Uranium-enrichment in soils and plants in the vicinity of a pitchblende vein at La Creusaz-Les Marecottes (W of Martigny, Valais, Switzerland)

In the NE part of the Aiguilles Rouges Massif near Martigny, at the eastern contact of the Variscan Vallorcine granite to adjacent gneisses, a series of pitchblende (UO2)-veins occur. This paper determines the level of enrichment and mobility of uranium in soils situated in the vicinity of such a UO2-vein 7 km west of Martigny. Within an area of 50 x 100 m, situated on a relatively steep slope and characterized by a strong gramma-ray anomaly, six soil profiles including their plant cover and a reference soil profile outside the influence of the UO2-vein have been examined. The soil shows pH-values between 4 and 5 and is colluvial. The applied analytical methods for the metal contents include extraction methods, common for soil studies, and bulk analysis performed with X-ray fluorescence and ICP-MS. Uranium contents found in the uppermost 20 cm of the soil profiles vary from 2,500 ppm close to the vein to 15 ppm at the lowermost point of the study area. The reference soil has around 3 ppm uranium. At greater depth (20 to 40 cm) the U-content decreases to about half of the surface values, indicating a vertical transport of uranium within the soil profile. No systematic dependance of uranium-contents to grain size (amount of clay) nor to the amount of organic matter has been found. However, the good correlation between uranium and free iron oxide concentration suggests adsorption of uranium on iron oxy-hydroxides. The ashes of grass and mosses contain up to 90 ppm U, the blueberry and redwood only up to 3 ppm. Our observations suggest that at the surface the uranium is transported by downhill creep (solifluxion) of uranium-rich rock fragments. Liberated by oxidation of the uppermost fragments in a given soil column, the uranium migrates vertically until the conditions are favourable to adsorption onto Fe-oxy-hydroxides. However, as high U-contents of local surface water show, this adsorption does not lead to a significant retention of the uranium.

Manganese-induced integrin affinity maturation promotes recruitment of alpha V beta 3 integrin to focal adhesions in endothelial cells: evidence for a role of phosphatidylinositol 3-kinase and Src.

Integrin activity is controlled by changes in affinity (i.e. ligand binding) and avidity (i.e. receptor clustering). Little is known, however, about the effect of affinity maturation on integrin avidity and on the associated signaling pathways. To study the effect of affinity maturation on integrin avidity, we stimulated human umbilical vein endothelial cells (HUVEC) with MnCl(2) to increase integrin affinity and monitored clustering of beta 1 and beta 3 integrins. In unstimulated HUVEC, beta 1 integrins were present in fibrillar adhesions, while alpha V beta 3 was detected in peripheral focal adhesions. Clustered beta 1 and beta 3 integrins expressed high affinity/ligand-induced binding site (LIBS) epitopes. MnCl(2)-stimulation promoted focal adhesion and actin stress fiber formation at the basal surface of the cells, and strongly enhanced mAb LM609 staining and expression of beta 3 high affinity/LIBS epitopes at focal adhesions. MnCl(2)-induced alpha V beta 3 clustering was blocked by a soluble RGD peptide, by wortmannin and LY294002, two pharmacological inhibitors of phosphatidylinositol 3-kinase (PI 3-K), and by over-expressing a dominant negative PI 3-K mutant protein. Conversely, over-expression of active PI 3-K and pharmacological inhibiton of Src with PP2 and CGP77675, enhanced basal and manganese-induced alpha V beta 3 clustering. Transient increased phosphorylation of protein kinase B/Akt, a direct target of PI 3K, occurred upon manganese stimulation. MnCl(2) did not alter beta 1 integrin distribution or beta1 high-affinity/LIBS epitope expression. Based on these results, we conclude that MnCl(2)-induced alpha V beta 3 integrin affinity maturation stimulates focal adhesion and actin stress fiber formation, and promotes recruitment of high affinity alpha V beta 3 to focal adhesions. Affinity-modulated alpha V beta 3 clustering requires PI3-K signaling and is negatively regulate by Src.

Low-pressure environment and remodelling of the forearm vein in Brescia-Cimino haemodialysis access.

