A new method to model change in cutaneous blood flow due to mechanical skin irritation part I: comparison between experimental and numerical data

Mechanical skin irritation creates vasodilation. Vasodilation of vascular networks induces increase in blood volume and blood velocity. Both can be measured by Laser Doppler Velocimetry. We propose in this article a method permitting comparison between experimental and numerical results. Experimental data was obtained by Laser Doppler Velocimetry. Numerical results were obtained by a continuous model of the vascular network. The model consists of three layers. First and last layer are described by anisotropic and heterogeneous porous media. They represent the irrigation and the drainage of the vascular system. The intermediate layer is described by a lumped parameter model that does not permit horizontal fluxes. All vessels are compliant. The permeabilities depend on the volumes of the specific layer. Skin irritation is modeled by a change in compliance of small arterial blood vessels. The comparison between experimental and numerical data is based on the model proposed by Bonner and Nossal [1981. Model for laser Doppler measurements of blood flow. Appl. Opt. 20, 2097-2107]. The model describes the Doppler frequency spectrum S(omega) as a function of the optical phenomena creating the frequency shift. The comparison is based on the model of the first moment M1 approximately integralomegaS(omega)domega. The variables of the first moment can be determined by results of the numerical model. We have shown, that it exists a linear relation between the change in compliance and the following increase in first moment. Using this linear relation experimental and numerical data can be compared.     

小脑后下动脉瘤经微血管多普勒超声辅助下的显微外科治疗

目的：探讨小脑后下动脉瘤（PICA）的微血管多普勒超声（MVD）辅助下显微外科治疗。方法：回顾性分析31例患者的显微外科手术的临床症状,影像特点,外科治疗方法及相关预后。结果：头颅CT表现主要为幕下为主的蛛网膜下腔出血或脑室出血或二者兼有（除1例未破裂）。其中经全脑数控减影血管造影术（DSA）和/或CT血管造影（CTA）检查确诊。其中手术路径为枕下旁正中16例,枕下正中入路14例,枕下乙状窦后入路1例。在MVD的辅助下行脉瘤夹闭术27例,动脉瘤包裹术1例,动脉瘤夹闭并动静脉畸形切除术2例,动脉瘤夹闭术并小脑血肿清除术1例。术后出现并发症10例,其中3例意识障碍致死亡或自动出院,其余患者术后无神经功能损伤或并发症,恢复良好。结论：小脑后下动脉瘤的治疗选择合适的手术入路行显微外科手术,辅助MVD下,能够降低手术风险,提高完全夹闭动脉瘤的成功率,降低手术并发症的发生。     

Treatment with atorvastatin is associated with a better prognosis in chronic heart failure with systolic dysfunction: results from The Daunia Heart Failure Registry

Background

Few works have evaluated the effect of statins on left ventricular dysfunction in patients with chronic heart failure (CHF), by using tissue Doppler imaging (TDI). We therefore aimed to investigate whether atorvastatin treatment may influence prognosis and myocardial performance evaluated by TDI in subjects with CHF.

Methods

Five hundred thirty-two consecutive CHF outpatients enrolled in a local registry, the Daunia Heart Failure Registry, were prospectively analysed. 195 patients with CHF and left ventricular ejection fraction (LVEF) ≤40 %, either in treatment with atorvastatin (N: 114) or without statins (N: 81), underwent TDI examination. Adverse events were evaluated during follow-up.

Results

The atorvastatin group showed a lower incidence of adverse events (cardiac death: 0 % vs 7 %, p < 0.01), and better TDI performance (E/E’ 15 ± 5.7 vs 18 ± 8.3, p < 001) than controls. Ischaemic CHF patients in treatment with atorvastatin also showed a lower incidence of adverse events (death: 10 % vs 26 %, p < 0.05; sustained ventricular arrhythmias: 5 % vs 19 %, p < 0.05, cardiac death: 0 vs 8 %, p < 0.05) and better TDI performance (E/E’ ratio: 15.00 ± 5.68 vs 19.72 ± 9.14, p < 0.01; St: 353.70 ± 48.96 vs 303.33 ± 68.52 msec, p < 0.01) than controls. The association between atorvastatin and lower rates of cardiac death remained statistically significant even after correction in a multivariable analysis (RR 0.83, 95 % CI 0.71–0.96, p < 0.05 in CHF with LVEF ≤40 %; RR 0.77, 95 % CI 0.62–0.95, p < 0.05 in ischaemic CHF with LVEF ≤40 %).

