3D-FS-SPGR序列在膝关节软骨损伤诊断中的应用价值

目的:观察及分析3D-FS-SPGR序列在膝关节软骨损伤诊断中的应用价值。方法:本研究对象为14例膝关节疼痛患者,均为2014年6月至2016年6月期间收治的患者,对所有病例均展开矢状三维抑脂扰相梯度回波序列以及脂肪抑制快速自旋回波T2W1序列检查,并以Outer bridge分级标准作为依据,实施分型,再展开关节镜检查,针对检查分级情况实施比较分析。结果:矢状三维抑脂扰相梯度回波序列获得到的膝关节软骨损伤敏感度为98.3%,特异度为98.7%,同关节镜检查结果对比Kappa=0.782,具有90.5%的完全一致率;并且对于Ⅱ级及其以下的膝关节软骨损伤得到的敏感度为94.0%,特异性为95.8%,同关节镜检查结果对比Kappa=0.768,具有88.3%的完全一致率;脂肪抑制快速自旋回波T2W1序列位于膝关节软骨损伤的敏感度为95.6%,特异性为73.4%,同关节镜检查结果对比Kappa=0.612,存在70.6%的完全一致率。结论:采取3D-FS-SPGR序列的MRI检查,对于膝关节软骨损伤诊断准确度较理想,能够使诊断结果更接近于关节镜诊断结果,推广应用价值巨大。     

膝关节软骨损伤在1.5T磁共振3D-FS-SPGR序列下的成像研究

目的:观察并分析膝关节软骨损伤应用1.5T磁共振3D-FS-SPGR序列下的成像情况。方法:纳入本院2018年1月至2018年12月间收治膝关节疼痛患者50例作为该次研究对象。患者均予以矢状三维抑脂扰相梯度回波(3D-FS-SPGR)序列以及脂肪抑制快速自旋回波T2W1(FS-FSE-T2W)序列进行检查,分析对比各序列检查情况。结果:应用3D-FS-SPGR序列对患者进行检查,膝关节软骨损伤的敏感度93.18%、特异度95.16%,与关节镜的检查结果一致性为94.00%。FS-FSE-T2W序列检查膝关节软骨损伤的敏感度81.82%、特异度84.68%,与关节镜的检查结果一致性为83.00%。3D-FS-SPGR序列与FS-FSE-T2W序列相比的诊断效能更高。结论:膝关节软骨损伤在1.5T磁共振3D-FS-SPGR序列下具有显著特性,3D-FS-SPGR序列获得的信号特征与组织结构存在密切关联性,其检测敏感度与特异性均相对较高,该检测结果较为理想,值得在临床推广应用。     

不同MR扫描序列对髌股关节软骨病变的评价

目的　评价SE序列、FSE序列、二维SPGR序列及三维脂肪抑制SPGR序列对髌股关节软骨病变的诊断价值。方法　 5例尸体膝关节 ,关节腔内注射 40ml生理盐水。所有髌股关节均作常规自旋回波 (SE)序列T1WI、快速自旋回波(FSE)序列T2 WI和PDWI、二维毁损梯度回波 (2DSPGR)序列以及三维脂肪抑制毁损梯度回波 (3DFS SPGR)序列轴位扫描。计算每种序列诊断髌股关节软骨病变的敏感性、特异性和总符合率。结果　在 3DFS SPGR序列正常髌股关节软骨表现为三层结构 ,其诊断髌股关节软骨病变的敏感性、特异性和总符合率分别为 92 %、86%和 90 %。结论　在髌股关节软骨病变的诊断中 ,3DFS SPGR序列的特异性及敏感性较SE、FSE和 2DSPGR序列要高 ,是观察关节软骨结构的最佳方法。     