BACKGROUND: The aim of the study was to determine which, and to what extent, haemodynamic parameters contribute to the remodelling of the venous limb of the Brescia-Cimino haemodialysis access. METHODS: The dimensions of the radial artery and the venous limb of the haemodialysis access were measured by an echo-tracking technique. In six ESRD patients undergoing primary arteriovenous fistula (AVF) formation, vessel diameter, wall thickness, blood pressure and blood flow were measured after the operation, and at 1 and 3 months follow-up. The contralateral forearm vessels in their native position served as baseline values for comparison. RESULTS: The diameter of the proximal antecubital vein progressively increased over the study period without reaching significant differences (4430, 5041 and 6620 microm at weeks 1, 4 and 12 respectively), whereas the intima-media thickness remained unchanged. The venous dilatation was associated with a reduction of the mean shear stress that culminated after the operation and progressively returned to normal venous values at 3 months (24.5 vs 10.4 dyne/cm(2), P<0.043). Thus the venous limb of the AVF undergoes eccentric hypertrophy as demonstrated by the increase in wall cross-sectional area (4.42 vs 6.32 mm(2) at week 1 vs week 12, P<0.028). At the time of the operation, the blood pressure in the AVF was 151+/-14/92.4+/-11 mmHg vs 49+/-19/24.5+/-6 mmHg (means+/-SEM) for the radial artery and the venous limb of the vascular access, respectively. One year after the operation the blood pressure in the venous limb had not changed: 42+/-14/25.3+/-7 mmHg (means+/-SEM). Under these conditions, the systolo-diastolic diameter changes observed in the radial artery and the antecubital vein were within a similar range at all time points: 56+/-17 vs 90+/-26 microm (means+/-SEM) at week 12. CONCLUSIONS: The increased circumferential stress resulting from the flow-mediated dilatation rather than the elevation of blood pressure appears to represent the main contributing factor to the eccentric hypertrophy of the venous limb of Brescia-Cimino haemodialysis access.

Prenatal brain atrophy due to a giant vein of Galen malformation.

We report a full-term newborn girl with a giant vein of Galen malformation and extreme cerebral atrophy of prenatal origin. She presented on the 3rd day of life with intractable congestive heart failure. The diagnosis of the vascular malformation was confirmed by ultrasound and magnetic resonance imaging.

Multiples hyperplasies nodulaires focales hépatiques associées à une agénésie congénitale de la veine porte [Multiple focal nodular hyperplasia of the liver associated with congenital absence of the portal vein]

We report the 32nd case of congenital absence of portal vein in an 18-year-old female adult associated with multiple focal nodular hyperplasia of the liver. The association of various hepatic tumors has been observed in half of the publications about congenital absence of portal vein. Hepatic tumors seem to result from systemic diversion of portal vein flow with a resultant increase of arterial flow causing important vascular and nutritif changes the liver and consequent parenchymal transformation.

Thrombolyse bei tiefer Venenthrombose? [Thrombolytic therapy in deep venous thrombosis?]

Sie sehen eine 45-jährige Patientin mit einem bläulich-zyanotischen rechten Bein. Vor fünf Tagen habe ein Spannungsschmerz in der Wade begonnen und sich zunehmend in den Oberschenkel hochgezogen. Die rechte Wade misst im Umfang 4 cm mehr als die linke. Die Anamnese ergibt keine familiäre oder persönliche Vorgeschichte einer thromboembolischen Erkrankung. Die Patientin ist übergewichtig ( BMI 35 kg/m2) und nimmt seit einigen Jahren eine Östrogen-Progesteron-Kombination. Der Ultraschall zeigt eine Thrombose der tiefen Beinvenen, die bis in die äussere Beckenvene reicht.

A challenging hernia: primary venous aneurysm of the proximal saphenous vein.

INTRODUCTION: Primary venous aneurysm is a rare, but essential consideration in the differential diagnosis of an inguinal and femoral hernia. METHODS: We report a case of a 43-year-old man who was referred for evaluation and treatment of a femoral hernia. RESULTS: The patient presented with a 3-month history of an asymptomatic tumor on his right upper inner thigh. Physical examination noted a non-tender, non-indurated tumor. CONCLUSION: Surgical exploration demonstrated a primary venous aneurysm of the proximal saphenous vein.

Evanescent vaso-occlusive choroidal pseudo-tumor with acute painful onset: a presumed vortex vein occlusion.

PURPOSE: The aim of our study was to describe the clinical presentation of an unusual evanescent, exudative, choroidal pseudo-tumor with acute painful onset, and propose a pathogenesis. METHODS: We carried out a retrospective, observational study using the case series of three patients presenting with an evanescent, exudative, choroidal pseudo-tumor with acute painful onset. Ultra-widefield fluorescein and indocyanine green angiography (ICGA) using the Heidelberg Retina Angiograph and the Staurenghi 230 SLO Retina Lens were used to propose a pathogenesis of this unusual entity. RESULTS: In all three cases, acute ocular pain led to discovery of an exudative, partially hemorrhagic choroidal mass (thickness 2.4 mm-4.1 mm on ultrasound) that quickly regressed within weeks. In the subacute phase, all patients showed choroidal circulation abnormalities on dynamic wide-field ICGA in the affected quadrant, with delayed arterio-venous filling in two patients, and a poorly-defined vortex vein in the third. The choroidal circulation abnormalities resolved within 8-12 weeks, simultaneously with the spontaneous resolution of the choroidal pseudo-tumor. The findings evoked a self-resolving vortex vein occlusion in the corresponding quadrants with acute, painful choroidal exudation. CONCLUSIONS: An evanescent, exudative, hemorragic choroidal pseudo-tumor with acute painful onset may be caused by a vortex vein occlusion. Future patients need to be studied with ICGA in the acute phase to confirm this hypothesis.

