环磷酰胺辅助化疗对不同年龄乳腺癌患者卵巢功能的损伤情况及机制研究

目的:以月经变化情况及血清激素水平为观察指标,探讨环磷酰胺辅助化疗方案对绝经前不同年龄段乳腺癌患者卵巢功能的损伤情况及可能的机制研究。方法:收集2017年1月至2018年12月期间在我院接受环磷酰胺辅助化疗的绝经前乳腺癌患者77例。患者年龄范围为26-48岁,并按年龄分为两组:≤35岁组为16例;>35岁组为61例。调查研究两组患者化疗前后的月经情况,以及血清激素水平(E、FSH、AMH)。同时进行动物实验,采用单剂量环磷酰胺(200 mg/kg)处理不同月龄组(3月龄和6月龄)雌性C57BL/6J小鼠,每组小鼠12例。在环磷酰胺处理前及处理后一周,检测小鼠血清AMH水平,计数小鼠卵巢卵泡数量。结果:环磷酰胺化疗后,>35岁组与≤35岁组间比较,>35岁组闭经率更高,复经率更低,血清AMH和E2水平下降幅度更大(P<0.05),FSH水平升高幅度也大于≤35岁组,但差异无明显统计学意义(P>0.05)。不同年龄组内比较,≤35岁组患者化疗后的血清AMH和E2下降水平无明显差异(P>0.05);血清FSH水平明显升高(P<0.05)。而>35岁组的患者化疗后,血清AMH和E2水平明显下降,FSH水平明显升高,差异均有统计学意义(P<0.05)。不同月龄组小鼠环磷酰胺处理前后,血清AMH水平明显下降,卵巢原始卵泡和生长卵泡数明显较少,差异均有统计学意义(P<0.05),且6月龄组小鼠下降程度更明显(P<0.05)。结论:环磷酰胺辅助化疗方案明显损伤患者卵巢功能,且对年龄越大者损伤程度越严重,更易导致不可逆性卵巢损伤。     

Comprehensive landscape and interference of clonal haematopoiesis mutations for liquid biopsy: A Chinese pan-cancer cohort

Tumour-derived DNA found in the plasma of cancer patients provides the probability to detect somatic mutations from circulating cell-free DNA (cfDNA) in plasma samples. However, clonal hematopoiesis (CH) mutations affect the accuracy of liquid biopsy for cancer diagnosis and treatment. Here, we integrated landscape of CH mutations in 11,725 pan-cancer patients of Chinese and explored effects of CH on liquid biopsies in real-world. We first identified 5933 CHs based on panel sequencing of matched DNA of white blood cell and cfDNA on 301 genes for 5100 patients, in which CH number of patients had positive correlation with their diagnosis age. We observed that canonical genes related to CH, including DNMT3A, TET2, ASXL1, TP53, ATM, CHEK2 and SF3B1, were dominant in the Chinese cohort and 13.29% of CH mutations only appeared in the Chinese cohort compared with the Western cohort. Analysis of CH gene distribution bias indicated that CH tended to appear in genes with functions of tyrosine kinase regulation, PI3K-Akt signalling and TP53 activity, suggesting unfavourable effects of CH mutations in cancer patients. We further confirmed effect of driver genes carried by CH on somatic mutations in liquid biopsy of cancer patients. Forty-eight actionable somatic mutations in 17 driver genes were considered CH genes in 92 patients (1.80%) of the Chinese cohort, implying potential impacts of CH on clinical decision-making. Taken together, this study exhibits strong evidence that gene mutations from CH interfere accuracy of liquid biopsies using cfDNA in cancer diagnosis and treatment in real-world.     

