Interaction of B and T lymphocyte subsets with high endothelial venules in the rat: binding in vitro does not reflect homing in vivo

Lymphocytes continuously migrate through the body, and their efficient extravasation from the blood via high endothelial venules (HEV) is essential for initiating an appropriate immune response. Most investigations have focused on the lymphocyte/HEV interaction in vitro. However, to what extent such systems reflect the situation in vivo is not known. It is also unclear whether lymphocyte subsets immigrate into the HEV in proportion to their presence in the blood, and whether import capacity is limited by the HEV. When rat mesenteric lymph node lymphocytes were incubated in vitro on cryostat sections, the well-known preferential binding of B lymphocytes to HEV of Peyer's patches (PP) and T cells to HEV of axillary lymph nodes (axLN) was observed (axLN vs. PP: B lymphocytes 21.2 ± 5.0% vs. 40.6 ± 11.0%, T lymphocytes 84.6 ± 6.3% vs. 56.5 ± 12.9%). However, when labeled mesenteric lymph node lymphocytes were injected and their location within the HEV was analyzed 15 min later, no preferential interaction was seen. After injection of labeled thoracic duct lymphocytes, the percentage of labeled cells among B and T lymphocytes in the blood was significantly different (4.4 ± 0.9% vs. 8.9 ± 3.6%), whereas that in HEV of axLN (19.0 ± 6.4% vs. 16.6 ± 6.0%) and PP (30.6 ± 6.1% vs. 33.9 ± 4.4%) was comparable. Although the number of injected lymphocytes was similar in magnitude to the total blood lymphocyte pool, after injection there was no increase in lymphocyte numbers in the HEV. Thus, the adhesion assay in vitro does not completely reflect immigration into HEV in vivo. In addition, our data suggest that both the availability of lymphocyte subsets in small venules and the immigration rate into HEV are actively regulated in vivo.     

High resolution electron paramagnetic resonance imaging of biological samples with a single line paramagnetic label

The application of electron paramagnetic resonance imaging (EPRI) to obtain information from biological samples has been limited by the lack of ideal single line radical labels. The commonly used nitroxides exhibit multiple lines causing either hyperfine-based limitations in the maximum obtainable image resolution or hyperfine-based artifacts in the reconstructed image. The use of a novel single-line triarylmethyl paramagnetic label that enables marked enhancement in image quality and resolution is reported. This label exhibits a single line EPR spectrum that is sharp (linewidth ～60 mG in the absence of oxygen) and relatively stable in tissues. The potential of this label in enabling high resolution EPR imaging of biological samples was demonstrated in a series of phantoms and isolated biological organs such as the rat kidney. The images demonstrate that resolutions better than 100 μm could be obtained at L-band on samples of up to 20 mm in size.     

重组血管内皮细胞生长因子在大肠杆菌的高效表达

目的:使重组血管内皮细胞生长因子(VEGF)在大肠杆菌中得到高效表达.方法:通过构建表达重组VEGF的质粒PRL621/VEGF,并在大肠杆菌中高效表达.结果:表达量约占菌体总蛋白的40%.对形成包含体的表达产物进行变性,初步复性处理,得到重组人VEGF粗提液,鸡胚绒毛尿囊膜试验表明有促血管生长活性,N-端15个氨基酸序列分析结果,与天然VEGF蛋白质相应序列一致.     

CT造影剂碘海醇注射液的制备及动物实验

本文报道了非离子型Ｘ－ＣＴ造影剂碘海醇注射液的制备及动物实验结果。磺海醇的最大吸收波长λ＿（ｍａｘ）为２４４ｎｍ。讨论了温度、浓度对磺海醇溶液粘度的影响：粘度随温度的升高而下降，呈负线型相关；粘度随浓度（Ｃ）升高而激剧升高，与浓度的四次方呈线性相关：Ｖ＿（３７℃）＝４７２．５８９［Ｃ］￣４＋１．１２１（ｒ＝０．９９７７）Ｖ＿（３０℃）＝６６３．８１３［Ｃ］￣４＋１．１５２（ｒ＝０．９９９６）Ｖ＿（２０℃）＝１０８２．９５３［Ｃ］￣４＋１．４３３（ｒ＝０．９９８２）使用该注射液进行狗的造影实验，获得了清晰的造影图像。     

Clinical correlates of high signal lesions on magnetic resonance imaging in Alzheimer's disease

Summary The pathophysiology and clinical significance of high signal lesions, visualized on magnetic resonance imaging (MRI) in patients with Alzheimer's disease (AD), remain controversial. Since they are known to correlate with vascular disease and vascular risk factors, we reviewed the clinical correlates of periventricular high signal (PVH) and subcortical white matter lesions (WML) in a sample of 106 patients with probable AD, excluding persons with treated vascular risk factors or symptomatic cerebrovascular and cardiovascular disease. Grade 2 PVH were seen in 26 (25%) and scattered WML were identified in 29 (18%). PHV were associated with advancing age and gait disturbance. WML were associated with gait disturbance and incontinence. Neither radiologic finding was related to dementia severity. The findings suggest that these lesions are common in patients with AD even when those with evidence of cerebrovascular disease are excluded; their presence, therefore, should not preclude a diagnosis of AD. Additionally, the data suggest that HSL on MRI may be one of many risk factors associated with functional disability in persons with probable AD.     