Comparative assessment of intimal hyperplasia development after 14 days in two different experimental settings: tissue culture versus ex vivo continuous perfusion of human saphenous vein.

BACKGROUND: Intimal hyperplasia (IH) is a vascular remodeling process which often leads to failure of arterial bypass or hemodialysis access. Experimental and clinical work have provided insight in IH development; however, further studies under precise controlled conditions are required to improve therapeutic strategies to inhibit IH development. Ex vivo perfusion of human vessel segments under standardized hemodynamic conditions may provide an adequate experimental approach for this purpose. Therefore, chronically perfused venous segments were studied and compared to traditional static culture procedures with regard to functional and histomorphologic characteristics as well as gene expression. MATERIALS AND METHODS: Static vein culture allowing high tissue viability was performed as previously described. Ex vivo vein support system (EVVSS) was performed using a vein support system consisting of an incubator with a perfusion chamber and a pump. EVVSS allows vessel perfusion under continuous flow while maintaining controlled hemodynamic conditions. Each human saphenous vein was divided in two parts, one cultured in a Pyrex dish and the other part perfused in EVVSS for 14days. Testing of vasomotion, histomorphometry, expression of CD 31, Factor VIII, MIB 1, alpha-actin, and PAI-l were determined before and after 14days of either experimental conditions. RESULTS: Human venous segments cultured under traditional or perfused conditions exhibited similar IH after 14 days as shown by histomorphometry. Smooth-muscle cell (SMC) was preserved after chronic perfusion. Although integrity of both endothelial and smooth-muscle cells appears to be maintained in both culture conditions as confirmed by CD31, factor VIII, and alpha-actin expression, a few smooth-muscle cells in the media stained positive for factor VIII. Cell-proliferation marker MIB-1 was also detected in the two settings and PAI-1 mRNA expression and activity increased significantly after 14 days of culture and perfusion. CONCLUSION: This study demonstrates the feasibility to chronically perfuse human vessels under sterile conditions with preservation of cellular integrity and vascular contractility. To gain insights into the mechanisms leading to IH, it will now be possible to study vascular remodeling not only under static conditions but also in hemodynamic environment mimicking as closely as possible the flow conditions encountered in reconstructive vascular surgery.

Intrauterine growth restriction is associated with structural alterations in human umbilical cord and decreased nitric oxide-induced relaxation of umbilical vein.

INTRODUCTION: Intrauterine growth restriction (IUGR) affects ∼8% of all pregnancies and is associated with major perinatal mortality and morbidity, and with an increased risk to develop cardiovascular diseases in adulthood. Despite identification of several risk factors, the mechanisms implicated in the development of IUGR remain poorly understood. In case of placental insufficiency, reduced delivery of oxygen and/or nutrients to the fetus could be associated with alterations in the umbilical circulation, contributing further to the impairment of maternal-fetal exchanges. We compared the structural and functional properties of umbilical cords from growth-restricted and appropriate for gestational age (AGA) term newborns, with particular attention to the umbilical vein (UV). METHODS: Human umbilical cords were collected at delivery. Morphological changes were investigated by histomorphometry, and UV's reactivity by pharmacological studies. RESULTS: Growth-restricted newborns displayed significantly lower growth parameters, placental weight and umbilical cord diameter than AGA controls. Total cross-section and smooth muscle areas were significantly smaller in UV of growth-restricted neonates than in controls. Maximal vasoconstriction achieved in isolated UV was lower in growth-restricted boys than in controls, whereas nitric oxide-induced relaxation was significantly reduced in UV of growth-restricted girls compared to controls. CONCLUSION: IUGR is associated with structural alterations of the UV in both genders, and with a decreased nitric oxide-induced relaxation in UV of newborn girls, whereas boys display impaired vasoconstriction. Further investigations will allow to better understand the regulation of umbilical circulation in growth-restricted neonates, which could contribute to devise potential novel therapeutic strategies to prevent or limit the development of IUGR.