Conclusions

Treatment with atorvastatin in outpatients with systolic CHF is associated with fewer cardiac deaths, and a better left ventricular performance, as assessed by TDI.     

Effect of pentoxifylline treatment on testicular perfusion and semen quality in Miniature horse stallions

The objective was to investigate the effects of pentoxifylline (PTX) on testicular perfusion and sperm production in stallions. In a preliminary study, six mature Miniature horse stallions were given 0, 8.5, or 17.0 mg/kg of PTX orally, twice daily, for 3 d. Total Arterial Blood Flow Rate (TABFR) was higher (P < 0.05) in all treated versus control stallions during and after treatment. Two months later (during the fall and winter), the same stallions received either 0 or 17 mg/kg of PTX orally, twice daily for 60 d. Resistance and pulsatility indices (RI and PI, respectively) decreased in PTX-treated stallions between Treatment 1 and Post-treatment periods. Arterial diameter, as well as Total Arterial Blood Flow (TABF), decreased in controls between Baseline and Treatment 1 (P < 0.05). A similar decrease in arterial diameter was delayed in Group TREATED, but reached significance during Post-treatment (P < 0.05), whereas TABF did not change in this group. Furthermore, TABFR had a transient tendency to increase during Treatment 1 (P < 0.1), whereas it steadily decreased in controls and reached significance in the Post-treatment period (P < 0.05). Both RI and PI were negatively correlated with end diastolic velocity (EDV) in both groups (P < 0.0001). There were positive correlations between RI and peak systolic velocity (PSV) in treated stallions during Treatment 1 (RI: r = 0.53, P = 0.021; PI: r = 0.59, P = 0.007). Also, there were negative correlations between Time Averaged Maximum Velocity (TAMAX) and Doppler indexes in treated stallions during Treatment 2 period (RI: r = −0.49, P = 0.006; PI: r = −0.47, P = 0.008), and during Post-treatment periods (RI: r = −0.40, P = 0.049; PI: r = −042, P = 0.039). Transient hydrocele occurred in all treated stallions (a potential complication of high-dose PTX). Semen end points were not significantly affected by PTX treatment. In conclusion, PTX delayed the seasonal decrease of testicular perfusion in stallions. Sperm quality and quantity were not significantly affected; perhaps they would have been enhanced by prolonged treatment.     

Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians. Although historically invasive methods have comprised the only means available, the development of noninvasive imaging modalities (echocardiography, MRI, CT) having high temporal and spatial resolution provide a new window for quantitative diastolic function assessment. Echocardiography is the agreed upon standard for diastolic function assessment, but indexes in current clinical use merely utilize selected features of chamber dimension (M-mode) or blood/tissue motion (Doppler) waveforms without incorporating the physiologic causal determinants of the motion itself. The recognition that all left ventricles (LV) initiate filling by serving as mechanical suction pumps allows global diastolic function to be assessed based on laws of motion that apply to all chambers. What differentiates one heart from another are the parameters of the equation of motion that governs filling. Accordingly, development of the Parametrized Diastolic Filling (PDF) formalism has shown that the entire range of clinically observed early transmitral flow (Doppler E-wave) patterns are extremely well fit by the laws of damped oscillatory motion. This permits analysis of individual E-waves in accordance with a causal mechanism (recoil-initiated suction) that yields three (numerically) unique lumped parameters whose physiologic analogues are chamber stiffness (k), viscoelasticity/relaxation (c), and load (x_o). The recording of transmitral flow (Doppler E-waves) is standard practice in clinical cardiology and, therefore, the echocardiographic recording method is only briefly reviewed. Our focus is on determination of the PDF parameters from routinely recorded E-wave data. As the highlighted results indicate, once the PDF parameters have been obtained from a suitable number of load varying E-waves, the investigator is free to use the parameters or construct indexes from the parameters (such as stored energy 1/2kx_o², maximum A-V pressure gradient kx_o, load independent index of diastolic function, etc.) and select the aspect of physiology or pathophysiology to be quantified.     

Storage Organs and Plant Growth

The purpose of this activity is to model the expansion of the universe by investigating the behavior of water waves. It is designed for students in the upper grades of physics and physical science who are learning about the wave nature of light and are ready to discover such important questions about science. The article explains first the Doppler effect through water waves and then extends to how to interpret light waves coming from other galaxies. Therefore, in addition to raising the scientific curiosity of the students, this activity also gives them an understanding of the hypothesis–evidence relation and the interpretation of data.     

