-8-O-β-D-葡萄糖苷和大黄素甲醚-8-O-(6'-O-乙酰基)-β-D-葡萄糖苷显示一定的细胞毒作用,其IC50分别为71.07,125.62,242.27,402.32μmol·L-1,而其他7个化合物的毒性很小。肝切片试验结果显示,大黄酸400μmol·L-1组能引起肝切片ALT,AST,LDH漏出率的显著升高(P0.01),100μmol·L-1组能引起肝切片LDH漏出率的显著升高(P0.05);随药物浓度增大,肝切片中蛋白含量显著下降(P0.05),显示有一定的量毒关系。大黄素400μmol·L-1组可引起肝切片ALT,GGT,LDH漏出率的显著升高(P0.01)。大黄素甲醚-8-O-β-D-葡萄糖苷800μmol·L-1组能引起肝切片ALT,AST,LDH漏出率的显著升高(P0.01或P0.05),200μmol·L-1组能引起肝切片LDH漏出率的显著升高(P0.05);且随药物浓度的增大肝切片中ALT,AST,LDH漏出率呈升高趋势,蛋白含量呈下降趋势。此外,浓度为800μmol·L-1的大黄素甲醚-8-O-β-D-葡萄糖苷还可使肝切片MTT还原能力显著下降(P0.01)。结果提示,大黄酸、大黄素及大黄素甲醚-8-O-β-D-葡萄糖苷只有在高浓度(≥400μmol·L-1)时才可能对肝组织产生一定的损害作用。但是,据文献报道这3个成分的体内暴露水平都很低,要达到毒性浓度(400μmol·L-1或800μmol·L-1)的暴露水平,转化为健康成人至少分别需要单次口服4 898,339,5 581 g的何首乌药材,这与何首乌的临床使用剂量(生首乌3~6 g,制首乌6~12 g)相差甚远,因此,"蒽醌类成分是何首乌肝毒性成分"这一说法是缺乏科学依据的。     

Association between early glycemic management and diabetes complications in type 1 diabetes mellitus: A retrospective cohort study

AimsTo investigate the association between early HbA1c levels near diagnosis and future glycemic management, and analyzed risk factors of complications in people with T1DM.MethodsThis retrospective cohort study included 201 children and adolescents with T1DM. Patient data including sex, age at diagnosis, duration of disease, HbA1c levels, HbA1c variability during the follow-up period, and diabetes complications and comorbidities were collected.ResultsThe mean follow-up period of patients was 16.4 years. HbA1c levels in all three examined time points after diagnosis (first year, second year, and first two years) were significantly associated with recent HbA1c level, and second-year HbA1c was most closely correlated with recent HbA1c level. Elevated second-year HbA1c was a risk factor of diabetic ketoacidosis (DKA) and retinopathy, and increased variability of HbA1c was significantly related to various microvascular complications. When HbA1c is stratified into quartiles, the subjects of each quartile trend to stay within that quartile over the follow-up period.ConclusionsEarly HbA1c levels were closely associated with recent HbA1c levels and diabetes complications in patients with T1DMs. Strict glucose management after diagnosis and reducing variability of HbA1c may prevent future diabetes complications and comorbidities.     

Screening and confirmation of microRNA markers for distinguishing between menstrual and peripheral blood

The identification of menstrual blood (MB) and peripheral blood (PB) left at a crime scene is crucial for crime reconstruction, especially in sexual assaults. MicroRNAs (miRNAs), a class of non-protein coding molecules, have been demonstrated to be a viable tool for body fluid identification in forensic casework. Several groups have searched for miRNAs that are specific to different body fluids. Blood has been studied the most extensively. However, menstrual blood was only involved in five studies, and the results confirming the presence of specific miRNAs could not be reproduced in other studies. In this study, we attempted to screen new markers that can differentiate between menstrual blood and peripheral blood by using Exiqon’s miRCURY™ LNA Array. Five miRNAs were selected based on the microarray results, namely, miR-141-3p, miR-373-3p, miR-497-5p, miR-143-5p, and miR-136-5p, whose expression levels exhibited 27.95-, 17.96-, 16.74-, 10.14-, and 9.21-fold changes, respectively, compared to the level in peripheral blood. Two classic quantitative methods, TaqMan hydrolysis probes (TaqMan for short) and SYBR Green fluorochrome (SYBR Green for short), were applied in the confirmation step to study the impact of different quantitative methods on the results. Three miRNAs (miR-141-3p, miR-497-5p, and miR-143-5p) were confirmed by TaqMan and one (miR-141-3p) by SYBR Green. Furthermore, bioinformatic methods were applied to interpret the candidate miRNAs. Our results established a multi-step procedure for body fluid identification and showed that the choice of quantitative method is important when miRNAs are used to identify the origin of blood samples.