磁共振扩散加权成像诊断脑脓肿的价值

目的: 评价磁共振扩散加权成像对脑脓肿的诊断及与颅内囊性、坏死性肿瘤鉴别诊断的价值.材料和方法: 对14例脑脓肿与17例颅内囊性、坏死性肿瘤的DWI信号特征进行分析,测量并比较病灶的表观扩散系数 (ADC) 值、病灶与对照区的ADC值比率(ADC率,rADC).结果: 14例脑脓肿在DWI上均呈程度不等的高信号,其中12例在ADC上呈低信号,平均ADC值为(0.62±0.29)×10-3mm2/ s,平均rADC为0.77±0.36;17例囊性、坏死性肿瘤中15例在DWI上呈低信号,16例在ADC上呈高信号,平均ADC值为(2.37±0.70)×10-3mm2/ s,平均rADC为3.24±1.08.统计分析显示脑脓肿与囊性坏死性肿瘤的平均ADC值及rADC的差异均有显著性意义(P<0.01),前者均显著低于后者; DWI与ADC相结合对脑脓肿的诊断敏感度和特异度分别为84.6%、94.1%,显著高于文献报道相应常规MRI的60%、27.27%.结论: DWI与ADC能有效反映脓肿与囊性、坏死性肿瘤的不同液态性质,对脑脓肿的诊断与鉴别诊断具有重要价值.     

磁共振DWI和ADC值在包膜期脑脓肿与坏死囊变性脑肿瘤鉴别诊断中的应用

目的探讨磁共振扩散加权成像(DWI)及表观扩散系数(ADC)值在包膜期脑脓肿与坏死囊变脑肿瘤鉴别中的临床应用价值。方法经手术病理证实的包膜期脑脓肿15例和坏死囊变脑肿瘤20例患者均经常规MRI扫描和DWI扫描,对比分析包膜期脑脓肿及坏死囊变脑肿瘤的DWI和ADC图表现,并测量脑脓肿脓腔及脑肿瘤坏死囊变区内的平均ADC值,进行统计学分析。结果包膜期脑脓肿脓腔在DWI上表现为高信号,ADC图呈低信号;脑肿瘤坏死囊变区在DWI上表现为低信号,ADC图呈高信号。所有脑脓肿的平均ADC值为(0.69±0.18)×10-3mm2/s,坏死囊变脑肿瘤的平均ADC值为(2.43±0.16)×10-3mm2/s,两者比较有显著性差异(P<0.01)。结论 DWI与ADC值测量能准确反映包膜期脑脓肿与坏死囊变脑肿瘤的不同液态性质,对其鉴别诊断有重要价值。     

磁共振扩散加权成像对恶性胶质瘤及脑转移瘤瘤周水肿的鉴别诊断价值

目的 探讨磁共振扩散加权成像(DWI)对恶性胶质瘤及脑转移瘤瘤周水肿的鉴别诊断价值.资料与方法 42例恶性胶质瘤(Ⅲ级及Ⅲ级以上)和32例脑转移瘤,所有病例均行T_1WI、T_2WI、T_1WI Gd-DTPA增强扫描和DWI检查,均经病理或临床证实.分析肿瘤的边缘特征并测量瘤周近、远侧水肿带的表观扩散系数(ADC)和相对表观扩散系数(rADC).用统计分析软件SPSS 14.0分别对ADC值和rADC值进行统计学分析,统计结果均以哥x±s表示,P<0.05为差异有统计学意义,P>0.05为差异无统计学意义.结果 DWI上36例恶性胶质瘤边缘毛糙,其中27例呈"晕"状改变;28例脑转移瘤边缘清楚,4例稍毛糙但无"晕"状改变.恶性胶质瘤近瘤水肿带的ADC.值及rADC值分别为(1.44±0.15)×10~(-3)mm~2/s和2.01 ±0.24,远瘤水肿带分别为(1.81±0.21)×10-3mm2/s和2.49±0.33.脑转移瘤近瘤水肿带的ADC值及rADC值分别为(1.70±0.22)×10~(-3)mm~2/s和2.43±0.44,远瘤水肿带分别为(1.81±0.18)×10~(-3)mm~2/s和2.54±0.41.恶性胶质瘤和脑转移瘤近瘤水肿带的ADC值和rADC值之间的差异有统计学意义(P<0.01),而远瘤水肿带间的差异无统计学意义(P>0.1);恶性胶质瘤近、远瘤水肿带的ADC值和rADC值之间的差异有统计学意义(P<0.001);脑转移瘤近、远瘤水肿带的ADC值和rADC值之间的差异无统计学意义(P>0.1).结论 在DWI上,恶性胶质瘤和脑转移瘤瘤周近、远侧水肿带的ADC值及rADC值的统计学分析以及它们的边缘特征对两者的鉴别诊断具有重要价值.     

