人淋巴瘤白血病细胞系Molt-4的31P核磁共振研究

用³¹P核磁共振(NMR)观察了人淋巴瘤白血病细胞系Molt-4的³¹P谱.NMR测试温度为37℃、20℃和4℃时,随着测试时间增长,细胞³¹P谱中ATP峰降低,无机磷峰升高,细胞³¹P谱的变化随测试温度降低依次减缓.实验温度为4℃,从收集细胞至开始NMR累加在30min内,NMR累加在60min内,获得活细胞的稳定的³¹P谱.根据细胞内无机磷的化学位移数值,对细胞内pH值进行了测定.     

噻胺酮麻醉剂对鼠S180肿瘤31P MRS的影响

对实验动物肿瘤进行活体³¹P MRS研究首要的是有效地固定动物.本文初步研究了用噻胺酮麻醉后的小鼠S180肿瘤在麻醉过程中³¹P MRS随时间的变异性.研究发现噻胺酮是一个安全系数高、起效快、麻醉过程适宜且对肿瘤的³¹P MRS无显著影响的麻醉药.因而噻胺酮适用于连续测定³¹P MRS的需要.     

活体肝胵Fasciola hepatica及其高氯酸萃取物的31P及13C NMR研究

本工作报道了用³¹P NMR谱定量分析活体肝胵Fasiciola hepatica中含磷化合物的实验方法及一些初步结果,测定了活体肝胵体内含磷化合物的弛豫时间T₁,观察了无灌注循环系统时肝胵体内pH值变化。利用高氯酸萃取物测得的³¹P NMR谱,定出了各谱峰的归属,观察了用含糖及缺糖培养液培养的肝胵糖类养料的代谢变化,并利用¹³C NMR谱肯定了肝胵体内主要含磷化合物之一的α-甘油磷酰胆碱³¹P NMR谱峰的归属。     

高温核磁共振探头

本文设计研制了一种用于动态核磁共振研究的高温探头,它适用于磁铁极间距离为30mm的核磁共振波谱仪,探头中样品处的温度从室温至1300K连续可变,探头既可用于质子(¹H)也可用于其它核(如¹¹B,³¹P,²³Na等),并给出了高温探头的结构、指标及实际应用于测量的例子。     

高场磁共振成像1H/31P双调谐射频线圈研究进展

在众多可产生磁共振现象的原子核中,¹H核凭借其在生物体中含量高、磁共振信号强的优势,成为磁共振成像的主要研究对象．但其它杂核在生命科学相关研究中同样具有不可替代的独特性,如³¹P核广泛参与了生物体内的能量代谢过程,是非质子成像研究领域的重要内容．MRI向更高场强的发展使得杂核成像逐渐普及,其核心部件是高质量的¹H/³¹P双调谐射频线圈．本文总结了与¹H/³¹P双调谐射频线圈相关的研究与应用,展示了9.4 T下小鼠脑的质子磁共振成像及磁共振磷谱,并讨论了高场¹H/³¹P双调谐射频线圈的潜在应用价值．     

活体动物代谢过程的31P NMR研究——方法与初步结果

利用表面线圈探头测得了小鼠大脑,大腿肌肉和肝脏的体内³¹P NMR谱图。观察到PCr,ATP,PME,PDE,P_i等化合物的共振峰,并确定了各谱峰的化学位移。由大脑的P_i化学位移计算得到其细胞内pH值为7.15.用差谱方法解决了因定位不准而造成的肝脏谱图不纯。观察了小鼠大脑在缺氧状态下的代谢变化过程。当O₂浓度降至2%时,PCr开始下降,降到1%时,P_i明显升高。从空气变化到1%的O₂含量,致使小鼠死亡,小鼠大脑的pH值从7.16降到6.46。     

S-烷基-O-(邻烷氧基羰基苯基)-硫(赶)代磷酰胺的NMR研究

本工作记录了六种通式为H₂N RS P=O-O-COOR'(R=Me,Et,i-Pr,n-Pr;R'=Me,Et,i-Pr)的有机磷农药的¹H、¹³C、³¹P NMR谱及¹³C,¹H异核化学位移相关谱。确定了各¹H、¹³C、³¹P的化学位移值和¹H-¹H、³¹P-¹H、³¹P-¹³C的偶合常数。讨论了核磁参数与分子结构和运动以及³¹P化学位移与生物活性之间的关系。     

