Possible extracardiac predictors of aortic dissection in Marfan syndrome

BACKGROUND: According to previous studies, aortic diameter alone seems to be insufficient to predict the event of aortic dissection in Marfan syndrome (MFS). Determining the optimal schedule for preventive aortic root replacement (ARR) aortic growth rate is of importance, as well as family history, however, none of them appear to be decisive. Thus, the aim of this study was to search for potential predictors of aortic dissection in MFS. METHODS: A Marfan Biobank consisting of 79 MFS patients was established. Thirty-nine MFS patients who underwent ARR were assigned into three groups based on the indication for surgery (dissection, annuloaortic ectasia and prophylactic surgery). The prophylactic surgery group was excluded from the study. Transforming growth factor-beta (TGF-beta) serum levels were measured by ELISA, relative expression of c-Fos, matrix metalloproteinase 3 and 9 (MMP-3 and -9) were assessed by RT-PCR. Clinical parameters, including anthropometric variables - based on the original Ghent criteria were also analyzed. RESULTS: Among patients with aortic dissection, TGF-beta serum level was elevated (43.78 +/- 6.51 vs. 31.64 +/- 4.99 ng/l, p < 0.0001), MMP-3 was up-regulated (Ln2alpha = 1.87, p = 0.062) and striae atrophicae were more common (92% vs. 41% p = 0.027) compared to the annuloaortic ectasia group. CONCLUSIONS: We found three easily measurable parameters (striae atrophicae, TGF-beta serum level, MMP-3) that may help to predict the risk of aortic dissection in MFS. Based on these findings a new classification of MFS, that is benign or malignant is also proposed, which could be taken into consideration in determining the timing of prophylactic ARR

Persistence of Environmental DNA in Freshwater Ecosystems

The precise knowledge of species distribution is a key step in conservation biology. However, species detection can be extremely difficult in many environments, specific life stages and in populations at very low density. The aim of this study was to improve the knowledge on DNA persistence in water in order to confirm the presence of the focus species in freshwater ecosystems. Aquatic vertebrates (fish: Siberian sturgeon and amphibian: Bullfrog tadpoles) were used as target species. In control conditions (tanks) and in the field (ponds), the DNA detectability decreases with time after the removal of the species source of DNA. DNA was detectable for less than one month in both conditions. The density of individuals also influences the dynamics of DNA detectability in water samples. The dynamics of detectability reflects the persistence of DNA fragments in freshwater ecosystems. The short time persistence of detectable amounts of DNA opens perspectives in conservation biology, by allowing access to the presence or absence of species e.g. rare, secretive, potentially invasive, or at low density. This knowledge of DNA persistence will greatly influence planning of biodiversity inventories and biosecurity surveys

Prediction of paravalvular leakage after transcatheter aortic valve implantation

Significant paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI) is related to patient mortality. Predicting the development of PVL has focused on computed tomography (CT) derived variables but literature targeting CoreValve devices is limited, controversial, and did not make use of standardized echocardiographic methods. The study included 164 consecutive patients with severe aortic stenosis that underwent TAVI with a Medtronic CoreValve system©, with available pre-TAVI CT and pre-discharge transthoracic echocardiography. The predictive value for significant PVL of the CT-derived Agatston score, aortic annulus size and eccentricity, and “cover index” was assessed, according to both echocardiographic Valve Academic Research Consortium (VARC) criteria and angiographic Sellers criteria. Univariate predictors for more than mild PVL were the maximal diameter of the aortic annulus size (for both angiographic and echocardiographic assessment of PVL), cover index (for echocardiographic assessment of PVL only), and Agatston score (for both angiographic and echocardiographic assessment of PVL). The aortic annulus eccentricity index was not predicting PVL. At multivariate analysis, Agatston score was the only independent predictor for both angiographic and echocardiographic assessment of PVL. Agatston score is the only independent predictor of PVL regardless of the used imaging technique for the definition of PVL

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia)

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia

Materials for filtering and frequency control in the next generations of mobile communication systems

A very large development of the mobile radiocommunications is expected to occur in the 15 next years. In the introduction, the most important among the present and future systems are listed and their main characteristics are briefly indicated. The case of the Universal Mobile Telecommunication System (UMTS) presently studied in the European community to enter service in the beginning of the 2000's is particularly discussed since, it is now, the most ambitious project in this field. The equipments of the future numerical radiocommunication systems will include a large number of piezo-electric devices for filtering and frequency generation. New characteristics (higher frequencies, larger bandwidth, very reduced dimensions, etc...) will be required for these devices so that new developments will be necessary to find solutions to these requirements. It is believed, that the corresponding evolutions will be very significant of the main trends in piezo-electricity for the next ten years. This paper review the UHF and VHF filtering technologies and the frequency generation techniques the most likely to be used in the future radiomobile systems. For each kind of devices (filters for either UHF or an intermediate frequency and frequency sources), we discuss the most probable requirements, the present state of the different technologies, the new advances required to develop highly miniaturized devices for the mobile equipments or high performances sub-assembly for the base stations. In most cases, it appears that the availability of new piezo-electric materials and the obtainment of better characteristics for the existing materials will be essential factors in the achievement of the required characteristics for these devices. The possibilities of integrating piezo-electric resonators or filters with the micro-electronics contributing to the same or to related functions is also discussed together with the interest of developing new thin film piezo-electric materials permitting this integration

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia)

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia)

Lithobates catesbeianus (Shaw), american bullfrog (Ranidae, Amphibia

Invasions biologiques dans les zones humides de France : historique, évolution, enjeux

National audienc

Invasions biologiques dans les zones humides de France : historique, évolution, enjeux

National audienc