端粒长度与10种常见肌肉骨骼疾病的关系孟德尔随机化分析

背景:多项观察性研究表明,端粒长度与肌肉骨骼疾病之间存在潜在的关联,然而它们之间的潜在机制仍不清楚。目的:利用两样本孟德尔随机化分析来探索端粒长度与肌肉骨骼疾病之间的遗传因果关系。方法:从英国生物银行中获得端粒长度的全基因组关联研究汇总数据。从FinnGen财团中获得了关于10种常见肌肉骨骼疾病(骨坏死、骨髓炎、骨质疏松、类风湿关节炎、腰痛、椎管狭窄、痛风、肩周炎、强直性脊柱炎和下肢深静脉血栓)的全基因组关联研究汇总数据。使用逆方差加权、孟德尔随机化-Egger和加权中位数方法评估端粒长度与10种肌肉骨骼疾病的因果关系,逆方差加权作为主要的孟德尔随机化分析方法,并进行敏感性分析探讨结果稳健性。结果与结论:①逆方差加权法结果表明,遗传预测的端粒长度与类风湿关节炎(OR=0.78,95%CI:0.64-0.95,P=0.015)和骨坏死(OR=0.56,95%CI:0.36-0.90,P=0.016)风险之间存在负向因果关系,但未发现端粒长度与其他8种肌肉骨骼疾病之间存在因果关系(P均>0.05)。②敏感性分析结果表明因果关系稳健,孟德尔随机化-Egger截距分析未检测到潜在的水平多效性(P均>0.05)。③此项孟德尔随机化研究支持端粒长度对类风湿关节炎和骨坏死的保护作用的结论,然而,未来将需要更多的基础和临床研究来验证。

Activin A receptor type 1C single nucleotide polymorphisms associated with esophageal squamous cell carcinoma risk in Chinese population

BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and metastasis.Activin A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis through binding to dif-ferent ligands.AIM To evaluate the correlation between single nucleotide polymorphisms(SNPs)of ACVR1C and susceptibility to esophageal squamous cell carcinoma(ESCC)in Chinese Han population.METHODS In this hospital-based cohort study,1043 ESCC patients and 1143 healthy controls were enrolled.Five SNPs(rs4664229,rs4556933,rs77886248,rs77263459,rs6734630)of ACVR1C were assessed by the ligation detection reaction method.Hardy-Weinberg equilibrium test,genetic model analysis,stratified analysis,linkage disequi-librium test,and haplotype analysis were conducted.RESULTS Participants carrying ACVR1C rs4556933 GA mutant had significantly decreased risk of ESCC,and those with rs77886248 TA mutant were related with higher risk,especially in older male smokers.In the haplotype analysis,ACVR1C Trs4664229Ars4556933Trs77886248Crs77263459Ars6734630 increased risk of ESCC,while Trs4664229Grs4556933Trs77886248Crs77263459Ars6734630 was associated with lower susceptibility to ESCC.CONCLUSION ACVR1C rs4556933 and rs77886248 SNPs were associated with the susceptibility to ESCC,which could provide a potential target for early diagnosis and treatment of ESCC in Chinese Han population.

南美白对虾多密度高通量液相分型技术芯片设计与评估

针对南美白对虾育种研究中开展大规模全基因组重测序成本非常昂贵的问题,本研究对来自两个人工选择品种和四个市场领先公司的共180只南美白对虾进行全基因组重测序及全基因组单核苷酸多态性(Single nucleotide polymorphisms,SNPs)标记开发,并设计了12k、46k和92k三种密度规格的高通量液相分型技术芯片。对三款芯片性能进行评估的结果显示,三款芯片分别覆盖了11618、20055和20056个基因,基因覆盖度分别为43.50%、75.08%和75.09%;位于基因区位点分别为11618、35071和65138,占芯片总位点93.15%、76.24%和70.80%。次等位基因频率(Minor allele frequency,MAF)分别为0.27±0.11、0.34±0.12和0.27±0.12。三款芯片的位点在染色体上均匀分布,其中51.11%、76.63%和93.87%的位点平均间距范围为1~50 kB,均覆盖了MAPK、mTOR、Wnt和NOD-like受体等多个参与生长免疫功能的信号通路。本研究为南美白对虾HD-Marker体系建立提供了基础,从而为全基因组选择育种、种质资源评估、数量性状位点(Quantitative trait locus,QTL)定位和全基因组关联分析(Genome-wide association study,GAWS)提供技术支持。

Separation of Nucleotides in Swine Tissues Using Capillary Zone Electrophoresis

Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the method, separation and identification of nuclotides in swine tissues were completed.

