Traitement de la maladie thromboembolique veineuse

Purpose: To describe the drugs used to treat venous thromboembolism (VTE) and to review particular aspects of the management (elastic stockings, thrombolysis, thrombectomy, vena cava filter). Source: Our review of the literature is focused on consensus documents and recent large randomized trials. Principal findings: Subcutaneous low molecular weight heparins (LMWH) have been shown to be both safe and effective for the initial treatment of VTE and have largely replaced unfractionated heparin, unless there is a contraindication to LMWH such as severe renal insufficiency. Low molecular weight heparins or unfractionated heparin are usually administered for five to seven days. Treatment is gradually switched from heparin to oral vitamin K antagonists (VKA) which are usually started the same day as heparin. The duration of oral anticoagulation must be tailored to the individual patient according to the presence of reversible or continuing risk factors. In patients with active cancer, long-term treatment of VTE with LMWH has been shown to be more effective than oral anticoagulation and is recommended for the first three to six months of long-term anticoagulant therapy as an alternative approach to VKA. Elastic stockings are recommended because they have been shown to prevent postthrombotic syndrome. Thrombolysis is, usually, not justified for the treatment of deep venous thrombosis, but is used in cases of massive pulmonary embolism with arterial hypotension and/or shock. Vena cava filter placement is mainly indicated in patients with a proximal deep venous thrombosis and an absolute contraindication to anticoagulation. Conclusions: The initial management of patients with acute VTE has largely been simplified due to the use of LMWH. Early conversion to VKA is recommended for the great majority of patients. New agents, such as anti-Xa or oral thrombin inhibitors, are promising alternatives to heparins or VKA. Objectif: Présenter les médicaments utilisés pour traiter la maladie thromboembolique veineuse (MTEV) et revoir des aspects particuliers de la thérapie comme les bas élastiques, la thrombolyse, la thrombectomie et le filtre cave. Source: Revue de documents de consensus et de grandes études récentes. Constatations principales: Les héparines de bas poids moléculaire (HBPM) sont sûres et efficaces comme traitement initial de la MTEV et remplacent largement ľhéparine non fractionnée, à moins ďune contre-indication à ľHBPM comme ľinsuffisance rénale sévère. Les HBPM ou ľhéparine non fractionnée sont habituellement administrées pendant cinq à sept jours. Puis, on passe graduellement de ľhéparine à la prise orale ďantagonistes de la vitamine K (AVK), débutés en général le même jour que ľhéparine. La durée de ľanticoagulation orale doit être adaptée au patient en fonction de facteurs de risque réversible ou continu. Dans les cas de cancer actif, le traitement de la MTEV avec ľHBPM s'est montré plus efficace que ľanticoagulation orale et il est recommandé pour les trois à six premiers mois de traitement. Les bas élastiques sont recommandés pour prévenir le syndrome post-thrombotique. La thrombolyse n'est pas habituellement justifiée pour traiter la thrombose veineuse profonde, mais est utilisée en cas ďembolie pulmonaire massive avec hypotension et/ou choc artériels. La mise en place ďun filtre cave est principalement indiquée chez les patients souffrant de thrombose veineuse profonde proximale chez qui ľanticoagulation est une contre-indication absolue. Conclusion: Le traitement initial des patients atteints de MTEV a été grandement simplifié avec ľusage de ľHBPM. Le passage précoce aux AVK est recommandé pour la grande majorité des patients. De nouveaux médicaments comme les anti-Xa ou les inhibiteurs de la thrombine oraux, sont des équivalents prometteurs des héparines ou des AV

Strongly triggered collapse model confront observations

Detailed modelling of individual protostellar condensations, is important to test the various theories. Here we present comparisons between strongly induced collapse models with one young class-0, IRAS4A in the Perseus cloud and one prestellar cloud observed in the Coalsack molecular cloud.Comment: IAU 237, Triggering of star formation in turbulent molecular clouds, eds B. Elmegreen and J. Palou

A Two-Site Immunoradiometric Assay for Serum Calcitonin Using Monoclonal Anti-Peptide Antibodies

We have produced a library of monoclonal antibodies of various affinities by immunizing mice with synthetic calcitonin (CT) 1-32. These monoclonal antibodies defined two antigenic determinants on the molecule of CT. The first was located in the 11-17 region of the hormone: the second was present on the 26-32 portion of CT. The C-terminal epitope was restricted to the mature form of the hormone and immunologically silent on synthetic peptides with sequences analogous lo the biosynthetic precursors for CT. Using two high-affinity monoclonal antibodies, designated as CT07 and CT08, we developed a two-site immunoradiometric assay (m-lRMA) for serum CT. This m-lRMA provided a sensitivity of 10 pg/mL using a one-step overnight incubation at room temperature. Gel filtration analyses of serum samples from patients with medullary thyroid carcinoma (MTC) demonstrated that the CT07-CT08 m-lRMA was specific for the circulating mature form of CT

