MR T2*成像无创评估多发性硬化患者肝脏铁含量

目的 通过MR T2^*技术定量测定多发性硬化(MS)患者肝脏的铁含量,探讨MS患者肝脏铁含量是否与正常人存在差异。 方法 对35例MS患者(MS组)及17名健康志愿者(对照组)分别进行肝脏T2^*扫描,测量肝脏各段的T2^*值,并计算其平均值。结合实验室检查检测血清铁、铁蛋白水平,综合评估MS患者机体的铁负载水平。 结果 MS组与对照组肝脏平均T2^*值分别为17.46±2.82和17.17±3.69(P>0.05)。MS组中9例(9/35,25.71%)、对照组中4例(4/17,23.53%)出现铁过载,但均在可接受范围内(5.0~15.8 ms),两组铁过载发病率差异无统计学意义(χ²=0.029,P>0.05)。MS组与对照组血清铁、铁蛋白水平差异均无统计学意义(P均>0.05)。MS组及对照组的T2^*值与铁蛋白水平均呈负相关(r=-0.448,P=0.032;r=-0.742,P=0.009),与血清铁未见相关性(P均>0.05)。 结论 MS患者机体中的铁负载水平与健康志愿者无明显差异,提示MS患者脑内过度的铁沉积并非由整个机体的铁过载引起。     

IDEAL-IQ技术定量测量健康青年女性颈部锁骨上脂肪

目的 评估基于最小二乘法估计和不对称回波迭代分解的水脂分离（IDEAL-IQ）技术定量测量健康青年女性颈部锁骨上脂肪的可行性。方法 招募87名20~35岁健康青年女性,根据体质量指数（BMI）分为BMI<24 kg/m²组（n=72）和BMI ≥ 24 kg/m²组（n=15）。对受试者行IDEAL序列扫描,分别测量颈部锁骨上、胸壁、腹壁皮下脂肪及肝脏的脂肪分数（FF）及T2^*弛豫率（R2^*）值,比较两组间及锁骨上与胸壁皮下脂肪FF、R2^*值的差异,并分析FF、R2^*与BMI的相关性。结果 颈部锁骨上脂肪FF低于胸壁皮下脂肪FF值;锁骨上脂肪R2^*值高于胸壁皮下脂肪R2^*值。BMI<24 kg/m²组与BMI ≥ 24 kg/m²组间颈部锁骨上、胸壁皮下脂肪,腹壁、肝脏的FF、R2^*值及颈部/胸壁FF值、颈部/胸壁R2^*值差异均有统计学意义（P均<0.05）。颈部锁骨上脂肪FF值与BMI呈正相关（r=0.601,P<0.001）,R2^*值与BMI呈负相关（r=-0.409,P=0.001）。结论 MR IDEAL-IQ技术可定量测定颈部锁骨上与体部脂肪的差异,两者间FF及R2^*值存在差别。     

3.0T磁共振R2*值评价足月出生婴儿脑深部灰质核团年龄相关性铁沉积

目的 采用3.0T MR R2^*值观察婴儿脑深部灰质核团铁沉积与周龄的关系。方法 纳入婴儿53名,校正周龄(PMA)37~92周。采用GE 3.0T磁共振扫描仪进行增强T2^*加权血管成像(ESWAN)序列扫描,测量脑内双侧深部灰质核团(尾状核、壳核、苍白球、丘脑、红核和黑质)的R2^*值。对各部位R2^*值与脑铁含量进行相关分析,并分析R2^*值与PMA的关系。结果 婴儿期脑深部灰质核团R2^*值与脑铁含量均呈正相关(P均<0.001)。尾状核、壳核、苍白球、丘脑、红核和黑质的R2^*值与PMA均呈正相关(r=0.865、0.818、0.893、0.844、0.742和0.834,P均<0.001)。结论 婴儿期脑深部灰质核团的R2^*值随周龄增大逐渐增加,其可反映局部脑铁沉积随周龄的增加。     

MRI-T2*技术定量分析β-重型地中海贫血心脏、肝脏、胰腺铁沉积及其与糖代谢的相关性

目的 采用MRI-T2^*技术定量分析β-重型地中海贫血（β-TM）心肌、肝脏、胰腺铁沉积,观察其与糖代谢的相关性。方法 回顾性分析109例β-TM患者,其中91例于MR检查前后2周内接受空腹血糖检测,根据检测结果将其分为血糖升高组（n=19）及血糖正常组（n=72）,比较组间临床资料及MRI指标差异,分析心肌、肝脏、胰腺R2^*值（1/T2^*）与血糖代谢指标的相关性。采用Logistics回归分析糖代谢异常的危险因素,绘制心肌、肝脏、胰腺R2^*预测血糖升高的受试者工作特征（ROC）曲线,评价其诊断效能。结果 109例β-TM患者心肌T2^*值27.72（15.87,31.16）ms,肝脏T2^*值1.71（1.34,3.07）ms,胰腺T2^*值6.09（3.76,15.02）ms。血糖升高组与血糖正常组间年龄、输血年限、总输入铁量、去铁年限、空腹血糖、胰岛素抵抗指数、心肌R2^*及胰腺R2^*差异均有统计学意义（P均<0.05）。心肌及胰腺R2^*均与空腹血糖呈正相关（r=0.36、0.41,P均<0.01）,肝脏R2^*与空腹血糖无明显相关（P=0.76）。肝脏R2^*、胰腺R2^*均为糖代谢异常危险因素（P均<0.05）。心肌及胰腺R2^*预测空腹血糖升高的曲线下面积（AUC）均为0.80（P均<0.01）。结论 心肌、胰腺铁沉积与β-TM血糖代谢存在一定相关性;心肌和胰腺R2^*预测β-TM血糖升高的诊断效能佳。     

