Dynamic and static phantoms for evaluation of digital subtraction angiographic systems

Two types of phantoms were developed with which to evaluate the overall performance of digital subtraction angiography (DSA) systems. A dynamic phantom, called a "fish bone" phantom, consists of polyethylene tubes that simulate blood vessels with various lesions, such as stenoses, ulcers, and aneurysms. With this phantom, washout curves were obtained representing the relationship between iodine content and time. It will be useful for qualitative assessment of DSA images, evaluation of different image-processing schemes, and studies of blood flow analysis. A static phantom, called a "C-D" phantom, can be used for measurement of quantitative contrast-detail (C-D) diagrams and for daily monitoring of DSA systems. This was constructed of tubes of seven different diameters (2.15-0.28 mm) and 14 different concentrations of contrast medium (100%-1.1% Renografin-76 [meglumine and sodium diatrizoate]). The C-D diagrams were determined from an observer performance study using C-D phantom images obtained at four different DSA settings.     

Brain tumors: MR imaging with gadolinium-DTPA

Magnetic resonance (MR) imaging was performed on 40 patients with intracranial tumors, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA). Precontrast studies included a comprehensive protocol of spin-echo sequences. Tumors were visualized on precontrast images either directly or indirectly by anatomic distortion caused by the mass. However, differentiation of the tumor from adjacent tissues was possible in only 17 of 40 cases. Delineation of the tumor was best on precontrast, T2-weighted images. After administration of Gd-DTPA (0.1 mmol/kg), increased signal intensity from the tumor was observed in all patients. The localized increase in signal intensity in the tumor considerably improved the tumor delineation in 36 of 40 patients. Whereas most of the meningiomas, neuromas, and adenomas could be delineated prior to administration of contrast material if appropriate pulse sequences were applied, glioblastomas and intracranial metastases required Gd-DTPA administration for diagnostically sufficient tumor display.     

Bridging the Gap: establishing the necessary infrastructure and knowledge for teaching and research in neuroscience in Africa

Advances in neuroscience research over the last few decades have increased our understanding of how individual neurons acquire their specific properties and assemble into complex circuits, and how these circuits are affected in disease. One of the important motives driving neuroscience research is the development of new scientific techniques and interdisciplinary cooperation. Compared to developed countries, many countries on the African continent are confronted with poor facilities, lack of funding or career development programs for neuroscientists, all of which deter young scientists from taking up neuroscience as a career choice. This article highlights some steps that are being taken to promote neuroscience education and research in Africa.     

Atrial natriuretic peptide infusion and nitric oxide inhalation in patients with acute respiratory distress syndrome

Aim  

To study the effects of infusion of atrial natriuretic peptide (ANP) versus the inhalation of nitric oxide (NO) in patients with an early acute respiratory distress syndrome (ARDS).     

Changes in Plant-Based Diet Indices and Subsequent Risk of Type 2 Diabetes in Women and Men: Three U.S. Prospective Cohorts

OBJECTIVEWe evaluated the associations between changes in plant-based diets and subsequent risk of type 2 diabetes.RESEARCH DESIGN AND METHODSWe prospectively followed 76,530 women in the Nurses’ Health Study (NHS) (1986–2012), 81,569 women in NHS II (1991–2017), and 34,468 men in the Health Professionals Follow-up Study (1986–2016). Adherence to plant-based diets was assessed every 4 years with the overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI). We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs). We pooled results of the three cohorts using meta-analysis.RESULTSWe documented 12,627 cases of type 2 diabetes during 2,955,350 person-years of follow-up. After adjustment for initial BMI and initial and 4-year changes in alcohol intake, smoking, physical activity, and other factors, compared with participants whose indices remained relatively stable (±3%), participants with the largest decrease (>10%) in PDI and hPDI over 4 years had a 12–23% higher diabetes risk in the subsequent 4 years (pooled HR, PDI 1.12 [95% CI 1.05, 1.20], hPDI 1.23 [1.16, 1.31]). Each 10% increment in PDI and hPDI over 4 years was associated with a 7–9% lower risk (PDI 0.93 [0.91, 0.95], hPDI 0.91 [0.87, 0.95]). Changes in uPDI were not associated with diabetes risk. Weight changes accounted for 6.0–35.6% of the associations between changes in PDI and hPDI and diabetes risk.CONCLUSIONSImproving adherence to overall and healthful plant-based diets was associated with a lower risk of type 2 diabetes, whereas decreased adherence to such diets was associated with a higher risk.     

