Die dopplersonographische Bestimmung der maximalen Blutströmungsgeschwindigkeit in der Diagnostik peripherer arterieller Verschlußkrankheiten bei Diabetes mellitus

Summary Seventy-five diabetic and 40 nondiabetic subjects who where suffering from peripheral vascular disease were studied in order to determine whether the degree of the severity of their disease can be better calculated by Doppler ultrasound examinations of the peak velocity than by the systolic pressure of the peripheral bloodstream. In 46 examinations of normal controls the mean value of the peak velocity was 13.3±3.3 cm/s with a standard deviation of 15.4%±13.2% on one day and 16.1%±15.9% on different days. Considering patients with or without diabetes mellitus the velocity was significantly decreased in correlation to an increasing degree of severity of the vascular disease (P<0.001); however, the decrease was lower in diabetic than in nondiabetic subjects (6.9±2.8 vs 4.6±6.2,P<0.05). The systolic pressure hardly decreased, but remained higher in all stages of peripheral vascular disease of diabetics than in the nondiabetic subject (P<0.05 toP<0.005). There was a significant decrease of the systolic pressure only in diabetic subjects with the most advanced degree of the disease, i.e. stage IV (P<0.05).It is concluded from this study that Doppler ultrasound measurements of the peak velocity of the peripheral bloodstream are a useful parameter to calculate the degree of severity of the peripheral vascular disease. In addition, it is concluded than peak velocity is an even better prognostic indicator of peripheral vascular disease than is measurement of the systolic blood pressure at the feet.

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Abkürzungen AVK periphere arterielle Verschlußkrankheit - USDI Ultraschall-Doppler-Index - MSBG maximale Blutströmungsgeschwindigkeit - HFV Herzfrequenzvariation     

The modular architecture of the neglect syndrome: Implications for action control in visual neglect

In our recent review of action control deficits in hemispatial neglect we concluded that many patients with the disorder have deficits in visuomotor control [Coulthard, E., Parton, A., & Husain, M. (2006). Action control in visual neglect. Neuropsychologia, 44(13), 2717-2733]. This conclusion has been questioned and it has been argued instead that there are no action deficits in neglect [Himmelbach, M., Karnath, H.-O., & Perenin, M.-T. (2007). Action control is not affected by spatial neglect: A comment on Coulthard et al. Neuropsychologia, 45(8), 1979-1981]. We proposed that rather than being specific to the neglect syndrome, action control deficits are more likely to relate to lesion location. Although many of these impairments may contribute to the manifestation of neglect, they may also occur in brain-damaged patients without the condition. In this article, we explore this framework further, discussing how neglect behaviour may emerge from damage to a set of visuomotor or cognitive modules, or their connections. Central to our view is the idea that the critical combination of deficits leading to neglect varies considerably between cases, and that visuomotor or cognitive modules disrupted in the syndrome may not, in fact, be specific to neglect.     

Pathological variables determining the prognosis of non-Hodgkin''s lymphomas

The aim of the study was to assess the role of pathological grade, cell proliferation, ploidy, immunophenotype and site in determining the prognosis of non-Hodgkin's lymphomas. Of particular interest was the relative value of grades derived from the Kiel classification as opposed to the National Cancer Institute (NCI) working formulation. The study consisted of 181 cases, treated in a relatively uniform way over an 18-month period spanning 1986. Using life table analysis, both NCI working formulation grade and Kiel grade correlated strongly with survival. However, the differences between grades were entirely due to an excess of early deaths in the high-grade and intermediate-grade categories. In patients surviving greater than 0.1 years (37 days), phenotype, site, ploidy and cell proliferation had no effect on survival. There was no evidence that intermediate-grade tumours, when subdivided into Kiel low- and high-grade types, differed in survival from tumours graded as low- or high-grade by both methods. However, NCI working, formulation high-grade tumours, especially those with a high proliferation rate, formed a group with a very high likelihood of death within 0.1 years.     

D2-43病毒E蛋白在酵母细胞表面的展示

目的：在酵母细胞表面展示登革2型病毒43株(D2—43)的E基因，探索利用酵母表面展示系统建立DNA改组筛选平台的可行性。方法：通过RT-PCR扩增获得D2-43的E基因，将该基因亚克隆至T载体后，再克隆至酵母表面展示载体pYDI，于酿酒酵母EBY100中利用半乳糖进行诱导表达。表达产物采用间接免疫荧光法和FACS进行检测。结果：酵母表面展示产物可与D2-43的腹水抗体特异性地结合；在半乳糖诱导后24h，展示E蛋白的酵母细胞百分数达22．07％。结论：本研究为建立基于酵母表面展示系统的DNA改组筛选平台奠定了基础。     

Combining spin echoes with gradient echoes in the context of the global coherent free precession pulse sequence.

To extend the signal longevity of magnetically excited spins in flowing fluids while in a state of global coherent free precession (GCFP), a refocusing radiofrequency (RF) pulse and bipolar gradient waveforms were combined with the GCFP sequence. The data demonstrate that RF refocusing in the presence of flowing blood is possible, but the improvement in signal amplitude depends on the static magnetic field homogeneity along the direction of motion and the displacement of the spins between the excitation and the RF refocusing pulse, as well as displacement during subsequent RF refocusing pulses. The least amount of phase dispersion and thus the longest lasting signal is obtained with the shortest echo spacing where only one line of data is recorded between two RF refocusing pulses. This approach was successfully used in a phantom and in vivo to image fast and slow blood flow. Depending on the experimental conditions, signal persistence is improved significantly compared to playing the same sequence without RF refocusing, but the improvement is limited by the product of blood flow velocity and the time between RF refocusing pulses.     