高频超声检测颈动脉内膜-中层厚度及外周血管内皮功能评价动脉粥样硬化

目的 探讨高频超声检测颈动脉内膜-中层厚度与肱动脉内皮依赖性舒张功能在动脉粥样硬化中的诊断价值.方法 冠状动脉造影的老年患者69例及青年志愿者20例,分别行颈动脉超声检查,同时采用充气加压法测定肱动脉血流介导的内径扩张值,超声测值与冠脉造影结果对照分析.结果 ①颈动脉内膜-中层厚度值随粥样硬化斑块的增多、冠脉狭窄程度的加重而增高;②动脉粥样硬化患者在内膜-中层厚度值增高之前即可出现内皮功能损伤,肱动脉内径扩张值降低早于内膜-中层厚度值增高之前出现,内径扩张值随冠脉狭窄程度加重而下降.结论 高频超声检测颈动脉内膜-中层厚度、内径扩张值诊断早期动脉粥样硬化敏感性高,并且有助于对冠脉狭窄程度作出判断.     

实时超声造影在乳腺肿块诊断中的价值

目的:研究实时超声造影在乳腺良恶性肿块诊断中的价值。方法:实时观察48例乳腺肿块内造影剂微泡的分布,分析造影增强特点,并用ACQ分析软件进行时间-强度曲线分析。结果:乳腺恶性肿块的周围可见蟹足样等一些特征性表现;恶性组明显增强时间及达峰时间比良性组早,峰值强度及曲线下面积较良性组高。结论:实时超声造影有助于乳腺良恶性肿块的鉴别及估测预后。     

Optimized and combined T1 and B1 mapping technique for fast and accurate T1 quantification in contrast-enhanced abdominal MRI.

Fast T(1) mapping techniques are a valuable means of quantitatively assessing the distribution and dynamics of intravenously or orally applied paramagnetic contrast agents (CAs) by noninvasive imaging. In this study a fast T(1) mapping technique based on the variable flip angle (VFA) approach was optimized for accurate T(1) quantification in abdominal contrast-enhanced (CE) MRI. Optimization methods were developed to maximize the signal-to-noise ratio (SNR) and ensure effective RF and gradient spoiling, as well as a steady state, for a defined T(1) range of 100-800 ms and a limited acquisition time. We corrected B(1) field inhomogeneities by performing an additional measurement using an optimized fast B(1) mapping technique. High-precision in vitro and abdominal in vivo T(1) maps were successfully generated at a voxel size of 2.8 x 2.8 x 15 mm(3) and a temporal resolution of 2.3 s per T(1) map on 1.5T and 3T MRI systems. The application of the proposed fast T(1) mapping technique in abdominal CE-MRI enables noninvasive quantification of abdominal tissue perfusion and vascular permeability, and offers the possibility of quantitatively assessing dilution, distribution, and mixing processes of labeled solutions or drugs in the gastrointestinal tract.     

不同海拔高度严重烧伤延迟复苏大鼠脑组织中能量负荷的变化及其意义

目的：探讨不同海拔高度严重烧伤延迟复苏大鼠脑组织能量负荷变化及其意义。方法：以120只雄性Wistar大鼠建立高原（海拔3800m）实验模型（TBSA30％，Ⅲ度），随机分为延迟、即时复苏组和正常对照组，分别于伤后1、6、12、24、72h及7d取材。兰州地区取相等数量动物重复实验。应用高效液相色谱法检测脑组织中AMP、ADP、ATP的含量，并计算能量负荷。结果：能量负荷在高原正常对照组与兰州地区正常对照组差异显著（P〈0．01）。高原烧伤后脑组织能量负荷与对照组相比均降低，即时复苏组伤后早期即出现显著变化（P〈0．01），伤后72h开始恢复，伤后7d差异无显著，延迟复苏组伤后7d仍星显著差异（P〈0．01）。与即时复苏组比较伤后6～24h无显著差异，伤后72h～7d呈显著性差异（P〈0．01）。高原地区各时相点与兰州地区比较，EC值均降低，除即时复苏组6h外，具有统计学意义。结论：不同海拔高度严重烧伤延迟复苏大鼠脑组织能量负荷的改变一定程度上反映了脑损伤的严重程度。