Correlation between cerebral neurotransmitters levels by proton magnetic resonance spectroscopy and HbA1c in patients with type 2 diabetes

BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.

7.0T nuclear magnetic resonance evaluation of the amyloid beta(1–40) animal model of Alzheimer's disease: comparison of cytology verification

3.0T magnetic resonance spectroscopic imaging brain function in Alzheimer＇s disease. However, is a commonly used method in the research ot the role of 7.0T high-field magnetic resonance spectroscopic imaging in brain function of Alzheimer＇s disease remains unclear. In this study, 7.0T magnetic resonance spectroscopy showed that in the hippocampus of Alzheimer＇s disease rats, the N-acetylaspartate wave crest was reduced, and the creatine and choline wave crest was elevated. This finding was further supported by hematoxylin-eosin staining, which showed a loss of hippocampal neurons and more glial cells. Moreover, electron microscopy showed neuronal shrinkage and mitochondrial rupture, and scanning electron microscopy revealed small size hippocampal synaptic vesicles, incomplete synaptic structure, and reduced number. Overall, the results revealed that 7.0T high-field nuclear magnetic resonance spectroscopy detected the lesions and functional changes in hippocampal neurons of Alzheimer＇s disease rats in vivo, allowing the possibility for assessing the success rate and grading of the amyloid beta （1-40） animal model of Alzheimer＇s disease.

Investigation of formation of dimeric G-quadruplex of HIV-1 integrase inhibitor by nuclear magnetic resonance

In this research, an unusually dimeric G-quadruplex of d（GGGTGGGTGGGTGGGT） （SI）, the potent nanomolar HIV-1 integrase inhibitor, was detected by nuclear magnetic resonance （NMR）. This result has been confirmed by electrospray ionization mass spectrometry （ESI-MS） and circular dichroism （CD）.

Three dimensional structure prediction and proton nuclear magnetic resonance analysis of toxic pesticides in human blood plasma

The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural prop- erties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using ~H-NMR. The ~H- NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm （8） with the coupling constants of 11-16 Hz （Je-cns）. In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm （8） with the coupling constant of 10 Hz （Je-cH2） and the methylene resonances was 4.2-4.4 ppm （8） with the coupling constant of 0.8 Hz （Jp-cH3）, respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.

Specific Patterns of Spinal Metabolite Ratio Underlying a-Me-5-HTevoked Pruritus Compared with Compound 48/80 Based on Proton Nuclear Magnetic Resonance Spectroscopy

Summary:Mechanisms of pruritus are implicated in the dysregulation of the metabolites in the spinal cord.We investigated pruritus behavioral testing in three groups of young adult male C57B1/6 mice,including one group treated with normal saline,while the other groups intradermally injected with a-Me-5-HT(histamine-independent pruritogen),compound 48/80(histaminedependent pruritogen)at the nape skin of the neck,respectively.Proton nuclear magnetic resonance spectroscopy(MRS)was used to compare spinal metabolites from the vertebral cervical among three groups,and to study the association of spinal metabolite ratio and pruritus intensity.The MRS-measured N-acetylaspartate-to-myoinositol ratio(NAA/Ins)was significantly correlated with the number of scratches between normal saline group and 48/80 group or a-Me-5-HT group(both P<0.0001),indicating that NAA/Ins may be a robust surrogate marker of histamine-independent/dependent pruritogen.There was significant difference in Glu/Ins between normal saline group and 48/80 group(P=0.017),indicating that Glu/Ins may be a surrogate marker of histamine-dependent pruritogen,while GABA/Ins was highly significantly different between normal saline group and a-Me-5-HT group(P=0.008),suggesting that GABA/Ins may be a surrogate marker of histamineindependent pruritogen.MRS may reflect the extent of pruritus intensity elicited by a-Me-5-HT and compound 48/80 with sensitivity similar to the number of scratches,and above potential markers need to be further validated in pre-clinical and clinical treatment trials.