扩散加权成像在鉴别颅内环形强化病灶的价值

目的讨论扩散加权成像(DWI)和表观扩散系数(ADC)在鉴别颅内环形强化病灶性质的价值。资料与方法应用1.5TMR对16例胶质瘤、6例转移瘤、4例脑脓肿进行常规MR及DWI成像和ADC测量,分析其影像学表现。结果4例脑脓肿在DWI上呈高信号,16例胶质瘤和6例转移瘤呈低信号,脓肿腔平均ADC值为0.44×10-3cm2/s,脑肿瘤坏死囊变区平均ADC值为1.82×10-3cm2/s(P<0.01)。结论DWI和ADC值可以用来鉴别脑脓肿及坏死囊变的肿瘤病灶。     

DWI和ADC值测量在颅内囊性病变鉴别诊断中的价值

目的:评价DWI与ADC值对颅内囊性病变的鉴别诊断价值以及相关的生物物理学机制.方法:经手术病理证实的脑脓肿20例、囊变坏死性脑肿瘤50例、表皮样囊肿20例和蛛网膜囊肿35例,在术前均接受了常规MRI和DWI检查.结果:脑脓肿在DWI上表现为明显的高信号,ADC值为(0.67±0.178)×10-3mm2/s;脑肿瘤囊变坏死灶在DWI上表现为明显的低信号,ADC值为(2.48±0.156)×10-3mm2/s,脑脓肿ADC值明显低于脑肿瘤囊变坏死灶ADC值(P<0.01).表皮样囊肿在DWI上表现为明显的高信号,ADC值为(1.19±0.157)×10-3mm2/s;蛛网膜囊肿在DWI上表现为明显的低信号,ADC值为(3.01±0.321)×10-3mm2/s,表皮样囊肿ADC值明显低于蛛网膜囊肿ADC值(P<0.01).结论:DWI和ADC值测量可有效鉴别脑脓肿与囊变坏死性脑肿瘤;DWI和ADC值测量能有效鉴别表皮样囊肿和蛛网膜囊肿.     

磁共振弥散加权像在脑脓肿诊断中的临床应用价值

目的 研究磁共振弥散加权像及表观弥散系数值在鉴别脑脓肿与坏死囊变脑转移瘤中的应用价值.方法 病理及临床证实脑脓肿14例,坏死囊变脑转移瘤17例,经常规磁共振检查及弥散加权检查,在脑脓肿脑炎期、包膜期及吸收期进行弥散信号及表观弥散系数值的测量,并与坏死囊变脑转移瘤相比较.结果 脑脓肿包膜期弥散加权像为高信号,表观弥散系数值低,与坏死囊变脑转移瘤弥散加权像及表观弥散系数值正好相反.吸收期及脑炎期脑脓肿弥散加权像为低信号或等信号,而表观弥散系数值为高信号,与坏死囊变脑转移瘤正好相类似.所有脑脓肿的平均表观弥散系数值为0.88×10-3 mm2/s,坏死囊变脑转移瘤平均表观弥散系数值1.8×10-3 mm2/s,两者比较有显著性差异(P＜0.05).弥散加权像信号诊断的敏感性为64.5%(20/31),特异性为100%(17/17),准确性为77.0%(37/48).结论 弥散加权像及表观弥散系数值有助于鉴别包膜期脑脓肿与坏死囊变脑转移瘤,对吸收期脑脓肿与坏死囊变脑转移瘤的鉴别诊断无明显意义.     