二维彩色多普勒显像在下肢静脉血栓诊断中的应用

目的:探讨二维(2-DE)彩色多普勒显像(CDF1)在下肢静脉血栓中的诊断及治疗效果观察中的应用价值。方法:应用ACUSON-128XP10及GE-VIVID7超声仪对来自于血管外科73例98人次(111条)下肢静脉血栓病人进行检查。结果:下肢深静脉完全阻塞57例(62条),部分阻塞3例(4条),少部分再通(<50％)18人次(23条),大部分再通(75％)15人次(17条),完全再通2人次(2条),其中再通人次包含治疗后复查的部分二次及三次复检者及来诊时即为部分再通者。另外,有3例(3条)合并大隐静脉曲张及血栓形成。结论:二维彩色多普勒显像对下肢静脉血栓的阻塞程度、范围及治疗后再通情况可做出较为肯定的诊断,对指导下肢静脉血栓的治疗及预后判断具有重要价值。     

Signal-to-noise ratio effects in quantitative cerebral perfusion using dynamic susceptibility contrast agents.

Theoretical and simulation evidence is presented in support of the idea that the optimal manner of determining blood flow from MR perfusion studies is not necessarily obtained by setting experimental conditions to maximize either the arterial input or the measured tissue concentration level for a particular echo time (TE). The noise power in the contrast concentration curve is associated with its peak because of the nonlinear relationship between the contrast concentration and MR signal intensity curves. The optimum signal-to-noise ratio (SNR), SNR(C), for a particular contrast concentration curve can be obtained when the experimental concentration level and TE are adjusted to produce an MR intensity curve whose signal loss is 63% of the precontrast MR signal intensity. It is demonstrated that the stability of the singular valued decomposition (SVD) deconvolution approach to determine blood flow parameters is increased when the tissue curve maximum signal loss is in the range of 40-80%. The accuracy and stability of the SVD-determined blood flow parameters are affected by deviations from these optimum conditions in a manner that depends on the mean transit time (MTT) associated with the residue function. It is recommended that the experimental TE value be set so that neither the tissue nor the arterial curves are placed a region of rapidly deteriorating SNR(C).     

Functional magnetic resonance imaging based on changes in vascular space occupancy.

During brain activation, local control of oxygen delivery is facilitated through microvascular dilatation and constriction. A new functional MRI (fMRI) methodology is reported that is sensitive to these microvascular adjustments. This contrast is accomplished by eliminating the blood signal in a manner that is independent of blood oxygenation and flow. As a consequence, changes in cerebral blood volume (CBV) can be assessed through changes in the remaining extravascular water signal (i.e., that of parenchymal tissue) without need for exogenous contrast agents or any other invasive procedures. The feasibility of this vascular space occupancy (VASO)-dependent functional MRI (fMRI) approach is demonstrated for visual stimulation, breath-hold (hypercapnia), and hyperventilation (hypocapnia). During visual stimulation and breath-hold, the VASO signal shows an inverse correlation with the stimulus paradigm, consistent with local vasodilatation. This effect is reversed during hyperventilation. Comparison of the hemodynamic responses of VASO-fMRI, cerebral blood flow (CBF)-based fMRI, and blood oxygenation level-dependent (BOLD) fMRI indicates both arteriolar and venular temporal characteristics in VASO. The effect of changes in water exchange rate and partial volume contamination with CSF were calculated to be negligible. At the commonly-used fMRI resolution of 3.75 x 3.75 x 5 mm(3), the contrast-to-noise-ratio (CNR) of VASO-fMRI was comparable to that of CBF-based fMRI, but a factor of 3 lower than for BOLD-fMRI. Arguments supporting a better gray matter localization for the VASO-fMRI approach compared to BOLD are provided.     

Outcome in Children With Significantly Abnormal Cerebral Blood Flow Detected by Doppler Ultrasonography: Focus on the Survivors

BACKGROUND AND PURPOSE: The Doppler waveform patterns of loss of diastolic flow, appearance of retrograde diastolic flow, or no detectable flow in the cerebral arteries suggest significantly abnormal cerebral blood flow (CBF). A retrospective study was performed to show that significantly abnormal CBF alone, without clinical criteria, is not necessarily specific to brain death in the young pediatric population. PATIENTS AND METHODS: Forty-seven pediatric patients, from newborn to 4 years of age, were found to have significantly abnormal CBF, including 7 patients with loss of diastolic flow, 28 with retrograde diastolic flow, and 23 with no detectable cerebral flow on serial Doppler sonographic examinations. Their clinical data and sonographic results were collected and analyzed. RESULTS: Forty-two patients died, a few of whom had only transient improvement of cerebral flow. All of the patients with no detectable cerebral flow expired. Five patients survived with or without sequelae. Their underlying conditions that caused increased intracranial pressure were treated by medical and/or surgical intervention, and diastolic reversal of CBF corrected within 1 day in all 5. CONCLUSIONS: Although no detectable flow is a lethal sign, pediatric patients with loss or reversal of diastolic flow may survive with prompt and effective treatment. Using Doppler ultrasound to diagnose cerebral circulatory arrest should be done with caution in pediatric patients.     

我对子午流注阴阳盛衰转换的认识

阐述了时相与阴阳的关系，阴阳昼夜的盛衰转换与经脉循行、气血流注密切相关；对传统流注说和任督为主的阴阳循环说进行了分析，认为子午流注阴阳盛衰转换在妇科学中有重要意义，子午流注所指出的4个较重要的时期与月经周期中的4期(行经期、经后期、经间排卵期、经前期)相关。重视研究日相阴阳太极钟的变化，将能更加深入地认识月经周期中阴阳消长转化的规律变化，从而推动中医妇科学向前发展。