肠道菌群与骨质疏松性骨折

背景:骨质疏松性骨折是骨质疏松症最严重的并发症,既往的研究已经证实了肠道菌群对骨骼组织具有调节作用,肠道菌群与骨质疏松性骨折有着重要关系,但是二者之间的因果关系尚不清楚。目的:使用孟德尔随机化(MR)方法探索肠道菌群与骨质疏松性骨折之间的因果关系。方法:从IEU Open GWAS数据库和芬兰数据库R9中分别获得了肠道菌群和骨质疏松性骨折的GWAS数据集,以肠道菌群作为暴露因素,骨质疏松性骨折作为结局变量,采用随机效应逆方差加权法、MR-Egger回归、加权中位数法、简单模型法以及加权模型法进行孟德尔随机化分析来评估肠道菌群与骨质疏松性骨折之间是否存在因果关系,通过敏感性分析来检验结果的可靠性和稳健性,并进行反向孟德尔随机化分析来进一步验证正向孟德尔随机化分析中确定的因果关系。结果与结论:①此孟德尔随机化分析结果表明,肠道菌群与骨质疏松性骨折之间存在因果关系。放线菌目(OR=1.562,95%CI:1.027-2.375,P=0.037)、放线菌科(OR=1.561,95%CI:1.027-2.374,P=0.037)、放线菌属(OR=1.544,95%CI:1.130-2.110,P=0.006)、丁酸球菌属(OR=1.781,95%CI:1.194-2.657,P=0.005)、粪球菌属-2(OR=1.550,95%CI:1.068-2.251,P=0.021)、Family ⅩⅢ UCG-001属(OR=1.473,95%CI:1.001-2.168,P=0.049)、产甲烷短杆菌属(OR=1.274,95%CI:1.001-1.621,P=0.049)、罗氏菌属(OR=1.429,95%CI:1.015-2.013,P=0.041)的丰度升高,会增加患者骨质疏松性骨折的风险;②拟杆菌纲(OR=0.660,95%CI:0.455-0.959,P=0.029)、拟杆菌目(OR=0.660,95%CI:0.455-0.959,P=0.029)、克里斯滕森氏菌科(OR=0.725,95%CI:0.529-0.995,P=0.047)、瘤胃球菌科(OR=0.643,95%CI:0.443-0.933,P=0.020)、肠杆菌属(OR=0.558,95%CI:0.395-0.788,P=0.001)、直肠真杆菌属(OR=0.631,95%CI:0.435-0.916,P=0.016)、毛螺菌科-UCG008(OR=0.738,95%CI:0.546-0.998,P=0.048)、瘤胃梭菌属-9(OR=0.492,95%CI:0.324-0.746,P=0.001)的丰度升高,会降低患者骨质疏松性骨折的风险。③文章通过孟德尔随机化方法发现了16种与骨质疏松性骨折相关的肠道菌群,即以肠道菌群为暴露因素,骨质疏松性骨折为结局变量,8种肠道菌群与骨质疏松性骨折呈正向因果关联,另外8种肠道菌群与骨质疏松性骨折呈负向因果关联。④此研究结果不仅为临床上骨质疏松性骨折的早期预测及潜在治疗靶点确定了新的生物标志物,还为骨组织工程中研究通过肠道菌群改善骨质疏松性骨折的发生与预后提供了实验基础和理论依据。