扩散张量成像对脑脓肿与坏死囊变性胶质瘤的鉴别诊断价值

目的 探讨磁共振扩散张量成像(DTI)对脑脓肿与坏死囊变性胶质瘤的鉴别诊断价值.资料与方法 回顾性分析2例经手术病理、3例经临床复查证实的脑脓肿和10例经手术病理证实的坏死囊变性胶质瘤.所有病例均行常规MR平扫、增强及DTI检查.构建表观扩散系数(ADC)图和各向异性分数(FA)图.测量病灶的坏死囊变区及其周围水肿区的ADC和FA值,计算其平均值,并行组间统计学分析.结果 脑脓肿脓腔扩散加权图像(DWI)表现为高信号者4例,低信号1例;胶质瘤坏死囊变区DWI表现为高信号者1例,混杂信号1例,低信号8例.脓腔、胶质瘤坏死囊变区ADC平均值分别为(0.79±0.11)×10-3 mm2/s、(2.38±0.28)×10-3 mm2/s,二者之间ADC值差异有统计学意义(t=6.45,P＜0.01).胶质瘤与脑脓肿周围水肿区ADC值分别为(1.65±0.13)×10-3 mm2/s、(1.94±0.17)×10-3 mm2/s,二者之间差异有统计学意义(t=1.98,P＜0.05).在FA图上,脓腔、胶质瘤坏死囊变区均表现为低信号,FA值分别为0.17±0.06、0.11±0.03,二者差异有统计学意义(t=2.42,P＜0.05),二者周围水肿区FA值分别为0.21±0.04、0.19±0.08,二者之间差异无统计学意义(t=1.13,P＞0.05).结论 DTI通过构建DWI图、ADC图和FA图能有效反映脓肿与坏死囊变性胶质瘤的不同液态性质.绝大多数脑脓肿的脓腔在DWI图上表现为高信号,ADC图上为低信号,而胶质瘤坏死囊变区则与之相反;脑脓肿周围水肿ADC值高于胶质瘤瘤周水肿.DTI对脑脓肿与坏死囊变性胶质瘤的鉴别诊断具有重要价值.     

ADC值与MR T_1WI最大强化值相关性分析评估肝癌的临床随访价值

目的定量分析原发性及继发性肝癌肿瘤组织的表观扩散系数(ADC)值,探讨MR扩散加权成像(DWI)在临床上评估肝癌患者的治疗疗效及预后的能力。资料与方法对53例肝癌患者行MR DWI、常规平扫T1WI、T2WI和T1WI钆对比剂增强扫描,系统化分析并观察病灶内部存活的肿瘤组织与肿瘤液化坏死组织成分的DWI与增强图像上的信号特征,测量各组信号强度值,并计算出各组ADC值与对应的MR T1WI增强扫描最大强化值,进行统计学相关性分析。结果 MR DWI像上肝癌病灶内残存或复发的肿瘤组织表现为稍高信号,增强扫描显示明显正性强化;液化坏死部分表现为明亮高信号,增强扫描无明显强化;ADC图上肿瘤组织为稍高于正常肝实质的高信号,肿瘤坏死组织部分为低信号;均数ADC值分别为:b=500 s/mm2时,肝癌肿瘤组织约为(1.15±0.43)×10-3mm2/s,肿瘤坏死囊变组织约为(1.88±0.43)×10-3 mm2/s,正常肝实质约为(1.31±0.16)×10-3 mm2/s;b=800 s/mm2时,肝癌肿瘤组织约为(1.02±0.37)×10-3mm2/s,肿瘤坏死组织约为(1.71±0.32)×10-3mm2/s...     