The catabolic pathways of in situ rhizosphere PAH degraders and the main factors driving PAH rhizoremediation in oil-contaminated soil

Rhizoremediation is a potential technique for polycyclic aromatic hydrocarbon (PAH) remediation; however, the catabolic pathways of in situ rhizosphere PAH degraders and the main factors driving PAH rhizoremediation remain unclear. To address these issues, stable-isotope-probing coupled with metagenomics and molecular ecological network analyses were first used to investigate the phenanthrene rhizoremediation by three different prairie grasses in this study. All rhizospheres exhibited a significant increase in phenanthrene removal and markedly modified the diversity of phenanthrene degraders by increasing their populations and interactions with other microbes. Of all the active phenanthrene degraders, Marinobacter and Enterobacteriaceae dominated in the bare and switchgrass rhizosphere respectively; Achromobacter was markedly enriched in ryegrass and tall fescue rhizospheres. Metagenomes of ¹³C-DNA illustrated several complete pathways of phenanthrene degradation for each rhizosphere, which clearly explained their unique rhizoremediation mechanisms. Additionally, propanoate and inositol phosphate of carbohydrates were identified as the dominant factors that drove PAH rhizoremediation by strengthening the ecological networks of soil microbial communities. This was verified by the results of rhizospheric and non-rhizospheric treatments supplemented with these two substances, further confirming their key roles in PAH removal and in situ PAH rhizoremediation. Our study offers novel insights into the mechanisms of in situ rhizoremediation at PAH-contaminated sites.     

Thr28突变对虎纹捕鸟蛛毒素-Ⅳ钠通道活性的影响

虎纹捕鸟蛛毒素-Ⅳ(HWTX-Ⅳ)是从虎纹捕鸟蛛粗毒中分离纯化到的一种新型多肽类神经毒素,能明显抑制表达于大鼠背根神经节细胞的河豚毒素敏感型(TTX-S)钠通道.为了更好地研究该毒素的结构与功能之间的关系,采用芴甲氧羰基(Fmoc)固相多肽化学合成法合成了用谷氨酸(Glu)替代HWTX-Ⅳ第28位苏氨酸残基的突变体T28D-HWTX-Ⅳ,线性多肽合成产物经反相高效液相色谱(HPLC)分离纯化后进行谷胱甘肽氧化复性.复性产物采用基质辅助激光解析飞行时间质谱(MALDI-TOF/TOF MS)技术鉴定分子质量,通过全细胞膜片钳电生理技术测定其电压门控钠通道药理学活性.当第28位Thr残基被Glu取代后,突变体T28D-HWTX-Ⅳ对表达于大鼠DRG细胞膜上的TTX-S钠通道的IC50值约为362 nmol/L,对TTX-S钠通道的抑制活性比天然HWTX-Ⅳ(IC50值=30 nmol/L)下降了约12倍,显示第28位的Thr残基是HWTX-Ⅳ与TTX-S型钠通道相互作用的关键活性残基.目前的研究为进一步探索HWTX-Ⅳ的结构与功能关系及新型镇痛药物的研发奠定了基础.     

Farsenyl pyrophosphate synthase is a potential molecular drug target of risedronate in Babesia bovis

A cDNA encoding farnesyl pyrophosphate synthase of Babesia bovis (BbFPPS) has been isolated, cloned and characterized as molecular drug target. Sequence analysis revealed that BbFPPS contains an open reading frame of 1011 bp with predicted 336 amino acids and molecular mass of 38 kDa. Antiserum raised in mice against recombinant BbFPPS expressed in Escherichia coli specifically reacted with native protein of B. bovis parasites by Western blot analysis and indirect immunofluorescent test. Enzymatic assay using recombinant BbFPPS revealed that the K_m value of the enzyme for isopentenyl pyrophosphate and dimethylallyl pyrophosphate was 2.494 ± 1.536 μM. Risedronate inhibited the activity of BbFPPS yielding IC₅₀ value of 8.4 ± 1.2 nM. Furthermore, the in vitro growth of B. bovis was significantly inhibited in the presence of a micromolar concentration of risedronate (IC₅₀ = 4.02 ± 0.91 μM). No regrowth of B. bovis was observed at 10 μM of risedronate in the subsequent viability test. These results demonstrate that BbFPPS is the molecular target of risedronate, which could inhibit the in vitro growth of B. bovis.     

128-Slice Acceletated-Pitch Dual Energy CT Angiography of the Head and Neck: Comparison of Different Low Contrast Medium Volumes

Background

Our study aims to evaluate the image quality and feasibility of 128-slice dual-energy CTA (DE-CTA) for supra-aortic arteries using reduced amounts of contrast medium (CM).

