运动性疲劳肾气虚大鼠睾丸超微结构和性激素改变及补肾益元中药的作用

目的探讨运动性疲劳肾气虚的实质及补肾益气中药的作用机理。方法以健康雄性二月龄SD大鼠为研究对象,随机分为安静对照组、运动实验组、运动肾气虚组和服药组(服用补肾益元中药),采用递增负荷游泳加悬吊应激的方案建立运动性疲劳肾气虚动物模型。实验后检测各组大鼠血清睾酮和促性腺激素含量,称量大鼠睾丸重量并观察睾丸的超微结构。结果(1)运动实验组和运动肾气虚组大鼠血清睾酮含量显著低于安静对照组(P<0.05);(2)服药组大鼠血清睾酮水平显著高于运动肾气虚组(P<0.05);(3)电镜观察运动实验组和运动肾气虚组大鼠睾丸间质严重水肿(Ⅳ),细胞固缩,染色质边集,呈凋亡改变。而服药组大鼠睾丸间质水肿不明显,大多数细胞结构基本正常,线粒体嵴大多数清晰,趋于正常。结论补肾益元中药能保护过度训练大鼠的睾丸间质细胞及细胞内线粒体结构以维持睾酮的正常分泌、促进内源性睾酮的再生,这种对睾丸组织结构的保护作用可能是延缓运动性疲劳肾气虚发生的机理之一。     

大负荷运动训练与模拟失重对大鼠HPA轴影响的对比研究

目的:对比分析大负荷运动训练与模拟失重对大鼠HPA(下丘脑-垂体-肾上腺)轴的影响及其作用机制。方法:40只雄性SD大鼠随机分为安静对照组、游泳训练组、后肢悬垂(模拟失重模型)组,游泳训练组又分为运动即刻组和运动后恢复24小时组;游泳训练大鼠进行6周递增负荷游泳运动训练,后肢悬垂大鼠在完成腹股沟管环缩手术后1周开始为期6周的尾部悬吊;大鼠断头处死后,取血样检测T(睾酮)与ACTH(促肾上腺皮质激素),分别检测下丘脑CRH(促肾上腺皮质激素释放激素)、垂体ACTH与睾丸组织T水平。结果:游泳训练运动后即刻组大鼠血清ACTH水平显著高于安静对照组(P<0.05),游泳训练运动后即刻组与恢复24小时后以及后肢悬垂组大鼠垂体ACTH水平显著高于安静对照组(P<0.05);游泳训练运动后恢复24小时组大鼠下丘脑CRH水平较安静对照组有所升高,但无统计学意义(P=0.108),后肢悬垂组大鼠下丘脑CRH水平显著高于安静对照组(P<0.05)。结论:大负荷运动训练与模拟失重导致大鼠持续处于应激状态,垂体ACTH与下丘脑CRH显著增加可能会抑制HPG(下丘脑-垂体-性腺)轴有关激素的合成与分泌,这可能是大负荷运动训练与模拟失重导致大鼠血清睾酮水平下降的原因之一。     

运动训练对糖尿病大鼠糖代谢和下丘脑神经肽Y mRNA的影响

目的:探讨运动训练对糖尿病大鼠糖代谢及其下丘脑神经肽Y(NPY)mRNA表达的影响。方法:30只SD大鼠随机分为对照组、糖尿病组(由链脲佐菌素诱导)和糖尿病 运动训练组(糖尿病大鼠进行无负重游泳运动,第1天游泳10min,以后每天递增10min,直到每天60min,每周5天,共10周)。10周后检测各组大鼠安静时血糖、血清胰岛素含量及下丘脑NPY mRNA表达。结果:与对照组相比,糖尿病组大鼠血糖显著升高,血清胰岛素水平显著降低;与糖尿病组相比,糖尿病 运动训练组大鼠血糖显著下降,血清胰岛素水平显著上升。糖尿病组大鼠下丘脑NPY mRNA表达显著高于对照组,糖尿病 运动训练组大鼠下丘脑NPY mRNA表达显著低于糖尿病组。结论:适宜的运动训练可能通过下调下丘脑NPY mRNA表达来改善糖尿病大鼠糖代谢异常。     