扩散加权成像鉴别诊断囊性星形细胞瘤与包膜期脑脓肿的价值

目的 评价扩散加权成像(DWI)和表观扩散系数(ADC)值鉴别诊断囊性星形细胞瘤(CA)与包膜期脑脓肿(BACP)的价值.方法 回顾性分析经手术病理或临床随访证实的16例CA和12例 BACP,治疗前均接受常规MRI及DWI检查,分别测量CA与BACP囊变区及对侧相应脑组织(CCBT)的平均ADC值.结果 DWI上16例CA均呈低信号,10例BACP呈高信号(2例低信号).CA、BACP和两者的CCBT的平均ADC值为 (1.42±0.16)×10-3mm2/s、(0.61±0.20)×10-3 mm2/s、(0.89±0.08)×10-3mm2/s、(0.90±0.08)×10-3 mm2/s,CA、BACP囊变区之间以及与CCBT的ADC值间显著差异(P<0.01).结论 DWI和ADC值鉴别诊断CA与BACP时具有重要价值.     

MR扩散加权成像在脑实质结核中的应用价值

目的：探讨MR扩散加权成像（DWI）在脑实质结核中的应用价值。方法：搜集脑实质结核病例48例,回顾性分析其DWI表现特点,并测量脑实质结核表观扩散系数（ADC）值。结果：脑实质结核的DWI表现复杂,病灶中心约1/2表现为等信号,余表现为高、低或混杂信号。测得在T1增强扫描上呈均匀强化、环形强化伴实性中心及环形强化伴液性中心的病灶中心平均ADC值分别为（0.92±0.14）×10-3mm2/s、（0.99±0.17）×10-3mm2/s和（2.00±0.55）×10-3mm2/s,环形强化病灶的壁平均ADC值为（1.05±0.19）×10-3mm2/s,病灶周围水肿平均ADC值为（1.18±0.24）×10-3mm2/s,均大于正常脑实质ADC值[（0.83±0.09）×10-3mm2/s],差异均具统计学意义（P〈0.05）。结论：脑实质结核病灶扩散不受限,DWI检查及ADC值的测量对脑实质结核的诊断及鉴别诊断具有一定的价值。     

Physiologic and pathologic calcifications and ossifications in the face and neck

The aim was to give a systematic presentation of physiologic and pathologic calcifications and ossifications in the face and neck with a special emphasis on clinical relevance. In a sometimes subacute setting one should recognize specific calcifications which often lead to important diagnoses such as fungal sinusitis or sclerosing labyrinthitis. In a more chronic situation intraocular calcifications in small children are pathognomonic for retinoblastoma. Juxtatumoral sclerosis of the laryngeal cartilage in laryngopharyngeal carcinoma is usually caused by tumor infiltration of the cartilage resulting in a higher tumor stage and, this way, has a major impact on the therapeutical strategy. Calcified lymph nodes are mainly unspecific but can be the result of tuberculosis or metastases of thyroid cancer. Cross-sectional imaging methods, most of all computed tomography, are ideally suited to reveal head and neck calcifications and ossifications, especially those which are clinically relevant.     

Head and neck infection and inflammation

This article discusses the imaging manifestations of infectious and inflammatory conditions of the head and neck. Special attention is paid to the sites, routes of spread, and complications of neck infections. Because the clinical signs and symptoms and the complications of these conditions are often determined by the precise anatomic site involved, anatomic considerations are stressed. Familiarity with the fascial layers, spaces of the neck, and the contents of each space is helpful for this discussion. The fascial layers of the neck are important barriers to infection, and once infection is established, the fascial layers play a part in directing its spread.     