核磁共振氢谱法（~1H-NMR）测定西他沙星标准物质的含量

目的建立核磁共振氢谱法测定西他沙星标准物质的绝对含量。方法采用Bruker AVANCE-500型和AVANCE-300型仪器,分别以盐酸吉西他滨和齐多夫定为内标,西他沙星中质子信号在δ8.69,δ7.76,δ3.43和δ3.14,盐酸吉西他滨质子信号在δ8.12,δ6.21和δ6.02,齐多夫定中质子信号在δ7.61和δ6.01作为定量峰,0.5 mL DMSO-d6∶氚代盐酸（DCl,44.8mg·L^-1）=4∶1为溶剂,测定条件为：探头温度303K,谱宽11.0,中心频率4.9,脉冲序列为zg 30°,延迟时间20s,采样次数32次,窗函数0.3Hz。结果在此条件下,样品与内标盐酸吉西他滨及齐多夫定的定量峰分离良好,进样精密度及重复性较好,线性范围宽,样品与内标盐酸吉西他滨和齐多夫定质量比分别在0.354 9~1.343 9和0.312 4~1.189 2范围内,其线性拟合方程分别为：Y=1.440 9X＋0.017 8（r=1.000 0,n=5）,Y=1.634 6X＋0.008 5（r=0.999 9,n=5）。结果西他沙星的含量分别为99.26%（RSD为0.06%）和99.22%（RSD为0.17%）。结论该方法准确、专属、简便、快速,适用于该药物标准物质的绝对含量测定。

基于~1H-NMR的原发性肝癌脾虚湿盛证患者尿液代谢组学研究

目的 通过对原发性肝癌脾虚湿盛证患者尿液代谢组学研究,以探讨原发性肝癌脾虚湿盛证患者代谢变化机理。方法 选取35例脾虚湿盛证肝癌患者、35例非脾虚湿盛证肝癌患者和40例和平质健康体检者的尿液进行核磁共振氢谱检测(proton nuclear magnetic resonance spectroscopy,1H-NMR),谱图积分结果使用正交偏最小二乘判别分析法(partial least square discriminant analysis,PLS-DA)进行分析。结果 原发性肝癌患者尿中肌酐、马尿酸、氧化三甲胺(TMAO)、柠檬酸、丙氨酸、亮氨酸、谷氨酸含量均较较对照组健康人低(P<0.01),且脾虚湿盛证组低于非脾虚湿盛证组(P<0.05);而牛磺酸、琥珀酸的含量显著高于对照组,且脾虚湿盛证组高于非脾虚湿盛证组(P<0.05),差异具有统计学意义。原发性肝癌患者尿中乙酸含量显著性高于对照组(P<0.05),而在脾虚湿盛证组与非脾虚湿盛证组中比较,无统计学差异。结论 原发性肝癌患者存在糖代谢、脂类代谢、氨基酸分解代谢紊乱,且原发性肝癌脾虚湿盛证患者体内多种生命代谢的紊乱程度较非脾虚湿盛证患者严重。

基于^(1)H-NMR的冠心病血瘀证、痰浊证的代谢组学研究

目的:冠心病以其极高的发病率严重威胁着人类的健康,对冠心病药物治疗及作用靶点的研究仍非常迫切。本研究旨在运用核磁共振氢谱(^(1)H nuclear magnetic resonance spectroscopy,^(1)H-NMR)代谢组学技术建立冠心病血瘀证及痰浊证的指纹代谢图谱,寻找这2种证型的血浆标志性代谢物,并揭示血府逐瘀汤治疗冠心病血瘀证的机制。方法:采集符合纳入标准的69例冠心病血瘀证患者、60例冠心病痰浊证患者及40例健康对照受试者的清晨空腹血浆,基于^(1)H-NMR构建冠心病血瘀证及痰浊证的^(1)H-NMR指纹代谢图谱。使用多元统计分析方法主成分分析(principal component analysis,PCA)、正交化偏最小二乘判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)寻找冠心病血瘀证及冠心病痰浊证的标志性代谢物。随机抽取冠心病血瘀证患者30例,予血府逐瘀汤治疗30 d,对治疗前后的清晨空腹血浆进行^(1)H-NMR检测,分析冠心病血瘀证患者服药前后标志性代谢物的变化。结果:冠心病血瘀证组与对照组存在显著性差异的代谢物有以下15种:3-羟基丁酸、乳酸、丙氨酸、谷氨酸、谷氨酰胺、丙酮酸、磷脂酰胆碱、甘油磷脂酰胆碱、甘氨酸、葡萄糖、苯丙氨酸、柠檬酸、酪氨酸、甲酸盐、极低密度脂蛋白,除葡萄糖、3-羟基丁酸、极低密度脂蛋白水平升高外,其他12种代谢物水平均下降。冠心病痰浊证组与对照组存在显著性差异的代谢物有以下16种:缬氨酸、乳酸、丙氨酸、N-乙酰-β-葡萄糖苷酶、谷氨酸、谷氨酰胺、丙酮酸、肌酸、胆碱、甘氨酸、葡萄糖、苯丙氨酸、柠檬酸、组氨酸、酪氨酸、甲酸盐,除葡萄糖和胆碱2种水平升高外,其他14种代谢物水平均下降。冠心病血瘀证患者服用血府逐瘀汤治疗后胆碱、磷脂/甘油磷脂类、肌酸、脂质、柠檬酸水平升高,乳酸水平下降。结论:^(1)H-NMR结合多元统计学方法能够建立诊断冠心病血瘀证和痰浊证证型的有效模型,找到证型相关标志性代谢物;血府逐瘀汤可通过调节脂质代谢、能量代谢治疗冠心病血瘀证。