高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查的相关性研究

摘要 目的：探讨与研究高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查的相关性。方法：2018年2月到2020年1月在本院进行建档分娩的高危孕妇108例作为研究对象,都给予彩色多普勒超声结合四维超声检查,记录影像学特征,判定胎儿缺氧发生情况并进行相关性分析。结果：在高危孕妇108例中,发生宫内缺氧28例（宫内缺氧组）,发生率为25.9 %;宫内缺氧组的大脑中动脉、脐动脉的阻力指数（RI）、搏动指数（PI）、收缩期峰值流速舒张期流速比值（S/D）均高于非宫内缺氧组（P<0.05）;宫内缺氧组的上腔静脉血流心室收缩期峰值流速（S波）、心房收缩期速度（A波）、心室舒张期峰值流速（D波）均高于非宫内缺氧组（P<0.05）;高危孕妇108例中,Spearsman分析显示大脑中动脉、脐动脉的RI、PI、S/D以及上腔静脉血流S、D、A均与宫内缺氧都存在相关性（P<0.05）;logistic多因素回归分析显示：大脑中动脉、脐动脉的S/D与上腔静脉血流S、A为导致胎儿缺氧的主要影响因素（P<0.05）。结论：高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查特征具有相关性,彩色多普勒超声结合四维超声可作为检查胎儿缺氧的可行、简单无创、方便快捷的方式,具有极高的应用价值。     

多层螺旋CT联合彩色多普勒超声对小儿先天性胆总管囊肿的诊断价值分析

摘要 目的：探讨多层螺旋CT（MSCT）联合彩色多普勒超声对小儿先天性胆总管囊肿（CCC）的诊断价值。方法：选取2018年1月～2021年12月来我院治疗的78例CCC患儿为研究对象,所有患儿均接受彩色多普勒超声检查及MSCT检查,以病理诊断结果为金标准,对比两种检查方法对CCC的诊断价值。结果：所有CCC患儿中均未出现肝门部纤维斑块（TC征）阳性、肝动脉内径增宽,33例出现囊肿内胆泥沉积和肝内胆管扩张,16例出现胆囊异常;囊肿长径、宽径分别为（5.41±0.60）cm、（3.26±0.38）cm,脾脏内径为（1.56±0.17）cm。所有患者的Todani分型结果显示：Ⅰ型67例,Ⅱ型2例,Ⅲ型2例,Ⅳ型5例,Ⅴ型2例。与病理学诊断结果对比,彩色多普勒超声对CCC患儿Todani分型有一定的诊断效能,对Ⅰ型、Ⅳ型、Ⅴ型的诊断准确率分别为83.33%、93.59%、93.59%（P＜0.05）。与病理学诊断结果对比,MSCT对CCC患儿Todani分型有较好的诊断效能,对Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型、Ⅴ型的诊断准确率分别为88.46%、89.74%、93.59%、94.87%、97.43（P＜0.05）。彩色多普勒超声联合MSCT检查的诊断准确率高达96.15%,明显高于两种方法单独应用（P＜0.05）。结论：不同Todani分型的CCC患儿具有不同的超声征象,彩色多普勒超声及MSCT对CCC患儿Todani分型均有一定的的诊断价值,且两者联合应用时诊断价值较高。     

彩色多普勒超声评估卵巢癌周围血管受侵程度及可切除性的应用价值

摘要 目的：探讨彩色多普勒超声评估卵巢癌周围血管受侵程度及可切除性的应用价值。方法：选择2018年2月至2019年8月在本院诊治的卵巢癌患者548例作为研究对象,所有患者都给予彩色多普勒超声,评估患者的周围血管受侵程度及可切除性,记录患者的超声血流频谱。结果：超声诊断为卵巢癌周围血管受侵犯78例,占比14.2 %,诊断敏感性与特异性为97.5 %和100.0 %, ROC曲线面积为0.963。超声诊断为卵巢癌可切除450例,占比82.1 %,诊断敏感性与特异性为99.1 %和90.4 %,ROC曲线面积为0.897。手术切除患者的年龄、体重指数、病理类型、病程等与未手术切除患者对比差异无统计学意义(P>0.05)。手术切除患者的搏动指数(pulsation index,PI)和阻力指数(resistance index,RI)高于非手术切除患者,血管舒张末期流速(end-diastolic velocity,EDV)、峰值流速(peak systolic velocity,PSV)低于非手术切除患者,差异均有统计学意义(P<0.05)。结论：彩色多普勒超声评估卵巢癌周围血管受侵程度及可切除性具有很好的敏感性与特异性,有利于指导卵巢癌患者的病情评估与治疗。