运动性免疫抑制大鼠肝、脾糖皮质激素受体表达变化探讨

目的:研究运动性免疫抑制时糖皮质激素受体(glucocorticoid receptor,GR)mRNA和蛋白表达变化,探讨GR在运动性免疫抑制发生中的作用。方法:40只SD大鼠随机分为安静对照组(C组,n=10)、中强度运动组(M组,n=10)和过度疲劳运动组(O组,n=20)。后两组分别进行不同强度的8周递增负荷训练,每周训练6天。每周称量大鼠体重。8周训练结束后采血,检测Hb、血睾酮、皮质酮水平,外周血T细胞亚群(CD3+、CD4+、CD8+)、自然杀伤细胞(NK细胞)数量和辅助性T淋巴细胞1、2(Th1、Th2)特异性细胞因子IFN-γ、IL-4水平。之后断头处死动物,采用real time PCR和Western blot方法分别检测大鼠肝、脾GR mRNA和蛋白水平。结果:(1)与安静对照组和中强度运动组相比,过度疲劳运动组大鼠体重从第4周起明显下降(维持至实验结束),Hb、血浆睾酮水平、睾酮/皮质酮比值均显著下降,血浆皮质酮水平显著升高,表明过度疲劳训练组大鼠已发生过度疲劳。(2)8周训练后,与安静对照组和中强度运动组相比,过度疲劳运动组大鼠CD3+细胞、NK细胞数量显著减少、IFN-γ/IL-4比值显著下降,Th1/Th2失衡,但CD4+/CD8+比值无显著性差异,表明运动性免疫抑制大鼠模型建立成功。(3)与安静对照组和中强度运动组相比,8周训练后,过度疲劳运动组大鼠肝、脾GR mRNA和蛋白水平均显著下降;与安静对照组相比,中强度运动组大鼠肝、脾GR mRNA和蛋白水平均无显著变化。(4)相关性分析显示,肝、脾GR mRNA和蛋白水平与血浆GC的相关系数分别为-0.752、-0.613、-0.144和-0.397,均P<0.05。结论:(1)运动性免疫抑制大鼠肝、脾GR mRNA和蛋白表达水平较安静对照组和中强度运动组显著降低。(2)运动性免疫抑制大鼠肝、脾GR mRNA减少和脾GR蛋白水平下降可能与血浆GC升高有关。     

耐力训练引起大鼠免疫机能低下及补充中药多糖的干预效果研究

目的:观察6周耐力训练及补充多糖提取物对大鼠血清IL-1β和外周血单核细胞(PBMC)培养后上清液IL-1β含量、下丘脑室旁核IL-1R表达和血清皮质酮、睾酮含量的影响。方法:6周龄雄性Wistar大鼠40只随机分为安静对照组、耐力训练组、训练+黄芪多糖组、训练+牛膝多糖组4组,每组10只。安静对照组不运动,其他3组进行6周递增负荷游泳训练,训练时间由40 min/d逐渐增加到160 min/d。训练+黄芪多糖组每天给予黄芪多糖提取物灌胃(2 g.kg-1),训练+牛膝多糖组给予牛膝多糖提取物灌胃(1 g.kg-1),安静对照组和耐力训练组给予等量双蒸水。6周后取材测试相关指标。结果:6周训练后,耐力训练组大鼠血清IL-1β含量、PBMC培养后上清液IL-1β含量、大鼠下丘脑室旁核IL-1R表达、血清皮质酮含量均显著高于安静对照组(P<0.05或P<0.01),血清睾酮含量显著低于安静对照组(P<0.05)。训练同时补充牛膝多糖组大鼠血清IL-1β、下丘脑室旁核IL-1R表达显著低于耐力训练组(P<0.05或P<0.01),且与安静对照组水平接近;训练同时补充牛膝多糖或黄芪多糖组PBMC生成IL-1β能力低于耐力训练组、高于安静对照组,但差异均无统计学意义,训练同时补充牛膝多糖组血清皮质酮显著低于耐力训练组(P<0.01)。训练同时补充牛膝多糖或黄芪多糖组大鼠血清睾酮高于耐力训练组(分别高54.3%和54.4%)、低于安静对照组(分别低21.4%和21.2%)。结论:耐力训练引起细胞免疫功能下降可能与血清及PBMC中IL-1β升高和下丘脑室旁核IL-1R表达增加并激活HPA轴有关,补充牛膝多糖、黄芪多糖有保护作用。     

