重度OSAS患者前额叶皮质及岛叶1H-MR波谱研究

目的:利用氢质子MRS(1H-MRS)探讨重度阻塞性呼吸睡眠暂停综合症(Severe obstructive sleep apnea syndrome,S-OSAS)患者前额叶皮质及岛叶脑代谢产物特征。方法:选择18例S-OSAS患者(S-OSAS组)和15名健康志愿者(HC组)行左侧前额叶皮质及岛叶1H-MRS检查,测量两组左侧前额叶皮质区及岛叶N-乙酰天冬氨酸/肌酸(NAA/Cr)、胆碱/肌酸(Cho/Cr)值。对患S-OSAS累计时间与前额叶皮质及岛叶NAA/Cr作直线相关分析。结果:与正常对照组相比,S-OSAS患者左侧前额叶皮质、岛叶NAA/Cr比值降低,分别为1.43±0.47、1.34±0.06,对照组分别为1.51±0.65、1.45±0.07;S-OSAS组患者左侧前额叶皮质、岛叶Cho/Cr分别为0.90±0.08、1.19±0.13,对照组分别为0.87±0.07、1.09±0.02,两组差异有统计学意义。前额叶皮质及岛叶代谢物NAA/Cr与患S-OSAS累计时间成负相关性(r值分别为-0.965、-0.955,P<0.01)。结论:1H-MRS显示S-OSAS患者前额叶皮质及岛叶病理生理变化,从该区代谢物的改变反应出S-OSAS患者执行及情感功能的异常,其NAA/Cr改变程度与患S-OSAS累计时间相关。     

1H-MRS评估慢性肝病脑部代谢异常与肝硬化的相关性

目的:利用~1H-MRS研究慢性肝病脑部代谢改变,并探讨~1H-MRS评估慢性肝病脑部代谢异常与肝硬化Child-Pugh分级的相关性。方法:选取经临床确诊为慢性肝炎肝硬化患者42例(child A 19例,child B14例,child C 9例)及健康志愿者15例(对照组),行磁共振平扫及磁共振单体素~1H-MRS检查,计算相关代谢物N-乙酰天门冬氨酸(NAA)、谷氨酰胺复合物(Glx)、胆碱(Cho)、肌醇(mI)和肌酸(Cr)的峰下面积及前四项指标与Cr的比值(NAA/Cr、Glx/Cr、Cho/Cr、mI/Cr),并进行统计学分析,同时对相关代谢物的变化与肝硬化Child-Pugh分级及肝硬化Child-Pugh分级与肝性脑病的关系进行相关性分析。结果:~1HMRS分析显示与正常对照组相比,慢性肝炎肝硬化组Glx/Cr值升高,Cho/Cr与mI/Cr值降低,且差异均有统计学意义(P0.05);不同程度肝硬化病例组对比显示,Glx/Cr值均随着肝硬化程度加重而增大,且Glx/Cr值的差异在child A、child B、child C组中均有统计学意义(P0.05);肝性脑病(HE)组与非肝性脑病组脑代谢物峰下面积比值Glx/Cr、Cho/Cr、mI/Cr比较,差异有统计学意义(P0.05);Child-Pugh分级与Glx/Cr呈正相关,与Cho/Cr、mI/Cr呈负相关;随着肝硬化程度加重,肝性脑病出现概率越高,差异有统计学意义(P0.05)。结论:~1H-MRS作为一种无创性的评价手段,能够反映慢性肝硬化及肝性脑病患者存在脑代谢物浓度异常改变,可作为早期诊断肝硬化、肝性脑病及评价肝硬化、肝性脑病严重程度的一项指标,在一定程度上评估肝性脑病与肝硬化分级具有相关性。     