Preexisting memory CD4+ T cells contribute to the primary response in an HIV-1 vaccine trial

Naive and memory CD4⁺ T cells reactive with human immunodeficiency virus type 1 (HIV-1) are detectable in unexposed, unimmunized individuals. The contribution of preexisting CD4⁺ T cells to a primary immune response was investigated in 20 HIV-1–seronegative volunteers vaccinated with an HIV-1 envelope (Env) plasmid DNA prime and recombinant modified vaccinia virus Ankara (MVA) boost in the HVTN 106 vaccine trial (clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02296541","term_id":"NCT02296541"}}NCT02296541). Prevaccination naive or memory CD4⁺ T cell responses directed against peptide epitopes in Env were identified in 14 individuals. After priming with DNA, 40% (8/20) of the elicited responses matched epitopes detected in the corresponding preimmunization memory repertoires, and clonotypes were shared before and after vaccination in 2 representative volunteers. In contrast, there were no shared epitope specificities between the preimmunization memory compartment and responses detected after boosting with recombinant MVA expressing a heterologous Env. Preexisting memory CD4⁺ T cells therefore shape the early immune response to vaccination with a previously unencountered HIV-1 antigen.     

基于椎弓根三维形态测量实施个体化置钉技术

目的:观察胸腰段椎弓根CT测量在椎弓根螺钉内固定中的作用,寻找一种个体化椎弓根螺钉置入的方法。方法:选择1999-02/2006-03河北工程大学附属医院收治的T12和/或L1段骨折患者59例,行螺旋CT检查及图像三维重建,重建结束后,得到胸腰段标本的三维图像,通过旋转和切割进行图像处理并测量,模拟出T11～L2的椎弓根形态,根据CT测量椎弓根的实际投照点进行调整,即横断面上椎弓根轴线与矢状位上椎弓根轴线的交点,在确定进钉点时选择下关节突为参照物,选用合适直径的螺钉进行植钉,植入螺钉后,连接棒或板系统。结果:262个椎弓根行植钉术,242个完全在椎弓根内,仅有20个螺钉穿透椎弓根皮质。术后平均随访16.1个月,均无临床并发症的发生,Frankel平均增加1.4级。术后有2例患者出现断钉(3枚),1例患者出现断棒,所植入的螺钉与机体生物相容性好,无不良反应的发生。结论:利用三维CT测量的数据辅助,严格按照个体化的椎弓根的轴线方向植钉,在置钉时应考虑到螺钉本身直径的因素,可以提高植钉的成功率。     