金属核的磁共振研究*Ⅱ含磷配体铂(Ⅱ)络合物的195Pt和31P-NMR谱

本文测定了12个含苯基环戊基磷、亚磷酸、卤素等配体的铂(Ⅱ)络合物的¹⁹⁵Pt、³¹P-NMR谱,考察了溶剂、浓度、温度对¹⁹⁵Pt谱的影响,研究了¹⁹⁵Pt、³¹P化学位移、偶合常数与络合物几何构型的关系及对卤素的依赖关系。讨论1,2-丙二胺溶液中络合物³¹P谱的变化,以及各种含亚磷酸配体的铂络合物¹⁹⁵Pt和³¹P谱的变化。     

紫杉醇治疗小鼠S180肉瘤的体内31P MRS研究

为了研究紫杉醇治疗小鼠S180肉瘤的³¹P MRS参数的变化及这些参数的变化是否早于常规观察的瘤体积的变化.方法:利用表面线圈³¹P NMR方法,研究小鼠皮下接种的S180肉瘤.结果:用药48h后给药组的PCr/Pi、β-NTP/Pi、PME/β-NTP比值与对照组有显著性差别(P<0.05),而肿瘤体积在给药组和对照组之间无显著性差别,³¹P MRS参数的变化早于瘤体积变化.结论:小鼠S180肉瘤³¹P MRS不仅可以给出定量的结果,而且可以较早地显示出治疗的效果.     

31P NMR表面线圈探头射频场B1的空间分布特性研究

对本实验室自制的³¹P表面线圈探头的射频场B₁强度的空间分布和脉冲宽度进行了初步研究.结果表明该表面线圈中心的90°脉冲约为10μs.得到的信号主要是线圈圆周内射频场B₁作用的结果,在垂直线圈平面的方向上随距离增加,信号迅速减弱.因此该表面线圈射频场B₁有效的作用范围在一个近半圆球体内,底面积半径约为线圈外半径,有效作用深度约为线圈半径.     

In vivo 31P MRS of human brain at high/ultrahigh fields: a quantitative comparison of NMR detection sensitivity and spectral resolution between 4 T and 7 T

The primary goal of this study was to establish a rigorous approach for determining and comparing the NMR detection sensitivity of in vivo ³¹P MRS at different field strengths (B₀). This was done by calculating the signal-to-noise ratio (SNR) achieved within a unit sampling time at a given field strength. In vivo ³¹P spectra of human occipital lobe were acquired at 4 and 7 T under similar experimental conditions. They were used to measure the improvement of the human brain ³¹P MRS when the field strength increases from 4 to 7 T. The relaxation times and line widths of the phosphocreatine (PCr) resonance peak and the RF coil quality factors (Q) were also measured at these two field strengths. Their relative contributions to SNR at a given field strength were analyzed and discussed. The results show that in vivo ³¹P sensitivity was significantly improved at 7 T as compared with 4 T. Moreover, the line-width of the PCr resonance peak showed less than a linear increase with increased B₀, which leads to a significant improvement in ³¹P spectral resolution. These findings indicate the advantage of high-field strength to improve in vivo ³¹P MRS quality in both sensitivity and spectral resolution. This advantage should improve the reliability and applicability of in vivo ³¹P MRS in studying high-energy phosphate metabolism, phospholipid metabolism and cerebral biogenetics in the human at both normal and diseased states noninvasively. Finally, the approach used in this study for calculating in vivo ³¹P MRS sensitivity provides a general tool in estimating the relative NMR detection sensitivity for any nuclear spin at a given field strength.     

小鼠大脑急性缺血过程中31P NMR研究

利用³¹P NMR研究了小鼠大脑在急性缺血状态下能量代谢的特点,结扎带迷走神经的颈总动脉后,PCr/Pi、β-ATP/Pi比值迅速下降,且PCr/Pi下降速度较快,同时脑细胞内酸中毒加重.缺血5min后恢复供血,可部分地逆转缺血造成的损伤.     

Alzheimer''s disease histologically proven studied by MRI and MRS: Two cases

Two patients affected by severe Alzheimer's disease (AD) were investigated by MRI and image-guided ³¹P MRS. In one case, ¹H MRS was additionally performed. In both cases the diagnosis of AD was confirmed, post mortem, by the pathologist. The spectral parameters of the ³¹P MR spectra were estimated by fitting the ³¹P MR signals in the time domain. Our ³¹P MRS results suggest that it is possible to detect the membrane catabolism, as indexed with the level of PDE resonances visible in in vivo ³¹P MRS, at least in severe AD cases. The ¹H spectrum from AD brain showed a marked decrease of NAA signal respect to choline.     

生物活性有机磷化合物31P NMR化学位移的计算

利用统一计算公式,计算了106个各类开环有机磷化合物的化学位移值,与文献值比较吻合.结果表明:统一计算公式比以往各种化学位移计算方程具有更普遍的意义.核外电子云球对称效应是影响³¹P NMR化学位移的主要因素之一.