Fingerprinting Analysis of Rhizoma Chuanxiong of Commercial Types using ~1H Nuclear Magnetic Resonance Spectroscopy and High Performance Liquid Chromatography Method

The ^1 H nuclear magnetic resonance （^1 H NMR） fingerprints of fractionated non-polar extracts （control substance for a plant drug （CSPD） A） from Rhizoma chuanxiong, the rhizomes of Ligusticum chuanxiong Hort., of seven specimens from different sources were measured on Fourier Transform （FT）-NMR spectrometer and assigned by comparing them with the ^1 H NMR spectra of the isolated pure compounds. The ^1 H NMR fingerprints showed exclusively characteristic resonance signals of the major special constituents of the plant. Although the differences in the relative intensity of the ^1H NMR signals due to a discrepancy in the ratio of the major constituents among these samples could be confirmed by high performance liquid chromatography analysis, the general features of the ^1H NMR fingerprint established for an authentic sample of the rhizomes of L. chuanxiong e. hibited exclusive data from those special compounds and can be used for authenticating L. Chuanxiong species.

Establishing 1H nuclear magnetic resonance based metabonomics fingerprinting profile for spinal cord injury： a pilot study

Background Spinal cord injury （SCI） is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using 1H nuclear magnetic resonance （NMR） based metabonomics methodology and principal component analysis techniques.Methods Nine Sprague-Dawley （SD） male rats were randomly divided into SCI, normal and sham-operation control groups. Plasma samples were collected for 1H NMR spectroscopy 3 days after operation. The NMR data were analyzed using principal component analysis technique with Matlab software.Results Metabonomics analysis was able to distinguish the three groups （SCI, normal control, sham-operation）. The fingerprinting atlas indicated that, compared with those without SCI, the SCI group demonstrated the following characteristics with regard to second principal component： it is made up of fatty acids, myc-inositol, arginine, very low-density lipoprotein （VLDL）, low-density lipoprotein （LDL）, triglyceride （TG）, glucose, and 3-methyl-histamine.Conclusions The data indicated that SCI results in several significant changes in plasma metabolism early on and that a metabonomics approach based on 1H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes. The results also provided support for further development and application of metabonomics technologies for studying SCI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

Prediction of Response of Collagen-induced Arthritis Rats to Methotrexate： An ~1H-NMR-based Urine Metabolomic Analysis

Over one half the patients with rheumatoid arthritis （RA） are being treated with methotrexate （MTX）. Although well proven, the efficacy of MTX varies in individual patients. This study examined the metabolic biomarkers that can be used to predict the therapeutic effect of MTX by using metabolomic analysis. Rats were immunized with collagen to rapidly cause collagen-induced arthritis （CIA） and then treated with 0.1 mg/kg MTX for 4 weeks. The clinical signs and the histopathological features of CIA were observed to evaluate the therapeutic effects. Urine samples of CIA rats were collected, and analyzed by using 600 M 1H-nuclear magnetic resonance （1H-NMR） for spectral binning after the therapy. The urine spectra were divided into spectral bins, and 20 endogenous metabolites were assigned by Chenomx Suite. Multivariate analyses were performed to identify the spectral pattern of endogenous metabolites related to MTX therapy. The results showed that the clustering of the spectra of the urine samples from the responsive rats （n=20） was different from that from the non-responsive rats （n=11）. Multivariate analysis showed difference in metabolic profiles between the responsive and non-responsive rats by using partial least squares-discrimination analysis （PLS-DA） （R2=0.812, Q2=0.604）. In targeted profiling, 13 endogenous metabolites （uric acid, taurine, histidine, methionine, glycine, etc.） were selected as putative biomarkers for predicting therapeutic response to MTX. It was suggested that 1H-NMR-based metabolomic analysis can be used to predict the therapeutic effect of MTX, and several metabolites were found to be related to the therapeutic effects of MTX.