九十一种炎症蛋白与颈椎间盘退变的因果关系

背景:颈椎间盘退变是一种常见的退行性疾病,而炎症蛋白在颈椎间盘退变中起到重要作用,但其中的具体机制仍有待深入研究。目的:采用孟德尔随机化方法来评估91种炎症蛋白与颈椎间盘退变之间的潜在因果关系。方法:获取91种炎症蛋白的全基因组关联分析统计数据(从GCST90274758到GCST90274848)和芬兰数据库中颈椎间盘退变的全基因组关联分析数据(finngen_R10_M13_CERVICDISCV)。采用逆方差加权法、MR-Egger回归法、加权中位数法、加权模型法和简单模型法来研究炎症蛋白与颈椎间盘退变之间的因果关系。敏感性分析检验孟德尔随机化分析结果是否可靠,然后以同样方法进行反向孟德尔随机化分析。结果与结论:①正向分析结果表明,共有6种炎症蛋白与颈椎间盘退变有显著的因果关系,其中胶质细胞系源性神经营养因子水平(OR=1.095,95%CI:1.012-1.184,P=0.023)、白细胞介素4水平(OR=1.094,95%CI:1.002-1.194,P=0.045)和单核细胞趋化蛋白1水平(OR=1.062,95%CI:1.001-1.127,P=0.048)与颈椎间盘退变风险呈直接的正向因果关联;白细胞介素17 C水平(OR=0.906,95%CI:0.839-0.979,P=0.013)、白细胞介素18水平(OR=0.924,95%CI:0.866-0.986,P=0.017)和白细胞介素2水平(OR=0.894,95%CI:0.821-0.973,P=0.010)与颈椎间盘退变风险呈直接的负向因果关联。②反向分析结果表明,当颈椎间盘退变作为暴露数据时,与91种炎症蛋白均不具有显著因果关系。③敏感性分析结果显示:双向孟德尔随机化的Cochran’s Q检验、MR-Egger回归法和MR-PRESSO结果P值均大于0.05,表明炎症蛋白与颈椎间盘退变之间的因果效应分析不存在显著的异质性和多效性。④上述结果证实,胶质细胞系源性神经营养因子水平、白细胞介素4水平、单核细胞趋化蛋白1水平、白细胞介素17C水平、白细胞介素18水平和白细胞介素2水平与颈椎间盘退变之间可能具有较为显著的潜在因果关系,这为研究颈椎间盘退变潜在的机制、探索颈椎间盘退变的早期防治以及相关的药物治疗提供了有价值的线索。

内脏脂肪组织与骨关节炎因果关联的分析

背景:尽管肥胖与骨关节炎之间存在关联,但作为肥胖关键因素的内脏脂肪组织与骨关节炎之间的因果关系尚不明确。目的:采用两样本孟德尔随机化方法探讨内脏脂肪组织与骨关节炎的因果关系。方法:从大规模全基因组关联分析(GWAS)中筛选出221个与内脏脂肪组织强相关且无连锁不平衡的单核苷酸多态性。骨关节炎的汇总数据来自一项大型全基因组关联分析,纳入了来自9个不同人群多达826690名受试者(177517名骨关节炎患者和649173名对照)。采用两样本孟德尔随机化评估内脏脂肪组织与早期任意部位骨关节炎(45岁之前)、任意部位骨关节炎、膝骨关节炎、髋骨关节炎、膝/髋骨关节炎、脊柱骨关节炎、拇指骨关节炎、手指骨关节炎之间的因果关联。以逆方差加权为主要方法进行孟德尔随机化分析,同时将加权中位数法、MR-Egger法用于补充说明。结果与结论:①逆方差加权分析结果显示,内脏脂肪组织对早期任意部位骨关节炎(OR=1.91,95%CI:1.64-2.24,P=6.04×10^(-16))、任意部位骨关节炎(OR=1.44,95%CI:1.38-1.49,P=3.65×10^(-75))、膝骨关节炎(OR=1.87,95%CI:1.75-2.00,P=1.29×10-79)、髋骨关节炎(OR=1.34,95%CI:1.24-1.45,P=2.84×10^(-14))、膝/髋骨关节炎(OR=1.71,95%CI:1.62-1.80,P=2.97×10^(-83))、脊柱骨关节炎(OR=1.42,95%CI:1.31-1.54,P=8.89×10^(-17))、拇指骨关节炎(OR=1.26,95%CI:1.10-1.44,P=6.21×10^(-4))、手指骨关节炎(OR=1.29,95%CI:1.13-1.49,P=2.68×10^(-4))具有正向因果效应;②敏感性分析结果显示,内脏脂肪组织对8种骨关节炎的因果效应没有异质性、多效性或异常值;③结果提示内脏脂肪组织是骨关节炎的风险因素,过多的内脏脂肪组织可能会增加患骨关节炎的风险。