幽门螺杆菌分泌与重组表达的VacA蛋白的分离纯化及其致细胞空泡效应与凋亡的对比研究

目的：分离纯化幽门螺杆菌分泌和重组表达的细胞空泡毒素抗原（ VacA）蛋白,并评价其致细胞空泡效应及致细胞凋亡效应。方法分别从幽门螺杆菌ATCC26695菌株培养上清和重组表达VacA蛋白的pQE30-VacA-E．coliM15基因工程菌中分离纯化VacA蛋白,经酸化后,以不同终浓度（5,10 ng／ml）分别与人胃腺癌AGS细胞共孵24 h,观察致空泡效应,并通过流式细胞术检测细胞凋亡。结果成功分离纯化出幽门螺杆菌分泌和重组表达的VacA蛋白;幽门螺杆菌分泌的VacA蛋白能显著引起AGS细胞的空泡样改变及凋亡（P＜0．01）,而重组表达的VacA蛋白致细胞空泡样改变及凋亡不显著（ P＞0．05）。结论幽门螺杆菌分泌的VacA蛋白有良好的空泡毒性及致凋亡效应,而重组表达的VacA蛋白无致空泡及凋亡效应,幽门螺杆菌分泌的VacA蛋白可用于VacA作用机制的研究。     

化学和生物学融合对国际武器公约履约的影响

化学武器公约（ CWC）和生物武器公约（ BWC）是为禁止生产、发展、储存和使用化学武器和生物武器而制定的国际公约。近年来,科学技术快速发展,知识交叉渗透,学科之间出现整合和融合,促进了科技进步和经济发展。其中化学和生物学融合在有力促进制药、健康卫生、绿色化学和环境保护等产业进步的同时,也对化学和生物武器公约的履约产生了重要的影响。该文综述了与化学武器和生物武器公约相关的化学和生物学融合进展,并分析其对公约履约的影响。     

Oxygen uptake and ventilation during rowing and running in females and males

This study evaluated if the ventilatory response to exercise is impaired by the cramp position of rowing. Maximal oxygen uptake (VO2max), maximal expiratory volume (VEmax), and maximal heart rate (HRmax) during rowing and running were compared in 55 males (age, mean +/- SD, 21 +/- 3 years; height 176 +/- 5 cm; body mass 72 +/- 6 kg) and 18 females (age 20 +/- 2 years; height 164 +/- 5 cm; body mass 61 +/- 4 kg). VEmax was larger during rowing than during running (males, 157 +/- 16 vs. 147 +/- 13 L min(-1); 114 +/- 9 vs. 105 +/- 11 L min(-1), P<0.01). Also VO2max was larger during rowing than during running (males, 4.5 +/- 0.5 vs. 4.3 +/- 0.4 L min(-1); females, 3.3 +/- 0.4 vs. 3.2 +/- 0.4 L min(-1), P<0.01). However, HRmax was lower during rowing than during running (males, 194 +/- 8 vs. 198 +/- 11 beats min(-1); females, 192 +/- 6 vs. 196 +/- 8 beats min(-1), P<0.05). VEmax was correlated to body mass and fat-free mass, as was VO2max. Thus, the oxygen pulse (VO2max/HRmax) was larger during rowing than during running, while the ventilatory equivalent for oxygen (VEmax/VO2max) was similar. We showed that bending the body during rowing does not seem to impair ventilation either in males or in females. The results indicate that VEmax and VO2max relate to body size and fat-free mass for both females and males. The findings indicate that the involvement of more muscles, the entrainment, and the body position during rowing facilitates ventilation and venous return and lowers maximal heart rate.     

Coracoclavicular and coracoacromial ligament calcification and ossification

Thirty-six patients with calcification or ossification at or around the coracoclavicular and coracoacromial regions were analyzed with regard to type, location, and configuration of the deposits and related clinical history. Calcification or ossification in the coracoclavicular region resulted largely from trauma (36%) or renal failure (28%). Trauma patients may develop punctate calcification or ossification but do not develop the tumoral type of calcification. About 5% of the renal failure patients had coracoclavicular ligament calcifications, one-half of which were of the tumoral type. Renal failure patients may have punctate or tumoral calcifications but do not develop ossification.     