Methods

A prospective study was performed in 54 patients receiving CTA of the head and neck with a 128-slice dual-source CT system. Patients were randomized into two groups with a volume of either 40 mL of CM (Group I) or 50 mL of CM (Group II). Arterial and venous enhancements were recorded for quantitative assessment. Qualitative assessments for images without bone removal (BR) were based on a) the visualization of the circle of Willis and b) streak artifacts due to residual CM in the subclavian or internal jugular veins ipsilateral to injection of CM. Qualitative assessment of dual-energy images using BR was based on the presence of bone remnants and vessel integrity. Quantitative data was compared using the Student t test. The χ² test was used for the qualitative measurements of streak artifacts in veins while the Mann-Whitney U test was used for the qualitative measurements of images with BR.

Results

Arterial and venous attenuation was significantly higher in Group II (P=0.000). Image quality regarding the circle of Willis was excellent in both groups (3.90±0.30 for Group I and 4.00±0 for Group II) . Imaging of the internal jugular veins was scored higher in Group I (1.87±0.72) compared with Group II (1.48±0.51) (P=0.021). Within Group I using BR, mean scores for bone remnants did not differ significantly (P>0.05) but mean scores of vessel integrity (P<0.05) did.

Conclusions

Contrast-enhanced head and neck CTA is feasible using a scan protocol with low amounts of contrast medium (40 mL) on a 128-slice dual-energy CTA. The 40-mL protocol provides satisfactory image quality before and after dual-energy bone-removal post-processing.     

Natures of benzene-water and pyrrole-water interactions in the forms of σ and π types: theoretical studies from clusters to liquid mixture

A combined and sequential use of quantum mechanical (QM) calculations and classical molecular dynamics (MD) simulations was made to investigate the σ and π types of hydrogen bond (HB) in benzene-water and pyrrole-water as clusters and as their liquid mixture, respectively. This paper aims at analyzing similarities and differences of these HBs resulted from QM and MD on an equal footing. Based on the optimized geometry at ωb97xD/aug-cc-pVTZ level of theory, the nature and property of σ and π types of HBs are unveiled by means of atoms in molecules (AIM), natural bond orbital (NBO) and energy decomposition analysis (EDA). In light of the above findings, MD simulation with OPLS-AA and SPC model was applied to study the liquid mixture at different temperatures. The MD results further characterize the behavior and structural properties of σ and π types HBs, which are somewhat different but reasonable for the clusters by QM. Finally, we provide a reasonable explanation for the different solubility between benzene/water and pyrrole/water.

At-line near-infrared spectroscopy for monitoring concentrations in temperature-triggered glutamate fermentation

Rapid development in the glutamate fermentation industry has dictated the need for effective fermentation monitoring by rapid and precise methods that provide real-time information for quality control of the end-product. In recent years, near-infrared (NIR) spectroscopy and multivariate calibration have been developed as fast, inexpensive, non-destructive and environmentally safe techniques for industrial applications. The purpose of this study was to develop models for monitoring glutamate, glucose, lactate and alanine concentrations in the temperature-triggered process of glutamate fermentation. NIR measurements of eight batches of samples were analyzed by partial least-squares regression with several spectral pre-processing methods. The coefficient of determination (R ²), model root-mean square error of calibration (RMSEC), root-mean square error of prediction (RMSEP) and residual predictive deviation (RPD) of the test calibration for the glutamate concentration were 0.997, 3.11 g/L, 2.56 g/L and 19.81, respectively. For the glucose concentration, R ², RMSEC, RMSEP and RPD were 0.989, 1.37 g/L, 1.29 g/L and 9.72, respectively. For the lactate concentration, R ², RMSEC, RMSEP and RPD were 0.975, 0.078 g/L, 0.062 g/L and 6.29, respectively. For the alanine concentration, R ², RMSEC, RMSEP and RPD were 0.964, 0.213 g/L, 0.243 g/L and 5.29, respectively. New batch fermentation as an external validation was used to check the models, and the results suggested that the predictive capacity of the models for the glutamate fermentation process was good.