磁共振关节软骨成像的不同序列信号比较

目的:通过比较软骨信号噪声比(SNR)和对比度噪声比(CNR),分析临床常用的磁共振(MR)序列显示关节软骨的能力与限度。方法:选取12例成人离体膝关节标本行软骨磁共振成像(MRI)。应用的MR序列包括:①自旋回波T1加权序列(SE T1W);②快速自旋回波T2加权序列(FSE T2W);③短T1翻转恢复序列(STIR);④脂肪抑制质子密度序列(FS-PD);⑤三维脂肪抑制扰相梯度回波序列(3D-FS-SPGR);⑥重度T2加权梯度回波序列(T2*W GRE)。在股骨髁间凹中央层面上分别测量股骨髁软骨、股骨干骺端骨髓、小腿腓肠肌和背景噪声信号强度(SI),计算软骨SNR和软骨-关节液、软骨-骨髓、软骨-肌肉CNR。结果:3D-FS-SPGR和FS-PD序列软骨SNR最高(P<0.001)。结论:在目前临床应用的序列中,3D-FS-SPGR和FS-PD序列是进行软骨MRI的理想序列组合。     

MR在诊断膝关节周围骨隐匿性损伤中的价值

目的评价膝关节周围骨质隐匿性损伤MRI诊断价值。方法31例外伤患者共33个膝关节均行X线平片检查及MR快速自旋回波(FSE)T1WI、FSET2WI、快速梯度回波(FFE)T2WI、频率选择及反转脉冲抑脂序列(SPIR)T2WI、SPIRPDWI以及三维水激励快速梯度回波T1WI软骨成像(3D/WATSc/FFE/T1WI)序列扫描。结果31例患者中33个膝关节周围骨均发现异常,其中骨挫伤20例,隐匿性骨折8例,关节软骨或骨软骨骨折5例。T2W/SPIR对骨挫伤显示清楚,呈大片状高信号;PDW/SPIR能清晰显示隐匿性骨折线,呈锐利的细线状、条带状高信号;3D/WATSc/FFE/T1WI显示软骨骨折最佳。结论MRI能准确显示并诊断外伤后膝关节周围骨隐匿性病灶,不同的扫描序列对不同类型的隐匿性病灶显示各有优势,应结合使用。     

水脂分离技术在低场磁共振膝关节软骨检查中的应用

目的:探讨水脂分离技术在低场磁共振膝关节软骨检查中的的应用价值.方法:对42例疑有膝关节软骨病变的被检查者均采用以下扫描序列:SE T1-WI;FSE T2-WI;STIR;对水脂分离自旋回波序列的磁共振资料进行回顾性分析.结果:水脂分离技术自旋回波序列对膝关节软骨面的显示清晰度明显优于其他检查序列,更有利于对膝关节软骨疾病的诊断.结论:在低场磁共振膝关节软骨检查中水脂分离自旋回波序列可替代STIR序列,并应作为MRI常规检查序列之一.     

2D与3D MR快速自旋回波序列对膝关节交叉韧带及半月板损伤的诊断价值比较

目的:探究膝关节交叉韧带与半月板损伤经2D与3D MR快速自旋回波序列诊断的临床价值。方法:选取2018年3月至2019年9月我院收治的64例膝关节半月板损伤与交叉韧带患者,所有患者均实施2D与3D快速自旋回波序列扫描,扫描图像由高资医师进行评分,术前独立评价患者半月板与交叉韧带损伤状况。结果:3D快速自旋回波序列主观评分明显低于2D快速自旋回波序列组,参照关节镜检查结果,3D快速自旋回波序列组诊断半月板与交叉韧带损伤准确度、特异度及敏感度基本一致。结论:3D快速自旋回波序列与2D快速自旋回波序列诊断膝关节半月板损伤与交叉韧带损伤价值基本相同,3D快速自旋回波序列检查真确率更高,可对前交叉韧带损伤程度进行准确评估。     

低场强磁共振梯度回波和脂肪抑制成像在膝关节外伤中的诊断价值

目的:探讨低场强磁共振梯度回波和脂肪抑制成像在膝关节外伤中的诊断价值。材料与方法:87例患者经低场强MR不同序列检查,显示半月板、韧带、关节囊、关节软骨及关节面骨质等受损情况,用关节镜和/或手术结果做为金指标验证检查结果。结果:半月板损伤诊断准确率GRS100%IRS98.6%、T2WI94.5%、T1WI87.8%;韧带损伤IRS97.1%、T2WI94.3%、GRS93.7%、T1WI90.8%;MR可发现关节镜无法发现的骨损伤和少量关节积液。结论:低场强MRI常规序列加脂肪抑制和梯度回波序列对内、外侧半月板损伤,前、后交叉韧带、侧副韧带撕裂及关节软骨和骨质损伤的显现率高,诊断准确可靠,是膝关节损伤最佳的检查手段。     

