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Abnormal uteroplacental vascular development is one of the primary causes of the major disorders of pregnancy. Identification of this aberrant development in the preconception stage and in the first trimester, when measures to prevent complications are most effective, remains a challenge. Recent advances in offline imaging processing and Doppler techniques have allowed ultrasonographic analysis of placental volume (PV) and uteroplacental vascular volume (uPVV) in the first trimester. The ability of ultrasound to assess specific vascular morphology is not fully understood.The aim of this study was to investigate morphologic development of the first-trimester human uteroplacental vasculature in vivo using 3-dimensional power Doppler ultrasound and advanced image processing to generate the uteroplacental vascular skeleton (uPVS). Data were obtained from the VIRTUAL Placenta study, an ongoing observational study including adult women carrying a singleton pregnancy at less than 10-week gestational age (GA). At least 2 study visits were scheduled in the first trimester, at 7, 9, and 11 weeks' GA. The image quality of ultrasound scans was scored on a 4-point scale ranging between 0 (optimal) and 3 (unusable), and PV was measured using VOCAL software. The uPVV was measured using a virtual reality desktop system with the V-scope volume-rendering application. A skeletonization algorithm was then applied to the uPVV segmentation to generate the uPVS, and 7 morphological uPVS characteristics were used to determine the density of vascular branching within the placenta.A total of 214 women from the VIRTUAL cohort were eligible for inclusion, and 81% of all ultrasound data were of sufficient quality for generation of the uPVS. The distribution of endpoints, vessel points, bifurcation points, and crossing points in the uPVS and the distribution of uPVS characteristics per cm3uPVV show consistent morphologic patterns throughout the first trimester. Moderate to strong positive correlations between uPVS characteristics and PV and strong positive correlations between uPVS characteristics and uPVV were identified. All uPVS characteristics increased significantly through the first trimester, except for uPVS average length, which remained constant between 7, 9, and 11 weeks' GA. When stratifying for placenta-related complications among the cohort, no significant differences in the uPVS characteristics were seen at 7 weeks' GA (n = 94). However, at 9 weeks (n = 170), there were significantly fewer number of vessel points (P= 0.040), bifurcation points (P= 0.050), crossing points (P= 0.020), and a shorter total network length (P= 0.023) among pregnancies with placenta-related complications. At 11 weeks' GA (n = 129), uPVS average vascular thickness was significantly lower in pregnancies with placenta-related complications (P= 0.007), but no other uPVS differences were observed. At 11 weeks' GA, pregnancies with placenta-related complications were found to have an increased density of vascular branching in the uPVV.The results of this study demonstrate a quantitative morphologic analysis of the human uteroplacental vasculature in the first trimester of pregnancy and key differences in the vascular morphology between pregnancies with and without placenta-related complications.

ABSTRACTA large community outbreak of Q fever occurred in the Netherlands in the period 2007 to 2010. Some of the infected patients developed chronic Q fever, which typically includes pathogen dissemination to predisposed cardiovascular sites, with potentially fatal consequences. To identify the immune mechanisms responsible for ineffective clearance of Coxiella burnetiiin patients who developed chronic Q fever, we compared serum concentrations of 47 inflammation-associated markers among patients with acute Q fever, vascular chronic Q fever, and past resolved Q fever. Serum levels of gamma interferon were strongly increased in acute but not in vascular chronic Q fever patients, compared to past resolved Q fever patients. Interleukin-18 levels showed a comparable increase in acute as well as vascular chronic Q fever patients. Additionally, vascular chronic Q fever patients had lower serum levels of gamma interferon-inducible protein 10 (IP-10) and transforming growth factor ß (TGF-ß) than did acute Q fever patients. Serum responses for these and other markers indicate that type I immune responses to C. burnetiiare affected in chronic Q fever patients. This may be attributed to an affected immune system in cardiovascular patients, which enables local C. burnetiireplication at affected cardiovascular sites.

Conjoined twins are rare. High-quality imaging techniques are essential for proper first-trimester diagnosis. Technological development leads to new imaging techniques such as 3-dimensional virtual embryoscopy. The aim of this review was to explore imaging techniques used in the first-trimester diagnosis of conjoined twins and provide a systematic diagnostic table for making this diagnosis.