1周不同负荷运动对运动性血睾酮降低大鼠睾丸Leydig细胞胆固醇代谢的影响

目的:探讨运动性血睾酮降低的胆固醇代谢机制。方法:大鼠在经过5周间歇性负重游泳训练(TA组),造成运动性血睾酮降低的基础上,停训1周(TB组),继续训练1周:维持原负荷(负重5%体重,1组/日,TC组)、负荷量加倍(负重5%体重,2组/日,TD组)、负荷强度增加(负重6%体重,1组/日,TE组),检测大鼠Leydig细胞胆固醇代谢关键环节上的HMG-CoA还原酶、LDL-R、SR-BI及StAR mRNA表达。结果:(1)5周间歇性游泳训练后TA组大鼠血清睾酮显著降低,睾丸Leydig细胞LDL-R mRNA表达量显著升高,SR-BI、HMG-CoA还原酶、StAR mRNA表达量无显著变化。(2)与TA组相比,TB组血清睾酮水平显著升高,LDL-R mRNA表达量显著降低(P<0.01),SR-BI基因的表达量显著增加(P<0.01);TC组血清睾酮有进一步降低的趋势,但无统计学意义,LDL-R mRNA表达量显著降低(P<0.01),SR-BI、HMG-CoA还原酶、StAR mRNA表达量无显著变化;TD组血清睾酮显著降低(P<0.05),LDL-R、SR-BI、HMG-CoA还原酶和StAR mRNA表达量显著降低(P<0.01,P<0.05);TE组血清睾酮有进一步降低的趋势,LDL-R、SR-BI、HMG-CoA还原酶mRNA表达量均显著性降低(P<0.05,P<0.01),StAR mRNA表达量未见显著变化。结论:(1)Leydig细胞内胆固醇代谢障碍的发生具有阶段性特征;(2)Leydig细胞内胆固醇代谢障碍不是导致运动性血睾酮降低的起始原因,而细胞内HMG-CoA还原酶、LDL-R、SR-BI、StAR基因表达量降低会加速运动引起的血睾酮降低。     

葛根总黄酮对力竭运动大鼠肝脏部分抗氧化指标和超微结构的影响

目的:探讨补充葛根总黄酮对耐力训练大鼠力竭运动后肝脏部分抗氧化指标、肝糖原含量和超微结构的影响。方法:24只雄性SD大鼠随机分为安静对照组、运动训练组和训练服药组。运动训练组和训练服药组进行7周递增强度耐力训练。训练服药组每天灌服一次葛根总黄酮悬浮液,安静对照组和运动训练组灌服相同体积的蒸馏水。测定运动训练组和训练服药组力竭运动后即刻及安静对照组安静时肝脏超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)的活性与丙二醛(MDA)含量、糖原含量及运动至力竭的时间等指标,并在电镜下观察大鼠肝脏超微结构的变化。结果:(1)训练服药组大鼠力竭时间(116.32±6.20min)显著长于运动训练组(94.82±9.05min)(P<0.05)。(2)运动训练组肝脏组织T-SOD、GSH-Px和CAT活性显著低于安静对照组(P<0.05),CuZn-SOD活性和MDA含量显著高于安静对照组((P<0.05);训练服药组T-SOD、GSH-Px、CAT、铜锌超氧化物歧化酶(CuZn-SOD)活性显著高于运动训练组(P<0.05),而MDA显著低于运动训练组(P<0.05)。训练服药组肝糖原含量显著高于运动训练组(P<0.05)。训练服药组血清谷丙转氨酶(GPT)活性显著低于运动训练组(P<0.05)。(3)电镜观察发现,安静对照组线粒体结构完整;运动训练组线粒体形态变异明显,其膜、嵴均有溶解,断裂现象,甚至整个线粒体崩解,出现空泡化,基质电子密度降低,粗面内质网减少,出现不规则扩张、断裂、扭曲;训练服药组线粒体、粗面内质网发生了损伤,但程度较运动训练组轻。结论:葛根总黄酮可提高肝脏抗氧化酶的活性,促进机体自由基的消除,维护肝细织的正常结构,促进肝糖原合成,具有延缓运动疲劳发生的作用。     

5周间歇性负重游泳训练对大鼠睾丸Leydig细胞胆固醇代谢的影响

采用实时荧光定量PCR的Taqman技术探讨5周间歇性负重游泳训练导致大鼠血清睾酮水平降低时,大鼠睾丸Leydig细胞胆固醇代谢关键环节上的HMG-CoA还原酶、LDL-R、SR-BI、类固醇激素合成急性调控蛋白(StAR)基因表达的变化。结果显示,运动引起血清睾酮显著降低时(P<0.01),Leydig细胞内LDL-R mRNA表达量显著增加(P<0.05),HMG-CoA还原酶、SR-BI、StAR mRNA表达量无显著性变化。结果表明当大鼠以负重5%体重的负荷强度进行5周的间歇性游泳训练引起血清睾酮显著降低时,Leydig细胞通过LDL-R介导的内吞作用摄取外源性胆固醇作用加强,Leydig细胞内胆固醇的合成、摄取和转运的关键环节未发生障碍。     