肥胖症与弥漫性特发性骨肥厚症的关系

背景:弥漫性特发性骨肥厚症是一种以韧带、肌腱等软组织及其附着部位的钙化和骨化为主要表现的全身性非炎症疾病,主要影响50岁以上的男性。研究表明肥胖症患者中弥漫性特发性骨肥厚症的发病率更高,但二者的因果关系尚不明确。目的:旨在通过孟德尔随机化分析方法,探讨肥胖症与弥漫性特发性骨肥厚症之间的因果关系。方法:研究选取全基因组关联研究数据库中的单核苷酸多态性作为工具变量,包括肥胖症和弥漫性特发性骨肥厚症相关数据。使用双向双样本孟德尔随机化分析方法评估肥胖症与弥漫性特发性骨肥厚症之间的因果关系,同时进行多效性、异质性和敏感性评价。结果与结论:孟德尔随机化分析发现肥胖症与弥漫性特发性骨肥厚症之间存在显著的正向因果关系。逆方差加权法显示“肥胖”(OR=1.111,95%CI:1.068-1.156,P=1.598×10^(-7))、“肥胖,热量过剩”(OR=1.093,95%CI:1.042-1.146,P=0.000)和“肥胖,其他/不详”(OR=1.109,95%CI:1.069-1.152,P=4.908×10^(-8))均与弥漫性特发性骨肥厚症显著相关。反向孟德尔随机化分析未发现弥漫性特发性骨肥厚症与肥胖症之间存在因果关系。多效性、异质性和敏感性检验结果验证了孟德尔随机化分析结果的可靠性。这表明肥胖症显著增加了弥漫性特发性骨肥厚症的风险,但弥漫性特发性骨肥厚症并不是肥胖症的危险因素。

椎间盘退行性变与473种肠道菌群的关系:芬兰数据库大数据信息可借鉴的意义

背景:有研究表明,调节肠道菌群可能会影响椎间盘退变的进程。然而,肠道菌群与椎间盘退变的因果关系尚不清楚。目的:采用孟德尔随机化方法来评估肠道菌群与椎间盘退变之间的潜在因果关系。方法:应用公开发表最新的473种肠道菌群的全基因组关联分析汇总统计数据和芬兰数据库R11中的椎间盘退变的全基因组关联分析汇总数据(椎间盘退变病例46 205例和对照组322 314例)。采用逆方差加权法、MR-Egger回归法、加权中位数法、加权模型法和简单模型法来研究肠道菌群与椎间盘退变之间的因果关系。敏感性分析用于检验孟德尔随机化分析结果是否可靠。反向孟德尔随机化以全部肠道菌群作为结局进行效应分析和敏感性分析。结果与结论:(1)正向孟德尔随机化的逆方差加权法结果显示,毛螺菌目,UBA-6960科、嗜热厌氧杆菌科、盐单胞菌科、丛毛单菌属、戈登氏菌属和欧陆森氏菌属与椎间盘退变呈现正相关。短螺旋体目、假单胞菌目、短螺旋菌科、CAG-776属、螺杆菌属、CAG-448种sp003150135、CAG-776种sp000438195、布劳特氏菌种-A sp000285855和汉逊布劳氏菌种与椎间盘退变呈现负相关。(2)反向孟德尔随机化结果显示,椎间盘退变与玫瑰巴氏菌属、地电细菌属C、弗氏埃希菌种、弗氏丙酸杆菌种、UBA-1777种sp900319835、铜绿假单胞菌种和韦氏芽孢杆菌种呈正相关,与明串珠菌属、普雷沃氏菌种sp000434975、布劳特氏菌种-A sp000285855、CAG-194种sp002441865和CAG-590种sp000431135呈负相关。(3)双向敏感性分析均未发现存在异质性或水平多效性。(4)上述结果说明,基于芬兰数据库探究肠道菌群与椎间盘退变的因果关系,为临床上椎间盘退变的早期预测及治疗探索了新的生物标志物。另外,对于中国生物医学研究,可以借鉴建立大型数据库,整合多中心的医疗数据,为肠道菌群与椎间盘退变关系的研究提供坚实基础,与其他国家的科研团队加强交流与合作,共同推动肠道菌群与疾病关系的研究,为全球医学发展作出贡献。

Synthesis of Isonucleoside-Incorporated Oligonucleotides and Their Binding Abilities with Complementary Sequences