常规磁共振成像结合磁共振波谱在临床脑胶质瘤诊断及鉴别诊断中的应用价值

目的:分析磁共振氢质子磁共振波谱(Proton Magnetic Resonance Spectroscopy,1H-MRS)的特征与脑胶质瘤病理分级的相关性,探讨氢质子磁共振波谱及常规磁共振成像(Magnetic Resonance Imaging,MRI)联合应用在提高脑胶质瘤的临床诊断中的应用价值.方法:脑胶质瘤(经临床手术证实及病理诊断确诊)患者34例,参照国际卫生组织诊断标准,分为低级别胶质瘤组及高级别胶质瘤组.其中,低级别组16例,高级别组18例,在行常规MRI检查的同时,配合1H-MRS检查,测NAA(N-乙酰天门冬氨酸)、Cho(胆碱)、Cr(肌酸)值,在不同级别胶质瘤、同级别胶质瘤不同位置的代谢物进行综合分析.结果:在获得常规MRI图像并进行诊断后,进行氢质子磁共振波谱检测分析:在低级别胶质瘤及高级别胶质瘤患者中,Cr(肌酸)的总量变化不大,有轻度的下降;而NAA(N-乙酰天门冬氨酸)下降程度较为明显;Cho(胆碱)则明显升高.低级别胶质瘤及高级别胶质瘤患侧的肿瘤组织同对侧的正常脑组织的各种代谢物及其比值(Cho、NAA、NAA/Cho、NAA/Cr值)具有显著性差异(P＜0.05);低级别胶质瘤及高级别胶质瘤的肿瘤组织的代谢物比值NAA/Cr、NAA/Cho值差异具有显著性(P＜0.05).低级别胶质瘤及高级别胶质瘤的Cho/Cr、NAA/Cho、NAA/Cr值与脑胶质瘤的病理分级具有相关性;在各个比值中,NAA/Cr与NAA/Cho值能够较好地反映脑胶质瘤的病理分级,二者的值呈现负相关;Cho/Cr值呈正相关.结论:常规MRI联合1H-MRS在脑胶质瘤的诊断中,能够有效提高准确性,在临床评估脑胶质瘤的分级、确定范围和鉴别诊断都具有重要的指导作用.     

重度OSAS患者前额叶皮质及岛叶1H—MR波谱研究

目的：利用氢质子MRS（IH-MRS）探讨重度阻塞性呼吸睡眠暂停综合症（Severeobstructivesleepapneasyndrome,S-OSAS）患者前额叶皮质及岛叶脑代谢产物特征。方法：选择18例S-OSAS患者（S-OSAS组）和15名健康志愿者（HC组）行左侧前额叶皮质及岛叶1H-MRS检查,测量两组左侧前额叶皮质区及岛叶N-乙酰天冬氨酸／肌酸（NAA／Cr）、胆碱／肌酸（Cho／Cr）值。对患S-OSAS累计时间与前额叶皮质及岛叶NAA／Cr作直线相关分析。结果：与正常对照组相比,S-OSAS患者左侧前额叶皮质、岛叶NAA／Cr比值降低,分别为1．43±0．47、1．34±0．06,对照组分别为1．51±0．65、1．45±0．07;S-OSAS组患者左侧前额叶皮质、岛叶Cho／Cr分别为0．90±0．08、1．195：0．13,对照组分别为0．87±0．07、1．09±0．02,两组差异有统计学意义。前额叶皮质及岛叶代谢物NAA／Cr与患S-OSAS累计时间成负相关性（r值分别为-0．965、-0．955,P〈0．01）。结论：1H-MRS显示S-OSAS患者前额叶皮质及岛叶病理生理变化,从该区代谢物的改变反应出S-OSAS患者执行及情感功能的异常,其NAA/Cr改变程度与患S-OSAS累计时间相关。     