肝、脾及腰椎R2*值评估慢性肾衰竭患者体内铁含量

目的 观察肝、脾及腰椎R2^*值用于评估慢性肾衰竭(CKD)患者体内铁含量的价值。方法 回顾性纳入52例CKD患者,根据转铁蛋白饱和度≤20%与否分为绝对缺铁组(n=22)和非绝对缺铁组(n=30)。基于改良Dixon定量(mDIXON-quant)MRI观察组间肝、脾及腰椎R2^*值差异,并分析上述R2^*值与铁代谢指标的相关性;行logistic回归分析,观察绝对缺铁的影响因素,并分析其诊断效能。结果 绝对缺铁组与非绝对缺铁组脾和腰椎R2^*值差异均有统计学意义(P均＜0.05)。CKD患者脾、腰椎R2^*值与铁蛋白、转铁蛋白饱和度均呈正相关(P均＜0.05),与不饱和铁结合力、总铁结合力及转铁蛋白呈负相关(P均＜0.05)。腰椎R2^*值减低是CKD患者绝对缺铁的影响因素(P＜0.05)。以腰椎R2^*值=134.26 Hz为最佳截断值,其诊断CKD患者绝对缺铁的敏感度为86.70%,特异度为68.20%,曲线下面积为0.727。结论 腰椎R2^*值有助于评估CKD患者体内铁含量。     

输血依赖性疾病多脏器铁沉积MRI量化分析

目的 探讨MRI T2^*Map评价输血依赖性疾病患者多脏器铁沉积的价值。方法 收集输血依赖性疾病患者30例,按输血量分为未输血组(n=7)、少量输血组(3年内累计输血量1~150 U,n=13)和大量输血组(3年内输血量>150 U,n=10);收集同期健康志愿者28名(正常组)。采用3.0T MR多回波梯度回波序列获得肝脏、心脏、胰腺的T2^* Map,比较组间同器官T2^*值,分析不同器官T2^*值的相关性及T2^*值与血清铁蛋白(SF)、输血量的相关性。结果 正常组和未输血组肝脏T2^*值高于少量输血组(q=13.23、12.29)与大量输血组(q=13.10、12.23);正常组和未输血组胰腺T2^*值高于少量输血组(q=4.23、3.63)与大量输血组(q=7.14、5.88),少量输血组高于大量输血组(q=2.54);正常组、未输血组心脏T2^*值高于大量输血组(q=2.29、3.11);差异均有统计学意义(P均<0.05)。心脏与胰腺T2^*值呈正相关(r=0.542,P=0.017),心脏、胰腺与肝脏T2^*值均无明显相关性(r=0.32、0.65,P>0.05)。肝脏T2^*值与SF呈中度负相关(r=-0.503,P=0.028),心脏、胰腺T2^*值与SF无明显相关性(r=-0.30、-0.61,P>0.05);肝脏、胰腺T2^*值与3年内输血量呈中度负相关(r=-0.528、-0.793,P均<0.01),心脏T2^*值与3年内输血量无明显相关性(r=-0.252,P=0.246)。结论 输血依赖性疾病患者铁最早沉积于肝脏,胰腺、心肌次之;MRI T2^* Map可直接、可靠地检测各器官的铁沉积水平。     

双回波序列和1H-MRS检测非酒精性脂肪肝大鼠肝内脂肪含量

目的 探讨双回波序列和¹H-MRS在非酒精性脂肪肝(NAFLD)大鼠肝内脂肪含量测定中的应用价值。方法 对25只NAFLD SD大鼠首先行双回波序列扫描和¹H-MRS检查,并测定肝内脂肪含量,再行组织病理学检测,分析双回波序列与¹H-MRS、组织病理学结果的相关性。结果 双回波序列与¹H-MRS所测肝内脂肪含量呈正相关(r=0.936,P<0.001);双回波序列与组织病理学所测肝内脂肪含量呈正相关(r=0.946,P<0.001),Bland-Ahman曲线分析显示双回波序列和病理学测定的大鼠肝内脂肪含量一致性非常好。结论 双回波序列测定NAFLD肝内脂肪含量简便、易行,且准确性高,有望取代组织病理学检查。     