Aim To synthesize isonucleoside-incorporated oligonucleotides and investigatetheir binding abilities with complementary sequences. Methods The synthesis was performed on DNAsynthesizer, and the binding behavior was investigated by thermal denaturation studies. Results Fourkinds of single isonucleoside containing oligonucleotides were synthesized. The results of thermaldenaturation showed that the existence of isonucleoside decreased the stability of duplex, and theeffect was more obvious when the isonucleoside was in the middle of the sequence. No obviousdifference was observed when 6'-OH of isonucleoside was free or was protected by allyl group.Conclusions The existence of isonucleoside in oli-gonucleotide makes chain twist and decreased thestability of duplex.

Response to an Escherichia coli K88 oral challenge and productivity of weanling pigs receiving a dietary nucleotides supplement

Background： Dietary nucleotides, considered as antibiotics alternative, were shown to have positive effects on intestinal hyperaemia, systemic immunity, small-intestinal growth, and hepatic composition in pigs. However, there is no previous research on nucleotide supplementation in weanling pigs under an oral challenged E. coil K88. Therefore, 2 experiments were conducted to investigate the effects of dietary nucleotides on weanling pig growth performance, nutrient digestibility, fecal score, and blood profile after being orally challenged with E. coli K88. Methods： In Exp. 1, a total of 140 weanling pigs [8.33 ± 0.33 kg of body weight （BW）, 28-d old] were used in this 42-d feeding trial. Pigs were distributed into 1 of 4 treatments, 5 pigs/pen （3 barrows and 2 gilts） and 7 pens/treatment. Treatments were a control basal diet （CON） or the CON supplemented with 150 （R150）, 220 （R220）, or 275 （R275） mg/kg to give the three treatment diets. In Exp. 2, 28 weanling pigs （BW = 8.40 ± 0.22 kg, 28-d old） were distributed into 1 of 4 treatments to give 1 pig/pen and 7 pens/treatment in a 42-d feeding and challenge trial. Dietary treatments were the same as in Exp. 1. 0n d 14, all those pigs （BW= 13.3±0.15 kg, 42-d old） were orally dosed with 1.5 mL suspension containing 10 cfu/mL of E. coli K88. Twenty four hours after challenge, blood and excreta samples were collected from each pigs for analysis. Fecal scores were measured on d 7, 14, 21, and 28 of the study. Results： In Exp. 1, overall BW, average daily gain （ADG）, gain/feed （G/F） ratio, and nutrient digestibilities were lower （P 〈 0.05） in CON group compared with the nucleotides fed pigs. In Exp. 2, after challenge, IgA, IgM, and IGF-I were higher （P〈 0.05） in the nucleotide groups compared with CON. However, the nucleotide groups had lower （P 〈 0.05） cortisol and TNF-o compared with CON. Fecal E. coil counts and fecal score for the nucleotide groups were lower （P 〈 0.05） than for CON. Conclusions： In conclusion, dietary nucleotides supplementation could improve growth performance, nutrient digestibility, immune status, microbial balance, reduce diarrhea, and provide protection against enterotoxigenic E. coli K88 infection in weanling pigs.