The influence of soil C stabilization mechanisms is normally not considered in studies on the effects of land use changes. Instead, observed changes are typically explained by differences in litter input. As a result, it is not well known if and how quickly newly incorporated C is stabilized in soils. Our goals were to find out how much soil C was stabilized in two different soil orders (Andisols and Inceptisols) and which are the responsible mechanisms of C stabilization. Furthermore, we looked for evidence that newly incorporated soil C was stabilized in these contrasting soil orders. We selected 25 sites in northwestern Ecuador with two paired plots per site: one plot where pasture was converted to secondary forest and one plot where forest was converted to pasture. In all the plots, soil C content, stocks, and stable isotope (δ13C) signal were measured in the surface soil. The δ13C values were used to estimate the stocks of soil C derived from forest (Cdf) and from pasture (Cdp) in all plots. We calculated correlations between these stocks and soil and environmental characteristics to identify mechanisms of soil C stabilization. Our results show that long‐term stabilization in Andisols was through formation of metal–humus complexes and allophane, while in Inceptisols long‐term stabilization was through sorption to clay minerals. We found evidence that recently incorporated C was not stabilized in Andisols, while in Inceptisols, poorly crystalline (hydr‐) oxides seemed to have stabilized part of this soil C. We conclude that unless soil C stabilizing mechanisms are explicitly considered, we will not be able to predict the direction and magnitude of changes in soil C stocks following land use changes in the tropics.

Parallel volume visualization is of interest to a variety of application areas since current single-processor systems fall short in interactively rendering complex, large-sized datasets. This article presents a survey of volume-visualization methods on general-purpose parallel architectures, with special attention being paid to medical imaging applications. First, the various approaches to volume visualization are briefly discussed, followed by a description of relevant aspects of parallel architectures. Next, the implications of the various architectures are illustrated on the basis of a number of existing implementations of visualization algorithms on parallel architectures and their results. For parallel volume visualization, multiple instruction, multiple data (MIMD) architectures are found to be superior to single instruction, multiple data (SIMD) architectures. The latter type suffers from a lack of performance as well as flexibility. For most applications of interactive volume visualization, including the important area of medical imaging, shared memory MIMD architectures are preferred over distributed memory MIMD architectures. The ease of programming of shared memory architectures allows existing algorithms to be readily implemented without loss of performance or flexibility.

Tonstad S, Ose L, G0rbitz C, Harrison EM, de Koning Gans HJ. Effectiveness of low-dose lovastatin combined with low-dose colestipol in moderate to severe primary hypercholesterolaemia. Scand J Clin Lab Invest 1993; 53: 457-463.The effect of the combination of low-dose lovastatin and low-dose colestipol was studied among 57 subjects with moderate to severe primary hypercholesterolaemia (total cholesterol ≥≥ 7.0mmoll−−1). Following an 8-week dietary phase, participants were randomized to treatment with 20 mg of lovastatin combined with 5 g or with 10 g of colestipol, or to matching placebo. Baseline total cholesterol was 7.7±± 0.9mmoll−−1after dietary stabilization. Total cholesterol levels were reduced to 5.6 ±± 0.7mmoir' and 5.8 ±± 0.7mmoll−−1after 4 and 8 weeks of treatment in the lovastatin 5g−−1colestipol group, and 74% of the subjects achieved the goal of low density lipoprotein (LDL) cholesterol levels of ≥≥ 4.0mmoll−−l. Among the lovastatin 10 g−−1colestipol group, total cholesterol was reduced to 5.4±± 0.5mmoll−−1and 5.5 ±± 0.9mmoH−−1following 4 and 8 weeks, and 80% of subjects achieved the LDL cholesterol goal. No change was seen in the placebo group. Thus, low-dose combination therapy with lovastatin and colestipol, in conjunction with dietary treatment, is effective in moderate to severe primary hypercholesterolaemia, and is well tolerated.

Originally the only way to look inside the human body without opening it up was by means of two dimensional (2D) images obtained using X-ray equipment. The fact that human anatomy is inherently three dimensional leads to ambiguities in interpretation and problems of occlusion. Three dimensional (3D) imaging modalities such as CT, MRI and 3D ultrasound remove these drawbacks and are now part of routine medical care. While most hospitals 'have gone digital', meaning that the images are no longer printed on film, they are still being viewed on 2D screens. However, this way valuable depth information is lost, and some interactions become unnecessarily complex or even unfeasible. Using a virtual reality (VR) system to present volumetric data means that depth information is presented to the viewer and 3D interaction is made possible. At the Erasmus MC we have developed V-Scope, an immersive volume visualization system for visualizing a variety of (bio-)medical volumetric datasets, ranging from 3D ultrasound, via CT and MRI, to confocal microscopy, OPT and 3D electron-microscopy data. In this talk we will address the advantages of such a system for both medical diagnostics as well as for (bio)medical research.