磁共振波谱分析与帕金森病患者Hoehn&Yahr分级的相关性研究

目的:探讨磁共振波谱分析(MRS)与帕金森病(PD)HoehnYahr分级之间的相关性。方法:选择2016年9月-2017年8月我院收治的60例PD患者为研究对象,根据HoehnYahr分级将患者分为早期PD组32例、中期PD组18例、晚期PD组10例,并选择同时期在门诊进行健康体检的20例志愿者作为对照组。对各组研究对象的双侧基底节、双侧额叶、双侧丘脑区进行MRS,并分析PD患者HoehnYahr分级与MRS的关系。结果:晚期PD组双侧基底节、双侧额叶、双侧丘脑区NAA/Cr、NAA/Cho、Cho/Cr比值均低于中期PD组、早期PD组、对照组,且中期PD组低于早期PD组、对照组,早期PD组低于对照组,差异有统计学意义(P0.05)。通过Spearman相关性分析显示,MRS检测出PD患者NAA/Cr、NAA/Cho、Cho/Cr比值与HoehnYahr分级间呈负相关性(P0.05)。结论:MRS与PD患者的HoehnYahr分级具有负相关性,并且可通过MRS预测患者疾病的严重程度,以对其进行相应的治疗以及预后评估。     

磁共振波谱分析在颅脑胶质瘤分级中的应用研究

目的 分析脑胶质瘤的氢质子磁共振波谱（proton magnetic resonance spectroscopy,1H-MRS）表现及其临床意义;探讨脑胶质瘤的1H-MRS特点与其病理级别相关性.方法 搜集经临床手术、病理证实的脑胶质瘤病例49例,按照WHO诊断标准分成两组：低级别脑胶质瘤组、高级别脑胶质瘤组.所有患者在术前行1H-MRs检查,均在MR非增强成像的基础上获得.使用Philips Achieva 1.5T超导磁共振扫描仪,单体素或多体素扫描,点分辨法,检测不同区域代谢物变化.结果 脑胶质瘤的1H-MRS表现：肌酸（Cr）轻度下降,N-乙酰天门冬氨酸（NAA）显著下降,胆碱（Cho）显著增高.低、高级别脑胶质瘤的肿瘤组织与对侧止常脑组织的NAA、Cho、NAA/Cr、NAA/Cho值存在显著性差异（P〈0.05）;低级别和高级别脑胶质瘤的肿瘤组织的NAA/Cr、NAA/Cho值存在显著性差异（P〈0.05）.脑胶质瘤的NAA/Cho、Cho/Cr、NAA/Cr值与病理级别相关,其中NAA/Cho和NAA/Cr值反映肿瘤级别较稳定;NAA/Cr、NAA/Cho值呈负相关关系,Cho/Cr值呈正相关关系.结论 ：1H-MRS结合MKI能提高脑胶质瘤术前诊断的准确性.1H-MRS能对胶质瘤进行分级,反映胶质瘤代谢特性以及肿瘤生长潜能.     

3.0T 1H-MRS对脑胶质瘤及脑转移瘤的鉴别诊断

目的：利用3.0T氢质子磁共振波谱对胶质瘤和转移瘤的肿瘤组织区、瘤周水肿区进行细胞代谢物水平的检测,试图找出胶质瘤和脑转移瘤的鉴别诊断的依据,以及胶质瘤高、低级别组间的差别。方法：对经病理证实的20例高级别胶质瘤组、16例低级别胶质瘤组和19例脑转移瘤组患者,先行MRI平扫及增强扫描,波谱均在增强扫描的基础上获得,使用MR点分辨波谱序列,检测肿瘤组织区、瘤周水肿组织区NAA/Cr、Cho/Cr、NAA/Cho、NAA、Cho、Cr、Lip/Lac等值,进行比较。结果：（1）高级别胶质瘤与转移瘤在肿瘤组织区NAA/Cr代谢物浓度的比值有统计学意义。（2）高、低级别胶质瘤肿瘤组织内Cho/Cr比值有统计学意义。（3）转移瘤与高、低级别胶质瘤在瘤周水肿区NAA/Cr,以及低级别胶质瘤与转移瘤Cho/Cr代谢物浓度的比值有统计学意义;高级别胶质瘤与转移瘤瘤周区NAA代谢物浓度有明显差异。（4）胶质瘤高、低级别组间在肿瘤周围区NAA峰、Cho峰及NAA/Cho Cho/Cr代谢物浓度比值有统计学意义。（5）高级别胶质瘤和转移瘤分别与低级别胶质瘤在肿瘤组织区及瘤周水肿区Lip/Lac有显著性差异（P〈0.01）。结论：利用氢质子波谱可对胶质瘤和转移瘤进行鉴别诊断;Cho/Cr及NAA/Cho比值可对胶质瘤进行分级;Lip/Lac峰的出现与肿瘤的恶性度呈正相关,但不特异。     