Oswestry功能障碍指数评分中久坐和体力活动水平与椎间盘退变的因果关系

背景:观察性研究表明,椎间盘退变会影响久坐和体力活动水平,然而Oswestry功能障碍指数评分中久坐和体力活动水平与椎间盘退变之间的因果关系尚不明确。目的:通过孟德尔随机化方法探讨Oswestry功能障碍指数评分中久坐和体力活动水平与椎间盘退变的因果关系。方法:从大规模人群全基因组关联分析中选择5个与Oswestry功能障碍指数评分中行为学相关的特征:看电视的时间、用电脑的时间、轻度/中度/剧烈体力活动,分别提取这些行为学相关特征的工具变量。结合Finn Gen最新第9版数据库中提取椎间盘退变作为结局,进行孟德尔随机化分析。使用逆方差加权法、MR-Egger回归、简单中位数法、加权中位数法、加权中值法等回归模型OR值和95%CI评估Oswestry功能障碍指数评分中久坐和体力活动水平与椎间盘退变的因果关系。使用Cochran’s Q检验异质性、MR-Egger截距检验多效性、“留一法”检验单核苷酸多态性观察暴露因素和椎间盘退变因果关系的敏感性。结果与结论:孟德尔随机化逆方差加权法结果显示,看电视/用电脑的时间与椎间盘退变发病风险呈正向因果关联(OR=1.775,95%CI:1.418-2.221,P<0.001)/(OR=1.384,95%CI:1.041-1.839,P<0.001),轻度体力活动与椎间盘退变发病风险呈反向因果关联(OR=1.000,95%CI:0.999-1.000,P=0.020);MR-Egger截距分析轻度体力活动与椎间盘退变存在潜在的水平多效性(P=0.005),看电视的时间、用电脑的时间与椎间盘退变不存在水平多效性(P=0.521,P=0.851)。Cochran’s Q异质性分析看电视的时间、用电脑的时间与椎间盘退变存在异质性(P=3.33×10^(-11),P=0.001),轻度体力活动与椎间盘退变没有观察到显著的异质性(P=0.186)。以上结果表明:Oswestry功能障碍指数评分中久坐和体力活动水平与椎间盘退变存在双向因果关系,即不仅椎间盘退变会影响Oswestry功能障碍指数评分中久坐和体力活动水平,Oswestry功能障碍指数评分中久坐和体力活动水平也会影响椎间盘退变。补充了轻度体力活动对椎间盘退变积极影响的遗传证据,表明中度/剧烈体力活动与椎间盘退变没有显著的因果关系,并扩大了长时间看电视/用电脑的久坐行为是椎间盘退变危险因素的证据基础。

Individual and Combined Effects of Nucleotides and Human Milk Oligosaccharides on Proliferation, Apoptosis and Necrosis in a Human Fetal Intestinal Cell Line

Nucleotides (NT) and human milk oligosaccharides (HMO) individually affect epithelial cell growth, but their combined effects had not been studied. Herein, the impact of NT and HMO on cell proliferation, apoptosis, necrosis and cell cycle in the fetal epithelial cell line (FHs-74 Int) was determined. Cells were incubated with media containing 2.5% FBS and no epidermal growth factor (Control);fucosyllactose (FL) mix [85% 2’FL/15% 3’FL], sialyllactose (SL) mix [40% 6’SL/10% 3’SL/50% sialic acid (SA)] or LNnT at 125, 250, 500 or 1000 μg/mL with and without 250 μg/mL NT (43% CMP, 18.5% UMP, 16.4% AMP, and 22.0% GMP) for 24 or 72 h. NT alone significantly increased proliferation, but did not affect cell cycle or apoptosis/necrosis. All HMO treatments at 1000 μg/mL significantly decreased proliferation and some were also inhibitory at 250 or 500 μg/mL. When NT and HMO were simultaneously added, NT ameliorated the anti-proliferative effect of HMO. FL significantly increased cells in S phase and SL and LNnT treatments significantly increased cells in G2/M and S phases, which concomitantly decreased cells in G0/G1. HMO with NT significantly decreased the percent of cells in the G2/M phase compared to HMO alone. Higher HMO doses significantly increased the percentage of apoptotic and necrotic cells compared to control. In conclusion, HMO reduced cell proliferation and this effect is partially ameliorated by NT. It appears that HMO initially induced apoptosis/necrosis, which was later evidenced by G2/M cell cycle arrest and decreased proliferation.

肠道菌群与骨质疏松症的遗传关系:来自英国数据库211个肠道微生物群分析

背景:骨质疏松症被定义为一种慢性代谢性骨病,大量的证据表明肠道菌群与骨质疏松症有关。然而,肠道菌群对骨质疏松症的因果关系尚不清楚。目的:采用双样本孟德尔随机化方法来评估肠道菌群与骨质疏松症之间的潜在因果关系。方法:使用MiBioGen联盟肠道菌群的全基因组关联分析汇总统计数据和英国生物样本数据库中骨质疏松症的全基因组关联分析数据。采用逆方差加权法(Inverse variance weighting,IVW)、MR-Egger回归法、加权中位数法、加权模型法和简单模型法来研究肠道菌群与骨质疏松症之间的因果关系。敏感性分析用于检验孟德尔随机化分析结果是否可靠。结果与结论:逆方差加权法结果表明,肠道菌群与骨质疏松症之间存在因果关系。克里斯滕森菌科R7属(MR Egger:β=-0.007;IVW:β=-0.004,P=0.028)、粪球菌3属(MR Egger:β=-0.008;IVW:β=-0.003,P=0.046)和毛螺菌属(MR Egger:β=-0.009;IVW:β=-0.004,P=0.003),可能是骨质疏松的保护性因素,而霍氏菌属(MREgger:β=0.006;IVW:β=0.002,P=0.033)和氧化真杆菌属(MREgger:β=0.001;IVW:β=0.003,P=0.046),可能为骨质疏松症潜在危险性因素。数据分析结果显示,氧化真杆菌属和霍氏菌属可增加骨质疏松风险,克里斯滕森菌科R7属、粪球菌3属和毛螺菌属可降低骨质疏松风险。此结论是否也适用于非欧洲人群,未来需要不同群体的大样本临床试验来验证。