抑郁症综合式家庭治疗：76例单盲随机对照

目的:探讨综合式家庭治疗对抑郁患者及家属的效果。方法:于2002-11/2003-11选择郑州市第八人民医院符合中国精神障碍分类与诊断标准第3版抑郁症诊断标准的抑郁患者为实验对象。患者家住郑州市区并有直系亲属与其同住,无严重躯体疾病。76例自愿参加本实验,按随机数字表分为实验组与对照组。实验组男14例,女25例,平均(36±6)岁,首次发病年龄(28±7)岁,病程(5.6±5.4)年,住院次数(2.1±2.8)次,读书年限(11.2±2.4)年。对照组男13例,女24例,平均(35±6)岁,首次发病年龄(28±7)岁,病程(5.9±5.8)年,住院次数(2.2±2.6)次,读书年限(10.8±5.8)年。以上各变量两组间差异无显著性意义,具有较好的可比性。于患者住院时与实验组家属见面建立初步医患关系,但不干预住院期间的治疗。出院后实验组接受家庭治疗,对照组接受普通门诊治疗。家庭治疗是结合中国家庭心理行为特征,参考国外家庭系统模式、心理教育模式、认知行为模式等心理治疗理论发展起来的。分积极干预和维持治疗两个阶段。积极干预的疗程一般为1年半至2年,以药物治疗、心理教育、家庭干预为主要手段。采用汉密顿抑郁量表评价临床症状,用临床总体量表-疗效总评量表评定临床疗效,用修订社会功能缺陷筛选表评价患者社会功能,用修订社会功能缺陷筛选表得分百分率描述患者最近半年社会功能缺陷的严重程度(0%为最好,100%为最差),分别于入院时、出院时、随访6个月后进行评定。评价家庭负担的方法:要求关键亲属从6个方面评价疾病最近半年对家庭生活的影响程度(0:没有影响;1:轻度;2:中度;3:重度)。结果:76例患者均均进入结果分析。①两组患者入院时和出院时的汉密顿抑郁量表及临床整体量表-疗效总评估量表评分差异无显著性意义,但通过出院后24个月家庭心理治疗之后,实验组与对照组汉密顿抑郁量表及临床整体量表-疗效总评估量表评分差异有显著性意义,实验组疗效要明显好于对照组[汉密顿抑郁量表:(7.08±4.21),(12.26±0.85)分,P<0.01;临床整体量表-疗效总评估量表评分:(1.48±0.15),(2.63±0.12)分,P<0.05]。②随访期间实验组总的社会功能缺陷轻于对照组[再住院天数:(0.97±15.41),(7.61±26.14)d;全天工作时间:(86.7±48.10)%,(68.4±32.10)%;社会功能缺陷程度:(12.10±18.10)%,(38.10±15.20)%,P均<0.01]。实验组家庭随访期间受到的经济压力和情绪影响明显低于对照家庭,家属之间关系明显好于对照组[(0.78±0.61),(1.51±0.83)分;(1.76±0.52),(2.15±0.68)分;(0.43±0.69),(0.96±0.78)分,P均<0.05]。结论:综合式家庭治疗是治疗抑郁症的一个有效方法。     

不同孔径纳米羟基磷灰石人工骨修复兔桡骨缺损效果比较

目的:纳米级的羟基磷灰石材料与人体内组织成分更为相似,具有更佳的生物性能。评价不同孔径的多孔纳米羟基磷灰石人工骨的骨缺损修复能力,从而筛选出适合的孔径以达到骨传导功能与生物力学性能的良好统一。方法:实验于2005-10/2006-10在深圳市第二人民医院中心实验室完成。①实验材料:纳米羟基磷灰石人工骨以硝酸钙和磷酸二氢铵为原料,采用溶胶-絮凝法制备粉体,运用压力成型、木模成型和浸渍成型分别制得孔隙分布均匀的孔径分别为50～150μm、100～250μm和300～500μm的多孔纳米羟基磷灰石人工骨。②实验动物:雄性新西兰大白兔60只随机分为植入50～150μm孔径材料组、植入100～250μm孔径材料组、植入300～500μm孔径材料组、空白对照组,每组15只。实验过程中对动物处置符合动物伦理学要求。③实验方法:制备双侧桡骨骨缺损动物模型,然后用3种不同孔径的纳米羟基磷灰石人工骨材料植入骨缺损处进行修复,空白对照组不植入任何材料。④实验评估:术后4,8和12周分别行大体标本观察、X射线片观察、扫描电镜观察及生物力学测试,比较各组材料修复骨缺损的能力。结果:实验动物均进入结果分析。①X射线片检查结果:术后4周、8周、12周,植入100～250μm孔径材料组X射线评分高于植入50～150μm,300～500μm孔径材料组,差异有显著性意义(P<0.05)。②生物力学检测结果:术后4周、8周、12周,植入100～250μm孔径材料组生物力学强度高于植入50～150μm,300～500μm孔径材料组,差异有显著性意义(P<0.05)。③扫描电镜观察结果:植入100～250μm孔径材料组成骨效果明显优于植入50～150μm,300～500μm孔径材料组和空白对照组。结论:纳米羟基磷灰石人工骨具有良好的成骨能力,但其骨修复能力受孔径因素的影响,孔径100～250μm的纳米羟基磷灰石人工骨材料成骨能力较好。