A Preliminary Urinary Metabolomics Study of Sprague-Dawley Rats after Short‑term Ketamine Administration by Proton Nuclear Magnetic Resonance Spectroscopy

Drug abuse has become a global problem.The mass spectrometry‑based metabolic consequences of ketamine administration in anesthesia and therapy have been well studied,but to the best of our knowledge,metabolomic studies of ketamine abuse based on nuclear magnetic resonance(NMR)spectroscopy are still lacking.In this study,twenty Sprague–Dawley rats were randomly assigned into two groups:a control group(n=10)and a ketamine group(n=10).The animals in the ketamine group received intraperitoneal injections of ketamine twice daily at 12‑h intervals at progressively increasing doses over a period of 9 days,while the control group received an equal volume of saline.The urine samples were collected for 24 h at days 0,1,3,5,7,and 9 for the metabolomics study.The metabolic changes in urine after short‑term ketamine administration were analyzed by proton NMR coupled with multivariate statistical analysis.The results indicated that short‑term ketamine exposure led to significant alterations of the metabolites in the urine of the rats.Specifically,1,3,7‑trimethyluric acid,1,3‑dimethyluric acid,acetoacetic acid,acetylglycine,creatine,sarcosine,dimethylglycine,glycine,and theobromine were significantly increased in the urine.Significant changes were also found in metabolites related to antioxidant and energy metabolism,including acetoacetic acid,succinate,1,3,7‑trimethyluric acid,1,3‑dimethyluric acid,creatine,and taurine.Our findings indicated that short‑term ketamine administration leads to disorder of energy metabolism and oxidative stress.In addition,the modified metabolites identified could serve as the new biological markers and potential biological indices reflecting the underlying mechanism of ketamine abuse.

基于T_(1)-T_(2)二维核磁共振方法研究温度对复合驱提高采收率的影响

一维核磁共振(nuclear magnetic resonance,NMR)测量方法无法分辨驱替过程中油水弛豫信号,因此采用T_(1)-T_(2)二维核磁共振测量方法分辨岩心中流体类型及分布。通过驱替实验研究聚合物BRH-325和表面活性剂GSS-A复合体系分别在65、70、75℃条件下的驱油效果,并利用纵向弛豫-横向弛豫(T_(1)-T_(2))二维NMR测量方法对岩心内部的油水两相驱替规律及分布特征进行可视化研究,并对比实验测量结果与NMR测量结果。结果表明:70℃下,复合驱提高采收率的效果最为明显。因此,T_(1)-T_(2)二维核磁共振能够直接、直观区分驱替过程中油水的弛豫信号。

Two-state kinetics characterized by image analysis of nuclear magnetic resonance spectra

Nuclear magnetic resonance (NMR) spectros-copy has become an important tool in modern biological research. NMR spectra image analysis can be used to analyze the kinetics of biomacromolecular conformational changes. The relationship between the image parameters and the protein dynamics was investigated by using a small globular protein ω-conotoxin SO3 (ω-CTX SO3). The physical meanings of the image parameters were characterized from the results. Comparison of the data from the traditional integral area of specific resonance peaks method and the NMR image analysis method showed the advantages of using NMR spectra image analysis for kinetic analysis of two-state processes monitored by 1D proton NMR.