弥散加权成像及1H磁共振波谱在新生儿缺氧缺血性脑病中的诊断价值

目的:探讨弥散加权成像、1H磁共振波谱诊断新生儿缺氧缺血性脑病的应用价值。方法:以本院收治的缺氧缺血性脑病新生儿37例为研究组,另选择健康新生儿40例作为对照组,两组新生儿均接受弥散加权成像及1H磁共振波谱检查,观察研究组新生儿普通MRI与弥散加权成像检查结果,对比研究组和对照组新生儿的脑代谢化合物相对浓度。结果:与普通MRI检出率相比,研究组患儿的弥散加权成像信号明显升高,差异存在统计学意义(P0.05)。研究组NAA/Cr比值低于对照组,Cho/Cr、MI/Cr、Glu-Gln/Cr、Lac/Cr比值高于对照组,差异存在统计学意义(P0.05)。结论:临床上诊断新生儿缺氧缺血性脑病时,弥散加权成像与1H磁共振波谱的联合应用可提升诊断准确率,通过对代谢物浓度的分析有利于评价缺氧缺血导致脑组织损害的严重程度。     

兔实验性肝性脑病1H磁共振波谱初步研究

目的:研究兔实验性肝性脑病1H磁共振波谱(magnetic resonance spectroscopy,MRS)变化。方法:将24只兔子随机分三组:对照组,肝硬化组,肝性脑病组,各8只。肝性脑病组采用四氯化碳(CCl4)联合内毒素方法制作肝性脑病兔子模型,肝硬化组采用CCl4制作肝硬化模型。分别在第4、6、8、10、12周取肝脏病理活检,第12周测量血氨值,并进行兔子脑组织的MRS扫描。计算N-乙酰天门冬氨酸(N-acetyl asparte,NAA)、肌酸(creatine,Cr)、胆碱(choline,Cho)、肌醇(myo-inositol,mI)和谷氨酰胺复合物(glutamine and glutamate,Glx)的峰下面积,计算NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr。结果:与对照组及肝硬化组相比,肝性脑病组兔血氨上升,脑部MRS显示Glx/Cr升高,Cho/Cr降低,差异显著(P0.05)。与对照组相比,肝硬化组血氨以及MRS改变无统计学意义。结论:兔实验性肝性脑病1H磁共振波谱存在变化。     

磁共振波谱成像结合扩散加权成像在脑胶质瘤及脑转移瘤鉴别诊断中的意义

目的:评估磁共振波谱成像(Proton Magnetic Resonance Spectroscopy,1H-MRS)联合磁共振扩散加权成像(Diffusion Weighted Imaging,DWI)在鉴别脑胶质瘤及孤立的脑转移瘤中的作用。方法:应用3.0T磁共振扫描仪,对临床手术确诊及组织病理学诊断证实的49例脑肿瘤患者(35例多形性胶质母细胞瘤,14例脑转移瘤)进行常规磁共振成像、磁共振波谱成像及磁共振扩散加权成像,并并对获得的数据进一步测量瘤内及瘤周区的代谢比、N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)值以及表观弥散系数(ADC值),分析两肿瘤组之间不同参数的统计学差异。此外,我们研究了感兴趣区域(ROI)的大小对肿瘤区域的病变扩散性能潜在影响。结果:胶质母细胞瘤瘤周N-乙酰天门冬氨酸(NAA)、肌酸(Cr),胆碱(Cho)/Cr,Cho/NAA和r CBV显著高于颅内转移瘤(P0.05);ADC值在两肿瘤组之间无显著差异(P0.05)。结论:在瘤周区1H-MRS有助于鉴别胶质母细胞瘤与单发的脑转移瘤。在瘤内扩散性的定量特性依赖ROI大小的设置。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.