Vasomotion in rat diaphragm microcirculation at rest and during stepwise arterial pressure reduction

The effect of haemorrhagic hypotension on the incidence, frequency and relative amplitude of vasomotion in rat diaphragm microcirculation was assessed by laser Doppler flowmetry (LDF). Graded bleeding to four hypotension levels (80, 60, 40 and 30% of the control state) were performed in 24 Sprague–Dawley rats. The incidence of vasomotion was 83% in the control state, 96% at the 80% level, 100% at the 60% level, 96% at the 40% level, and 46% at the 30% level. The median fundamental frequency of vasomotion determined manually during the control state and at the hypotension levels (in descending order) was 4.11 (range, 3.29–5.58) cycles min^?1 (cpm), 4.48 (3.21–5.92) cpm, 4.20 (3.5–5.56) cpm, 4.01 (3.33–5.36) cpm, 3.71 (3.25–4.49) cpm (P < 0.01 from the fundamental frequency at 80 and 60% hypotension levels). The median relative amplitudes determined manually during the control state and descending hypotension levels were 44.5% (range, 24.9–135.9%), 69.4% (26.6–147.2%), 84.0% (40.3–177.1%) (P < 0.01 from resting and last stage of bleeding), 90.40% (26.2–189.6%) (P < 0.01 from resting and last stage of bleeding), 69.2% (35.6–93.2%). We concluded first that during the resting condition, vasomotion was frequently present in diaphragm microcirculation, which is distinct from other vascular beds of skeletal muscles. Second, the relative amplitude of vasomotion during haemorrhagic hypotension plotted against decreasing blood pressure exhibited a reverse U-shaped curve with a maximum at 40–60% of the control blood pressure, while the frequency of vasomotion remained relatively constant until the last stage of haemorrhage and centred around 3–5 cpm.     

不同年龄和部位女性皮肤微循环变化

目的观察不同部位皮肤血管结构和形态差异,研究年龄对真皮微循环功能的影响.方法采用活体电视毛细血管镜(Intravital Video-capillaroscopy)和激光多谱勒血流仪(laser Doppler flowrnetry)对50名年龄在20～74岁,光皮肤类型为Ⅱ～Ⅲ型白人女性志愿者的前额、眼角、前臂内侧和手背血管作初步观察.并用计算机图象处理技术,对前臂和手背活体真皮血管密度作定量分析.结果真皮乳头毛细血管襻在活体电视毛细血管镜下为点状或逗点状;乳头下的血管丛表现为线条状或网状;年轻人皮肤血管排列整齐,年龄较大者血管扩张增粗、扭曲,排列不规则.年龄与襻状血管数、襻状血管面积显著负相关;与襻状血管间距、平行血管总长正相关;真皮血流量面部高于肢端;随年龄的增加真皮血流有逐渐增加趋势.结论年龄影响真皮微循环的形态和功能.两种无创性检测技术联合应用能动态研究活体真皮血管的形态和结构,在皮肤血管性疾病的诊断和治疗方面有较高的应用前景.     

一种新型多普勒血流仪的研制

目的 研制一种具有数据采集、存储、传输、显示及声音辅助诊断功能,可以面向社区和家庭应用的便携式多普勒血流仪.方法 基于多普勒测量血流原理,以STM32微处理器为核心,采用定向型正交相位解调法获取多普勒频移信号,通过电源模块、数据采集模块、USB模块、按键模块、数据存储模块、音频处理模块、液晶显示模块、网络收发模块等外围电路,结合PC构成一个完整的血流检测系统.结果 该血流仪能够实现对患者血流数据的采集、处理、存储、传输,可实时显示脉率、诊听血流声音及输出双向血流频移波形和血流速度波形,可用于糖尿病足的诊断.结论 该血流仪使用方便,通过血流声音、血流速度波形、频移波形和脉率等反映血流特征的信息,进行糖尿病足等与血流相关慢性病的早期检测.     

用激光多普勒血流仪检测升主动脉缩窄心衰大鼠的皮肤微循环

目的观察升主动脉缩窄大鼠心衰模型的皮肤微循环。方法用激光多普勒血流仪检测心衰大鼠与对照组大鼠的皮肤血流量、血流速度和血含量。结果实验组的血流量、血流速度较对照组明显降低 ,血流量降低了30 % ,血流速度降低了28 % ,而血含量没有明显改变。结论血流速度变慢可能是升主动脉缩窄大鼠心衰时皮肤微循环改变的一个重要特点。     

高压氧对大鼠肢体缺血再灌注所致肾损伤的作用

目的探讨高压氧（HBO）对减轻大鼠肢体缺血再灌注（I／R）致肾脏损伤的作用及机制。方法复制I2h／R1h模型，分为3组，即A组（假手术组）、B组（I／R模型组）、C组（HBO治疗组）。观察肾脏微血流变化；对肾脏组织行电镜病理检查；记录血清CD31、CD61平均荧光强度和CD62p的阳性率。结果与B组比较，C组肾脏微血流速度明显升高，差异有统计学意义著（P〈0．05）。与B组比，C组肾脏组织病理改变较轻。与A组比较，B组CD31、CD61及CD62p均有升高，其中CD31和CD62p升高显著（P〈0．05）；与B组比较，C组CD31、CD61及CD62p均有下降，其中CD31和CD62p下降尤为显著（P〈0．05）。结论早期行HBO处理可显著减少急性下肢I／R大鼠模型血小板膜糖蛋白CD31和CD62p的表达，从而有助于减轻下肢I／R继发肾脏损伤。     

Influence of physiological and supraphysiological hyperinsulinemia on skin microcirculation in healthy volunteers

AIM: To examine skin perfusion in dependency on insulinemia in healthy subjects.METHODS: All volunteers were informed in detail about the procedures and signed informed consent. The protocol of this study was approved by the ethical committee. In our study, a two stage hyperinsulinemic euglycemic clamp was performed, with insulinemia 100 and 250 mIU/mL and glycemia 5.0 mmol/L (3% standard deviation). Before the clamp and in steady states, microcirculation was measured by laser Doppler flowmetry and transcutaneous oximetry and energy expenditure was measured by indirect calorimetry. Results (average and standard deviation) were evaluated with paired t-test.RESULTS: Physiological (50 mIU/L) insulinemia led to higher perfusion in both tests; hyperemia after heating to 44%-1848% (984-2046) vs 1599% (801-1836), P < 0.05, half time of reaching peak perfusion after occlusion release 1.2 s (0.9-2.6) vs 4.9 s (1.8-11.4), P < 0.05. Supraphysiological (150 mIU/L) insulinemia led to even higher perfusion in both tests; hyperemia after heating to 44%-1937% (1177-2488) vs 1599% (801-1836), P < 0.005, half time to reach peak perfusion after occlusion release 1.0 s (0.7-1.1) vs 4.9 s (1.8-11.4), P < 0.005. A statistically significant increase occurred in tissue oxygenation in both insulinemia. The difference in perfusion and oxygenation between physiological and supraphysiological hyperinsulinemia was not statistically significant.CONCLUSION: The post occlusive hyperemia test in accordance with heating test showed significantly increasing skin perfusion in the course of artificial hyperinsulinemia. This effect rises non-linearly with increasing insulinemia. Dependency on the dose was not statistically significant.     

Evaluation of the patency of endoscopic third ventriculostomy using phase contrast MRI-CSF flowmetry as diagnostic approach

Purpose

The aim is to assess the usefulness of cine phase-contrast MRI for evaluation of patency of endoscopic third ventriculostomy operation and correlation with clinical state postoperatively.