耐力训练和一次性力竭运动对大鼠心肌和骨骼肌硫氧还蛋白还原酶的影响

目的:观察运动对大鼠心肌、骨骼肌硫氧还蛋白还原酶(TR)的影响.方法:SD大鼠30只,随机分成安静对照组、耐力训练组和力竭组.训练组进行6周渐增游泳训练,5次/周.最后1次训练后24小时,断头处死安静对照组和训练组大鼠,力竭组大鼠在一次性力竭运动后即刻处死.DTNB法检测心肌、骨骼肌TR活性,RT-PCR法观察TR mRNA水平变化.结果:6周耐力训练大鼠心肌TR活性显著高于安静对照组,一次性力竭组大鼠心肌TR活性显著低于安静对照组.各组大鼠心肌TR mRNA均无显著性差异.结论:6周耐力训练显著提高大鼠心肌TR活性,而在mRNA水平上无显著性差异.     

长期力竭性耐力训练对大鼠不同类型骨骼肌湿重和Hsp72表达的影响

目的:探讨长期力竭性耐力训练对大鼠不同类型骨骼肌适应能力与热休克蛋白72(Hsp72)表达的影响。方法:36只雄性2月龄SD大鼠随机分成6组:6、7、8周三组安静组(n=4)和6、7、8周三组训练组(n=8)。各训练组大鼠在第1、2周适应性游泳30min至2h,在第3周至第8周进行力竭性游泳训练,每周6天。按分组分别在第6、7、8周末次力竭游泳后记录训练组力竭运动时间,36小时后处死大鼠测定其血清肌酸激酶(CK)浓度及同侧比目鱼肌、红腓肠肌和白腓肠肌湿重和Hsp72蛋白含量。结果:(1)训练组大鼠力竭时间逐周下降(P<0.05),第8周降到最低;血清CK虽有逐周增加的趋势,但无统计学意义;6、7、8周训练组大鼠比目鱼肌湿重有渐增趋势,红腓肠肌和白腓肠肌湿重的变化趋势由减少、不变到增加。(2)6和7周训练组比目鱼肌Hsp72表达与安静组相比无显著性差异,第8周训练组显著低于安静组(P<0.05);6、7和8周训练组红腓肠肌Hsp72表达较安静组分别增长133%、214%、157%,有统计学意义(P<0.01),各训练组间无显著性差异;7周训练组白腓肠肌Hsp72表达显著高于6周训练组(P<0.01),而8周训练组与其它两训练组比较无显著差异。结果表明:长期力竭性游泳训练导致大鼠不同类型骨骼肌运动适应能力不同,不同类型骨骼肌Hsp72异常表达变化早于骨骼肌运动适应能力变化,提示骨骼肌运动适应能力与其Hsp72表达变化可能有关。     

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。     

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.     

Kidney and iodinated and gadolinium-based contrast agents

In patients with renal failure, iodinated contrast agents may cause acute deterioration of the renal function and gadolinium-based contrast agents (GBCAs) may cause nephrogenic systemic fibrosis (NSF). The administration of a contrast agent must thus be reviewed for each patient and evaluation of renal function is paramount even though its estimation using formulas derived from the creatinine level may fluctuate. For iodinated contrast agents, contrast induced nephropathy is reduced by hydratation, preferably intravenous, when the GFR is less than 60 ml/min. The risk for intravenous injections is less than the risk for arterial injections, and the GFR threshold may be reduced to 45 ml/min. For gadolinium-based contrast agents, patients at risk for NSF are those with end-stage renal disease and patients undergoing dialysis. In such cases, the injection of a gadolinium-based contrast agent is only considered after a risk-benefit analysis has been completed, an alternate linear or macrocyclic agent issued and the dose limited to 0,1 mmol Gd/kg. Recently, recommendations from US and European agencies have converged. Learning objectives: to be familiar with the risk factors of CIN with iodinated contrast agents; to be familiar with hydration procedures for patients at risk of CIN; to be familiar with the diagnostic criteria of NSF; to be familiar with the classification of GBCA with regards to the risk of NSF; to be familiar with the contraindications of the different groups of GBCA.