压缩感知三维快速自旋回波序列诊断膝关节软骨损伤

目的探讨压缩感知技术加速的三维快速自旋回波序列调制反转角成像技术(modulated flip angle technique in refocused imaging with extended echo train,MATRIX)在诊断膝关节软骨损伤中的应用价值。材料与方法收集62例膝关节损伤的住院患者,同时行常规二维快速自旋回波(two dimensional fast spin echo,2D FSE)序列与MATRIX序列扫描。由2名放射科医师独立阅片,测量2D FSE与MATRIX图像软骨组织的信噪比(signal to noise ratio,SNR)及其与周围组织的对比噪声比(contrast to noise ratio,CNR),先后采用两种序列评估膝关节软骨损伤,以关节镜诊断结果为金标准,计算2D FSE与MATRIX序列诊断关节软骨损伤的敏感度、特异度及准确度。采用配对t检验比较两序列软骨SNR、CNR,McNemar检验比较两者软骨损伤诊断的差异。结果在MATRIX序列图像中,软骨组织的SNR及其与周围组织的CNR均显著高于2D FSE序列(P<0.01)。MATRIX序列与常规2D FSE序列诊断膝关节软骨损伤的敏感度、特异度及准确度分别为70.8%/59.2%、75.5%/84.2%及74.1%/76.6%,二者诊断软骨损伤的敏感度及特异度有统计学差异(P<0.01),准确度无显著差异(P=0.067)。结论与2D FSE序列相比,MATRIX序列图像中软骨具有较高的SNR与CNR,MATRIX序列诊断关节软骨损伤具有更高的敏感性,但是其特异度较低。     

多回波合并梯度回波成像序列与脂肪抑制质子密度加权成像序列在膝关节软骨成像中的应用研究

目的：比较多回波合并梯度回波成像（multiple echo combined with two dimensional disturbed phase gradient echo,MEGRE）序列与脂肪抑制质子密度加权成像序列（fat-suppression proton density weighted imaging,FS-PDWI序列）在早期膝关节软骨损伤诊断中的应用价值。方法：选取2021年10月—2022年1月在重庆大学附属三峡医院就诊的100例骨性关节炎早期膝关节软骨损伤患者,采用GE1.5TMR成像系统进行多回波合并梯度回波成像和脂肪抑制质子密度加权成像,进行软骨损伤分级诊断,计算序列对膝关节软骨显示质量及损伤检出的准确度;Kappa一致性检验分析多回波合并梯度回波成像、脂肪抑制质子密度加权成像序列评分的一致性。结果：阅片者1评价200个图像序列中191个序列图像质量很好,9个序列图像质量一般;阅片者2评价188个序列图像质量很好,12个序列图像一般;MEGRE序列图像质量显著高于FS-PDWI序列（P <0.05）。MEGRE序列对膝关节软骨缺损程度分级的总体准...     

3-hydroxy-3-methylglutaric aciduria: Deficiency of 3-hydroxy-3-methylglutaryl coenzyme a lyase

A marked deficiency of 3-hydroxy-3-methylglutaryl coenzyme A lyase activity is present in cultured skin fibroblasts from a baby with 3-hydroxy-3-methylglutaric aciduria.     

Pharmacokinetics of 3''-fluoro-3''-deoxythymidine and 3''-deoxy-2'',3''-didehydrothymidine in rats.

Concentrations of 3'-fluoro-3'-deoxythymidine (FDT) and 3'-deoxy-2',3'-didehydrothymidine (D4T) in plasma declined in a biexponential fashion. Total clearance of D4T (1.75 +/- 0.22 liters/h/kg; mean +/- standard deviation) was significantly greater than that of FDT (1.19 +/- 0.19 liters/h/kg) owing to greater renal and nonrenal clearances of the former. Steady-state volumes of distribution of FDT (1.20 +/- 0.12 liters/kg) and D4T (1.07 +/- 0.15 liters/kg) were similar.     