CLIP相关技术的研究进展

在真核生物基因表达的转录后调节中,RNA结合蛋白（ RBP）起着关键作用,很多RBP的异常与人类疾病的发生密切相关。自2000年的RNA免疫沉淀和芯片分析方法（ RNA immunoprecipitation with differential display or microarray analysis , RIP-ChIP）出现以来,人们开始就RBP与RNA相互作用进行了系统而广泛的研究。经过改良和发展,基于体内实时紫外交联免疫沉淀法（ ultraviolet crosslinking and immunoprecipitation , CLIP ）、交联免疫沉淀cDNA文库高通量测序法（ high-throughput sequencing of CLIP cDNA library , HITS-CLIP）、光催化核糖核苷增强交联和免疫沉淀法（ photoactivatable-ribonucleoside-enhanced crosslinking and immunprecipitation , PAR-CLIP）以及提高个别核苷酸分辨率交联和免疫共沉淀法（ individual nucleotide resolution CLIP , iCLIP）等RIP-ChIP衍生方法相继产生,使用这些方法,可以解析RBP的RNA识别特异性,而且通过与高通量测序技术结合,可以实现转录组尺度的RBP的靶序列的鉴定,分辨率也得到极大提高。该文就RNA与蛋白的相互作用的基本原理及其研究进展、相关技术存在的问题以及发展趋势进行简要综述。     

Cross-sectional and longitudinal comparisons of self-reported and device-assessed physical activity and sedentary behaviour

ObjectivesTo examine the longitudinal associations and differences between self-reported and device-assessed physical activity (PA) and sedentary behaviour (SB), using a multifaceted statistical approach.DesignLongitudinal measurement burst.MethodsIn total, 52 university students (78% female) aged 18–38 years (mean = 21.94 ± 4.57 years) participated. The study consisted of three blocks of six days of measurement, during which participants wore an accelerometer on their wrist for the entire block, and self-reported their PA over the 6 days at the end of each block.ResultsMeaningful latent differences between methods were observed for moderate PA and SB across all three assessment periods, such that participants underreported the time spent in each activity. Bland–Altman plots revealed a positive mean difference for vigorous PA, with over-reporting increasing as mean levels increased. Negative mean differences were observed for all other intensities. Underreporting of moderate PA increased as the mean level increased, whereas for light PA and SB, underreporting decreased at high levels. Repeated measures correlations revealed a meaningful association for vigorous PA only, suggesting that as self-reported minutes increase so too do device-measured minutes.ConclusionsWe found evidence of cross-sectional and longitudinal differences and weak associations between self-reported and device-assessed PA and SB. Future work is needed to enhance the quality of self-reported methods to assess PA and SB (e.g., face and content validity), and consider improvements to the processing of device-based data.     

Old and dangerous: Prison and dementia

Older prisoners are the fastest growing group of prisoners in many countries. The purpose of this study is to explore the phenomenon of detention of persons suffering from dementia. Medline searches were conducted for relevant articles, chapters and books published until August 2016. Search terms included dementia, elderly, prison and criminal. Publications found through this indexed search were reviewed for further relevant references. As results, there is a lack of data about elderly with dementia in prisons. Given the rise in the average age, it is reasonable to hypothesize that the number of older prisoners is growing. Moreover, some elderly are imprisoned with a concomitant cognitive impairment or psychiatric disorder while others will develop such diseases once incarcerated. At the present time, legal and social systems seem unprepared to handle the phenomenon of dementia in prison. As proposal, health assessments for older first time offenders should become a practice inside the correctional facilities and include an evaluation for specific health issues, such as psychiatric comorbidity and cognitive impairment.