Pitfall of hepatitis B surface antigen testing in a kidney transplant recipient presenting hepatitis B reactivation

Summary Diagnosis of hepatitis B virus (HBV) infection based on hepatitis B surface antigen (HBsAg) detection can be hampered in the setting of HBV reactivation in immunocompromized patients with prior serology indicating past cured infection, and can be associated with severe or fulminant and fatal hepatitis. We present a case of HBV reactivation in a renal transplant patient in whom HBsAg failed to be confirmed as a true positive result. One year after transplantation, systematic testing showed HBsAg positivity with a titer at 244 pg/mL, anti-hepatitis B core antibody and concurrent anti-hepatitis B surface antibody positivity. Confirmation of HBsAg detection by seroneutralization did not confirm HBsAg positivity, indicating that HBsAg detection was a false positive result. Notwithstanding, HBV DNA titer in serum was concurrently 8.6 Log IU/mL. HBV DNA sequencing showed a genotype D and several amino acid substitutions within HBsAg, including some previously involved in impaired diagnosis and altered immunogenicity. Although no perturbation of liver biochemical markers was observed, treatment with tenofovir was introduced. One month later, HBV DNA level had decreased by 2.6 Log IU/mL and no clinical and biochemical symptoms of hepatitis had occurred. The present case underlines that serologic diagnosis of HBV reactivation can be tricky in transplant recipients with a prior serology indicating past HBV infection. This prompts to perform HBV DNA testing in case of positive HBsAg testing, regardless of the result of neutralization by anti-HBs antibodies

Quiescent Dense Gas in Protostellar Clusters: the Ophiuchus A Core

We present combined BIMA interferometer and IRAM 30 m Telescope data of N2H+ 1-0 line emission across the nearby dense, star forming core Ophiuchus A (Oph A) at high linear resolution (e.g., ~1000 AU). Six maxima of integrated line intensity are detected which we designate Oph A-N1 through N6. The N4 and N5 maxima are coincident with the starless continuum objects SM1 and SM2 respectively but the other maxima are not coincident with previously-identified objects. In contrast, relatively little N2H+ 1-0 emission is coincident with the starless object SM2 and the Class 0 protostar VLA 1623. The FWHM of the N2H+ 1-0 line, Delta V, varies by a factor of ~5 across Oph A. Values of Delta V < 0.3 km/s are found in 14 locations in Oph A, but only that associated with N6 is both well-defined spatially and larger than the beam size. Centroid velocities of the line, V_LSR, vary relatively little, having an rms of only \~0.17 km/s. Small-scale V_LSR gradients of <0.5 km/s over ~0.01 pc are found near SM1, SM1N, and SM2, but not N6. The low N2H+ abundances of SM2 or VLA 1623 relative to SM1, SM1N, or N6 may reflect relatively greater amounts of N2 adsorption onto dust grains in their colder and probably denser interiors. The low Delta V of N6, i.e., 0.193 km/s FWHM, is only marginally larger than the FWHM expected from thermal motions alone, suggesting turbulent motions in the Oph A core have been reduced dramatically at this location. The non-detection of N6 in previous thermal continuum maps suggests that interesting sites possibly related to star formation may be overlooked in such data.Comment: LaTex with 7 figures, produces 36 pages. Accepted for publication in ApJ. Typo related to Equation 3 fixed, caused derived values of N(N2H+) and X(N2H+) to be low by factors of ~40%. Conclusions of paper are unchange

Core Mass Function: The Role of Gravity

We analyze the mass distribution of cores formed in an isothermal, magnetized, turbulent, and self-gravitating nearly critical molecular cloud model. Cores are identified at two density threshold levels. Our main results are that the presence of self-gravity modifies the slopes of the core mass function (CMF) at the high mass end. At low thresholds, the slope is shallower than the one predicted by pure turbulent fragmentation. The shallowness of the slope is due to the effects of core coalescence and gas accretion. Most importantly, the slope of the CMF at the high mass end steepens when cores are selected at higher density thresholds, or alternatively, if the CMF is fitted with a log-normal function, the width of the lognormal distribution decreases with increasing threshold. This is due to the fact that gravity plays a more important role in denser structures selected at higher density threshold and leads to the conclusion that the role of gravity is essential in generating a CMF that bears more resemblance with the IMF when cores are selected with an increasing density threshold in the observations.Comment: 13 pages, 4 figures, accepted to ApJ Letters. An additional simulation has been added. The sign of the beta values in Fig. 1 changed to fit their definition in the text. The main conclusions, however unchanged, are better clarifie