Pharmacokinetics of 3''-fluoro-3''-deoxythymidine and 3''-deoxy-2'',3''-didehydrothymidine in rhesus monkeys.

3'-Fluoro-3'-deoxythymidine and 3'-deoxy-2',3'-didehydrothymidine are nucleoside analogs which inhibit human and simian immunodeficiency virus in vitro. The pharmacokinetic properties of these compounds in rhesus monkeys after intravenous, oral, and subcutaneous administration of the drug were compared. Half-lives, total clearances, and steady-state volumes of distribution of the two drugs were determined. The half-lives for the drugs by the different routes were between 0.58 and 1.4 h. Oral bioavailability of 3'-deoxy-2',3'-didehydrothymidine was incomplete, with an average of 42% +/- 15% of the dose reaching the systemic circulation. Absorption of 3'-fluoro-3'-deoxythymidine after oral administration was variable, with bioavailability ranging from 21 to 95%. Bioavailability after subcutaneous administration ranged from 59 to 77% for 3'-deoxy-2',3'-didehydrothymidine and from 52 to 59% for 3'-fluoro-3'-deoxythymidine. The ratio of concentrations in cerebrospinal fluid and serum for the drugs was about 0.15 at 1 h after drug administration and was independent of the route of administration, suggesting that a nucleoside carrier-mediated process is involved in the transport of these compounds to the central nervous system. Because of the similar metabolism of nucleoside analogs in monkeys and humans, the potential glucuronide formation was assessed. Whereas the glucuronide of 3'-fluoro-3'-deoxythymidine was readily detected in urine, the amount of 3'-deoxy-2',3'-didehydrothymidine glucuronidated was small or not detectable in one-half of the urine samples. Pharmacokinetic parameters for the two drugs were similar to each other and analogous to those for 3'-azido-3'-deoxythymidine in monkeys, suggesting that the same dose and scheduling of the drug can be used for all three compounds in prophylactic and therapeutic efficacy drug studies in rhesus monkeys.     

Antiviral Activity of 3-Deazaguanine, 3-Deazaguanosine, and 3-Deazaguanylic Acid

3-Deazaguanine (ICN 4221), 3-deazaguanosine (ICN 4793), and 3-deazaguanylic acid (ICN 5412) represent a new class of synthetic guanine analogs having antiviral activity. In vitro, nine ribonucleic acid and seven deoxyribonucleic acid viruses were inhibited, including influenza, parainfluenza, rhino-, vesicular stomatitis, adeno-, herpes-, cytomegalo-, vaccinia, pseudorabies, and myxoma viruses. They were effective orally against influenza types A and B and parainfluenza type 1 (Sendai) virus infections in mice, with a therapeutic index of 16 against the latter two viruses. The course of herpes encephalitis was altered only when the drugs were applied directly into the brain. In addition, these drugs were effective inhibitors of Friend leukemia virus-induced splenomegaly in mice; treatment also produced extensions of life in these animals.     

亚急性甲状腺炎33例临床分析

目的 探讨亚急性甲状腺炎的病因、临床表现、诊断及治疗。方法 对33例患者的病史，临床表现，实验室资料及治疗进行总结分析。结果 患病的女性多见，占78．7％，病前无上怂病史记载：所有病例均有甲状腺肿大并触痛，彩超均有甲状腺肿大伴低回声，所有患者经口服泼尼松治疗效果好。结论 为减少漏诊、误诊，对咽痛伴发热病例，按上感治疗无效且持续时间较长应警惕本病。注意触诊甲状腺有无肿痛并进行必要的辅助检查。肾上腺糖皮质激素是治疗本病唯一确切有效药物。     

3-Methylcrotonylglycine excretion in 3-hydroxy-3-methylglutaric aciduria

1. 3-Methylcrotonylglycine was identified in urine from an infant with 3-hydroxy-3-methylglutaric aciduria. 2. The concentration of 3-methylcrotonylglycine in urine was approximately one sixth of that of the other metabolite of 3-methylcrotonyl-CoA, 3-hydroxyisovaleric acid. 3. The presence of both metabolites in the infant's urine indicates an inhibition of 3-methylcrotonyl-CoA carboxylase activity in tissues of the infant.     