3.0T磁共振T2* mapping成像诊断腰椎间盘退变

目的 评价T2^* mapping成像技术在诊断腰椎间盘退变中的临床应用价值。方法 对12例下腰痛患者(症状组)及12名无症状志愿者 (对照组)行腰椎间盘MR扫描,在L₁-S₁共120个椎间盘放置ROI,测量相应的T2^*值,并按Pfirrmann标准对常规 T2WI显示的椎间盘进行分级,分析并比较症状组和对照组腰椎间盘内T2^*值的差异,对T2^*值与椎间盘分级间的相关性采用Spearman相关分析。结果 症状组椎间盘Pfirrmann分级平均得分高于对照组(t=5.04,P<0.05)。症状组腰椎间盘平均T2^*值为(76.90±33.10)ms,低于对照组[(116.00±71.60)ms,P<0.05]。症状组和对照组T2^*值均与Pfirrmann分级呈负相关(r=-0.84、-0.76,P均<0.05)。结论 T2^* mapping成像技术能为影像学量化诊断腰椎间盘退变提供依据。     

BOLD-MRI评价2型糖尿病患者降血糖治疗前后肾组织氧合状况

目的 采用BOLD-MRI评价糖尿病患者降血糖治疗前后肾组织氧合水平改变情况及其与血糖水平的相关性。方法 对23例2型糖尿病患者（糖尿病组）于降血糖治疗前后及23名健康志愿者（对照组）行肾脏BOLD-MRI,测量肾脏皮、髓质R2^*值,并进行统计学分析。结果 糖尿病组降血糖前、降血糖后及对照组肾皮质的R2^*值均低于肾髓质（P均<0.001）。糖尿病组降血糖前肾髓质R2^*值高于降血糖后和对照组（P均=0.001）,降血糖后肾髓质R2^*值与对照组差异无统计学意义（P=0.941）。糖尿病组降血糖前、降血糖后、对照组间肾皮质R2^*值差异无统计学意义（P=0.572）。糖尿病组肾髓质R2^*值与血糖值呈正相关（r=0.365,P=0.002）,而肾皮质R2^*值与血糖值无明显相关性（r=-0.014,P=0.908）。结论 降血糖治疗可以改善肾髓质的氧合状况;BOLD-MRI可用于评价糖尿病患者降血糖治疗前后肾组织氧含量的变化。     

磁共振血氧水平依赖成像观察原发性肝细胞癌高强度聚焦超声治疗前后氧摄取变化特点

目的 通过观察原发性肝细胞癌(HCC)高强度聚焦超声(HIFU)治疗前后氧摄取变化特点,探讨BOLD MRI评估HIFU治疗原发性HCC疗效的潜在价值。方法 16例原发性HCC患者于HIFU治疗前及治疗后2周内接受常规MRI、BOLD MRI及动态增强扫描。BOLD MRI采用梯度回波序列。将BOLD图像数据传输至工作站,采用R2^*软件对图像进行后处理生成R2^*图及T2^*图。在病灶中心、周围正常肝组织以及背部肌肉设置ROI,测量R2^*值、T2^*值及信号强度(SI)。对3个ROI R2^*值、T2^*值及SI在HIFU治疗前后的差异进行比较。结果 与治疗前比较,HCC R2^*值在HIFU治疗后2周内明显升高 ,而T2^*值、SI值在HIFU治疗后2周内明显降低 。周围肝组织及背部肌肉R2^*值、T2^*值及SI值在HIFU治疗前后的无明显变化(P＞0.05)。结论 BOLD MRI在评价原发性肝细胞癌缺氧及HIFU疗效方面有一定潜力。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Modified micro-superior percutaneously-assisted total hip: early experiences & case reports

Because of the extensile nature and familiarity of the standard posterior-lateral approach to the hip, a family of "micro-posterior" approaches has been developed. This family includes the Percutaneously-Assisted Total Hip (PATH) approach, the Supercapsular (SuperCap) approach and a newer hybrid approach, the Supercapsular Percutaneously-Assisted Total Hip (SuperPATH) approach. Such approaches should ideally provide a continuum for the surgeon: from a "micro" (external rotator sparing) posterior approach, to a "mini" (external rotator sacrificing) posterior approach, to a standard posterior approach. This could keep a surgeon within his comfort zone during the learning curve of the procedure, while leaving options for complicated reconstructions for the more practiced micro-posterior surgeons. This paper details one author's experiences utilizing this combined approach, as well as permutations of this entire micro-posterior family of approaches as applied to more complex hip reconstructions.     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Structure and function of "metalloantibiotics"

Although most antibiotics do not need metal ions for their biological activities, there are a number of antibiotics that require metal ions to function properly, such as bleomycin (BLM), streptonigrin (SN), and bacitracin. The coordinated metal ions in these antibiotics play an important role in maintaining proper structure and/or function of these antibiotics. Removal of the metal ions from these antibiotics can cause changes in structure and/or function of these antibiotics. Similar to the case of "metalloproteins," these antibiotics are dubbed "metalloantibiotics" which are the title subjects of this review. Metalloantibiotics can interact with several different kinds of biomolecules, including DNA, RNA, proteins, receptors, and lipids, rendering their unique and specific bioactivities. In addition to the microbial-originated metalloantibiotics, many metalloantibiotic derivatives and metal complexes of synthetic ligands also show antibacterial, antiviral, and anti-neoplastic activities which are also briefly discussed to provide a broad sense of the term "metalloantibiotics."