利用^1H MRS进行在体乳腺癌中复合胆碱外参照法定量的研究

目的探讨如何用外参照法利用氢质子磁共振波谱(1HMRS)对在体乳腺癌中的复合胆碱进行绝对定量。方法配制5个不同浓度的胆碱测试模型及一个胆碱校对模型。在基本相同的条件下,对各测试模型的同一位置进行MRS采集,统计胆碱峰峰下面积与胆碱浓度之间是否呈线性相关。对水模进行T1WI成像,绘制不同位置信号强度的变化曲线。对同一校对模型的同一位置采用不同大小的体素进行MRS采集,统计体素大小与胆碱峰峰下面积是否呈线性相关。测量胆碱测试模型及校对模型中胆碱的T1及T2值。验证胆碱浓度绝对定量的校对公式。对7例乳腺癌病人进行乳腺MRS采集,利用校对公式以胆碱校对模型中的胆碱浓度为参照计算出乳腺癌中复合胆碱的浓度。结果胆碱测试模型的胆碱峰峰下面积与胆碱浓度之间呈线性相关。同一模型同一位置胆碱峰峰下面积与体素大小呈线性相关。测试模型及校对模型中胆碱的T1及T2值分别为1902.5/1032.8、2426.3/989.4。利用校对公式估计出的校对模型的胆碱浓度为(5.2±1.0)mM,与校对模型的实际浓度比较二者无显著差异(t=0.6,P>0.05)。7例乳腺癌中的复合胆碱浓度为(3.64±2.52)mM。结论外参照法是进行乳腺癌中复合胆碱浓度定量的可行及可靠的方法。

葡萄糖基(α-1→6)β-环糊精的波谱学数据与结构确证

对酶法合成的葡萄糖基(α-1→6)β-环糊精的红外(IR)光谱、质谱(MS)、氢谱(1H-NMR)、碳谱(13C-NMR)、氢氢相关谱(1H1-H COSY)、氢氢完全相关谱(1H1-H TCOSY)、异核单量子相干相关谱(HSQC)和异核多键相关谱(HMBC)进行了解析报道,对所有的1H-NMR和13C-NMR谱进行了归属,讨论了红外特征吸收峰所对应的官能团的振动形式。

氯化1-甲基-3-丁基咪唑的制备与表征

用N-甲基咪唑和氯代正丁烷反应,合成了作为室温离子液体中间体的氯化1-甲基-3-丁基咪唑,对其合成过程进行优化和改进。通过核磁共振谱对氯化1-甲基-3-丁基咪唑进行化学结构的表征,使用差示扫描量热法对合成的中间体进行熔点和熔化热的测定,合成了纯度较高的氯化1-甲基-3-丁基咪唑。

1H NMR研究溶质浓度对三碳多元醇水溶液氢键作用以及玻璃化的影响

为考察溶质浓度对三碳多元醇水溶液氢键作用以及不同物质玻璃态形成能力的影响,采用~1H NMR外标法研究不同浓度的1-丙醇（NPA）,2-丙醇（IPA）,1,2-丙二醇（PG）,1,3-丙二醇（PD）和丙三醇（glycerol）的水溶液在室温常压下质子化学位移.结果表明：具有CH_3CH（OH）一基团的PG烷基质子的化学位移变化趋势与其他几种醇相比有较大差异.醇羟基质子与水分子的氧形成较强O-H…O氢键.相同摩尔分数下,羟基数的增加导致水质子和羟基质子的化学位移降低,而且羟基位置不同也会导致水质子和羟基质子化学位移差异.这几种三碳多元醇碱性强弱的顺序和降低冰的均相成核温度能力的顺序一致,即glycerol〉PG〉PD〉IPA〉NPA,~1H NMR技术表明glycerol和PG更适合用作低温保护剂.

4-氨基-5-[2-(4-氯苯氧甲基)苯并咪唑-1-亚甲基]-1,2,4-三唑-3-硫酮的核磁共振研究

在无水乙醇和KOH存在下,将2-(4-氯苯氧甲基)-1-苯并咪唑乙酰肼(1)与CS2反应,合成出了中间体酰肼二硫代甲酸钾盐。此中间体再与过量的水合肼反应,经环化得到一种新化合物4-氨基-5-[2-(4-氯苯氧甲基)苯并咪唑-1-亚甲基]-1,2,4-三唑-3-硫酮。采用元素分析、IR及NMR技术确定了新化合物的结构,并利用2D NMR技术对其两种异构体(硫酮和硫醇)的1H和13C NMR谱带进行了全归属,给出了相应的偶合常数J值以及异构体所占的比例。实验表明,新化合物在DMSO中存在硫酮和硫醇两种异构体的互变,并且硫酮占主导,含量为81.9%,而硫醇的含量仅为18.1%。

N-取代苯基马来酰亚胺合成的^1H—NMR研究

采用核磁共振氢谱对合成的N 取代苯基马来酰亚胺系列产物和反应过程的跟踪表征.通过研究产物和反应过程混合物的碳碳双键上质子、苯环上质子的化学位移和强度变化,判断反应进行程度.同时还研究了取代基对反应产物和中间产物的碳碳双键质子和苯环质子偶合常数的影响.