In-plane stimulated emission of polycrystalline CH3NH3PbBr3 perovskite thin films

Hybrid organic–inorganic lead halide perovskites have been investigated extensively within the last decades, for its great potential in efficient solar cells and as an ideal light source. Among the studies on stimulated emission (SE), the emission is either out-of-plane for polycrystalline films or in-plane with randomly aligned single microcrystals and nanowires. In this work, we revealed in-plane propagation of SE from bromine-based perovskite polycrystalline thin films (CH₃NH₃PbBr₃, or MAPbBr₃). The output from in-plane SE is an order higher than the out-of-plane emission. It is proposed that large crystalline flakes in the films lead to the in-plane lasing phenomena. The output coupling can be found at grain boundaries, intergrain gaps, and artificial structures. Simulative results support the experimental phenomenon that large crystalline grains are profitable for in-plane propagation and over 90% photons can be sufficiently outcoupled when the gap is larger than a micron. Considering the fabrication and handling convenience, we propose that the MAPbBr₃ thin films can be easily integrated for in-plane applications as the light source for photonic chips etc.

MAPbBr₃ perovskite thin film contains large crystal flakes, which support the in-plane stimulated emission and its propagation within these polycrystalline films. The emission scatters at the natural or artificial edge of the film.     

3-Hydroxy-3-methylglutaric aciduria: a new assay of 3-hydroxy-3-methylglutaryl-CoA lyase using high performance liquid chromatography

A new assay has been developed for 3-hydroxy-3-methylglutaryl-CoA lyase, the final enzyme in the leucine degradative pathway. The assay was performed by incubating lysates of fibroblasts with [glutaryl-3-¹⁴C](d,l)-3-hydroxy-3-methylglutaryl coenzyme A. The products were analysed by high performance liquid chromatography with continuous liquid scintillation counting. This provided simultaneous identification and quantification of one of the enzymatic products, [3-¹⁴C] acetoacetic acid. The mean 3-hydroxy-3-methylglutaryl-CoA lyase activity in fibroblasts from five controls was 732 ± 81 (SD) pmol/min · mg protein. Using this assay, we have studied skin fibroblasts cultured from a patient with 3-hydroxy-3-methylglutaric aciduria and found 3% of normal 3-hydroxy-3-methylglutaryl-CoA lyase activity. The activities in skin fibroblasts cultured from the parents were 46 and 53% of control activity which is consistent with heterozygocity. Kinetic studies of 3-hydroxy-3-methylglutaryl-CoA lyase in skin fibroblasts cultured from two normal subjects yielded K_m values of 14.4 and 18.8 μmol/l for 3-hydroxy-3-methylglutaryl-CoA.     

Low temperature scintillation performance of a Br-doped CH3NH3PbCl3 single-crystalline perovskite

Time response and light yield are two of the most important features of a scintillation detector, and are mostly determined by the luminescence properties of the scintillator. Here we have investigated the radioluminescence (RL) characteristics of a single-crystalline hybrid lead halide perovskite at both room temperature and low temperature. A dual-channel single photon correlation (DCSPC) system with a vacuum chamber is employed for the measurement. A rise time faster than 100 ps and several times enhancement of the crystal scintillation performances at low temperature have been observed. These behaviors demonstrated that bulk solution-grown single crystals of hybrid lead halide perovskites (MAPbCl₃ and Br-doped MAPbBr_0.08Cl_2.92, where MA = CH₃NH₃) can serve as stable scintillating materials for pulsed gamma detectors. In addition, this work provides a pathway for perovskite application and also attracts attention to investigating low-temperature scintillators.

Time response and light yield are two of the most important features of a scintillation detector, and are mostly determined by the luminescence properties of the scintillator.