Purine nucleotides and their metabolites in patients with type 1 and 2 diabetes mellitus

We measured the erythrocyte levels of principal nucleotides (ATP, ADP, AMP, GTP, GDP, GMP, IMP), nucleosides (Ado, Guo, Ino) and Hyp with HPLC. Purine concentrations were determined in the erythrocytes of 36 type 1 and 40 type 2 diabetic patients. The increased dephosphorylation of adenine and guanine nucleotides, indicated by increased Ado, Ino, Guo and Hyp concentrations as the products of purine nucleotide degradation, suggests serious energy metabolism disruptions in diabetes. An increase in AMP, GMP, IMP concentrations, as well as a decrease in AEC and GEC values, points to significant alterations in erythrocyte purine nucleotide concentration.

Frequency and Correlation of Nearest Neighboring Nucleotides in Human Genome

Zipf＇s approach in linguistics is utilized to analyze the statistical features of frequency and correlation of 16 nearest neighboring nucleotides （AA, AC, AG, …, TT） in 12 human chro- mosomes （Y, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, and 12）. It is found that these statistical features of nearest neighboring nucleotides in human genome： （i） the frequency distribution is a linear function, and （ii） the correlation distribution is an inverse function. The coefficients of the linear function and inverse function depend on the GC content. It proposes the correlation distribution of nearest neighboring nucleotides for the first time and extends the descriptor about nearest neighboring nueleotides.

Cleavage of Nucleotides by Lanthanide Metal Complexes

The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyadenosine monophosphate(dcAMP),5adenosine monophosphate(5AMP)and 5deoxyadenosine monophosphate(5dAMP)under mild conditions.Both cAMP and dcAMP were hydrolyzed sitespecifically,yielding predominantly 3monophosphates,the main products of the cleavage of 5AMP and 5dAMP included adenosine(Ado),deoxyadenosine(dAdo)and free phosphates respectively.A hydrolytic mechanism was proposed for cAMP,dcAMP,5AMP and 5dAMP.

DNA sequence representation by trianders and determinative degree of nucleotides

A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological prop-erties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the “strength” of branch. A general method for identifying DNA sequence “by triander” which can be treated as a unique “genogram” (or “gene passport”) is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.

Quick and Simple Spectrophotometric Method of Identification of the Thermal State of Meat on the Basis of Composition and Content of Free Nucleotides

At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the structural and mechanical properties of muscle tissue, the formation of taste and its biological value is known. In this article we compared methods for identifying the thermal state of meat based on the determination of the composition and content of free nucleotides by high-performance liquid chromatography (HPLC) and spectrophotometry [SF]. High-purity reference substances were used: free nucleotides—ATP, ADP, AMP, IMP and nucleosides-inosine and hypoxanthine. It has been experimentally established that the characteristic peaks of the absorption spectra for extracts of free nucleotides of meat frozen depended from thermal state of meat. The content of ATP is 21.8 times higher in meat frozen in a fresh state, and the amount of IMF is 12.3 times lower than in meat frozen after cooling. The results of studies of meat frozen using the HPLC method and the developed SF method show the adequacy of the data obtained by both methods. SF-method based on the determination of the optical density of the extracts of free nucleotides is recommended to justify the choice of technological process meat defrost modes.

STUDIES ON SYNTHESIS OF SUGAR NUCLEOTIDES

Glucosyl phosphotriester of adenosine and glucosyl thiophosphotriester of adenosine were synthesized by phosphite-triester methodology.